JPH0316372B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a heat-resistant resin composition for molding that has excellent heat resistance, mechanical strength, heat insulation properties, and slidability. [Technical background of the invention and its problems] Asbestos fibers have conventionally been used as base materials for molding materials and friction materials with excellent heat insulation properties. However, asbestos is now considered to be harmful and its use is now prohibited. In addition, thermosetting phenolic resins and epoxy resins are mainstream as binder resins, but they have poor heat resistance and are limited in their use under high load conditions. [Object of the Invention] The present invention aims to provide a heat-resistant resin composition for molding that eliminates the above-mentioned conventional drawbacks and has excellent heat resistance, mechanical strength, heat insulation properties, and sliding properties. [Summary of the Invention] As a result of intensive research aimed at achieving the above object, the present invention has revealed that the use of the thermosetting resin, fluororesin, and aromatic polyamide fiber as a composite filler produces an excellent molding composition. It was discovered that the results obtained were as follows. That is, the present invention relates to (A)(a) general formula (In the formula, R ¹ is an n-valent organic group, X ¹ and X ² are the same or different monovalent atoms or groups selected from hydrogen atoms, halogen atoms, or organic groups, and n is 2
Each of the above integers is represented. ) and (b) general formula (In the formula, R ² represents a monovalent atom or group selected from a hydrogen atom, a halogen atom, or an organic group, and m represents an integer of 1 to 5.) An addition reaction product with aminophenol represented by ( c) 20 to 80% by weight of a thermosetting resin whose essential component is an epoxy compound having two or more epoxy groups in one molecule; (B) 60 to 97% by weight of a thermosetting element and an aromatic polyamide fiber.
Composite filler composed of 40-3% by weight
80 to 20% by weight of a heat-resistant resin composition for molding. Examples of the polymaleimide (A) (a), which is one of the essential components of the thermosetting resin in the present invention, include ethylene bismaleimide, hexamethylene bismaleimide, m- or p-phenylene bismaleimide,
4,4'-diphenylmethane bismaleimide, 4,
4'-diphenyl ether bismaleimide, 4,
4'-diphenylsulfone bismaleimide, 4,
4'-Dicyclohexylmethane bismaleimide, m
- or p-xylylene bismaleimide, 4,
Examples include 4'-diphenylene bismaleimide. In addition, N-
A small amount of monomaleimide such as 3-chlorophenylmaleimide or N-4-nitrophenylmaleimide can be used in combination. In addition, as the essential component (b) aminophenol,
o-, m-, - or P-aminophenol and aminocresol, aminooxylenol with various substituent isomers, aminochlorophenol, aminobromophenol, aminocatechol, aminoresorcinol, aminobis(hydroxyphenol)propane, aminooxy Examples include benzoic acid. In the present invention, one or more of these polymaleimides and aminophenols are selected and reacted to obtain an addition reaction product. The proportion of aminophenol (b) is 5 to 40 parts by weight, more preferably 10 to 30 parts by weight.
If the amount of aminophenol is less than 5 parts by weight, the compatibility between the addition reaction product and the epoxy compound described below will not be sufficient;
If the amount exceeds 1 part by weight, the amino groups become excessive and the heat resistance of the resin decreases, which is not preferable. The addition reaction temperature is generally 50 to 200°C, more preferably 80 to 180°C, and the reaction time is from several minutes to several minutes.
The time period can be arbitrarily selected within the range of 10 hours depending on the reaction components. In the present invention, the epoxy compounds having two or more epoxy groups in one molecule of the essential component (c) to be mixed with the addition reaction product thus obtained include bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol F type epoxy resin. type epoxy resins, novolac type epoxy resins, polyglycidyl esters of polycarboxylic acids, polyglycidyl ethers of polyols, urethane-modified epoxy resins, aliphatic or alicyclic polyepoxides made by epoxidizing unsaturated compounds, epoxy resins with heterocycles , epoxy resins having heterocyclic rings, epoxy resins in which amines are glycidylated, etc., and one or more of these may be selected and used. There are preferable conditions for the blending ratio of the polymaleimide-aminophenol adduct and these epoxy compounds, and it is desirable that the adduct be 30 to 80% by weight and the epoxy compound be 70 to 20% by weight.
If it is less than 30% by weight, the heat resistance will not be sufficient, and if it is less than 80% by weight.
Exceeding this is not preferable because even if the heat resistance is sufficient, the mechanical strength decreases. Within the above blending range, a thermosetting resin with good curability and moldability and excellent heat resistance can be obtained without limiting the order of mixing or reaction. However, usually, the addition reaction product is obtained by first making an addition reaction between the polymaleimide (a) and the aminophenol (b). A thermosetting resin is obtained by mixing the compounds. Therefore, the composition of the present invention can be obtained by uniformly mixing and kneading the thermosetting resin obtained as described above and a composite filler consisting of a fluororesin and an aromatic polyamide fiber. . Examples of the fluororesin used in the present invention include tetrafluoroethylene resin, fluoride alkoxyethylene resin, fluoride ethylene propylene ether resin, tetrafluoroethylene hexafluoride propylene copolymer resin, and calcined Teflon powder. Examples of aromatic polyamide fibers used as other fillers include Kepler (trade name of Dupont) and Cornex (trade name of Teijin). The shape of the aromatic polyamide fibers is preferably short, choppy, and preferably has a fiber length of 1 to 3 mm. If it is less than 1 mm, its properties as a fiber will not be fully exhibited and no improvement in mechanical strength will be observed, and if it exceeds 3 mm, mixing and kneading properties will be poor and workability will be reduced, which is not preferred. The heat-resistant resin composition for molding of the present invention is a composite comprising 20 to 80% by weight of the thermosetting resin described above, 60 to 90% by weight of fluororesin, and 40 to 3% by weight of aromatic polyamide fiber. It is characterized by consisting of 80 to 20% by weight of filler. The blending ratio was limited to the above range because if the thermosetting resin was less than 20% by weight, workability and moldability would be poor, and if it exceeded 80% by weight, a molded product with the required properties could not be obtained. . In addition, if the blending ratio of the fluororesin and aromatic polyamide fiber as a filler is less than 60% by weight of the fluororesin (accordingly, if the aromatic polyamide fiber exceeds 40% by weight), it will not have any effect on sliding properties, and if the content of the fluororesin is less than 40% by weight, it will not have an effect on the sliding property, and if the content of the fluororesin is less than 60% by weight (Accordingly, if the amount of aromatic polyamide fiber is less than 3% by weight), no effect can be obtained on mechanical properties and heat insulation properties. Further, the resin composition of the present invention is thermosetting,
Generally, it is cured by heating to a temperature of 150 to 250°C, but if necessary, various additives can be added to further improve various properties. For example, curing catalysts such as known acid anhydrides, boron fluoride complexes, tertiary amines, imidazoles, quaternary ammonium salts, and peroxides can be added to further improve curability. [Effects of the Invention] The composition of the present invention not only has excellent heat resistance, mechanical strength, heat insulation properties, and sliding properties, but also has excellent workability and
It has good moldability and can be used in a wide range of applications such as sliding materials, friction materials, and electrical insulation materials. [Examples of the Invention] The present invention will be specifically described below with reference to Examples. Examples 1-6 N,N'-methylene bismaleimide, meta-aminophenol, epoxy resin, 2-ethyl-4-
A thermosetting resin was synthesized by selecting each component of methylimidazole according to the weight composition ratio shown in Table 1.
A fluororesin and an aromatic polyamide fiber were blended with the obtained resin in the weight composition ratio shown in Table 1, and the mixture was uniformly stirred and mixed to obtain a heat-resistant resin composition for molding. Comparative Examples 1 to 4 Resin compositions were obtained in the same manner as in the examples using the composition ratios shown in Table 1. In this way, the resin compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were molded using a pressure molding machine at a temperature of 200 to 220.
℃, a pressure of 100 to 300 kg/cm ² , and a time of 1 to 2 minutes/mm per mm, followed by a curing treatment at 200 to 230° C. for 5 to 15 hours to produce various test molded products. The mechanical properties of this test molded article are JIS-
Measured according to K-6911. In addition, the sliding properties were measured using a thrust type friction and wear tester under the conditions of 2 cm ²
(Ring shape with outer diameter 25.6φ and inner diameter 20.0φ, 3S finish)
Made of aluminum metal with a sliding area of 10 to 50 kg/cm ² (10
The coefficient of dynamic friction was calculated using the cumulative load (after 10 minutes of operation at Kg/ ^cm2 ). In addition, the sliding speed is 0.3 cm/sec, the load is 10 kg/
The amount of wear was measured after continuous operation for 24 hours under the condition of ^cm2 .
The results are shown in Table 2.

【table】

[Table] As is clear from the above results, it shows excellent mechanical properties even at high temperatures, and also exhibits excellent sliding properties with a small coefficient of friction and little wear. For this reason, it can withstand use as a molded product even at high temperatures of 200°C.

Claims (1)

[Claims] 1 (A)(a) General formula (In the formula, R ¹ is an n-valent organic group, X ¹ and X ² are the same or different monovalent atoms or groups selected from hydrogen atoms, halogen atoms, or organic groups, and n is 2
Each of the above integers is represented. ) and (b) general formula (In the formula, R ² represents a monovalent atom or group selected from a hydrogen atom, a halogen atom, or an organic group, and m represents an integer of 1 to 5.) An addition reaction product with aminophenol represented by ( c) 20 to 80% by weight of a thermosetting resin whose essential component is an epoxy compound having two or more epoxy groups in one molecule, and (B) 60 to 97% by weight of a fluororesin and 40% by weight of aromatic polyamide fiber. A heat-resistant resin composition for molding, comprising 80 to 20% by weight of a composite filler, and 80 to 20% by weight of a composite filler.