Photocurable resin composition, substrate with cured film and method for producing same

Abstract

To provide a photocurable resin composition capable of forming a cured film having excellent visible light transparency, substrate adhesion, water resistance, moist heat resistance, long-term hydrophilicity, and a long-term antifogging property.SOLUTION: A photocurable resin composition according to the present invention is a photocurable resin comprising silica (A) having a chain structure, a (meth)acrylate (B) having a polyoxyalkylene structure, and a photopolymerization initiator (C). The content of the silica (A) having a chain structure is 20 mass% or more based on 100 mass% of the solid content of the photocurable resin composition.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] Conventionally, hydrophilicity has been imparted to the cured coating of industrial products. For example, in the case of industrial products such as automobile parts and water-related products such as bathrooms and kitchens, it was necessary to maintain hydrophilicity for a long period of time, about 3 to 10 years. As a method for imparting hydrophilicity to the cured coating of industrial products, a method of blending a surfactant into the curable composition or a method of blending a compound having an organic hydrophilic group such as polyethylene glycol was generally used. However, in the case of the method of blending a non-reactive surfactant to make the cured coating hydrophilic, there was a problem that the non-reactive surfactant was washed away when the cured coating was washed with water, and hydrophilicity could not be maintained. In addition, in the case of the method of blending polyethylene glycol or the like to make the cured coating hydrophilic, there was a problem that hydrophilicity could not be maintained when the water absorption performance of polyethylene glycol or the like reached an upper limit. In other words, it was difficult to maintain hydrophilicity in industrial products for a long period of time with the conventional method.

[0003] For example, it has been proposed to improve hydrophilicity and anti-fogging properties by forming a cured coating using an active energy ray-curable organic-inorganic hybrid resin composition containing (A) silica fine particles having a chain structure, (B) an organic compound having a (meth)acryloyl group or a (meth)acrylamide group, and (C) a photopolymerization initiator (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-083846 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have found that even if the active energy ray-curable organic-inorganic hybrid resin composition described in Patent Document 1 is used, the silica fine particles flow out of the cured coating film after a long period of time, making it difficult to maintain long-term hydrophilicity and long-term anti-fogging properties.

[0006] The present invention has been made in view of the above-mentioned background art and problems, and an object of the present invention is to provide a photocurable resin composition capable of forming a cured coating film that is excellent in visible light transmittance, substrate adhesion, water resistance, moist heat resistance, long-term hydrophilicity, and long-term anti-fogging property. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems, and have found that the above problems can be solved by using a photocurable resin composition containing silica (A) having a chain structure, (meth)acrylate (B) having a polyoxyalkylene structure, and a photopolymerization initiator (C), with the content of silica (A) having a chain structure adjusted. The present invention has been completed based on this finding.

[0008] That is, according to the present invention, the following inventions are provided. [1] A photocurable resin composition comprising: silica (A) having a chain structure; (meth)acrylate (B) having a polyoxyalkylene structure; and a photopolymerization initiator (C), The content of the silica (A) having a chain structure is 20% by mass or more based on 100% by mass of the solid content of the photocurable resin composition. [2] The photocurable resin composition according to [1], wherein the content of the silica (A) having a chain structure is 25% by mass or more and 60% by mass or less, based on 100% by mass of the solid content of the photocurable resin composition. [3] The photocurable resin composition according to [1] or [2], wherein the silica having a chain structure (A) has not been subjected to a hydrophobic treatment. [4] The photocurable resin composition according to any one of [1] to [3], wherein the (meth)acrylate (B) having a polyoxyalkylene structure has two or more (meth)acryloyl groups in one molecule. [5] The photocurable resin composition according to any one of [1] to [4], further comprising a surfactant (D) having a photopolymerizable unsaturated group. [6] The photocurable resin composition according to any one of [1] to [5], further comprising a (meth)acrylate (E) other than the component (B). [7] The photocurable resin composition according to any one of [1] to [6], which is used as a coating material. [8] A cured coating formed from the photocurable resin composition according to any one of [1] to [7]. [9] A substrate having a cured coating, the substrate having, on at least a part of a surface thereof, a cured coating formed from the photocurable resin composition according to any one of [1] to [7].

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

[0009] According to the present invention, it is possible to provide a photocurable resin composition capable of forming a cured coating film having excellent visible light transmittance, substrate adhesion, water resistance, moist heat resistance, long-term hydrophilicity, and long-term anti-fogging property. In addition, according to the present invention, it is also possible to provide a cured coating film formed from such a photocurable resin composition, a substrate with the cured coating film, and a method for producing the substrate with the cured coating film. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will now be described in more detail. In this specification, "(meth)acrylate" refers to acrylate and methacrylate, "(meth)acryl" refers to acryl and methacryl, and "(meth)acryloyl" refers to acryloyl and methacryloyl. The term "solid content" refers to the components remaining after removing volatile components such as organic solvents from the photocurable resin composition, which constitute a cured coating when cured.

[0011] <Photocurable resin composition> The photocurable resin composition according to the present invention contains silica (A) having a chain structure, (meth)acrylate (B) having a polyoxyalkylene structure, and photopolymerization initiator (C). In the present invention, the photocurable resin composition contains components (A) to (C), and by adjusting the content of silica (A) having a chain structure, a cured coating film excellent in visible light transmittance, substrate adhesion, water resistance, moist heat resistance, long-term hydrophilicity, and long-term antifogging properties can be formed. In addition, the photocurable resin composition according to the present invention may further contain a surfactant (D) having a photopolymerizable unsaturated group, and a (meth)acrylate (E) other than component (B), etc. The photocurable resin composition according to the present invention can be suitably used as a coating material. The cured coating film formed from such a photocurable resin composition can be applied to various fields requiring visible light transmittance, substrate adhesion, water resistance, moist heat resistance, long-term hydrophilicity, and long-term antifogging properties. For example, it can be used in automobile parts such as headlamps and windshields, water-related products such as bathrooms and kitchens, glasses, goggles, show windows, face shields, etc. Each component constituting the photocurable resin composition will be described in detail below.

[0012] (Silica having a chain structure (A)) Silica having a chain structure is silica in which silica particles are bonded in a chain to form an elongated shape, and more preferably silica in which silica particles are bonded in a chain to form an elongated shape extending only in one plane. In addition to the above basic structure, silica having a chain structure may partially have at least one fine structure selected from the group consisting of a branched structure, a cyclic structure, a crosslinked structure, a spherical structure, a rod-like structure, a flat structure, and a scale-like structure. By blending silica having a chain structure, the surface area of ​​the silica is improved, so that the number of silanol groups exposed on the cured coating surface increases, and fine irregularities are formed on the cured coating surface, so that the structural hydrophilic effect becomes more pronounced. Therefore, by using silica having a chain structure, it is possible to make it more hydrophilic than when using spherical silica.

[0013] It is preferable that the silica having a chain structure is not subjected to hydrophobic treatment so that it is easy to maintain hydrophilicity for a long time. On the other hand, in order to further improve the hydrophilicity of the silica having a chain structure, a hydrophilic treatment for introducing hydrophilic groups to the surface may be performed. The method of hydrophilic treatment is not particularly limited, and can be performed by a conventionally known method. Examples of hydrophilic groups to be introduced include hydroxyl groups, alkali metal salts thereof, silanol groups, alkali metal salts thereof, carboxylic acid groups, alkali metal salts thereof, sulfonic acid groups, alkali metal salts thereof, phosphate groups, alkali metal salts thereof, polyalkylene oxide groups, addition / inclusion compounds with alkali metal compounds thereof, quaternary ammonium bases, quaternary phosphonium bases, etc. Among these, polyalkylene oxide groups and silicate groups having a high concentration of hydroxyl groups or silanol groups are particularly preferable, and it is preferable to introduce these hydrophilic groups by chemically bonding them to the surface of the silica via an appropriate functional group. In particular, from the viewpoint of prolonging hydrophilicity, surface-untreated silica having a high concentration of silanol groups is particularly preferable.

[0014] The primary average particle size of the silica particles is preferably 1 nm to 300 nm, more preferably 3 to 100 nm, and even more preferably 5 to 50 nm. As long as the primary average particle size of the silica particles is within the above range, the shape of each silica particle unit may be spherical or rod-like. The chain structure of silica is preferably a combination of 3 to 20 silica particle units, more preferably 4 to 10 silica particle units. The average length of the chain structure of silica is preferably 10 nm to 500 nm, more preferably 30 to 300 nm, and even more preferably 40 to 200 nm. The primary average particle size of silica can be measured by the BET method, dynamic light scattering method, electron microscope observation, etc. As long as the primary average particle size of the silica particles and the average length of the chain structure are within the above numerical range, the long-term hydrophilicity can be further improved.

[0015] As the silica having a chain structure, commercially available products can be used, such as those available from Nissan Chemical Industries, Ltd. under the trade names Snowtex ST-UP, Snowtex ST-OUP, PGM-ST-UP, and IPA-ST-UP.

[0016] The content of the silica having a chain structure is 20% by mass or more, preferably 25% by mass or more and 60% by mass or less, and more preferably 30% by mass or more and 55% by mass or less, based on 100% by mass of the solid content of the photocurable resin composition. If the content of the silica having a chain structure is within the above range, a cured coating film excellent in visible light transmittance, substrate adhesion, water resistance, moist heat resistance, long-term hydrophilicity, and long-term anti-fogging property can be obtained.

[0017] ((Meth)acrylate (B) Having a Polyoxyalkylene Structure) The (meth)acrylate having a polyoxyalkylene structure is preferably one having two or more (meth)acryloyl groups in one molecule, and for example, an alkylene oxide modified product of a polyfunctional (meth)acrylate can be used. The alkylene oxide modified product of a polyfunctional (meth)acrylate is preferably obtained by esterifying an adduct of a polyhydric alcohol and an alkylene oxide with (meth)acrylic acid. Examples of the polyhydric alcohol include glycerol, polyglycerol, ethylene glycol, polyethylene glycol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, and tris(2-hydroxyethyl)isocyanuric acid. Examples of the alkylene oxide include ethylene oxide, propylene oxide, isopropylene oxide, and butylene oxide.

[0018] Examples of the difunctional polyfunctional (meth)acrylate modified product include alkylene oxide modified products of trimethylolpropane di(meth)acrylate such as ethylene oxide modified product of trimethylolpropane di(meth)acrylate, propylene oxide modified product of trimethylolpropane di(meth)acrylate, isopropylene oxide modified product of trimethylolpropane di(meth)acrylate, butylene oxide modified product of trimethylolpropane di(meth)acrylate, and ethylene oxide / propylene oxide modified product of trimethylolpropane di(meth)acrylate; alkylene oxide modified products of glyceryl di(meth)acrylate, such as ethylene oxide modified products of glyceryl di(meth)acrylate, propylene oxide modified products of glyceryl di(meth)acrylate, isopropylene oxide modified products of glyceryl di(meth)acrylate, butylene oxide modified products of glyceryl di(meth)acrylate, and ethylene oxide / propylene oxide modified products of glyceryl di(meth)acrylate; Alkylene oxide modified products of pentaerythritol di(meth)acrylate, such as ethylene oxide modified products of pentaerythritol di(meth)acrylate, propylene oxide modified products of pentaerythritol di(meth)acrylate, isopropylene oxide modified products of pentaerythritol di(meth)acrylate, butylene oxide modified products of pentaerythritol di(meth)acrylate, and ethylene oxide / propylene oxide modified products of pentaerythritol di(meth)acrylate; alkylene oxide modified products of neopentyl glycol di(meth)acrylate, such as ethylene oxide modified products of neopentyl glycol di(meth)acrylate, propylene oxide modified products of neopentyl glycol di(meth)acrylate, isopropylene oxide modified products of neopentyl glycol di(meth)acrylate, butylene oxide modified products of neopentyl glycol di(meth)acrylate, and ethylene oxide / propylene oxide modified products of neopentyl glycol di(meth)acrylate; alkylene oxide modified products of 1,4-butanediol di(meth)acrylate, such as ethylene oxide modified products of 1,4-butanediol di(meth)acrylate, propylene oxide modified products of 1,4-butanediol di(meth)acrylate, isopropylene oxide modified products of 1,4-butanediol di(meth)acrylate, butylene oxide modified products of 1,4-butanediol di(meth)acrylate, and ethylene oxide / propylene oxide modified products of 1,4-butanediol di(meth)acrylate; Alkylene oxide modified products of 1,6-hexanediol di(meth)acrylate, such as ethylene oxide modified products of 1,6-hexanediol di(meth)acrylate, propylene oxide modified products of 1,6-hexanediol di(meth)acrylate, isopropylene oxide modified products of 1,6-hexanediol di(meth)acrylate, butylene oxide modified products of 1,6-hexanediol di(meth)acrylate, and ethylene oxide·propylene oxide modified products of 1,6-hexanediol di(meth)acrylate; and Examples of the alkylene oxide modified 1,9-nonanediol di(meth)acrylate include ethylene oxide modified 1,9-nonanediol di(meth)acrylate, propylene oxide modified 1,9-nonanediol di(meth)acrylate, isopropylene oxide modified 1,9-nonanediol di(meth)acrylate, butylene oxide modified 1,9-nonanediol di(meth)acrylate, and ethylene oxide / propylene oxide modified 1,9-nonanediol di(meth)acrylate.

[0019] Examples of trifunctional polyfunctional (meth)acrylate modified products include alkylene oxide modified products of trimethylolpropane tri(meth)acrylate such as ethylene oxide modified product of trimethylolpropane tri(meth)acrylate, propylene oxide modified product of trimethylolpropane tri(meth)acrylate, isopropylene oxide modified product of trimethylolpropane tri(meth)acrylate, butylene oxide modified product of trimethylolpropane tri(meth)acrylate, and ethylene oxide / propylene oxide modified product of trimethylolpropane tri(meth)acrylate; alkylene oxide modified products of glyceryl tri(meth)acrylate, such as ethylene oxide modified products of glyceryl tri(meth)acrylate, propylene oxide modified products of glyceryl tri(meth)acrylate, isopropylene oxide modified products of glyceryl tri(meth)acrylate, butylene oxide modified products of glyceryl tri(meth)acrylate, and ethylene oxide / propylene oxide modified products of glyceryl tri(meth)acrylate; Alkylene oxide modified products of pentaerythritol tri(meth)acrylate, such as ethylene oxide modified products of pentaerythritol tri(meth)acrylate, propylene oxide modified products of pentaerythritol tri(meth)acrylate, isopropylene oxide modified products of pentaerythritol tri(meth)acrylate, butylene oxide modified products of pentaerythritol tri(meth)acrylate, and ethylene oxide / propylene oxide modified products of pentaerythritol tri(meth)acrylate; and Examples of the alkylene oxide modified tris-(2-acryloxyethyl)isocyanurate include ethylene oxide modified tris-(2-acryloxyethyl)isocyanurate, propylene oxide modified tris-(2-acryloxyethyl)isocyanurate, isopropylene oxide modified tris-(2-acryloxyethyl)isocyanurate, butylene oxide modified tris-(2-acryloxyethyl)isocyanurate, and ethylene oxide / propylene oxide modified tris-(2-acryloxyethyl)isocyanurate.

[0020] Examples of tetrafunctional polyfunctional (meth)acrylate modified products include alkylene oxide modified products of pentaerythritol tetra(meth)acrylate such as ethylene oxide modified product of pentaerythritol tetra(meth)acrylate, propylene oxide modified product of pentaerythritol tetra(meth)acrylate, isopropylene oxide modified product of pentaerythritol tetra(meth)acrylate, butylene oxide modified product of pentaerythritol tetra(meth)acrylate, and ethylene oxide / propylene oxide modified product of pentaerythritol tetra(meth)acrylate; and Examples of the alkylene oxide modified ditrimethylolpropane tetra(meth)acrylate include ethylene oxide modified ditrimethylolpropane tetra(meth)acrylate, propylene oxide modified ditrimethylolpropane tetra(meth)acrylate, isopropylene oxide modified ditrimethylolpropane tetra(meth)acrylate, butylene oxide modified ditrimethylolpropane tetra(meth)acrylate, and ethylene oxide / propylene oxide modified ditrimethylolpropane tetra(meth)acrylate.

[0021] Specific examples of polyfunctional (meth)acrylate modified products having five or more functionalities include alkylene oxide modified products of dipentaerythritol poly(meth)acrylates such as ethylene oxide modified products of dipentaerythritol poly(meth)acrylates, propylene oxide modified products of dipentaerythritol poly(meth)acrylates, isopropylene oxide modified products of dipentaerythritol poly(meth)acrylates, butylene oxide modified products of dipentaerythritol poly(meth)acrylates, and ethylene oxide / propylene oxide modified products of dipentaerythritol poly(meth)acrylates, ethylene oxide modified products of polyglycerin acrylates, and propylene oxide modified products of polyglycerin acrylates.

[0022] As the (meth)acrylate having a polyoxyalkylene structure, commercially available products can be used. For example, ethylene oxide modified polyglycerin acrylates include products manufactured by Sakamoto Yakuhin Co., Ltd. under the trade names: SA-TE-6 and SA-TE-60. Ethylene oxide modified trimethylolpropane triacrylates include products manufactured by Shin-Nakamura Chemical Co., Ltd. under the trade names: NK Ester A-TMPT-3EO, A-TMPT-9EO, AT-20E, and AT-30E. Propylene oxide modified trimethylolpropane triacrylates include products manufactured by Shin-Nakamura Chemical Co., Ltd. under the trade names: NK Ester A-TMPT-3PO and NK Ester A-TMPT-9PO. Ethylene oxide modified pentaerythritol acrylates include products manufactured by Shin-Nakamura Chemical Co., Ltd. under the trade names: NK Ester ATM-4E, ATM-4EL, and ATM-35E. Examples of propylene oxide modified pentaerythritol triacrylate include NK Ester ATM-4P and ATM-4PL, both of which are manufactured by Shin-Nakamura Chemical Co., Ltd. Examples of ethylene oxide modified dipentaerythritol acrylate include NK Ester A-DPH-12E and A-DPH-12EL, both of which are manufactured by Shin-Nakamura Chemical Co., Ltd. Examples of ethylene oxide modified glyceryl triacrylate include NK Ester A-GLY-3E, A-GLY-9E and A-GLY-20E, both of which are manufactured by Shin-Nakamura Chemical Co., Ltd. Examples of polyethylene glycol diacrylate include NK Ester A-200, A-400, A-600 and A-1000, both of which are manufactured by Shin-Nakamura Chemical Co., Ltd.

[0023] The content of the (meth)acrylate having a polyoxyalkylene structure is preferably 10% by mass or more and 60% by mass or less, more preferably 15% by mass or more and 55% by mass or less, and even more preferably 20% by mass or more and 50% by mass or less, based on 100% by mass of the solid content of the photocurable resin composition. If the content of the (meth)acrylate having a polyoxyalkylene structure is within the above range, a cured coating film excellent in visible light transmittance, substrate adhesion, water resistance, moist heat resistance, long-term hydrophilicity, and long-term anti-fogging property can be obtained.

[0024] (Photopolymerization initiator (C)) The photopolymerization initiator is not particularly limited, and a conventionally known photopolymerization initiator for UV curing can be used. Examples of the photopolymerization initiator include acylphosphine oxide-based polymerization initiators, acetophenone-based polymerization initiators, benzoyl formate-based polymerization initiators, thioxanthone-based polymerization initiators, oxime ester-based polymerization initiators, hydroxybenzoyl-based polymerization initiators, benzophenone-based polymerization initiators, and α-aminoalkylphenone-based polymerization initiators.

[0025] Examples of the acylphosphine oxide 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, benzyl dimethyl ketal, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, and benzoin alkyl ether. Benzoyl formate-based polymerization initiators include methyl benzoyl formate and the like. An example of the thioxanthone-based polymerization initiator is isopropylthioxanthone. Examples of the oxime ester polymerization initiator include 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime), and the like. Benzophenone-based polymerization initiators include benzophenone, 4-chlorobenzophenone, and 4,4'-diaminobenzophenone. Examples of the α-aminoalkylphenone polymerization initiator include 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and the like. These polymerization initiators may be used alone or in combination of two or more. Among these, it is preferable to use an acetophenone-based polymerization initiator.

[0026] From the viewpoints of curability and transparency, the content of the photopolymerization initiator is preferably 0.1 mass % or more and 10 mass % or less, more preferably 0.5 mass % or more and 7.0 mass % or less, and even more preferably 1.0 mass % or more and 5.0 mass % or less, based on 100 mass % of the solid content of the photocurable resin composition.

[0027] (Surfactant having a photopolymerizable unsaturated group (D)) The surfactant having a photopolymerizable unsaturated group can be any surfactant having a photopolymerizable unsaturated group such as a (meth)acryloyl group, a vinyl group, or an allyl group, without any particular limitation. The surfactant may be either a nonionic surfactant or an anionic surfactant. These may be used alone or in combination of two or more. The surfactant is preferably hydrophilic in order to impart hydrophilicity to the cured coating. For example, the HLB value of the surfactant is preferably 10 to 18, more preferably 12 to 16. By blending a surfactant having a photopolymerizable unsaturated group into the photocurable resin composition, the cured coating is imparted with hydrophilicity, and by chemically bonding with the components in the cured coating, the surfactant does not flow out even after washing with water, and a cured coating excellent in long-term hydrophilicity and long-term anti-fogging properties can be obtained.

[0028] Examples of the surfactant having a photopolymerizable unsaturated group include compounds represented by the general formulas (1) to (12). 1 is an alkyl group, R 2 is hydrogen or a methyl group, R 3 is an alkylene group, n is an integer of 1 or greater, m and l are integers of 1 or greater (m+l=3), and X is H, SO3NH4, or SO3Na. [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka]

[0029] Examples of nonionic surfactants include those in which X is changed to H in the above general formulas (1) to (12). Commercially available products include trade names of AQUALON AN-10, AQUALON AN-20, AQUALON AN-30, AQUALON KN-10, AQUALON KN-20, AQUALON KN-30, AQUALON RN-10, AQUALON RN-20, and AQUALON RN-30 manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade names of ADEKA REASOAP ER-10, ADEKA REASOAP ER-20, ADEKA REASOAP ER-30, ADEKA REASOAP ER-40, ADEKA REASOAP NE-10, ADEKA REASOAP NE-20, and ADEKA REASOAP NE-30 manufactured by ADEKA CORPORATION, trade names of LATEMURU PD-420, LATEMURU PD-430, LATEMURU PD-430-S, and LATEMURU PD-450 manufactured by Kao Corporation.

[0030] Examples of anionic surfactants include those in which X is changed to SO3NH4 or SO3Na in the above general formulas (1) to (12). Commercially available products include trade names: Aqualon AR-10, Aqualon AR-20, Aqualon BC-10, Aqualon BC-20, Aqualon KH-05, Aqualon KH-10, etc., manufactured by Daiichi Kogyo Seiyaku Co., Ltd.; trade names: Adeka Reasoap SR-10, Adeka Reasoap SR-20, Adeka Reasoap SE-10N, Adeka Reasoap SE-1025A, Adeka Reasoap PP-70, etc., manufactured by ADEKA Corporation; and trade names: Latemul PD-104, Latemul PD-105, etc., manufactured by Kao Corporation.

[0031] The content of the surfactant having a photopolymerizable unsaturated group 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 even 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. If the content of the surfactant having a photopolymerizable unsaturated group is within the above range, a cured coating film having excellent long-term hydrophilicity and long-term antifogging properties can be obtained.

[0032] ((Meth)acrylate (E) other than component (B)) As the (meth)acrylate other than component (B), a trifunctional or higher (meth)acrylate can be used. A trifunctional or higher (meth)acrylate means a compound having three or more (meth)acryloyloxy groups as functional groups in the molecule. Examples of the trifunctional or higher (meth)acrylate include poly(meth)acrylates of trivalent or higher aliphatic polyols such as glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. These may be used alone or in combination of two or more.

[0033] The content of the (meth)acrylate other than component (B) is preferably 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 45% by mass or less, and even more preferably 15% by mass or more and 40% by mass or less, based on 100% by mass of the solid content of the photocurable resin composition. If the content of the (meth)acrylate other than component (B) is within the above range, a cured coating film having an excellent balance between substrate adhesion and durability of anti-fogging performance can be obtained.

[0034] (Other Ingredients) The photocurable resin composition according to the present invention may contain other components in addition to the above components (A) to (E) within the scope of the present invention. As other components, a leveling agent, a polymerization inhibitor, an antistatic agent, an antioxidant, a non-reactive diluent, a matting agent, an antifoaming agent, a dispersant, an anti-settling agent, a dispersant, a heat stabilizer, an adhesion improver, a photosensitizer, a light stabilizer, a silane coupling agent, a plasticizer, etc. may be blended as necessary.

[0035] The leveling agent has a function of adjusting the fluidity of the photocurable resin composition and flattening the applied coating. Examples of the leveling agent include fluorine-based leveling agents, silicone-based leveling agents, and acrylic polymer-based leveling agents. Commercially available UV-reactive fluorine-based leveling agents include Ftergent 601AD, Ftergent 601ADH2, Ftergent 602A, Ftergent 650AC, and Ftergent 681 manufactured by Neos Co., Ltd. Examples of UV non-reactive fluorine-based leveling agents include FTX-218, Ftergent 215M, Ftergent 710FL, Ftergent 220P, Ftergent 228P, Ftergent 208G, Ftergent 240G, Ftergent 710FM, Ftergent 710FS, Ftergent 710FL, Ftergent 730LM, Ftergent 710FM, and Ftergent 683. Examples of UV reactive silicone-based leveling agents include BYK-UV3500, BYK-UV3505, BYK-UV3510, BYK-UV3530, BYK-UV3570, BYK-UV3575, and BYK-UV3576, both of which are trade names manufactured by BYK Japan Co., Ltd. Examples of UV non-reactive silicone leveling agents include BYK-3550, BYK-SILCLEAN3700, and BYK-SILCLEAN3720. Examples of acrylic and other leveling agents include BYK-UV3535 as a UV reactive type, and BYK-399 and BYK-3440 as UV non-reactive types. These may be used alone or in combination of two or more. Among these, fluorine-free, silicone-free BYK-UV3535, which has a photopolymerizable unsaturated group and does not inhibit the orientation of hydrophilic groups on the coating film surface, is particularly preferred.

[0036] <Method for preparing photocurable resin composition> The photocurable resin composition according to the present invention can be obtained by mixing and stirring the above-mentioned components using a conventionally known device such as a mixer, disperser, stirrer, etc. Examples of such devices include a mixing and dispersion mill, a homodisper, a mortar mixer, a roll, a paint shaker, a homogenizer, etc.

[0037] In the present invention, the photocurable resin composition can be diluted with a solvent as necessary, for example, to adjust the viscosity of the photocurable resin composition to a suitable viscosity as a coating composition. The solvent is not particularly limited as long as it dissolves the resin content in the 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, monomethyl ether of propylene glycol, and monoethyl ether of diethylene glycol), 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, etc. can be mentioned.

[0038] (hardened film) The cured coating is formed from the photocurable resin composition. The thickness of the cured coating is not particularly limited, but is usually 1 to 100 μm, preferably 2 to 20 μm, and more preferably 3 to 10 μm. From the viewpoint of drying and curing properties, the upper limit is preferably 100 μm, and from the viewpoint of hydrophilicity, antifogging properties, and adhesion, the lower limit is preferably 1 μm. The film thickness in the present invention refers to the thickness of the cured coating when the cross section of the cured coating is observed with an optical microscope, a scanning electron microscope (SEM), or the like. When forming a coating with such a thickness, a coating of the desired thickness may be formed by one coating, or a coating of the desired thickness may be formed by multiple coatings.

[0039] When the cured coating formed from the photocurable resin composition has a thickness of 3 to 10 μm, the haze measured according to JIS K 7136 is preferably less than 1.00%, more preferably 0.90% or less, and even more preferably 0.80% or less. Furthermore, the cured coating having a thickness of 3 to 10 μm has a total light transmittance measured according to JIS K 7361-1 of preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more. When the haze and total light transmittance are within the above ranges, the transparency is excellent.

[0040] <Substrate with hardened film> The substrate with a cured coating according to the present invention is provided with a cured coating formed from the above-mentioned photocurable resin composition on at least a part of the substrate surface. 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, polymethylmethacrylic resin, polymethacrylimide resin, etc. In addition, since the photocurable resin composition of the present invention can form a transparent cured coating having a high total light transmittance and low haze, it is preferable to use a transparent plastic film.

[0041] The thickness of the substrate is not particularly limited, but is usually from 10 μm to 500 μm, and preferably from 30 to 400 μm.

[0042] <Method of manufacturing substrate with coating film> The coated substrate according to the present invention includes a coating step of coating the above-mentioned photocurable resin composition on at least one surface of a substrate, a curing step of curing the photocurable resin composition by ultraviolet irradiation to form a cured coating after the coating step; Each step will be described in detail below.

[0043] (Coating process) The coating step is a step of coating one side of the substrate with the above-mentioned photocurable resin composition by a conventionally known method. For coating, for example, a coater 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, the coating method using a gravure coater is preferred from the viewpoint of workability and productivity.

[0044] The thickness of the film after curing and drying is preferably within the above range of the thickness of the cured film.

[0045] When the resin composition is used after diluting with a solvent, it is preferable to dry it after coating. For example, hot air drying (dryer, etc.) can be used as the drying method. The drying temperature is preferably 10 to 200°C, and from the viewpoint of the smoothness and appearance of the coating film, the more preferable upper limit is 150°C, and from the viewpoint of the drying speed, the more preferable lower limit is 30°C.

[0046] (hardening process) The curing step is a step of irradiating the coated surface of the substrate with ultraviolet light to cure the coated photocurable resin composition and form a cured coating. Examples of a method of curing with ultraviolet light include a method of irradiating ultraviolet light using a high-pressure mercury lamp, metal halide lamp, xenon lamp, chemical lamp, UV-LED, or the like that emits light in the wavelength range of 200 to 500 nm. The amount of ultraviolet light irradiation is preferably 100 to 3,000 mJ / cm from the viewpoint of the curability of the photocurable resin composition and the flexibility of the cured product. 2 and more preferably 200 to 1,000 mJ / cm 2 It is. EXAMPLES

[0047] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0048] The following materials were used to prepare the photocurable resin composition. Silica 1 (chain-like, hydrophilic, untreated, primary average particle size 12 nm, average length of chain structure 50 nm, silica content in solids 15%, Nissan Chemical Co., Ltd., product name: PGM-ST-UP) Silica 2 (no chain structure, spherical, hydrophilic, untreated, primary average particle size 12 nm, silica content in solids 30%, Nissan Chemical Co., Ltd., product name: PGM-ST) Silica 3 (non-chain structure, spherical, hydrophobic, surface-treated, primary average particle size 12 nm, silica content in solids 42%, Nissan Chemical Co., Ltd., product name: PGM-AC-2140Y) (Meth)acrylate 1 having a polyoxyalkylene structure (ethylene oxide modified polyglycerin acrylate, functional group number: approximately 6, manufactured by Sakamoto Yakuhin Co., Ltd., product name: SA-TE-60) (Meth)acrylate 2 having a polyoxyalkylene structure (ethylene oxide modified glyceryl triacrylate, functional group number: 3, manufactured by Shin-Nakamura Chemical Co., Ltd., product name: GLY-9E) (Meth)acrylate 3 having a polyoxyalkylene structure (ethylene oxide modified glyceryl triacrylate, functional group number: 3, manufactured by Shin-Nakamura Chemical Co., Ltd., product name: GLY-20E) (Meth)acrylate 4 having a polyoxyalkylene structure (polyethylene glycol diacrylate, number of functional groups: 2, manufactured by Shin-Nakamura Chemical Co., Ltd., product name: NK Ester A-600) Photopolymerization initiator 1 (acetophenone-based polymerization initiator, manufactured by IGM Resin, product name: Omnirad 184) Reactive surfactant 1 (photopolymerizable unsaturated group: allyl group, nonionic surfactant with HLB value of 12.6, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Aqualon KN-10) Reactive surfactant 2 (photopolymerizable unsaturated group: allyl group, nonionic surfactant with HLB value of 15.5, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Aqualon KN-20) Reactive surfactant 3 (photopolymerizable unsaturated group: allyl group, anionic surfactant of sulfate ester salt, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Aqualon KH-05) Reactive surfactant 4 (photopolymerizable unsaturated group: allyl group, anionic surfactant of sulfate ester salt, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Aqualon KH-10) (Meth)acrylate 1 other than component (B) (dipentaerythritol hexaacrylate, manufactured by Toagosei Co., Ltd., product name: Aronix M-403) (Meth)acrylate 2 other than component (B) (pentaerythritol triacrylate, manufactured by Toagosei Co., Ltd., product name: Aronix M-305) Polymerization inhibitor (hydroquinone) Leveling agent (UV reactive modified polyether, manufactured by BYK, product name: BYKUV-3535) Solvent 1 (Ethyl acetate) Solvent 2 (Propylene glycol monomethyl ether)

[0049] [Examples 1 to 11, Comparative Examples 1 to 6] [Preparation of Photocurable Resin Composition] According to the formulations shown in Tables 1 and 2, the components were stirred and mixed to prepare photocurable resin compositions.

[0050] [Manufacturing of substrates with cured coating] The photocurable resin composition prepared above was applied once to a PET film (thickness: 100 μm, Toyobo Co., Ltd., product name: Cosmoshine A4300) using a wire bar coater so that the dry film thickness was about 3 μm, and then dried at 80° C. for 1 minute. Next, the applied surface of the PET film was irradiated with ultraviolet light from a high-pressure mercury lamp (irradiation amount: 300 mJ / cm 2 ), the coating was cured to form a cured coating, and a substrate with a cured coating was produced.

[0051] [Evaluation of substrate with cured coating] (transparency) For the substrates with the cured coating produced above, the haze (HZ) was measured in accordance with JIS K 7136 using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., model number: NDH4000), and the total light transmittance (TT) was measured in accordance with JIS K 7361-1. The measurement results are shown in Tables 3 and 4. If the haze value was less than 1%, it was deemed to have passed. On the other hand, if the haze value was 1% or more, it was deemed to have failed. In addition, if the total light transmittance was 90% or more, it was deemed to have passed. On the other hand, if the total light transmittance was less than 90%, it was deemed to have failed.

[0052] (Adhesion to substrate) According to the method of the cross-cut test described in JIS K 5600-5-6, 100 squares (10 squares x 10 squares) were cut with a cutter on the cured coating of the substrate with the cured coating produced above to prepare a test piece with a cross-cut pattern. Cellotape (registered trademark) (trade name, manufactured by Nichiban Co., Ltd.) was attached to the test piece. Then, the Cellotape (registered trademark) was quickly pulled in an upward diagonal direction at an angle of 45 degrees to the cross-cut pattern to peel it off. The number of remaining cross-cut coatings was counted, and this number of coatings was used as an index of substrate adhesion, and was evaluated according to the following criteria. The measurement results are shown in Tables 3 and 4. [Evaluation Criteria] ◯: No peeling occurred at all (100 / 100 coatings). △: Slight peeling occurred (coating count 90 to less than 100 / 100) ×: Many peeled off (less than 90 coatings / 100)

[0053] (Hydrophilicity: initial) For the substrates with cured coatings produced above, the water contact angle on the surface of the cured coating was measured using a contact angle meter (Model DM-500, manufactured by Kyowa Interface Science Co., Ltd.). If the contact angle was 30° or less 10 seconds after 1 μL of water was dropped onto the cured coating surface, it was judged to have passed. On the other hand, if the contact angle exceeded 30° under the same conditions, it was judged to have failed. The measurement results are shown in Tables 3 and 4.

[0054] (hydrophilicity: after water washing test) In addition, a water washing test was performed by exposing the surface of the cured coating of the substrate with the cured coating produced above to running water for about 10 seconds. The cured coating after the water washing test was dried at 60°C for 10 minutes. 1 μL of water was dropped onto the dried cured coating surface, and the contact angle was measured 10 seconds later and evaluated in the same manner as above. The measurement results are shown in Tables 3 and 4.

[0055] (hydrophilicity: after constant temperature and humidity test) Furthermore, the substrates with the cured coating prepared above were placed in a thermohygrostat set at 85°C and 85%RT for 250 and 500 hours to carry out a thermohygrostat test. After each time, 1 μL of water was dropped onto the cured coating surface, and the contact angle was measured 10 seconds later in the same manner as above and evaluated. The measurement results are shown in Tables 3 and 4.

[0056] (Breathability: Initial) For the substrates with the cured coating produced above, breath was blown onto the surface of the cured coating, and the surface was visually checked for cloudiness and rated according to the following criteria. The evaluation results are shown in Tables 3 and 4. A rating of "○" or "△" was considered a pass, and a rating of "×" was considered a fail. [Evaluation Criteria] ○: There was no cloudiness at all. △: Partly cloudy. ×: Overall it was cloudy.

[0057] (Breath anti-fog: after water washing test) The substrate with the cured coating produced above was subjected to a water washing test in the same manner as above. The cured coating after the water washing test was dried at 60°C for 10 minutes. Breath was blown onto the dried cured coating surface, and cloudiness was confirmed visually. Evaluation was performed in the same manner as above. The evaluation results are shown in Tables 3 and 4.

[0058] (Anti-fog breathability: after constant temperature and humidity test) The substrate with the cured coating produced above was subjected to a constant temperature and humidity test in the same manner as above. After that, breath was blown onto the surface of the cured coating after the constant temperature and humidity test, and cloudiness was visually confirmed. Evaluation was performed in the same manner as above. The evaluation results are shown in Tables 3 and 4.

[0059] (Steam anti-fogging: initial stage) The cured coating of the substrate produced above was placed 1 cm above 60°C hot water, and after 1 minute, the coating was visually checked for cloudiness and rated according to the following criteria. The evaluation results are shown in Tables 3 and 4. A rating of "○" or "△" was considered a pass, and a rating of "×" was considered a fail. [Evaluation Criteria] ○: There was no cloudiness at all. △: No cloudiness, but water droplets were generated. ×: It was cloudy.

[0060] (Steam anti-fogging: after water washing test) The substrate with the cured coating produced above was subjected to a water washing test in the same manner as above. The cured coating after the water washing test was dried at 60°C for 10 minutes. The dried cured coating was placed 1 cm above hot water at 60°C, and after 1 minute, the cloudiness was visually confirmed. Evaluation was performed in the same manner as above. The evaluation results are shown in Tables 3 and 4.

[0061] (Steam anti-fogging properties: after constant temperature and humidity testing) The substrate with the cured coating prepared above was subjected to a constant temperature and humidity test in the same manner as above. The cured coating after the constant temperature and humidity test was then placed 1 cm above hot water at 60°C, and after 1 minute, the cloudiness was visually confirmed. Evaluation was performed in the same manner as above. The evaluation results are shown in Tables 3 and 4.

[0062] [Table 1]

[0063] [Table 2]

[0064] [Table 3]

[0065] [Table 4]

Claims

1. A photocurable resin composition comprising: silica (A) having a chain structure; a (meth)acrylate (B) having a polyoxyalkylene structure; a photopolymerization initiator (C); and a surfactant (D) having a photopolymerizable unsaturated group, the content of the silica (A) having a chain structure is 30% by mass or more and 60% by mass or less based on 100% by mass of the solid content of the photocurable resin composition, a content of the (meth)acrylate (B) having a polyoxyalkylene structure in the photocurable resin composition is 20% by mass or more and 50% by mass or less, based on 100% by mass of the solid content of the photocurable resin composition.

2. 2. The photocurable resin composition according to claim 1, wherein the content of the silica (A) having a chain structure is 30% by mass or more and 55% by mass or less, based on 100% by mass of the solid content of the photocurable resin composition.

3. The photocurable resin composition according to claim 1 , wherein the silica (A) having a chain structure has not been subjected to a hydrophobic treatment.

4. The photocurable resin composition according to any one of claims 1 to 3, wherein the (meth)acrylate (B) having a polyoxyalkylene structure has two or more (meth)acryloyl groups in one molecule.

5. A photocurable resin composition described in any one of claims 1 to 4, wherein the content of the surfactant (D) having a photopolymerizable unsaturated group is 1.0 mass% or more and 5.0 mass% or less, based on 100 mass% of the solid content of the photocurable resin composition.

6. The photocurable resin composition according to any one of claims 1 to 5, further comprising a (meth)acrylate (E) other than the component (B).

7. The photocurable resin composition according to any one of claims 1 to 6, which is used as a coating material.

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

9. A substrate having a cured coating 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 coating after the coating step; A method for producing a substrate with a cured coating, comprising:

Images