JP2009108211A - Curable composition and hardened material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable composition having a low viscosity and excellent easiness in handling and working, assuring a high hardness of a molding or coating film after hardening to result in a hardened material unlikely to have flaw, assuring less shrinkage, good strain precision of the molding, or less warp and/or curl of a laminate when applied to a base material, and yielding a hardened material having a high heat resistance and excellent in the transparency of the resin component of the hardened material. <P>SOLUTION: The curable composition includes: (a) a compound having two or more unsaturated polymerizable functional group in one molecule; and (b) a monomer having an α-methylene lactone structure. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a novel curable composition and a cured product thereof. More specifically, the viscosity of the curable composition is low, the handleability and workability are excellent, the cure shrinkage is small, the moldability is good, and the resulting cured product has heat resistance, high hardness, and scratch resistance (scratch resistance). The present invention relates to a novel curable composition having excellent transparency and a cured product thereof.

  In recent years, curable materials have made significant progress in various applications. For curable inks, transparent cover layers, liquid crystal display panels, color filter protective films, eyeglass lenses, Fresnel lenses, lenticular lenses, TFT (Thin Film Transistors) Various studies such as prism lens sheets, aspherical lenses, optical disk coatings and adhesives, optical fiber cores and claddings, optical fiber connection adhesives, optical waveguide cores and claddings, etc. It has been broken. Curable materials are used in a wide range of applications because of their easy processing and lightness.

  For example, important properties required for curable ink applications include low viscosity, dye solubility, pigment dispersibility, curability, etc. Furthermore, the cured ink film has strength and adhesion. Properties such as heat resistance, solvent resistance, water resistance, and weather resistance are required. In recent years, further improvement of these properties has been demanded, and curable materials applicable to various coating applications using various monomers and oligomers have been studied.

  However, in general, radical curable reactive diluents are 1) polymerized by oxygen, 2) have a large volume shrinkage during curing, 3) have strong odor and skin irritation, and 4) have good adhesion to metals. There have been problems such as not so good, and reactive diluents that can overcome these problems have been studied. Patent Document 1 discloses a method using oligomers and monomers of polyfunctional acrylates containing a (meth) acryloyl group. However, there was room for improvement in coating strength and weather resistance.

On the other hand, in an optical disk or the like, a transparent cover layer such as a scratch-resistant hard coat may be laminated in order to prevent surface scratches that cause information reading errors. There is a spin coating method in which an ultraviolet curable resin is applied by spin coating, and the resin is cured by irradiating ultraviolet rays. Currently, the spin coating method has become mainstream from the viewpoint of cost. However, if the transparent cover layer is formed using an ultraviolet curable resin, the optical disk warps due to shrinkage that occurs during curing. This warpage can be improved by lowering the crosslinking density at the time of curing, but there is a problem that the surface of the disk is easily scratched due to a decrease in hardness and scratch resistance (abrasion resistance).
These transparent cover layers are required not only to have scratch resistance, but also to have physical properties such as the surface hardness of the cured product, the warpage of the laminate, and the cured composition having a low viscosity and good workability. Recently, heat resistance has been required.

  As a method for forming the transparent cover layer, various studies have been conventionally made. For example, Patent Document 2 discloses a method of forming a 3 μm surface layer after forming a 97 μm inner layer. However, the ultraviolet curable resin forming the inner layer has a high viscosity, and there is a problem in the coatability in spin coating. On the other hand, transparent plastics used as optical members are important as required performance, such as low specific gravity, moldability, heat resistance, light resistance, resilience, impact resistance, high hardness, low water absorption, Examples include distortion accuracy and dyeability of molded products. In recent years, further improvement of these properties has been required, and plastic materials applicable to various optical applications using various monomers and oligomers have been studied.

  Examples of a method for producing a casting such as an optical lens using a plastic material include a pressing method and a casting method. When the plastic material is molded by the press method, the productivity is not good because the plastic material is manufactured by a cycle of heating, pressurizing, and cooling. In the case of the casting method, since the resin is poured into the mold and cured by heating, the manufacturing time becomes long, and a large number of molds are required, which increases the manufacturing cost. In order to solve such a problem, Patent Documents 3 and 4 describe a proposal of using an active energy ray-curable resin composition as a plastic material.

JP 2000-239327 A JP 2002-157782 A JP-A 64-6935 JP-A-63-163330

Problems to be solved by the present invention are:
<1> A curable composition having a low viscosity and excellent workability and workability.
<2> The cured product or coating film has a high hardness and is not easily damaged.
<3> Shrinkage is small, for example, the distortion accuracy of a molded product is good, or when applied to a substrate, there is little warpage or curl of the laminate,
<4> The heat resistance of the cured product is high,
<5> To provide a cured composition and a cured product excellent in transparency of the resin component of the cured product.

As a result of intensive studies, the present inventors have
(A) a compound having two or more unsaturated polymerizable functional groups in one molecule;
(B) a monomer having an α-methylene lactone structure,
The present invention has been completed by finding that the curable composition containing the above solution solves the above problems all at once.

That is, the present invention provides at least (a) a compound having two or more unsaturated polymerizable functional groups in one molecule,
(B) a monomer having an α-methylene lactone structure of the following formula (1),

[Wherein R 1, R 2, R 3 and R 4 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, a cycloalkyl group, a —OAc group, a —CN group, a —CO—R 5 group. Or a —C—O—R 6 group, an Ac group represents an acetyl group, and R 5 and R 6 each independently represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms. R1 and R2, and R3 and R4 may be bonded to form a ring structure. ]
It is a curable composition characterized by including.

Moreover, this invention is as said (a) component,
Following formula (2):

[Wherein R ¹ is an alkylene group having 2 to 8 carbon atoms, R ² is a hydrogen atom or a methyl group, and m is a positive integer]
A curable composition comprising a vinyl polymer having a repeating unit represented by the formula:
In addition to the above (a) and (b), the present invention further comprises (c) a polymerization initiator.
Moreover, this invention is the hardened | cured material obtained by hardening the curable composition in any one of the above.

  According to the present invention, since the curable composition has a low viscosity, good handleability and workability, and extremely excellent fluidity, for example, the amount of the diluted solvent used can be effectively reduced. Further, the cured product obtained by curing the curable composition of the present invention has a small curing shrinkage and good moldability, and the obtained cured product has heat resistance, high hardness, scratch resistance (scratch resistance), Excellent transparency. For example, curable ink, transparent cover layer, liquid crystal display panel, color filter protective film, spectacle lens, Fresnel lens, lenticular lens, prism lens sheet for TFT (Thin Film Transistor), aspherical lens, etc. It can be suitably used for optical disk coating agents and adhesives, optical fiber core materials and cladding materials, optical fiber connection adhesives, optical waveguide core materials and cladding materials, and the like.

≪Curable composition≫
The curable composition of the present invention comprises:
(A) a compound having two or more unsaturated polymerizable functional groups in one molecule;
(B) a monomer having an α-methylene lactone structure,
including.

<(A) Compound having two or more unsaturated polymerizable functional groups in one molecule>
In the curable composition of the present invention, (a) a compound having two or more unsaturated polymerizable functional groups in one molecule (hereinafter sometimes simply referred to as a crosslinking component (a)) is a monomer, oligomer or polymer. Any of these may be used, preferably an oligomer or a polymer, more preferably a polymer, and most preferably a vinyl polymer or a polyfunctional (meth) acrylate having a repeating unit represented by the following formula (2).

[Wherein R ¹ is an alkylene group having 2 to 8 carbon atoms, R ² is a hydrogen atom or a methyl group, and m is a positive integer]
The crosslinking component (a) may be a monomer, oligomer or polymer used alone or in combination of two or more. In the present application, the monomer is defined as having a molecular weight of less than 200, the oligomer is defined as having a (number average) molecular weight of 200 to 1,000, and the polymer is defined as having a number average molecular weight of 1,000 or more.

  Specific examples of component (a) include, for example, urethane (meth) acrylate; epoxy (meth) acrylate; polyester (meth) acrylate; unsaturated polyester; styrene-based crosslinking component such as divinylbenzene; , Allyl ester-based crosslinking components such as diallyl isophthalate, triallyl cyanurate, triallyl isocyanurate; ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) Acrylate, neopentyl glycol di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, dimethylol-tri Cyclodecandi (Meth) acrylate, pentacyclopentadecane dimethanol di (meth) acrylate, di (meth) acrylic acid adduct of bisphenol A diglycidyl ether, cyclohexanedimethanol di (meth) acrylate, norbornane dimethanol di (meth) acrylate, p- Menthane-1,8-diol di (meth) acrylate, p-menthane-2,8-diol di (meth) acrylate, p-menthane-3,8-diol di (meth) acrylate, bicyclo [2.2.2] -octane- Bifunctional (meth) acrylate compounds such as 1-methyl-4-isopropyl-5,6-dimethylol di (meth) acrylate; trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, glycerin tri ( (Meth) acrylic acid-based derivatives such as tri- or more functional (meth) acrylate compounds such as acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate; 2-vinyloxyethyl (meth) acrylate Of ethylene oxide adducts of 2- (2-vinyloxyethoxy) ethyl (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, trimethylolpropane (Meth) acrylic derivatives having an ether structure such as tri (meth) acrylate and di (meth) acrylate of ethylene oxide adduct of bisphenol A; triethylene glycol divinyl ether, cyclohexane Vinyl ether crosslinking components such as sandimethanol divinyl ether; Allyl ether crosslinking components such as trimethylolpropane diallyl ether, pentaerythritol triallyl ether and the like, and adipic acid ester of glyceryl diallyl ether; side chain double bond-containing polymer Etc. These polymerizable crosslinking components may be used alone or in combination of two or more.

  The amount of the crosslinking component (a) is preferably 10 to 95% by mass, more preferably 30 to 90% by mass, and still more preferably 50 to 90% by mass with respect to the total amount of the composition. When the blending amount of the crosslinking component (a) is less than 10% by mass, the crosslinking density is lowered, so that the curing rate is lowered and the coating strength of the cured product may be insufficient. Further, when the amount of the crosslinking component (a) is more than 95% by mass, the viscosity of the composition becomes too high and the handleability becomes worse, or the component (b) described later: a single amount having an α-methylene lactone structure The blending amount of the body is relatively decreased, and the hardness and shrinkage of the cured product may be increased.

  The vinyl polymer (A) having a repeating unit represented by the following formula (2), which is a particularly preferred embodiment, will be described in detail below.

  In the vinyl polymer (A) represented by the above formula (2), when the low molecular weight component is increased, the strength of the cured product may be decreased. The number average molecular weight (Mn) of the vinyl polymer is preferably 500 or more, more preferably 750 to 200,000, and still more preferably 1,000 to 50,000. When the number average molecular weight (Mn) of the vinyl polymer is less than 500, the curing rate may be decreased and the strength of the cured product may be decreased. Moreover, when it exceeds 200,000, when adjusting a curable composition, mixing time becomes long, or a viscosity becomes high and workability | operativity, such as coating property, may fall. Here, the number average molecular weight (Mn), the weight average molecular weight (Mw) and the molecular weight distribution (Mw / Mn) were measured using Tosoh Corporation under the conditions of THF as a mobile phase, a temperature of 40 ° C., and a flow rate of 0.3 mL / min. This is a value obtained by standard polystyrene conversion using a column permeation chromatography (GPC) apparatus HLC-8220GPC manufactured by Tosoh Corporation using two TSK-gel SuperHM-H columns and one TSK-gel SuperH2000 column.

  The vinyl polymer (A) represented by the above formula (2) can be obtained as a liquid viscous material except in the case of a polymer having a high solid monomer content. If it is a liquid viscous body, since the solubility with the monomer which has (b) (alpha) -methylene lactone structure mentioned later is good, the improvement of working efficiency can be achieved when adjusting a curable composition.

In the above formula (2), examples of the alkylene group having 2 to 8 carbon atoms represented by R ¹ include an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, and a heptamethylene group. , Octamethylene group, cyclohexylene group, 1,4-dimethylcyclohexane-α, α′-diyl group, 1,3-dimethylcyclohexane-α, α′-diyl group, 1,2-dimethylcyclohexane-α, α ′ -Diyl group, 1,4-dimethylphenyl-α, α'-diyl group, 1,3-dimethylphenyl-α, α'-diyl group, 1,2-dimethylphenyl-α, α'-diyl group, etc. Can be mentioned. There are m substituents represented by R ¹ in the above formula (2), but they may be the same or different.

  In the above formula (2), m is a positive integer, preferably an integer of 1 to 20, more preferably an integer of 1 to 10, more preferably an integer of 1 to 5, and n is a positive integer, preferably 50. An integer of ˜400, more preferably an integer of 100 to 300, and even more preferably an integer of 150 to 250.

<Preparation of vinyl polymer (A)>
The vinyl polymer (A) represented by the above formula (1) has the following formula (3):

[Wherein R ¹ , R ² and m are as defined in the above formula (1)]
It is possible to adjust the heteropolymerizable monomer (A-1) represented by the formula (1) by a conventionally known cationic polymerization, and living by the method described in JP-A-2006-241189. It can also be easily prepared by cationic polymerization. At this time, the heteropolymerizable monomer represented by the above formula (3) may be used alone or in combination of two or more. In the latter case, the resulting copolymer may be a random copolymer, an alternating copolymer, a periodic copolymer, a block copolymer, or a combination thereof. Moreover, a graft copolymer may be sufficient.

  Specific examples of the heteropolymerizable monomer (A-1) represented by the above formula (3) include, for example, 2-vinyloxyethyl (meth) acrylate, 3-vinyloxypropyl (meth) acrylate, (meth) 2-vinyloxypropyl acrylate, 1-vinyloxypropyl (meth) acrylate, 1-methyl-2-vinyloxyethyl (meth) acrylate, 4-vinyloxybutyl (meth) acrylate, 3-vinyloxybutyl (meth) acrylate, (Meth) acrylic acid 2-vinyloxybutyl, (meth) acrylic acid 1-methyl-3-vinyloxypropyl, (meth) acrylic acid 2-methyl-3-vinyloxypropyl, (meth) acrylic acid 1-methyl-2- Vinyloxypropyl, 1,1-dimethyl-2-vinyloxyethyl (meth) acrylate, 6-vinyloxyhex (meth) acrylate Sil, 4-vinyloxycyclohexyl (meth) acrylate, 4-vinyloxymethylcyclohexylmethyl (meth) acrylate, 3-vinyloxymethylcyclohexylmethyl (meth) acrylate, 2-vinyloxymethylcyclohexyl (meth) acrylate Methyl, 4-vinyloxymethylphenylmethyl (meth) acrylate, 3-vinyloxymethylphenylmethyl (meth) acrylate, 2-vinyloxymethylphenylmethyl (meth) acrylate, 2- (2) (meth) acrylic acid -Vinyloxyethoxy) ethyl, 2- (2-vinyloxyisopropoxy) ethyl (meth) acrylate, 2- (2-vinyloxyethoxy) propyl (meth) acrylate, 2- (2-) (meth) acrylate Vinyloxyisopropoxy) propyl, (meth) acrylic acid 2- (2- Nyloxyethoxy) isopropyl, (meth) acrylic acid 2- (2-vinyloxyisopropoxy) isopropyl, (meth) acrylic acid 2- {2- (2-vinyloxyethoxy) ethoxy} ethyl, (meth) acrylic acid 2 -{2- (2-vinyloxyisopropoxy) ethoxy} ethyl, 2- {2- (2-vinyloxyisopropoxy) isopropoxy} ethyl (meth) acrylate, 2- (2- (2-) (meth) acrylate 2-vinyloxyethoxy) ethoxy} propyl, (meth) acrylic acid 2- {2- (2-vinyloxyethoxy) isopropoxy} propyl, (meth) acrylic acid 2- {2- (2-vinyloxyisopropoxy) Ethoxy} propyl, 2- (2- (2-vinyloxyisopropoxy) isopropoxy} propyl (meth) acrylate, (meth) acrylic acid 2- {2- (2-vinyloxyethoxy) ethoxy} isopropyl silylate, 2- {2- (2-vinyloxyethoxy) isopropoxy} isopropyl (meth) acrylate, 2- {2- (meth) acrylic acid (2-vinyloxyisopropoxy) ethoxy} isopropyl, (meth) acrylic acid 2- {2- (2-vinyloxyisopropoxy) isopropoxy} isopropyl, (meth) acrylic acid 2- [2- {2- (2 -Vinyloxyethoxy) ethoxy} ethoxy] ethyl, 2- (2- {2- (2-vinyloxyisopropoxy) ethoxy} ethoxy] ethyl (meth) acrylate, 2- (2- [2] (meth) acrylate -{2- (2-vinyloxyethoxy) ethoxy} ethoxy] ethoxy) ethyl; and the like. Among these different polymerizable monomers, 2-vinyloxyethyl (meth) acrylate, 3-vinyloxyethyl (meth) acrylate, 2-vinyloxypropyl (meth) acrylate, 1-methyl-2 (meth) acrylate -Vinyloxyethyl, 4-vinyloxybutyl (meth) acrylate, 6-vinyloxyhexyl (meth) acrylate, 4-vinyloxycyclohexyl (meth) acrylate, 4-vinyloxymethylcyclohexylmethyl (meth) acrylate, (meth) 2- (2-vinyloxyethoxy) ethyl acrylate, 2- (2-vinyloxyisopropoxy) propyl (meth) acrylate, 2- {2- (2-vinyloxyethoxy) ethoxy} ethyl (meth) acrylate Is preferred.

The heteropolymerizable monomer (A-1) represented by the above formula (3) can be produced using a conventionally known method. For example, in the above formula (3), when R ¹ is an ethylene group and m is 1, a metal salt of (meth) acrylic acid and 2-halogenoethyl vinyl ether are condensed, or methyl (meth) acrylate and , 2-hydroxyethyl vinyl ether can be transesterified, or (meth) acrylic acid halide and 2-hydroxyethyl vinyl ether can be condensed. In the above formula (3), when R ¹ is an ethylene group and m is 2, a metal salt of (meth) acrylic acid and 2- (2-halogenoethoxy) ethyl vinyl ether are condensed or (meta ) By transesterifying methyl acrylate with 2- (2-hydroxyethoxy) ethyl vinyl ether or condensing (meth) acrylic acid halide with 2- (2-hydroxyethoxy) ethyl vinyl ether, Can be manufactured.

  When the vinyl polymer (A) represented by the above formula (2) is a copolymer having a structural unit derived from a monomer capable of cationic polymerization, the copolymer is represented by the above formula (3). The different polymerizable monomer (A-1) and the cationically polymerizable monomer (A-2) can be easily prepared by cationic polymerization or living cationic polymerization. At this time, the heteropolymerizable monomer represented by the above formula (3) may be used alone or in combination of two or more. The resulting copolymer may be a random copolymer, an alternating copolymer, a periodic copolymer, a block copolymer, or a combination thereof. Moreover, a graft copolymer may be sufficient.

  Examples of the monomer (A-2) capable of cationic polymerization include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl. Vinyl ether compounds such as vinyl ether, octadecyl vinyl ether, 2-chloroethyl vinyl ether, 4-hydroxybutyl vinyl ether, dihydrofuran; styrene, 4-methylstyrene, 3-methylstyrene, 2-methylstyrene, 2,5-dimethylstyrene, 2, 4-dimethylstyrene, 2,4,6-trimethylstyrene, 4-t-butylstyrene, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene Styrene derivatives such as 4-methoxystyrene and 4-chloromethylstyrene; N-vinyl compounds such as N-vinylcarbazole and N-vinylpyrrolidone; isopropenylstyrene, 2-vinyloxyethyl cinnamate, 2-vinyloxyethyl sorbate, etc. And divinyl compounds and trivinyl compounds. These cationically polymerizable monomers may be used alone or in combination of two or more. Of these cationically polymerizable monomers, vinyl ether compounds such as isobutyl vinyl ether, cyclohexyl vinyl ether, and dihydrofuran are preferable.

  The heterogeneous polymerizable monomer (A-1) represented by the above formula (3) has a radically polymerizable or anionically polymerizable (meth) acryloyl group and a cationically polymerizable vinyl ether group at the same time. By selecting this, a polymer having a (meth) acryloyl group or a vinyl ether group as a pendant group can be obtained. In the present invention, the vinyl ether group of the heteropolymerizable monomer represented by the above formula (3) is subjected to cation polymerization or living cation polymerization alone or together with a monomer capable of cation polymerization, so that (meth) A vinyl polymer represented by the above formula (2) having an acryloyl group as a pendant group is obtained.

  When the heteropolymerizable monomer (A-1) represented by the above formula (3) and the cationically polymerizable monomer (A-2) are subjected to cationic polymerization or living cationic polymerization, the molar ratio of the monomers (Cationically polymerizable monomer / heterogeneous polymerizable monomer represented by the above formula (3)) is preferably 0.1 to 10, more preferably 0.5 to 8, and still more preferably 0.8 to Within the range of 5.

<(B) Monomer having α-methylene lactone structure>
The curable composition of the present invention has the following general formula (1):

[Wherein R 1, R 2, R 3 and R 4 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, a cycloalkyl group, a —OAc group, a —CN group, a —CO—R 5 group. Or a —C—O—R 6 group, an Ac group represents an acetyl group, and R 5 and R 6 each independently represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms. R1 and R2, and R3 and R4 may be bonded to form a ring structure. ]
A monomer having an α-methylene lactone structure represented by the formula (hereinafter sometimes referred to as (b) methylene lactone component) is included as an essential component.

  In general formula (1), R1, R2, R3, and R4 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, a cycloalkyl group, a —OAc group, a —CN group, —CO—R5. Group, or a —C—O—R 6 group, the Ac group represents an acetyl group, and R 5 and R 6 each independently represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms. R1 and R2, and R3 and R4 may be bonded to form a ring structure. R1, R2, R3 and R4 are preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an aryl group, and more preferably a hydrogen atom and an alkyl group having 1 to 4 carbon atoms.

  (B) Specific examples of the methylene lactone component include α-methylene-γ-butyrolactone (MBL), α-methylene-γ-methyl-γ-butyrolactone, α-methylene-γ-ethyl-γ-butyrolactone, α-methylene. -Γ-propyl-γ-butyrolactone, α-methylene-γ-butyl-γ-butyrolactone, α-methylene-γ, γ-dimethyl-γ-butyrolactone, α-methylene-β-methyl-γ-butyrolactone, α-methylene -Β-ethyl-γ-butyrolactone, α-methylene-β-propyl-γ-butyrolactone, α-methylene-β-methyl-γ-methyl-γ-butyrolactone, α-methylene-β-methyl-γ-dimethyl-γ -Butyrolactone, α-methylene-β-methyl-γ-ethyl-γ-butyrolactone, α-methylene-β-methyl-γ-propyl-γ-butyrola , Α-methylene-β-methyl-γ-cyclohexyl-γ-butyrolactone, α-methylene-β-ethyl-γ-methyl-γ-butyrolactone, α-methylene-β-ethyl-γ, γ-dimethyl-γ- Butyrolactone, α-methylene-β-ethyl-γ-ethyl-γ-butyrolactone, α-methylene-β-ethyl-γ-propyl-γ-butyrolactone, α-methylene-β-ethyl-γ-cyclohexyl-γ-butyrolactone, Examples include α-methylene-γ-butyrolactam, α-methylene-δ-butyrolactone, and the like. Among these, in terms of transparency, heat resistance and optical properties, α-methylene-γ-butyrolactone (MBL), α-methylene-γ-methyl-γ-butyrolactone (also known as α-methylene-γ-valerolactone ( MVL)), α-methylene-γ, γ-dimethyl-γ-butyrolactone is preferred. As for the monomer represented by the general formula (1), only one type may be used, or two or more types may be used in combination.

In the curable composition of the present invention, the content of the (b) methylene lactone component is preferably 5 to 90% by weight, more preferably 10 to 70% by weight, and 10 to 50% by weight. More preferably. When the amount is less than 5% by weight, the viscosity is high and workability is poor and it may be difficult to apply uniformly or the heat resistance may not be sufficiently improved. The strength of the object may be insufficient.
(B) By containing the methylene lactone component in the above-described content, the curable composition of the present invention improves the surface hardness and mechanical strength of the molded product after curing, and can be easily reduced in viscosity and adjusted in viscosity. Thus, various physical properties such as improved moldability and workability, reduced shrinkage in curing, low warpage in the laminate, and improved strain accuracy for the molded product were dramatically improved. Although the detailed reason is unknown, the adhesion to plastic or glass has dramatically improved. Good adhesion to plastic or glass is suitably used for laminates such as hard coats and curable inks.
<(C) Polymerization initiator>
The curable composition of the present invention preferably contains a polymerization initiator. (C) As the polymerization initiator, since (a) the crosslinking component and (b) the methylene lactone component have a radical polymerizable unsaturated double bond group, for example, thermal polymerization starts to generate a polymerization initiating radical by heating. Agents; photopolymerization initiators that generate polymerization initiation radicals upon irradiation with ultraviolet rays; and the like. These polymerization initiators may be used alone or in combination of two or more. It is also preferable to further add a thermal polymerization accelerator, a photosensitizer, a photopolymerization accelerator, and the like.

  Examples of the thermal polymerization initiator include methyl ethyl ketone peroxide, cyclohexanone peroxide, methylcyclohexanone peroxide, methyl acetoacetate peroxide, acetyl acetate peroxide, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1 , 1-bis (t-hexylperoxy) -cyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) -2-methylcyclohexane 1,1-bis (t-butylperoxy) -cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 1,1-bis (t-butylperoxy) butane, 2,2-bis (4 4-di-t-butylperoxy Chlohexyl) propane, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, t-butyl hydroperoxide, α, α'- Bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5 -Dimethyl-2,5-bis (t-butylperoxy) hexyne-3, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, Succinic acid peroxide, m-toluoyl benzoyl peroxide, benzoyl peroxide, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis (4-tert-butylcyclohexyl) peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate , Di-2-ethoxyhexyl peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-s-butyl peroxydicarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, α, α′- Bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methyl Tylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutyl Peroxy 2-ethylhexanoate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexanoate, 1-cyclohexyl-1-methylethylperoxy 2-ethylhexanoate, t-hexylperoxy- 2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-hexylperoxysopropyl monocarbonate, t-butylperoxysobutyrate, t-butylperoxymalate, t-butylperoxy-3, 5,5-trimethylhexano Tate, t-butylperoxylaurate, t-butylperoxysopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-butylperoxyacetate, t-butylperoxy-m-toluylbenzoate, t-butylperoxy Benzoate, bis (t-butylperoxy) isophthalate, 2,5-dimethyl-2,5-bis (m-toluylperoxy) hexane, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis (benzoyl) Peroxy) hexane, t-butylperoxyallyl monocarbonate, t-butyltrimethylsilyl peroxide, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 2,3-dimethyl-2,3-diphenylbutene Organic peroxide initiators such as tan; 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, 1-[(1-cyano-1-methylethyl) azo] formamide, 1,1′-azobis (Cyclohexane-1-carbonitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile) ), 2,2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile), 2,2′-azobis (2-methylpropionamidine) dihydrochloride, 2,2′-azobis (2-methyl-) N-phenylpropionamidine) dihydrochloride, 2,2′-azobis [N- (4-chlorophenyl) -2-methylpropionamidine)] dihydrochloride, 2,2′-azobis [N (4-Hydrophenyl) -2-methylpropionamidine)] dihydrochloride, 2,2′-azobis [2-methyl-N- (phenylmethyl) propionamidine] dihydrochloride, 2,2′-azobis [2 -Methyl-N- (2-propenyl) propionamidine] dihydrochloride, 2,2'-azobis [N- (2-hydroxyethyl) -2-methylpropionamidine)] dihydrochloride, 2,2'-azobis [2- (5-Methyl-2-imidazolin-2-yl) propane) dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane) dihydrochloride, 2,2 ′ -Azobis [2- (4,5,6,7-tetrahydro-1H-1,3-diazepin-2-yl) propane) dihydrochloride, 2,2'-azobis [2- (3,4,5, 6-tetrahydropyrimidine- -Yl) propane) dihydrochloride, 2,2'-azobis [2- (5-hydroxy-3,4,5,6-tetrahydropyrimidin-2-yl) propane) dihydrochloride, 2,2'-azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane} dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane], 2, 2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2′-azobis {2-methyl-N- [1,1-bis (Hydroxymethyl) ethyl] propionamide}, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2′-azobis (2-methylpropionamide), 2,2 '-Azo Bis (2,4,4-trimethylpentane), 2,2′-azobis (2-methylpropane), 2,2-azobis (2-methylpropionic acid) dimethyl, 4,4′-azobis (4-cyanopentane) Acid) and azo initiators such as 2,2′-azobis [2- (hydroxymethyl) propionitrile]; and the like. These thermal polymerization initiators may be used alone or in combination of two or more. Among these thermal polymerization initiators, radicals can be efficiently generated by the catalytic action of metal soaps such as methyl ethyl ketone peroxide, cyclohexanone peroxide, cumene hydroperoxide, t-butylperoxybenzoate, benzoyl peroxide, and / or amine compounds. Preferred compounds are 2,2′-azobisisobutyronitrile and 2,2′-azobis (2,4-dimethylvaleronitrile).

  Examples of the photopolymerization initiator include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2 -Propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholino Acetophenones such as phenyl) butanone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomer; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether Etc. Zoins; benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyl-diphenyl sulfide, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 2 , 4,6-trimethylbenzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethananium bromide, (4-benzoylbenzyl) trimethylammonium chloride Benzophenones such as 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino-2-hydroxy) Thioxanthones such as 3,4-dimethyl -9H- thioxanthone-9-Onmesokurorido; and the like. These photopolymerization initiators may be used alone or in combination of two or more. Of these photopolymerization initiators, acetophenones, benzophenones, and acylphosphine oxides are preferable, and 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-2-morpholino (4- Thiomethylphenyl) propan-1-one, 1-hydroxycyclohexyl phenyl ketone are particularly preferred.

  The blending amount of the polymerization initiator is preferably 0.05 to 20% by mass, more preferably 0.1 to 15% by mass, and further preferably 0.2 to 10% by mass with respect to the total amount of the curable composition. It is. When the blending amount of the polymerization initiator is less than 0.05% by mass, the curable composition may not be sufficiently cured. On the other hand, if the blending amount of the polymerization initiator exceeds 20% by mass, the physical properties of the cured product will not be further improved, and adverse effects such as coloring may be adversely affected and the economy may be impaired.

  When a thermal polymerization initiator is used as the polymerization initiator, the thermal polymerization can accelerate the decomposition of the thermal polymerization initiator and effectively generate radicals in order to lower the decomposition temperature of the thermal polymerization initiator. An agent can be used. Examples of the thermal polymerization accelerator include metal soaps such as cobalt, copper, tin, zinc, manganese, iron, zirconium, chromium, vanadium, calcium, and potassium, primary, secondary, tertiary amine compounds, and quaternary ammonium. Examples thereof include salts, thiourea compounds, and ketone compounds. These thermal polymerization accelerators may be used alone or in combination of two or more. Among these thermal polymerization accelerators, cobalt octylate, cobalt naphthenate, copper octylate, copper naphthenate, manganese octylate, manganese naphthenate, dimethylaniline, trietalamine, triethylbenzylammonium chloride, di (2-hydroxy) Ethyl) p-toluidine, ethylenethiourea, acetylacetone, methyl acetoacetate are preferred.

  The blending amount of the thermal polymerization accelerator is preferably 0.001 to 20% by mass, more preferably 0.01 to 10% by mass or more, further preferably 0.05 to 5%, based on the total amount of the curable composition. It is in the range of mass%. When the blending amount of the thermal polymerization accelerator is within such a range, it is preferable from the viewpoints of curing performance of the curable composition, physical properties of the cured product, and economical efficiency.

  When using a photopolymerization initiator as a polymerization initiator, it is possible to transfer excitation energy from an excited state generated by photoexcitation to the photopolymerization initiator to promote the decomposition of the photopolymerization initiator and generate radicals effectively. The photosensitizer which can be used can be used. Examples of the photosensitizer include 2-chlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone. These photosensitizers may be used alone or in combination of two or more.

  The blending amount of the photosensitizer is preferably 0.05 to 20% by mass, more preferably 0.1 to 15% by mass, and still more preferably 0.2 to 10% by mass with respect to the total amount of the curable composition. %. If the compounding quantity of a photosensitizer is in such a range, it is preferable at the point of the hardening performance of a curable composition, the physical property of hardened | cured material, and economical efficiency.

  When a photopolymerization initiator is used as the polymerization initiator, a photopolymerization accelerator capable of promoting the decomposition of the photopolymerization initiator and effectively generating radicals can be used. Examples of the photopolymerization accelerator include triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, and 4-dimethylaminobenzoic acid. Examples include 2-n-butoxyethyl, 2-dimethylaminoethyl benzoate, N, N-dimethylparatoluidine, 4,4′-dimethylaminobenzophenone, and 4,4′-diethylaminobenzophenone. These photopolymerization accelerators may be used alone or in combination of two or more. Of these photopolymerization accelerators, triethanolamine, methyldiethanolamine, and triisopropanolamine are preferable.

  The blending amount of the photopolymerization accelerator is preferably 0.05 to 20% by mass, more preferably 0.1 to 15% by mass, and further preferably 0.2 to 10% by mass with respect to the total amount of the curable composition. %. When the blending amount of the photopolymerization accelerator is within such a range, it is preferable from the viewpoint of the curing performance of the curable composition, the physical properties of the cured product, and the economical efficiency.

  When blending a combination of a thermal polymerization initiator, a photopolymerization initiator, a thermal polymerization accelerator, a photosensitizer, a photopolymerization accelerator, etc., the total amount of the blending amount is based on the total amount of the curable composition. , Preferably it is 0.05-20 mass, More preferably, it is 0.1-15 mass%, More preferably, it exists in the range of 0.2-10 mass. If the total amount of the combination amount such as the polymerization initiator is within such a range, it is preferable from the viewpoint of the curing performance of the curable composition, the physical properties of the cured product, and the economical efficiency.

<Other ingredients>
The curable composition of the present invention may contain a polymerizable monomer, inorganic particles, and the like in addition to the (a) crosslinking component, (b) methylene lactone component, and (c) initiator. When a polymerizable monomer is included, the physical properties of a cured product obtained by curing can be adjusted.

  The polymerizable monomer is not particularly limited as long as it can be co-cured with the above-mentioned (a) crosslinking component and (b) methylene lactone component. -Styrene monomers such as t-butylstyrene, α-methylstyrene, 4-chlorostyrene, 4-methylstyrene, 4-chloromethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meta ) Acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, 1-adamantyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl ( (Meth) acrylate, 2-hydroxypropyl (Meth) acrylate derivatives such as (meth) acrylate, glycidyl (meth) acrylate, trifluoroethyl (meth) acrylate, perfluorooctylethyl (meth) acrylate; vinyl ether monomers such as hydroxybutyl vinyl ether and dodecyl vinyl ether Allyl ether monomers such as allyl glycidyl ether, allyl ether of methylol melamine, adipic acid ester of glyceryl diallyl ether, allyl acetal, allyl ether of methylol glyoxalurein; maleic acid esters such as diethyl maleate and dibutyl maleate Monomers; fumaric acid ester monomers such as dibutyl fumarate and dioctyl fumarate; 4- (meth) acryloyloxymethyl-2-methyl-2-ethyl-1 , 3-dioxolane, 4- (meth) acryloyloxymethyl-2-methyl-2-isobutyl-1,3-dioxolane, 4- (meth) acryloyloxymethyl-2-cyclohexyl-1,3-dioxolane, 4- ( 1,3-dioxolane-based monomers such as (meth) acryloyloxymethyl-2,2-dimethyl-1,3-dioxolane; (meth) acryloylmorpholine; N-vinylformamide; N-vinylpyrrolidone; . These polymerizable monomers may be used alone or in combination of two or more. Of these polymerizable monomers, (meth) acrylic ester compounds are preferred.

  The compounding amount of the polymerizable monomer is preferably 0 to 50% by mass, more preferably 0 to 30% by mass, and further preferably 0 to 20% by mass with respect to the total amount of the composition. When the compounding quantity of a polymerizable monomer exceeds 50 mass%, hardening shrinkage will become large and the distortion and curvature of hardened | cured material may become large.

  The curable composition of the present invention may use an organic solvent. In the case of containing an organic solvent, it becomes possible to easily dissolve or disperse a metal oxide or an additive.

  Examples of the organic solvent used include aromatic hydrocarbons such as benzene, toluene and chlorobenzene; aliphatic or alicyclic hydrocarbons such as pentane, hexane, cyclohexane and heptane; carbon tetrachloride, chloroform and ethylene dichloride. Halogenated hydrocarbons; Nitro compounds such as nitromethane and nitrobenzene; Ethers such as diethyl ether, methyl t-butyl ether, tetrahydrofuran and 1,4-dioxane; Esters such as methyl acetate, ethyl acetate, isopropyl acetate and amyl acetate; Dimethyl Alcohols such as formamide, methanol, ethanol, and propanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; and the like can be used.

  The blending amount of the organic solvent is preferably 0 to 80% by mass, more preferably 0 to 50% by mass, based on the total amount of materials. When the blending amount of the solvent exceeds 80% by mass, it may take time or may remain in the cured product when the solvent is distilled off from the composition.

  The curable composition of the present invention may preferably contain fine particles made of a metal oxide. When fine particles comprising a metal oxide are contained, the hardness of the cured product after curing is improved, it is more difficult to be damaged, and physical properties such as refractive index can be adjusted.

More preferably, the metal oxide constituting the fine particles contains at least one metal element selected from the group consisting of Si, Ti, Zr, Zn, Sn, In, La, and Y. The metal oxide constituting the fine particles may be a single oxide containing these elements or a complex oxide containing these elements. Specific examples of the metal oxide constituting the fine particles, for _{example, SiO, SiO 2, TiO 2} , ZrO 2, ZnO, SnO 2, In 2 O 3, La 2 O 3, Y 2 O 3, SiO 2 -Al ₂ O ₃ , SiO ₂ —Zr ₂ O ₃ , SiO ₂ —Ti ₂ O ₃ , Al ₂ O ₃ —ZrO ₂ , TiO ₂ —ZrO _{2 and the} like. The fine particles comprising these metal oxides may be used alone or in combination of two or more. Of these fine particles made of a metal oxide, SiO ₂ , TiO ₂ , ZrO ₂ , and ZnO ₂ are preferable. Moreover, it is preferable that the surface of the metal oxide fine particles is organically treated for improving dispersibility.

  The average particle diameter of the fine particles made of a metal oxide is preferably 1 to 300 nm, more preferably 1 to 50 nm. If the average particle diameter of the fine particles exceeds 300 nm, the transparency of the cured product may be impaired. In addition, the average particle diameter of fine particles means the volume average particle diameter calculated | required by measuring using a dynamic light scattering type particle size distribution measuring apparatus.

  The blending amount of the fine particles composed of the metal oxide is preferably 0 to 80% by mass, more preferably 0 to 50% by mass with respect to the total amount of the composition. If the amount of fine particles exceeds 80% by mass, the cured product may become brittle.

  The curable composition of the present invention may further contain, as necessary, inorganic fillers such as aluminum hydroxide, talc, clay, barium sulfate, non-reactive resins and / or reactive resins (for example, acrylic resins). Polyester resin, polyurethane resin, polystyrene resin, polyvinyl chloride resin, etc.), color pigment, release agent, lubricant, plasticizer, chain transfer agent, polymerization inhibitor, ultraviolet absorber, near infrared absorber, light stabilizer, Add antioxidants, flame retardants, matting agents, dyes, antifoaming agents, leveling agents, antistatic agents, dispersants, slip agents, surface modifiers, thixotropic agents, thixotropic agents, etc. be able to. The presence of these additives does not particularly affect the effects of the present invention. These additives may be used alone or in combination of two or more.

  The compounding amount of the additive may be appropriately set according to the type and purpose of use of the additive, the use and usage of the composition, and is not particularly limited. For example, the compounding amount of the inorganic filler is preferably in the range of 1 to 80% by mass, more preferably 10 to 60% by mass, and still more preferably 20 to 50% by mass with respect to the total amount of the composition. The compounding amount of the non-reactive resin, the color pigment, the plasticizer or the thixotropic agent is preferably 1 to 40% by mass, more preferably 5 to 30% by mass, and still more preferably 10 to 10%, based on the total amount of the composition. It is in the range of 25% by mass. Release agent, polymerization inhibitor, UV absorber, antioxidant, matting agent, dye, antifoaming agent, leveling agent, antistatic agent, dispersant, slip agent, surface modifier or thixotropic agent The amount is preferably in the range of 0.0001 to 5% by mass, more preferably 0.001 to 3% by mass, and still more preferably 0.01 to 2% by mass, based on the total amount of the composition. In particular, when obtaining a molded article, it is important to select a release agent.

Examples of the mold release agent include metal soaps such as zinc stearate, calcium stearate, magnesium stearate, lithium stearate, barium stearate, and sodium stearate;
Sodium bistridecyl sulfosuccinate, sodium dioctyl sulfosuccinate, sodium dihexyl sulfosuccinate, sodium dicyclohexylsulfosuccinate, sodium diamylsulfosuccinate, sodium diisobutylsulfosuccinate, N-octadecylsulfosuccinamide disodium, N- (1 , 2-dicarboxyethyl) -N-octadecyl sulfosuccinamide tetrasodium salt, sulfosuccinic ester surfactants;
Caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, myristoleic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, 12-hydroxystearic acid Fatty acids such as acids, ricinoleic acid;
Higher alcohols such as lauryl alcohol, stearyl alcohol, behenyl alcohol;
Fatty acid esters such as methyl stearate, stearyl stearate, behenyl behenate, sorbitan monostearate;
Silicone mold release agents such as KF96, KF965, KF410, KF412, KF4701, KF54, KS61, KM244F, KS702, KF725, KS707, KS800P, which are products of Shin-Etsu Chemical Co., Ltd .;
Product names of Polynova PF-136A, PF-156A, PF-151N, PF-636, PF-6320, PF-656, PF-6520, PF-651, PF-652, PF-3320, etc. Fluorinated surfactants of
Etc., and only one of these may be used, or two or more may be used in combination. Among these, sulfosuccinate ester surfactants, fatty acids, higher alcohols, fatty acid esters, and fluorine surfactants are particularly preferable because they can exhibit releasability while maintaining transparency.

≪Curable composition, cured product, curing method≫
The curable composition of the present invention comprises:
(A) a compound having two or more unsaturated polymerizable functional groups in one molecule;
(B) a monomer having an α-methylene lactone structure of the following formula (1),
It can be obtained by blending (c) a polymerization initiator if necessary, and (d) other components if necessary, and mixing and stirring.

  In the curable composition of the present invention, the viscosity can be appropriately selected depending on the use, but is preferably 10000 mPa · s or less. More preferably, it is 1-5000 mPa * s, More preferably, it is 2-2000 mPa * s. When the viscosity is greater than 10,000 mPa · s, there may be a problem in moldability. In the present application, the viscosity is a value measured with a B-type viscometer at 25 ° C. (model RB-80L manufactured by Toki Sangyo).

  The curable composition of the present invention can be cured by heating when a thermal polymerization initiator is blended or by irradiating ultraviolet rays when a photopolymerization initiator is blended. In addition, the hardened | cured material of this invention is obtained by hardening a curable composition. Here, the “cured product” means a substance having no fluidity.

  For example, in the case of curing by heating, infrared rays, far infrared rays, hot air, high frequency heating, or the like may be used. The heating temperature may be appropriately adjusted according to the type of the substrate, and is not particularly limited, but is preferably 80 to 200 ° C, more preferably 90 to 180 ° C, and still more preferably 100 to 170 ° C. Within range. The heating time may be appropriately adjusted according to the application area and the like, and is not particularly limited, but is preferably 1 minute to 24 hours, more preferably 10 minutes to 12 hours, and even more preferably 30 minutes to 6 hours. Is within the range.

For example, in the case of curing with ultraviolet rays, a light source including light within a wavelength range of 150 to 450 nm may be used. Examples of such a light source include sunlight, low-pressure mercury lamp, high-pressure mercury lamp, ultrahigh-pressure mercury lamp, metal halide lamp, gallium lamp, xenon lamp, flash type xenon lamp, and carbon arc lamp. Together with these light sources, it is possible to use heat by infrared rays, far infrared rays, hot air, high-frequency heating or the like. The irradiation integrated light quantity is preferably in the range of 0.1 to 5 J / cm ² , more preferably 0.15 to 3 J / cm ² , and still more preferably 0.2 to 1 J / cm ² .

  For example, in the case of curing with an electron beam, an electron beam having an acceleration voltage of preferably 10 to 500 kV, more preferably 20 to 300 kV, and even more preferably 30 to 200 kV may be used. The irradiation amount is preferably in the range of 2 to 500 kGy, more preferably 3 to 300 kGy, and still more preferably 4 to 200 kGy. Along with an electron beam, it is possible to use heat by infrared rays, far infrared rays, hot air, high-frequency heating or the like.

  On the other hand, the curable composition of the present invention has a very small curing shrinkage when cured, and various curing methods can be used. Furthermore, the low cure shrinkage can provide a molded product with highly controlled strain accuracy when molding a molded product, and does not cause warping of the laminate when used for ink or coating. It also has the ability to obtain a body.

  The cured product of the present invention has very good transparency when it does not contain coloring components such as pigments or dyes, has a high glass transition temperature, and is excellent in heat resistance. The glass transition temperature can be appropriately selected depending on the application and is not particularly limited. However, the preferred glass transition point is 40 to 200 ° C, more preferably 70 to 180 ° C, still more preferably 100 to 160 ° C, and most preferably 120 to 150 ° C. is there. When the glass transition point is lower than 40 ° C., the heat resistance of the coating film or molded product is insufficient, and there is a possibility of causing deformation depending on conditions, which is not preferable. Further, when the glass transition temperature is higher than 200 ° C., a problem may occur in formability. The cured product of the present invention has high hardness and excellent scratch resistance. The preferable hardness is 2B or more, more preferably H or more, and further preferably 2H or more in terms of pencil hardness. When the pencil hardness is lower than 2B, the hardness is insufficient, and a coating film or molded product that is very easily damaged is not preferable.

  Moreover, although the detailed reason is unknown, the curable composition of this invention can obtain hardened | cured material with favorable surface smoothness. This characteristic makes it possible to obtain a molded body whose strain accuracy is highly controlled as described above. Furthermore, when used for ink or coating, it becomes possible to highly control the surface properties of the laminate.

When a curable ink is produced using the curable composition of the present invention, for example, hand coating such as brush coating, roll coating, gravure coating, gravure offset coating, curtain flow coating, reverse coating, screen printing, spraying, etc. It can apply | coat to a base material by a well-known method according to use purposes, such as coating and a dipping method. As an application quantity, 0.2-100 g / m < ² > is preferable and 0.5-70 g / m < ² > or more is more preferable.

In the case of obtaining a laminate such as a transparent cover layer using the curable composition of the present invention, various coating methods such as gravure printing, bar coater method, spin coater method, hand coating such as brush coating, A conventionally known method such as spray coating or dipping may be selected according to the purpose of use. The coating amount is preferably 0.2 to 100 g / m ² , more preferably 0.5 to 70 g / m ² . Moreover, as application | coating thickness, Preferably it is 1-500 micrometers, More preferably, it exists in the range of 2-200 micrometers.

  Moreover, as a method of forming the cured film layer of this invention, there exists the shaping | molding simultaneous decorating method using the film for decorating containing a curable composition. This method is a resin molding in which a decorative film composed of at least a film and a decorative layer is placed in a mold for injection molding, and after closing the mold, a molding resin is injected into a cavity and the molding resin is solidified. A decorative sheet is obtained by integrally bonding a decorative sheet to the surface of the product.

  When using the curable composition of the present invention to obtain a molded member such as an eyeglass lens, a Fresnel lens, or a lenticular lens, a conventionally known method such as a cast method or a press method may be selected depending on the intended use. Good.

  In the case of forming a laminate in the present invention, examples of the base material include polyethylene (PE), polypropylene (PP), polymethyl methacrylate (PMMA), polyacrylate, polyvinyl alcohol (PVA), polystyrene (PS), and polyethylene. Terephthalate (PET), polybutylene terephthalate (PBT), ethylene-vinyl acetate copolymer (EVA), acrylonitrile-butadiene-styrene copolymer (ABS), triacetyl cellulose (TAC), cycloolefin polymer (COP), polycarbonate (PC), polyether ketone (PEEK), polyamide imide (PAI), polyimide (PI), polyether amide (PEI), nylon (NY), polyvinyl chloride (PVC), polyvinylidene chloride, Resin moldings and films such as heat-resistant acrylic resins disclosed in Japanese Patent Publication No. 20151562, Patent Publication 3178733, JP 2001-151814, JP 2007-70607, etc .; Coated paper such as polyethylene coated paper, polyethylene terephthalate coated paper, Paper such as uncoated paper; wood; glass; metals such as stainless steel, iron, aluminum, copper, and alloys; Among these, polyethylene terephthalate (PET), triacetyl cellulose (TAC), polymethyl methacrylate (PMMA), polyacrylate, cycloolefin polymer (COP), polycarbonate (PC), and heat-resistant acrylic resin are preferable.

  Depending on the purpose, the molded product or coating film of the present invention has an antistatic layer, an adhesive layer, an adhesive layer, an easy adhesion layer, a strain relaxation layer, an antiglare (non-glare) layer, a photocatalyst layer, and the like. Various functional coating layers such as a layer, an antireflection layer, an ultraviolet ray shielding layer, a heat ray shielding layer, an electromagnetic wave shielding layer, and a gas barrier property may be laminated and applied. The lamination method is not particularly limited.

  According to the present invention, the curable composition has excellent curing characteristics, low viscosity, and good handleability. Since the curable composition of the present invention has a low viscosity and extremely excellent fluidity, for example, it is possible to effectively reduce the amount of the diluent used. In the present invention, a cured product having extremely high heat resistance, low shrinkage, and high hardness can be obtained. For example, curable ink, transparent cover layer, liquid crystal display panel, color filter coloring resist for liquid crystal display element, protective film for color filter, resin black matrix, overcoat agent for protective film, columnar spacer, liquid crystal sealing material, optical Hard coat for film, AG binder, diffusion film binder, AR material, LR material, transparent electrode, retardation film, organic fine particles used for diffusion plate and AG applications, solder resist for printed wiring board, etching resist, none Electrolytic plating resist, optical sensor element, IC card adhesive, hologram material such as photorefractive photopolymer, copying machine, printer, facsimile image forming toner, image forming member, organic EL hole transport layer, light emitting layer, PS Plates and CTP printing plates Photosensitive materials for plates, spectacle lenses, Fresnel lenses, lenticular lenses, prism lens sheets for TFT (Thin Film Transistor), various lenses such as camera lenses, microlens arrays, aspherical lenses, optical disc coatings and adhesives It can be used for various articles such as an agent, an optical fiber core material and a clad material, an optical fiber connecting adhesive, an optical waveguide core material and a clad material. In particular, it can be suitably used for a curable ink, a transparent cover layer, and an optical disk coating agent.

  Specific examples of articles having a transparent cover layer, which is a preferred application in the present invention, include optical recording disks, plastic films, OA equipment, communication equipment such as mobile phones, household appliances, automotive interior / exterior parts, furniture It is suitably used for exterior members, plastic lenses, cosmetic containers, beverage containers, displays such as organic EL displays, touch panels such as home appliances, sinks, washstands, show windows, window glass, and the like. In particular, it can be suitably used for optical recording disks and plastic films. Moreover, since the cured film layer of the present invention is particularly excellent in scratch resistance and hardness, it can be suitably used particularly for a hard coat layer cured product.

<Production Example 1>
The polymerization reaction was carried out in a dry nitrogen atmosphere using a sufficiently dried glass container with a three-way cock. First, 159 mL of sufficiently dried and purified toluene, 5 mL of ethyl acetate, and 5 mL of a 1-isobutoxyethyl acetate 0.2 mol / L toluene solution were added to the glass container at room temperature. Further, 25 mL of a 0.1 mol / L toluene solution of ethylaluminum dichloride was added and mixed, and then allowed to stand for 30 minutes to generate a reaction starting species. Next, after the system was cooled to 0 ° C., 0.2 mol of 2- (2-vinyloxyethoxy) ethyl acrylate (VEEA) precooled to 0 ° C. was added, and tin tetrachloride precooled to 0 ° C. was added. The reaction was started by adding 25 mL of a 0.05 mol / L toluene solution. After polymerization for 14 minutes, methanol was added to stop the reaction. Chloroform was added to the mixed solution after the reaction, and the residue of the polymerization initiator was removed by washing with water. Subsequently, after concentrating with an evaporator, it was made to vacuum-dry and the vinyl polymer (henceforth P-VEEA) was obtained. The reaction rate of the monomer was found to be 98% by analyzing the mixed solution after stopping the reaction by gas chromatography (GC). Moreover, the number average molecular weight (Mn) of the obtained vinyl polymer was 12,200, and molecular weight distribution (Mw / Mn) was 1.10. The viscosity at 25 ° C. was 41250 mPaS. Further, when the obtained vinyl polymer was subjected to ¹ H-NMR measurement (measuring solvent: deuterated chloroform, measuring instrument: 400 MHz ¹ H-NMR UNITYplus 400 manufactured by Varian), the acryloyl group remained and was selected. In particular, it was confirmed that the acryloyl group pendant polymer has a vinyl ether group polymerized and has a double bond capable of radical polymerization in the side chain.
<Example 1>
80 parts by mass of an acryloyl group pendant type vinyl polymer (P-VEEA) having a double bond capable of radical polymerization in the side chain obtained in Production Example 1, α-methylene-γ-butyrolactone (manufactured by Tokyo Chemical Industry) 20 parts, photopolymerization initiator 1-hydroxy-cyclohexyl-phenyl-ketone (trade name “Irgacure 184”, manufactured by Ciba Specialty Chemicals), surface modifier polyether-modified polydimethylsiloxane (trade name “ BYK306 "(by Big Chemie Japan Co., Ltd.) 0.1 part was mixed and stirred to prepare a coating solution. The viscosity of the obtained coating liquid at 25 ° C. was 2010 mPaS.

Next, the coating liquid was applied using an applicator on a polyethylene terephthalate (PET) film having both surfaces subjected to easy adhesion treatment. Then, this film was UV-cured using a high-pressure mercury lamp under a nitrogen atmosphere under conditions of an illuminance of 150 mW / cm 2 and an integrated irradiation light quantity of 300 mJ / cm ² . When the thickness of the resin layer was measured, it was 5 μm.

Table 1 shows the physical properties of the obtained coating liquid and the evaluation of the film with a resin layer (laminate).

<Examples 2 to 4, Comparative Examples, Reference Examples>
In the same manner as in Example 1, a coating solution was prepared with the raw material and composition mixing ratio shown in Table 1.
Next, physical properties of the coating liquid and evaluation of the film with a resin layer (laminate) were performed. The results are shown in Table 1.

<Appearance evaluation>
The resin cured product surface of the obtained laminate was visually evaluated according to the following criteria.

○: Good surface smoothness ×: Uneven surface, poor surface smoothness <Glass transition temperature, transparency evaluation>
A coating solution is injected into a glass mold having a silicon spacer with a thickness of 100 μm sandwiched between two glass plates, and ultraviolet rays are used under the conditions of an illuminance of 150 mW / cm 2 and an integrated irradiation light quantity of 300 mJ / cm ² using a high-pressure mercury lamp. Harden. The obtained cured product is subjected to dynamic viscoelasticity measurement to measure the glass transition temperature (° C.). As measurement conditions, a tensile mode, a frequency of 1 Hz, a clamp distance of 25 mm, an amplitude of 0.1%, a temperature rising rate of 5 ° C./min are set, and when the temperature is raised from −20 ° C. to 150 ° C., the loss tangent (tan δ) The temperature at which the value reaches a peak is defined as the glass transition temperature (° C.). Moreover, transparency (total light transmittance) of the obtained cured product was measured according to JIS-K7361-1 using a turbidimeter (type: NDH2000, manufactured by Nippon Denshoku Industries Co., Ltd.).

<Scratch resistance>
Using a wear resistance tester (model IMC-154A, manufactured by Imoto Seisakusho Co., Ltd.) on the surface of the cured resin of the laminate, steel wool # 0000 was reciprocated at a reciprocating speed of 30 mm / sec. Then, after reciprocating 10 times at a load of 200 g / cm ² and a reciprocating distance of 25 mm, the degree of damage was visually observed and evaluated according to the following criteria.

○: No change (no scratches are observed)
Δ: Several scratches are observed ×: Several tens of scratches are observed XX: Countless scratches are observed <Pencil hardness>
It measured based on JIS-K5400 using the pencil scratch hardness tester (made by Yasuda Seiki Seisakusyo Co., Ltd.) with respect to the resin cured material surface of a laminated body. The load was 1,000 g.

<Warpage amount>
The laminated body cut out to 15 cm × 15 cm was placed on a horizontal platform under the condition of a temperature of 25 ° C., and the average value of the floating height from the horizontal platform at the four corners was measured and evaluated according to the following criteria: did.

◎: Less than 3 mm ○: 3 mm or more and less than 5 mm △: 5 mm or more and less than 8 mm ×: 8 mm or more <Adhesion Evaluation>
According to JIS K5400, a grid cut (1 mm × 1 mm, 100 mm) was made on the surface of the cured resin product of the laminate, and a peel test using a cellophane adhesive tape was performed. The numerical value is shown by the remaining number.

○: 100 (no peeling)
X: 99-0

Abbreviations in Table 1 are shown below.

P-VEEA: Acrylyl group pendant type vinyl polymer having a double bond capable of radical polymerization in the side chain obtained in Production Example 1

UV-7510B: urethane acrylate (manufactured by Nippon Synthetic Chemical)

SR423D: Isobornyl acrylate (manufactured by Sartomer)
Glass transition temperature: 110 ° C (from Sartomer product catalog)

SR833: Tricyclodecane diacrylate (manufactured by Sartomer)
Glass transition temperature: 187 ° C (from Sartomer product catalog)

MBL: α-methylene-γ-butyrolactone (manufactured by Tokyo Chemical Industry)

MVL: α-methylene-γ-valerolactone (manufactured by Tokyo Chemical Industry)

Claims (4)

At least (a) a compound having two or more unsaturated polymerizable functional groups in one molecule;
(B) a monomer having an α-methylene lactone structure of the following formula (1),

[Wherein R 1, R 2, R 3 and R 4 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, a cycloalkyl group, a —OAc group, a —CN group, a —CO—R 5 group. Or a —C—O—R 6 group, an Ac group represents an acetyl group, and R 5 and R 6 each independently represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms. R1 and R2, and R3 and R4 may be bonded to form a ring structure. ]
A curable composition comprising: (A)
Following formula (2):

[Wherein R ¹ is an alkylene group having 2 to 8 carbon atoms, R ² is a hydrogen atom or a methyl group, and m is a positive integer]
The curable composition according to claim 1, comprising a vinyl polymer having a repeating unit represented by the formula: (C) The curable composition of Claim 1 or 2 containing a polymerization initiator. Hardened | cured material obtained by hardening the curable composition in any one of Claims 1-3.