JP5485205B2 - Soluble polyfunctional (meth) acrylic acid ester copolymer having alicyclic structure, curable resin composition, cured product, and optical material - Google Patents

Description

  The present invention has excellent optical properties such as low color dispersion and high light transmittance, heat resistance, and processability, in addition, optical properties under severe actual use conditions such as wet heat conditions, and low water absorption. Soluble polyfunctional (meth) acrylic acid ester copolymer having an alicyclic structure with improved mold release properties and improved precision mold transfer, and the soluble polyfunctional (meth) acrylic The present invention relates to a curable resin composition, a cured product and an optical article comprising an acid ester copolymer.

  Many of the monomers having a reactive active unsaturated bond can generate a multimer by selecting an appropriate reaction condition and a catalyst that causes a chain reaction by cleavage of the unsaturated bond. In general, the types of monomers having an unsaturated bond are extremely diverse, so the variety of types of resins obtained is also remarkable. However, there are relatively few types of monomers that can obtain a high molecular weight compound having a molecular weight of 10,000 or more, generally called a high molecular compound. For example, ethylene, substituted ethylene, propylene, substituted propylene, styrene, alkyl styrene, alkoxy styrene, norbornene, various acrylic esters, butadiene, cyclopentadiene, dicyclopentadiene, isoprene, maleic anhydride, maleimide, fumaric ester, allyl A compound etc. can be mentioned as a typical monomer. A wide variety of resins have been synthesized by using these monomers alone or copolymerizing them.

  Applications of these resins are mainly limited to the field of relatively inexpensive consumer equipment, and advanced technology fields that require high heat resistance, dimensional stability, and fine workability in the field of optical and electronic materials. There is almost no application to. The reason for this is that polymers synthesized from the above-mentioned monomers are thermoplastic, and it is necessary to use a considerably high molecular weight to satisfy the mechanical properties. The characteristic required in the technical field is sacrificed.

  As a method for solving the disadvantages of such vinyl-based thermoplastic polymers, Patent Documents 1 to 3 disclose polymers having pendant (meth) acryloyl groups or vinyl ether groups. For example, Patent Document 1 discloses a photosensitivity composed of a (meth) acryloyl group pendant polymer obtained by cationic polymerization of a different polymerizable monomer such as 2-vinyloxyethyl acrylate (VEA) and a photopolymerization initiator. A composition is disclosed. Patent Document 2 discloses a photosensitive composition comprising a (meth) acryloyl group pendant polymer, a compound having a photoreactive unsaturated carboxyl group, and a photopolymerization initiator. Further, Patent Document 3 discloses that a heteropolymerizable monomer such as 2-vinyloxyethyl acrylate (VEA) is itself contained in a carboxylic acid ester solvent compound having a photoreactive unsaturated group that is inert to cationic polymerization. A production method for obtaining a polymer solution by homopolymerization or copolymerization using a cationic polymerization catalyst is disclosed.

  However, when using a reactive polymer produced according to the technology using a heterogeneous polymerizable monomer disclosed in these patent documents, low water absorption required in the field of advanced optical lens / prism applications, It has a balance of properties such as heat resistance, moldability, and advanced optical properties. In addition, it has optical properties under severe usage conditions such as wet heat conditions, low water absorption and good releasability during molding, and precise A polymer having improved mold transferability and a curable resin composition have not been obtained.

  On the other hand, Patent Document 4 is obtained by copolymerizing a monovinyl aromatic compound and a bifunctional (meth) acrylic acid ester, and has a reactive (meth) acrylate group derived from the bifunctional (meth) acrylic acid ester on the side chain. A soluble polyfunctional vinyl aromatic copolymer having a structural unit is disclosed. However, the soluble polyfunctional vinyl aromatic copolymer obtained by the technique disclosed therein has excellent thermal decomposition resistance against heat history at high temperature, and is reactive (meth) acrylate in the side chain. Although it has a base, excellent processability, and solvent solubility, it has practical limitations that it cannot be used for optical lenses for low color dispersion, and it has not achieved high hardness. It was a material.

Further, Patent Document 5 contains 1 to 25% by weight of a di (meth) acrylate of a linear aliphatic dihydric alcohol having 4 to 8 carbon atoms as a constituent component in methyl methacrylate (MMA) syrup. A featured composition is disclosed. Here, the production of the MMA-based syrup composition is carried out in the atmosphere of MMA, MMA and a vinyl copolymer copolymerizable therewith, or a chain transfer agent in the presence of a polymerization initiator in an inert gas (for example, N ₂ gas). It is disclosed that the polymerization is carried out at room temperature or by heating. Specific examples of chain transfer agents are only sulfur compounds such as lauryl mercaptan, octyl thioglycolic acid ester, thiocresol, thionaphthol, benzyl mercaptan, and 2,4-diphenyl-4-methyl. -1-Pentene (c) was not specifically disclosed. Furthermore, it exists simultaneously with the terminal group derived from a thiol compound and the terminal group derived from 2,4-diphenyl-4-methyl-1-pentene, and has a monofunctional and / or bifunctional (meth) having an alicyclic structure. It has not been suggested that the coexistence of the structural unit derived from the acrylate ester (a) can synergistically control the heat-resistant optical properties and the precise transferability of the mold shape. In addition, the composition obtained by the technique disclosed therein has not been improved in adhesion to inorganic materials under severe actual use conditions such as wet heat conditions.

  Patent Document 6 discloses a polymerizable composition comprising a vinyl monomer and a di (meth) acrylate compound, and the use of 2,4-diphenyl-4-methyl-1-pentene (c) is also disclosed. Although it is disclosed, the amount used is about a few percent of comma as a normal chain transfer agent, and the product is also cross-linked gel and does not show solvent solubility.

  Further, Patent Document 7 includes structural units composed of 1) an epoxy group-containing (meth) acrylate, 2) a hydroxyl group-containing (meth) acrylate, 3) (meth) acrylic acid, and 4) an aromatic group-containing (meth) acrylate. The thermosetting resin composition for color filters characterized by including the self-curable copolymer containing and the organic solvent is disclosed. The self-curing copolymer obtained by the technology disclosed therein can be used in the polymerization stage to achieve a desired molecular weight range, such as mercaptopropionic acid, mercaptopropionic acid ester, thioglycol, thioglycerin, dodecyl. It is said that known molecular weight regulators such as mercaptans and α-methylstyrene dimers can be used. However, in the technique disclosed therein, since a bifunctional or higher functional vinyl compound having a plurality of vinyl groups is not added at the time of polymerization, only one or less end groups derived from a molecular weight regulator can be introduced into the polymer chain. It was not possible, and there was a disadvantage that the function derived from the terminal group could not be sufficiently imparted. Furthermore, although the self-curable copolymer obtained by the technique disclosed therein forms a thermosetting resin composition in a resin composition with an epoxy resin, there is a curing reaction with the acrylate resin. Since it did not occur, there was a drawback that the strength and heat resistance of the blended resin composition were lowered.

Japanese Patent Publication No.49-13212 Japanese Patent Publication No.51-34433 Japanese Patent Publication No.54-27394 JP 2008-247978 A JP-A-57-167340 JP 2002-121228 A JP 2009-1770 A

  Therefore, it has excellent optical properties such as low color dispersion and high light transmittance, has a good balance of properties such as low water absorption, moldability and heat resistance, and optical properties under severe actual use conditions such as wet heat conditions. So far, there has been no soluble polyfunctional (meth) acrylic acid ester copolymer with improved precision transferability of the mold shape, and a curable resin composition using the copolymer.

  The present invention has excellent optical characteristics such as low color dispersion and high light transmittance, and various characteristic balances required for optical lens / prism materials in advanced technical fields such as low water absorption, processability and heat resistance. Polyfunctional (meth) acrylic acid ester copolymer with improved optical properties and adhesion to inorganic materials under harsh actual use conditions such as wet heat conditions and curable resin composition containing the same An object is to provide a cured product, a cured product, and an optical article.

  The present invention relates to monofunctional (meth) acrylic acid ester (a), bifunctional (meth) acrylic acid ester (b), 2,4-diphenyl-4-methyl-1-pentene (c) having an alicyclic structure. And a copolymer obtained by copolymerizing a component containing a thiol compound (d) having a reactive (meth) acrylate group derived from a bifunctional (meth) acrylic acid ester (b) in the side chain , A copolymer having structural units derived from 2,4-diphenyl-4-methyl-1-pentene (c) and thiol compound (d) at the end, having a weight average molecular weight of 2000 to 60000, and further toluene, It is a soluble polyfunctional (meth) acrylate copolymer that is soluble in xylene, tetrahydrofuran, dichloroethane, or chloroform.

  Examples of the monofunctional (meth) acrylic acid ester (a) having an alicyclic structure include isobornyl methacrylate, isobornyl acrylate, cyclohexyl methacrylate, cyclohexyl acrylate, dicyclopentenyl acrylate, and dicyclopentenyloxyethyl. One or more monofunctional (meta) selected from the group consisting of acrylate, dicyclopentanyl acrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentenyloxyethyl methacrylate, and dicyclopentanyl methacrylate ) Acrylic acid esters.

  The bifunctional (meth) acrylic acid ester (b) is at least one selected from the group consisting of cyclohexanedimethanol diacrylate, cyclohexanedimethanol dimethacrylate, dimethylol tricyclodecane diacrylate and dimethylol tricyclodecane dimethacrylate. The bifunctional (meth) acrylic acid ester is mentioned.

  The present invention also relates to a monofunctional (meth) acrylic acid ester (a) having a cycloaliphatic structure, a bifunctional (meth) acrylic acid ester (b), 2,4-diphenyl-4-methyl-1-pentene ( It is a method for producing the above-mentioned soluble polyfunctional (meth) acrylic acid ester copolymer, wherein a component containing c) and a thiol compound (d) is copolymerized.

  The present invention also provides: (A) component: soluble polyfunctional (meth) acrylic acid ester copolymer according to claim 1, (B) component: polyfunctional (meth) acrylate, and (C) component: An amount of the component (B) is 5 to 250 parts by weight with respect to 100 parts by weight of the component (A), and the amount of the component (C) is A) It is 0.1-10 weight part with respect to a total of 100 weight part of the compounding quantity of a component, It is a curable resin composition characterized by the above-mentioned.

  Furthermore, the present invention is a resin cured product obtained by curing the above curable resin composition, and an optical material formed from the resin cured product. Here, the optical material includes an optical plastic lens.

  The present invention has excellent optical characteristics such as low color dispersion and high light transmittance, and various characteristic balances required for optical lens / prism materials in advanced technical fields such as low water absorption, processability and heat resistance. In addition, it is possible to obtain a material having improved optical properties under severe use conditions such as wet heat conditions and improved adhesion to inorganic materials. Such an optical material is suitably used in fields centering on the imaging field such as an imaging device that requires high optical characteristics.

  Hereinafter, the soluble polyfunctional (meth) acrylic acid ester copolymer of the present invention will be described in detail. This soluble polyfunctional (meth) acrylic acid ester copolymer has an alicyclic structure and a structural unit derived from 2,4-diphenyl-4-methyl-1-pentene and a thiol compound at the terminal. Hereinafter, this soluble polyfunctional (meth) acrylic acid ester copolymer may be abbreviated as a copolymer.

  The copolymer of the present invention comprises a monomer containing a monofunctional (meth) acrylic acid ester (a) and a bifunctional (meth) acrylic acid ester (b) having an alicyclic structure, and 2,4-diphenyl-4 -Copolymer obtained by copolymerization in the presence of methyl-1-pentene (c) and thiol compound (d), and the reactivity derived from the bifunctional (meth) acrylic acid ester (b) in the side chain And a polyfunctional (meth) acrylic acid having a structural unit derived from 2,4-diphenyl-4-methyl-1-pentene (c) and a thiol compound (d) at the terminal It is an ester copolymer. Here, soluble means that it is soluble in toluene, xylene, tetrahydrofuran, dichloroethane or chloroform. The solubility test is performed under the conditions shown in the examples.

  The chain structure of the copolymer is mainly obtained by copolymerizing a monofunctional (meth) acrylate and a bifunctional (meth) acrylate, and thus has a branched structure or a crosslinked structure. The abundance is limited to the extent that it is soluble. Accordingly, the copolymer has a structural unit (b1) containing an unreacted (meth) acryl group derived from the bifunctional (meth) acrylic acid ester (b) in the side chain. This unreacted (meth) acrylic group is also referred to as a pendant (meth) acrylic group, and since this exhibits polymerizability, it can be polymerized by a further polymerization treatment to give a solvent-insoluble cured resin.

  Further, the copolymer has a structural unit derived from 2,4-diphenyl-4-methyl-1-pentene (c) and a thiol compound (d) at the terminal. By introducing this structural unit at the end of the copolymer, moldability such as releasability is improved, the coefficient of linear expansion advantageous for adhesion to inorganic materials is low, and further, heat discoloration and weight loss are reduced. A cured product having excellent heat resistance can be obtained.

  The copolymer is a structural unit derived from a monofunctional (meth) acrylic acid ester (a) having an alicyclic structure, a structural unit derived from a bifunctional (meth) acrylic acid ester (b), 2,4-diphenyl It has a structural unit derived from -4-methyl-1-pentene (c) and a thiol compound (d). Here, in the structural unit derived from the bifunctional (meth) acrylic acid ester (b), both polymerizable double bonds (referred to as vinyl groups) contained in the two (meth) acrylic groups are involved in the polymerization. A structural unit (b2) which forms a branched structure or a crosslinked structure, and a structural unit containing an unreacted (meth) acrylic group in which only one vinyl group is involved in the polymerization and the other vinyl groups remain unreacted ( b1). 2,4-diphenyl-4-methyl-1-pentene (c) and thiol compound (d) act as a chain transfer agent to prevent an increase in molecular weight, and are present at the end of the copolymer.

The amount of 2,4-diphenyl-4-methyl-1-pentene (c) and thiol compound (d) introduced into the copolymer is 0. As the molar fraction M _cd represented by the following formula (1). It is 02 to 0.35, preferably 0.03 to 0.30, particularly preferably 0.08 to 0.27.
M _cd = (c) + (d) / [(a) + (b) + (c) + (d)] (1)
Here, (a), (b), (c) and (d) are structural units derived from a monofunctional (meth) acrylic acid ester (a) having an alicyclic structure (a) and a bifunctional (meth) acrylic acid ester. The number of moles of the structural unit derived from (b), the structural unit derived from 2,4-diphenyl-4-methyl-1-pentene (c) and the thiol compound (d) is shown. By introducing a structural unit derived from 2,4-diphenyl-4-methyl-1-pentene (c) and thiol compound (d) into the above range at the terminal of the copolymer, heat resistance, releasability and low water absorption Etc. can be improved.

In addition, the ratio of 2,4-diphenyl-4-methyl-1-pentene (c) to thiol compound (d) (2,4-diphenyl-4-methyl-1-pentene (c) is 5 to 50%. In particular, the ratio is preferably 10 to 30%, where the ratio is calculated by the following equation.
(C) / [(c) + (d)]

  The bifunctional (meth) acrylic acid ester (b) causes the copolymer to branch or crosslink, and also generates a pendant vinyl group, imparts curability to the copolymer, and provides heat resistance during curing. It plays an important role as an ingredient.

  Bifunctional (meth) acrylic acid esters include cyclohexane dimethanol diacrylate, dimethylol tricyclodecane diacrylate, cyclohexane dimethanol dimethacrylate, dimethylol tricyclodecane dimethacrylate, ethylene glycol diacrylate, propylene glycol diacrylate, 1 , 4-butanediol diacrylate, hexanediol diacrylate, diethylene glycol diacrylate, ethylene glycol diacrylate, propylene glycol diacrylate, 1,4-butanediol dimethacrylate, hexanediol dimethacrylate, diethylene glycol dimethacrylate, etc. ) Acrylic acid esters can be used, but are not limited thereto.

  Preferable specific examples of the bifunctional (meth) acrylic acid ester include cyclohexanedimethanol diacrylate, cyclohexanedimethanol dimethacrylate, and dimethylol tricyclo in terms of cost, ease of polymerization control, and heat resistance of the obtained polymer. Decane diacrylate or dimethylol tricyclodecane dimethacrylate is preferably used.

The copolymer has a structural unit (b1) containing a reactive (meth) acrylate group derived from a bifunctional (meth) acrylic acid ester (b) in the side chain, but the structural unit represented by the formula (2) The molar fraction M _b1 of (b1) is preferably 0.05 or more, preferably 0.1 to 0.7, and more preferably 0.3 to 0.5.
M _b1 = (b1) / [(a) + (b)] (2)
Here, (a) and (b) in the formula are structural units derived from a monofunctional (meth) acrylic acid ester (a) having an alicyclic structure and a bifunctional (meth) acrylic acid ester ( The number of moles of the structural unit derived from b) is shown. (B1) in the formula represents the number of moles of the structural unit (b1) containing a (meth) acrylate group. By satisfying the molar fraction, a molded article having excellent curability with light and heat and excellent in heat resistance and mechanical properties after curing can be obtained.

  The monofunctional (meth) acrylic acid ester (a) having an alicyclic structure is important for improving the solvent solubility, low water absorption, heat resistance, optical properties and processability of the copolymer. Monofunctional (meth) acrylic acid esters having such an alicyclic structure include isobornyl methacrylate, isobornyl acrylate, cyclohexyl methacrylate, cyclohexyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate. One or more cycloaliphatic structures selected from the group consisting of a dirate, dicyclopentanyl acrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentenyloxyethyl methacrylate, and dicyclopentanyl methacrylate. Examples of the monofunctional (meth) acrylic acid ester may include, but are not limited thereto. By introducing structural units derived from these components into the copolymer, not only can the gelation of the copolymer be prevented and the solubility in the solvent can be increased, but also the low color dispersion of the copolymer. The optical properties such as properties, low water absorption, and heat resistance can be improved.

  Preferable specific examples include isobornyl methacrylate, isobornyl acrylate, cyclohexyl methacrylate, cyclohexyl acrylate, dicyclopentenyl acrylate, dicyclopropylene in terms of cost, prevention of gelation and moldability of the resulting polymer. One or more alicyclic rings selected from the group consisting of pentenyloxyethyl acrylate, dicyclopentanyl acrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentenyloxyethyl methacrylate and dicyclopentanyl methacrylate Mention may be made of monofunctional (meth) acrylic acid esters having the formula structure.

  2,4-diphenyl-4-methyl-1-pentene (c) and the thiol compound (d) function as a chain transfer agent and control the molecular weight of the copolymer. The molecular weight of the copolymer of the present invention is in the range of 2000 to 60000, preferably 3000 to 50000, as the weight average molecular weight Mw. By using a copolymer having a relatively low molecular weight, the moldability and releasability of the cured resin are enhanced.

  The thiol compound (d) may be any thiol compound known to act as a chain transfer agent, but preferably t-dodecyl mercaptan, n-butyl mercaptan, isobutyl mercaptan, n-octyl mercaptan, n- And dodecyl mercaptan and t-butyl mercaptan.

  Furthermore, a monofunctional (meth) acrylic acid ester having no alicyclic structure can be added as the component (e) for the purpose of improving the solvent solubility and processability of the copolymer. Examples of such (meth) acrylic acid esters include methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-methylhexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, 2-hydroxyethyl methacrylate, and the like. Among them, methyl methacrylate and n-butyl acrylate are preferable. These (meth) acrylic acid ester monomers may be used alone or in combination of two or more. However, one or more kinds selected from the group consisting of methyl methacrylate, methyl acrylate and n-butyl acrylate ( Most preferred is a (meth) acrylic ester.

  In addition, the structural unit derived from these other monomer components (e) is preferably within a range of less than 30 mol% with respect to the total amount of structural units derived from the monomer component (a).

  From another point of view, the soluble polyfunctional (meth) acrylic acid ester copolymer of the present invention has a structural unit derived from a monofunctional (meth) acrylic acid ester (a) having an alicyclic structure and bifunctional ( When the sum of the structural units derived from the (meth) acrylate ester (b) is 100 mol%, the structural unit derived from (a) may be 10 to 60 mol%, preferably 15 to 50 mol%. is there. The structural unit derived from (b) may be 40 to 90 mol%, preferably 50 to 85 mol%, more preferably 50 to 80 mol%. If the structural unit derived from (b) is less than 10 mol%, the heat resistance of the cured product is insufficient, and if it exceeds 60 mol%, the molding processability is lowered, and the strength of the molded product is remarkably lowered. .

  The soluble polyfunctional aromatic (meth) acrylic acid ester copolymer of the present invention comprises monofunctional (meth) acrylic acid ester (a), bifunctional (meth) acrylic acid ester (b) and 2 having an alicyclic structure. 2,4-diphenyl-4-methyl-1-pentene (c) and thiol compound (d) with respect to 100 moles of monomer, 2,4-diphenyl-4-methyl-1-pentene (c) and thiol compound It is obtained by polymerizing a monomer containing 2 to 120 mol of (d) at a temperature of 50 to 200 ° C. Here, 2,4-diphenyl-4-methyl-1-pentene (c) and thiol compound (d) are known compounds as chain transfer agents, but in the present invention, the amount used is a chain transfer agent. It becomes a part of the monomer component because it is larger than the amount used. The amount of 2,4-diphenyl-4-methyl-1-pentene (c) and the thiol compound (d) used is 2,2 contained in the soluble polyfunctional aromatic (meth) acrylic acid ester copolymer of the present invention. Although the molar fraction of the structural unit derived from 4-diphenyl-4-methyl-1-pentene (c) and the thiol compound (d) is adjusted to be in the range of 0.02 to 0.35, this is a reaction. It can be used in excess of the theoretical amount because it has low properties and may remain unreacted. Therefore, it is used in the range of 2 to 120 mol with respect to 100 mol of the monomer, preferably 20 to 100 mol, and more preferably 50 to 80 mol.

  From the viewpoint that 2,4-diphenyl-4-methyl-1-pentene (c) and thiol compound (d) also function as a chain transfer agent, the amount used is limited to the crosslinking reaction, pendant (meth) acrylate. From the viewpoint of group generation and control of molecular weight distribution, it is preferably within the range of 10 to 500 parts by weight, with respect to 100 parts by weight of the bifunctional (meth) acrylic acid ester (b), More desirably, it is within the range. Most preferably, it is in the range of 90 to 110 parts by weight.

  The amount of the mono (meth) acrylic acid ester (a) having an alicyclic structure is selected from the monofunctional (meth) acrylic acid ester (a) and the bifunctional (meth) acrylic acid ester (b) having an alicyclic structure. It is good to set it as 10-60 mol% with respect to a total of 100 mol, Preferably it is 15-50 mol%. The usage-amount of bifunctional (meth) acrylic acid ester (b) is good to set it as 40-90 mol%, Preferably it is 50-85 mol%, More preferably, it is 50-80 mol%.

  In the production of the copolymer of the present invention, a radical polymerization initiator may be added when the initiation reaction rate due to the thermal initiation reaction is low. In this case, the radical polymerization initiator used includes organic peroxides such as ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxycarbonates and peroxyesters. Examples thereof include oxide-based polymerization initiators and azo-based polymerization initiators. The amount of these radical polymerization initiators used is not particularly limited, but it is usually preferably 0.01 to 25 parts by weight based on 100 parts by weight of the total amount of monomer components. More preferably, it is in the range of 0.05 to 20 parts by weight. Most preferably, it is in the range of 0.1 to 15 parts by weight.

  The polymerization reaction can be basically carried out by bulk polymerization without using a solvent, but is carried out in one or more organic solvents that dissolve the soluble polyfunctional (meth) acrylate aromatic copolymer to be formed. You can also. The organic solvent is a compound that does not essentially inhibit radical polymerization, and dissolves the chain transfer agent, initiator, monomer, and polyfunctional (meth) acrylate aromatic copolymer of the present invention, and is homogeneous. If it forms a solution, it can be used without particular limitation.

  Compounds that can be used as organic solvents include aromatic hydrocarbons, straight chain aliphatic hydrocarbons, branched aliphatic hydrocarbons, cycloaliphatic hydrocarbons, paraffin oil obtained by hydrorefining petroleum fractions. Etc. Of these, toluene, xylene, methylcyclohexane and ethylcyclohexane are preferred from the viewpoints of the balance between polymerizability and solubility and easy availability.

  These compounds as organic solvents are used alone or in combination of two or more. There is no restriction | limiting in particular in the usage-amount of a solvent.

  During the production of the copolymer of the present invention, the polymerization is carried out in the temperature range of 50 to 200 ° C. If the polymerization reaction is carried out at a temperature lower than 50 ° C., the polymerization rate will be low, which is not preferable from the viewpoint of industrial implementation. This is not preferable because an insoluble gel is easily generated.

  The method for recovering the copolymer after the termination of the polymerization reaction is not particularly limited, and for example, a commonly used method such as a heating / vacuum devolatilization method, a steam stripping method, or precipitation with a poor solvent may be used.

  The soluble polyfunctional (meth) acrylic acid ester copolymer of the present invention is soluble in at least one solvent selected from toluene, xylene, THF, dichloroethane, dichloromethane and chloroform. Preferably, it is soluble in all of the above solvents. Here, the term “soluble” means that 1 g or more, preferably 10 g or more, is dissolved in 100 ml of solvent at room temperature (25 ° C.). And, it is desirable that no gel formation is observed after dissolution.

  Next, the curable resin composition of this invention and each component mix | blended with this are demonstrated in detail. The curable resin composition of the present invention includes components (A) to (C), and the soluble polyfunctional (meth) acrylic acid ester copolymer is used as the component (A).

  As the component (B), polyfunctional (meth) acrylate is used. The polyfunctional (meth) acrylate has two or more (meth) acryloyl groups in the molecule, and one or more are used. When these polyfunctional acrylates used as the component (B) are used in combination with the component (A), in addition to heat resistance, optical properties such as low color dispersion and high light transmittance are simultaneously improved.

  The polyfunctional (meth) acrylate is preferably copolymerizable with the component (A), such as 1,4-butanediol di (meth) acrylate and 1,6-hexanediol di (meth) acrylate. 1,9-nonanediol di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, bisphenol A polypropoxy di (meth) acrylate, bisphenol F polyethoxydi (meth) acrylate, ethylene Glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol Tetral (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyethylene glycol di (meth) acrylate, tris (acryloxyethyl) isocyanurate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, di Pentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, hydroxypentylglycol dipentaglycol di (meth) acrylate, and ε-caprolactone Adduct di (meth) acrylate (for example, KAYARAD HX-220, HX-620, etc., manufactured by Nippon Kayaku Co., Ltd.), trimethylo Rupuropantori (meth) acrylate, trimethylolpropane polyethoxy tri (meth) acrylate, and ditrimethylolpropane tetra (meth) monomers such as acrylates. Particularly preferred are 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, and pentaerythritol tri (meth) acrylate.

  Moreover, in this invention, 1 or more types of monofunctional (meth) acrylate which has one (meth) acryloyl group in a molecule | numerator can also be used as another copolymerization component (D). These monofunctional (meth) acrylates can be used synergistically with the component (A) to simultaneously improve optical properties such as low color dispersion and high light transmittance, and improve moldability by increasing fluidity. Can be made. As a usage-amount, it is 0-40 weight part with respect to 100 weight part of (A) component, Preferably it is 0-20 weight part. If the amount used is large, the fluidity becomes too high, and molding defects such as burrs and moles are likely to occur, which is not preferable.

  As the monofunctional functional (meth) acrylate that can be used as the copolymer component (D), a monofunctional (meth) acrylate having an alicyclic structure used for producing the copolymer as the component (A) ( The (meth) acrylic acid ester (a) is preferably used, but other examples include acryloylmorpholine, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and polyethylene. Glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, cyclohexane-1,4-dimethanol mono (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, phenyl polyethoxy (meth) Acrylate, -Hydroxy-3-phenyloxypropyl (meth) acrylate, o-phenylphenol monoethoxy (meth) acrylate, o-phenylphenol polyethoxy (meth) acrylate, p-cumylphenoxyethyl (meth) acrylate, isobornyl (meth) Examples include acrylate, tribromophenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentenyloxyethyl (meth) acrylate.

Next, the component (C) will be described.
Examples of the photopolymerization initiator (C) include benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, and benzoin isobutyl ether; acetophenone, 2,2-diethoxy-2-phenylacetophenone, 2, 2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-phenylpropan-1-one, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4 Acetophenones such as-(methylthio) phenyl] -2-morpholinopropan-1-one; 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 2-chloroanthraquinone, 2-amylanthraquinone Any anthraquinones; thioxanthones such as 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; benzophenone, 4-benzoyl-4′-methyldiphenyl Benzophenones such as sulfide and 4,4′-bismethylaminobenzophenone; phosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide Can be mentioned.

  These can be used alone or as a mixture of two or more thereof, and further, tertiary amines such as triethanolamine and methyldiethanolamine, N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester Can be used in combination with an accelerator such as a benzoic acid derivative.

  Although the curable resin composition of this invention contains the said (A) component, (B) component, and (C) component, the content rate is as follows. (B) The compounding quantity of a component is 5-250 weight part with respect to 100 weight part of (A) component, Preferably it is 20-100 weight part. The amount of component (C) is 0.1 to 10 parts by weight, preferably 1.0 to 5 parts by weight, based on 100 parts by weight of the total amount of components (B) and (A).

  From another point of view, in the curable resin composition, (A) component: 30 to 89 wt%, (B) component: 10 to 70 wt%, and (A) component and (B) component total (C) Component: It is good to contain 0.1-10 wt%. More preferably, (A) component: 35-80 wt%, (B) component: 10-40 wt%. With the blending ratio of the component (A), the component (B) and the component (C) within the above range, the moldability, heat resistance, and optical properties that are synergistically seen in the mold release property and curability. The property balance is improved. Moreover, when there are too few (C) components, it will be easy to produce insufficient hardening, heat resistance and light resistance will fall, and when too large, mechanical strength will fall or heat resistance will fall. In addition, when an organic solvent and a filler are included in the curable resin composition, the content is calculated excluding these.

  In addition, the curable resin composition of the present invention includes a polymerization inhibitor, an antioxidant, a release agent, a photosensitizer, an organic solvent, a silane coupling agent, a leveling agent, an antifoaming agent, and an antistatic agent as necessary. Furthermore, ultraviolet absorbers, light stabilizers, various inorganic and organic fillers, fungicides, antibacterial agents, and the like can be added to the curable resin composition of the present invention to impart desired functionality, respectively. is there.

  The curable resin composition of this invention can be obtained by mixing the said (A) component, (B) component, (C) component, and another component as needed in arbitrary orders. The curable resin composition of the present invention is stable over time.

The curable resin composition of this invention can obtain hardened | cured material by irradiating active energy rays, such as an ultraviolet-ray. Here, specific examples of the light source used for curing by irradiating with active energy rays include, for example, a xenon lamp, a carbon arc, a germicidal lamp, a fluorescent lamp for ultraviolet rays, a high pressure mercury lamp for copying, a medium pressure mercury lamp, and a high pressure mercury lamp. An ultra high pressure mercury lamp, an electrodeless lamp, a metal halide lamp, or an electron beam using a scanning type or curtain type electron beam acceleration path can be used. Moreover, when hardening | curing the curable resin composition of this invention by ultraviolet irradiation, the ultraviolet irradiation amount required for hardening may be about 300-20000 mJ / cm < ² >. In order to sufficiently cure the resin composition, it is desirable to irradiate active energy rays such as ultraviolet rays in an inert gas atmosphere such as nitrogen gas.

  The curable resin composition of the present invention can be used for castings such as plastic lenses. As a method for producing a plastic lens using the resin composition of the present invention, a mold made of a gasket made of polyvinyl chloride, an ethylene vinyl acetate copolymer or the like and two glass molds having a desired shape is prepared. There is a method in which after the resin composition of the present invention is injected, the resin composition is cured by irradiating active energy rays such as ultraviolet rays, and the cured product is peeled off from the mold.

  Moreover, as a method of apply | coating the curable resin composition of this invention to a film-form base material as a resin composition for prism lens sheets, various methods well-known in the industry can be used. As a specific method, for example, a resin composition is coated on a mold having a prism lens shape on the surface, a resin composition layer is provided, and a colorless and transparent film-like substrate is formed on the resin composition layer. A material (for example, polyvinyl chloride, polystyrene, polycarbonate, poly (meth) acrylate, polyester, polyethylene terephthalate, etc.) is pressure-bonded so that bubbles do not enter, and then in that state, ultraviolet light is used from the film-like substrate side using a high-pressure mercury lamp. The film-like base material on which the prism lens-like resin layer is formed can be peeled off from the mold after curing the resin composition layer.

  The refractive index of the cured product of the resin composition of the present invention obtained by irradiating active energy rays such as ultraviolet rays is preferably 1.50 or more at 25 ° C., more preferably 1.52 or more at 25 ° C. is there. In particular, when a prism lens sheet is produced with the resin composition of the present invention, if the refractive index of the cured product is less than 1.50 at 25 ° C., there may be a problem that sufficient front luminance cannot be secured. Further, the Abbe number of the cured product (a numerical value specific to a substance that defines the property of changing the refractive index depending on the wavelength of light) is preferably 40.0 or more, and more preferably 50.0 or more. If the Abbe number of the cured product is less than 40.0, chromatic aberration is large and color blurring occurs, which is not preferable.

  A cured resin obtained by molding and curing the curable resin composition of the present invention is excellent as an optical material. In particular, it is useful as a material for optical plastic lenses such as prism lens sheets, Fresnel lenses, lenticular lenses, spectacle lenses, and aspheric lenses. And such a lens is used advantageously for an imaging device. In addition, the curable resin composition or the cured resin can also be used for optical electronics, optical fiber, optical waveguide and other optoelectronic applications, printing inks, paints, clear coating agents, glossy varnishes, and the like.

  EXAMPLES Next, the present invention will be described with reference to examples, but the present invention is not limited thereto. In addition, all the parts in each example are parts by weight unless otherwise specified. Moreover, the measurement of the softening temperature etc. in an Example performed sample preparation and a measurement with the method shown below.

(Measurement of physical properties of copolymer and its cured product)
1) Molecular weight and molecular weight distribution of polymer GPC (manufactured by Tosoh Corporation, HLC-8120GPC) was used for measuring the molecular weight and molecular weight distribution of the soluble polyfunctional (meth) acrylic acid ester copolymer, solvent: tetrahydrofuran (THF), flow rate: 1 0.0 ml / min, column temperature: 40 ° C. The molecular weight of the copolymer was measured as a molecular weight in terms of polystyrene using a calibration curve with monodisperse polystyrene.

2) Polymer structure It was determined by 13C-NMR and 1H-NMR analysis using a JNM-LA600 type nuclear magnetic resonance spectrometer manufactured by JEOL. Chloroform-d1 was used as a solvent, and the tetramethylsilane resonance line was used as an internal standard.

3) Sample preparation and measurement of glass transition temperature (Tg) and softening temperature measurement A soluble polyfunctional (meth) acrylic acid ester copolymer solution was uniformly applied to a glass substrate so that the thickness after drying was 20 μm. Then, it heated at 90 degreeC for 30 minutes using the hotplate, and was made to dry. The obtained resin film on the glass substrate is set in a TMA (thermomechanical analyzer) measuring device together with the glass substrate, heated to 220 ° C. at a temperature rising rate of 10 ° C./min under a nitrogen stream, and further 220 ° C. The resin was cured by heating for 20 minutes (this cured product is referred to as a sample). After allowing the glass substrate to cool to room temperature, the measurement probe is brought into contact with the sample in the TMA measuring apparatus, and measurement is performed by scanning from 30 ° C. to 360 ° C. at a temperature rising rate of 10 ° C./min under a nitrogen stream. The softening temperature was determined by the tangential method. If the probe does not penetrate the resin film due to the heat resistance of the sample and does not show a probe penetration depth smaller than the film thickness, in addition to the softening temperature, the penetration rate for the probe penetration temperature and film thickness is expressed as a percentage. displayed.

4) Measurement of thermal weight loss and heat discoloration resistance The measurement of the thermal decomposition temperature and heat discoloration of the soluble polyfunctional (meth) acrylic acid ester copolymer is carried out by setting the sample in a TGA (thermobalance) measuring device and nitrogen. Measurement is performed by scanning from 30 ° C to 320 ° C at a heating rate of 10 ° C / min under an air flow, and the amount of weight loss at 300 ° C is obtained, and the amount of discoloration of the sample after measurement is visually confirmed. , ：: no thermal discoloration, ○: pale yellow, Δ: brown, x: black, and the heat discoloration was evaluated.

5) Measurement of water absorption The weight of a sample vacuum-dried at 60 ° C. for 24 hours is defined as Wo, and is weighed on a scale capable of measuring up to ± 0.1 mg. The temperature is 85 ° C. and the relative humidity is 85%. Humidification was performed for 1 week in a wet tank. After humidification, water attached to the test sample was wiped off, and the sample was weighed with a scale capable of measuring up to ± 0.1 mg. The water absorption was calculated by the following formula (3). Three identical test samples were prepared and tested in the same manner.
Wo / W × 100 = water absorption (3)

6) Measurement of solvent resistance and measurement of solvent solubility The solvent resistance of the soluble polyfunctional (meth) acrylic acid ester copolymer was measured by subjecting the copolymer to vacuum press molding at 200 ° C for one hour. Was immersed in toluene at room temperature for 10 minutes, and the changes in the sample after immersion were confirmed visually, and the solvent resistance was evaluated by classifying as follows: ○: No change, Δ: Swelling, ×: Deformation and swelling. It was.
The solvent solubility was measured by adding 5 g of a soluble polyfunctional (meth) acrylic acid ester copolymer to 100 ml of solvent and observing the dissolution state after stirring at 25 ° C. for 10 minutes. When it was dissolved uniformly and the presence of undissolved matter and gel was not recognized, it was determined to be soluble.

7) Measurement of refractive index The synthesized soluble polyfunctional (meth) acrylic acid ester copolymer is dissolved in toluene, and perbutyl O is used as an initiator, and the soluble polyfunctional (meth) acrylic acid ester copolymer is 100 parts by weight. 1.0 part by weight was added. A cast sheet was prepared from the polymer solution, the cast sheet was crushed, pelletized, filled into a press mold, and cured with a press molding machine at 170 ° C. for 1 hour. The obtained cured parallel flat plate was used as a test piece, and the refractive index of d-line (587.6 nm) was measured with KPR-200 (manufactured by Shimadzu Carnew Co., Ltd.). The measurement timing was set immediately after molding for 1 week in a high-temperature high-humidifier with a moist heat condition of 85 ° C. × 85 RH. Moreover, the Abbe number was measured with the Abbe refractometer (Atago Co., Ltd.) using the same test piece.

8) Adhesion test A varnish obtained by diluting the copolymer with a solvent (methyl ethyl ketone) was coated on a glass substrate, dried at 80 ° C for 5 minutes, and then in an inert oven at 200 ° C under a nitrogen stream. Time curing was performed. Next, in accordance with JIS K 5400, the glass substrate on which the copolymer-cured coating film was placed was cut into 11 grids at 1 mm intervals on the surface of the coating film to form 100 grids. After the cellophane tape was brought into close contact with the surface, the number of cells that did not peel when peeled at a stretch was counted.

(Measurement of physical properties of composition)
(1) Measurement of refractive index In order to measure various physical properties of the resin composition, a silicon tape having a thickness of 1.0 mm and a width of 10 mm is used between two glass plates having a width of 60 mm, a length of 60 mm, and a thickness of 1.0 mm. The composition was poured into a glass mold in which a gap having a width of 50 mm and a length of 50 mm was formed and the outer periphery was wound and fixed with a polyimide tape. 1) Irradiate UV light for several seconds from one side of this glass mold with the above-mentioned high-pressure mercury lamp, or 2) Put this glass mold in an inert gas oven under a nitrogen gas stream and heat at 180 ° C. for 1 hour. Cured by The cured resin plate was removed from the glass mold to obtain Sample B. The refractive index and Abbe number of Sample B were measured with an Abbe refractometer (manufactured by Atago Co., Ltd.).
(2) Hue A flat plate having a thickness of 1.0 mm was measured with a color difference meter (trade name “MODEL TC-8600”, manufactured by Tokyo Denshoku Co., Ltd.), and the YI value was shown.
(3) Haze (turbidity) and total light transmittance A test piece having a thickness of 0.2 mm was prepared, and the Haze (turbidity) and total light transmittance were measured using an integrating sphere light transmittance measuring device (Nippon Denshoku). Measurement was performed using SZ-Σ90).

(4) Releasability Evaluation was made based on the degree of difficulty when the sample B used for measuring the refractive index was released from the glass mold.
○ ························································································································ 5 The surface shape and the surface shape of the glass mold were observed.
○ ····························································································································································································································· The degree of resin leakage into the glass mold clearance was evaluated.
B: The amount of burrs produced is less than 0.05 mm, and resin leakage into the glass mold clearance is less than 1.0 mm.
Δ: The amount of burrs generated is 0.05 mm or more and less than 0.2 mm. The resin leakage into the glass clearance is 1.0 mm or more and less than 3.0 mm.
× ··· Burr generation amount is 0.2 mm or more, and resin leakage into the glass mold clearance is 3.0 mm or more.

(7) Air bubbles: When the cured resin was released from the glass mold, evaluation was made based on the presence and size of air bubbles generated in the product portion of the molded product.
○ ··· Bubble formation is not observed.
Δ ··· Bubble formation was observed, and the size of the bubbles was less than 2% of the volume of the molded product.
X: Formation of bubbles was observed, and the size of the bubbles was 2% or more with respect to the volume of the molded product.
(8) Cracking: When the cured resin was released from the glass mold, it was evaluated based on the presence or absence of cracks and the degree of size generated in the product part of the molded product.
○ ··· No crack formation is observed.
Δ ······ Although crack formation is observed, crack occurrence is observed only at the corner of the outer peripheral portion of the molded product.
X: Although generation of cracks is observed, cracks are observed at locations other than the corners of the outer periphery of the molded product.

(7) Reflow heat resistance: Using Sample B, the spectral transmittance at a wavelength of 400 nm was measured with a spectrocolorimeter CM-3700d (manufactured by Konica Minolta). The measurement timing was before the heat resistance test after post-cure at 190 ° C. for 60 minutes and after the heat resistance test at 260 ° C. for 8 minutes in an air oven. The results of changes in spectral transmittance obtained by these measurements are shown in Table 3 below.
(8) Water absorption rate The weight of a test sample vacuum-dried at 60 ° C. for 24 hours using Sample B is defined as Wo, and weighed with a scale capable of measuring up to ± 0.1 mg. Temperature: 85 ° C., relative humidity : Humidification was performed for 1 week in an 85% constant temperature and humidity chamber. After humidification, water attached to the test sample was wiped off, and the sample was weighed with a scale capable of measuring up to ± 0.1 mg. The water absorption was calculated by the following formula (1). Three identical test samples were prepared and tested in the same manner.
Wo / W × 100 = water absorption (1)

Example 1
Dimethylol tricyclodecane diacrylate 1.6 mol (463.2 ml), dicyclopentanyl methacrylate 1.2 mol (254.2 ml), 1,4-butanediyl diacrylate 1.2 mol (226.3 ml), 2,4-diphenyl-4-methyl-1-pentene 0.4 mol (95.5 ml), t-dodecyl mercaptan 2.4 mol (564.8 ml) and toluene 600 ml were charged into a 3.0 L reactor. At 90 ° C., 40 mmol (11.5 g) of t-butylperoxy-2-ethylhexanoate was added and reacted for 2 hours and 45 minutes. After stopping the polymerization reaction by cooling, the reaction mixture was poured into a large amount of hexane at room temperature to precipitate a copolymer. The obtained copolymer was washed with hexane, filtered, dried and weighed to obtain 536.4 g of copolymer A (yield: 73.2 wt%).

Mw of the obtained copolymer A was 34200, Mn was 5620, and Mw / Mn was 6.1. By performing ¹³ C-NMR, ¹ H-NMR analysis and elemental analysis, the copolymer A contains 39.6 mol% of the structural unit (1) derived from dimethylol tricyclodecane diacrylate in total, and dicyclopentanyl. A total of 31.1 mol% of the structural unit (2) derived from methacrylate and 29.3 mol% of the structural unit (3) derived from 1,4-butanediol diacrylate were contained. Here, in the above calculation, the total of the structural unit derived from the monofunctional (meth) acrylic acid ester (a) having an alicyclic structure and the structural unit derived from the bifunctional (meth) acrylic acid ester (b) is 100 mol. It is calculated as a percentage.
The terminal group (4) having a structure derived from 2,4-diphenyl-4-methyl-1-pentene includes the structural units (1), (2) and (3), the terminal group (4) and t-dodecyl. It was present in an amount of 1.8 mol% with respect to the total number of terminal groups (5) having a structure derived from mercaptan (hereinafter referred to as the total amount of all structural units). On the other hand, the terminal group (5) was present in an amount of 7.2 mol% based on the total amount of all the structural units.
Moreover, the ratio of the pendant acrylate calculated by the said Formula (2) was 39.9 mol%.
Copolymer A was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was formed. The cast film of copolymer A was a transparent film without fogging.
Copolymer A was used as a cured sheet under various measurement conditions. The sample obtained by cutting out the cured sheet was measured for optical properties, water absorption, thermal weight loss, heat discoloration resistance and solvent resistance.
As a result, the linear expansion coefficient was 67 ppm / ° C., the water absorption rate was 0.48%, and the solvent resistance was ○.
Moreover, the softening temperature was 300 degreeC or more as a result of the TMA measurement. As a result of TGA measurement, the weight loss at 300 ° C. was 0.8 wt%, and the heat discoloration was ◎.
Furthermore, when the refractive index measurement of the copolymer A was performed, the refractive index after hardening (589 nm): 1.522 and the refractive index after the wet heat test (589 nm): 1.523.
Furthermore, when the number of cells remaining in the adhesion test was counted, it was confirmed that 100 cells remained on the substrate without being lost.

Example 2
Dimethylol tricyclodecane diacrylate 2.64 mol (764.3 ml), dicyclopentanyl acrylate 0.24 mol (47.2 ml), 1,4-butanediyl diacrylate 0.96 mol (181.0 ml), 2-hydroxypropyl acrylate 0.96 mol (118.5 ml), 2,4-diphenyl-4-methyl-1-pentene 0.48 mol (114.6 ml), t-dodecyl mercaptan 3.12 mol (734.3 ml) ), 720 ml of toluene was put into a 3.0 L reactor, 62 mmol (13.9 g) of t-butylperoxy-2-ethylhexanoate was added at 90 ° C., and the mixture was reacted for 2 hours and 30 minutes. After stopping the polymerization reaction by cooling, the reaction mixture was poured into a large amount of hexane at room temperature to precipitate a polymer. The obtained polymer was washed with hexane, filtered, dried and weighed to obtain 517.2 g of copolymer B (yield: 71.5 wt%).

Mw of the obtained copolymer B was 39500, Mn was 7240, and Mw / Mn was 5.5. By performing ¹³ C-NMR, ¹ H-NMR analysis, and elemental analysis, the copolymer B was found to have a total of 55.2 mol% of structural units (1) derived from dimethylol tricyclodecane diacrylate, and dicyclopentanyl. A total of 5.1 mol% of acrylate-derived structural units (2), 20.3 mol% of structural units (3) derived from 1,4-butanediol diacrylate, and structural units derived from 2-hydroxypropyl acrylate (6) Was 19.4 mol%. Further, the terminal group (4) having a structure derived from 2,4-diphenyl-4-methyl-1-pentene was present in an amount of 1.2 mol% based on the total amount of all the structural units.
On the other hand, the terminal group (5) having a structure derived from t-dodecyl mercaptan was present in an amount of 7.6 mol% based on the total amount of all the structural units.
Copolymer B was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was formed. Further, the cast film of the copolymer B was a transparent film without fogging.
Copolymer B was made into a cured sheet under various measurement conditions. The sample obtained by cutting out the cured sheet was measured for optical properties, water absorption, thermal weight loss, heat discoloration resistance and solvent resistance.
As a result, the linear expansion coefficient was 71 ppm / ° C., the water absorption rate was 0.76%, and the solvent resistance was ◯.
Moreover, the softening temperature was 300 degreeC or more as a result of the TMA measurement. As a result of TGA measurement, the weight loss at 300 ° C. was 0.92 wt%, and the heat discoloration was ◎.
Furthermore, when the refractive index measurement of the copolymer B was performed, the refractive index after hardening (589 nm): 1.507 and the refractive index after wet heat test (589 nm): 1.509.
Furthermore, when the number of cells remaining in the adhesion test was counted, it was confirmed that 100 cells remained on the substrate without being lost.

Examples 3-8 and Comparative Examples 1-4
Using various monofunctional (meth) acrylates and bifunctional acrylates, polymerization was carried out in the same manner as in Example 1 with the raw material compositions shown in Table 1, to obtain copolymers C to K.
Table 1 shows the amount of raw materials used in the reaction, and Table 2 shows the test results of the copolymer and its cured product. Unless otherwise specified, other reaction conditions and measurement conditions are the same as in Example 1. In Table 1, the amount of raw material used is expressed in terms of mole and weight (g), but the described format was mole / g. The molar fraction was calculated with the sum of the component (a) and the component (b) as 100.

Examples 9 to 11 and Comparative Examples 5 and 6
Each component was mix | blended in the ratio shown in Table 3 (a number is a weight part), and Adeka tab AO-60 0.1 weight part made from Adeka Co., Ltd. was added as a stabilizer, and the curable resin composition was obtained. Next, this curable resin composition was cured by the various test methods described above, and performance evaluation was performed. Table 4 shows the performance evaluation results.

Abbreviations used in the table are shown below.
DMTCD: dimethylol tricyclodecane diacrylate (bifunctional)
BDDA: 1,4-butanediol diacrylate (bifunctional)
DCPM: Dicyclopentanyl methacrylate (monofunctional)
DCPA: Dicyclopentanyl acrylate (monofunctional)
HOP-A: 2-hydroxypropyl acrylate (monofunctional)
αMSD: 2,4-diphenyl-4-methyl-1-pentene (c) component TDM: t-dodecyl mercaptan (d) component TMPTA: trimethylolpropane triacrylate (trifunctional)
TMP: Trimethylolpropane trimethacrylate (trifunctional)
CD536: Dioxolane diacrylate (bifunctional)
HPNDA: Neopentyl glycol diacrylate hydroxypivalate (bifunctional)
Perbutyl O: t-butyl peroxy-2-ethylhexanate (manufactured by NOF Corporation)
Perocta O: 1,1,3,3-tetramethylbutyl-peroxy-2-ethylhexanoate (manufactured by NOF Corporation)

Claims (8)

  Monofunctional (meth) acrylic acid ester (a) having bicyclic structure (a), bifunctional (meth) acrylic acid ester (b), 2,4-diphenyl-4-methyl-1-pentene (c) and thiol compound ( a copolymer obtained by copolymerizing a component containing d), having a reactive (meth) acrylate group derived from a bifunctional (meth) acrylic acid ester (b) in the side chain, and 2 at the end , 4-diphenyl-4-methyl-1-pentene (c) and a copolymer having structural units derived from the thiol compound (d), having a weight average molecular weight of 2000 to 60000, and further, toluene, xylene, tetrahydrofuran, A soluble polyfunctional (meth) acrylic acid ester copolymer that is soluble in dichloroethane or chloroform.   The monofunctional (meth) acrylic acid ester (a) having the alicyclic structure is formed by isobornyl methacrylate, isobornyl acrylate, cyclohexyl methacrylate, cyclohexyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate. One or more monofunctional (meth) compounds selected from the group consisting of a rate, dicyclopentanyl acrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentenyloxyethyl methacrylate, and dicyclopentanyl methacrylate The soluble polyfunctional (meth) acrylic acid ester copolymer according to claim 1, which is an acrylic acid ester.   The bifunctional (meth) acrylic acid ester (b) is one or more selected from the group consisting of cyclohexane dimethanol diacrylate, cyclohexane dimethanol dimethacrylate, dimethylol tricyclodecane diacrylate and dimethylol tricyclodecane dimethacrylate. The soluble polyfunctional (meth) acrylic acid ester copolymer according to claim 1 or 2, which is a bifunctional (meth) acrylic acid ester.   Monofunctional (meth) acrylic acid ester (a) having bicyclic structure (a), bifunctional (meth) acrylic acid ester (b), 2,4-diphenyl-4-methyl-1-pentene (c) and thiol compound ( The method for producing a soluble polyfunctional (meth) acrylic acid ester copolymer according to claim 1, wherein a component containing d) is copolymerized. (A) component: The soluble polyfunctional (meth) acrylic acid ester copolymer according to claim 1,
(B) component: polyfunctional (meth) acrylate, and (C) component: a composition containing an initiator, and the blending amount of component (B) is 5 to 100 parts by weight of component (A). 250 parts by weight and a curable resin characterized in that the blending amount of component (C) is 0.1 to 10 parts by weight with respect to 100 parts by weight in total of blending amounts of component (B) and component (A) Composition.   A cured resin obtained by curing the curable resin composition according to claim 5.   An optical material formed from the cured resin according to claim 6.   The optical material according to claim 7, wherein the optical material is an optical plastic lens.