JP2000017047A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition excellent in impregnatability in a molten state and in adhesive property and mechanical characteristics after cure by compounding a specific epoxy resin, specific phenols and/or an epoxy resin, and a curing accelerator. SOLUTION: The objective composition comprises an epoxy resin represented by formula I, phenols and/or an epoxy resin comprising a compound represented by formula II, and a curing accelerator. R1-2 are each H, a halogen, a 1-5C alkyl, and preferably R1 is t-butyl at the 2-position and R2 is t-butyl at the 5-position; (m) is 0-5; R3-4 are each H, a halogen or a 1-5C alkyl; R5 is OH or glycidyl ether; and (n) is 0-10. In case that R5 of the compound of formula II is glycidyl ether, the curing agent is preferably a compound of formula II wherein R5 is OH. Preferably is further compounded as a filler a powder inorganic compound having an average particle size of 1-60 μm. Preferable fillers are spherical silica, fused crushed silica, crystalline crushed silica, CaCO3 or Al(OH)3.

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 which is excellent in impregnating properties into coils and fine gaps in a molten state, and has excellent adhesion to an object to be coated after curing, and an article using the same. Things.

[0002]

2. Description of the Related Art Conventionally, in the fields of adhesion and insulation of coils and the like, or binders for forming molded articles from inorganic powders, liquid compositions containing a low-viscosity or diluting solvent are often used because of their advantages of impregnation. It has been. However, when a liquid composition is used, dripping tends to occur during impregnation, causing a problem of contaminating jigs and other equipment, and furthermore, environmental pollution due to diffusion of a diluting solvent into the air remains a major problem. It had been. From the viewpoints of recyclability, air pollution, etc., fixation and impregnation with a solid epoxy resin composition has been studied, but since the viscosity at the time of melting does not become lower than that of liquid resin, it is necessary for products that require high impregnation into the coil. Was difficult to apply.

[0003] In recent years, crystalline epoxy resins have an extremely low viscosity when melted and have excellent impregnation properties. Therefore, studies have been made in fields requiring high impregnation. However, depending on the type of crystalline epoxy resin, when manufacturing a solid epoxy resin composition using a melt kneading method, which is an inexpensive and general manufacturing method, the melting point drop is remarkable, and even after cooling, pulverization is impossible and it is not practical. Had the problem of being unsuitable. Investigations have been started to use a crystalline epoxy resin that can cover such problems.However, in applications where high-speed rotation or external stress is applied, there is a problem in its mechanical properties, and it is still insufficient. is there.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to an epoxy resin which is excellent in impregnating properties at the time of melting, and which is particularly excellent in adhesion properties and mechanical properties after curing and which is suitable for coil impregnation and / or as an inorganic powder binder. For the development of compositions.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have obtained an epoxy resin composition which can solve the above-mentioned problems. That is, the present invention provides the following equation (1):

[0006]

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(R ₁ and R ₂ in the formula (1) each represent a hydrogen atom, a halogen atom, or an alkyl group of C _{1 to} C ₅ , and m is an integer of 0 to 5.) Epoxy resin (a) represented, formula (2)

[0008]

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(In the formula (2), R ₃ and R ₄ represent a hydrogen atom, a halogen atom or a C ₁ -C ₅ alkyl group, R ₅ represents a hydroxyl group or a glycidyl ether group, and n represents 0-10
Is an integer up to. An epoxy resin composition containing the compound (b) represented by the formula (1) and a curing accelerator (c), (2)
The epoxy resin composition according to (1), wherein in the epoxy resin (a), R ₁ in the formula (1) is a 2-position t-butyl group and R ₂ is a 5-position t-butyl group, (3) The compound (b) is a compound (b1) in which R ₅ in the formula (2) is a hydroxyl group, the epoxy resin composition according to (1) or (2), and (4) the compound (b) is a compound represented by the formula (b): R ₅ in 2)
Is the compound (b2) which is a glycidyl ether group, the epoxy resin composition according to (1) or (2), (5)
The epoxy resin composition according to (4), comprising a curing agent,
(6) the epoxy resin composition according to (5), wherein the curing agent is the compound (b1) according to (3);

(7) The filler has an average particle size of 1 to 60.
(1) to (6) containing a powdery inorganic substance having a size of μm
The epoxy resin composition according to any one of the above, (8) the filler is spherical silica, melt-crushed silica, crystal-crushed silica,
An epoxy resin composition according to (7), wherein calcium carbonate or aluminum hydroxide is used in an amount of 5% by weight to 70% by weight in the composition, wherein (9) any one of (1) to (8). Cured product of the epoxy resin composition described in (1)
0) An article having a cured product of the epoxy resin composition of (9). (11) the article of (10), which is a coil, (12)
(1) an inorganic molded article obtained by impregnating an inorganic powder with the epoxy resin composition according to any one of (1) to (8) and molding;

(13) An epoxy resin (A) obtained by reacting hydroquinones with epihalohydrin, a compound (B1) obtained by subjecting dicyclopentadiene to a phenol condensation reaction under an acid catalyst, and a curing accelerator An epoxy resin composition containing (c). (14) (1
Epoxy resin (B2) obtained by reacting the epoxy resin (A) described in 3), the compound (B1) described in (13) with epihalohydrin under a base catalyst, and a curing agent (d)
And an epoxy resin composition containing a curing accelerator (c),
About.

DETAILED DESCRIPTION OF THE INVENTION

The epoxy resin (A) used in the present invention is preferably an epoxy resin obtained by reacting a hydroquinone with epihalohydrin, and more preferably an epoxy resin containing a chemical structure represented by the above formula (1). a) is more preferred. In the formula (1), R ₁ , R
₂ is a hydrogen atom, a halogen atom, or C ₁ -C
_{5 represents} an alkyl group, and m is an integer from 0 to 5. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of the C ₁ -C ₅ alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-pentyl group. m
Can be measured by the GPC method. As the above-mentioned hydroquinones, 2,5-dialkyl-substituted hydroquinones are preferable. For example, 2,5-di-tert-butylhydroquinone, 2,5-di-isobutylhydroquinone, 2,5
-Diethylhydroquinone and the like.

Among these epoxy resins, those having a viscosity of 5 poise or less when melted by an ICI viscometer are preferable in consideration of impregnation. Also, in the melt kneading method,
In order not to impart tackiness to the composition after kneading, among the compounds represented by the formula (1), t- in which R ₁ is 2-position is used.
A compound in which a butyl group and R ₂ are a 5-tert-butyl group, and a compound having a melting point of 90 to 150 ° C. is particularly preferable.
As such a material, for example, YDC-1312 (manufactured by Toto Kasei) can be mentioned. The amount of the epoxy resin (a) used is preferably 30 to 100% by weight, more preferably 4 to 100% by weight of the total of all epoxy resins, in consideration of impregnation.
0 to 100% by weight, particularly preferably 50 to 100% by weight
It is.

The compound (B1) used in the present invention is a compound obtained by subjecting dicyclopentadiene and a phenol to a condensation reaction in the presence of an acid catalyst. The phenol is phenol or phenol substituted with one or two alkyl and / or halogen atoms, and the position of the substituent is arbitrary. When a phenol is represented by a chemical formula, for example, the compound (b1) in which R5 in the formula (2) is a hydroxyl group is exemplified. The epoxy resin compound (B2) used in the present invention is the same as the compound (B1)
And the hydroxyl group of the compound is further reacted with epihalohydrin. When represented by a chemical formula, for example, the compound (b2) in which R ₅ in the formula (2) is a glycidyl ether group can be mentioned. Compound (B1) or epoxy resin compound (B
2) is preferable since the adhesion to the object to be coated is further enhanced. Further, since the compound (B1) has a function as a curing agent, if it is used, the curing agent (d) may not be used. Needless to say, a curing agent may be used in combination.

The compound (B1) and the epoxy resin compound (B
The amounts of 2) used are, as the total amount of both, epoxy resin (A), compound (B1) and epoxy resin compound (B2).
Is 5 to 80% by weight, preferably 10 to 70% by weight, more preferably 10 to 60% by weight based on the total amount of The amount of the compound (B1) to be used is 0.05 to 1.20, preferably 0.10 to 1.10, more preferably 0.20 to 1.00, in terms of equivalent ratio to all epoxy groups. Particularly preferably, it is 0.3 to 1.00. The amount of the epoxy resin compound (B2) used is based on the total amount of the epoxy resin.
It is 3 to 70% by weight, preferably 3 to 60% by weight, more preferably 3 to 50% by weight.

The compound (b) represented by the formula (2) is
It is more preferable from the viewpoint of further increasing the adhesion to the coating. formula
In (2), R_Three, R_FourAre hydrogen and halogen atoms
Or C ₁~ C_FiveRepresents an alkyl group represented by_FiveIs a hydroxyl group or
A glycidyl ether group; n is an integer from 0 to 10
It is. Examples of the halogen atom include a fluorine atom and a salt
Elemental atom, bromine atom and iodine atom. C₁~ C_Five
Examples of the alkyl group include a methyl group, an ethyl group, and n-
Propyl group, isopropyl group, n-butyl group, isobutyl
And t-butyl, n-pentyl and the like.
n can be measured by the GPC method. R in the formula (2)_FiveIs a hydroxyl group
A compound (b1)

R in the equation (2)_FiveIs a hydroxyl group
(B1) and R in the formula (2)_FiveIs a glycidyl ether group
Certain epoxy resin compounds (b2) are used alone or separately in the composition.
And / or at the same time. With flame retardant
In order to provide, R in formula (2) _Three, R_FourBrom atom
And / or a compound containing a chloro atom (b1) or
R_Three, R_FourContaining bromo and / or chloro atoms
It is preferable to use the epoxy resin (b2).
Further, the compound (b1) has a function as a curing agent.
When this is used, it is not necessary to use the curing agent (d).
No. Needless to say, a curing agent may be used in combination. Conversion
Use amount of compound (b1) and epoxy resin compound (b2)
Are the epoxy resin (a) and the compound
5 to 8 in the total amount of (b1) and the epoxy resin compound (b2)
0% by weight, preferably 10-70% by weight, more preferably
Or 10 to 60% by weight.

As the compound (b1), it is preferable to use a resin having a softening point of from 30 to 130 ° C., more preferably from 50 to 110 ° C., particularly preferably from 50 to 110 ° C. in consideration of the difficulty in causing tacking and impregnation. Is 50-1
It is better to use one at 00 ° C. The amount used is 0.05 to 1.2 in equivalent ratio to all epoxy groups.
0, preferably in the range of 0.10 to 1.10, more preferably 0.20 to 1.00, particularly preferably 0.3 to
1.00.

As the compound (b2), a resin having a softening point of 30 to 110 ° C. is preferable, more preferably 40 to 100 ° C., and particularly preferably, in consideration of the difficulty in causing tacking and impregnation. Is 50-9
It is better to use the one at 0 ° C. In addition, the amount used
3 to 70%, preferably 3%, based on the total amount of epoxy resin
-60%, more preferably 3-50%.

An epoxy resin other than the above-mentioned epoxy resins can be used in combination with the epoxy resin composition of the present invention. Epoxy resins other than the above epoxy resins,
Any one can be selected as long as it does not significantly affect the viscosity after melting, for example, an epoxy resin having a glycidyl ether group bonded to a phenolic compound, an alicyclic epoxy resin having an aliphatic skeleton such as cyclohexane, an isocyanuric ring And a heterocyclic epoxy resin having a heterocyclic ring such as a hydantoin ring, and an epoxy resin in which a glycidyl ether group is bonded to a phenolic compound is preferable.

Examples of the phenolic compound in the epoxy resin in which a glycidyl ether group is bonded to the phenolic compound include bisphenol A, bisphenol F, bisphenol S, 4,4'-biphenylphenol, and 2,2'-methylene. -Bis (4-methyl-
6-tert-butylphenol), 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol), 4,4′-butylene-bis- (3-methyl-6
-Tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenol), trishydroxylmethane, pyrogallol, phenols having a diisopropylidene skeleton, 1,1- Examples include phenols having a fluorene skeleton such as di-4-hydroxyphenylfluorene, polyphenol compounds such as phenolized polybutadiene, and various novolak resins. Various novolak resins include phenol, cresols, ethylphenols, butylphenols, octylphenols, bisphenol A, bisphenol F, bisphenol S,
Novolak resin using various phenols such as naphthols, phenol novolak resin containing xylylene skeleton, phenol novolak resin containing fluorene skeleton,
Various novolak resins such as a phenol novolak resin containing a biphenyl skeleton are exemplified. These epoxy resins are
A material preliminarily mixed with other raw materials may be used.

In the present invention, a curing agent (d) may be used as an optional component. The curing agent (d) is other than the compound (B1) and the compound (b1). As the curing agent (d), those generally known can be used. In the case of a non-crystalline substance, those having a softening point of 40 to 150 ° C are preferable, those having a softening point of 40 to 120 ° C, more preferably 50 to 110 ° C. ° C. In the case of a crystalline substance, the melting point is 50 to 250 ° C, and further 80 to 200 ° C.
It is preferred to use Examples of other curing agents include acid anhydrides, amines, phenols, amides, imidazoles and the like. Examples of the acid anhydride include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride,
Alicyclic carboxylic anhydrides such as aromatic carboxylic anhydrides such as ethylene glycol trimellitic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, nadic anhydride, hetanoic anhydride, and hymic anhydride. Objects and the like.

Examples of the amines include diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenylether and the like. Examples of the amides include:
Dicyandiamide and the like. Examples of phenols include bisphenol A, tetrabromobisphenol A, bisphenol F, bisphenol S,
4′-biphenylphenol, 2,2′-methylene-bis (4-methyl-6-tert-butylphenol),
2,2'-methylene-bis (4-ethyl-6-tert
-Butylphenol), 4,4′-butylylene-bis (3-methyl-6-tert-butylphenol),
1,1,3-tris (2-methyl-4-hydroxy-5
-Tert-butylphenol), trishydroxyphenylmethane, pyrogallol, phenols having a diisopropylidene skeleton, phenols having a fluorene skeleton such as 1,1-di-4-hydroxyphenylfluorene, polyphenol compounds such as phenolized polybutadiene, Novolak resin, xylylene skeleton made from various phenols such as phenol, cresols, ethylphenols, butylphenols, octylphenols, bisphenol A, brominated bisphenol A, bisphenol F, bisphenol S, naphthols,
Examples include various phenol novolak resins containing either a biphenyl skeleton or a fluorene skeleton.

Examples of imidazoles include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole,
2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2 -Undecyl imidazole,
2,4-diamino-6 (2′-methylimidazole (1 ′)) ethyl-s-triazine, 2,4-diamino-6 (2′-undecylimidazole (1 ′)) ethyl-s-triazine, , 4-Diamino-6 (2′-ethyl, 4-methylimidazole (1 ′)) ethyl-s-triazine, 2,4-diamino-6 (2′-methylimidazole (1 ′)) ethyl-s-triazine Isocyanuric acid adduct, 2-methylimidazole isocyanuric acid 2: 3 adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-3,5-dihydroxymethylimidazole, 2-phenyl-4-hydroxymethyl-
Various imidazoles of 5-methylimidazole and 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole, and those imidazoles and phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, naphthalene Salts with polycarboxylic acids such as dicarboxylic acid, maleic acid, and oxalic acid are included. These other curing materials can be used alone or as a mixture of two or more, or may be used in advance as a preliminary mixture with other raw materials.

The amount of use is preferably adjusted so that the total equivalent ratio of all the curing agents is 0.60 to 1.20 in consideration of the curability and the decrease in mechanical properties due to the unreacted curing agent. . More preferably, it is adjusted to be 0.70 to 1.10, particularly preferably 0.8 to 1.0.

The curing accelerator (c) used in the present invention includes the above-mentioned amides such as imidazoles and dicyandiamide; diaza compounds such as 1,8-diaza-bicyclo (5.4.0) undecene-7; Their phenols, salts with the above-mentioned polycarboxylic acids or phosphinic acids, phosphines such as triphenylphosphine and tetraphenylphosphonium tetraphenylborate, 2,
And phenols such as 4,6-trisaminomethylphenol. Which of these curing accelerators is used is appropriately selected depending on the curing speed, curing properties, and type of curing agent of the obtained epoxy resin composition, but preferably imidazoles, phosphines, and more preferably imidazole azine derivatives For example, 2,4-diamino-6
(2′-methylimidazole (1 ′)) ethyl-s-triazine and triphenylphosphine. The mixing ratio of these curing accelerators is usually 0.01 to 6 parts by weight based on 100 parts by weight of the epoxy resin. Further, the composition of the present invention may cause dripping due to low viscosity at the time of melting, and is preferably 0.3 to accelerate the curing reaction.
-5 parts by weight, more preferably 1-4 parts by weight.

Examples of the powdery inorganic filler used in the present invention include fused silica, crystal-crushed silica, spherical silica, silicon carbide, silicon nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, and mica. , Talc, clay, aluminum oxide, magnesium oxide, zirconium oxide, aluminum hydroxide, magnesium hydroxide, calcium silicate, aluminum silicate, lithium aluminum silicate, zirconium silicate, barium titanate, glass fiber, carbon fiber, molybdenum disulfide, etc. Preferred are fused crushed silica, crystal crushed silica, spherical silica, calcium carbonate, aluminum oxide, aluminum hydroxide, and calcium silicate. In view of crack resistance, fused crushed silica, crystal crushed silica, spherical silica Ca, calcium carbonate, aluminum hydroxide. These fillers may be used alone or as a mixture of two or more. The amount of the filler used must be such that the required viscosity is not affected. Specifically, the powdery average particle size to be used is 1 to
It is 60 μm, preferably 2 to 50 μm, more preferably 5 to 45 μm, and particularly preferably 8 to 40 μm. The filling amount is 5% to 70% by weight, preferably 5% to 65% by weight, more preferably 5% to 55% by weight, particularly preferably 5% to 50% by weight. Those fillers that have been surface-treated with a coupling agent can also be used.

The composition of the present invention may contain a coloring agent,
Coupling agents, leveling agents, lubricants and the like can be added. There is no particular limitation on the coloring agent, for example, phthalocyanine, azo, disazo, quinacridone, anthraquinone, flavanthrone, perinone, perylene, dioxazine, condensed azo, azomethine or methine-based various organic dyes, and inorganic pigments such as titanium oxide , Lead sulfate, zinc oxide, chrome yellow, zinc yellow, chrome vermilion, red iron oxide, cobalt purple, navy blue, ultramarine blue, carbon black, chrome green, chromium oxide, cobalt green and the like.

As the coupling agent, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) Ethyltrimethoxysilane, N-
(2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxy Silane, N- (2- (vinylbenzylamino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, 3-methacryloxypropyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, etc. Silane-based coupling agent, isopropyl (N-ethylaminoethylamino) titanate, isopropyl triisostearoyl titanate, titanium di (dioctyl pyrophosphate) oxyacetate, tetraisopropyl di (dithio) (Cutyl phosphite) Titanate coupling agents such as titanate and neoalkoxytri (p-N- (β-aminoethyl) aminophenyl) titanate, Zr-acetylacetonate, Zr-methacrylate, Zr-propionate, neoalkoxyzirconate , Neoalkoxytris neodecanoyl zirconate, neoalkoxytris (dodecanoyl) benzenesulfonyl zirconate, neoalkoxytris (ethylenediaminoethyl) zirconate, neoalkoxytris (m-aminophenyl) zirconate, ammonium zirconium carbonate, Al- Examples include zirconium such as acetylacetonate, Al-methacrylate, and Al-propionate, or an aluminum-based coupling agent. Coupling agent or titanate coupling agent.

Examples of the leveling agent include acrylates such as ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate having a molecular weight of 4000.
~ 12000 oligomers, epoxidized soy fatty acids,
Epoxidized aviethyl alcohol, hydrogenated castor oil, titanium-based coupling agents and the like can be mentioned. Examples of the lubricant include hydrocarbon lubricants such as paraffin wax, micro wax, and polyethylene wax, higher fatty acid lubricants such as lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, and behenic acid, stearylamide, palmitylamide, Higher fatty acid amide lubricants such as oleylamide, methylenebisstearamide, ethylenebisstearamide, hydrogenated castor oil, butyl stearate, ethylene glycol monostearate, pentaerythritol (mono-, di-, tri- or tetra-) ) Higher fatty acid ester lubricants such as stearate, cetyl alcohol,
Alcohol-based lubricants such as stearyl alcohol, polyethylene glycol, and polyglycerol; magnesium, calcium, cadmium, barium, zinc, and lead such as lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, ricinoleic acid, and naphthenic acid And metal waxes such as carnauba wax, candelilla wax, beeswax, and montan wax.

The epoxy resin composition of the present invention is obtained by melting and mixing each of the above components, and is usually used after pulverization at ordinary temperature. The particle size of the solid epoxy resin composition is usually 2
It is preferably in the range of 50 μm or less. In order to prepare the epoxy resin composition of the present invention, for example, in addition to the above-described epoxy resin, curing agent, curing accelerator, and filler, if desired, blending of a coupling agent, a flame retardant, a coloring agent, a leveling agent, a lubricant, etc. After dry-mixing the components using a Henschel mixer, etc., any machine that can be heated and melted and mixed, such as a kneader, extruder, batch kneader, reaction vessel, etc., may be used. Is cooled and solidified, finely pulverized and then classified to obtain a desired particle size to obtain an epoxy resin composition. The epoxy resin composition is used as a coil fixing agent and / or a coil insulating agent, and for example, as a binder for binding a functional inorganic powder. Specific examples to which these epoxy resin compositions can be applied are described below. For the purpose of fixing the coil and / or insulating the coil, electric / electronic parts such as a driving stator or a rotor motor, an actuator, a transformer, a magnetic field generating coil, a noise preventing toroidal core, and the like, However, the present invention is not limited to this, and can be applied to applications for fixing or impregnating the coil. As a binder, it can be used as a binder when processing an arbitrary molded product from magnetic powder, grinding stone powder, and other powders.

The article of the present invention has a cured product of the above epoxy resin composition. Examples of the article include coils for electric and electronic components. In order to produce the coil of the present invention, for example, the above epoxy resin composition is applied to the coil surface by a method such as an electrostatic flow method, an electrostatic spray method, a heat spray method, a heated fluid immersion method, a sprinkling method, and the like. The coil may be melt-impregnated with the epoxy resin composition and cured by heating. Such coils are used for electric and electronic components such as driving stators or rotor motors, actuators, transformers, magnetic field generating coils, and noise preventing toroidal cores.

The inorganic molded article of the present invention is obtained by impregnating the above-mentioned epoxy resin composition with a functional inorganic powder and molding. The functional inorganic powder is, for example, an inorganic powder having a property of giving an intended function to an inorganic molded article such as a magnetic powder and a grinding wheel raw material powder. Examples of the inorganic molded article include a magnet and a grindstone. In order to produce an inorganic molded article, the epoxy resin-based powder coating composition is dry-mixed with a functional inorganic powder, molded under pressure, and then heat-cured.

[0034]

Next, the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the examples only as long as it applies to this concept. In the examples and comparative examples, “parts” means parts by weight.

Example 1 2,5-di-tert-butyl-hydroquinone diglycidyl ether (YDC-1312, manufactured by Toto Kasei, melting point 142 ° C., ICI viscosity 0.1 poise or less) 100
Part, special phenol novolak resin (DPP-L, manufactured by Nippon Petrochemical, softening point 89 ° C, R ₃ and R ₄ are hydrogen atoms, R ₅ is a hydroxyl group, and n is 0 to 10 in the above formula (2)) 48 parts, phenol novolak resin (PN-
100, 30 parts of Meiwa Kasei, softening point 100 ° C), 2-methylimidazole azine (2MZ-A, Shikoku Chemical)
After pulverizing 2.0 parts by a mixer and dry-mixing, the mixture was heated and melt-kneaded using a kneader. This molten mixture was pulverizable without cooling at room temperature after cooling. This was pulverized and passed through a 250 μm sieve to obtain the epoxy resin composition of the present invention. The ICI viscosity and the tensile shear strength of this epoxy resin composition were measured. Table 1 shows the results.

Example 2 2,5-Di-tert-butyl-hydroquinone diglycidyl ether (YDC-1312, manufactured by Toto Kasei, melting point 142 ° C., ICI viscosity 0.1 or less) 80
Part, special novolak epoxy resin (XD-1000L,
Nippon Kayaku, softening point 65 ° C. In the above formula (2), R ₃ and R ₄ are hydrogen atoms, R ₅ is a glycidyl ether group, n
Is a compound having 0 to 10), 20 parts of special phenol novolak resin (DPP-L, manufactured by Nippon Petrochemical, softening point 89)
), Phenol novolak resin (PN-10)
1, 35 parts of 2-methylimidazole azine (2MZ-A, manufactured by Shikoku Chemicals).
After pulverizing and dry-mixing 0 part with a mixer, the mixture was heated and melt-kneaded using a kneader. This molten mixture was pulverizable without cooling at room temperature after cooling. Crush this 2
The epoxy resin composition of the present invention was obtained by passing through a 50 μm sieve. The ICI viscosity and the tensile shear strength of this epoxy resin composition were measured. Table 1 shows the results.

Comparative Example 1 2,5-di-tert-butyl-hydroquinone diglycidyl ether (YDC-1312, manufactured by Toto Kasei, melting point 142 ° C., ICI viscosity 0.1 poise or less) 100
Parts, phenol novolak resin (PN-100, manufactured by Meiwa Kasei Co., Ltd., softening point 100 ° C.), 60 parts, and 2-methylimidazole azine (2MZ-A, manufactured by Shikoku Kasei) 2.0 parts were pulverized by a mixer, and then dry-mixed. And heat-kneading using a kneader. After cooling, the molten mixture was pulverizable at room temperature without tacking. This was pulverized and passed through a 250 μm sieve to obtain the epoxy resin composition of the present invention. The ICI viscosity and the tensile shear strength of this epoxy resin composition were measured. Table 1 shows the results.

[0038]

Table 1 Example 1 Example 1 Example 2 Comparative Example 1 ICI viscosity (P, poise) 0.45 0.60 0.45 Tensile shear strength (kgf / cm ² ) 130 135 70

ICI viscosity: C. I. CONE & PL
Using ATE VISCOMETER, sample 0.
05 g was weighed, placed on a 150 ° C. heat-retaining plate and left for 1 minute, and then the cone was lowered and rotated, and the indicated viscosity 30 seconds later was read. Tensile shear strength: A blast surface of an SPCC steel plate was used as an adherend, and 0.2 g of each composition was applied to an adhesive area of 5 square centimeters. The test sample was cured at 180 ° C. for 1 hour, and the tensile shear strength was measured at a moving speed of 3 mm / min.

As is clear from Table 1, in Example 1 of the present invention in which part of the phenol novolak resin used as the curing agent in Comparative Example 1 was replaced with the special phenol novolak resin of the above formula (2), Adhesion and mechanical strength are dramatically improved without affecting the viscosity which affects the impregnation.

[0041]

The epoxy resin composition of the present invention has an extremely low viscosity when melted, and its cured product has tough adhesion and high mechanical strength, and is used as an epoxy resin composition for impregnating coils and the like. It is also useful as a binder.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 3/36 C08K 3/36 C08L 63/00 C08L 63/00 C (72) Inventor Akiki Niimoto Saitama 7-6-2-906 Suzuya, Yono Pref. DC41 DC45 DD07 FA01 FA03 FA05 FA11 FB02 FB03 FB08 GA28

Claims (14)

[Claims] (1) Formula (1) (R ₁ and R ₂ in the formula (1) each represent a hydrogen atom, a halogen atom, or an alkyl group from C _{1 to} C ₅ , and m is an integer from 0 to 5.) Epoxy resin (a), formula (2) (R ₃ and R ₄ in the formula (2) represent a hydrogen atom, a halogen atom or a C _{1 to} C ₅ alkyl group, R ₅ represents a hydroxyl group or a glycidyl ether group, and n is an integer of 0 to 10. An epoxy resin composition containing the compound (b) represented by the formula (1) and a curing accelerator (c). 2. The epoxy resin composition according to claim 1, wherein R ₁ in the formula (1) is a 2-position t-butyl group and R ₂ is a 5-position t-butyl group. 3. The epoxy resin composition according to claim 1, wherein R ₅ in formula (2) is a compound (b1) wherein R ₅ is a hydroxyl group. 4. The epoxy resin composition according to claim 1, wherein R ₅ in the formula (2) is a compound (b2) wherein the glycidyl ether group. 5. The epoxy resin composition according to claim 4, which contains a curing agent (d). 6. The epoxy resin composition according to claim 5, wherein the curing agent (d) is the compound (b1) according to claim 3. 7. The epoxy resin composition according to claim 1, wherein the filler contains a powdery inorganic substance having an average particle diameter of 1 to 60 μm. 8. The epoxy resin composition according to claim 7, wherein the filler is spherical silica, fused silica, crystal-crushed silica, calcium carbonate or aluminum hydroxide, and the amount of the filler is 5 to 70% by weight of the composition. . 9. A cured product of the epoxy resin composition according to any one of claims 1 to 8. 10. An article having a cured product of the epoxy resin composition according to claim 9. 11. The article of claim 10, which is a coil. 12. An inorganic molded article obtained by impregnating a functional inorganic powder with the epoxy resin composition according to claim 1 and molding the same. 13. An epoxy resin (A) obtained by reacting a hydroquinone with epihalohydrin, a compound (B1) obtained by subjecting dicyclopentadiene to a phenol condensation reaction under an acid catalyst, and a curing accelerator (A). An epoxy resin composition containing c). 14. An epoxy resin (B2) obtained by reacting the epoxy resin (A) according to claim 13 with the compound (B1) according to claim 13 and epihalohydrin in the presence of a base catalyst, and a curing agent ( An epoxy resin composition containing d) and a curing accelerator (c).