JPWO2014157214A1 - Polyfunctional (meth) acrylic acid ester copolymer, curable resin composition and cured product thereof - Google Patents

Abstract

A polyfunctional (meth) acrylic acid ester copolymer that has excellent optical properties, does not deteriorate adhesion to inorganic materials even under long-term wet heat conditions, and can maintain high optical properties; A curable resin composition is provided. Monofunctional (meth) acrylic acid ester (a) generated from (meth) acrylic acid and alcohol having 9 to 30 carbon atoms, bifunctional represented by CH2 = CR-CO-O-R2-O-OC-CR = CH2 ( A copolymer obtained by copolymerizing a meth) acrylic acid ester (b) and monomers containing 2,4-diphenyl-4-methyl-1-pentene (c), wherein (b) A polyfunctional (meth) acrylic acid ester copolymer having a reactive (meth) acrylate group derived from, having a structural unit derived from (c) at the terminal, and being soluble in a solvent such as toluene.

Description

  The present invention has excellent optical properties such as optical isotropy and high light transmittance, heat resistance, and processability, and in addition, heat resistance and inorganic materials under severe actual use conditions such as wet heat conditions. The present invention relates to a curable resin composition having improved adhesion and a cured product thereof.

  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 acid ester, allyl compound And the like as typical monomers. 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.
On the other hand, the curable resin composition is useful as, for example, a machine part material, an electric / electronic part material, an automobile part material, a civil engineering building material, a molding material, or the like, and also used as a material for a paint or an adhesive. It is. Furthermore, when a hybrid member is combined with an inorganic base material, not only can the thermal expansion coefficient be lowered, but also the appearance of the resin composition and its cured product can be controlled by combining the refractive index of the inorganic substance and the resin. Since transparency can also be expressed, it is particularly useful as a material in electrical / electronic component materials and optical applications. For example, digital camera modules are being miniaturized, such as being mounted on mobile phones, and cost reduction is also required. Furthermore, needs for new applications such as in-vehicle cameras and barcode readers for home delivery companies are increasing. When applied to these applications, heat resistance during solder reflow during manufacturing is not only required, but also high heat resistance for long periods of time, low water absorption, etc. in consideration of high temperature exposure in summer during actual use, etc. Reliability is required.

  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 comprising 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 inactive 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 technique using the heterogeneous polymerizable monomer disclosed therein, the processability, heat resistance, high transparency, etc. required in the advanced optical application field In addition, a polymer and a curable resin composition having a balance of properties and improved optical properties under severe actual use conditions such as wet heat conditions and adhesion to inorganic materials have not been obtained.

  On the other hand, Patent Document 4 is obtained by copolymerizing a monovinyl aromatic compound and a bifunctional (meth) acrylate, and has a reactive (meth) acrylate group derived from a bifunctional (meth) acrylate 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 workability, and solvent solubility, it has practical restrictions that it cannot be used for optical lenses for low-color dispersion, and has improved adhesion to inorganic materials. It was not a material.

Furthermore, Patent Document 5 discloses a composition containing 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. Is disclosed. The MMA-based syrup composition disclosed therein is produced by using MMA or MMA and a vinyl copolymer copolymerizable therewith, a chain transfer agent in the presence of a polymerization initiator in an inert gas (for example, N It is disclosed that the polymerization is carried out at room temperature or under heat in a ₂ gas) atmosphere. Specific examples of the chain transfer agent are only sulfur compounds such as lauryl mercaptan, octyl ester of thioglycolic acid, thiocresol, thionaphthol, and benzyl mercaptan, and 2,4-diphenyl-4-methyl -1-pentene was not specifically disclosed. Furthermore, the presence of a terminal group derived from 2,4-diphenyl-4-methyl-1-pentene and a structural unit derived from a monofunctional (meth) acrylic ester synergistically leads to refractive index branching during wet heat. There was no suggestion that it could be suppressed. 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 also discloses the use of 2,4-diphenyl-4-methyl-1-pentene. However, the amount used was about several percent of comma as a normal chain transfer agent, and the product was also crosslinked and gelled and did 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. A thermosetting resin composition for a color filter comprising a self-curable copolymer and an 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 techniques disclosed in these, 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 this technique forms a thermosetting resin composition in a resin composition with an epoxy resin, a curing reaction does not occur with an acrylate resin. There was also a defect that the strength and heat resistance of the blended resin composition were lowered.

In order to solve these problems, Patent Document 8 discloses a soluble polyfunctional (meth) acrylic acid ester copolymer having an alicyclic structure. However, the technique disclosed therein has a drawback that the adhesion with an inorganic material is lowered in a long-term reliability test under a high temperature and high humidity condition.
Therefore, it has excellent optical properties such as optical isotropy and high light transmittance, has a balance of properties such as easy processability and heat resistance, and optical properties under severe actual use conditions such as long-term wet heat conditions. There has never been a curable resin composition with improved heat resistance and adhesion between inorganic materials.

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 JP 2011-127008 A

  The present invention has excellent optical properties such as optical isotropy and high light transmittance, and is excellent in various property balances required for optical materials in advanced technical fields such as easy processability and heat resistance. Even under harsh actual use conditions such as long-term wet heat conditions, adhesion to inorganic materials does not deteriorate, high optical properties are maintained, and new multifunctional functionality that combines controlled molecular weight distribution and solvent solubility ( It aims at providing the curable resin composition formed by mix | blending a (meth) acrylic acid ester copolymer, the said copolymer, and it.

The present invention relates to the following general formula (1)
CH ₂ = CR-COOR1 (1)
(Wherein R1 is a linear or branched hydrocarbon group having 9 to 30 carbon atoms, and the hydrocarbon group may contain an oxygen atom, a sulfur atom or a nitrogen-containing group. It is a methyl group.)
Monofunctional (meth) acrylic acid ester (a) represented by
The following general formula (2)
CH ₂ = CR-COO-R2-OOC-CR = CH ₂ (2)
(Wherein R2 is a hydrocarbon group having 2 to 30 carbon atoms, and the hydrocarbon group may contain an oxygen atom, a sulfur atom or a nitrogen-containing group. R is H or a methyl group.)
A bifunctional (meth) acrylic acid ester (b) represented by:
A copolymer obtained by copolymerizing monomers containing 2,4-diphenyl-4-methyl-1-pentene (c),
A structural unit derived from 2,4-diphenyl-4-methyl-1-pentene (c) having a reactive (meth) acrylate group derived from a bifunctional (meth) acrylic acid ester (b) in the side chain Having a weight average molecular weight of 10,000 to 1,000,000, and the molar fraction Mb of units derived from the component (b) in all acrylate units is a monofunctional (meth) acrylate (a) When the introduction amount (mole) of the unit derived from the unit derived from the unit derived from the bifunctional (meth) acrylic acid ester (b) is a and b, respectively, as b / (a + b), 0.01 to 0.5 Furthermore, it is a polyfunctional (meth) acrylate copolymer that is soluble in toluene, xylene, propylene glycol monomethyl ether acetate, tetrahydrofuran, dichloroethane, or chloroform.

  In the general formula (1), the present invention is such that R1 is a linear or branched fatty chain having 9 to 30 carbon atoms, or an ethylene glycol chain, or in the general formula (2) Wherein R2 is one or more of a linear aliphatic chain having 2 to 30 carbon atoms and an ethylene glycol chain, the polyfunctional (meth) acrylate copolymer described above, It is.

  Further, in the present invention, when the introduction amount (mol) of the reactive (meth) acrylate group-containing unit derived from the bifunctional (meth) acrylic acid ester (b) is b1, the molar fraction Mb1 of the unit is When b1 / (a + b) is 0.02 to 0.5, or the introduction amount (mol) of a unit derived from 2,4-diphenyl-4-methyl-1-pentene (c) is c, The polyfunctional (meth) acrylic acid ester copolymer described above, wherein the molar fraction Mc of the unit satisfies at least one of 0.005 to 0.3 as c / (a + b + c). It is a polymer.

  Furthermore, the present invention comprises a curable resin composition comprising the polyfunctional (meth) acrylic acid ester copolymer, a monomer having one or more functional groups having an unsaturated double bond, and an initiator. It is also an optical article obtained by curing and molding this curable resin composition.

  According to the present invention, it has excellent optical properties such as optical isotropy and high light transmittance, and in advanced technical fields such as low water absorption, processability and heat resistance, engineering members such as optical lenses / prisms and adhesive materials It is possible to provide a curable resin composition that is excellent in various property balances required in addition to the above, and that has improved optical properties and adhesion to inorganic materials under severe actual use conditions such as long-term wet heat conditions. .

  Hereinafter, the polyfunctional (meth) acrylic acid ester copolymer and the curable resin composition of the present invention will be described in detail.

  The polyfunctional (meth) acrylic acid ester copolymer of the present invention (hereinafter sometimes abbreviated as a copolymer) is composed of a monofunctional (meth) acrylic acid ester (a) and a bifunctional (meth) acrylic acid ester. A copolymer obtained by copolymerizing a monomer containing (b) and 2,4-diphenyl-4-methyl-1-pentene (c), wherein the side chain has a bifunctional (meta) ) Soluble multifunctional having a reactive (meth) acrylate group derived from an acrylate ester (b) and a structural unit derived from 2,4-diphenyl-4-methyl-1-pentene (c) at the terminal It is a (meth) acrylic acid ester copolymer. Here, the term “soluble” means soluble in toluene, xylene, propylene glycol monomethyl ether acetate (PGMEA), tetrahydrofuran, dichloroethane or chloroform. The solubility test is performed under the conditions shown in the examples. The monofunctional (meth) acrylic acid ester (a) is the component (a), the bifunctional (meth) acrylic acid ester (b) is the component (b), and 2,4-diphenyl-4-methyl-1-pentene. (C) is also referred to as component (c) or DMP.

  Since the copolymer is obtained by copolymerizing a monofunctional (meth) acrylic acid ester and a bifunctional (meth) acrylic acid ester, it has a branched structure or a crosslinked structure. 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.

  Moreover, a copolymer has the structural unit derived from (c) component in the terminal. By introducing this structural unit at the terminal of the copolymer, a cured product having improved moldability such as releasability can be obtained.

  The copolymer has a structural unit (a) derived from the component (a), a unit (b) derived from the component (b), and a structural unit (c) derived from the component (c). Here, in the structural unit (b) derived from the component (b), both of the polymerizable double bonds (referred to as vinyl groups) contained in the two (meth) acrylic acid esters are involved in the polymerization and are branched structures. Alternatively, the structural unit (b1) that forms a crosslinked structure and the unreacted (meth) acryl group in which only one vinyl group is involved in the polymerization and the other vinyl group remains unreacted. There is. The component (c) DMP acts as a chain transfer agent to prevent an increase in molecular weight and exists at the end of the copolymer. By introducing the structural unit derived from the component (c) into the above range at the end of the polymer, the releasability and the low water absorption can be improved. The component (c) is included in the monomers together with the components (a) to (b).

  The introduction amounts (moles) of the structural units (a), (b), (c), (b1) and (b2) into the copolymer are represented by a, b, c, b1 and b2, respectively. Are represented by Ma, Mb, Mc, Mb1 and Mb2, respectively.

The amount of the component (c) introduced into the copolymer is 0.005 to 0.3, preferably 0.01 to 0.25, particularly preferably as the molar fraction Mc represented by the following formula (4). 0.03 to 0.15.
Mc = c / (a + b + c) (4)

  Monofunctional (meth) acrylic acid ester (a) is important for improving the solvent solubility, low water absorption, heat resistance, optical properties and processability of the copolymer, especially for adhesion in long-term wet heat tests. is important. As such a monofunctional (meth) acrylic acid ester (a), a compound represented by the general formula (1) is used. In the formula, R 1 is a hydrocarbon group having 9 to 30 carbon atoms, and a hetero atom or group such as an oxygen atom, a nitrogen-containing group, or a sulfur atom may be present in the hydrocarbon group. In the case of a structure in which different atoms or groups may be present, it is preferably a structure in which these different atoms or groups are present between the carbon-carbon bonds constituting the hydrocarbon group. For example, it is a structure in which an oxygen atom or a sulfur atom exists as an ether bond or a thioether bond. Further, examples of the nitrogen-containing group include an amide group and an imide group.

R1 is preferably a linear chain having 9 to 30 carbon atoms, or a fatty chain having a partially branched structure, or a (meth) acrylic acid ester that is an ethylene glycol chain. Preferred is an alkylene chain represented by C _n H _2n , an ethylene oxide chain represented by (C ₂ H ₄ O) _n (n is a number of 1 or more), or a structure in which this alkylene chain and ethylene oxide chain are bonded. . In this case, H is bonded to one end. When the number of carbon atoms is 9 or more, the elastic modulus of the copolymer decreases, and the ratio of hydrocarbon groups to polar groups increases, so that the copolymer has excellent water resistance. Further, the linear and partially branched structure further reduces the elastic modulus and improves the adhesion. In addition, introduction of an ethylene glycol chain is preferable because flexibility is improved. Specifically, 2-ethylhexyl EO modified (n≈2) (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, methoxypolyethylene glycol # 400 acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.), Methoxy polyethylene glycol # 550 acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) and the like are preferred, and among these, fatty chains represented by 2-ethylhexyl EO-modified (n≈2) (meth) acrylate and ethylene Those having a glycol chain are particularly preferred.

  Further, as the monofunctional (meth) acrylic acid ester, in addition to the chain acrylic acid ester, other monofunctional (meth) acrylic acid ester (d) components may be used in combination. Thereby, other physical properties can be adjusted. In particular, a (meth) acrylic acid ester having a ring structure is preferable because the heat resistance, elastic modulus, solubility, refractive index, and the like can be adjusted according to the application. Specific examples of the monofunctional (meth) acrylic acid ester having a ring structure include isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl ( (Meth) acrylate, and dicyclopentanyloxyethyl (meth) acrylate, phenoxypolyethylene glycol acrylate, ethoxylated o-phenylphenol acrylate, and nonylphenol EO adduct acrylate.

  In addition, monofunctional (meth) acrylates having 8 or less carbon atoms may be used in combination, and as these (meth) acrylates, methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2 -Methylhexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate and the like. Moreover, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxy Although hexyl (meth) acrylate and partially ethoxylated 2-hydroxy (meth) acrylate can be used, methyl methacrylate, n-butyl acrylate and 2-hydroxyethyl methacrylate are preferred. These low molecular weight (meth) acrylic acid ester monomers may be used alone or in combination of two or more.

  The structural unit derived from these other monofunctional components (d) should be in the range of 60 mol% or less, particularly preferably 50 mol% or less, based on the total amount of structural units derived from the monofunctional component.

  Next, the bifunctional (meth) acrylic acid ester (b) branches or cross-links the copolymer, generates a pendant vinyl group, imparts curability to the copolymer, and develops heat resistance during curing. Plays an important role as a crosslinking component.

  As the bifunctional (meth) acrylic acid ester (b), a compound represented by the general formula (2) is used. In the formula, R2 is a hydrogenated group having 2 to 30 carbon atoms, preferably 9 to 30 carbon atoms, and a hetero atom or group such as an oxygen atom, a nitrogen-containing group, or a sulfur atom exists in a part of the hydrocarbon group. It is a structure that may be. These heteroatoms or groups and structures substituted with these are the same as R1 except that R2 is a divalent group having 2 to 30 carbon atoms.

  Examples of the bifunctional (meth) acrylic acid ester (b) represented by the general formula (2) include cyclohexane dimethanol diacrylate, dimethylol tricyclodecane diacrylate, cyclohexane dimethanol dimethacrylate, and dimethylol tricyclode Candimethacrylate, 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, Bifunctional (meth) acrylic acid esters such as hexanediol dimethacrylate and diethyleneglycol dimethacrylate can be used, However, it is not limited to these. In particular, from the viewpoint of reactivity, solubility, and heat resistance, a linear fatty chain having 9 to 30 carbon atoms or a (meth) acrylic acid ester that is an ethylene glycol chain is preferable. Specifically, 1,9-nonanediol di (meth) acrylate, 2-methyl-1,8-octanediol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate Tetradecane ethylene glycol di (meth) acrylate and 2-butyl-2-ethyl-1,3-propanediol di (meth) acrylate are preferable. In addition to the chain acrylate ester, the bifunctional (meth) acrylate ester having a ring structure is used in combination to adjust the heat resistance, elastic modulus, solubility, refractive index, etc. according to the application. I can do it. Specific examples of the bifunctional (meth) acrylic acid ester having a ring structure include dimethylol tricyclodecane di (meth) acrylate, bisphenol A / EO addition di (meth) acrylate, and bisphenol A / PO addition (meth) di. An acrylate etc. are mentioned.

The structural unit derived from the bifunctional (meth) acrylic acid ester (b) may include the structural unit (b1) and other structural units, but all the bifunctional (meth) acrylic acid esters (b) including these structural units. The molar fraction Mb calculated by the formula (5) of the derived structural unit (b) is 0.01 to 0.5, preferably 0.15 to 0.45.
Mb = b / (a + b) (5)

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 (3) The molar fraction Mb1 of (b1) is preferably 0.02 to 0.5, preferably 0.1 to 0.3.
Mb1 = b1 / (a + b) (3)
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.

  From another point of view, the copolymer contains 5 to 70 mol% of structural units derived from component (a), 5 to 50 mol%, preferably 7 to 45 mol% of structural units derived from component (b). Preferably, it contains 10 to 40 mol% and 0.5 to 30 mol%, preferably 1 to 25 mol%, particularly preferably 3 to 15 mol% of the structural unit derived from the component (c). If the structural unit derived from the component (a) is less than 5 mol%, the adhesion under moisture resistance is insufficient, which is not preferable. If the structural unit derived from the bifunctional (meth) acrylic acid ester (b) is less than 5 mol%, the heat resistance of the cured product is insufficient, and this is not preferable. As the rate increases, the molding processability decreases, and the strength of the molded product significantly decreases. Moreover, the structural unit derived from the other monofunctional (d) component is preferably within a range of 60 mol% or less with respect to the total amount of the structural unit derived from the monofunctional component.

  Although it does not specifically limit as a manufacturing method of a copolymer, It adjusts so that DMP, a monofunctional acrylate compound, and bifunctional (meth) acrylic acid ester may become desired content, and it is a radical polymerization initiator as needed. And a solvent at a temperature of 20 to 200 ° C., and recovered by a commonly used method such as a steam stripping method or precipitation with a poor solvent.

  The weight average molecular weight Mw of this copolymer is 10,000 to 1,000,000. When the amount is 10,000 or less, the yield of the polymer is lowered, and when it is 1,000,000 or more, the reactivity is lowered. Further, from the viewpoint of high reactivity, high solubility, low viscosity, and shrinkage stress, Mw is preferably in the range of 20,000 to 500,000.

  This copolymer is soluble to dissolve 1 g or more in 100 g of the above-mentioned solvent. Preferably, at 25 ° C., 5 g or more is dissolved in 100 g of the above solvent.

  The curable resin composition of the present invention includes a polyfunctional (meth) acrylic acid ester copolymer (A), a monomer (B) having one or more functional groups having an unsaturated double bond, and an initiator (C ).

The monomer (B) having one or more functional groups having an unsaturated double bond may include an oligomer but is not the same as the polyfunctional (meth) acrylic acid ester copolymer (A). If the same, the polyfunctional (meth) acrylate copolymer (A) is calculated. The oligomer may be a homopolymer or a copolymer, and the molecular weight (Mw) may be a low molecular weight polymer of 10,000 or less, preferably 6000 or less, more preferably 5000 or less. More preferably, it is 1000 or less. The monomer (B) may be a compound having no molecular weight distribution, and in this case, a plurality of compounds can be used. Preferably, the monomer has a molecular weight of 1000 or less. When the monomer is an oligomer, the molecular weight means Mw. Further, in the relationship with the soluble polyfunctional (meth) acrylic acid ester copolymer, the molecular weight Mw of the monomer is preferably lower than that in the relationship with Mw of the copolymer (A), and is preferably 1000 or more lower. .
The monomer (B) has at least one functional group having a polymerizable unsaturated double bond. Examples of the functional group having a polymerizable unsaturated double bond include a vinyl group and (meth) acryloyl. There are groups.

  The monomer having one or more functional groups having an unsaturated double bond is preferably a (meth) acrylate monomer. The (meth) acrylate monomer has one or more (meth) acryloyl groups in the molecule, and one or more are used. These (meth) acrylates can be used in combination with a copolymer to adjust the viscosity of the composition without reducing curability, and synergistically, in addition to heat resistance, low color dispersion, Optical characteristics such as high light transmittance are simultaneously improved. In addition, physical properties such as hardness and flexibility of the cured product can be improved.

  The (meth) acrylate monomer may be a monomer having a molecular weight of 6000 or less, preferably 5000 or less, particularly 1000 or less. Further, it may be a monomer (oligomer) having a molecular weight distribution such as polyethylene glycol di (meth) acrylate. In this case, Mw is 6000 or less, preferably 5000 or less, more preferably 2000 or less, particularly 1000 or less. . Preference is given to monomers or mixtures thereof consisting of compounds having no molecular weight distribution.

  As said (meth) acrylate monomer, what can be copolymerized with copolymer (A) is good, for example, (meth) acrylic acid ester which has an alicyclic structure is preferable, and it is monofunctional, bifunctional, or trifunctional. (Meth) acrylic acid esters are more preferred, and monofunctional (meth) acrylic acid esters are even more preferred. The (meth) acrylate monomer is preferably a C4-20 aliphatic acrylate, and preferably has 1 to 3 unsaturated bonds derived from the acrylate. Aliphatic (meth) acrylic acid ester is excellent in compatibility with the copolymer, and therefore, in order to improve the overall composition in combination with the copolymer with low water absorption, low elasticity, optical properties and processability. It is effective. Urethane-modified (meth) acrylates and ethylene oxide-modified (meth) acrylates are effective in improving the flexibility of the cured product. Furthermore, a trifunctional or higher functional (meth) acrylate monomer is effective for improving the hardness of the cured product.

  Examples of the (meth) acrylate monomer include acryloylmorpholine, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, and polypropylene. Glycol mono (meth) acrylate, cyclohexane-1,4-dimethanol mono (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, phenyl polyethoxy (meth) acrylate, 2-hydroxy-3- Phenyloxypropyl (meth) acrylate, o-phenylphenol monoethoxy (meth) acrylate, o-phenylphenol polyethoxy (meth) acrylate, p-kumi Phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, tribromophenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, bisphenol A polyethoxydi ( (Meth) acrylate (eg, Sartomer, SR-349, SR-348, etc.), bisphenol A polypropoxydi (meth) acrylate, bisphenol F polyethoxydi (meth) acrylate, ethyl Glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, polyethylene Glycol di (meth) acrylate (for example, SR-344, SR-268, etc. manufactured by Sartomer), tris (acryloxyethyl) isocyanurate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, di Pentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, hydro Di (meth) acrylate of ε-caprolactone adduct of hydroxypenic acid neopent glycol di (meth) acrylate, hydroxybivalic acid neopen glycol (for example, KAYARAD HX-220, HX-620, etc., manufactured by Nippon Kayaku Co., Ltd.) ), Trimethylolpropane tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, urethane-modified (meth) acrylate (for example, EBCRYL 8405, manufactured by Daicel Cytec Co., Ltd.) And monomers such as EBCRYL8402). Particularly preferably, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) ) Acrylate, urethane-modified (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, and ethylene glycol di (meth) acrylate.

  The curable resin composition of the present invention contains a polymerization initiator, preferably a photopolymerization initiator. The curable resin composition of the present invention can be molded and cured even by thermal polymerization. However, when molding and curing an optical material such as a lens, photocuring capable of strictly controlling the shape is advantageous. Therefore, it is advantageous to add a photopolymerization initiator.

  Examples of the photopolymerization initiator 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- (methylthio) phenyl Acetophenones such as 2-morpholinopropan-1-one; ant such as 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 2-chloroanthraquinone, 2-amylanthraquinone Quinones; thioxanthones such as 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; benzophenone, 4-benzoyl-4′-methyldiphenyl sulfide Benzophenones such as 4,4′-bismethylaminobenzophenone; phosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide It is done.

  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.

  The curable resin composition of the present invention contains the above copolymer, a monomer having one or more functional groups having an unsaturated double bond, and an initiator as essential components, and the content ratios thereof are as follows. . The compounding amount of the monomer is 90 to 30 parts by weight, preferably 80 to 30 parts by weight, and more preferably 60 to 45 parts by weight with respect to 100 parts by weight of the total amount of the copolymer and the monomer. Furthermore, the compounding amount of the initiator is 0.1 to 10 parts by weight, preferably 1.0 to 5 parts by weight with respect to 100 parts by weight as the total of the copolymer and the monomer.

  When the blending ratio is within the above range, the balance between the moldability that is synergistically seen in the mold release property and curability, the heat resistance, and the optical properties is improved. Moreover, when there are too few initiators, 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 copolymer, a monomer, an initiator, and other components 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.

  A cured resin obtained by molding and curing the curable resin composition of the present invention is excellent as an optical material such as a prism and a lens. In particular, it is useful to be used as an adhesive layer, and exhibits an excellent effect in adhesion between optical materials in a moisture-resistant environment. In addition, it is useful as a material for optical plastic lenses such as prism lens sheets, Fresnel lenses, and lenticular lenses.

  When laminating the polarizing film and the protective plate using the curable resin composition of the present invention, for example, not limited to a protective plate made of alkali-free glass or quartz glass that is excellent in active energy ray permeability, A protective plate such as an acrylic plate or polycarbonate that absorbs a large amount of ultraviolet rays can also be used because of good reaction curability of the composition.

  The curable resin composition of the present invention is applied to a base material such as a polarizing film using a roll coater, a spin coater, a screen printing method or the like such that the adhesive film thickness is 1 to 100 μm, The protective plates can be bonded together and bonded by irradiating with ultraviolet rays from above the protective plates and curing.

  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. Moreover, the measurement of the softening temperature etc. in an Example performed sample preparation and a measurement with the method shown below.

1) Molecular weight and molecular weight distribution of polymer GPC (manufactured by Tosoh Corporation, HLC-8120GPC) is used to measure the molecular weight and molecular weight distribution of the polyfunctional (meth) acrylic acid ester copolymer. / 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 ¹³ C-NMR and ¹ H-NMR analysis using a JNM-LA600 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) Measurement of solvent solubility and gel formation The solubility of the polyfunctional vinyl aromatic copolymer was measured by dissolving 2 g of sample in 10 g of various solvents (toluene, xylene, propylene glycol monomethyl ether acetate, tetrahydrofuran, dichloroethane or chloroform). The transparency of the sample after dissolution was visually confirmed, and the solubility was evaluated by classifying into ○: transparent, Δ: translucent, ×: opaque or not dissolved. At the same time, the formation of the gel was also visually confirmed to evaluate the presence or absence of the gel.
4) Sample preparation and measurement of elastic modulus measurement Polyfunctional (meth) acrylic acid ester copolymer was dissolved in PGMEA, and perbutyl O (manufactured by NOF Corporation) was blended as a thermal polymerization initiator to obtain a curable resin composition. The varnish was applied on a glass substrate, dried at 100 ° C./10 min under a nitrogen stream, and then cured at 200 ° C./1 h under a nitrogen stream to prepare a 200 μm thick sample for measurement. This is set in a DMA (dynamic viscoelasticity analyzer) measuring device and measured by scanning from 20 ° C to 150 ° C at a rate of temperature increase of 10 ° C / min under a nitrogen stream. The value of E 'at 30 ° C Was read to determine the elastic modulus of the sample.

5) Measurement of thermal weight loss and heat discoloration resistance The thermal decomposition temperature and heat discoloration resistance of the polyfunctional (meth) acrylic acid ester copolymer are measured by placing the sample in a TGA (thermobalance) measuring device and using a nitrogen stream. The measurement is performed by scanning from 30 ° C to 320 ° C at a heating rate of 10 ° C / min, and the weight loss at 300 ° C is obtained, and the amount of discoloration of the sample after measurement is visually confirmed. ◎: No thermal discoloration, ○: light yellow, Δ: brown, x: black, and the heat discoloration was evaluated.

6) Measurement of refractive index Polyfunctional (meth) acrylate copolymer is dissolved in toluene, and perbutyl O as an initiator is added to 100 parts by weight of soluble polyfunctional (meth) acrylate copolymer. 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 Calnew). The measurement timing was immediately after molding (initial stage) and after one week (after wet heat) in a high-temperature high-humidifier with wet heat conditions of 85 ° C x 85RH.

7) Hygroscopic adhesion test A varnish obtained by diluting the copolymer with PGMEA was applied to a glass substrate, dried at 100 ° C for 10 minutes, and then cured in an inert oven at 200 ° C for 1 hour in a nitrogen stream. Went. Next, in accordance with JISK5400, 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 make 100 grids. After the cellophane tape was brought into close contact with the surface, the number of squares that did not peel off when peeled at once was counted (initial). Furthermore, after immersing the glass substrate on which the coating film was placed in 85 ° C hot water for a predetermined time, wipe off the water on the surface, adhere the cellophane tape to the surface again, peel off all at once, and determine the number of cells remaining without peeling. Counted (after immersion).

The abbreviations of the raw materials used are shown below.
DMTCD: dimethylol tricyclodecane diacrylate
NDDA: 1,9-nonanediol diacrylate
BDDA: 1,4-butanediol diacrylate
HOP: 2-hydroxypropyl acrylate
HO: 2-hydroxyethyl methacrylate
EHDGA: 2-ethylhexyl EO (n ≒ 2) modified acrylate
LA: Lauryl acrylate
LM: Lauryl methacrylate
nBA: n-butyl acrylate
DCPA: Dicyclopentanyl acrylate αMSD: 2,4-diphenyl-4-methyl-1-pentene
DDME: n-dodecyl mercaptan

Example 1
Charge NDDA252.35g, DCPA309.42g, EHDGA544.76g, HOP65.07g, αMSD222.32g, toluene 700ml into 3.0L reactor, add 65.60mmol benzoyl peroxide at 85 ° C and let it react for 2 hours. It was. After stopping the polymerization reaction by cooling, the reaction mixture was poured into a large amount of methanol at room temperature to precipitate a polymer. The obtained polymer was washed with methanol, filtered, dried and weighed to obtain 431.1 g of copolymer A (yield: 31 wt%).

The obtained copolymer A had Mw of 117,234, Mn of 20,874, and Mw / Mn of 5.6. By performing ¹³ C-NMR, ¹ H-NMR analysis and elemental analysis, copolymer A has a total of 11.8 mol% of NDDA-derived structural units, 30.1 mol% of DCPA-derived structural units, and a structure derived from EHDGA. The unit contained 49.7 mol% and the structural unit derived from HOP was 9.4 mol%. Further, the terminal group of the structure derived from αMSD was present at 2.7 mol%. The mole fraction of structural units derived from acrylates is calculated with the structural unit derived from all acrylates as 100, and the mole fraction such as αMSD is 100 structural units derived from all acrylates + αMSD, etc. Is the value calculated as Mb1 is the molar fraction of the pendant acrylate, and is calculated with the structural unit derived from all acrylates as 100.
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.

Examples 2 and 3 and Comparative Examples 1 and 2
Polymerization was carried out in the same manner as in Example 1 using various bifunctional acrylates and monofunctional (meth) acrylates with the raw material compositions shown in Table 1.
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.

Claims (7)

The following general formula (1)
CH ₂ = CR-CO-OR1 (1)
(Wherein R1 is a linear or branched hydrocarbon group having 9 to 30 carbon atoms, and the hydrocarbon group may contain an oxygen atom, a sulfur atom or a nitrogen-containing group. It is a methyl group.)
Monofunctional (meth) acrylic acid ester (a) represented by
The following general formula (2)
CH ₂ = CR-CO-O-R2-O-OC-CR = CH ₂ (2)
(Wherein R2 is a hydrocarbon group having 2 to 30 carbon atoms, and the hydrocarbon group may contain an oxygen atom, a sulfur atom or a nitrogen-containing group. R is H or a methyl group.)
A bifunctional (meth) acrylic acid ester (b) represented by:
A copolymer obtained by copolymerizing monomers containing 2,4-diphenyl-4-methyl-1-pentene (c),
A structural unit derived from 2,4-diphenyl-4-methyl-1-pentene (c) having a reactive (meth) acrylate group derived from a bifunctional (meth) acrylic acid ester (b) in the side chain Having a weight average molecular weight of 10,000 to 1,000,000, and the molar fraction Mb of units derived from the component (b) in all acrylate units is a monofunctional (meth) acrylate (a) When the introduction amount (mole) of the unit derived from the unit derived from the unit derived from the bifunctional (meth) acrylic acid ester (b) is a and b, respectively, as b / (a + b), 0.01 to 0.5 Further, a polyfunctional (meth) acrylate copolymer that is soluble in toluene, xylene, propylene glycol monomethyl ether acetate, tetrahydrofuran, dichloroethane, or chloroform.   In the general formula (1), R1 is a linear or branched fatty chain having 9 to 30 carbon atoms, or an ethylene glycol chain. ) Acrylic ester copolymer.   The polyfunctional (meth) acrylic acid ester according to claim 1 or 2, wherein in the general formula (2), R2 is a linear fatty chain having 2 to 30 carbon atoms, or an ethylene glycol chain. Copolymer.   When the introduction amount (mole) of the reactive (meth) acrylate group-containing unit derived from the bifunctional (meth) acrylate ester (b) is b1, the molar fraction Mb1 of the unit is b1 / (a + b). 0.02-0.5, The polyfunctional (meth) acrylic acid ester copolymer according to any one of claims 1 to 3.   When the introduction amount (mol) of the unit derived from 2,4-diphenyl-4-methyl-1-pentene (c) is c, the molar fraction Mc of the unit is 0.005 as c / (a + b + c). It is -0.3, The polyfunctional (meth) acrylic acid ester copolymer in any one of Claims 1-4 characterized by the above-mentioned.   The polyfunctional (meth) acrylic acid ester copolymer according to any one of claims 1 to 5, a monomer having one or more functional groups having an unsaturated double bond, and an initiator. Curable resin composition.   An optical article obtained by curing and molding the curable resin composition according to claim 6.