Multi-layer dry-wet hard coat for flexible cover lens

Abstract

To provide a flexible cover lens having high hardness, light permeability, elasticity, and abrasion resistance.SOLUTION: A flexible cover lens film 200 includes improved strength, elasticity, light permeability, and abrasion resistance, and contains a multi-layer hard coat 212 deposited on a substrate layer 202. The substrate layer 202 has a thickness of 2 μm to 100 μm, and the multi-layer hard coat 212 has a thickness of 1 μm to 30 μm. The multi-layer hard coat 212 contains a first layer 204 deposited using a wet deposition process, a second layer 208 deposited using a dry deposition process, and one or more adhesion promotion layers 206. For optical characteristics, the multi-layer hard coat 212 has total transmittance greater than 88%, a haze of about 1% or less, and a yellowness index of b*<1. By combining the wet and dry deposition processes to form the multi-layer hard coat 212, the cover lens film 200 is both flexible and strong with a hardness between 4H and 9H.SELECTED DRAWING: Figure 2A

Description

[Technical field]

[0001] TECHNICAL FIELD Implementations described herein relate generally to flexible displays, and more particularly to flexible cover lenses. [Background technology]

[0002] Electronic devices often have displays, such as liquid crystal displays and organic light-emitting diode displays. Such displays can be fragile and sensitive to moisture, pressure, or particle contamination. Typically, display devices use several layers of optical devices to color, polarize, and shutter light from an illumination source. To prevent damage to the underlying films, a rigid display cover lens layer is attached over the other layers to prevent damage to the underlying layers. The inclusion of a rigid display cover lens may add undesirable weight to the electronic device. The device can be made smaller and lighter by omitting the cover lens, but omitting the cover lens may make the display more susceptible to scratches.

[0003] Currently, as the demand for new product functionality increases and new and wider applications are developed, there is a demand for thinner and lighter lens substrates with new properties such as flexibility. Broadly speaking, three main properties are desired for cover lenses for these new flexible or foldable displays: 1) optical performance, 2) high hardness, and 3) flexibility. A cover lens with high optical performance ensures high light transmission with very little haze. High hardness relates to scratch and abrasion resistance. The flexibility of the cover lens means that it has a critical strain high enough to avoid breakage by cracks or delamination when repeatedly bent or folded.

[0004] Traditionally, cover lenses made of glass are excellent in meeting the first two properties (i.e., optical performance and hardness), but are poor in the third property, i.e., flexibility, due to the brittleness of glass. To improve this, the prior art has made great efforts in increasing the critical strain at glass breakage, mainly by reducing the thickness of the glass or by chemical modification of the material. Nevertheless, glass as a material for cover lenses has been found to be insufficient to meet the flexibility of the required radius of curvature. Other materials, such as various metals, exist with high hardness and flexibility, but lack the required optical performance in terms of passing light. Alternatively, there are materials such as polymer-based films that have high transparency, optical properties, and flexibility, but poor abrasion or scratch resistance.

[0005] Therefore, there is a demand for a flexible cover lens that has high hardness, optical transparency, elasticity, and abrasion resistance. Summary of the Invention

[0006] The implementations described herein relate generally to flexible displays, and specifically to flexible cover lens films. The flexible cover lens films have improved strength, elasticity, light transmission, and abrasion resistance. The flexible cover lens films include a multi-layer hard coat disposed on a substrate layer. The substrate layer has a thickness between 2 μm and 100 μm, and the multi-layer hard coat has a thickness between 1 μm and 10 μm. The multi-layer hard coat includes a first layer deposited using a wet deposition process, a second layer deposited using a dry deposition process, and one or more adhesion-promoting layers. In terms of optical properties, the multi-layer hard coat has a total transmittance of more than 88%, a haze of about 1% or less, and a yellowness index of b*<1. By combining wet and dry deposition processes to form the multi-layer hard coat, the cover lens film has both flexibility and strength with a hardness between 4H and 9H.

[0007] In one implementation, the cover lens film includes a substrate layer having a thickness between 2 μm and 100 μm and a multi-layer hard-coat disposed on the substrate layer. The multi-layer hard-coat includes a first layer deposited using a wet deposition process, a second layer deposited using a dry deposition process, and an adhesion-promoting layer. The multi-layer hard-coat has a thickness between 1 μm and 30 μm. The multi-layer hard-coat has a total transmittance of more than 88%, a haze of about 1% or less, and a yellowness index of b*<1.

[0008] In another implementation, the cover lens film includes a substrate layer having a thickness between 2 μm and 100 μm and a multi-layer hard-coat disposed on the substrate layer. The multi-layer hard-coat includes a first layer deposited using a wet deposition process, a second layer deposited using a dry deposition process, a first adhesion-promoting layer, and a second adhesion-promoting layer. The multi-layer hard-coat has a thickness between 1 μm and 30 μm. The multi-layer hard-coat has a total transmittance of greater than 88%, a haze of about 1% or less, and a yellowness index of b*<1.

[0009] In another implementation, a method of forming a cover lens film includes depositing a multi-layer hard-coat on a substrate layer, the multi-layer hard-coat including a first layer deposited using a wet deposition process, a second layer deposited using a dry deposition process, and one or more adhesion-promoting layers.

[0010] So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description of the present disclosure briefly summarized above can be had by reference to implementations, some of which are illustrated in the accompanying drawings. It should be noted, however, that since the present disclosure may admit of other equally effective implementations, the accompanying drawings merely illustrate typical implementations of the present disclosure and therefore should not be considered as limiting the scope of the present disclosure. [Brief description of the drawings]

[0011] [Figure 1] 1A-B show schematic cross-sectional views of a display device according to various embodiments described herein. [Diagram 2] AE shows schematic cross-sectional views of cover lens films according to various embodiments described herein. [Diagram 3] 1 shows an exemplary embodiment of a flexible cover lens film including a dual laminate multilayer hard coat according to embodiments disclosed herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] For ease of understanding, wherever possible, the same reference numbers have been used to designate identical elements that are common to multiple figures. It is contemplated that elements and features of one implementation may be beneficially incorporated in other implementations without further recitation.

[0013] The implementations described herein relate generally to flexible displays, and specifically to flexible cover lens films. The flexible cover lens films have improved strength, elasticity, light transmission, and abrasion resistance. The flexible cover lens films include a multi-layer hard coat disposed on a substrate layer. The substrate layer has a thickness between 2 μm and 100 μm, and the multi-layer hard coat has a thickness between 1 μm and 30 μm. The multi-layer hard coat includes a first layer deposited using a wet deposition process, a second layer deposited using a dry deposition process, and one or more adhesion-promoting layers. In terms of optical properties, the multi-layer hard coat has a total transmittance of more than 88%, a haze of about 1% or less, and a yellowness index of *<1. By combining wet and dry deposition processes to form the multi-layer hard coat, the cover lens film has both flexibility and strength with a hardness between 4H and 9H.

[0014] FIG. 1A shows a schematic cross-sectional view of a display device 100 according to one implementation described herein. FIG. 1B shows a schematic cross-sectional view of a display device 150 according to another implementation described herein. The display device 100 of FIG. 1A and the display device 150 of FIG. 1B include the same layers, but the layers of each display device 100, 150 are in a different order. The display devices 100, 150 can be fabricated using plasma enhanced chemical vapor deposition, chemical vapor deposition, physical vapor deposition, atomic layer deposition, photolithography, etching, or other such suitable fabrication processes. Suitable fabrication equipment can be purchased from Applied Materials, Inc. of Santa Clara, California.

[0015] The display devices 100, 150 each include a cover lens film 102, a film layer 104, a touch panel 106, a display structure 108, a substrate 110, and a shielding layer 112. The cover lens film 102 can be bonded to a foldable glass substrate (e.g., ultra-thin glass). In the implementation of FIG. 1A, the film layer 104 is between the cover lens film 102 and the touch panel 106. In one implementation, the film layer 104 is a multi-functional film layer including a polarizer film. The film layer 104, such as a polarizer film, is used to reduce undesirable reflections caused by reflective metals that make up the electrode lines or metal structures inside the display device 100. The film layer 104 can include a quarter-wave retarder or linear polarizer formed from a flexible lens film having a thickness of less than 0.2 mm. The cover lens film 102 can be bonded to the film layer 104 and the touch panel 106 with an optically clear adhesive (OCA). In one implementation, the OCA is a liquid-based adhesive utilized to bond the cover lens film 102 to the touch panel 106. In another implementation, the OCA is an optically clear adhesive tape for bonding the cover lens film 102 to the touch panel 106. The touch panel 106 includes a touch sensor IC board 114 and a touch sensor 116. In one implementation, the touch sensor IC board 114 is a flexible, metal-based printed circuit board.

[0016] 1A , the display structure 108 is disposed between the touch panel 106 and the substrate 110. In one implementation, the display structure 108 is an organic light emitting diode display. However, other suitable display devices, such as light emitting diode displays or liquid crystal displays utilizing a cover lens film, are contemplated herein. The display structure 108 can include a thin film encapsulation, an organic light emitting layer, a driver IC board, and a thin film transistor.

[0017] 1B, the film layer 104 and touch panel 106 can be laminated on top of the display structure 108 such that the film layer 104 and touch panel 106 are disposed between the display structure 108 and the cover lens film 102. In such an embodiment, the cover lens film 102 provides abrasion resistance and impact protection.

[0018] In one implementation, the substrate 110 is made of a polyimide material. However, any flexible plastic substrate can be used. For example, the substrate is a polyetheretherketone layer, a transparent conductive polyester layer, polycarbonate, or any other polymer from the polyaryletherketone family. In the implementation of FIG. 1, the substrate 110 is adjacent to a shielding layer 112. In one implementation, the substrate 110 is polyester terephthalate. In one embodiment, the shielding layer 112 is a copper foil. Additional layers, such as an adhesion promoting layer, can be deposited adjacent to the substrate 110 before any additional layers, such as the shielding layer 112.

[0019] 2A-2E show schematic cross-sectional views of flexible cover lens films 200, 220, 230, 240, 250, respectively, according to various embodiments. Each of the flexible cover lens films 200, 220, 230, 240, 250 may be the cover lens film 102 of FIG. 1. The flexible cover lens films 200, 220, 230, 240, 250 may be utilized in a display device, such as the display device 100 of FIG. 1A and / or the display device 150 of FIG. 1B. Each of the flexible cover lens films 200, 220, 230, 240, 250 includes a substrate layer 202, one or more adhesion promoting layers 206, a first layer 204 deposited using a wet deposition process, and a second layer 208 deposited using a dry deposition process. The wet deposition process can include a solution containing the hard coat chemicals and solvents that is deposited using a slot-die coating head, a gravure coating head, or a bar coating head in a roll-to-roll solution processing system. The deposited solution is then cured using ultraviolet radiation and / or thermal methods.

[0020] Dry deposition processes may include chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), physical vapor deposition (PVD), thermal evaporation, e-beam evaporation, and the like. Dry deposition processes may be optionally plasma enhanced and processed in sheet-to-sheet or roll-to-roll equipment. Dry deposition processes may be carried out in a fully equipped sheet processing equipment, in some implementations, where a carrier glass sheet is loaded with a substrate layer 202 including a first layer 204. For implementations, the substrate layer 202 may be loaded directly onto a carrier glass sheet or bonded to a slimmed or ultra-thin glass substrate, which may then be loaded onto a carrier for dry deposition processing.

[0021] In the embodiment of FIG. 2A, the flexible cover lens film 200 includes a first layer 204, deposited using a wet deposition process, deposited on a substrate layer 202. An adhesion promoting layer 206 is deposited on the first layer 204. A second layer 208, deposited using a dry deposition process, is deposited on the adhesion promoting layer 206. The first layer 204, the adhesion promoting layer 206, and the second layer 208 form a multi-layer hard coat 212. An anti-smudge layer 210 is deposited on the second layer 208. The anti-smudge layer 210 may be an anti-fingerprint layer. The anti-smudge layer 210 may be deposited using a dry deposition process or a wet deposition process.

[0022] In the embodiment of FIG. 2B, the flexible cover lens film 220 includes an adhesion promoting layer 206 deposited on the substrate layer 202. The adhesion promoting layer 206 can be deposited using a dry vacuum deposition process such as CVD, PECVD, ALD, PVD, thermal evaporation, e-beam evaporation, or using a wet vapor deposition process. A second layer 208, deposited using a dry deposition process, is deposited on the adhesion promoting layer 206. A first layer 204, deposited using a wet deposition process, is deposited on the second layer 208. In one embodiment, the first layer 204 includes an anti-smudge or anti-fingerprint additive. In another embodiment, an anti-smudge layer (not shown) is deposited on the first layer 204, and the anti-smudge layer 210 can be deposited using a dry deposition process or a wet deposition process. The first layer 204, the adhesion promoting layer 206, and the second layer 208 form a multi-layer hard coat 212.

[0023] In the embodiment of Figure 2C, the flexible cover lens film 230 includes an adhesion promoting layer 206 deposited on a substrate layer 202. A first layer 204, deposited using a wet deposition process, is deposited on the adhesion promoting layer 206. A second layer 208, deposited using a dry deposition process, is deposited on the first layer 204. The first layer 204, the adhesion promoting layer 206, and the second layer 208 form a multi-layer hard coat 212. A soiling prevention layer 210 is deposited on the second layer 208. The soiling prevention layer 210 can be deposited using a dry deposition process or a wet deposition process.

[0024] In the embodiment of FIG. 2D, the flexible cover lens film 240 includes a first adhesion promoting layer 206a deposited on the substrate layer 202. A first layer 204, deposited using a wet deposition process, is deposited on the first adhesion promoting layer 206a. A second adhesion promoting layer 206b is deposited on the first layer 204. A second layer 208, deposited using a dry deposition process, is deposited on the second adhesion promoting layer 206b. The first adhesion promoting layer 206a, the first layer 204, the second adhesion promoting layer 206b, and the second layer 208 form a multi-layer hard coat 212. A dirt prevention layer 210 is deposited on the second layer 208. The dirt prevention layer 210 can be deposited using a dry deposition process or a wet deposition process.

[0025] In the embodiment of FIG. 2E, the flexible cover lens film 250 includes a first adhesion promoting layer 206a deposited on the substrate layer 202. A second layer 208, deposited using a dry deposition process, is deposited on the first adhesion promoting layer 206a. A second adhesion promoting layer 206b is deposited on the second layer 208. A first layer 204, deposited using a wet deposition process, is deposited on the second adhesion promoting layer 206b. In one embodiment, the first layer 204 includes an anti-smudge additive. In another embodiment, an anti-smudge layer (not shown) is deposited on the first layer 204, and the anti-smudge layer 210 can be deposited using a dry deposition process or a wet deposition process. The first adhesion promoting layer 206a, the second layer 208, the second adhesion promoting layer 206b, and the first layer 204 form a multi-layer hard coat 212.

[0026] The flexible cover lens film 200, 220, 230, 240, 250 of Figures 2A-2E has a pencil hardness between 4H and 9H, a total transmittance greater than 88%, a haze of about 1% or less, and a yellowness index of b*<1. In one embodiment, the flexible cover lens film 200, 220, 230, 240, 250 has a pencil hardness of 9H, a total transmittance greater than 92%, and a haze of 0.5%. The flexible cover lens film 200, 220, 230, 240, 250 has the flexibility to bend up to an inner radius of curvature of 1 mm or an outer radius of curvature of 2 mm over repeated cycles. The flexible cover lens film 200, 220, 230, 240, 250 has a scratch resistance measured by a standard steel wool test, capable of withstanding a load of up to 1 kg and numerous cycles, for example 2000 cycles. The haze change of the flexible cover lens films 200, 220, 230, 240, 250 after the steel wool abrasion test is less than 1%, demonstrating that the flexible cover lens films 200, 220, 230, 240, 250 have high abrasion resistance, respectively. The flexible cover lens films 200, 220, 230, 240, 250 have abrasion resistance that can withstand multiple cycles, such as 100 cycles, loaded up to 1 kg as measured by the Taber abrasion test. The haze change of the flexible cover lens films 200, 220, 230, 240, 250 after the Taber abrasion test is less than 2%.

[0027] 2A-2E, the first layer 204 may be deposited using a roll-to-roll solution processing method. The second layer 208 may be deposited using CVD, PVD, PECVD, or ALD. In one embodiment, the second layer 208 may be deposited using CVD. The multi-layer hard-coat 212 may have a thickness between 1 μm and 30 μm. In one embodiment, the multi-layer hard-coat 212 has a thickness between 5 μm and 10 μm.

[0028] In Figures 2A-2E, the first layer 204 can include one or more materials selected from the group consisting of urethane acrylate chemistry, sol-gel-siloxane hybrids with or without silica nanoparticles, or combinations thereof. Hybrid siloxanes can include organic and inorganic elements including metal alkoxides. The first layer 204 deposited using a wet deposition process can further include one or more materials selected from radiation curable acrylates, aliphatic urethane acrylates, copolymers thereof, elastomers thereof, and combinations thereof. The first layer 204 can have a thickness between about 0.5 μm and about 40 μm. The first layer 204 can have a refractive index of about 1.430 to about 1.150, an optical transmittance of about 85% to about 98%, and a pencil hardness of about 2H to about 9H. The first layer 204 may have a nanoindentation hardness of about 0.5 GPa to about 1.5 GPa, or an elastic modulus ranging from about 5 GPa to about 13 GPa as measured by nanoindentation.

[0029] The wet deposition process for depositing the first layer 204 may include applying a chemical solution using various Mayer rods, heating in a non-reactive convection oven at between 75° C. and 85° C. for between 100 and 140 seconds, and irradiating with a UV lamp at between 300 mJ / cm2 and 500 mJ / cm2 for between 100 and 140 seconds. The wet deposition process solution can be processed in an ion atmosphere by bar, slot die coating, gravure coating, or casting. In one embodiment, the deposition solution of the wet deposition process is cured using ultraviolet light. In another embodiment, the deposition solution of the wet deposition process is cured using electron beam processing.

[0030] The second layer 208 may include one or more materials selected from the group consisting of silicon oxide, silicon nitride, silicon oxycarbide (SiCxOy), silicon oxynitride, and silicon carbide (SiC). The second layer 208 may have a thickness between about 0.05 μm and about 30 μm. Precursors used in the dry deposition process may include carbon-bearing organic polymer precursors (liquid or gaseous), such as one or more of hexamethyldisiloxane (HMDSO), plasma-polymerized HMDSO (ppHMDSO), tetramethylcyclotetrasiloxane (TOMCAT), hexamethyldisilazane (HMDSN), or tetraethyl orthosilicate (TEOS). Precursors used in the dry deposition process may further include sputtering various silica or quartz to deposit various carbon-mixed silicon oxides or nitrides, or carbon-free precursors (e.g., silane (SiH4)).

[0031] The second layer 208 can have a refractive index of about 1.450 to about 1.150, an optical transmittance of about 85% to about 98%, and a pencil hardness of about 2H to about 9H. The second layer 208 can have a nanoindentation hardness of about 1 GPa to about 8 GPa or a modulus of elasticity lasing of about 5 GPa to about 70 GPa as measured by nanoindentation. The second layer 208 can have a high hardness controlled by the ratio of oxidizer or initiator to precursor, such as oxygen (O2), nitrous oxide (N2O), tert-butyl peroxide (TBPO), or a crosslinker such as acrylate monomers, particularly ethyl-hexyl acrylate, and / or butanediol-diacrylate (BDDA), to minimize carbon present in the second layer 208.

[0032] The substrate layer 202 of Figures 2A-2E has a thickness between 2 μm and 100 μm. The substrate layer 202 includes a material selected from the group consisting of polyethylene terephthalate, triacetyl cellulose, polycarbonate, polyamide, polymethacrylic acid methyl ester, cycloolefin polymer, polyethylene naphthalene (PEN), and colorless polyimide (CPI). In one embodiment, the substrate layer 202 has a thickness of about 25 μm to 50 μm and is a CPI layer. The anti-smudge layer 210 is an oleophobic film. The anti-smudge layer 210 may be perfluoropolymer (PFPE)-based silane polymer molecules (e.g., various chlorosilanes, oxysilanes, fluoroethylenes, etc.) covalently bonded to the surface of the following layers. The anti-smudge layer may be wet or vacuum dry coated. The anti-smudge layer 210 may have a thickness between 3 nm and 50 nm.

[0033] The one or more adhesion promoting layers 206 may have a thickness between 50 nm and 1500 nm. The one or more adhesion promoting layers 206 may be deposited using a dry deposition process and may include silicon oxide, silicon nitride, silicon oxycarbide, or silicon oxynitride. Precursors used in the dry deposition process may include carbon-containing organic polymer precursors (liquid or gaseous), such as one or more of HMDSO, ppHMDSO, TOMCAT, HMDSN, or TEOS. Precursors used in the dry deposition process may further include sputtering various silicas or quartz to deposit various carbon-mixed silicon oxides or silicon nitrides.

[0034] The adhesion promoting layer(s) 206 may also be deposited by a wet deposition process and may include one or more polymeric or oligomeric materials, such as acrylates, silicones, or optically clear adhesives (OCAs). In one or more embodiments, the adhesion promoting layer(s) 206 deposited using a wet deposition process may be dispensed by a variety of methods (e.g., Mayer rod, slot die, gravure head, bar coater, etc.) and cured by UV exposure, or may be formed from a liquid optically clear adhesive (LOCA) that is heat, moisture, and / or pressure sensitive and can be cured by adjusting or controlling the same.

[0035] Each of the one or more adhesion promoting layers 206 may have a refractive index of about 1.430 to about 1.150 and an optical transmittance of about 85% to about 98%. Each of the one or more adhesion promoting layers 206 may have a nanoindentation hardness of about 0.4 GPa to about 5 GPa or an elastic modulus lasing of about 2.5 GPa to about 70 GPa as measured by nanoindentation. Each of the one or more adhesion promoting layers 206 may have a high hardness controlled by the ratio of oxidizer or initiator to precursor, such as O2, N2O, TBPO, or acrylate monomers, particularly ethyl-hexyl acrylate, and / or crosslinkers such as BDDA to precisely control the carbon present.

[0036] One or more of the flexible cover lens films 200, 220, 230, 240, 250 can be stacked on top of each other. For example, the flexible cover lens film 200 can be stacked on top of the flexible cover lens film 220, or the flexible cover lens film 200 can be doubled so that there are two flexible cover lens films 200. In addition, the multi-layer hard coat 212 can be laminated one or more times onto the substrate layer 202. The one or more flexible cover lens films 200, 220, 230, 240, 250 or the laminated multi-layer hard coat 212 can be independently adhered, bonded, or otherwise held together by one or more adhesives, such as one or more OCAs. The one or more flexible cover lens films 200, 220, 230, 240, 250 or the laminated multi-layer hard coat 212 can be independently adhered, bonded, or otherwise held together without the use of adhesives.

[0037] FIG. 3 illustrates an exemplary embodiment of a flexible cover lens film 300 including a bi-laminate multi-layer hard coat of the flexible cover lens film 200. In the flexible cover lens film 300, a first multi-layer hard coat 212a is disposed on a substrate layer 202, and a second multi-layer hard coat 212b is disposed on the first multi-layer hard coat 212a. One or more adhesive layers 306 are disposed between the first multi-layer hard coat 212a and the second multi-layer hard coat 212b. The one or more adhesive layers 306 may be sacrificial adhesive layers. The one or more adhesive layers 306 may be one or more adhesion promoting layers 206 of FIGS. 2A-2E. Both the first and second multi-layer hard coats 212a, 212b include a first layer 204, an adhesion promoting layer 206 disposed on the first layer 204, and a second layer 208 disposed on the adhesion promoting layer 206. A stain resistant layer 210 may be deposited over the second multi-layer hardcoat 212b.

[0038] If it is desirable to remove and replace a top flexible cover lens film, such as the second multi-layer hard-coat 212b of FIG. 3 (e.g., due to being scratched or otherwise damaged), one or more adhesive layers, such as adhesive layer 306, can be selectively degraded, destroyed, or otherwise removed to separate the top cover lens (e.g., the second multi-layer hard-coat 212b of FIG. 3) from the bottom cover lens film (e.g., the first multi-layer hard-coat 212a of FIG. 3). The adhesive bonding the two stacks of cover films (e.g., adhesive layer 306 of FIG. 3) can be degraded at a predetermined temperature, a predetermined wavelength, and / or dose of ultraviolet (UV) light, and / or a predetermined mechanical removal mechanism.

[0039] In some examples, the sacrificial adhesive (e.g., adhesive layer 306 in FIG. 3) bonding two laminated flexible cover lens films (e.g., first and second multilayer hardcoats 212a, 212b in FIG. 3) can be decomposable at a predetermined temperature. For example, the adhesive can be decomposable at a temperature of about 80° C., about 90° C., or about 100° C. to about 120° C. In other examples, the sacrificial adhesive can be decomposable when exposed to a predetermined wavelength and / or a predetermined dose of UV light. For example, the adhesive can be decomposable when exposed to UV light having a wavelength of about 350 nm to about 375 nm, e.g., about 365 nm. The adhesive can be degraded by exposing the adhesive to UV light for about 0.5 seconds, about 1 second, or about 5 seconds to about 30 seconds, about 60 seconds, or about 90 seconds.

[0040] A method of forming the flexible cover lens film 200, 220, 230, 240, 250 can include positioning a substrate layer 202 and depositing a multi-layer hard-coat 212 on the substrate layer 202. The layers 204-208 of the multi-layer hard-coat 212 can be deposited using both wet and dry deposition processes, such as CVD, PVD, atmospheric solution processing methods in sheet-to-sheet processing equipment, and / or roll-to-roll equipment. It is further contemplated that there can be additional layers in the flexible cover lens film 200, 220, 230, 240, 250, such as additional adhesion-promoting or impact-resistant layers. The cover lens films described herein can be used in any display device.

[0041] By combining wet and dry deposition processes to form a multi-layer hard coat, an optically transparent, high-hardness and bendable cover lens film is obtained. The combination of dry film and wet film improves the abrasion resistance and elasticity of the cover lens film, while allowing an anti-fouling layer to be deposited on the multi-layer hard coat. By combining wet and dry deposition processes to form a multi-layer hard coat, the cover lens film has improved elasticity, strength, light transmittance, abrasion resistance, wear resistance and thermal stability.

[0042] While the above is directed to implementations of the present disclosure, other and further implementations may be devised without departing from the basic scope of the application, the scope of which is determined by the claims that follow.

Claims

1. a substrate layer having a thickness between 2 μm and 100 μm; A multi-layer hard coat disposed on a substrate layer; A cover lens film comprising: The multi-layer hard coat includes a first layer deposited using a wet deposition process, a second layer deposited using a dry deposition process, and an adhesion-promoting layer; the multi-layer hard coat has a thickness between 1 μm and 30 μm; The multi-layer hard coat has a total transmittance of greater than 88% and a haze of about 1% or less; ＊ and a yellowness index of <1; Cover lens film.

2. 10. The cover lens film of claim 1, wherein a first layer is disposed on a substrate layer, an adhesion promoting layer is deposited on the first layer, a second layer is deposited on the adhesion promoting layer, and a dirt preventing layer is deposited on the second layer.

3. 10. The cover lens film of claim 1, wherein the adhesion promoting layer is disposed on the substrate layer, the first layer is disposed on the adhesion promoting layer, and the second layer is disposed on the first layer.

4. 10. The cover lens film of claim 1, wherein the adhesion promoting layer is disposed on the substrate layer, the second layer is disposed on the adhesion promoting layer, and the first layer is disposed on the second layer.

5. 10. The cover lens film of claim 1, wherein the multi-layer hard coat has high abrasion resistance, a haze change of less than 1 after a steel wool abrasion test, and a pencil hardness of about 4H to about 9H.

6. 10. The cover lens film of claim 1, wherein the first layer comprises a material selected from the group consisting of urethane acrylate chemistry, sol-gel-siloxane hybrids with or without silica nanoparticles, or combinations thereof.

7. 10. The cover lens film of claim 1, wherein the second layer comprises a material selected from the group consisting of silicon oxide, silicon nitride, silicon oxycarbide, silicon oxynitride, and silicon carbide.

8. 10. The cover lens film of claim 1, wherein the multi-layer hardcoat further comprises a second adhesion promoting layer.

9. an adhesion promoting layer is deposited on the substrate layer, a second layer is deposited on the adhesion promoting layer, a second adhesion promoting layer is deposited on the second layer, and the first layer is deposited on the second adhesion layer; or a first adhesion promoting layer is deposited on the substrate layer, a first layer is deposited on the first adhesion promoting layer, a second adhesion promoting layer is deposited on the first layer, and a second layer is deposited on the second adhesion layer; The cover lens film of claim 8 .

10. 1. A method of forming a cover lens film comprising depositing a multi-layer hard coat on a substrate layer, the multi-layer hard coat comprising: a first layer deposited using a wet deposition process; a second layer deposited using a dry deposition process; and one or more adhesion promoting layers; The method includes:

11. 11. The method of claim 10, wherein the first layer is deposited using roll-to-roll solution processing and the second layer is deposited using a process selected from the group consisting of physical vapor deposition, chemical vapor deposition, plasma enhanced chemical vapor deposition, and atomic layer deposition, and the second layer is processed in a sheet-to-sheet or roll-to-roll apparatus.

12. the substrate layer has a thickness between 2 μm and 100 μm, the multilayer hardcoat has a thickness between 1 μm and 30 μm, and the multilayer hardcoat has a total transmittance of greater than 88% and a haze of about 1% or less; ＊ The method of claim 10 having a Yellowness Index of <1.

13. 11. The method of claim 10, wherein the first layer comprises a material selected from the group consisting of urethane acrylate chemistry, sol-gel-siloxane hybrid with or without silica nanoparticles, or a combination thereof, and the second layer comprises a material selected from the group consisting of silicon oxide, silicon nitride, silicon oxycarbide, silicon oxynitride, and silicon carbide.

14. 11. The method of claim 10, wherein the one or more adhesion promoting layers are deposited using a dry deposition process, and the one or more adhesion promoting layers comprise one or more materials selected from the group consisting of silicon oxide, silicon nitride, silicon oxycarbide, and silicon oxynitride.

15. 11. The method of claim 10, wherein the one or more adhesion promoting layers are deposited using a wet deposition process, the one or more adhesion promoting layers comprising one or more of a polymeric material, an oligomeric material, and an optically clear adhesive.

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