JP2001164090A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition excellent in dissolution dispersibility, reduction in stress (reduction in modulus of elasticity) and fracture toughness coefficient. SOLUTION: This epoxy resin composition comprises 100 pts.wt. of an epoxy resin and 1-100 pts.wt. of a thermoplastic resin prepared by reacting highly cross-linked particles having 50-500 nm average particle diameter and >=75 wt.% content of a toluene-insoluble fraction with a vinylic monomer and having <=0.25 dl/g intrinsic viscosity [η] of an acetone-soluble fraction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition having excellent dispersibility, low stress (low elastic modulus), and excellent fracture toughness coefficient.

[0002]

2. Description of the Related Art It has been known that a cured product of an epoxy resin has excellent physical and chemical properties. For example, since they are excellent in heat resistance, corrosion resistance, electrical properties, and chemical resistance, they are used in a wide range of fields such as adhesives, paints, sealing materials, sealing materials, and laminates. However, a cured product of an epoxy resin has these excellent properties, but has a weak point of being brittle. There is a strong demand in the epoxy resin industry to compensate for this brittleness and to obtain a product having high impact resistance and flexibility. To solve this problem, Japanese Patent Publication No. 55-33732.
Acrylonitrile-butadiene copolymer (modified NBR) into which various functional groups such as a carboxyl group that can be expected to react with an epoxy resin or a curing agent are introduced, as can be seen in JP-B-57-30133 and JP-B-57-30133. It is used as a modifier for epoxy resins. In some applications, silicone oil modified with a functional group is also used. However, since the polymers used as these modifiers are all uncrosslinked polymers, depending on the type and curing conditions of the curing agent, the particle size of the polymer dispersed in the epoxy resin composition and the Since the distribution changes and the dispersion state of the polymer in the epoxy resin differs, there is a disadvantage that the characteristics of the cured product of the epoxy resin change.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and solves the above-mentioned problems by dissolving and dispersing, reducing stress (reducing elastic modulus), and fracture toughness coefficient. An object of the present invention is to provide an epoxy resin composition excellent in the above.

[0004]

According to the present invention, the following (B) thermoplastic resin (1) is used per 100 parts by weight of epoxy resin (A).
The present invention provides an epoxy resin composition characterized by containing 〜100 parts by weight. (B) a thermoplastic resin;
The average particle diameter is 50 to 500 nm, and the toluene insoluble matter is 75
(C) 30 to 80% by weight of the highly crosslinked particles which is at least
And (D) 70 to 20% by weight of a vinyl monomer [provided that
(C) + (D) = 100% by weight].
A thermoplastic resin having an intrinsic viscosity [η] (30 ° C., methyl ethyl ketone solvent) of acetone-soluble component of 0.25 dl / g or less. (D) above the solubility parameter of the vinyl monomer (Sp value) 8.0~9.5 (cal ^1/2 · cm ^-3/2)
It is preferred that

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The epoxy resin (A) used in the present invention includes bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolak type epoxy resin, phenol novolak type epoxy resin, and cycloaliphatic type epoxy resin. And long-chain aliphatic epoxy resins, glycidyl ester epoxy resins, glycidylamine epoxy resins, isocyanate epoxy resins, dimer acid-modified epoxy resins, NBR-modified epoxy resins, urethane-modified epoxy resins, and the like. It can be selected from the above epoxy resins according to the purpose of use. The modification effect of the addition of the component (B) of the present invention is observed for all of these epoxy resins.

Next, the thermoplastic resin (B) of the present invention comprises:
It is obtained by reacting (C) highly crosslinked particles with (D) a vinyl monomer, and shows a modifying effect on component (A). (C) The highly crosslinked particles include a diene (co) polymer and a non-diene (co) polymer. Examples of the diene (co) polymer include polybutadiene, polyisoprene, butyl rubber, styrene-butadiene copolymer, styrene-isoprene copolymer, butadiene-acrylonitrile copolymer, and butadiene- (meth) acrylate copolymer. Coal, isobutylene-isoprene copolymer, styrene-
Butadiene-styrene block copolymer, styrene-butadiene-styrene radial tereblock copolymer, styrene-isoprene-styrene block copolymer, and the like. Non-diene (co) polymers include (meth) such as butyl acrylate-methyl acrylate copolymer
Acrylic ester-based copolymers, polyurethane rubbers, silicone-based rubbers and the like can be mentioned. These highly crosslinked particles can be used alone or in combination of two or more.

Among these, polybutadiene, styrene-butadiene copolymer, butadiene-acrylonitrile copolymer, (meth) acrylate copolymer, and silicone rubber are preferable, and polybutadiene is more preferable. It is a styrene-butadiene copolymer. In the case where silicone rubber is used for (C) the highly crosslinked particles, a graft crosslinking agent (for example, one containing a vinyl group, γ-methacryloxypropylmethyldimethoxysilane, etc.) is contained in the silicone rubber in an amount of 0.01 to 10% by weight. When used, an epoxy resin composition having excellent dispersibility in an epoxy resin can be obtained.

The above (co) polymer [diene (co)
Polymerization and non-diene (co) polymer] during the polymerization, hydroxyl group, carboxyl group, acid anhydride group, epoxy group, oxazoline group, maleimide group, ester group, amide group, amino group, ether group, etc. May be copolymerized. Furthermore, a crosslinkable monomer such as polyfunctional (meth) acrylate such as allyl methacrylate or divinylbenzene can also be used.

(C) The average particle size of the highly crosslinked particles is from 50 to
It is 500 nm, preferably 50 to 400 nm, and more preferably 50 to 350 nm. Average particle size is 50nm
If it is less than 3, the viscosity increases at the time of mixing with the component (A), so that industrial handling becomes difficult. Furthermore, since it is difficult to mix with a curing agent, a uniform cured product of the epoxy resin composition cannot be obtained, and the mechanical properties deteriorate. on the other hand,
If it exceeds 500 nm, agglomeration of particles occurs at the time of mixing with the component (A), resulting in poor dispersion, so that sufficient characteristics cannot be obtained. In particular, the fracture toughness coefficient is significantly reduced. The method for measuring the average particle size of the present invention will be described in the section of various measurement items described below. As the highly crosslinked particles (C), one type may be used alone, or two or more types may be used in combination.

(C) The toluene-insoluble content of the highly crosslinked particles is 7
It is at least 5% by weight, preferably at least 80% by weight, more preferably at least 85% by weight. When the content is less than 75% by weight, the uncrosslinked portion dissolves in the epoxy resin (A), so the epoxy resin composition [component (A) + component (B)]
Becomes high, and industrial handling becomes difficult. Furthermore, since it is difficult to mix with a curing agent, a uniform cured product of the epoxy resin composition cannot be obtained, and the mechanical properties deteriorate. The method for measuring the toluene insoluble content will be described in the section of various measurement items described below.

(C) The method for producing highly crosslinked particles includes a method of conducting polymerization by emulsion polymerization, solution polymerization, suspension polymerization, bulk polymerization, or the like. Among these, emulsion polymerization is preferable in consideration of the control of the average particle diameter and the toluene-insoluble content, but is not limited thereto.

The content of the highly crosslinked particles (C) in the component (B) is 30 to 80% by weight, preferably 35 to 75% by weight,
More preferably, it is 40 to 75% by weight. When the content of the component (C) is less than 30% by weight, if a cured product of the epoxy resin composition has a crack, the energy absorption capacity of the highly crosslinked particles is reduced, so that the bending strength and the fracture toughness coefficient are reduced. On the other hand, when it exceeds 80% by weight, the amount of the component (D) is relatively small, so that the compatibilized phase with the epoxy resin becomes thin (less), and the dispersibility of the component (B) in the epoxy resin composition is dispersible. And the flexural strength and fracture toughness coefficient decrease.

The (D) vinyl monomer of the present invention includes:
For example, styrene, t-butyl styrene, octyl styrene, α-methyl styrene, methyl-α-methyl styrene, p-methyl styrene, ethyl styrene, α-ethyl styrene, vinyl toluene, vinyl xylene, vinyl pyridine, dimethyl styrene, , 1-diphenylstyrene, N, N-diethyl-p-aminoethylstyrene,
N, N-diethyl-p-aminomethylstyrene, divinylbenzene, monochlorostyrene, dichlorostyrene,
Chlorinated styrene such as trichlorostyrene, brominated styrene such as monobromostyrene, dibromostyrene, tribromostyrene, aromatic vinyl monomers such as fluorostyrene, vinylnaphthalene, sodium styrenesulfonate; acrylonitrile, methacrylonitrile, etc. Vinyl cyanide monomer; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, ethylhexyl acrylate, octyl acrylate, 2-
Acrylic ester monomers such as ethylhexyl acrylate, cyclohexyl acrylate, dodecyl acrylate, octadecyl acrylate, phenyl acrylate, and benzyl acrylate; methyl methacrylate,
Examples include methacrylate monomers such as ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, phenyl methacrylate, and benzyl methacrylate. These vinyl monomers (D) can be used alone or in combination of two or more. Among them, styrene, acrylonitrile, butyl acrylate, ethyl acrylate and methyl methacrylate are preferred.

The solubility parameter (Sp value) of the vinyl monomer (D) is 8.0 to 9.5 (cal ^1/2 · cm).
^-3/2 ). The solubility parameter referred to here is generally used as a scale representing the polarity of a compound, and in the present invention, it is referred to as “POLYMER HAN”.
DBOOOK THIRD EDITION ", A WI
LEY-INTERSCIENCE PUBLICAT
The values described in ION JOHN WILEY & SONS are applied.

Vinyl monomers falling within the above solubility parameter (Sp value) range include butyl methacrylate [Sp value: 8.25 (cal ^1/2 · cm ^−3/2 )] and ethyl methacrylate [Sp value. : 8.3 (cal ^1/2 cm)
^-3/2 )], ethyl acrylate [Sp value: 8.6 (ca)
l ^1/2 · cm ^-3/2 )], butyl acrylate [Sp value:
8.8 (cal ^1/2 · cm ^−3/2 )], methyl methacrylate [Sp value: 8.8 (cal ^1/2 · cm ⁻³ / 2)], methyl acrylate [Sp value: 8.9 ( cal ^1/2 · cm
^-3/2 )], styrene [Sp value: 9.3 (cal ^1/2 · c)
m ^-3/2 )]. Among them, preferably,
Butyl acrylate, ethyl acrylate, methyl methacrylate and styrene. When a vinyl monomer corresponding to the above-mentioned solubility parameter (Sp value) range is used, the dispersibility of the component (B) in the epoxy resin (A) is further improved. Therefore, it is possible to further improve the brittleness of the epoxy resin, which is the greatest purpose of adding the thermoplastic resin (B).

The content of the vinyl monomer (D) in the component (B) of the present invention is 70 to 20% by weight, preferably 65 to 20% by weight.
It is 25% by weight, more preferably 60 to 25% by weight. When the content of the component (D) is less than 20% by weight, the compatibilizing phase with the epoxy resin becomes thin (less), so that
The dissolution and dispersibility of the component (B) in the epoxy composition is poor, and the flexural strength and the discard toughness coefficient are reduced. On the other hand, when the content exceeds 70% by weight, when a crack occurs in the cured product of the epoxy resin composition, the energy absorption by the highly crosslinked particles is reduced, so that the bending strength and the fracture toughness coefficient are reduced.

The thermoplastic resin (B) of the present invention comprises (C) 30 to 80% by weight of highly crosslinked particles, (D) a vinyl monomer 7
0 to 20% by weight (provided that (C) + (D) = 100% by weight). The component (B) can be produced by subjecting the component (D) to radical polymerization by emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, or the like in the presence of the component (C). As the content of the component (C) increases, the energy due to cracks can be absorbed, and the fracture toughness coefficient is improved. Emulsion polymerization is preferred for producing a polymer containing a large amount of the component (C). In the case of emulsion polymerization, a polymerization initiator, a chain transfer agent (molecular weight regulator), an emulsifier, water and the like are used. The highly crosslinked particles (C) and the vinyl monomer (D) used to produce the thermoplastic resin (B) are polymerized by adding the component (D) all at once in the presence of the total amount of the component (C). And may be divided or added continuously for polymerization. Further, the polymerization may be carried out by an addition method combining these. Further, the whole or a part of the component (C) may be added during the polymerization for polymerization.

As the polymerization initiator, general ones can be used. Specifically, cumene hydroperoxide,
Redox system by combining organic hydroperoxides represented by diisopropylbenzene hydroperoxide and paramenthane hydroperoxide with reducing agents represented by sugar-containing pyrophosphoric acid formulations and sulfoxylate formulations, or potassium persulfate Persulfates such as, azobisisobutyronitrile (AIBN),
Peroxides such as benzoyl peroxide (BPO), lauroyl peroxide, t-butylperoxylaurate, and t-butylperoxymonocarbonate are used. Preferably, it is an oil-soluble initiator, represented by organic hydroperoxides represented by cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide and the like, sugar-containing pyrophosphoric acid formulation, sulfoxylate formulation and the like. A redox system based on a combination with a reducing agent to be used is preferred. The above-mentioned polymerization initiators can be used alone or in combination of two or more. Moreover, you may combine the said oil-soluble initiator and a water-soluble initiator. When combined, the addition ratio of the water-soluble initiator is preferably 50% by weight or less, more preferably 25% by weight or less of the total amount. Further, the polymerization initiator can be added to the polymerization system all at once or continuously. The amount of the polymerization initiator to be used is usually 0.1 to 0.1% based on the vinyl monomer (D).
It is 1.5% by weight, preferably 0.2-0.7% by weight.

Known chain transfer agents can be used.
Specifically, mercaptans such as octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-hexyl mercaptan, n-hexadecyl mercaptan, n-tetradecyl mercaptan, t-tetradecyl mercaptan, tetraethylthiuram sulfide, Hydrocarbons such as carbon chloride, ethylene bromide, and pentaphenylethane, terpenes, or acrolein;
Examples include methacrolein, allyl alcohol, 2-ethylhexylthioglycol, and α-methylstyrene dimers. These chain transfer agents can be used alone or in combination of two or more. Examples of the method for adding the chain transfer agent include batch addition, divisional addition, continuous addition, and a combination thereof.
The amount of the chain transfer agent used is (D) vinyl monomer,
Usually, it is about 0 to 2.0% by weight.

As the emulsifier used in the emulsion polymerization, known emulsifiers such as anionic surfactants, nonionic surfactants, and amphoteric surfactants can be used. Among them, examples of the anionic surfactant include sulfates of higher alcohols, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, aliphatic sulfonates such as sodium lauryl sulfate, higher aliphatic carboxylate, phosphorus Acid salts and the like. As the nonionic surfactant, an alkyl ester type, an alkyl ether type, an alkylphenyl ether type or the like of ordinary polyethylene glycol is used. Further, examples of the amphoteric surfactant include those having a carboxylate, a sulfate, a sulfonate or a phosphate as an anion portion and an amine salt or a quaternary ammonium salt as a cation portion. These emulsifiers can be used alone or in combination of two or more. Examples of the method for adding the emulsifier include batch addition, divisional addition, continuous addition, and a combination thereof. The amount of the emulsifier used is usually (D)
It is usually about 0 to 5.0% by weight based on the vinyl monomer.

The thermoplastic resin (B) of the present invention is preferably subjected to emulsion polymerization at a polymerization temperature of 10 to 95 ° C., preferably 30 to 95 ° C. After the polymerization, an antioxidant may be added in some cases.

When the thermoplastic resin (B) of the present invention is produced by emulsion polymerization, the powder obtained by coagulation with a coagulant is usually washed with water, dried and purified to obtain a powder. Examples of the coagulant include acids such as sulfuric acid, acetic acid and hydrochloric acid, and inorganic salts such as magnesium sulfate, aluminum sulfate, calcium chloride, magnesium chloride and sodium chloride. Preferred are sulfuric acid, magnesium sulfate and calcium chloride. In addition, spray drying with a spray dryer may be performed without coagulation. Further, atomizer coagulation, which is a spray coagulation method, may be performed.

In the thermoplastic resin (B) of the present invention,
The ratio (reaction efficiency) of the (D) vinyl monomer reacted with the (C) highly crosslinked particles is not particularly limited, but may be 4%.
0% or more is preferable. The reaction efficiency referred to here is (B)
The components were put into acetone, shaken for 2 hours with a shaker, and then centrifuged at 23,000 rpm for 30 minutes using a centrifuge to separate the insoluble matter from the soluble matter and measure the weight. It is a value calculated from the content (% by weight) of these in the component (B) according to the following formula (I). Reaction efficiency (%) = [content of insoluble component−content of component (C)] / [content of component (D)] (I) The above reaction efficiency (%) is based on the polymerization initiator and the chain transfer. It can be easily controlled by changing the type and amount of the agent, emulsifier, solvent, and the like, as well as the polymerization time and the polymerization temperature. The reaction efficiency can also be changed by the method of adding the vinyl monomer (D). Examples of the addition method include batch addition, divided addition, continuous addition, and a method in which these are combined.

In the thermoplastic resin (B) of the present invention,
The molecular weight of the (C) polymer component of the (C) vinyl monomer that has reacted with the (C) highly crosslinked particles is the same as the matrix component [the (C) component that has not reacted with the (C) component in the (B) component]. Polymer Component] can be assumed to be the same. And, the molecular weight is the intrinsic viscosity of the acetone-soluble component [η]
(Measured in a methyl ethyl ketone solvent at 30 ° C.). Intrinsic viscosity [η] of the thermoplastic resin (B) of the present invention (measured in a methyl ethyl ketone solvent at 30 ° C.)
Is 0.25 dl / g or less, preferably 0.20 dl / g
g, more preferably 0.15 dl / g or less. When the intrinsic viscosity [η] exceeds 0.25 dl / g,
Because the dissolution and dispersibility of the component (B) in the epoxy resin is poor,
The fracture toughness coefficient decreases. The intrinsic viscosity [η] can be easily controlled by changing the type and amount of the polymerization initiator, the chain transfer agent, the emulsifier, the solvent, and the like, as well as the reaction efficiency, and further, by changing the polymerization time, the polymerization temperature, and the like. it can. Also,
(D) The intrinsic viscosity [η] can also be changed by the method of adding the vinyl monomer. Examples of the addition method include batch addition, divided addition, continuous addition, and a method in which these are combined.

The component (B) of the present invention may be the thermoplastic resin (B) alone or a blend of two or more (B) thermoplastic resins. Also, if necessary,
(B) A (co) polymer may be blended with the thermoplastic resin.
Here, the (co) polymer may have the same composition as the (D) vinyl-based monomer or may have a different composition.

The epoxy resin composition of the present invention comprises: (A) 100 parts by weight of an epoxy resin;
-100 parts by weight, preferably 1-50 parts by weight. The blending amount of the component (A) and the component (B) has an optimum value depending on the application. When the amount of the component (B) is less than 1 part by weight, the effect of improving the epoxy resin (A) by adding the component (B) is not exhibited, and the fracture toughness coefficient is not improved. On the other hand, if it exceeds 100 parts by weight, the solubility and dispersibility of the component (B) are inferior, so that the values of various physical properties decrease. The component (B) of the present invention has an effect of suppressing an increase in viscosity when blended with an epoxy resin. For example, it has a structure represented by the following formula (II), where n (the number of repeating units) is 0 to 1;
Viscosity 12-15 Pa · s, epoxy equivalent 184-194
To 100 parts by weight of epoxy resin
When blended by weight, the resulting mixture has a viscosity of 200
The component (B) which becomes Pa · s or less is preferable.

[0027]

Embedded image

In order to obtain a cured product of the epoxy resin composition of the present invention, a curing agent and a curing accelerator are required. As a curing agent, diethylenetriamine, triethylenetetramine, isophoronediamine, ethylenediamine, m-phenylenediamine, hexamethylenediamine, diethylenetriamine, tetraethylenepentamine, piperidine,
N, N'-dimethylpiperazine, 1,4-diazadicyclo (2,2,2) octane, pyridine, picoline, benzyldimethylamine, 2- (dimethylaminomethyl) phenol, DBU [1,8-diazabicyclo (5,4 ,
0-undecene-7)], dimethylcyclohexylamine, dimethylbenzylamine, dimethylhexylamine, dimethylaminomethylphenol, dimethylamino p-cresol, tetraethylenepentamine, N-aminoethylpiperazine, trisdimethylaminomethylphenol, dicyandiamide, 4,4'-diaminodiphenyl sulfone, 2-n-heptadecyl imidazole, melamine, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydro Phthalic anhydride, endomethylenetetrahydrophthalic anhydride, dodecenylsuccinic anhydride, hexahydrophthalic anhydride, chlorendic anhydride, BF3 (boron trifluoride) -mono Ethylamine and the like. These can be used alone or as a mixture of two or more. The curing agent is selected according to its use.

The amount of the curing agent used varies depending on the purpose.
It is used in an amount of 1 to 200 parts by weight, preferably 1 to 180 parts by weight, based on 100 parts by weight of the epoxy resin.
In addition, a curing accelerator is used as needed. The curing accelerator is used in an amount of 0.1 to 100 parts by weight of the epoxy resin.
It is 1 to 20 parts by weight, preferably 0.1 to 10 parts by weight. Tertiary amines are generally used as curing accelerators.
Others include 2-ethyl-4-methylimidazole, D
BU, quaternary phosphonium salts, amine imides, triphenylphosphine and the like. In the epoxy resin composition of the present invention, if necessary, known antioxidants, stabilizers, plasticizers, flame retardants, flame retardant aids, softeners, various inorganic or organic fillers, reinforcing agents, crosslinking Additives such as an agent, an antistatic agent, a coloring agent, a coupling agent, a viscosity modifier, a weathering agent, a lubricant, and silicone oil.

The method for curing the epoxy resin composition of the present invention includes the following methods and the like, which can be appropriately selected depending on the application. A method in which component (B) is directly added to component (A), dissolved and dispersed, and then a curing agent, a curing accelerator, and other additives are added, and the mixture is cured at a predetermined temperature. Component (B) is an organic solvent [xylene, toluene, butanol, methyl ethyl ketone, ethyl acetate, butyl acetate,
Cell dissolve (methyl, ethyl or butyl mono- or diether) etc.] and then added to the component (A), the solvent is distilled off, and a curing agent, curing accelerator and other additives are added. A method of heating and curing at a predetermined temperature. A method of curing without removing the solvent by the above method.

The above components (A), (B), the curing agent and other methods of mixing may be mixed with conventional processing machines, for example, dispersers, kneaders, planetary mixers, paddle mixers, intermixers, homomixers, banbury mixers, It can be performed using various extruders and the like.
The epoxy resin composition of the present invention mixed as described above can be molded by a molding method such as compression molding, lamination molding, transfer molding, cast molding, and press molding. The curing temperature of the epoxy resin composition of the present invention,
The temperature ranges widely from room temperature to 200 ° C., and varies greatly depending on the type of curing agent used.

The epoxy resin composition of the present invention can be used, for example, undercoating a metal,
Powder coatings, structural adhesives for civil engineering and construction, sealing agents, adhesives for electrical and electronic materials, adhesives for printed wiring,
It can be used in a wide range of fields such as laminate adhesives and sealing materials for electronic materials.

[0033]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. In the Examples and the like, parts and% are based on weight unless otherwise specified. Various measurement items in Reference Examples, Examples, and Comparative Examples were as described below.

The average particle diameter of the dispersed particles was determined by an electron microscope, and it was confirmed by an electron microscope that the particle diameter of the latex synthesized in advance in an emulsified state directly indicates the particle diameter of the dispersed particles in the resin. Was measured by a light scattering method. The measuring instrument used is LPA-3100 manufactured by Otsuka Electronics Co., Ltd.
The particle diameter was measured using the cumulant method at 70 times of accumulation.

The crosslinked particles (A) (g) of (A) which had been coagulated and dried with toluene-insoluble components were 100 m
of toluene and left at room temperature for 48 hours.
The solution was filtered using a 0 mesh wire mesh, and a part of the filtrate [(c) m
l] was accurately collected and evaporated to dryness, and the obtained residual solid content [toluene-insoluble content: (b) g] was weighed, and the following formula (II)
It is the value obtained by I). Toluene-insoluble matter (% by weight) = {[ab × (100 / c)] / a} 100 (III) Intrinsic viscosity [η ] (B) A certain amount of thermoplastic resin is dissolved in acetone. The solution was charged, shaken with a shaker for 2 hours, and then centrifuged at 23,000 rpm for 30 minutes using a centrifuge to separate acetone-insoluble components from soluble components. This soluble matter was completely dissolved in methyl ethyl ketone, five kinds of samples having different concentrations were prepared, and the reduced viscosity of each concentration sample was measured at 30 ° C. using an Ubbelohde viscometer. I asked.

Epoxy Resin Composition Viscosity The viscosity of the modified epoxy resin composition obtained by dissolving and dispersing the component (B) in the component (A) is determined by TOKIMECINIC CO., LTD.
Was measured using a BH-type viscometer manufactured by Toshiba Corporation. The measurement temperature is 25
C. was performed. Dissolution and dispersibility The state of the epoxy resin composition in which the component (B) was dissolved and dispersed in the component (A) was visually judged according to the following criteria. A: Completely dissolved and dispersed. ：: Some undissolved parts (bubbles) X: Half or more insoluble parts (bubbles) are present.

Evaluation of Physical Properties of Cured Epoxy Resin Composition Flexural strength: Measured according to JIS K6911. Flexural modulus: Measured according to JIS K6911. Energy: Measured according to JIS K6911 (calculated from the results of the tensile test). Fracture toughness coefficient: Measured according to JIS K6911.

Reference Example 1 (C) Preparation of Highly Crosslinked Particles In a reactor equipped with a stirrer having a capacity of 100 liters, 100 parts of 1,3-butadiene, 60 parts of water and 2.4 parts of potassium rosinate were added.
Parts, potassium phosphate 0.5 parts, potassium hydroxide 0.1
Parts, t-dodecyl mercaptan as a chain transfer agent in 0.1 part.
Add 3 parts and 0.3 part of potassium persulfate, and add 60 to 70 ° C.
For 30 hours. The polymerization conversion was 95%. To this polymerization system, 0.2 part of N, N-diethylhydroxyamine was added as a polymerization terminator to terminate the reaction. Thereafter, 1,3-butadiene is removed under reduced pressure,
Polybutadiene latex [Highly crosslinked particles (C-1)]
(56.5% solids). The obtained polybutadiene-based latex had a toluene-insoluble content of 85% and an average particle size of 270 nm. Similarly, highly crosslinked particles (C-2) to (C-4) were obtained by changing the type and formulation of the monomer component, the amount of the chain transfer agent used, the polymerization temperature, the polymerization time, and the like.
(C) The average particle diameter and the toluene insoluble content of the highly crosslinked particles are shown in Tables 2 and 3 below.

Reference Example 2 (D) Preparation of Vinyl Monomer Table 1 shows the solubility parameters of those used as the vinyl monomer (D).

[0040]

[Table 1]

Reference Example 3 (B) Preparation of Thermoplastic Resin The highly crosslinked particles (C) obtained in Reference Example 1 were placed in a separable flask having an internal volume of 10 liters equipped with a dropping bottle, a condenser, a nitrogen inlet, and a stirrer. 65 parts in terms of solid content,
0.1 part of potassium rosinate as an emulsifier and 10 parts of water
0 parts were mixed and heated to 65 ° C., and when the temperature reached 65 ° C., 0.2 parts of sodium pyrophosphate and 0.25 g of glucose were added.
And 0.01 part of ferrous sulfate were added, and subsequently 0.2 parts of cumene hydroperoxide, 28 parts of methyl methacrylate, 7 parts of styrene, 20 parts of water and 1 part of potassium rosinate were added dropwise over 5 hours. did. After completion of the dropwise addition, 0.1 part of cumene hydroperoxide, 0.1 part of sodium pyrophosphate, 0.13 part of glucose, 0.005 ferrous sulfate
The polymerization reaction was further performed for 1 hour. The polymerization conversion was 97.5%. The obtained polymer is coagulated with sulfuric acid, neutralized with sodium hydroxide, and the coagulated product is thoroughly washed with water and then dried to obtain a powdery thermoplastic resin (B-1).
I got Similarly, as shown in Tables 2 and 3, the component (C)
(D) The thermoplastic resins (B-2) to (B-12) were obtained by changing the type of the vinyl monomer component, the mixing ratio, the amount of the chain transfer agent used, the polymerization temperature, the polymerization time, and the like. Tables 2 and 3 show the intrinsic viscosity [η] of the obtained thermoplastic resin (B).

[0042]

[Table 2]

[0043]

[Table 3]

Reference Example 4 (A) Preparation of epoxy resin, curing agent and curing accelerator (A) The following chemicals were used as the epoxy resin, curing agent and curing accelerator. Epoxy resin: Epicoat 828 (manufactured by Yuka Shell Epoxy Co., Ltd.), viscosity: 12 to 15 Pa · s, epoxy equivalent: 1
84-194 Curing agent; ADEKA HARDNER H3326 [Asahi Denka Co., Ltd.]
Manufactured by Ancamine K-54 [ACI.
Japan Co., Ltd.)

Examples 1 to 6 and Comparative Examples 1 to 8 According to the formulation shown in Tables 4 to 6, (A) an epoxy resin was stirred with a homomixer at a rotation speed of 500 rpm, and (B) a thermoplastic resin was gradually added. did. After that, the rotation speed 6,000r
pm and then stirred for 2 hours. After defoaming under reduced pressure,
At room temperature, a curing agent and a curing accelerator were added and stirred. This was poured into a mold and heated and cured at 90 ° C./2 hours and 120 ° C./1 hour to obtain a cured product of the epoxy resin composition. Table 4-
6 shows the physical properties of the epoxy resin composition.

[0046]

[Table 4]

[0047]

[Table 5]

[0048]

[Table 6]

As shown in Table 4, each of the epoxy resin compositions of the present invention was prepared by dissolving and dispersing (B) a thermoplastic resin in (A) an epoxy resin, and an epoxy resin composition [(A) +
(B)] and the cured product had excellent mechanical properties. On the other hand, as is clear from Tables 5 and 6, in Comparative Example 1,
Since the amount of the component (B) exceeds 100 parts with respect to 100 parts of the component (A), the epoxy resin composition [(A) +
(B)], the dissolution and dispersibility of the component (B) in the component (A) was poor, and an evaluable cured product could not be obtained. In Comparative Example 2, component (A) 1
Since the amount of the component (B) is less than 1 part with respect to 00 parts,
The modification effect by the addition of the component (B) did not appear. In Comparative Example 3, since the average particle diameter of the component (C) was less than 50 nm, the viscosity of the epoxy resin composition [(A) + (B)] was increased, and various physical properties were also reduced. In Comparative Example 4, (C)
Since the average particle diameter of the components exceeds 500 nm,
The dissolution and dispersibility of the component (B) in the component (A) was poor, and various physical properties were also reduced. In Comparative Example 5, since the intrinsic viscosity [η] of the component (B) exceeds 0.25 dl / g, the viscosity of the epoxy resin composition [(A) + (B)] was increased, and various physical properties were reduced. . In Comparative Example 6, since the amount of the component (C) in the component (B) was less than 30 parts, the viscosity of the epoxy resin composition [(A) + (B)] was high, and the composition was further vulnerable to impact. , Physical properties decreased. In Comparative Example 7,
Since the amount of the component (C) in the component (B) exceeds 80 parts, the dissolution and dispersibility of the component (B) in the component (A) was inferior, whereby the physical properties were also reduced. In Comparative Example 8, since the toluene-insoluble content of the component (C) was less than 75%,
The energy absorption by the component (C) was insufficient, and various physical properties were reduced.

[0050]

The epoxy resin composition of the present invention containing the epoxy resin (A) and the thermoplastic resin (B) as main components is excellent in dispersibility and viscosity (low viscosity) of the thermoplastic resin in the epoxy resin. Since the cured product is excellent in mechanical properties and the like, using its properties, for example, undercoat paint for metals, powder paint, structural adhesives for civil engineering and construction, sealing agents, electric and It can be used in a wide range of fields such as adhesives for electronic materials, adhesives for printed wiring, adhesives for laminated boards, and sealing materials for electronic materials.

Continuation of front page (72) Inventor Takateru Imai 1-18-1 Kyobashi, Chuo-ku, Tokyo Techno Polymer Co., Ltd. F term (reference) 4J002 BN12X BN14X BN15X BN16X BN21X BN22X BN23X BP01X CD01W CD02W CD05W CD06W CD08W CD13W CD14W CD18W CD20W CP17X FA08X

Claims (2)

[Claims] 1. An epoxy resin composition comprising: (A) 100 to 100 parts by weight of an epoxy resin; and (B) 1 to 100 parts by weight of a thermoplastic resin. (B) thermoplastic resin; (C) highly crosslinked particles 30 to 80 having an average particle diameter of 50 to 500 nm and a toluene insoluble content of 75% by weight or more.
% (C) + (D) = 100% by weight] of vinyl monomer (D) = 100% by weight, and the intrinsic viscosity [η] of acetone-soluble component (30 ° C., methyl ethyl ketone solvent) 0.25 dl / g or less. 2. The solubility parameter (Sp value) of the vinyl monomer (D) is 8.0 to 9.5 (cal ^1/2 · cm).
The epoxy resin composition according to claim 1, wherein the composition is ^-3/2 ).