JPH046205B2 - - 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 to 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 fiber is effective against hard metals such as steel, it has 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 Addition reaction product ^{of polymaleimide} and aminobenzoic ^acid represented by (n represents an integer of 2 or more), and (b) 30 to 70% by weight of a thermosetting resin whose main component is an epoxy compound having two or more epoxy groups in one molecule; (B) Fluorine resin 50-83% by weight and novoloid fiber 38%
70 to 30% by weight of a composite filler containing 5% by weight of a composite filler. 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. Type 1 or 2
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 etc., these include 1
Used as a species or a combination of two or more species. 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 5 parts by weight of aminobenzoic acid is terminal, 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 50 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 and bisphenol F type epoxy resin. Epoxy resins, novolac type epoxy resins, polyglycidyl diester resins of polycarboxylic acids, polyglycidyl ethers of polyols, urethane-modified epoxy resins, aliphatic or alicyclic polyepoxides made by epoxidizing unsaturated compounds, epoxy resins with heterocycles , an epoxy resin having a heterocyclic ring, an epoxy resin in which an amine is 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 epoxy compound are blended within the above range, there is no need to limit the reaction order, etc. No matter how they are blended, (A) thermosetting with excellent curability, moldability, and heat resistance. It is possible to obtain a synthetic resin. However, usually, first, polymaleimide and aminobenzoic acid are subjected to an addition reaction to obtain (a) an addition reaction product, and to this, (b) an epoxy compound having two or more epoxy groups in one molecule is added.
(A) Obtain a thermosetting resin. Examples of the fluororesin used as the first component of the composite filler (B) used in the present invention include tetrafluoroethylene resin, fluoride alkoxyethylene resin, fluoride ethylene propylene ether resin, and tetrafluoroethylene hexafluoride resin. Examples include propylene copolymer resin, calcined Teflon powder, etc., and one or two of these
Select and use more than one species. Further, examples of the novoloid fiber used as the second component of the composite filler include Kynol (trade name, manufactured by Gun-ei Chemical Industry Co., Ltd.). Kynol is an organic fiber with a three-dimensional structure made by melt-spinning phenol formaldehyde, and its chemical structure is estimated to be as follows. The Kynol used in the present invention is preferably in the form of fibers, and those with a fiber length of 6 mm or less are particularly effective. The reason for this is that Kynol fiber has a three-dimensional structure, so during the kneading and crushing process, the fiber structure breaks down and becomes powder, which is estimated to have good sliding properties on soft metals.The length of the fiber is 6 mm. This is because it becomes difficult to break if it exceeds this. The blending ratio of the fluororesin and novoloid fiber is preferably 50 to 83% by weight of the fluororesin and 5 to 38% by weight of the novoloid fiber relative to the composite filler. Less than 50% by weight of fluororesin and less than 5% by weight of novoloid fiber have no effect on sliding properties.
Moreover, if each exceeds 83% by weight and 38% by weight, heat resistance deteriorates, which is not preferable. Furthermore, (B) other components of the composite filler include graphite,
Molybdenum disulfide, boron nitride, etc. can also be added. In addition, internal mold release agents include carnauba wax, higher saturated fatty acid esters, stearic acid,
Examples include zinc stearate, which can be added as necessary. The heat-resistant resin composition for molding of the present invention is as described above.
(A) Thermosetting resin 30-70% by weight, (B) Composite filler 70%
It is characterized by consisting of ~30% by weight,
The reason why these blending ratios are limited to the above range is because if the thermosetting resin is less than 30% by weight, workability and moldability are poor, and if it exceeds 70% by weight, a molded product that satisfies the required properties cannot be obtained. It is. Furthermore, the resin composition of the present invention is thermosetting, and generally has a
It hardens by heating to a temperature of 250℃, but
If necessary, various additives may be added 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 against soft metals such as aluminum and brass, but also has good workability and moldability, and is used in a wide range of applications such as sliding materials, friction materials, and electrical insulation materials. be able to. [Examples of the Invention] Next, the present invention will be specifically explained using 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. Composite filler components were 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] 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. In addition, for sliding characteristics (dynamic friction coefficient, wear amount), a thrust type friction and wear test was used, and the measurement conditions were 2 cm ² (outer diameter 25.6φ, inner diameter 20.0φ
Made of aluminum (A5052-BD) metal with a cylindrical shape, 3S finish) sliding area, no lubrication,
Sliding speed 1m/sec, pressurized load 10-50Kg/cm ² (10
Kg/ ^cm2 , cumulative load after 10 minutes of operation), sliding speed 0.3cm/sec, pressurized load 10
The amount of wear after continuous operation for 24 hours under the condition of Kg/cm ² was measured. These results are shown in Table 2.

[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 Addition reaction product ^{of polymaleimide} and aminobenzoic ^acid represented by (n represents an integer of 2 or more), and (b) 30 to 70% by weight of a thermosetting resin whose main component is an epoxy compound having two or more epoxy groups in one molecule. , (B) Fluororesin 50-83% by weight and novoloid fiber 38%
70 to 30% by weight of a composite filler containing 5% by weight of a composite filler.