Solar mirrors and methods of making solar mirrors having improved properties

Solar mirror and method of making solar mirror with improved characteristics

[0001] This application is titled "Solar Mirror and Method for Making Solar Mirror with Improved Characteristics", the application date is July 14, 2016, the international application number is PCT/US2016/042181, and the national application number is 201680053848.8 Divisional application of the PCT application.

[0002] Announcement of government support

[0003] The present invention was made under contract No. DE-FC36-08GO18033 awarded by the U.S. Department of Energy with the support of the government. The U.S. government may have certain rights in this invention.

[0004] Cross-reference to related applications

[0005] This application claims priority to the United States provisional patent application UNo.62/219,386 entitled "SOLAR MIRRORS AND METHODS OF MAKING SOLAR MIRRORS HAVING IMPROVED SELECTED PROPERTIES" filed on September 16, 2015. The entire contents of this U.S. Provisional Patent Application Serial No. 62/219,386 are incorporated herein by reference.

Technical field

[0006] The present application relates to articles for reflecting electromagnetic energy, especially for reflecting electromagnetic energy emitted by the sun. The article includes, but is not limited to, solar mirrors, and the present invention relates to a method of making solar mirrors with improved physical characteristics, such as but not limited to spectral characteristics, to improve the useful life and performance of solar mirrors.

[0007] Currently available technologies

[0008] As understood by those skilled in the field of solar mirrors, solar power is becoming a more commercially acceptable and economically viable energy source. By way of example and not limited to the present invention, a known application is to use solar mirrors to concentrate sunlight for power generation. As used herein, the term "sunlight" means the electromagnetic energy emitted by the sun. Solar mirrors with high solar radiation reflectivity are used in "Concentrated Solar Thermal Power Generation" (CSTP) facilities. Several different mirror geometries are used for these applications. One system uses curved parabolic solar mirrors to concentrate solar energy on a tube positioned along the focal line. The heat transfer medium in the tube carries the absorbed thermal energy to the power station where the thermal energy is used to generate electricity. Another system uses a solar tower in which solar mirrors reflect sunlight and concentrate the sunlight on a receiving surface on the tower. The heat generated by the focused sunlight is transferred to a working fluid such as sodium, and the heated working fluid is used to generate electricity.

[0009] Another application of this type of mirror is for "concentrated photovoltaics" (CPV). In this application, the mirror focuses or concentrates sunlight onto photovoltaic (PV) devices, thereby improving the energy output of each device.

[0010] In these systems, and as discussed above, it is desirable for the mirror to reflect as much sunlight as possible. It is also desirable for the mirror to have as long a commercial life as possible to exclude frequent changes of the mirror. A mirror with a reflective surface is used to reflect solar energy to the focal point so that the device converts sunlight or solar energy into electrical energy and/or thermal energy. In practice of a non-limiting embodiment, the solar mirror includes a glass substrate having a first major surface and an opposite second major surface. The first major surface is designated to face the solar light source, and the opposite second major surface of the glass substrate faces away from the solar light source. In this non-limiting embodiment, a reflective coating is applied on the first major surface of the substrate. In another non-limiting embodiment of the invention, a reflective coating is applied on the second major surface of the light-transmitting or transparent substrate. In the following discussion, the solar reflective coating is applied on the second major surface of the transparent substrate. The second main surface faces away from the source of sunlight or solar energy.

[0011] Further as understood by those skilled in the field of solar mirror technology, it is desirable to maximize the amount of sunlight reflected from the solar mirror and maximize the useful service life of the solar mirror. The percentage reflectivity of the sunlight from the solar mirror is equal to the irradiance of the sunlight reflected from the solar mirror divided by the irradiance of the sunlight incident on the solar mirror. The reflectance can be measured in any convenient way. For example, but not limited to, the reflectance of sunlight is measured using a spectrophotometer in the practice of the present invention.

[0012] Disclosed herein are methods and articles for increasing the percentage reflectivity of sunlight from solar mirrors and increasing the useful life of solar energy.

Summary of the invention

[0013] The present invention relates to an article for reflecting solar energy, the article particularly comprising a substrate and a solar reflective coating, the substrate having a first surface and an opposite second surface. The solar reflective coating especially includes: a first metal solar reflective film, which is also referred to as a "first metal film" in the following, the first metal film having a first surface and an opposite second surface; a second metal solar reflective film Film, which is also referred to as a "second metal film" hereinafter, the second metal film having a first surface and an opposite second surface; and a separation layer or separation film having a first surface and an opposite second surface Surface, wherein the first surface of the separation film is on the second surface of the first metal film, and the first surface of the second metal film is on the second surface of the separation film, wherein , The first surface of the first metal film is on the second surface of the substrate and is attached to the second surface of the substrate.

[0014] The present invention further relates to an article for reflecting solar energy, the article particularly having: a coating stack, the coating stack particularly having a solar reflective film and a metal oxide film, the coating stack being applied to the glass On the main surface of the substrate; and a polymer encapsulant on the outer wall surface of the coating stack, on the second surface of the protective outer coating, and on the peripheral edge of the coated article, The encapsulant includes, but is not limited to, a base layer, a top layer, and metallic zinc flakes in the base layer.

[0015] The above-mentioned article further includes a marginal portion of the top of the coating stack covered with a base layer and an outer wall of the coating stack, and the base layer defines an uncoated area on the top surface of the coating stack, and the top layer is covered (overlays) The uncoated area and base layer of the top surface of the coating stack.

[0016] The present invention still further relates to an article for reflecting solar energy, the article particularly comprising a coating stack, the coating stack being fixed to the main surface of the glass substrate, the coating stack comprising a solar reflective layer , Wherein the surface of the coating stack spaced apart from the substrate is conductive, and the polymer encapsulant is on the outer wall surface of the coating stack, the encapsulant includes a top layer, and the top layer is electrodeposited (also Known as "electrophoresis") to the outer surface of the coating stack, where the base layer of the encapsulant uses metallic zinc flakes.

Description of the drawings

[0017] FIG. 1 is a cross-sectional view of a prior art solar mirror, which shows a solar reflective coating.

[0018] FIG. 2 is an isometric view of a shaped solar mirror of the prior art, which shows an enlarged view of solar rays incident on the concave surface of the solar mirror.

[0019] FIG. 3 is a view similar to the view of FIG. 1, which shows the solar reflective mirror of the present invention with the solar reflective coating of the present invention.

[0020] FIG. 4 is a view similar to the view of FIG. 3, which shows another non-limiting embodiment of the solar reflective coating of the present invention.

[0021] FIG. 5 is a view similar to the view of FIG. 1, which shows another prior art embodiment of a solar mirror with an additional coating, and the hatching is not shown in FIG. 5 for the sake of clarity .

[0022] FIG. 6 is a view similar to the view of FIG. 5, which shows the solar reflective coating of the present invention with the additional coating and film of FIG. String.

[0023] FIG. 7 is a graph showing the solar energy weighted Rg reflectivity "SpEx WIRg") of the solar energy mirror of the prior art and the reflector of the present invention, which approximately excludes specular reflection.

[0024] FIG. 8 is a graph showing the approximately specularly excluded solar energy of samples 3a and 4a with their coatings in a deposited and non-heated condition and samples 3b and 4b with their coatings in a deposited and heated condition Weighted Rg reflectivity "SpEx WIRg") chart.

[0025] FIGS. 9 to 13 are views similar to the views of FIG. 3, which show a non-limiting embodiment of an enclosure having an enclosure according to the teachings of the present invention.

[0026] FIG. 14 is an isometric view of a flat solar mirror incorporating the features of the present invention.

[0027] FIG. 15 is a view taken along the line of FIG. 14.

Detailed ways

[0028] As used herein, spatial or directional terms, for example, "left", "right", "inner", "outer", "upper", "lower" and similar terms, refer to the present invention, as attached As shown in the picture. However, it should be understood that the present invention can take various alternative orientations, and therefore, these terms will not be considered restrictive. In addition, as used herein, all numbers expressing dimensions, physical characteristics, processing parameters, amounts of raw materials, reaction conditions, and similar parameters used in this specification and claims will be understood as passing the terminology in all cases "About" was modified. Therefore, unless stated to the contrary, the numerical values set forth in the following text and claims may vary according to the desired characteristics sought to be obtained by the present invention. At the very least, it is not an attempt to limit the application of the doctrine of equivalence to the scope of the claims. Each value should be interpreted in light of at least the number of significant figures reported and by applying ordinary rounding techniques. In addition, all ranges disclosed herein should be understood to include the beginning and ending range values and any and all sub-ranges included therein. For example, the specified range of "1 to 10" should be considered to include any and all sub-ranges between the minimum value of 1 and the maximum value of 10 (and including the minimum value of 1 and maximum value of 10); A value of 1 or greater starts and End with a maximum value of 10 or less, for example, 1 to 3.3, 4.7 to 7.5, 5.5 to 10, and similar values. In addition, as used herein, the terms "formed on", "deposited on", and "disposed on" mean being formed, deposited or disposed on a surface But not necessarily in direct contact with the surface. For example, a coating "formed on a substrate" does not exclude the presence of one or more other coatings or films of the same or different composition between the formed coating and the substrate.

[0029] As used herein, the term "polymer" or "polymeric" includes oligomers, homopolymers, copolymers, and terpolymers, for example, composed of two or more types of monomers or Polymer formed by polymer. The term "ultraviolet region" or "ultraviolet radiation" means electromagnetic energy having a wavelength in the range of 100 nanometers (hereinafter "nanometer" is also referred to as "nm") to less than 380 nm. The term "visible light region" or "visible light" refers to electromagnetic radiation having a wavelength in the range of 380 nm to 780 nm. The term "infrared region" or "infrared radiation" refers to electromagnetic radiation having a wavelength in the range of greater than 780 nm to 100,000 nm. Also, parameters such as "visible light transmittance" and "visible light reflectance" and the like are those determined using conventional methods. Those skilled in the art will understand that characteristics such as visible light transmittance or visible light reflectance may vary based on the physical dimensions (eg, thickness) of the article being tested. Therefore, any comparison of the present invention should be equivalent to

Calculate under the thickness.

[0030] Before discussing several non-limiting embodiments of the present invention, it will be understood that because the present invention can be other embodiments, the present invention in its application is not limited to the specific non-limiting embodiments shown and discussed herein. Details of a restrictive example. Further, other terms used herein to discuss the present invention are for descriptive purposes and not for limitation. Furthermore, unless otherwise indicated, similar reference numerals in the following discussion indicate similar elements.

[0031] A non-limiting embodiment of the invention relates to solar mirrors. As can be understood, the solar mirror can be a flat solar mirror, such as but not limited to the prior art flat solar mirror 5 (Figure 1) and/or the flat solar mirror 7 (Figure 3) containing the features of the present invention, or solar The mirror can be a shaped solar mirror, such as but not limited to a shaped solar mirror 9 having a concave surface 10 and an opposite convex surface 11 (Figure 2), and is published in the US Patent Application 2010/0242953 (hereinafter also referred to as " Pub. '953") is discussed in detail. The entire content of Pub '953 is hereby included by reference.

[0032] Non-limiting embodiments of the present invention are discussed with reference to the reflection of electromagnetic radiation, such as but not limited to electromagnetic waves having a wavelength in the range of 300 nm to 2500 nm. As used herein, the term "reflective article" refers to any article, such as, but not limited to, configured to reflect electromagnetic radiation such as ultraviolet radiation, visible radiation, and/or infrared radiation, for example for use in concentrating solar power The "solar mirror" in the system. However, it should be understood that the embodiments of the present invention are not limited to use with solar mirrors, but can be practiced with products in other fields, such as, but not limited to, layered or non-layered products. Residential mirrors and/or commercial mirrors and/or windows and/or reflectors for use in optical systems (for example, video projectors or optical scanners), to name a few. Therefore, it should be understood that only the specifically disclosed exemplary embodiments are introduced to explain the general concept of the present invention, and the present invention is not limited to these specific exemplary embodiments.

[0033] Non-limiting embodiments of the invention that will be discussed herein include, but are not limited to (A) a solar reflective coating with improved optics and stability; and (B) an encapsulated coating stack of a solar mirror with Improve the useful life of solar mirrors. In the following discussion, the coating stack of the solar mirror uses magnetron sputtering to vacuum-deposit solar reflective films, layers and coatings. However, the present invention is not limited to this, and the present invention can be implemented by means of any type of deposited film, layer and/or coating such as a chemical vapor deposition coating process. It should be understood that the embodiments of the present invention are presented in separately identified chapters for understanding the non-limiting embodiments of the present invention, and it is not indicated in one form or another that the embodiments of the present invention are Independent and unique from each other. As understood, the non-limiting embodiments of the present invention can be used alone or in combination with each other.

[0034] Solar reflective coating with improved optics and stability

[0035] This non-limiting embodiment of the present invention provides a solar reflective coating and a solar reflective coating applied to a substrate to provide improved optical and thermal stability compared to prior art solar mirrors Sexual solar mirror. The prior art solar mirror 5 shown in FIG. 1 includes a substrate or ply 12 having a first main surface 14 that is an outer main surface 14 and an opposite second main surface 16 or inner main surface 16. The solar mirror 9 shown in FIG. 2 has a solar reflective concave surface 10 that faces the sun 20 to reflect solar energy to the focal point 21. In the following discussion, the first major surface or outer surface 14 of the substrate 12 and the concave surface 10 or outer surface 10 of the solar mirror 9 are designated as facing incident radiation, for example, the sun 20 (only the sun is shown in FIG. 2 20), and the second surface 16 of the substrate 12 and the convex surface 11 of the solar mirror 9 face the opposite direction of the incident radiation. With continued reference to FIG. 1, the surface 16 of the substrate 12 is designated to support the prior art solar reflective coating 22, as shown in FIG. Optionally, a bottom layer 24 is provided between the reflective coating 22 and the surface 16 of the laminate 12. On top of the solar reflective coating 22 is applied a protective coating 25 discussed in detail below.

[0036] The solar mirror 7 of the present invention shown in FIG. 3 includes a substrate or a laminate 12, and the substrate or laminate 12 has a first

One major surface 14 is the outer major surface and the opposite second major surface 16 is the inner major surface. When the bottom layer is present, the solar reflective coating 27 of the present invention is applied on the surface 29 of the bottom layer 24, and when the bottom layer is not present, the solar reflective coating 27 of the present invention is applied on the surface 16 of the substrate 12 And the protective coating 25 is applied on the solar reflective coating 27. In the following discussion, the first major surface 14 of the solar mirror 7 is designed to face incident radiation, that is, the sun, and the second surface 16 of the substrate 12 faces the opposite direction of the incident radiation, and is designated to support the present invention The solar reflective coating 27. 3, the solar mirror 7 of the present invention includes a solar reflective coating 27, which has two sub-layers 28a, 28b separated by a separation layer 30. Shown in FIG. 4 is the solar mirror 26 of the present invention, which includes three sub-layers, for example, three sub-layers 28a, 28b, and 28c separated by separation films or media 30a and 30b to reduce crystal growth. The solar reflective coating 27 of the present invention is discussed in more detail below.

[0037] In the broad practice of the present invention, the substrate or laminate 12 may include any desired material having any desired characteristics. For example, when the first major surface 14 of the laminate 12 faces incident radiation such as the sun 20 (only the sun 20 is shown in FIG. 3), the second major surface 16 of the substrate or laminate 12 supports or carries the solar reflective coating. The sub-layer 28 and the separation layer 30 of the layer, such as but not limited to the sub-layers 28a and 28b. The laminate 12 is preferably transparent or translucent to visible light. The term "transparent" means having a transmittance of greater than 0% up to 100% in a desired wavelength range, for example, visible light. Alternatively, the laminate 12 may be translucent, "translucent" meaning that electromagnetic radiation (eg, visible light) is allowed to transmit, but diffuses or scatters the radiation. Examples of suitable materials for the laminate 12 include, but are not limited to, thermoplastic, thermoset, or elastomeric polymeric materials, glass, ceramics, and metals or metal alloys, and combinations, composites, or mixtures thereof. Specific examples of suitable materials include, but are not limited to, plastic substrates (e.g., acrylic polymers, e.g., polyacrylate; polyalkylmethacrylate, e.g., polymethylmethacrylate, polyethylmethacrylate) , Polymethyl acrylate and the like; polyurethane; polycarbonate; polypropylene terephthalate, for example, polyethylene terephthalate (PET), polypropylene terephthalate, polybutylene terephthalate Glycol esters and similar Thing; polysiloxane-containing polymer; or copolymer of any monomer used to prepare these, or any mixture thereof); ceramic substrate; glass substrate; or a mixture or combination of any of the above Things. For example, the laminate 12 may include conventional soda lime silicate glass, borosilicate glass, or lead-containing glass. The glass may be transparent glass. The term "clear glass" means uncolored or uncolored glass. Alternatively, the glass may be opaque, colored or otherwise colored glass. The glass can be annealed or heat-treated glass. As used herein, the term "heat treatment" means to be thermally tempered, thermally bent, thermally strengthened, or laminated. The glass can be any type of glass, for example, conventional float glass, and can be any composition having any optical properties, for example, any of visible light transmittance, ultraviolet transmittance, infrared transmittance, and/or total solar energy transmittance. value. Although not limited to the present invention, examples of glass suitable for the substrate or laminate 12 are described in US Patent Nos. 4,746,347; 4,792,536; 5,030,593; 5,030,594; 5,240,886; 5,385,872; and 5,393,593. The substrate or laminate 12 may be of any desired size, for example, length, width, shape, or thickness. In an exemplary embodiment, the first layer 12 may have a thickness greater than 0 to 25 mm (1.00 inch) thickness, for example, a thickness of 1 mm to 10 mm, for example, a thickness of 1 mm to 5 mm, for example, a thickness of less than 4 mm, for example, a thickness of 3 mm to 3.5 mm, for example, a thickness of 3.2 mm. Additionally, the laminate 12 may have any desired shape, for example, a flat shape, a curved shape, a parabolic shape, or the like. Moreover, when one or more primary reflective coatings such as reflective coating 27 rest on the second primary surface 16 of the solar mirror, the laminate 12 may include, but is not limited to, one or more such materials, namely, the The material exhibits a low electromagnetic radiation absorption rate for electromagnetic radiation in one or more electromagnetic radiation regions that are expected to be reflected.

[0038] In a non-limiting embodiment of the present invention, the laminate 12 may have a higher visible light transmittance at a reference wavelength of 550 nanometers (nm) and a reference thickness of 3.2 mm. The term "higher visible light transmittance" means that the visible light transmittance at 550nm is greater than or equal to 85%, for example, greater than or equal to the reference thickness for the laminate of 3.2mm

87%, for example, greater than or equal to 90%, for example, greater than or equal to 91%, for example, greater than or equal to 92%, for example, greater than or equal to 93%, for example, greater than or equal to 95%. Particularly useful glasses for practicing the present invention are disclosed in U.S. Patent Nos. 5,030,593 and 5,030,594. Non-limiting examples of glasses that can be used to practice the present invention include, but are not limited to, Starphire.RTM, Solarphire.RTM, Solarphire.RTM.PV, Solargreen.RTM, Solextra.RTM, GL-20.RTM, GL-35. TM, Solarbronze. RTM, CLEAR and Solargray. RTM glass, all of which are commercially available from PPG Industries of Pittsburgh, Pennsylvania.

[0039] As can be understood by those skilled in the art, when the layer 12 is located between the sun 20 and the reflective coating 22, the layer 12 (see FIGS. 1 and 3) is transparent, and when the reflective coating is located Between the sun 20 and the laminate, the laminate may be opaque or transparent.

3, in another non-limiting embodiment of the present invention, a layer 24 or primer is provided between the sub-layer 28b of the solar reflective coating 18 and the second main surface 16 of the laminate 12 Layer 24 or bottom layer 24. The undercoat layer 24 is preferably deposited using a vacuum-based process immediately before depositing the vacuum-deposited silver (Ag) reflective coating 27 without breaking the vacuum, thereby providing an uncontaminated surface to receive the solar reflective coating 27. The primer layer 24 can provide a stronger or more durable interface between the laminate 12 and the reflective coating 27. The undercoat layer 24 may include, but is not limited to, one or more materials, which are selected so that the interface between the undercoat layer 24 and the solar reflective coating 27 is greater than that between the laminate 12 and the main reflective coating 27. The interface is more stable mechanically, chemically and/or environmentally. Moreover, the undercoat layer 24 can be used as a diffusion barrier against element exchange between the laminate 12 and the reflective coating 27 (for example, sodium leaves the glass laminate 12 and migrates into one or more overlay coatings or The migration of metals such as silver from the reflective coating 27 to the glass), especially as may occur due to subjecting the coated article to elevated temperatures, for example for bending or thermal strengthening.

[0041] Additionally or alternatively, the primer layer 24 may provide a smoother or more planar surface on which a paving coating, for example, a solar reflective coating 27, is deposited. Examples of materials suitable for the undercoat layer 24 include, but are not limited to, inorganic materials, such as, but not limited to, light-transmitting and low-absorbing dielectrics, such as metal oxides, metal nitrides and/or combinations thereof, metal oxides and/or A composition or mixture of metal nitrides. Examples of suitable metal oxides include aluminum oxide, silicon dioxide, titanium dioxide, aluminum oxide, zinc oxide, zinc stannate, tin dioxide, or mixtures or combinations thereof. Other examples for the bottom layer 24 include one or more layers of silicon dioxide and/or silicon nitride or combinations thereof. In a non-limiting embodiment, the primer or underlayer 24 includes, but is not limited to, titanium dioxide. The primer layer 24 may have any composition or thickness to provide sufficient functionality to the article (for example, mechanical, chemical, passivation, planarization, adhesion, diffusion barrier properties, environmental protection and durability enhancement, optical enhancement). In a specific embodiment in which the undercoat layer 24 is titanium dioxide, the undercoat layer 24 has a thickness in the range of 0.1 nm to 5 nm, for example, 0.1 nm to 3 nm, for example, 0.5 nm to 3 nm, for example, 1 nm to 3 nm. 3nm, for example, 0.5nm to 2nm, for example, 1nm to 2nm, for example, 1.5nm to 2nm, for example, 1.8nm.

[0042] Referring to FIGS. 3 and 4 as needed, in the preferred practice of the present invention, the sub-layer 28b of the solar reflective coating 27 of the solar mirror 7 (FIG. 3) and the solar reflective coating of the solar mirror 26 (FIG. 4) The sublayer 28c of 27 is formed on at least a portion of the second major surface 16 of the substrate 12, for example, on at least a portion of the bottom layer 24, if present. Optionally, a protective coating 25 is provided on at least a part of the solar reflective coating 27. Although in the illustrative embodiment shown in FIGS. 3 and 4, the bottom layer 24, the solar reflective coating 27, and the protective coating 25 are formed on the second main surface 16 of the substrate 12, it should be understood that At least some of the coatings may alternatively be formed on the first main surface 14 of the substrate 12. The selection of the materials of the solar mirrors 7 and 26 of the present invention, for example, but not limited to, the material of the substrate 12, especially the material used as the optional undercoat or bottom layer 24 of the barrier coating of the solar reflective coating 27, And the material of the protective coating 25 is also discussed in U.S. Patent No. 8,445,098 "Patent '098", which is hereby incorporated by reference, and

And it was deemed unnecessary for further discussion.

[0043] In order to facilitate the reference coating or film, the coating or film is discussed as each coating and film, such as but not limited to the present invention, each film of the solar mirror 7 of the present invention shown in FIG. 3 is the bottom layer 24, The solar reflective coating 27 and the protective film 25 including the sub-layers 28a and 28b and the separation film 30 are as shown in FIG. 3. The respective films of the solar mirror 26 of the present invention shown in FIG. 4 are the bottom layer 24, the reflective coating 27 including the sub-layers 28a to 28c and the separation films 30a to 30b, and the protective film 25, as shown in FIG. Optionally, the films of the solar mirror 26 shown in FIG. 4 may be collectively referred to as the coating stack 34. For the prior art solar mirror 5 shown in FIG. 1, the various films of the prior art solar mirror 5 shown in FIG. 1 are the bottom layer 24, the solar reflective coating 22 and the protective film 25, as shown in FIG. As shown in, they can optionally be referred to as prior art coating stacks 35.

[0044] Referring back to FIGS. 3 and 4 as needed, the solar reflective coating 27 is formed on at least a portion of the second main surface 16, for example, is formed on at least a portion of the undercoat layer 24, if present . The solar reflective coating 27 of the present invention includes, but is not limited to, two or more sublayers 28, for example, the sublayers 28a and 28b in FIG. 3 and the sublayers 28a to 28c in FIG. 4. In the preferred practice of the present invention, the component sublayer 28 is one or more solar reflective materials that reflect portions of the electromagnetic spectrum. In a non-limiting embodiment of the present invention, the solar reflective coating 28 includes, but is not limited to, radiation reflective metal sublayers 28a and 28b or 28a and 28b and 28c, and so on. Examples of suitable reflective metals for the sublayer 28 of the solar reflective coating 27 include, but are not limited to, metallic silver, aluminum, gold, copper, platinum, iridium, osmium, palladium, nails, aluminum, or other precious metals and alloys, mixtures thereof , Its blends or combinations thereof. In a non-limiting embodiment of the present invention, the solar reflective coating 27 includes but is not limited to the metallic silver sub-layer 28, so that the thickness of the solar reflective coating 27 is in the range of 50 nm to 500 nm, preferably 100 nm. The solar reflective coating 27 of FIG. 4 can be deposited to a thickness such that the solar mirrors 7 and 26 have any specific desired level of reflectivity within the desired range of the electromagnetic radiation to be reflected. The sub-layer 28a of the solar reflective coating 27, 28b and 28c may be deposited to a thickness sufficient to make the solar reflective coating 27 opaque in the desired wavelength range, such as visible light. The solar reflective coating 27 may be particularly useful in reflecting visible light and infrared solar energy. In a specific non-limiting embodiment of the present invention, the solar reflective coating 27 is deposited by a conventional sputtering process, as described in more detail below. In another non-limiting embodiment of the present invention, the coating stack 32 of the solar mirror 7 may include, but is not limited to, a "high reflector", which has a plurality of alternating high refractive index and low refractive index material films, As is known in the art, see, for example, the discussion of Figure 11 and Figure 11 for additional membranes.

[0045] The protective coating 25 assists in protecting the coating stack 32 of the solar mirror 7 shown in FIG. 3 and the coating stack 34 of the solar mirror 26 shown in FIG. 4 and/or the lower layer of the film, respectively. Mechanical and chemical attack during manufacturing, storage, transportation, handling, handling, and/or during the service life of mirrors in the field. The protective coating 25 also helps to protect the lower layer from the entry of liquid water, water vapor, and other environmental solid pollutants, liquid pollutants, or gaseous pollutants. The protective coating 25 may be an oxygen barrier coating to prevent or reduce the introduction of ambient oxygen into the underlying layer during subsequent processing, such as during heating or bending. The protective coating 25 may be any desired material or mixture of materials, such as but not limited to one or more inorganic materials. In an exemplary embodiment, the protective coating 25 may include a layer having one or more metal oxide materials, such as but not limited to aluminum, silicon or alloys thereof, blends thereof, The oxide of its composition and/or its mixture. For example, the protective coating 25 may be a single coating that contains an oxide deposited by sputtering such a sputtering target, the sputtering target including silicon and aluminum, the silicon and aluminum at 0wt. % To 100wt.% of aluminum and/or 100wt, in the range of% to 0 Asx·% of silicon, for example, 1wt.% to 99w soil·% of aluminum and 99wt. % To 1w soil ·% of silicon, for example, 5wt ·% to 95wt ·% of aluminum and 95wt ·% to 5wt.% of silicon, for example, 10wt.% to 90wt.% of aluminum and 90wt.% to 10w soil. % Of silicon, for example, 15wt.% to 90wt,% of aluminum and 85wt,% to 10w soil.% of silicon, for example,

% To 75wt.% of aluminum and 50wt.% to 25wt.% of silicon, for example, 50wt.% to 70wt.% of aluminum and 50wt.% to 30wt.% of silicon, for example, 35wt.% to 100wt. % Of aluminum and 65wt.% to 0wt.% of silicon, for example, 70wt.% to 90wt.% of aluminum and 30wt.% to 10wt.% of silicon, for example, 75wt.% to 85wt.% of aluminum and 25wt. % To 15wt.% silicon, for example, 88wt.% aluminum and 12wt.% silicon, for example, 65wt.% to 75wt.% aluminum and 35wt.% to 25wt.% silicon, for example, 70wt.% Aluminum and 30wt.% silicon, for example, 60wt.% to less than 75wt. % Aluminum and greater than 25wt.% to 40wt.% silicon. In a specific non-limiting embodiment, the protective coating 23 comprises an oxide deposited by sputtering such a sputtering target which contains 40wt.% to 15wt.% aluminum and 60wt.% To 85wt.% silicon, for example, 85wt.% silicon and 15wt.% aluminum. Other materials may also be present, such as aluminum, ingot, hafnium, yttrium, nickel, boron, phosphorus, titanium, aluminum, and/or oxides thereof, for example, to adjust the refractive index of the protective coating 25. In a non-limiting embodiment, the refractive index of the protective coating 25 may be in the range of 1 to 3, for example, 1 to 2, for example, 1.4 to 2, for example, 1.4 to 1.8.

[0046] In a non-limiting embodiment of the present invention, the protective coating 25 includes, but is not limited to, a combination of silica and alumina. The protective coating 25 may be sputtered from two cathodes (e.g., one cathode is silicon and one cathode is aluminum) or from a single cathode containing both silicon and aluminum. The silicon aluminum oxide protective coating 25 can be written as: Si .sub.xAI.sub.1-xO.sub.1.5+x/2, where x can vary from greater than 0 to less than 1. In a specific non-limiting embodiment of the present invention, the protective coating 25 may be a silicon aluminum oxide coating (Si.sub.xAI.sub.1 xO.sub. 1.5+x/2), which has a thickness in the range of 5nm to 5000nm, for example, 5nm to 1000nm, for example, 10nm to 100nm, for example, 10nm to 50nm, for example, 10nm to 40nm, for example, 20nm to 30nm, for example , 25nm. In addition, the protective coating 25 may have a non-uniform thickness. The term "non-uniform thickness" means that the thickness of the protective coating 25 may vary over a given unit area, for example, the protective coating 25 may have high and low points or areas. In another non-limiting embodiment, the protective coating 25 includes, but is not limited to, a silicon aluminum oxide coating or a mixture, composition, alloy, or blend of silicon dioxide and aluminum oxide, for example, 85 wt.% of two Silicon oxide and 15wt.% aluminum oxide, and have a thickness in the range of 10nm to 500nm, for example, 20nm to 300nm, for example, 50nm to 300nm, for example, 50nm to 200nm, for example, 50nm to 150nm, for example, 50nm to 120nm, for example, 75nm to 120nm, for example, 75nm to 100nm. In a specific non-limiting embodiment, the protective coating 25 may have a thickness of at least 50 nm, for example, at least 75 nm, for example, at least 100 nm, for example, at least 110 nm, for example, at least 120 nm, for example, at least 150 nm, for example, at least 200nm.

[0047] In another non-limiting embodiment of the present invention, the protective coating 25 includes but is not limited to silicon dioxide, which has a thickness in the range of 10 nm to 100 nm, for example, 10 nm to 80 nm, for example, 20 nm To 80 nm, for example, 30 nm to 70 nm, for example, 40 nm to 60 nm, for example, 50 nm. In yet another non-limiting embodiment, the protective coating 25 includes, but is not limited to, silicon dioxide, which has a thickness in the range of 10 nm to 500 nm, for example, 10 nm to 400 nm, for example, 20 nm to 300 nm, for example, 50 nm To 200 nm, for example, 75 nm to 150 nm, for example, 75 nm to 120 nm.

[0048] In another non-limiting embodiment of the present invention, the protective coating 25 may include a multilayer structure, for example, a first layer having at least one second layer formed on the first layer. In a specific non-limiting embodiment, the first layer may include, but is not limited to, alumina or a mixture, composition, blend, or alloy containing alumina and silica. For example, the first layer may include, but is not limited to, silicon aluminum oxide deposited by sputtering a sputtering target that has more than 5 wt.% aluminum, for example, more than 10 wt.% aluminum, for example, % Of aluminum, for example, more than 30wt.% of aluminum, for example, more than 40wt.% of aluminum, for example, 50wt.% to 60wt.% of aluminum, for example, in the range of 70wt.% to 1000±% The inner aluminum and 40wt.% to 0wt.% silicon, for example, more than 90wt.% aluminum, for example, more than 95wt.% aluminum. In a non-limiting embodiment, all or substantially all of the first layer is alumina. In a non-limiting embodiment, the first layer may have a thickness in the range of greater than 0 nm to 1 micrometer, for example, 5 nm to 10 nm, for example, 10 nm to 25 nm,

For example, 10nm to 15nm. The second layer may include silica or a mixture, composition, blend, or alloy containing silica and alumina. For example, the second layer may comprise silicon aluminum oxide deposited by sputtering such a sputtering target, the sputtering target has more than 40wt.% silicon, for example, more than 50wt.% silicon, for example, more than 60wt. % Silicon, for example, more than 70wt.% silicon, for example, more than 80wt.% silicon, for example, in the range of 80wt.% to 90wt.% silicon and 10wt.% to 20wt.% aluminum, for example, 85wt.% silicon and 15wt.% aluminum. In a non-limiting embodiment, the second layer may have a thickness in the range of greater than 0 nm to 2 microns, for example, 5 nm to 500 nm, for example, 5 nm to 200 nm, for example, 10 nm to 100 nm, for example, 30 nm to 50 nm , For example, 35nm to 40nm. In another non-limiting embodiment, the second layer may have a thickness in the range of greater than 0 nm to 1 micrometer, for example, 5 nm to 10 nm, for example, 10 nm to 25 nm, For example, 10nm to 15nm. In another non-limiting embodiment, the protective coating 25 may be a double layer formed of a layer containing a metal oxide (for example, a first layer containing silicon dioxide and/or aluminum oxide) It is formed on another metal oxide-containing layer (for example, a second layer containing silicon dioxide and/or aluminum oxide), wherein the two components of the double-layer protective coating have different chemical compositions. The individual layers of the multi-layer protective coating 25 can be any desired thickness. Non-limiting examples of suitable protective coatings 25 are described, for example, in U.S. Patent Serial Nos. 10/007,382; 10/133,805; 10/397,001; 10/422,094; 10/422,095; and 10/422,096, which are incorporated by reference Here. [0049] Comparing the solar mirrors 7 and 26 of the present invention shown in Figs. 3 and 4 with the prior art solar mirror 5 shown in Fig. 1, the difference of interest for this discussion is the prior art The solar reflective coating 22 of the solar mirror 5 and the solar reflective coating 27 of the solar mirrors 7 and 26 of the present invention. More specifically, the substrate 12, bottom layer 24, and protective coating 25 of the prior art solar mirror 5 shown in FIG. 1 are similar to those of the solar mirrors 7 and 26 shown in FIGS. 3 and 4, respectively. , If not exactly the same. Based on the above content, it can be understood that the difference between the solar mirror of the prior art and the solar mirror of the present invention is the solar reflective coating. More specifically, the prior art solar reflective coating 22 is a monolithic solar reflective film 22, for example, a single silver (Ag) film, while the solar reflective coating 27 of the present invention includes a solar reflective film or Sublayer 28.

[0050] In the following discussion, reference is made to a non-limiting embodiment of the solar reflective coating 27 of the solar mirror 7 of the present invention (see FIG. 3). However, this discussion can also be applied to a non-limiting embodiment of the solar reflective coating 27 of the solar mirror 26 of the present invention unless otherwise indicated (see FIG. 4). Referring to FIGS. 3 and 4 as needed, the solar reflective coating 27 of the present invention has a separation layer 30 between the sublayers 28a and 28b (see FIGS. 1 and 3) and between the sublayers 28a, 28b, and 28c Separating layers 30a and 30b (Figure 4). 4, the surface 38 of the separation layer 30a may be in surface contact with the adjacent surfaces 40 of the sublayers 28a or 28b and 28c, if present, or may be between the surface 38 of the separation layer 30 and the surfaces 40 of the sublayers 28a and 28b. There is a coating or film between. Without limiting the scope of the present invention, the non-limiting embodiment of the present invention may consider such a solar mirror 7, that is, the solar mirror 7 has a solar reflective coating 27, the solar reflective coating 27 has two solar reflective sub-layers 28a and 28b (Figure 3) and 28c (Figure 4) separated by separation layers 30a (Figure 3) and 30b (Figure 4). In the practice of the present invention, the surface 40 of the sub-layer 28a is in surface contact with the adjacent surface 38 of the separation layer 30 or is Above the adjacent surface 38, and the surface 40 of the sub-layer 28b is in surface contact with the surface 38 of the separation layer 30. Nevertheless, the present invention contemplates having an additional coating between the surface 40 of the sub-layers 28a and 28b of the solar reflective coating 27 and the surface 38 of the separation films 30a and 30b, respectively, as shown in FIG. 4. This non-limiting embodiment of the invention is discussed in more detail below.

[0051] Practicing the present invention provides solar mirrors 7 and 26 that are in a temperature range suitable for high-temperature heat treatment of glass at elevated temperatures (for example, 1180°F to 1200°F) Optically more stable, the high-temperature heat treatment of the glass is, for example, thermal tempering, thermal strengthening or thermal bending of the glass. In addition, the solar reflective coating 27 can be used in the electromagnetic spectrum

(For example, ultraviolet, visible, near-infrared, far-infrared, microwave, radio waves, etc.) within one or more regions of interest exhibit a certain range of solar reflectance or solar transmittance. For example, but not limited to the present invention, solar mirrors 7 and 26 (see FIGS. 3 and 4, respectively) may have phases with one or more silver sub-layers 28a, 28b (FIG. 3) and 28c (FIG. 4) at a wavelength of 550 nm. The adjacent "visible light" reflectivity is at least 85%, such as at least 90%, such as at least 95% of visible light reflection. [0052] The practice of the present invention alleviates the potential decrease in the specular reflectivity of the solar mirrors of the present invention, such as but not limited to the solar mirrors 7 and 26 of FIGS. 3 and 4, respectively. 26 The amount of light reflected non-specularly (ie, diffusely) is achieved.

[0053] To clarify the benefits of the present invention, the term "reflectance including specular reflection" is adopted to mean that all specular and non-specular reflections (ie, diffusion) contribute to the reflectance of the mirror. Typically, an attempt is made to minimize the amount of reflectivity that excludes specular reflection (ie, diffusion) in order to maximize the specular reflectivity of the mirror. A commercially available spectrophotometer can be used to measure the reflectance including specular reflection (which includes both specular reflection components and non-specular reflection components) and the components excluding specular reflection. The instrument used to do this is the Hunter Ultrascan PRO spectrophotometer. The measured wavelength range is 350nm to 1000nm. The reflectance of the glass side (ie, the energy incident on the uncoated surface of the sample) measured by the instrument, including the specular reflection, is tabulated as the percentage of incident light, which is specular and non-specular The ground reflects to the wavelength. Similarly, the reflectance of the glass side excluding specular reflections measured by the instrument is tabulated as a percentage of incident light, which is non-specular reflection versus wavelength. The tabular value of the reflectance excluding specular reflection can be weighted by the solar irradiance function and digitally integrated to produce a single number. Referred to as "SpEx WIRg"), its "WIR" means "(solar) weighted integral reflectance", "SpEx" means "excluding specular reflection", and the "g" subscript indicates that the light energy is incident on the glass side of the solar mirror 7 (ie, not Coated surface). For solar mirror applications, one or more surfaces intended to receive the flux of reflected sunlight are called "receivers". It is typically desirable to minimize the solar-weighted glass-side reflectance (SpEx WIRg) that excludes specular reflections, because any light energy that is non-specularly reflected from the solar mirror will not be intercepted by the surface of the receiver, thereby This constitutes the loss of available incident solar energy.

[0054] Two samples were made for comparison. Sample 1 is a prior art solar mirror shown in FIG. 5 and designated by the number 70, and sample 2 is a non-limiting solar mirror of the present invention shown in FIG. 6 and designated by the number 72 Examples. 5, the prior art solar mirror 70 (sample 1) includes:

1. A low-iron glass substrate 12 of the type sold under the registered trademark SOLARPHIRE PV by PPG Industries, which has a nominal thickness of 3.2 millimeters ("mm");

[0056] 2. Titanium dioxide (TiO2) primer or bottom layer 74, which has a thickness of 2 nm, which is applied to the surface 16 of the glass substrate 12 by MSVD;

[0057] 3. The solar reflective coating 22 of silver ("Ag"), which has a thickness of 100 nm, is applied on the TiO2 undercoat film 74 by MSVD;

[0058] 4. Ti (Ox) "primer" or "barrier" or "barrier" layer 76, which has a thickness of 2.5 nm, which is applied on the Ag film 22 by MSVD;

[0059] 5.52wt.% of Zn and 48wt.% of Sn oxide film ("Zn52-Sn48 oxide") top coating layer 78, which has a thickness of 140nm; the oxide is also called zinc stannate (Zn2SnO4), the top coating 78 is applied on the Ti (Ox) "primer" layer 76 by MSVD;

[0060] 6. 850% 51 and 150% 41% oxide (Long 185R115") aluminosilicate film 25, which is also known as a permanent protective overcoat ("PPO"), the The film has a thickness of 75nm, which is applied on the "Zn52-Sn48 oxide" film

78; ("Si85-Al15) aluminosilicate film 80 is applied on the "Zn52-Sn48" top coating film 78.

[0061] Referring to FIG. 6, the solar mirror 72 (Sample 2) of the present invention includes but is not limited to:

[0062] 1. A low-iron glass substrate 12 of the type sold under the registered trademark SOLARPHIRE PV by PPG Industries, which has a nominal thickness of 3.2 millimeters "mm");

. [0063] 2 Titanium dioxide (TiO2) undercoat layer film 74 having a thickness of 2 nm, which is applied to the surface of the glass substrate 12 through 16 MSVD;

[0064] 3. A sublayer 28b of the silver "Ag") film 27, which has a thickness of 50 nm, which is applied on the TiO2 film 74;

4. Ti (Ox) first separation film 82, which has a thickness of 1.3 nm, which is applied on the sub-layer 28b of the Ag (50 nm) film;

[0066] 5. Zn2SnO4 second separation film 84, which has a thickness of 3.5 nm on the separation Ti (Ox) film 82;

[0067] 6. Silver "Ag") coated silver sublayer 28a, which has a thickness of 50 nanometers "nm"), which is applied on the second separation film 84 of Zn2SnO4;

[0068] 7. Ti (Ox) "primer" or "barrier" or "barrier" layer 76, which has a thickness of 2.5nm on the Ag sublayer 28a; [0069] 8. 52wt.% Zn and 48wt. % Sn oxide film "Zn52-Sn48 oxide") top coating 84, which has a thickness of 140 nm; the oxide is also called zinc stannate (Zn2SnO4), the top coating 84 is applied by MSVD On the Ti (Ox) "substrate" layer 76;

[0070] 9. 85wt.% Si and 15wt.% Al oxide "Si85-Al15 oxide") aluminosilicate film (PPO film)

25, which has a thickness of 75nm, which is applied on the Zn52 "Sn48" oxide film.

[0071] The Ti (Ox) film 76 used for the solar mirrors 70 and 72 does not have a sub-number. This is because titanium (Ti) is deposited as a metal titanium in a vacuum system, and will interact with oxygen as the coating process continues. Start a chemical reaction. After the coating deposition is completed, titanium (Ti) has been completely oxidized or almost completely oxidized. In the deposited state, titanium is not completely oxidized, and any remaining TiOx metallic titanium is expected to be completely oxidized by subsequent high temperature heat treatment (eg, thermal tempering, thermal strengthening, thermal bending).

[0072] FIG. 7 shows an experimental solar mirror coating with and without the solar reflective coating 27 of the present invention, estimated using spectral R reflectance data from 350 nm to 1000 nm, and approximately excluding specular reflection. The solar energy weighted Rg reflectivity "SpEx WIRg") chart, the solar reflective coating 27 of the present invention has separation layers 82 and 84 and sub-layers 28a and 28b. As can be understood from the above discussion, the coating stack 86 of the solar mirror 70 of the prior art and the coating stack 88 of the solar mirror 72 of the present invention are nominally the same, except that the solar mirror 70 of the prior art uses a single piece of Ag. The film 22 and the solar mirror 72 of the present invention have separation layers 82 and 84 in the coating stack 88 of the solar mirror 72 of the present invention. The left side of the graph shows the solar-weighted glass side reflectivity of both solar mirrors 70 and 72 in their deposited/non-heat-treated state, excluding specular reflections. The right side of the graph shows the solar-weighted glass-side reflectance of both solar mirrors 70 and 72 after heat treatment to simulate thermal tempering, excluding specular reflections. Considering the left side of the graph, the leftmost column is for the solar mirror 70 without the separator films 82 and 84 of the present invention, and the column immediately to the right is for the solar mirror 70 with the separator films 82 and 84 of the present invention. 72 data. As can be seen from Figure 7, the two solar mirrors 70 and 72 In the deposited state/non-heat-treated state, the solar-weighted glass side reflectivity of both solar mirrors 70 and 72 excluding specular reflection is similar. Considering the right side of the graph in FIG. 7, the rightmost column is for the solar mirror 72 with the separation films 82 and 84 of the present invention, and the column immediately to the left is for the separation films 82 and 84 without the present invention. The data of the solar mirror 70. As can be seen from Figure 8, after heat treatment to simulate thermal tempering, the solar-weighted glass side reflectivity of the solar mirror 72 that excludes the specular reflection: (a) and the SpEx WIRg of the solar mirror 72 in its deposited state Value class

Similarly, and (b) is lower than the value of SpEx WIRg of the solar mirror 70 after the solar mirror 70 has undergone heat treatment. As is now understood, it is typically desirable to minimize SpEx WIRg for solar mirror applications.

[0073] The information in FIG. 7 proves that the solar mirror of the prior art and the solar mirror of the present invention have approximately the same level of reflectivity excluding specular reflection in their deposited state, but have a significant difference when heat-treated. Specifically, in the deposited state/non-heat-treated state, the coated substrate 12 (solar mirror 70) of the prior art and the coated substrate 12 (solar mirror 72) of the present invention exhibit relatively high results based on qualitative visual evaluation. With little haze/no haze, the solar mirrors 70 and 72 were observed under incandescent floodlight illumination in terms of reflectivity in the qualitative visual evaluation.

[0074] In addition, the "truncated" (350nm to 1000nm) of the solar mirrors 70 and 72 in their as-deposited/non-heat-treated state inferred (solar) weighted reflectance SpEx WIRg that excludes specular reflections. It is similar at about 0.09% to 0.1%. After heat treatment to simulate thermal tempering, the reflectance of the solar energy weighted Rg that excludes specular reflection of the solar mirror 70 of the prior art exhibits an increase of about 3 times to SpEx WIRg~0.33%, while the reflectance of the solar mirror 72 of the present invention It only showed a slight increase to SpEx WIRg~0.13% (see Figure 7).

[0075] Thus, FIG. 7 shows one benefit of using the spacer layer of the present invention, that is, it is possible to suppress an increase in the reflectance "SpEx WIRg" of the solar weighted Rg that excludes specular reflection immediately after the high-temperature heat treatment. Here, we refer to the SpEx WIRg value measured immediately after the high temperature heat tempering heat treatment/shortly after the high temperature heat tempering heat treatment, and there is no significant additional aging at room temperature or other temperatures, such as "time zero SpEx WIRg" . In addition, the terms "haze", "non-specularly reflective", "WIRg reflectivity excluding specular reflection" and "SpEx WIRg" are sometimes used synchronously.

[0076] Another feature of the solar reflective coating of the present invention improves the thermal stability of heat-treated mirrors that are aged at elevated temperatures. Experiments were carried out at a temperature of 150°C over a period of time greater than 10,000 hours to simulate the performance of the solar mirror of the prior art (Figure 3) and the solar mirror of the present invention (Figure 4). Referring to Figure 5, sample 3 includes but is not limited to:

[0077] 1. SOLARPHIRE PV glass substrate 12, which has a nominal thickness of 3.2 mm;

[0078] 2. A TiO2 film 74, which has a thickness of 2 nm, is applied on the surface 16 of the substrate 12 facing away from incident light, such as but not limited to the sun 20 (see FIG. 2);

3. Silver "Ag") film 22, which has a thickness of 100 nanometers "nm), which is applied on the film 74 of TiO2;

4. Inconel 600 has enhanced corrosion resistance and UV absorption film 90, which has a thickness of (30nm), which is applied on

On the Ag silver film 22, Inconel 600 is shown in phantom and only shown in FIG. 5;

[0081] 5. Ti (Ox) "priming" (or "barrier" or "barrier") layer 76 (~2.5nm) on the Inconel 600 layer 90 on the Inconel 600 layer 90; [0082] 6.52wt.% Zn And 48wt.% Sn oxide film "Zn52-Sn48 oxide") top coating 78, which is in

The Ti (Ox) "primer" layer 76 has a thickness of (140nm); and

[0083] 7. Permanent protective outer coating 25, which has a thickness of (75 nm) on the "Zn52-Sn48 oxide) top coating 78.

[0084] Sample 4 is the solar mirror of the present invention and is similar to the solar mirror 72 shown in FIG. 6. More specifically, sample 4 has:

[0085] 1. SOLARPHIRE PV glass substrate 12, which has a nominal thickness of 3.2 mm;

[0086] 2. A TiO2 film 74, which has a thickness of 2 nm on the main surface 16 of the substrate 12 facing away from incident light, such as but not limited to the sun 20 (see FIG. 3);

[0087] 3. The first silver (Ag) sublayer 28b of the silver (Ag) solar reflective coating 27, which has a thickness of 50 nm on the TiO2 film 74;

4. The first Ti (Ox) separation film 82, which has a thickness of about 1 nm on the Ag sub-layer 28b having a thickness of 50 nm;

[0089] 5. A second separation film comprising 52wt.% of Zn and 48wt.% of Sn oxide "Zn52"Sn48 oxide")

84. The oxide is also called zinc stannate (Zn2SnO4); the second separation oxide film 84 of Zn52-Sn48 has a thickness of about 1 nm on the first Ti (Ox) separation film 82;

[0090] 6. The second sub-layer Ag film 28a, which has a thickness of 50 nm on the first Ti (Ox) separation film 82;

[0091] 7. Incosil 600 corrosion resistance enhancement and UV absorption layer (not shown), which has on the second Ag sub-layer 28a

30nm thickness;

[0092] 8. Ti (Ox) "priming" (or "barrier" or "barrier") layer 76, which has ~ on the Incosil 600 layer 90

2.5nm thickness;

[0093] 9. 52wt.% of Zn and 48wt.% of Sn oxide film ("Zn52-Sn48 oxide") top coating 78, which is

The Ti (Ox) "base material" 76 has a thickness of 140 nm; and

[0094] 10. Permanent protective outer coating (PPO) 25, which has a thickness of 75 nm on the Zn52-Sn48 oxide top coating 78.

[0095] It should be noted that the sample 4 has two separation films 82 and 84 between the two layers (see the two separation films shown in FIG. 6), and the separation film 84 is a titanium oxide or a titanium suboxide film Its function is similar to the Ti (Ox) film 76 of the solar mirror 72 shown in FIG. 6. The thickness of the separation layer is the sum of the total thickness of the separation film between the layers of the solar reflective coating (for example, but not limited to 28a and 28b). For example, but not limited to the present invention, the thickness of the separation layer between the layers 28a and 28b including the separation films 82 and 84 of the sample 4 is about 2 nm.

[0096] The corrosion resistance enhancement such as Incosil 600 film 90 and the use of the UV absorbing layer are not limited to the present invention and are optional features of the present invention. The corrosion resistance enhancement and UV absorption layer (hereinafter also referred to as "corrosion resistance absorption layer") provides various benefits such as corrosion inhibition and ultraviolet shielding benefits. Moreover, the corrosion-resistant absorbing layer can provide a certain amount of electromagnetic energy reflection, which can tolerate a thinner primary reflective layer, such as but not limited to a silver film. The corrosion-resistant absorbent layer 90 may also provide mechanical and/or chemical protection for the underlying coating. The corrosion-resistant absorbing layer may be provided under, under, or between one or more coatings, such as one or more solar reflective layers 27 or top coatings 78 (described above). Examples of suitable materials for the corrosion-resistant absorption layer include, but are not limited to, elemental metals and alloys of two or more metal elements, which are in the periodic table of the elements. Members of groups 2 to 16, including but not limited to silver and silver-containing alloys, ferroalloys and iron-containing alloys (for example, stainless steel), aluminum and aluminum-containing alloys, copper and copper-containing alloys, Ming and Ming-containing alloys, titanium and titanium-containing alloys , Brass (for example, marine brass (alloy of Cu, Zn and Sn), navy brass (alloy of Zn, Sn and Cu), and aluminum brass alloy (alloy of Cu, Zn and A1)), drill and containing Drill alloy (for example, drill and Ming alloy), zinc And zinc-containing alloys, tin and tin-containing alloys, aluminum and aluminum-containing alloys, molybdenum and molybdenum-containing alloys, bustard and bustard-containing alloys, aluminum and mixed gold, indium and indium-containing alloys, lead and lead-containing alloys, substances and inclusions alloy. Specific non-limiting examples include corrosion-resistant metals and metal alloys, including but not limited to silver and silver-containing alloys (for example, Nickel 200), Incosil alloys (for example, Incosil 600 and Incosil Alloy 625), stainless steel (for example, stainless steel 304 and stainless steel 316), Monel® alloy (for example, Monel 400), Hastelloy® alloy, diamond and diamond-containing alloys (for example, Stellite® alloy), Inco alloy (for example, in_ ___ (S;

Incoloy 0276 and Incoloy 020), Incoloy alloys (Incoloy 800 and Incoloy 825), copper and copper-containing alloys (for example, brass, especially marine brass (about 59% copper, 40% zinc and 1% tin) And navy brass (approximately 69% copper, 30% zinc and 1% tin), silicon and silicon-containing alloys, titanium and titanium-containing alloys, and aluminum and aluminum alloys (for example, aluminum 6061). If present, the one or more anti-corrosion coatings 90 can have any desired thickness. In certain non-limiting embodiments, the corrosion-resistant absorbing layer may have a thickness in a range, but the range is not limited to 1 nm to 500 nm, for example, 1 nm to 400 nm, for example, 1 nm to 300 nm, for example, Inm. To 200nm, for example, Inm to 100nm, for example, 10nm to 100nm, for example, 20nm to 100nm, for example, 30nm to 100nm, for example, 40nm to 100nm, for example, 50nm to 100nm, for example, 20nm to

40nm, for example, 30nm to 40nm, for example, 30nm to 35nm.

[0097] Corrosion resistant absorber layers are well known in the art and are deemed unnecessary for further discussion. For a more detailed discussion of the corrosion-resistant absorbent layer, see US Patent No. 8445,098, column 9, line 45 to column 11, line 2, the entire content of which is incorporated herein by reference.

[0098] FIG. 8 shows the samples 3a and 4a in the deposited state and non-heated condition of the coating and the samples maintained at 150°C (heated) in the deposited and heated condition. The graphs of the solar weighted Rg reflectance "SpEx WIRg") of samples 3b and 4b, which are approximately excluded from specular reflection. For the sake of clarity, sample 3a is designed to be heat treated at time zero to simulate the prior art solar mirror after thermal tempering (hereinafter referred to as "heated"); sample 3b is designed to be in its deposited state (also referred to as "heated"). The solar mirror of the prior art called "non-heating" and/or "deposited state"); sample 4a is designed to be the solar energy of the present invention in its deposited state ("non-heated and/or deposited state") Mirror, and sample 4b was designed to be heat treated at time zero to simulate the solar mirror of the present invention after thermal tempering (also known as "heated").

[0099] In its as-deposited (ie, non-heat-treated) state, sample 3a and sample 4a exhibit relatively low SpEx WIRg values as a function of aging time. In contrast, after heat treatment at time zero to simulate thermal tempering, Sample 3b (prior art) exhibited a rapid increase in SpEx WIRg under a relatively short aging time (for example, 10 hours to 100 hours) It increases more gradually with longer aging time, as shown by curve 3b in FIG. 8. In contrast, the heat-treated sample 4b exhibited a lower SpEx WIRg than the heat-treated sample 3b at an aging time greater than about 10 hours, and only gradually increased with the aging time, which implies that the heat-treated sample 4b was better than the heat-treated sample 4b. The sample 3b is inherently more heat stable. In addition, it is noted that throughout most of the aging of the sample at 150°C, the SpEx WIRg value of the heat-treated sample 4b is similar to the SpEx WIRg value of the samples 3a and 4a in their as-deposited state.

[0100] From the above discussion, the benefits and limitations of the solar reflective coating 27 of the present invention including two or more layers 28a and 28b can now be understood. In the preferred practice of the present invention, the separation film 30 (FIG. 3) and the separation films 82 and 84 (FIG. 6) are less than 5% of the thickness of the solar reflective film. It is assumed that the separation film is a material that prevents or destroys the growth of silver crystals; smaller silver crystallites are expected to scatter light less strongly than larger silver crystallites. Therefore, a coating with a solar reflective coating containing smaller silver crystallites is expected to exhibit a lower haze and lower solar energy that excludes specular reflection than a coating with a solar reflective coating containing larger silver crystallites. Weighted glass side reflectance (SpEx WIRg). The materials that can be used for the separation film may include, but are not limited to, metal oxides, such as, but not limited to, Ti, Sn, Zn oxides and combinations thereof. However, as desired, a metal such as titanium can be used as the separation layer, but this metal material will tend to be absorptive and therefore reduce the overall level of solar reflectance.

[0101] In this embodiment of the present invention, the solar reflective coating 27 can be any material that reflects solar energy, such as but not limited to gold, silver, aluminum, copper, platinum, osmium, iridium, nail, aluminum, palladium or other materials. Precious metals and their compositions, alloys, mixtures and/or blends. The solar reflective coating 27 may have two films 28a and 28b of the same material, for example, silver films 28a and 28b, or may have two films 28a and 28b of different materials, for example, a silver film or sublayer 28a and a gold film.membrane or sublayer 28b. The solar reflective layer may include two films having the same thickness or two films having different thicknesses. Furthermore, the solar reflective coating 27 may have more than two films, for example, the solar reflective coating may include three, four, five or more films, which are between adjacent solar reflective films. With one or more separation layers.

[0102] The present invention is not limited to the thickness of one or more separation layers. However, in the practice of the present invention, the separation layer 30 has a thickness sufficient to inhibit thermally excited crystal growth of the layer, such as but not limited to layer 28a. And 28b, for example, the thermally excited crystal growth may occur when the coated article is used at ambient temperature or elevated temperature. By way of illustration and not limited to the present invention, the prior art solar reflective coating 22 (see FIG. 1) has a thickness of 100 nm

Silver coating, and may include silver crystallites ranging in size from greater than zero up to the full thickness of the solar reflective layer 22 (100 nm in this example). In contrast, the solar reflective coating 27 of the present invention (see FIG. 3) has a solar reflective coating including two layers, such as but not limited to the present invention, each having a silver layer 28a with a thickness of 50 nm and 28b. Thus, the layer 28a may include silver crystallites in a range that is only greater than zero up to the full thickness of the silver layer 28a (only 50 nm in this example). Similarly, layer 28b may include silver crystallites in a range that is only greater than zero up to the full thickness of silver layer 28b (only 50 nm in this example). The thickness of the separation film 30 is selected to cooperate with the film, coating, and layer of the coating stack to provide the optical performance (eg, spectral reflectance) of the solar mirror. In a non-limiting embodiment of the present invention, the separation film 30 has a thickness in the range of greater than 0 nm to 5 nm.

[0103] In addition, the present invention is not limited to the optical characteristics of the solar mirror. However, in the preferred practice of the present invention, the solar energy passes through the substrate 12 and the film stacked through the coating layer to reflect the solar energy from the solar reflective film 27 to the selected Fixed position to act on the reflected solar energy.

[0104] In a specific embodiment, the layers 28a and 28b of the reflective coating 27 are silver films, each of which has a thickness in the range of 1 nm to 150 nm, the range being, for example, 2 nm to 125 nm, For example, 25 nm to 150 nm, such as 50 nm to 100 nm, such as 100 nm to 200 nm, such as 100 nm to 150 nm, such as 110 nm to 140 nm, such as 120 nm to such as 140 nm, such as 128 nm to 132 nm. In another specific embodiment, the reflective coating 27 includes metallic silver having a thickness in the range of 1 nm to 500 nm, such as 50 nm to 500 nm, such as 50 nm to 300 nm, such as 50 nm to 200 nm, For example, 50 nm to 150 nm, such as 70 nm to 150 nm, such as 90 nm to 120 nm, such as 90 nm to such as 130 nm, such as 90 nm to 100 nm, such as 90 nm to 95 nm. In the preferred practice of the present invention, the silver layers 28a and 28b have a thickness in the range of 25nm to 75nm, the range is preferably 40nm to 60nm, for example, 50nm.

[0105] In a non-limiting embodiment of the present invention, for example, but not limited to, the thickness of the layers 28a and 28b of the solar reflective film 27 of FIG. The solar mirror of a single solar reflective film is determined, as currently done in the field. The calculated thickness of the solar reflective layer is divided by the number of solar reflective films to be used. For example, for two solar reflective films, the thickness of the reflective layer is divided by 2, and for three solar reflective films, the thickness of the reflective layer is 3 division, and so on.

[0106] With continued reference to FIG. 3, the surface 16 of the substrate 12 designated as facing away from the sun 20 (see FIG. 2) is coated with TiO₂Layer 24, the first sub-layer 28b of the silver reflective coating 27 is applied on the TiO₂On the films 24 (Figure 3), 74 (Figure 6), the separator film 30 is applied on the layer 28b of silver, the layer 28a of the coating 27 is applied on the separator 30, and the protective coating 25 is applied on Above layer 28a. As can be appreciated, the present invention is not limited to the coatings discussed herein, and any combination of coatings may be used in the practice of the present invention, such as, but not limited to, the coatings of solar mirrors disclosed in Pat '098.

[0107] The equipment for coating the substrate 12 is not limited to the present invention, and may include any type of equipment known in the art to apply coatings and films to the substrate and to each other, such as but not limited to MSVD and coating vapor deposition.

[0108] From the above discussion, the benefits and limitations of the solar reflective coating of the present invention can now be understood. More specifically, the separation film is a material that can be deposited on the layer of the solar reflective coating to inhibit the growth of silver crystallites, the layer of the solar reflective coating including the solar reflective film, for example, layers 28a and 28b. In the practice of the present invention, the thickness of the separation layer 30 is in the range of 0.005% to 10% of the thickness of the solar reflective film 27, preferably, in the range of 0.05% to 7.5% of the thickness of the solar reflective film 27, and more Preferably, in the range of 0.5% to 5% of the thickness of the solar reflective film 27, and most preferably in the range of 1.0% to 4% of the thickness of the solar reflective film 27, the solar reflective film 27 includes sub-layers. 28a and 28b. Materials that can be used include but are not limited to metal oxides, such as but not limited to Ti, Sn, Zn oxides and combinations thereof. However, as desired, a metal such as titanium can be used as the separation film, but this metal material

The material will tend to absorb the solar energy passing through the substrate and the coated base paper, and therefore can reduce the overall level of solar reflectance.

[0109] Encapsulated coating stack for solar mirrors to increase the useful life of solar mirrors

[0110] In the above discussion of solar mirrors, the solar mirrors are, for example, but not limited to, solar mirrors 5 (Figure 1), solar mirrors 7 (Figure 3), solar mirrors 26 (Figure 4), and solar mirrors 70 (Figure 5). And solar mirror 72 (Figure 6), refer to the permanent protective outer coating ("PP0") 25. PP0 protects the coating stacks 35, 32, 34, 86 and 88 between the surface 16 of the substrate 12 and the corresponding PP0 layers of the coating stack 32 (Figure 1, Figure 2, Figure 4, Figure 5 and Figure 6, respectively ) Of the film. For example, but not limited to the present invention, the pp0 coating 25 of the solar mirror 26 in FIG. 4 protects the surface 89 of the sub-layer 28a of the solar reflective coating 28 from chemical and mechanical damage during handling and transportation of the solar mirror.

[0111] Shown in FIGS. 9 and 10 are non-limiting embodiments of the solar mirrors 100 and 102 of the present invention having the outer encapsulation 104 and the pPO coating 25 of the present invention, respectively. Generally, the solar mirror 100 shown in FIG. 9 includes a coating stack 35 on the inner surface 16 of the substrate 12 and an encapsulation 104 covering the outer wall 106 and the top surface 108 of the coating stack 35. Generally, the solar mirror 102 shown in FIG. 10 includes a coating stack 32 applied to the inner surface 16 of the substrate 12 and an encapsulation 104 covering the outer wall 110 and the top surface 112 of the coating stack 32.

[0112] As understood by those skilled in the art, solar reflective coatings, especially those using one or more silver layers, are used in environments where solar mirrors are used, such as in outdoor environments. In the environment, it is susceptible to mechanical damage and/or environmental degradation/corrosion. In the practice of the present invention, the encapsulant used for the second-surface solar mirror is transparent, because the source of solar energy faces the surface 16 of the substrate 12, and the first-surface solar reflective solar mirror has a surface facing the solar energy. The surface 14 of the source substrate. In other words, the encapsulant 104 covering the coating stacks 32 and 35 of the first surface mirror is transparent because the encapsulant 104 is in the optical path of incident and reflected light. The encapsulant 104 covering the coating stacks 32 and 35 of the second surface mirror is opaque because the encapsulant 104 is not in the optical path of incident and reflected light. The primary durability screen for solar mirrors with an encapsulant on top of the coating stack is generally accepted as the copper salt accelerated acetic acid salt spray test ("CASS"). The CASS test is well known in the art, and further discussion on the CASS test is not deemed necessary.

[0113] In addition to the encapsulant that failed the CASS test, another disadvantage of the currently available encapsulant is the use of lead (W)-based corrosion inhibitors to adequately protect the underlying Ag-based reflective coating from Corrosion/degradation and loss of reflectivity. In recent years, since the deployment of "high-Pb" encapsulants, the emerging concentrated solar power (CSP) industry has preferred encapsulants with reduced amounts of Pb and preferably substantially free of lead (Pb"), for example, consider To the U.S. Patent No. The encapsulant disclosed in 8445,098 (this US patent is incorporated herein by reference). 9 and 10 as needed, in a non-limiting embodiment of the present invention, the encapsulant 104 completely covers the top surfaces 108 and 112 of the coating stacks 32 and 35 of the solar mirrors 102 and 100, respectively. And it extends toward the surface 14 of the substrate 12 over the surface 16 of the substrate 12 and is fixed to the peripheral side or edge 114 of the substrate 12, as shown in FIGS. 9 and 10. In a non-limiting embodiment of the present invention, the top surfaces 108 and 112 of the coating stacks 35 and 32 may be completely covered by the encapsulant 104, as shown in FIGS. 9 and 10, or the coating stack 35 The marginal edge portions of the outer surfaces 108 and 112 of the and 32 may be covered by an encapsulant, as will be discussed below. By way of interest and not limited to the present invention, the tested prior art encapsulants can be obtained from the Finzi Group (headquartered in Tribiano, Italy) and sold under the registered trademark SolaHux.

[0114] With continued reference to FIGS. 9 and 10, the encapsulant 104 of the present invention includes a bottom layer or base layer 120, which is applied on the outer wall 116 and the top surface 108 of the coating stack 35 and/or coated On the outer wall 110 and the top surface 112 of the layer stack 32 and on the peripheral side 114 of the substrate 12, the top coating 122 is applied on the bottom layer 120 of the encapsulant 104. In this hair

In a non-limiting example, the encapsulant includes a bottom layer 120 and a top coating layer 122. The bottom layer 120 has the composition and amount listed in Table 1, and the top coating layer 122 has the composition and amount listed in Table 2. Listed ingredients and amounts.

[0115] Suitable methods for applying the encapsulant include, but are not limited to: (1) curtain coating, (2) spray coating, (3) flow coating, (4) draw-down coating and electrical Curtain coating, as disclosed in, for example, but not limited to, U.S. Patent No. 8,557,099 (which patent is incorporated herein by reference). In a non-limiting embodiment of the present invention, the preferred method of applying the encapsulant 104 is curtain coating. The base coating 120 and top coating 122 of the encapsulant 104 are applied such that their geometric thickness in their cured state (ie, after the encapsulant is thermally cured) is each approximately 1 mil (0.001 inch = 25.4 mm). However, a certain range of the thickness of each base coat 120 and top coat 122 is acceptable, such as but not limited to a range of 0.9 mils to 1.5 mils.

[0116] Before applying the encapsulant 104 to the coating stack, such as but not limited to the coating stack 35 and/or 32, the coating stack is pre-treated to remove any sharpness of the coating stack (ie , "Raw" or "cut") edges, preferably sharp edges are passivated or ground before applying the encapsulant 104 using grinding media such as grinding belts or grinding wheels. This practice is called "edge-stitching" or simply "stitching". The sharp-edged edge-stitching of the reflective-coated substrate finally makes the finished mirror with the so-called "SP" (stitch-and-paint) before applying the encapsulant. Edge-stitching is believed to facilitate the "winding" of the bottom layer 120 of the encapsulant 104 to the peripheral side 114 of the substrate 12 to some extent, thereby limiting the direct exposure of the "sidewalls" of the reflective coating to potential corrosion Environmental factors that are potentially corrosive may chemically react with or degrade the reflective coating 22 and/or one or more layers including Ag or solar reflective layers in other ways. The practice of edge-stitching is also considered to remove some or all of the reflective coating from the extreme edges/peripheries of the coated surface of the substrate on a microscopic scale. This concept is called "micro-edge-delete" or "micro-delete". Similar practices are sometimes followed in order to "edge-remove" Ag-based coatings (eg, Ag-based low emissivity and/or solar Controlled coating). This micro-edge-removal process involves removing the microscopic width (typically a few millimeters) of the coating from the periphery of the coated substrate. This micro-edge-deletion helps protect the coating from direct exposure to environmental factors that may corrode or otherwise degrade the Ag-based coating 27 (see Figure 10) and coating 22 (see Figure 9). After the edge-stitching step, the reflection-coated substrate is thoroughly cleaned and dried in any convenient way, such as using a flat glass washer.

[0117] Prior to applying the encapsulant 104, pretreatment is preferably applied to the outer wall 110 and top surface 108 of the coating stack 32 of the solar mirrors 102 and 100 and the outer wall 106 and top surface 108 of the coating stack 35, respectively, so as to Promotes the adhesion of the encapsulant to the outer surface of the coating stack. A preferred pretreatment includes silane-based chemicals; a suitable composition is 0.15 wt.% gammaaminopropyltriethoxysilane in deionized (DI) water. The pretreatment chemicals are sprayed onto the outer surfaces of the coating stacks 25 and 27 or the outer walls 106 and 110, the top surfaces 108 and 112, and the exposed surface of the substrate 12, and are allowed to remain on the surface for a residence time of about 30 seconds, and then It is thoroughly rinsed off by rinsing the surface with deionized water. Immediately after the rinsing process, the remaining rinsing water is sheeted off from the outer surfaces 106 and 110, the top surfaces 108 and 112 of the coating stacks 32 and 35, and the exposed surface of the substrate 12, respectively. Prior to applying the base coating or bottom layer 120 of the encapsulant 104, the pre-treated coating stacks such as coating stacks 32 and 35 and the substrate 12 are preheated to approximately 150°F (66°C).

[0118] A sufficient amount of the chemical substance of the base coating 120 is applied to the outer wall or outer surface 106 and top surface 108 of the coating stack 35 and the outer wall or outer surface 110 and top surface 112 of the coating stack 32 to be on the finished product A base coat dry film thickness (DFT) of approximately 1.1 mils (27.94 microns) was obtained. The processing parameters (for example, the width of the hole of the curtain coater, the conveyor line speed of the substrate passing through the paint curtain, etc.) for the base coating application process are typically adjusted empirically to obtain the desired base coating Layer DFT. Immediately after the application of the base coating chemistry, the substrate travels through the "flash section" in which the application continues

Heating is applied to enable the solvent to evaporate from the liquid-based coating 120 of the applied encapsulant 104. A suitable temperature for this "flash section" is about 150°C (66°C). The application of heat in this flash section also preheats the substrate 12 to prepare it to receive the base coating 120 of the encapsulant 104. It is recommended that the minimum substrate surface temperature immediately before applying the base coating of the encapsulant is about 120°C (49°C), but it is not limited to the present invention.

[0119] Immediately after removal from the "flash section" for the top coat 122, the encapsulant 104 of the coated substrate is cured in a suitable ventilated oven designed It is used to cure polymer coatings/paints on larger area substrates. For any given encapsulated substrate, the typical recommended residence time in the furnace ("line time") is 251 seconds. The recommended outlet temperature of the encapsulated surface of the substrate immediately upon exiting the curing oven is about 280°F (138°C). After exiting the furnace, the encapsulated reflective coated solar mirror cools down. 9 and 10 and not limited to the present invention, the encapsulated reflective coated glass substrate is a finished solar mirror, which has but is not limited to the present invention (1) substrate (for example, glass substrate 12); (2) in the substrate The Ag-based double layers 28a and 28b deposited by MSVD of the reflective substrate 27 above one main surface of the bottom, one main surface of the substrate is such as but not limited to the surface 16 of the substrate 12; (3) On the Ag-based sublayer The separation layer 30 on 28b; (4) the double layer 28a on the separation film 30; and (5) applied to the outer wall 106 and top surface 108 of the coating stack 35 and the outer surface 106 and top surface of the reflective coating deposited by MSVD The base coating 120 of the encapsulant 104 on or on 108 and the top layer 122 applied on the base coating 120.

[0120] Optionally, the bottom surface 14 of the substrate 12 of the finished solar mirrors 100 and 102 may be cleaned using an acid etching process and rinsed/dried before unloading. The purpose of this bottom surface etching treatment is to remove any contaminants that may absorb light and thereby negatively affect the overall reflectivity of the finished mirror, especially silver-based contaminants. Ferric chloride in deionized water (FeCl₃) The solution is a suitable bottom surface etchant/cleaner.

[0121] After the entire mirror is exposed to the etchant, the entire mirror is thoroughly rinsed with water to remove all traces of the etchant from the finished mirror, and an air knife or similar device is used to dry it.

[0122] The finished solar mirror of the present invention encapsulated in the manner described above with the encapsulant 104 exhibits acceptable adhesion to the glass substrate 12, as determined using the ASTM D3359 cross-hatch adhesion test; typical The level of adhesion is "4B" or better. Similarly, the mirror exhibits an acceptable level of cure, as determined using the ASTM D5402 solvent rub test; typically using a xylene soaked cloth with a double rub of 200 or more in the absence of visible degradation of the encapsulant. many.

[0123] Unless otherwise indicated, in the following discussion of the non-limiting examples of the present invention, before applying the encapsulant, the above methods for preparing the coating stacks 32 and 35 for applying the encapsulant 104 are practiced. method.

[0124] Now, the discussion relates to a non-limiting embodiment of the solar mirror of the present invention having an encapsulated coated stack such as, but not limited to, the coating stack 35 (FIG. 9) And the coating stack 32 (Figure 10). These non-limiting embodiments of the present invention relate to solar mirrors, such as but not limited to highly reflective solar mirrors, such as but not limited to solar mirrors having coated solar reflective sublayers 28a and 28b separated by a separation medium 30 (FIG. 9) And a solar mirror with a solar reflective coating, such as a solar reflective coating 22 of the type shown and discussed in relation to FIG. 9. The silver reflective coatings 27 and 22 highly reflect solar radiation and are commonly used in concentrated solar thermal power (CSTP) and concentrated photovoltaic (CPV) applications. CSTP/CPV technology is sometimes more commonly referred to as concentrated solar power (CSP) technology. However, it should be understood that the solar mirror of the present invention can be used in other applications, which generally include but are not limited to display applications, projection applications, lighting applications, entertainment applications, laser applications, directed energy weapon applications, optical applications or used for Any application of highly reflective articles of the solar wavelength spectrum or any of its sub-devices, or any application in which the present invention described therein exhibits suitable optical properties/performance or other suitable characteristics. As used in this article, height

Reflective solar films, such as but not limited to silver reflective solar films, have solar energy reflection in the range of 85% to 95%. 9 and 10 as needed, the encapsulant 104 of the solar mirror 100 (FIG. 9) and/or the solar mirror 102 (FIG. 10) includes but is not limited to polyester melamine with a bottom layer or a base layer 120 and/or a top layer 122 , The selected layer in the layers 120 and 122 has a metal resistance enhancing film or particles of Inconel 600, zinc, aluminum, copper, magnesium, or a mixture, alloy, or combination of two or more of the foregoing. In the preferred practice of the present invention, the selected metal is zinc ("Zn"), because in addition to Zn being a resistance enhancing metal, Zn is a highly conductive metal and can be used in electrodeposition coatings.

[0125] The present invention is not limited to the form of zinc, and the present invention contemplates Zn in the form of flakes, powders, and coated MSVD coating films. In the preferred practice of the present invention, Zn is in the form of flakes. Because the sample of the encapsulant coating is made to have Zn flakes, Zn powder and Zn film, and Zn flakes are better performers for the electrodeposition of the encapsulant, the ZnoZn flakes in the form of flakes are selected by numbers 124 is identified and only shown in dashed lines in FIG. 11.

[0126] In the practice of the present invention, when Zn flakes are used as a resistance-enhancing metal or sacrificial cathodic protection, the Zn flakes are mixed with the chemicals of the bottom layer 120 of the encapsulant 104 and the chemicals of the top layer 122. When the Zn flakes are used to provide resistance-enhancing metal or sacrificial cathodic protection and are used as a cathode for electrode deposition, the Zn flakes are mixed with the chemicals of the base layer 120 of the encapsulant 104. In the following discussion, Zn flakes are used to provide resistance-enhancing metals or sacrificial cathodic protection and are used as cathodes for electrode deposition; Zn flakes 124 are formulated in a moisture-stable binder, namely polyester melamine, to match curtain coating. Cloth application. For a more detailed discussion of Zn flakes in polyester melamine, refer to US Published Patent Application No. 2013/0003206 (Publication '206). U.S. Published Patent Application No. 2013/0003206 is incorporated herein by reference.

[0127] In the practice of this embodiment of the invention, the Zn-rich polyester melamine-based topcoat 122 of the encapsulant 104 (FIGS. 9 and 10) is used. For some end-use applications, it may be desirable for the finished solar mirror to undergo certain types of high temperature treatments, such as thermal tempering, thermal strengthening, thermal bending, and so on. In that event, before applying the encapsulant 104, the reflection-coated substrate is preferably subjected to such high temperature processing. Although the coating stack 35 of the solar mirror 100 and the coating stack 32 of the solar mirror 102 may survive high temperature processing, it is expected that the polymer-based encapsulant 104 on the coating stack 35 and/or 32 will unfortunately be spared This treatment.

[0128] Shown in FIG. 11 is a non-limiting embodiment of a solar mirror 130. The solar mirror 130 is a solar mirror 70 or 72 with an encapsulation 104. Unless otherwise indicated, the following discussion can be applied to the solar mirror 70 or 72. 11, the encapsulant 104 of the present invention includes but is not limited to (1) a polyester melamine-based coating 120 impregnated with a metal corrosion inhibiting pigment 124 (for example, a metal Zn flake 124) and (2) no metal corrosion inhibiting A polyester melamine-based top coat 122 of pigment (eg, metallic Zn flake 124). Such an encapsulant 104 is also referred to herein as a "PEM encapsulant". The solar mirror 130 includes, but is not limited to, MSVD coating stacks 32 and/or 35 with coatings 74, 76, 78, and 25, which are described in U.S. Patent No. 6,916,542 (hereinafter also referred to as "patent '542" ) PPO coating 25 of the type disclosed. The '542 patent is hereby incorporated by reference. In this discussion of the non-limiting embodiment of the present invention, the base coating 120 of the PEM encapsulant 104 is applied to the layer 25 of PPO (the top surfaces 108 and/or 112 of the coating stacks 32 and 35, respectively). And on the outer walls 106 and 110 of the coating stacks 32 and 35.

[0129] As understood by those skilled in the art, the PPO coating or MSVD film 25 or 80 is non-conductive, and the Zn flakes 124 in the base layer 120 of the PEM encapsulant 104 have a dual function, that is, the PEM encapsulant The Zn flakes 124 in the base coating 120 of 104 slow down the corrosion of the Ag reflective coatings 22 and 27 by absorbing moisture. More specifically, the Zn flakes 124 absorb moisture passing through the top coating or layer 122 of the PEM encapsulant 104 into the base coating 120 of the PEM encapsulant 104 and are corroded, after which the moisture moves through the PEM encapsulant 104 The second function of the base coating 122 of the base coating 122 and eroding the coating stack 32 and/or 35, in particular the Ag reflective coating 28 and/or 220 PEM encapsulant 104, is when the electrical coating is applied to the PEM package The base of enclosure 104

A cathode is provided when above the layer 120. The present invention is not limited to the manner of applying the electrocoating top layer 122, and the top coating 122 of the PEM encapsulant 104 may be applied in the manner disclosed in U.S. Patent Application Publication No. 2013/0003206 (Publication '206"). '206 is included here by reference.

[0130] A detailed discussion of PEM encapsulants is provided in Publication '206 and US Patent No. 8,557,099 ("Patent '099"). The entire document content of the publication '206 and the patent '099 are incorporated herein by reference.

[0131] Shown in Table 1 and Table 2 are the formulations of the base coating 120 (Table 1) and the top coating 122 (Table 2) used in the practice of the present invention as shown in FIG. 10 according to the present invention. The encapsulant 104 that is curtain-coated on the coating stack 32 is shown.

[0132] The following Table 1 shows the main ingredients and the general functions of each ingredient:

[0133] Table 1

<td>Ingredients</td><td>Weight / grams)</td>

<td>Polyester resin</td><td>57.74</td>

<td>Phosphating epoxy resin2</td><td>4.41</td>

<td>Tripolyfluoroamine (3)</td><td>45.80</td>

<td>Solvent </td><td>127.9</td>

<td>Flow aid</td><td>2.17</td>

<td>Anti-settling agent</td><td>23.18</td>

<td>Catalyst</td><td>1.41</td>

<td>Zinc flakes</td><td>381.53</td>

<td>Silane A-187</td><td>5.00</td>

[0136] The polyester resin is POLYMAC HS 57-5776 from Momentive Specialty Chemicals, which has a solid weight of 85 weight percent based on the total weight, a hydroxyl value of 178 (based on solid weight), and a hydroxyl equivalent of 315 (based on solid weight) And an acid value of 10 (based on solid weight).

[0137] (2) Phosphate epoxy resin is commercially available from PPG Industries under the brand name HEQ-9346.

[0138] The trimeric ratamine is RESIMENE 1718, which is commercially available from INEOS Melamines.

[0139] The solvent is composed of 20.4% by weight of SOLVESSO 100 (from Exxon Mobil), 25.8% by weight of butyl CELLOSOLVE and 53.8% by weight of butanol in each case based on the total weight of the solvent.

[0140] The flow aid is composed of the following: AL-61-1477, polyolefin oil (18.4% by weight, available on the market from Shamrock Technologies); AWY-3046, silicone fluid (27.6 by weight) %, available on the market from Momentive Performance Materials); and RCH-8794, polybutyl acrylate (54.0% by weight, available on the market from E. I. du Pont de Nemours and Company), The percentage weights are in each case based on the total weight of the flow aid.

[0141] (6) The anti-settling agent is composed of the following: 53.2% by weight of 8F^0mSD-2 clay material (available from Elemintis Specialties on the market), 30.6 percentage of AEROSIL 200 fused silica (available on the market from Evonik Industries company purchased U) and 4.1 weight percent BYK 410 rheology additive (available from BYK on the market

USA company), the percentage weights are each based on the total weight.

[0142] (7) The catalyst is NACURE 2500 amine-neutralized p-toluenesulfonic acid, which is available from King

Industries.

[0143] The zinc flake 124 has the trade name Z45, which is commercially available from Purity Zinc Metals, and has a length to thickness ratio of 20:1.

[0144] The ingredients in Table 1 were mixed using cowles blades for at least 30 minutes until reaching a Hegman rating of 6.5 (on a scale of 1 to 8). The solvent (1:1 by weight mixture of SOLVESSO 100 and butyl CELLOSOLVE) is mixed with the abrasive paste to form a sacrificial cathodic coating composition with a viscosity suitable for spray application.

[0145] The sacrificial cathode coating composition was curtain-coated on the reflective glass substrate and allowed to flash at ambient room temperature to remove the solvent. The applied sacrificial cathodic coating has a thickness in the range of 1.0 mil to 1.2 mil.

[0146] The polyester melamine coating composition (without lead) used as the outer organic polymer coating top coat 122 of the encapsulant 104 was prepared as shown in Table 2 below:

<td>[0147]</td><td colspan="2">Table 2</td>

<td rowspan="8">[0148]</td><td>Ingredients</td><td>Weight / grams)</td>

<td>Polyester resin</td><td>120.90</td>

<td>Phosphating epoxy resin2</td><td>7.97</td>

<td>Melamine (3)</td><td>18.19</td>

<td>Solvent </td><td>38.1</td>

<td>Flow aid</td><td>2.17</td>

<td>Catalyst</td><td>0.47</td>

<td>TiO₂</td><td>89.8</td>

(9) The polyester resin is commercially available from PPG Industries under the brand name HP 73-5480 SP3, and has a solid weight of 65 weight percent based on the total weight, a hydroxyl value of 89.2 (based on the solid weight), and 628.9 The hydroxyl equivalent weight (based on solid weight) and an acid value of 3.8 (based on solid weight).

[0150] The ingredients in Table 2 were mixed using cowles blades for at least 30 minutes until reaching a Hegman rating of 6.5 (on a scale of 1 to 8). The solvent (1:1 by weight mixture of SOLVESSO100 and butyl CELLOSOLVE) is mixed with the abrasive paste to form an external organic polymer coating composition with a viscosity suitable for spray application.

[0151] The lead-free external organic polymer top coat 122 prepared from the polishing paste of Table 1 was curtain-coated on the previously applied sacrificial cathodic coating using a mini curtain coater, that is, curtain-coated. Coated on the base coating 120. The sacrificial cathodic coating (ie, base coating 122) and the outer organic polymer coating (ie, top coating 122) were cured together in a Hedinair oven (not shown) at 320°F for 4 minutes and 11 seconds . The outer organic polymer coating, that is, the top coating 122 has a thickness of 1 mil (25 microns).

[0152] In a non-limiting embodiment of the present invention, the coating process involves cleaning a glass substrate 12 with a size of 6 inches X 12 inches X 3.3 mm MSVD mirror with DI water, and then using it in 5% (25 % Isopropanol and 75% water) A1100 silane pretreated the glass substrate. Then, the glass substrate 12 is preheated for 1 minute to 150F before applying the base coating 120 (see FIG. 11). Then, the glass substrate 120 is flashed at 150F for about 1 minute to remove some of the solvents in the applied base coat 120 and top coat 122. The composition was then cured together in a Hedinair oven for 3 minutes and 20 seconds. Cure was confirmed by using &gt;100 double MEK wipes. Then, the sample is cut to expose the edges and tested in a screening test such as CASS.

[0153] The base layer 120 and the top layer 122 of the PEM encapsulant 104 are applied on top of the MSVD-deposited solar reflective coating stack 32 or 35 shown in FIG. 11. Suitable methods for applying the encapsulant 104 include but are not limited to: (1) curtain coating, (2) spray coating, (3) flow coating, (4) vertical coating and (5) electric curtain coating. The preferred method of application is curtain coating.

[0154] The base coating 120 and the top coating 122 of the PEM encapsulant 104 are applied such that their geometric thickness in their cured state (ie, after the encapsulant is thermally cured) is each approximately 1 mil (0.001 Inches = 25.4 microns). However, in the practice of the present invention, certain thickness ranges of each layer will be expected to be acceptable, such as but not limited to 0.5 mils to 2 mils.

[0155] Before applying the pretreatment and encapsulant, any sharp (ie, "raw" or "cut") edges of the reflective coated substrate are removed, and the surface is cleaned as described above.

[0156] In addition, pretreatment is preferably applied to the surface 131 of the coating 80 before applying the Pem encapsulant 104. The coating 80 is a protective outer coating for protecting the Si (85%)-Al (15%) oxide layer of the solar reflective coating stacks 32 and 35 (see FIG. 11). The pretreatment of the surface 131 promotes the adhesion of the Pem encapsulant 104 to the surface 131 of the coating 80. The present invention anticipates cleaning the outer surfaces of the coating stacks 32 and 35 to enhance the adhesion of the coating stack of the encapsulant 104 of the solar cell 130 and the base layer 120. A detailed discussion of pPO coating 25 is provided in U.S. Patent No. 8,445,098.

[0157] The present invention is not limited to the adhesion promoters that can be used in the practice of the invention, and any of the known adhesion promoters can be used in the practice of the invention. In a non-limiting embodiment of the present invention, preferred pretreatments include, but are not limited to, silane-based chemicals; a suitable ingredient is isopropanol at 25 wt.%: deionized water at 75 wt.% The gamma aminopropyl triethoxy silane of 5wt.% on the total solution weight in the pre-mixed matrix of the silane; the form of the silyl chemical substance available on the market is available from Momentive Corporation or General Electric Corporation To the Silquest® A-1100. The pretreatment chemicals are sprayed onto the coated columns or stacks 32 and/or 35 and allowed to stay on the surface for a residence time of 30 seconds, and then rinsed off thoroughly by rinsing the surface with deionized water. Immediately after the rinsing process, the remaining rinsing water is flowed down in sheets from the coating stack 32 and/or 35 using an air knife or similar device. Then, before applying the PEM-based coating 120, the pre-treated coating stack is preheated to about 20 CTF (93°C).

[0158] The present invention is not limited to the method of applying the PEM-based coating 104 chemical substance, and the method includes, but is not limited to, curtain coating, spray coating, flow coating, electrophoretic coating, and drawdown coating. For application via curtain coating, the acceptance state zη-ρeM-based coating chemistry uses a suitable solvent such as 2-butoxyethanol (also known as "butyl cellulose"), xylene, Solvesso® 100 solvent , The similar solvent or its composition is reduced to the recommended applied viscosity (15-23 seconds, #3 Zahn cup). A sufficient amount of base coating chemistry is applied to the reflective coated substrate to achieve a base coating dry film thickness (DFT) of approximately 1" mil (27.94 microns) on the finished article. The processing parameters (for example, the width of the hole of the curtain coater, the conveyor line speed of the substrate passing through the paint curtain, etc.) for the base coating application process are typically adjusted empirically to obtain the desired base coating Layer DFT. Immediately after the application of the PEM-based coating chemistry is the movement of the substrate through the furnace in which heat is continuously applied to enable the solvent to evaporate from the applied liquid-based coating. The area where the solvent is removed is called the "flash section" for clarity.

[0159] The application of heat in the flash section also preheats the substrate to prepare the substrate to receive the chemicals of the PEM encapsulant 104; immediately after applying the top coat 122 of the PEM encapsulant 104 The previous minimum substrate surface temperature was about 120. F (49 °C) ο

[0160] A variety of methods are acceptable to apply the PEM topcoat 122 chemistry, including but not limited to curtain coating, spray coating, flow coating, and drawdown coating. For application via a curtain coating process, the acceptance state PEM topcoat chemistry 122 uses a suitable solvent such as 2-butoxyethanol (also known as "butyl cellulose"), xylene, SolveSSO%o0

Reduce to the recommended application viscosity (15-23 seconds, #3 Zahn cup). A sufficient amount of topcoat chemistry is applied to the substrate to achieve a topcoat dry film thickness (DFT) of approximately 1.0 mil (25.4 microns) on the finished article. The processing parameters (for example, the width of the hole of the curtain coater, the conveyor line speed of the substrate passing through the paint curtain, etc.) for the top coat application process are typically adjusted empirically to obtain the desired top coat Layer DFT. Immediately after applying the topcoat chemistry of the ZnPEM encapsulant, the substrate optionally travels through a second "flash section", allowing the solvent to evaporate from the applied liquid topcoat.

[0161] Immediately after emergence from any "flash section" of the topcoat 122 for the PEM encapsulant 104, the coated substrate is cured in a suitable ventilated oven/oven, the suitable The ventilated oven/oven is designed to cure the polymer coating/paint on a larger area of the substrate. For any given substrate coated with PEM encapsulant 104, the typical recommended residence time in the furnace (also known as the "ride time") is about 251 seconds. The recommended temperature of the encapsulated surface of the substrate immediately after exiting the curing oven is about 280°C (138°C). After exiting the furnace, the encapsulated reflective coated glass is allowed to cool down during preparation for unloading from the manufacturing line. At this time, the solar mirror constitutes a finished mirror, which includes: (1) a substrate (for example, a glass substrate 12), an Ag-based reflection deposited by MSVD on one main surface of the substrate (coated column or stack 166) The coating, and (3) the PEM encapsulant 104 applied on top of the MSVD deposited reflective coating stack 32 or 35.

[0162] Optionally, the bottom surface of the finished mirror, for example, the surface 14 of the substrate 12 (see FIG. 11) may be cleaned using an acid etching process and rinsed/dried before unloading. Then, the finished mirror is stored and shipped in any usual way.

[0163] The finished solar mirror encapsulated with the PEM encapsulant 104 in the manner described above exhibits acceptable adhesion to the substrate, as determined using the ASTM D3359 cross-hatch adhesion test; typically "4B "Or better, the level of adhesion of the cross-cut method. Similarly, the mirror exhibits an acceptable level of cure, as determined using the ASTM D5402 solvent rub test; typically 100 double rubs or more using methyl ethyl ketone soaked cloth without visible degradation of the encapsulant .

[0164] Non-limiting embodiment of the present invention using a PEM encapsulant on a coating stack without a PPO layer

[0165] As understood by those skilled in the art, the PPO layer 25 of the coating stack 32 and/or 35 has a sheet resistance value greater than 1 Mohm/square. As discussed above, for electrodeposited coatings, the electrical connection to the outer surface or top of the PPO layer 25 of the coating stack 35 of the solar mirror 100 is achieved by adding a conductive material to the base layer 120 of the PEM encapsulant 104. The surface 108 (see FIG. 9) and the outer surface 112 (see FIG. 10) of the coating stack 32 electrically connected to the PPO layer 25 of the solar mirror 102. In the practice of the present invention, Zn flakes 124 are added to the base layer 120 of the PEM encapsulant 104 (see Table 1), because in addition to zinc providing electrical conductivity, zinc is also a metal resistance enhancement film. The coating stack 32 and/or 35 without the PPO layer 25 has a surface 78A of the layer 78 available for electrical connection (Figure 11). Surface 78A is expected to have a sheet resistance value of less than 0.5 Mohm/square. In the non-limiting embodiment of the present invention discussed below, one or both of the layers 120 and 122 of the PEM encapsulant 104 covering the surface of the coating stack 32 and/or 35 do not contain lead (see Table 1 And Table 2). 9 and 10 as needed, the encapsulant 104 of the solar mirror 100 (FIG. 9) and/or the solar mirror 102 (FIG. 10) includes but is not limited to having a bottom layer or a base The polyester melamine of the layer 120 and/or the top layer 122, the selected layer in the layers 120 and 122 has Inconel 600, zinc, aluminum, copper, magnesium, or a mixture, alloy, or combination of two or more of the foregoing. The metal resistance of the composition enhances the film or particle. In the preferred practice of the present invention, the selected metal is zinc because in addition to Zn being a resistance enhancing metal, Zn is a highly conductive metal and can be used in electrodeposition coating. In either case, the absence of the PPO layer 25 allows to reduce the level of expensive Zn flakes 124 used in the base layer 120 of the PEM encapsulant 104 by eliminating the PPO layer 23, while maintaining or improving the solar reflective surface 22 And/or the level of cathodic protection of 27.

[0166] As can be understood, the formula for the base layer 120 of the PEM encapsulant 104 is shown in Table 1 and is used for the PEM encapsulant

The formula of the top layer 122 of 104 is shown in Table 2. The presence of the Zn flakes 124 listed in Table 1 is optional and is discussed in detail below.

[0167] In the following non-limiting embodiments of the present invention, a solar mirror such as but not limited to the solar mirror 130 of FIG. 11 has a coating stack without the PPO layer 25 and has two layers of encapsulants 104 (see FIG. 11 ). As described above, the PPO layer 25 provides chemical and mechanical protection to the major surface 78A of the film or coating 78 of the coating stacks 32 and 35. In the presence or absence of the PPO layer 25, the PEM encapsulant 104 provides chemical and mechanical protection to the main surface 75A and the coating stacks 32 and 35. The protection provided by the PPO layer 25 to the coating stack 32 and/or 35 is now provided by the PEM encapsulant 104. More specifically, shown in FIG. 11 is a solar mirror 130 with an MSVD coating stack 32 or 35 having layers 24, 76, and 78 and a solar reflective coating 22 or 27. The base coating 120 of the PEM encapsulant 104 with zinc flakes 124 is applied over the outer walls 106 and 110 of the coating stacks 32 and 35 of the reflective article or solar mirror 130 and the top surface 78A of the layer 78.

[0168] The Zn flakes 124 in the bottom layer 120 and the top layer 122 of the PEM encapsulant 104 have a function of slowing down the corrosion of the Ag layer 27 and/or 22 by absorbing moisture in the atmosphere into the top layer 122 and the bottom layer 120. More specifically, Zn flakes are used to provide resistance-enhancing metals or sacrificial cathodic protection and are used as cathodes for electrode deposition; Zn flakes 124 are formulated in a moisture-stable binder, namely polyester melamine, to match curtain coating application. For a more detailed discussion of Zn flakes in polyester melamine, refer to U.S. Published Patent Application No. 2013/0003206 (Publication '206).

[0169] As can be appreciated, the present invention further contemplates reduction and/or modification of the solar mirror 130. For example and not limited to the present invention, the bottom layer 120 may have zinc flakes, and the top layer 122 may not contain zinc flakes, as shown in FIG. 11, or both layers 120 and 122 may not contain zinc flakes, or the two layers 120 and Each 122 may have zinc flakes. The encapsulant 104 may have only one layer, which may be any thickness.

[0170] As can be appreciated, the present invention can envisage additional non-limiting embodiments of the present invention by alternating the components of the solar mirror 130 shown in FIG. 11. Unless otherwise specified, the solar mirror 130 discussed below can be modified to the solar mirror discussed above, such as but not limited to solar mirror 5 (Figure 1), solar mirror 7 (Figure 3), solar mirror 70 (Figure 5). ), solar mirror 72 (Figure 6), solar mirror 100 (Figure 9), solar mirror 102 (Figure 10), solar mirror 130 (Figure 11), and solar mirror 134 (Figure 13, discussed below).

[0171] Non-limiting embodiments of the present invention include, but are not limited to:

[0172] The solar mirror A includes, but is not limited to, the coating stack 32 or 35; each of the bottom layer 120 and the top layer 122 of the PEM encapsulant has no metal resistance enhancement film or particles, for example, Zn flakes 124. Because the surface 78A of the coating stack 32 or 35 is conductive, the layer 122 can be electrodeposited.

[0173] The solar mirror B includes, but is not limited to, no metal resistance enhancement film or particles in the bottom layer 120 of the PEM encapsulant, for example, Zn flakes 124, and a metal resistance enhancement film in the top layer 122 of the PEM encapsulant Or particles, for example, Zn flakes 124. Preferably, but not limited to the present invention, the layers 120 and 122 of the PEM encapsulant may be deposited by electrocoating. Instead of using zinc, the present invention anticipates the use of other metal resistance enhancing films or particles.

[0174] The solar mirror C includes, but is not limited to, metal resistance enhancing films or particles, such as Zn flakes 124, in the bottom layer 120 of the PEM encapsulant and the top layer 122 of the PEM encapsulant. Metal resistance enhancing films or particles other than Zn can be used. [0175] The solar mirror D includes a metal resistance enhancement film or particles, for example, Zn flakes 124, in the bottom layer 120 of the Zn-PEM encapsulant, and does not include Zn in the top layer 122 of the Zn-PEM encapsulant. The layer 122 may be electrocoated. Metal resistance enhancing films or particles other than Zn can be used in the practice of the present invention.

[0176] Preferably but not limited to the present invention, the coating films and layers of solar mirrors A to D can be applied by any suitable coating treatment, including but not limited to slots, curtains. Coating and/or electrodeposition.

[0177] The present invention is not limited to the manner in which the electrocoating top layer 122 is applied, and the top coating layer 122 of the PEM encapsulant 104 may be flow-coated to be disclosed in U.S. Patent Application Publication No. 2013/0003206 (Publication '206) The publication is hereby incorporated by reference. As can be appreciated, the addition of Zn flakes 124 to help electrocoating increases the additional cost of the PEM encapsulant 104 of the coating stack. In another non-limiting embodiment of the present invention, it is provided that the use of Zn is reduced. Zn flakes 124 are added to the base layer 120 of the PEM encapsulant 104 to provide a conductive surface for electrocoating. The elimination of the PPO layer 25 reduces the amount of metal resistance enhancing films or particles, such as the amount of Zn flakes 124 required in the PEM encapsulant 104, by about 50%. The solar mirror 130 of the present invention shown in FIG. 11 now includes a coating stack and a base layer of a PEM encapsulant 104 with a reduced amount of Zn. It is concluded that the Zn content in this embodiment of the present invention can have a 50% reduction in Zn flakes.

[0178] In either case, the absence of the insulating PPO layer 25 should also allow the elimination of the PPO layer 25 to reduce the level of expensive Zn flakes in the base coating of the PEM encapsulant, while maintaining (or improving ) The level of cathodic protection of silver.

[0179] US Patent No. 8,557,099 (Patent '099) discloses an apparatus and method for coating reflective articles, such as solar mirrors with electrodeposited coatings.

[0180] Previously, second-surface solar mirrors have typically been encapsulated with a two-layer or even a three-layer system that involves first applying a corrosion-resistant base coating followed by a protective top coating. These coatings can be applied by conventional wet coating methods such as curtain coating.

[0181] If the base coating is electrically conductive, for example, the base coating of the partially organic metal-containing base coating 120 of the PEM encapsulant 104, the top coating, for example, but not limited to, is applied to the PEM encapsulant 104 The top coat 122 on the base coat 120 may be an electrodeposited top coat, for example, an electrodeposited top coat of the type disclosed in the '099 patent, which provides many additional advantages, for example, better Uniform thickness control, higher transfer efficiency, less waste, lower VOC content, etc. However, if the top layer of the reflective structure as described in the '099 patent is an insulating material, a conductive base coating is still required in this case to easily perform electrodeposition. If the mirror film is considered such that there is no significant insulating film on the top surface of the coating stack, the mirror can be encapsulated by direct electrodeposition of the electrodeposition coating formulation without the need for a conductive base coating, so The conductive base coating is, for example, but not limited to, the base coating 120 of the encapsulant 104.

[0182] The single-layer PEM encapsulant coating provides significant cost reduction and potential processing advantages, including more flexibility in manufacturing design, for example, it can also be applied without a base coating. Next, a cascade electrodeposition coater of the type disclosed in the '099 patent was installed at the MSVD production facility.

[0183] Referring to FIG. 12, this figure shows a non-limiting embodiment of a solar mirror 150. The solar mirror 150 includes a substrate 12, a bottom layer 24, and a solar reflective layer 22 or 27. Instead of the conductive encapsulant, the base coating 120 of the PEM encapsulant 104 is the solar reflective layer 22 or 27 of the coating stack 32 or 35 without the PPO layer 25. The function of the encapsulant-based coating 120 is replaced with the solar reflective layer 22 or 27 of the electrodeposited encapsulant 152 or the coating stack 32 or 35 without the PPO layer 25 of the type disclosed in the '099 patent.

[0184] The electrodeposited encapsulant 152 of the solar mirror 150 was manufactured and tested and passed the CASS fog test.

[0185] Referring to FIG. 13, it can now be understood that, based on the above, the solar mirror 156 shown in FIG. 13 can be reduced to the substrate 12, the bottom layer 24, the solar reflective coating 22 or 27, and the electrodeposited encapsulant 152.

[0186] Non-limiting embodiment of the present invention using a framed PEM encapsulant on a coating stack with a PPO layer

[0187] The following discussion refers to the solar mirror 160 shown in FIGS. 14 and 15, however, it should be understood that unless otherwise noted

In addition, the discussion can be applied to all solar mirrors discussed in this article. 15, the solar mirror 160 includes a coating stack 32 or 35 applied to the surface 16 of the substrate 12. The coating stacks 32 and 35 each include a bottom layer 24 on the surface 16 of the substrate 12; a solar reflective coating 27 or 22 on the bottom layer 24, and a layer 76 on the solar reflective coating 27 or 22. And 78, and the PPO layer 25 on the coatings 76 and 78. As can now be understood, in order to prevent or reduce the corrosion of the solar reflective coatings 27 and 22 and the corrosion of other films of the coating stacks 32 and 35, the coating stack includes the PPO layer 25 and the PEM encapsulation system discussed above.

[0188] During the CASS test, it was noted that the location is that the corrosion of the coating stacks 32 and 35 usually starts at the outer wall 106 of the coating stack 35 and the outer wall 110 of the coating stack 32 and goes inwards The position of movement rarely starts on the main surface, which is, for example, the top surface 108 of the PPO coating 25. The conclusion drawn is that the central portion 164 of the top surface 108 of the PPO layer 25 does not necessarily need to be coated with the base layer 120 of the PEM encapsulant 104 and the zinc flake 124. As can be appreciated, the elimination of the base coating 120 of the PEM encapsulant 104 and the zinc flakes 124 therein on the central portion 164 of the PPO layer 25 provides a significant reduction in material cost and manufacturing time.

[0189] As can be recalled, in the above discussion, the base layer 120 with zinc flakes is applied on the top surface 108 of the PPO layer 25 so that the top layer 122 of the PEM encapsulant 104 can be electrically coated to the PEM encapsulant 104 of the bottom layer 120.

[0190] Shown in FIGS. 14 and 15 is a solar mirror 160. The solar mirror 160 has the base coating 120 of the PEM encapsulant 104 on the marginal edge 166 of the PPO layer 25 and extends over the edge or outer wall 110 of the coating stacks 32 and 35. The top coat 122 of the PEM encapsulant 104 is applied on the base layer 120 and on the central portion 164 of the PPO layer 25. The central portion 164 of the surface of the PPO layer 25 is blocked in any convenient way during the application of the Zn-based coating 120. The top coat 122 can be applied by selecting one of the coating processes discussed herein.

[0191] By applying the Zn-based coating 120 to the peripheral edge of the coating film and the marginal edge of the PPO film 25 and by applying the top coating 122 on the Zn-based coating and the exposed PPO surface, sufficient corrosion protection is obtained Protect to pass the CASS fog test.

[0192] The present invention is not limited to the width of the Zn-based coating applied to the marginal edge of the PPO layer 25. The sample used for the CASS fog test has a length of 3 feet and a width of 2 feet. The Zn-based coating 120 on the marginal edge of the PPO layer 25 has a width in the range of 1 cm to 2 cm. The sample has passed the CASS fog test. Optionally, a top coat 122 may be applied over the exposed surfaces of the base coat 120 and the PPO layer 25 for added protection.

[0193] The width of the base layer 120 covering the marginal edge of the PPO layer 25 is generally in the range of greater than zero to 5 inches, in the range of greater than zero to 4.5 inches, in the range of greater than zero to 4.0 inches, in the range of greater than zero. In the range of to 3.5 inches, in the range of greater than zero to 3.0 inches, and in the range of greater than zero to 2.5 inches.

[0194] In another experiment, two samples of an MSVD mirror of about 5 inches X 6 inches were masked in the center and coated with a base coat 120 by hanging, flashed at 245°F, and After removing the center mask, it is coated with a top coat 122 by hanging. After curing, each side of the sample was cut off by 1 inch, leaving a 3 inch X 4 inch sample with four painted but then cut edges and no base coating 120 and only the center of the top coating 122 area. After 120 hours of CASS fog test exposure, there was no corrosion along any of the cut edges, nor was there any corrosion on the center of the face protected only by the top coat of the encapsulation part. In contrast, the samples with the top coat 122 of the PEM encapsulant 104 but without the base coat 120 of the PEM encapsulant 104 all failed the CASS fog test over 12 hours.

[0195] The advantage of this embodiment of the present invention is that (1) compared with the many gallons of coating required to establish a process such as curtain coating for full surface coverage of the outermost sheet, the use of anti-corrosion The coating covers the edge of the coating stack and the marginal edge of the outermost sheet by radiation/spraying/printing/electric coating, as disclosed in the patent '099 and the publication '206

(2) Only cover a small percentage of the area of the mirror near the edge, which greatly reduces the material cost, and (3) reduces the weight of the solar mirror.

[0196] The present invention can be practiced to make a second surface mirror as described above, but if the protective outer coating is transparent or if the first surface mirror itself has sufficient durability to survive only with edge protection, then The present invention can also be practiced to make a first surface mirror. By applying the Zn-based coating (anti-corrosion coating) only to the edge of the mirror, sufficient cathodic protection is obtained to prevent the onset of corrosion, while at the same time it is possible to significantly reduce the cost and weight of the two-layer encapsulation system.

[0197] In the non-limiting embodiment discussing the present invention, the coating stack is applied to the second surface of the substrate, the second surface facing away from the sun. In this way, the sun's rays pass through the first surface and the second surface of the substrate. However, the present invention is not limited to this, and the coating stack with the PEM encapsulant can be mounted on the first surface of the substrate (for example, The surface facing away from the sun). In this way, the sun's rays pass through the encapsulation to reach the solar reflective film and are reflected back through the encapsulation.

[0198] The present invention is not limited to the embodiments of the present invention proposed and discussed above for illustrative purposes only, and the scope of the present invention is limited only by the scope of the following claims and any appended claims. Any additional claims are added to applications that are directly or indirectly linaged with this application.