Low-refractive index photocurable coating liquid, antireflection film, and method for producing the same

Abstract

The application discloses a low-refractive photo-curing coating liquid, an anti-reflection film and a preparation method thereof. The low-refractive photo-curing coating liquid comprises the following raw material components in parts by weight: 50-80 parts of fluorine-containing multifunctional (methyl) acrylic resin; 3-10 parts of multifunctional acrylic monomer; 20-70 parts of composite particle dispersion liquid; 3-6 parts of photoinitiator; and 50-100 parts of solvent. The application provides a low-refractive photo-curing coating liquid, and further provides an anti-reflection film on the basis of the low-refractive photo-curing coating liquid. The coating layer formed by the low-refractive photo-curing coating liquid can reduce reflection and increase permeability, and has excellent steel wool rubbing resistance and rubber rubbing resistance. In the low-refractive photo-curing coating liquid, the fluorine-containing multifunctional (methyl) acrylic resin improves crosslinking property, further enhances the wear resistance of the coating layer, and the fluorine atom can increase the water contact angle of the coating layer, endows the coating layer with stain resistance, and also has a synergistic effect on improving wear resistance.

Description

Technical Field

[0001] This invention relates to the field of antireflective coating preparation technology, and in particular to a low refractive index photocurable coating, an antireflective coating, and a preparation method thereof. Background Technology

[0002] Anti-reflective coatings, also known as anti-reflective films, primarily function to reduce or eliminate reflected light from optical surfaces such as lenses, prisms, and plane mirrors, thereby increasing the light transmittance of these components and reducing or eliminating stray light in the system. With the rapid development of electronic products and people's higher demands for quality, the application range of anti-reflective films has become more extensive. Anti-reflective films are typically adhered to the display surfaces of image display devices such as touch panels and LCD monitors to reduce reflections from external light, thereby improving visual experience and alleviating eye strain. Since they are applied to the outermost layer of a product, anti-reflective films are required to have a certain degree of scratch and abrasion resistance; simultaneously, due to the frequent use of touch controls, they also require good abrasion resistance against rubber-like materials. The low-refractive-index layer is a crucial component of anti-reflective films, and improving the abrasion resistance of the outermost low-refractive-index layer has become a current research focus. Most current solutions can achieve a low refractive index to achieve the anti-reflective and anti-reflective effects, but they cannot simultaneously meet the requirements of abrasion resistance, lacking scratch resistance or having insufficient scratch resistance.

[0003] Current research on low refractive index layers mainly focuses on two aspects. One is resin modification. Fluorine atoms have very low polarizability, resulting in low surface energy after film formation, and are therefore widely used. For example, adding organosilicon materials with a polydimethylsiloxane structure or adding fluorinated surfactants can achieve antifouling properties in low refractive index layers. However, resins containing fluorine atoms tend to soften, leading to reduced coating strength and poor adhesion. The other aspect involves preparing low refractive index layers by adding particles. Many studies utilize the hollow shell structure of hollow silica to reduce the refractive index, but insufficient bonding between hollow silica and resin results in low coating strength and hardness, and the surface texture is not wear-resistant. Although introducing solid inorganic particles to create an uneven surface improves the wear resistance of the texture, the effect is still unsatisfactory, and problems such as low transmittance and poor resistance to rubber friction also exist. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a low refractive index photocurable coating liquid and its preparation method in view of the shortcomings of the prior art, and based on the coating liquid, to provide an antireflective film that can maintain excellent antireflection and antireflection performance while also being resistant to steel wool and rubber friction.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In its first aspect, the present invention provides a low-refractive-index photocurable coating liquid, comprising the following raw material components in parts by weight:

[0006]

[0007] Preferably, the fluorinated polyfunctional (meth)acrylic resin is 1,3-bis{(meth)acryloxy}-2,2-difluoropropane, 1,5-bis{(meth)acryloxy}-2,2,3,3,4,4-hexafluoropentane, 1,6-bis{(meth)acryloxy}-2,2,3,3,4,4,5,5-octafluorohexane, 1,7-bis{(meth)acryloxy}-2,2,3,3,4,4,5,5,6,6-decafluoroheptane, 1,8- bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6,7,7-dodecanoic acid, 1,9-bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6,7,7,8,8-tetrafluorononane, 1,10-bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecanoic acid, 1,11-bis{(meth)acryloyloxy}- 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-octadecylfluoroethane, 1,12-bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11-eicofluorododecane, 1,2,7,8-tetra{(meth)acryloyloxy}-4,4,5,5-tetrafluorodecane, 1,2,8,9-tetra{(meth)acryloyloxy}- At least one of the following: 4,4,5,5,6,6-hexafluorononane, 1,2,9,10-tetra(meth)acryloyloxy)-4,4,5,5,6,6,7,7-octafluorodecane, 1,2,10,11-tetra(meth)acryloyloxy)-4,4,5,5,6,6,7,7,8,8-decafluoroheptane, and 1,2,11,12-tetra(meth)acryloyloxy)-4,4,5,5,6,6,7,7,8,8,9,9-dodecanoyldodecane.

[0008] Preferably, the multifunctional acrylate monomer is at least one of pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.

[0009] Preferably, the composite particles in the composite particle dispersion are obtained by modifying the surface of inorganic particles with hollow silica particles under the action of a silane coupling agent;

[0010] The inorganic particles are at least one of silicon oxide, titanium oxide, aluminum oxide, and zirconium oxide.

[0011] Preferably, the inorganic particles have a diameter of 20-100 nm, and the hollow silica particles have a diameter of 10-100 nm.

[0012] Preferably, the silane coupling agent is a silane coupling agent containing double bonds, and is at least one of γ-methacryloyloxypropyltrimethoxysilane (KH-570), vinyltrimethoxysilane (A171), and vinyltris(b-methoxyethoxy)silane (KH-A172).

[0013] Preferably, the composite particle dispersion is prepared by the following method:

[0014] 1) The hollow silica particles are dispersed in methyl isobutyl ketone to obtain a hollow silica particle dispersion with a solid content of 10-40%.

[0015] 2) The inorganic particles are dispersed in methyl isobutyl ketone to obtain an inorganic particle dispersion with a solid content of 10-40%.

[0016] 3) Mix the weakly acidic aqueous solution with a pH of 3.5 to 4.5 with the silane coupling agent, then adjust the pH to 6.7 to 7.2 with alkali, and stir for 15 to 90 minutes to obtain the hydrolysate of the silane coupling agent;

[0017] 4) Mix the hollow silica particle dispersion prepared in step 1) and the hydrolysate of the silane coupling agent prepared in step 3), stir for 10-40 minutes, then add the inorganic particle dispersion prepared in step 2), and stir for 15-60 minutes; wherein, the mass ratio of the added hollow silica particles to inorganic particles is 1:1 to 4:1.

[0018] 5) After the reaction is complete, the product is concentrated and dehydrated to obtain the composite particle dispersion with a solid content of 5-40%.

[0019] Preferably, the photoinitiator is one or more of 1-hydroxycyclohexylphenyl ketone (initiator 184), 1,1'-(methylenedi-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone] (initiator 127), and 2-hydroxy-2-methyl-1-phenyl-1-propanone (initiator 1173);

[0020] The solvent is one or more of 4-methyl-2-pentanone, 2-butanone, propylene glycol methyl ether, ethyl acetate, and isopropanol.

[0021] A second aspect of the present invention provides a method for preparing a low-refractive-index photocurable coating as described above, characterized by comprising the following steps: adding a fluorinated polyfunctional (meth)acrylic resin, a polyfunctional acrylate monomer, and a photoinitiator to a solvent according to a weight ratio, stirring until homogeneous, then adding a composite particle dispersion, stirring until homogeneous, to obtain the low-refractive-index photocurable coating.

[0022] A third aspect of the present invention provides an antireflective film comprising a substrate, a hardening layer, a high refractive index layer, and a low refractive index layer stacked sequentially, wherein the low refractive index layer is obtained by coating the high refractive index layer with a low refractive index photocurable coating liquid as described above and then curing it by ultraviolet light irradiation.

[0023] The beneficial effects of this invention are:

[0024] This invention provides a low-refractive-index photocurable coating liquid, and further provides an anti-reflection film based on it. The coating formed by the low-refractive-index photocurable coating liquid can reduce reflection and increase light transmission while also being resistant to steel wool friction and rubber friction, and the effect is excellent.

[0025] In the low-refractive-index photocurable coating of this invention, a composite particle is obtained by modifying the surface of hollow silica particles with inorganic particles under the action of a silane coupling agent. The (meth)acryloyloxy group of the silane coupling agent undergoes a crosslinking reaction with a fluorinated polyfunctional (meth)acrylic resin, which tightly binds the composite particle to the fluorinated resin. This allows the hollow silica and inorganic particles to work synergistically and continuously, significantly improving the coating's abrasion resistance while also maintaining its anti-reflective and anti-reflective properties. Furthermore, by selecting inorganic oxide particles with a diameter of 20-80 nm, surface smoothness is ensured while improving wear resistance, thus providing good wear resistance even against soft media such as erasers.

[0026] In the low-refractive-index photocurable coating of the present invention, the crosslinking property is improved by fluorinated polyfunctional (meth)acrylic resin, which further enhances the wear resistance of the coating. Combined with fluorine atoms, the water contact angle of the coating can be increased, giving the coating stain resistance, and at the same time, it also plays a synergistic role in improving wear resistance. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0028] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0029] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. For examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer are followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available products.

[0030] This invention provides a low-refractive-index photocurable coating, comprising the following raw material components in parts by weight:

[0031]

[0032]

[0033] In preferred embodiments, the fluorinated polyfunctional (meth)acrylic resin is 1,3-bis{(meth)acryloyloxy}-2,2-difluoropropane, 1,5-bis{(meth)acryloyloxy}-2,2,3,3,4,4-hexafluoropentane, 1,6-bis{(meth))acryloyloxy}-2,2,3,3,4,4,5,5-octafluorohexane, 1,7-bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6-decafluoroheptane, 1,8 -bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6,7,7-dodecanoic acid, 1,9-bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6,7,7,8,8-tetrafluorononane, 1,10-bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecanoic acid, 1,11-bis{(meth)acryloyloxy} -2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-octadecylfluoroethane, 1,12-bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11-eicosyldodecane, 1,2,7,8-tetra{(meth)acryloyloxy}-4,4,5,5-tetrafluorodecane, 1,2,8,9-tetra{(meth)acryloyloxy}- At least one of 4,4,5,5,6,6-hexafluorononane, 1,2,9,10-tetra(meth)acryloyloxy)-4,4,5,5,6,6,7,7-octafluorodecane, 1,2,10,11-tetra(meth)acryloyloxy)-4,4,5,5,6,6,7,7,8,8-decafluoroheptane, and 1,2,11,12-tetra(meth)acryloyloxy)-4,4,5,5,6,6,7,7,8,8,9,9-dodecanoyldodecane. Fluorinated polyfunctional (meth)acrylic resins can be manufactured by known methods, such as the esterification reaction of acrylates with (meth)acryloyl chloride; commercially available products can also be used.

[0034] In this invention, the hydrophobicity of the low refractive index layer is improved by combining fluorine atoms with the resin participating in the reaction, thereby improving the stain resistance of the coating; at the same time, its double bond structure can improve the cross-linking reaction between the resin and other components, thereby increasing the hardness of the coating after curing and enhancing its wear resistance.

[0035] The multifunctional acrylic monomer has a functionality of ≥3. In a preferred embodiment, the multifunctional acrylate monomer is at least one of pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate. Multifunctional acrylic monomers have low irritation and high crosslinking density. Furthermore, high functionality is beneficial for improving the curing rate, thereby giving the coating excellent scratch resistance and solvent resistance.

[0036] In a preferred embodiment, the composite particles in the composite particle dispersion are obtained by modifying the surface of inorganic particles with hollow silica particles under the action of a silane coupling agent. The hollow silica shell structure allows the cured coating to maintain a low refractive index, while the surface modification of the inorganic particles increases wear resistance. Simultaneously, under the action of the silane coupling agent, the composite particles can more tightly crosslink with the fluorinated polyfunctional (meth)acrylic resin, further enhancing the hardness of the coating.

[0037] In a preferred embodiment, the inorganic particles are at least one of silicon oxide, titanium oxide, aluminum oxide and zirconium oxide. The diameter of the inorganic particles is 20-100 nm. If the particle size is too large, it will affect the smoothness of the coating surface and have poor wear resistance to soft media such as rubber.

[0038] In a preferred embodiment, the diameter of the hollow silica particles is 10-100 nm. To better achieve the surface modification effect, hollow silica particles with a diameter of 20-80 nm are more preferred.

[0039] The silane coupling agent is a silane coupling agent containing double bonds. In a preferred embodiment, the silane coupling agent is a silane coupling agent containing double bonds, and is at least one of γ-methacryloyloxypropyltrimethoxysilane (KH-570), vinyltrimethoxysilane (A171), and vinyltris(b-methoxyethoxy)silane (KH-A172).

[0040] In a preferred embodiment, the composite particle dispersion is prepared by the following method:

[0041] 1) Disperse hollow silica particles in methyl isobutyl ketone to obtain a hollow silica particle dispersion with a solid content of 10-40%.

[0042] 2) Disperse inorganic particles in methyl isobutyl ketone to obtain an inorganic particle dispersion with a solid content of 10-40%.

[0043] 3) Mix a weakly acidic aqueous solution with a pH of 3.5 to 4.5 with the silane coupling agent, then adjust the pH to 6.7 to 7.2 with alkali, and stir for 15 to 90 minutes to obtain a hydrolysate of the silane coupling agent;

[0044] 4) Mix the hollow silica particle dispersion prepared in step 1) and the hydrolysate of the silane coupling agent prepared in step 3), stir for 10-40 minutes, then add the inorganic particle dispersion prepared in step 2), and stir for 15-60 minutes; wherein, the mass ratio of the added hollow silica particles to inorganic particles is 1:1 to 4:1.

[0045] 5) After the reaction is complete, the product is concentrated and dehydrated to obtain the composite particle dispersion with a solid content of 5-40%.

[0046] In a preferred embodiment, the photoinitiator is one or more of 1-hydroxycyclohexylphenyl ketone (initiator 184), 1,1'-(methylenedi-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone] (initiator 127), and 2-hydroxy-2-methyl-1-phenyl-1-propanone (initiator 1173). The selection of a photoinitiator with good solubility, high initiation activity, excellent thermal stability, and excellent resistance to yellowing can ensure the curing effect while taking into account the transparency of the coating.

[0047] The solvent is one or more of 4-methyl-2-pentanone, 2-butanone, propylene glycol methyl ether, ethyl acetate, and isopropanol.

[0048] The present invention also provides a method for preparing the above-mentioned low refractive index photocurable coating, comprising the following steps: adding fluorinated polyfunctional (meth)acrylic resin, polyfunctional acrylate monomer and photoinitiator to a solvent according to the weight ratio, stirring evenly, then adding composite particle dispersion, stirring evenly to obtain low refractive index photocurable coating.

[0049] The present invention also provides an antireflective film, comprising a substrate, a hardening layer, a high refractive index layer and a low refractive index layer stacked sequentially, wherein the low refractive index layer is obtained by coating the high refractive index layer with the above-mentioned low refractive index photocurable coating liquid and then curing it by ultraviolet light irradiation.

[0050] In some preferred embodiments, the antireflective film prepared by the present invention can achieve the following properties: static water contact angle of 110°, transmittance ≥93%, reflectance <1%, abrasion resistance of steel wool 500 times (1kg), and abrasion resistance of rubber 450 times (1kg).

[0051] In a preferred embodiment, the substrate may be a transparent PET film with a thickness of 20-150 μm.

[0052] In a preferred embodiment, the hardening layer is obtained by applying a conventional known hardening coating. The hardening coating may consist of reactive silicon compounds such as tetraethoxysilane and curable multifunctional acrylic resins with added initiators. The coating thickness may be 2-7 μm and the refractive index may be 1.49-1.7.

[0053] In a preferred embodiment, the high refractive index layer is obtained by coating with a conventionally known high refractive index coating, which can be a mixture formed by combining photocurable resin with inorganic particles with high refractive index such as metal oxide particles. The coating thickness can be 50-200 nm and the refractive index is 1.6-1.8.

[0054] The above is the general concept of the present invention. Based on this, detailed embodiments and comparative examples are provided below to further illustrate the present invention.

[0055] In the following examples and comparative examples, the substrate, hardening layer, and high refractive index layer are all the same, as detailed below:

[0056] The substrate is a transparent PET film with a thickness of 100μm, manufactured by Toray Industries, U-403.

[0057] The hardened layer was prepared by the following method: 100 parts by weight of resin UV-7605B (produced by Japan Synthetic Chemical Industry Co., Ltd.) was mixed with 4 parts by weight of photoinitiator 184 to obtain a hardened coating, which was then applied to the surface of the substrate, dried, and cured under ultraviolet light to obtain a hardened layer with a thickness of about 5.5 μm.

[0058] The high refractive index layer was prepared by the following method: 100 parts by weight of UV-7600B UV-curable resin (produced by Japan Synthetic Chemical Industry Co., Ltd.) and 20 parts by weight of titanium dioxide (RTTMIBK15WT%-N24, produced by Tokyo Chemical Industry Co., Ltd.) were mixed evenly to obtain a high refractive index coating, which was then coated on the surface of the hardened layer, dried, and UV-cured to obtain a high refractive index layer with a thickness of 120 nm.

[0059] Example 1

[0060] An antireflective coating includes a substrate, a hardening layer, a high refractive index layer, and a low refractive index layer stacked sequentially. The method for preparing the low refractive index layer includes the following steps:

[0061] S1. Preparation of low-refractive-index photocurable coating:

[0062] According to the weight ratio, weigh out 50 parts of fluorinated polyfunctional (meth)acrylic resin 1,6-bis{(meth))acryloyloxy}-2,2,3,3,4,4,5,5-octafluorohexane, 5 parts of polyfunctional acrylate monomer pentaerythritol triacrylate, and 5 parts of initiator (127). Add 80 parts of solvent methyl isobutyl ketone and stir thoroughly. Then add 40 parts of composite particle dispersion and stir thoroughly to obtain the finished coating liquid.

[0063] S1. Apply the finished coating liquid onto the high refractive index coating layer and cure it under ultraviolet light to form a low refractive index layer with a thickness of 90nm, thus obtaining an antireflective film.

[0064] Among them, 1,6-bis{(methyl))acryloyloxy}-2,2,3,3,4,4,5,5-octafluorohexane was produced by Shanghai Aladdin; pentaerythritol triacrylate, SR444 NS, was produced by Sardoma.

[0065] The composite particle dispersion was prepared by the following method:

[0066] 1) Hollow silica particles were dispersed in methyl isobutyl ketone to obtain a hollow silica particle dispersion with a solid content of 30%.

[0067] 2) Inorganic titanium dioxide particles were dispersed in methyl isobutyl ketone to obtain an inorganic particle dispersion with a solid content of 20%.

[0068] 3) Mix a weakly acidic aqueous solution with a pH of 4.5 with the silane coupling agent, then adjust the pH to 7.2 with alkali, and stir for 45 minutes to obtain a hydrolysate of the silane coupling agent;

[0069] 4) Mix the hollow silica particle dispersion prepared in step 1) and the hydrolysate of the silane coupling agent prepared in step 3), stir for 20 minutes, then add the inorganic particle dispersion prepared in step 2), and stir for 30 minutes; wherein, the mass ratio of the added hollow silica particles to the inorganic particles is 3:1.

[0070] 5) After the reaction is complete, the product is concentrated and water is removed to obtain a composite particle dispersion with a solid content of 20%.

[0071] Among them, the inorganic titanium dioxide particles: RTTMIBK15WT%-N24, produced by Tokyo Chemical Co., Ltd.; the hollow silica particles: ELCOM JX-1009SIV, produced by Nippon Chemicals.

[0072] Example 2

[0073] The only difference between this example and Example 1 is that the preparation method of the low refractive index photocurable coating in this example is as follows:

[0074] According to the weight ratio, weigh out 60 parts of fluorinated polyfunctional (meth)acrylic resin 1,6-bis{(meth))acryloyloxy}-2,2,3,3,4,4,5,5-octafluorohexane, 5 parts of polyfunctional acrylate monomer pentaerythritol triacrylate, and 5 parts of initiator (127). Add 80 parts of solvent methyl isobutyl ketone and stir thoroughly. Then add 20 parts of composite particle dispersion and stir thoroughly to obtain the finished coating liquid.

[0075] Example 3

[0076] The only difference between this example and Example 1 is that the preparation method of the low refractive index photocurable coating in this example is as follows:

[0077] According to the weight ratio, weigh out 80 parts of fluorinated polyfunctional (meth)acrylic resin 1,6-bis{(meth))acryloyloxy}-2,2,3,3,4,4,5,5-octafluorohexane, 5 parts of polyfunctional acrylate monomer pentaerythritol triacrylate, and 5 parts of initiator (127). Add 90 parts of solvent methyl isobutyl ketone and stir thoroughly. Then add 40 parts of composite particle dispersion and stir thoroughly to obtain the finished coating liquid.

[0078] Example 4

[0079] The only difference between this example and Example 1 is that the preparation method of the low refractive index photocurable coating in this example is as follows:

[0080] According to the weight ratio, weigh out 80 parts of fluorinated polyfunctional (meth)acrylic resin 1,6-bis{(meth))acryloyloxy}-2,2,3,3,4,4,5,5-octafluorohexane, 5 parts of polyfunctional acrylate monomer pentaerythritol triacrylate, and 5 parts of initiator (127). Add 100 parts of solvent methyl isobutyl ketone and stir thoroughly. Then add 70 parts of composite particle dispersion and stir thoroughly to obtain the finished coating liquid.

[0081] Example 5

[0082] The only difference between this example and Example 1 is that the preparation method of the low refractive index photocurable coating in this example is as follows:

[0083] According to the weight ratio, weigh out 70 parts of fluorinated polyfunctional (meth)acrylic resin 1,6-bis{(meth))acryloyloxy}-2,2,3,3,4,4,5,5-octafluorohexane, 5 parts of polyfunctional acrylate monomer pentaerythritol triacrylate, and 4 parts of initiator (127). Add 100 parts of solvent methyl isobutyl ketone and stir thoroughly. Then add 50 parts of composite particle dispersion and stir thoroughly to obtain the finished coating liquid.

[0084] Example 6

[0085] The only difference between this example and Example 1 is that the inorganic titanium dioxide particles in the composite particle dispersion are replaced with inorganic aluminum oxide particles (Akk Industries, Ltd., Z-607-ALU).

[0086] Example 7

[0087] The only difference between this example and Example 1 is that the inorganic titanium dioxide particles in the composite particle dispersion are replaced with inorganic silicon dioxide particles (THRULYA 4320, Nichibukai Catalyst Chemical Co., Ltd.).

[0088] Comparative Example 1

[0089] The only difference between this example and Example 1 is that the preparation method of the low refractive index photocurable coating in this example is as follows:

[0090] According to the weight ratio, weigh out 50 parts of fluorinated polyfunctional (meth)acrylic resin 1,6-bis{(meth))acryloyloxy}-2,2,3,3,4,4,5,5-octafluorohexane, 5 parts of polyfunctional acrylate monomer pentaerythritol triacrylate, and 5 parts of initiator (127). Add 80 parts of solvent methyl isobutyl ketone and stir thoroughly until homogeneous to obtain the finished coating liquid.

[0091] Comparative Example 2

[0092] The only difference between this example and Example 1 is that the preparation method of the low refractive index photocurable coating in this example is as follows:

[0093] According to the weight ratio, 50 parts of fluorinated polyfunctional (meth)acrylic resin 1,6-bis{(meth))acryloyloxy}-2,2,3,3,4,4,5,5-octafluorohexane, 5 parts of polyfunctional acrylate monomer pentaerythritol triacrylate, and 5 parts of initiator (127) were weighed in sequence. 80 parts of solvent methyl isobutyl ketone were added and stirred thoroughly. 40 parts of dispersion containing only hollow silica, i.e., the hollow silica particle dispersion in step 1) of Example 1, were added and stirred thoroughly to obtain the finished coating liquid.

[0094] Comparative Example 3

[0095] The only difference between this example and Example 1 is that the preparation method of the low refractive index photocurable coating in this example is as follows:

[0096] According to the weight ratio, 50 parts of fluorinated polyfunctional (meth)acrylic resin 1,6-bis{(meth))acryloyloxy}-2,2,3,3,4,4,5,5-octafluorohexane, 5 parts of polyfunctional acrylate monomer pentaerythritol triacrylate, and 5 parts of initiator (127) were weighed in sequence. 80 parts of solvent methyl isobutyl ketone were added and stirred thoroughly. 40 parts of dispersion containing only inorganic titanium dioxide particles were added, i.e., the inorganic particle dispersion in step 2) of Example 1. After stirring thoroughly, the finished coating liquid was obtained.

[0097] The antireflective film products prepared in Examples 1-7 and Comparative Examples 1-3 were tested for static water contact angle, steel wool abrasion resistance, rubber abrasion resistance, reflectivity, transmittance, haze and other properties.

[0098] Static water contact angle: The reading is taken within 6 seconds of the droplet being dropped using a static water contact angle meter.

[0099] Steel Wool Wear Resistance: Steel Wool Model (#0000), Size 2cm*2cm, Stroke 4cm, Speed ​​40-60 times / minute, Load 1kg;

[0100] Rubber friction: Model: Korean Minoan, stroke 4cm, speed 40-60 times / minute, load 1kg;

[0101] Transmittance: Measured using a 752N spectrophotometer and an "8-degree specular reflection accessory";

[0102] Haze: WGT-S haze meter.

[0103] The test results are shown in Tables 1 and 2 below:

[0104] Table 1

[0105]

[0106] Table 2

[0107]

[0108]

[0109] Based on the test results in Tables 1 and 2, it can be seen from Examples and Comparative Example 1 that the coating obtained without the addition of the composite particle dispersion has very poor wear resistance. Examples and Comparative Examples 2 and 3 show that without inorganic oxide particle modification, the improvement in wear resistance of the coating is not significant. Furthermore, with only inorganic oxide particles added, the reflectivity is high, failing to achieve an anti-reflection effect. Therefore, the solution provided by this invention has crucial guiding significance for improving the wear resistance of anti-reflection films.

[0110] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.

Claims

1. A low-refractive-index photocurable coating, characterized in that, Includes the following raw material components by weight: 50-80 parts of fluorinated polyfunctional (meth)acrylic resin; 3-10 parts of multifunctional acrylate monomer; 20-70 parts of composite particle dispersion; 3-6 parts of photoinitiator; Solvent 50-100 parts; The composite particles in the composite particle dispersion are obtained by modifying the surface of inorganic particles with hollow silica particles under the action of a silane coupling agent; the silane coupling agent is a silane coupling agent containing double bonds. The inorganic particles are at least one of silicon dioxide, titanium dioxide, aluminum oxide, and zirconium oxide; The composite particle dispersion was prepared by the following method: 1) The hollow silica particles are dispersed in methyl isobutyl ketone to obtain a hollow silica particle dispersion with a solid content of 10-40%. 2) The inorganic particles are dispersed in methyl isobutyl ketone to obtain an inorganic particle dispersion with a solid content of 10-40%. 3) Mix the weakly acidic aqueous solution with a pH of 3.5 to 4.5 with the silane coupling agent, then adjust the pH to 6.7 to 7.2 with alkali, and stir for 15 to 90 minutes to obtain the hydrolysate of the silane coupling agent; 4) Mix the hollow silica particle dispersion prepared in step 1) and the hydrolysate of the silane coupling agent prepared in step 3), stir for 10-40 minutes, then add the inorganic particle dispersion prepared in step 2), and stir for 15-60 minutes; wherein, the mass ratio of the added hollow silica particles to inorganic particles is 1:1 to 4:

1. 5) After the reaction is complete, the product is concentrated and dehydrated to obtain the composite particle dispersion with a solid content of 5-40%.

2. The low refractive index photocurable coating liquid according to claim 1, characterized in that, The fluorinated polyfunctional (meth)acrylic resin is 1,3-bis{(meth)acryloyloxy}-2,2-difluoropropane, 1,5-bis{(meth)acryloyloxy}-2,2,3,3,4,4-hexafluoropentane, 1,6-bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5-octafluorohexane, 1,7-bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6-decafluoroheptane, 1,8-bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6-decafluoroheptane, etc. {(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6,7,7-dodecanoic acid, 1,9-bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6,7,7,8,8-tetrafluorononane, 1,10-bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecanoic acid decane, 1,11-bis{(meth)acryloyloxy}-2, 2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-octadecylfluoroethane, 1,12-bis{(meth)acryloyloxy}-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11-eicofluorododecane, 1,2,7,8-tetra{(meth)acryloyloxy}-4,4,5,5-tetrafluorodecane, 1,2,8,9-tetra{(meth)acryloyloxy}-4 At least one of the following: 4,5,5,6,6-hexafluorononane, 1,2,9,10-tetra(meth)acryloyloxy)-4,4,5,5,6,6,7,7-octafluorodecane, 1,2,10,11-tetra(meth)acryloyloxy)-4,4,5,5,6,6,7,7,8,8-decafluoroheptane, and 1,2,11,12-tetra(meth)acryloyloxy)-4,4,5,5,6,6,7,7,8,8,9,9-dodecanoyldodecane.

3. The low refractive index photocurable coating liquid according to claim 1, characterized in that, The multifunctional acrylate monomer is at least one of pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.

4. The low refractive index photocurable coating liquid according to claim 1, characterized in that, The inorganic particles have a diameter of 20-100 nm, and the hollow silica particles have a diameter of 10-100 nm.

5. The low refractive index photocurable coating liquid according to claim 1, characterized in that, The silane coupling agent is at least one of γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, and vinyltri(b-methoxyethoxy)silane.

6. The low refractive index photocurable coating liquid according to claim 1, characterized in that, The photoinitiator is one or more of 1-hydroxycyclohexylphenyl ketone, 1,1'-(methylenedi-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone], and 2-hydroxy-2-methyl-1-phenyl-1-propanone; The solvent is one or more of 4-methyl-2-pentanone, 2-butanone, propylene glycol methyl ether, ethyl acetate, and isopropanol.

7. A method for preparing a low-refractive-index photocurable coating as described in any one of claims 1-6, characterized in that, The process includes the following steps: according to the weight ratio, fluorine-containing multifunctional (meth)acrylic resin, multifunctional acrylate monomer, and photoinitiator are added to a solvent and stirred evenly. Then, composite particle dispersion is added and stirred evenly to obtain the low refractive index photocurable coating.

8. An antireflective film, characterized in that, The material comprises a substrate, a hardening layer, a high refractive index layer, and a low refractive index layer stacked sequentially. The low refractive index layer is obtained by coating the high refractive index layer with a low refractive index photocurable coating liquid as described in any one of claims 1-6, followed by curing under ultraviolet light.

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