JP6065496B2 - Photopolymerizable composition, cured product thereof, and plastic lens sheet - Google Patents

Description

  INDUSTRIAL APPLICABILITY The present invention is used as an antireflection film for a prism sheet or a microlens sheet used as a backlight for a Fresnel lens sheet, a lenticular sheet, a liquid crystal display device or the like used for a projection screen such as a projection television. The present invention relates to a photocurable resin composition suitable for a moth-eye film or the like.

  In recent years, displays such as liquid crystal display devices have a fine uneven shape formed on the surface, and an optical sheet that exhibits a desired function by refracting light in the uneven structure is indispensable. Performance such as holding power is required. As such an optical sheet shape, for example, a Fresnel lens sheet or a lenticular sheet used for a projection screen such as a projection television, a prism sheet or a microlens sheet used as a backlight for a liquid crystal display, etc. Examples include a moth-eye film that is attracting attention as an antireflection film.

Such an optical sheet is, for example, a prism sheet (optical sheet) used as a backlight of a liquid crystal display device or the like on the fine concavo-convex structure of the optical functional layer of the optical sheet, In actual use, such as a diffusion plate or a diffusion film, it is often used as a laminate. Therefore, deformation, cracking, and chipping may occur with respect to the load from the upper layer surface when used as a laminate. For example, deformation or chipping at the top of a fine concavo-convex structure may cause white spots on the display surface of the display device. Display unevenness such as (white pattern) is caused to deteriorate display performance.

For example, therefore, ε-caprolactone-modified tris [(meth) acryloxyethyl] isocyanurate is blended with bisphenol A epoxy resin diacrylate as a technology to prevent the cracking and chipping caused by external force due to the high hardness of the optical sheet. There is known a technique in which an optical sheet is formed and cured into a sheet shape having an uneven surface shape using the photocurable resin composition (Patent Document 1 below).
However, the optical sheet described in Patent Document 1 has a good shape retention force against an external load on the uneven surface of the sheet, but the strength against impact or vibration is not at a sufficient level. Specifically, the strength against the above-described impact or vibration requires the ability to restore the shape even if the uneven portion is deformed by an external force by lowering the glass transition point of the sheet itself. However, the shape restoration property of the concavo-convex portion with respect to such an impact or vibration was not exhibited. In addition, in order to reduce the glass transition point of the sheet itself, when a large amount of ε-caprolactone-modified tris [(meth) acryloxyethyl] isocyanurate is blended, the refractive index of the optical sheet is significantly decreased. In particular, the high refractive index required for increasing the brightness as a lens sheet was not satisfied.

Japanese Patent Laid-Open No. 2003-277452

  Therefore, the problem to be solved by the present invention is that a plastic lens sheet having a fine concavo-convex shape is excellent in shape restoration property when deformed by an external force such as impact or vibration, and is capable of exhibiting a high refractive index. An object of the present invention is to provide a curable resin composition, a cured product having such performance, and a plastic lens sheet.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors incorporated a dibenzoylmethane-based compound as an additive together with a photopolymerizable substance and a photopolymerization initiator, so that the cured product is fine. When shaped into a plastic lens sheet having a concavo-convex shape, it has been found that the concavo-convex portion is excellent in shape restoration when deformed by an external force and can exhibit a high refractive index, and the present invention has been completed. .

  That is, the present invention relates to a photopolymerizable substance (A) having a (meth) acryloyl group in the molecular structure, the following structural formula (1)

（式中、Ｒ^１は、水素原子、又は炭素原子数１〜４のアルキル基、Ｒ^２は、水素原子、又は炭素原子数１〜４のアルキル基、Ｒ^３は、水素原子、炭素原子数１〜４のアルキル基、又は炭素原子数１〜４のアルコキシ基、Ｒ^４は、水素原子、炭素原子数１〜４のアルキル基、又は炭素原子数１〜４のアルコキシ基を表す。）で表される化合物（Ｂ）、及び光重合開始剤（Ｃ）を、前記分子構造内に（メタ）アクリロイル基を有する光重合性物質（Ａ）で表される化合物（Ｂ）、及び光重合開始剤（Ｃ）を、前記分子構造内に（メタ）アクリロイル基を有する光重合性物質（Ａ）１００質量部に対して、
前記化合物（Ｂ）が１〜３０質量部、重合開始剤（Ｃ）が０．５〜２０質量部となる割合で含有することを特徴とする光硬化性樹脂組成物に関する。

(In the formula, R ¹ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ³ is a hydrogen atom or the number of carbon atoms. An alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and R ⁴ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. A compound (B) represented by a photopolymerizable substance (A) having a (meth) acryloyl group in the molecular structure, and a photopolymerization initiator. The agent (C) is added to 100 parts by mass of the photopolymerizable substance (A) having a (meth) acryloyl group in the molecular structure.
It is related with the photocurable resin composition characterized by containing the said compound (B) in the ratio used as 1-30 mass parts and a polymerization initiator (C) at 0.5-20 mass parts.

  The present invention further relates to a cured product obtained by curing the photopolymerizable composition.

  The present invention further relates to a plastic lens obtained by curing the photocurable resin composition.

  According to the present invention, in a plastic lens sheet having a fine concavo-convex shape, a photocurable resin composition that is excellent in shape restoration property when deformed by an external force such as impact or vibration, and can exhibit a high refractive index, The cured product having such performance and a plastic lens sheet can be provided.

  The photopolymerizable substance (A) having a (meth) acryloyl group in the molecular structure used in the present invention includes, for example, epoxy (meth) acrylate, urethane (meth) acrylate, fluorene skeleton-containing di (meth) acrylate, polyoxy Examples thereof include acrylate compounds having an alkylene structure and other monomeric acryloyl group-containing compounds.

  Here, specific examples of the epoxy (meth) acrylate include those obtained by reacting an epoxy resin with (meth) acrylic acid or an anhydride thereof.

Specifically, the epoxy resin reacted with such (meth) acrylic acid or its anhydride is:
Diglycidyl ethers of dihydric phenols such as hydroquinone and catechol; diglycidyl ethers of biphenol compounds such as 3,3′-biphenyldiol and 4,4′-biphenyldiol; bisphenol A type epoxy resins, bisphenol B type epoxy resins, bisphenols Bisphenol type epoxy resins such as F type epoxy resin and bisphenol S type epoxy resin; 1,4-naphthalenediol, 1,5-naphthalenediol, 1,6-naphthalenediol, 2,6-naphthalenediol, 2,7-naphthalene Polyglycidyl ethers of naphthol compounds such as diol, binaphthol and bis (2,7-dihydroxynaphthyl) methane; Triglycidyl ethers such as 4,4 ′, 4 ″ -methylidynetrisphenol; Phenol novolac type epoxy Resins, novolak epoxy resins such as cresol novolak resin

  Various types such as the biphenol compound, bisphenol A, bisphenol B, bisphenol F, bisphenol S, naphthol compound, ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, etc. A polyglycidyl ether of a polyether-modified aromatic polyol obtained by ring-opening polymerization with a cyclic ether compound;

  Examples thereof include polyglycidyl ethers of lactone-modified aromatic polyols obtained by polycondensation of the biphenol compounds, bisphenol A, bisphenol B, bisphenol F, bisphenol S, naphthol compounds and lactone compounds such as ε-caprolactone.

  Among these, those having an aromatic ring skeleton in the molecular structure are preferable from the viewpoint that the refractive index of the cured product in the finally obtained epoxy (meth) acrylate is high, and in particular, exhibit a higher refractive index, and The bisphenol-type epoxy resin or the polyglycidyl ether of the naphthol compound, particularly the bisphenol-type epoxy, in that a cured coating film showing high adhesion to a plastic film substrate can be obtained even under high temperature and high humidity conditions. A resin is more preferable.

  Among bisphenol-type epoxy resins, a coating film having a higher refractive index and higher hardness is obtained, and therefore, an epoxy equivalent having a range of 160 to 1,000 g / eq is preferred, and a range of 165 to 600 g / eq is preferred. Is more preferable.

  On the other hand, (meth) acrylic acid or its anhydride to be reacted with the epoxy resin is more preferably acrylic acid because a photocurable resin composition having excellent curability can be obtained.

  It is preferable that the epoxy (meth) acrylate has a refractive index of 1.50 or higher under a 25 ° C. refractive index of the epoxy (meth) acrylate itself.

  The epoxy (meth) acrylate thus obtained gives a composition with a lower viscosity, exhibits high adhesion over a long period of time to a plastic film substrate, and is capable of being used under high temperature and high humidity conditions. However, the weight average molecular weight (Mw) is preferably in the range of 350 to 5,000, more preferably in the range of 500 to 4,000 in that a cured coating film exhibiting high substrate adhesion is obtained. preferable.

  Moreover, it is preferable that the refractive index of epoxy (meth) acrylate itself is a thing with a refractive index of 1.50 or more on 25 degreeC conditions from the point from which the refractive index of hardened | cured material itself becomes high.

In the present invention, the weight average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) under the following conditions.

Measuring device: HLC-8220GPC manufactured by Tosoh Corporation
Column: TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation TSK-GEL SuperHZM-M × 4 manufactured by Tosoh Corporation
Detector: RI (differential refractometer)
Data processing: Multi-station GPC-8020 model II manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate: 0.35 ml / min Standard: Monodispersed polystyrene Sample: Filtered 0.2% by mass tetrahydrofuran solution in terms of resin solids with a microfilter (100 μl)

  Next, the urethane (meth) acrylate is obtained by, for example, reacting a polyisocyanate compound (u1) with a (meth) acrylate compound (u2) having one hydroxyl group in the molecular structure. Urethane (meth) acrylate (U1), a polyisocyanate compound (u3), a (meth) acrylate compound (u2) having one hydroxyl group in the molecular structure, and a polyol compound (u4) ( U2).

  Examples of the polyisocyanate compound (u1) used as a raw material for the urethane (meth) acrylate (U1) include various diisocyanate monomers and nurate type polyisocyanate compounds having an isocyanurate ring structure in the molecule.

  Examples of the diisocyanate monomer include aliphatic diisocyanates such as butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate;

  Cycloaliphatic diisocyanates such as cyclohexane-1,4-diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate;

  1,5-naphthylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,2′-bis (paraphenyl isocyanate) propane, 4,4′-dibenzyl diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3 Examples include aromatic diisocyanates such as -phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, and m-tetramethylxylylene diisocyanate.

  Specifically, the nurate type polyisocyanate compound having an isocyanurate ring structure in the molecule is obtained by reacting the diisocyanate monomer alone with the nurate type polyisocyanate, or reacting the diisocyanate monomer with a low molecular weight glycol. Examples thereof include urethane prepolymers having a terminal isocyanate group having a nurate structure, and nurate polyisocyanate compounds obtained by further modifying these with a low molecular weight monoalcohol from the viewpoint of viscosity adjustment and prevention of gelation.

  Here, the low molecular weight glycol is preferably an aliphatic / aliphatic cyclic low molecular weight glycol, such as ethylene glycol (EG), 1,2-propanediol, 1,3-propanediol, 1,3-butane. Diol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 3-methyl-1 , 5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, aliphatic diol such as 2-methyl-1,3-propanediol, or 1,4-cyclohexanediol, 1,4-cyclohexane Such as dimethanol, hydrogenated bisphenol A, etc. Cyclic diols, or glycerin, trimethylolpropane, tri- or higher functional hydroxyl group-containing compound such as pentaerythritol, and the like. The glycol may have a linear, branched or cyclic structure. These may be used alone or in combination of two or more.

  The low molecular weight monoalcohol is preferably a linear or branched alcohol having 1 to 9 carbon atoms, an alicyclic alcohol such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, n- Examples include pentanol, n-hexanol, n-octanol, n-nonanol, 2-ethylbutanol, 2,2-dimethylhexanol, 2-ethylhexanol, cyclohexanol, methylcyclohexanol, and ethylcyclohexanol. These may be used alone or in combination of two or more.

  The (meth) acrylate compound (u2) having one hydroxyl group in the molecular structure used as a raw material for the urethane (meth) acrylate (U1) is, for example, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxy Aliphatic (meth) acrylate compounds such as butyl acrylate, glycerin diacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate;

4-hydroxyphenyl acrylate, β-hydroxyphenethyl acrylate, 4-hydroxyphenethyl acrylate, 1-phenyl-2-hydroxyethyl acrylate, 3-hydroxy-4-acetylphenyl acrylate, 2-hydroxy-3-phenoxy Examples include (meth) acrylate compounds having an aromatic ring in the molecular structure such as propyl acrylate. These may be used alone or in combination of two or more.

  Among the urethane (meth) acrylates (U1), a resin composition having a low viscosity and a high refractive index of the cured product is obtained, so that the aromatic diisocyanate and the aliphatic (meth) acrylate compound are reacted. The urethane (meth) acrylate obtained by reacting the urethane (meth) acrylate obtained by reaction with an aliphatic or alicyclic diisocyanate and a (meth) acrylate compound having an aromatic ring in the molecular structure is preferred.

  Furthermore, since a coating film with higher toughness can be obtained, one (meth) acryloyl group is present in the molecular structure of tolylene diisocyanate and 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate and the like. Particularly, urethane (meth) acrylate obtained by reacting an aliphatic (meth) acrylate compound having a urethane (meth) acrylate obtained by reacting isophorone diisocyanate with 2-hydroxy-3-phenoxypropyl acrylate preferable.

  The method for producing the urethane (meth) acrylate (U1) includes, for example, the polyisocyanate compound (u1) and the (meth) acrylate compound (u2) having one hydroxyl group in the molecular structure. The molar ratio [(NCO) / (OH)] between the isocyanate group of the compound (u1) and the hydroxyl group of the (meth) acrylate compound (x2) having one hydroxyl group in the molecular structure is 1 / 0.0. Examples of the method include a method in which the catalyst is used at a ratio in the range of 95 to 1 / 1.05 and is used in a temperature range of 20 to 120 ° C. using a known and commonly used urethanization catalyst as necessary.

  Next, the polyisocyanate compound (u3) used as the raw material for the urethane (meth) acrylate (U2) is the polyisocyanate compound (u1) listed as the raw material for the urethane (meth) acrylate (U1) or the polyisocyanate. Examples thereof include adduct-type polyisocyanate compounds obtained by reacting the compound (u1) with various polyols and having a urethane bond site in the molecule.

  The polyol used as a raw material for the adduct type polyisocyanate compound is ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butane. Diol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, trimethylolethane, trimethylolpropane, glycerin, etc. may be used, each of which may be used alone or in combination of two or more. May be.

  Among these polyisocyanate compounds (u3), various diisocyanate monomers are preferable because a resin composition having a low viscosity and a high refractive index of the cured product can be obtained.

  Examples of the polyol compound (u4) used as a raw material for the urethane (meth) acrylate (U2) include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,3-butanediol. Aliphatic polyols such as 3-methyl-1,3-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, trimethylolethane, trimethylolpropane, glycerin;

Hydroquinone, catechol, 1,4-benzenedimethanol, 3,3′-biphenyldiol, 4,4′-biphenyldiol, biphenyl-3,3′-dimethanol, biphenyl-4,4′-dimethanol, bisphenol A , Bisphenol B, bisphenol F, bisphenol S, 1,4-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,7-naphthalenediol, binaphthol, bis (2,7-dihydroxynaphthyl) methane, 4,4 ′, 4 "-Aromatic polyols such as methylidyne trisphenol;

  Polyether modification obtained by ring-opening polymerization of the aromatic polyol and various cyclic ether compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether. Aromatic polyols;

  Lactone-modified aromatic polyol obtained by polycondensation of the aromatic polyol and a lactone compound such as ε-caprolactone:

  An aromatic ring-containing polyester polyol obtained by reacting an aliphatic dicarboxylic acid such as malonic acid, succinic acid, glutaric acid, adipic acid or pimelic acid with the aromatic polyol;

  Examples thereof include aromatic ring-containing polyester polyols obtained by reacting aromatic dicarboxylic acids such as phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid and the like with the aliphatic polyols. These may be used alone or in combination of two or more. Among these, bisphenol compounds such as bisphenol A, bisphenol B, bisphenol S, bisphenol F, and these and various cyclic ether compounds, in that the cured coating film exhibits a high refractive index and particularly high toughness. A polyether-modified bisphenol compound obtained by ring-opening polymerization is preferred.

  The method for producing the urethane (meth) acrylate (U2) includes, for example, a polyol compound (u4) and a polyisocyanate compound (u3), a hydroxyl group of the polyol compound (u4), and a polyisocyanate compound (u3). The molar ratio [(OH) / (NCO)] with the isocyanate group it has is used in a ratio that is in the range of 1 / 1.5-1 / 2.5, within the temperature range of 20-120 ° C., if necessary Reaction is carried out using a known and usual urethanization catalyst to obtain an isocyanate group-containing intermediate as a reaction product, and then the intermediate and the (meth) acrylate compound (u2) having one hydroxyl group in the molecular structure are obtained. The molar ratio of the hydroxyl group of the (meth) acrylate compound (u2) having one hydroxyl group in the molecular structure to the isocyanate group of the intermediate (OH) / (NCO)] is used in a range of 1 / 0.95 to 1 / 1.05, and a known and commonly used urethanization catalyst is used as necessary within a temperature range of 20 to 120 ° C. And the like.

  In addition, the method for producing the urethane (meth) acrylate (U2) includes, for example, the polyol compound (u4), the polyisocyanate compound (u3), and a (meth) acrylate compound having one hydroxyl group in the molecular structure ( A method in which u2) is charged in a batch and reacted, or after reacting the polyisocyanate compound (u3) with the (meth) acrylate compound (u2) having one hydroxyl group in the molecular structure, the polyol compound (u4) The method of making this react is mentioned.

  Among these urethane (meth) acrylates, the urethane (meth) acrylate (U2) is preferable in that a cured coating film having a higher refractive index and excellent toughness is obtained, and the diisocyanate and the aliphatic mono ( A urethane (meth) acrylate having a bis (phenylene) alkane skeleton in the molecular structure obtained by reacting a (meth) acrylate with a bisphenol compound and a polyether-modified bisphenol compound is more preferred.

  Since the urethane (meth) acrylate thus obtained has a lower viscosity composition and is excellent in the toughness of the resulting coating film, the weight average molecular weight (Mw) is 350 to 5,000. The range is preferable, and the range of 400 to 3,500 is more preferable.

In the present invention, the weight average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) under the following conditions.

Measuring device: HLC-8220GPC manufactured by Tosoh Corporation
Column: TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation
+ Tosoh Corporation TSK-GEL SuperHZM-M x 4
Detector: RI (differential refractometer)
Data processing: Multi-station GPC-8020 model II manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate: 0.35 ml / min Standard: Monodispersed polystyrene Sample: Filtered 0.2% by mass tetrahydrofuran solution in terms of resin solids with a microfilter (100 μl)

  Among the urethane (meth) acrylates described in detail above, it is particularly preferable that the refractive index of the urethane (meth) acrylate itself is 1.50 or higher under a 25 ° C. condition.

  Next, the fluorene skeleton-containing di (meth) acrylate is specifically represented by the following structural formula (2).

（式中、Ｘは水素原子又はメチル基であり、ｍ及びｎはそれぞれ独立に０〜５の整数である。）で表される化合物が挙げられる。

(Wherein, X is a hydrogen atom or a methyl group, and m and n are each independently an integer of 0 to 5).

  The acrylate compound having a polyoxyalkylene structure has a polyoxyalkylene structure such as a polyethylene glycol chain or a polypropylene glycol chain in its molecular structure. For example, a polyethylene glycol having 4 to 15 ethylene oxide units. Diacrylate of polyethylene glycol having 4 to 15 ethylene oxide units, polypropylene glycol diacrylate having 4 to 15 propylene oxide units, monoacrylate of polypropylene glycol having 4 to 15 propylene oxide units, ethylene oxide modified glycerol tri Acrylate (3 to 10 EO units), propylene oxide modified glycerol triacrylate (3 to 1 PO units) ), Ethylene oxide modified trimethylolpropane triacrylate (EO unit number 4 to 20), propylene oxide modified trimethylolpropane triacrylate (PO unit number 4 to 20), ethylene oxide unit 4 to 15 bisphenol ethylene oxide adduct Examples include diacrylate and diacrylate of propylene oxide adduct of bisphenol having 4 to 15 propylene oxide units.

  Among these, polyethylene glycol diacrylate having 4 to 15 ethylene oxide units, ethylene oxide-modified trimethylolpropane triacrylate (4 to 20 EO units), propylene oxide from the point that the effect of lowering the glass transition point is good. Modified trimethylolpropane triacrylate (4 to 20 PO units), diacrylate of ethylene oxide adduct of bisphenol having 4 to 15 ethylene oxide units, or diacrylate of propylene oxide adduct of bisphenol having 4 to 15 propylene oxide units In particular, a diacrylate or propylene oxide unit of 4 to 15 ethylene oxide adducts of bisphenol having 4 to 30 ethylene oxide units is preferred. The diacrylate of propylene oxide adduct of sphenol is preferable from the viewpoint of excellent effect of lowering the glass transition point and excellent compatibility of the other photopolymerizable substance (A). Particularly, the former bisphenol having 4 to 30 ethylene oxide units is preferred. Diacrylate of an ethylene oxide adduct is preferred from the point that the effect of shape restoration is remarkable.

  Here, the diacrylate of ethylene oxide adduct of bisphenol having 4 to 30 ethylene oxide units is specifically di (meth) acrylate of ethylene oxide adduct of bisphenol A, di (meth) acrylate of ethylene oxide adduct of bisphenol F ( And (meth) acrylate.

  In addition, the blending ratio of the acrylate compound having the polyoxyalkylene structure described above is a photopolymerizable substance (A) having a (meth) acryloyl group in the molecular structure from the point that the effect of improving the shape restoring property becomes remarkable. It is preferable that it is the range of 5-30 mass% inside.

Next, examples of the other monomer-type acryloyl group-containing compounds include various monofunctional (meth) acrylate compounds, bifunctional aliphatic (meth) acrylate compounds, and trifunctional or higher functional aliphatic (meth) acrylate compounds. Specifically, as the monofunctional (meth) acrylate compound, phenylbenzyl (meth) acrylate (PBA), phenylthioethyl (meth) acrylate (PTEA),
High refractive index monofunctional (meth) acrylate compounds such as o-phenylphenoxyethyl (meth) acrylate (OPPEA) and naphthylthioethyl (meth) acrylate (NTEA); other n-butyl (meth) acrylate, isobutyl (meth) acrylate , Tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) ) Acrylate, glycidyl (meth) acrylate, morpholine (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, Ethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) acrylate, 2-methoxyethyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate , Methoxypolyethylene glycol (meth) acrylate, 2-butoxyethyl (meth) acrylate, butoxytriethylene glycol (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (2-ethoxyethoxy) ethyl (meth) acrylate, Ethoxypolyethylene glycol (meth) acrylate, 4-nonylphenoxyethylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) Acrylate, caprolactone-modified tetrahydrofurfuryl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclohexylmethyl (meth) acrylate, Cyclohexylethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, phenoxyethyl (meth) ) Acrylate, phenoxydiethylene glycol (meth) acrylate, and the like.

  Next, as the bifunctional aliphatic (meth) acrylate compound, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol Di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, tetrabutylene glycol di (meth) acrylate, 1,4-butanediol di (meth) ) Acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dicyclopentanyl (Meth) acrylate, glycerol di (meth) acrylate, neopentyl glycol hydroxypivalate ester di (meth) acrylate, caprolactone-modified hydroxypivalate neopentyl glycol di (meth) acrylate, hydropivalaldehyde-modified trimethylolpropane di (meth) Examples include acrylate and 1,4-cyclohexanedimethanol di (meth) acrylate.

  Next, as trifunctional or higher aliphatic (meth) acrylate compounds, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide adduct tri (meth) acrylate, trimethylolpropane propylene oxide adduct Tri (meth) acrylate, pentaerythritol tri (meth) acrylate, glycerol tri (meth) acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, ditrimethylolpropane ethylene oxide addition Tetra (meth) acrylate, ditrimethylolpropane propylene oxide adduct tetra (meth) acrylate, dipentaerythritol penta (meth) a Relate, trifunctional or more aliphatic, such as hexa (meth) acrylate of dipentaerythritol (meth) acrylate compounds, and the like.

  Among the photopolymerizable substances (A) having a (meth) acryloyl group in the molecular structure detailed above, epoxy (meth) acrylate, urethane (meth) acrylate, and bisphenol are particularly effective because of their excellent shape restoring effect. Alkylene oxide adduct diacrylate is preferred, especially epoxy (meth) acrylate and bisphenol alkylene oxide adduct diacrylate, or urethane (meth) acrylate and bisphenol alkylene oxide adduct diacrylate and It is preferable to use a combination of these in view of the fact that moderate flexibility can be imparted to the finally obtained cured product, and the effect of improving the shape restoring property becomes remarkable.

  In this case, the mixing ratio of the epoxy (meth) acrylate or urethane (meth) acrylate and the diacrylate of the bisphenol alkylene oxide adduct is [epoxy (meth) acrylate from the point that the effect of improving flexibility becomes remarkable. Or, the mass ratio of urethane (meth) acrylate / diphenol of bisphenol alkylene oxide adduct] is preferably a ratio of 8/2 to 4/6.

  Moreover, it is preferable to mix | blend an above described high refractive index monofunctional (meth) acrylate compound with an epoxy (meth) acrylate or urethane (meth) acrylate from the point that the hardened | cured material will show a higher refractive index. Among the high refractive index monofunctional (meth) acrylate compounds, phenylbenzyl (meth) acrylate (PBA) or o-phenylphenoxyethyl (PBA) or o-phenylphenoxyethyl (particularly from the viewpoint that the compound itself is less colored and has a high refractive index. Meth) acrylate (OPPEA) is preferred.

  When this high refractive index monofunctional (meth) acrylate compound is blended, the blending ratio is 40 to 80% by mass in the photopolymerizable substance (A) having a (meth) acryloyl group. This is preferable because the effect is remarkable.

Next, the compound (B) used in the present invention is as described above.
The following structural formula (1)

（式中、Ｒ^１は、水素原子、又は炭素原子数１〜４のアルキル基、Ｒ^２は、水素原子、又は炭素原子数１〜４のアルキル基、Ｒ^３は、水素原子、炭素原子数１〜４のアルキル基、又は炭素原子数１〜４のアルコキシ基、Ｒ^４は、水素原子、炭素原子数１〜４のアルキル基、又は炭素原子数１〜４のアルコキシ基を表す。）で表されるものである。

(In the formula, R ¹ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ³ is a hydrogen atom or the number of carbon atoms. An alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and R ⁴ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. It is expressed.

  In the present invention, by blending the compound (B), an appropriate flexibility can be imparted to the cured product without lowering the refractive index of the cured product, and in a plastic lens sheet having a fine uneven shape. It is possible to combine shape recovery and high refractive index.

  Specific examples of such compound (B) include those represented by the following structural formulas b1 to b9.

  Among these, the compound represented by the structural formula b1 or b5 is particularly preferable from the viewpoint of the refractive index, and the compound represented by the structural formula b1 is particularly preferable from the viewpoint that the effect of the present invention is particularly remarkable.

  The compounding ratio of the compound (B) is such that the compound (B) is 1 to 30 parts by mass with respect to 100 parts by mass of the photopolymerizable substance (A) having the (meth) acryloyl group. When the blending ratio is less than 1 part by mass, the effect of imparting flexibility cannot be obtained, and when it exceeds 30 parts by mass, the compound (B) itself is easily crystallized and precipitated. ) Mixing effect cannot be obtained.

  Next, the photopolymerization initiator (C) used in the photocurable resin composition of the present invention is, for example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1 -[4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2,2′-dimethoxy-1,2-diphenylethane-1-one, 2,4 , 6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl -2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, benzophenone, 4-methylbenzophenone 4-phenylbenzophenone, 4- (4-methylphenylthio) benzophenone, thioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2 , 4-dichlorothioxanthone and the like.

  Among these, the photopolymerization initiator having a melting point of 70 to 105 ° C. is particularly excellent in compatibility with the compound (B) and excellent in stability when the compounding ratio of the compound (B) is increased. Specific examples include 4-phenylbenzophenone, 4- (4-methylphenylthio) benzophenone, thioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthen-9-one, and the like. It is done. Among these, benzophenone photopolymerization initiators having aromatic nuclei as substituents such as 4-phenylbenzophenone and 4- (4-methylphenylthio) benzophenone are particularly excellent in compatibility with the compound (B). preferable.

  These photopolymerization initiators (C) are used in an amount of 0.1 to 25 parts by mass with respect to 100 parts by mass of the photopolymerizable substance (A) having a (meth) acryloyl group in order to exhibit sufficient curability. It is preferable to mix | blend in the range, and it is more preferable that it is the range of 2-25 mass parts especially.

  Here, as the photopolymerization initiator (C), a photopolymerization initiator having a melting point of 70 to 105 ° C. is used in an amount of 5 to 20 with respect to 100 parts by mass of the photopolymerizable substance (A) having a (meth) acryloyl group. When used at a ratio of mass parts, the compounding ratio of the compound (B) is 15-30 mass parts with respect to 100 mass parts of the photopolymerizable substance (A) having a (meth) acryloyl group. Even if it is used in a proportion, it will be difficult to crystallize in the composition and it will be present stably, so that a cured product having a higher refractive index and a higher refractive index can be obtained. In addition, as a photoinitiator (C), when not using the photoinitiator in the range of melting | fusing point 70-105 degreeC, the compounding ratio of the said compound (B) is photopolymerization which has a (meth) acryloyl group. The compatibility between the compound (B) and the photopolymerizable substance (A) having a (meth) acryloyl group is 1 part by mass or more and less than 15 parts by mass with respect to 100 parts by mass of the active substance (A). It is preferable from the point which becomes favorable.

  In the present invention, as the photopolymerization initiator (C), a benzophenone photopolymerization initiator having an aromatic nucleus as a substituent such as 4-phenylbenzophenone and 4- (4-methylphenylthio) benzophenone is used. In combination with these, a photopolymerization initiator having photosensitivity in a long wavelength region of 380 nm to 600 nm, such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, is used in combination with good curability. In addition, those having photosensitivity in a short wavelength region of 200 nm to 380 nm, such as 1-hydroxycyclohexyl phenyl ketone and 2,2-dimethoxy-1,2-diphenylethane-1-one, This is preferable from the viewpoint of excellent curability. In particular, it is preferable that the photopolymerization initiator having photosensitivity in the long wavelength region and the photopolymerization initiator having photosensitivity in the short wavelength region are used in combination because the curability is further improved. .

  When the photocurable resin composition of the present invention is cured by photopolymerization, various photosensitizers may be added together with the photopolymerization initiator (C). Examples of the photosensitizer include amines, ureas, sulfur-containing compounds, phosphorus-containing compounds, chlorine-containing compounds, nitriles or other nitrogen-containing compounds, and these can be used alone or in two types. You may use the above together. When these photosensitizers are added, the addition amount is preferably in the range of 0.01 to 25 parts by mass with respect to 100 parts by mass of the photopolymerizable substance (A) having a (meth) acryloyl group.

  The photocurable resin composition of the present invention may contain various other additives as necessary. Examples of various additives include ultraviolet absorbers, antioxidants, silicone additives, fluorine additives, rheology control agents, defoaming agents, antistatic agents, and antifogging agents. The addition amount in the case of adding these additives is 0.01 to 40 with respect to 100 parts by mass of the photocurable resin composition of the present invention as long as the effect of the additive is sufficiently exhibited and ultraviolet curing is not inhibited. It is preferable that it is the range of a mass part.

  The viscosity of the photocurable resin composition of the present invention is such that the active energy ray-curable resin composition can pass through the mold without any defects even under high-speed coating conditions. 000 mPa · s or less is preferable.

  The photocurable resin composition of the present invention can be cured by irradiation with ultraviolet rays or visible light.

In the case of curing by ultraviolet rays, it can be cured by irradiation with a mercury lamp such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, a carbon arc, a metal height lamp or the like. In this case, the exposure amount of ultraviolet rays is preferably in the range of 0.1 to 1000 mJ / cm ² .

  The cured product of the photocurable resin composition of the present invention exhibits a high refractive index, is excellent in flexibility, and is not easily cracked or chipped during cutting. Taking advantage of these features, for example, plastic lenses such as eyeglass lenses, digital camera lenses, Fresnel lenses, and prism lenses, optical overcoat agents, hard coat agents, antireflection films, optical fibers, optical waveguides, holograms, prisms It can be suitably used for various optical materials such as lenses, LED sealing materials, and solar cell coating materials, and among these, it is particularly suitable for plastic lenses such as prism lenses for liquid crystal substrates.

  The prism lens for a liquid crystal substrate has a plurality of fine prism-shaped portions on one side of a sheet-like molded body, and usually the prism surface faces the back side (light source side) of the liquid crystal display element toward the element side. Further, a sheet-like lens used so that a light guide sheet is provided on the back surface thereof, or a sheet-like lens in which the prism lens also functions as the light guide sheet.

  Here, the prism portion of the prism lens preferably has a prism apex angle θ in the range of 70 to 110 ° from the viewpoint of excellent light-collecting properties and improved luminance, particularly in the range of 75 to 100 °. In particular, the range of 80 to 95 ° is particularly preferable.

  The pitch of the prisms is preferably 100 μm or less, and particularly preferably in the range of 70 μm or less from the viewpoint of preventing the occurrence of moire patterns on the screen and further improving the definition of the screen. Further, the height of the unevenness of the prism is determined by the value of the prism apex angle θ and the prism pitch, but is preferably in the range of 50 μm or less. Further, the sheet thickness of the prism lens is preferably thick from the viewpoint of strength, but optically thin is preferable in order to suppress the absorption of light, and it is in the range of 50 μm to 1000 μm from the viewpoint of these balances. preferable.

  The method for producing the prism lens using the photocurable resin composition of the present invention includes, for example, applying the composition to a mold having a prism pattern formed thereon or a mold such as a resin mold, and then applying the surface of the composition. After smoothing, a transparent base material is overlap | superposed, the active energy ray is irradiated from this transparent base material side, and the method of making it harden | cure is mentioned.

  Examples of the transparent substrate used here include a plastic substrate made of acrylic resin, polycarbonate resin, polyester resin, polystyrene resin, fluororesin, polyimide resin, and glass.

  The prism sheet obtained by the above method may be used as it is, or may be used in the state of a prism lens alone after peeling the transparent substrate. When using with the prism part formed on the transparent base material, the surface of the transparent base material should be subjected to adhesion improvement treatment such as primer treatment for the purpose of improving the adhesion between the prism lens and the transparent base material. Is preferred.

  On the other hand, when the transparent substrate is peeled and used, it is preferable to treat the surface of the transparent substrate with silicone or a fluorine-based release agent so that the transparent substrate can be easily peeled off.

  When the photocurable resin composition of the present invention is used as an optical material for prism lens applications, the refractive index of the cured product is preferably 1.550 or more, more preferably 1.570 or more. preferable.

  EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not limited to these. All parts and% in the examples are based on weight except for light transmittance.

  In the present invention, the weight average molecular weight (Mw) was measured by gel permeation chromatography (GPC) under the following conditions.

Measuring device: HLC-8220GPC manufactured by Tosoh Corporation
Column: TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation
+ Tosoh Corporation TSK-GEL SuperHZM-M x 4
Detector: RI (differential refractometer)
Data processing: Multi-station GPC-8020 model II manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate: 0.35 ml / min Standard: Monodispersed polystyrene Sample: Filtered 0.2% by mass tetrahydrofuran solution in terms of resin solids with a microfilter (100 μl)

  In the present invention, the viscosity was measured using an E-type rotational viscometer (“RE80U” manufactured by Toki Sangyo Co., Ltd.) under 25 ° C. conditions.

  In the present invention, the refractive index was measured using an Abbe refractometer (“NAR-3T” manufactured by Atago Co., Ltd.). The temperature condition was usually 25 ° C., and a solid at 25 ° C. was measured by setting an appropriate temperature.

Production Example 1 [Production of urethane (meth) acrylate]
In a 1 liter flask equipped with a stirrer, a gas inlet tube, a condenser, and a thermometer, 174 parts by mass of tolylene diisocyanate, 1.02 parts by mass of tertiary butylhydroxytoluene, 0.15 parts by mass of methoxyhydroquinone, dibutyltin 0.05 parts by mass of acetate was added, the temperature was raised to 80 ° C., and 162.6 parts by mass of an ethylene oxide 2-mole adduct of bisphenol A was added in portions over 1 hour. After the entire amount was added, the mixture was reacted at 80 ° C. for 3 hours, and then 118.3 parts by mass of 2-hydroxyethyl acrylate was added and further reacted at 80 ° C., and the infrared absorption spectrum at 2250 cm ⁻¹ indicating the isocyanate group disappeared. To obtain urethane acrylate having a refractive index of 1.582 and a weight average molecular weight (Mw) of 3,000.

Examples 1-3 and Comparative Examples 1-3
An active energy ray-curable resin composition for casting polymerization was prepared by blending each component with the blending composition shown in Table 1.
After filling the obtained active energy ray-curable resin composition for casting polymerization between a chromium-plated metal plate and a transparent untreated polyethylene terephthalate film (PET film), and adjusting the thickness Then, an ultraviolet ray of 800 mJ / cm2 is irradiated from the PET film side with an ultra-high pressure mercury lamp and cured, and then the active energy ray cured resin layer is peeled off from the metal plate and the PET film, and the surface has a smooth thickness of 200 ± 25 μm. A cured resin film (F) was produced.

 In addition, the obtained active energy ray-curable resin composition for casting polymerization is made up of a mold having a linear arrangement of unit prisms (pitch 50 μm, height 25 μm) and a transparent substrate as a transparent substrate. After filling with an easily adhesive-treated PET film (trade name: A4300, thickness: 125 μm, manufactured by Toyobo Co., Ltd.), it was cured by irradiating UV light of 800 mJ / cm 2 from the PET film side with an ultra-high pressure mercury lamp, The PET film was peeled from the mold together with the active energy ray-curable resin layer, and a cured product (L) with a PET film shape to which a required shape was transferred was prepared.

Furthermore, after filling the obtained active energy ray-curable resin composition for casting polymerization between a chrome-plated metal plate and a transparent acrylic resin plate, adjusting the thickness, 800 mJ / A cured resin layer having a smooth surface with a thickness of 200 ± 25 μm is peeled off from the metal plate together with the active energy ray curable resin layer by irradiating ultraviolet rays of cm2 from the acrylic resin plate side. An acrylic resin plate smooth cured product (S) having

 Using the obtained active energy ray-curable resin composition for casting polymerization, cured resin film (F), cured product with PET film shape (L), and acrylic resin plate smooth cured product (S) Was measured and evaluated. The results are shown in Table 1, Table 2 (1) and Table 2 (2). These are shown as examples of measurement results in all Examples and Comparative Examples.

(1) Viscosity measurement: Using an E-type rotational viscometer, the viscosity (mPa · s) of the active energy ray-curable resin composition for casting polymerization was measured at 25 ° C.
(1) Viscosity measurement: Using an E-type rotational viscometer, the viscosity (mPa · s) of the active energy ray-curable resin composition for casting polymerization was measured at 25 ° C.
(2) Refractive index measurement: It measured about the liquid sample and the hardening sample. For the liquid sample, the active energy ray-curable resin composition for casting polymerization was directly applied to the prism of the Abbe refractometer, and the measurement was performed at 25 ° C.
(3) Glass transition point: The cured resin film (F) obtained above was measured with a solid viscoelasticity measuring device RSAII manufactured by TA Instruments.

(4) Restorability: The time until the trace of the metal round bar having a diameter of 10 mm completely disappeared from the PET film-shaped cured product (L) obtained above was measured.
◎ ... Disappeared instantly.
○: Disappeared within 60 seconds.
Δ ···· disappeared within 1 to 60 minutes.
× ··· Disappeared.

(5) Scratch resistance: The optical sheet obtained above is affixed on the movable plate of a rubbing tester made by Taihei Rika Kogyo so that the top of the shaped cured product faces the load part side. As a wearer, a polarizing film was attached, and the matte layer of the polarizing film was installed so as to rub against the top of the shaped cured product. After the rubbing tester was operated by applying a load of 2000 g to the load portion and the movable platen was moved in one direction, the state of the top of the test piece immediately after the test was visually observed on the backlight. The evaluation was carried out in a room at 25 ° C. and judged as follows.
◎ ・ ・ ・ ・ No scratches are observed.
○ ··· Several streaks are observed.
Δ: A band-shaped flaw is partially observed.
× ··· Strip-shaped scratches are observed on the entire surface.

(6) Transparency evaluation: Using the cured resin film (F), the light transmittance in the wavelength region of 400 to 900 nm was measured, and the one showing a transmittance of 85% or more in all regions was marked as ◯. The following were marked with x.

(7) Adhesion evaluation: Using an acrylic resin plate smooth cured product (S), the adhesion between the transparent substrate and the cured resin layer was measured according to JIS K-5400. The time when 95/100 or more squares remained was marked with ◯, the time when (60 to 94) / 100 squares remained was marked with △, and the time when 59/100 or less was marked with x.

<Footnotes in Table 1>
Epoxy acrylate: Epoxy acrylate obtained by reacting bisphenol A type epoxy resin (epoxy equivalent 188 g / eq) with acrylic acid
TPGDA: tripropylene glycol diacrylate BPA ethoxylate diacrylate: bisphenol A ethoxylate diacrylate M-325: ε-caprolactone modified tris [(meth) acryloxyethyl] isocyanurate (“Aronix M-325” manufactured by Toagosei Co., Ltd.)
OPPEA: 2-phenylphenoxyethyl acrylate photoinitiator a: 1-hydroxycyclohexyl phenyl ketone photoinitiator b: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide

Claims (12)

Photopolymerizable substance (A) having a (meth) acryloyl group in the molecular structure, the following structural formula (1)

(In the formula, R ¹ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ³ is a hydrogen atom or the number of carbon atoms. An alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and R ⁴ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. The compound (B) and the photopolymerization initiator (C) are represented by 100 parts by mass of the photopolymerizable substance (A) having a (meth) acryloyl group in the molecular structure. 1-30 mass parts, a photoinitiator (C) contains in the ratio used as 0.1-25 mass parts, The photocurable resin composition characterized by the above-mentioned. The photocurable resin composition according to claim 1, wherein the photopolymerizable substance (A) having a (meth) acryloyl group in the molecular structure is urethane (meth) acrylate. The photocurable resin composition according to claim 1, wherein the photopolymerizable substance (A) having a (meth) acryloyl group in the molecular structure is an epoxy (meth) acrylate. The photocurable resin composition according to claim 1, wherein the photopolymerization initiator (C) is a benzophenone photopolymerization initiator having an aromatic nucleus as a substituent. The photocurable resin composition according to claim 4, wherein the benzophenone photopolymerization initiator is 4-phenylbenzophenone or 4- (4-methylphenylthio) benzophenone. Benzophenone-based photopolymerization having 1 to 30 parts by mass of the compound (B) and the aromatic nucleus as a substituent with respect to 100 parts by mass of the photopolymerizable substance (A) having a (meth) acryloyl group in the molecular structure. The photocurable resin composition of Claim 4 or 5 which contains an initiator in the ratio used as 0.1-25 mass parts. The photocurable resin composition according to claim 4, wherein an alkylphenone photopolymerization initiator or a phosphine oxide photopolymerization initiator is used as the photopolymerization initiator (C) together with a benzophenone photopolymerization initiator. As a photopolymerizable substance (A) having a (meth) acryloyl group in the molecular structure , a high refractive index monofunctional (meth) acrylate compound having a refractive index at 25 ° C. of 1.557 or more together with urethane (meth) acrylate. The photocurable resin composition according to claim 2 to be used. The photocurable resin composition according to claim 2, wherein an acrylate compound having a polyoxyalkylene structure is used together with urethane (meth) acrylate as the photopolymerizable substance (A) having a (meth) acryloyl group in the molecular structure. High refractive index monofunctional (meth) acrylate compound having a refractive index at 25 ° C. of 1.557 or more as a photopolymerizable substance (A) having a (meth) acryloyl group in the molecular structure together with epoxy (meth) acrylate The photocurable resin composition according to claim 3, wherein A cured product obtained by curing the photopolymerizable composition according to any one of claims 1 to 1 0. A plastic lens obtained by curing the photocurable resin composition according to any one of claims 1 to 10 .