Reflective article

Description

BACKGROUND OF THE INVENTION

Technical field

[0001] The invention relates generally to coated substrates, and in one particular embodiment of a coated glass substrate, particularly suitable for reflecting electromagnetic radiation, such as solar electromagnetic radiation.

State of the art

[0002] With the rising cost of fossil fuels, solar energy is becoming a more commercially acceptable and viable source of energy. One known application is the use of mirrors to concentrate solar energy to generate electricity. High-reflectance mirrors are used in concentrated solar thermal power (CSTP) installations. Several different mirror geometries are used in these applications. One conventional system uses curved parabolic solar mirrors to focus solar energy on tubes along a focal line. The heat carrier in the pipes transfers the absorbed heat energy to the generator station, where it is used to generate electricity. Another conventional system uses a solar tower in which a number of flat solar mirrors direct the solar energy to a specific point on the tower. The heat generated by the focused solar energy is transferred to a working fluid such as sodium, and the heated working fluid is used to generate electricity.

[0003] Another application of such mirrors is in the concentrator photovoltaics (CPV) systems. In this application, the mirrors concentrate, i.e. concentrate, solar energy on high-efficiency totovoltaic (PV) devices, which increases the amount of energy obtained per device.

[0004] In these known systems, it is desirable that the mirrors reflect as much of the solar energy as possible. It is also desirable that the mirrors have a service life as long as possible to prevent frequent mirror changes.

[0005] Conventional mirror technology employs a chemical wet plating process in which silver is precipitated onto a glass substrate from a silver nitrate solution. One problem with this known system is that the used solution must be disposed of in an environmentally friendly manner. Moreover, such conventional systems do not allow the coated article to be processed at high temperatures (e.g. for heat hardening, annealing or bending) after the silver layer has been deposited as this would damage it. While some conventional mirrors have a chemically wet-applied copper layer on the silver layer to retard silver corrosion, these conventional copper layers cannot protect the silver layer sufficiently to allow the coated glass to be heated to its softening point. Moreover, the deposition of copper in wet processes is non-traction for ecological reasons, especially due to the disposal of the wet chemical waste stream.

[0006] It is therefore advantageous to provide a retroreflective article and a method of producing a retroreflective article that eliminate or reduce at least some of the problems associated with such conventional articles.

[0007] WO2007 / 007570 discloses a reflective article.

SUMMARY OF THE INVENTION

[0008] The retroreflective article comprises a transparent substrate having a first major surface and a second major surface. An undercoat is formed over at least a portion of the second major surface. A base reflective coating is formed over at least a portion of the backing. Over at least part of it

An inorganic protective coating is formed in the base reflective coating. In one non-limiting embodiment, the backing comprises an inorganic material such as a transparent dielectric material.

[0009] Another reflective product comprises a transparent glass substrate having a first major surface and a second major surface. An inorganic primer is formed over at least a portion of the second major surface, which includes at least one metal oxide selected from alumina, titanium dioxide, zirconium dioxide, zinc oxide, zinc tinate, tin dioxide, or mixtures or combinations thereof, the primer having thickness ranging from 0.1 nm to 5 nm. A base reflective coating is formed over at least a portion of the primer, which includes at least one metal selected from platinum, iridium, osmium, palladium, aluminum, gold, copper, silver, or mixtures, alloys or combinations thereof, the base reflective coating having a thickness of range from 50 nm to 500 nm, and where the base reflective coating is opaque to visible light. An anti-corrosion coating is formed over at least a portion of the base reflective coating that includes at least one metal or metal alloy containing elements of groups 2-16 of the Periodic Table of the Elements and has a thickness ranging from 20 nm to 40 nm. A topcoat is formed over at least a portion of the anti-corrosive coating which includes at least one layer comprising a material selected from metal oxides, nitrides, oxynitrides, borides, fluorides or carbides, wherein the topcoat has a thickness ranging from 5 nm to 500 nm. An inorganic protective coating is formed over at least a portion of the topcoat, which comprises a material selected from silicon dioxide and alumina, or a mixture of silicon dioxide and alumina, and has a thickness ranging from 50 nm to 500 nm.

[0010] A further reflective article comprises a transparent glass substrate having a first major surface and a second major surface. An inorganic primer is formed over at least a portion of the second major surface, which includes titanium dioxide with a thickness ranging from 1 nm to 3 nm. A base reflective coating is formed over at least a portion of the substrate, which includes silver with a thickness ranging from 50 nm to 200 nm. An anti-corrosion coating is formed over at least a portion of the base reflective coating which comprises a nickel alloy with a thickness ranging from 20 nm to 40 nm. A topcoat is formed over at least part of the anti-corrosion coating, which comprises zinc tinate with a thickness ranging from 100 nm to 200 nm. An inorganic protective coating is formed over at least a portion of the topcoat, which comprises a material selected from silicon dioxide and alumina, or a mixture of silicon dioxide and alumina, and has a thickness ranging from 50 nm to 200 nm.

[0011] The method of manufacturing the retroreflective article comprises the steps of: providing a transparent substrate having a first major surface and a second major surface; depositing an inorganic backing over at least a portion of the second major surface; depositing the at least one base reflective coating over at least a portion of the substrate, wherein the base reflective coating is opaque to visible light; and depositing an inorganic protective coating over at least a portion of the base reflective coating.

DESCRIPTION OF DRAWING FIGURES

[0012] The invention will now be described with reference to the following figures, in which like reference numerals identify like parts.

Fig. 1A is a sectional side view (not to scale) of a retroreflective article incorporating features of the invention therein;

Fig. 1B is a sectional side view (not to scale) of another retroreflective article incorporating features of the invention therein;

Fig. 1C is a sectional side view (not to scale) of a further retroreflective article comprising w

The features of the invention;

Fig. 2 is a sectional side view (not to scale) of another retroreflective article of the invention;

Fig. 3 is a sectional side view (not to scale) of a further retroreflective article of the invention;

Fig. 4 is a sectional side view (not to scale) of an additional retroreflective article of the invention; and

Fig. 5 is a side view (not to scale) of the retroreflective article of the invention attached to a substrate.

DESCRIPTION OF EXAMPLES OF EXAMPLES

[0013] As used herein, spatial or directional terms such as "left", "right", "inner", "outer", "over", "under" and the like refer to the invention as shown in the figures. However, it should be understood that the invention may take various alternative orientations and, accordingly, such terms are not to be considered as limiting. Furthermore, as used herein, all numbers expressing dimensions, physical characteristics, processing parameters, amounts of ingredients, reaction conditions, and the like used in the specification and claims are to be understood as modified in all instances by the term "about". Accordingly, unless otherwise indicated, the numerical values ​​set forth in this specification and claims may vary depending upon the properties desired to be achieved by the invention. At least and not in an attempt to limit the application of the equivalence principle to the scope of the claims, each numerical value should be understood at least in the light of the significant figures indicated and by the use of common rounding techniques. In addition, all ranges disclosed herein are to be understood to include the starting and ending values ​​of the range, and all subranges therefor. For example, a range defined as "from 1 to 10" should be considered as including all subranges between (and including) the Minimum Value 1 and the Maximum Value 10; that is, all sub-ranges starting with a minimum value of 1 or greater and ending with a maximum value of 10 or less, e.g., 1 to 3.3, 4.7 to 7.5, 5.5 to 10, and the like. Furthermore, as used herein, the terms "formed over", "embedded over" or "provided over" mean an element formed, embedded or provided on a surface, but not necessarily in direct contact therewith. For example, a coating layer "formed above" a substrate does not prevent the presence of one or more coating layers or layers of the same or a different composition between the coating layer formed and the substrate. As used herein, the terms "polymer" or "polymeric" include oligomers, homopolymers, copolymers, and terpolymers, eg, polymers formed from two or more types of monomers or polymers. The terms "visible range" or "visible light" refer to electromagnetic radiation in the wavelength range from 380 nm to 780 nm. The terms "infrared range" or "infrared radiation" refer to electromagnetic radiation in the wavelength range greater than 780 nm to 100,000 nm. The terms "ultraviolet range" or "ultraviolet radiation" mean electromagnetic energy with a wavelength ranging from 100 nm to less than 380 nm. Additionally, all documents referenced herein, such as, but not limited to, patents granted and patent applications, are to be deemed "incorporated by reference" in their entirety. Moreover, parameters such as "visible light transmittance" and "visible light reflection" and the like are determined by conventional methods. Those skilled in the art will understand that properties such as visible light transmittance or visible light reflection may vary depending on physical dimensions, e.g. thickness of the tested product. Thus, any comparisons with the invention should be converted to an equivalent thickness.

[0014] For the purposes of this discussion, the invention will be discussed in relation to use with a retroreflective article for reflecting electromagnetic radiation, such as, but not limited to, a sun mirror for reflecting solar electromagnetic radiation. As used herein, the term "solar mirror" refers to any article configured to reflect solar electromagnetic radiation, such as visible and / or infrared and / or ultraviolet radiation, e.g.

EP 2 260 339 for use in concentrated solar energy systems. However, it should be understood that the invention is not limited to use with solar mirrors, but may be practiced with articles in other fields such as, inter alia, laminated or non-laminated household and / or commercial mirrors, or to name a few - reflectors for high-performance optical systems (e.g. video projectors or optical scanners). By this, it is to be understood that the specific illustrative embodiments disclosed are merely illustrative of the general concepts of the invention and that the invention is not limited to these specific illustrative embodiments.

[0015] In a broad aspect, the retroreflective article of the invention includes at least some of the following components: (1) a light transmissive substrate or top layer (top layer) having low absorption of solar radiation in the electromagnetic spectrum that the product is intended to reflect, (2) one or more primary reflective layers having high solar radiation retlectance in the electromagnetic spectrum, which should be reflected , (3) an optional "primer" or "blocking" or "barrier" layer (s), which can help maintain the reflective properties of the reflective layer or layers and / or improve the adhesion of adjacent components, (4) one or more optional additional reflective layers such as an additional metal, semiconductor, dielectric and / or composite layer, which may increase the reflectance of the product in part or all of the desired wavelength range and / or protect the primary reflective layers and / or prevent diffusion of chemicals between the layers and / or substrates / overlays, (5) optional inhibitory layer (s) corrosion, (6) an optional sacrificial layer (s) containing materials that are more susceptible to corrosion than the materials contained in components 2, 3 and / or 4, (7) an optional layer (s) of materials (e.g. metals or metal alloys) that are resistant to corrosion and / or form passivation layers that prevent the interaction / reaction of chemically reactive substances from the environment with other components, (8) possible surrounding layer (s) that protect lower layers (especially / y reflective / e) against attack by environmental threats (e.g. atmospheric contamination, water, mechanical hazards), (9) possible binder layer (s) that bind the product to any sub-layer (s) or other load-bearing structures, (10) optional polymer layer (s), ( 11) optional secondary layers / substrates / overlays, (12) an optional easy-care top layer (e.g. hydrophilic and / or photocatalytic or hydrophobic), and (13) optional edge seals.

A non-limiting reflective article incorporating the features of the invention is shown in Figure 1A and will be described herein as a solar mirror 1. The solar mirror 1 may have any desired reflectance or transmission within the desired range (s) in the electromagnetic spectrum (e.g. ultraviolet light spectrum). , visible, near infrared, far infrared, microwave, radio etc.). For example, the solar mirror 1 may have a visible light retlectance at 550 nm of at least 85%, such as at least 90%, such as at least 95%.

[0017] In the embodiment shown in Fig. 1A, the solar mirror 1 comprises a substrate or layer 12 with a first major surface 14, i.e. an outer major surface, and an opposite second major surface 16, i.e. an inner major surface. In the discussion that follows, the first major surface 14 faces the incident radiation and the second major surface 16 faces the opposite of the incident radiation. An optional primer 102 may be provided over at least a portion of one of the major surfaces, such as the second major surface 16. In the non-limiting embodiment shown, the base reflective coating 22 is formed over at least a portion of the second major surface 16, e.g., over at least a portion of the backing 102. if present. A protective coating 50 is provided over at least a portion of the base reflective coating 22. While in the embodiment shown the coatings are formed over the second major surface 16, it is understood that at least a portion

EP 2 260 339 coatings could alternatively be formed over the first major surface 14.

[0018] In a broad practice of the invention, layer 12 may comprise any desired material having any desired characteristics. For example, layer 12 can be transparent or translucent to visible light. By "transparent" is meant having a transmittance greater than 0% up to 100% in a desired wavelength range such as visible light. Alternatively, layer 12 may be translucent. By "translucent" is meant allowing electromagnetic radiation (eg visible light) to pass through, but with its blurring or diffusion. Examples of suitable materials for layer 12 include, but are not limited to, thermoplastic, thermosetting or elastomeric polymeric materials, glasses, 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 (such as acrylic polymers such as polyacrylates; poly (alkyl methacrylates) such as poly (methyl methacrylates), polymethyl methacrylates), polympropyl methacrylates, and the like; polyurethanes; polycarbonates; poly (alkyl terephthalates) such as poly (ethylene terephthalate), poly (propylene terephthalates), poly (butylene terephthalates), and the like; polysiloxane-containing polymers; or copolymers of any monomers for their preparation, or any mixtures thereof); ceramic substrates; glass substrates; or mixtures or combinations of any of the above. For example, layer 12 may include conventional soda lime silicate glass, borosilicate glass, or lead glass. The glass may be clear glass. By "clear glass" is meant uncolored or non-tinted glass. Alternatively, the glass may be tinted or otherwise tinted glass. The glass may be annealed glass or heat-treated glass. As used herein, the term "heat treated" means toughened, bent, heat strengthened or bonded. The glass may be of any type, such as conventional float glass, and may be of any composition with any optical properties, e.g., any visible light transmittance, ultraviolet transmittance, infrared transmittance, and / or solar total transmittance. Layer 12 may, for example, be clear float glass, or may be tinted or tinted glass. Examples of glass suitable for layer 12, although not limiting the invention, 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. Layer 12 can have any desired dimensions, such as length, width, shape, or thickness. In one illustrative embodiment, the first layer 12 may have a thickness greater than 0 up to 10mm, such as from 1mm to 10mm, e.g., from 1mm to 5mm, e.g., less than 4mm, e.g. 3.5mm, e.g. 3.2mm. Additionally, layer 12 may have any desired shape, such as flat, curved, parabolic, or the like. Moreover, when the base reflective layer (s) 22 is located on the second major surface 16 of the article, layer 12 may include one or more materials exhibiting low electromagnetic absorption in the electromagnetic radiation range (s) whose reflection is desirable.

[0019] In one non-limiting embodiment, layer 12 may have high visible transmittance with a reference wavelength of 550 nanometers (nm) and a reference thickness of 3.2 mm. By "high visible transmittance" is meant a visible light transmittance at 550 nm of greater than or equal to 85%, such as greater than or equal to 87%, such as greater than or equal to 90%, such as greater than or equal to 91%, such as as greater than or equal to 92%, such as greater than or equal to 93%, such as greater than or equal to 95%, with a reference layer thickness of 3.2mm. Glass particularly useful in the practice of the invention is disclosed in US Patent Nos. 5,030,593 and 5,030,594. Non-limiting examples of glass that can be used in the practice of the invention include, but are not limited to, Starphire®, Solarphire®, Solarphire® PV, Solargreen®, Solextra®, GL-20®, GL-35 ™, Solarbronze®, CLEAR, and Solargray®, all available from PPG Industries Inc. from Pittsburgh, Pennsylvania.

[0020] The backing 102 may provide a stronger or more durable contact surface between the layer 12

EP 2 260 339 and the base reflective coating 22. The primer 102 may include one or more materials selected so that the interface between the primer 102 and the base reflective coating 22 is mechanically, chemically, and / or environmentally more durable than the interface between the base layer 12 and the base layer. reflective layer 22. In addition, the primer 102 may serve as a diffusion barrier for the exchange of elements between layer 12 and the base reflective layer 22 (such as migration of sodium from the glass substrate into the overlay coating or coatings, or metal migration, e.g., silver, from the underlying reflective coating 22 into the glass), especially such as would occur by subjecting a coated article to elevated temperatures, for example for bending or heat strengthening. Additionally or alternatively, the backing 102 may provide a smoother or flatter surface on which the overlying coating will be deposited, e.g., a reflective base coat 22. Examples of suitable materials for the backing 102 include, but are not limited to, inorganic materials such as, but not limited to, low-cut transparent dielectrics. absorption, such as metal oxides or combinations, composites or mixtures of metal oxides. Examples of suitable metal oxides include alumina, titanium dioxide, zirconium dioxide, zinc oxide, zinc tinate, tin oxide, or mixtures or combinations thereof. Other examples of the primer 102 include one or more layers of silicon dioxide and / or silicon nitride. In one non-limiting embodiment, primer 102 comprises titanium dioxide. The backing 102 can be of any composition or thickness to provide the product with the desired functionality (e.g. mechanical, chemical, passivation, flattening, adhesive properties, diffusion barrier, enhancement of environmental durability, optical). In one specific embodiment, where the substrate 102 is titanium dioxide, the substrate 102 has a thickness ranging from 0.1 nm to 5 nm, such as from 0.1 nm to 3 nm, such as from 0.5 nm to 3 nm. such as from 1 nm to 3 nm, such as from 0.5 nm to 2 nm, such as from 1 nm to 2 nm, such as from 1.5 nm to 2 nm, such as from 1.8 nm.

[0021] The base reflective coating 22 is formed over at least a portion of the second major surface 16, e.g., over at least a portion of the backing 102, if present. The base reflective coating 22 comprises one or more inorganic or organic dielectrics, metals, or semiconductors selected from for reflecting one or more portions of the electromagnetic spectrum, such as one or more portions in the range of solar electromagnetic radiation. In one non-limiting embodiment, the base reflective coating 22 comprises one or more radiation-reflecting metallic layers or layers. Examples of suitable reflective metals include, but are not limited to, metallic platinum, iridium, osmium, palladium, aluminum, gold, copper, silver, or mixtures, alloys, or combinations thereof. In one non-limiting embodiment, the base reflective coating 22 comprises a metallic silver layer having a thickness ranging from 50 nm to 500 nm, such as from 50 nm to 300 nm, such as from 60 nm to 400 nm, such as from 60 nm to 300 nm. such as from 70 nm to 300 nm, such as from 80 nm to 200 nm, such as from 80 nm to 150 nm, such as from 90 nm to 150 nm, such as from 90 nm to 140 nm, such as from 90 nm to 130 nm, such as from 100 nm to 130 nm, such as from 120 nm to 130 nm. In one specific non-limiting embodiment, the base reflective coating 22 comprises metallic silver and has a thickness of at least 50 nm, such as at least 60 nm, such as at least 70 nm, such as at least 80 nm (e.g., in the range from 70 nm to 90 nm). The base reflective coating 22 may be thickness deposited such that the article 1 has any desired level of reflectance within the desired range of electromagnetic radiation it is intended to reflect. The base reflective coating 22 may be deposited to a thickness sufficient to make the coating opaque over a desired wavelength range, such as visible light. The base reflective coating 22 may be particularly useful for reflecting visible and infrared solar energy. In one specific non-limiting embodiment, the base reflective coating 22 is deposited using a conventional sputtering process as described in more detail.

EP 2 260 339 in detail below. In another non-limiting embodiment, the base reflective coating 22 may include a "highly reflective mirror" comprising a plurality of alternating high and low refractive index materials.

[0022] The protective coating 50 helps protect the underlying layers, such as the base reflective layer 22, from mechanical and chemical damage during manufacturing, shipping, handling, processing, and / or the life of the mirror in the field. The protective coating 50 also helps protect the lower layers from ingress of liquid water, steam, and other environmental contaminants (whether they are solid, liquid, or gaseous). The protective coating 50 can be an oxygen barrier coating to prevent or reduce the ingress of oxygen from the surroundings into the underlying layers during subsequent processing, such as heating or bending, such as heating or bending. Protective coating 50 can be of any desired materials or mixture of materials, such as, but not limited to, one or more inorganic materials. In one illustrative embodiment, the protective coating 50 may include a layer having one or more metal oxide materials, such as, but not limited to, aluminum, silicon, or mixtures thereof. For example, the protective coating 50 may be a single coating layer having from 0 wt. up to 100 wt.% % alumina and / or from 100 wt. to 0 wt.% % silicon dioxide, such as from 1 wt. up to 99 wt.% % alumina and from 99 wt. up to 1 wt.% % silicon dioxide, such as from 5 wt. up to 95 wt.% % alumina and from 95 wt. up to 5 wt.% % silicon dioxide, such as from 10 wt. up to 90 wt.% % alumina and from 90 wt. up to 10 wt.% % silicon dioxide such as from 15 wt. up to 90 wt.% % alumina and 85 wt. up to 10 wt.% % silicon dioxide such as from 50 wt. up to 75 wt.% % alumina and 50 wt. % up to 25 wt. % silicon dioxide such as from 50 wt. up to 70 wt.% % alumina and from 50 wt. up to 30 wt.% % silicon dioxide such as from 35 wt. up to 100 wt.% % alumina and from 65 wt. to 0 wt.% silicon dioxide, e.g. from 70 wt.% up to 90 wt.% % alumina and from 30 wt. up to 10 wt.% % silicon dioxide, e.g. from 75 wt. up to 85 wt.% % alumina and from 25 wt. up to 15 wt.% silicon dioxide, e.g. 88 wt.% % alumina and 12 wt. % silicon dioxide, e.g. from 65 wt. up to 75 wt.% % alumina and 35 wt. % up to 25 wt. silicon dioxide, e.g. 70 wt. % alumina and 30 wt. % silicon dioxide, e.g. from 60 wt. % to less than 75 wt.%. % alumina, and greater than 25 wt. % up to 40 wt.% silicon dioxide. In one specific non-limiting embodiment, the protective coating 50 comprises 40 wt. up to 15 wt.% % alumina and from 60 wt. up to 85 wt.% % silicon dioxide such as 85 wt. % silicon dioxide and 15 wt. alumina. Other materials such as aluminum, chromium, hafnium, yttrium, nickel, boron, phosphorus, titanium, zirconium and / or their oxides may also be present, e.g., to adjust the refractive index of a protective coating 50. In one non-limiting embodiment, the protective coating 50 may have an index of refraction of 1 to 3, such as 1 to 2, such as 1.4 to 2, such as 1.4 to 1.8.

[0023] In one non-limiting embodiment, the protective coating 50 comprises a combination of silicon dioxide and alumina. The protective coating 50 may be sputtered from two cathodes (e.g., one silicon and one aluminum) or from one cathode containing both silicon and aluminum. This silicon-aluminum oxide protective coating 50 can be written by the formula SixAli-_xOi, 5 + x / 2, where x can be greater than 0 to less than 1. In one specific non-limiting embodiment, the protective coating 50 can be a silicon aluminum oxide coating (SixAh-_xOi.5 + x / 2) with a thickness ranging from 5 nm to 5.000 nm, such as from 5 nm to 1,000 nm, such as from 10 nm to 100 nm, e.g. from 10 nm to 50 nm, such as from 10 nm to 40 nm, such as from 20 nm to 30 nm, such as 25 nm. Moreover, the protective coating 50 may be non-uniform in thickness. By "non-uniform thickness" is meant that the thickness of the protective coating 50 may vary over a given unit area, eg, the protective coating 50 may have high and low points or areas. In another non-limiting embodiment, the protective coating 50 comprises a coating of silica and alumina or a mixture of silicon dioxide and alumina, such as 85 wt. % silicon dioxide and 15 wt. alumina, and has a thickness ranging from 10 nm to 500 nm, such as from 20 nm to 300 nm, such as from 50 nm to 300 nm, e.g. from 50 nm to 200 nm, such as from 50 nm to 150 nm , such as from 50 nm to 120 nm, such as from 75 nm to

EP 2 260 339

120 nm, such as from 75 nm to 100 nm. In a particular non-limiting embodiment, the protective coating 50 may have a thickness of at least 50 nm, such as at least 75 nm, such as at least 100 nm, such as at least 110 nm, such as at least 120 nm, such as at least 150 nm. such as at least 200 nm. [0024] In another non-limiting embodiment, the protective coating 50 comprises silicon dioxide with a thickness ranging from 10 nm to 100 nm, such as from 10 nm to 80 nm, such as from 20 nm to 80 nm, such as from 30 nm to 70 nm. nm, such as from 40 nm to 60 nm, such as 50 nm. In a further non-limiting embodiment, the protective coating 50 comprises silicon dioxide with a thickness ranging from 10 nm to 500 nm, such as from 10 nm to 400 nm, such as from 20 nm to 300 nm, such as from 50 nm to 200 nm, such as such as from 75 nm to 150 nm, such as from 75 nm to 120 nm.

[0025] In another non-limiting embodiment, the protective coating 50 may include a multi-layer structure, e.g., a first layer with at least one second layer formed over the first layer. In one specific non-limiting embodiment, the first layer may comprise alumina or a mixture or alloy comprising alumina and silicon dioxide. For example, the first layer may comprise a silicon dioxide / alumina mixture of greater than 5 wt.%. % alumina, such as greater than 10 wt. % alumina, such as greater than 15 wt. % alumina, such as greater than 30 wt. % alumina, such as greater than 40 wt. % alumina, such as from 50 wt. up to 70 wt.% alumina, such as in the range of 70 wt. up to 100 wt.% % alumina and from 30 wt. to 0 wt.% % silicon dioxide, such as greater than 90 wt. % alumina, such as greater than 95 wt. alumina. In one non-limiting embodiment, the first layer comprises only or substantially only alumina. In one non-limiting embodiment, the first layer may have a thickness ranging from greater than 0 nm to 1 micrometer, such as from 5 nm to 10 nm, such as from 10 nm to 25 nm, such as from 10 nm to 15 nm. The second layer may contain silicon dioxide or a mixture or alloy containing silicon dioxide and alumina. For example, the second layer may comprise a silicon dioxide / alumina mixture of greater than 40 wt.%. % silicon dioxide, such as greater than 50 wt. % silicon dioxide, such as greater than 60 wt. % silicon dioxide, such as greater than 70 wt. % silicon dioxide, such as greater than 80 wt. % silicon dioxide, such as in the range of 80 wt. up to 90 wt.% % silicon dioxide and from 10 wt. up to 20 wt.% alumina, e.g. 85 wt. % silicon dioxide and 15 wt. alumina. In one non-limiting embodiment, the second layer may have a thickness ranging from greater than 0 nm to 2 micrometers, such as from 5 nm to 500 nm, such as from 5 nm to 200 nm, such as from 10 nm to 100 nm, such as from 30 nm to 50 nm, such as from 35 nm to 40 nm. In another non-limiting embodiment, the second layer may have a thickness ranging from greater than 0 nm to 1 micrometer, such as from 5 nm to 10 nm, such as from 10 nm to 25 nm, such as from 10 nm to 15 nm. In another non-limiting embodiment, the protective coating 50 may be a bimolecular layer formed by one layer comprising a metal oxide (e.g., a first layer comprising silicon dioxide and / or alumina) formed over another layer comprising a metal oxide (e.g., a second layer comprising silicon dioxide and / or alumina). or alumina). The individual layers of the multi-layer protective coating may have any desired thickness. Non-limiting examples of suitable protective coatings are described, for example, in US Patent Applications Nos. 10 / 007,382; 10 / 133,805; 10 / 397.001; 10 / 422,094; 10 / 422,095 and 10 / 422,096.

[0026] As discussed above, the reflective article of the invention may include one or more optional additional layers, layers, coatings, or structures. Additional reflective articles of the invention incorporating such additional structures thereon will now be described. However, it should be understood that the specific optional structures or coatings described are not limited to the specific embodiments shown, but that these structures may be used interchangeably in any of the embodiments of the invention.

[0027] Another non-limiting retroreflective article incorporating the features of the invention is shown in Fig. 1B as a solar mirror 3. In the embodiment shown in Fig. 1B, the solar mirror 3 includes a layer

ΕΡ 2 260 339 with a first major surface 14, ie, an outer major surface, and an opposing second major surface 16, ie, an inner major surface, as described above. An optional primer 102 may be provided over at least a portion of one of the major surfaces, such as the second major surface 16. Over at least a portion of the second major surface 16, e.g., over at least a portion of the backing 102, if present, a base reflective coating 22 is formed. . One or more of the optional corrosion resistant or anti-corrosive 104 may be provided, e.g., over at least a portion of the base reflective coating 22. A film of primer 106 may be provided over or under at least a portion of the anti-corrosive coating 104. Over at least a portion of the anti-corrosive coating 104 , e.g., a topcoat 40 may be provided over at least a portion of the primer film 106. A protective coating 50 may be provided over at least a portion of the topcoat 40. An optional encapsulating structure 24 may be provided over at least a portion of the protective coating 50. While only one anti-corrosion coating 104 is shown, the article could have multiple anti-corrosive coatings 104 and multiple primer layers 106 over and above. / or under anti-corrosion coatings 104.

[0028] Layer 12, primer 102, base reflective coating 22, and protective coating 50 may be as described above. However, in this embodiment, the retroreflective article 3 also comprises other layers having other functions.

[0029] For example, anti-corrosion coating 104 may provide various benefits such as corrosion inhibition and ultraviolet shielding. In addition, the anti-corrosion coating 104 may provide some reflection of electromagnetic energy, which may enable a thinner reflective base layer 22 to be applied. The anti-corrosion coating 104 may also provide mechanical and / or chemical protection to the underlying coating layers. The anti-corrosion coating 104 may be provided beneath, over, or between one or more coating layers, e.g., the base coat (s) 22 of the top coat (described below). Alternatively, or in addition to, an anti-corrosion coating 104 may be provided beneath, over, or between one or more layers of the protective coating 50. It is believed that the anti-corrosion coating 104 increases the corrosion resistance of the coatings beneath it, and / or increases the reflection of visible light by the sun mirror 3, and / or blocks or reduces the transmission of UV radiation. Examples of suitable materials for anti-corrosion coating 104 include, but are not limited to, elemental metals and alloys of two or more metallic elements that are members of groups 2-16 of the Periodic Table of the Elements, including, but not limited to, nickel and nickel-containing alloys, iron alloys, and alloys containing iron such as stainless steels, aluminum and alloys containing aluminum, copper and alloys containing copper, chromium and alloys containing chromium, titanium and alloys containing titanium brasses such as marine brass (Cu, Zn and Sn alloy), marine brass (Zn, Sn and Cu alloy) and aluminum brass (Cu, Zn and Al alloy), cobalt and cobalt containing alloys such as cobalt and chromium alloys, zinc and alloys containing zinc, tin and alloys containing tin, zircon and alloys containing zircon, molybdenum and alloys containing molybdenum, tungsten and alloys containing tungsten, niobium and alloys containing niobium, indium and alloys containing indium, lead and alloys containing lead and bismuth and alloys containing bismuth. Specific non-limiting embodiments include corrosion resistant metals and metal alloys, including, but not limited to, nickel and nickel-containing alloys such as nickel 200, Inconel (r) alloys such as Inconel 600 and Inconel 625, stainless steels such as 304 stainless steel, and 316 stainless steel, Monel (r) alloys such as Monel 400, Hastelloy (r) alloys, cobalt and cobalt containing alloys such as Stellite (r) alloys, Inco alloys such as Inco C-276 alloy and Inco 020 alloy, Incoloy (r) alloys such as Incoloy 800 and Incoloy 825, copper and copper-containing alloys such as brass, especially marine brass (about 59% copper, 40% zinc, and 1% tin) and marine brass (about 69% copper, 30 % zinc, 1% tin), silicon and silicon-containing alloys, titanium and titanium-containing alloys, and aluminum and aluminum-containing alloys such as aluminum 6061. If present, the anti-corrosion coating (s) 104 may be of any desired thickness. In some non-limiting embodiments, anti-corrosion coatings 104 may have a thickness ranging from, among others, 1 nm to 500 nm, such as from 1 nm to

EP 2 260 339

400 nm, such as from 1 nm to 300 nm, such as from 1 nm to 200 nm, such as from 1 nm to 100 nm, such as from 10 nm to 100 nm, such as from 20 nm to 100 nm, such as from 30 nm to 100 nm, such as from 40 nm to 100 nm, such as from 50 nm to 100 nm, such as from 20 nm to 40 nm, such as from 30 nm to 40 nm, such as from 30 nm to 35 nm . In other non-limiting embodiments, the anti-corrosive coating (s) 104 may have a thickness of at least 10 nm, such as at least 20 nm, such as at least 30 nm, such as at least 40 nm, such as at least 50 nm, such as at least at least 100 nm, such as at least 200 nm. In one specific non-limiting embodiment, the anti-corrosive coating 104 comprises Inconel and may have a thickness ranging from 10 nm to 100 nm, such as from 10 nm to 80 nm, such as from 15 nm to 50 nm. such as from 20 nm to 40 nm, such as from 30 nm to 40 nm, such as from 30 nm to 35 nm.

[0030] An optional primer layer 106 may be formed above and / or below the anti-corrosive coating (s) 104. The primer layer 106 has one or both of the following functions: (a) a chemical absorber of oxygen or other chemicals (either endogenous or exogenous to the article) such that it reacts with the primer layer (s) in place of the base reflective coating 22, and / or (b) a physical diffusion barrier that prevents chemicals from reaching and influencing the base reflective coating 22 (not necessarily through chemical reactions). In one specific embodiment, optional primer layer (s) 106 may include a metal or metal alloy having a high affinity for oxygen and / or a metal chemical reaction product or metal alloy with oxygen. The optional primer layer (s) 106 may also include diffusion barrier materials to prevent diffusion of molecular or atomic oxygen, water vapor, or other gaseous substances chemically reacting with the base reflective coating 22. In one specific embodiment, the primer layer 106 comprises titanium, titanium dioxide, or a mixture / combination thereof. In one specific embodiment, the primer layer 106 may have a thickness ranging from 0.1 to 10 nm, such as from 0.5 to 5 nm, such as from 0.5 to 4 nm, such as from 0.5 to 2 nm. nm, such as from 1 nm to 2 nm.

A topcoat 40 is formed over at least a portion of the base reflective coating 22, e.g., over at least a portion of the anti-corrosion layer 104, e.g., a topcoat 40 is formed over at least a portion of the primer layer 106. The topcoat 40 may include one or more layers, e.g. one or more layers of dielectrics such as one or more metal oxides, nitrides, oxynitrides, borides, fluorides or carbides. In one non-limiting embodiment, the topcoat 40 may be a single layer comprising zinc oxide and tin oxide, such as zinc tinate. In another specific non-limiting embodiment, the topcoat 40 may include a multi-layer structure as described below with reference to Fig. 1C. However, it should be understood that the invention is not limited to oxide coatings. In one non-limiting embodiment, the topcoat 40 comprises zinc tinate. The topcoat may have a thickness of at least 10 nm, such as at least 20 nm, such as at least 50 nm, such as at least 75 nm, such as at least 100 nm, such as at least 150 nm, such as at least 200 nm. In one specific non-limiting embodiment, the topcoat may have a thickness ranging from 5 nm to 500 nm, such as from 10 nm to 500 nm, such as from 50 nm to 500 nm, e.g., from 50 nm to 300 nm, such as from 100 nm to 250 nm, such as from 100 nm to 200 nm, such as from 120 nm to 165 nm, such as from 110 nm to 165 nm. In general, the thicker the topcoat, the better the protection provided to the underlying coat layers.

[0032] Optional enclosing structure 24 may be formed over and / or around at least a portion of the skin layer 12 described above. In one non-limiting embodiment, enclosing structure 24 is formed at least in part by enclosing material 92. Suitable enclosing materials 92 include polymeric materials, inorganic materials, or composites, combinations, blends, and mixtures thereof.

Mixtures and alloys. When a substantial portion or all of the surrounding material 92 comprises a polymeric material, the surrounding material 92 may be deposited by any conventional means such as, but not limited to, brush coating, roller coating, spray coating, curtain coating, dip coating, spin coating, knife coating, and more. , screen printing, pour coating, electroplating (also known as electroplating) and powder coating. Suitable polymeric envelope materials 92 include, but are not limited to, thermoplastics, thermosetting materials, elastomers, and thermoplastic elastomers made by polyaddition or polycondensation, with or without cross-linking, and copolymers, composites, combinations, mixtures, blends, and alloys thereof. However, encapsulating materials containing polymeric materials can use a variety of additives and fillers, including initiators, photoinitiators, plasticizers, stabilizers, preservatives, biocides, matting agents, flow aids, antioxidants, UV absorbers, surfactants, dyes, pigments, and inorganic fillers or organic. Potentially all polymeric surrounding materials can include, but are not limited to, polyacrylates, polyalkydals, polyacrylonitriles, polyesters, polyfluorocarbons, polyvinyls, polyureas, polycarbonates, and polycarbonates. The enclosing structure 24 may include, for example, acrylic coatings, urethane coatings, fluoropolymer and / or chlorofluoropolymer coatings (e.g. poly (fluroethylene), poly (chlorotrifluoroethylene), etc.), coatings based on poly (vinylidene chloride), coatings based on ethylene-vinyl alcohol copolymer, polyacrylonitrile coatings, coatings based on polymers or cyclic olefins copolymers, organic / inorganic composite coatings : an organic polymer matrix with one or more inorganic phases (e.g. ceramic materials such as silicon dioxide and alumina) dispersed in it either evenly or unevenly, inorganic plasma sprayed coatings: ceramics (e.g. silicon dioxide, aluminum oxide, silicon nitride, titanium boride, titanium carbide, boron nitride, silicon carbide) and metals / metal alloys (aluminum, titanium, nickel based alloys such as Inconel, iron alloys such as stainless steel), coatings based on vulcanized butadiene (e.g. sulfur-cross-linked synthetic rubber), ultraviolet cured polysiloxane coatings, laminates containing polymer interlayers (e.g. ethylene vinyl acetate or polyvinylidene chloride interlayers) and glass back plates. In one non-limiting embodiment, the polymeric material is free of heavy metals such as lead. For surrounding materials containing only inorganic materials, suitable materials include, but are not limited to, metals, metal alloys, or ceramics and composites or combinations thereof. Examples of suitable deposition processes for such inorganic surrounding materials include physical vapor vapor deposition (e.g. sputtering, electron beam evaporation, thermal vaporization, cathodic arc vaporization, plasma sputtering, flame sputtering, pyrolysis sputtering, ion assisted sputtering), chemical vacuum vapor deposition (e.g. thermal, plasma assisted / plasma enhanced), sol-gel deposition, other wet chemical processes (e.g. ceramic enamels) and their combinations. In addition, the surrounding structure 24 may include both polymeric and inorganic materials in combination.

[0033] Specific coatings suitable for the surrounding structure 24 include, but are not limited to, the Corabond® coating family (e.g., Corabond® HC7707 coating) available from PPG Industries, Inc. of Pittsburgh, Pennsylvania, Ferro GAL-1875 "Etch" ceramic enamel, Cosmichrome® coating (available from Gold Touch, Inc.), Sureguard® mirror base coat (available from Spraylat Corporation), EcoBrite® ink coatings (for from PPG Industries, Inc), PRC 4429 and PRC 4400 coatings available from PRC DeSoto, and Spraylat Lacryl Series 700 or 800 coatings (available from Spraylat Corporation). Alternatively, the surrounding structure 24 could be metallic, such as formed by one or more metallic layers, such as those described above in relation to the anti-corrosion coating 104, formed over the second reflective coating 22 with optional polymeric material formed over the layer (s).

EP 2 260 339 metallic. Additional examples of non-polymeric / inorganic surrounding materials include ceramic enamels, sol-gel ceramic coatings, flame sputtering ceramic or metal coatings, plasma sputtering ceramic or metal coatings, and arc-deposited ceramic or metal sputtering coatings. In one specific non-limiting embodiment, the enclosing structure 24 may be a multilayer structure, such as a bimolecular coating having a low lead or lead free primer and a low lead or lead free topcoat.

[0034] A further non-limiting solar mirror 10 incorporating the features of the invention is shown in Fig. 1C. In the embodiment shown in Fig. 1C, the solar mirror 10 comprises a first layer 12 with a first major surface 14, i.e., an outer major surface, and an opposite second major surface 16, i.e., an inner major surface, as described above. In one non-limiting embodiment, an optional secondary reflective coating 20 is formed over at least a portion of the inner surface 16. In another non-limiting embodiment, an optional secondary reflective coating 20 may be formed over at least a portion of the outer major surface 14. The primary reflective coating 22 is formed over at least part of the second major surface 16, e.g. An anti-corrosion coating 104 may be formed over at least a portion of the secondary reflective coating 20 if present and is on the second major surface 16. Over at least a portion of the primary reflective coating 22, an anti-corrosion coating 104 may be formed. Over at least a portion of the anti-corrosive coating 104, a topcoat 40 may be formed. Protective film 50 may be formed at least part of topcoat 40. Mirror 10 may also include enclosing structure 24.

[0035] An optional secondary reflective coating 20, if present, may provide one or more functions in the solar mirror 10. In one non-limiting embodiment, the secondary reflective coating 20 may be selected to increase the overall reflection of the electromagnetic radiation of the reflective article in a specific area or range of electromagnetic radiation. The secondary reflective coating 20 may be selected or designed to enhance the reflection of electromagnetic radiation in one or more parts of the electromagnetic spectrum (e.g., visible, infrared, ultraviolet). In one non-limiting embodiment, the secondary reflective coating 20 may be selected to enhance the reflection of shortwave radiation, such as less than 600 nm, less than 550 nm, ranging from 400 nm to 550 nm. Alternatively, the secondary reflective coating 20 can be tuned, such as by changing its thickness to reflect UV radiation. The secondary reflective coating 20 may include one or more layers of reflective material, such as one or more layers of metal oxide materials. In one specific non-limiting embodiment, the secondary reflective coating 20 comprises alternating layers of a relatively high refractive index material and a relatively low refractive index material. A material with a "large" refractive index is any material that has an index of refraction greater than that of a material with a "small" refractive index. In one non-limiting embodiment, the low refractive index material is a material having a refractive index less than or equal to 1.75. Non-limiting examples of low refractive index materials include silicon dioxide and alumina, fluorides (such as magnesium fluoride and calcium fluoride), and alloys, mixtures, or combinations thereof. In one non-limiting embodiment, the high refractive index material has a refractive index greater than 1.75. Non-limiting examples of such materials include titanium dioxide, zirconium dioxide, zinc tinate, silicon nitride, zinc oxide, tin doped zinc oxide, niobium oxide, tantalum oxide, and alloys thereof, mixtures and combinations thereof. The secondary reflective coating 20 may be, for example, but not limited to, a multi-layer coating such as

EP 2 260 339 is shown in Fig. 1C having a first layer 26, e.g., a first dielectric layer, and a second layer 28, e.g., a second dielectric layer. In one non-limiting embodiment, the first layer 26 has a high refractive index and the second layer 28 has a low refractive index. In one non-limiting embodiment, the first layer 26 comprises titanium dioxide and the second layer 28 comprises silicon dioxide. In one specific non-limiting embodiment, the first layer, e.g., titanium dioxide, has a thickness ranging from 15 nm to 35 nm, such as from 20 nm to 30 nm, such as from 22 nm to 27 nm, such as 25 nm. The second layer, e.g. silicon dioxide, may have a thickness ranging from 30 nm to 60 nm, such as from 35 nm to 50 nm, such as from 40 nm to 50 nm, such as 42 nm. It should be understood that the materials of the secondary reflective coating 20 are not limited to metal oxides. Any material can be used such as, but not limited to, oxides, nitrides, oxynitrides, fluorides, etc.

[0036] In the non-limiting embodiment shown in Figure 1C, an optional adhesive layer 30 may be provided between the secondary reflective coating 20 and the primary reflective coating 22. The adhesive layer 30 may be any layer that improves adhesion between the secondary and primary reflective coating 20, 22 or increases the mechanical and / or chemical durability of the secondary or primary reflective coating 20, 22. Binder layer 30 may include at least one material selected from dielectrics, semiconductors, polymers, organic materials, or layers of metal or metal alloys. In one non-limiting embodiment, binder layer 30 comprises at least one material selected from oxides, nitrides, or oxynitrides of zinc, tin, titanium, or combinations thereof, such as, but not limited to, zinc oxide, titanium dioxide, or zinc / tin oxide such as (IV ) zinc. For example, binder layer 30 may have a thickness less than or equal to 5 nm, such as less than or equal to 4 nm, such as less than or equal to 3 nm, such as less than or equal to 2 nm, such as less than or equal to 1 nm. .

[0037] In the illustrative embodiment shown in Fig. 1C, a topcoat 40 is formed over at least a portion of the base reflective coating 22. The topcoat 40 may be as described above. In one specific non-limiting embodiment, the topcoat may include one or more layers, e.g. one or more layers of a dielectric such as one or more metal oxides, nitrides, oxynitrides, borides, fluorides, or carbides. In one specific non-limiting embodiment, the topcoat 40 comprises a multilayer structure having a first layer 42, e.g., a metal oxide film, a second layer 44, e.g., a metal alloy oxide film or an oxide mixture film, and optionally a third layer 46, e.g., a metal oxide layer. However, it should be understood that the invention is not limited to oxide coatings, and that other coatings such as nitrides or oxynitrides, among others, could be used. In one non-limiting embodiment, the topcoat 40 may include zinc oxide or zinc / tin oxide, such as zinc tinate, and may have a thickness ranging from 1 nm to 500 nm, such as from 5 nm to 500 nm, such as from 10 nm to 500 nm, such as from 50 nm to 500 nm, e.g. 50 nm to 300 nm, such as from 100 nm to 250 nm, such as from 100 nm to 200 nm, such as from 120 nm to 165 nm.

[0038] In one non-limiting embodiment, first layer 42 may be a zinc-containing film, such as zinc oxide. The zinc oxide film may be deposited from a zinc cathode containing other materials to enhance the conductivity and sputter characteristics of the cathode. For example, the zinc cathode may contain a small amount (e.g., 10 wt.% Or less, such as from 0 wt. up to 5 wt.%) of a conductive material such as tin to increase the sputter characteristics of the cathode. In this case, the resulting zinc oxide film would contain a small percentage of tin oxide, e.g., from 0 to 10 wt.%. tin oxide, e.g. 0 to 5 wt.% tin oxide. A coating layer deposited from a zinc cathode having 10 wt. or less tin is referred to in this document as the "zinc oxide" layer, even though a small amount of tin (eg, 10 wt.%) may be present. It is believed that there is a small amount of tin in the cathode

EP 2 260 339 forms a small amount of tin oxide in the film mainly containing zinc oxide. In one non-limiting embodiment, the first zinc oxide layer 42 comprises 90 wt. % zinc and 10 wt. of tin and has a thickness ranging from 1 nm to 200 nm, such as from 1 nm to 150 nm, such as from 1 nm to 100 nm, such as from 1 nm to 50 nm, such as from 1 nm to 25 nm, such as such as from 1 nm to 20 nm such as from 1 nm to 10 nm such as from 2 nm to 8 nm such as from 3 nm to 8 nm such as from 4 nm to 7 nm such as from 5 nm to 7 nm, such as 6 nm.

[0039] In one non-limiting embodiment, the second layer 44 may be a zinc-tin alloy oxide or a zinc / tin mixture oxide layer. The zinc-tin alloy oxide can be obtained by vacuum magnetron sputtering from a zinc-tin cathode, which may contain zinc and tin in proportions of 10 wt.%. up to 90 wt.% % zinc and from 90 wt. up to 10 wt.% tin. One suitable metal alloy oxide that may be present in the second layer 44 is zinc tinate. By "zinc (IV) tinate" is meant the composition of Zn_xSnixO2x (Formula 1), where "x" ranges from greater than 0 to less than 1. For example, "x" can be greater than 0 and can be any fraction or decimal between greater than 0 and less than 1 For example, when x = 2/3, Formula 1 is Zn2 / 3Sni / 3O4 / 3, more commonly referred to as "Zn2SnO4". One or more forms of Formula 1 are predominantly present in the film containing zinc tinate. In one non-limiting embodiment, the second zinc tin (IV) layer 44 may have a thickness ranging from 1 nm to 200 nm, such as from 1 nm to 150 nm, such as from 1 nm to 100 nm, such as from 1 nm to 50 nm. nm such as from 1 nm to 25 nm such as from 1 nm to 20 nm such as from 5 nm to 15 nm such as from 6 nm to 14 nm such as from 8 nm to 14 nm such as from 10 nm to 14 nm, such as 11 nm, such as 13 nm, such as 12 nm.

[0040] In one non-limiting embodiment, optional third layer 46 may be a zinc-containing film similar to the first layer 42, e.g., a zinc oxide film. In one non-limiting embodiment, optional third zinc oxide film 46 has a thickness ranging from 1 nm to 200 nm, such as from 1 nm to 150 nm, such as from 1 nm to 100 nm, such as from 1 nm to 50 nm, such as from 1 nm to 25 nm, such as from 1 nm to 10 nm, such as in the range from 2 nm to 8 nm, such as in the range from 3 nm to 8 nm, such as in the range from 4 nm to 7 nm , such as in the range of 5 nm to 7 nm, such as 6 nm.

[0041] In one non-limiting embodiment, the solar mirror 10 may have a photosensitive coating 60, such as a photocatalytic coating and / or a photohydrophilic coating, formed over at least a portion of the first surface 14. A non-limiting example of some suitable material for the photosensitive coating 60 is titanium dioxide. The photosensitive coating 60 may be deposited directly on the first surface 14, or a barrier layer may be provided between the first surface 14 and the photosensitive coating 60, such as a sodium ion diffusion barrier (SIDB) layer. A non-limiting example of a suitable material for the SIDB layer is silicon dioxide or alumina, or combinations thereof. Alternatively, the photosensitive coating 60 may be omitted and only a SIDB layer formed over the first surface 14.

[0042] Some or all of the coatings described above for the reflective articles of the invention may be deposited by any conventional method such as, but not limited to, wet chemical methods (e.g., precipitation of the coating from solution, electroless plating, sol-gel processes, etc.), electrochemical methods ( e.g. electroplating / electroplating), sputtering (e.g. magnetron sputter vapor deposition (MSVD)), vapor deposition (e.g. thermal vaporization or electron-beam vapor deposition), chemical vapor deposition (CVD), spray pyrolysis, flame spraying or plasma spraying. In one non-limiting embodiment, some or all of the coatings may be deposited by MSVD. Examples of MSVD coating equipment and methods will be better understood by those skilled in the art, and are described in

EP 2 260 339 for example in US Patent Nos. 4,379,040; 4,861,669; 4,898,789; 4,898,790; 4,900,633; 4,920.006; 4,938,857; 5,328,768 and 5,492,750. For example, the base reflective coating 22 may be applied by wet chemical methods (e.g., wet silver deposition - by precipitating silver from the silver nitrate solution) if desired. In one non-limiting embodiment, one or more layers of the secondary reflective coating 20 may be applied by conventional CVD methods, for example, to a float ribbon while it is in a tin bath. The base reflective coating 22 and one or more layers of the topcoat 40 may then be applied by a different process such as MSVD. Alternatively, all coatings can be applied by the same process such as MSVD. The sputter coating of at least a portion of the coatings is believed to have advantages over many other techniques. For example, it is possible to deposit a wide variety of materials in a single vacuum chamber. In addition, sputtering is expected to produce layers of greater chemical purity than conventional wet chemistry methods. In addition, sputtering eliminates the liquid waste stream generated by wet chemical methods, and also allows the easy deposition of other metals. In addition, sputtering enables the deposition of inorganic oxides used for binder layers, chemical barriers and mechanical protection.

The surrounding structure 24 may be formed over and / or around at least a portion of the skin layer described above. The surrounding structure 24 is not limited to the examples described above, but may include any material to protect the underlying coating materials from chemical and / or mechanical attack. . For example, in the solar mirror 80 shown in Figure 2, the surrounding structure 24 includes a second layer 82 joined to the first layer 12, e.g. a protective coating 50, a polymeric layer 84. The second layer 82 may be selected from the materials described above for the first layer 12 and may be the same or different to the first layer 12. Additionally, the second layer 82 need not be transparent to electromagnetic radiation in any part of the electromagnetic spectrum. .

[0044] The polymeric layer 84 can be of any desired materials and can include one or more layers. The layer (s) 84 may include thermoplastics, thermosetting materials, elastomers and / or thermoplastic elastomers. Layer 84 can be a polymeric material or a plastic such as, for example, poly (vinyl butyral), softened poly (vinyl chloride), or a multi-layer thermoplastic material including poly (ethylene terephthalate), ethylene vinyl acetate (EVA), poly (vinyl chloride). , poly (vinylidene chloride), polycarbonate, polyacrylates (e.g. poly (methyl acrylate, polyacrylonitrile), polysiloxanes, fluoropolymers, polyesters, melamines, polyureas, polyurethanes, polyalkydals, phenol-formaldehyde resins, etc. Some suitable materials are disclosed in US Pat. Nos. 4,287,107 and 3,762,988. Layer 84 holds the first and second layers together, can provide energy absorption, and can increase the strength of the laminate structure. In one non-limiting embodiment, the layer 84 is poly (vinyl butyral) and has a thickness ranging from 0.5 mm to 1.5 mm, such as from 0.75 mm to 0.8 mm.

[0045] The solar mirror 90 of the invention shown in Fig. 3 may employ a polymeric enclosing structure 24 formed at least in part by enclosing material 92 as described above. The surrounding material 92 may wrap around at least a portion of the sides (minor surfaces) of the solar mirror 90 to provide an edge seal of the article. Alternatively, the edges of the product, i.e. minor surfaces, conventional edge sealant such as but not limited to polyvinylidene chloride (PVDC) may be applied prior to application of the surrounding material.

[0046] Another solar mirror 100 of the invention is shown in Fig. 4. The solar mirror 100 includes a first layer 12 as described above. In this embodiment, the secondary reflective coating 20 is absent. A base reflective coating 22 may be applied to at least a portion of second major surface 16. In one specific embodiment, between second major surface 16,

Primer 102 is provided and the base reflective coating 22 is provided with a primer 102. The primer 102 may be the same as described above.

[0047] In this embodiment, the base reflective coating 22 may be any of the materials described above with respect to the prior embodiments. In one specific embodiment, the base reflective coating 22 comprises metallic silver with a thickness ranging from 10 nm to 500 nm, such as from 50 nm to 500 nm, such as from 50 nm to 300 nm, such as from 50 nm to 200 nm. such as from 100 nm to 200 nm, such as from 100 nm to 150 nm, such as from 110 nm to 140 nm, such as from 120 nm to 140 nm, such as from 128 nm to 132 nm. In another specific embodiment, the base reflective coating 22 comprises metallic silver with a thickness ranging from 1 nm to 500 nm, such as from 50 nm to 500 nm, such as from 50 nm to 300 nm, such as from 50 nm to 200 nm. such as from 50 nm to 150 nm, such as from 70 nm to 150 nm, such as from 90 nm to 120 nm, such as from 90 nm to 130 nm, such as from 90 nm to 100 nm, such as from 90 nm up to 95 nm.

[0048] The topcoat 40 may be a single layer or a multilayer structure having a first layer 110 and a second layer 112. In one specific embodiment, the first metal oxide layer 110 comprises zinc oxide with a thickness ranging from 1 nm to 30 nm, such as from 1 nm to 30 nm. nm to 25 nm, such as from 5 nm to 20 nm, such as from 10 nm to 20 nm, such as from 10 nm to 17 nm. The second layer 112 comprises zinc tinate with a thickness ranging from 10 nm to 100 nm, such as from 40 nm to 45 nm.

[0049] The solar mirror 100 may also include a protective coating 114, which may be the same as or similar to the protective coating 50 described above. In one specific embodiment, the protective coating 114 comprises silicon dioxide with a thickness ranging from 10 nm to 500 nm, such as from 10 nm to 300 nm, such as from 10 nm to 100 nm, such as from 20 nm to 100 nm, such as such as from 30 nm to 80 nm, such as from 40 nm to 60 nm, such as from 50 nm to 60 nm, such as from 57 nm.

[0050] Fig. 5 shows the reflective article of the invention (e.g., solar mirror 1, 3, 10, 80, 90, 100) mounted on a base 120. The reflective article is mounted with the first major surface 14 facing outward. The retroreflective article may be mounted by any conventional means such as by glue or by mechanically securing the article to a frame, to name a few. The base 120 can be connected to the surrounding structure 24 as described above. Alternatively, the enclosing structure 24 may be omitted and the base 120 may be joined to the outer skin layer of the coating stack, e.g., a protective coating 50. The base 120 may be of any desired materials such as metal (such as aluminum, stainless steel, etc.) or a material among others. polymeric such as plastic.

[0051] The invention provides highly reflective articles that are useful in many applications such as, but not limited to, solar mirrors. The reflective articles of the invention may have a solar weighted hemispherical integrated reflectance Rg (WIRg) of at least 50%, such as at least 60%, such as at least 70%, such as at least 80%, such as at least 90%. such as at least 91%, such as at least 92%, such as at least 93%, such as at least 94%, such as at least 95%, such as in the range from 90% to 96%.

[0052] As described above and as shown in the examples below, an advantage of the inventive reflective article over conventional wet chemistry mirrors is that the inventive reflective article can be coated and then heated to a temperature sufficient to heat treat or bend the article (before the application of any polymeric enclosing structure) without adversely affecting the reflectance of the article. In addition, the coatings of the invention may show an improvement in spectral performance (i.e. an increase in reflectance in part or all of the spectral range measured) and an increase in solar weighted reflectance after heating. For example, the reflective article of the invention having an undercoat and / or a base reflective coating, and / or

The secondary reflective coating and / or anti-corrosive coating and / or topcoat and / or protective coating may be heated to a temperature sufficient to bend or heat treat the article prior to application of the enclosing structure. For example, the substrate and coatings could be heated to at least 300 ° F (144 ° C), such as at least 350 ° F (177 ° C), such as at least 400 ° F (204 ° C), such as at least 500 ° F (260 ° C), such as at least 750 ° F (399 ° C), such as at least 800 ° F (427 ° C), such as at least 900 ° F (482 ° C), such as at least 1000 ° F (538 ° C), such as at least 1022 ° F (550 ° C), such as at least 1100 ° F (59 ° C), such as at least 1200 ° F (649 ° C) such as at least 1,300 ° F (704 ° C), such as in the range of 350 ° F (177 ° C) to 1300 ° F (704 ° C).

[0053] The invention will now be described with reference to specific examples showing various mirror structures incorporating various aspects of the invention therein. However, it is understood that the invention is not limited to these specific examples.

Examples

[0054] Table 1 shows the structure of the various mirrors (samples 1-10) of the invention.

EP 2 260 339

TABLE 1

<td>Sample No.</td><td>TiO primer₂</td><td>Ag</td><td>Primer Ti</td><td>T1O2</td><td>ZnO</td><td>Zn2SnO4</td><td>Inconel 600</td><td>Primer Ti</td><td>Ti02</td><td>ZnO</td><td>Zn2SnO4</td><td>Si85 / Al 15</td>

<td> 1</td><td> 1,5</td><td> 130</td><td> 2,5</td><td> 0</td><td> 12</td><td> 10</td><td> 33</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 60</td>

<td> 2</td><td> 1,5</td><td> 130</td><td> 2,5</td><td> 0</td><td> 9</td><td> 10</td><td> 0</td><td> 0</td><td> 0</td><td> 9</td><td> 0</td><td> 60</td>

<td> 3</td><td> 1,5</td><td> 120</td><td> 1,5</td><td> 0</td><td> 12</td><td> 10</td><td> 33</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 60</td>

<td> 4</td><td> 1,5</td><td> 120</td><td> 1,5</td><td> 0</td><td> 9</td><td> 10</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 60</td>

<td> 5</td><td> 1,5</td><td> 120</td><td> 1,5</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 10</td><td> 21</td><td> 60</td>

<td> 6</td><td> 1,5</td><td> 120</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 33</td><td> 0</td><td> 0</td><td> 10</td><td> 12</td><td> 60</td>

<td> 7</td><td> 1,5</td><td> 120</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 33</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 60</td>

<td> 8</td><td> 1,5</td><td> 120</td><td> 1,5</td><td> 0</td><td> 5</td><td> 21</td><td> 33</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 60</td>

<td> 9</td><td> 1,8</td><td> 127</td><td> 1,6</td><td> 1,8</td><td> 0</td><td> 0</td><td> 33</td><td> 0</td><td> 0</td><td> 17</td><td> 42</td><td> 57</td>

<td> 10</td><td> 1,8</td><td> 132</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 20</td><td> 1</td><td> 0</td><td> 10</td><td> 42</td><td> 57</td>

<td> 11</td><td> 1,6</td><td> 128</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 33</td><td> 1</td><td> 0</td><td> 0</td><td> 48</td><td> 111</td>

<td> 12</td><td> 2</td><td> 128</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 33</td><td> 1</td><td> 0</td><td> 0</td><td> 110-120</td><td> 85-120</td>

<td> 13</td><td> 2</td><td> 128</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 33</td><td> 1</td><td> 0</td><td> 0</td><td> 120-165</td><td> 75-120</td>

<td> 14</td><td> 2</td><td> 91</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 31</td><td> 1</td><td> 0</td><td> 0</td><td> 153</td><td> 100</td>

<td> 15</td><td> 2</td><td> 95</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 33</td><td> 1</td><td> 0</td><td> 0</td><td> 137</td><td> 76</td>

EP 2 260 339

[0055] Table 2 shows the hemispherical WIRg reflectance (solar weighted hemispherical integrated reflectance Rg) of the mirrors of samples 1-15 before and after heating. These results indicate that the hemispherical integrated reflectance weighted for the solar radiation of the mirrors of the invention can increase with heating. The column "Softening point" means that the coated articles were placed in an oven at 1300 ° F (704 ° C) and heated (for about 5 minutes) to the softening temperature of the glass (maximum temperature of the coated surface was about 1185 ° F (641 ° C).

TABLE 2

<td colspan="3">After seating (without heating)</td><td colspan="2">30 minutes. at 350 ° F (177 ° C)</td><td colspan="2">Softening point</td>

<td>Sample No.</td><td>ASTM G- 173- 3 AM-1.5D</td><td>ISO 9050</td><td>ASTM G- 173- 3 AM-1.5D</td><td>ISO 9050</td><td>ASTM G- 173- 3 AM-1.5D</td><td>ISO 9050</td>

<td> 1</td><td> 92,9</td><td> 92,7</td><td> 93,6</td><td> 93,4</td><td> 93,1</td><td> 92,8</td>

<td> 2</td><td> 92,6</td><td> 92,4</td><td> 93,5</td><td> 93,3</td><td> 94,2</td><td> 94,1</td>

<td> 3</td><td>Not measured</td><td>Not measured</td><td>Not measured</td><td>Not measured</td><td>Not measured</td><td>Not measured</td>

<td> 4</td><td>Not measured</td><td>Not measured</td><td>Not measured</td><td>Not measured</td><td>Not measured</td><td>Not measured</td>

<td> 5</td><td> 92,8</td><td> 92,6</td><td> 93,4</td><td> 93,3</td><td> 93,8</td><td> 93,6</td>

<td> 6</td><td> 92,8</td><td> 92,6</td><td> 93,4</td><td> 93,3</td><td> 93,9</td><td> 93,8</td>

<td> 7</td><td> 92,9</td><td> 92,7</td><td> 93,5</td><td> 93,4</td><td> 93,9</td><td> 93,7</td>

<td> 8</td><td> 92,9</td><td> 92,7</td><td> 93,5</td><td> 93,3</td><td> 88,5</td><td> 88,1</td>

<td> 9</td><td> 92,7</td><td> 92,4</td><td> 93,7</td><td> 93,5</td><td> 94,2</td><td> 94,0</td>

<td> 10</td><td> 93,1</td><td> 92,9</td><td>No data</td><td>No data</td><td> 93,9</td><td> 93,8</td>

<td> 11</td><td> 94,0</td><td> 93,8</td><td>No data</td><td>No data</td><td> 95,5</td><td> 95,3</td>

<td> 12</td><td>No data</td><td>No data</td><td>No data</td><td>No data</td><td>No data</td><td>No data</td>

<td> 13</td><td>No data</td><td>No data</td><td>No data</td><td>No data</td><td>No data</td><td>No data</td>

<td> 14</td><td> 93,7</td><td> 93,4</td><td>No data</td><td>No data</td><td> 95,4</td><td> 95,2</td>

<td> 15</td><td> 94,0</td><td> 93,7</td><td>No data</td><td>No data</td><td> 95,4</td><td> 95,2</td>

[0056] Those skilled in the art will appreciate that modifications can be made to the invention without departing from the concepts disclosed in the foregoing description. Accordingly, the specific embodiments described in detail herein are illustrative only and are not intended to limit the scope of the invention to which the full breadth of the appended claims and any and all equivalents thereof are accorded.