Stack including heater layer and drain layer

ES 2 806 257 T3

DESCRIPTION

Stack including heating layer and drainage layer

Background

Static precipitation (P-static) can occur on air vehicles (for example, aircraft) as a consequence of the vehicle being in different types of weather conditions (for example, storms) and / or from airborne particles, such as ice, snow, raindrops and dust, striking the vehicle and inducing a triboelectric charge (eg friction charging). P-static can interfere with the electronic systems of the vehicle. For example, an electrical discharge from P-static can interfere with vehicle radio systems.

P-static can also cause the failure of the heating layer (eg a heating film) of the glazing (eg cover or window windshield) of the vehicle. The heating layer can be used to de-ice and / or demist the glazing (eg, the windshield) and thus, the failure of the heating layer affects the operability of the vehicle. Additionally, excessive build-up on the aircraft windshield can cause curling, which can cause the substrate (eg, glass or plastic) of the windshield to break.

Summary

Aspects of the disclosed target material embodiments are directed to a multilayer stack that includes a drainage layer to reduce the amount or likelihood of damage to the heating layer or a multilayer stack substrate as a result of loading. electrical induced in the heating layer. The present invention relates to a multilayer stack as defined in claim 1, including:

a transparent substrate; a drainage layer on a first side of the substrate; and a heating layer on top of the drainage layer. The multilayer stack further includes a dielectric layer between the heating layer and the drain layer; and a protective coating on the heating layer, the protective coating including a material selected from the group consisting of diamond-like carbon, polyurethanes, polyacrylates, polysiloxanes, epoxies, silicon oxides, aluminum oxides, silicon oxycarbons, zirconium oxynitrides, cerium oxides, and combinations thereof, wherein the heating layer is between the dielectric layer and the protective coating, and wherein the drainage layer has a sheet strength of less than about 10⁶ ohms per square.

The dielectric layer may be configured to electrically isolate the heating layer from the drainage layer so that the heating layer is capable of converting the electrical current applied to the heating layer into heat to (or is capable of) melting the ice or dissipate the condensed moisture formed on the multilayer pile. For example, the dielectric layer can have a dielectric constant of at least about 2, for example within the range of 2 to 10, or at least about.

In some examples, the drainage layer has a sheet strength of less than about 10⁴ ohms per square, or less than about 2,000 ohms per square. For example, the drain layer may have a sheet resistance of less than about 500 ohms per square.

In some embodiments, the substrate includes a glass, a polyacrylate (eg, a stretched polyacrylate or molded polyacrylate), a polycarbonate, a polyurethane, or a combination thereof.

The drainage layer may include a conductive oxide layer, a transparent conductive metallic layer, a conductive metallic mesh, or a combination thereof. For example, the transparent oxide layer may include indium tin oxide, aluminum doped zinc oxide, tin oxide, antimony doped tin oxide, or a combination thereof. In some embodiments, the metal of the transparent conductive metallic layer is gold, silver, palladium, platinum, or a combination thereof. The conductive wire mesh may include ink jet printed electrically conductive lines, litho patterned electrically conductive lines, woven wire wire mesh, or a combination thereof.

In some embodiments, the dielectric layer includes an organic layer, an inorganic layer, or a combination thereof. For example, the organic layer can include a polysiloxane, a polyacrylate, a polyurethane, an epoxy, or a combination thereof. In some embodiments, the inorganic layer includes a diamond-like carbon, a silicon oxide, a titanium oxide, an aluminum oxide, a silicon oxycarbide, an aluminum oxynitride, or a combination thereof.

In some examples, the heating layer has a sheet resistance within the range of 0.02 to 1,000 ohms per square.

ES 2 806 257 T3

In some embodiments, the multilayer stack further includes a base layer between the substrate and the drainage layer. The base coat can include a polysiloxane, a polyacrylate, an epoxy, a polyurethane, and a combination thereof.

In some embodiments, the multilayer stack also includes a second protective coating over the heating layer. The second protective coating can be any suitable protective coating. For example, the second protective coating may include a diamond-like carbon, a polyurethane, a polyacrylate, a polysiloxane, an epoxy, a silicon oxide, a titanium oxide, an aluminum oxide, a silicon oxycarbide, a zirconium oxynitride. , cerium oxide, or a combination thereof.

According to another embodiment, a glazing for an air vehicle includes a multilayer stack as defined above, in which the drainage layer is configured for grounding the air vehicle.

In some embodiments, the multilayer stack is configured to have a first side of the substrate face toward the interior of the air vehicle, and the substrate has a second side opposite the first side, the second side being configured to face the exterior of the air vehicle. air vehicle.

The dielectric layer may be configured to electrically isolate the heating layer from the drainage layer so that the heating layer is capable of converting the electrical current applied to the heating layer into heat to (or is capable of) melting the ice or dissipate condensed moisture formed on the glazing.

In some embodiments, the substrate has a second side opposite the first side, and the drainage layer is configured for grounding with the air vehicle in order to dissipate an induced charge on a second side of the substrate and to reduce the amount induced load in the heating layer.

Brief description of the drawings

The accompanying drawings, together with the specification, illustrate exemplary embodiments of the present invention and examples useful in understanding the invention, and, together with the description, serve to explain the principles of the present invention.

Figure 1 is an exploded cross-sectional view of an example of a multilayer stack.

Figure 2 is an exploded cross-sectional view of another example of a multilayer stack.

Figure 3 is an exploded cross-sectional view of another example of a multilayer stack.

Figure 4 is an exploded cross-sectional view of another example of a multilayer stack.

Figure 5 is an exploded cross-sectional view of one embodiment of a multilayer stack.

Figure 6 is an exploded cross-sectional view of another embodiment of a multilayer stack.

Detailed description

In the following detailed description, only certain exemplary embodiments of the present invention are shown, by way of illustration. As those skilled in the art would recognize, the invention can be made in many different ways and should not be construed as limited to the embodiments set forth herein. Also, in the context of the present application, when a first element is referred to as on a second element, it may be directly on the second element or indirectly on the second element with one or more intermediate elements interposed between them, and over can mean under. For example, a layer that is on top of another layer can also be considered to be below the other layer, depending on the point of view. The substrate and glazing described herein may be formed of glass, plastic, or other appropriate materials, may or may not be coated, and may form a roof, window, or windshield of a car, aircraft, ship, building, or any other. another appropriate vehicle or structure. In the drawings, some features, such as layer thicknesses and regions, may be enlarged or exaggerated for clarity. The present disclosure is not limited to the sizes and thicknesses shown in the drawings. Like reference numerals designate like elements throughout the specification.

Aircraft glazing (for example, windows, windshields, or roofs) can fail when the glazing heating layer is damaged. Because the heating layer is used to de-ice and / or defog the glazing, damage to the heating layer can affect the pilot's visibility in adverse weather conditions and can affect the operability of the aircraft. Damage to the heating layer may be related to static electrification of the glazing as a consequence of Pesttica. The glazing can act in a similar way to that of a two-plate condenser, with the heating layer acting as a conductive plate. As a result, an increase in electrical voltage on the external surface of the glazing can cause a similar (or related) increase in electrical voltage in the heating layer as a consequence of capacitor effects. Increased electrical stress in the heating layer can result in damage to the heating layer or the glazing substrate, for example

ES 2 806 257 T3 example, through bending.

Although the glazing may include an outer conductive layer (eg, an antistatic layer) to dissipate some P-static, the sheet strength of such a layer is limited by considerations of environmental durability of the outer layer. For example, the outer conductive layers do not have a foil resistance of less than 10⁶ohms per square nor the appropriate environmental durability. Additionally, although grounding the heating layer can prevent induction in the heating layer, grounding the heating layer prevents or inhibits the heating layer from producing heat as the electrical current applied to the Heating layer is transmitted to the ground. For example, United States Patent No. 4,078,107 discloses an outer layer and cables on the outer layer, and EP 0 314 153 A2 discloses a heating means including cables and a static drainage band system. Neither US Patent No. 4,078,107 nor EP 0 314 153 A2, however, discloses a dielectric layer between the heating layer and the drain layer, the drain layer exhibiting a sheet strength of less of about 10⁶ ohms per square, or a protective coating having a composition as described herein.

As shown in Figure 1, in accordance with an example of the present disclosure, a multilayer stack 100 includes a substrate 102, a drain layer 104 (or ground layer) on a first side of the substrate, a heating layer 108 over the drain layer, and a dielectric layer 106 between the heating layer and the drain layer. The multilayer stack can be included in a glazing, such as a glazing for an aerial vehicle (eg, an aircraft). The air vehicle may be an appropriate aircraft, such as a jet powered aircraft (commercial passenger, cargo, private or military) or a powered aircraft (commercial passenger, cargo, private or military), such as a tiltrotor aircraft, but the present disclosure is not limited thereto.

The first side of the substrate 102 may be configured to face the interior of an air vehicle (eg, aircraft). Accordingly, the drainage layer 104 can be on the inner side of the substrate. As such, the drainage layer may not be subject to the same environmental considerations as the outer conductive layer. Accordingly, the drainage layer 104 may be more conductive (eg, have a lower sheet resistance) than the outer conductive coating for a glazing. For example, because the drainage layer is on the inner side of the substrate, the drainage layer is protected from the environment outside the vehicle and therefore may include materials that are less durable than those included in an external conductive layer.

In some embodiments, the drain layer 104 may have a sheet strength of less than about 10⁶ ohms per square (that is, ω / Π). For example, the drain layer may have a sheet resistance of less than about 2,000 ohms per square, or less than about 500 ohms per square. For example, the drainage layer may have a sheet resistance in the range of 0.1 to 50 ohms per square. In some embodiments, the drain layer has a sheet resistance within the range of 10 to 2,000 ohms per square. In other embodiments, the drain layer has a sheet resistance within the range of 50-500 ohms per square.

With a sheet strength of less than about 10⁶ ohms per square, the drain layer 104 can drain additional P-static not dissipated by an outer conductive layer. By means of the additional drainage of Pestática, the drainage layer reduces the amount of electrical charge induced in the heating layer 108, or even avoids the induction of electrical charge in the heating layer, as a consequence of the accumulation of P-static in the glazing (for example, on a second side or outer side of the substrate 102 opposite the first side of the substrate facing the drainage layer), extending the life expectancy of the glazing. Accordingly, aspects of embodiments of the present disclosure are directed to a multilayer stack that includes a drainage layer to reduce the amount (or probability) of damage to the heating layer or a substrate of a glazing as a result of the Induced electrical charge in the heating layer.

Drainage layer 104 may include any suitable material, such as a material that provides a drainage layer that has a sheet strength of less than about 10⁶ ohms per square. For example, the drainage layer may include a transparent conductive oxide layer, a transparent conductive metallic layer, a conductive metallic mesh, or a combination thereof. For example, the transparent conductive oxide layer can include indium tin oxide (ITO), aluminum doped zinc oxide (AZO), tin oxide, antimony doped tin oxide, or a combination thereof. The metal of the transparent conductive metallic layer can be gold, silver, palladium, platinum, or a combination thereof. The conductive wire mesh may include ink jet printed electrically conductive lines, litho patterned electrically conductive lines, woven wire wire mesh, or a combination thereof.

For example, ITO can be prepared using a direct current magnetron sputtering plating system. First, a chamber for the preparation of a drainage layer including ITO can be pumped to a vacuum level within the range of 10^-5 to 10^-6torr (from 13.10^-4 to 13.10^-5 Nm^-2) or less. The substrate to which ITO is applied can be heated to a temperature within the range of 100 to 200 ° F (37 to 93 ° C), and argon and oxygen can be flushed into the chamber during ITO deposition. For example, argon can be flowed with a flow rate within the range of 300 to 900 sccm and oxygen can be flowed with a flow rate within the range of 300 to 900 sccm.

ES 2 806 257 T3 range from 10 to 400 sccm. ITO can be deposited by applying an energy density within the range of 0.5 to 5 kW to the target. The resulting drainage can have a thickness in the range of 15 to

500 nm. The ITO-including drainage layer may have a sheet resistance in the range of 10 to 2,000 ohms per square, and a light transmission in the range of 80 to 88%.

A drainage layer including a conductive metal (eg, gold) can be prepared by sputtering or evaporation in a coating chamber. The chamber can be pumped first to a vacuum level within the range of 10^-5 to 10^-6 torr (13.10-4 to 13.10-5 Nm-2) or less. Evaporation can be carried out at room temperature for a time period of 5 to 20 seconds. The drainage layer including gold prepared by evaporation may have a foil resistance in the range of 50 to 500 ohms per square, and a light transmission in the range of 70 to 80%.

Gold can also be sputtered using a DC magnetron sputtering system. Gold can be sputtered in a chamber that is first pumped to a vacuum level within the range of 10-⁵ to 10^-6 torr (13.10-4 to 13.10-5 Nm-2) or less. The substrate to which gold is applied can be heated to a temperature within the range of 100 to 200 ° F (37 to 93 ° C), and argon can be flushed into the chamber during sputtering. For example, argon can be flushed at a flow rate in the range of 300 to 900 sccm during gold deposition. Gold can be sputtered by applying an energy density within the range of 0.5 to 2 kW at the desired point. The drainage layer including gold prepared by sputtering may have a sheet resistance in the range of 50 to 500 ohms per square, and a light transmission in the range of 70 to 80%.

Drainage layer 104 may include a metal mesh as described in US Patent Application No. 13 / 411,476. The conductive wire mesh may include a plurality of electrically conductive lines (eg, ink jet printed electrically conductive lines, litho patterned electrically conductive lines, woven wire wire mesh, or a combination thereof). At least one electrically conductive line intersects at least one other electrically conductive line. The metal mesh can be a polymeric film, and the electrically conductive lines can be in physical contact with the polymeric film. Alternatively, the electrically conductive lines can be ink jet printed or litho patterned directly onto the substrate 102 (eg, the electrically conductive lines can be brought into physical contact with the substrate). The present disclosure, however, is not limited to having a single conductive mesh. For example, the conductive mesh can be repeated to form a stacked structure on the substrate 102.

In accordance with certain embodiments of the present invention, the electrically conductive lines are separated from each other. For example, the electrically conductive lines may be spaced any appropriate distance for the drainage layer 104 to prevent or reduce the induction of an electrical charge in the heating layer 108.

The configuration of the electrically conductive lines of the metal mesh is not limiting. That is, the metal mesh (that is, the electrically conductive lines) can be configured with any shape of pattern or tile. For example, the metal mesh may be arranged in the form of a square grid, triangular tile, hexagonal tile, or a grid formed from straight, wavy, sinusoidal, or zigzag lines. The metal mesh can be arranged in any way following a uniform, non-uniform, repeating or random pattern. Each of the electrically conductive lines can have a width of about 25 µml, but is not limited to this. Additionally, each square between the electrically conductive lines may have a width of 250 µm, but is not limited thereto.

Examples of conductive wire mesh are available from CIMA Nanotech, Inc., Dontech, Inc., Applied Nanotech Holdings, Inc., NanoMas Technologies, Inc., and FUJIFILM Dimatix, Inc. In other embodiments, the conductive wire mesh is formed of a plurality of electrically conductive lines printed by inkjet or a plurality of electrically conductive lines with lithographic pattern on (eg, in physical contact) the substrate 102, wherein at least one electrically conductive line intersects at least one other electrically conductive line.

The electrically conductive lines can be inkjet or lithographically printed onto any suitable polymeric film, such as, for example, polyethylene terephthalate, polycarbonate or polyurethane. In accordance with other embodiments of the present invention, the conductive metal mesh is formed by a plurality of electrically conductive lines printed by inkjet or lithographic pattern on glass, polyacrylate, polycarbonate or any other suitable substrate. In any of the embodiments of the invention, the plurality of electrically conductive lines can be prepared by means of conductive inkjet inks, such as METALON® conductive inks available from Novacentrix. In certain embodiments, the plurality of electrically conductive lines include any appropriate inkjet printed metal, such as copper (Cu), gold (Au), nickel (Ni), silver (Ag), or a combination thereof. For example, the plurality of electrically conductive lines can include Cu. The plurality of electrically conductive lines

ES 2 806 257 T3 may further include epoxy, or any other material having appropriate bonding properties.

In certain embodiments, the conductive wire mesh has a foil resistance within the range of 0.02 to about 1,000 ohms per square. In other embodiments, the wire mesh has a foil resistance of less than about 400 ohms per square. In still other embodiments, the wire mesh has a foil resistance of less than about 100 ohms per square.

The conductive wire mesh can be on a polymeric film. The polymeric film can include any suitable polymer, such as polyethylene terephthalate, polycarbonate, or polyurethane, but the present disclosure is not limited thereto. In certain embodiments, the plurality of electrically conductive lines are in physical contact with the polymeric film. For example, the plurality of electrically conductive lines can be inkjet or lithographic patterning on the polymeric film (eg, deposited on the polymeric film by inkjet printing or lithographic patterning). The polymeric film can have a thickness in the range of about 70 µm to about 1,000 µm. The plurality of electrically conductive lines can have a width within the range of about 20 µm to about 50 µm. The plurality of electrically conductive lines can have a thickness within the range of about 50 nm to about 5 µm. The thickness and / or width of the electrically conductive lines can be varied in order to modify the electrical charge drainage properties of the drainage layer 104.

Electrically conductive lines can be formed by ink jet printing of any ink on the substrate. For example, electrically conductive lines can be prepared by means of conductive inkjet inks, such as METALON® conductive inks available from Novacentrix, on substrate 102. Inkjet printing can be carried out according to any appropriate inkjet printing technique, such as those described in Huang, Lu, et al., Graphene-based conducting inks for direct inkjet printing of flexible conductive patterns. and their applications in electric circuits and chemical sensors, Nano Research (2011), vol. 4, number 7, 675-684.

In another embodiment, the glazing preparation method includes laminating a polymeric film and a substrate together, wherein the metal mesh is formed by a plurality of electrically conductive lines on the polymeric film. For example, the polymeric film, a second film, and the substrate 102 can be laminated together in a laminating process to form a laminated substrate. The laminating process can include heating the polymeric film, the second polymeric film, and the substrate to a temperature within the range of about 200 to about 300 ° F (93 to 148 ° C). Additionally, the laminating process may include compressing the polymeric film, the second polymeric film, and the substrate to a pressure within the range of about 50 to about 250 psi (344 to 1723 Nm^-2). Lamination of the polymeric film, the second tie film, and the substrate together can be carried out for a period of time within the range of about 15 minutes to about 5 hours. The laminating process can be carried out in an airtight plastic vacuum bag that has been emptied. Additionally or alternatively, the laminating process can be carried out in an autoclave.

Substrate 102 can be any suitable substrate, such as a transparent substrate. Examples of the substrate include glasses (eg, a clear glass), polyacrylates (eg, drawn or cast acrylics), polycarbonates, polyurethanes, and similar materials formed from an organic resin. In some embodiments, the polyurethane in the substrate is OPTICOR, available from PPG Industries. OPTICOR is a trademark of PPG Industries Inc. For example, the polyurethane of the substrate can be any polyurethane discussed in US Patent Application No. 2009/0280329 A1.

Dielectric layer 106 may be between drainage layer 104 and heating layer 108. Thus, if the dielectric layer is not electrically insulating enough, then current leakage from the heating layer to the heating layer. drainage can be a problem. For example, if the dielectric layer is not electrically insulating sufficiently, then leakage of electrical current may occur from the heating layer through the dielectric layer to the drain layer. If leakage of electrical current takes place from the heating layer to the drainage layer, the electrical charge passes through the ground, and the heating layer does not convert the electrical energy into heat sufficiently to defrost or demist the glazing. As used herein, the term "dielectric layer" refers to a layer capable of electrically isolating the drain layer and the heating layer from each other, so that the heating layer can convert current electrical applied to the heating layer in sufficient heat to remove condensed moisture (eg, ice and / or mist) from the glazing (eg, to defog or defog the glazing). For example, the dielectric layer can be configured to electrically isolate the heating layer from the drain layer so that the heating layer is capable of converting the electrical current applied to the heating layer into heat to melt ice or dissipate the condensed moisture formed on the multilayer pile. In some embodiments, the dielectric layer has a dielectric constant of at least about 2 (eg, in a range of 2 to 10). For example, the dielectric layer may include silicon oxide having a dielectric constant in the range of about 3.7 to about 3.9, ALOs having a dielectric constant in the range of about 9 to

ES 2 806 257 T3 about 10 (eg, about 9.7), silicon oxycarbide having a dielectric constant in the range of about 3.1 to about 3.8, a polyacrylate (eg, acrylic) having a dielectric constant in the range of about 2.1 to about 3.9, a polysiloxane having a dielectric constant in the range of about 2 to about 6, a diamond-like carbon having a dielectric constant in the range of about 3.5 to about 5, or a glass having a dielectric constant in a range of about 3.5 to about 3.9.

Dielectric layer 106 can include an organic layer, an inorganic layer, or a combination thereof. For example, the organic layer can include a polysiloxane, a polyacrylate, a polyurethane, an epoxy, or a combination thereof. The inorganic layer may include a diamond-like carbon, a silicon oxide, a titanium oxide, an aluminum oxide, zirconium oxynitride, any suitable material deposited via plasma enhanced chemical vapor deposition (PECVD), such as silicon oxycarbide or a combination thereof. The inorganic layer can be prepared using vacuum coating techniques, such as radio frequency magnetron bombardment metallization, radio frequency superimposed on direct current power supply, plasma enhanced chemical vapor deposition and / or layer deposition.

In some embodiments, dielectric layer 106 includes a polyacrylate. The polyacrylate can include a mixture of monomeric, oligomeric, and polymeric acrylic compounds. The monomeric acrylic can be monofunctional, difunctional, trifunctional, tetrafunctional, pentafunctional, or hexafunctional, but the present disclosure is not limited thereto. When the functionality is greater than 1, the monomer participates in crosslinking which improves the chemical resistance, solvent resistance and abrasion resistance of the dielectric layer. In some embodiments, polyacrylates are prepared from monomers that are difunctional. The polyacrylate backbone can be based on poly (epoxy urethane acrylate) and polycarbonate chemistry. Polyacrylates provide good resilience, flexibility, and film-forming properties. The dielectric layer including polyacrylates can be cured using UV and / or thermal energy.

For example, a dielectric layer 106 having a dielectric constant can be prepared by flow coating a polyacrylate coating composition over the drainage layer 104 in a temperature and humidity controlled claim environment. The coating composition can be air dried for 1 to 2 hours. The air-dried coating composition can be heat or UV cured. For example, thermal curing can be carried out at a temperature in the range of 100 to 200 ° F (37 to 93 ° C) for a time period of 1 to 4 hours. UV curing can be carried out at a total energy of 6 joules using multiple passes. The thickness of the dielectric layer including polyacrylate may be within the range of 1 to 20 µm.

Heating layer 108 has a sheet resistance in the range of 0.02 to 1,000 ohms per square, such as a sheet resistance in the range of 5 to 20 ohms per square or 7 to 20 ohms per square. The heating layer may include a layer that is the same or substantially the same as the drain layer 104 described above. For example, the heating layer may include a transparent conductive oxide layer, a transparent conductive metallic layer, a conductive metallic mesh, or a combination thereof. For example, the transparent conductive oxide layer may include indium tin oxide (ITO), aluminum doped zinc oxide (AZO), tin oxide, antimony doped tin oxide, or a combination thereof. The metal of the transparent conductive metallic layer can be gold, silver, palladium, platinum, or a combination thereof. The conductive wire mesh can include ink jet printed electrically conductive lines, litho patterned electrically conductive lines, or a combination thereof. The conductive metal mesh is the same or substantially the same as that described above and, therefore, its further description is omitted in this case.

ITO can be prepared using a DC magnetron sputtering system. First, a chamber for the preparation of a drainage layer including ITO can be pumped to a vacuum level within the range of 10^-5 to 10^-6 torr (13 · 10-4 to 13 · 10-5 Nm-2) or less. The substrate to which ITO is applied can be heated to a temperature within the range of 100 to 200 ° F (37 to 93 ° C), and argon and oxygen can be flushed into the chamber during ITO deposition. For example, argon can be flowed with a flow rate within the range of 300 to 900 sccm and oxygen can be flowed with a flow rate within the range of 10 to 400 sccm. ITO can be deposited by applying an energy density within the range of 0.5 to 5 kW to the target. The resulting heating layer can have a thickness within the range of 200 to 2,000 nm. The heating layer including ITO may have a sheet resistance in the range of 5 to 20 ohms per square, and a light transmission in the range of 70 to 85%.

A heating layer 108 that includes a conductive metal (eg, gold) can be prepared by sputtering or evaporation in a coating chamber. The chamber can be pumped first to a vacuum level within the range of 10^-5 to 10^-6 torr (13.10-4 to 13.10-5 Nm-2) or less. Evaporation can be carried out at room temperature for a time period of 10 to 30 seconds. The heating layer including gold prepared by evaporation may have a foil resistance in the range of 7 to 20 ohms per square, and a light transmission in the range of 50 to 70%.

ES 2 806 257 T3

Gold can also be sputtered using a DC magnetron sputtering system. Gold can be sputtered in a chamber that is first pumped to a vacuum level within the range of 10^-5 to 10^-6 torr (13.10-4 to 13.10-5 Nm-2) or less. The substrate to which gold is applied can be heated to a temperature within the range of 100 to 200 ° F (37 to 93 ° C), and argon can be flushed into the chamber during sputtering. For example, argon can be flushed at a flow rate in the range of 300 to 900 sccm during gold deposition. Gold can be sputtered by applying an energy density within the range of 0.5 to 2 kW at the desired point. The thickness of the layer including gold may be within the range of 6 to 15 nm. The drainage layer including gold prepared by sputtering may have a foil resistance in the range of 5 to 20 ohms per square, and a light transmission in the range of 50 to 65%.

Additional features and layers (eg, films) of the multilayer stack and glazing in accordance with the present disclosure are described below. Depending on the particular examples or embodiments, these additional features and / or layers may or may not be present in the multilayer and / or glazing stack. For example, the multilayer stack 200 according to an example of the present invention is shown in Figure 2. The multilayer stack includes a substrate 202, a drainage layer 204, a dielectric layer 206, and a heating layer 208, each of which is the same or substantially the same as the corresponding layers described above and is therefore omitted. in this case the detailed description of them. The multilayer stack further includes lines or tabs 211 and 212 for grounding the drain layer. For example, the lines or tabs may be configured to ground the drainage layer to an air vehicle (eg, an aircraft), for example when the multilayer stack is included in an air vehicle glazing. The multilayer stack may also include lines or tabs 213 and 214 to supply electrical current to heating layer 208.

Figure 3 shows another example of a multilayer stack 300. The multilayer stack includes a substrate 302, a drain layer 304, a dielectric layer 306, and a heating layer 308, each of which is the same or substantially the same. than the corresponding layers described above and, therefore, the detailed description thereof is omitted in this case. The multilayer stack further includes a base layer 303 between the substrate and the drain layer. The base coat can provide a suitable surface to deposit the drain coat and can improve the adhesion of the base coat to the substrate. The base coat can be prepared from a silane or mixture of silanes. In a non-limiting example, the base coat can be prepared by mixing vinyltrimethoxysilane and 3-aminopropyltriethoxysilane together and hydrolyzing in the presence of water to form the corresponding silanol. Silanols can be reacted under ambient conditions to form a precondensate. The precondensate can be diluted with a mixture of isopropyl alcohol (IPA) and ethanol to form a solution. The solution can be flow coated onto the substrate by means of a saturation technique, can be air dried for a period of time within the range of 30 to 90 minutes, and can subsequently be cured at a temperature within the range of 100 to 200 ° F (37 to 93 ° C) for a time period of 2 to 6 hours to form the base coat.

Figure 4 shows another example of a multilayer stack 400. The multilayer stack includes a substrate 402, a drain layer 404, a dielectric layer 406, and a heating layer 408, each of which is the same or substantially the same. than the corresponding layers described above and, therefore, the detailed description thereof is omitted in this case. The multilayer stack further includes a first protective coating 401 on a second side (eg, an outer side) of the substrate. The first protective coating can be any suitable protective coating. For example, the first protective coating may include a diamond-like carbon, a polyurethane, a polyacrylate, a polysiloxane, an epoxy, a silicon oxide, an aluminum oxide, a material deposited by plasma enhanced chemical vapor deposition. (eg, a silicon oxycarbide), zirconium oxynitride, cerium oxide, or a combination thereof. The first protective coating protects the multilayer pile from the external environment. The first protective coating can also be conductive and dissipate some amount of P-static.

For example, the first protective coating can be formed from a coating composition that includes a first hydrophobic aliphatic polyisocyanate, a second hydrophobic aliphatic polyisocyanate that includes a hydrophilic part, a poly (ester polyol), a fluorinated polyol, and a polyol. hydrophilic. The coating composition can be reacted to form a first coating that includes a poly (urethane polymer). Thus, as described herein, the first coating can include the various components of the coating composition in their reacted and unreacted forms, for example, the first hydrophobic aliphatic isocyanate and the poly (ester polyol). they can be included in the first protective coating in their reacted forms (eg, such as monomers in a urethane or carbamate polymer bond).

Various isocyanates and polyisocyanates (such as difunctional, polyfunctional, aromatic, aliphatic, monomeric, and oligomeric isocyanates) can be used in coating compositions for the formation of polyurethane coatings. Aliphatic isocyanates have good hydrolytic stability and UV resistance. Non-limiting examples of monomeric aliphatic diisocyanates include hexamethylene diisocyanate, methylene bis- (4-cyclohexylisocyanate), and isophorone diisocyanate. Monomeric aliphatic diisocyanates can be used

ES 2 806 257 T3 for preparing polyisocyanate adducts, prepolymers and thermoplastic polyurethanes (TPUs). For example, monomeric aliphatic diisocyanates can be used to prepare biuret-based polyisocyanates (eg, polyisocyanates that include the (HN-CO-) 2N functional group), isocyanurate ring-based polyisocyanates (eg, isophorone diisocyanate trimers ) and other polyisocyanate oligomers. More specifically, hexamethylene diisocyanate (HDI) can be used to prepare the HDI-based biuret shown in Structure 1 below or the HDI-based trimer including an isocyanurate ring shown in Structure 2 below. Isophorone diisocyanate (IPDI) can be used to prepare the IPDI-based trimer shown in Structure 3 below, which is an isocyanurate ring-based polyisocyanate. HDI trimers that include an isocyanurate ring have much lower viscosity than HDI-based biurets. IPDI trimers have lower reactivity than HDI trimers.

[Structure 1]

<img file="ES2806257T3_D0001.tif" />

[Structure 3]

[Structure 2]

According to embodiments of the present invention, the first aliphatic polyisocyanate may be one or more of a biuret-based polyisocyanate, an isocyanurate ring-based polyisocyanate, or an isophorone diisocyanate oligomer. For example, the first aliphatic polyisocyanate may include one or more of the HDI-based biuret shown in Structure 1 above (or a derivative thereof), an HDI-based trimer that includes an isocyanurate ring shown in Structure 2 above (or a derivative thereof) or the IpDi-based trimer shown in Structure 3 above (or a derivative thereof). Non-limiting commercially available examples of the first aliphatic polyisocyanate (or mixtures including the first aliphatic polyisocyanate) include methylene bis- (4-cyclohexylisocyanate) (eg, DESMOdUr® W), polyisocyanates based on methylene 1,6-hexamethylene diisocyanate (for example, DESMODUR® N-75, DESMODUR® N-100, DESMODUR® N-3200, DESMODUR® N-3300, DESMODUR® N-3600 and

ES 2 806 257 T3

DESMODUR® N-3790) and isophorone diisocyanate-based polyisocyanates (eg, DESMODUR® Z-4470) (each available from Bayer Material Science). DESMODUR® is a registered trademark of Bayer Material Science, Leverkusen, Germany. Some of the following examples include an aliphatic polyisocyanate dispersed in (or diluted with) a solvent, which reduces the viscosity of the polyisocyanate, thereby improving the ease of handling of the first aliphatic polyisocyanate.

The first aliphatic polyisocyanate can have a functionality of 3 or more (eg, have 3 or more isocyanate functional groups). In some embodiments, the first aliphatic polyisocyanate has an isocyanate functionality within the range of 3.0 to 4.2. For example, the first aliphatic polyisocyanate can have an isocyanate functionality of about 3.2, 3.5, 3.8, or 4.1. In some embodiments, for example, the first aliphatic polyisocyanate may have an isocyanate functionality of about 3.8.

According to embodiments of the present invention, the coating composition that includes the first aliphatic polyisocyanate described herein (eg, a biuret-HDI-based polyisocyanate) is capable of forming a first elastic protective coating (or film) having good low temperature flexibility, thereby providing resistance to rain erosion not achieved with other polyisocyanates. The first protective coating may also have good first and second alterability and mechanical strength. Some examples of the first protective coating composition including an HDI biuret-based polyisocyanate formed a first protective coating that had good durability, but reduced resistance to rain erosion. Some examples of the coating composition including a polyisocyanate based on an isocyanurate ring (for example, a polyisocyanate based on HDI trimer) formed a first protective coating that had good resistance to rain erosion, but reduced chemical resistance (for example , solvent). Some examples of the coating composition including an isocyanurate ring-based polyisocyanate formed a first protective coating that had a reduced tack-free time and good chemical resistance, but, due to the high Tg value of the isocyanurate ring-based polyisocyanate ( ~ 60 ° C), the resulting first protective coating was rigid and had poor resistance to rain erosion. In comparison, the Tg of some HDI biuret-based polyisocyanates (eg, DESMODUR® N-75 and DESMODUR® N-100) is approximately -60 ° C.

According to embodiments of the invention, the coating composition further includes a second aliphatic polyisocyanate that includes a hydrophilic part. The hydrophilic part of the second aliphatic polyisocyanate can include a polyether chain. In some embodiments, the second aliphatic polyisocyanate further includes a hydrophobic portion. The hydrophobic part of the second aliphatic isocyanate may include an isophorone diisocyanate moiety or a derivative thereof. Non-limiting commercially available examples of the second aliphatic polyisocyanate (or mixtures including the second aliphatic polyisocyanate) include polyether modified HDI trimer-based polyisocyanates (e.g. (e.g., BAYHYDUR® 302 and BAyHyDUR® 303), HDI allophonate modified with polyether (for example, BAYHYDUR® 304, and / or BAYHYdUr® 305), hydrophobically modified aliphatic polyisocyanate based on isophorone diisocyanate (for example, polyether-modified isophorone diisocyanate trimer, such as BAYHYDUR® 2150BA and / or BAYHYdUr® 401-70), aminosulfonic acid-modified HDI polyisocyanates (for example, BAYHYDUR® XP2547, BAYHYDUR® XP2487 / 1, and / or BAYHYDUR® XP2487 / 1, and / or BAYHYDUR® XP2487 / 1, and / or BAYHYDUR® XP2487 / 1, and / or BAYHYDUR® XP2487 / 1 2655) (each available from Bayer Material Science). DESMODUR® is a registered trademark of Bayer Material Science. The second aliphatic polyisocyanate can have a functionality of 2 or more (eg, 2 or more isocyanate functional groups).

An example of a polyether modified HDI trimer-based polyisocyanate (nonionic) is shown in Structure 4 below, which is hydrophilic and readily dispersible in water. Examples of the coating composition including a polyether modified HDI trimer-based polyisocyanate (nonionic) as the second aliphatic polyisocyanate formed first protective coatings that had improved antistatic properties, but the first coatings exhibited reduced integrity against certain tests such as humidity tests (for example, exposure to 100% condensing humidity at 122 ° F (50 ° C)) and 50/50 water / IPA tests (for example, exposure to a 50% isopropanol / 50% water mixture). Accordingly, while these polyisocyanates can be used as the second aliphatic polyisocyanate, other polyisocyanates can provide better coating integrity.

[Structure 4]

<img file="ES2806257T3_D0002.tif" />

An example of a polyether-modified HDI allophonate-based polyisocyanate is shown in Structure 5 below, which is more hydrophobic than the polyether-modified (nonionic) HDI trimer-based polyisocyanates described above, and has higher NCO functionality. The examples of the coating composition including a polyether modified HDI allophonate-based polyisocyanate as the second aliphatic polyisocyanate formed first protective coatings that had improved film strength and durability, but the first protective coatings exhibited less dissipation of static charge, particularly at -40 ° F (-57 ° C). For

Consequently, while these polyisocyanates can be used as the second aliphatic polyisocyanate, other polyisocyanates can provide better charge dissipation.

[Structure 5]

<img file="ES2806257T3_D0003.tif" />

Structure 6 below shows an example of an aminosulfonic acid modified DHI ionic polyisocyanate having high NCO functionality. HDI aminosulfonic acid modified ionic polyisocyanates (CAPS) are commercially available from Bayer Material Science as BAYHYDUR® XP2547, BAYhYdUR® XP2487 / 1 and BAYHYDUR® XP 2655. The examples of the coating composition including an aminosulfonic acid modified HDI ionic polyisocyanate as the second aliphatic polyisocyanate formed first protective coatings that had good chemical (e.g. solvent) resistance, but the first protective coatings exhibited minimal improvement in antistatic properties. . Accordingly, while these polyisocyanates can be used as the second aliphatic polyisocyanate, other polyisocyanates can provide better antistatic properties.

[Structure 6]

<img file="ES2806257T3_D0004.tif" />

In some embodiments, the second aliphatic polyisocyanate includes a polyether modified IPDI trimer, which includes a polyether chain linked to an isophorone diisocyanate trimer. An example of a polyether modified IPDI trimer-based polyisocyanate is shown in Structure 7 below. Examples of the coating composition including a polyether modified IPDI trimer-based polyisocyanate as the second aliphatic polyisocyanate unexpectedly formed first protective coatings having good film integrity as well as good static charge dissipation properties. A commercial example of a polyether-modified IPDI trimer-based polyisocyanate is BAYHYDUR® 401-70, which has a Tg of approximately 30 ° C, forms first protective coatings that have improved adhesion-free time (i.e., a shorter time to become adhesion free), better surface adhesiveness and improved antistatic properties. However, when excessive amounts of polyether-modified IPDI trimer-based polyisocyanate are included in the coating composition as the second aliphatic isocyanate, the first protective coating formed from the coating composition exhibits better resistance to rain erosion, higher sensitivity. to moisture and lower resistance to abrasion than Bayer. Accordingly, in some embodiments, the weight ratio of the first hydrophobic aliphatic polyisocyanate to the second aliphatic polyisocyanate is within the range of 95: 5 to 85:15, such as, for example, 95: 5, 92: 8, 90 : 10, 87:13 or 85:15.

ES 2 806 257 T3

[Structure 7]

In some embodiments, the coating composition further includes a poly (ester polyol). For example, the poly (ester polyol) can be an aliphatic compound having 2 to 4 hydroxyl groups or a mixture of aliphatic compounds averaging 2 to 4 hydroxyl groups. The poly (ester polyol) can provide cross-linking and resilience to a first protective coating formed from the coating composition. Non-limiting examples of the poly (ester polyol) include diols and poly (caprolactone polyols). For example, the poly (ester polyol) can be a poly (caprolactone polyol), poly (caprolactone diol), or a mixture thereof having a weight average molecular weight within the range of 300 to 5,000 g / mol, for example, 500 to 1,500 g / mol, and in some embodiments, about 1,000 g / mol.

Polycaprolactone polyols and diols can be prepared using ring-opening polymerization under mild conditions that results in well-controlled polymerization that results in little or no by-products (eg, water). Poly (caprolactone polyols) and diols prepared using ring-opening polymerization have low acid values, highly defined functionality, low polydispersity numbers, and can be prepared with very high reproducibility. Poly (caprolactone polyols) and diols can also be prepared with low levels of impurities, are non-toxic and biodegradable, and have high flexibility at low temperatures, good hydrolytic stability, good tear resistance, consistent reactivity, and low viscosity (in comparison with other polyols). The high flexibility and good tear resistance of poly (caprolactone polyols) and diols can impart resilience to a first protective coating formed from a coating composition that includes a poly (caprolactone polyol) and / or a poly ( caprolactone diol). Early protective coatings that have improved resilience exhibit improved Bayer abrasion test results (for example, tests in accordance with ASTM F735 for 300 cycles and 600 cycles) and erosion resistance properties (for example, improved results from rain erosion test carried out using simulated rain at various wind speeds, such as 550 mph (246 m / s)). Additionally, a low viscosity of the poly (caprolactone polyols) and diols is beneficial for coating compositions that have high solids content. In some embodiments, the poly (ester polyol) includes a poly (caprolactone polyol), a poly (caprolactone diol), or a mixture thereof.

In some embodiments, the poly (ester polyol) is a poly (caprolactone polyol) that includes four hydroxyl groups. For example, the poly (ester polyol) can be a poly (caprolactone polyol) that includes four polycaprolactone chains. In some embodiments, each of the poly (caprolactone) chains includes one of the four hydroxyl groups at a terminal end of the polycaprolactone chain. An example of the poly (ester polyol) (eg, a poly (caprolactone polyol)) is shown in Structure 8 below. In the poly (ester polyol) shown in Structure 8, n may be in the range of 1 to 6, such as in the range of 2 to 4. For example, in the poly (ester polyol) shown in Structure 8, n can have an average value of 2. When the poly (ester polyol) is a poly (caprolactone polyol) that includes four polycaprolactone chains that include a hydroxyl group at a terminal end of each polycaprolactone chain, the coating composition can form a first protective coating having density improved crosslinking, which in turn improves the resistance of the first protective coating against salt-mist and SO₂, chemicals (eg solvents) and inorganic acids (eg sulfuric acid and nitric acid). Additionally, the resulting first protective coating may have appropriate flexibility due to the presence of the caprolactone units (eg, 1 to 6 caprolactone units) in each of the four chains.

ES 2 806 257 T3

[Structure 8]

<img file="ES2806257T3_D0005.tif" />

In some embodiments, the poly (ester polyol) is a poly (ester diol). The poly (ester diol) can be a linear aliphatic diol having a first end that includes one hydroxyl group and a second end that includes another primary hydroxyl group. The primary hydroxyl groups can be connected via a polycaprolactone backbone. An example of the poly (ester polyol) (eg, a poly (caprolactone diol)) is shown in Structure 9 below. In the poly (ester diol) shown in Structure 9, n may be in the range of 1 to 8, such as in the range of 2 to 6. For example, in the poly (ester polyol) shown in Structure 9, n can have an average value of 4.

When the coating composition includes a poly (ester polyol), such as a poly (caprolactone diol), a first protective coating formed from the coating composition has improved resilience. For example, the relatively long polycaprolactone backbone between the hydroxyl groups can provide the first protective coating with improved resilience. Exemplary embodiments of the first protective coating prepared without the poly (ester diol), but including another poly (ester polyol), exhibited a Bayer abrasion resistance (described in more detail above) after 60 ° shaking of about 3 to 4%, while exemplary embodiments of the first protective coating made with the poly (ester diol) exhibited a Bayer abrasion resistance of less than 1% after 600 shakes. Including the poly (ester diol) in the coating composition in excess increases the adhesiveness of the first protective coatings formed from the coating composition and reduces the chemical (eg, solvent) resistance of the first protective coating. Accordingly, in some embodiments, the poly (ester polyol) and the poly (ester diol) are present in the coating composition in a weight ratio of 95: 5 to 50:50, for example a weight ratio of 75:25. Non-limiting commercially available examples of the poly (ester polyol) and poly (ester diol) include Capa ™ 2101, Capa ™ 3031, Capa ™ 3θ41 and Capa ™ 4101, each of which are available from Perstop Group, Perstop, Sweden.

[Structure 9]

<img file="ES2806257T3_D0006.tif" />

In some embodiments, the coating composition further includes a fluorinated alcohol. For example, fluorinated alcohol can have a reactive functional group (eg, a hydroxyl group). Presenting a reactive group, the fluorinated alcohol can be a migratory fluorinated compound capable of migrating to a surface of the coating composition during the formation (eg, reaction or curing) of the first protective coating. While the extent of migration of the first fluoro compound (e.g. migratory fluoro compound) is not fully known, based on the acid resistance of the first protective coating formed from the composition and the observed contact angle of water on the first protective coating, it is thought that at least some of the fluorinated alcohol (e.g. migratory fluorinated compound) migrates to the surface of the coating composition (e.g. the surface of a first protective coating formed from the composition of

ES 2 806 257 T3 coating).

It is believed that the migration of the fluorinated alcohol to the surface of the coating composition (or the surface of the first protective coating) improves the hydrophobic nature of the surface of the resulting first protective coating and improves the resistance of the first protective coating against moisture and acid rain. In some embodiments, the fluorinated alcohol has a relatively low molecular weight to improve migration of the fluorinated alcohol. For example, the fluorinated alcohol may have a weight average molecular weight within the range of about 300 g / mole to about 400 g / mole, such as a weight average molecular weight of about 364 g / mole. The fluorinated alcohol can include a perfluorinated carbon chain and a hydroxyl group. The fluorinated alcohol can also include a linking group between the perfluorinated carbon chain and the hydroxyl group. Non-limiting examples of the linking group include alkylene groups, such as ethylene, propylene, and vinylene groups, and sulfonamide groups.

According to embodiments of the invention, a first protective coating from the coating composition may include the fluorinated alcohol on a surface of the first protective coating. By including the fluorinated alcohol on the surface of the first protective coating, the hydrophobic nature and the acid resistance of the surface of the first protective coating are increased, thereby improving the corrosion resistance of the first protective coating. The presence of the fluorinated alcohol on the surface of the coating composition (or the first coating) also increases the corrosion resistance of the coated substrate that includes the coating composition, for example, as a first protective coating. The fluorinated alcohol can be included in the coating composition in an amount within the range of about 0.1% by weight to about 5% by weight, eg, 1% by weight, based on the total weight of the contents. solids of the coating composition.

In some embodiments, the fluorinated alcohol is a partially fluorinated compound that includes a hydroxyl group. For example, in certain parts of the compound, most or all of the hydrogen atoms may be substituted by fluorine atoms, while other parts of the compound may include carbon-bonded hydrogen. In other embodiments, the fluorinated alcohol is a perfluorinated compound that includes a carbon and perfluorinated backbone and a hydroxyl group. As will be understood by those skilled in the art, a perfluorinated compound (or chain) is a compound (or chain) in which all hydrogen atoms attached to carbon atoms are replaced by fluorine atoms. Fluorinated alcohol can have a carbon backbone having 1 to 20 carbon atoms.

Non-limiting examples of fluorinated alcohol include perfluorinated or partially fluorinated aliphatic compounds. For example, commercially available perfluorinated aliphatic compounds and / or solutions of perfluorinated aliphatic compounds such as, for example, N-ethyl-N- (2-hydroxyethyl) perfluorooctylsulfonamide can be used (for example, FLUORAD ™ FC-10; available at 3M Company, St. Paul, Minnesota); and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-1-octanol (for example CAPSTONE ™ 62-AL), and perfluoroalkyl-1-ethanol (for example , ZONYL® BA) (each available from EI du Pont de Nemours and Company, Wilmington, Delaware). ZONYL® is a registered trademark of EI du Pont de Nemours and Company. Examples of fluorinated alcohol include Structures 10 and 11 below (Structure 10] F

[Structure 11]

FF

F

In some embodiments, the coating composition further includes a fluoropolyol. The fluorinated polyol can be a compound having a carbon backbone of 1 to 20 carbon atoms, and two or more reactive groups, such as hydroxyl groups. That is, the fluoropolyol can be multifunctional. For example, the fluorinated polyol can be bifunctional, such as a compound that has two or more hydroxyl groups. As a result of having

ES 2 806 257 T3 two or more functional groups, the fluorinated polyol can react to form a three-dimensional network. Unlike fluorinated alcohol, most fluorinated polyol does not migrate to a surface of the coating composition (or a surface of a first protective coating from the composition) and is instead distributed throughout the thickness. of the coating composition or coating (for example, it is distributed throughout the material by volume of the coating composition, or the material by volume of a first protective coating formed from the coating composition). The fluoropolyol enhances the hydrophobic nature of a first protective coating formed from the coating composition, thereby improving the acid rain resistance of the first protective coating. Existing coatings (for example, protective coatings), such as FX-446 (available from PPG Industries Inc.), provide some resistance to acid rain, but first coatings in accordance with embodiments of the present invention that include the fluoropolyol (or a reacted fluoropolyol) in the volume of the first protective coating provide improved resistance to acid rain compared to coatings existing.

The inclusion of the fluoropolyol causes the coating composition to form a three-dimensional polymeric network. Specifically, the two or more reactive functional groups (eg, hydroxyl groups) of the fluorinated polyol each react with the other polymer molecules to form the three-dimensional network structure. The stiffness of the three-dimensional polymeric network formed with the fluorinated polyol affects the resilience of a first protective coating formed from the coating composition. Similarly, other components of the coating composition, such as non-fluorinated polyols (eg, poly (ester polyols)), can form part of the three-dimensional network and contribute to the resilience of a first protective coating formed from the composition. . As an example, the stiffness of the three-dimensional network of the composition is influenced, in part, by the number of reactive functional groups (eg, hydroxyl groups) present in the fluorinated polyol. Thus, the number of reactive functional groups in the fluorinated polyol affects the resilience of a protective coating formed from the coating composition. Similarly, the number of reactive functional groups (eg, hydroxyl groups) included in the non-fluorinated polyol (eg, the poly (ester polyol)) also affects the resilience of a first protective coating formed from the composition. Coating.

In general, the higher crosslinking density (which is directly related to the number of reactive functional groups (eg hydroxyl groups) included in each of the components of the composition) leads to higher stiffness, better chemical and solvent resistance , and less resistance to abrasion. The resilience of a first protective coating formed from the coating composition is also influenced by the molecular weight, size, and backbone type of the fluorinated and non-fluorinated compounds in the coating composition. When the composition includes compounds having stiffer backbone structures, the composition is also stiffer, while compounds having more flexible backbone structures produce a composition which has relatively more resilience. For a particular polyol, increasing the molecular weight of the polyol generally results in a compound that forms coatings that have higher resilience, compared to corresponding lower molecular weight polyols.

Accordingly, the desired resilience of the composition can be achieved by appropriately selecting the number of reactive functional groups (eg, hydroxyl groups) and molecular weights of the fluorinated compounds or the non-fluorinated compounds. For example, a fluoropolyol that has a fluorocarbon backbone and two reactive functional groups (for example, two hydroxyl groups) form a three-dimensional network that is more flexible than the three-dimensional web formed by a fluoropolyol that has a similar chemical composition, the same (or substantially the same) molecular weight, and a carbon and fluorinated backbone and three reactive groups (eg, three hydroxyl groups). Similarly, a fluorinated polyol that has three reactive functional groups (e.g., three hydroxyl groups) forms a three-dimensional network that is more flexible than the three-dimensional network formed by a fluorinated polyol that has the same (or substantially the same) chemical structure, the same (or substantially the same) molecular weight, one fluorinated carbon chain, but four reactive groups (eg, four hydroxyl groups). The increased flexibility of the three-dimensional network that results from the use of a fluorinated polyol having two hydroxyl groups increases the resilience of a first protective coating formed from the coating composition. Thus, in some embodiments, the coating composition (or first protective coating) includes a fluorinated polyol (for example, a compound having two hydroxyl groups), said coating compositions produce first protective coatings that have greater resilience with respect to coatings produced from coating compositions that include trifunctional or tetrafunctional fluorinated polyols (for example, compounds having three or four hydroxyl groups, respectively). The principles described above can also be applied to other components of the coating composition, such as non-fluorinated compounds. For example, the desired resilience of the first protective coating can be achieved by using an appropriate blend of non-fluorinated difunctional and tetrafunctional poly (ester polyols) in the coating composition.

Non-limiting examples of the fluorinated polyol include fluoropolymers and fluoropolymer precursors, examples of which include, but are not limited to, neat resins and / or solutions of commercially available fluoropolymers and / or fluoropolymer precursors such as LUMIFLON® LF 600X, LUMIFLON® LF 9716, LUMIFLON® LF 9721, LUMIFLON®-910LM and LUMIFLON® LF 916F (available from AGC Chemicals Inc., Exton, Pennsylvania); FLUOROLINK® D10-H, FLUOROLINK® E10-H, FLUOROLINK® D, FOMBLIN® ETX, FOMBLIN® MF-402 and FLUOROBASE Z-1030 (each available from Solvay Solexis, Inc.); and POLYFOX® PF-656 and POLYFOX® PF-7002

ES 2 806 257 T3 (available from Omnova Solutions, Fairlawn, Ohio). LUMIFLON® is a registered trademark of Asahi Glass Co., Ltd., FLUOROLINK® is a registered trademark of Solvay Solexis, Inc, FOMBLIN® is a registered trademark of Solvay Fluorati Holding SPA, Corporation and POLYFOX® is a registered trademark of Ampac Fine Chemicals LLC.

Of the fluoropolyol examples above, LUMIFLON®-910LM, which is a fluoroethylene vinyl ether, exhibited the best compatibility with other components of the coating composition. LUMIFLON®-910LM was compatible with the other components of the coating composition over a wide range of amounts. The alternating fluoroethylene and vinyl ether segments of LUMIFLON®-910LM provide the resulting first protective coating with good first and second alterability. For example, fluoroethylene segments can improve the durability and hydrophobic nature of the resulting first protective coating. Accordingly, in some embodiments, the fluorinated polyol includes a backbone that includes alternating substituted or unsubstituted fluoroethylene and substituted or unsubstituted vinyl ether segments. An example of the fluorinated polyol is shown in Structure 12 below, where FE indicates a repeating fluoroethylene unit and VE indicates a repeating vinyl ether unit. In Structure 12, Ri can provide transparency, gloss and hardness; R2 can provide flexibility; R3 can provide crosslinking ability; and R4 can provide adhesion.

[Structure 12]

<img file="ES2806257T3_D0007.tif" />

The fluorinated polyol can be included in the coating composition in an amount in the range of about 5% by weight to about 35% by weight, such as in the range of about 15% by weight to about 25% by weight. weight, based on the total weight of the solids in the resin composition. In some embodiments, the fluoropolyol is present in an amount of about 20% by weight based on the total weight of the solids in the coating composition. At 5% by weight and 10% by weight of the fluorinated polyol, there is some improvement in the acid resistance of the resulting first protective coating. At 15% by weight and 20% by weight of the fluorinated polyol, the resulting first protective coating exhibited substantially improved resistance to sulfuric acid and nitric acid (eg, a 50:50 mixture of sulfuric acid and nitric acid) in compared to existing coatings such as FX-446. The resulting first protective coating exhibited improved surface tack and resistance to vapor, moisture, and QUV, compared to existing coatings, such as FX-446. Unexpectedly, the fluoropolyol did not appreciably reduce the anti-static properties of the first protective coating. However, the fluoropolyol does not reduce the Bayer abrasion resistance of the resulting first protective coating. For example, an example of the coating composition that includes 20% by weight of the fluorinated polyol (based on the total weight of the coating composition solids) formed a first protective coating that exhibited a haze change of 3, 5-4.0% after 600 shakes from the Bayer abrasion test (described in more detail above), while an example of the coating composition that did not include the fluoropolyol exhibited a haze change of approximately 1% after 600 shakes from the Bayer abrasion test.

The coating composition described herein can be formed by mixing (or homogenizing) a mixture of Pate A (eg, a base component) with a mixture of Part B (eg, a curing component) . For example, Part A blend and Part B blend can be mixed together and cured to form a durable composition (or first protective coating) that is highly unalterable to the first and second, abrasion resistant, acid resistant and resistant to chemicals or solvents. After mixing the Part A mixture and the Part B mixture, the resulting coating composition can be air dried for a period of time within the range of 1.5 to 2 hours and subsequently cured at approximately 200 ° F ( 93 ° C) for a period of time of approximately 5 hours to form a first protective coating. For example, the coating composition (or first protective coating) can form a first protective polyurethane coating that has antistatic properties.

The Part A mixture and the Part B mixture can be mixed to achieve a ratio of reactive isocyanate groups to hydroxyl groups (e.g., a ratio of NCO to OH) within the range of 1.05 to 1, 5, such as a ratio of about 1.3. An NCO to OH ratio of approximately 1.05 resulted in a first protective coating exhibiting good abrasion resistance, but compromised QUV resistance (e.g., poor test results after exposure to UV radiation at 158 ​​° F (70 ° C) followed by exposure to condensation for 4 hours at 122 ° F (50 ° C). An NCO to OH ratio of about 1.3 resulted in a first protective coating exhibiting good

ES 2 806 257 T3 abrasion resistance, good QUV resistance, and good resistance to rain erosion. An NCO to OH ratio of about 1.4 resulted in a first protective coating exhibiting good QUV resistance, but low abrasion resistance and lower resistance to rain erosion, compared to the first protective coating formed at starting from the coating composition having an NCO to OH ratio of about 1.3. The NCO to OH ratio of about 1.5 resulted in a coating composition that had a short pot life, poor surface flow, and poor cosmetic properties.

The Part A mixture may include, for example, any or all of the poly (ester polyol) (for example, the first and / or second poly (ester polyol)), the fluorinated polyol, the hydrophilic polyol, and the fluorinated alcohol. The Part A mixture may include additives, such as, for example, a migratory ultraviolet (UV) light absorber, a reactive UV absorber that includes a hydroxyl group, a migratory UV stabilizer, a reactive UV stabilizer that includes a hydroxyl group, a antistatic agent (eg, a conductive compound), an antioxidant, a catalyst, a flow control agent, and / or a solvent. However, the Part A mixture need not contain each of these components. The Part A mix can include additional additives as well.

A migratory UV absorber and / or a reactive UV absorber can be included in the coating composition to absorb UVA and UVB radiation striking the resulting first protective coating. UV absorbers increase the resistance of the resulting first protective coating to yellowing and / or degradation, and improve the long-term outdoor durability of the first protective coating. The migratory UV absorber and the reactive UV absorber can be based on any suitable UV absorber. The migrating UV absorber does not include a reactive functional group (e.g., a hydroxyl group) and migrates to the surface of the coating composition (or first protective coating) during formation (e.g., curing) of the coating composition (or first protective coating). By including the migratory UV absorber, the first protective coating includes a higher concentration of a UV absorber on the surface of the composition than the first protective coating that does not include a migrating UV absorber. The presence of a higher concentration of UV absorber on the surface of the composition (or first protective coating) improves the useful life of the first protective coating formed from the composition. However, it is desirable to also have a UV absorber in the volume of the composition, since having UV absorbers both on the surface of the composition and in the volume of the composition extends the useful life of a first protective coating formed from of the composition compared to the coating formed by a composition that only includes a UV absorber on the surface.

Additionally, if the compounds migrate to the surface of the composition too quickly, the composition can form haze. For example, UV absorbers that do not include a hydroxyl group (eg, a reactive hydroxyl group) can migrate to the surface of the first protective coating too quickly resulting in haze. Accordingly, in some embodiments, the coating composition includes the migratory UV absorber only in small amounts (eg, within the range of about 0.5% by weight to about 0.75% by weight, based on weight total solids of the coating composition), if at all. Examples of migratory uV absorbers are shown in Structures 1317 below.

[Structure 13]

ES 2 806 257 T3

[Structure 14]

<img file="ES2806257T3_D0008.tif" />

[Structure 15]

[Structure 16]

<img file="ES2806257T3_D0009.tif" />

[Structure 17]

<img file="ES2806257T3_D0010.tif" />

A coating composition according to embodiments of the present invention may include a UV absorber as well as, or in place of, a migrating UV absorber. The reactive UV absorber can include one or more reactive functional groups such as a hydroxyl group. By including the hydroxyl groups, a majority of the reactive UV absorber cannot migrate to the surface of the coating composition or the resulting protective coating and is instead distributed throughout the thickness of the coating composition or the resulting protective coating ( that is, it is distributed throughout the mass of the coating composition or the resulting protective coating). Also, if the reactive UV absorber is multifunctional, it can contribute to the three-dimensional polymer network formed by reacting the components of the composition. A non-limiting example of the reactive UV absorber is shown in the following structure 18 and an example of a commercial mixture of a migrating UV absorber and a reactive UV absorber is shown in the following structure 19.

ES 2 806 257 T3

[Structure 18]

<img file="ES2806257T3_D0011.tif" />

[Structure 19]

<img file="ES2806257T3_D0012.tif" />

Non-limiting commercially available examples of the migratory UV absorber and reactive UV absorber include propanoic acid, ester 2- [4- [4,6-bis ([1,1'-biphenyl] -4-yl) -1,3,5 -triazin-2-yl] -3-hydroxyphenoxy] -isooctyl (e.g. TINUVIN® 479), p- [3- (2-H-benzotriazol-2-yl) -4-hydroxy-5-t-butylphenyl acid ] -propionic 3θθ ester of poly (ethylene glycol), bis {p¿3- (2-H-benzotriazol-2-yl) -4-hydroxy-5-t-butylphenyl] -propionic} -ester 300 of poly ( ethylene glycol) (for example, TINUVIN® 1130), TINUVIN® 477 and 2- [4 - [(2-hydroxy-3- (2'-ethyl) hexyl) oxy] -2-hydroxyphenyl] 4,6- bis (2,4-dimethylphenyl) 1,3,5- triazine (eg, TINUVIN® 405) (each available from BASF Resins); and p-phenylenebis (methylenemalonic acid) tetraethyl ester (for example, HOSTAVIN® B-CAP), 2-ethyl, 2'-ethoxy-oxalanilide (for example, HOSTAVIN® VSU) and propanedioic acid, 2 - [(4- methoxyphenyl) methylene] -, 1,3-dimethyl ester (eg, HoStAViN® PR25) (each available from Clariant International Ltd.). TINUVIN® is a registered trademark of Ciba Specialty Chemical Corporation. HOSTAVIN® is a registered trademark of Hoechst GMBH Corporation.

The first example protective coatings from coating compositions including the UV absorber according to Structure 18 did not exhibit any discernible signs of haze formation. It is thought that the presence of the hydroxyl group of the above UV absorbers prevented (or reduced) the migration of the UV absorbers to the surface of the first protective coating by reacting with the isocyanate functional groups to form urethane linkages and become part of the three-dimensional lattice, thereby avoiding (or reducing) haze formation. TINUVIN® 1130 includes both a reactive UV absorber and a migrating UV absorber and therefore can cause haze in the first protective coating when used in excess. The migratory UV absorber can be included in the coating composition in a small amount without causing haze in the resulting first protective coating. For example, the migratory UV absorber shown in Structure 13 can be included in the coating composition in an amount within the range of about 0.5% by weight to about 0.75% by weight, based on total weight. of the coating composition solids without causing appreciable haze in the resulting first protective coating, while also improving the QUV strength of the resulting first protective coating. The migratory UV absorber shown in Structure 13 is thought to be present at a higher concentration on the surface of the resulting first protective coating than in the bulk material of the first protective coating, thereby providing additional protection against UV light. Some UV absorbers, such as HOSTAVIN® B-CAP, exhibited poor solubility as a result of poor compatibility with the other components of the coating composition.

The migratory UV stabilizer and the reactive UV stabilizer can be based on any appropriate UV stabilizer, such as any appropriate free radical scavenger agent, that has been modified to be reactive or migratory. Migratory UV Stabilizer and Reactive UV Stabilizer reduce degradation of the first protective coating by UV light by neutralizing free radicals formed by

ES 2 806 257 T3 of dissociation of chemical bonds as a result of absorption of UV light. The migrating UV stabilizer does not include a reactive functional group (eg, a hydroxyl group) and migrates to the surface of the first protective coating during formation (eg, curing) of the first protective coating. By including the migratory UV stabilizer, the first protective coating includes a higher concentration of UV stabilizer on the surface of the first protective coating than the coating that does not include a migrating UV stabilizer. The presence of a higher concentration of UV stabilizer on the surface of the first protective coating improves the useful life of the first protective coating, and further improves the useful life of the first protective coating formed from the coating composition.

However, it is desirable to also have UV stabilizers in the volume of the first protective coating, since having UV stabilizers both on the surface of the first protective coating and in the volume of the first protective coating extends the useful life of the first protective coating, in compared to a coating that only includes UV stabilizers on the surface. Additionally, if the compounds migrate to the surface of the first protective coating too quickly, the first protective coating can develop haze. Accordingly, the composition according to embodiments of the present invention can include the reactive UV stabilizer, the migratory UV stabilizer, or both. The reactive UV stabilizer can include one or more reactive functional groups, such as hydroxyl groups. By including the reactive groups, the majority of the reactive UV stabilizer does not migrate to the surface of the first protective coating but remains inside the first protective coating (for example, in the bulk material of the first protective coating) due to the reaction of functional groups with other components of the coating composition. Additionally, if the reactive UV stabilizer is multifunctional, it can contribute to the formation of the three-dimensional network. Non-limiting commercially available examples of UV stabilizer include propanedioic acid [(4-methoxyphenyl) -methylene] -bis (1,2,2,6,6-pentamethyl-4-piperidinyl) ester (e.g. HOSTAVIN® PR31 available from Clariant International Ltd.), Sanduvor 3055 (available from Clariant International Ltd.) and commercially available sterically hindered aminoether light stabilizers such as TINUVIN® 123, TINUVIN® 292, TINUVIN® 326, TINUVIN® 328, TINUVIN® 765, TINUVIN® 900, TINUVIN® 900 and TINUVIN® 152 (each available from BASF Resins). TINUVIN® is a registered trademark of Ciba Specialty Chemical Corporation. HOSTAVIN® is a registered trademark of Hoechst GMBH Corporation. Examples of reactive UV stabilizers and migratory UV stabilizers are shown in Structures 20-29. Early example protective coatings from coating compositions including the UV stabilizer according to Structure 21 exhibited no appreciable sign of haze formation.

[Structure 20]

<img file="ES2806257T3_D0013.tif" />

ES 2 806 257 T3

[Structure 21]

<img file="ES2806257T3_D0014.tif" />

[Structure 22]

<img file="ES2806257T3_D0015.tif" />

[Structure 23]

<img file="ES2806257T3_D0016.tif" />

[Structure 24]

<img file="ES2806257T3_D0017.tif" />

ES 2 806 257 T3

[Structure 25]

<img file="ES2806257T3_D0018.tif" />

[Structure 26]

<img file="ES2806257T3_D0019.tif" />

[Structure 27]

[Structure 28]

<img file="ES2806257T3_D0020.tif" />

ES 2 806 257 T3

[Structure 29]

<img file="ES2806257T3_D0021.tif" />

The Part A mixture may include antistatic agents (for example, conductive compounds, such as conductive metal oxides, quaternary ammonium salts, inherently conductive polymers, and / or appropriate conductive agents), such as those described in U.S. Patent Application USA No. Publication 2010/0025533 and US Patent Application Publication No. 2010/0028684. Non-limiting commercially available examples of antistatic agents include Antistat SD100 (available from EI du Pont de Nemours and Company), EA Antistat (available from Wells Plastics Ltd) and MAXOMER® AS-1018 / 75DC (available from PCC Chemax, Inc. ). MAXOMER® is a registered trademark of PCC Chemax, Inc.

Antistatic agents (eg, conductive compounds) can be used to reduce the electrical resistance (eg, sheet resistance) of the resulting first protective coating to acceptable levels for P-static dissipation, which should be maintained even at low temperatures (eg, -40 ° F (-40 ° C). The hydrophilic polyisocyanates discussed above can act as a conductive compound. Alternatively or additionally, a hydrophilic polyol can be included in the coating composition.

For example, the first protective coating described herein may have a foil resistance such that electrical charge (e.g., P-static) can pass through the first protective coating to another layer (e.g., an electrically conductive cell). ), which can subsequently dissipate or drain the charge. If the resistance of the first protective coating is too high, the amount of electrical charge that can pass through the first protective coating is reduced, and the conductive layer does not provide acceptable levels of P-static dissipation. In some embodiments, the primer layer (eg, a polyacrylate primer) can be included between a first protective coating and the conductive layer (eg, electrically conductive cell). Although the primer layer can have a high sheet strength (e.g., higher than the coating), the filler can pass through the first protective coating and the primer layer to the conductive layer if the primer layer is thin enough . Thus, if a primer layer is included, it can be thin enough to allow sufficient electrical charge to pass through the first protective coating and primer layer to the conductive layer to provide P-static dissipation.

The general resistance of polyurethane protective coatings is greater than or equal to 10¹² ω / π to independently dissipate static charge. The sheet strength of the first protective coating described herein varies depending on the sheet strength of the material on which the first protective coating is formed. For example, if the first protective coating is over a layer of dielectric (e.g. polycarbonate), the sheet strength of the first protective coating can be about 10⁹ ohms per square, even if a final primer layer is included between the first protective coating and the dielectric layer. If the first protective coating is on a conductive layer (for example, titanium oxide / Au / titanium oxide stack), the sheet strength of the first protective coating can be 10⁷ ohms per square.

Hydrophilic polyisocyanates, such as those described above, improve conductivity in early protective coatings. Additionally, as described above, hydrophobic polyisocyanates provide durability to early protective coatings. Thus, as described above, through the combination of hydrophobic and hydrophilic polyisocyanates (eg hydrophobic / hydrophilic HDI and IPDI-based polyisocyanates), a first protective coating having a good balance of hardness can be obtained. , resilience, surface adhesiveness and conductivity.

According to some embodiments, the coating composition may further include a hydrophilic polyol (eg, a reactive antistatic resin), such as a hydrophilic polyol having a functionality greater than 2. The p-static properties of a first protective coating are can be significantly improved by the introduction of the hydrophilic polyol. The hydrophilic polyol can be any suitable hydrophilic polymer having salt moieties and pendent reactive hydroxyl groups. A non-limiting example of a suitable hydrophilic polyol is Superstat 463, which is commercially available from Advanced Materials &amp; Coating Specialties, Azusa, California. The hydrophilic polyol reacts with the polyisocyanates and becomes part of the three-dimensional network. Subsequently, a first transparent protective coating is formed without appreciable sign of migration of the hydrophilic polyol to the surface of the first

ES 2 806 257 T3 protective coating. Conductivity is thought to be achieved by absorbing moisture into the first protective coating, but the hydrophilic polyol appears to have some inherent conductivity.

A first protective coating is formed having an electrical resistance of 10⁵ ω / π (on polycarbonate) and good optical properties when the combined amount of the poly (ester polyol) and the hydrophilic polyol includes 50% by weight of Superstat 463. Said first protective coating has good performance in pest tests, even at -40 ° F (-57 ° C). The hydrophilic polyol (eg, Superstat 463) can be included in the coating composition in an amount within the range of about 5% by weight to about 30% by weight, based on the total weight of the solids in the composition. Coating. When the hydrophilic polyol (eg, Superstat 463) is included in the coating composition in an amount that is outside the above range (eg, it is greater than 30% by weight), the resulting coating may have high surface tack and it can be susceptible to moisture attack when exposed to it. Surface tack can be reduced by the addition of BYK 3700 (a poly (dimethylsiloxane resin) with pendant hydroxyl groups), incorporation of ethylene glycol or trimethylol propane (TMP) and / or partial substitution of N-75 by IPDI trimer. None of these improvements in surface tack resulted in a first surface coating with good weatherability, but some of the coatings exhibited good abrasion resistance.

Useful antistatic first topcoats were formulated by reducing the hydrophilic polyol content (eg, Superstat 463) to a range of 14% by weight to 26% by weight (depending on the other components of the coating composition). A typical two-part polyurethane coating has a strength of more than 10¹² ohms / square and is dielectric. By adding 24% by weight of Superstat 463, the resistance is reduced to a value in the range of 10⁸ to 10⁹ ohms / square on polycarbonate and 10⁷to 10⁸ ohms / square on a conductive layer, such as a battery including titanium oxide / Au / titanium oxide, a battery including AZO / Au / AZO, an ITO layer, an Au layer, an Al layer, and the like . It has been repeatedly demonstrated, through specification test results, that a conductive layer / primer / protective coating combination can easily dissipate p-static charge even at temperatures as low as -40 ° F (-57 ° C).

Superstat 463 can improve the conductivity of the first protective coating. Superstat 463 is compatible with all components of the coating composition and provides a first protective coating with high transparency, low haze, good surface flow, and superior cosmetic appearances. Interestingly, without the presence of Superstat 463, the coating composition may exhibit poor film-forming properties. Therefore, Superstat may be beneficial in improving the compatibility between the hydrophilic / hydrophobic components of the coating composition.

The Part A mixture may further include a catalyst, flow control agent, and solvents as is known in the art. The selection of the appropriate catalyst, flow control agent, and solvent is within common knowledge in the art and, therefore, further discussion of those components is omitted.

The Part B mixture (eg, the curing component) can include the isocyanate as previously described. The cure component may further include cure accelerators, cure retarders, plasticizers, additives, and / or fillers. However, as with the Part A mix, the Part B mix need not contain each of these components. The Part B mix can include additional additives as well. The selection of appropriate cure accelerators, cure retarders, plasticizers, additives, and fillers is within the skill of common knowledge in the art and, therefore, further discussion of those components is omitted.

In accordance with embodiments of the present invention, the coating composition includes at least one solvent. The solvent (s) can be added to the Part A mixture, the Part B mixture, or both the Part A mixture and the Part B mixture. reduce (s) the viscosity of the coating composition to render it suitable for fluid coating. The integrity and appearance of the resulting first protective coating can be affected by the nature of the solvents used, although solvents are not a permanent component of the cured first protective coating. The evaporation rate of the solvent (or solvent mixture) can be adjusted so that evaporation occurs quickly during initial drying (for example, after flow coating) to avoid excessive flow, but slow enough to provide Sufficient adhesion and leveling. The solvent (s) used can be non-reactive (s) with isocyanates and non-aggressive towards the substrate and / or the coated surfaces, so that no attack (or the attack is reduced) during flow coating and / or air drying process. The solvent (s) used also affects the rate of the isocyanate-hydroxyl reactions, for example during the air drying period, depending on the extent of hydrogen bonding and the character of the solvent's dipole moment. .

Non-limiting examples of the solvent include isobutyl acetate, 2,6-dimethyl-4-heptanol, butoxy ethyl acetate, isobutyl acetate, 2-butoxyethyl acetate, diisobutyl ketone, dipropylene glycol dimethyl ether, and propylene glycol dimethyl ether. In some embodiments, the solvent includes diacetone alcohol (DAA). DAA has a slow evaporation rate and good flow properties. DAA effectively dissolves all (or most) of the components of the coating composition to provide a clear and homogeneous solution. DAA

ES 2 806 257 T3 has a tertiary hydroxyl group, but the reactivity of the tertiary hydroxyl with isocyanate is much lower than the hydroxyls of the other components of the coating composition, and since DAA begins to evaporate during the air-drying period, the reaction of DAA with polyisocyanates is negligible.

The solvent can also be used to adjust the solids content of the coating composition. It may be beneficial to maximize the thickness of the resulting first protective coating for improved performance in the rain erosion test. At 70% solids content, the coating composition is too viscous for successful flow coating application with existing equipment. At a solids content of 65%, the coating composition forms a first protective coating that is free from cosmetic defects, has good surface quality, and provides good performance in the rain erosion test. A coating composition having a solids content of 65% applied to a production F-22 test deck by means of a two-component mixer (for example, a mixer, such as a DL 2 mixer, available from Liquid Control Ltd., Wellingborough, England) formed a coating having good surface quality. The test cover cuttings showed no apparent damage after 44 minutes of rain erosion test at 550 mph.

Figure 5 shows one embodiment of a multilayer stack 500. The multilayer stack includes a substrate 502, a drain layer 504, a dielectric layer 506, and a heating layer 508, each of which is the same or substantially the same. than the corresponding layers described above and, therefore, the detailed description thereof is omitted in this case. The multilayer stack also includes a second protective coating 509 over the heating layer. The second protective coating can be any suitable protective coating. For example, the second protective coating may include a diamond-like carbon, a polyurethane, a polyacrylate, a polysiloxane, an epoxy, a silicon oxide, a titanium oxide, an aluminum oxide, a material deposited by chemical deposition. plasma enhanced vapor (eg, a silicon oxycarbide), zirconium oxynitride, cerium oxide, or a combination thereof. The second protective coating can protect the heating layer. The materials of the second protective coating may be the same or substantially the same as those described above with respect to the first protective coating, and therefore the detailed description thereof is omitted here. In a non-limiting example, the second protective coating may include a polyacrylate coating having a thickness within the range of 1 to 10 µm applied by means of flow coating in a clean environment of controlled temperature and humidity. The wet coating can be air dried for a period of time within a range of 1 to 2 hours. Air-dried coating can be post-UV cured at 6 Joule energy using multiple passes.

Figure 6 shows another embodiment that includes a multilayer stack 600. The multilayer stack includes a first protective coating 601, a substrate 602, a base layer 603, a drainage layer 604, a dielectric layer 606, a layer of heating 608 and a second protective coating 609, each of which is the same or substantially the same as the corresponding layers described above and, therefore, the detailed description thereof is omitted in this case.

Example

A multilayer stack was prepared including a polycarbonate substrate, a heating layer including ITO prepared according to the above description, and a drainage layer including a laminated film including inkjet printed electrically conductive lines as mesh. conductive metal prepared according to the above description. The multilayer cell was subsequently tested for electrical charge induced in the heating layer, using an electrostatic diagnostic test kit available from Dayton-Granger, Fort Lauderdale, Florida. An electrostatic diagnostic test set probe was used to apply a voltage to the substrate and the induced voltage in the heating layer and in the drainage layer was measured. Table 1 shows the data collected when neither the ITO heating layer nor the drain layer (ie, the laminated film including inkjet printed electrically conductive lines) were grounded. As can be seen from Table 1, when neither the heating layer nor the drain layer was grounded, substantial stress was induced in the heating layer.

Table 1

<td>Applied Voltage (kV)</td><td>Induced Voltage (kV) in the Heating Layer</td><td>Induced Voltage (kV) in the Drainage Layer</td>

<td> 0</td><td> 0</td><td> 0</td>

<td> 10</td><td> 0,88</td><td> 1</td>

<td> 20</td><td> 7,49</td><td> 8,30</td>

Table 1 shows the data collected when neither the ITO heating layer nor the drain layer (ie, the laminated film including inkjet printed electrically conductive lines) were grounded. As can be seen from Table 1, when neither the heating layer nor the drain layer was grounded, substantial stress was induced in the heating layer.

ES 2 806 257 T3

Table 2

<td>Applied Voltage (kV)</td><td>Induced Voltage (kV) in the Heating Layer</td><td>Induced Voltage (kV) in the Drainage Layer</td>

<td> 0</td><td> 0</td><td> 0</td>

<td> 10</td><td> 0</td><td> 0</td>

<td> 20</td><td> 0</td><td> 0</td>

Table 2 shows the data collected when the ITO heating layer, but not the drain layer (ie, the laminated film that includes inkjet printed electrically conductive lines), was grounded. As can be seen from Table 2, when the heating layer is grounded, there is no stress induction in the heating layer or drainage layer. However, the heating layer is inappropriate for substantially heating the substrate in the present configuration.

Table 3

<td>Applied Voltage (kV)</td><td>Induced Voltage (kV) in the Heating Layer</td><td>Induced Voltage (kV) in the Drainage Layer</td>

<td> 0</td><td> 0</td><td> 0</td>

<td> 10</td><td> 0</td><td> 0</td>

<td> 20</td><td> 0</td><td> 0</td>

Table 3 shows the data collected when the drain layer (ie laminated film including inkjet printed electrically conductive lines) is grounded, but not the ITO heating layer. As can be seen from Table 3, when the drain layer is grounded, there is no stress induction in the heating layer or drain layer.

Although the present invention has been described in relation to certain exemplary embodiments, it should be understood that the invention is not limited to the disclosed embodiments, but is instead intended to encompass equivalent modifications and configurations included within the scope of the appended claims, and equivalents thereof.