Resin composition for hard coat layer formation

Abstract

This invention provides a resin composition for forming a hard coating that not only has high hardness but also excellent scratch resistance, flexural resistance, and crack resistance. The resin composition for forming a hard coating of this invention contains the following components (A) to (D): Component (A): a trifunctional or higher alicyclic epoxy compound and / or a trifunctional or higher oxobutane compound; Component (B): a polyfunctional (meth)acrylic acid compound; Component (C): a photocationic polymerization initiator; Component (D): a photoradical polymerization initiator.

Description

[0001] This application is a divisional application of the application filed on January 23, 2019, with application number 201980009773.7 and invention title "Resin Composition for Hard Coating Formation". Technical Field

[0002] This invention relates to resin compositions for forming hard coatings, hard coating films having hard coatings formed from their cured products, electronic devices, and molded articles. This application claims priority to Japanese Patent Application No. 2018-009929, filed January 24, 2018, and Japanese Patent Application No. 2018-211263, filed November 9, 2018, the contents of which are incorporated herein by reference. Background Technology

[0003] Hard coatings with a hard coating layer are laminated onto the touch panels and displays of electronic devices such as LCD TVs, LCD screens, laptops, mobile displays, tablet PCs, and smartphones. These hard coatings possess high surface hardness and scratch resistance, thereby preventing scratches on the screen, preventing fingerprints from adhering to the screen, and facilitating the wiping of dirt adhering to the screen. Furthermore, hard coatings are applied to lenses and sensors to prevent surface scratches and maintain performance. In addition, the application of hard coatings to automotive interior components, exterior components, electrical installation components, and windshields has been explored to maintain appearance and prevent reduced transmittance. Moreover, in recent years, there has been a demand for further improvements in the scratch resistance and surface hardness of hard coatings.

[0004] As a method to improve the scratch resistance of hard coatings, there are known methods such as incorporating inorganic particles such as alumina, silica, and titanium dioxide into the resin, which are called so-called organic-inorganic hybrid methods (Patent Documents 1-3, etc.).

[0005] Furthermore, the multifunctionalization of the resin forming the hard coating has been widely used as a method to improve the surface hardness of the hard coating. Patent Document 4 describes a resin composition containing a trifunctional or more radical polymerizable compound and a bifunctional alicyclic epoxy compound. Patent Document 5 describes a resin composition containing a polyfunctional urethane (meth)acrylate and a (meth)acrylate copolymer resin.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Publication No. 2-60696

[0009] Patent Document 2: Japanese Patent Application Publication No. 2005-76005

[0010] Patent Document 3: Japanese Patent Application Publication No. 2003-34761

[0011] Patent Document 4: Japanese Patent Application Publication No. 8-73771

[0012] Patent Document 5: Japanese Patent Application Publication No. 2006-316249 Summary of the Invention

[0013] The problem that the invention aims to solve

[0014] However, while incorporating inorganic particles into the resin and multifunctionalizing the resin can improve the scratch resistance and surface hardness of the hard coating, it also has the disadvantage of causing the cured product to become brittle as the hardness increases. Furthermore, it has been found that this leads to a greater difference in the coefficients of thermal expansion between the cured product and the substrate. Under thermal shock or when the hard coating is made into a thick film, cracks are easily generated in the hard coating due to the stress of curing shrinkage. It has also been found that cured products containing trifunctional or higher free radical polymerizable compounds and bifunctional epoxy compounds are difficult to balance scratch resistance and crack resistance (e.g., Comparative Examples 1 and 2 of this application). In addition, cured products containing polyfunctional urethane (meth)acrylate and (meth)acrylate copolymer resins have high curling properties; therefore, when coating the film, it is necessary to coat both sides or use a thick substrate. Furthermore, the following drawbacks were also discovered: the coating cannot follow the bending of the film, resulting in cracking (insufficient bending resistance), or cracking occurs when thermal shock is applied as the coating thickens (insufficient crack resistance).

[0015] Therefore, the object of the present invention is to provide a resin composition for forming a hard coating that can form a cured product that not only has high hardness, but also excellent scratch resistance, flexural resistance and crack resistance.

[0016] Another object of the present invention is to provide hard coatings, electronic devices, and molded articles having a hard coating that not only has high hardness but also excellent scratch resistance, bending resistance, and crack resistance.

[0017] Problem Solving Methods

[0018] To address the aforementioned problems, the inventors conducted in-depth research and discovered that irradiating resin compositions containing trifunctional or higher alicyclic epoxy compounds, polyfunctional (meth)acrylic acid compounds, photocationic polymerization initiators, and photoradical polymerization initiators with active energy rays can yield cured products that not only possess high hardness but also exhibit excellent scratch resistance, flexural strength, and crack resistance. This invention is based on these insights.

[0019] That is, the present invention provides a resin composition for forming a hard coating containing the following components (A) to (D).

[0020] Component (A): Trifunctional or higher alicyclic epoxy compounds and / or trifunctional or higher oxetane compounds

[0021] Component (B): Polyfunctional (meth)acrylic acid compound

[0022] Component (C): Photocationic polymerization initiator

[0023] Component (D): Photoradical polymerization initiator

[0024] Preferably, the content of component (A) of the present invention is 1 to 75% by weight of the total amount of curable compounds contained in the resin composition.

[0025] Preferably, component (A) of the present invention contains at least one selected from compounds represented by formulas (a-3), (a-4), and (a') as a trifunctional or higher alicyclic epoxy compound.

[0026] [Chemical Formula 1]

[0027]

[0028] [In equation (a-3), n3 and n4 may be the same or different, representing integers from 1 to 30.]

[0029] [Chemical Formula 2]

[0030]

[0031] [In equation (a-4), n5, n6, n7, and n8 may be the same or different, representing integers from 1 to 30.]

[0032] [Chemical Formula 3]

[0033]

[0034] [In formula (a'), R is a group (p-valent organic group) formed by removing p hydroxyl groups (-OH) from the structural formula of p-hydronic alcohol, and p and n represent natural numbers respectively].

[0035] In addition, the present invention provides a hard coating film having a hard coating formed from a cured product of the above-mentioned resin composition for forming a hard coating.

[0036] In addition, the present invention provides an electronic device having a hard coating formed from a cured product of the above-described resin composition for forming a hard coating.

[0037] In addition, the present invention provides a molded article having a hard coating formed from the cured product of the above-described resin composition for forming a hard coating.

[0038] The effects of the invention

[0039] The resin composition for forming a hard coating of the present invention, having the above-described structure, can form a hard coating that not only has high hardness, but also excellent scratch resistance, bending resistance and crack resistance by irradiation with active energy rays.

[0040] Furthermore, if the resin composition for forming a hard coating of the present invention is used, a hard coating film, molded article, or electronic device can be provided that has not only high hardness but also excellent scratch resistance, flexural resistance, and crack resistance. Detailed Implementation

[0041] The resin composition for forming a hard coating of the present invention (hereinafter, sometimes simply referred to as the "resin composition") contains the following components (A) and (B) as curable compounds, and further contains the following components (C) and (D) as polymerization initiators. Component (A): a trifunctional or higher alicyclic epoxy compound and / or a trifunctional or higher oxetane compound; Component (B): a polyfunctional (meth)acrylic acid compound; Component (C): a photocationic polymerization initiator; Component (D): a photoradical polymerization initiator.

[0042] It should be noted that in this specification, "(meth)acrylic acid" refers to acrylic acid and / or methacrylic acid (either or both of acrylic acid and methacrylic acid), and the same applies to (meth)acrylate and (meth)acryloyl group.

[0043] [Ingredients (A)]

[0044] In this invention, component (A) is a trifunctional or higher alicyclic epoxy compound and / or a trifunctional or higher oxobutane compound. However, component (A) does not include those belonging to component (E) (siloxane compounds having two or more epoxy groups in the molecule) described later.

[0045] Trifunctional or higher alicyclic epoxides are compounds that have three or more epoxy groups as functional groups within a single molecule and possess an alicyclic (aliphatic) ring. Trifunctional or higher alicyclic epoxides may also have functional groups other than epoxy groups. Examples of functional groups other than epoxy groups include: cationic polymerizable groups other than epoxy groups, reactive functional groups such as free radical polymerizable groups, and non-reactive functional groups such as alkyl groups.

[0046] Examples of trifunctional or higher alicyclic epoxide compounds include: (i) compounds having three or more epoxy groups (alicyclic epoxide groups) formed by two adjacent carbon atoms and an oxygen atom constituting the alicyclic ring; and (ii) compounds having three or more epoxy groups directly connected to the alicyclic ring by single bonds.

[0047] As for the above-mentioned (i) compounds having three or more epoxy groups (alicyclic epoxy groups) formed by two adjacent carbon atoms and oxygen atoms constituting an alicyclic ring, examples include compounds represented by formula (a-1) below and compounds represented by formula (a-2) below.

[0048] [Chemical Formula 4]

[0049]

[0050] In formulas (a-1) and (a-2), n1 represents an integer of 3 or more. n2 represents an integer of 1 or more. X1, X2, and X3 represent optional linking groups with substituents (divalent groups with one or more atoms). It should be noted that X2 and X3 in formula (a-2) can be the same or different. In addition, when n2 is 2 or more, the n2 X2s can be the same or different.

[0051] n1 is not particularly limited as long as it is an integer of 3 or more, but is preferably 3 to 15, more preferably 3 to 9, even more preferably 3 to 8, and particularly preferably 3 to 6. n2 is not particularly limited as long as it is an integer of 1 or more, but is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 4. By making n1 and n2 within the above ranges, there is a tendency for the obtained resin composition to have excellent coatability.

[0052] Examples of substituents that can be optionally included as the linking group include: alkyl groups with 1 to 6 carbon atoms, aryl groups with 6 to 10 carbon atoms, hydroxyl groups, amino groups, nitro groups, cyano groups, and halogen atoms. Examples of alkyl groups with 1 to 6 carbon atoms include: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, and other straight-chain or branched alkyl groups. Examples of aryl groups with 6 to 10 carbon atoms include: phenyl, naphthyl, etc.

[0053] Examples of linking groups include divalent hydrocarbon groups, carbonyl groups, ether bonds, ester bonds, carbonate bonds, amide bonds, and groups formed by the linkage of multiple of these groups. Groups containing divalent hydrocarbon groups and ester bonds are preferred. Examples of divalent hydrocarbon groups include straight-chain or branched alkylene groups and divalent alicyclic hydrocarbon groups. Examples of straight-chain or branched alkylene groups include methylene, methylmethylene, dimethylmethylene, ethylene, propylene, butylene, and trimethylene, which are straight-chain or branched alkylene groups with 1 to 18 carbon atoms (preferably 2 to 12, more preferably 3 to 6). Examples of divalent alicyclic hydrocarbon groups include cycloalkylene groups (including cycloalkylene groups) with 3 to 18 carbon atoms, such as 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, and cyclohexylene.

[0054] It should be noted that alkyl groups (e.g., alkyl groups with 1 to 6 carbon atoms) may be bonded to one or more carbon atoms constituting the cyclohexane ring (epoxycyclohexyl) in formulas (a-1) and (a-2).

[0055] Representative examples of compounds represented by formulas (a-1) and (a-2) include compounds represented by formulas (a-3) and (a-4) (where n3 to n8 may be the same or different, representing integers from 1 to 30, preferably 1 to 20, and more preferably 1 to 10). Specific products include alicyclic epoxy compounds such as tetra(3,4-epoxycyclohexylmethyl) ester modified with ε-caprolactone (e.g., trade name "EPOLEAD GT401", manufactured by Daicel Co., Ltd.).

[0056] [Chemical Formula 5]

[0057]

[0058] [Chemical Formula 6]

[0059]

[0060] As (ii) compounds having three or more epoxy groups directly connected to an alicyclic ring by single bonds, examples include compounds represented by the following formula (a').

[0061] [Chemical Formula 7]

[0062]

[0063] In formula (a'), R is a group (p-valent organic group) formed by removing p hydroxyl groups (-OH) from the structural formula of a p-hydronic alcohol, and p and n represent natural numbers. As a p-hydronic alcohol [R-(OH)] pExamples of compounds represented by formula (a') include polyols such as 2,2-bis(hydroxymethyl)-1-butanol (preferably polyols with 1 to 15 carbon atoms). p is preferably 1 to 6, and n is preferably 1 to 30. When p is 2 or more, the n in the groups within each square bracket (outer bracket) can be the same or different. It should be noted that p and n satisfy the condition that the groups within the square brackets (outer brackets) are 3 or more. Specific examples of compounds represented by formula (a') include 1,2-epoxy-4-(2-epoxyethylene)cyclohexane adducts of 2,2-bis(hydroxymethyl)-1-butanol (e.g., trade name "EHPE3150", manufactured by Daicel Co., Ltd.).

[0064] Trifunctional or higher oxetane compounds refer to compounds having three or more oxetyl groups as functional groups within one molecule. Trifunctional or higher oxetane compounds may also have functional groups other than oxetyl groups. Examples of functional groups other than oxetyl groups include: cationic polymerizable groups other than oxetyl groups, reactive functional groups such as free radical polymerizable groups, and non-reactive functional groups such as alkyl groups. However, trifunctional or higher oxetane compounds do not include those belonging to trifunctional or higher alicyclic epoxide compounds.

[0065] Examples of trifunctional or higher oxetane compounds include: phenolic varnish resins, poly(p-hydroxystyrene), calixarenes, resorcinol-type calixarenes, or compounds formed by oxetane-butanizing resins with three or more hydroxyl groups; and resins containing unsaturated monomers with oxetane groups (e.g., oxetane-containing (meth)acrylates) as structural units. Specific examples of trifunctional or higher oxetane compounds include Aron Oxetane PNOX-1009 and OX-SC (manufactured by Toa Synthetic Co., Ltd.).

[0066] [Ingredient (B)]

[0067] Component (B) in this invention is a polyfunctional (meth)acrylic acid compound, which is a free radical curable compound having two or more (meth)acryloyl groups within one molecule. However, compounds belonging to component (A) are excluded.

[0068] The molecular weight of the polyfunctional (meth)acrylic acid compound [in the case where the polyfunctional (meth)acrylic acid compound is an oligomer or polymer, the weight-average molecular weight (based on GPC and converted to polystyrene)] is not particularly limited, for example, less than 5000, preferably 2000 to 100, more preferably 1000 to 200, and particularly preferably 500 to 250. By making the molecular weight within the above range, there is a tendency for the obtained resin composition to have excellent coatability.

[0069] The number (total number) of (meth)acryloyl groups within the molecule of a polyfunctional (meth)acrylic acid compound is not particularly limited as long as it is two or more, with a lower limit of three and a more preferably four. Furthermore, the upper limit is, for example, 15, preferably 12, and more preferably 10.

[0070] Examples of multifunctional (meth)acrylate compounds include aliphatic (meth)acrylates, alicyclic (meth)acrylates, and aromatic (meth)acrylates. In this invention, aliphatic (meth)acrylates (e.g., linear or branched aliphatic (meth)acrylates) are preferred from the viewpoint of the non-coloring properties of the cured product.

[0071] Specifically, examples of polyfunctional (meth)acrylate compounds include: 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, tricyclodecanediethanol di(meth)acrylate, glycerol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. Di(meth)acrylates of alcohols, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene, 2,2-bis[4-((meth)acryloyloxydiethoxy)phenyl]propane, and their derivatives, etc., are difunctional (meth)acrylates; ethoxylated isocyanurate tri(meth)acrylate, ε-caprolactone-modified tri(2-(meth)acryloyloxyethyl)isocyanurate, glycerol tri(meth)acrylate, ethoxylated glycerol tri(meth)acrylate, propoxylated... Glyceryl tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, tri(meth)acrylate of 3 moles of trimethylolpropane ethylene oxide adduct, tri(meth)acrylate of 3 moles of trimethylolpropane propylene oxide adduct, tri(meth)acrylate of 6 moles of trimethylolpropane ethylene oxide adduct, tri(meth)acrylate of 6 moles of trimethylolpropane propylene oxide adduct, di(trimethylolpropane)tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate Acrylates, dipentaerythritol poly(meth)acrylates (e.g., dipentaerythritol hexa(meth)acrylate, hexa(meth)acrylate of the caprolactone adduct of dipentaerythritol, etc.), and their derivatives, polyester (meth)acrylates, polyether (meth)acrylates, acrylic (meth)acrylates, urethane (meth)acrylates, epoxy (meth)acrylates, polydiolefin (meth)acrylates (e.g., polybutadiene (meth)acrylates, etc.), melamine (meth)acrylates, polyacetal (meth)acrylates, and other trifunctional or higher polyfunctional (meth)acrylates, etc.

[0072] As a multifunctional (meth)acrylic acid compound, commercially available products can be used, such as: pentaerythritol (tri / tetra)acrylate (a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate, product name "PETIA", manufactured by Daicel Ornex Co., Ltd.).

[0073] [Ingredient (C)]

[0074] In this invention, component (C) is a photocationic polymerization initiator. A photocationic polymerization initiator is a compound that generates acid through light irradiation, thereby initiating a curing reaction of cationic polymerizable groups in a resin composition. It consists of a cationic portion that absorbs light and an anionic portion that becomes the acid generation source.

[0075] Examples of photocationic polymerization initiators include: diazonium salts and iodine. Salt compounds, sulfonium salt compounds, phosphonium salt compounds, selenium salt compounds, oxygen Salt compounds, ammonium salt compounds, bromide salt compounds, etc.

[0076] Among these, sulfonium salt compounds are preferred from the perspective of forming cured products with excellent curability. Examples of sulfonium salt compounds as the cationic part include aryl sulfonium ions such as (4-hydroxyphenyl)methylbenzylsulfonium ion, triphenylsulfonium ion, diphenyl[4-(phenylthio)phenyl]sulfonium ion, 4-(4-biphenylthio)phenyl-4-biphenylphenylsulfonium ion, and tri-p-tolylsulfonium ion (especially triarylsulfonium ion).

[0077] Examples of anionic components that serve as photocationic polymerization initiators include: [(Y)] s B(Phf) 4-s ] - (In the formula, Y represents phenyl or biphenyl. Phf represents a phenyl group in which at least one hydrogen atom is substituted by at least one of the following: perfluoroalkyl, perfluoroalkoxy, and halogen atoms. s is an integer from 0 to 3.) BF4 - 、[(Rf) t PF 6-t ] - (In the formula, Rf represents an alkyl group in which more than 80% of the hydrogen atoms are replaced by fluorine atoms. t represents an integer from 0 to 5), AsF6 - SbF6 - SbF5OH - wait.

[0078] As photocationic polymerization initiators, examples include: (4-hydroxyphenyl)methylbenzylsulfonium tetra(pentafluorophenyl)borate, 4-(4-biphenylthio)phenyl-4-biphenylphenylsulfonium tetra(pentafluorophenyl)borate, 4-(phenylthio)phenyl diphenylsulfonium phenyl tri(pentafluorophenyl)borate, [4-(4-biphenylthio)phenyl]-4-biphenylphenylsulfonium phenyl tri(pentafluorophenyl)borate, diphenyl[4-(phenylthio)phenyl]sulfonium tri(pentafluoroethyl)trifluorophosphate, diphenyl[4-( [4-(phenylthio)phenyl]sulfonium tetra(pentafluorophenyl)borate, diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate, 4-(4-biphenylthio)phenyl-4-biphenylphenylsulfonium tri(pentafluoroethyl)trifluorophosphate, bis[4-(diphenylsulfonium)phenyl]sulfide phenyl tri(pentafluorophenyl)borate, [4-(2-thioxanthoneylthio)phenyl]phenyl-2-thioxanthoneylsulfonium phenyl tri(pentafluorophenyl)borate, 4-(phenylthio)phenyl diphenylsulfonium hexafluoroantimonate, trade name "CYRACURE" "UVI-6970", "CYRACURE UVI-6974", "CYRACURE UVI-6990", "CYRACURE UVI-950" (all manufactured by US Union Carbide), "Irgacure250", "Irgacure261", "Irgacure264" (all manufactured by BASF), "CG-24-61" (manufactured by Ciba-Geigy), "OPTOMER SP-150", "OPTOMER SP-151", "OPTOMER SP-170", "OPTOMER SP-171" (all manufactured by ADEKA Co., Ltd.), "DAICAT" II (manufactured by Daicel Co., Ltd.), "UVAC1590", "UVAC1591" (manufactured by DAICL-CYTEC Co., Ltd.), "CI-2064", "CI-2639", "CI-2624", "CI-2481", "CI-2734", "CI-2855", "CI-2823", "CI-2758", "CIT-1682" (manufactured by Nippon Soda Co., Ltd.), "PI-2074" (manufactured by Rhodia Co., Ltd., tetra(pentafluorophenyl)borate tolueneisopropylphenyl iodide) Commercially available products include: "FFC509" (manufactured by 3M), "BBI-102", "BBI-101", "BBI-103", "MPI-103", "TPS-103", "MDS-103", "DTS-103", "NAT-103", "NDS-103" (manufactured by Green Chemical Co., Ltd.), "CD-1010", "CD-1011", "CD-1012" (manufactured by Sartomer America), "CPI-100P", and "CPI-101A" (manufactured by San-Apro Co., Ltd.).

[0079] [Ingredient (D)]

[0080] Component (D) in this invention is a photoradical polymerization initiator. A photoradical polymerization initiator is a compound that generates free radicals through light irradiation, thereby initiating a curing reaction of the free radical polymerizable groups in the resin composition. Examples include: benzophenone, benzyl acetophenone, benzyl dimethyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, dimethoxyacetophenone, dimethoxyphenylacetophenone, diethoxyacetophenone, diphenyl disulfite, methyl phthalate, ethyl 4-dimethylaminobenzoate (manufactured by Nippon Kayaku Co., Ltd., trade name "Kayacure EPA", etc.), 2,4-diethylthioxanone (manufactured by Nippon Kayaku Co., Ltd., trade name "Kayacure"). DETX, etc.), 2-methyl-1-[4-(methyl)phenyl]-2-morpholino-1-propanone (manufactured by BASF, trade name "Irgacure 907", etc.), 1-hydroxycyclohexylphenyl ketone (manufactured by BASF, trade name "Irgacure 184", etc.), 2-amino-2-benzoyl-1-phenylalanine compounds such as 2-dimethylamino-2-(4-morpholino)benzoyl-1-phenylpropane, tetra(tert-butylperoxycarbonyl)benzophenone, benzoin, 2-hydroxy-2-methyl- 1-Phenylacetyl-1-one, aminobenzene derivatives such as 4,4'-bis(diethylamino)benzophenone, imidazole compounds such as 2,2'-bis(2-chlorophenyl)-4,5,4',5'-tetraphenyl-1,2'-biimidazole (manufactured by Hodogaya Chemical Co., Ltd., trade name "B-CIM", etc.), halomethylated triazine compounds such as 2,6-bis(trichloromethyl)-4-(4-methoxynaphthyl-1-yl)-1,3,5-triazine, and 2-trichloromethyl-5-(2-benzofuran-2-yl-vinyl)-1,3,4- Halogenated methyl groups such as diazole Diazole compounds, etc.

[0081] [Ingredient (E)]

[0082] The resin composition of the present invention may contain a siloxane compound having two or more epoxy groups within its molecule as component (E). The aforementioned siloxane compound is a compound having two or more epoxy groups within its molecule and having a backbone composed of siloxane bonds (-Si-O-Si-). The siloxane backbone (Si-O-Si backbone) in the aforementioned siloxane compound is not particularly limited, and examples include: cyclic siloxane backbones; linear siloxanes; cage-like or ladder-like polysilsesquioxanes; and other polysiloxane backbones. Among these, from the viewpoint of improving the crack resistance of the cured product, cyclic siloxane backbones and linear siloxane backbones are preferred as the siloxane backbone. That is, cyclic siloxanes having two or more epoxy groups within their molecule and linear siloxanes having two or more epoxy groups within their molecule are preferred as the aforementioned siloxane compound.

[0083] When the above-mentioned siloxane compound is a cyclic siloxane having two or more epoxy groups in the molecule, the number of Si-O units forming the siloxane ring (equal to the number of silicon atoms forming the siloxane ring) is not particularly limited, but from the viewpoint of improving the crack resistance of the cured product, it is preferably 2 to 12, more preferably 4 to 8.

[0084] The weight-average molecular weight of the aforementioned siloxane compounds is not particularly limited, but from the viewpoint of improving the crack resistance of the cured product, it is preferably 100 to 3000, more preferably 180 to 2000. It should be noted that the weight-average molecular weight of the aforementioned siloxane compounds can be calculated based on the molecular weight of standard polystyrene determined by GPC (gel permeation chromatography).

[0085] The number of epoxy groups in the molecule of the above-mentioned siloxane compound is not particularly limited as long as there are 2 or more epoxy groups. From the viewpoint of improving the crack resistance of the cured product, it is preferred to have 2 to 4 (2, 3 or 4).

[0086] The epoxy equivalent of the aforementioned siloxane compounds is not particularly limited, but from the viewpoint of improving the crack resistance of the cured product, it is preferably 180 to 2000, more preferably 180 to 1500, and even more preferably 180 to 1000. It should be noted that the epoxy equivalent is a value determined based on JIS K7236.

[0087] The epoxy groups in the aforementioned siloxane compounds are not particularly limited, but from the viewpoint of improving the crack resistance of the cured product, alicyclic epoxy groups are preferred, and epoxy cyclohexyl groups are particularly preferred.

[0088] Examples of the aforementioned siloxane compounds include, for example, siloxane compounds represented by the following formula (e).

[0089] [Chemical Formula 8]

[0090]

[0091] In equation (e), R a "Same" or "different" indicates a group containing an epoxy group or an alkyl group. However, R in formula (e) is different. a At least two (e.g., two to four) of these groups are epoxy groups. The aforementioned epoxy groups are groups containing at least one epoxy group (epoxy ring). Examples include: groups obtained by epoxidation of at least one double bond in a straight-chain or branched aliphatic hydrocarbon group having a carbon-carbon unsaturated double bond, such as an alkenyl group; and groups obtained by epoxidation of at least one double bond in a cyclic aliphatic hydrocarbon group having a carbon-carbon unsaturated double bond (e.g., cycloalkenyl; cyclohexenylethyl, etc., cycloalkenylalkyl, etc.). More specifically, examples include: 1,2-epoxyethyl (epoxy group), 1,2-epoxypropyl, 2,3-epoxypropyl (glycidyl), 2,3-epoxy-2-methylpropyl (methylglycidyl), 3,4-epoxybutyl, 3-glycidyloxypropyl, 3,4-epoxycyclohexylmethyl, 2-(3,4-epoxycyclohexyl)ethyl, etc. Preferably, the group is obtained by epoxidation of at least one double bond of a cyclic aliphatic hydrocarbon group having a carbon-carbon unsaturated double bond. Examples of alkyl groups include straight-chain or branched alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, hexyl, octyl, isooctyl, decyl, and dodecyl. Among these, straight-chain or branched alkyl groups with 1 to 10 carbon atoms are preferred.

[0092] In formula (e), m represents an integer from 2 to 12. In particular, from the viewpoint of improving the crack resistance of the cured product, m is preferably 4 to 8, more preferably 4 or 5.

[0093] More specifically, examples of the aforementioned siloxane compounds include: 2,4-bis[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,4,6,6,8,8-hexamethyl-cyclotetrasiloxane, 4,8-bis[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,2,4,6,6,8-hexamethyl-cyclotetrasiloxane, 2,4-bis[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-6,8-dipropyl-2,4,6,8-tetramethyl-cyclotetrasiloxane, 4,8-bis[2-(3-{oxabicyclo[4.1.0]heptyl}] Sesquioxanes having two or more epoxy groups in their molecules, such as [2,6-dipropyl-2,4,6,8-tetramethyl-cyclotetrasiloxane], 2,4,8-tris[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,4,6,6,8-pentamethyl-cyclotetrasiloxane, 2,4,8-tris[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-6-propyl-2,4,6,8-tetramethyl-cyclotetrasiloxane, and 2,4,6,8-tetra[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,4,6,8-tetramethyl-cyclotetrasiloxane. More specifically, examples include cyclic siloxanes having two or more epoxy groups in their molecules, represented by the following formula.

[0094] [Chemical Formula 9]

[0095]

[0096] Alternatively, as the aforementioned siloxane compound, for example, an organosilicon resin containing an alicyclic epoxy group as described in Japanese Patent Application Publication No. 2008-248169, or an organopolysilsesquioxane resin having at least two epoxy functional groups in one molecule as described in Japanese Patent Application Publication No. 2008-19422, may be used.

[0097] It should be noted that in the resin composition of the present invention, the above-mentioned siloxane compound can be used alone or in combination of two or more.

[0098] The aforementioned siloxane compounds can be obtained, for example, as commercially available products under trade names such as "X-40-2678", "X-40-2670", and "X-40-2720" (all manufactured by Shin-Etsu Chemical Co., Ltd.) which are cyclic siloxanes having two or more epoxy groups within their molecules. Furthermore, the aforementioned siloxane compounds can be manufactured using known or conventional methods.

[0099] [Other ingredients]

[0100] Without impairing the effects of the present invention, the resin composition of the present invention may contain other components besides those described above. For example, it may contain curing compounds other than components (A), (B), and (E) (hereinafter sometimes referred to as "other curing compounds"). In addition, it may contain various additives other than components (C) and (D) (hereinafter sometimes referred to as "other additives").

[0101] Other examples of curable compounds include: monofunctional or difunctional alicyclic epoxy compounds, epoxy compounds other than alicyclic epoxy compounds, and monofunctional (meth)acrylic acid compounds. Examples of monofunctional or difunctional alicyclic epoxy compounds include compounds represented by the following formula (f).

[0102] [Chemical Formula 10]

[0103]

[0104] In formula (f), X4 represents a linking group (a divalent group having one or more atoms). Examples of linking groups include divalent hydrocarbon groups, carbonyl groups, ether bonds, ester bonds, carbonate bonds, amide bonds, and groups formed by the linkage of multiple of these groups. It should be noted that alkyl groups (e.g., alkyl groups with 1 to 6 carbon atoms) may also be bonded to one or more carbon atoms constituting the cyclohexane ring (epoxycyclohexyl) in formula (f).

[0105] Examples of divalent hydrocarbon groups include straight-chain or branched alkylene groups and divalent alicyclic hydrocarbon groups. Examples of straight-chain or branched alkylene groups include: methylene, methylmethylene, dimethylmethylene, ethylene, propylene, trimethylene, and other straight-chain or branched alkylene groups with 1 to 18 carbon atoms. Examples of divalent alicyclic hydrocarbon groups include: 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, cyclohexylene, and other cycloalkylene groups with 3 to 18 carbon atoms (including cycloalkylene groups).

[0106] Representative examples of compounds represented by formula (f) include (3,4,3',4'-diepoxy)bicyclohexane, bis(3,4-epoxycyclohexylmethyl) ether, 1,2-epoxy-1,2-bis(3,4-epoxycyclohexane-1-yl)ethane, 2,2-bis(3,4-epoxycyclohexane-1-yl)propane, 1,2-bis(3,4-epoxycyclohexane-1-yl)ethane, or compounds represented by formulas (f-1) to (f-8) below. In formula (f-5) below, L is an alkylene group having 1 to 8 carbon atoms, preferably a straight-chain or branched alkylene group having 1 to 3 carbon atoms, such as methylene, ethylene, propylene, or isopropylene. In formulas (f-5) and (f-7) below, n9 and n10 represent integers from 1 to 30, respectively.

[0107] [Chemical Formula 11]

[0108]

[0109] Other additives include, for example: polyols, curing aids, organosiloxane compounds, metal oxide particles, rubber particles, defoamers, silane coupling agents, fillers, plasticizers, leveling agents, antistatic agents, mold release agents, surfactants, flame retardants, colorants, antioxidants, ultraviolet absorbers, ion adsorbents, and phosphors.

[0110] Furthermore, the resin composition of the present invention may be supplemented with solvents as appropriate, depending on the coating conditions. Examples of solvents include butyl acetate, methyl ethyl ketone, and 1-methoxy-2-propyl acetate. These solvents may be used alone or in combination of two or more.

[0111] The resin composition of the present invention can be prepared by stirring / mixing the above-mentioned components under heating conditions as needed. Stirring / mixing can be performed using various mixers such as dissolvers and homogenizers, kneaders, rollers, bead mills, and self-rotating / revolutionary stirring devices, or other known or conventional stirring / mixing mechanisms. Alternatively, degassing can be performed under vacuum after stirring / mixing. It should be noted that the resin composition of the present invention can be a single-component system composition in which the components are pre-mixed, or a multi-component system (e.g., a two-component system) composition in which components divided into two or more parts (each component may be a mixture of two or more components) are mixed in a given proportion before use.

[0112] The resin composition of the present invention contains one or more trifunctional or higher alicyclic epoxy compounds and / or trifunctional or higher oxetane compounds as component (A). The content of component (A) is not particularly limited, and is, for example, 1 to 75% by weight of the total amount of curable compounds contained in the resin composition of the present invention. The upper limit is preferably 70% by weight, more preferably 60% by weight, further preferably 50% by weight, particularly preferably 40% by weight, and most preferably 35% by weight. The lower limit is preferably 3% by weight, more preferably 5% by weight, further preferably 10% by weight, particularly preferably 20% by weight, and most preferably 30% by weight. By setting the content of component (A) within the above range, there is a tendency for excellent scratch resistance, flexural resistance, and crack resistance. It should be noted that, from the viewpoint of improving flexural resistance and crack resistance, the content of component (A) is preferably, for example, 10 to 75% by weight of the total amount of curable compounds contained in the resin composition, more preferably 20 to 75% by weight, and even more preferably 30 to 75% by weight.

[0113] The resin composition of the present invention contains one or more polyfunctional (meth)acrylic acid compounds as component (B). The content of component (B) is not particularly limited, but is, for example, 25 to 99% by weight of the total amount of curable compounds contained in the resin composition of the present invention. The upper limit is preferably 97% by weight, more preferably 95% by weight, further preferably 90% by weight, particularly preferably 80% by weight, and most preferably 70% by weight. The lower limit is preferably 30% by weight, more preferably 40% by weight, further preferably 50% by weight, particularly preferably 60% by weight, and most preferably 65% ​​by weight. By setting the content of component (B) within the above range, there is a tendency for excellent scratch resistance, flexural resistance, and crack resistance. It should be noted that, from the viewpoint of improving flexural resistance and crack resistance, the content of component (B) is preferably, for example, 25 to 90% by weight of the total amount of curable compounds contained in the resin composition, more preferably 25 to 80% by weight, and even more preferably 25 to 70% by weight.

[0114] The content of components (A) and (B) in the resin composition of the present invention is not particularly limited, and is, for example, 50 to 100% by weight of the total amount of curable compounds contained in the resin composition of the present invention. The upper limit is preferably 99% by weight, more preferably 95% by weight, and particularly preferably 90% by weight. The lower limit is preferably 60% by weight, more preferably 70% by weight, and particularly preferably 80% by weight.

[0115] The ratio of component (A) to component (B) in the resin composition of the present invention (component (A) / component (B)) is not particularly limited, and is, for example, 1 / 99 to 75 / 25. The upper limit is preferably 70 / 30, more preferably 60 / 40, further preferably 50 / 50, and particularly preferably 40 / 60. The lower limit is preferably 3 / 97, more preferably 5 / 95, further preferably 10 / 90, particularly preferably 20 / 80, and most preferably 30 / 70.

[0116] By controlling the content or ratio of components (A) and (B) within the above range, it is possible to improve the resistance to bending and cracking while maintaining the resistance to scratches.

[0117] The resin composition of the present invention contains one or more photocationic polymerization initiators as component (C). The content of component (C) is, for example, 0.05 to 5 parts by weight relative to 100 parts by weight of the curable compound contained in the resin composition of the present invention. When the content of component (C) is below the above range, there is a risk of poor curing. On the other hand, when the content of component (C) is above the above range, there is a tendency for the cured product to become easily colored.

[0118] The resin composition of the present invention contains one or more photoradical polymerization initiators as component (D). The content of component (D) is, for example, 1 to 10 parts by weight relative to 100 parts by weight of the curable compound contained in the resin composition of the present invention. When the content of component (D) is lower than the above range, there is a risk of poor curing. On the other hand, when the content of component (D) is higher than the above range, there is a tendency for the cured product to become easily colored.

[0119] When the resin composition of the present invention contains a siloxane compound having two or more epoxy groups in its molecule as component (E), its content is not particularly limited, but is preferably 0.1 to 30% by weight, more preferably 0.5 to 20% by weight, and even more preferably 1.0 to 10% by weight, of the total amount of curable compound contained in the resin composition of the present invention. By controlling the content of the above-mentioned siloxane compound within the above range, there is a tendency to improve the crack resistance of the cured product.

[0120] The content of other curing compounds (e.g., compounds represented by formula (f)) may be appropriately set according to the application, and relative to the total amount of curing compounds contained in the resin composition of the present invention, for example, is 50% by weight or less, preferably 30% by weight or less, more preferably 20% by weight or less, and particularly preferably 10% by weight or less.

[0121] The content of other additives can be appropriately set according to the application, for example, 40 parts by weight or less, preferably 20 parts by weight or less, more preferably 10 parts by weight or less, and particularly preferably 5 parts by weight or less, relative to 100 parts by weight of the curing compound contained in the resin composition of the present invention.

[0122] The resin composition of this invention can be cured in an extremely short time after coating by irradiation with active energy rays such as ultraviolet light or electron beams, resulting in a cured product with high hardness and excellent scratch and crack resistance. High-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, xenon lamps, metal halide lamps, etc., can be used as the light source for ultraviolet irradiation. The irradiation time varies depending on the type of light source, the distance between the light source and the coating surface, and other conditions, ranging from tens of seconds to several seconds. Typically, an irradiation source with a lamp output power of approximately 80-300 W / cm is used. The UV irradiation dose is 50-3000 mJ / cm. 2 Approximately. When irradiated with an electron beam, it is preferable to use an electron beam with an energy range of 50–1000 keV and an irradiation dose of 2–5 Mrad. After irradiation with active energy rays, heating (post-curing) can also be performed as needed to accelerate curing.

[0123] The cured resin composition of the present invention exhibits excellent scratch resistance, with the number of rubbing cycles up to 300 times or more, preferably 500 times or more, and particularly preferably 1000 times or more, until scratches occur due to the scratch resistance evaluation test described in the examples.

[0124] The cured resin composition of the present invention has high hardness, for example, a pencil hardness of 2H or higher.

[0125] The cured resin composition of the present invention exhibits excellent transparency, with a light transmittance of 80% or more (converted to a thickness of 20 μm) at a wavelength of 450 nm. It should be noted that the light transmittance can be measured, for example, using a spectrophotometer (e.g., the trade name "UV-2400," manufactured by Daizu Corporation).

[0126] <Hard Coating>

[0127] The hard coating of the present invention is characterized in that at least a portion of it has one or more hard coating layers formed by the cured resin composition of the present invention.

[0128] As the hard coating film of the present invention, a laminate having at least one substrate layer and at least one hard coating layer is preferred. As the substrate for forming the substrate layer, plastic films such as TAC (cellulose triacetate) and PET (polyethylene terephthalate) are preferred.

[0129] The hard coating of the present invention can be manufactured, for example, by applying the resin composition for forming the hard coating of the present invention to at least one side of a substrate and then curing it.

[0130] The thickness of the hard coating layer is, for example, about 3 to 50 μm. Additionally, the overall thickness of the hard coating film is, for example, about 30 to 300 μm.

[0131] The hard coating film of this invention possesses high hardness and excellent scratch and crack resistance. Therefore, it is suitable for use in protecting the touch panels and displays of electronic devices such as LCD TVs, LCD screens, laptops, mobile displays, tablet PCs, and smartphones. In other words, the hard coating film of this invention is suitable for use as a protective film for the touch panels and displays of electronic devices.

[0132] <Electronic Devices>

[0133] The electronic device of the present invention has at least a portion of its surface having a hard coating formed from a cured product of the resin composition of the present invention.

[0134] The electronic devices of the present invention include, for example, LCD TVs, LCD screens, laptops, mobile displays, tablet PCs, smartphones, etc.

[0135] The electronic device of the present invention can be manufactured, for example, by directly coating the surface of the electronic device with the resin composition of the present invention and curing it, or by attaching the above-mentioned hard coating film to the surface of the electronic device.

[0136] The electronic devices of the present invention are protected by a hard coating with excellent surface hardness and scratch resistance formed by the cured resin composition of the present invention, which is used to protect the touch panel and display. Therefore, they are not easily damaged or contaminated and can maintain high quality for a long time.

[0137] <Molded Products>

[0138] The molded article of the present invention has at least a portion of its surface having a hard coating formed by the cured product of the resin composition of the present invention.

[0139] Examples of molded articles of the present invention include: lenses, sensors, resins (or resin windows) that replace glass, automotive parts (such as interior parts like dashboards, exterior parts like door handles, roof rails, and electrical installation parts like headlight lenses), etc.

[0140] The molded articles of the present invention can be manufactured, for example, by directly coating the surface of the molded article with the resin composition of the present invention and curing it, or by attaching the above-mentioned hard coating film to the surface of the molded article.

[0141] The molded articles of the present invention have a hard coating with excellent surface hardness and scratch resistance formed by the cured resin composition of the present invention, and are therefore not easily damaged or contaminated, and can maintain high quality for a long time.

[0142] Example

[0143] The present invention will now be described in more detail with reference to the embodiments, but the present invention is not limited to these embodiments.

[0144] [Preparation of Resin Composition]

[0145] The components were mixed according to the proportions shown in Table 1 (unit: parts by weight), and stirred / degassed using a rotary agitator (trade name "Awatori Rentaro AR-250", manufactured by THINKY Co., Ltd.) to obtain a resin composition.

[0146] [Preparation of Hard Coating]

[0147] The resin composition obtained above was coated onto a 1 mm thick polycarbonate substrate using a wire bar coater to achieve a dried film thickness of 25 μm, forming a coating film. The coating film was then dried at 80°C for 1 minute and then irradiated with ultraviolet light (irradiation amount shown in Table 1) in a sealed container purged with nitrogen, followed by post-curing (temperature and time shown in Table 1), forming a cured coating film. A laminate (hard coating film (1)) having the structure of "PC substrate / cured product (cured coating film)" obtained as described above was obtained.

[0148] Next, the polycarbonate substrate was changed to a 100 μm thick PET substrate, and the coating thickness was changed to 15 μm. Otherwise, the same procedure was performed as above to obtain a laminate (hard coating (2)) having the structure of "PET substrate / cured product (cured coating)".

[0149] Furthermore, the thickness of the polycarbonate substrate was changed to 5 mm, and the thickness of the coating was changed to 40 μm. Otherwise, the same procedure was performed as described above to obtain a laminate (hard coating (3)) having the structure of "PC substrate / cured product (cured coating)".

[0150] It should be noted that in Comparative Example 3, a cured coating was formed without post-curing.

[0151] [Pencil Hardness (1)]

[0152] The evaluation of pencil hardness is based on JIS K5600.

[0153] First, scratch the cured coating surface of the sample for pencil hardness evaluation with a pencil of a certain hardness. If no damage is found, scratch with a pencil of a higher hardness. If damage is confirmed, scratch again with a pencil of a lower hardness to confirm whether damage is found. If no damage is confirmed, scratch again with a pencil of a higher hardness to confirm whether damage is found. If reproducibility can be confirmed more than twice, the hardness of the hardest pencil that did not cause damage is taken as the pencil hardness of the sample. The evaluation conditions are as follows.

[0154] Evaluation sample: hard coating (1)

[0155] Evaluation pencil: "Pencil Hardness Test Pencil" manufactured by Mitsubishi Pencil Co., Ltd.

[0156] Load: 750gf

[0157] Scratching distance: 50mm or more

[0158] Scraping angle: 45°

[0159] Test environment: 23℃, 50%RH

[0160] [Pencil Hardness (2)]

[0161] The evaluation sample was changed from hard coating (1) to hard coating (2), and the pencil hardness was evaluated by the same method as that used for pencil hardness (1).

[0162] [Abrasion Resistance]

[0163] Use #0000 steel wool at 500g / cm 2 The surface of the cured hard coating (1) was rubbed under load, and the scratch resistance was evaluated based on the number of rubs until scratches were produced.

[0164] [Bending resistance (1)]

[0165] Based on JIS K5600-5-1 (bending resistance (cylindrical mandrel method)), the coating surface of the hard coating (2) was bent into a mandrel with a diameter of 5 mm 10 times with the coating surface facing inward. Cracks were observed by visual inspection and evaluated according to the following criteria.

[0166] ◎: No cracks have appeared

[0167] ○: One or two tiny cracks have appeared.

[0168] △: 3-5 cracks were generated.

[0169] ×: More than 6 cracks have appeared.

[0170] [Bending resistance (2)]

[0171] The coating surface of the hard coating (2) was bent in such a way that the coating surface was on the outside, and otherwise, the bending resistance (1) was evaluated in the same way.

[0172] [Bending resistance (3)]

[0173] The diameter of the mandrel was set to 1 mm. Otherwise, the bending resistance was evaluated in the same way as the bending resistance (1).

[0174] [Bending resistance (4)]

[0175] The diameter of the mandrel was set to 1 mm, and it was bent so that the coating surface of the hard coating (2) was on the outside. Otherwise, the same evaluation as the bending resistance (1) was carried out.

[0176] [Crack resistance]

[0177] The operation of exposing the hard coating film (3) to a gas atmosphere at -40°C for 30 minutes and then to a gas atmosphere at 100°C for 30 minutes was considered as one cycle, and 200 cycles of thermal shock were performed using a thermal shock testing machine. Then, the surface of the cured coating film (3) was observed for cracks using a digital microscope (trade name "VHX-900", manufactured by Keyence Co., Ltd.), and the crack resistance was evaluated according to the following criteria.

[0178] ○: No cracks

[0179] ×: Cracks present

[0180]

[0181] Based on the above results, in Examples 1-6, cured products with not only high hardness but also excellent scratch resistance, flexural resistance, and crack resistance can be obtained. Among them, Examples 5 and 6 were found to exhibit extremely high flexural resistance.

[0182] Additionally, the abbreviations used in the table are explained below.

[0183] [Ingredients (A)]

[0184] EPOLEAD GT-401: Butanetetracarboxylate tetra(3,4-epoxycyclohexylmethyl) ester modified ε-caprolactone, molecular weight: 789, manufactured by Daicel Co., Ltd.

[0185] EHPE3150: 1,2-epoxy-4-(2-epoxyethylene)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, manufactured by Daicel Inc.

[0186] [Other curing compounds]

[0187] (3,4,3',4'-diepoxy)bicyclohexane, molecular weight: 194, manufactured by Daicel Corporation.

[0188] [Ingredient (B)]

[0189] PETIA: A mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate, molecular weight: 298 / 352, manufactured by Daicel Ornex Co., Ltd.

[0190] [Ingredient (C)]

[0191] CPI-210S: Diphenyl[4-(phenylthio)phenyl]sulfonium tri(pentafluoroethyl)trifluorophosphate, manufactured by San Apro Corporation.

[0192] [Ingredient (D)]

[0193] Irgacure 184: 1-Hydroxycyclohexylphenyl ketone, manufactured by BASF.

[0194] In summary, the technical solution of the present invention and its variations are described below.

[0195] [1] A resin composition for forming a hard coating, comprising the following components (A) to (D):

[0196] Component (A): Trifunctional or higher alicyclic epoxy compounds and / or trifunctional or higher oxocyclic butane compounds;

[0197] Component (B): Polyfunctional (meth)acrylic acid compound;

[0198] Component (C): Photocationic polymerization initiator;

[0199] Component (D): Photoradical polymerization initiator.

[0200] [2] The resin composition for forming a hard coating according to [1], wherein,

[0201] The content of component (A) is 1 to 75% by weight of the total amount of curable compounds contained in the resin composition, with the upper limit preferably being 70% by weight, more preferably 60% by weight, further preferably 50% by weight, particularly preferably 40% by weight, and most preferably 35% by weight, and the lower limit preferably being 3% by weight, more preferably 5% by weight, further preferably 10% by weight, particularly preferably 20% by weight, and most preferably 30% by weight.

[0202] [3] The resin composition for forming a hard coating according to [1] or [2], wherein,

[0203] Component (A) contains at least one of the following compounds as a trifunctional or higher alicyclic epoxy compound: a compound represented by formula (a-3) [where n3 and n4 are the same or different and represent integers from 1 to 30], a compound represented by formula (a-4) [where n5, n6, n7 and n8 are the same or different and represent integers from 1 to 30], and a compound represented by formula (a') [where R is a group (p-valent organic group) formed by removing p hydroxyl groups (-OH) from the structure of a p-hydrol, and p and n represent natural numbers].

[0204] [4] The resin composition for forming a hard coating according to any one of [1] to [3], wherein,

[0205] The polyfunctional (meth)acrylic acid compound has two or more (meth)acryloyl groups in its molecule, with a lower limit of three, more preferably four, and an upper limit of 15, more preferably 12, and more preferably 10.

[0206] [5] The resin composition for forming a hard coating according to any one of [1] to [4], wherein,

[0207] Component (B) contains at least one selected from aliphatic (meth)acrylates, alicyclic (meth)acrylates, and aromatic (meth)acrylates as a polyfunctional (meth)acrylate compound.

[0208] [6] The resin composition for forming a hard coating according to any one of [1] to [5], wherein,

[0209] The polyfunctional (meth)acrylic acid compound has two or more (meth)acryloyl groups in its molecule, with a lower limit of three, more preferably four, and an upper limit of 15, more preferably 12, and more preferably 10.

[0210] [7] The resin composition for forming a hard coating according to any one of [1] to [6] further contains a siloxane compound having two or more epoxy groups in the molecule as component (E).

[0211] [8] The resin composition for forming a hard coating according to any one of [1] to [7], wherein,

[0212] The content of component (B) is 25 to 99% by weight of the total amount of curable compounds contained in the resin composition, with the upper limit preferably being 97% by weight, more preferably 95% by weight, further preferably 90% by weight, particularly preferably 80% by weight, and most preferably 70% by weight, and the lower limit preferably being 30% by weight, more preferably 40% by weight, further preferably 50% by weight, particularly preferably 60% by weight, and most preferably 65% ​​by weight.

[0213] [9] The resin composition for forming a hard coating according to any one of [1] to [8], wherein,

[0214] The content of components (A) and (B) is 50 to 100% by weight of the total amount of curable compounds contained in the resin composition, with the upper limit preferably being 99% by weight, more preferably 95% by weight, particularly preferably 90% by weight, and the lower limit preferably being 60% by weight, more preferably 70% by weight, particularly preferably 80% by weight.

[0215]

[10] The resin composition for forming a hard coating according to any one of [1] to [9], wherein,

[0216] The ratio of the content of component (A) to component (B) (component (A) / component (B)) is 1 / 99 to 75 / 25, with the upper limit preferably being 70 / 30, more preferably 60 / 40, further preferably 50 / 50, particularly preferably 40 / 60, and the lower limit preferably being 3 / 97, more preferably 5 / 95, further preferably 10 / 90, particularly preferably 20 / 80, and most preferably 30 / 70.

[0217]

[11] The resin composition for forming a hard coating according to any one of [1] to

[10] , wherein,

[0218] The content of component (C) is 0.05 to 5 parts by weight relative to 100 parts by weight of the curable compound contained in the resin composition.

[0219]

[12] The resin composition for forming a hard coating according to any one of [1] to

[11] , wherein,

[0220] The content of component (D) is 1 to 10 parts by weight relative to 100 parts by weight of the curable compound contained in the resin composition.

[0221]

[13] A hard coating film having a hard coating formed from a cured product of a resin composition for forming a hard coating as described in any one of [1] to

[12] .

[0222]

[14] An electronic device having a hard coating formed from a cured product of a resin composition for forming a hard coating as described in any one of [1] to

[12] .

[0223]

[15] A molded article having a hard coating formed from a cured product of a resin composition for forming a hard coating as described in any one of [1] to

[12] .

[0224] Industrial applicability

[0225] Because the resin composition for forming a hard coating of the present invention has the above-described structure, it can form a hard coating that not only has high hardness but also excellent scratch resistance, bending resistance, and crack resistance by irradiation with active energy rays. Furthermore, by using the resin composition for forming a hard coating of the present invention, hard coating films, molded articles, and electronic devices with a hard coating that not only has high hardness but also excellent scratch resistance, bending resistance, and crack resistance can be provided.

Claims

1. A resin composition for forming a hard coating, comprising the following components (A) to (D): Component (A): The compound represented by the following formula (a-4), ， In equation (a-4), n5, n6, n7, and n8 may be the same or different, representing integers from 1 to 30; Ingredient (B): A mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate; Component (C): Photocationic polymerization initiator; Component (D): Photoradical polymerization initiator, in, The content of component (A) is 40-75% by weight of the total amount of curable compounds contained in the resin composition. The weight ratio of component (A) to component (B), i.e., component (A) / component (B), is 40 / 60~75 / 25. The resin composition for forming the hard coating contains only component (A) and component (B) as curing compounds.

2. A hard coating film comprising a hard coating formed from a cured product of the resin composition for forming a hard coating as described in claim 1.

3. An electronic device comprising a hard coating formed from a cured product of the resin composition for forming a hard coating as described in claim 1.

4. A molded article having a hard coating formed from a cured product of the resin composition for forming a hard coating as described in claim 1.

Images