JPS632286B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to thermosetting resin compositions. More specifically, the present invention relates to a thermosetting resin composition that provides a cured product with excellent heat resistance and excellent mechanical and electrical properties by heat curing. The cured product of the resin composition of the present invention is particularly useful as an electrical insulating material, and has a wide range of other uses such as impregnating resins, casting resins, and laminating resins. Traditionally, epoxy resin has been widely used as an electrical insulating material, and although it exhibits excellent properties at room temperature, it cannot withstand high temperatures or long-term use.
In terms of heat resistance, the upper limit is Class F (can be used continuously at 155°C). However, with the recent advances in the performance and reliability of electrical equipment, the need for even better heat-resistant resins is increasing. In the field of such heat-resistant resins, cured products of resin compositions containing maleimide compounds have been attracting attention, and are disclosed in various documents including French Patent No. 1455514. However, all of them have drawbacks such as too high crosslinking density and brittle materials, and their range of use is limited. The present invention was made in view of such conventional problems, and can provide a cured product with excellent heat resistance and good mechanical and electrical properties, and is also thermosetting with good workability such as impregnation casting. The purpose is to provide a resin composition. That is, the present invention provides (A) 20 to 95 parts (parts by weight, hereinafter referred to as (same) and (B) polyfunctional maleimide compound 5-95% (wt%,
(same below) and general formula (): (In the formula, R ₁ represents an aliphatic diamino residue or an aromatic diamino residue, R ₂ represents an alkyl group or an aryl group, and n represents an integer from 0 to 5). The present invention relates to a thermosetting resin composition comprising 80 to 5 parts of a composition comprising 95 to 5% of a prepolymer. During curing of the composition of the present invention, the carboxyl group of the unsaturated monocarboxylic acid compound and the epoxy group of the polyfunctional epoxy compound react, and at the same time, the vinyl group of the former reacts with the maleimide group of the polyfunctional maleimide compound and the epoxy group of the polyfunctional epoxy compound. Since it is copolymerized with the najitsukimide group of the quinazolone prepolymer, it forms a crosslinkable network structure, resulting in a cured product with excellent heat resistance (type H or higher) and excellent electrical and mechanical properties. The composition (A) used in the present invention is blended in such a manner that the blending ratio of the unsaturated monocarboxylic acid compound to the polyfunctional epoxy compound is 0.8 to 1.5 equivalents of the carboxyl group of the latter to 1 equivalent of epoxy group of the former. be done. Carboxyl group is less than 0.8 equivalent or 1.5
If the amount is greater than the equivalent, the electrical properties may deteriorate, possibly due to an increase in the amount of epoxy groups or carboxyl groups remaining after curing, respectively, which is not preferable. Specific examples of polyfunctional epoxy compounds that can be used in the present invention include bisphenol A type Epicote 828, Epicote 834, and Epicote 1001.
(both manufactured by Ciel Chemical Co., Ltd.), alicyclic type CY-
179, CY-185 (manufactured by Ciba, Switzerland), novolac type DEN431, DEN438 (manufactured by Dow Chemical Company, USA), and ECN1273 (manufactured by Ciba, Switzerland). Specific examples of unsaturated monocarboxylic acid compounds that can be used in the present invention include acrylic acid, methacrylic acid, and cinnamic acid. Furthermore, in the present invention, it is also possible to use a compound prepared by reacting the composition (A) in advance, and a specific example thereof is Aronix M-
Commercially available products include 6100 and Aronix M-6300 (both manufactured by Toagosei Chemical Industry Co., Ltd.). The composition (B) used in the composition of the present invention has excellent heat resistance because its constituent components, namely a polyfunctional maleimide compound and a najitsuimidoquinazolone prepolymer, copolymerize during curing to form a dense crosslinked structure. give. Furthermore, since the quinazolone structure of the najitsukiimidoquinazolone prepolymer has the effect of improving both heat resistance and flexibility, it not only improves heat resistance but also provides flexibility at the same time. Furthermore, by increasing the molecular weight between crosslinks, flexibility can be imparted more easily. The nadic imidoquinazolone prepolymer represented by the general formula () can be easily obtained by reacting a diamine compound, an oxazinone compound, and nadic acid anhydride in a conventional manner. Such diamine compounds may be either aliphatic diamine compounds or aromatic diamine compounds, and specifically include hexamethylene diamine, 4,4'-diaminodiphenylmethane,
4,4'-diaminodiphenyl ether, 4,4'-
Examples include diaminodiphenylsulfone, 4,4'-diaminodicyclohexylmethane, and isophoronediamine. In addition, as an oxazinone compound, the general formula (): Any compound represented by (wherein R ₂ is the same as above) may be used. Further, as the najitsukiimidoquinazolone prepolymer represented by the general formula (), those in which n is an integer of 0 to 5 are used. When n is larger than 5, the molecular weight of the prepolymer increases too much, resulting in lower solubility during blending, leading to problems such as lower working efficiency. The polyfunctional maleimide compound used in the present invention may have two or more maleimide groups in one molecule, and specifically, for example, N,N'-(methylenedi-p-phenylene) dimaleimide, N,
N'-(oxydi-p-phenylene) dimaleimide, N,N'-m-phenylene dimaleimide, N,
N'-p-phenylene dimaleimide, N, N'-2,
4-Tolylene dimaleimide, N,N'-2,6-
Examples include tolylene dimaleimide, N,N'-m-xylylene dimaleimide, and N,N'-hexamethylene dimaleimide. In addition to these compounds, a maleimide compound obtained by reacting an aromatic amine mixture obtained by the reaction of aniline and formaldehyde with maleic anhydride can also be used in the present invention. The blending ratio of the above-mentioned Najitsukiimidoquinazolone prepolymer and the polyfunctional maleimide compound is 95~
5%, while the latter ranges from 5% to 95%. If the latter is less than 5%, polymerization will be insufficient due to the low reactivity of the najitsukimido quinazolone prepolymer, and if it is more than 95%, the polymerization will be insufficient. The effect obtained, that is, imparting heat resistance to the cured product becomes insufficient. The blending ratio of composition (A) and composition (B) is the total composition.
Out of 100 copies, the former is said to be 20-95 copies, and the latter 80-5 copies. If the latter is less than 5 parts, the heat resistance of the cured product will be insufficient, and if more than 80 parts is used, the heat resistance will improve, but the crosslinking density will become too high, leading to a decrease in mechanical properties. Therefore, both are unfavorable. The resin composition of the present invention may optionally contain (i) vinyl monomers such as styrene, vinyltoluene, and divinylbenzene, (ii) tertiary amines as a catalyst to facilitate the reaction between epoxy groups and carboxyl groups, and Quaternary ammonium salts, Lewis acids, (iii) Polymerization initiators for curing such as benzoyl peroxide, dicumyl peroxide, cumene hydroperoxide, etc. (iv) Silica, alumina, calcium carbonate, mica, asbestos, graphite Aite, titanium oxide,
Fillers such as molybdenum disulfide can also be added. By heating and curing the thermosetting resin composition of the present invention constructed as described above, it can be cured with excellent heat resistance (class H or higher) and good electrical and mechanical properties. It has a wide range of uses, including impregnating resins for electrical equipment, casting resins, and laminating resins. Next, the thermosetting resin composition of the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Note that the najitsukiimidoquinazolone prepolymer used in the following examples is either of the following two types. That is, the formula (): The compound represented by (hereinafter referred to as NIQ-1)
and expression(): It is called the compound represented by (hereinafter referred to as NIQ-2). Example 1 DER-332 (manufactured by Dow Chemical Company, USA, epoxy equivalent weight 170) was used as a polyfunctional epoxy compound.
g, acrylic acid as unsaturated monocarboxylic acid 72
g. A maleimide compound obtained by reacting MDA-150 (manufactured by Mitsui Toatsu Chemical Co., Ltd.), an aromatic amine mixture produced by the reaction of aniline and formaldehyde, with maleic anhydride in a stoichiometric amount as a polyfunctional maleimide compound. 121 g of maleimide compound M (hereinafter referred to as maleimide compound M) and 100 g of NIQ-1 as a najitsukiimide quinazolone prepolymer were blended to obtain a thermosetting resin composition. The obtained composition was treated at 150°C for 15 hours and at 220°C for 8 hours to form a cured product. The properties of the obtained cured product were investigated regarding the following items. (a) Bending strength (Kg/mm ² ) Measured at ambient temperatures of 25°C and 200°C according to the method of JIS 6911. (b) Tanδ value (%) Measured at ambient temperatures of 25°C and 200°C according to the method of JIS 6911. (c) Volume resistivity (Ω・cm) Measured at an ambient temperature of 25°C and 200 kg. (d) Heat distortion temperature (°C) Measured according to the method of JIS K 7207. (E) Weight loss on heating (%) The cured product of the sample was left at an ambient temperature of 240°C for 500 hours, and then the weight loss rate was measured. The results obtained are shown in Table 1. Examples 2 to 4 Resin compositions having the amounts shown in Table 1 were prepared and heat-cured under the same conditions as in Example 1 to obtain cured products. The properties of each cured product were investigated in the same manner as in Example 1. The results obtained are shown in Table 1. Comparative Example 1 An acid anhydride-cured epoxy resin consisting of 100 g of Epicote 828, 1 g of benzyltriethylammonium chloride, and 80 g of methyltetrahydrophthalic anhydride was cured at 150° C. for 15 hours. The properties of the obtained cured product were investigated in the same manner as in Example 1. The results obtained are shown in Table 1.

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Claims (1)

[Claims] 1 (A) 20 to 95 of a composition comprising a polyfunctional epoxy compound and an unsaturated monocarboxylic acid compound in an amount of 0.8 to 1.5 equivalents per equivalent of the epoxy group.
Parts by weight and (B) 5 to 95% by weight of polyfunctional maleimide compound and general formula (): (In the formula, R ₁ represents an aliphatic diamino residue or an aromatic diamino residue, R ₂ represents an alkyl group or an aryl group, and n represents an integer from 0 to 5). A thermosetting resin composition comprising 80 to 5 parts by weight of a composition comprising 95 to 5% by weight of a prepolymer.