JPH0348932B2 - - 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 resistance. However, the use of asbestos is now prohibited as it is considered harmful. Carbon fiber, which has good heat resistance and sliding properties, has come to be widely used as a substitute for asbestos fiber. However, although carbon fibers are effective against hard metals such as steel, they have the drawback of high wear and poor sliding properties against soft metals such as aluminum and brass. Furthermore, although phenol resins, epoxy resins, and the like are the mainstream resins for binders, these resins have poor heat resistance and are limited in their use under high load conditions. [Object of the Invention] The object of the present invention has been made in view of the above-mentioned circumstances, and is to provide a heat-resistant resin composition for molding that has heat resistance, mechanical properties, and excellent sliding properties on soft metals. This is what we are trying to provide. [Summary of the Invention] As a result of extensive research to achieve the above object, the present invention has shown that excellent results can be obtained as a molding composition by using a thermosetting resin and a composite filler, which will be described later. It was discovered that the purpose could be achieved. That is, the present invention provides (A)(a) general formula An addition reaction product of polymaleimide and aminobenzoic acid represented by (in the formula, R ¹ is an n-valent organic group,
X ¹ and X ² represent the same or different monovalent atoms or groups selected from hydrogen atoms, halogen atoms, or organic groups, and n represents an integer of 2 or more, respectively),
and (b) a thermosetting resin whose main component is an epoxy compound having two or more epoxy groups in one molecule.
(B) a composite filler containing 30 to 70% by weight, (B) 50 to 83% by weight of fluororesin powder, and 38 to 5% by weight of aromatic polyamide powder.
70 to 30% by weight of a heat-resistant resin composition for molding. The addition reaction product of (a) polymaleimide and aminobenzoic acid, which is one of the main components of the thermosetting resin (A) used in the present invention, is obtained by addition reaction of polymaleimide and aminobenzoic acid. Examples of the polymaleimide used here include ethylene bismaleimide, hexamethylene bismaleimide, m- or p-phenylene bismaleimide, 4,4'-diphenylmethane bismaleimide, and 4,4'-diphenyl ether bismaleimide. , 4,4'-diphenylsulfon bismaleimide, 4,4'-dicyclohexylmethane bismaleimide, m- or p-xylylene bismaleimide, 4,4'-diphenylene bismaleimide, etc. Single or two
Used as a combination of more than one species. Further, if necessary, a small amount of monomaleimide such as N-3-chlorophenylmaleimide or N-4-nitrophenylmaleimide can be used together with the polymaleimide. Examples of aminobenzoic acids include p-aminobenzoic acid, m-aminobenzoic acid, o-aminobenzoic acid, and o-aminobenzoic acid.
Examples include aminobenzoic acid, and these are used alone or in combination of two or more. The blending ratio of the polymaleimide and aminobenzoic acid should be 5 to 40 parts by weight, more preferably 10 to 30 parts by weight, per 100 parts by weight of the polymaleimide. If the amount of aminobenzoic acid is less than 5 parts by weight, the compatibility between the polymaleimide-aminobenzoic acid addition reaction product and the epoxy compound (b) described later will be insufficient, which is not preferable. On the other hand, if the blending amount of aminobenzoic acid exceeds 40 parts by weight, the amino groups will be excessive and the heat resistance of the resin will decrease, 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. The other main components of (A) thermosetting resin used in the present invention (b) epoxy compounds having two or more epoxy groups in one molecule include bisphenol A type epoxy resin, bisphenol F type epoxy resin, 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 an unsaturated compound, epoxy resin having a heterocycle, heterocycle There are epoxy resins having rings, epoxy resins in which amines are glycidylated, etc., and one or more of these may be selected and used. (A) thermosetting resin is obtained by blending (a) polymaleimide-aminobenzoic acid addition reaction product and (b) epoxy compound, but there are favorable conditions for blending the addition reaction product and epoxy compound. ing. The proportion is 30 to 80% by weight of the addition reactant and 70 to 80% by weight of the epoxy compound.
It is necessary to make it 20% by weight. The addition reactant
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. As long as the addition reaction product and the epoxy compound are blended within the above range, there is no need to limit the reaction order, etc. (A) Thermosetting with excellent curability, moldability, and heat resistance no matter how they are blended Resin can be obtained. However, usually, first, an addition reaction is carried out between polymaleimide and aminobenzoic acid to obtain (a) an addition reaction product, and (b) an epoxy compound having two or more epoxy groups in one molecule is added to this (A). ) Obtain a thermosetting resin. The composite filler (B) used in the present invention is made of fluororesin powder, aromatic polyamide powder, etc., and preferably has a particle size of 30 mesh or more. Here the first
Examples of the fluororesin powder used as a component include tetrafluoroethylene resin, fluoride alkoxyethylene resin, fluoride ethylene propylene ether resin, tetrafluoroethylene hexafluoride propylene copolymer resin, and calcined Teflon powder. These can be used alone or in combination of two or more. Further, examples of the aromatic polyamide powder used as the second component include Cornex (trade name, manufactured by Teijin Ltd.). The blending ratio of the fluororesin powder and aromatic polyamide powder to the composite filler needs to be 50 to 83% by weight of the fluororesin powder and 38 to 5% by weight of the aromatic polyamide powder. Less than 50% by weight of the fluororesin powder and less than 5% by weight of the aromatic polyamide powder have no effect on sliding properties, and greater than 83% and 38% by weight, respectively, result in poor heat resistance. Furthermore, if necessary, fillers such as graphite, molybdenum disulfide, and boron nitride may be added to the composite filler, as well as internal mold release agents such as carnauba wax, higher saturated fatty acid esters, stearic acid, and zinc stearate. The heat-resistant resin composition for molding of the present invention is as described above.
It consists of (A) a thermosetting resin and (B) a composite filler, and is characterized by a blending ratio of 30 to 70% by weight of the thermosetting resin and 70 to 30% by weight of the composite filler. 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, molded products with good mechanical properties and sliding properties will not be obtained. This is so that you will not be affected. 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 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 has excellent mechanical properties, especially sliding properties on soft metals such as aluminum and brass, and has excellent workability and
It also 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 to 6 N,N'-methylene bismaleimide, m-aminobenzoic acid, epoxy resin, and 2-ethyl-4-methylimidazole were selected at the weight composition ratios shown in Table 1 and thermally cured. A synthetic resin was synthesized. A composite filler 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.

【table】

[Table] As described above, Examples 1 to 6 and Comparative Examples 1 to 4
The resin composition obtained in
200~220℃, pressure 100~300Kg/ ^cm2 , time 1~2
Pressure molding at 200-230°C for 5 min/mm.
After curing for ~15 hours, molded articles for various tests were manufactured. Test items and test methods are JIS-K- for mechanical properties (bending strength, tensile strength, compressive strength).
Tested according to 6911. Regarding sliding properties (coefficient of dynamic friction, amount of wear), a thrust type friction and wear tester was used, and the measurement conditions were 2 cm ² (outer diameter 25.6φ, inner diameter
20.0φ cylinder shape, 3S finish) Aluminum (A5052-BD) metal with sliding area, no lubrication, sliding speed 1m/sec, pressurized load 10-50Kg/cm ²
(Cumulative load after 10 minutes of operation at 10Kg/ ^cm2 ), dynamic friction coefficient, sliding speed of 0.3cm/sec, and pressurized load
The amount of friction and wear was measured after continuous operation for 24 hours under the condition of 10 kg/cm ² . These results are shown in Table 2.

【table】

[Table] As is clear from Table 2, the present invention 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.

Claims (1)

[Claims] 1 (A)(a) General formula An addition reaction product of polymaleimide and aminobenzoic acid represented by (in the formula, R ¹ is an n-valent organic group, and ^{X 1 and} (n represents an integer of 2 or more), and (b) a thermosetting resin whose main component is an epoxy compound having two or more epoxy groups in one molecule.
and (B) 70 to 30 weight % of a composite filler containing 50 to 83 weight % of fluororesin powder and 38 to 5 weight % of aromatic polyamide powder. Heat-resistant resin composition for use.