Double anti-UV antireflection film and preparation method thereof

Abstract

The invention discloses a double anti-UV antireflection film and a preparation method thereof. The double anti-UV antireflection film comprises an anti-UV optical thin film, an anti-UV hardened coating formed on the surface of the anti-UV optical thin film and a low-refractive-index anti-UV coating formed on the surface of the anti-UV hardened coating. According to the invention, the problems of coating shedding, mechanical performance reduction and the like caused by too fast aging of the material can be effectively prevented; wherein the ultraviolet absorber can prevent ultraviolet rays from entering the resin polymer to cause degradation in the resin, so that the degradation speed of the resin polymer is greatly slowed down; as a free radical capturing agent, the light stabilizer can cut off an oxidation chain reaction in the photooxidation process, the degradation rate of the resin polymer can be remarkably reduced, and the situation that the appearance and mechanical performance of the material become poor due to degradation of the material is prevented; the inorganic particles added in the coating liquid can also be used as a light shielding agent to absorb or reflect ultraviolet rays, so that the ultraviolet rays cannot penetrate into the coating.

Description

Technical Field

[0001] The invention relates to the field of anti-reflection film materials, and in particular to a double-UV anti-reflection film and a preparation method thereof. Background Art

[0002] In recent years, transparent plastics such as polymethyl methacrylate (PMMA), polyethylene terephthalate (PET) and polycarbonate (PC) have been widely used in electronic displays due to their low cost. Although they have excellent optical properties, they usually need to be coated with a hard, scratch-resistant hardened coating to improve their impact resistance and wear resistance. In addition, an anti-reflective coating with anti-fingerprint function is usually required on the substrate to minimize unnecessary reflections from the substrate. Anti-reflective film uses the destructive interference between the reflected light from different interfaces of the thin film coating to reduce the overall reflectivity of the substrate material, reduce the reflection of external light and surface contamination, and improve the contrast, readability and image quality of electronic displays.

[0003] Today, people are increasingly dependent on electronic products. It is inevitable that they will often use consumer electronic devices such as mobile phones and tablets outdoors, which will greatly increase the total amount of UV exposure. At the same time, long-term exposure to the outdoors will cause damage to electronic displays, causing color distortion, fading, yellowing, cracking, shedding, embrittlement and delamination, affecting the clarity and brightness of the screen. When coatings or films are exposed outdoors, factors such as moisture, heat and UV radiation can cause coatings and films to degrade. UV radiation and moisture can cause chemical degradation of film-forming resins, and these degradation reactions tend to accelerate when the temperature rises.

[0004] Patent CN109557604B discloses an anti-ultraviolet anti-reflection film layer and its application. The film layer is formed by alternately stacking dielectric material layers with different refractive indices, and utilizes the different reflection and refraction effects of light waves with different wavelengths at the interface between different dielectric material layers to make it have excellent reflection effect on ultraviolet light; but its ultraviolet light transmittance is still as high as 5.9%.

[0005] Therefore, it is necessary to improve the existing technology to provide a more reliable solution. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a double-UV anti-reflection film and a preparation method thereof in view of the deficiencies in the above-mentioned prior art.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: In a first aspect of the present invention, a double anti-UV anti-reflection film is provided, comprising an anti-UV optical film, an anti-UV hardening coating formed on the surface of the anti-UV optical film, and a low refractive index anti-UV coating formed on the surface of the anti-UV hardening coating;

[0008] The anti-UV hardening coating is obtained by coating an anti-UV hardening coating liquid on the surface of the anti-UV optical film and then curing it. The anti-UV hardening coating liquid includes the following raw material components in parts by weight: 6 to 12 parts by weight of acrylate monomers, 15 to 30 parts by weight of acrylic resin oligomers, 3 to 6 parts by weight of first inorganic particles, 60 to 80 parts by weight of solvents, 1 to 2 parts by weight of ultraviolet light absorbers, 1 to 2 parts by weight of light stabilizers and 2 to 3 parts by weight of photoinitiators.

[0009] Preferably, the low-refractive-index anti-UV coating is obtained by coating a low-refractive-index anti-UV coating liquid on the surface of the anti-UV hardening coating and then curing it, and the low-refractive-index anti-UV coating liquid includes the following raw material components in parts by weight: 3 to 7 parts by weight of acrylate monomers, 5 to 11 parts by weight of fluorinated modified acrylic resin oligomers, 2 to 4 parts by weight of second inorganic particles, 100 to 200 parts by weight of solvents, 1 to 2 parts by weight of ultraviolet light absorbers, 1 to 2 parts by weight of light stabilizers and 2 to 3 parts by weight of photoinitiators.

[0010] Preferably, the acrylic resin oligomer is one or a mixture of epoxy acrylate, polyurethane acrylate, polyester acrylate and polyether acrylate.

[0011] Preferably, the first inorganic particles are zirconium oxide or titanium oxide, or a mixture of the two.

[0012] Preferably, the acrylate monomer is one or a mixture of trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, trihydroxypropane tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, and neopentyl glycol diacrylate.

[0013] Preferably, the solvent is one or a mixture of ethyl acetate, n-butyl acetate, methyl isobutyl ketone and isopropanol;

[0014] The ultraviolet light absorber is one or a mixture of 2-(2ˊ-hydroxy-5ˊ-methylphenyl)benzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,4,6-tris(2ˊn-butoxyphenyl)-1,3,5-triazine, 2-(2ˊ-hydroxy-3ˊ,5ˊ-di-tert-butylphenyl)-5-chlorobenzotriazole and 2,4-dihydroxybenzophenone;

[0015] The light stabilizer is one or a mixture of tris(1,2,2,6,6-pentamethylpiperidinyl)phosphite, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, and hexamethylphosphoric triamide.

[0016] The photoinitiator is one or a mixture of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 1,1'-(methylenebis-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone].

[0017] Preferably, the second inorganic particles are hollow mesoporous silica microspheres.

[0018] A second aspect of the present invention provides a method for preparing the dual-UV anti-reflection film as described above, comprising the following steps:

[0019] S1. Preparation of UV-resistant hardening coating solution:

[0020] 6 to 12 parts by weight of acrylate monomers, 15 to 30 parts by weight of acrylic resin oligomers, 3 to 6 parts by weight of first inorganic particles, 60 to 80 parts by weight of solvents, 1 to 2 parts by weight of ultraviolet light absorbers, 1 to 2 parts by weight of light stabilizers and 2 to 3 parts by weight of photoinitiators are mixed and stirred to obtain an anti-UV curing coating solution;

[0021] S2, coating the anti-UV hardening coating liquid obtained in step S1 on the anti-UV optical film, and forming an anti-UV hardening coating on the anti-UV optical film after drying and UV curing;

[0022] S3. Preparation of low refractive index anti-UV coating liquid:

[0023] 3 to 7 parts by weight of acrylate monomers, 5 to 11 parts by weight of fluorinated modified acrylic resin oligomers, 2 to 4 parts by weight of second inorganic particles, 100 to 200 parts by weight of solvents, 1 to 2 parts by weight of ultraviolet light absorbers, 1 to 2 parts by weight of light stabilizers and 2 to 3 parts by weight of photoinitiators are mixed and stirred to obtain a low refractive index anti-UV coating liquid;

[0024] S4, coating the low-refractive-index anti-UV coating liquid prepared in step S3 on the anti-UV hardening coating formed in step S2, and forming a low-refractive-index anti-UV coating on the anti-UV hardening coating after drying and UV curing to obtain the double anti-UV anti-reflection film.

[0025] Preferably, the anti-UV optical film is selected from PET, PMMA, PC, TAC or SRF film with anti-UV function;

[0026] The thickness of the UV-resistant hardening coating is 2 to 6 μm, and the thickness of the low-refractive-index UV-resistant coating is 90 to 110 nm.

[0027] Preferably, the drying temperature in steps S2 and S4 is 90-110° C., and the drying time is 1-3 min.

[0028] The beneficial effects of the present invention are:

[0029] The present invention obtains a double anti-UV anti-reflection film by sequentially coating an anti-UV hardening coating liquid and a low-refractive index anti-UV coating liquid on an anti-UV optical film, which can effectively prevent the problems of coating shedding and mechanical property degradation caused by excessive aging of the material; the ultraviolet light absorber in the anti-UV hardening coating liquid can quickly absorb ultraviolet light in the environment, avoid the chromophore in the material absorbing ultraviolet light energy, and convert the absorbed light energy into harmless heat and release it; the ultraviolet light absorber can prevent ultraviolet light from penetrating into the interior of the resin polymer and causing the internal degradation of the resin, thereby greatly slowing down the degradation rate of the resin polymer; in the photooxidation process, the light stabilizer acts as a free radical scavenger It can cut off the oxidation chain reaction in the photooxidation process, significantly reduce the degradation rate of resin polymers, and prevent the material from deteriorating due to degradation, resulting in poor appearance and mechanical properties; the inorganic particles added to the coating liquid can also be used as light shielding agents to absorb or reflect ultraviolet rays to prevent them from penetrating into the coating; the anti-UV optical film can further prevent ultraviolet rays from damaging the resin polymer, improve the product's anti-aging properties, and extend its service life; the double-UV anti-reflection film of the present invention can increase transmittance and reduce reflectivity, thereby reducing image distortion and glare, allowing users to enjoy clearer image quality, and the added fluorinated modified resin can improve friction resistance and extend service life.

[0030] In the present invention, the multifunctional acrylate monomer added to the hardening coating liquid and the anti-reflection coating liquid has high reactivity, high crosslinking density, high hardness of the cured film, and excellent tensile resistance, which can improve the light curing efficiency and crosslinking density of the hardening film and the anti-reflection film; the ultraviolet light absorber is a filter for ultraviolet rays, which absorbs most of the radiation light with high energy and harmful to the polymer, and then releases it as heat energy, so that the degradation rate of the resin polymer is greatly slowed down; after the polymer is dissociated by light radiation to generate free radicals, the light stabilizer captures the active free radicals, making it a stable compound and greatly delaying the aging of the polymer material; the disadvantage of the ultraviolet light absorber is that it cannot protect the entire thickness of the coating, and it requires a limited path length to obtain significant absorbance, that is, the closer to the coating surface, the weaker its protective ability, while the effect of the light stabilizer does not change with the reduction of the thickness of the coating. By compounding the ultraviolet light absorber and the light stabilizer, there is a mutual protective effect between the ultraviolet light absorber and the light stabilizer, showing a synergistic effect, thereby achieving a better protective effect;

[0031] In the present invention, the inorganic particles in the coating liquid can not only improve the hardness of the coating and reduce the reflectivity of the coating, but also absorb or reflect ultraviolet rays, reduce the direct radiation of light to the interior of the resin polymer, reduce the harm of ultraviolet rays, and further inhibit photo-oxidative degradation;

[0032] Since the ultraviolet light absorber can absorb ultraviolet light, it will affect the initiation efficiency of the photoinitiator. The proportion of the photoinitiator added in the present invention to the monomer and the oligomer is increased to 6-9%, which prevents the initiator from being added too little, resulting in incomplete curing of the coating and affecting the adhesion and wear resistance of the coating. At the same time, it prevents the initiator from being added too much, which may lead to the formation of reaction by-products, thereby affecting the photo-initiated polymerization or curing effect.

[0033] In the present invention, the fluorinated modified acrylic resin oligomer can form a smooth fluorine film on the coating surface after curing, which can not only prevent the adhesion of water and oil and maintain excellent slipperiness, but also protect the surface from scratches, greatly enhance the friction resistance and extend the service life of the product. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with embodiments so that those skilled in the art can implement the invention with reference to the description.

[0035] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0036] The test methods used in the following examples are conventional methods unless otherwise specified. The materials and reagents used in the following examples are all commercially available unless otherwise specified. In the following examples, if no specific conditions are specified, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

[0037] The invention provides a double anti-UV anti-reflection film, comprising an anti-UV optical film, an anti-UV hardening coating formed on the surface of the anti-UV optical film, and a low-refractive-index anti-UV coating formed on the surface of the anti-UV hardening coating.

[0038] In a preferred embodiment, the anti-UV hardening coating is obtained by coating an anti-UV hardening coating liquid on the surface of the anti-UV optical film and then curing it. The anti-UV hardening coating liquid includes the following raw material components in parts by weight: 6 to 12 parts by weight of acrylate monomers, 15 to 30 parts by weight of acrylic resin oligomers, 3 to 6 parts by weight of first inorganic particles, 60 to 80 parts by weight of solvents, 1 to 2 parts by weight of ultraviolet light absorbers, 1 to 2 parts by weight of light stabilizers and 2 to 3 parts by weight of photoinitiators.

[0039] In a preferred embodiment, the low refractive index anti-UV coating is obtained by coating a low refractive index anti-UV coating liquid on the surface of the anti-UV hardening coating and then curing it. The low refractive index anti-UV coating liquid includes the following raw material components in parts by weight: 3 to 7 parts by weight of acrylate monomers, 5 to 11 parts by weight of fluorinated modified acrylic resin oligomers, 2 to 4 parts by weight of second inorganic particles, 100 to 200 parts by weight of solvents, 1 to 2 parts by weight of ultraviolet light absorbers, 1 to 2 parts by weight of light stabilizers and 2 to 3 parts by weight of photoinitiators.

[0040] In a preferred embodiment, the acrylic resin oligomer is one or a mixture of epoxy acrylate, polyurethane acrylate, polyester acrylate and polyether acrylate.

[0041] In a preferred embodiment, the first inorganic particles are zirconium oxide or titanium oxide, or a mixture of the two.

[0042] In a preferred embodiment, the acrylate monomer is one or a mixture of trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, trihydroxypropane tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, and neopentyl glycol diacrylate.

[0043] In a preferred embodiment, the solvent is one or a mixture of ethyl acetate, n-butyl acetate, methyl isobutyl ketone and isopropanol.

[0044] In a preferred embodiment, the ultraviolet light absorber is one or a mixture of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,4,6-tris(2'-n-butoxyphenyl)-1,3,5-triazine, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole and 2,4-dihydroxybenzophenone.

[0045] In a preferred embodiment, the light stabilizer is one or a mixture of tris(1,2,2,6,6-pentamethylpiperidinyl)phosphite, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, and hexamethylphosphoric triamide.

[0046] In a preferred embodiment, the photoinitiator is one of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1,1'-(methylenebis-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone] or a mixture thereof.

[0047] In a preferred embodiment, the second inorganic particles are hollow mesoporous silica microspheres.

[0048] The present invention also provides a method for preparing the above dual-UV anti-reflection film, comprising the following steps:

[0049] S1. Preparation of UV-resistant hardening coating solution:

[0050] 6 to 12 parts by weight of acrylate monomers, 15 to 30 parts by weight of acrylic resin oligomers, 3 to 6 parts by weight of first inorganic particles, 60 to 80 parts by weight of solvents, 1 to 2 parts by weight of ultraviolet light absorbers, 1 to 2 parts by weight of light stabilizers and 2 to 3 parts by weight of photoinitiators are mixed and stirred to obtain an anti-UV curing coating solution;

[0051] S2, coating the anti-UV hardening coating liquid obtained in step S1 on the anti-UV optical film, and forming an anti-UV hardening coating on the anti-UV optical film after drying and UV curing;

[0052] S3. Preparation of low refractive index anti-UV coating liquid:

[0053] 3 to 7 parts by weight of acrylate monomers, 5 to 11 parts by weight of fluorinated modified acrylic resin oligomers, 2 to 4 parts by weight of second inorganic particles, 100 to 200 parts by weight of solvents, 1 to 2 parts by weight of ultraviolet light absorbers, 1 to 2 parts by weight of light stabilizers and 2 to 3 parts by weight of photoinitiators are mixed and stirred to obtain a low refractive index anti-UV coating liquid;

[0054] S4, coating the low-refractive-index anti-UV coating liquid prepared in step S3 on the anti-UV hardening coating formed in step S2, and forming a low-refractive-index anti-UV coating on the anti-UV hardening coating after drying and UV curing to obtain a double anti-UV anti-reflection film.

[0055] In a preferred embodiment, the thickness of the UV-resistant hardening coating is 2-6 μm, and the thickness of the low-refractive-index UV-resistant coating is 90-110 nm.

[0056] In a preferred embodiment, the drying temperature in steps S2 and S4 is 90-110° C., and the drying time is 1-3 minutes.

[0057] In a preferred embodiment, the stirring time in steps S1 and S3 is 1 to 2 hours, and the rotation speed is 600 to 800 rpm.

[0058] In a preferred embodiment, the anti-UV optical film is selected from PET, PMMA, PC, TAC or SRF film having anti-UV function.

[0059] When the material is exposed to the outdoors, ultraviolet radiation triggers a reaction, oxygen in the atmosphere participates in chemical degradation, and chromophores in the material absorb radiation photons to trigger degradation. In addition to photooxidation, especially when the temperature of the coating rises under high-temperature sunlight, the film-forming resin in the coating can also be degraded by hydrolysis. The present invention obtains a double-UV anti-reflection film by sequentially coating an anti-UV hardening coating liquid and a low-refractive index anti-UV coating liquid on an anti-UV optical film, which can effectively prevent problems such as coating shedding and mechanical property degradation caused by rapid aging of the material; the ultraviolet light absorber in the anti-UV hardening coating liquid can quickly absorb ultraviolet light in the environment, avoid the chromophores in the material from absorbing ultraviolet light energy, and convert the absorbed light energy into harmless heat and release it; the ultraviolet light absorber can prevent ultraviolet rays from penetrating into the interior of the resin polymer and causing internal degradation of the resin, thereby greatly slowing down the degradation rate of the resin polymer; in the photooxidation process, the light stabilizer acts as Free radical scavengers can cut off the oxidation chain reaction, significantly reduce the degradation rate of resin polymers, and prevent the material from deteriorating due to degradation, resulting in poor appearance and mechanical properties; the inorganic particles added to the coating liquid can also act as light shielding agents to absorb or reflect ultraviolet rays to prevent them from penetrating into the coating; anti-UV optical films can further prevent ultraviolet rays from damaging resin polymers, improve the product's anti-aging properties, and extend its service life; anti-reflection films can increase transmittance and reduce reflectivity, thereby reducing image distortion and glare, allowing users to enjoy clearer image quality, and the added fluorinated modified resin can improve friction resistance and extend service life.

[0060] The above is the overall concept of the present invention, and detailed embodiments and comparative examples are provided below on the basis of the overall concept of the present invention to further illustrate the present invention.

[0061] Example 1

[0062] A method for preparing the dual-UV anti-reflection film as described above comprises the following steps:

[0063] S1. Preparation of UV-resistant hardening coating solution:

[0064] 9 parts by weight of dipentaerythritol hexaacrylate, 22 parts by weight of polyurethane acrylate, 4.5 parts by weight of zirconium oxide particles (SZR-CW, particle size 25 nm, Sakai Chemical Industry Co., Ltd.), 20 parts by weight of ethyl acetate, 50 parts by weight of methyl isobutyl ketone, 1.5 parts by weight of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.5 parts by weight of tris(1,2,2,6,6-pentamethylpiperidinyl)phosphite and 2.5 parts by weight of 2-hydroxy-2-methyl-1-phenyl-1-propanone were added to a reaction kettle in sequence, and the mixture was stirred and dispersed at 700 rpm for 1.5 hours to obtain a UV-resistant hardening coating solution;

[0065] S2, coating the anti-UV curing coating liquid obtained in step S1 on the anti-UV optical PET film (XF7LA7, thickness 50 μm, Toray Industries, Ltd.), drying at 100° C. for 2 min, and then UV curing (UV energy 400 mj / cm under high pressure mercury lamp) 2 ), forming an anti-UV hardening coating with a thickness of 4 μm on the anti-UV optical film;

[0066] S3. Preparation of low refractive index anti-UV coating liquid:

[0067] 5 parts by weight of dipentaerythritol hexaacrylate, 8 parts by weight of fluorinated modified acrylic resin (2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl acrylate, D154301, Shanghai Aladdin), 3 parts by weight of hollow mesoporous silica microspheres (ELCOM JX-1009SIV, particle size 30 nm, JGC Catalysts & Chemicals Co., Ltd.), 40 parts by weight of ethyl acetate, 120 parts by weight of methyl isobutyl ketone, 1.5 parts by weight of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 1.5 parts by weight of tris(1,2,2,6,6-pentamethylpiperidinyl)phosphite and 2.5 parts by weight of 1-hydroxycyclohexyl phenyl ketone were added to the reaction kettle in sequence, and the mixture was stirred and dispersed at 700 rpm for 1.5 hours to obtain a low refractive index UV-resistant coating solution;

[0068] S4, coating the low refractive index anti-UV coating prepared in step S3 on the anti-UV hardening coating formed in step S2, drying at 100°C for 2 minutes, and then UV curing (UV energy 600mj / cm2 under nitrogen protection high pressure mercury lamp) 2 ), a low refractive index anti-UV coating is formed on the anti-UV hardening coating to obtain the double anti-UV anti-reflection film with a thickness of 100 nm.

[0069] Example 2

[0070] This example is basically the same as Example 1, except that the acrylic ester monomer added to the anti-UV hardening coating liquid and the low-refractive index anti-UV coating liquid is dipentaerythritol pentaacrylate.

[0071] Example 3

[0072] This example is basically the same as Example 1, except that the acrylic ester monomer added to the anti-UV hardening coating liquid and the low-refractive index anti-UV coating liquid is trihydroxypropane tetraacrylate.

[0073] Example 4

[0074] This example is basically the same as Example 1, except that the first inorganic particles added to the UV-resistant hardening coating solution are titanium oxide (RTTMIBK15WT%-N24, particle size 50 nm, Tokyo Chemical Industry Co., Ltd.).

[0075] Example 5

[0076] This example is basically the same as Example 1, except that the ultraviolet light absorber added to the anti-UV hardening coating liquid and the low-refractive index anti-UV coating liquid is 2,4,6-tris(2'-n-butoxyphenyl)-1,3,5-triazine.

[0077] Example 6

[0078] This example is basically the same as Example 1, except that the light stabilizer added to the anti-UV hardening coating liquid and the low-refractive index anti-UV coating liquid is 4-benzoyloxy-2,2,6,6-tetramethylpiperidine.

[0079] Example 7

[0080] This example is basically the same as Example 1, except that the photoinitiator added to the UV-resistant hardening coating liquid and the low-refractive index UV-resistant coating liquid is 1,1'-(methylenebis-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone].

[0081] Comparative Example 1

[0082] This example is basically the same as Example 1, except that no ultraviolet light absorber (2-(2'-hydroxy-5'-methylphenyl)benzotriazole) is added to the anti-UV hardening coating liquid and the low-refractive index anti-UV coating liquid.

[0083] Comparative Example 2

[0084] This example is basically the same as Example 1, except that no light stabilizer (tris(1,2,2,6,6-pentamethylpiperidinyl)phosphite) is added to the UV-resistant hardening coating liquid and the low-refractive index UV-resistant coating liquid.

[0085] Comparative Example 3

[0086] This example is basically the same as Example 1, except that a common optical PET film without UV resistance (U483, thickness 50 μm, Toray Industries, Inc.) is used instead of the UV resistance optical PET film in Example 1.

[0087] Comparative Example 4

[0088] This example is basically the same as Example 1, except that a conventional acrylic resin (CN9006NS acrylate oligomer, Sartomer) not modified by fluorination is used in the low refractive index anti-UV coating liquid instead of the fluorinated modified acrylic resin in Example 1.

[0089] Comparative Example 5

[0090] This example is basically the same as Example 1, except that the amount of the photoinitiator 1-hydroxycyclohexyl phenyl ketone added in the anti-UV hardening coating liquid and the low-refractive index anti-UV coating liquid is 1.9 parts by weight.

[0091] Comparative Example 6

[0092] This example is basically the same as Example 1, except that the amount of 1-hydroxycyclohexyl phenyl ketone added to the anti-UV hardening coating liquid and the low-refractive index anti-UV coating liquid is 3.1 parts by weight.

[0093] The products prepared in Examples 1-7 and Comparative Examples 1-6 were subjected to the following performance tests:

[0094] (1) Transmittance / Haze: The transmittance and haze of the film samples were tested using a spectrophotometer in transmission mode.

[0095] (2) Reflectivity: Cut the film sample into a size of 50 mm*50 mm, attach the sample substrate surface to the surface of the screen module, and test its reflectivity at 550 nm in the reflection mode.

[0096] (3) Pencil hardness: Place the film sample on a horizontal, stable surface, insert a sharpened MITSU-BISHI UNI test pencil into the test instrument, with the pencil lead in contact with the surface to be tested at a 45° angle. Draw five parallel lines of 5 cm in length under a load of 1000 g, and then observe the optical film coating under a fluorescent light. When there is no scratching or whitening throughout the entire process, the hardest pencil number is the scratch hardness.

[0097] (4) Adhesion: Use a 1*1 cm grid cutter to draw a 10×10 grid with a spacing of 1 mm on the surface of the film sample. Use 3M600 tape to stick to the tested grid and flatten it with a rubber roller to ensure that the tape is in good contact with the coating. After standing for 90 seconds, quickly tear off the tape and check the coating shedding condition.

[0098] (5) Elongation at break: Cut the film sample into strips of 10 mm*200 mm in size, fix the strips between the upper and lower clamps of the tensile testing machine, with a clamp spacing of 50 mm, and start the tensile testing machine for testing. Stop the machine when the test strip reaches the predetermined test strain, take out the strip, observe whether the coating has cracks, and record the results.

[0099] (6) Solar radiation: The film sample was attached to a glass cover plate and placed in a test chamber. A test was conducted under simulated solar radiation and temperature with one cycle of 20 hours of light and 4 hours of darkness (lighting conditions: chamber temperature 40°C, blackboard temperature 50°C, humidity 35%, irradiance of the lamp at 340 nm of 0.55 W / m 2, wavelength range 300-800nm; dark conditions: set temperature to 40℃, humidity 50%), test 5 cycles. After the test is completed, wait for the sample to return to room temperature before conducting adhesion test.

[0100] (7) Steel wool wear resistance: Attach the film sample to the glass cover plate and fix it to the friction tester. Apply a load of 1000g to the test surface of the sample. Use Bonstar #0000 steel wool with a test head area of ​​20*20mm. Test at a speed of 40cycle / min and a stroke of about 40mm. After the specified number of cycles, observe whether there are scratches or marks under D65 light source. If there are more than 5 scratches or marks, it is judged as NG.

[0101] The test results of the dual-UV anti-reflection films obtained in the examples and comparative examples are shown in Table 1 below:

[0102] Table 1

[0103]

[0104]

[0105] As can be seen from the above table, the double anti-UV anti-reflection film prepared in each embodiment has the characteristics of high visible light transmittance, low haze, low ultraviolet light transmittance, low reflectivity, high pencil hardness, good coating adhesion, high elongation at break, and high wear resistance, and the coating adhesion performance simulated for long-term exposure to ultraviolet rays is good, and the elongation at break does not decrease significantly. The visible light transmittance of Example 1 is 94.7%, the haze is 0.39%, the ultraviolet light transmittance at 380nm is 1.9%, the reflectivity at 550nm is 0.64%, the pencil hardness is 1H, the hundred grids are 5B, the hundred grids after solar radiation are 5B, the elongation at break is 6.0%, the elongation at break after solar radiation is 4.8%, and the steel wool wear resistance is OK for 2300 times.

[0106] Compared with Comparative Example 1, no ultraviolet light absorber was added to the anti-UV hardening coating and the low-refractive index anti-UV coating in Example 1, and the ultraviolet light transmittance at 380nm was significantly improved, and the 100B after solar radiation and the elongation at break were significantly reduced. Compared with Comparative Example 2, no light stabilizer was added to the anti-UV hardening liquid and the low-refractive index anti-UV coating in Example 2, and the ultraviolet light transmittance at 380nm was not significantly improved, and the 100B after solar radiation and the elongation at break were significantly reduced. Compared with Comparative Example 3, the optical film substrate in Comparative Example 3 did not have an anti-UV function, and the ultraviolet light transmittance at 380nm was significantly improved, and the 100B after solar radiation and the elongation at break were significantly reduced. Compared with Comparative Example 4, the low-refractive index coating in Comparative Example 4 added a non-fluorinated modified resin, and the steel wool wear resistance was only OK for 10 times. Compared with Example 5, in Example 1, 1.9 parts by weight of photoinitiator was added to the anti-UV curing liquid and the low-refractive index anti-UV coating liquid in Example 5, and the 100-grid 1B and elongation at break were significantly reduced after solar radiation. Compared with Example 6, in Example 1, 3.1 parts by weight of photoinitiator was added to the anti-UV curing liquid and the low-refractive index anti-UV coating liquid in Example 6, and the 100-grid 2B and elongation at break were significantly reduced after solar radiation.

[0107] From the comparison between the above embodiments and the comparative examples, it can be seen that: the effect of using only ultraviolet light absorbers, light stabilizers or substrates with anti-UV function is not ideal. The synergistic effect of ultraviolet light absorbers, light stabilizers and anti-UV films can effectively reduce the damage caused by ultraviolet rays through the resin polymer and prevent the material from aging too quickly; adding fluorinated modified resins can significantly improve the friction resistance of the anti-reflection film; adding too little or too much photoinitiator will affect the adhesion of the coating after material aging.

[0108] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims

1. A dual-UV anti-reflection film, characterized in that: It includes an anti-UV optical film, an anti-UV hardening coating formed on the surface of the anti-UV optical film, and a low-refractive-index anti-UV coating formed on the surface of the anti-UV hardening coating; The anti-UV hardening coating is obtained by coating an anti-UV hardening coating liquid on the surface of the anti-UV optical film and then curing it. The anti-UV hardening coating liquid includes the following raw material components in parts by weight: 6 to 12 parts by weight of acrylate monomers, 15 to 30 parts by weight of acrylic resin oligomers, 3 to 6 parts by weight of first inorganic particles, 60 to 80 parts by weight of solvents, 1 to 2 parts by weight of ultraviolet light absorbers, 1 to 2 parts by weight of light stabilizers and 2 to 3 parts by weight of photoinitiators.

2. The dual-UV anti-reflection film according to claim 1, characterized in that: The low-refractive-index anti-UV coating is obtained by coating a low-refractive-index anti-UV coating liquid on the surface of the anti-UV hardening coating and then curing it. The low-refractive-index anti-UV coating liquid includes the following raw material components in parts by weight: 3 to 7 parts by weight of acrylate monomers, 5 to 11 parts by weight of fluorinated modified acrylic resin oligomers, 2 to 4 parts by weight of second inorganic particles, 100 to 200 parts by weight of solvents, 1 to 2 parts by weight of ultraviolet light absorbers, 1 to 2 parts by weight of light stabilizers, and 2 to 3 parts by weight of photoinitiators.

3. The dual-UV anti-reflection film according to claim 1, characterized in that: The acrylic resin oligomer is one or a mixture of epoxy acrylate, polyurethane acrylate, polyester acrylate and polyether acrylate.

4. The dual-UV anti-reflection film according to claim 1, characterized in that: The first inorganic particles are zirconium oxide or titanium oxide, or a mixture of the two.

5. The dual-UV anti-reflection film according to claim 1 or 2, characterized in that: The acrylic ester monomer is one or a mixture of trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, trihydroxypropane tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, and neopentyl glycol diacrylate.

6. The dual-UV anti-reflection film according to claim 1 or 2, characterized in that: The solvent is one or a mixture of ethyl acetate, n-butyl acetate, methyl isobutyl ketone and isopropanol; The ultraviolet light absorber is one or a mixture of 2-(2ˊ-hydroxy-5ˊ-methylphenyl)benzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,4,6-tris(2ˊn-butoxyphenyl)-1,3,5-triazine, 2-(2ˊ-hydroxy-3ˊ,5ˊ-di-tert-butylphenyl)-5-chlorobenzotriazole and 2,4-dihydroxybenzophenone; The light stabilizer is one or a mixture of tris(1,2,2,6,6-pentamethylpiperidinyl)phosphite, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, and hexamethylphosphoric triamide; The photoinitiator is one or a mixture of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 1,1'-(methylenebis-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone].

7. The dual-UV anti-reflection film according to claim 2, characterized in that: The second inorganic particles are hollow mesoporous silica microspheres.

8. A method for preparing a dual-UV anti-reflection film as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Preparation of UV-resistant hardening coating solution: 6 to 12 parts by weight of acrylate monomers, 15 to 30 parts by weight of acrylic resin oligomers, 3 to 6 parts by weight of first inorganic particles, 60 to 80 parts by weight of solvents, 1 to 2 parts by weight of ultraviolet light absorbers, 1 to 2 parts by weight of light stabilizers and 2 to 3 parts by weight of photoinitiators are mixed and stirred to obtain an anti-UV curing coating solution; S2, coating the anti-UV hardening coating liquid obtained in step S1 on the anti-UV optical film, and forming an anti-UV hardening coating on the anti-UV optical film after drying and UV curing; S3. Preparation of low refractive index anti-UV coating liquid: 3 to 7 parts by weight of acrylate monomers, 5 to 11 parts by weight of fluorinated modified acrylic resin oligomers, 2 to 4 parts by weight of second inorganic particles, 100 to 200 parts by weight of solvents, 1 to 2 parts by weight of ultraviolet light absorbers, 1 to 2 parts by weight of light stabilizers and 2 to 3 parts by weight of photoinitiators are mixed and stirred to obtain a low refractive index anti-UV coating liquid; S4, coating the low-refractive-index anti-UV coating liquid prepared in step S3 on the anti-UV hardening coating formed in step S2, and forming a low-refractive-index anti-UV coating on the anti-UV hardening coating after drying and UV curing to obtain the double anti-UV anti-reflection film.

9. The method for preparing a dual-UV anti-reflection film according to claim 8, characterized in that: The anti-UV optical film is selected from PET, PMMA, PC, TAC or SRF film with anti-UV function; The thickness of the UV-resistant hardening coating is 2 to 6 μm, and the thickness of the low-refractive-index UV-resistant coating is 90 to 110 nm.

10. The method for preparing a dual-UV anti-reflection film according to claim 8, characterized in that: The drying temperature in steps S2 and S4 is 90-110° C., and the drying time is 1-3 minutes.

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