Resin composition for photocurable lining material, photocurable lining material and cured product thereof

Abstract

Provided is a photocurable resin composition for lining materials, characterized in that it contains: a resin component (A) having a carboxyl group-containing epoxy (meth)acrylate (a1) and an unsaturated monomer (a2) as essential components, a thickener (B) and a photopolymerization initiator (C). The photocurable resin composition for lining materials exhibits appropriate thickening behavior, has excellent curability, and can obtain a lining material cured product having excellent bending strength, tensile elongation and heat resistance, and can therefore be suitably used for pipe repair of sewer pipes and the like.

Description

Technical Field

[0001] The present invention relates to a resin composition for a photocurable lining material, a photocurable lining material and a cured product thereof. Background Art

[0002] As a method for repairing aged pipes such as sewer pipes, a thermosetting repair method using a lining material using a styrene-based unsaturated polyester resin composition and a vinyl ester resin composition is often used, but these materials are required to shorten the construction time.

[0003] Under such circumstances, a curable resin composition has been proposed, which includes an unsaturated polyester having a number average molecular weight in the range of 500 to 4000, and a monofunctional (meth)acrylate monomer having a group containing a cyclic hydrocarbon group having one carbon-carbon double bond or a nitrogen atom in the ring as an alcohol residue (see, for example, Patent Document 1). However, if the lining material using the curable resin composition is used, it is difficult to achieve both toughness and heat resistance.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2007-77218 Summary of the invention

[0007] Problems to be solved by the invention

[0008] The problem to be solved by the present invention is to provide a photocurable resin composition for a lining material which exhibits appropriate thickening behavior, is excellent in curability, and can provide a cured product of a lining material having excellent flexural strength, tensile elongation and heat resistance.

[0009] Means for solving problems

[0010] The present inventors have found that a photocurable resin composition for a lining material containing a specific resin component, a thickener, and a photopolymerization initiator can solve the above-mentioned problems, and have completed the present invention.

[0011] That is, it relates to a resin composition for a photocurable lining material, characterized in that it contains: a resin component (A) having an epoxy (meth)acrylate having a carboxyl group (a1) and an unsaturated monomer (a2) as essential components, a thickener (B) and a photopolymerization initiator (C).

[0012] Effects of the Invention

[0013] The photocurable lining material obtained from the photocurable lining material resin composition of the present invention has excellent curability, and can obtain a cured lining material having excellent bending strength, tensile elongation and heat resistance, and thus can be suitably used for pipe repair of sewer pipes, etc. In addition, it can also be used for infrastructure repair purposes such as gas pipes and power pipes represented by water pipes, and repair prepregs for waterproof floors in bathrooms, etc. DETAILED DESCRIPTION

[0014] The photocurable resin composition for a lining material of the present invention comprises a resin component (A) containing an epoxy (meth)acrylate having a carboxyl group (a1) and an unsaturated monomer (a2) as essential components, a thickener (B) and a photopolymerization initiator (C).

[0015] In addition, in the present invention, "(meth)acrylate" means one or both of acrylate and methacrylate, and "(meth)acrylic acid" means one or both of acrylic acid and methacrylic acid.

[0016] The epoxy (meth)acrylate (a1) having a carboxyl group is obtained, for example, by an ester reaction between epoxy (meth)acrylate and a dibasic acid. From the viewpoint of further improving curability, the dibasic acid is preferably an unsaturated dibasic acid, and more preferably maleic anhydride.

[0017] Examples of the dibasic acid include unsaturated dibasic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, and itaconic anhydride; and saturated dibasic acids such as phthalic acid, phthalic anhydride, halogenated phthalic anhydride, isophthalic acid, terephthalic acid, hexahydrophthalic acid, hexahydrophthalic anhydride, hexahydroterephthalic acid, hexahydroisophthalic acid, succinic acid, succinic anhydride, malonic acid, glutaric acid, adipic acid, sebacic acid, 1,12-dodecane dioic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 2,3-naphthalene dicarboxylic acid, 2,3-naphthalene dicarboxylic anhydride, 4,4′-biphenyl dicarboxylic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, nadic anhydride, and methylnadic anhydride.

[0018] The epoxy (meth)acrylate is obtained by, for example, reacting an epoxy resin with (meth)acrylic acid.

[0019] Examples of the epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol fluorene epoxy resin, biscresol fluorene type epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, oxazolidinone modified epoxy resin, brominated epoxy resins of these resins, glycidyl ethers of phenols, dipropylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl ether of alkylene oxide adducts of bisphenol A, glycidyl ethers of polyols such as diglycidyl ether of hydrogenated bisphenol A, 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, 1-oxiranyl-3,4 Alicyclic epoxy resins such as cyclohexene oxide, diglycidyl phthalate, diglycidyl tetrahydrophthalate, diglycidyl-p-hydroxybenzoic acid, glycidyl dimer acid glycidyl esters, tetraglycidyl diaminodiphenylmethane, tetraglycidyl-m-xylylenediamine, triglycidyl-p-aminophenol, glycidylamines such as N,N-diglycidylaniline, 1,3-diglycidyl-5,5-dimethylhydantoin, heterocyclic epoxy resins such as triglycidyl isocyanurate, etc., among which, bisphenol A type epoxy resins are preferred from the viewpoint of being easy to adjust the refractive index of the above-mentioned resin component (A) to a certain range and being able to further improve the curability. It should be noted that these epoxy resins can be used alone or in combination of two or more.

[0020] The reaction of the epoxy resin and (meth)acrylic acid is preferably carried out using an esterification catalyst at 60 to 140° C. A polymerization inhibitor or the like may also be used.

[0021] From the viewpoint of exhibiting a more appropriate thickening behavior, the molar ratio (OH / COOH) of the hydroxyl group to the carboxyl group in the epoxy (meth)acrylate (a1) having a carboxyl group is preferably 95 / 5 to 50 / 50, and more preferably 90 / 10 to 60 / 40.

[0022] The acid value of the epoxy (meth)acrylate (a1) having a carboxyl group is preferably 10 to 50, more preferably 15 to 40, from the viewpoint of obtaining a more appropriate thickening behavior.

[0023] Examples of the unsaturated monomer (a2) include benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, polyethylene glycol (meth)acrylate alkyl ether, polypropylene glycol (meth)acrylate alkyl ether, 2-ethylhexyl methacrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, isotridecyl (meth)acrylate, n-stearyl (meth)acrylate, tetrahydrofurfuryl methacrylate, isobornyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentyl methacrylate, methyl methacrylate and the like; monofunctional (meth)acrylate compounds such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, and the like; , 1,3-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, bisphenol di(meth)acrylate, 1,4-cyclohexanedimethanol di(meth)acrylate and other di(meth)acrylate compounds; trimethylolpropane tri(meth)acrylate, tri(meth)acrylates such as pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate and other multifunctional (meth)acrylate compounds, styrene, α-methylstyrene, vinyltoluene, diallyl phthalate, divinylbenzene, etc., among these, from the perspective of excellent copolymerizability with the above-mentioned resin component (A), being able to further improve curability and bending strength, tensile elongation, and heat resistance, it is preferred to include multifunctional (meth)acrylate compounds. It should be noted that these unsaturated monomers can be used alone or in combination of two or more.

[0024] From the perspective of further improving the balance between the resin impregnation and curing properties of the fiber, the mass ratio (a1 / a2) of the radical curable resin (a1) to the unsaturated monomer (a2) is preferably in the range of 25 / 75 to 75 / 25, and more preferably in the range of 30 / 70 to 70 / 30.

[0025] The refractive index of the resin component (A) is preferably in the range of 1.530 to 1.550 from the viewpoint of further improving curability.

[0026] The resin component (A) contains the epoxy (meth)acrylate (a1) and the unsaturated monomer (a2) as essential components, but may contain other resin components.

[0027] As the thickener (B), for example, metal oxides such as magnesium oxide, magnesium hydroxide, calcium oxide, calcium hydroxide, metal hydroxides, isocyanate compounds, thermoplastic powder resins, etc. can be cited. From the aspect of obtaining a more appropriate viscosity behavior, magnesium oxide is preferred. These thickeners can be used alone or in combination of two or more. In addition, in order to improve the thickening behavior, in addition to magnesium oxide as a thickener, thickening aids such as quaternary ammonium salts can also be used in combination.

[0028] The amount of the thickener (B) used is preferably in the range of 0.1 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, based on 100 parts by mass of the resin component (A), from the viewpoint of obtaining more appropriate viscosity behavior.

[0029] As the photopolymerization initiator (C), for example, acetophenone compounds such as 4-phenoxydichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, 1-hydroxycyclohexylphenylketone, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propanone, and 2,2-dimethoxy-2-phenylacetophenone; benzoin compounds such as benzoin, benzoin methyl ether, benzoin isoethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; and benzophenone can be used. , benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3'-dimethyl-4-methoxybenzophenone and other benzophenone compounds; thioxanthone compounds such as 2-chlorothioxanthone, 2,4-dichlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone and other thioxanthone compounds; 4,4'-dimethylaminothioxanthone (alias = Michler's ketone), 4,4'-diethylaminobenzophenone, α-acyl oxime esters, benzil, methylbenzoyl formate ("Vicure 55”), anthraquinone compounds such as 2-ethylanthraquinone; acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, acryloylbenzophenone, etc. It should be noted that these photopolymerization initiators (C) can be used alone or in combination of two or more.

[0030] The amount of the photopolymerization initiator (C) used is preferably in the range of 0.1 to 3 parts by mass, more preferably 0.1 to 2 parts by mass, based on 100 parts by mass of the resin component (A), from the viewpoint of excellent curability.

[0031] The photocurable resin composition for a lining material of the present invention contains a resin component (A), a thickener (B) and a photopolymerization initiator (C), and may contain other additives as necessary.

[0032] Examples of the other additives include polymerization inhibitors, antioxidants, light stabilizers, solvents, defoamers, thixotropy-imparting agents, leveling agents, tackifiers, antistatic agents, flame retardants, curing accelerators, pigments, fillers, reinforcing materials, aggregates, and the like.

[0033] The photocurable lining material of the present invention comprises the above-mentioned resin composition for a photocurable lining material and a glass fiber reinforcement material.

[0034] As the form of the above-mentioned glass fiber reinforced material, for example, a roving cloth made of a plain weave made of roving, a chopped strand mat made of a non-woven fabric made of randomly oriented chopped strands cut into 2 inches and bonded with a binder, a unidirectional sheet made of rovings pulled in the same direction and integrated with auxiliary weft yarns and a binder, a multi-axial sewn base material made of sheets pulled in one direction and stacked in multiple directions and integrated with sutures, and a sewn felt made of sheets pulled in one direction and randomly oriented chopped strands integrated with sutures, etc. can be made into a cylindrical or felt-like form. In addition, these glass fiber reinforced materials can be used alone or in combination of two or more.

[0035] As the above-mentioned glass fiber, for example, glass fibers obtained from alkali glass (C glass), low-alkali glass, alkali-free glass (E glass), etc. as raw materials can also be used, but it is preferable to use acid-resistant glass (ECR glass) with excellent mechanical properties and corrosion resistance for infrastructure repair purposes.

[0036] From the viewpoint of further improving mechanical properties, the content of the glass fiber reinforcement in the photocurable lining material of the present invention is preferably in the range of 30 to 60% by mass.

[0037] As construction and application methods of the lining material of the present invention, there are methods of directly laminating and impregnating the photocurable lining resin composition of the present invention and the glass fiber reinforced material on the repair surface of concrete or the like to form a lining material layer; and methods of laminating and impregnating the photocurable lining resin composition of the present invention and the glass fiber reinforced material in advance in a factory or the like to prepare a prepreg covered with films on both sides, peeling off the film of the adhered surface as needed at the repair site, pressing and bonding with a roller or the like according to the shape of the repaired part, and curing it by irradiation with light.

[0038] Examples of methods for curing the photocurable lining material of the present invention include irradiation with ionizing radiation such as ultraviolet rays, electron beams, α rays, β rays, and γ rays. Examples of specific energy sources or curing devices include germicidal lamps, fluorescent lamps for ultraviolet rays, carbon arcs, xenon lamps, high-pressure mercury lamps for copying, medium-pressure or high-pressure mercury lamps, ultrahigh-pressure mercury lamps, electrodeless lamps, metal halide lamps, fluorescent chemical lamps, LED lamps, ultraviolet rays using natural light as a light source, or electron beams using scanning or curtain-type electron beam accelerators.

[0039] The photocurable lining material of the present invention is excellent in rapid curing and thick film curing, and therefore can be suitably used for pipe repair of sewer pipes, etc. In addition, it can also be used for infrastructure repair purposes such as gas pipes and power pipes represented by water pipes, and repair prepregs for waterproof floors in bathrooms, etc.

[0040] Example

[0041] The present invention will be described in more detail below with reference to specific examples. It should be noted that the refractive index of the resin component was measured using a general-purpose Abbe refractometer ("ER-7MW" manufactured by ERMA Sales Co., Ltd.), the acid value was measured in accordance with JIS-K-6901, and the epoxy equivalent was measured in accordance with JIS-K-7236.

[0042] (Synthesis Example 1: Synthesis of epoxy (meth)acrylate (a1-1) having a carboxyl group)

[0043] In a 2L flask equipped with a thermometer, a nitrogen introduction tube, and a stirrer, 488.8 parts by mass of bisphenol A epoxy resin ("EPICLON 850" manufactured by DIC Corporation, epoxy equivalent 188), 215.7 parts by mass of methacrylic acid, and 0.25 parts by mass of tert-butyl hydroquinone were added in a gas circulation atmosphere in which nitrogen and air were mixed at a ratio of 1:1. After heating to 90°C for 1 hour, 0.7 parts by mass of 2-methylimidazole was added, and the reaction temperature was raised to 110°C for 2 hours. Then, 0.7 parts by mass of 2-methylimidazole was further added, and the acid value and epoxy equivalent were measured. After confirming that the acid value was 7.0 or less and the epoxy equivalent was 5000 or more, the reaction was terminated. After cooling to about 40°C, 0.05 parts by mass of tert-butyl hydroquinone and 300 parts by mass of phenoxyethyl methacrylate were added and dissolved. After stirring for 10 minutes, 75.4 parts by mass of maleic anhydride was added, and the temperature was raised to 90°C for reaction for 5 hours. Then, the acid value was confirmed to be less than 50, and the reaction was terminated. After cooling to about 50°C, the reaction vessel was taken out to obtain epoxy (meth) acrylate (a1-1) having a carboxyl group with a molar ratio (OH / COOH) of hydroxyl group to carboxyl group of 70 / 30 as maleic acid-modified epoxy (meth) acrylate. The acid value was 50.0.

[0044] (Synthesis Example 2: Synthesis of epoxy (meth)acrylate (a1-2))

[0045] Under nitrogen flow, 368.3 parts by mass of bisphenol A epoxy resin ("EPICLON 850" manufactured by DIC Corporation, epoxy equivalent 188) was added to a 2L flask equipped with a thermometer, a nitrogen inlet tube, and a stirrer, and heated to 60° C., then 83.4 parts by mass of bisphenol A was added, and the temperature was raised to 110° C. Then, 0.55 parts by mass of 2-methylimidazole was added, and it was confirmed that the epoxy equivalent was within the range of 375±10, and the mixture was cooled to 100° C. Nitrogen was removed using a vacuum pump, and then air replacement was performed. Next, in a gas circulation atmosphere in which nitrogen and air are mixed in a ratio of 1 to 1, 102.2 parts by mass of methacrylic acid and 0.20 parts by mass of tert-butyl hydroquinone are added at a temperature of 100°C, and reacted for 2 hours. Then, 0.277 parts by mass of 2-methylimidazole is added, and the acid value and epoxy equivalent are measured. After confirming that the acid value is less than 7.0 and the epoxy equivalent is more than 5000, 0.05 parts by mass of tert-butyl hydroquinone and 277 parts by mass of phenoxyethyl methacrylate are added to dissolve the mixture. After stirring for 10 minutes, 39.6 parts by mass of maleic anhydride are added, the temperature is raised to 90°C, and the mixture is reacted for 5 hours. After confirming that the acid value is less than 30, the reaction is terminated. After being cooled to about 50°C, the mixture is taken out from the reaction vessel, and as maleic acid-modified epoxy (meth) acrylate, an epoxy (meth) acrylate (a1-2) having a carboxyl group having a molar ratio (OH / COOH) of hydroxyl group to carboxyl group of 80 / 20 is obtained. The acid value is 27.0.

[0046] (Synthesis Example 3: Synthesis of unsaturated polyester resin (1))

[0047] In a 2L flask equipped with a thermometer, a nitrogen inlet tube, and a stirrer, 416 parts by mass of neopentyl glycol, 76 parts by mass of propylene glycol, 332 parts by mass of isophthalic acid, and 294 parts by mass of maleic anhydride were added, and the mixture was added in batches in a two-stage reaction according to a conventional method, and the temperature was raised to 200°C. After confirming that the acid value was 25 or less, the reaction was terminated. After the obtained unsaturated polyester was cooled to 130°C, 0.015 parts by mass of hydroquinone was added to 100 parts by mass of the obtained unsaturated polyester, and after further cooling to 60°C, the mixture was taken out from the reaction container to obtain an unsaturated polyester resin (1). The acid value was 24.0.

[0048] (Synthesis Example 4: Synthesis of epoxy (meth)acrylate (Ra1-1))

[0049] In a 2L flask equipped with a thermometer, a nitrogen inlet tube, and a stirrer, 488.8 parts by mass of bisphenol A epoxy resin ("EPICLON 850" manufactured by DIC Corporation, epoxy equivalent 188), 215.7 parts by mass of methacrylic acid, and 0.25 parts by mass of tert-butyl hydroquinone were added in a gas circulation atmosphere in which nitrogen and air were mixed in a ratio of 1:1. After heating to 90°C for 1 hour, 0.7 parts by mass of 2-methylimidazole was added, and the reaction temperature was raised to 110°C for 2 hours. Then, 0.7 parts by mass of 2-methylimidazole was further added, and the acid value and epoxy equivalent were measured. After confirming that the acid value is less than 7.0 and the epoxy equivalent is more than 5000, the reaction is terminated. After cooling to about 50°C, 0.05 parts by mass of tert-butyl hydroquinone was added, and the mixture was taken out from the reaction vessel to obtain epoxy (meth) acrylate (Ra1-1). The acid value is 3.0.

[0050] (Example 1: Production of a photocurable lining material resin composition (1))

[0051] 60 parts by mass of the epoxy (meth)acrylate (a1-1) having a carboxyl group obtained in Synthesis Example 1, 25 parts by mass of phenoxyethyl methacrylate, 15 parts by mass of diethylene glycol dimethacrylate, 1.5 parts by mass of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (hereinafter referred to as “photopolymerization initiator (C-1)”), and 3.0 parts by mass of a thickener (“Magmicron MD504-2” manufactured by Mikoku Pigments Co., Ltd.; hereinafter referred to as “thickener (B-1)”) were mixed to obtain a resin composition (1) for a photocurable lining material.

[0052] Here, the refractive index of the resin component (A-1) containing epoxy (meth)acrylate (a1-1), phenoxyethyl methacrylate, and diethylene glycol dimethacrylate is 1.530.

[0053] (Example 2: Production and evaluation of a photocurable resin composition for a lining material (2))

[0054] 40 parts by mass of the epoxy (meth)acrylate (a1-2) having a carboxyl group obtained in Synthesis Example 2, 40 parts by mass of phenoxyethyl methacrylate, 20 parts by mass of trimethylolpropane trimethacrylate, 1.5 parts by mass of a photopolymerization initiator (C-1), and 2.0 parts by mass of a thickener (B-1) were mixed to obtain a resin composition (2) for a photocurable lining material.

[0055] Here, the refractive index of the resin component (A-2) containing epoxy (meth)acrylate (a1-1), phenoxyethyl methacrylate, and trimethylolpropane trimethacrylate is 1.530.

[0056] (Comparative Example 1: Preparation and Evaluation of Photocurable Lining Material Resin Composition (R1))

[0057] 40 parts by mass of the unsaturated polyester resin (1) obtained in Synthesis Example 3, 40 parts by mass of phenoxyethyl methacrylate, 20 parts by mass of trimethylolpropane trimethacrylate, 1.5 parts by mass of a photopolymerization initiator (C-1), and 2.0 parts by mass of a thickener (B-1) were mixed to obtain a resin composition (R1) for a photocurable lining material.

[0058] Here, the refractive index of the resin component (RA-1) containing the unsaturated polyester resin (1), phenoxyethyl methacrylate, and trimethylolpropane trimethacrylate is 1.510.

[0059] (Comparative Example 2: Preparation and Evaluation of Photocurable Lining Material Resin Composition (R2))

[0060] 60 parts by mass of the epoxy (meth)acrylate (Ra1-1) obtained in Synthesis Example 4, 25 parts by mass of phenoxyethyl methacrylate, 15 parts by mass of diethylene glycol dimethacrylate, 1.5 parts by mass of a photopolymerization initiator (C-1), and 3.0 parts by mass of a thickener (B-1) were mixed to obtain a resin composition (R2) for a photocurable lining material.

[0061] Here, the refractive index of the resin component (RA-2) containing epoxy (meth)acrylate (Ra1-1), phenoxyethyl methacrylate, and diethylene glycol dimethacrylate is 1.530.

[0062] [Thickening behavior]

[0063] The viscosity of the photocurable lining resin composition obtained above was measured at a liquid temperature of 25° C. using a Brookfield viscometer (BF rotational viscometer, manufactured by Toki Sangyo Co., Ltd.). The viscosity after standing at 25° C. for 24 hours was measured, and the thickening behavior was evaluated according to the following criteria.

[0064] 0: Viscosity after 24 hours is 1000 dPa·s or more and less than 20000 dPa·s

[0065] ×: Viscosity after 24 hours is less than 1000 dPa·s or more than 20000 dPa·s

[0066] [Evaluation of physical properties of cured product]

[0067] The surface of the photocurable lining material resin composition obtained above was irradiated with a metal halide lamp M045-31L (light emission length: 375 mm, 4.5 kW) manufactured by Eye Graphics Corporation equipped with a cold light mirror from a height of 20 cm for 300 seconds to obtain a cured product, and various physical properties were evaluated.

[0068] [Bending strength]

[0069] The flexural strength of the cured product obtained above was measured in accordance with JIS K7171-1 and evaluated based on the following criteria.

[0070] ○: 100MPa or more

[0071] ×: less than 100MPa

[0072] [Tensile elongation]

[0073] The cured product obtained above was subjected to a tensile test of a 1B test piece in accordance with JIS K7161-1 and 2, and the tensile elongation was measured and evaluated according to the following criteria.

[0074] ○: 2% or more

[0075] ×: less than 2%

[0076] [Heat resistance]

[0077] The deflection temperature under load of the cured product obtained above was measured in accordance with JIS K7191-1, and the heat resistance was evaluated according to the following criteria.

[0078] ○:Above 85℃

[0079] ○: less than 85℃

[0080] Table 1 shows the evaluation results of the photocurable lining material resin compositions (1) to (2) and (R1) to (R2) obtained above.

[0081] [Table 1]

[0082]

[0083] It was confirmed that the photocurable lining material obtained from the photocurable lining material resin composition of the present invention in Examples 1 and 2 had excellent thickening behavior, and the cured product thereof had excellent flexural strength, tensile elongation, and heat resistance.

[0084] On the other hand, in Comparative Example 1, which is an example in which an unsaturated polyester resin was used instead of the epoxy (meth)acrylate (a1) having a carboxyl group, it was confirmed that the bending strength and heat resistance were insufficient.

[0085] Comparative Example 2 is an example in which epoxy (meth)acrylate (a1) having no carboxyl group was used instead of epoxy (meth)acrylate (a1) having a carboxyl group, and it was confirmed that the thickening property was insufficient.

Claims

1. A photocurable resin composition for a lining material, characterized in that: The invention comprises: a resin component (A) containing an epoxy (meth)acrylate having a carboxyl group (a1) and an unsaturated monomer (a2) as essential components, a thickener (B) and a photopolymerization initiator (C), The molar ratio of the hydroxyl group to the carboxyl group in the epoxy (meth)acrylate (a1) having a carboxyl group is 95 / 5 to 50 / 50. The acid value of the epoxy (meth)acrylate (a1) having a carboxyl group is 10 to 50, The unsaturated monomer (a2) comprises a multifunctional (meth)acrylate, The mass ratio of the epoxy (meth)acrylate (a1) having a carboxyl group to the unsaturated monomer (a2), i.e., a1 / a2, is in the range of 25 / 75 to 75 / 25. The thickener (B) is magnesium oxide, The amount of the thickener (B) used is in the range of 0.1 to 15 parts by mass based on 100 parts by mass of the resin component (A). The photocurable resin composition for a lining material has a viscosity at 25° C. of 1000 dPa·s or more and less than 20000 dPa·s as measured by a Brookfield viscometer at 25° C. after being left to stand at 25° C. for 24 hours.

2. The photocurable resin composition for a lining material according to claim 1, wherein The epoxy (meth)acrylate (a1) having a carboxyl group is a reaction product of epoxy (meth)acrylate and a dibasic acid.

3. A light-curing lining material, characterized in that: The invention comprises: the resin composition for a photocurable lining material according to claim 1 or 2, and a glass fiber reinforcement material.

4. A cured product of the photocurable lining material according to claim 3.

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