Photocurable resin composition, base material with cured coating film and method for producing the same

Abstract

To provide a photocurable resin composition capable of forming a cured coating film having excellent coating film appearance, transparency, adhesion to a base material, hardness, visible light transmission properties and infrared absorption properties.SOLUTION: There is provided a photocurable resin composition comprising a urethane (meth)acrylate (A), a (meth)acrylate monomer (B), a photopolymerization initiator (C) and an infrared absorber (D), wherein the urethane (meth)acrylate (A) includes at least a urethane (meth)acrylate (a1) having a carbonate skeleton and a urethane (meth)acrylate (a2) having a functional group number of 6 or more excluding the component (a1) and the (meth)acrylate monomer (B) includes at least a (meth)acrylate monomer (b1) having a functional group number of 2 and a (meth)acrylate monomer (b2) having a functional group number of 5 or more.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a photocurable resin composition. The present invention also relates to a cured film formed from the photocurable resin composition, a substrate with the cured film, and a method for manufacturing the substrate with the cured film.

Background Art

[0002] Generally, polycarbonate resin is widely used as an engineering plastic because of its excellent transparency, moldability, and impact resistance. For example, it is often used for headlamp lenses and side cover lamp lenses for vehicles. However, since polycarbonate resin is soft and has low scratch resistance, a cured film as a protective film is provided on the surface. The cured film is formed by applying a coating agent on the surface and curing it.

[0003] Conventionally, heat ray shielding films have been pasted on the surfaces of windows of houses and vehicles, carports, terrace roofing materials, etc. from the viewpoints of improving habitability and energy saving. In recent years, development of a head-up display that displays driving support information for the driver as an image on the front glass of an automobile has also been carried out. In a head-up display, a form in which an image is reflected and projected from a display unit onto the front glass is common. In this form, since sunlight from the front glass is condensed on the display unit, there is a problem that an image display device such as an LCD element constituting the display unit tends to become high temperature and is liable to thermally deteriorate. Therefore, heat insulation for the display unit is required. Further, since the image data projected from the image display device is displayed on the front glass through the cover film, it is useful as a heat insulation measure to use an infrared cut film coated with a composition having infrared absorption performance for the cover film.

[0004] Such an infrared cut film is composed of, for example, a plastic film substrate and a near-infrared absorption layer provided on one or both sides of the plastic film substrate. The near-infrared absorption layer is formed, for example, by coating and curing a photocurable resin composition (coating agent) having near-infrared absorption properties.

[0005] Therefore, as an infrared cut hard coat resin that can achieve a balance between visible light transmittance and infrared absorption performance and has excellent heat-resistant adhesion to a polycarbonate film, a polyfunctional (meth)acrylate monomer (A) containing a hexafunctional or higher (meth)acrylate monomer, an infrared absorption component (B), and at least two types of intramolecular cleavage type photoinitiators (C) including an oxime ester type are included, and an infrared cut hard coat resin composition characterized in that the blending ratio of (A) in (a1) is 35 to 80% by weight and an infrared cut hard coat film formed therefrom have been proposed (see Patent Document 1). Further, an infrared absorbing composition having an oxide (A) having infrared absorption ability, an acrylic compound (B) not containing fluorine, and an acrylic compound (C) containing fluorine has been proposed for forming an infrared absorption layer of a heat shielding film (see Patent Document 2).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present inventors have been developing a resin film excellent in coating film appearance, transparency, visible light transmittance, and infrared absorption. When using a polycarbonate resin as an adherend (substrate) to which the resin film is adhered, since the polycarbonate resin is soft and has low scratch resistance, it is necessary to improve the hardness while maintaining the adhesiveness to the substrate. However, generally, the adhesiveness to the substrate and the hardness are in a trade-off relationship, and it has been difficult to improve both. In addition, for imparting near-infrared absorption, it is effective to contain a specific near-infrared absorber in the hard coat layer, but there is a problem that physical properties such as visible light transmittance and substrate adhesiveness deteriorate.

[0008] The present invention has been made in view of the above background art and problems, and an object thereof is to provide a photocurable resin composition capable of forming a cured film excellent in coating film appearance, transparency, substrate adhesiveness, hardness, visible light transmittance, and infrared absorption.

Means for Solving the Problems

[0009] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a photocurable resin composition containing a specific urethane (meth) acrylate (A), a specific (meth) acrylate monomer (B), a photopolymerization initiator (C), and an infrared absorber (D). The present invention has been completed based on such findings.

[0010] That is, according to the present invention, the following inventions are provided. [1] A photocurable resin composition containing a urethane (meth) acrylate (A), a (meth) acrylate monomer (B), a photopolymerization initiator (C), and an infrared absorber (D), wherein the urethane (meth) acrylate (A) contains at least a urethane (meth) acrylate (a1) having a carbonate skeleton and a urethane (meth) acrylate (a2) having 6 or more functional groups excluding the component (a1), The content of the urethane (meth)acrylate (A) is 15% by mass or more and 45% by mass or less based on 100% by mass of the solid content of the photocurable resin composition, and the content of the urethane (meth)acrylate (a1) having a carbonate skeleton is 25% by mass or more and 80% by mass or less based on the total amount of the urethane (meth)acrylate (A). The (meth)acrylate monomer (B) contains at least a (meth)acrylate monomer (b1) having 2 functional groups and a (meth)acrylate monomer (b2) having 5 or more functional groups. The content of the (meth)acrylate monomer (B) is 30% by mass or more and 65% by mass or less based on 100% by mass of the solid content of the photocurable resin composition, and the content of the (meth)acrylate monomer (b2) having 5 or more functional groups is 35% by mass or more and 85% by mass or less based on the total amount of the (meth)acrylate monomer (B). A photocurable resin composition. [2] The content of the urethane (meth)acrylate (a2) having 6 or more functional groups excluding the component (a1) is 20% by mass or more and 75% by mass or less based on the total amount of the urethane (meth)acrylate (A). The photocurable resin composition according to [1]. [3] The content of the (meth)acrylate monomer (b1) having 2 functional groups is 15% by mass or more and 65% by mass or less based on the total amount of the (meth)acrylate monomer (B). The photocurable resin composition according to [1] or [2]. [4] The infrared absorber (D) has the general formula: M x W y O z (In the formula, M is one or more elements selected from H, He, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, Yb, W is tungsten, O is oxygen, 0.001 ≦ x / y ≦ 1, 2.0 < z / y ≦ 3.0). It is a composite tungsten oxide. The photocurable resin composition according to any one of [1] to [3]. [5] The photocurable resin composition according to any one of [1] to [4], wherein the content of the infrared absorber (D) is 1% by mass or more and 30% by mass or less based on 100% by mass of the solid content of the photocurable resin composition. [6] The photocurable resin composition according to any one of [1] to [5], further comprising at least one selected from the group consisting of an ultraviolet absorber (E), a light stabilizer (F), and a leveling agent (G). [7] The photocurable resin composition according to any one of [1] to [6], which is used as a paint. [8] A cured film formed from the photocurable resin composition according to any one of [1] to [7]. [9] A substrate with a cured film having a cured film formed from the photocurable resin composition according to any one of [1] to [7] on at least a part of the surface of the substrate.

[10] A coating step of applying the photocurable resin composition according to any one of [1] to [7] to at least one surface of the substrate, a curing step of curing the photocurable resin composition by ultraviolet irradiation to form a cured film after the coating step, A method for producing a substrate with a cured film, comprising: [Effect of the Invention]

[0011] According to the present invention, it is possible to provide a photocurable resin composition capable of forming a cured film excellent in coating film appearance, transparency, substrate adhesion, hardness, visible light transmittance, and infrared absorption. Further, according to the present invention, it is also possible to provide a cured film formed from such a photocurable resin composition, a substrate with the cured film, and a method for producing the substrate with the cured film.

[0012] A film provided with a cured film formed from the photocurable resin composition of the present invention is attached to optical members such as windows and displays of vehicles and buildings, and by cutting infrared rays, it is possible to suppress the temperature rise inside the room and the thermal deterioration of the members. Further, a film provided with such a cured film exhibits high light absorption in the infrared wavelength region and high transparency in the visible light wavelength region, so that high visibility can be obtained even when applied to optical members such as displays.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, the present invention will be described in more detail. In this specification, “(meth)acrylate” represents acrylate and methacrylate, “(meth)acrylic” represents acrylic and methacrylic, and “(meth)acryloyl” represents acryloyl and methacryloyl. “Solid content” refers to the content obtained by removing volatile components such as organic solvents from the photocurable resin composition, and indicates the components that constitute the cured film when cured.

[0014] <Photocurable Resin Composition> The photocurable resin composition according to the present invention contains urethane (meth)acrylate (A), (meth)acrylate monomer (B), photopolymerization initiator (C), and infrared absorber (D). In the present invention, since the photocurable resin composition contains components (A) to (D), a cured film excellent in coating film appearance, transparency, substrate adhesion, hardness, visible light transmittance, and infrared absorption can be formed. Further, the photocurable resin composition according to the present invention may further contain an ultraviolet absorber (E), a light stabilizer (F), a leveling agent (G), and the like. Such a photocurable resin composition can be applied to various fields where both visible light transmittance and infrared absorption are required, and can be used, for example, for window films of vehicles and buildings and optical members such as displays. Hereinafter, each component constituting the photocurable resin composition will be described in detail.

[0015] (Urethane (meth)acrylate (A)) Urethane (meth) acrylate (A) has an acryloyl group (CH2=CHCO-) and / or a methacryloyl group (CH2=C(CH3)-CO-) as a functional group in the molecule, and a urethane bond (-NH·COO-). The urethane (meth) acrylate is not particularly limited, but can be obtained, for example, by reacting a polyisocyanate with a hydroxyl group-containing (meth) acrylate and, if necessary, a polyol other than the hydroxyl group-containing (meth) acrylate. The urethane (meth) acrylate (A) is preferably an oligomer or a polymer, and more preferably an oligomer.

[0016] From the viewpoint of the substrate adhesion of the cured film, the content of the urethane (meth) acrylate (A) is 15% by mass or more and 45% by mass or less, preferably 17% by mass or more and 43% by mass or less, more preferably 19% by mass or more and 41% by mass or less, and still more preferably 20% by mass or more and 40% by mass or less, based on 100% by mass of the solid content of the photocurable resin composition.

[0017] (Urethane (meth) acrylate (a1) having a carbonate skeleton) The urethane (meth) acrylate (A) contains a urethane (meth) acrylate (a1) having a carbonate skeleton. The urethane (meth) acrylate (a1) having a carbonate skeleton has an acryloyl group (CH2=CHCO-) and / or a methacryloyl group (CH2=C(CH3)-CO-) as a functional group in the molecule, a urethane bond (-NH·COO-), and at least one carbonate group in the molecule.

[0018] The urethane (meth) acrylate having a carbonate skeleton can be obtained, for example, by reacting a polyol having a carbonate skeleton with a polyisocyanate and a hydroxyl group-containing (meth) acrylate.

[0019] The polyol having the carbonate skeleton is not particularly limited, and examples thereof include reaction products obtained by polycondensing the following component A and component B. That is, component A is not particularly limited, and examples thereof include diols such as 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, 1,4-cyclohexanedimethanol, 2-methylpropanediol, dipropylene glycol, and diethylene glycol, or reaction products of these diols with dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, and hexahydrophthalic acid. Component B is not particularly limited, and examples thereof include aromatic carbonates or aliphatic carbonates such as diphenyl carbonate, bis(chlorophenyl) carbonate, dinaphthyl carbonate, phenyltolyl carbonate, phenylchlorophenyl carbonate, 2-tolyl-4-tolyl carbonate, dimethyl carbonate, diethyl carbonate, diethylene carbonate, and ethylene carbonate.

[0020] The above polyisocyanate is obtained by reacting a polyol and a diisocyanate. The polyol as a raw material for synthesizing the polyisocyanate is not particularly limited, and examples thereof include polyester polyol, polyether polyol, etc. Only one of these may be used, or two or more thereof may be used in combination.

[0021] There are no particular restrictions on the production method of the polyester polyol. For example, those obtained by known methods such as polycondensing a diol and a dicarboxylic acid or a dicarboxylic acid chloride, or subjecting a diol or a dicarboxylic acid to an esterification reaction and then a transesterification reaction can be used. The diols used in the synthesis of polyester polyols are not particularly limited, and examples thereof include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, dibropylene glycol, triethylene glycol, tripropylene glycol, tetraethylene glycol, tetrapropylene glycol, and the like. The dicarboxylic acids used in the synthesis of polyester polyols are not particularly limited, and examples thereof include adipic acid, succinic acid, glutaric acid, pimelic acid, sebacic acid, azelaic acid, dimaleic acid, terephthalic acid, isophthalic acid, phthalic acid, and the like.

[0022] The polyether polyols are not particularly limited, and examples thereof include polyethylene oxide, polypropylene oxide, ethylene oxide-propylene oxide random copolymer, and the like.

[0023] The diisocyanates as raw materials for the synthesis of polyisocyanates are not particularly limited, and linear or alicyclic aliphatic diisocyanates or aromatic diisocyanates can be used. Specifically, for example, isocyanate group-containing linear hydrocarbons such as tetramethylene diisocyanate and hexamethylene diisocyanate, isocyanate group-containing branched-chain hydrocarbons such as 2,2,4-trimethylhexamethylene diisocyanate, isocyanate group-containing cyclic hydrocarbons such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate, hydrogenated toluene diisocyanate, etc., and isocyanate group-containing aromatic hydrocarbons such as p-phenylene diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, 1,3-xylene diisocyanate, dianisidine diisocyanate, tetramethylxylene diisocyanate, 1,5-naphthalene diisocyanate, tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, etc.

[0024] As the above-mentioned hydroxyl group-containing (meth)acrylate, a (meth)acrylate having at least one or more, preferably 1 to 5 hydroxyl groups can be used. Further, such a hydroxyl group-containing (meth)acrylate preferably desirably has a hydrocarbon moiety having 2 to 20 carbon atoms. Here, the hydrocarbon moiety refers to an organic group having a linear or branched aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, and the aliphatic hydrocarbon group and the alicyclic hydrocarbon group may be saturated or unsaturated. In addition, a part of the hydrocarbon moiety may contain an ether bond (C-O-C bond).

[0025] Examples of the (meth)acrylate monomer having a hydroxyl group include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate, and their caprolactone adducts (Placcel FA1, FA2, etc. manufactured by Daicel Corporation), OH group-terminated polyalkylene glycol mono(meth)acrylates such as polyethylene glycol mono(meth)acrylate and polypropylene glycol mono(meth)acrylate, their ethylene oxide-modified products (AM-90G, AM-130G manufactured by Shin-Nakamura Chemical Co., Ltd., Light Acrylate EC-A, MTG-A, EHDG-AT, etc. manufactured by Kyoeisha Chemical Co., Ltd.), glycerin mono(meth)acrylate (Blemmer GLM, etc. manufactured by NOF Corporation), glycerin di(meth)acrylate (Aronix MT3560, etc. manufactured by Toagosei Co., Ltd.), isocyanuric acid EO-modified di(meth)acrylate (Aronix M-313, M-315, etc. manufactured by Toagosei Co., Ltd.), pentaerythritol tri / tetra(meth)acrylate (Biscoat 300 manufactured by Osaka Organic Chemical Industry Co., Ltd., Aronix M-305, M-306, M-450, MT-3548 manufactured by Toagosei Co., Ltd., Light Acrylate PE-3A manufactured by Kyoeisha Chemical Co., Ltd., NK Ester A-TMM-3L manufactured by Shin-Nakamura Chemical Co., Ltd., etc.), dipentaerythritol penta(meth)acrylate (Aronix M-400, M-402, M-403, MT-3549 manufactured by Toagosei Co., Ltd., Light Acrylate DPE-6A manufactured by Kyoeisha Chemical Co., Ltd., NK Ester A-DPH manufactured by Shin-Nakamura Chemical Co., Ltd., etc.). Among these, from the viewpoints of the weather resistance, abrasion resistance, and scratch resistance of the cured film, it is preferable to use isocyanuric acid EO-modified diacrylate or pentaerythritol tri / tetraacrylate. Such hydroxyl group-containing (meth)acrylate may be used alone or in combination of two or more.

[0026] The content of urethane (meth)acrylate (a1) having a carbonate skeleton is 25% by mass or more and 80% by mass or less, preferably 26% by mass or more and 79% by mass or less, more preferably 27% by mass or more and 78% by mass or less, and still more preferably 28% by mass or more and 77% by mass or less, from the viewpoint of the adhesion of the cured film to the substrate, based on the total amount of urethane (meth)acrylate (A).

[0027] (Urethane (meth)acrylate (a2) having 6 or more functional groups excluding the component (a1)) Urethane (meth)acrylate (A) contains urethane (meth)acrylate (a2) having 6 or more functional groups excluding the component (a1). The upper limit of the number of functional groups of the 6-functional or higher urethane (meth)acrylate (a2) is not particularly limited. For example, it may be 12-functional or less, or 10-functional or less. By using a 6-functional or higher urethane (meth)acrylate (a2) instead of a urethane (meth)acrylate having a small number of functional groups (for example, 2-3 functional groups), the hardness of the cured film can be improved.

[0028] The urethane (meth)acrylate having 6 or more functional groups excluding the component (a1) can be obtained, for example, by reacting a polyol having no carbonate skeleton, a polyisocyanate, and a hydroxyl group-containing (meth)acrylate.

[0029] Examples of the polyol having no carbonate skeleton include the above polyester polyol and polyether polyol. The same polyisocyanate and hydroxyl group-containing (meth)acrylate as those of the above component (a1) can be used.

[0030] The content of urethane (meth)acrylate (a2) having 6 or more functional groups excluding the component (a1) is preferably 20% by mass or more and 75% by mass or less, more preferably 21% by mass or more and 74% by mass or less, still more preferably 22% by mass or more and 73% by mass or less, and even more preferably 23% by mass or more and 72% by mass or less, based on the total amount of urethane (meth)acrylate (A), from the viewpoint of the hardness of the cured film.

[0031] ((Meth)acrylate monomer (B)) (Meth)acrylate monomer (B) is a monomer having at least one (meth)acryloyl group, and forms a cured film together with the above urethane (meth)acrylate (A) when the photocurable resin composition is irradiated with ultraviolet rays.

[0032] From the viewpoints of the substrate adhesion and hardness of the cured film, the content of (meth)acrylate monomer (B) is 30% by mass or more and 65% by mass or less, preferably 32% by mass or more and 63% by mass or less, more preferably 35% by mass or more and 60% by mass or less, and still more preferably 37% by mass or more and 58% by mass or less, based on 100% by mass of the solid content of the photocurable resin composition.

[0033] ((Meth)acrylate monomer (b1) having a functional group number of 2) (Meth)acrylate monomer (B) contains a (meth)acrylate monomer (b1) having a functionality of 2. The (meth)acrylate monomer having a functionality of 2 means a compound having two (meth)acryloyloxy groups as functional groups in the molecule. Examples of the (meth)acrylate monomer having a functionality of 2 include alkylene glycol di(meth)acrylates such as ethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol diacrylate, and neopentyl glycol di(meth)acrylate; polyoxyalkylene glycol di(meth)acrylates such as diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polytetramethylene glycol di(meth)acrylate; di(meth)acrylates of halogen-substituted alkylene glycols such as tetrafluoroethylene glycol di(meth)acrylate; di(meth)acrylates of aliphatic polyols such as trimethylolpropane di(meth)acrylate, ditrimethylolpropane di(meth)acrylate, pentaerythritol di(meth)acrylate, and polycarbonate diol di(meth)acrylate; di(meth)acrylates of hydrogenated dicyclopentadiene or tricyclodecane dialkanol such as hydrogenated dicyclopentenyl di(meth)acrylate and tricyclodecane dimethanol di(meth)acrylate; di(meth)acrylates of dioxane glycol or dioxane dialkanol such as 1,3-dioxane-2,5-diyl di(meth)acrylate [alias: dioxane glycol di(meth)acrylate]; di(meth)acrylates of alkylene oxide adducts of bisphenol A or bisphenol F such as bisphenol A ethylene oxide adduct diacrylate and bisphenol F ethylene oxide adduct diacrylate;Epoxy di(meth)acrylates of bisphenol A or bisphenol F such as acrylic acid adducts of bisphenol A diglycidyl ether, acrylic acid adducts of bisphenol F diglycidyl ether; silicone di(meth)acrylate; di(meth)acrylate of neopentyl glycol hydroxypivalate; 2,2-bis[4-(meth)acryloyloxyethoxyethoxyphenyl]propane; 2,2-bis[4-(meth)acryloyloxyethoxyethoxycyclohexyl]propane; di(meth)acrylate of 2-(2-hydroxy-1,1-dimethylethyl)-5-ethyl-5-hydroxymethyl-1,3-dioxane; tris(hydroxyethyl)isocyanurate di(meth)acrylate; etc. are mentioned. Among these (meth)acrylate monomers having a functionality of 2, alkylene glycol di(meth)acrylate, polyoxyalkylene glycol di(meth)acrylate, di(meth)acrylate of halogen-substituted alkylene glycol, di(meth)acrylate of aliphatic polyol, di(meth)acrylate of hydrogenated dicyclopentadiene or tricyclodecane dialkanol, di(meth)acrylate of dioxane glycol or dioxane dialkanol, silicone di(meth)acrylate, di(meth)acrylate of neopentyl glycol hydroxypivalate, 2,2-bis[4-(meth)acryloyloxyethoxyethoxyphenyl]propane, 2,2-bis[4-(meth)acryloyloxyethoxyethoxycyclohexyl]propane, di(meth)acrylate of [2-(2-hydroxy-1,1-dimethylethyl)-5-ethyl-5-hydroxymethyl-1,3-dioxane], tris(hydroxyethyl)isocyanurate di(meth)acrylate are preferred, alkylene glycol di(meth)acrylate is more preferred, 1,6-hexanediol di(meth)acrylate and 1,9-nonanediol di(meth)acrylate are particularly preferred. These (meth)acrylate monomers having a functionality of 2 may be used alone or in combination of two or more kinds.;

[0034] The content of the (meth)acrylate monomer (b1) having a functionality of 2 is preferably 15% by mass or more and 65% by mass or less, more preferably 16% by mass or more and 62% by mass or less, still more preferably 17% by mass or more and 60% by mass or less, and even more preferably 18% by mass or more and 50% by mass or less, based on the total amount of the (meth)acrylate monomer (B) from the viewpoint of the substrate adhesion of the cured film.

[0035] ((meth)acrylate monomer (b2) having a functionality of 5 or more) (The (meth)acrylate monomer (B) contains a (meth)acrylate monomer (b2) having a functionality of 5 or more. The functionality of the (meth)acrylate monomer (b2) is preferably 5 or more and 6 or less. The (meth)acrylate monomer having a functionality of 5 or more means a compound having 5 or more (meth)acryloyloxy groups as functional groups in the molecule. Examples of the (meth)acrylate monomer having a functionality of 5 or more include dipentaerythritol penta(meth)acrylate, alkoxylated dipentaerythritol penta(meth)acrylate, caprolactone-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, alkoxylated dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, and the like. Among these, dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate are preferred. These (meth)acrylate monomers having a functionality of 5 or more may be used alone or in combination of two or more.

[0036] The content of the (meth)acrylate monomer (b2) having a functionality of 5 or more is 35% by mass or more and 85% by mass or less, preferably 38% by mass or more and 84% by mass or less, more preferably 40% by mass or more and 83% by mass or less, and still more preferably 50% by mass or more and 82% by mass or less, based on the total amount of the (meth)acrylate monomer (B) from the viewpoints of the substrate adhesion and hardness of the cured film.

[0037] (Photoinitiator (C)) The photoinitiator is not particularly limited, and a conventionally known photoinitiator for a photocurable resin composition can be used. Examples of the photoinitiator include acylphosphine oxide-based polymerization initiators, acetophenone-based polymerization initiators, benzoylformate-based polymerization initiators, thioxanthone-based polymerization initiators, oxime ester-based polymerization initiators, hydroxybenzoyl-based polymerization initiators, benzophenone-based polymerization initiators, α-aminoalkylphenone-based polymerization initiators, and the like.

[0038] Examples of the acylphosphine oxide-based polymerization initiator include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide. Examples of the acetophenone-based polymerization initiator include acetophenone, 3-methylacetophenone, benzyldimethylketal, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one, and the like. Examples of the benzoylformate-based polymerization initiator include methyl benzoylformate. Examples of the thioxanthone-based polymerization initiator include isopropyl thioxanthone. Examples of the oxime ester-based polymerization initiator include 2-[(benzoyloxy)imino]-1-[4-(phenylthio)phenyl]octan-1-one, and 1-[9-ethyl-6-(2-methylbenzoyl)carbazol-3-yl]-3-(cyclopentyl)propan-1-one O-acetoxyoxime. Examples of the hydroxybenzoyl-based polymerization initiator include benzoin alkyl ether and the like. Examples of the benzophenone-based polymerization initiator include benzophenone, 4-chlorobenzophenone, 4,4'-diaminobenzophenone, and the like. Examples of the α-aminoalkylphenone-based polymerization initiator include 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-(N,N-dimethylamino)-1-(4-morpholinophenyl)butan-1-one, and the like. These polymerization initiators may be used alone or in combination of two or more.

[0039] From the viewpoints of the curability of the photocurable resin composition and the transparency of the cured film, the content of the photoinitiator (C) is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 7.0% by mass or less, and still more preferably 1.0% by mass or more and 5.0% by mass or less, based on 100% by mass of the solid content of the photocurable resin composition.

[0040] (Infrared absorber (D)) Examples of the infrared absorber (D) include the general formula M x W y O z(In the formula, M is one or more elements selected from H, He, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, Yb; W is tungsten; O is oxygen; 0.001 ≦ x / y ≦ 1; 2.0 < z / y ≦ 3.0). It is preferable to use a composite tungsten oxide represented by the formula. The composite tungsten oxide is preferably composite tungsten oxide fine particles. If the value of x / y is 0.001 or more, it becomes easier to obtain near-infrared absorption characteristics. If the value of x / y is 1 or less, it is possible to avoid the formation of an impurity phase in the composite tungsten fine particles. Further, when the value of z / y exceeds 2.0, it becomes easier to avoid the appearance of the crystal phase of WO2, which is a compound other than the target, in the composite tungsten oxide, and it becomes easier to obtain chemical stability as a material, so it can be applied as an effective infrared absorber. On the other hand, if the value of z / y is 3.0 or less, the required amount of free electrons is generated in the tungsten oxide, and it becomes an infrared absorber with good efficiency.

[0041] The composite tungsten oxide transmits visible light and absorbs near-infrared light, making it easier to shield. Therefore, as the M element, Cs, Rb, K, Tl, Ba, Cu, Al, Mn, In are preferable, Cs and Rb are more preferable, and Cs is even more preferable. Regarding the value of x / y, 0.01 ≦ x / y ≦ 0.7 is more preferable, 0.1 ≦ x / y ≦ 0.5 is more preferable, 0.2 ≦ x / y ≦ 0.4 is even more preferable, and 0.3 ≦ x / y ≦ 0.35 is most preferable. Further, regarding the value of z / y, 2.2 ≦ z / y ≦ 3.0 is preferable, 2.6 ≦ z / y ≦ 3.0 is more preferable, and 2.7 ≦ z / y ≦ 3.0 is even more preferable.

[0042] Infrared absorbers other than those described above can also be used. For example, organic infrared absorbers such as porphyrin-based dyes, porphycene-based dyes, phthalocyanine-based dyes, naphthalocyanine-based dyes, squarylium-based dyes, cyanine-based dyes, perylene-based dyes, coronene-based dyes, diketopyrrolopyrrole-based dyes, dithiol metal complex-based dyes, triarylmethane-based dyes, naphthoquinone-based dyes, anthraquinone-based dyes, quinacridone dyes, nitroso compounds and their metal complexes, imonium-based dyes, diimonium-based dyes, copper phosphate esters and other organometallic complexes, polycyclic aromatic hydrocarbons, aromatic heterocyclic compounds, etc., and inorganic infrared absorbers such as titanium oxide, tungsten oxide, tantalum oxide, niobium oxide, zinc oxide, indium oxide, tin-doped indium oxide, antimony-doped tin oxide, aluminum zinc composite oxide, gallium-doped zinc oxide, indium zinc composite oxide, zinc antimonate, cesium oxide, LaB6, CeB6, PrB6, NdB6, GdB6, TbB6, DyB6, HoB6, YB6, SmB6, EuB6, ErB6, TmB6, YbB6, LuB6, SrB6, CaB6, (La, Ce)B6 and other hexaborides. Such infrared absorbers may be used alone or in combination of two or more.

[0043] As the infrared absorber, commercially available infrared absorbers can be used. For example, product names such as EX Color IX-2-IR-14, IX-2-IR-28, IR-10, 12, 14, HA-1, 14, etc. manufactured by Nippon Shokubai Co., Ltd., product names such as YKR-2016, 2100, 2900, 2081, 2200, 2090, 3070, 3080, etc. manufactured by Yamamoto Chemical Co., Ltd., product names such as TAP-2, TAP-HTB, FDG-007, FDR-001, 002, 003, 004, 005, etc. manufactured by Yamada Chemical Industry Co., Ltd., product names such as NIR700A, 714A, 728A, 733A, 757A, 762A, 775B, 783C, 790B, 795A, 800A, 805B, 811A, 819C, 828B, 836C, 844A, 856A, 864A, 868A, 880C, 886A, 902A, 910C, 912C, 935A, 949C, 956A, 960A, 979C, 980B, 983A, 989A, 1003A, 1021A, 1031M, 1035A, 1047A, 1072C, etc. manufactured by QCR Solutions Corp, product names such as SDO-4, SDO-5, SDO-7, SDO-2, SDO-3, etc. manufactured by Arimoto Chemical Industry Co., Ltd., product names such as Optogen NIR-840S, 760S, etc. manufactured by Sumika Color Co., Ltd., product name such as Carens IRT manufactured by Resonac Co., Ltd., product names such as Lumogen IR-765, 788, etc. manufactured by BASF, product names such as Kayasorb IRG-022, 023, CY-40MC(F), etc. manufactured by Nippon Kayaku Co., Ltd., product names such as CIR-960, 1081, 1083, 1085, RL, FS265, etc. manufactured by Nippon Carlit Co., Ltd. can be mentioned.

[0044] From the viewpoints of the visible light transmittance and infrared absorption property of the cured film, the content of the infrared absorber (D) is preferably 1% by mass or more and 30% by mass or less, more preferably 2% by mass or more and 25% by mass or less, still more preferably 3% by mass or more and 20% by mass or less, and even more preferably 5% by mass or more and 15% by mass or less with respect to 100% by mass of the solid content of the photocurable resin composition.

[0045] (Ultraviolet absorber (E)) The ultraviolet absorber (E) is not particularly limited, and conventionally known ultraviolet absorbers can be used. Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers, hydroxyphenyltriazine-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, and the like. These ultraviolet absorbers may be used alone or in combination of two or more.

[0046] Examples of benzotriazole-based ultraviolet absorbers include 2-[2’-hydroxy-5’-(methacryloyloxymethyl)phenyl]-2H-benzotriazole, 2-[2’-hydroxy-5’-(methacryloyloxyethyl)phenyl]-2H-benzotriazole, 2-[2’-hydroxy-5’-(methacryloyloxypropyl)phenyl]-2H-benzotriazole, 2-[2’-hydroxy-5’-(methacryloyloxyhexyl)phenyl]-2H-benzotriazole, 2-[2’-hydroxy-3’-tert-butyl-5’-(methacryloyloxyethyl)phenyl]-2H-benzotriazole, 2-[2’-hydroxy-5’-tert-butyl-3’-(methacryloyloxyethyl)phenyl]-2H-benzotriazole, 2-[2’-hydroxy-5’-(methacryloyloxyethyl)phenyl]-5-chloro-2H-benzotriazole, 2-[2’-hydroxy-5’-(methacryloyloxyethyl)phenyl]-5-methoxy-2H-benzotriazole, 2-[2’-hydroxy-5’-(methacryloyloxyethyl)phenyl]-5-cyano-2H-benzotriazole, 2-[2’-hydroxy-5’-(methacryloyloxyethyl)phenyl]-5-tert-butyl-2H-benzotriazole, 2-[2’-hydroxy-5’-(methacryloyloxyethyl)phenyl]-5-nitro-2H-benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole, 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy-benzenepropanoic acid, C7-9 branched or linear alkyl ester, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol, and the like.

[0047] Examples of the hydroxyphenyltriazine-based ultraviolet absorber include 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4dimethylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-(2-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-butyloxyphenyl)-6-(2,4-bis-butyloxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, 2,2’,2’’-[1,3,5-triazine-2,4,6-triyltris(3-hydroxy-4,1-phenylene)oxy]-1,1’,1’’-trioctyl propionate, and the like.

[0048] Examples of the benzophenone-based ultraviolet absorber include 2,2’,4,4’-tetrahydroxybenzophenone, 2,2’-dihydroxy-4,4’-dimethoxybenzophenone, 2,2’-dihydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-acetoxyethoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2’-dihydroxy-4-methoxybenzophenone, 2,2’-dihydroxy-4,4’-dimethoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2,2’-dihydroxy-4,4’-dimethoxy-5,5’-disulfobenzophenone disodium salt, and the like.

[0049] From the viewpoint of the weather resistance of the cured film, the content of the ultraviolet absorber (E) is preferably 0.1% by mass or more and 5% by mass or less, more preferably 0.2% by mass or more and 4% by mass or less, and still more preferably 0.3% by mass or more and 3% by mass or less with respect to 100% by mass of the solid content of the photocurable resin composition.

[0050] (Light stabilizer (F)) The light stabilizer (F) is not particularly limited, and conventionally known light stabilizers can be used, and it is preferable to use a hindered amine-based light stabilizer. Examples of the light stabilizer include bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1-[2-[3-(3,5-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl]-4-[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy]-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4,5] decane-2,4-dione, bis-(1,2,2,6,6-pentamethyl-4-piperidyl)-2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butyl malonate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, (Mixed 1,2,2,6,6-pentamethyl-4-piperidyl / tridecyl)-1,2,3,4-butanetetracarboxylate, Mixed{1,2,2,6,6-pentamethyl-4-piperidyl / β,β,β’,β’-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro(5,5)undecane]diethyl}-1,2,3,4-butanetetracarboxylate, (Mixed 2,2,6,6-tetramethyl-4-piperidyl / tridecyl)-1,2,3,4-butanetetracarboxylate, Mixed{2,2,6,6-tetramethyl-4-piperidyl / β,β,β’,β’-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro(5,5)undecane]diethyl}-1,2,3,4-butanetetracarboxylate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, poly[(6-(1,1,3,3-tetramethylbutyl)imino-1,3,5-triazine-2,4-diyl)][(2,2,6,(6-Tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)iminoal], a polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, N,N’,N’’,N’’’-tetrakis-(4,6-bis-(butyl-(N-methyl-2,2,6,6-tetramethylpiperidin-4-yl)amino)-triazin-2-yl)-4,7-diazadecane-1,10-diamine, a polycondensate of dibutylamine-1,3,5-triazine-N,N’-bis(2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethylpiperidyl)butylamine, bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) decanedioate, and the like can be mentioned.,

[0051] From the viewpoint of the weather resistance of the cured film, the content of the light stabilizer (F) is preferably 0.1% by mass or more and 5% by mass or less, more preferably 0.2% by mass or more and 3% by mass or less, and still more preferably 0.3% by mass or more and 1% by mass or less with respect to 100% by mass of the solid content of the photocurable resin composition.

[0052] (Leveling agent (G)) The leveling agent (G) has a function of adjusting the fluidity of the photocurable resin composition and flattening the applied film. Examples of the leveling agent include fluorine-based leveling agents, silicone-based leveling agents, and acrylic polymer-based leveling agents.

[0053] Examples of fluorine-based leveling agents include fluorine-based leveling agents having a perfluoroalkenyl group in the main chain or side chain, such as perfluoroalkenyl carboxylates, perfluoroalkenyl sulfonates, perfluoroalkenyl phosphates, and perfluoroalkenyl betaines; and fluorine-based leveling agents having a perfluoroalkyl group in the main chain or side chain, such as perfluoroalkyl polyoxyethylene ethers, perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, perfluoroalkyl phosphates, and perfluoroalkyl betaines.

[0054] Examples of silicone-based leveling agents include polydimethylsiloxane, polymethylphenylsiloxane, polymethylhydrogensiloxane, polyether-modified polydimethylsiloxane, polyether-modified polymethylphenylsiloxane, and polyether-modified polymethylhydrogensiloxane.

[0055] As the acrylic polymer-based leveling agent, a polyether-modified (meth)acrylic compound represented by the following general formula (1) can be used.

Chemical formula

Chemical formula

[0056] As such a leveling agent, commercially available leveling agents can also be used. For example, as fluorine-based leveling agents, there are those with the trade name Ftergent 602A manufactured by Neos Co., Ltd., and those with the trade name KY-1203 manufactured by Shin-Etsu Chemical Co., Ltd. As silicone-based leveling agents, there are those with the trade name BYK-307, BYK-315N, BYK-325N, BYK-342, BYK-378, etc. manufactured by BYK, those with the trade name Polyflow KL-401 manufactured by Kyoeisha Chemical Co., Ltd., and those with the trade name Tego flow 425 manufactured by EVONIK. As acrylic polymer-based leveling agents, there are those with the trade name Polyflow No. 75 manufactured by Kyoeisha Chemical Co., Ltd., and those with the trade name BYK-350, BYK-381, etc. manufactured by BYK. As other leveling agents, there is those with the trade name BYK-399 manufactured by BYK.

[0057] From the viewpoint of the lubricity of the cured film, the weight average molecular weight (Mw) of the leveling agent (G) is preferably 1,000 to 100,000, more preferably 1,500 to 50,000, and even more preferably 2,000 to 30,000. The weight average molecular weight (Mw) can be measured using gel permeation chromatography (GPC).

[0058] The content of the leveling agent (G) is preferably 0.01% by mass or more and 2.0% by mass or less, more preferably 0.05% by mass or more and 1.5% by mass or less, and still more preferably 0.1% by mass or more and 1.0% by mass or less, based on 100% by mass of the solid content of the photocurable resin composition, from the viewpoints of the transparency and smoothness of the cured film.

[0059] (Other components) The photocurable resin composition according to the present invention may contain other components other than the above components (A) to (I) as long as the object of the present invention is not impaired. Examples of other components include inorganic particles, dispersants, antioxidants, antistatic agents, polymerization inhibitors, non-reactive diluents, matting agents, defoaming agents, anti-settling agents, heat stabilizers, adhesion improvers, photosensitizers, antibacterial agents, fungicides, antiviral agents, silane coupling agents, plasticizers, etc., which can be blended as needed.

[0060] <Method for preparing photocurable resin composition> The photocurable resin composition according to the present invention can be obtained by mixing and stirring the above components using a conventionally known apparatus such as a mixer, disperser, stirrer, etc. Examples of such an apparatus include a mixing and dispersing mill, a homodisper, a mortar mixer, a roll, a paint shaker, a homogenizer, etc.

[0061] The viscosity of the photocurable resin composition (resin solution) at 25°C is preferably 0.5 to 500 mPa·s, more preferably 1 to 250 mPa·s, and still more preferably 5 to 100 mPa·s. The viscosity can be measured using a B-type viscometer. If the viscosity is within the above numerical range, it is easy to use as a paint and has excellent processability.

[0062] In the present invention, it can be diluted with a solvent as necessary, such as adjusting the photocurable resin composition to a viscosity suitable for a paint. The solvent is not particularly limited as long as it can dissolve the resin component in the photocurable resin composition. Specifically, aromatic hydrocarbons (e.g., toluene, xylene, and ethylbenzene), esters or ether esters (e.g., ethyl acetate, butyl acetate, and methoxybutyl acetate), ethers (e.g., diethyl ether, tetrahydrofuran, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and diethylene glycol monoethyl ether), ketones (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone, and cyclohexanone), alcohols (e.g., methanol, ethanol, n- or i-propanol, n-, i-, sec- or t-butanol, 2-ethylhexyl alcohol, and benzyl alcohol), amides (e.g., dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc.), sulfoxides (e.g., dimethyl sulfoxide), water, and mixed solvents of two or more of these can be mentioned.

[0063] (Cured film) When the cured film formed from the photocurable resin composition according to the present invention has a thickness of 3 μm to 10 μm, the haze measured in accordance with JIS K 7136 is preferably less than 1.0%, more preferably 0.9% or less, and even more preferably 0.8% or less. Further, for a cured film with a thickness of 5 μm to 10 μm, the total light transmittance measured in accordance with JIS K 7361-1 is preferably 70.0% or more, and more preferably 75.0% or more. If the haze and the total light transmittance are within the above ranges, the transparency is excellent.

[0064] When the cured film formed from the photocurable resin composition according to the present invention has a thickness of 5 μm to 10 μm, the transmittance at 500 nm is preferably 75% or more, more preferably 80% or more, and the transmittances at 1000 nm, 1500 nm, and 2000 nm are preferably 25% or less, more preferably 20% or less. If the transmittance at 500 nm is within the above range, the visible light transmittance is excellent, and if the transmittances at 1000 nm, 1500 nm, and 2000 nm are within the above range, the infrared absorption property is excellent.

[0065] <Substrate with cured film> The substrate with a cured film according to the present invention comprises a cured film formed from the above photocurable resin composition on at least a part of the surface of the substrate. The substrate is not particularly limited, and various plastic films can be used. Examples of the plastic film include films of polyester resin, polycarbonate resin, polystyrene resin, polyolefin resin, polyethersulfone resin, acrylonitrile-styrene copolymer resin, polyamide resin, cellulose resin, polyarylate resin, polymethyl methacrylate resin, polymethacrylimide resin, etc. Since the photocurable resin composition of the present invention can form a transparent cured film with high total light transmittance and low haze, it is preferable to use a transparent plastic film. Since the cured film of the present invention has excellent adhesion to polycarbonate resin, it is more preferable to use a film of polycarbonate resin as the substrate.

[0066] The thickness of the substrate is not particularly limited, but is usually 10 μm or more and 500 μm or less, preferably 30 to 400 μm.

[0067] <Method for producing substrate with cured film> The substrate with a cured film according to the present invention includes a coating step of applying the above photocurable resin composition to at least one surface of the substrate, a curing step of curing the above photocurable resin composition by ultraviolet irradiation to form a cured film after the coating step, It includes the following. Hereinafter, each step will be described in detail.

[0068] (Coating Step) The coating step is a step of coating one side of a substrate with the above-described photocurable resin composition by a conventionally known method. For coating, for example, coaters such as a bar coater, a gravure coater, a roll coater (such as a natural roll coater and a reverse roll coater), an air knife coater, a spin coater, and a blade coater can be used. Among these, a coating method using a gravure coater is preferable from the viewpoints of workability and productivity.

[0069] The coating film thickness is not particularly limited and is appropriately selected depending on the type of the substrate. For example, the coating film thickness is preferably 0.5 to 25 μm as the film thickness after curing and drying. The more preferable upper limit is 15 μm from the viewpoints of drying property, curability, curl resistance during curing, and transparency, and the more preferable lower limit is 1 μm from the viewpoints of hardness and infrared absorbency.

[0070] When the resin composition is diluted with a solvent and used, it is preferably dried after coating. Examples of the drying method include hot air drying (such as a dryer). The drying temperature is preferably 10 to 200 °C, the more preferable upper limit is 150 °C from the viewpoints of the smoothness and appearance of the coating film, and the more preferable lower limit is 30 °C from the viewpoint of the drying rate.

[0071] (Curing Step) The curing step is a step of irradiating the coated surface of the substrate with ultraviolet rays to cure the applied photocurable resin composition to form a cured film. Examples of the method of curing with ultraviolet rays include a method of irradiating ultraviolet rays using a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, a UV-LED, etc. that emit light in the wavelength range of 200 to 500 nm. The irradiation of ultraviolet rays can be carried out in an inert gas atmosphere such as nitrogen or argon as necessary to suppress the curing inhibition by oxygen. The irradiation amount of ultraviolet rays is preferably 100 to 3,000 mJ / cm 2and more preferably 200 to 1,000 mJ / cm 2 is.

Example

[0072] Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.

[0073] (Synthesis Example 1) As the isocyanate compound (a1), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI, diisocyanate group content 31.8%) was prepared. Further, as the polycarbonate diol compound (a2), ETERNACOLL UM-90(3 / 1) (manufactured by Ube Industries, Ltd.) was prepared. Furthermore, as the photoreactive compound (a3), isocyanuric acid EO-modified di- and triacrylate (manufactured by Toagosei Co., Ltd., Aronix M-313) was prepared. Subsequently, into a four-necked flask equipped with a stirrer, a reflux condenser, and a thermometer, 192.8 g of the component (a2), 480.8 g of the component (a3), 0.15 g of 4-methoxyphenol, 0.45 g of dibutylhydroxytoluene, and 1.5 g of dibutyltin dilaurate were added, and after heating to 80°C in an oil bath, 112.3 g of the component (a1) was added dropwise over 1 hour, and then reacted at 90°C for 3 hours. After completion of the reaction, 450 g of propylene glycol monomethyl ether was added for dilution to obtain a urethane (meth)acrylate (A1) having a carbonate skeleton. The end point of the reaction was confirmed by the disappearance of the peak derived from the isocyanate group by infrared absorption analysis. This component (A1) had a functional group number of 4, a weight average molecular weight (MW) of 2900, and a solid content of 64%.

[0074] (Synthesis Example 2) As the isocyanate compound (a1), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI, diisocyanate group content 31.8%) was prepared. Further, as the (meth)acrylate monomer (a2) having a hydroxyl group and a photopolymerizable unsaturated group, pentaerythritol triacrylate (hydroxyl value 110 mg / KOH) was prepared. Subsequently, 32.8 g of component (a1), 102 g of component (a2), 3.3 g of diethylene glycol, 0.05 g of p-methoxyphenol, 0.17 g of dibutylhydroxytoluene, 0.17 g of dibutyltin dilaurate, and 17.3 g of butyl acetate were added to a 200 mL reaction vessel equipped with a stirrer, a thermometer, and an air inlet tube, and reacted at 80 °C for 5 hours. Thereafter, 17.3 g of propylene glycol monomethyl ether was added for dilution to obtain urethane (meth)acrylate (A2). This component (A2) had a functionality of 6, a weight average molecular weight (MW) of 2400, and a solid content of 80%.

[0075] Next, the following materials were prepared for the photocurable resin composition. · (A) (a1) Tetrafunctional urethane (meth)acrylate (containing a carbonate skeleton, Mw 2900, urethane (meth)acrylate obtained in Synthesis Example 1) · (A) (a1) Bifunctional urethane (meth)acrylate (containing a carbonate skeleton, Mw 5000, manufactured by Negami Kogyo Co., Ltd., trade name: Art Resin UN-9000PEP) · (A) (a1) Urethane (meth)acrylate (containing a carbonate skeleton, manufactured by Elementis Specialties, trade name: Hypomer UR-802) · (A) (a2) Hexafunctional urethane (meth)acrylate 1 (Mw 2400, urethane (meth)acrylate obtained in Synthesis Example 2) · (A) (a2) Hexafunctional urethane (meth)acrylate 2 (Mw 1100, manufactured by Mitsubishi Chemical Corporation, trade name: Shinsei UV-7600B) · (A) (a2) Hexafunctional urethane (meth)acrylate 3 (Mw 1400, manufactured by Sartomer, trade name: CN968NS) · (A) (a2) Hexafunctional urethane (meth)acrylate 4 (isophorone diisocyanate type, Mw 1500, manufactured by Negami Kogyo Co., Ltd., trade name: Art Resin UN-CMP-1) · (A) (a2) Nonafunctional urethane (meth)acrylate (Mw 3400, manufactured by Negami Kogyo Co., Ltd., trade name: Art Resin UN-908RU3) · (B)(b1) 2-functional (meth)acrylic monomer 3: 1,6 - hexanediol diacrylate, manufactured by Sartomer, product name: SR238NS · (B)(b2) 5 / 6-functional (meth)acrylate monomer (dipentaerythritol (penta / hex) acrylate (DPPA / DPHA), manufactured by Toagosei Co., Ltd., product name: Aronix M-400) · (B)(b2) 6-functional (meth)acrylate monomer (manufactured by Eternal Chemical, product name: ETERMER 2692) · (C) Photoinitiator 1 (1 - hydroxycyclohexyl phenyl ketone, manufactured by IGM Resin, product name: Omnirad 184) · (C) Photoinitiator 2 (2,4,6 - trimethylbenzoyl diphenylphosphine oxide, manufactured by Chitec Technology, product name: CHIVACURE TPO) · (D) Infrared absorber (cesium tungsten oxide (Cs 0.33 WO3) containing 18.5%, manufactured by Sumitomo Metal Mining Co., Ltd., product name: YMF-02A) · (E) Ultraviolet absorber (manufactured by BASF, product name: TINUVIN 479) · (F) Light stabilizer (manufactured by Rianlon, product name: RIASORB UV-123) · (G) Levelling agent (fluorine-based surface conditioner, lipophilic, manufactured by Neos, product name: Fujagent 602A) · Solvent (propylene glycol monomethyl ether)

[0076] [Examples 1 - 17, Comparative Examples 1 - 12] [Preparation of photocurable resin composition] According to the formulations described in Tables 1 and 2, each component was mixed to obtain a photocurable resin composition.

[0077] [Evaluation of photocurable resin composition] (Storage stability) Regarding the solution state of the photocurable resin composition prepared above after storage in a constant temperature bath at 25°C for 7 days, it was evaluated based on the following evaluation criteria. The evaluation results are shown in Table 6. <Evaluation Criteria> ○: No abnormalities such as discoloration or precipitation formation in the solution. ×: Abnormalities such as discoloration or precipitation formation in the solution.

[0078] [Manufacture of Substrate with Cured Coating] On a substrate film (polycarbonate (PC) / polymethyl methacrylate (PMMA) composite film, thickness 375 μm, 150 mm × 210 mm), the photocurable resin composition prepared above was applied once on the PC surface with a bar coater so that the dry film thickness became 8 μm, and dried at 80°C for 1 minute. Subsequently, the coated surface of the substrate film was irradiated with ultraviolet light using a high-pressure mercury lamp (irradiation dose: 1000 mJ / cm 2 ) to cure the coating film and form a cured coating, thereby obtaining a substrate with a cured coating.

[0079] [Evaluation of Substrate with Cured Coating] For the substrate with a cured coating manufactured above, evaluations of the coating film appearance, transparency, substrate adhesion, hardness, and light transmittance were performed. The evaluation results are shown in Tables 4 to 6.

[0080] (Coating Film Appearance) The appearance of the substrate with a cured coating manufactured above was visually evaluated based on the following evaluation criteria. If the evaluation was ○, it was considered qualified. <Evaluation Criteria> ○: No abnormalities such as whitening, peeling, insufficient smoothness, and cracking in the cured coating. ×: Abnormalities such as whitening, peeling, insufficient smoothness, and cracking in the cured coating.

[0081] (Transparency) For the substrate with a cured coating manufactured above, haze (HZ) was measured in accordance with JIS K 7136 and total light transmittance (TT) was measured in accordance with JIS K 7361-1 using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., model number: NDH4000). If the haze value was less than 1.0% and the total light transmittance was 75.0% or more, it was considered excellent in transparency and qualified.

[0082] (Substrate Adhesion) In accordance with the method of the cross-cut test described in JIS K 5600-5-6:1990, a test piece with a 1 mm wide and 100-cell scratch and a cross-cut pattern was prepared on the cured film of the substrate with the cured film manufactured above using a cutter. Subsequently, after attaching cellophane tape (registered trademark) (product name, manufactured by Nichiban Co., Ltd.) to the test piece, the cellophane tape was peeled off by pulling it in a direction 45 degrees obliquely upward with respect to the cross-cut surface, and the number of cured films remaining on the remaining cross-cuts was counted. This remaining number was used as an index of adhesion. If the number of cured films remaining on the cross-cuts was 100 / 100, it was evaluated as having excellent adhesion.

[0083] (Hardness) The hardness of the coating film surface of the substrate with the cured film manufactured above was evaluated by scratch hardness (pencil method). For the measurement of pencil hardness, a scratch hardness tester (manufactured by Yasuda Seiki Co., Ltd., 553-M) and a pencil certified by the Japan Paint Inspection Association (manufactured by Mitsubishi Pencil Co., Ltd., Hi-uni) were used. After attaching the pencil to press against the coating film at an angle of 45° and a load of 750 g, the scratch test was repeated 5 times with pencils of each hardness grade. If the number of times without observing breakage, depression, scratches, etc. of the coating film was 3 or more, it was considered qualified, and the hardness grade of the hardest pencil that passed was taken as the pencil hardness of the coating film. If the pencil hardness was HB or higher, it was evaluated as having sufficient coating film surface hardness.

[0084] (Light Transmittance) The light transmittance of the substrate with the cured film manufactured above was evaluated by the transmittance of light at wavelengths of 500 nm, 1000 nm, 1500 nm, and 2000 nm. The transmittance was measured in the wavelength range of 2000 nm to 300 nm using an ultraviolet-visible-infrared spectrophotometer (manufactured by Shimadzu Corporation, SolidSpec-3700). Regarding the transmittance, if it satisfied 75% or more at 500 nm and 25% or less at 1000 nm, 1500 nm, and 2000 nm, it was considered qualified because it had excellent visible light transmittance and excellent infrared absorption.

[0085]

Table 1

[0086] [Table 2]

[0087] [Table 3]

[0088] [Table 4]

[0089] [Table 5]

[0090] [Table 6]

Claims

1. A photocurable resin composition containing urethane (meth)acrylate (A), (meth)acrylate monomer (B), a photopolymerization initiator (C), and an infrared absorber (D), wherein the urethane (meth)acrylate (A) contains at least urethane (meth)acrylate (a1) having a carbonate skeleton and urethane (meth)acrylate (a2) having 6 or more functional groups excluding the component (a1), the content of the urethane (meth)acrylate (A) is 15% by mass or more and 45% by mass or less based on 100% by mass of the solid content of the photocurable resin composition, and the content of the urethane (meth)acrylate (a1) having a carbonate skeleton is 25% by mass or more and 80% by mass or less based on the total amount of the urethane (meth)acrylate (A), the (meth)acrylate monomer (B) contains at least (meth)acrylate monomer (b1) having 2 functional groups and (meth)acrylate monomer (b2) having 5 or more functional groups, the content of the (meth)acrylate monomer (B) is 30% by mass or more and 65% by mass or less based on 100% by mass of the solid content of the photocurable resin composition, and the content of the (meth)acrylate monomer (b2) having 5 or more functional groups is 35% by mass or more and 85% by mass or less based on the total amount of the (meth)acrylate monomer (B), a photocurable resin composition.

2. The photocurable resin composition according to claim 1, wherein the content of the urethane (meth)acrylate (a2) having 6 or more functional groups excluding the component (a1) is 20% by mass or more and 75% by mass or less based on the total amount of the urethane (meth)acrylate (A).

3. The photocurable resin composition according to claim 1, wherein the content of the (meth)acrylate monomer (b1) having 2 functional groups is 15% by mass or more and 65% by mass or less based on the total amount of the (meth)acrylate monomer (B).

4. The infrared absorber (D) has the general formula: M ｘ W ｙ O ｚ (wherein M is one or more elements selected from H, He, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, Yb; W is tungsten; O is oxygen; 0.001 ≦ x / y ≦ 1; 2.0 < z / y ≦ 3.0), and is a composite tungsten oxide, and the photocurable resin composition according to Claim 1.

5. The photocurable resin composition according to claim 1, wherein the content of the infrared absorber (D) is 1% by mass or more and 30% by mass or less based on 100% by mass of the solid content of the photocurable resin composition.

6. The photocurable resin composition according to claim 1, further comprising at least one selected from the group consisting of an ultraviolet absorber (E), a light stabilizer (F), and a leveling agent (G).

7. The photocurable resin composition according to claim 1, which is used as a paint.

8. A cured film formed from the photocurable resin composition according to any one of claims 1 to 7.

9. A substrate with a cured film having a cured film formed from the photocurable resin composition according to any one of claims 1 to 7 on at least a part of the surface of the substrate.

10. A coating step of coating at least one surface of a substrate with the photocurable resin composition according to any one of claims 1 to 7; A curing step of curing the photocurable resin composition by ultraviolet irradiation to form a cured film after the coating step; A method for producing a substrate with a cured film, comprising:

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