JPS62257927A - Curable epoxy resin composition - Google Patents

Abstract

PURPOSE:To provide the titled composition containing an epoxy resin, a specific carboxylic acid anhydride, a polymerizable vinyl monomer, a radial polymerization initiator and a specific cure accelerator, exhibiting low viscosity at room temperature, having excellent workability and processability and suitable as a material for copper-clad laminated. CONSTITUTION:The objective composition contains, as essential components, (A) an epoxy resin, (B) a carboxylic acid anhydride free from ethylenic unsaturated bond (preferably glycerol tristrimellitate, etc.), (C) a polymerizable vinyl monomer (e.g. styrene), (D) a radical polymerization initiator [e.g. 2,5- dimethyl-2,5-di(t-tubylperoxy)hexane] and (E) an epoxy resin cure accelerator containing an onium salt of formula (Z is H or P; R<1>-R<4> are organic group provided that at least one of R<1>-R<4> is >=14C group; X is organic or inorganic acid ion; n is atomic valence of X ion) (e.g. tetradecyl dimethylbenzyl ammonium chloride).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to curable epoxy resin compositions using specific onium salts as epoxy curing accelerators.

[Prior Art] An epoxy resin composition containing an epoxy resin, a carboxylic acid anhydride having no ethylenic unsaturation, a polymerizable vinyl nitrate, and a radical initiator is known, and is disclosed in JP-A-56-1.
59215 discloses that when onium salts are used as curing accelerators in such compositions, high heat deflection temperatures (HD T
) is disclosed.

[Problems to be Solved by the Invention] However, the onium salt in the above publication is difficult to dissolve in the epoxy resin/vinyl aromatic hydrocarbon mixture.
The inventors' studies have revealed that this method has the disadvantage of poor workability. Particularly preferred are
Tetramethylammonium chloride and tetrabutylammonium bromide (1) do not dissolve in the above mixture, and therefore are not uniformly dispersed during dissolution, resulting in poor workability.

■Due to poor dispersion, physical properties of the cured product vary.

It has the following drawback. In addition, ethylene triphenylphosphonium iodite (1) requires heating to dissolve in a short time, resulting in poor liquid stability and workability of the mixture.

■High HDT is difficult to obtain.

It has the following drawback.

[Means for Solving the Problems] The present inventors have conducted intensive research to solve the above-mentioned problems, and have found that the solubility of onium salts depends on the carbon of the substituent directly bonded to N or P. I was able to find out that it can change depending on the number. Furthermore, as a result of repeated research,
We have discovered that an onium salt that has good solubility and other good physical properties such as high HDT is an onium salt in which at least one of its substituents has 14 or more carbon atoms, leading to the present invention. be.

That is, the present invention relates to a curable epoxy resin composition characterized by containing the following (a) to (e) as essential components.

(a) Epoxy resin (b) Carboxylic acid anhydride without ethylenic unsaturation (C) Polymerizable vinyl monomer (d) Radical initiator (e) Epoxy curing acceleration containing an onium field of the following general formula (1) agent (wherein Z is N or P, R1, R4 are the same or different organic groups, at least one of R1-R4 contains 14 or more carbon atoms, X is An ion of an organic or inorganic acid, and n is the valence of the compound is used. Such epoxy resins generally have a molecular weight of 70 to 8000, particularly 170 to 400
Having an epoxy equivalent of 0 means that the composition liquid has a viscosity of 1
Desirable in terms of workability and heat resistance of the cured product. Examples of epoxy resins that can be suitably used in the present invention include the following general formula % formula % (
1) It is a bisepoxy compound represented by: The above general formula (
In 1), n is an integer of 0 or 1 or more, and suitable examples of the divalent organic group R are biphenyl, diphenylmethane, α,
α-dimethyldiphenylmethane, diphenyl ether,
Diphenyl dimethylene ether, diphenyl thioether, diphenyl ketone, diphenylamine, diphenyl sulfoxide, diphenyl sulfone.

A group derived from triphenyl phosphite, triphenyl phosphate, etc. An epoxy resin that is easily available and suitable for the purposes of the present invention is bisphenol A.
Alternatively, it is an epoxy resin derived from the chloro or the bromine-substituted derivative of bisphenol A and an epihalohydrin. In addition to these glycidyl-based epoxy resins, non-glycidyl-based epoxy resins such as cyclohexene derivative type alicyclic resins can also be used in the present invention. The amount of epoxy resin used is 2 in the epoxy resin composition of the present invention.
0 to 80wtX, preferably 30 to 70wtX12.

Examples of carboxylic acid anhydrides that do not cause ethylenic unsaturation and are curing agents in the present invention include glycerol tristrimeritite, methylhexahydrophthalic anhydride, trimellitic anhydride, methyltetrahydrophthalic anhydride, Methylnadic anhydride, dodecenylsuccinic anhydride, trialkyltetrahydrophthalic anhydride (YH-308 or YH-307 manufactured by Yuka Shell Epoxy Co., Ltd.).

These include phthalic acid and pyromellitic anhydride.

Preferably glycerol tristrimeritide, methylhexahydrophthalic anhydride, trimellitic anhydride,
Methyltetrahydrophthalic anhydride and methylnadic anhydride. These carboxylic acid anhydrides can be used alone or in combination of two or more. The amount of these carboxylic acid anhydrides used is 0.5 to 50 in the epoxy resin composition.
VtX, preferably 1.0 to 40wt$.

Examples of the polymerizable vinyl monomer in the present invention include styrene, nuclear-substituted alkylstyrene (methylstyrene,
Dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, t-butylstyrene, etc.
), styrene monomers such as nuclear-substituted alkoxystyrene (methoxystyrene, etc...) lα-methylstyrene, halogenated styrene (chlorstyrene), dichlorostyrene, bromustyrene, hydroxystyrene, aminostyrene, acrylic acid , acrylic esters (such as methyl acrylate).

Acrylic acid monomers such as methacrylic acid and methacrylic esters (ethyl methacrylate, butyl methacrylate, etc.), other acrylonitrile, methacrylonitrile,
Vinyl acetate and the like can be used alone or in combination. The amount of the polymerizable vinyl monomer used in the present invention is 2 to 50 wt%, preferably 5 to 50 wt% in the epoxy resin composition.
It is 30wt%. If the amount used is small, the composition liquid will have high viscosity and workability will be poor, and if the amount used is too large, the heat resistance of the cured product will be reduced.

The radical initiator for the polymerizable vinyl monomer in the present invention includes organic peroxides such as dialkyl peroxides, diacyl peroxides, ketone peroxides,
Peroxyketals, hydroperoxides, peroxyesters, peroxycarbonates, specifically 2,5-dimethyl-2,5-di(t-butylperox)hexane, di-t-peroxide, benzoylperoxide oxide, t-butyl hydroperoxide, methylcyclohexyl peroxide.

Cumene hydroperoxide, dicumyl peroxide, acetylbenzoyl peroxide, tetrahydroperoxide, phenylcyclohexane bidroperoxide, butyl isopropyl hydroperoxide, E-
Butyl peracetate, t-butyl perhe7zoate,
These include di[-amyl perphthalate, di-t-butyl peradipate, and t-amyl percarbonate. In addition, azo compounds such as 2,2'-azobisinbutyronitrile can also be used. The amount of the radical initiator to be used in the epoxy resin composition is preferably 0.005 to 5 wt$, preferably tl,<haO,OI to 3 wt$.

In the onium salt represented by the general formula (1), RIR; - R3 and R4 are the same or different, and at least one of them is aryl, alkyl, alkenyl, cycloalkyl containing 14 or more carbon atoms. , cycloalkenyl or alkaryl group. 4
Preferably, ν is an alkyl group having 14 to 18 carbon atoms; if the number of carbon atoms is 13 or less, the solubility in the epoxy resin composition will be poor, and if the number of carbon atoms is too large, it will act plastically, X, which is undesirable because it lowers the heat deflection temperature, is
an ion of an organic or inorganic acid, in particular a halogen atom or a nitrate, sulfate or phosphate-14;
n is the valence of the X ion.

Preferred specific examples include tetradecyldimethylbenzylammonium chloride, tetradecyltrimethylammonium chloride, tetradecylbenzylmethylethylammonium chloride, tetradecyldimethylethylammonium chloride, tetradecyltriethylammonium chloride, tetradecyldimethylphenylammonium chloride, tetradecyl Diphenylmethylammonium chloride.

Tetradecyldibutylbenzylammonium chloride, Tetradecylbutylmethylbenzylammonium chloride, Tetradecylbutyl ethylbenzylammonium chloride, Tetradecyldibutylbenzylammonium chloride, Tetradecyldiethylphenylammonium chloride, Tetradecyldiethyldiphenylammonium chloride, Tetradecyldibutylphenylammonium chloride , tetradecylbutylethylphenylammonium chloride, tetradecyldimethylcyclohexylammonium chloride, and the like. Among the above, pentadecyl, hexadecyl, heptadecyl, octadecyl or nonadecyl may be used instead of tetradecyl. Further, instead of chloride, bromide, iodide, nitrate, sulfate, or phosphate may be used. Particularly preferred examples include tetradecyldimethylammonium chloride, tetradecyldimethylammonium chloride, hexadecyldimethylbenzylammonium chloride, and tetradecylbromide.

Furthermore, in the present invention, other curing accelerators such as imidazoles, tertiary amines, stannous salts of monocarboxylic acids, phenols, and boron trifluoride may be used as necessary.
As with the onium salts, amine complexes, alkali total salts, alkaline earth and alkali metal hydroxides are contained in the epoxy resin composition in an amount of 0.01 to 5 wt%, preferably 0.
．． 1 to 3 wt% can be used.

Examples of imidazoles include imidazole, 2-ethyl-4-methylimidazole, 1-inbutyl-2-
There are methylimidazole and l-benzyl-2-methylimidazole. Examples of tertiary amines include benzyldimethylamine, dimethylamine methylphenol, and tris(
(dimethylaminomethyl)phenol, pyridine, etc.

Examples of the stannous salts of monocarboxylic acids include stannous octanoate, stannous laurate, and stannous naphthinate. Phenols include phenol, salicylic acid 1
Examples include m-cresol, 0-cresol, and catechol. Examples of the boron trifluoride-amine complex include monoethylamine-boron trifluoride complex, piperidine boron trifluoride complex, and aniline boron trifluoride complex. Hydroxides include sodium hydroxide, potassium hydroxide,
Calcium hydroxide, etc. Among these, preferred are 2-ethyl-4-methylimidazole and bendimethylamine.

The composition of the present invention may be prepared by mixing each component simultaneously, or by mixing an epoxy resin and a polymerizable vinyl nitrate,
A mixture A is mixed with a carboxylic acid anhydride, a radical initiator, and a curing accelerator, and a warm mixture B is prepared.
and B may be mixed. The curable compositions of the present invention may be supplemented with conventional modifiers such as extenders, fillers and reinforcing agents, pigments, dyes, organic solvents, plasticizers, flow modifiers, sootropy imparters, at any stage prior to curing. additives, flame retardants or mold release agents can be added. Extending Agents 1 Fibers formed from glass fibers, asbestos fibers, boron fibers, carbon fibers, aromatic polyamides, coal powder, as examples of reinforcing agents, fillers and pigments.

Minerals like silicates like mica, asbestos powder, slate powder, kaolin, aluminum oxide, chalk powder, antimony trioxide, bentone, silica aerogel, lithopone, barite, titanium dioxide, carbon black, graphite, iron oxide leprosy, colorants, or metal powders such as aluminum or iron powder.

The composition of the present invention can be used in a variety of applications, for example, in the production of adhesives applied to metals, wood, cement, etc., and also in laminated products, sheet molding compounds (SMC), 7' lint wiring boards, etc. laminates, molded powders, fluidized powders, sealing resins, etc. In the case of manufacturing molded articles, it is placed in a mold and heated to, for example, 100°C to 20°C.
A method of curing at a temperature of 0°C is preferred.

[Example] As the epoxy resin, liquid glycidyl polyether of 2,2-bis(4-hydroxyphenyl)propane (Epicor 82B, manufactured by Yuka Shell Epoxy Co., Ltd.) having an epoxy equivalent of 188 was used.

As the carboxylic anhydride, methyltetrahydrophthalic anhydride (eTHPA) and trimellitic anhydride (TMA) were used. Perhexa 25B is a radical initiator, 2,5-dimethyl-2,5-bis(te
rt-butylperoxy)hexane.

Example 1 80 parts of epoxy resin, 20 parts of styrene, 25 parts of perhexa
0.8 parts of B and 1.2 parts of tetradecyldimethylbenzylammonium chloride were stirred and mixed at room temperature to obtain a colorless and transparent homogeneous solution. 42 parts of TMA was added to this and mixed with stirring.

The mixed formulation was then cast into a fluororesin mold, which was placed in an oven heated to 150°C.
It was heated and cured for 2 hours. Thereafter, the cast product was taken out to obtain a disk having a thickness of 3 mm and a diameter of 50II11.

This was then weighted to 1259g using a Toyo Seiki Vicat heat softening point measuring device at a heating rate of 50°C/hr and 0.1
Determine the temperature at which the mm collapses and calculate it as the thermal softening temperature (
VST).

Example 2 A disk was prepared in the same manner as in Example 1, except that tetradecyldimethylbenzylammonium chloride was changed to tetradecyltrimethylammonium bromide, and VST was measured.

Example 3 In Example 1, except that tetradecyldimethylbenzylammonium chloride was changed to hexadecyldimethylbenzylammonium chloride, a disk was prepared in the same manner as in Example 1, and 5Tt- was measured.

Example 4 In Example 1, 1.2 parts of tetradecyldimethylbenzyl ammonium chloride was replaced with 1.2 parts of tributylhexadecylphosphonium bromide, and the rest was repeated to prepare a disk and measure VST.

Comparative Example 1 In Example 1, 1.2 parts of tetradecyldimethylbenzylammonium chloride was changed to 1.2 parts of tetramethylammonium chloride, and the rest was carried out in the same manner as above, with 80 parts of epoxy resin, 20 parts of styrene, and 0 parts of Perhexa 25B.
．． 6 parts were stirred and mixed at room temperature. In this case, tetramethylammonium chloride was insoluble in the composition and could not be homogeneously dispersed. TMA for this
Mix 42 parts and make a disk in the same manner as in Example 1. VS
T was determined as Jllll.

Comparative Example 2 A disk was prepared in the same manner as in Comparative Example 1, except that 42 parts of TMA was replaced with 64 parts of MeTHPA, and VST was measured.

Comparative Example 3 A disk was made in the same manner as in Example 1 except that tetradecyldimethylbenzylammonium chloride was not used, and VST was measured.

The above measurement results are shown in Table 1.

Table 1 [Effects of the Invention] The curable epoxy resin composition of the present invention has a long pot life, exhibits extremely low viscosity near room temperature, and has excellent workability and
It has the advantage of excellent processability, good dispersibility of the composition, and no variation in physical properties of the cured product. Furthermore, the cured product has high heat resistance, making it an excellent material for, for example, copper-clad laminate boards.

Claims (1)

[Claims] 1. A curable epoxy resin composition containing the following (a) to (e) as essential components. (a) Epoxy resin (b) Carboxylic acid anhydride without ethylenic unsaturation (c) Polymerizable vinyl monomer (d) Radical initiator (e) Epoxy curing accelerator containing onium salt of the following general formula (I) Agent▲There are mathematical formulas, chemical formulas, tables, etc.▼…(I) (In the formula, Z is N or P, R^1 to R^4 are the same or different organic groups, and R^1 to R^ At least one of 4 contains 14 or more carbon atoms,
X is an ion of an organic or inorganic acid, and n is the valence of the X ion. )