JPS6136526B2 - - 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 resins have the property of becoming chemically, mechanically and electrically excellent cured products when cured with organic polyamines, organic acid anhydrides, etc., and are 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, glycidyl ester of timer acid is blended into an epoxy resin. (3) Use of polyalkylene glycols, such as dilycidyl ether of tripropylene glycol, in combination with aromatic epoxy resins. (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 with alicyclic epoxy resin, but alicyclic epoxy resin has problems in handling hygiene and is expensive. There is no balance between the heat resistance and thermal shock resistance of the 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) Component: An aromatic epoxy resin containing two or more 1,2-epoxy groups in one molecule.(b) Component: Reacting maleic anhydride with a diene or triene having 8 to 10 carbon atoms. Acid anhydride or its isomer or hydrogenated product thereof (c) Component Dicarboxylic acid having 36 carbon atoms or/and 54
In the present invention, the aromatic epoxy resin as the component (a) is, for example, a polycarboxylic acid whose main component is tricarboxylic acid. (In the formula, R ₁ is two alkylene groups having 1 to 6 carbon atoms or -S- group,

【formula】

[Formula] -O- group and

[Formula] One of the groups, R ₂ is -CH ₃ or -H, n is 0
~representing a number of about 2), an epoxy resin represented by
Novolak-type epoxy resin obtained from novolak-type phenolic resin and epichlorohydrin, epoxy resin obtained from phthalic acid and epichlorohydrin, epoxy resin obtained from parahydroxybenzoic acid and epichlorohydrin, epoxy resin obtained from aromatic amine such as toluidine or aniline and epichlorohydrin Examples include epoxy resin. Among these, the epoxy equivalent obtained from bisphenol A and epichlorohydrin is 160 to 230,
A liquid epoxy resin in which n is about 0.1 to 0.5 in the above formula [] 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 ethers of dodecyl alcohol, glycidyl esters of synthetic fatty acids [for example, #Cardilla-E (trade name) manufactured by Ciel Chemical Co., Ltd.], dodecene oxide, etc., which are compatible with the polycarboxylic acid of component (c) are used. is preferred. Next, as the acid anhydride of component (b), myrcene,
alloocimene, ocimene, α-terpinene, 2.
7-dimethyl-1,3,7-octatriene,
2,6-dimethyl-1,3,6-octatriene, 1,3,5-n-octatriene, 1,3.
Diels-Alder reaction products of trienes such as 7-n-octatriene, 1,4,6-n-octatriene and maleic anhydride, dienes and maleic anhydride such as butadiene dimer, isoprene dimer, etc. Diels-Alder reaction products with acids,
Isomers obtained by heating these or isomerizing them in the presence of an amic acid, an alkali metal hydroxide, sodium iodide, or an organic phosphorus compound (Japanese Patent Application No. 103230/1982, Specification of 137032/1982) ), an acid anhydride obtained by heating limonene and maleic anhydride in the presence or absence of an acidic catalyst, and partially or completely hydrogenating the double bonds of the acid anhydride mentioned above. Examples include acid anhydrides obtained by. Among these are Diels-Alder reaction products of alloocimene or a mixture of alloocimene and myrcene, or a mixture of alloocimene and α-terpinene, and maleic anhydride;
Preferably, these are made into a liquid by isomerization treatment. In addition, the polycarboxylic acid of component (c) has 36 carbon atoms.
containing at least 40% by weight, preferably 65% by weight or more of dicarboxylic acid or tricarboxylic acid having 54 carbon atoms, or the sum of both, and these include cottonseed oil, rapeseed oil, safflower oil, sesame oil, and sunflower oil. Monomers such as oleic acid, linoleic acid, linolenic acid, lysinic acid, ricinoleic acid, etc. derived from oil, drying oil such as soybean oil, tung oil, linseed oil, oiticica oil, and edible oil, semi-drying oil, etc. It is produced by dimerizing or trimerizing fatty acids, and is generally commercially available as dimer acid or trimer acid. Such commercial products include versadyme #216 and #228 (both dimer) manufactured by Japan General Mills Chemical Co., Ltd.
acid, trade name), same #213 (trimer acid, trade name),
Manufactured by Pacific Vegetable Oil Co.
Safflower#122Z-3 (dimer acid, trade name),
#122Z-8 (dimer acid, trade name), Empol #1014, #1016, #1018, #1022, #1024 manufactured by Emery
(all dimer acids, trade names), same #1040,
#1041 (all trimer acids, trade names) is mentioned. Among these, those manufactured by Japan General Mills Chemical Co., Ltd. and Emery Company are preferred. Of course, hydrogenated products of the dimer acid and trimer acid can also be used. These dimer acids and trimer acids rarely have a single composition and generally contain a small amount of monocarboxylic acid. These polycarboxylic acids and stearic acid,
Monocarboxylic acids such as linoleic acid, linolenic acid, and 2-ethyl-1-hexylic acid may also be used in combination. The proportion of each component in the resin composition of the present invention is component (a)
For 100 parts by weight, component (b) is 30 to 150 parts by weight, preferably 50 to 130 parts by weight, component (c) is 10 to 100 parts by weight,
Preferably it is 20 to 70 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-diazabicyclo[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, adhesives, paints, lacquers, and compression molding resins. 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. Production Example of Component (b) 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, 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 at 130-140°C for 10 minutes 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 allocimene was distilled off under reduced pressure (degree of vacuum: 20 mmHg) using aspirator suction at a temperature of 100° C. or lower. The melting point of the anhydrous maleated allocimene produced was 70-80°C. Production Example 2 60 g of 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 is complete, add 500 c.c. of n-hexane to 10%
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 alloocimene did not crystallize even if it was 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 distillation under reduced pressure 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 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-terhinene, 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 mixed acid 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 added to the mixture and left in the refrigerator (5°C), it remained stable in liquid form for over 2 months. Production Example 7 In Production Example 6, anhydrous maleation reaction was carried out in the same manner as Production Example 6 except that 70 g of alloocymene and 40 g of Mincel 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 the same stability test as in Production Example 6 was conducted on this liquid mixed acid anhydride, 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), 90 parts of liquid maleated alloocymene obtained in Production Example 2, Versatime 216
[Product name manufactured by Japan General Mill Chemical, (dimer acid 75
%, trimer acid 20%, monocarboxylic acid 5%)] 35
30 to 40 parts of 1-benzyl-2-methylimidazole (hereinafter referred to as "IB2MZ") as an accelerator.
Stir and mix uniformly at °C and under reduced pressure (2 mmHg or less).
An epoxy resin composition was prepared by defoaming. The viscosity of this composition was 2460 cps at 25°C. This resin composition was precured at 100°C for 4 hours,
Then, when it was post-cured at 150℃ for 4 hours, Table 1
A flexible cured resin shown in Figure 1 was obtained. Example 2 Example except that a composition was used in which 100 parts of Epicote 828, 25 parts of glycidyl ether of dodecyl alcohol [Epolite, M-1200 (trade name) manufactured by Kyoeisha Yushi Co., Ltd.] and 20 parts of Versatime 216 were used. It was cured in the same manner as in 1. Table 1 shows the physical properties of the obtained cured product. Comparative Example 1 65 parts of Epikote 828, 35 parts of Epicoat 871 (trade name, glycidyl ester of timer acid), 55 parts of HN-2200 (product name, Hitachi Chemical Co., Ltd.; methyltetrahydrophthalic anhydride) as a curing agent
Curing was carried out 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 2 Epicote 828, 100 parts, dodecenyl succinic anhydride [manufactured by Sanyo Chemical Co., Ltd.; DSA (trade name)]
Curing was carried out in the same manner as in Example 1 except that a composition consisting of 130 parts was used. Table 1 shows the physical properties of the obtained cured product. Comparative Example 3 Using 100 parts of Epicote 828 and 120 parts of the liquid maleated alloocymene obtained in Production Example 2,
The composition was cured in the same manner as in Example 1 except that dimer acid was not blended. Table 1 shows the physical properties of the obtained cured product.

[Table] Examples 3 to 12 The compositions shown in Table 2 were precured at 80°C for 3 hours, then heated to 120°C, and kept at the same temperature for 6 hours for postcuring. Table 2 shows the physical properties of the obtained cured product.

[Table] Comparative Example 4 Curing was carried out in the same manner as in Example 3 using a composition consisting of 100 parts of Epicote 828, 160 parts of dimer acid (Versadime 216), and 1 part of 1-benzyl-2-methylimidazole. The cured product was completely separated into two layers, with the upper layer being sticky and the lower layer being hard. Comparative Example 5 The composition was cured in the same manner as in Example 3, except that 100 parts of Epicote 828, 20 parts of dimer acid (Versadime 216), and 70 parts of methyltetrahydrophthalic anhydride (HN-2200) were used. Ta. The cured product was completely separated into two layers, with the upper layer being soft and the lower layer being hard. Comparative Example 6 The composition was cured in the same manner as in Example 3, except that 100 parts of Epicote 828 and 130 parts of dodecenyl succinic anhydride were used. The cured product was transparent, but had a heat distortion temperature of 67° C. and a heat crack index of 1 (the balance between heat distortion temperature and heat crack index was inferior to that of the composition of the present invention). Comparative Example 7 100 parts of alicyclic epoxy resin, #Chitsonox 221 (trade name manufactured by Chitso Corporation) and HN-2200 60
1 part, 60 parts of Versadime 216 (dimer acid), and 1 part of IB2MZ were mixed and cured in the same manner as in Example 1. The cured product was transparent, but had a heat distortion temperature of 60° C. and a heat crack index of 2 (the balance between heat distortion temperature and heat crack index was inferior to that of the composition of the present invention).

Claims (1)

[Scope of Claims] 1. An epoxy resin composition containing the following components (a), (b) and (c). (a) Component: An aromatic epoxy resin containing two or more 1,2-epoxy groups in one molecule.(b) Component: Reacting maleic anhydride with a diene or triene having 8 to 10 carbon atoms. Acid anhydride or its isomer or hydrogenated product thereof (c) Component Dicarboxylic acid having 36 carbon atoms or/and 54
A polycarboxylic acid whose main component is tricarboxylic acid. 2. Claim 1, characterized in that component (b) is blended in a ratio of 30 to 150 parts by weight and component (c) is blended in a ratio of 10 to 100 parts by weight to 100 parts by weight of component (a). The epoxy resin composition described. 3. The epoxy resin composition according to claim 1, wherein component (a) is an epoxy resin produced from bisphenol A and epichlorohydrin and having an epoxy equivalent of 160 to 230. 4. The epoxy resin composition according to claim 1, wherein component (b) is a Diels-Alder reaction product of alloocimene and maleic anhydride. 5. The epoxy resin composition of claim 1, wherein component (b) is a Diels-Alder reaction product of a mixture of alloocymene and myrcene and maleic anhydride. 6. The epoxy resin composition of claim 1, wherein component (b) is a Diels-Alder reaction product of a mixture of allocimene and α-terpinene and maleic anhydride.