JPS6157327B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an epoxy resin composition that provides a cured product with excellent flexibility and a good balance between thermal shock resistance and heat resistance. The composition of the present invention is particularly useful as an insulation impregnating material and a sealing material for electrical parts. Epoxy resin has the property of becoming a cured product with excellent chemical, mechanical and electrical properties when cured with organic polyamines, organic acid anhydrides, etc., and can be used as paints, adhesives, casting materials, laminate forming materials, etc. Widely used. Acid anhydrides are used as curing agents because they are less toxic than polyamines, produce less heat when curing epoxy resins, provide products with low shrinkage, and provide cured products with excellent electrical properties. Liquid epoxy resins that use solids as hardeners are widely used as insulating impregnation materials and sealants for electrical parts, but they have the disadvantage of being poor in flexibility and prone to cracking when subjected to mechanical or thermal shock. . The following various methods have been proposed for the purpose of improving this drawback. (1) Use a high molecular weight epoxy resin with an epoxy equivalent of 400 or more. (2) long-chain alkylene polyglycidyl ester,
For example, a glycidyl ester of dimer acid is blended into an epoxy resin. (3) Polyalkylene glycol, such as diglycidyl ether of tripropylene glycol, is used in combination with an aromatic epoxy resin. (4) Add polyhydric alcohol ester of acid anhydride as a hardening agent. (5) An acid anhydride containing a long-chain alkyl group, such as dodecenylsuccinic anhydride, is used as a curing agent. (6) Compound rubber that is compatible with epoxy resin. (7) Mix epoxy resin and non-reactive plasticizer. However, these conventional methods have the following drawbacks. In method (1), the epoxy resin is solid, and it is necessary to melt it by heating and add a curing agent. In method (2), the transparency of the cured product decreases and the thermal shock resistance does not improve much. In method (3), the heat resistance of the cured product is significantly reduced. In method (4), the viscosity of the composition is very high, making it difficult to handle and only producing a cured product with poor water resistance. Method (5) cannot be expected to improve thermal shock resistance. In method (6), the composition has a high viscosity and is difficult to handle, and the physical properties of the product vary. Furthermore, the cured product has a so-called sea-island structure in which rubber particles are dispersed in the resin, and its uses are limited. Method (7) only yields a cured product with poor heat resistance, and the plasticizer oozes out over a long period of time, causing contamination. Furthermore, it is known that a flexible cured product can be obtained by blending dimer acid, which is mainly composed of dicarboxylic acids with 36 carbon atoms, with alicyclic epoxy resin, but alicyclic epoxy resin must be handled for hygienic reasons. It is problematic and expensive, and furthermore, there is no balance between the heat resistance and thermal shock resistance of the cured product, so it is hardly put to practical use. It is easy to think of using a bisphenol type epoxy resin instead of the alicyclic epoxy resin and adding dimer acid as a hardening agent to impart flexibility to the epoxy resin, but in this case, the dimer acid and It has a disadvantage that it has poor compatibility with aromatic epoxy resins and cannot obtain a uniform cured product. The present invention has been made to improve the drawbacks of these conventional techniques, and provides an epoxy resin composition that provides a cured product that has excellent flexibility, impact resistance, and heat resistance as well as thermal shock resistance. For details, see (a) and (b) below.
The present invention provides an epoxy resin composition containing component (c). (a) Aromatic epoxy resin containing two or more 1,2-epoxy groups in one molecule (b) Acid anhydrides of alicyclic compounds and/or acid anhydrides of chain compounds (c) The following: Organic acids whose main components are dicarboxylic acids represented by the general formula [], [] or [] and their hydrogenated products (In the formula, x and y are integers from 3 to 9, and the sum of x and y is
12, and among Z, one is −H and the other is −
COOH. ) HOOC−(CH ₂ ) ₅ −R ₁ −(CH ₂ ) ₆ −COOH [] (wherein, R ₁ is

[Formula] or -CH ₂ -CH=CH-. ) HOOC−(CH ₂ ) ₅ −R ₂ −CH=CH −(CH ₂ ) ₆ −COOH [] (In the formula, R ₂ is

[Formula] or -(CH ₂ ) ₃ -CH=CH-. ). In the present invention, the aromatic epoxy resin as the component (a) is, for example, (In the formula, R ₁ is a divalent alkylene group having 1 to 6 carbon atoms or -S- group,

【formula】

[Formula] -O- group and

[Formula], R ₂ is -CH ₃ or -H, n is a number from 0 to about 2), a novolak type epoxy resin obtained from a novolak type phenolic resin and epichlorohydrin Epoxy resins include epoxy resins obtained from phthalic acid and epichlorohydrin, epoxy resins obtained from parahydroxybenzoic acid and epichlorohydrin, and epoxy resins obtained from aromatic amines such as toluidine and aniline and epichlorohydrin. Among these, those obtained from bisphenol A and epichlorohydrin have an epoxy equivalent of 160 to 230, and in the above formula [1], n is about
A liquid epoxy resin of 0.1 to 0.5 is preferred. A portion (within 30% by weight) of these epoxy resins can be added to glycidyl esters of higher fatty acids; alicyclic epoxy resins; phenyl glycidyl ether; oxides of olefins such as octylene and dodecene; butanol, 2-ethylhexyl alcohol, dodecyl alcohol, and ethylene. Reactive diluents such as glycidyl ethers of alcohols such as glycol, butanediol, polyethylene glycol, polypropylene glycol, pentaerythritol, glycerin, neopentyl glycol, and propanetriol can be used instead. Among these diluents, glycidyl ether of dodecyl alcohol, which is compatible with the dicarboxylic acid of component (c), glycidyl ester of synthetic fatty acid [for example, #Cardular E (trade name) manufactured by Ciel Chemical Co., Ltd.],
Dodecene oxide and the like are preferred. Next, as the acid anhydride of the alicyclic compound of component (b), methyltetrahydrophthalic anhydride, which is liquid at room temperature,
Examples include methylhexahydrophthalic anhydride, methylnadic anhydride and hexahydrophthalic anhydride having a melting point of 34°C and the following compounds.
myrcene, alloocymene, α-terpinene,
2,7-dimethyl-1,3,7-octatriene, 2,6-dimethyl-1,3,6-octatriene, 1,3,5-n-octatriene, 1.
3.7-n-octatriene, 1.4.6-n-
Diels-Alder reaction products of trienes such as octatriene and maleic anhydride, Diels-Alder reaction products of dienes such as butadiene dimer, isoprene dimer and maleic anhydride, etc. by heating or Isomers obtained by isomerization treatment in the presence of amines, alkali metal hydroxides, sodium iodide, and organic phosphorus compounds (see Japanese Patent Application No. 52-103230 and 53-137032), limonene and maleic anhydride obtained by heating in the presence or absence of an acidic catalyst, an acid anhydride obtained by partially or completely hydrogenating the double bond of the acid anhydride mentioned above. Examples include acid anhydrides. Furthermore, examples of the acid anhydride of the linear compound include dodecenylsuccinic anhydride. Among these components (b), alloocimene, or a mixture of alloocimene and myrcene, or a mixture of alloocimene and α-terpinene,
Diels-Alder reaction products with maleic anhydride, which are isomerized into liquids, are preferred. Next, as the organic acid mainly composed of a specific dicarboxylic acid and its hydrogenated product as component (c) used in the present invention, the following can be mentioned. The main component obtained by reacting a mixture of fatty acids containing linoleic acid with acrylic acid is a dicarboxylic acid having 21 carbon atoms represented by the following formula
66659, 49-134620, 51-28627, 52-106812) and their hydrogen additives (In the formula, x and y are integers from 3 to 9, and the sum of x and y is
12, and among z, one is −H and the other is −
COOH. ) The organic acid whose main components are those in which x is 5 and y is 7 as shown in this formula [] is Westvaco
DIACID #1550 and #1525 from Worldwide
It is commercially available under the trade name. An organic acid whose main component is a dicarboxylic acid represented by the following formula [] or [] obtained by ring-opening dimerization of cyclohexanone with Fendt's reagent in the presence of butadiene, and its hydrogenated product HOOC-( _CH2 ) _5- R ₁ −(CH ₂ ) ₆ −COOH ………[] (In the formula, R ₁ is

[Formula] or -CH ₂ -CH=CH-. ) HOOC−(CH ₂ ) ₅ −R ₂ −CH=CH −(CH ₂ ) ₆ −COOH ………[] (In the formula, R ₂ is

[Formula] or -(CH ₂ ) ₃ -CH=CH-. ) This product is ULB-16 from Okamura Essential Oil Co., Ltd.
It is sold under product names such as 20 and SB-20. Even if component (c) dicarboxylic acid has a single composition,
It may contain up to 65% of other organic acids, preferably up to 40%. Other organic acids include (a) drying and semi-drying oils such as cottonseed oil, rapeseed oil, safflower oil, sesame oil, sunflower oil, soybean oil, tung oil, linseed oil, oyster oil, and edible oil; Those produced by dimerization and trimerization of derived monomeric fatty acids such as oleic acid, linoleic acid, linolenic acid, lysine acid, and ricinoleic acid, and are generally commercially available as dimer acids and trimer acids, and those Hydrogen additives [e.g., manufactured by Japan General Mills Chemical Co., Ltd.]
versadyme #216, #228 (both dimer acid), versadyme #213 (trimer acid), Safflower #122z−3 manufactured by Pacific Vegetable Oil Co.
(dimer acid), #122z-8 (dimer acid), Empol #1014 manufactured by Emery Co., Ltd.
#1016, #1018, #1022, #1024 (all dimer acids), #1040, #1041 (all trimer acids)] (b) Stearic acid, linoleic acid, linolenic acid, 2
Monocarboxylic acids such as -ethyl-1-hexylic acid and the like can be mentioned. The proportion of each component in the resin composition of the present invention is component (a)
For 100 parts by weight, component (b) is 10 to 130 parts by weight, preferably 20 to 100 parts by weight, component (c) is 10 to 100 parts by weight,
Preferably it is 20 to 80 parts by weight. If the amount of component (c) added is too small, the flexibility of the cured product will be insufficient; if it is too large, the heat deformation temperature will be below room temperature (20 to 30° C.), which will significantly limit the uses. Component (b) acts as a curing agent like component (c), so depending on the amount of component (c) added, it is at least the minimum amount necessary for curing the epoxy resin, and the amount of component (a) and (c) Select the amount necessary to compensate for the compatibility of the components. Accelerators can be added to these compositions to accelerate curing. Such promoters include, for example, trialkylamines, N-dimethylbenzylamine, triethanolamine, piperidine,
Dimethylaminomethylphenol, tris(dimethylaminomethyl)phenol, hexoate of tris(dimethylaminomethyl)phenol, imidazoles (e.g. 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, etc.), triphenylphosph yne, 8-diaza-bicyclo[5.4.0]undecene-7, tin octylate, and the like. Furthermore, fillers, reinforcing agents, pigments, dyes, flame-resistant substances, mold release agents, etc. can be mixed into the composition of the present invention at any stage before curing. Examples of fillers and reinforcing agents include glass fiber, carbon fiber, mica, quartz powder, aluminum oxide trihydrate, gypsum, kaolin, aluminum powder, calcium carbonate, and the like. The curable compositions described above are particularly useful in their unfilled or filled state as laminating resins or potting and insulation formulations for the electrical industry. They can also be used in all other industrial fields in which epoxy resins are commonly used, such as adhesives, glues, paints, lacquers and compression molding resins. The specific dicarboxylic acid-based organic acid and its hydrogenated product, component (c) of the present invention, are composed of an aromatic epoxy resin, component (a), an acid anhydride, component (b), and a relatively low temperature 60°C. Since a uniformly miscible mixture is obtained even at temperatures below 0.degree. C., a flexible and homogeneous cured product can be obtained by heating and curing this mixture. This means that in order to blend dicarboxylic acids such as adipic acid (melting point 152°C, carbon number 6) and azelaic acid (melting point 106°C, carbon number 9) into components (a) and (b),
This is surprising considering that it is necessary to heat the composition to a temperature of 0.degree. C. or higher and that the cured composition shows no improvement in flexibility. In addition, the dicarboxylic acid of component (c) is liquid at room temperature or has a melting point close to room temperature, and if a liquid epoxy resin and a liquid acid anhydride of component (b) are selected, it has a low viscosity at room temperature. It forms a composition and is useful as a material for insulation impregnation and embedding of electrical parts. Next, the present invention will be explained in more detail with reference to production examples and examples. Note that parts and percentages in these production examples and examples are by weight. (b) Production example of component Production example 1 686 g (7.0 mol) of maleic anhydride was placed in a 3-capacity four-necked flask equipped with a stirrer, thermometer, condenser, dropping funnel, and nitrogen inlet tube, and stirred and nitrogen gas was added. The mixture was heated to 140°C while being introduced. 1000g while maintaining a temperature of 130-140℃
(7.35 mol) of alloocimene (manufactured by Yasushi Oil Industries Co., Ltd.) was gradually added dropwise. Since the temperature rose due to the heat of reaction, the reaction temperature was maintained at 130-140°C by cooling with a water bath. After about 1 hour of dropping alloocimene, stirring was continued for 10 minutes at 130-140°C to complete the reaction.
The reaction solution was red when alloocimene was added dropwise;
As the reaction was completed, the color changed to light brown. After the reaction was completed, excess alloocimene was distilled off under reduced pressure (degree of vacuum: 20 mmHg) using aspirator suction at a temperature of 100° C. or lower. The separation point of the anhydrous maleated allocimene produced was 75-80°C. Production Example 2 60 g of the anhydrous maleated allocimene obtained in Production Example 1 above was placed in a four-necked flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube, and heated to about 100°C to dissolve it. . 1.8 g of sodium iodide was added to this and stirred at 200°C for 2 hours (sodium iodide was not completely dissolved but finely dispersed.) After the reaction was completed, 500 c.c. of n-hexane was added and the mixture was stirred for 2 hours at 200°C. %
The product was washed with 500 c.c. of sodium thiosulfate aqueous solution. After washing with water, the aqueous layer was removed, and the oil layer was dehydrated by adding sodium sulfate, followed by distillation at a reduced pressure of 0.5 mmHg.
54 g (yield 90%) of pale yellow liquid anhydrous maleated alloocymene was obtained from a fraction of 160-185°C/0.5 mmHg. This liquid anhydrous maleated allocimene was left in a refrigerator at 5°C, in a freezer at -20°C, and at room temperature for more than two months, but did not crystallize. Its viscosity (E-type viscometer) was 122 cps at 25°C. Production Example 3 Anhydrous maleated alloocymene 60 obtained in Production Example 1
g was placed in a four-necked flask equipped with a stirrer, thermometer, condenser, and nitrogen inlet tube, and heated to about 100°C to dissolve. 0.3 g of tri-n-butylamine was added to this, and the mixture was stirred at 190° C. for 1 hour while introducing nitrogen. During this time, tri-n-butylamine was uniformly dissolved. The treated product was simply distilled at a reduced pressure of 0.5 mmHg,
As a fraction of 147-175°C/0.5 mmHg, 57 g of pale yellow liquid anhydrous maleated allocimene (yield 95% based on the raw material anhydrous maleated allocimene) was obtained. Its viscosity (E-type viscometer) was 87 cps at 25°C. This liquid anhydrous maleated allocimene did not crystallize even when left at room temperature (20 to 25°C) for more than two weeks or in a refrigerator (5°C) for 5 days. Production Example 4 Production Example 1 except that 2000 g (7.35 mol) of α-terpinene with a purity of 50% (manufactured by Yasuyu Kogyo Co., Ltd.) was used instead of alloocymene and the reaction temperature was 70 to 80°C.
The reaction was carried out in the same manner. 160-180℃/0.5mmHg
The product was purified by distillation under reduced pressure to obtain 1556 g (yield 95%) of anhydrous maleated α-terpinene. Production Example 5 The reaction was carried out in the same manner as in Production Example 1, except that 1333 g (7.35 mol) of myrcene with a purity of 75% (manufactured by Yasushi Kogyo Co., Ltd.) was used instead of alloocimene, and the reaction temperature was 70 to 80°C. The product was purified by vacuum distillation at 155-175°C/1 mmHg to obtain 1523 g (yield 93%) of anhydrous maleated myrcene. Production Example 6 69 g (0.7 mol) of maleic anhydride was placed in a 200 ml four-necked flask equipped with a stirrer, thermometer, condenser, dropping funnel, and nitrogen introduction tube.
Heat to 130-140°C while stirring and introducing nitrogen gas, and while maintaining this temperature, add 60 g (0.44 mol) of alloocymene and 80 g (0.29 mol) of α-terpinene with a purity of 50% (product of Yasushi Oil Industries Co., Ltd.). The mixed solution was gradually added dropwise. The dropwise addition was completed after about 1 hour, and the mixture was stirred for an additional 10 minutes. The obtained product was purified by distillation at a reduced pressure of 20 mmHg.The product immediately after distillation, that is, a mixed acid anhydride consisting of anhydrous maleated allocimene and anhydrous maleated α-terpinene, was in a liquid state, but crystallized after 3 days. It became. 0.8 g of tri-n-butylamine (0.5% by weight based on the theoretical yield of the acid anhydride mixture) was added to the mixture of anhydrous maleated allocimene and anhydrous maleated α-terpinene obtained as above, and 190
Stirred at ℃ for 0.5 hour. The obtained product is decompressed
Simple distillation at 0.5 mmHg yielded 153 g of pale yellow liquid mixed acid anhydride (yield
93%). Its viscosity was 222 cps at 25°C. This liquid mixture anhydride is at room temperature (20-25℃),
Both were kept in a stable liquid state for more than two months in a refrigerator at 5°C and a refrigerator at -20°C.
In addition, to 10 g of this liquid mixed acid anhydride, Production Example 1
0.1 g of crystals of anhydrous maleated allocimene obtained in
When the mixture was left in the refrigerator (5°C), it remained stable in a liquid state for over two months. Production Example 7 In Production Example 6, an anhydrous maleation reaction was carried out in the same manner as in Production Example 6, except that 70 g of alloocimene and 40 g of myrcene used in Production Example 5 were used instead of α-terpinene, and the obtained anhydride maleic product was subjected to an isomerization reaction in the same manner. The viscosity at 25° C. of each mixed acid anhydride after liquefaction was 112 cps, and the yield was 92%. Further, when this liquid mixed acid anhydride was subjected to the same stability test as in Production Example 6, all of them remained stable in liquid form for more than two months. Example 1 100 parts of Epicote 828 (trade name, Schiel Kagaku Co., Ltd., epoxy equivalent: 189, glycidyl ether of bisphenol A), 85 parts of liquid maleated alloocymene obtained in Production Example 2, DIACID-1550
(Manufactured by Westvaco Worldwide, trade name, dicarboxylic acid 92%, monocarboxylic acid 7%) 50 parts, 1 part 1-benzyl-2-methylimidazole (hereinafter referred to as "IB2MZ") as an accelerator were uniformly added at 30 to 40℃. The mixture was stirred and mixed and defoamed under reduced pressure (2 mmHg or less) to prepare an epoxy resin composition. The viscosity of this composition was 3150 cps at 25°C. When this resin composition was pre-cured at 80°C for 3 hours and then post-cured at 120°C for 6 hours, a flexible cured resin shown in Table 1 was obtained. Example 2 Instead of 85 parts of liquid anhydrous maleated alloocymene
HN-2200 (methyltetrahydrophthalic anhydride,
Example 1 except that 55 parts of Hitachi Chemical (trade name) was used.
The composition was cured in the same manner as above. Table 1 shows the physical properties of the obtained cured product. Comparative Example 1 The same procedure as in Example 1 was carried out except for using a composition consisting of 65 parts of Epikot 828, 35 parts of Epikot 871 (glycidyl ester of dimer acid: trade name manufactured by Ciel Chemical Co., Ltd.), 55 parts of HN-2200, and 1 part of IB2MZ. The composition was cured. Table 1 shows the physical properties of the obtained cured product. Comparative Example 2 100 parts of Epicote 828, 130 parts of dodecenyl succinic anhydride (hereinafter referred to as "DSA"),
The composition was cured in the same manner as in Example 1 except that a composition consisting of 1 part IB2NZ was used. Table 1 shows the physical properties of the obtained cured product. Comparative Example 3 100 parts of Epicote 828, 120 parts of liquid anhydrous maleated alloocymene obtained in Production Example 2, IB2NH 1
The composition was cured in the same manner as in Example 1 except that a composition consisting of 1. Table 1 shows the physical properties of the obtained cured product. Comparative example 4 Epicote 828 100 parts, HN-2200 80 parts,
The composition was cured in the same manner as in Example 1 except that a composition consisting of 1 part of IB2MZ was used. Table 1 shows the physical properties of the obtained cured product. Comparative example 5 Epicote 828 100 parts, Diacld 1550 50 parts,
The composition was cured as in Example 1 except that a composition consisting of 1 part IB2MZ was used. The heat distortion temperature of the obtained cured product was lower than 30°C, and the heat crack index was 5. Comparative Example 6 Epicote 828 100 parts, Azelaic acid 35 parts,
A mixture consisting of 30 parts of HN-2200 and 1 part of IB2MZ was prepared.
Although it was heated to 80°C, azelaic acid did not dissolve and a uniform composition could not be obtained.

【table】

[Table] Examples 3 to 19 The compositions shown in Table 2 were cured in the same manner as in Example 1. The physical properties of the obtained cured product are shown in the same table.

【table】

【table】

Claims (1)

[Scope of Claims] 1. An epoxy resin composition containing the following components (a), (b), and (c) (a) component: an aromatic composition containing two or more 1,2-epoxy groups in one molecule; Group-based epoxy resin (b) Component Acid anhydride of alicyclic compound or/and acid anhydride of chain compound (c) Component Main component is dicarboxylic acid represented by the following general formula [], [] or [] organic acids and their hydrogenated products (In the formula, x and y are integers from 3 to 9, and the sum of x and y is
12, and among Z, one is −H and the other is −
COOH. ) HOOC−(CH ₂ ) ₅ −R ₁ −(CH ₂ ) ₆ −COOH [] (In the formula, R ₁ is [formula] or −CH ₂ −CH=CH−.) HOOC−(CH ₂ ) ₅ −R ₂ −CH=CH −(CH ₂ ) ₆ −COOH [] (In the formula, R ₂ is [formula] or −(CH ₂ ) ₃ −CH=CH−.) 2 (a) Component 100 The epoxy resin composition according to claim 1, wherein the component (b) is blended in a ratio of 10 to 13 parts by weight and the component (c) is 10 to 100 parts by weight, based on parts by weight. .