JPH1160696A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cured material having an excellent resistance against discoloring by blending an epoxy resin, an organic acid anhydride type curing agent, at least one kind of curing accelerator selected from tertiary amines and optionally other assistants. SOLUTION: A composition comprises 100 pts.wt. of an epoxy resin, 0.5-1.5 equivalent per an equivalent of an epoxy group of an organic acid anhydride type curing agent such as tetrahydrophthalic acid anhydride, 0.1-20 pts.wt. of at least one kind of curing accelerator selected from poly amine type tertiary amines of formula I, hexahydrotriazine type tertiary amines of formula II and tertiary amines containing a hydroxyl group of formula III and optionally other assistants. In the formulas, R1-R5 and R9-R11 are each a 1-5C alkyl; R6-R8 are each a 1-5C alkyl, a hydroxyalkyl or a dialkylaminoalkyl; R2 is H or a 1-5C alkyl; m1 is 0-5; m2 is 0-3; n1-n3 are each an integer of 2-12; and X is an oxygen atom or a nitrogen atom. A quick hardenability is achieved.

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 fast-curing properties, discoloration resistance and heat resistance.

[0002]

2. Description of the Related Art Conventionally, epoxy resins have excellent electrical, chemical, and mechanical properties, and are therefore cast, laminated, impregnated, and so on.
It is widely used for insulating materials, paints, adhesives, etc. of electrical components such as molding. In particular, when an acid anhydride is used as a curing agent, a cured product having the above properties can be obtained, but has disadvantages such as a slow curing speed, a high temperature and a long period of time.

Therefore, when an acid anhydride-based curing agent is used, tertiary amines such as dimethylbenzylamine and trisdimethylaminomethylphenol and salts thereof are usually used as a curing accelerator to improve the curing speed. It is planned.

[0004]

However, even in such a conventional epoxy resin composition, the curing speed is still insufficient, and the curing temperature must be increased or a long curing time is required. There are problems that the discoloration resistance and heat resistance of the product are deteriorated, the working environment is deteriorated such as leaving a bad smell during the work and in the final cured product, and the production cost is disadvantageous.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an epoxy resin composition which achieves a fast curing property and at the same time improves the discoloration resistance and heat resistance of a cured product. It is to be.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve various problems of known curing accelerators, and as a result, have found that an organic acid anhydride is used as a curing agent and a curing accelerator is used. As a result, it was found that the use of specific tertiary amines achieves rapid curability and, at the same time, improves the discoloration resistance and heat resistance of the cured product, thereby completing the present invention.

That is, the present invention provides an epoxy resin composition comprising an epoxy resin, an organic acid anhydride-based curing agent, a curing accelerator, and, if necessary, other auxiliaries. , The following general formula (1)

[0008]

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Wherein R1 to R5 each independently represent an alkyl group having 1 to 5 carbon atoms, m1 represents an integer of 0 to 5, and n1 and n2 each independently represent an integer of 2 to 12. Tertiary amines represented by the following general formula (2):

[0010]

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(Wherein R6 to R8 each independently represent an alkyl group having 1 to 5 carbon atoms, a hydroxyalkyl group or a dialkylaminoalkyl group), and the following tertiary amines: Equation (3)

[0012]

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(Wherein, R9 to R11 each independently represent an alkyl group having 1 to 5 carbon atoms, R12 represents hydrogen or an alkyl group having 1 to 5 carbon atoms, and m2 represents an integer of 0 to 3) , N3 represents an integer of 2 to 12. Further, X represents an oxygen or nitrogen atom, and when X is an oxygen atom, R11 does not exist.) An epoxy resin composition characterized by using one or more compounds selected from the group.

Hereinafter, the present invention will be described in detail.

The curing accelerator of the present invention has the general formula (1)
A tertiary amine represented by the general formula (2), a tertiary amine based on hexahydrotriazine represented by the general formula (2), and a tertiary amine containing a hydroxyl group represented by the general formula (3). One or two selected from the group
At least one compound is an essential component.

Specific examples of the polyamine tertiary amines represented by the above general formula (1) include N, N, N ',
N ", N" -pentamethyldiethylenetriamine, N,
N, N ', N ", N" -pentamethyldipropylenetriamine, N, N, N', N ", N" -pentamethyl (3
-Aminopropyl) ethylenediamine, N, N, N ',
N'-tetramethylhexamethylenediamine, bis (N, N-dimethylaminohexyl) -N'-methylamine and the like are exemplified. Of these, N, N, N ', N "
-Tetramethylhexamethylenediamine, bis (N, N
-Dimethylaminohexyl) -N'-methylamine is preferred because of its particularly high catalytic activity and excellent heat resistance and discoloration resistance of the resin.

The hexahydrotriazine-based tertiary amines represented by the general formula (2) include, specifically,
1,3,5-tris (N, N-dimethylaminoethyl)
Hexahydro-S-triazine, 1,3,5-tris (N, N-dimethylaminopropyl) hexahydro-S
-Triazine, 1,3,5-tris (2-hydroxyethyl) hexahydro-S-triazine and the like, among which 1,3,5-tris (N, N-dimethylaminopropyl) hexahydro-S- Triazine is preferred because of its particularly high catalytic activity and excellent heat resistance and discoloration resistance of the resin.

Specific examples of the hydroxyl-containing tertiary amine represented by the general formula (3) include dimethylethanolamine, dimethylaminoethoxyethanol, N, N, N'-trimethylaminoethylethanolamine, N- (2-hydroxyethyl) -N′-piperazine, N-dimethylaminobutanol, N, N-dimethylaminohexanol and the like are exemplified.
N, N-dimethylaminobutanol and N, N-dimethylaminohexanol are preferred because they have particularly high catalytic activity and are excellent in heat resistance and discoloration resistance of the resin.

In the present invention, the method for producing the compounds represented by the general formulas (1) to (3) is not particularly limited as long as it is a conventional production method. For example, the starting materials such as amines, alcohols and halides can be produced by a method such as reductive methylation and amination.

In the present invention, the use amount of the curing accelerator is not particularly limited, but is 0.1 to 20 parts by weight, more preferably 0.1 to 20 parts by weight, per 100 parts by weight of the epoxy resin.
A range of 10 parts by weight is preferable in terms of production speed and economy.

In the present invention, as the curing accelerator, the compounds represented by the above general formulas (1) to (3) alone may be used.
Alternatively, it can be used in combination with or mixed with a known curing accelerator.

Known curing accelerators include triethylamine, N, N, N ', N ", N"' N "'-hexamethyltriethylenetetramine, N, N, N'-trimethylaminoethylpiperazine, triethylenediamine , N,
Tertiary amines such as N-dimethylbenzylamine, tris (dimethylaminomethyl) phenol, N, N-dimethylcyclohexylamine, lauryldimethylamine, 1,8-diazabicyclo (5.4.0) -7-undecene; 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-ethyl-4
Imidazole compounds such as -methylimidazole and 1-cyanoethyl-2-methylimidazole; and organic phosphine compounds such as triphenylphosphine, tributylphosphine and tri (4-methylphenyl) phosphine. Also, Lewis acid salts of these amine compounds,
Organic acid salts and modified products of adducts such as epoxy resin type, urea type, isocyanate type, acid anhydride type and hydrazide type, benzylphosphonium salt, benzylsulfonium salt, benzylammonium salt and benzylpyridinium salt type cationic polymerization catalyst , A microcapsule type, a photopolymerization type, etc., may be used as appropriate within a range that does not lose the function of the curing accelerator of the present invention.

The curing accelerator of the present invention has the general formula (1)
The compound represented by the general formula (3) may be used alone or as a mixture with other known curing accelerators. In the preparation of the mixture, if necessary, toluene, xylene, propanol, isopropanol, Butanol, isobutanol, benzyl alcohol, cyclohexane,
Furfuryl alcohol, diacetone alcohol, cyclohexanone, methyl isobutyl ketone, butyl acetate,
Solvent naphtha, cellosolve acetate, methyl cellosolve, butyl cellosolve, butyl carbitol acetate, butyl carbitol, dipropylene glycol,
Ethylene glycol, diethylene glycol, polyethylene glycol or 1,4-butanediol can be used. The amount of the solvent is not particularly limited, but is preferably 70% by weight or less based on the total amount of the catalyst. 7
If it exceeds 0% by weight, the physical properties of the resin may be adversely affected due to the plasticizing effect of the solvent.

The curing accelerator thus prepared may be used by directly adding it to an epoxy resin or a curing agent, or may be used by adding various curing accelerators separately to the curing agent. There is no particular limitation.

The epoxy resin of the present invention is not particularly limited. Examples thereof include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, glycidyl dimer acid epoxy resin, and polyalkylene ether. Type epoxy resin, phenol novolak type epoxy resin, orthocresol novolak type epoxy resin, alicyclic epoxy resin, heterocycle-containing epoxy resin, diglycidyl epoxy resin, glycidylamine type epoxy resin, halogenated bisphenol A type epoxy resin, etc. are suitable. And these may be used alone or in combination of two or more. still,
A compound containing one epoxy group in a molecule used as a reactive diluent may be included in a part of the epoxy resin. The epoxy equivalent and viscosity of the epoxy resin are not particularly limited, but those having an epoxy equivalent in the range of 100 to 3000 are preferable in view of fluidity, heat resistance and chemical resistance of the resin.

In the present invention, the curing agent is preferably a curing accelerator itself or an organic acid anhydride in view of the electrical properties and heat resistance of the cured product.

Examples of the organic acid anhydride include, but are not particularly limited to, for example, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, nadic anhydride, methylnal anhydride. Dic anhydride, trialkyltetrahydrophthalic anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, dodecenyl succinic anhydride, ethylene glycol anhydrotrimellitic, glycerin tris Anhydrotrimerit and the like can be used.

The amount of the organic acid anhydride to be added is appropriately determined depending on the purpose of use, the curing characteristics, and the type of the curing agent, and is not limited, but is usually 0.5 to 1 per equivalent of epoxy group. 0.5 equivalents, preferably in the range of 0.6 to 1.2 equivalents. If the amount of the organic acid anhydride is outside this range, the heat resistance, discoloration, and other mechanical and electrical properties of the resin may deteriorate.

In the present invention, a compound that reacts with the epoxy resin may be used in combination with the acid anhydride-based curing agent. The compound that reacts with the epoxy resin is not particularly limited, for example, phenol novolak, o-cresol novolak, p-cresol novolak, t-butylphenol novolak, alkylphenols such as dicyclopentadiene cresol, ethylenediamine, diethylenetriamine, triethylenetetramine, Tetraethylenepentamine, pentaethylenehexamine, N-
Aliphatic amines such as hydroxyethylethylenediamine, tetra (hydroxyethyl) diethylenetriamine,
Polyether polyamines such as triethylene glycol diamine, tetraethylene glycol diamine, diethylene glycol bis (propylamine), polyoxypropylene diamine, polyoxypropylene triamines, isophorone diamine, methadenediamine, N-aminoethyl piperazine, bis (4 -Amino-3-methyldicyclohexyl) methane, bis (aminomethyl) cyclohexane, 3,9-bis (3-aminopropyl) 2,
Alicyclic amines such as 4,8,10-tetraoxaspiro (5,5) undecane, norbornenediamine, m-xylenediamine, α- (m / p-aminophenyl) ethylamine, metaphenylenediamine, diaminodiphenylsulfone , Diaminodiphenylmethane, diaminodiethyldimethyldiphenylmethane, α, α'-bis (4-
Aromatic amines such as aminophenyl) -p-diisopropylbenzene, amidoamines derived from the above amines and carboxylic acids, formic acid, acetic acid, propionic acid, acetic acid, valeric acid, caproic acid, 2-ethylhexanoic acid, Monocarboxylic acids such as octylic acid, lauric acid, capric acid, stearic acid, oleic acid, linoleic acid, cyanoacetic acid, crotonic acid, pyruvic acid, salicylic acid, benzoic acid, hydroxystearic acid, acrylic acid and methacrylic acid, and adipic acid Dicarboxylic acids such as azelaic acid, sebacic acid, succinic acid, maleic acid, isophthalic acid, terephthalic acid, oxydiacetic acid, fumaric acid, oxalic acid, maleic acid, suberic acid, pimelic acid, glutaric acid, malonic acid, phenol, Cresol, catechol, pyrogallol, hydroquinone, Le phenols, phenols such as dodecylphenol, methanol, ethanol,
Alcohols such as propanol, butanol, ethylene glycol, propylene glycol, dipropylene glycol, glycerin, trimethylolpropane, 2-ethylhexanol, octanol, decyl alcohol, benzyl alcohol, sucrose, sorbitol, diphenylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate And isocyanates such as xylylene diisocyanate.

The epoxy resin composition of the present invention may contain, if necessary, a dye, a discoloration inhibitor, an antioxidant, a release agent, a flexibility-imparting agent, a liquid rubber, a solvent, a leveling agent, a tackifier, Other conventionally known additives such as a coupling agent, an inorganic filler, an antifoaming agent, and a reactive or non-reactive diluent can be appropriately compounded.

The epoxy resin composition of the present invention is usually in the form of a liquid, a powder, or a tablet obtained by tableting the same. Generally, a predetermined amount of a raw material component and other conventionally known additives are mixed at room temperature. Alternatively, it can be prepared by uniformly mixing or stirring under heating. In some cases, the epoxy resin composition can be produced by cooling, pulverizing, and, if necessary, tableting. The molding method using such an epoxy resin composition is not particularly limited. For example, a resin cured product is produced by a known molding method such as a casting method, an impregnation method, a transfer molding method, and a compression molding method. be able to.

[0032]

The epoxy resin composition of the present invention is characterized in that the curing speed and productivity of the resin are remarkably improved, and the heat resistance and discoloration resistance of the obtained cured product are remarkably improved. Furthermore, the cured composition has a low odor, improves the working environment in the resin manufacturing process, and does not leave a bad odor in the final cured product itself, so that it can be used as an electrical insulating material for electronic components, a semiconductor sealing material, a paint, an adhesive material. Useful as

[0033]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

Examples 1 to 5 Bisphenol A type epoxy resin (manufactured by Yuka Shell Co., product name: Epicoat 828, epoxy equivalent 190) preheated to 50 ° C. was treated with 3-methyltetrahydrophthalic anhydride (New Nippon Rika Co., Ltd., product name: MT-500) and various curing accelerators were mixed at the compounding ratio shown in Table 1, and the mixture was stirred at 6500 rpm for 7 seconds with a laboratory mixer to conduct a curing test. The obtained epoxy resin composition was tested on the following evaluation items.

Gelation time: 1 according to JIS K5059
It was measured at 00 ° C. by the hot plate method.

Heat resistance: The heat distortion temperature, which is an index of the heat resistance of the cured resin, was measured using an HDT tester S-3M (Toyo Seiki) according to JIS K7207. The curing conditions were as follows: 100 ° C. for 2 hours, and then 130 ° C. for 2 hours.

Discoloration of the cured product: The test piece prepared in the heat resistance evaluation was visually evaluated on the following five scales. 1: No discoloration 2: Small 3: Medium 4: Large 5: Very large.

Odor of hardener: According to 10 panelists,
The odor of each curing accelerator was smelled and evaluated according to the following criteria.

Large: Everyone feels strong odor.

Medium: 4 or more out of 10 people feel a strong odor.

Small: Less than 3 out of 10 people feel a weak odor.

Table 1 shows the results.

[0043]

[Table 1]

Comparative Examples 1 to 4 Example 1 was repeated using dimethylbenzylamine, tris (dimethylaminomethyl) phenol, dimethylcyclohexylamine and triethylenediamine as curing accelerators.
A comparison test was performed with the mixing ratio of Table 2 shows the results.
Shown in

[0045]

[Table 2]

As shown in Examples 1 to 5 in Table 1,
The epoxy resin composition of the present invention has a high curing rate and can achieve a high heat distortion temperature by curing in a short time. Also,
The obtained cured product has a characteristic of extremely low discoloration.
Furthermore, the working environment is improved because the odor of the curing accelerator is small.

On the other hand, the epoxy resin compositions of Comparative Examples 1 to 4 in Table 2 had a low curing rate and were inferior in heat resistance to the cured product in a short time. Further, the cured product was inferior in discoloration resistance, had a large odor of the curing accelerator, and deteriorated the working environment.

Claims (8)

[Claims] 1. An epoxy resin composition comprising an epoxy resin, an organic acid anhydride-based curing agent, a curing accelerator and, if necessary, other auxiliaries. 1) (Wherein, R1 to R5 each independently represent an alkyl group having 1 to 5 carbon atoms, m1 represents an integer of 0 to 5, n1 and n2
Each independently represents an integer of 2 to 12. ) Tertiary amines represented by the following general formula (2): (Wherein R6 to R8 each independently represent an alkyl group having 1 to 5 carbon atoms, a hydroxyalkyl group or a dialkylaminoalkyl group), and a tertiary amine of the following formula: (3) (Wherein, R9 to R11 each independently represent an alkyl group having 1 to 5 carbon atoms, R12 represents hydrogen or an alkyl group having 1 to 5 carbon atoms, m2 represents an integer of 0 to 3, and n3 represents Two
Represents an integer of 12. X represents an oxygen or nitrogen atom, and when X is an oxygen atom, R11 does not exist. An epoxy resin composition characterized by using one or more compounds selected from the group consisting of hydroxyl-containing tertiary amines represented by the formula (1). 2. The polyamine-based tertiary amines are N,
N, N ', N ", N" -pentamethyldiethylenetriamine, N, N, N', N ", N" -pentamethyldipropylenetriamine, N, N, N ', N ", N" -pentamethyl (3 -Aminopropyl) ethylenediamine, N,
N, N ', N'-tetramethylhexamethylenediamine and bis (N, N-dimethylaminohexyl) -N'-
The epoxy resin composition according to claim 1, which is a compound selected from the group consisting of methylamine. 3. The polyamine-based tertiary amines are N,
N, N ', N'-tetramethylhexamethylenediamine and bis (N, N-dimethylaminohexyl) -N'-
The epoxy resin composition according to claim 2, which is a compound selected from the group consisting of methylamine. 4. The hexahydrotriazine-based tertiary amines are 1,3,5-tris (N, N-dimethylaminoethyl) hexahydro-S-triazine, 1,3,5-tris (N, N- The epoxy resin according to claim 1, which is a compound selected from the group consisting of (dimethylaminopropyl) hexahydro-S-triazine and 1,3,5-tris (2-hydroxyethyl) hexahydro-S-triazine. Composition. 5. The method according to claim 4, wherein the hexahydrotriazine-based tertiary amine is 1,3,5-tris (N, N-dimethylaminopropyl) hexahydro-S-triazine. Epoxy resin composition. 6. A tertiary amine containing a hydroxyl group,
Dimethylethanolamine, dimethylaminoethoxyethanol, N, N, N'-trimethylaminoethylethanolamine, N- (2-hydroxyethyl) -N'-
Piperazine, N-dimethylaminobutanol and N, N
The epoxy resin composition according to claim 1, which is a compound selected from the group consisting of-dimethylaminohexanol. 7. A tertiary amine containing a hydroxyl group,
The epoxy resin composition according to claim 6, which is a compound selected from the group consisting of N, N-dimethylaminobutanol and N, N-dimethylaminohexanol. 8. The heat according to claim 1, wherein the amount of the curing agent is in the range of 0.5 to 1.5 equivalents per equivalent of the epoxy group. Curable epoxy resin composition.