JPS60184545A - Friction material composition - Google Patents

Abstract

PURPOSE:The titled composition having excellent friction and wear properties and heat resistance, comprising a thermoplastic resin containing a specified copolymer, a solid lubricant, and a higher fatty acid (derivative). CONSTITUTION:An unsaturated dicarboxylic acid anhydride (e.g. maleic anhydride) and an aromatic vinyl monomer (e.g. styrene) are copolymerized, which is then reacted with NH3 and/or a primary amine (e.g. aniline) at 80-350 deg.C in the presence of a catalyst (e.g. triethylamine) to form an imide bond, thus giving a copolymer containing 35-75wt% aromatic vinyl monomer residue and 23- 65wt% unsaturated dicarboximide derivative residue. Then, 100pts.wt. thermoplastic resin containing at least 15wt% copolymer thus obtained, 0.1-100pts.wt. solid lubricant (e.g. MoS2), and 0-10pts.wt. one or more compounds selected from among a higher fatty acid (ester) (e.g. stearic acid or polyoxyethylene distearate), a higher fatty acid amide (e.g. stearamide), and silicone oil are compounded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composition for sliding materials containing an aromatic vinyl-unsaturated dicardenimide copolymer.

Compositions for sliding materials containing solid lubricants have been known (Japanese Patent Publication No. 50-5748, Japanese Patent Publication No. 50-6024, Japanese Patent Publication No. 54-87752).

However, these compositions for sliding materials have low heat resistance, so their uses are limited.

The present invention has been made as a result of intensive research aimed at improving this drawback, and has resulted in 35 to 75% by weight of aromatic vinyl monomer residues and unsaturated radicals. 100 parts by weight of a thermoplastic resin containing 15% by weight or more of a copolymer containing 25 to 65% by weight of phosphoric acid imide rust conductor residues (hereinafter often referred to as "aromatic vinyl-unsaturated dicarboxylic acid imide copolymer"). , solid lubricant 0.
A composition containing 1 to 100 parts by weight and 0 to 10 parts by weight of at least one selected from the group of higher fatty acids, higher fatty acid esters, higher fatty acid amides, and silicone oil has better friction and wear characteristics and heat resistance than expected. The present invention was achieved based on the discovery that the method is excellent in the following.

Is the thermoplastic resin used in the present invention an aromatic vinyl monounsaturated radical? The copolymer may be composed only of phosphoric acid imide copolymer, but as long as it contains at least 15% by weight of this copolymer, it may further contain acrylonitrile-butadiene-styrene copolymer, acrylonitrile-citadiene-copolymer, etc.
Styrene-α-methylstyrene copolymer, acrylonitrile-styrene copolymer, acrylonitrile-α-methylstyrene copolymer, acrylonitrile-acrylic is moose styrene copolymer, acrylonitrile-ethylene propylene is moose styrene copolymer, methyl methacrylate A mixture of thermoplastic resins such as -butadiene-styrene copolymer, aromatic polycarbonate, polybutylene terephthalate, polyethylene terephthalate, nylon-6, nylon-6,6, polyphenylene sulfide, and polysulfone may also be used.

Here, the aromatic vinyl-unsaturated dicarimide copolymer and its production method will be explained.

Examples of the aromatic vinyl monomers constituting the copolymer include styrene monomers and substituted products thereof such as styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, and chlorostyrene. Particularly preferred. Aromatic vinyl-unsaturated radical? Acid imide copolymers can be produced by copolymerizing unsaturated dicarboxylic acid anhydrides with aromatic vinyl polymers and then reacting with ammonia and/or primary amines to form imide derivatives, or by copolymerizing maleimide, N,
-Methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-
- An imide monomer such as naphthylmaleimide may be directly copolymerized with an aromatic vinyl monomer. However, as a method for producing these copolymers, the former method, that is, the method of copolymerizing unsaturated cyclonic anhydride with an aromatic vinyl monomer and then imidizing it, is more preferable in terms of copolymerizability and economical efficiency. .

Examples of unsaturated dicarboxylic anhydrides include anhydrides such as maleic acid, itaconic acid, citraconic acid, and aconitic acid.
Maleic anhydride is particularly preferred. Ammonia and primary amines used in the imidization reaction may be obtained in the form of anhydrous or aqueous solutions. Examples of primary amines include alkyl amines such as methylamine, ethylamine, propylamine, and cyclohexylamine; Examples include aromatic amines such as chloro- or bromine-substituted alkyl amines, aniline, tolylamine, and naphthylamine, and chloro- or bromo-substituted aromatic amines, among which aniline is particularly preferred.

When the imidization reaction of a copolymer of an aromatic vinyl monomer and an unsaturated dicarboxylic anhydride is carried out in a solution or suspension state, it is preferable to use a conventional reaction vessel such as an autoclave. If the reaction is carried out in a state in which the reaction is carried out, an extruder equipped with a devolatilization device may be used. The temperature of the imidization reaction is about 80 to 350°C, preferably 1o.

~300°C. If the temperature is lower than 80°C, the reaction rate is slow and the reaction takes a long time, which is not practical.

On the other hand, if the temperature exceeds 350°C, the physical properties will deteriorate due to thermal decomposition of the polymer.

A catalyst may be used during the imidization reaction, and in that case, a tertiary amine such as triethylamine is preferably used.

The aromatic vinyl monomer residue in the aromatic vinyl-unsaturated dicarimide copolymer of the present invention is 35 to 75% by weight, and the content of aromatic vinyl monomer residue is 35% by weight. If it is less than that, the moldability and dimensional stability, which are characteristics of aromatic vinyl compounds, will be lost. Furthermore, if the unsaturated dicarboxylic acid imide derivative residue is less than 25% by weight, the molded product will not have sufficient heat resistance, hot water resistance, and chemical resistance. On the other hand, if the amount of imide derivative residue exceeds 65% by weight, the mechanical strength of the molded product will not be sufficient and the moldability will also deteriorate significantly.

Aromatic vinyl monomer residue and unsaturated radical used in the present invention? The copolymer containing a phosphoric acid imide derivative residue contains 0 to 40% by weight of a rubbery polymer and/or an aromatic vinyl monomer, an unsaturated dicarboxylic acid anhydride, and/or an unsaturated dicarboxylic acid imide derivative. 0 to 4 copolymerizable monomer residues
It can be contained in an amount of 0% by weight. Rubbery polymers include butadiene polymers, copolymers of butadiene and copolymerizable vinyl monomers, ethylene-propylene copolymers, ethylene-propylene-diene copolymers, and blocks of butadiene and aromatic vinyl. Copolymers, acrylic ester polymers, copolymers of diotyl acrylate and vinyl monomers copolymerizable therewith, and the like are used.

Aromatic vinyl monomer, unsaturated dicartz? Pyric acid anhydride and/or unsaturated radical? Monomers that can be copolymerized with phosphoric acid imide derivatives include vinyl cyanide monomers such as acrylonitrile, methacrylonitrile, and α-chloroacrylonitrile, and acrylics such as methyl acrylate, ethyl acrylate, and glylacrylate. Acid ester monomers, methacrylic ester monomers such as methyl methacrylic ester, ethyl methacrylic ester,
Examples include vinyl caldic acid monomers such as acrylic acid and methacrylic acid, acrylamide, and methacrylic acid amide.

The solid lubricants used in the present invention include MO82, Darafite, asbestos, fluorinated graphite, ? Examples include Ron Night Ride.

The amount of solid lubricant used in the present invention is 0.0 parts by weight of the thermoplastic resin containing the aromatic vinyl-unsaturated dicarboxylic acid imide copolymer, considering the effect of improving friction and abrasion properties. 1 part by weight or more, and 100 parts by weight or less, preferably 0.5 to 20 parts by weight, considering the mechanical strength of the resin.

Examples of the higher fatty acids used in the present invention include myristic acid, palmitic acid, stearic acid, montanic acid, oleic acid, erucic acid, linoleic acid, and lylunic acid.

Higher fatty acid esters include compounds obtained by condensation of higher fatty acids and alcohols, such as stearic acid derivatives such as polyoxyethylene distearate, dalicerol monostearate, nrubitan stearate, propylene glycol monostearate, and polyoxysolo. - Examples include lengelicol monostearate and holoxyethylene sorbitan monostearate. Similarly, esters of myristic acid, palmitic acid, montanic acid, oleic acid, erucic acid, linoleic acid, lylunic acid and the like are also included.

Examples of higher fatty acid amides include palmitic acid, amide, stearic acid amide, oleic acid amide, linoleic acid amide, linoleic acid amide, and erucic acid amide.

The sliding material composition of the present invention has further improved friction and wear characteristics by adding higher fatty acids, higher fatty acid esters, higher fatty acid amides, or silicone oil. Based on 100 parts by weight of the thermoplastic resin, the amount added is limited to 10 parts by weight or less, preferably 3 parts by weight or less, taking into consideration the heat resistance of the resin, smoke generation during processing, and adverse effects such as treed awning on the surface of the molded product.

For each sliding material composition of the present invention, a stabilizer, a flame retardant, a plasticizer,
It may contain lubricants, ultraviolet absorbers, colorants, fillers such as Merck, clay, silica, alumina, mica, calcium carbonate, fluororesins, antistatic agents, and the like.

The composition for sliding materials of the present invention has significantly superior heat resistance compared to conventional compositions for sliding materials, so it can be used particularly advantageously in fields where a high degree of heat resistance is required. .

The present invention will be further explained below with reference to Examples, but is not limited to the following Examples.

In addition, all parts and parts in the examples are expressed on a weight basis.

Experimental Example (1) 60 parts of styrene and 100 parts of methyl ethyl ketone were placed in an autoclave equipped with a stirrer.

After replacing the inside of the system with nitrogen gas, the temperature was raised to 83 ° C.
40 parts of maleic anhydride and 0 parts of benzoyl oxide
．． A solution of 15 parts dissolved in 200 parts of methyl ethyl ketone was continuously added over 8 hours. The temperature was maintained at 83° C. for an additional 3 hours after the addition. A portion of the viscous reaction solution was sampled and the amount of unreacted monomer was determined by gas chromatography. As a result, the polymerization rate was 94.5.

The amount of maleic anhydride was 99%. The copolymer solution obtained here was added with an amount of aniline 38 equivalent to maleic anhydride.
1 part, and 0.3 part of triethylamine were added thereto, and the mixture was reacted at 140°C for 7 hours. 200 parts of methyl ethyl ketone was added to the reaction solution, cooled to room temperature, and mixed with 15 parts of methanol with vigorous stirring.
00 parts, precipitated, separated by F, and dried to obtain an imidized polymer. C-13 NMR analysis showed that the conversion rate of sialic anhydride groups to imide groups was 98%. This imidized polymer was a copolymer containing 54.6 units of N-phenylmaleimide as an unsaturated dicarboxylic acid imide derivative, and was designated as Polymer A.

Experimental Example (2) Styrene 60 was placed in the same autoclave as Experimental Example (1).
1 part, 100 parts of methyl ethyl ketone, and 10 parts of polybutadiene cut into small pieces were charged, stirred overnight at room temperature to dissolve the rubber, and then the system was replaced with nitrogen gas and the temperature was lowered to 83 °C.
The temperature was raised to ℃.

A solution of 0.075 parts of methyl ethyl ketone dissolved in 200 iK of methyl ethyl ketone was added continuously over 8 hours. From this point on, exactly the same operations as in Experimental Example (1) were performed.

The polymerization rate was 96% for styrene and 99% for maleic anhydride. This imidized polymer contains 49.9% of the N-phenylmaleimide unit as an unsaturated dicarimide compound.
A copolymer containing 9% was designated as Polymer B.

Experimental example (3) Styrene 50 was placed in the same auto crane as in experimental example (1).
0.15 parts of benzoyl peroxide in Experimental Example (1) was replaced with 0.15 parts of azobis-imbutyronitrile, and 38 parts of aniline was replaced with 30 parts of aniline and 2.67 parts of methylamine. The operation was exactly the same as in Experimental Example (1) except for the following. The polymerization rate is
The content was 98% styrene, 91% acrylonitrile, and 98% maleic anhydride. The conversion rate of acid anhydride groups to imide groups was 99%. Is this imidized polymer an unsaturated radical? A copolymer containing 52.5% of N-phenylmaleimide and )--methylmaleimide units as a phosphoric acid imide conductor was designated as Polymer C.

Experimental example (4) 143 parts of poly-lysotadiene latex (solid content 35g6
, weight average particle size o, 35μ, dull content 9%), potassium stearate 1 part, sodium polymaldehyde sulfoxylate 0.1 part, tetradium ethylenediamine tetraacetic acid 0.03 part, sulfuric acid 1 iron 0
．． 0.003 parts of t-dodecyl mercap and 150 parts of water were heated to 50°C, and to this was added 50 parts of a monomer mixture consisting of 70% styrene and 30% acrylonitrile, and 0.03 parts of t-dodecylmercaptan.
2 parts, 6 parts of cumene hydroperoxide 0.15 parts
After the addition, the temperature was raised to 65° C. and polymerization was carried out for 2 hours. The polymerization rate was 98% for styrene and 97% for acrylonitrile as determined by gas chromatography analysis. After adding an antioxidant to the obtained latex, it was coagulated with calcium chloride, washed with water, and dried to obtain a graft copolymer as a white powder. This was made into a polymer.

Example 1 46 parts of Polymer A obtained in Experimental Example (1) and 46 parts of Polymer A obtained in Experimental Example (4)
), 24 parts of Al38 resin (manufactured by Denki Kagaku Kogyo Co., Ltd., GR-2000), 10 parts of flaky natural graphite with an average particle size of 1 μm, 1 part of tristearylphosphite, 3 parts of octadecyl After mixing 0.5 part of (3,5-ditertiarybutyl-4-hydroxyphenyl)-globionate in a Henschel mixer, it was extruded into pellets using a vented extruder, and test pieces were prepared using an injection molding machine. The molded product thus prepared was subjected to physical property tests and the results are shown in Table 1.

Example 2 A physical property test was conducted by mixing, pelletizing, and molding in the same manner as in Example 1, except that 10 parts of MoJ with an average particle size of 5 μm was used instead of 10 parts of scaly natural graphite with an average particle size of 10 μm. The results are shown in Table 1.

Examples 3 to 1° Polymers A-D and ABS obtained in Experimental Examples (1) to (4)
Resin (GR-2000 manufactured by Denki Kagaku Kogyo Co., Ltd.), scaly natural graphite with an average particle size of 10μ, MoS2 with an average particle size of 5A, and 73? with an average particle size of 5μ. Ronnitride, higher fatty acid, higher fatty acid ester, higher fatty acid amide, and silicone oil were mixed, pelletized, and molded in the same manner as in Example 1 in the proportions shown in Table 1, and the physical properties of each were tested. are shown in Table 1. Additionally, 0.5 part of octadecyl 3-(3,5-ditertiaryphthyl-4-hydroxyphenyl)-propionate was added to the composition.

Comparative Examples 1-3? Listyrene (manufactured by Denki Kagaku Kogyo Co., Ltd., MW-2
), nylon-6 (Toshi Co., Ltd. product, 0M1026)
, scale-like natural graphite with an average particle size of 10 μm, and MOS with an average particle size of 5 μm were mixed, pelletized, and molded in the same manner as in Example 1 in the proportions shown in Table 1, and the physical properties of each were tested. The results are shown in Table 1.

Claims (1)

[Claims] Thermoplastic resin 100 containing 15% by weight or more of a copolymer containing 35 to 75% by weight of aromatic vinyl monomer residues and 25 to 65% by weight of unsaturated dicarboxylic acid imide derivative residues
parts by weight, 0.1 to 100 parts by weight of a solid lubricant, and 0 to 10 parts by weight of at least one selected from the group of higher fatty acids, higher fatty acid esters, higher fatty acid amides, and silicone oils.
A composition for a sliding material, characterized in that it contains parts by weight.