Multi-layer wet-dry hardcoats, including double-sided wet hardcoats, for flexible cover lens structures, and related methods and coating systems - Patents.com

Abstract

The embodiments of the present disclosure relate to a flexible display device including a double-sided wet hard-coat for a flexible cover lens structure, as well as related methods and coating systems. The flexible cover lens film has beneficial strength, elasticity, light transmission and abrasion resistance properties. In one or more embodiments, a cover lens structure for a display device includes a substrate layer including a first surface and a second surface. The cover lens structure includes a first wet hard-coat layer deposited on the first surface of the substrate layer and a second wet hard-coat layer deposited on the second surface of the substrate layer. The cover lens structure includes one or more adhesion-promoting layers formed above the second surface and a dry hard-coat layer formed above the second surface.

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Embodiments of the present disclosure relate to flexible display devices that include a double-sided moisturizable hard coat for a flexible cover lens structure, and related methods and coating systems. [Background technology]

[0002] Electronic devices often have displays, such as liquid crystal displays (LCDs), organic light-emitting diode (OLED) displays, and quantum dot (QD) displays. Such displays can be fragile and sensitive to moisture, pressure, and / or particle contamination. Typically, display devices use several layers of optical devices to color, polarize, and block light from an illumination source. To prevent damage to the film underneath, a rigid display cover lens layer is applied over the remaining layers to prevent damage to the underlying layers. The inclusion of a rigid display cover lens can add undesirable weight to the electronic device.

[0003] Furthermore, the cover lens may be hindered in terms of optical device performance (e.g., the cover lens may have limited light transmission and haze), flexibility (e.g., crack or plastically deform at a critical strain), and / or mechanical properties (e.g., hardness and impact resistance). For example, the cover lens may be sensitive to temperature and may exhibit increased particle migration and / or increased haze. As an example, the cover lens may have oligomer migration. Replacement of the cover lens may involve expertise, time and significant expense.

[0004] Thus, there is a need for flexible cover lenses that have reduced haze, mitigated oligomer migration, high hardness, high light transmission, high elasticity, beneficial mechanical properties, and anti-abrasion properties. Summary of the Invention

[0005] Embodiments of the present disclosure relate to flexible display devices, and related methods and coating systems, that include a double-sided moisturizable hard coat for a flexible cover-lens structure, which has beneficial strength, elasticity, light transmission, and abrasion resistance properties.

[0006] In one or more embodiments, a cover lens structure for a display device includes a substrate layer including a first side and a second side. The cover lens structure includes a first wet hard-coat layer deposited on the first side of the substrate layer and a second wet hard-coat layer deposited on the second side of the substrate layer. The cover lens structure includes one or more adhesion-promoting layers formed over the second side and a dry hard-coat layer formed over the second side.

[0007] In one or more embodiments, a method of forming a cover lens structure includes depositing a first hard-coat layer on a first side of a substrate layer using a first wet deposition process and depositing a second hard-coat layer on a second side of the substrate layer using a second wet deposition process. The method includes depositing one or more adhesion-promoting layers over the second side and depositing a third hard-coat layer over the second side using a dry deposition process. The method includes depositing an anti-fouling layer over the second side and positioning the cover lens structure to position the first hard-coat layer over a touch panel and a display structure of a display device.

[0008] In one or more embodiments, the coating system includes a first rotatable stem configured to receive a first storage reel and a second rotatable stem configured to receive a second storage reel. The coating system includes a plurality of transfer rollers disposed along a transfer path between the first storage reel and the second storage reel, and a coating module that interfaces with a first section of the transfer path. The coating module includes one or more of a bar, a slot die, one or more comma rollers, a microgravure, a gravure, one or more casting nozzles, one or more casting rollers, or one or more spray nozzles. The coating system includes a curing module that interfaces with a second section of the transfer path.

[0009] So that the above-listed features of the present disclosure can be understood in detail, a more detailed description of the present disclosure briefly outlined above can be obtained by reference to embodiments, some of which are illustrated in the attached drawings. It should be noted, however, that the attached drawings represent only typical embodiments of the present disclosure and therefore should not be considered as limiting the scope of the present disclosure, since the present disclosure may embrace other embodiments that are equally effective. [Brief description of the drawings]

[0010] [Figure 1A] 1 is a schematic cross-sectional view of a display device according to one or more embodiments. [Figure 1B] 1 is a schematic cross-sectional view of a display device according to one or more embodiments. [Figure 2A] 1A-1D are schematic cross-sectional views of a flexible cover lens film, according to one or more embodiments. [Figure 2B] 1A-1D are schematic cross-sectional views of a flexible cover lens film, according to one or more embodiments. [Figure 2C]1A-1D are schematic cross-sectional views of a flexible cover lens film, according to one or more embodiments. [Figure 2D] 1A-1D are schematic cross-sectional views of a flexible cover lens film, according to one or more embodiments. [Figure 2E] 1A-1D are schematic cross-sectional views of a flexible cover lens film, according to one or more embodiments. [Diagram 3] FIG. 2 is a schematic cross-sectional view of an exemplary embodiment of a flexible cover lens film including a doubly stacked multi-layer hard-coat of the flexible cover lens film and a doubly stacked first wet hard-coat layer according to one or more embodiments. [Figure 4A-B] 4A and 4B are schematic plan views of a coating system during a first and second wet deposition process, according to one or more embodiments. [Diagram 5] 1 is a schematic block diagram of a method of forming a cover lens structure according to one or more embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] For ease of understanding, wherever possible, identical reference numerals have been used to designate identical elements common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without additional description.

[0012] The embodiments of the present disclosure relate to a flexible display device including a double-sided wet hard-coat for a flexible cover lens structure, and related methods and coating systems. The flexible cover lens film has beneficial strength, elasticity, light transmission and anti-abrasion properties. The flexible cover lens film has beneficial strength, elasticity, light transmission and anti-abrasion properties. The flexible cover lens film includes a hard-coat layer, a multi-layer hard-coat and a substrate layer. The substrate layer can have a thickness of 2 μm to 100 μm, and the multi-layer hard-coat can have a thickness of 1 μm to 30 μm, for example, 1 μm to 10 μm. The hard-coat layer is deposited using a first wet deposition process. The multi-layer hard-coat includes a second hard-coat layer deposited using a second wet deposition process, and a third hard-coat layer deposited using a dry deposition process, and one or more adhesion-promoting layers. The substrate layer is a double-sided substrate layer in such an embodiment that a hard-coat layer is disposed on a first side of the substrate layer, and a second hard-coat layer is disposed on a second side of the substrate layer. In terms of optical properties, the flexible cover lens has a total transmission of over 88%, a haze of about 1% or less, and * It has a yellowness index of < 1. By combining wet and dry deposition processes to form a multi-layer hard coat, the cover lens film is flexible and strong with a hardness of 3H~9H.

[0013] FIG. 1A is a schematic cross-sectional view of a display device 100 according to one or more embodiments.

[0014] FIG. 1B is a schematic cross-sectional view of a display device 150 according to one or more embodiments.

[0015] 1A and 150 include the same layers, but the layers of each display device 100, 150 are arranged in a different order. Display devices 100, 150 may be fabricated using roll-to-roll deposition, plasma enhanced chemical vapor deposition, chemical vapor deposition, physical vapor deposition, atomic layer deposition, photolithography, etching, and / or other suitable similar fabrication processes. Suitable fabrication equipment from Applied Materials, Inc. of Santa Clara, Calif. may be used. Other fabrication equipment may be used.

[0016] 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 may be bonded to a foldable glass substrate (e.g., ultra-thin glass). In the embodiment of FIG. 1A, the film layer 104 is between the cover lens film 102 and the touch panel 106. In one or more embodiments, the film layer 104 is a multi-functional film layer including a polarizer film. The film layer 104, such as a polarizer film, may be used to reduce unwanted reflections from reflective metals that make up the electrode lines or metal structures in the display device 100. The film layer 104 may include a quarter-wave retarder or linear polarizer formed from a flexible lens film, such as a flexible lens film having a thickness of less than 0.2 mm. The cover lens film 102 may be bonded to the film layer 104 and the touch panel 106 using an optically clear adhesive (OCA). In one or more embodiments, the OCA is a liquid-based adhesive utilized to bond the cover lens film 102 to the touch panel 106. In one or more embodiments, 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 metal-based flexible printed circuit board.

[0017] 1A , a display structure 108 is disposed between the touch panel 106 and the substrate 110. In one or more embodiments, the display structure 108 is an organic light emitting diode display. Other suitable display devices utilizing a cover lens film are also contemplated herein, such as a light emitting diode display or a liquid crystal display utilizing a cover lens film. The display structure 108 may include a thin film encapsulation, an organic light emitting layer, a driver IC board, and thin film transistors.

[0018] 1B, the film layer 104 and touch panel 106 are laminated over 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 aids in abrasion resistance and impact protection.

[0019] In one or more embodiments, the substrate 110 is made of a polymeric material, such as a polyimide material. The present disclosure also contemplates the use of any flexible plastic substrate for the substrate 110. For example, the substrate 110 may include a polyetheretherketone layer, a transparent conductive polyester layer, polycarbonate, or any other polymer of the polyaryletherketone family. In the implementation of FIG. 1, the substrate 110 is adjacent to the shielding layer 112. In one or more embodiments, 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, may be deposited adjacent to the substrate 110 prior to any additional layers, such as the shielding layer 112.

[0020] 2A-2E are schematic cross-sectional views of flexible cover lens films 200, 220, 230, 240, 250, respectively, according to one or more embodiments. Each of the flexible cover lens films 200, 220, 230, 240, 250 may be the cover lens film 102 of FIG. 1. Each of 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 wet hard-coat layer 205 deposited using a first wet deposition process, a second wet hard-coat layer 204 deposited using a second wet deposition process, and a dry hard-coat layer 208 deposited using a dry deposition process. The wet deposition process may include depositing a solution comprising a solvent and the hard-coat chemistry using a slot-die coating head, a gravure coating head, or a bar coating head of a roll-to-roll solution processing system. In one or more embodiments, the wet deposition process includes coating (e.g., spraying or rolling) the hard-coat liquid (comprising the hard-coat chemistry dissolved in a solvent) onto the substrate layer 202, and then the deposited solution or hard-coat liquid is cured using ultraviolet radiation and / or thermal methods.

[0021] A first wet hard-coat layer 205 is deposited on a first side 221 of the substrate layer 202 and a second wet hard-coat layer 204 is deposited on a second side 222 of the substrate layer 202. In one or more embodiments, the first wet hard-coat layer 205 is deposited on a first outer surface of the substrate layer 202 on the first side 221 and the second wet hard-coat layer 204 is deposited on a second outer surface of the substrate layer 202 on the second side 222.

[0022] The dry deposition process may include chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), physical vapor deposition (PVD), thermal evaporation, electron beam evaporation, and / or other deposition techniques. The dry deposition process may be optionally plasma enhanced and processed in sheet-to-sheet or roll-to-roll equipment. The dry deposition process may be carried out in a fully equipped sheet processing equipment, where a carrier glass sheet is loaded with a substrate layer 202 including a first wet hard coat layer 205 and a second wet hard coat layer 204 deposited in a double-sided configuration. For the dry deposition process, the substrate layer 202 may be loaded directly onto the carrier glass sheet, or the substrate layer 202 may be bonded to a thin or ultra-thin glass substrate, which is then loaded onto a carrier.

[0023] In the embodiment of FIG. 2A, one or more adhesion promoting layers 206 are deposited on the second wet hard-coat layer 204. The one or more adhesion promoting layers 206 can be hard-coat layers deposited using a dry deposition process. A dry hard-coat layer 208 is deposited on the adhesion promoting layer 206, the dry hard-coat layer 208 being deposited using a dry deposition process. The second wet hard-coat layer 204, the adhesion promoting layer 206 and the dry hard-coat layer 208 form a multi-layer hard-coat 212. An anti-smudge layer 210 is deposited on the dry hard-coat layer 208. The anti-smudge layer 210 can be an anti-fingerprint layer. The anti-smudge layer 210 can be deposited using a dry deposition process or a wet deposition process.

[0024] 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 may be deposited using a dry vacuum deposition process, such as CVD, PECVD, ALD, PVD, thermal evaporation, e-beam evaporation and / or other dry deposition processes, or may be deposited using a wet deposition process. Deposited on the adhesion promoting layer 206 is a dry hard-coat layer 208 deposited using a dry deposition process. Deposited on the dry hard-coat layer 208 is a second wet hard-coat layer 204 deposited using a wet deposition process. In one or more embodiments, the second wet hard-coat layer 204 includes an anti-smudge or anti-fingerprint additive and / or no anti-smudge layer is deposited on the second wet hard-coat layer 204. In one or more embodiments, an anti-fouling layer (such as the anti-fouling layer 210 shown in FIG. 2B) is deposited on the second wet hardcoat layer 204, which may be deposited using a dry deposition process or a wet deposition process. The second wet hardcoat layer 204, the adhesion promoting layer 206 and the dry hardcoat layer 208 form a multi-layer hardcoat 212.

[0025] In the embodiment of FIG. 2C, the flexible cover lens film 230 includes an adhesion promoting layer 206 deposited on a substrate layer 202. A second wet hard-coat layer 204 is deposited on the adhesion promoting layer 206 using a wet deposition process. A dry hard-coat layer 208 is deposited on the second wet hard-coat layer 204 using a dry deposition process. The second wet hard-coat layer 204, the adhesion promoting layer 206 and the dry hard-coat layer 208 form a multi-layer hard-coat 212. An anti-fouling layer 210 is deposited on the dry hard-coat layer 208. The anti-fouling layer 210 may be deposited using a dry deposition process or may be deposited using a wet deposition process.

[0026] 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 second wet hard-coat layer 204 is deposited on the first adhesion promoting layer 206a using a wet deposition process. A second adhesion promoting layer 206b is deposited on the second wet hard-coat layer 204. A dry hard-coat layer 208 is deposited on the second adhesion promoting layer 206b using a dry deposition process. The first adhesion promoting layer 206a, the second wet hard-coat layer 204, the second adhesion promoting layer 206b and the dry hard-coat layer 208 form a multi-layer hard-coat 212. An anti-fouling layer 210 is deposited on the dry hard-coat layer 208. The anti-fouling layer 210 may be deposited using a dry deposition process or may be deposited using a wet deposition process.

[0027] 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 dry hard-coat layer 208 is deposited on the first adhesion promoting layer 206a using a dry deposition process. A second adhesion promoting layer 206b is deposited on the dry hard-coat layer 208. A second wet hard-coat layer 204 is deposited on the second adhesion promoting layer 206b using a wet deposition process. In one or more embodiments, the second wet hard-coat layer 204 includes an anti-fouling additive. In one or more embodiments, an anti-fouling layer is deposited on the second wet hard-coat layer 204, which may be deposited using a dry deposition process or a wet deposition process. The first adhesion promoting layer 206 a , the dry hardcoat layer 208 , the second adhesion promoting layer 206 b and the second wet hardcoat layer 204 form a multi-layer hardcoat 212 .

[0028] The flexible cover lens films 200, 220, 230, 240, 250 of FIGS. 2A-2E have a pencil hardness of 3H-9H, a total transmission of greater than 88% (e.g., 90% or greater), a haze of about 1% or less (e.g., less than 1%), and a* The flexible cover lens film 200, 220, 230, 240, 250 has a yellowness index of <1. In one or more embodiments, the flexible cover lens film 200, 220, 230, 240, 250 has a pencil hardness of 9H, a total transmission of more than 92%, and a haze of 0.5% or less. The flexible cover lens film 200, 220, 230, 240, 250 has flexibility to bend to an inner radius of curvature of up to 1 mm or an outer radius of curvature of up to 2 mm over repeated cycles. The flexible cover lens film 200, 220, 230, 240, 250 has a scratch resistance that can withstand many cycles, for example 2000 cycles, as measured by a standard steel wool test with a maximum load of 1 kg. The haze of the flexible cover lens film 200, 220, 230, 240, 250 after the steel wool abrasion test is changed by less than 1%, which indicates that the flexible cover lens film 200, 220, 230, 240, 250 can have high abrasion resistance. The flexible cover lens film 200, 220, 230, 240, 250 has an abrasion resistance that can withstand many cycles, for example 100 cycles, as measured by Taber abrasion resistance test with a maximum load of 1 kg. The haze of the flexible cover lens film 200, 220, 230, 240, 250 after the Taber abrasion resistance test is changed by less than 2%.

[0029] 2A-2E, the first wet hard-coat layer 205 and the second wet hard-coat layer 204 may each be deposited using roll-to-roll solution processing. The dry hard-coat layer 208 may be deposited using CVD, PVD, PECVD, or ALD. In one or more embodiments, the dry hard-coat layer 208 is deposited using CVD or PVD. The multi-layer hard-coat 212 may have a thickness T1 between 1 μm and 30 μm. In one or more embodiments, the thickness T1 is between 5 μm and 10 μm.

[0030] In Figures 2A-2E, the first wet hardcoat layer 205 and / or the second wet hardcoat layer 204 may include one or more of urethane acrylates, polyester resins, polyester acrylates, epoxy acrylates, urethanes, epoxy polycarbonates, celluloses, acetals, polyethylenes, polystyrenes, polyamides, polyimides, melamines, phenolics, silicones, sol-gel siloxane hybrids, silica nanoparticles, and / or combinations thereof. The hybrid siloxanes may include organic and inorganic components including metal alkoxides. The second wet hardcoat layer 204 deposited using a wet deposition process may further include one or more of radiation curable acrylates, aliphatic urethane acrylates, copolymers thereof, elastomers thereof, and / or combinations thereof. The first wet hardcoat layer 205 and the second wet hardcoat layer 204 may each have a thickness T2 of about 0.5 μm to about 40 μm. The first wet hard coat layer 205 and the second wet hard coat layer 204 may each 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 wet hard coat layer 205 and the second wet hard coat layer 204 may each have a nanoindentation hardness of about 0.5 GPa to about 1.5 GPa, and / or an elastic modulus measured by a nanoindentation method in the range of about 5 GPa to about 13 GPa.

[0031] The wet deposition process for depositing the first wet hard-coat layer 205 and the second wet hard-coat layer 204 may involve applying a chemical solution (e.g., hard-coat solution) using a spray nozzle and / or various Mayer rods, heating (e.g., before, during and / or after application) in a non-active convection oven at between 75° C. and 85° C. for 100 to 140 seconds, and / or applying a UV lamp at 300 mJ / cm 2 . 2 ~500mJ / cm 2and irradiating (e.g., curing) for 100 seconds to 140 seconds between the first and second exposures, respectively. The solution of the wet deposition process may be processed by bar coating, slot die coating, comma coating, microgravure coating, spin coating, gravure coating, and / or cast coating in an ionizing atmosphere. In one or more embodiments, the deposition solution of the wet deposition process is cured using ultraviolet radiation. In one or more embodiments, the deposition solution of the wet deposition process is cured using electron beam processing. In one or more embodiments, the deposition solution of the wet deposition process is cured using a thermal process.

[0032] The dry hard coat layer 208 may be made of oxides and / or nitrides of silicon, silicon oxycarbide (SiC x O y ), silicon oxynitride, and / or silicon carbide (SiC). The dry hard coat layer 208 may have a thickness T3 of about 0.05 μm to about 30 μm. Precursors used in this dry deposition process may include carbon-containing organic polymer precursors (liquid or gaseous), such as one or more of hexamethyldisiloxane (HMDSO), plasma polymerized HMDSO (ppHMDSO), tetramethylcyclotetrasiloxane (TOMCAT), hexamethyldisilazane (HMDSN), and / or tetraethylorthosilicate (TEOS). Precursors used in this dry deposition process may include sputtering various silica and / or quartz materials to deposit various carbon mixed oxides and / or nitrides of silicon, or carbon-free precursors such as silane (SiH4).

[0033] The dry hard-coat layer 208 may have a refractive index of about 1.450 to about 1.150, an optical transmission of about 85% to about 98%, and a pencil hardness of about 2H to about 9h. The dry hard-coat layer 208 may have a nanoindentation hardness of about 1 GPa to about 8 GPa, and / or an elastic modulus in the range of about 5 GPa to about 70 GPa as measured by nanoindentation. The dry hard-coat layer 208 may have a high hardness controlled by an oxidizer or initiator-to-precursor ratio such as oxygen (O2), nitrous oxide (N2O), tert-butyl peroxide (TBPO), and / or a crosslinker such as acrylate monomers, particularly ethylhexyl acrylate, and / or butanediol diacrylate (BDDA), to minimize the carbon present in the dry hard-coat layer 208.

[0034] The substrate layer 202 in FIGS. 2A-2E has a thickness T4 of 2 μm-100 μm. The substrate layer 202 is formed of one or more polymer materials. The substrate layer 202 includes one or more of polyethylene terephthalate (PET), triacetyl cellulose, polycarbonate, polyamide, polymethacrylic acid methyl ester, cycloolefin polymer, polyethylene naphthalene (PEN), and / or colorless polyimide (CPI). In one or more embodiments, the thickness T4 of the substrate layer 202 is about 25 μm-50 μm and is a CPI layer. The anti-soiling layer 210 can be an oleophobic film. The anti-soiling layer 210 can be perfluoropolyether (PFPE)-based silane polymer molecules (including, for example, various chlorosilanes, oxysilanes, and / or fluoroethylenes, etc.) covalently bonded to the surface of the layer below the anti-soiling layer 210. The anti-soiling layer 210 can be wet-coated or vacuum-dry-coated. The anti-soiling layer 210 may have a thickness of 3 nm to 150 nm, for example, about 50 nm to about 70 nm.

[0035] The adhesion promoting layer(s) 206 may have a thickness of 50 nm to 1500 nm. The adhesion promoting layer(s) 206 may be deposited using a dry deposition process and may include oxides and / or nitrides of silicon, silicon oxycarbide, and / or silicon oxynitride. Precursors used in this dry deposition process may include carbon-containing organic polymer precursors (liquid or gaseous), such as one or more of HMDSO, ppHMDSO, TOMCAT, HMDSN, and / or TEOS. Precursors used in this dry deposition process may include sputtering various silica and / or quartz materials to deposit various carbon mixed oxides and / or nitrides of silicon, or carbon-free precursors such as silane (SiH4).

[0036] The adhesion promoting layer(s) 206 may be deposited by a wet deposition process and may include one or more polymeric and / or oligomeric materials, such as acrylates, silicones, and / or optically clear adhesives (OCAs). In one or more embodiments, the adhesion promoting layer(s) 206 deposited using a wet deposition process may be formed from a liquid optically clear adhesive (LOCA), which may be applied in a variety of ways (e.g., spray nozzle, Mayer rod, slot die, gravure head, and / or bar coater, etc.), cured by UV exposure or by heat, and / or may be sensitive to moisture and / or pressure, and / or may be cured by regulating or controlling moisture and / or pressure.

[0037] 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 transmission 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 and / or an elastic modulus measured by nanoindentation in the range of about 2.5 GPa to about 70 GPa. Each of the one or more adhesion promoting layers 206 may have a relatively high hardness controlled by an oxidizer such as O2, N2O, TBPO and / or an acrylate monomer, e.g., ethylhexyl acrylate, and / or a crosslinker such as BDDA, or an initiator to precursor ratio to precisely control the carbon present.

[0038] One or more of the flexible cover lens films 200, 220, 230, 240, 250 may be stacked on top of each other. For example, the flexible cover lens film 200 may be stacked on the flexible cover lens film 220, or the flexible cover lens film 200 may be doubled such that there are two flexible cover lens films 200. The multi-layer hard-coat 212 may be stacked one or more times on the substrate layer 202. The first wet hard-coat layer 205 may be stacked one or more times under the substrate layer 202. The one or more flexible cover lens films 200, 220, 230, 240, 250, the stacked first wet hard-coat layer 205, and / or the stacked multi-layer hard-coat 212 may be independently adhered, bonded, or otherwise held together by one or more adhesives, for example by one or more OCAs. The one or more flexible cover lens films 200, 220, 230, 240, 250, the stacked first moist hardcoat layer 205, and / or the stacked multi-layer hardcoat 212 may be independently adhered, bonded, or otherwise held together without the use of adhesives.

[0039] FIG. 3 is a schematic cross-sectional view of an exemplary embodiment of a flexible cover lens film 300 including a doubly stacked multi-layer hard-coat of the flexible cover lens film 200 and a doubly stacked first wet hard-coat layer 205 according to one or more embodiments. In the flexible cover lens film 300, a first multi-layer hard-coat 212a is disposed on a second side of a substrate layer 202, and a second multi-layer hard-coat 212b is disposed on the first multi-layer hard-coat 212a. Two first wet hard-coat layers 205a, 205b are disposed on a first side of the substrate layer 202. 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 hardcoats 212a, 212b include a second wet hardcoat layer 204, an adhesion-promoting layer 206 disposed on the second wet hardcoat layer 204, and a dry hardcoat layer 208 disposed on the adhesion-promoting layer 206. An anti-fouling layer 210 may be deposited on the second multi-layer hardcoat 212b (as shown in FIG. 3). The present disclosure also contemplates omitting the anti-fouling layer 210.

[0040] If it is desired to remove and replace a top flexible cover lens film, such as the second multilayer hardcoat 212b of FIG. 3 (e.g., due to scratches or other damage), one or more adhesive layers, such as adhesive layer 306, may be selectively degraded, destroyed, or otherwise removed to separate the top cover lens (e.g., the second multilayer hardcoat 212b of FIG. 3) from the bottom cover lens film (e.g., the first multilayer hardcoat 212a of FIG. 3). The adhesive (e.g., adhesive layer 306 of FIG. 3) bonding these two stacks of cover films may be degraded at a predetermined temperature, with a predetermined wavelength and / or dose of ultraviolet (UV) light, and / or with a predetermined mechanical removal mechanism.

[0041] In one or more embodiments, the sacrificial adhesive (e.g., adhesive layer 306 in FIG. 3) bonding two stacked flexible cover lens films (e.g., first and second multilayer hardcoats 212a, 212b in FIG. 3) may be decomposable at a predetermined temperature. For example, the adhesive may be decomposable at a temperature of about 80° C., about 90° C., or about 100° C. to about 120° C. In one or more embodiments, the sacrificial adhesive is decomposable when exposed to a predetermined wavelength and / or a predetermined dose of UV light. For example, the adhesive is decomposable when exposed to UV light having a wavelength of about 350 nm to about 375 nm, e.g., 365 nm. The adhesive may be decomposed by exposure to the UV light for a period of about 0.5 seconds, about 1 second, or about 5 seconds to about 30 seconds, about 60 seconds, or about 90 seconds.

[0042] A method of forming the flexible cover lens film 200, 220, 230, 240, 250 may include disposing 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 may be deposited in sheet-to-sheet processing equipment and / or roll-to-roll equipment using both wet and dry deposition processes, such as CVD, PVD, ambient (e.g., atmospheric) solution processing methods. It is also contemplated that there may be additional layers, such as additional adhesion-promoting or impact-resistant layers, in the flexible cover lens film 200, 220, 230, 240, 250. The cover lens films described herein may be used in any display device.

[0043] The combination of wet deposition process and dry deposition process to form a multi-layer hard coat facilitates a bendable optically transparent and high hardness cover lens film. The combination of dry film and wet film facilitates enhancing the anti-wear properties and elasticity of the cover lens film, and at the same time allows the deposition of an anti-fouling layer on the multi-layer hard coat. By combining wet deposition process and dry deposition process to form a multi-layer hard coat, the cover lens film has enhanced elasticity, strength, light transmission, abrasion resistance, anti-wear properties and thermal stability.

[0044] FIG. 4A is a schematic top view of a coating system 400 during a first wet deposition process, according to one or more embodiments.

[0045] The coating system 400 includes a first rotatable stem 402 configured to receive a first storage reel 404, a second rotatable stem 406 configured to receive a second storage reel 408, and a number of transfer rollers 410. The transfer rollers 410 are disposed along a transfer path between the first storage reel 404 and the second storage reel 408. The coating system 400 includes a coating module 414 that interfaces with a first section 412a of the transfer path, the coating module 414 including a bar, a slot die, one or more comma rollers, a microgravure, a gravure, one or more cast nozzles, one or more cast rollers, and / or a number of spray nozzles 415. The present disclosure also contemplates the use of one or more spray nozzles 415. The coating system 400 includes a curing module 416 that interfaces with a second section 412b of the transfer path. The curing module 416 includes one or more ultraviolet (UV) light sources 417. The present disclosure also contemplates using other energy sources in place of the UV light source 417, such as a microwave source, a heat source, and / or an electron beam source.

[0046] The first storage reel 404 is mounted on the first rotatable stem 402, and the second storage reel 408 is mounted on the second rotatable stem 406. The first storage reel 404 has a substrate layer 202 wound on it. During a first wet deposition process, the first rotatable stem 402 is driven to rotate the first storage reel 404 in a first rotational direction RD1, and the second rotatable stem 406 is driven to rotate the second storage reel 408 in a second rotational direction RD2. The substrate layer 202 is transferred from the first storage reel 404 to the second storage reel 408. During the transfer, the coating module 414 coats (e.g., sprays or rolls) a liquid hard-coat on the first surface 221 of the substrate layer 202 to form a first wet hard-coat layer 205. During transport, the second surface 222 passes over transport rollers 410. During transport, a UV light source 417 directs energy (e.g., UV light) toward the first wet hardcoat layer 205 to cure the first wet hardcoat layer 205.

[0047] When the first storage reel 404 is rotated in a first rotational direction RD1 and the second storage reel 408 is rotated in a second rotational direction RD2 opposite to the first rotational direction RD1, the substrate layer 202 and the first moisture hard coat layer 205 are wound around the second storage reel 408 in such a manner that the first surface 221 and the second surface 222 are inverted (see FIG. 4B).

[0048] FIG. 4B is a schematic top view of coating system 400 during a second wet deposition process according to one or more embodiments.

[0049] Between the first wet deposition process of FIG. 4A and the second wet deposition process of FIG. 4B, the positions of the first storage reel 404 and the second storage reel 408 are changed. In one or more embodiments, the second storage reel 408 is placed in place of the first storage reel 404 (e.g., mounted on the first rotatable stem 402) for the second wet deposition process. In one or more embodiments, the third storage reel 418 is mounted on the second rotatable stem 406. In one or more embodiments, the positions of the first storage reel 404 and the second storage reel 408 are swapped such that the second storage reel 408 is mounted on the first rotatable stem 402 and the first storage reel 404 is mounted on the second rotatable stem 406.

[0050] The first side 221 and the second side 222 are flipped over in such a manner that the second side 222 faces the coating module 414 and the first side 221 and the first wet hard-coat layer 205 face the transfer roller 410. During the second wet deposition process, the second storage reel 408 is rotated in a first rotational direction RD1 and the third storage reel 418 is rotated in a second rotational direction RD2.

[0051] The substrate layer 202 and the first wet hard-coat layer 205 are transferred from the second storage reel 408 to a third storage reel 418. During transfer, the coating module 414 coats (e.g., sprays or rolls) a liquid hard-coat onto the second side 222 of the substrate layer 202 to form the second wet hard-coat layer 204. During transfer, the first wet hard-coat layer 205 advances over the transfer rollers 410. During transfer, the UV light source 417 directs energy (e.g., UV light) towards the second wet hard-coat layer 204 to cure the second wet hard-coat layer 204. At the same time as rotating the third storage reel 418, the third rotatable stem 421 is driven to rotate the fourth storage reel 422 (in the second rotational direction RD2) to transfer the protective film 423 from the fourth storage reel 422 to the third storage reel 418. The protective film 423 wound on the third storage reel 418 is deposited on the cured second wet hard-coat layer 204. The protective film 423 is deposited between the second wet hard-coat layer 204 and the first wet hard-coat layer 205.

[0052] The present disclosure also contemplates the use of other deposition equipment in place of coating module 414. In one or more embodiments, a first hardcoat roller can roll apply liquid adhesive to first side 221 to form first wet hardcoat layer 205, and a second hardcoat roller can simultaneously roll apply liquid adhesive to second side 222 to form second wet hardcoat layer 204.

[0053] FIG. 5 is a schematic block diagram of a method 500 of forming a cover lens structure according to one or more embodiments.

[0054] Operation 502 includes depositing a first hard-coat layer on a first side of the substrate layer using a first wet deposition process. The substrate layer is a polymer layer. In one or more embodiments, the substrate layer is formed of one or more of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), cellulose triacetate (TAC), polyimide (PI), and / or colorless polyimide (CPI). The present disclosure also contemplates using other polymeric materials for the substrate layer. In one or more embodiments, depositing the first hard-coat layer includes coating a hard-coat liquid on the first side and curing the hard-coat liquid on the first side. In one or more embodiments, depositing the first hard-coat layer includes rotating a first storage reel in a first rotational direction and rotating a second storage reel in a second rotational direction opposite the first rotational direction to transfer the substrate layer from the first storage reel to the second storage reel. In one or more embodiments, transferring the substrate layer from the first storage reel to the second storage reel includes moving the substrate layer over a plurality of transfer rollers disposed along a transfer path between the first storage reel and the second storage reel.

[0055] Operation 503 includes changing the position of the first storage reel and the second storage reel. In one or more embodiments, the changing includes swapping the positions of the first storage reel and the second storage reel. In one or more embodiments, the changing includes placing the second storage reel in place of the first storage reel and placing a third storage reel in place of the second storage reel.

[0056] Operation 504 includes depositing a second hard-coat layer on a second side of the substrate layer using a second wet deposition process. In one or more embodiments, depositing the second hard-coat layer includes coating a hard-coat liquid on the second side and curing the hard-coat liquid on the second side. In one or more embodiments, depositing the second hard-coat layer includes rotating the second storage reel in a first rotational direction and rotating the third storage reel in a second rotational direction opposite the first rotational direction to transfer the substrate layer from the second storage reel to the third storage reel. In one or more embodiments, method 500 includes rotating a fourth storage reel in a second rotational direction while rotating the third storage reel to transfer a barrier film from the fourth storage reel to the third storage reel and depositing the barrier film between the first hard-coat layer and the second hard-coat layer.

[0057] The first wet deposition process of operation 502 and the second wet deposition process of operation 504 each use roll-to-roll equipment (such as the transfer roller 410 and storage reels 404, 408, 418, 422 shown in Figures 4A and 4B) to deposit the first and second hardcoat layers.

[0058] Operation 506 includes depositing one or more adhesion promoting layers. In one or more embodiments, the one or more adhesion promoting layers are deposited on the second hardcoat layer.

[0059] Operation 508 includes depositing a third hardcoat layer using a dry deposition process. In one or more embodiments, the third hardcoat layer is deposited on the one or more adhesion promoting layers.

[0060] Operation 510 includes depositing an anti-soiling layer. In one or more embodiments, a third anti-soiling layer is deposited on the hardcoat layer.

[0061] The first hardcoat layer and the second hardcoat layer are each deposited at a roll temperature below 58 degrees Celsius. In one or more embodiments, the roll temperature is ambient temperature, for example room temperature.

[0062] Operation 512 includes disposing a cover lens structure to position a first hardcoat layer over the touch panel and display structure of the display device.

[0063] Benefits of the present disclosure include robust mechanical properties (e.g., hardness and impact resistance), abrasion resistance, flexibility, elasticity, light transmission, and / or wear resistance. Benefits of the present disclosure further include low haze, low oligomer migration (e.g., within and out of the substrate layer 202), and / or low yellowness. As an example, the present disclosure promotes lower oligomer migration within and out of the substrate layer, lower haze, lower yellowness, and enhanced light transmission (and optical device performance) in the context of relatively robust mechanical properties.

[0064] It is also contemplated that the embodiments described herein may be combined. For example, one or more features, aspects, components, operations and / or characteristics of the flexible cover lens film 200, 220, 230, 240, 250 and / or 300, the display device 100, the coating system 400, the first wet deposition process shown in FIG. 4A, the second wet deposition process shown in FIG. 4B, and / or the method 500 may be combined. It is also contemplated that the combination will achieve the benefits described above.

[0065] The above description is directed to embodiments of the present disclosure, however, other and additional embodiments of the present disclosure may be devised without departing from the basic scope of the disclosed embodiments. The present disclosure also contemplates the use of one or more aspects of the embodiments described herein in place of one or more aspects of the remaining aspects described. The scope of the present disclosure is determined by the following claims.

[0066] Certain embodiments and features are described using a set of numerical upper limits and a set of numerical lower limits. It should be understood that unless otherwise stated, ranges including combinations of any two values ​​are also contemplated, such as combinations of any lower value with any higher value, combinations of any two lower values, and / or combinations of any two higher values. Certain lower limits, upper limits, and ranges may be described in one or more claims below.

Claims

1. 1. A cover lens structure for a display device, comprising: a substrate layer including a first surface and a second surface; a first wet hardcoat layer deposited on the first surface of the substrate layer; a second moisture hardcoat layer deposited on the second surface of the substrate layer; one or more adhesion promoting layers formed over the second surface of the substrate layer; a dry hardcoat layer formed over the second surface of the substrate layer; A cover lens structure comprising:

2. 10. The cover lens construction of claim 1, further comprising an anti-soiling layer formed over the dry hard coat layer, wherein the one or more adhesion promoting layers are formed over the first wet hard coat layer, and the dry hard coat layer is formed over the one or more adhesion promoting layers.

3. The cover lens structure of claim 1 , wherein the substrate layer is formed of one or more polymeric materials.

4. The cover lens construction of claim 3 , wherein the substrate layer is formed of polyethylene terephthalate (PET).

5. 4. The cover lens construction of claim 3, wherein the first and second wet hardcoat layers each comprise one or more of urethane acrylates, polyester resins, polyester acrylates, epoxy acrylates, urethanes, epoxy polycarbonates, celluloses, acetals, polyethylenes, polystyrenes, polyamides, polyimides, melamines, phenolics, silicones, one or more sol-gel siloxane hybrids, or silica nanoparticles.

6. 4. The cover lens construction of claim 3, wherein the dry hard coat layer comprises one or more of one or more silicon oxides, one or more silicon nitrides, one or more silicon oxycarbides, one or more silicon oxynitrides, or one or more silicon carbides.

7. 1. A method of forming a cover lens structure, comprising: depositing a first hardcoat layer on a first surface of the substrate layer using a first wet deposition process; depositing a second hardcoat layer on a second surface of the substrate layer using a second wet deposition process; depositing one or more adhesion promoting layers over the second surface; depositing a third hardcoat layer over the second surface using a dry deposition process; depositing an anti-soiling layer over the second surface; disposing the cover lens structure so as to position the first hard coat layer over a touch panel and a display structure of a display device; A method comprising:

8. 8. The method of claim 7, wherein the first hardcoat layer and the second hardcoat layer are each deposited at a roll temperature below 58 degrees Celsius, the one or more adhesion promoting layers are deposited on the second hardcoat layer, the third hardcoat layer is deposited on the one or more adhesion promoting layers, and the antifouling layer is deposited on the third hardcoat layer.

9. The method of claim 7 , wherein the substrate layer is formed of one or more polymeric materials.

10. The method of claim 9 , wherein the substrate layer is formed of polyethylene terephthalate (PET).

11. depositing the first hardcoat layer and depositing the second hardcoat layer comprises: spraying a hard coat liquid onto each of the first surface and the second surface; curing the hard coat liquid on each of the first surface and the second surface; The method of claim 7 , each comprising:

12. Depositing the first hard coat layer comprises: rotating a first storage reel in a first rotational direction; rotating a second storage reel in a second rotational direction opposite to the first rotational direction to transfer the substrate layer from the first storage reel to the second storage reel; The method of claim 11 further comprising:

13. transferring the substrate layer from the first storage reel to the second storage reel; moving the substrate layer over a plurality of transfer rollers disposed along a transfer path between the first storage reel and the second storage reel; The method of claim 12, comprising:

14. The method of claim 12 , further comprising changing positions of the first storage reel and the second storage reel.

15. depositing the second hard coat layer comprises: rotating the second storage reel in the first rotational direction; rotating a third storage reel in the second rotational direction to transfer the substrate layer from the second storage reel to the third storage reel; The method of claim 14 further comprising:

16. rotating a fourth storage reel in the second rotational direction while rotating the third storage reel to transfer a barrier film from the fourth storage reel to the third storage reel and deposit the barrier film between the first hard coat layer and the second hard coat layer. The method of claim 15 further comprising:

17. a first rotatable stem configured to receive a first storage reel; a second rotatable stem configured to receive a second storage reel; a plurality of transfer rollers disposed along a transfer path between the first storage reel and the second storage reel; a coating module interfaced with the first section of the transport path, the coating module comprising one or more of a bar, a slot die, one or more comma rollers, a microgravure, a gravure, one or more casting nozzles, one or more casting rollers, or one or more spray nozzles; a curing module interfacing with a second section of the transport path; A coating system comprising:

18. 20. The coating system of claim 17, wherein the curing module comprises one or more ultraviolet (UV) light sources.

19. 20. The coating system of claim 17, wherein the first storage reel is mounted on the first rotatable stem, the second storage reel is mounted on the second rotatable stem, and the first storage reel has a substrate layer wound thereon.

20. 20. The coating system of claim 19, wherein the substrate layer is formed of one or more polymeric materials.

Images