TWI628195B - Multifunctional (meth) acrylate copolymer, curable resin composition, and cured product thereof - Google Patents

Abstract

An object of the present invention is to provide a (meth) acrylate copolymer and a curable resin composition formed by blending the (meth) acrylate copolymer. The (meth) acrylate copolymer has excellent optical properties. A multifunctional (meth) acrylate copolymer that does not decrease its adhesion to inorganic materials and maintains high optical characteristics even under long-term humid and hot conditions.

The multifunctional (meth) acrylate copolymer of the present invention is a monofunctional (meth) acrylate (a) produced by (meth) acrylic acid and an alcohol having 9 to 30 carbon atoms, and CH ₂ = CR -CO-O-R2-O-OC-CR = CH ₂ bifunctional (meth) acrylate (b) and 2,4-diphenyl-4-methyl-1-pentene (c) The copolymer obtained by copolymerization of monomers is characterized in that the side chain has a reactive (meth) acrylate group derived from (b), the terminal has a structural unit derived from (c), and is soluble in toluene, etc. Solvent.

Description

Multifunctional (meth) acrylate copolymer, curable resin composition, and cured product thereof

The present invention relates to a curable resin composition and a cured product thereof. The curable resin composition has excellent optical characteristics, heat resistance, and processability, which are called directivity such as optics and high light transmittance. It can improve heat resistance under severe practical conditions like wet and hot conditions, and adhesion to inorganic materials.

Most monomers with reactive unsaturated bonds are able to generate masses by selecting the appropriate reaction conditions with the catalyst that will produce a chain reaction by cracking the unsaturated bonds. In general, the types of monomers having unsaturated bonds are extremely different, and the types of resins obtained are also rich in variety. However, generally, a monomer having a high molecular weight of 10,000 or more, which is called a polymer compound, can be obtained, and there are relatively few kinds of monomers. Examples include ethylene, substituted ethylene, propylene, substituted propylene, styrene, alkylstyrene, alkoxystyrene, norbornene, various acrylates, butadiene, cyclopentadiene, dicyclopentadiene Monomers such as olefin, isoprene, maleic anhydride, maleimide, fumarate, allyl compounds and the like are representative. These The monomers can be synthesized alone or copolymerized to synthesize various resins.

The use of these resins is mainly limited to the field of relatively low-cost consumer equipment, in light. In the field of electronic materials, it is hardly applicable to advanced technical fields that are required to have high heat resistance, dimensional stability, or fine processability. The reason is that polymers synthesized from the above monomers are usually thermoplastic, and in order to satisfy mechanical properties, they must have a high molecular weight to a certain extent. Therefore, they are sacrificed at the apex of heat resistance or fine processability. Characteristics required in the technical field.

On the other hand, the curable resin composition can be used, for example, as a material for mechanical parts and electrical. Electronic part materials, auto parts materials, civil construction materials, forming materials, etc., can also be used as coatings or adhesive materials. In addition, if it is a mixed member combined with an inorganic base material, not only the thermal expansion rate can be reduced, but also the refractive index of the inorganic substance and the resin can be blended to control the appearance of the resin composition and its hardened product and to exhibit transparency. Therefore, it is particularly useful as electrical. Materials for electronic parts or materials in optical applications. For example, digital camera modules have been miniaturized due to being mounted on mobile phones and the like, and cost reduction has also been demanded. Furthermore, in terms of novel applications, the demand for automotive cameras or bar code readers used by home furnishers is increasing. When applied to these applications, not only the heat resistance during solder reflow during manufacture, but the high temperature exposure in summer during actual use, etc. are required, and high reliability such as long-term heat resistance and low water absorption is also required.

In order to solve the disadvantages of such a vinyl-based thermoplastic polymer, Patent Documents 1 to 3 disclose polymers having a (meth) acrylfluorene group or a vinyl ether group in a pendant group. For example, Patent Document 1 discloses A photosensitive composition comprising a (meth) acrylfluorenyl pendant type polymer obtained by cationically polymerizing a different polymerizable monomer such as 2-vinyloxyethyl acrylate (VEA), and a photopolymerization initiation A photosensitive composition formed by an agent. In addition, Patent Document 2 discloses a photosensitive composition composed of a (meth) acrylfluorene side group type polymer, a compound having a photoreactive unsaturated carboxyl group, and a photopolymerization initiator. In addition, Patent Document 3 discloses a method for producing a polymer solution, in which a heteropolymerizable monomer such as 2-vinyloxyethyl acrylate (VEA) has a light that is inert to cationic polymerization itself. In a reactive unsaturated carboxylic acid ester solvent compound, a cationic polymerization catalyst is used to separately polymerize or copolymerize it to obtain a polymer solution.

However, when using the reactive polymer produced by the technique using the disclosed heterogeneous polymerizable monomer, it cannot obtain the processability, heat resistance, high transparency, etc. required for advanced optical applications. A balance of properties, and a polymer and a curable resin composition that have improved optical properties under practical conditions such as severe hot and humid conditions, and adhesion to inorganic materials.

On the other hand, Patent Document 4 discloses a reactive (meth) having a side chain containing a bifunctional (meth) acrylate derived by copolymerizing a monovinyl aromatic compound and a bifunctional (meth) acrylate. Soluble polyfunctional vinyl aromatic copolymer of acrylate-based structural unit. However, the soluble polyfunctional vinyl aromatic copolymer obtained by the technology disclosed here has excellent thermal decomposition resistance to thermal history at high temperature, and has reactive (meth) acrylate groups on the side chain. It is solvent-soluble with excellent processability, but it is also a material that does not improve the adhesion with inorganic materials in addition to practical limitations such as optical lenses that cannot be used for low-color dispersion applications.

Furthermore, Patent Document 5 discloses that bis (meth) acrylic acid containing methyl methacrylate (MMA) -based syrup contains 1 to 25% by weight of a linear aliphatic dihydric alcohol having 4 to 8 carbon atoms. Ester is a constituent of the composition. In addition, the manufacture of the MMA-based syrup composition disclosed therein is a process in which MMA, or a vinyl copolymer obtained by copolymerizing MMA or a copolymer thereof, a chain transfer agent, in the presence of a polymerization initiator, an inert gas (such as N ₂ In a gas) atmosphere, normal temperature or heating polymerization is performed. Furthermore, only sulfur compounds such as lauryl mercaptan, octyl thioglycolate, toluene mercaptan, thionaphthol, benzyl mercaptan and the like as chain transfer agents are specifically exemplified. Phenyl-4-methyl-1-pentene is not specifically disclosed. What's more, it is not taught that when the terminal group derived from 2,4-diphenyl-4-methyl-1-pentene and the structural unit derived from a monofunctional (meth) acrylate coexist, the damp heat can be doubled suppressed. The occurrence of refractive index branches. Moreover, the composition obtained by the technology disclosed therein is not a composition having improved adhesion to inorganic materials under severe practical conditions such as hot and humid conditions.

Further, Patent Document 6 discloses a polymerizable composition composed of a vinyl-based monomer and a di (meth) acrylate compound, and also discloses 2,4-diphenyl-4-methyl-1- The use of pentene, but its use amount is about a decimal point of the general chain transfer agent is used, and because the product is also cross-linked colloidal, does not show solvent solubility.

In addition, Patent Document 7 discloses self-hardening properties A thermosetting resin composition for a color filter of a copolymer and an organic solvent, wherein the self-curing copolymer contains (1) an epoxy-containing (meth) acrylate, and 2) a hydroxyl-containing (meth) ) Acrylic ester, 3) (meth) acrylic acid, and 4) A constituent unit formed of an aromatic group-containing (meth) acrylate. In addition, in order to achieve a desired molecular weight range at the polymerization stage, the self-hardening copolymer obtained by the technology disclosed therein can be used with hydrogen thiopropionic acid, hydrogen thiopropionate, thioglycol, Known molecular weight regulators such as thioglycerol, dodecyl mercaptan, and α-methylstyrene dimer. However, the disadvantage is that the technology disclosed in these methods does not add a vinyl compound having more than two functional vinyl groups during polymerization, and can only introduce one or less terminal groups from the molecular weight regulator into the polymer chain. The function imparted from the terminal group is not fully expressed. Furthermore, the self-curing copolymer obtained by this technology forms a thermosetting resin composition in the resin composition with the epoxy resin, but has the disadvantage that it does not harden with the acrylate resin. The reaction causes the strength and heat resistance of the resin composition to be reduced.

To solve these problems, Patent Document 8 discloses a soluble polyfunctional (meth) acrylate copolymer having an alicyclic structure. However, the technical drawback disclosed therein is that in long-term reliability tests under high temperature and high humidity conditions, the adhesion to inorganic materials is reduced.

Therefore, it has excellent optical characteristics such as optical directivity and high light transmittance, and has a balance of characteristics such as processability and heat resistance. In addition, it has improved the optical characteristics under severe practical conditions such as long-term wet and hot conditions. Hardening resin composition with heat resistance and adhesion to inorganic materials, to Does not exist today.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 49-13212

[Patent Document 2] Japanese Patent Publication No. 51-34433

[Patent Document 3] Japanese Patent Publication No. 54-27394

[Patent Document 4] Japanese Patent Laid-Open No. 2008-247978

[Patent Document 5] Japanese Patent Laid-Open No. 57-167340

[Patent Document 6] Japanese Patent Laid-Open No. 2002-121228

[Patent Document 7] Japanese Patent Laid-Open No. 2009-1770

[Patent Document 8] Japanese Patent Laid-Open No. 2011-127008

The present invention is to provide an excellent optical characteristic such as optical directivity, high light transmittance, etc., and easy processing, heat resistance, and other advanced technical fields. Various characteristics required for optical materials are well balanced, plus Under the severe practical conditions of long-term hot and humid conditions, the adhesion to inorganic materials will not be reduced, and high optical characteristics are maintained, and a novel polyfunctional (meth) acrylic acid with both a controllable molecular weight distribution and solvent solubility The purpose of the ester copolymer is as a copolymer and a curable resin composition prepared by blending the copolymer.

The present invention is a polyfunctional (meth) acrylate copolymer comprising a copolymer obtained by copolymerizing the following (a), (b), (c) monomers, (a): according to the following general formula ( 1) Monofunctional (meth) acrylate (a) 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; R is H or methyl) (b): a bifunctional (meth) acrylate represented by the following general formula (2) (b) CH ₂ = CR-COO-R2 -OOC-CR = CH ₂ (2) (where 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), (c ): 2,4-diphenyl-4-methyl-1-pentene (c), which is a reactive (meth) acrylate derived from a bifunctional (meth) acrylate (b) in the side chain Copolymer with a structural unit derived from 2,4-diphenyl-4-methyl-1-pentene (c) at the end, a weight average molecular weight of 10,000 to 1,000,000, and (b) in all acrylic units The molar fraction Mb of the unit of the component is such that the unit derived from the monofunctional (meth) acrylate (a) and the unit derived from the bifunctional (meth) acrylate (b) When the amount of introduction (mol) is a and b, b / (a + b) is 0.01 ~ 0.5, and it is soluble in toluene, xylene, propylene glycol monomethyl ether acetate, tetrahydrofuran, and dichloroethyl. Alkane or chloroform.

The above-mentioned multifunctional (meth) acrylate copolymer of the present invention satisfies the general formula (1), in which R1 is a linear or branched fatty chain having 9 to 30 carbon atoms, or The ethylene glycol chain is characterized in that R2 is a linear fatty chain having 2 or more and 30 or less carbon atoms or one or more of ethylene glycol chains in the general formula (2).

The above-mentioned multifunctional (meth) acrylate copolymer of the present invention satisfies the introduction amount of the reactive (meth) acrylate-containing unit derived from the bifunctional (meth) acrylate (b) ( When Mohr) is b1, the Mohr fraction of the unit Mb1 is b1 / (a + b) and is 0.02 ~ 0.5, or it is derived from 2,4-diphenyl-4-methyl-1-pentene When the introduction amount (mole) of the unit of (c) is c, the mole fraction Mc of the unit is c / (a + b + c) and any one of 0.005 to 0.3 is characterized.

Furthermore, the present invention is a curable resin composition characterized by containing the above-mentioned polyfunctional (meth) acrylate copolymer, a monomer having one or more functional groups containing an unsaturated double bond, and an initiator, and An optical article obtained by curing and molding this curable resin composition.

With the present invention, it is possible to provide an optical lens with excellent optical characteristics such as optical directivity, high light transmittance, etc., and in the advanced technical fields of low water absorption, processability, heat resistance, and the like. The various characteristics required in engineering components such as gadolinium, bonding materials, etc. are well-balanced, together with the optical characteristics under severe practical conditions such as long-term hot and humid conditions, and A curable resin composition having improved adhesion of an inorganic material.

[Forms for Implementing Invention]

Hereinafter, the polyfunctional (meth) acrylate copolymer and curable resin composition of this invention are demonstrated in detail.

The multifunctional (meth) acrylate copolymer (hereinafter referred to as a copolymer) of the present invention is a monomer containing a monofunctional (meth) acrylate (a) and a bifunctional (meth) acrylate (b) The copolymer obtained by copolymerization with 2,4-diphenyl-4-methyl-1-pentene (c) has a reactivity derived from a bifunctional (meth) acrylate (b) in a side chain. (Meth) acrylate group, and further, a soluble polyfunctional (meth) acrylate copolymer having a structural unit derived from 2,4-diphenyl-4-methyl-1-pentene (c) at the terminal Thing. Here, the term "soluble" means soluble in toluene, xylene, propylene glycol monomethyl ether acetate (PGMEA), tetrahydrofuran, dichloroethane, or chloroform. The solubility test was performed under the conditions shown in the examples. In addition, monofunctional (meth) acrylate (a) is also called (a) component, bifunctional (meth) acrylate (b) is also called (b) component, and 2,4-diphenyl-4-methyl 1-pentene (c) is also referred to as (c) component or DMP.

The copolymer is obtained by copolymerizing a monofunctional (meth) acrylate and a bifunctional (meth) acrylate. Although the copolymer has a branched structure or a crosslinked structure, the amount of the structure is limited by the degree of solubility. . Therefore, it becomes a structural unit (b1) having a side chain having an unreacted (meth) acrylic group derived from a bifunctional (meth) acrylate (b). Copolymer. This unreacted (meth) acrylic group is also referred to as a pendant (meth) acrylic group. Since it exhibits polymerizability, it can be polymerized by further polymerization treatment to give a solvent-insoluble resin hardened material.

The copolymer has a structural unit derived from the component (c) at the terminal. By introducing this structural unit at the end of the copolymer, a hardened product having improved moldability such as mold release properties can be obtained.

The copolymer has a structural unit (a) derived from the (a) component, a unit (b) derived from the (b) component, and a structural unit (c) derived from the (c) component. Here, in the structural unit (b) derived from the component (b), both of the polymerizable double bonds (called vinyl groups) contained in the two (meth) acrylates are involved in polymerization to form a branched structure or A structural unit (b2) of a cross-linked structure, and a structural unit (b1) containing only one vinyl group participating in the polymerization and the other vinyl groups remaining unreacted and remaining unreacted (meth) acrylic groups. DMP as the component (c) acts as a chain transfer agent to prevent molecular weight from increasing, and is present at the end of the copolymer. By introducing a structural unit derived from the component (c) in the above-mentioned range at the end of the polymer, the releasability and low water absorption can be improved. The component (c) is contained in the monomers together with the components (a) to (b).

Let the introduction amount (mole) of the structural units (a), (b), (c), (b1), and (b2) into the copolymer be represented by a, b, c, b1, and b2, respectively, and These Mol fractions are each represented by Ma, Mb, Mc, Mb1, and Mb2.

With regard to the introduction amount of the component (c) of the copolymer, the molar fraction Mc represented by the following formula (4) is 0.005 to 0.3, preferably 0.01 to 0.25, particularly preferred is 0.03 ~ 0.15.

M _c = c / (a + b + c) (4)

The monofunctional (meth) acrylate (a) is important in improving the solvent solubility, low water absorption, heat resistance, optical properties, and processability of the copolymer, and especially the adhesion in the long-term wet heat test is very important. For such a monofunctional (meth) acrylate (a), a compound represented by general formula (1) can be used. In the formula, the structure in which R1 is a hydrocarbon group having a carbon number of 9 or more and 30 or less, and an oxygen atom, a nitrogen-containing group, a sulfur atom, or the like is present in the hydrocarbon group. When it is a structure in which heteroatoms or radicals can exist, it is advantageous in that it is a structure in which such heteroatoms or radicals exist between the carbon-carbon bonds constituting the hydrocarbon group. For example, an oxygen atom or a sulfur atom is a structure existing as an ether bond or a thioether bond. In addition, as for the nitrogen-containing group, there are amidino group or amidino group.

R1 is preferably a linear chain having 9 to 30 carbon atoms, or a part of a branched fatty chain, or a (meth) acrylic acid ester as a glycol chain. The alkylene chain represented by C _n H _2n , the vinyloxy chain (n is a number of 1 or more) represented by (C ₂ H ₄ O) _n , or the alkylene chain and the vinyloxy chain are preferred. Bonding structure. At this time, H is bonded to a single end. The copolymer having a carbon number of 9 or more decreases the elastic modulus and increases the ratio of the hydrocarbon group to the polar group, so that it is a copolymer excellent in water resistance. Furthermore, with a straight-chain, partially branched structure, it is possible to reduce elasticity and improve adhesion. Moreover, those who introduce ethylene glycol chains are preferred because they can improve flexibility. Specifically, preferably, 2-ethylhexyl EO modified (n ≒ 2) (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, methoxy Base polyethylene glycol # 400 acrylate (manufactured by Shin Nakamura Chemical Industry Co., Ltd.), methoxy polyethylene glycol # 550 acrylate (manufactured by Shin Nakamura Chemical Industry Co., Ltd.), etc. Particularly preferred are those having both a fatty chain and a glycol chain represented by 2-ethylhexyl EO modified (n ≒ 2) (meth) acrylate.

In addition, in the aspect of the monofunctional (meth) acrylate, other monofunctional (meth) acrylate (d) components may be used in addition to the chain acrylate. Thereby, other physical properties can be adjusted. In particular, a (meth) acrylic acid ester having a ring structure is preferred because it can be adjusted for applications such as heat resistance, elastic modulus, solubility, and refractive index. As for the monofunctional (meth) acrylate having a ring structure, specific examples include isofluorenyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentyl (meth) acrylate. Acrylate), dicyclopentenyloxyethyl (meth) acrylate, and dicyclopentyloxyethyl (meth) acrylate, phenoxy polyethylene glycol acrylate, ethoxy Acetylated o-phenylphenol acrylate, nonylphenol EO adduct acrylate.

Alternatively, a monofunctional (meth) acrylate having a carbon number of 8 or less may be used in combination. Examples of the (meth) acrylate include methyl-methacrylate, ethyl-methacrylate, and methyl. Acrylate, ethyl acrylate, n-butyl acrylate, 2-methylhexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, and the like. Also, although 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) can be used Acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (Meth) acrylates and partially ethoxylated 2-hydroxy (meth) acrylates, etc., but are preferably methyl-methacrylate, n-butylacrylate, and 2-hydroxyethyl- Methacrylate. These low-molecular-weight (meth) acrylate-based monomers may be used alone or in combination of two or more.

These other structural units derived from the monofunctional component (d) may be in a range of 60 mol% or less, particularly preferably 50 mol% or less, with respect to the total amount of the structural units derived from the monofunctional component.

Next, the bifunctional (meth) acrylate (b) is used to branch or cross-link the copolymer, and at the same time generate a pendant vinyl group, and give the copolymer hardening properties, and show heat resistance during hardening. In the connection component, it plays an important role.

For the bifunctional (meth) acrylate (b), a compound represented by the general formula (2) can be used. In the formula, R2 is a hydrocarbon group having a carbon number of 2 to 30, preferably a carbon number of 9 to 30, and a part of the hydrocarbon group may have an oxygen atom or a hetero atom or a group containing a nitrogen group, a sulfur atom, or the like. These heteroatoms or radicals, or structures that can be substituted by them, are the same as those of R1 except that the carbon number of R2 is a divalent radical of 2-30.

As the bifunctional (meth) acrylate (b) represented by the general formula (2), for example, cyclohexanedimethanol diacrylate, dimethyloltricyclodecanediacrylate, and cyclohexanediacrylate can be used. Methanol di-methacrylate, dimethylol tricyclodecane di-methacrylate, ethylene glycol diacrylate, propylene glycol diacrylate, 1,4-butanediol diacrylate, hexanedi Alcohol diacrylate, diethylene glycol diacrylate, ethylene glycol dipropylene Bifunctionals such as acrylates, propylene glycol diacrylate, 1,4-butanediol di-methacrylate, hexanediol di-methacrylate, diethylene glycol di-methacrylate, etc. (Meth) acrylates, but not limited to these. Especially from the viewpoint of reactivity, solubility, or heat resistance, a (meth) acrylic acid ester having a linear fatty chain or ethylene glycol chain having a carbon number of 9 or more and 30 or less is preferred. Specifically, preferable examples include 1,9-nonanediol di (meth) acrylate, 2-methyl-1,8-octanediol di (meth) acrylate, and triethylene glycol. Di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tetradecane ethylene glycol di (meth) acrylate, 2-butyl-2-ethyl-1,3-propanedi Alcohol di (meth) acrylate. In addition to the chain acrylate, a bifunctional (meth) acrylate having a ring structure may be used in combination to adjust heat resistance, elasticity, solubility, refractive index, and the like according to the application. As the bifunctional (meth) acrylate having a ring structure, specifically, dimethyloltricyclodecanedi (meth) acrylate and bisphenol A. EO addition di (meth) acrylate, bisphenol A. PO addition (meth) diacrylate and the like.

The structural units derived from bifunctional (meth) acrylate (b) may include structural units (b1) and other structural units, but all of them are derived from bifunctional (meth) acrylate (b). The Mohr fraction Mb calculated by the structural unit (b) by the formula (5) may be 0.01 to 0.5, preferably 0.15 to 0.45.

Mb = b / (a + b) (5)

Although the copolymer has a structure containing a reactive (meth) acrylate group derived from a bifunctional (meth) acrylate (b) in a side chain The unit (b1), but the molar fraction Mb1 of the structural unit (b1) shown in formula (3) may be 0.02 to 0.5, and preferably 0.1 to 0.3.

Mb1 = b1 / (a + b) (3)

By satisfying the above-mentioned Mohr fraction, it is possible to obtain a molded article that is rich in change in hardenability by light or heat and has excellent heat resistance and mechanical properties after hardening.

From another point of view, the copolymer contains 5 to 70 mole% of the structural unit derived from the component (a), 5 to 50 mole% of the structural unit derived from the (b) component, and preferably 7 to 45. Molar%, more preferably 10-40 Molar% and structural units derived from component (c) 0.5-30 Molar%, preferably 1-25 Molar%, particularly preferably 3-15 Molar% good. If the structural unit derived from the component (a) is less than 5 mol%, the adhesiveness under moisture resistance is insufficient. If the structural unit derived from the bifunctional (meth) acrylate (b) is less than 5 mol%, the heat resistance of the cured product will be insufficient and inferior, and if the structural unit exceeds 50 mol%, the elastic modulus will be It rises while forming workability is reduced, and it is not good because the strength of the formed article is significantly reduced. The structural units derived from other monofunctional (d) components may be in a range of 60 mol% or less with respect to the total amount of structural units derived from monofunctional components.

Although the method for producing the copolymer is not particularly limited, DMP, a monofunctional acrylate compound, and a bifunctional (meth) acrylate may be adjusted to a desired content, and a radical polymerization initiator and a solvent may be used as required. It is produced by polymerization at a temperature of 20 to 200 ° C. For example, it can be recovered by a generally used method such as a steam stripping method and precipitation in a lean solvent.

The weight average molecular weight Mw of this copolymer is 10,000 to 1,000,000. If it is 10,000 or less, the yield of the polymer will decrease, and if it is 1,000,000 or more, the reactivity will decrease. Furthermore, from the viewpoint of high reactivity, high solubility, low viscosity, and shrinkage stress, a preferable range of Mw is 20,000 to 500,000.

This copolymer is soluble in 100 g or more of the solvent. It is preferred to dissolve 5 g or more of 100 g of the solvent at 25 ° C.

The curable resin composition of the present invention comprises the above-mentioned polyfunctional (meth) acrylate copolymer (A), a monomer (B) having one or more functional groups containing an unsaturated double bond, and an initiator (C) .

The monomer (B) having one or more unsaturated double bond-containing functional groups may contain an oligomer, but is not the same as the above-mentioned multifunctional (meth) acrylate copolymer (A), and when it is the same, Calculated as a polyfunctional (meth) acrylate copolymer (A). Moreover, the oligomer may be a single polymer or a copolymer, and may be a low molecular weight polymer having a molecular weight (Mw) of 10,000 or less, preferably 6,000 or less, more preferably 5,000 or less, and still more preferably 1,000 or less. The monomer (B) may be a compound having no molecular weight distribution. In this case, a plurality of compounds may be used. A monomer having a molecular weight of 1,000 or less is preferred. When the monomer is an oligomer, the above molecular weight means Mw. In addition, in terms of the relationship with the soluble polyfunctional (meth) acrylate copolymer, the relationship between the molecular weight Mw of the monomer and the Mw of the copolymer (A) may be lower than that and more preferably 1,000 or lower.

The above monomer (B) has one or more polymerizable unsaturated double bonds Among functional groups, functional groups having polymerizable unsaturated double bonds include vinyl, (meth) acryl, and the like.

The monomer having one or more unsaturated double bond-containing functional groups is preferably a (meth) acrylate monomer. The (meth) acrylic acid ester monomer is one having one or more (meth) acrylfluorenyl groups in a molecule, and one or two or more kinds can be used. These (meth) acrylates can be used in combination with copolymers to adjust the viscosity of the composition without reducing the hardenability. In addition to improving the heat resistance, they also have low color dispersion and high light transmittance. The optical characteristics of Etc. are also improved at the same time. In addition, physical properties such as hardness and flexibility of the cured product can be improved.

The (meth) acrylate monomer is preferably a monomer having a molecular weight of 6,000 or less, preferably 5,000 or less, and particularly 1,000 or less. In addition, it may be a monomer (oligomer) having a molecular weight distribution such as polyethylene glycol di (meth) acrylate. In this case, Mw is 6,000 or less, preferably 5,000 or less, more preferably 2,000 or less, particularly It is preferably below 1000. Monomers or mixtures of compounds that do not have a molecular weight distribution.

The (meth) acrylic acid ester monomer is preferably copolymerizable with the copolymer (A). For example, a (meth) acrylic acid ester having an alicyclic structure is preferred, and a monofunctional, difunctional, or trifunctional ( Meth) acrylates are more preferred, and monofunctional (meth) acrylates are even more preferred. In addition, the (meth) acrylate single system is preferably a C4-20 aliphatic acrylate, and may have one to three unsaturated bonds derived from acrylate. The aliphatic (meth) acrylate is excellent in compatibility with the copolymer, and can make low water absorption, low elasticity, optical characteristics, and processability of the composition as a whole. Polymers have synergistic effects for improvement. In addition, urethane-modified (meth) acrylates or vinyloxy-modified (meth) acrylates can effectively improve the flexibility of the cured product. Furthermore, a trifunctional or higher (meth) acrylate monomer can effectively improve the hardness of the cured product.

As the (meth) acrylate monomer, for example, acrylamidomorpholine, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl ( (Meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, cyclohexane-1,4-dimethanol mono (meth) acrylate, tetrahydrofurfuryl (Meth) acrylate, phenoxyethyl (meth) acrylate, phenylpolyethoxy (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate , O-phenylphenol monoethoxy (meth) acrylate, o-phenylphenol polyethoxy (meth) acrylate, p-cumylphenoxyethyl (meth) acrylate , Isofluorenyl (meth) acrylate, tribromophenyloxyethyl (meth) acrylate, dicyclopentyl (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, tricyclodecanedimethanol (meth) acrylate, Phenol A polyethoxy di (meth) acrylate (for example, manufactured by Sartomer, SR-349, SR-348, etc.), bisphenol A polypropoxy di (meth) acrylate, bisphenol F polyethoxy Di (meth) acrylate, ethylene glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, ginseng (2-hydroxyethyl) isocyanuric acid three (Meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, polyethylene glycol di (meth) acrylate (e.g., manufactured by Sartomer, SR-344, SR-268 Etc.), ginseng (propenyloxyethyl) isotricyanate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol Hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, hydroxytrimethylacetate neopentyl glycol di (meth) acrylate, ε-caprolactone hydroxytrimethylacetate neopentyl glycol Adducts of di (meth) acrylates (for example, manufactured by Nippon Kayaku Co., Ltd., KAYARAD HX-220, HX-620, etc.), trimethylolpropane tri (meth) acrylate, trimethylol Propane polyethoxytri (meth) acrylate, bistrimethylolpropane tetra (meth) acrylate, urethane-modified (meth) acrylate (for example, manufactured by Daicel-cytec , EBACRYL8405, EBACRYL8402, etc.). Particularly preferred are 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, ethylene diethylene glycol Alcohol di (meth) acrylate.

The curable resin composition of the present invention contains a polymerization initiator, and preferably contains a photopolymerization initiator. The curable resin composition of the present invention can be thermally polymerized, molded, and hardened. However, when optical materials such as lenses are molded and hardened, light hardening can be performed with tight shape control. Therefore, it is preferable to add a photopolymerization initiator.

As for the photopolymerization initiator, benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, etc .; acetophenone, 2,2-diethoxy- 2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-phenylpropane-1- Ketone, diethoxyacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinylpropane-1-one, etc. Acetophenones; 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-chloroanthraquinone, 2-pentylanthraquinone, and other anthraquinones; 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone and other thioxanthone; acetophenone dimethyl ketal, benzyl dimethyl ketal and other ketal; benzophenone, Benzophenones such as 4-benzylidene-4'-methyldiphenyl sulfide and 4,4'-bismethylaminobenzophenone; 2,4,6-trimethylbenzene Phosphine oxides such as formamyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzylfluorenyl) -phenylphosphine oxide, and the like.

These systems can be used alone or as a mixture of two or more kinds, and can be combined with tertiary amines such as triethanolamine, methyldiethanolamine, N, N-dimethylaminobenzoic acid ethyl ester, N, A promoter such as a benzoic acid inducer such as N-dimethylamino benzoic acid isoamyl ester and the like are used.

The curable resin composition of the present invention contains the above-mentioned copolymer, a monomer having one or more unsaturated double bond-containing functional groups, and an initiator as essential components, and its content ratio is described below, for example. The blending amount of the monomer is 100 parts by weight relative to the total blending amount of the copolymer and the monomer, which is 90 to 30 parts by weight, preferably 80 to 30 parts by weight, and more preferably 60 to 45 parts by weight. The compounding amount of the initiator is 0.1 to 10 parts by weight, and preferably 1.0 to 5 parts by weight, based on 100 parts by weight of the total amount of the copolymer and the monomer.

When the blending ratio falls within the above range, the balance between the moldability and heat resistance and optical characteristics seen in mold release or hardenability can be doubled. In addition, if the amount of the initiator is too small, insufficient curing is likely to occur, and heat resistance and light resistance are reduced. If the amount of the initiator is too large, mechanical strength is reduced, and heat resistance is reduced. When an organic solvent and a filler are contained in the curable resin composition, the above-mentioned content is calculated by removing these.

In the curable resin composition of the present invention, a polymerization inhibitor, an antioxidant, a mold release agent, a photosensitizer, an organic solvent, a silane coupling agent, a leveling agent, an antifoaming agent, and an antistatic agent may be used as necessary. In addition, even ultraviolet absorbers, light stabilizers, various inorganic and organic fillers, antifungal agents, antibacterial agents, etc. are added to the curable resin composition of the present invention to impart functionalities to their respective purposes.

The curable resin composition of the present invention can be obtained by mixing the above-mentioned copolymer, monomer, and initiator with other components as required in any order. The curable resin composition of the present invention is stable over time.

The curable resin composition of the present invention can be obtained by irradiating active energy rays such as ultraviolet rays. Specific examples of the light source used when the active energy ray is irradiated and hardened include, for example, xenon lamps, carbon arcs, germicidal lamps, ultraviolet fluorescent lamps, high-pressure mercury lamps for photocopying, medium-pressure mercury lamps, high-pressure mercury lamps, High-pressure mercury lamp, electrodeless lamp, metal halide lamp, or scanning type, curtain type electronic line acceleration path, etc. When the curable resin composition of the present invention is cured by ultraviolet irradiation, the amount of ultraviolet irradiation required for curing may be about 300 to 20,000 mJ / cm ² . In addition, in order to sufficiently harden the resin composition, it is expected that active energy rays such as ultraviolet rays are irradiated in an inert gas atmosphere such as nitrogen.

The hardened resin obtained by molding and hardening the hardenable resin composition of the present invention is excellent in optical materials such as cymbals and lenses. In particular, it can be used as a bonding layer, and exhibits excellent effects on bonding of optical materials to each other in a humidity-resistant environment. In addition, materials for optical plastic lenses, such as a pseudo lens sheet, a Fresnel lens, and a lenticular lens, can also be used.

When the curable resin composition of the present invention is used to adhere a polarizing film and a protective plate, for example, the protective plate is not limited to a protective plate made of alkali-free glass or quartz glass, which is excellent in active energy ray transmission, and is not limited thereto. Protective plates such as acrylic plates and polycarbonates with large ultraviolet absorption are also used because of their good reaction hardening properties.

The curable resin composition of the present invention is applied to a substrate such as a polarizing film, and is coated with a coating device such as a roll coater, a spin coater, or a screen printing method so that the thickness of the adhesive film is 1 to 100 μm, the protective plate is bonded, and it is cured by irradiating ultraviolet rays from above the protective plate to be cured.

[Example]

Next, the present invention will be described by way of examples, but the present invention is not limited thereto. In addition, "part" in each case is a weight part. The measurement of the softening temperature and the like in the examples were performed by preparing and measuring samples by a method shown below.

1) Molecular weight and molecular weight distribution of polymer

The molecular weight and molecular weight distribution of the polyfunctional (meth) acrylate copolymer are measured using GPC (manufactured by Tosoh TOSOH, HLC-8120GPC), using a solvent: tetrahydrofuran (THF), flow rate: 1.0 ml / min, and column temperature: It was carried out at 40 ° C. The molecular weight of the copolymer is measured using a calibration curve of monodisperse polystyrene as the polystyrene-equivalent molecular weight.

2) Structure of polymer

JNM-LA600 type nuclear magnetic resonance spectrometer manufactured by Japan Electronics was used, and it was determined by ¹³ C-NMR and ¹ H-NMR analysis. For the solvent, chloroform-d1 was used, and the resonance line of tetramethylsilane was used as an internal standard.

3) Determination of solvent solubility and colloid formation

The measurement of the solubility of the polyfunctional vinyl aromatic copolymer is to dissolve 2 g of the sample in various solvents (toluene, xylene, propylene glycol monomethyl ether acetate, tetrahydrofuran, dichloroethane, or chloroform). The transparency of the sample after the dissolution was confirmed, and the solubility was evaluated by classifying it into ○: transparent, △: translucent, ×: opaque or undissolved. And with At that time, the formation of colloid was visually confirmed, and the presence or absence of colloid was evaluated.

4) Sample preparation and measurement of elasticity measurement

A polyfunctional (meth) acrylate copolymer was dissolved in PGMEA, and PERBUTYL® O (manufactured by Nihon Grease) was blended as a thermal polymerization initiator. A varnish as a curable resin composition was coated on a glass substrate. After drying at 100 ° C / 10min under a nitrogen gas flow, it was hardened at 200 ° C / 1h under a nitrogen gas flow to produce a 200um thick measurement sample. This was mounted on a DMA (Dynamic Viscoelasticity Analysis Device) measurement device, and the measurement was performed by scanning at a temperature rise rate of 10 ° C / min from 20 ° C to 150 ° C under a nitrogen gas flow, and reading the value of E 'at 30 ° C to Find the elasticity of the sample.

5) Determination of thermal weight loss and heat discoloration resistance

The measurement of the thermal decomposition temperature and heat discoloration resistance of the polyfunctional (meth) acrylate copolymer is to install the sample on a TGA (thermal balance) measuring device, and make it under a nitrogen flow at a temperature rising rate of 10 ° C / min. Scan and measure at 30 ° C to 320 ° C, determine the weight reduction at 300 ° C, and visually confirm the amount of discoloration of the sample after measurement, and classify it into ◎: no thermal discoloration, ○: light yellow, △: brown, X: Black, evaluation of heat discoloration resistance was performed.

6) Measurement of refractive index

The polyfunctional (meth) acrylate copolymer is dissolved in toluene, and PERBUTYL® O is added as a starter, and the added amount is 1.0 weight based on 100 parts by weight of the soluble polyfunctional (meth) acrylate copolymer. The polymer solution was used to form a casting flake, and the casting flake was crushed, agglomerated, and filled in a pressure mold, and was cured at 170 ° C. for 1 hour using a pressure forming machine. The obtained hardened parallel flat plate was used as a test piece, and the refractive index of the d-line (587.6 nm) was measured in KPR-200 (manufactured by Shimadzu Kalnew). The measurement timing was immediately after the molding (initial stage), and the high-temperature and high-humidity humidifier under the humid and hot conditions of 85 ° C. × 85 RH was applied for one week (after the humid and hot).

7) Hygroscopic adhesion test

The varnish obtained by diluting the copolymer with PGMEA was coated on a glass substrate, dried at 100 ° C for 10 minutes, and then cured in an inactive oven under a nitrogen gas flow at 200 ° C for 1 hour. Next, the glass substrate on which the coating film obtained by curing the copolymer was mounted, and 100 checkerboard meshes with 11 vertical and horizontal tangent lines were formed on the surface of the coating film at 1 mm intervals in accordance with JISK5400. After the cellophane tape was adhered to the surface, the number of mesh grids that remained without peeling was counted at the time of primary peeling (initial stage). Furthermore, the glass substrate on which the coating film was mounted was immersed in hot water at 85 ° C for a predetermined period of time, and then the surface water was wiped off, and the cellophane tape was adhered to the surface again, and it was counted without peeling during one peeling and remained Number of mesh grids (after dipping).

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: Dicyclopentyl acrylate

αMSD: 2,4-diphenyl-4-methyl-1-pentene

DDME: n-dodecyl mercaptan

Example 1

NDDA252.35g, DCPA309.42g, EHDGA544.76g, HOP65.07g, αMSD222.32g, and 700ml of toluene were put into a 3.0L reactor, and 65.60mmol of benzamyl peroxide was added at 85 ° C to react 2 hour. After the polymerization reaction was stopped 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 a copolymer A (yield: 31 wt%).

Mw of the obtained copolymer A was 117,234, Mn was 20,874, and Mw / Mn was 5.6. By applying ¹³ C-NMR, ¹ H-NMR analysis and elemental analysis, it was found that the copolymer A contained 11.8 mol% of structural units derived from NDDA, 30.1 mol% of structural units derived from DCPA, and structures from EHDGA. The unit is 49.7 mole%, and the structural unit from HOP is 9.4 mole%. In addition, the terminal group derived from the structure of αMSD was 2.7 mole%. In addition, the Mohr fraction from the structural units of acrylic esters is a value calculated using the structural unit derived from all acrylic esters as 100, and the Mohr fraction of αMSD and the like is derived from all acrylic esters + αMSD And other structural units are calculated as 100. Mb1 is the Mohr fraction of the pendant acrylate, and is calculated on the basis of the structural unit derived from all acrylates as 100.

Copolymer A is soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, but does not form a colloid. The cast film of copolymer A is a transparent film without turbidity.

Examples 2, 3 and Comparative Examples 1, 2

The 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 as in Example 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. Without particular limitation, other reaction conditions and measurement conditions are the same as in Example 1. In Table 1, the amount of raw materials used is represented by Mohr and weight (g), and the description format is Mohr / g.

Claims (7)

A polyfunctional (meth) acrylate copolymer characterized by containing a monofunctional (meth) acrylate (a) represented by the following general formula (1) and a compound represented by the following general formula (2) Copolymer obtained by copolymerizing a bifunctional (meth) acrylate (b) and 2,4-diphenyl-4-methyl-1-pentene (c), CH ₂ = CR-CO -OR1 (1) (wherein R1 is a straight or branched hydrocarbon group having a carbon number of 9 or more and 30 or less, and the hydrocarbon group may contain an oxygen atom, a sulfur atom, or a nitrogen-containing group; R is H or a methyl group) CH ₂ = CR-CO-O-R2-O-OC-CR = CH ₂ (2) (where 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 (H or methyl) The copolymer has a reactive (meth) acrylate group derived from a bifunctional (meth) acrylate (b) in a side chain, and has a 2,4-diphenyl group derived at a terminal. The copolymer of the structural unit of 4-methyl-1-pentene (c) has a weight-average molecular weight of 10,000 to 1,000,000, and the molar fraction Mb of the unit derived from the component (b) in the unit of all acrylic esters is derived from monofunctional The amount of the (meth) acrylate (a) unit to be introduced from the unit of the bifunctional (meth) acrylate (b) ( Ear) when each of a and b, b / (a + b) is 0.01 to 0.5, furthermore, is soluble in toluene, xylene, propylene glycol monomethyl ether acetate, tetrahydrofuran, dichloroethane, or chloroform. The polyfunctional (meth) acrylate copolymer according to claim 1, wherein R1 in the general formula (1) is a fatty chain having a linear or branched structure having a carbon number of 9 to 30 or a glycol chain. The multifunctional (meth) acrylate copolymer according to claim 1 or 2, wherein R2 in the general formula (2) is a linear aliphatic chain or a glycol chain having 2 to 30 carbon atoms. The multifunctional (meth) acrylate copolymer according to claim 1, wherein the amount of the reactive (meth) acrylate-containing unit derived from the bifunctional (meth) acrylate (b) is introduced (mol) When it is b1, the molar fraction Mb1 of the unit is b1 / (a + b) is 0.02 to 0.5. The multifunctional (meth) acrylate copolymer according to claim 1, wherein the introduction amount (mol) of the unit derived from 2,4-diphenyl-4-methyl-1-pentene (c) is At c, the Mohr fraction Mc of the unit is c / (a + b + c) of 0.005 to 0.3. A curable resin composition comprising a polyfunctional (meth) acrylate copolymer according to any one of claims 1 to 5, a monomer having one or more functional groups containing an unsaturated double bond, And starters. An optical article characterized by being obtained by hardening and forming a curable resin composition according to claim 6.