JPWO2019123934A1 - Epoxy resin composition - Google Patents

Abstract

Provided is an epoxy resin composition having high adhesive strength and improved interfacial adhesiveness. An alkoxysilyl-modified polymer (A), an epoxy resin (B), and an epoxy curing agent having at least two alkoxysilyl groups in the molecule, having a glass transition temperature of 0 ° C. or lower, and having a number average molecular weight of 600 to 5000. An epoxy resin composition comprising C) and a core-shell polymer (D). The content of (A) is 0.01 to 10% by weight ((A) + (B) + (C) + (D) = 100% by weight), and (D) is a diene rubber or (meth) acrylate. It has one or more core layers selected from the group consisting of rubbers, organosiloxane rubbers, styrene polymers and (meth) acrylate polymers, and the proportion of the core layer in (D) is 70 to 95% by weight. Is.

Description

The present invention relates to epoxy resin compositions.

Epoxy resins have long been used in a wide range of applications because their cured products have excellent heat resistance, mechanical properties, and chemical resistance. However, the cured product of the epoxy resin has a drawback of being brittle, and in many cases, toughening is required.

As a method of toughening, various methods of adding a rubber component as a modifier to an epoxy resin have been studied and applied.

Among them, the method of adding core-shell rubber has come to be widely used in various fields such as structural adhesives and composite materials because it can toughen epoxy resins with high efficiency without impairing heat resistance (for example). , Patent Document 1).

However, when applied to an adhesive, the adhesive layer is toughened to improve the adhesive strength, but the interface between the adhesive layer and the base material may become a weak point and interface destruction may occur. Interfacial fracture is one of the causes of large fluctuations in adhesive strength, which is not preferable in terms of reliability. Therefore, a method for improving the interfacial adhesion between the toughened adhesive layer and the base material has been desired.

As a method for improving the interfacial adhesion, there is a method of adding a silane coupling agent having an epoxy group and a silane group or a butadiene / acrylonitrile liquid rubber (CTBN) having a terminal carboxylic acid to the epoxy resin composition. However, the effect of improving the interfacial adhesion by them was often not sufficient.

U.S. Pat. No. 4,778,851

An object of the present invention is to provide an epoxy resin composition having high adhesive strength and improved interfacial adhesiveness.

That is, in the present invention, the alkoxysilyl-modified polymer (A) and the epoxy resin (B) having at least two alkoxysilyl groups in the molecule, having a glass transition temperature of 0 ° C. or lower, and having a number average molecular weight of 600 to 5000. ), An epoxy resin composition containing an epoxy curing agent (C) and a core-shell polymer (D), wherein the content of the alkoxysilyl-modified polymer (A) is 0.01 to 10% by weight ((A) + (B)). + (C) + (D) = 100% by weight), and the core-shell polymer (D) is composed of a diene-based rubber, a (meth) acrylate-based rubber, an organosiloxane-based rubber, a styrene-based polymer, and a (meth) acrylate-based polymer. It relates to an epoxy resin composition having one or more core layers selected from the group, wherein the proportion of the core layer in the core-shell polymer (D) is 70 to 95% by weight.
(2) The alkoxysilyl-modified polymer (A) is preferably a polymer having an alkoxysilyl group at the end of the polymer.
(3) It is preferable that the main chain of the alkoxysilyl-modified polymer (A) is a polyalkylene oxide.
(4) It is preferable that the main chain of the alkoxysilyl-modified polymer (A) is at least one selected from polypropylene oxide, polybutylene oxide and an oxy-3-methyltetramethylene / oxybutylene copolymer.
(5) The epoxy curing agent (C) is preferably an acid anhydride.
(6) The number average particle size of the core-shell polymer (D) is preferably 0.01 to 0.6 μm.
(7) Further, the present invention relates to a cured product obtained by curing the epoxy resin composition.

The epoxy resin composition of the present invention can achieve both high adhesive strength and excellent interfacial adhesiveness.

The epoxy resin composition of the present invention has an alkoxysilyl-modified polymer (A) and an epoxy having at least two alkoxysilyl groups in the molecule, a glass transition temperature of 0 ° C. or lower, and a number average molecular weight of 600 to 5000. It contains a resin (B), an epoxy curing agent (C) and a core-shell polymer (D).

The combined use of an alkoxysiri-modified polymer and an epoxy resin has been practiced for a long time. However, in many cases, an epoxy resin is added to improve the strength of the alkoxysilyl-modified polymer, and a relatively large number of alkoxysilyl-modified polymers are used (see, for example, Japanese Patent Application Laid-Open No. 62-283120). ). As an example in which an epoxy resin and a relatively small amount of an alkoxysilyl-modified polymer are used, an epoxy resin composition for encapsulating electronic parts (see Japanese Patent Application Laid-Open No. 2003-034747) has been reported, but rubber (for example, core shell) has been reported. There is a description that the addition of rubber) increases the viscosity of the liquid epoxy resin composition, so that a sufficient effect cannot be obtained. Further, in this composition, the content of the alkoxysilyl-modified polymer is about 30 to 50% by weight (however, the epoxy resin, the epoxy resin curing agent and the alkoxysilyl-modified polymer are 100% by weight in total), which is also a small amount. could not say it all. In addition, the composition contains a significant amount of silanol condensation catalyst as an essential component. When the curing reaction is accelerated by the silanol condensation catalyst, a large amount of low molecular weight alcohol is co-produced and the cured product tends to foam, and there is a concern that the interfacial adhesiveness and the mechanical strength of the cured product may decrease. With an adhesive toughened by a core-shell rubber, a decrease in interfacial adhesiveness due to foaming or the like becomes a problem. Due to the high activity of silanol condensation catalysts, they tend to have other unfavorable effects.

Hereinafter, the epoxy resin composition of the present invention will be described in detail.

<Alkoxysilyl modified polymer (A)>
The alkoxysilyl-modified polymer (A) has a hydrolyzable alkoxysilyl group in the polymer molecule. Examples of the alkoxysilyl group include alkyldialkoxysilyl groups such as methyldimethoxysilyl group and methyldiethoxysilyl group, and trialkoxysilyl groups such as trimethoxysilyl group and triethoxysilyl group.

At least two alkoxysilyl groups are present in the polymer molecule and can be attached to the end and / or side chains of the polymer chain. In particular, it is preferable to have an alkoxysilyl group at the end of the polymer chain of the alkoxysilyl-modified polymer (A) because it is easy to impart flexibility to the cured product.

The glass transition temperature (Tg) of the alkoxysilyl-modified polymer (A) is usually 0 ° C. or lower, preferably −20 ° C. or lower, and more preferably −40 ° C. or lower. Since it is not preferable that the viscosity of the epoxy resin composition is increased by adding the alkoxysilyl-modified polymer (A), the alkoxysilyl-modified polymer (A) is preferably as flexible as possible. The number average molecular weight of the alkoxysilyl-modified polymer (A) of the present invention is defined by the molecular weight calculated in terms of hydroxyl value for the main chain before modification of the alkoxysilyl group, and is preferably 600 to 5000, but 700 to 4000. More preferably. If the molecular weight is too low or too high, good interfacial adhesion tends not to be obtained. In particular, when the molecular weight is too high, it becomes difficult to dissolve in the epoxy resin (B), and the addition effect becomes low.

The main chain of the alkoxysilyl-modified polymer (A) is not particularly limited, and those having various main chain skeletons can be used. However, since the obtained composition has excellent adhesiveness, hydrogen atoms and carbon atoms , A main chain skeleton consisting of one or more selected from nitrogen atom, oxygen atom and sulfur atom is preferable. Specific main chains include polyalkylene oxides such as polyethylene oxide, polypropylene oxide, polybutylene oxide, ethylene oxide-propylene oxide copolymer, and propylene oxide-butylene oxide copolymer, ethylene-propylene copolymer, polyisobutylene, and the like. Obtained by hydrogenating polychloroprene, polyisoprene, isoprene or a copolymer of butadiene and acrylonitrile and / or styrene, polybutadiene, isoprene or butadiene and acrylonitrile, styrene, etc., and olefin-based polymers thereof. Hydrocarbon-based polymers such as hydrogenated olefin-based polymers; polyesters obtained by condensation of dibasic acids such as adipic acid and glycols, or ring-open polymerization of lactones; ethyl (meth) acrylate, butyl (meth). ) A (meth) acrylate-based polymer obtained by radical polymerization of a monomer such as acrylate as a main component; a graft polymer obtained by polymerizing a vinyl monomer in the organic polymer; polysulfide and the like can be mentioned.

In particular, saturated hydrocarbon-based polymers such as polyisobutylene, hydrogenated polyisoprene, and hydrogenated polybutadiene, polyalkylene oxides, and (meth) acrylate-based polymers are more preferable as main chains because their glass transition temperatures are relatively low. Further, the main chain of the alkoxysilyl-modified polymer (A) is particularly preferably a polyalkylene oxide, particularly a polypropylene oxide, a polybutylene oxide, or an oxy-3-methyltetramethylene / oxybutylene copolymer. Most preferably.

These alkoxysilyl-modified polymers (A) may be used alone or in combination of two or more.

The content of the alkoxysilyl-modified polymer (A) is 0.01 to 10% by weight, more preferably 0, when the component (A) + (B) + (C) + (D) = 100% by weight. .1 to 5% by weight is preferable because good adhesiveness tends to be obtained. If the amount is too small or too large, good interfacial adhesiveness and high adhesive strength tend to be incompatible. Especially when it is too much, the heat resistance tends to be low.

<Epoxy resin (B)>
As the epoxy resin (B) of the present invention, any epoxy resin having two or more epoxy groups in the molecule can be used.

For example, glycidyl ether type epoxy resins such as bisphenol A diglycidyl ether and bisphenol F diglycidyl ether; cyclic aliphatic epoxy resins such as 3,4-epoxycyclohexylmethylcarboxylate and 1,4-cyclohexanedimethanol diglycidyl ether; Linear aliphatic epoxy resin such as 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, polypropylene glycol diglycidyl ether; glycidyl ester type epoxy resin such as hexahydrophthalic acid glycidyl ester, tetra Glysidylaminodiphenylmethane, glycidyl compound of xylenediamine, glycidylamine type epoxy resin such as triglycidylaminophenol, glycidylaniline, polysiloxane type epoxy resin having an epoxy group at the end or side chain of polydimethylsiloxane, or phenol novolac type epoxy resin , Cresol novolac type epoxy resin, triphenylglycidyl ether methane, tetraphenyl glycidyl ether methane; brominated phenol novolac type epoxy resin, dicyclopentadiene novolac type epoxy resin, naphthol novolac type epoxy resin and other epoxy resins can be mentioned. These epoxy resins can be used alone or in combination.

Since the content of the epoxy resin (B) tends to obtain good adhesiveness, 10 to 90 when the components (A) + (B) + (C) + (D) = 100% by weight. It is preferably by weight%, more preferably 20 to 80% by weight.

Further, a reactive diluent having one epoxy group in the molecule may be added to the epoxy resin (B). The reactive diluent has the effect of lowering the viscosity of the epoxy resin composition. The reactive diluent is preferably used from 0 part by weight to 45 parts by weight with respect to 100 parts by weight of the epoxy resin (B). If too much reactive diluent is used, the heat resistance of the cured product will be reduced.

Examples of the reactive diluent having one epoxy group in the molecule include alkyl monoglycidyl ethers such as butyl glycidyl ether, 2-ethylhexyl glycidyl ether, and alkyl glycidyl ethers having 8 to 14 carbon atoms, phenylglycidyl ether, and nonylphenyl glycidyl. Examples thereof include phenol monoglycidyl ether such as ether. These may be used in combination of 2 or more types.

<Epoxy curing agent (C)>
As the epoxy curing agent (C) of the present invention, conventionally known ones can be widely used. For example, aliphatic amines such as diethylaminopropylamine, hexamethylenediamine, methylpentamethylenediamine, trimethylhexamethylenediamine, guanidine, oleylamine; mensendiamine, isophoronediamine, norbornandiamine, piperidine, N, N'-dimethylpiperazine, N-aminoethylpiperazine, 1,2-diaminocyclohexane, bis (4-amino-3-methylcyclohexyl) methane, bis (4-aminocyclohexyl) methane, polycyclohexylpolyamine, 1,8-diazabicyclo [5,4,0 ] Alicyclic amines such as undecene-7 (DBU); 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro [5,5] undecane (ATU), morpholin, Amines having ether bonds such as N-methylmorpholin, polyoxypropylenediamine, polyoxypropylenetriamine, polyoxyethylenediamine; hydroxyl group-containing amines such as diethanolamine and triethanolamine; tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, Acid anhydrides such as methylnadic anhydride, hexahydrophthalic anhydride, and succinic anhydride; phenolic resins such as novolak type phenol resin and resol type phenol resin; urea resins such as methylol group-containing urea resin; methylol group-containing melamine resin Melamine resins such as; polyamides obtained by reacting dimer acids with polyamines such as diethylenetriamine and triethylenetetramine, polyamideamines such as polyamides using polycarboxylic acids other than dimeric acid; 2-ethyl-4-methylimidazole and the like. Imidazoles; dicyandiamide; epoxy-modified amines obtained by reacting the above amines with epoxy compounds, and modified amines such as Mannig-modified amines, Michael-added modified amines, and ketimines obtained by reacting the above amines with formalin and phenols. And so on. These curing agents may be used alone or in combination of two or more.

Among the above epoxy curing agents, acid anhydrides have conventionally been recognized as curing agents having low adhesive strength, but when acid anhydrides are used as the epoxy curing agent (C) in the present invention, conventional recognition On the other hand, there is an advantage that the adhesive strength can be remarkably increased and the viscosity of the epoxy resin composition can be reduced.

Further, among the above-mentioned epoxy curing agents, the phenol resin has also been conventionally recognized as a curing agent having low adhesive strength, but when the phenol resin is used as the epoxy curing agent (C) in the present invention, the conventional recognition is achieved. On the contrary, the adhesive strength can be remarkably increased, and the heat resistance of the cured product can be increased. Phenolic resin refers to all monomers, oligomers, and polymers that have two or more phenolic hydroxyl groups in one molecule. Specifically, it is a novolak-type resin such as phenol novolac resin, cresol novolak resin, and naphthol novolak resin; triphenol. Polyfunctional phenolic resin such as methane-type phenolic resin; Modified phenolic resin such as terpen-modified phenolic resin and dicyclopentadiene-modified phenolic resin; Phenolic aralkyl resin having phenylene skeleton and / or biphenylene skeleton, phenylene and / or biphenylene skeleton Aralkyl-type resins such as naphthol aralkyl resin; bisphenol compounds such as bisphenol A and bisphenol F can be mentioned.

Further, in order to accelerate the curing of the epoxy curing agent (C), the curing accelerator may be used together with the epoxy curing agent (C). Examples of curing accelerators include tertiary amines such as triethylamine and benzyldimethylamine, imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole, triphenylphosphine, tri-p-tolylphosphine, and subphosphorus. Organophosphorus compounds such as triphenyl acid, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylbolate, tetotaphenylphosphine bromide, tetra-n-butylphosphonium bromide, tetra n-butylphosphonium o, o-diethyl Tertiary phosphonium salts such as phosphorodithionate, diazabicycloalkenes such as 1,8-diazabicyclo [5.4.0] undecene-7 and its organolates, zinc octylate, tin octylate, aluminum acetylacetone complex, etc. Examples thereof include organometallic compounds of the above, quaternary ammonium salts such as tetraethylammonium bromide and tetrabutylammonium bromide, boron compounds such as boron trifluoride and triphenylborate, and metal halogen compounds such as zinc chloride and ferric chloride. Furthermore, microcapsule-type latent accelerators, amine salt-type latent curing accelerators, Lewis acid salts, blended acid salts, etc., in which the surface of a high melting point imidazole compound, dicyandiamide, phosphorus-based, or phosphine-based accelerator is coated with a polymer. A latent curing accelerator typified by a high-temperature dissociation type thermal cationic polymerization type latent curing accelerator can also be used. These curing accelerators can be used alone or in combination of two or more.

The amount of the epoxy curing agent (C) used depends on the chemical properties of the curing agent, the epoxy resin composition and the desired properties of the cured product. When the epoxy curing agent (C) has an amine group, the epoxy curing agent (C) is used so that the equivalent number of the amine groups to the epoxy group of the epoxy resin (B) is 1.7 to 2.3. When the epoxy curing agent (C) has an acid anhydride group or a phenolic hydroxy group, the equivalent of the acid anhydride group or the phenolic hydroxy group to the epoxy group of the epoxy resin (B). The epoxy curing agent (C) is preferably used so that the number is 0.7 to 1.3. It is preferable to use about 0.01 to 10 parts by weight of the curing accelerator with respect to 100 parts by weight of the epoxy resin (B).

<Core shell polymer (D)>
The core-shell polymer (D) is a particulate polymer having a structure of at least two layers. The ratio of the core layer in the core-shell polymer (D) is 70 to 95% by weight, more preferably 80 to 93% by weight, from the viewpoint of mechanical properties. When the ratio of the core layer is small, the viscosity of the epoxy resin composition tends to be high. If the ratio of core layers is too large, it will be difficult to prepare the core-shell polymer (synthesis itself is possible, but it will be difficult to remove it from the reaction solution in a practical form). The ratio of the core layer in the core-shell polymer can be measured from the absorbance ratio of the spectrum of infrared spectroscopic analysis.

The core-shell polymer (D) preferably has a number average particle size of 0.01 to 0.6 μm, more preferably 0.03 to 0.5 μm, and even more preferably 0.05 to 0.4 μm. An emulsion polymerization method is suitable for obtaining a core-shell polymer (D) having such an average particle size, but if it is too small or too large, economical and industrial production becomes difficult. The number average particle size can be measured using a Microtrack UPA150 (manufactured by Nikkiso Co., Ltd.) or the like.

The core-shell polymer (D) preferably has an insoluble content in methyl ethyl ketone (MEK), and the insoluble content (MEK insoluble content) is preferably 95% by weight or more, more preferably 97% by weight or more. More preferably, 98% by weight or more is more preferable. If it is less than 95% by weight, the viscosity of the epoxy resin composition tends to be high, which makes it difficult to handle. In the present specification, the method for obtaining the MEK insoluble amount of the core-shell polymer (D) is as follows. Approximately 2 g of core-shell polymer powder or film is weighed and immersed in 100 g of MEK at 23 ° C. for 24 hours. Then, the obtained MEK insoluble matter is separated, dried and weighed, and the weight fraction (%) with respect to the weight of the core-shell polymer used for the measurement is calculated as the MEK insoluble matter amount.

The content of the core-shell polymer (D) is preferably 0.5 to 30% by weight, preferably 1 to 20% by weight, when the components (A) + (B) + (C) + (D) = 100% by weight. Is more preferable. If the content is too low, interfacial fracture tends to occur or the adhesive strength tends to decrease, and if it is too high, the compounding viscosity tends to be too high, which tends to be unsuitable for applications requiring low viscosity.

The core-shell polymer (D) is preferably a polymer composed of a core layer made of a crosslinked polymer and a shell layer made of a polymer component graft-polymerized thereto. That is, it is preferable that a chemical bond exists between the shell layer and the core layer. Since the shell layer is formed by graft-polymerizing the monomers constituting the graft component to the core component, it covers a part or the whole of the surface of the core portion.

The core layer is one or more selected from the group consisting of a diene-based rubber, a (meth) acrylate-based rubber, an organosiloxane-based rubber, a styrene-based polymer, and a (meth) acrylate-based polymer. In the present invention, (meth) acrylate means acrylate and / or methacrylate.

The core layer is preferably a rubber-like crosslinked polymer from the viewpoint of toughening the epoxy resin (B). In order for the core layer to have a rubber-like property, the glass transition temperature of the core layer (hereinafter, may be simply referred to as “Tg”) is preferably 0 ° C. or lower, more preferably −20 ° C. or lower. It is preferably −40 ° C. or lower, and particularly preferably −40 ° C. or lower.

The Tg can be measured by, for example, a dynamic viscoelasticity measurement method or a differential scanning calorimetry method.

As the polymer capable of forming the core layer having the properties of rubber, at least one monomer (first monomer) selected from natural rubber and diene-based monomers (conjugated diene-based monomers) and (meth) acrylate-based monomers. 50 to 100% by weight, and other copolymerizable vinyl-based monomer (second monomer) of 0 to 50% by weight, a rubber polymer composed of, an organosiloxane-based rubber, or a combination thereof. Be done. When obtaining a higher toughening effect, a diene rubber using a diene monomer is preferable. When a balance of toughness, weather resistance, economy and the like is required, (meth) acrylate rubber (also referred to as acrylic rubber) is preferable. Further, when trying to obtain high toughness at a low temperature, the core layer is preferably an organosiloxane-based rubber.

Examples of the monomer (conjugated diene-based monomer) constituting the diene-based rubber used for forming the core layer include 1,3-butadiene, isoprene, 2-chloro-1,3-butadiene, and 2-methyl-1,3. − Butadiene and the like. These diene-based monomers may be used alone or in combination of two or more.

Butadiene rubber using 1,3-butadiene, butadiene-styrene rubber which is a copolymer of 1,3-butadiene and styrene, 1,3-butadiene and butyl acrylate or 2-ethylhexyl acrylate from the viewpoint of high toughening effect. Butadiene-acrylate rubber, which is a copolymer, is preferable, and butadiene rubber is more preferable. Further, butadiene-styrene rubber is more preferable when the transparency of the epoxy resin composition obtained by adjusting the refractive index can be enhanced and a product having a good balance of appearance and toughness can be obtained. Further, the butadiene-acrylate rubber is preferable when the weather resistance is improved because the double bond concentration of butadiene in the rubber is lowered by the introduction of the acrylate, and such characteristics are required.

Examples of the monomer constituting the (meth) acrylate-based rubber (also referred to as acrylic rubber) used for forming the core layer include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-. Alkyl (meth) acrylates such as ethylhexyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and behenyl (meth) acrylate; phenoxyethyl (meth) acrylate, benzyl (meth) acrylate. Aromatic ring-containing (meth) acrylates such as 2-hydroxyethyl (meth) acrylates, hydroxyalkyl (meth) acrylates such as 4-hydroxybutyl (meth) acrylates; glycidyl (meth) acrylates, glycidylalkyl (meth) acrylates, etc. Glycidyl (meth) acrylates; alkoxyalkyl (meth) acrylates; allylalkyl (meth) acrylates such as allyl (meth) acrylate and allylalkyl (meth) acrylate; monoethylene glycol di (meth) acrylate, triethylene glycol Examples thereof include polyfunctional (meth) acrylates such as di (meth) acrylate and tetraethylene glycol di (meth) acrylate. These (meth) acrylate-based monomers may be used alone or in combination of two or more. Preferably, it is ethyl (meth) acrylate, butyl (meth) acrylate, or 2-ethylhexyl (meth) acrylate.

Examples of the vinyl-based monomer (second monomer) copolymerizable with the first monomer include vinyl allenes such as styrene, α-methylstyrene, monochlorostyrene, and dichlorostyrene; vinylcarboxylic acids such as acrylic acid and methacrylic acid. Vinyl cyanes such as acrylonitrile and methacrylonitrile; vinyl halides such as vinyl chloride, vinyl bromide and chloroprene; vinyl acetate; alkenes such as ethylene, propylene, butylene and isobutylene; diallylphthalate and triallyl cyanurate, Examples thereof include polyfunctional monomers such as triallyl isocyanurate and divinylbenzene. These vinyl-based monomers may be used alone or in combination of two or more. Styrene is particularly preferable.

The organosiloxane-based rubber that can form the core layer is composed of an alkyl or aryl 2-substituted silyloxy unit such as dimethylsiloxane, diethylsiloxane, methylphenylsiloxane, diphenylsiloxane, and dimethylsiloxane-diphenylsiloxane. Examples thereof include an organosiloxane-based polymer composed of an alkyl or aryl1-substituted siloxane unit, such as an organosiloxane-based polymer in which a part of the alkyl in the side chain is substituted with a hydrogen atom. These organosiloxane-based polymers may be used alone or in combination of two or more. Further, a composite rubber made of (meth) acrylate-based rubber / organosiloxane-based rubber combined with (meth) acrylate-based rubber may be used. Among them, dimethylsiloxane rubber, methylphenylsiloxane rubber, and dimethylsiloxane / butylacrylate composite rubber are preferable in terms of weather resistance and mechanical properties, and dimethylsiloxane rubber and dimethylsiloxane / butyl acrylate composite rubber are easily available and economical. Most preferred.

In the embodiment in which the core layer is formed of an organosiloxane-based rubber, the organosiloxane-based polymer moiety contains at least 10% by weight, with the entire core layer as 100% by weight, so as not to impair the mechanical properties at low temperatures. Is preferable.

From the viewpoint of maintaining the dispersion stability of the core-shell polymer (D) in the epoxy resin (B), the core layer has a crosslinked structure introduced into a polymer component obtained by polymerizing the above-mentioned monomer or an organosiloxane-based polymer component. It is preferable to have. As a method for introducing the crosslinked structure, a generally used method can be adopted. For example, as a method of introducing a crosslinked structure into a polymer component obtained by polymerizing the above-mentioned monomer, a method of adding a crosslinked monomer such as a polyfunctional monomer or a mercapto group-containing compound to the monomer constituting the polymer component and then polymerizing. And so on. In addition, as a method for introducing a crosslinked structure into an organosiloxane polymer, a method in which a part of a polyfunctional alkoxysilane compound is used in combination at the time of polymerization, or a reactive group such as a vinyl reactive group, a mercapto group, or a methacryloyl group is used as an organo A method of introducing the polymer into a siloxane polymer and then adding a vinyl polymerizable monomer or an organic peroxide to cause a radical reaction, or adding a crosslinkable monomer such as a polyfunctional monomer or a mercapto group-containing compound to the organosiloxane polymer. Examples thereof include a method of adding and then polymerizing.

The polyfunctional monomer does not contain butadiene, and allylalkyl (meth) acrylates such as allyl (meth) acrylate and allylalkyl (meth) acrylate; allyloxyalkyl (meth) acrylates; (poly) ethylene glycol di. It has two or more (meth) acrylic groups such as (meth) acrylate, butanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and tetraethylene glycol di (meth) acrylate. Polyfunctional (meth) acrylates; examples thereof include diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene and the like. Particularly preferred are allyl methacrylate, triallyl isocyanurate, butanediol di (meth) acrylate, and divinylbenzene.

On the other hand, when a good balance between the strength and elastic modulus of the epoxy resin (B) is required, the Tg of the core layer is preferably larger than 0 ° C, more preferably 20 ° C or higher, and 50. It is more preferably ° C. or higher, particularly preferably 80 ° C. or higher, and most preferably 120 ° C. or higher.

As a polymer capable of forming a core layer having a Tg greater than 0 ° C. and not lowering or improving the elastic modulus of the epoxy resin (B), at least one monomer having a Tg greater than 0 ° C. of the homopolymer is used. 50 to 100% by weight (more preferably 65 to 99% by weight), and 0 to 50% by weight (more preferably 1 to 35% by weight) of at least one monomer having a Tg of the homopolymer below 0 ° C. Examples include polymers composed of inclusions.

Even when the Tg of the core layer is larger than 0 ° C., it is preferable that the core layer has a crosslinked structure introduced. By introducing the crosslinked structure, Tg is raised. Examples of the method for introducing the crosslinked structure include the above methods.

Examples of the monomers having a Tg higher than 0 ° C. of the homopolymer include those containing one or more of the following monomers, but are not limited thereto. For example, unsubstituted vinyl aromatic compounds such as styrene and 2-vinylnaphthalene; vinyl-substituted aromatic compounds such as α-methylstyrene; 3-methylstyrene, 4-methylstyrene, 2,4-dimethylstyrene, 2, Ring-alkylated vinyl aromatic compounds such as 5-dimethylstyrene, 3,5-dimethylstyrene, 2,4,6-trimethylstyrene; Ring-alkenylated vinyl aromatic compounds such as 4-methoxystyrene and 4-ethoxystyrene. Vinyl halide aromatic compounds such as 2-chlorostyrene and 3-chlorostyrene; Ring ester-substituted vinyl aromatic compounds such as 4-acetoxystyrene; Ring hydroxylated vinyl aromatic compounds such as 4-humanoxystyrene; Classes; vinyl esters such as vinyl benzoate and vinyl cyclohexanoate; vinyl halides such as vinyl chloride; aromatic monomers such as acenaphthalene and inden; alkyl methacrylates such as methyl methacrylate, ethyl methacrylate and isopropyl methacrylate; phenyl Aromatic methacrylates such as methacrylates; methacrylates such as isobornyl methacrylate and trimethylsilyl methacrylate; methacrylic monomers containing methacrylic acid derivatives such as methacrylonitrile; certain acrylic acid esters such as isobornyl acrylate and tert-butyl acrylate; Acrylic monomers containing an acrylic acid derivative such as acrylonitrile can be mentioned. Further, monomers such as acrylamide, isopropylacrylamide, N-vinylpyrrolidone, isobornyl methacrylate, dicyclopentanyl methacrylate, 2-methyl-2-adamantyl methacrylate, 1-adamantyl acrylate and 1-adamantyl methacrylate can be mentioned.

In the present invention, the core layer often has a single-layer structure, but may have a multi-layer structure. When the core layer has a multi-layer structure, the polymer composition of each layer may be different.

That is, a core composed of two layers having a second core layer having a different polymer composition outside the first core layer, or a core composed of two layers further formed a third core layer having a different polymer composition. It may be a core layer composed of three layers. When the second layer of the two-layer core and the third layer of the three-layer core are composed of a polymer obtained by polymerizing a polyfunctional monomer such as triallyl isocyanurate described above as a main component, a shell polymer described later is grafted. There is a merit that it becomes easy to do. However, the formation of a multilayer structure core has a drawback that the manufacturing process becomes complicated.

The outermost shell layer of the core-shell polymer (D), that is, the shell polymer, controls the compatibility with the alkoxysilyl-modified polymer (A), the epoxy resin (B), and the like, and makes the core-shell polymer (D) effective. It plays a role of distributing to.

Such shell polymers are preferably grafted onto the core layer. More precisely, it is preferable that the monomer component used for forming the shell polymer is graft-polymerized on the core polymer forming the core layer, and the shell polymer and the core polymer are substantially chemically bonded. That is, preferably, the shell polymer is formed by graft-polymerizing the shell-forming monomer in the presence of the core polymer, and by doing so, the shell polymer is graft-polymerized on the core polymer, and is one of the core polymers. It covers a part or the whole. This polymerization operation can be carried out by adding a monomer which is a component of the shell polymer to the latex of the core polymer which is prepared and existing in the state of an aqueous polymer latex and polymerizing it.

In order to uniformly disperse the core-shell polymer (D) in the epoxy resin (B), as a shell layer forming monomer, an epoxy group, an oxetane group, a hydroxyl group, an amino group, an imide group, a carboxylic acid group, a carboxylic acid anhydride group, A reactive group-containing monomer containing at least one selected from the group consisting of a cyclic ester, a cyclic amide, a benzoxazine group, and a cyanate ester group may be contained.

In particular, it is preferable to use an epoxy group or a hydroxyl group-containing vinyl monomer as a part of the shell layer forming monomer. These have a great effect of stabilizing the dispersion of the core-shell polymer (D) in the epoxy resin (B) for a long period of time.

The hydroxyl group-containing or epoxy group-containing vinyl monomer is preferably contained in the shell layer forming monomer in an amount of 1 to 40% by weight, more preferably 2 to 35% by weight. If too much hydroxyl group or epoxy group-containing vinyl monomer is contained in the shell-forming monomer, the dispersion of the core-shell polymer (D) in the epoxy resin (B) tends to be unstable.

Further, when a polyfunctional monomer having two or more double bonds is used as the monomer for forming the shell layer, a crosslinked structure is introduced into the shell layer. As a result, the interaction between the core-shell polymer (D) and the epoxy resin (B) is reduced, and as a result, the viscosity of the epoxy resin composition can be reduced. Therefore, it may be preferable to use a polyfunctional monomer having two or more double bonds. On the other hand, the elongation of the cured product of the epoxy resin composition tends to decrease, so if it is desired to improve the elongation to the maximum, a polyfunctional monomer having two or more double bonds is used as the monomer for forming the shell layer. It is preferable not to do so.

When used, the polyfunctional monomer is preferably contained in the shell layer forming monomer in an amount of 0.5 to 10% by weight, more preferably 1 to 5% by weight.

Specific examples of the (meth) acrylate monomer include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and octyl (meth). ) Acrylate and the like can be mentioned.

Specific examples of the aromatic vinyl monomer include styrene, α-methylstyrene, p-methylstyrene, divinylbenzene and the like.

Specific examples of the hydroxyl group-containing vinyl monomer include 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate.

Specific examples of the monomer having an epoxy group include glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, allyl glycidyl ether and the like. In particular, glycidylme methacrylate is preferable because of its stability and its reactivity.

Specific examples of the polyfunctional monomer having two or more double bonds include the same monomers as the above-mentioned polyfunctional monomer, but allyl methacrylate and triallyl isocyanurate are preferable.

The shell layer may be formed by containing other monomer components in addition to the above-mentioned monomer components.

The proportion of the shell layer in the core-shell polymer (D) is 5 to 30% by weight, more preferably 7 to 20% by weight, with the entire core-shell polymer as 100% by weight. If the proportion of the shell layer is too high, the viscosity of the epoxy resin composition tends to be too high. If the amount is too small, it becomes difficult to disperse the core-shell polymer (D) in the epoxy resin (B).

<< Manufacturing method of core-shell polymer (D) >>
(Manufacturing method of core layer)
The polymer forming the core layer constituting the core-shell polymer (D) used in the present invention is at least one monomer (first monomer) selected from a diene-based monomer (conjugated diene-based monomer) and a (meth) acrylate-based monomer. When composed of, the core layer can be formed by, for example, emulsion polymerization, suspension polymerization, microsuspension polymerization, or the like, and for example, the method described in International Publication No. 2005/028546 is used. Can be done.

When the polymer forming the core layer is composed of an organosiloxane-based polymer, the formation of the core layer can be produced by, for example, emulsion polymerization, suspension polymerization, microsuspension polymerization, or the like. The method described in EP1338625 can be used.

(Method of forming shell layer)
The shell layer can be formed by polymerizing a monomer for forming a shell layer by a known radical polymerization. When the core layer is obtained as an emulsion of the core-shell polymer (D) precursor, the polymerization of the shell layer forming monomer is preferably carried out by an emulsion polymerization method, for example, according to the method described in International Publication No. 2005/028546. Can be manufactured.

Examples of the emulsifier (dispersant) that can be used in emulsification polymerization include alkyl or aryl sulfonic acid represented by dioctyl sulfosuccinic acid and dodecylbenzene sulfonic acid, alkyl or aryl ether sulfonic acid, and alkyl or aryl represented by dodecyl sulfate. Sulfate, alkyl or aryl ether sulphate, alkyl or aryl substituted phosphoric acid, alkyl or aryl ether substituted phosphoric acid, N-alkyl or aryl zarcosic acid typified by dodecyl sarcosinic acid, alkyl represented by oleic acid or stearic acid or Various acids such as aryl carboxylic acids, alkyl or aryl ether carboxylic acids, anionic emulsifiers (dispersants) such as alkali metal or ammonium salts of these acids; nonionic emulsifiers (dispersants) such as alkyl or aryl-substituted polyethylene glycols. ); Dispersants such as polyvinyl alcohol, alkyl-substituted cellulose, polyvinylpyrrolidone, and polyacrylic acid derivatives can be mentioned. These emulsifiers (dispersants) may be used alone or in combination of two or more.

It is preferable to use a small amount of the emulsifier (dispersant) as long as the dispersion stability of the aqueous latex of the core-shell polymer (D) is not hindered. Further, the emulsifier (dispersant) is more preferably water-soluble. When the water solubility is high, the emulsifier (dispersant) can be easily removed by washing with water, and adverse effects on the finally obtained epoxy resin composition can be easily prevented.

Thermally decomposed initiators such as 2,2'-azobisisobutyronitrile, organic peroxides, hydrogen peroxide, potassium persulfate, and ammonium persulfate are well known as initiators for the emulsion polymerization method. Organic peroxides are particularly preferred in the present invention.

Preferred organic peroxides include t-butylperoxyisopropyl carbonate, paramentanhydroperoxide, cumenehydroperoxide, dicumyl peroxide, t-butylhydroperoxide, di-t-butyl peroxide, di-t-. Hexyl peroxide and the like can be mentioned. Among them, di-t-butyl peroxide (T ₁₀ : 124 ° C.) and paramentan hydroperoxide (T ₁₀ :) having a pyrolysis temperature (hereinafter, also referred to as T ₁₀ ) having a half-life of 10 hours of 120 ° C. or higher. 128 ° C.), Kumen Hydroperoxide (T ₁₀ : 158 ° C.), t-Butyl Hydroperoxide (T ₁₀ : 167 ° C.), and other organic peroxides can be used to determine the MEK insoluble content of the core-shell polymer (D). It is preferable in that it can be increased.

Also, organic peroxides, sodium formaldehyde sulfoxylate, reducing agents such as glucose, and transition metal salts such as iron (II) sulfate, if necessary, and disodium ethylenediaminetetraacetate, etc., if necessary. It is preferable to use a redox-type initiator in which the chelating agent of the above and, if necessary, a phosphorus-containing compound such as sodium pyrophosphate are used in combination.

When the redox-type initiator is used, the polymerization can be carried out even at a low temperature at which the peroxide is substantially not thermally decomposed, and the polymerization temperature can be set in a wide range, which is preferable.

The amount of the initiator used, and when the redox-type initiator is used, the amount of the reducing agent, transition metal salt, chelating agent, etc. used can be used within a known range.

Chain transfer agents can also be used if desired. The chain transfer agent may be any as long as it is used in ordinary emulsion polymerization, and is not particularly limited.

Specific examples of the chain transfer agent include t-dodecyl mercaptan, n-octyl mercaptan, n-tetradecyl mercaptan, n-hexyl mercaptan and the like.

Conditions such as polymerization temperature, pressure, and deoxidation at the time of polymerization can be applied within a known range.

<Other ingredients>
In the present invention, other compounding ingredients can be used, if necessary. For example, a silanol condensation catalyst can be used to cause the condensation reaction of the alkoxysilyl-modified polymer (A). Examples of the silanol condensation catalyst include organic tin compounds such as tin stearate, tin octylate, di-n-butyltin dilaurate, and dioctyltin dilaurate, aluminum alcoholate, aluminum chelate compounds, and titanium chelate compounds.

The blending amount of the silanol condensation catalyst is usually 0 to 0.09 parts by weight, preferably 0 to 0.07 parts by weight, and more preferably 0 to 0, based on 100 parts by weight of the alkoxysilyl-modified polymer (A). It is 0.05 parts by weight, more preferably 0 to 0.03 parts by weight, and even more preferably 0 to 0.01 parts by weight. Further, from the viewpoint of reducing the number of compounding components and stabilizing the physical properties of the cured product for a long period of time, it is most preferable not to use a silanol condensation catalyst. Excessive use of the silanol condensation catalyst tends to cause foaming when the epoxy resin composition is cured, which causes deterioration of the physical properties of the cured product.

In addition to the silanol condensation catalyst, other compounding components may be used without particular limitation as long as they are used in ordinary epoxy resin compositions. For example, fillers such as silica and calcium carbonate, dehydrators such as calcium oxide, tracking reducing agents / flame retardants such as aluminum hydroxide, heat dissipation agents such as aluminum oxide, silane coupling agents, defoaming agents, and sedimentation prevention. Agents, thioxogenic agents, colorants such as pigments and dyes, extender pigments, ultraviolet absorbers, antioxidants, stabilizers (antigels), plasticizers, leveling agents, antistatic agents, flame retardants, lubricants , A thickener, a low shrinkage agent, an organic filler, a thermoplastic resin, a desiccant, a dispersant and the like. Further, glass fiber, carbon fiber and the like used for fiber reinforced resin can also be used. Among them, inorganic substances such as silica, calcium carbonate, aluminum oxide, and aluminum hydroxide are particularly preferable because they tend to improve the interfacial adhesiveness. The amount of the inorganic substance used is preferably 1 to 600 parts by weight with respect to 100 parts by weight of the epoxy resin (B). In particular, the silane coupling agent is particularly preferable because it improves the adhesiveness between the filler, the adhesive base material, the glass fiber, the carbon fiber, and the like and the resin. Specific examples thereof include 3-glycidyloxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-aminopropyltrimethoxysilane. The amount of the silane coupling agent used is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the epoxy resin (B). Further, since it is necessary to reduce air bubbles in the epoxy resin composition as much as possible, it is preferable to add an antifoaming agent during blending. As the defoaming agent, for example, a silicone-based, fluorine-based, acrylic-based, polyoxyethylene-based, polyoxypropylene-based, or other defoaming agent may be appropriately selected. Specific examples include BYK-A500 and BYK-1790 manufactured by Big Chemie. The amount of the defoaming agent used is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the epoxy resin (B). Further, when a filler or the like is used in the epoxy resin composition, it is preferable to add a sedimentation inhibitor in order to improve the storage stability thereof. As the sedimentation inhibitor, additives that enhance the thixotropy of the epoxy resin composition, such as fumed silica and fine powdered organic bentonite, are preferable. The amount of the sedimentation inhibitor used is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the epoxy resin (B). These anti-settling agents can be used as thixotropic agents in the adhesive formulation. The amount used is preferably about the same. Flame retardants include inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide, tetrabromobisphenol A and its variants, halogen-based flame retardants such as tetrabromophthalade, triphenyl phosphate, bisphenol A bis (diphenyl) phosphate and Examples thereof include phosphorus-based flame retardants such as reactive bisphenol A bis (diphenyl) phosphate, and silicone-based flame retardants. The flame retardant is preferably used in an amount of 1 to 200% by weight based on 100 parts by weight of the epoxy resin (B).

<Manufacturing method of epoxy resin composition>
The epoxy resin composition of the present invention has an alkoxysilyl-modified polymer (A) and an epoxy having at least two alkoxysilyl groups in the molecule, a glass transition temperature of 0 ° C. or lower, and a number average molecular weight of 600 to 5000. A curable resin composition containing a resin (B), an epoxy curing agent (C), and a core-shell polymer (D).

In the above formulation, it is preferable to use a dispersion in which the core-shell polymer (D) is once dispersed in the epoxy resin (B) in the state of primary particles because the viscosity of the epoxy resin composition can be easily controlled.

Various methods can be used as a method for obtaining the dispersion in which the core-shell polymer (D) is dispersed in the epoxy resin (B) in the state of primary particles. For example, the core-shell polymer (D) obtained in the aqueous latex state is used. ) Is in contact with the epoxy resin (B) and then removes unnecessary components such as water. The core-shell polymer (D) is once extracted into an organic solvent, mixed with the epoxy resin (B), and then the organic solvent is removed. However, it is preferable to use the method described in International Publication No. 2005/0284546. The specific production method is that, in order, an aqueous latex containing the core-shell polymer (D) (specifically, a reaction mixture after producing the core-shell polymer by emulsification polymerization) has a solubility in water at 20 ° C. of 5% or more. The first step of aggregating the core-shell polymer by mixing with an organic solvent of 40% or less and then mixing with excess water, and separating and recovering the agglomerated core-shell polymer (D) from the liquid phase, and then re-organizing the organic solvent. Including a second step of obtaining an organic solvent solution of the core-shell polymer (D) by mixing with, and a third step of distilling off the organic solvent after further mixing the organic solvent solution with the epoxy resin (B). It is preferably prepared.

When the epoxy resin (B) is liquid at 23 ° C., the third step is facilitated, which is preferable. "Liquid at 23 ° C." means that the softening point is 23 ° C. or lower, and exhibits fluidity at 23 ° C.

If necessary, the composition obtained by dispersing the core-shell polymer (D) in the epoxy resin (B) in the state of primary particles (hereinafter, also referred to as the primary particle dispersion composition) obtained through the above steps is epoxy. The resin (B) is further added to appropriately dilute the primary particle dispersion composition, and the alkoxysilyl-modified polymer (A) and the epoxy curing agent (C) are additionally mixed, and if necessary, the other compounding components. By mixing the above, the epoxy resin composition of the present invention in which the core-shell polymer (D) is dispersed can be obtained.

On the other hand, the powdery core-shell polymer (D) obtained by solidifying by a method such as salting out and then drying uses a disperser having a high mechanical shearing force such as a three-paint roll, a roll mill, or a kneader. It is possible to redisperse in the epoxy resin (B). At this time, by applying a mechanical shearing force to the mixture of the epoxy resin (B) and the core-shell polymer (D) at a high temperature, the core-shell polymer (D) can be efficiently dispersed in the epoxy resin (B). To do. The temperature at the time of dispersion is preferably 50 to 200 ° C., more preferably 70 to 170 ° C., further preferably 80 to 150 ° C., and particularly preferably 90 to 120 ° C. If the temperature is lower than 50 ° C., the core-shell polymer (D) may not be sufficiently dispersed, and if the temperature is higher than 200 ° C., the epoxy resin (B) and the core-shell polymer (D) may be thermally deteriorated.

Further, in the epoxy resin composition of the present invention, an alkoxysilyl-modified polymer (A), an epoxy resin (B), an epoxy curing agent (C) and a core-shell polymer (D) are mixed as two liquids of a main component and a curing component. May be prepared. For example, the epoxy resin composition of the present invention is prepared by mixing a mixed component of an alkoxysilyl-modified polymer (A), an epoxy resin (B) and a core-shell polymer (D) as a main component and an epoxy curing agent (C) as a curing component. May be prepared, or a mixed component of the alkoxysilyl-modified polymer (A) and / or the core-shell polymer (D) and the epoxy curing agent (C) is used as the curing agent component, and then the main component is the epoxy resin (B). The epoxy resin composition of the present invention may be prepared by mixing.

<Cured product>
The present invention includes a cured product obtained by curing the epoxy resin composition. By using the specific alkoxysilyl-modified polymer (A) and the core-shell polymer (D) in combination, the obtained cured product has excellent adhesiveness. In particular, the curing temperature is preferably 60 ° C. or higher, and the cured product can obtain good adhesiveness.

<Use>
Since the composition of the present invention has good adhesiveness, it is suitable for various uses such as adhesives, paints, and composite materials.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto, and can be appropriately modified and carried out within a range that can be adapted to the gist of the above and the following. And all of them are included in the technical scope of the present invention. In the following Examples and Comparative Examples, "parts" and "%" mean parts by weight or% by weight.

The measurements and tests in the following synthetic examples, examples and comparative examples were carried out as follows.

[1] Measurement of Average Particle Diameter of Polymer Particles The arithmetic number average particle diameter (Mn) of the polymer particles dispersed in the aqueous latex was measured using Microtrac UPA150 (manufactured by Nikkiso Co., Ltd.). A sample diluted with deionized water was used as a measurement sample.

[2] Measurement of MEK Insoluble Content of Core Shell Polymer 2 g of core shell polymer obtained by drying from latex was immersed in 100 g of MEK for 24 hours at 23 ° C., and then the MEK insoluble component was centrifuged. The obtained insoluble matter was dried and weighed, and the weight fraction (%) of the MEK insoluble matter with respect to the weight of the core-shell polymer was calculated.

[3] Shear Adhesive Strength According to JIS K 6850, the compound was applied and bonded between two cold-rolled steel sheets having dimensions: 25 × 100 × 1.6 mm to obtain an adhesive thickness of 250 μm. This was cured under the conditions shown in the examples. Then, the test piece was subjected to a tensile shear adhesion test at 23 ° C. under a test speed of 1 mm / min.

The alkoxysilyl-modified polymer (A), epoxy resin (B), epoxy curing agent (C) and core-shell polymer (D) used in Examples and Comparative Examples are shown. The core-shell polymer (D) dispersed in the epoxy resin (B) was designated as the dispersion (E).

<Polymer (A)> Refer to the synthetic example described later. A-1: SPT3000, the trimethoxysilyl terminal obtained by converting the terminal of the polyoxypropylene triol having a number average molecular weight of 3000 described in Synthesis Example 1 below into a trimethoxysilyl group. Polypropylene oxide. Tg: -55 ° C
A-2: SPD400, a trimethoxysilyl-terminated polypropylene oxide obtained by converting the terminal of a polyoxypropylene diol having a number average molecular weight of 400 into a trimethoxysilyl group described in Synthesis Example 2 below. Tg: -8 ° C.
A-3: SPD700, a trimethoxysilyl-terminated polypropylene oxide obtained by converting the terminal of a polyoxypropylene diol having a number average molecular weight of 700 into a trimethoxysilyl group described in Synthesis Example 3 below. Tg: -32 ° C.
A-4: SPD1000, a trimethoxysilyl-terminated polypropylene oxide in which the terminal of a polyoxypropylene diol having a number average molecular weight of 1000 and described in Synthesis Example 4 below is converted into a trimethoxysilyl group. Tg: -52 ° C.
A-5: SPD4000: A trimethoxysilyl-terminated polypropylene oxide obtained by converting the terminal of a polyoxypropylene diol having a number average molecular weight of 4000 into a trimethoxysilyl group, which was described in Synthesis Example 5 below. Tg: -55 ° C.
A-6: PPT3000: Polyoxypropylene triol having a number average molecular weight of 3000 used in Synthesis Example 1 below. The end is a hydroxyl group. Tg: -55 ° C.
A-7: SPD5500: A trimethoxysilyl-terminated polypropylene oxide obtained by converting the terminal of a polyoxypropylene diol having a number average molecular weight of 5500 into a trimethoxysilyl group, which was described in Synthesis Example 6 below. Tg: -55 ° C.

<Epoxy resin (B)>
B-1: BPADGE, bisphenol A diglycidyl ether (jER828EL manufactured by Mitsubishi Chemical Corporation)
<Epoxy curing agent (C)>
C-1: Acceleration of curing of 1% 2-ethyl-4-methylimidazole (Curesol 2E4MZ manufactured by Shikoku Chemicals Corporation) in MTHPA-1% 2E4MZ, methyltetrahydrophthalic anhydride (HN2200 manufactured by Hitachi Chemical Co., Ltd.) Mixture of agents C-2: DICY, dicyandiamide (AMICURE CG-1200 manufactured by Ebonic)
C-3: UR, 1-Phenyl-3,3-Dimethylurea (AMICURE UR made by Evonik)
<Core-shell polymer (D)> See synthetic example described later. D-1: Core-shell polymer in which the main component of the core is a butadiene rubber core <Dispersion (E) in which the core-shell polymer (D) is dispersed in the epoxy resin (B)>
See the preparation example of the dispersion (E-1) described later.

<Filler (F)>
F-1: CMC-12S, crystalline silica, manufactured by Ryumori Co., Ltd., Crystallite CMC-12S, median diameter D50: 6 μm)
<Adhesion accelerator (G)>
G-1: CTBN-Adduct, butadiene acrylonitrile rubber (CTBN) added to bisphenol A diglycidyl ether. CTBN content 40% by weight (HyPox RA1340 manufactured by CVC)
G-2: Silane coupling agent, Z-6040, 3-glycidyloxypropyltrimethoxysilane (manufactured by Toray Dow Corning, Z-6040)
<Defoamer (H)>
H-1: BYK-1790, antifoaming agent (manufactured by BYK)
<Thixotropic agent (I)>
I-1: TS-720, fumed silica (CAB-O-SIL TS-720 manufactured by Cabot)

(Synthesis Example 1 Trimethoxysilyl End Polypropylene Oxide, SPT3000)
100 parts of polyoxypropylene triol (Actcol T-3000 manufactured by Mitsui Chemicals, Inc.) having a number average molecular weight of 3000 was charged in a pressure-resistant reactor and placed in a nitrogen atmosphere. Subsequently, 3.3 times the equivalent of sodium methoxide (NaOMe) of the hydroxyl group of polyoxypropylene triol was added in a methanol solution. Devolatile under reduced pressure with stirring to distill off methanol. After returning to a nitrogen atmosphere, 10.2 parts of allyl chloride was added dropwise and stirred for 4 hours to complete allylation.

300 parts of n-hexane and 300 parts of water were mixed and stirred with respect to 100 parts of the obtained unpurified polypropylene oxide having an allyl group at the terminal, and then water was removed by centrifugation. Further, 300 parts of water was mixed and stirred with the obtained hexane solution, water was removed by centrifugation again, and then hexane was removed by vacuum devolatile. From the above, a branched polypropylene oxide having a number average molecular weight of about 3000 in which about 90% of the polymer terminals are allyl groups was obtained.

To 100 parts of the obtained allyl-terminated polypropylene oxide, 12 parts of trimethoxysilane and 100 ppm of an isopropanol solution having a platinum content of 3% by weight of a platinum vinylsiloxane complex were added, and the mixture was reacted at 90 ° C. for 2 hours. Then, it was devolatile to obtain a trimethoxysilyl-terminated polypropylene oxide.

(Synthesis Example 2 Trimethoxysilyl End Polypropylene Oxide, SPD400)
A flask equipped with a stirrer is charged with 100 parts of polyoxypropylene diol having a number average molecular weight of 400 (Actcol D-400 manufactured by Mitsui Chemicals, Inc.) and 30 ppm of mercaptotin-based catalyst Neostan U-360 (Nitto Kasei Co., Ltd.), and nitrogen. In an atmosphere, 103 parts of γ-isocyanatepropyltrimethoxylane was added and reacted at 90 ° C. The IR spectrum was measured to confirm that the peak of the isocyanate group near 2280 cm- ¹ disappeared, and the reaction was terminated to obtain a trimethoxysilyl group-terminated polypropylene oxide (SPD400).

(Synthesis Example 3 Trimethoxysilyl End Polypropylene Oxide, SPD700)
A flask with a stirrer is charged with 100 parts of polyoxypropylene diol having a number average molecular weight of 700 (Actcol D-700 manufactured by Mitsui Chemicals, Inc.) and 30 ppm of mercaptotin-based catalyst Neostan U-360 (Nitto Kasei Co., Ltd.), and nitrogen. Under the atmosphere, 59 parts of γ-isocyanatepropyltrimethoxyrun was added and reacted at 90 ° C. The IR spectrum was measured to confirm that the peak of the isocyanate group near 2280 cm- ¹ disappeared, and the reaction was terminated to obtain a trimethoxysilyl group-terminated polypropylene oxide (SPD700).

(Synthesis Example 4 Trimethoxysilyl End Polypropylene Oxide, SPD1000)
A flask equipped with a stirrer is charged with 100 parts of polyoxypropylene diol having a number average molecular weight of 1000 (Actcol D-1000 manufactured by Mitsui Chemicals, Inc.) and 30 ppm of mercaptotin-based catalyst Neostan U-360 (Nitto Kasei Co., Ltd.), and nitrogen. In an atmosphere, 41 parts of γ-isocyanatepropyltrimethoxylane was added and reacted at 90 ° C. The IR spectrum was measured to confirm that the peak of the isocyanate group near 2280 cm- ¹ disappeared, and the reaction was terminated to obtain a trimethoxysilyl group-terminated polypropylene oxide (SPD1000).

(Synthesis Example 5 Trimethoxysilyl End Polypropylene Oxide, SPD4000)
In a flask equipped with a stirrer, 100 parts of polyoxypropylene diol having a number average molecular weight of 4000 (Actcol D-4000 manufactured by Mitsui Chemicals, Inc.) and 30 ppm of mercaptotin-based catalyst Neostan U-360 (Nitto Kasei Co., Ltd.) are charged, and nitrogen is charged. In an atmosphere, 11 parts of γ-isocyanatepropyltrimethoxylane was added and reacted at 90 ° C. The IR spectrum was measured to confirm that the peak of the isocyanate group near 2280 cm- ¹ disappeared, and the reaction was terminated to obtain a trimethoxysilyl group-terminated polypropylene oxide (SPD4000).

(Synthesis Example 6 Trimethoxysilyl End Polypropylene Oxide, SPD5500)
A trimethoxysilyl group-terminated polypropylene oxide (SPD5500) was obtained in the same manner as in Synthesis Example 5 except that a polyoxypropylene diol having a number average molecular weight of 5500 (Preminol S4006 manufactured by AGC Inc.) was used as the polyoxypropylene diol.

(Synthesis Example 7 Core Shell Polymer)
7-1. Formation of core layer Synthesis example 7-1-1; Preparation of polybutadiene rubber latex (R-1) In a pressure-resistant polymerizer, 200 parts of deionized water, 0.03 part of tripotassium phosphate, potassium dihydrogen phosphate 0. 25 parts, 0.002 part of ethylenediaminetetraacetic acid disodium (EDTA), 0.001 part of ferrous sulfate heptahydrate (Fe) and 0.2 part of sodium dodecylbenzenesulfonate (SDS) are added and stirred. After sufficiently replacing oxygen with nitrogen to remove oxygen, 100 parts of butadiene (BD) was added into the system and the temperature was raised to 45 ° C. 0.015 parts of paramentan hydroperoxide (PHP) and then 0.04 part of sodium formaldehyde sulfoxylate (SFS) were added to initiate polymerization. Four hours after the start of polymerization, 0.3 part of SDS, 0.01 part of PHP, 0.0015 part of EDTA and 0.001 part of Fe were added. Further, 0.4 part of SDS was added 7 hours after the polymerization. At 10 hours after the polymerization, the residual monomer was volatilized and removed under reduced pressure to complete the polymerization, and a latex (R-1) containing polybutadiene rubber particles was obtained. The polymerization reaction rate was 99% or more. The number average particle size of the polybutadiene rubber particles contained in the obtained latex was 0.14 μm.

7-2. Preparation of core-shell polymer (D) (formation of shell layer)
Synthesis Example 7-2-1; Preparation of latex (D-1LX) containing core-shell polymer (D-1) A 5-port glass container equipped with a reflux condenser, a nitrogen inlet, an additional port for monomers and emulsifiers, and a thermometer. 1575 parts of latex (R-1) (corresponding to 518 parts of polybutadiene rubber particles) and 315 parts of deionized water obtained in Synthesis Example 7-1-1 were charged into the mixture, and the mixture was stirred at 60 ° C. while performing nitrogen substitution. After adding 0.024 parts of EDTA, 0.006 parts of Fe, and 1.2 parts of SFS, graft monomers (57 parts of butyl acrylate (BA), 32 parts of methyl methacrylate (MMA), 3 parts of glycidyl methacrylate (GMA)) and CHP 0.4 The mixture of parts was continuously added over 2 hours for graft polymerization. After completion of the addition, the reaction was terminated with further stirring for 2 hours to obtain a latex (D-1LX) of the core-shell polymer (D-1). The polymerization reaction rate was 99% or more. The ratio of the rubber layer in the core-shell polymer (D-1) was 85% based on the charged amount and the reaction rate. The number average particle size of the core-shell polymer (D-1) contained in the obtained latex was 0.15 μm, and the MEK insoluble content was 98%.

7-3. Preparation of dispersion (E-1) in which the core-shell polymer (D) is dispersed in the epoxy resin (B-1) Synthesis Example 7-3-1: Of the epoxy resin (B-1) -based dispersion (E-1) Preparation 100 parts of methyl ethyl ketone (MEK) is introduced into a 1 L mixing tank at 25 ° C., and while stirring, the aqueous latex (D-1LX) of the core-shell polymer obtained in Synthesis Example 7-2-1 is equivalent to 30 parts of the core-shell polymer. I put in a minute. After mixing uniformly, 150 parts of water was added at a supply rate of 60 parts / minute. When the stirring was stopped promptly after the end of the supply, a slurry liquid consisting of a floating aggregate and an aqueous phase partially containing an organic solvent was obtained. Next, the aqueous phase was discharged from the discharge port at the bottom of the tank. 70 parts of MEK was added to the obtained aggregate and mixed uniformly to obtain a dispersion in which the core-shell polymer (D-1) was uniformly dispersed. 70 parts of epoxy resin (B-1) was mixed with this dispersion. MEK was removed from this mixture with a rotary evaporator. In this way, a dispersion (E-1) in which the core-shell polymer (D-1) was dispersed in 30% by weight was obtained in the epoxy resin (B-1).

(Examples 1 to 4, Comparative Examples 1 to 6)
Each component was weighed according to the formulation shown in Table 1, and mixed uniformly using a stirrer (rotational revolution mixer, Awatori Rentaro, manufactured by Shinky Co., Ltd.). The mixture was defoamed under reduced pressure to obtain an epoxy resin composition. The shear bond strength was evaluated using the obtained composition. The curing conditions at the time of preparing the test piece were 100 ° C. for 1 hour and 150 ° C. for 3 hours. The test results are shown in Table 1.

From Table 1, it can be seen that the epoxy resin compositions of Examples 1 to 4 are excellent in interfacial adhesiveness due to the progress of cohesive fracture in addition to exhibiting high adhesive strength. On the other hand, it can be seen that Comparative Examples 1 to 6 have low adhesive strength and are inferior in interfacial adhesiveness due to the progress of interfacial fracture.

Further, the viscosities of the epoxy resin compositions of Example 1 and Comparative Example 5 were measured with a spindle CPE-41 using a digital viscometer DV-II + Pro manufactured by BROOKFIELD at a measurement temperature of 25 ° C., Shear Rate 10 "1 / s". It was measured under the condition of. As a result, the viscosity of Example 1 was 2570 mPa · s, and the viscosity of Comparative Example 5 was 4100 mPa · s.

(Example 5, Comparative Examples 7 to 8)
Each component was weighed according to the formulation shown in Table 2, and mixed uniformly using a stirrer (rotational revolution mixer, Awatori Rentaro, manufactured by Shinky Co., Ltd.). The mixture was defoamed under reduced pressure to obtain an epoxy resin composition. The shear bond strength was evaluated using the obtained composition. The curing condition at the time of preparing the test piece was 170 ° C. for 30 minutes. The test results are shown in Table 2.

From Table 2, it can be seen that the epoxy resin composition of Example 5 is excellent in interfacial adhesiveness due to the progress of cohesive fracture in addition to exhibiting high adhesive strength. On the other hand, it can be seen that Comparative Examples 7 to 8 are inferior in interfacial adhesiveness due to the progress of interfacial fracture.

(Example 6, Comparative Examples 9 to 11)
Each component was weighed according to the formulation shown in Table 3, and mixed uniformly using a stirrer (rotational revolution mixer, Awatori Rentaro, manufactured by Shinky Co., Ltd.). The mixture was defoamed under reduced pressure to obtain an epoxy resin composition. The shear bond strength was evaluated using the obtained composition. The curing conditions at the time of preparing the test piece were 100 ° C. for 1 hour and 150 ° C. for 3 hours. The test results are shown in Table 3.

From Table 3, it can be seen that the epoxy resin composition of Example 6 is excellent in interfacial adhesiveness due to the progress of cohesive fracture in addition to exhibiting high adhesive strength. On the other hand, it can be seen that Comparative Examples 9 and 11 are inferior in interfacial adhesiveness due to low adhesive strength and advanced interfacial fracture. Further, in Comparative Example 10, although cohesive fracture proceeded, the adhesive strength was not sufficient.

Claims (7)

An alkoxysilyl-modified polymer (A), an epoxy resin (B), and an epoxy curing agent having at least two alkoxysilyl groups in the molecule, having a glass transition temperature of 0 ° C. or lower, and having a number average molecular weight of 600 to 5000. An epoxy resin composition containing C) and a core-shell polymer (D), wherein the content of the alkoxysilyl-modified polymer (A) is 0.01 to 10% by weight ((A) + (B) + (C) + ( D) = 100% by weight), and the core-shell polymer (D) is selected from the group consisting of diene rubber, (meth) acrylate rubber, organosiloxane rubber, styrene polymer and (meth) acrylate polymer 1 An epoxy resin composition having a core layer of more than one species and having a core layer ratio of 70 to 95% by weight in the core-shell polymer (D). The epoxy resin composition according to claim 1, wherein the alkoxysilyl-modified polymer (A) is a polymer having an alkoxysilyl group at the polymer terminal. The epoxy resin composition according to claim 1 or 2, wherein the main chain of the alkoxysilyl-modified polymer (A) is a polyalkylene oxide. The invention according to any one of claims 1 to 3, wherein the main chain of the alkoxysilyl-modified polymer (A) is at least one selected from polypropylene oxide, polybutylene oxide and an oxy-3-methyltetramethylene / oxybutylene copolymer. Epoxy resin composition. The epoxy resin composition according to any one of claims 1 to 4, wherein the epoxy curing agent (C) is an acid anhydride. The epoxy resin composition according to any one of claims 1 to 5, wherein the core-shell polymer (D) has a number average particle size of 0.01 to 0.6 μm. A cured product obtained by curing the epoxy resin composition according to any one of claims 1 to 6.