JPS6248973B2 - - 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 good heat resistance and mechanical properties, and in particular has excellent sliding properties on soft metals such as aluminum and brass. [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, the use of asbestos has now been banned as it is considered harmful. Regarding sliding properties, organic fibers are effective against hard metals such as steel, but organic fibers have the problem of large amounts of wear and poor sliding properties against soft metals such as aluminum and brass. It was hot. Furthermore, although thermosetting phenolic resins and epoxy resins are mainstream as binder resins, they lack heat resistance and are limited in their use under high load conditions. [Object of the invention] The present invention was made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a heat-resistant resin composition for molding that has excellent heat resistance, mechanical properties, and sliding properties on soft metals. The purpose is [Summary of the Invention] As a result of extensive research to achieve the above object, the present invention has revealed that excellent results can be obtained as a molding resin composition by using a thermosetting resin and a composite filler, which will be described later. This is what I found. That is, the present invention relates to (A) (a) general formula (In the formula, R ¹ is a divalent to tetravalent organic group, X ¹ , X ²
is the same or different monovalent atom or group selected from a hydrogen atom, a halogen atom, and an alkyl group, and n is an integer of 2 to 4, respectively), and (b) a polymaleimide represented by the general formula (In the formula, R ² represents a monovalent atom or group selected from a hydrogen atom, a halogen atom, an alkyl group, and a carboxyl group, and m represents an integer of 1 to 5, respectively.) (c) 30 to 70% by weight of a thermosetting resin whose essential component is an epoxy compound having two or more epoxy groups in one molecule, and (B) at least a fluororesin and an aromatic polyamide powder. , fluororesin for composite filler
50 to 83% by weight, or 70 to 30% by weight of a composite filler containing 5 to 38% by weight of aromatic polyamide powder. (A) One of the addition reactions between (a) and (b) in thermosetting resin is The addition reaction product and (c) undergo a thermosetting reaction as shown below to form a resin. or Examples of the polymaleimide (A) (a), which is one of the essential components of the thermosetting resin used 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'-diphenylsulfon bismaleimide, 4,
4'-dicyclohexylmethane bismaleimide, m
-or p-xylylene bismaleimide, 4,4'-
Diphenylene bimaleimide, trimaleimide represented by the following structural formulas (d) to (f), Examples include organic compounds in which 2 to 4 maleimides are bonded, such as poly(phenylmethylene) polymaleimide, which may be used alone or in combination of two or more. If necessary, a small amount of monomaleimide such as N-3-chlorophenylmaleimide or N-4-nitrophenylmaleimide can be used together with these polymaleimides. In addition, as the essential component (b) aminophenol,
o-, m-, or p-aminophenol and aminocresol, aminoxylenol with various substituent isomers, aminolorcuphenol, aminobromophenol, amicatecacol, aminoresormine, aminobis(hydroxyphenol)propane, aminooxybenzoic acid etc. In the present invention, one or more of these polymaleimides and aminophenols are selected and reacted to obtain an addition reaction product, but the proportion of each is (a) 100 parts by weight of the polymaleimide. On the other hand, 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 (c) described below will not be sufficient. On the other hand, the amount of aminophenol
If it exceeds 40 parts by weight, the amino groups become excessive and the heat resistance of the resin decreases, which is not preferable. The temperature of the addition reaction is generally 50 to 200°C, more preferably 80 to 180°C, and the reaction time can be arbitrarily selected from several minutes to several tens of 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 resin, novolac type epoxy resin, polyglycidyl diester resin of polycarboxylic acid, polyglycidyl ether of polyol,
Urethane-modified epoxy resin, aliphatic or alicyclic polyepoxide made by epoxidizing unsaturated compounds,
There are epoxy resins having a heterocycle, epoxy resins having a heterocyclic ring, epoxy resins in which an amine is glycidylated, and one or more of these can be selected and used. There are preferable conditions for the blending ratio of the polymaleimide-aminophenol addition reaction product and these epoxy compounds, and it is desirable that the addition reaction product 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 exceeds 80% by weight, the heat resistance will be sufficient but the mechanical strength will decrease, which is not preferable. 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 product is first obtained by addition-reacting the polymaleimides (a) and the aminophenol (b), and then the epoxy compound (c) having two or more epoxy groups in one molecule is added to the product. By adding , a thermosetting resin can be obtained. The fluororesin used as one component of the composite filler used in the present invention is a synthetic resin obtained by polymerizing olefin containing fluorine, such as tetrafluoroethylene resin, fluoroalkoxyethylene resin, fluoroethylene propylene ether. Examples include resin, tetrafluoroethylene hexafluoropropylene copolymer resin, and calcined Teflon powder. Further, the aromatic polyamide powder used as another component of the composite heavy filler is a synthetic polymer powder having an aromatic ring and an amide bond in the main chain, such as Cornex (trade name of Teijinsha), This powder preferably has a particle size of 30 mesh or more. The compounding ratio of the fluororesin and aromatic polyamide powder in the composite filler is preferably 50 to 83% by weight of the fluororesin and 38 to 5% by weight of the aromatic polyamide powder. Less than 50% by weight of fluororesin and less than 5% by weight of aromatic polyamide powder have no effect on sliding properties.
Moreover, if it exceeds 83% by weight or 38% by weight, heat resistance deteriorates, which is not preferable. Further, other components of the composite filler include graphite, molybdenum disulfide, boron nitride, and the like. In particular, when heat insulation is required, graphite is not preferred, so it is added as appropriate. Further, examples of internal mold release agents include carnauba wax, higher saturated fatty acid esters, stearic acid, zinc stearate, etc., which are added as necessary. The heat-resistant resin composition for molding of the present invention contains 30 to 70% by weight of the above-mentioned thermosetting resin and 70 to 30% by weight of the composite filler.
However, the reason for limiting these blending ratios to the above range is that if the thermosetting resin is less than 30% by weight, workability and moldability will be poor, and if it exceeds 70% by weight, the required This is because a molded product satisfying the characteristics cannot be obtained. 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 various additives can be added as necessary to further improve various properties. For example, curability can be further improved by adding a curing catalyst such as a known acid anhydride, boron fluoride complex, tertiary amine, imidazole, quaternary ammonium salt, or peroxide. [Effect of the invention] The heat-resistant resin composition for molding of the present invention has heat resistance,
It not only has excellent mechanical properties, especially sliding properties on soft metals such as aluminum and brass, but also has good workability and moldability, making it suitable for sliding materials, friction materials,
It can be used in a wide range of applications, including electrical insulation materials. [Examples of the Invention] Next, the present invention will be specifically explained using Examples. Examples 1 to 6 N,N'-methylene bismaleimide, m-aminophenol, epoxy resin, 2-ethyl-4-
Each component of methylimidazole was selected according to the weight composition ratio shown in Table 1, and a thermosetting resin was synthesized. A composite filler component was added to the obtained thermosetting 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 Resins and resin compositions were obtained in the same manner as in the examples using the composition ratios shown in Table 1. The resin compositions thus 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°C and a pressure of
Pressure molding was carried out at 100 to 300 Kg/cm ² for 1 to 2 minutes/mm, followed by curing treatment at 200 to 230° C. for 5 to 15 hours to produce various test molded products. Regarding the mechanical properties of this test molded product, JIS-K
- Measured according to 6911. In addition, the sliding properties were measured using a thrust type friction and wear tester under the measurement conditions of 2 cm ² (outer diameter
Aluminum (A5052-BD) with a sliding area of 25.6φ, 20.0φ inner diameter, cylindrical shape, 3S finish)
Metal without lubrication, sliding speed 1m/sec, pressurized load
10~50Kg/ ^cm2 (cumulative load after 10 minutes of operation at 10Kg/ ^cm2 )
The coefficient of dynamic friction was calculated using Also, the sliding speed is 0.3
The amount of wear was measured after continuous operation for 24 hours under the conditions of cm/sec and a load of 10 kg/cm ² . These results are shown in Table 2.

【table】

【table】

[Table] As is clear from Table 2, it exhibits excellent mechanical properties even at high temperatures, and also exhibits sliding properties with a small coefficient of friction and a small amount of wear. Therefore, 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 a divalent to tetravalent organic group, X ¹ , X ²
is the same or different monovalent atom or group selected from a hydrogen atom, a halogen atom, and an alkyl group, and n is an integer of 2 to 4, respectively), and (b) a polymaleimide represented by the general formula (In the formula, R ² represents a monovalent atom or group selected from a hydrogen atom, a halogen atom, an alkyl group, and a carboxyl group, and m represents an integer of 1 to 5, respectively.) (c) 30 to 70% by weight of a thermosetting resin containing an epoxy compound having two or more epoxy groups in one molecule as an essential component; (B) containing at least a fluororesin and an aromatic polyamide powder; Fluorine resin for composite filler
50-83% by weight, and 5% aromatic polyamide powder
~38% by weight of composite filler containing 70-30% by weight
A heat-resistant resin composition for molding, comprising: