Epoxy group-containing (meth)acrylic polymer and curable composition containing same

Abstract

To provide an epoxy group-containing (meth)acrylic polymer capable of forming a cured product that is liquid with low viscosity at room temperature, offering easy handleability, and also has high mechanical strength when cured, and a curable composition that contains the epoxy group-containing (meth)acrylic polymer and can sufficiently bond together members, for example, in the manufacture of electronic parts.SOLUTION: An epoxy group-containing (meth)acrylic polymer has a weight average molecular weight of 1,800 or more and less than 3,100, an epoxy value of 1.5 meq / g or more, and a viscosity of 80,000 mPa s or less at 25°C. An average number of epoxy groups per molecule is preferably 2.3 or more. Each molecule preferably includes carbon-carbon double bonds at a rate of 0.50-0.95 meq / g.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a liquid epoxy group-containing (meth)acrylic polymer and a curable composition containing the same. [Background technology]

[0002] Conventionally, epoxy resins have been widely used as components of adhesives, coating materials, sealing materials, heat dissipation materials, etc., because cured products of epoxy resins have excellent water resistance, chemical resistance, adhesiveness, electrical insulation, etc. However, cured products obtained by curing epoxy resins alone have excellent mechanical properties such as toughness, but have sometimes been poor in flexibility. To solve this problem, a technique is known in which a portion of the epoxy resin is replaced with an epoxy group-containing (meth)acrylic polymer (see Patent Document 1). On the other hand, it is known that cured products obtained by curing curable compositions containing epoxy group-containing (meth)acrylic polymers have high heat resistance and flexibility. Furthermore, since it is possible to suppress cure shrinkage by adjusting the epoxy value of the polymer, the compositions are also used as molding materials for adhesives, die attach materials, heat dissipation members, etc. (see Patent Documents 2 to 6). Patent Document 6 discloses an adhesive composition containing an epoxy resin and a copolymer having a weight-average molecular weight of 500 to 5,000 and including, as constituent units, a monomer unit having an epoxy group and a (meth)acrylic acid ester unit not having an epoxy group. Patent Document 7 discloses a resin composition containing 100 parts by mass of a resin and 1 to 30 parts by mass of a plasticizer made of a vinyl polymer having an epoxy group and having a glass transition temperature of 0°C or lower, a weight-average molecular weight of 500 to 30,000, and an epoxy value of 0.50 to 5.00 meq / g. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 179536 [Patent Document 2] Patent Publication No. 2008-222809 [Patent Document 3] International Publication No. 2018 / 034234 [Patent Document 4] International Publication No. 2018 / 154832 [Patent Document 5] Patent Publication No. 2020-160391 [Patent Document 6] Patent Publication No. 2006-96834 [Patent Document 7] Patent Publication No. 2005-60439 Summary of the Invention [Problem to be solved by the invention]

[0004] Among the epoxy group-containing polymers described in the above Patent Documents 1 to 5, there are polymers that are not only liquid but also solid in nature, but there is a problem that the solid epoxy group-containing (meth)acrylic polymers are difficult to handle and cannot be efficiently produced into curable compositions. In recent years, there has been a demand for liquid epoxy group-containing (meth)acrylic polymers that have low viscosity at room temperature, are easy to handle, and can form cured products with excellent mechanical properties when cured alone without using other resins in combination. There is also a need for a curable composition that contains an epoxy group-containing (meth)acrylic polymer and another resin having an epoxy group and that provides an adhesive composition that can sufficiently bond members together. In particular, there is a need for an epoxy group-containing (meth)acrylic polymer and a curable composition containing the same that provide a cured product with mechanical properties or adhesive performance that are superior to those of the specific epoxy group-containing polymers described in the above-mentioned Patent Documents 6 and 7. [Means for solving the problem]

[0005] The present inventors have found that the epoxy group-containing polymers disclosed in Patent Documents 6 and 7 have a weight-average molecular weight of 3,000 or less, but have very high viscosities at 25° C. and low epoxy values. Therefore, the inventors have investigated epoxy group-containing (meth)acrylic polymers having specific physical properties not specifically described in these documents, and have been able to solve the above problems, thereby completing the present invention.

[0006] The present invention is illustrated below. 1. A (meth)acrylic polymer having an epoxy group, which has a weight average molecular weight of 1,800 or more but less than 3,100, an epoxy value of 1.5 meq / g or more, and a viscosity at 25°C of 80,000 mPa·s or less. 2. A (meth)acrylic polymer according to item 1, wherein the average number of epoxy groups per molecule is 2.3 or more. 3. A (meth)acrylic polymer according to item 1 or 2, having carbon-carbon double bonds in the molecule in a proportion of 0.50 to 0.95 meq / g. 4. The (meth)acrylic polymer according to any one of items 1 to 3, which contains a structural unit derived from an alkyl (meth)acrylate and a structural unit derived from glycidyl (meth)acrylate. 5. A curable composition containing the (meth)acrylic polymer according to any one of items 1 to 4 above. 6. The curable composition according to item 5, further comprising an epoxy resin. 7. The curable composition according to item 5 or 6, further comprising a curing agent. 8. The curable composition according to any one of items 5 to 7, further comprising a cationic polymerization initiator. 9. An adhesive composition comprising the curable composition according to any one of items 5 to 8 above. 10. An electronic component obtained using the adhesive composition according to item 9 above.

[0007] In this specification, "(meth)acrylate" means acrylate and / or methacrylate. Also, "(meth)acryloyl" means acryloyl and / or methacryloyl. Furthermore, "(meth)acrylic" means acrylic and / or methacrylic. In this specification, "weight average molecular weight (Mw)" and "number average molecular weight (Mn)" are values ​​measured by gel permeation chromatography (GPC) in terms of standard polystyrene. Furthermore, "viscosity at 25°C" is a value measured using an E-type viscometer at 25°C±0.5°C, with a rotor rotation speed of 1 rpm or 5 rpm, and a 1°34' cone or a 3° cone. In this specification, the "epoxy value" is a value measured in accordance with ASTM D-1652. [Effects of the Invention]

[0008] The epoxy group-containing (meth)acrylic polymer of the present invention has low viscosity at room temperature and is easy to handle. When cured alone without using other resins, it can form a cured product with excellent mechanical properties (tensile strength or tensile elongation). Furthermore, by using the polymer together with other resins having epoxy groups, a curable composition can be efficiently produced. Furthermore, when the polymer contains structural units derived from an alkyl (meth)acrylate ester and structural units derived from glycidyl (meth)acrylate, a cured product with excellent tensile strength can be obtained, and a curable composition with excellent adhesion to components can be obtained. The curable composition of the present invention can form a cured product having excellent mechanical properties (tensile strength or tensile elongation). It can also provide an adhesive composition having excellent adhesion to components. Furthermore, because the curable composition of the present invention has excellent adhesion to components, it can provide a curable composition as a photocurable photosensitive resin suitable for forming electronic circuits such as semiconductors, liquid crystal displays, and printed circuit boards, and for fabricating micromachines. The electronic component of the present invention is an article obtained using an adhesive composition that has excellent adhesion to members, and therefore when the electronic component is, for example, a composite in which a semiconductor element such as an IC, LSI, or LED, or a chip such as a capacitor is adhered to a frame, substrate, or the like, the electronic component has excellent structural stability as an integrated product. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1. Epoxy group-containing (meth)acrylic polymer The epoxy group-containing (meth)acrylic polymer of the present invention is characterized by having a weight average molecular weight of 1,800 or more but less than 3,100, an epoxy value of 1.5 meq / g or more, and a viscosity at 25°C of 80,000 mPa·s or less.

[0010] The epoxy group-containing (meth)acrylic polymer of the present invention is a polymer containing a structural unit (hereinafter also referred to as "structural unit (s1)") derived from an epoxy group-containing (meth)acrylic monomer containing an epoxy group and a (meth)acryloyl group. The epoxy group-containing (meth)acrylic polymer of the present invention may be either a homopolymer or a copolymer, but is preferably a copolymer (hereinafter referred to as "epoxy group-containing (meth)acrylic copolymer") comprising at least one structural unit (s1) derived from an epoxy group-containing (meth)acrylic monomer and at least one structural unit (hereinafter referred to as "structural unit (s2)") derived from another vinyl monomer.

[0011] Examples of epoxy group-containing (meth)acrylic monomers include glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, etc. Among these, glycidyl (meth)acrylate is preferred, and glycidyl methacrylate is particularly preferred.

[0012] The other vinyl monomer is preferably a (meth)acrylic acid alkyl ester, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, , 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, stearyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, heneicosyl (meth)acrylate, behenyl (meth)acrylate, Tetracosyl (meth)acrylate, hexacosyl (meth)acrylate, octacosyl (meth)acrylate, triacontyl (meth)acrylate, dotriacontyl (meth)acrylate, tetratriacontyl (meth)acrylate, hexatriacontyl (meth)acrylate, octatriacontyl (meth)acrylate, tetracontyl (meth)acrylate, isodecyl (meth)acrylate, isoundecyl (meth)acrylate, isolauryl (meth)acrylate, isotridecyl (meth)acrylate, isotetradecyl (meth)acrylate, (meth)acrylate isopentadecyl (meth)acrylate, isohexadecyl (meth)acrylate, isoheptadecyl (meth)acrylate, isostearyl (meth)acrylate, isononadecyl (meth)acrylate, isoeicosyl (meth)acrylate, isoheneicosyl (meth)acrylate, isobehenyl (meth)acrylate, isotetracosyl (meth)acrylate, isohexacosyl (meth)acrylate, isooctacosyl (meth)acrylate, isotriacontyl (meth)acrylate, isodotriacontyl (meth)acrylate, isotetratriacontyl (meth)acrylate,Examples of such (meth)acrylic monomers include isohexatriacontyl (meth)acrylate, isooctatriacontyl (meth)acrylate, isotetracontyl (meth)acrylate, and the like, in which the alkyl ester moiety is a linear or branched aliphatic hydrocarbon group or an alicyclic hydrocarbon group. The epoxy group-containing (meth)acrylic polymer of the present invention preferably contains, as the structural unit (s2), a structural unit derived from a (meth)acrylic monomer in which the alkyl ester moiety is an aliphatic hydrocarbon group having 4 to 40 carbon atoms.

[0013] The epoxy group-containing (meth)acrylic polymer of the present invention may further contain structural units derived from other vinyl monomers. For example, (meth)acrylic acid alkoxyalkyl esters such as methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, methoxybutyl (meth)acrylate, methoxyhexyl (meth)acrylate, ethoxymethyl (meth)acrylate, ethoxyethyl (meth)acrylate, ethoxybutyl (meth)acrylate, ethoxyhexyl (meth)acrylate, butoxymethyl (meth)acrylate, butoxyethyl (meth)acrylate, butoxybutyl (meth)acrylate, and butoxyhexyl (meth)acrylate; aromatic (meth)acrylate esters such as phenyl (meth)acrylate, toluyl (meth)acrylate, and benzyl (meth)acrylate; functional group-containing monomers such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-trimethoxysilylpropyl (meth)acrylate, 3-methyldimethoxysilylpropyl (meth)acrylate, 2-aminoethyl (meth)acrylate, and ethylene oxide adducts of (meth)acrylic acid; fluorine-containing (meth)acrylic acid esters such as trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, 2-perfluoroethylmethyl (meth)acrylate, perfluoromethylmethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate, 2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, and 2-perfluorohexadecylethyl (meth)acrylate; fluorine-containing olefins such as perfluoroethylene, perfluoropropylene, and vinylidene fluoride; Aromatic vinyl compounds such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, styrenesulfonic acid and its salts; Unsaturated acid anhydrides such as maleic anhydride, itaconic anhydride, and citraconic anhydride; Unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, and their monoalkyl and dialkyl esters; Unsaturated acids such as acrylic acid, methacrylic acid, and crotonic acid; maleimide compounds such as maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, phenylmaleimide, and cyclohexylmaleimide; nitrile group-containing vinyl compounds such as acrylonitrile, methacrylonitrile, ethacrylonitrile, α-ethylacrylonitrile, and α-isopropylacrylonitrile; Amide group-containing vinyl compounds such as acrylamide and methacrylamide; vinyl esters such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and vinyl cinnamate; vinylsilanes such as vinyltrimethoxysilane and vinylmethyldimethoxysilane; Alkenes such as ethylene and propylene; conjugated dienes such as butadiene and isoprene; Examples thereof include vinyl chloride, vinylidene chloride, allyl chloride, allyl alcohol, vinyl glycidyl ether, allyl glycidyl ether, acrylic glycidyl ether, methallyl glycidyl ether, and 4-hydroxybutyl acrylate glycidyl ether.

[0014] In the epoxy group-containing (meth)acrylic copolymer which is a preferred embodiment of the present invention, the content of the structural unit (s1) contained therein is preferably 10 to 50 mass %, more preferably 20 to 40 mass %, based on the total amount of structural units constituting the copolymer, i.e., the total amount of structural units (s1) and (s2), since a cured product having excellent tensile strength can be obtained when the copolymer is cured alone without using any other resin in combination, and a curable composition having excellent adhesion to members can be obtained.

[0015] The epoxy group-containing (meth)acrylic polymer of the present invention contains an epoxy group contained in at least the structural unit (s1). The epoxy value of the polymer is 1.5 meq / g or more, preferably 1.7 to 5.0 meq / g, more preferably 2.0 to 4.0 meq / g, because a cured product having excellent tensile strength can be obtained when the polymer is cured alone without using any other resin in combination, and a curable composition having excellent adhesion to members can be obtained. The average number of epoxy groups per molecule of the epoxy group-containing (meth)acrylic polymer of the present invention is preferably 2.3 or more, more preferably 2.5 or more, although the upper limit is usually 6.0.

[0016] The epoxy group-containing (meth)acrylic copolymer, which is a preferred embodiment of the present invention, may be either a random copolymer or a block copolymer. When the copolymer is cured alone, a cured product having excellent tensile strength can be obtained, and a curable composition that provides an adhesive composition having excellent adhesion to members can be obtained. Therefore, it is preferable that the copolymer has a carbon-carbon double bond in the molecule, and it is particularly preferable that the copolymer has a portion containing a carbon-carbon double bond at the end of the structural unit at the end. Such a portion containing a double bond is preferably represented by the following general formula (1): C=C-CO-OR 1 It is a department. [ka] [In the formula, R 1 is a monovalent organic group or a hydrogen atom, (M) is a structural unit, and n is a natural number representing the degree of polymerization.

[0017] R in the above general formula (1) 1 Examples of the alkyl group include an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an alkyl group which may have other substituents, a phenyl group, a benzyl group, a polyalkylene glycol group, a dialkylaminoalkyl group, a trialkoxysilylalkyl group, and an alkyldialkoxysilylalkyl group.

[0018] In the present invention, when the epoxy group-containing (meth)acrylic polymer has a carbon-carbon double bond in the molecule, the content of the carbon-carbon double bond is preferably 0.50 to 0.95 meq / g, more preferably 0.60 to 0.90 meq / g.

[0019] In the present invention, the weight average molecular weight (Mw) of the epoxy group-containing (meth)acrylic polymer is 1,800 or more and less than 3,100, preferably 1,900 to 3,000, and more preferably 2,000 to 3,000. The epoxy group-containing (meth)acrylic polymer has a viscosity at 25° C. of 80,000 mPa·s or less, preferably 1,000 to 30,000 mPa·s, and more preferably 2,000 to 23,000 mPa·s. A viscosity within the above range makes it easy to handle, and allows the curable composition to be produced efficiently.

[0020] The glass transition temperature of the epoxy group-containing (meth)acrylic polymer of the present invention is not particularly limited, but from the viewpoint of workability, it is preferably −70° C. to −20° C., more preferably −60° C. to −40° C. The glass transition temperature can be measured by the method described in [Examples].

[0021] The method for producing the epoxy group-containing (meth)acrylic polymer of the present invention is not particularly limited, and a conventionally known method, i.e., a method in which monomers forming the above-mentioned structural units are polymerized in the presence of a polymerization initiator, can be applied. In the present invention, it is particularly preferable to use a pressure reactor, since a polymer having specific physical properties can be efficiently produced.

[0022] The production method using a pressure reactor can be, for example, a method in which a heatable and pressurizable reactor is set to a predetermined temperature under pressurized conditions, and then monomers (preferably, an epoxy group-containing (meth)acrylic monomer and a monomer containing a (meth)acrylic acid alkyl ester) are supplied to the reactor, and the monomers are polymerized while withdrawing a reaction liquid in an amount corresponding to the amount of the raw material supplied. When supplying the monomers, a polymerization solvent, a polymerization initiator, a chain transfer agent, etc. may be used in combination, if necessary.

[0023] The polymerization solvent is not particularly limited, and examples thereof include cyclic ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbon compounds such as benzene, toluene and xylene, carboxylic acid esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone and cyclohexanone, and alcohols such as methanol, ethanol and isopropanol. The polymerization solvent may consist of one or more of these. From the viewpoint of conversion, the amount of the polymerization solvent used is preferably 80 parts by mass or less, more preferably 30 parts by mass or less, based on 100 parts by mass of the total amount of the monomers used. If necessary, the polymerization solvent can be used in combination with a dehydrating agent. Examples of the dehydrating agent include trimethyl orthoacetate and trimethyl orthoformate.

[0024] The polymerization initiator is not particularly limited as long as it generates radicals at the polymerization temperature described below. Examples of suitable initiators include organic peroxides such as di-tert-butyl peroxide, di-tert-hexyl peroxide, tert-hexylperoxy-2-ethylhexanoate, tert-butylperoxy-2-ethylhexanoate, cumene hydroperoxide, and tert-butyl hydroperoxide; and azo compounds such as 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), azobiscyclohexacarbonitrile, azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-amidinopropane) dihydrochloride, and 4,4'-azobis(4-cyanovaleric acid). The polymerization initiator may consist of one or more of these. When a polymerization initiator with high hydrogen abstraction ability is used, the concentration of carbon-carbon double bonds in the resulting polymer tends to be high. For example, the use of organic peroxides rather than azo compounds tends to produce polymers with a higher double bond concentration. The amount of the polymerization initiator used can be adjusted appropriately depending on the type of monomer, the desired molecular weight, the polymerization conditions, etc., but is preferably 0.001 to 10 parts by mass, and more preferably 0.001 to 2 parts by mass, when the total amount of the monomers used is taken as 100 parts by mass. When producing a polymer of the same molecular weight, the double bond concentration in the obtained polymer tends to increase as the amount of the polymerization initiator used decreases.

[0025] The use of a chain transfer agent tends to lower the carbon-carbon double bond concentration in the resulting polymer. In general, the more the chain transfer agent is used, the lower the double bond concentration.

[0026] The polymerization temperature of the monomers is preferably 120° C. to 280° C., more preferably 150° C. to 250° C. The pressure inside the reactor is not particularly limited since it depends on the polymerization temperature, the boiling point of the monomers used, and the boiling point of the polymerization solvent, but may be any pressure that can maintain the above polymerization temperature. The residence time of the monomer in the reactor is adjusted appropriately depending on the size of the reactor and the like, but is preferably 1 to 60 minutes, more preferably 2 to 40 minutes.

[0027] After the polymerization of the monomers, the reaction solution containing the polymer can be extracted from the reactor and recovered as is. Alternatively, the polymer can be isolated by distilling off volatile components such as unreacted monomers, solvents, and low-molecular-weight oligomers from the recovered reaction solution using a distillation apparatus, a thin-film evaporator, or the like.

[0028] 2.Curable composition The curable composition of the present invention is a composition containing the above-mentioned epoxy group-containing (meth)acrylic polymer of the present invention. The curable composition of the present invention is suitable for a curing method using a curing agent, a curing method using a cationic polymerization initiator (a photocationic polymerization initiator or a thermal cationic polymerization initiator), and a curing method using an anionic polymerization initiator.

[0029] In the curable composition of the present invention, the main component involved in the curing reaction is an epoxy group-containing (meth)acrylic polymer (hereinafter referred to as "component (A)"). The curable composition of the present invention may contain this component (A) together with a curing agent, etc., but may also contain another compound having an epoxy group or a compound having an oxetanyl group (hereinafter collectively referred to as "component (B)") as another component involved in the curing reaction, and this component (B) may be contained together with component (A) and a curing agent, etc.

[0030] Among the components (B), examples of the compound having an epoxy group include bisphenol A type epoxy resins, bisphenol F type epoxy resins, and hydrogenated versions thereof; glycidyl ester epoxy resins such as orthophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, p-hydroxybenzoic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, and trimellitic acid triglycidyl ester; ethylene glycol epoxy resins; Glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether, tetraphenylglycidyl ether ethane, triphenylglycidyl ether ethane, polyglycidyl ether of sorbitol, poly Glycidyl ether-based epoxy resins such as polyglycidyl ether of triglycerol; glycidyl amine-based epoxy resins such as triglycidyl isocyanurate and tetraglycidyldiaminodiphenylmethane; linear aliphatic epoxy resins such as epoxidized polybutadiene and epoxidized soybean oil; novolac-type epoxy resins such as phenol novolac epoxy resin, o-cresol novolac epoxy resin, and bisphenol A novolac epoxy resin; phenoxy glycidyl ether, 2-ethylhexyl glycidyl ether, butyl glycidyl ether, lauryl glycidyl ether, monofunctional epoxy compounds such as glycidyl ether, stearyl glycidyl ether, and coconut fatty acid glycidyl ether; and alicyclic epoxy compounds such as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-meta-dioxane, bis(3,4-epoxycyclohexylmethyl)adipate, and trimethylcaprolactone-modified 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate. Among component (B), examples of compounds having an oxetanyl group include 3,3-dimethyloxetane, 3,3-bis(chloromethyl)oxetane, 2-hydroxymethyloxetane, 3-methyl-3-oxetanemethanol, 3-methyl-3-methoxymethyloxetane, 3-ethyl-3-phenoxymethyloxetane, resorcinol bis(3-methyl-3-oxetanylethyl)ether, and m-xylylene bis(3-ethyl-3-oxetanylethyl ether). In the present invention, component (B) is preferably an epoxy resin, and particularly preferably a bisphenol A type epoxy resin.

[0031] In a curable composition containing component (A) and component (B), the content ratios for sufficiently bonding members together are as follows: When the total of component (A) and component (B) is taken as 100 mass%, the content ratios are preferably 3 to 50 mass% and 50 to 97 mass%, more preferably 5 to 45 mass% and 55 to 95 mass%, and even more preferably 10 to 40 mass% and 60 to 90 mass%, respectively.

[0032] When the curable composition of the present invention is a composition containing a curing agent, the curing agent is not particularly limited, and conventionally known polycarboxylic acid compounds, acid anhydrides, and, as the curing agent and / or anionic polymerization initiator, polyamine compounds, imidazole compounds, latent amine compounds, photoanionic polymerization initiators, etc. can be used. Specific examples are shown below.

[0033] (C1-1) Polycarboxylic acid compounds Aliphatic polycarboxylic acids such as succinic acid, maleic acid, fumaric acid, adipic acid, azelaic acid, sebacic acid, dimer acid, and hydrogenated dimer acid; aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, and pyromellitic acid; polymers having carboxyl groups (e.g., polymers containing structural units derived from (meth)acrylic acid), and the like.

[0034] (C1-2) Acid anhydride Succinic anhydride, dodecenyl succinic anhydride, polyadipic anhydride, polyazelaic anhydride, polysebacic anhydride, methyltetrahydrophthalic acid, methylhexahydrophthalic acid, methylhimic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, and the like.

[0035] (C1-3) Polyamine compounds Ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexamethylenediamine, dipropylenediamine, N-aminoethylpiperazine, isophoronediamine, m-xylenediamine, and the like. (C1-4) Imidazole Compounds 2-Methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, epoxy-imidazole adduct, etc. (C1-5) Latent amine compounds Ketimine compounds that generate amines when exposed to moisture in the air. (C1-6) Photoanionic polymerization initiator [(4,5-Dimethoxy-2-nitrobenzyl)oxy]carbonyl-2,6-dimethylpiperidine, 1,2-dicyclohexyl-4,5,5,5-tetramethylbiguanidium n-butyltriphenylborate, 9-anthrylmethyl-N,N'-diethylcarbamate, (E)-1-[3-(2-hydroxyphenyl)-2-propenoyl]piperidine, guanidinium 2-(3-benzoylphenyl)propionate, 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidinium 2-(3-benzoylphenyl)propionate, and the like.

[0036] When the curable composition of the present invention contains a polycarboxylic acid compound (C1-1), the curable composition preferably contains component (A) or components (A) and (B) and the polycarboxylic acid compound (C1-1) such that the ratio of the number of moles of epoxy groups in component (A) or the total number of moles of epoxy groups in component (A) and component (B) to the number of moles of carboxyl groups in the polycarboxylic acid compound (C1-1) is preferably 0.1 to 10, more preferably 0.5 to 3, and even more preferably 0.8 to 1.5. A tough cured product can be obtained by heating the curable composition having the above-described configuration at a temperature of 70°C to 180°C for approximately 10 minutes to 10 hours. The curable composition containing the polycarboxylic acid compound (C1-1) may further contain a curing accelerator. Specific examples of the curing accelerator include quaternary ammonium salts such as tetramethylammonium chloride or bromide, tetraethylammonium chloride or bromide, tetrabutylammonium chloride or bromide, benzyltrimethylammonium chloride or bromide, and octylammonium chloride or bromide; tertiary amines such as triethylamine, benzyldimethylamine, 1,4-diazabicyclo[2,2,2]octane, and 1,8-diazabicyclo[5,4,0]undec-7-ene; imidazole compounds (C1-4); and phosphorus compounds such as triphenylphosphine. The content of the curing accelerator is preferably 0.01 to 3 parts by mass, based on 100 parts by mass of the total amount of component (A) or component (A) and component (B) and the polycarboxylic acid compound (C1-1), since this results in a transparent and tough cured product.

[0037] When the curable composition of the present invention contains an acid anhydride (C1-2), the curable composition preferably contains component (A) or components (A) and (B) and the acid anhydride (C1-2) such that the ratio of the number of moles of epoxy groups in component (A) or the total number of moles of epoxy groups in component (A) and component (B) to the number of moles of carboxyl groups in the acid anhydride (C1-2) is preferably 0.1 to 10, more preferably 0.5 to 3, and even more preferably 0.8 to 1.5. A tough cured product can be obtained by heating the curable composition having the above-described configuration at a temperature of 70°C to 180°C for approximately 10 minutes to 10 hours. The curable composition containing the acid anhydride (C1-2) may further contain the same curing accelerator as in the case where the polycarboxylic acid compound (C1-1) is used.

[0038] When the curable composition of the present invention contains a polyamine compound (C1-3), it is preferable that the curable composition contains component (A) or component (A) and component (B) and the polyamine compound (C1-3) so that the ratio of the number of moles of epoxy groups in component (A) or the total number of moles of epoxy groups in component (A) and component (B) to the number of moles of amino groups in the polyamine compound (C1-3) is preferably 0.1 to 10, more preferably 0.5 to 3, and even more preferably 0.8 to 1.5. The curable composition having the above configuration can be quickly cured by mixing at room temperature or by heating at about 40°C to 100°C.

[0039] When the curable composition of the present invention is a composition containing an imidazole compound (C1-4) or a photoanionic polymerization initiator (C1-6), the content of the imidazole compound (C1-4) or the photoanionic polymerization initiator (C1-6) is preferably 0.5 to 5 parts by mass relative to 100 parts by mass of the total amount of component (A), or components (A) and (B). When the content is 0.5 parts by mass or more, good curability is obtained, and when the content is 5 parts by mass or less, good adhesion is obtained.

[0040] Furthermore, when the curable composition of the present invention contains an imidazole compound (C1-4) or a photoanionic polymerization initiator (C1-6), a polyfunctional thiol compound, a liquid polymercaptan compound, or a polysulfide resin can be used in combination as a curing agent. When these thiol-containing compounds are contained in the curable composition, a cured product with excellent adhesion and moderate flexibility can be obtained. In particular, when a photoanionic polymerization initiator (C1-6) is used, high temperatures and long periods of time are not required for curing, making it suitable for use on components with low heat resistance.

[0041] When the curable composition of the present invention is a composition containing an anionic photopolymerization initiator, the photoanionic photopolymerization initiator is not particularly limited, as long as it generates an anion or a Lewis base upon exposure to active energy rays such as ultraviolet light, visible light, or an electron beam, and initiates polymerization of anionic curable groups such as epoxy groups contained in component (A) or the like. When the curable composition of the present invention is a composition containing a cationic photopolymerization initiator, the photocationic photopolymerization initiator is not particularly limited, as long as it generates a cation or a Lewis acid upon exposure to active energy rays such as ultraviolet light, visible light, or an electron beam, and initiates polymerization of cationic curable groups such as epoxy groups or oxetanyl groups contained in component (A) or the like. Examples of cationic photopolymerization initiators are listed below.

[0042] (C2-1) Sulfonium salt-based cationic photopolymerization initiator Triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, diphenyl-4-(phenylthio)phenylsulfonium hexafluorophosphate, diphenyl-4-(phenylthio)phenylsulfonium hexafluoroantimonate, 4,4'-bis[diphenylsulfonio]diphenylsulfide bishexafluorophosphate, 4,4'-bis[di(β-hydroxyethoxy)phenylsulfonio]di Phenyl sulfide bishexafluoroantimonate, 4,4'-bis[di(β-hydroxyethoxy)phenylsulfonio]diphenyl sulfide bishexafluorophosphate, 7-[di(p-toluyl)sulfonio]-2-isopropylthioxanthone hexafluoroantimonate, 7-[di(p-toluyl)sulfonio]-2-isopropylthioxanthone tetrakis(pentafluorophenyl)borate, 4-phenylcarbonyl-4'-diphenylsulfonio-diphenyl sulfide hexafluorophosphate, 4-(p-ter Triarylsulfonium salts such as 4-(p-tert-butylphenylcarbonyl)-4'-diphenylsulfonio-diphenylsulfide hexafluoroantimonate, 4-(p-tert-butylphenylcarbonyl)-4'-di(p-toluyl)sulfonio-diphenylsulfide tetrakis(pentafluorophenyl)borate; benzyl(4-hydroxyphenyl)(methyl)sulfonium hexafluoroantimonate, benzyl[4-(methoxycarbonyloxy)phenyl](methyl)sulfonium hexafluoroantimonate, (4-hydroxy (phenyl)methyl(2-methylbenzyl)sulfonium hexafluoroantimonate, (4-acetoxyphenyl)benzyl(methyl)sulfonium hexafluoroantimonate, (4-hydroxyphenyl)dimethylsulfonium hexafluoroantimonate, (4-acetoxyphenyl)dimethylsulfonium hexafluoroantimonate, (4-hydroxyphenyl)methyl(1-naphthylmethyl)sulfonium hexafluorophosphate, (4-acetoxyphenyl)benzyl(methyl)sulfonium hexafluorophosphate,(4-acetoxyphenyl)dimethylsulfonium hexafluoroantimonate, (4-hydroxyphenyl)methyl(1-naphthylmethyl)sulfonium hexafluoroantimonate, benzyl(4-hydroxyphenyl)(methyl)sulfonium hexafluorophosphate, (4-acetoxyphenyl)benzyl(methyl)sulfonium hexafluorophosphate, (4-acetoxyphenyl)dimethylsulfonium hexafluorophosphate, benzyl(4-hydroxyphenyl)(methyl)sulfonium tetrakis(pentafluorophenyl)borate, (4-acetoxyphenyl)methyl(2-methylbenzyl)sulfonium tetrakis(pentafluorophenyl)borate, (4-acetoxyphenyl)benzyl(methyl)sulfonium tetrakis(pentafluorophenyl)borate benzyl)borate, (4-hydroxyphenyl)methyl(4-methylbenzyl)sulfonium tetrakis(pentafluorophenyl)borate, benzyl[4-(methoxycarbonyloxy)phenyl](methyl)sulfonium tetrakis(pentafluorophenyl)borate, (4-hydroxyphenyl)dimethylsulfonium tetrakis(pentafluorophenyl)borate, (4-acetoxyphenyl)dimethylsulfonium tetrakis(pentafluorophenyl)borate, benzyl(4-hydroxyphenyl)(methyl)sulfonium trifluoromethanesulfonate, [4-(methoxycarbonyloxy)phenyl]dimethylsulfonium trifluoromethanesulfonate, (4-hydroxyphenyl)methyl(2-methylbenzyl)sulfonium trifluoromethanesulfonate, etc.

[0043] (C2-2) Iodonium salt-based cationic photopolymerization initiators Diaryl iodonium salts such as diphenyliodonium tetrakis(pentafluorophenyl)borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, di(4-tert-butylphenyl)iodonium hexafluorophosphate, di(4-tert-butylphenyl)iodonium hexafluoroantimonate, tolylcumyliodonium tetrakis(pentafluorophenyl)borate, (4-methylphenyl)[4-(2-methylpropyl)phenyl]-hexafluorophosphate, di(4-nonylphenyl)iodonium hexafluorophosphate, and di(4-alkylphenyl)iodonium hexafluorophosphate.

[0044] (C2-3) Diazonium salt photocationic polymerization initiator Benzenediazonium hexafluoroantimonate, benzenediazonium hexafluorophosphate, and the like.

[0045] As the cationic photopolymerization initiator, a sulfonium salt-based cationic photopolymerization initiator (C2-1) is particularly preferred.

[0046] When the curable composition of the present invention is a composition containing a photocationic polymerization initiator or a photoanionic polymerization initiator, the content of the photocationic polymerization initiator or the photoanionic polymerization initiator is preferably 0.1 to 5.0 parts by mass, more preferably 0.5 to 3.0 parts by mass, relative to 100 parts by mass of the content of component (A), or the total content of components (A) and (B) when component (B) is contained.

[0047] As described above, the curable composition containing the photocationic or anionic polymerization initiator can be cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, etc. As the active energy rays, ultraviolet rays are preferred. When irradiating with ultraviolet light, a light source that can be used is a UV-LED (ultraviolet light emitting diode), a high-pressure mercury lamp, a metal halide lamp, etc. In the case of a UV-LED, it is preferable to use a wavelength of 365 nm, 385 nm, 395 nm, 405 nm, etc.

[0048] When the curable composition of the present invention is a composition containing a thermal cationic polymerization initiator, the thermal cationic polymerization initiator is not particularly limited as long as it is a compound that, upon heating, induces ring-opening of a ring-opening polymerizable group, such as an epoxy group or an oxetanyl group, contained in component (A) or the like. Examples of thermal cationic polymerization initiators are listed below. Among the thermal cationic polymerization initiators, there are compounds that are useful as photo-cationic polymerization initiators.

[0049] (C3-1) Quaternary ammonium salt-based thermal cationic polymerization initiator A compound represented by the following general formula (2) is preferably used. [ka]

[0050] In the above general formula (2), each R 2 may be the same or different, and are an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, an alkenyl group having 3 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a group in which at least one hydrogen atom bonded to a carbon atom contained in these groups has been substituted with a monovalent group, or two R 2 are bonded to each other to form a heterocycle containing a N atom, a P atom, an O atom, or a S atom. X - is the counterion, BF4 - , AsF6 - , SbF6 - , SbCl6 - , (C6F5)4B - , SbF5(OH) - , HSO4 - , p-CH3C6H4SO3 - , HCO3 -, H2PO4 - , CH3CO2 - , halogen ions (Cl - , Br - , I - etc.) etc.

[0051] Examples of the compound represented by the general formula (2) include tetrabutylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, tetrabutylammonium hydrogen sulfate, tetraethylammonium tetrafluoroborate, tetraethylammonium p-toluenesulfonate, N,N-dimethyl-N-benzylanilinium hexafluoroantimonate, N,N-dimethyl-N-benzylanilinium tetrafluoroborate, N,N-dimethyl-N-benzylpyridinium hexafluoroantimonate, N,N-diethyl-N-benzyltrifluoromethanesulfonate, N,N-dimethyl-N-(4-methoxybenzyl)pyridinium hexafluoroantimonate, and N,N-diethyl-N-(4-methoxybenzyl)toluidinium hexafluoroantimonate.

[0052] (C3-2) Phosphonium salt-based thermal cationic polymerization initiator A compound represented by the following general formula (3) is preferably used. [ka]

[0053] In the above general formula (3), each R 3 may be the same or different, and R in the above general formula (2) 2 It can be configured as the same as X. - is a counter ion, and X in the above general formula (2) - The same configuration can be used.

[0054] Examples of the compound represented by the general formula (3) include ethyltriphenylphosphonium hexafluoroantimonate and tetrabutylphosphonium hexafluoroantimonate.

[0055] (C3-3) Sulfonium salt-based thermal cationic polymerization initiator Compounds represented by the following general formulas (4), (5) and (6) are preferably used.

[0056] [ka]

[0057] In the above general formula (4), each R 4 may be the same or different, and R in the above general formula (2) 2 It can be configured as the same as X. - is a counter ion, and X in the above general formula (2) - The same configuration can be used.

[0058] Examples of the compound represented by the general formula (4) include triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluoroarsinate, tris(4-methoxyphenyl)sulfonium hexafluoroarsinate, (4-hydroxyphenyl)methyl(1-naphthylmethyl)sulfonium hexafluoroantimonate, benzyl(4-hydroxyphenyl)(methyl)sulfonium hexafluorophosphate, (4-hydroxyphenyl)dimethylsulfonium hexafluoroantimonate, and (4-hydroxyphenyl)methyl(1-naphthylmethyl)sulfonium hexafluorophosphate.

[0059] [ka]

[0060] In the above general formula (5), each R 5may be the same or different, and R in the above general formula (2) 2 Ar is an aryl group which may have a substituent. X - is a counter ion, and X in the above general formula (2) - The same configuration can be used.

[0061] Examples of the compound represented by the above general formula (5) include diphenyl(4-phenylthiophenyl)sulfonium hexafluoroarsinate.

[0062] [ka]

[0063] In the above general formula (6), each R 6 may be the same or different, and R in the above general formula (2) 2 Each Ar may be the same or different and is an aryl group which may have a substituent. X - is a counter ion, and X in the above general formula (2) - The same configuration can be used.

[0064] Examples of the compound represented by the general formula (6) include 4,4'-bis[bis((β-hydroxyethoxy)phenyl)sulfonio]phenylsulfide-bis-hexafluoroantimonate).

[0065] In the present invention, the thermal cationic polymerization initiator is particularly preferably a sulfonium salt-based thermal cationic polymerization initiator represented by the above general formula (4).

[0066] When the curable composition of the present invention is a composition containing a thermal cationic polymerization initiator, the content of the thermal cationic polymerization initiator is preferably 0.1 to 5.0 parts by mass, more preferably 0.5 to 3.0 parts by mass, relative to 100 parts by mass of the content of component (A), or the total content of components (A) and (B) when component (B) is contained.

[0067] The curable composition containing a thermal cationic polymerization initiator can be cured by heating preferably at 50°C to 200°C, more preferably at 75°C to 180°C. The curing temperature may be constant or may be increased stepwise. In the latter case, the heat treatment may be performed for a predetermined time in three steps, for example, at 80°C to 110°C, 110°C to 130°C, and 130°C to 160°C. The total heating time until curing is set appropriately depending on the size, etc., but is usually at least 60 minutes.

[0068] The curable composition of the present invention may contain additives such as plasticizers, antioxidants, ultraviolet absorbers, light stabilizers, fillers, leveling agents, antifoaming agents, adhesion-imparting agents, thixotropy-imparting agents, antistatic agents, flame retardants, colorants, and matting agents.

[0069] Examples of the plasticizer include polyester-based plasticizers obtained from dicarboxylic acids and diols; etherified or esterified products of polyalkylene glycols such as polyethylene glycol and polypropylene glycol; polyether-based plasticizers such as saccharide-based polyethers obtained by addition polymerization of alkylene oxides such as ethylene oxide and propylene oxide to saccharide polyhydric alcohols such as sucrose, followed by etherification or esterification; polystyrene-based plasticizers such as poly-α-methylstyrene; polyurethane-based plasticizers; and poly(meth)acrylates having no crosslinkable functional groups.

[0070] Examples of the antioxidant include hindered amine antioxidants, phenolic antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers. Examples of the light stabilizer include hindered amine compounds, benzophenone compounds, benzotriazole compounds, benzoate compounds, and triazine compounds. Examples of fillers that can be used include particles made of calcium carbonate, silica, titanium oxide, carbon black, talc, calcined clay, kaolin, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, fosterite, steatite, spinel, zeolite, crosslinked polymers, and the like. As the adhesion promoter, a silane coupling agent such as aminosilane can be used.

[0071] Because the curable composition of the present invention contains component (A), i.e., the epoxy group-containing (meth)acrylic polymer of the present invention, not only compositions not containing component (B) but also compositions containing components (A) and (B) have a viscosity suitable for bar coating, screen printing, spin coating, roll coating, spray coating, application with a dispenser, etc. That is, the viscosity of the curable composition containing components (A) and (B) is preferably 1,000 to 30,000 mPa s, and more preferably 1,200 to 15,000 mPa s, when measured under the same viscosity measurement conditions as for component (A).

[0072] The curable composition of the present invention can be produced by mixing the raw material components all at once or in portions. For mixing, a kneader, a Raikai mixer, a Brabender, a three-roll mixer, a universal mixer, a planetary mixer, a homomixer, a homodisper, a bead mill, etc. can be used.

[0073] The curable composition of the present invention can be used as an adhesive (the adhesive composition described below) having excellent adhesion to members, a molding material for cured resin members, a sealant for ICs, LSIs, LEDs, etc.

[0074] 3. Adhesive composition The adhesive composition of the present invention is a composition containing the curable composition of the present invention. A preferred composition for use in bonding to an adherend (member) contains component (A), component (B), a curing agent, a cationic polymerization initiator, etc. In the present invention, preferred constituent materials of the adherend are inorganic materials (metals, ceramics, etc.), organic materials (resins, rubbers, etc.), or composite materials containing these. The adhesive composition of the present invention is also suitable for bonding adherends made of the same material or adherends made of different materials. The uses of the adhesive composition of the present invention are not particularly limited, and can be for civil engineering, construction, vehicles, general office use, medical use, electronic materials, etc. The adhesive composition of the present invention is suitable as an adhesive for producing electronic components, and can be used as an adhesive for forming polarizing plates, an adhesive for anisotropic conductive films, an adhesive for coverlay films, an adhesive for forming copper-clad films, an interlayer adhesive for multilayer substrates (build-up substrates, etc.), a die bonding material, an adhesive for semiconductors such as an underfill material, etc.

[0075] The method for adhering the adhesive composition of the present invention to an adherend and the method for adhering adherends to each other using the adhesive composition of the present invention are not particularly limited, and heating conditions, light irradiation conditions, etc. are selected appropriately depending on the types of curing agent, cationic polymerization initiator, etc. When an adhesive composition containing an epoxy group-containing (meth)acrylic polymer having a carbon-carbon double bond in its molecule and the curing agent or cationic polymerization initiator described above is used to bond adherends, the carbon-carbon double bond derived from the epoxy group-containing (meth)acrylic polymer tends to remain in the cured portion after adhesion. Therefore, for example, if radicals are generated due to heat generation or the like during use of an electronic component manufactured using the adhesive composition, the carbon-carbon double bond contained in the cured portion is expected to react with the radicals, thereby suppressing deterioration of the electronic component. Furthermore, the carbon-carbon double bond is expected to trap halogen molecules and ions contained in trace amounts in electronic materials, thereby suppressing deterioration of the electronic material.

[0076] 4. Electronic Components The electronic component of the present invention is an article in which components constituting the electronic component are bonded together using the adhesive composition of the present invention, preferably a composition containing components (A) and (B), a curing agent, a cationic polymerization initiator, etc. That is, the electronic component of the present invention is a composite comprising an adhesive layer at least between adherends made of the same material or between adherends made of different materials. This adhesive layer comprises a cured product of the adhesive composition, and in a preferred embodiment, mainly contains a cured product having a crosslinked structure formed by ring-opening polymerization of epoxy groups, etc., in components (A) and (B).

[0077] Examples of the electronic component of the present invention include composites in which semiconductor elements such as ICs, LSIs, and LEDs, and chips such as capacitors are bonded to a frame, substrate, or the like with an adhesive composition.

[0078] The method for producing the electronic component of the present invention is not particularly limited, and examples thereof include a method in which an adhesive composition is interposed between member X and member Y and then heat-cured or light-cured, and a method in which the adhesive composition is applied to the surface of member X, the coated portion is semi-cured by heating or light irradiation, and then member Y is brought into contact with the adhesive composition and then further heat-cured or light-cured. [Example]

[0079] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the following, "parts" and "%" are by mass unless otherwise specified.

[0080] 1.Method for measuring physical properties of polymers The methods for measuring the molecular weight (Mw and Mn), viscosity and epoxy value of the epoxy group-containing (meth)acrylic polymer are as follows.

[0081] (1)Molecular weight Four columns "TSKgel SuperMultipore HZ-M" (product name) manufactured by Tosoh Corporation were connected together and placed in a gel permeation chromatograph "HLC-8320" (model name) manufactured by Tosoh Corporation, and the number average molecular weight (Mn) and weight average molecular weight (Mw) calculated in terms of polystyrene were measured under the following measurement conditions. The molecular weight distribution (Mw / Mn) was also calculated from the measured values. Column temperature: 40℃ Eluent: tetrahydrofuran Detector: RI

[0082] (2) Viscosity The E-type viscosity was measured under the following conditions using a Toki Sangyo "TVE-20H type viscometer" (product name, salt water / plate method). Cone shape: angle 1°34′, radius 24 mm (for values ​​less than 10,000 mPa·s) Angle 3°, radius 7.7 mm (for 10,000 mPa·s or more) Temperature: 25℃±0.5℃ Rotor rotation speed: 1 rpm (for less than 10,000 mPa·s) 5 rpm (for 10,000 mPa·s or more)

[0083] (3) Epoxy value The epoxy value was measured according to ASTM D-1652.

[0084] (4) Number of epoxy groups per molecule (average value) When the total amount of monomers used to form the polymer was 100 parts and x parts of epoxy group-containing monomer were contained therein, the number of epoxy groups (average value) per polymer molecule was calculated using the following formula. Number of epoxy groups per molecule = x / [(molecular weight of epoxy group-containing monomer × 100) / Mn]

[0085] (5) Glass transition temperature (Tg) The glass transition temperature (Tg) was measured using a differential scanning calorimeter "Q-100" (model name) manufactured by TA Instruments in a nitrogen gas atmosphere at a temperature increase rate of 10°C / min.

[0086] (6) Carbon-carbon double bond concentration at the polymer terminals Deuterated chloroform was used as the solvent. 1 In the NMR spectrum obtained by H-NMR measurement, the double bond concentration per mass of the polymer was calculated from the ratio of the integral value of the signal at around 5.5 ppm derived from a hydrogen atom bonded to a carbon atom constituting a carbon-carbon double bond to the integral value of the signal at 3.0 to 4.5 ppm derived from a hydrogen atom bonded to a carbon atom adjacent to an ester group, as well as the composition of the polymer.

[0087] 2. Production of epoxy group-containing (meth)acrylic polymer In the following Examples 1-1 to 1-4 and Comparative Examples 1-1 and 1-2, various polymers were produced.

[0088] Example 1-1 The temperature of a 1000 mL oil-jacketed pressurized stirred tank reactor was set to the reaction temperature shown below. Next, while maintaining a constant internal pressure in the reactor, a monomer mixture consisting of 70 parts n-butyl acrylate (hereinafter referred to as "BA"), 30 parts glycidyl methacrylate (hereinafter referred to as "GMA"), 12 parts methyl ethyl ketone (hereinafter referred to as "MEK"), 3 parts trimethyl orthoacetate (manufactured by Nippoh Chemical Co., Ltd., trade name "MOA"; hereinafter referred to as "MOA"), and 1 part di-tert-hexyl peroxide (manufactured by NOF Corp., trade name "Perhexyl D"; hereinafter referred to as "DTHP") as a polymerization initiator was continuously fed from a raw material tank to the reactor at a constant feed rate (48 g / min). The polymerization reaction proceeded with a residence time of 12 minutes. A reaction liquid equivalent to the amount of monomer mixture fed was then continuously withdrawn and recovered from the reactor outlet. Immediately after the start of the reaction, the reaction temperature dropped temporarily, but a temperature rise due to the heat of polymerization was observed. Therefore, the reaction temperature was maintained at 238°C by controlling the temperature of the oil jacket. The point at which the liquid temperature in the reactor stabilized after the start of feeding the monomer mixture was defined as the start point for collecting the reaction liquid, and the reaction was continued for 25 minutes from this point. As a result, the amount of the monomer mixture fed was 1.2 kg, and the amount of the reaction liquid recovered was 1.2 kg. The reaction mixture was then introduced into a thin-film evaporator, and volatile components such as unreacted monomers were separated to obtain an epoxy-containing (meth)acrylic copolymer (hereinafter referred to as "Polymer A-1"). The resulting Polymer A-1 had a weight-average molecular weight of 2,030, a number-average molecular weight of 1,210, a viscosity of 2,200 mPa·s, an epoxy value of 2.1 meq / g, a number of epoxy groups per molecule of 2.5, a glass transition temperature of -55°C, and a terminal carbon-carbon double bond concentration of 0.86 meq / g (see Table 1).

[0089] Example 1-2 An epoxy group-containing (meth)acrylic copolymer (hereinafter referred to as "Polymer A-2") was obtained in the same manner as in Example 1-1, except that the amounts of BA and GMA used were changed to 60 parts and 40 parts, respectively, the amount of DTHP used was changed to 0.5 parts, and the reaction temperature was maintained at 230° C. The physical properties of the obtained Polymer A-2 are shown in Table 1.

[0090] Examples 1-3 An epoxy group-containing (meth)acrylic copolymer (hereinafter referred to as "Polymer A-3") was obtained in the same manner as in Example 1-1, except that the amounts of BA and GMA used were changed to 75 parts and 25 parts, respectively, the amount of DTHP used was changed to 0.5 parts, and the reaction temperature was maintained at 230° C. The physical properties of the obtained Polymer A-3 are shown in Table 1.

[0091] Examples 1-4 An epoxy group-containing (meth)acrylic copolymer (hereinafter referred to as "Polymer A-4") was obtained in the same manner as in Example 1-1, except that the amounts of BA and GMA used were changed to 50 parts and 50 parts, respectively, and the reaction temperature was maintained at 240° C. The physical properties of the obtained Polymer A-4 are shown in Table 1.

[0092] Comparative Example 1-1 An epoxy group-containing (meth)acrylic copolymer (hereinafter referred to as "Polymer A-5") was obtained in the same manner as in Example 1-1, except that the amounts of BA and GMA used were changed to 80 parts and 20 parts, respectively, the amount of DTHP used was changed to 0.5 parts, and the reaction temperature was maintained at 233° C. The physical properties of the obtained Polymer A-5 are shown in Table 1.

[0093] Comparative Example 1-2 An epoxy group-containing (meth)acrylic copolymer (hereinafter referred to as "Polymer A-6") was obtained in the same manner as in Example 1-1, except that the amount of DTHP used was changed to 0.5 parts and the reaction temperature was maintained at 193° C. The physical properties of the obtained Polymer A-6 are shown in Table 1.

[0094] [Table 1]

[0095] 3. Preparation and Evaluation of Curable Compositions (1) Each polymer listed in Table 1 was mixed with a cationic polymerization initiator, "San-Aid SI-60L" (trade name, 1-naphthylmethylmethyl p-hydroxyphenylsulfonium hexafluoroantimonate / γ-butyrolactone 1 / 2 mixture) manufactured by Sanshin Chemical Industry Co., Ltd. to produce a liquid curable composition. Then, a cured product was produced, and its tensile properties were evaluated.

[0096] Example 2-1 100 parts of polymer A-1 and 2 parts of a cationic polymerization initiator were mixed to obtain a curable composition. Then, this curable composition was placed in a container with a flat bottom made of release paper so that the thickness was about 1 mm, and subjected to heat treatment (at 60°C for 1 hour, then at 120°C for 1 hour, and then at 150°C for 1 hour) in an air atmosphere to obtain a cured product. The cured product was then processed to prepare tensile test dumbbells (JIS K 6251 No. 3 type), and the elongation at break and strength at break were measured at a tension rate of 5 mm / min using a Shimadzu Autograph AGS-J tensile tester. The results are shown in Table 2.

[0097] Examples 2-2 to 2-4 and Comparative Example 2-1 Curable compositions were produced and the cured products were evaluated in the same manner as in Example 2-1, except that polymers A-2 to A-5 were used instead of polymer A-1 (see Table 2).

[0098] [Table 2]

[0099] The following is clear from Table 2: Comparative Example 2-1 is an example of a curable composition containing polymer A-5, which has a low epoxy value of 1.4 meq / g, and the mechanical properties (tensile strength and tensile elongation) of the cured product were insufficient. On the other hand, Examples 2-1 to 2-4 are examples of the curable compositions of the present invention, and the mechanical properties of the cured product were excellent.

[0100] 4. Preparation and Evaluation of Curable Composition (2) Each polymer listed in Table 1 was mixed with a bisphenol A epoxy resin "jER828" (trade name) manufactured by Mitsubishi Chemical Corporation, and a cationic polymerization initiator, "San-Aid SI-60L" (trade name, a 1 / 2 mixture of 1-naphthylmethylmethyl p-hydroxyphenylsulfonium hexafluoroantimonate / γ-butyrolactone) manufactured by Sanshin Chemical Industry Co., Ltd. to produce a liquid curable composition. PET films were then bonded together using the curable composition as an adhesive, and the adhesiveness was evaluated.

[0101] Example 3-1 A curable composition (viscosity (25°C): 9,600 mPa·s) was obtained by mixing 30 parts of polymer A-1, 70 parts of an epoxy resin, and 2 parts of a cationic polymerization initiator. This curable composition was then applied to the surface of a 50 μm-thick PET film (trade name: Lumirror T-61) manufactured by Toray Industries, Inc. using a bar coater to a coating thickness of 25 μm. A separately prepared identical PET film was then bonded to the surface of the coating to obtain a laminated film. Then, using a high-pressure mercury lamp manufactured by Eye Graphics, UV-A irradiance was set to 500 mW / cm in an atmospheric environment using a condensed light method. 2 , the irradiation dose per time is 800mJ / cm 2 The laminated film was placed on a conveyer and was irradiated twice with light adjusted so that the intensity of the light was adjusted to be 1 / 2.0. The laminated film was placed on a conveyer and was moved, and an adhesive film was obtained. Next, the adhesive strength of this adhesive film (size: 25 mm × 100 mm) was measured by T-peel at a tensile speed of 200 mm / min using a tensile tester "Autograph AGS-J" (trade name) manufactured by Shimadzu Corporation. The results are shown in Table 3.

[0102] Examples 3-2 and 3-3 Except for changing the amounts of Polymer A-1 and epoxy resin used as shown in Table 3, the same procedures as in Example 3-1 were carried out to produce curable compositions and evaluate their adhesive properties (see Table 3).

[0103] Examples 3-4 to 3-6 and Comparative Examples 3-1 to 3-2 Except for using polymers A-2 to A-6 instead of polymer A-1, the same procedures as in Example 3-1 were carried out to produce curable compositions and evaluate their adhesive properties (see Table 3). Note that the curable composition of Comparative Example 3-2 could not be evaluated due to poor coating onto the PET film.

[0104] [Table 3]

[0105] The following is clear from Table 3: Comparative Example 3-1 is an example of a curable composition containing polymer A-5, which has a low epoxy value of 1.4 meq / g, and had insufficient adhesive strength. On the other hand, Examples 3-1 to 3-6 are examples of the curable compositions of the present invention, and all of them had high adhesive strength and excellent adhesiveness. [Industrial Applicability]

[0106] The epoxy group-containing (meth)acrylic polymer of the present invention is in a low-viscosity liquid state at room temperature and is easy to handle, and when cured, it can form a cured product with excellent mechanical properties (tensile strength or tensile elongation). Such a cured product is suitable for forming a sealant, a heat dissipation material, etc. The epoxy group-containing (meth)acrylic polymer of the present invention can be suitably used as a raw material for forming a curable composition (adhesive composition) together with other compounds having epoxy groups. For example, a composition containing an epoxy group-containing (meth)acrylic polymer and an epoxy resin has excellent adhesion to components and can be used, for example, as a polarizing plate adhesive for bonding a polarizer and a protective film. Furthermore, this composition can also be used, for example, as an adhesive composition that firmly bonds components constituting a semiconductor device together and provides excellent structural stability as an integrated product.

Claims

1. A curable composition comprising an epoxy resin and a (meth)acrylic polymer having an epoxy group, the (meth)acrylic polymer having a weight average molecular weight of 1,800 or more and less than 3,100, an epoxy value of 2.0 to 5.0 meq / g, and a viscosity at 25°C of 80,000 mPa s or less.

2. A curable composition as described in claim 1, wherein the average number of epoxy groups per molecule of the (meth)acrylic polymer is 2.3 or more.

3. A curable composition according to claim 1 or 2, wherein the (meth)acrylic polymer has carbon-carbon double bonds in the molecule at a ratio of 0.50 to 0.95 meq / g.

4. A curable composition described in any one of claims 1 to 3, wherein the (meth)acrylic polymer contains a structural unit derived from an alkyl (meth)acrylate ester and a structural unit derived from glycidyl (meth)acrylate.

5. The curable composition according to claim 1 , further comprising a curing agent.

6. The curable composition according to claim 1 , further comprising a cationic polymerization initiator.

7. An adhesive composition comprising the curable composition according to claim 1 .

8. An electronic component obtained by using the adhesive composition according to claim 7.

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