JPH02163163A - Lubricating resin composition - Google Patents

Abstract

PURPOSE:To obtain a lubricating resin composition, excellent in sliding properties within a region of a high load and speed, heat resistance and material physical properties and suitable as electrical, mechanical parts, etc., by blending a thermoplastic resin with a specific amount of aromatic polyamide particles. CONSTITUTION:A resin composition obtained by mixing (A) 100 pts.wt. powder of a thermoplastic resin (e.g. polyether imide or aromatic polyester) with (B) 1-100 pts.wt., preferably 5-50 pts.wt. particles prepared by pulverizing an aromatic polyamide (e.g. polyp-phenylene terephthalamide) of >=0.8 intrinsic viscosity, in which >=85mol% amide bonds consist of an aromatic cyclic diamine, aromatic cyclic dicarboxylic acid or aromatic cyclic aminocarboxylic acid component, and having 3-300mum, preferably 5-200mum average particle diameter and optionally a mold releasing agent, other lubricants, etc., in a Henschel mixer, etc., and melt kneading the resultant mixture in an extruder, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a lubricating resin composition. For more details,
The present invention relates to a lubricating resin composition having excellent sliding properties suitable for electrical parts, mechanical parts, etc.

(Prior art and its problems) In recent years, with the need to reduce the weight of equipment, synthetic resin products have come to be used in many mechanical parts instead of metal products. For example, synthetic resin products have also been used for sliding parts such as bearings. Resin products are beginning to be used.

In such sliding members, polyamide, polyacetal, polyethylene, fluororesin, etc. have conventionally been used as synthetic resins with good sliding properties.

In low load and low speed ranges, these materials satisfy the required sliding properties even without lubrication, but as the load and high speeds increase, they may seize or flow due to frictional heat. become unable to do so. In addition, fluorine resin,
In particular, tetrafluoroethylene resin itself provides high heat resistance and excellent sliding properties, but has the disadvantage that it undergoes significant plastic deformation in a high load region and cannot provide stable sliding properties over a long period of time.

In order to improve these drawbacks, a method was adopted in which lubricating oil was added to these synthetic resins to make so-called oil-impregnated plastics. On the other hand, instead of the liquid lubricant mentioned above, a solid lubricant was added to improve sliding performance. Methods for improving properties are also already known. For example, a method in which polyphenylene sulfide is made to contain tetrafluoroethylene resin, metal oxide powder, or aromatic polyamide fiber (Japanese Unexamined Patent Publication No. 100123/1983);
A method of adding nickel powder and carbon fiber to an olefin-based synthetic resin (JP-A-61-168645), or a method of blending a thermoplastic resin with polyphenylene sulfide resin powder treated to make it infusible by oxidation (JP-A-63
-275667), etc.

Although this method solves the above-mentioned problem caused by oil seepage in oil-impregnated plastics, the inclusion of metal or inorganic particles damages the sliding surface of the mating material, making it difficult to maintain stable sliding properties. I can't get it. In particular, in order to reduce the weight of equipment, the mating material may be resin or aluminum,
In the case of soft metals such as brass, it causes abnormal wear. Furthermore, although it is possible to improve the material properties of the resulting molded product by adding aromatic polyamide fibers or carbon fibers, it is difficult to disperse during molding, and fibrillar wear particles are generated during friction. This caused new problems such as accumulation. In addition, polyphenylene sulfide resin powder treated with oxidative infusibility treatment,
It does not have sufficient heat resistance, making it unsatisfactory as a sliding material for high-load, high-speed applications.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned circumstances, and it is possible to reduce the coefficient of friction and prevent sagging during sliding at high loads and high speeds without damaging the mating material. The object of the present invention is to provide a lubricating resin composition that has excellent sliding properties and excellent heat resistance and material properties.

(Means for Solving the Problems) In order to achieve the above object, the present inventor focused on aromatic polyamides that have excellent heat resistance and mechanical properties, and as a result of intensive research, developed a thermoplastic resin as described below. A composition containing a specific amount of aromatic polyamide particles has excellent heat resistance, sliding properties under high loads and high speeds, and molded products with excellent material properties can be easily and efficiently obtained by injection molding. This discovery led to the completion of the present invention.

That is, the present invention is a lubricating resin composition characterized in that 1 to 100 parts by weight of aromatic polyamide particles are blended with 100 parts by weight of a thermoplastic resin.

In the present invention, the thermoplastic resin is not particularly limited, and includes, for example, polyethylene resin (low density, high density, ultra-high molecular weight), chlorinated polyolefin resin, polypropylene resin, modified polyolefin resin, ethylene vinyl acetate, etc. Polymers, ethylene/ethyl acrylate copolymers, polystyrene resins, ABS resins, polyacecool resins, polyamide resins such as nylon 6.66.610.12, methacrylic resins, polycarbonate resins,
Polyurethane elastomer, thermoplastic polyimide resin,
Thermoplastic polyetherimide resin, thermoplastic polyamideimide resin, ionomer resin, polyphenylene oxide resin, methylpentene resin, polyallyl sulfone resin, polyallyl ether resin, polyether sulfone resin, polyether ketone resin, polyether ether ketone resin, Examples include polyphenylene sulfide resin, polysulfone resin, wholly aromatic polyester, polyethylene terephthalate resin, thermoplastic elastomer, and blends and copolymers of various thermoplastic polymer substances. Among these exemplified thermoplastic resins, in order to obtain a lubricating resin composition with particularly high heat resistance, fully aromatic polyester resin, polyallyl ether sulfone resin, polyphenylene sulfide resin, polyether ketone resin, polyether ether ketone resin, etc. Preferably, resins, thermoplastic polyamideimide, polyetherimide, polyimide resins, or blends of these resins are used.

The aromatic polyamide used in the present invention is one in which at least 85 mol% or more of the amide bonds are obtained from an aromatic cyclic diamine, an aromatic cyclic dicarboxylic acid, or an aromatic cyclic aminocarboxylic acid component. Specific structural examples include polyparabenzamide, polyparaphenylene terephthalamide, poly-4,4'-diaminobenzanilide terephthalamide, polyparaphenylene-2
．． 6-nutalamide, copoly-paraphenylene/4.
4'(3,3'-dimethylbiphenylene)-terephthalamide,copoly-paraphenylene/3.4' (oxydiphenylene) terephthalamide, copoly-paraphenylene/2,5-pyridylephthalamide, polyortho Phenylene phthalamide, polymetaphenylene phthalamide, polyparaphenylene phthalamide, polyorthophenylene isophthalamide, polymetaphenylene isophthalamide, polyparaphenylene isophthalamide, polyorthophenylene terephthalamide, polymetaphenylene terephthalamide, poly-1゜5-naphthalene phthalamide, poly-1,5-naphthalene isophthalamide, poly-4,4'-diphenylene isophthalamide, etc., and compounds in which a part of the benzene nucleus of these aromatic diamines is replaced with halogen, and Aromatic polyamides containing alicyclic amines, such as compounds in which part of the benzene nucleus of these aromatic diamines is replaced with piperazine, 2,5゛-dimethylpiperazine, 2,5-diethylpiperazine, or aromatic The cyclic diamine is 3.3'-
Ether groups such as oxydiphenylenediamine and 3,4'-oxydiphenylenediamine, alkylene groups, -S-
,-SO,-.

An aromatic polyamide containing two benzene rings linked by groups such as -C-, -NH-, or a multicomponent copolymer of the above-mentioned aromatic polyamides, such as poly-3,3'-
Examples include oxydiphenylene terephthalamide/polyparaphenylene terephthalamide copolymer and poly-3,4'-oxydiphenylene terephthalamide/polyparaphenylene terephthalamide copolymer. Among these aromatic polyamides, para-oriented aromatic polyamides in which the divalent aromatic ring bond is located at the para position, as represented by poly-paraphenylene terephthalamide, have high crystallinity, orientation, and heat resistance. It is particularly preferred in the present invention because it has good properties and chemical resistance.

Such an aromatic polyamide can be produced in high yield and with a high degree of polymerization by a so-called low-temperature solution polymerization method (for example, see Japanese Patent Publication No. 14399/1983) from the corresponding aromatic cyclic diamine and aromatic cyclic dibasic acid halide. Obtained as a polymer.

The degree of polymerization of the aromatic polyamide used in the present invention is not particularly limited, but usually the logarithmic viscosity (
η1nh) of 0.8 or more is used.

Particles can be obtained from such aromatic polyamides by pulverizing the isolated and purified polymer using commonly used mechanical pulverizing means such as ball mills, hammer mills, jet mills, etc. Further, fine particles can also be obtained by the method disclosed in, for example, Japanese Unexamined Patent Publication No. 6232123. In the present invention,
The means for obtaining particles is not particularly limited.

The particle size (representing the average particle size, hereinafter simply referred to as particle size) of the aromatic polyamide particles used in the present invention varies somewhat depending on the material of the other side when used as a sliding material, but is usually 3 μm to 3 μm. A thickness in the range of 300 μm is preferably used. In order to obtain especially high sliding properties, the particle size should be 5~
Preferably, particles in the 200 μm range are used.

High sliding properties can be obtained regardless of the shape of the particles, such as spherical, scale-shaped, rod-shaped, etc., but in order to obtain particularly high sliding properties, it is desirable that the particles be spherical. It also has excellent moldability during molding.

The lubricating resin composition of the present invention comprises the above-mentioned thermoplastic resin 10
1 to 0 parts by weight of the above-mentioned aromatic polyamide particles
It is important that the amount is 100 parts by weight. If the amount of aromatic polyamide particles is less than 1 part by weight, sufficient sliding properties cannot be obtained, and if the amount is more than 100 parts by weight, although high heat resistance can be obtained, the sliding property is rather deteriorated, which is not preferable. .

If the blending ratio of the aromatic polyamide particles is within the above range, the coefficient of friction will be small and excellent sliding properties can be exhibited even under high loads and high speeds, but if the blending ratio of the aromatic polyamide particles is 5 to 5. Particularly excellent sliding properties are exhibited at 50 parts by weight.

To prepare the lubricating resin composition of the present invention, a thermoplastic resin and aromatic polyamide particles may be mixed in the above-mentioned mixing ratio using a conventionally well-known method. powder and aromatic polyamide particles,
After mixing with a mixer such as a Henschel mixer ball mill or Kumbra mixer, it is fed to an injection molding machine or extruder with good melt mixing properties, or it is mixed in advance with a heated roller,
A method of melting and mixing the thermoplastic resin using a Banbury mixer or the like can also be used.

The method for molding the composition of the present invention into a sliding material or the like is not particularly limited, but it can easily be formed by injection molding, compression molding, or extrusion molding.

In addition to the thermoplastic resin and aromatic polyamide particles, the lubricating resin composition of the present invention may contain additives that can be widely incorporated into synthetic resins, as long as they do not reduce the properties of the lubricating resin composition. You can also do it. Examples of such additives include, but are not limited to, mold release agents, flame retardants, weather resistance improvers, etc.
It is of course possible to use conventionally known and publicly used solid or liquid lubricants, such as tetrafluoroethylene resin, graphite, graphite fluoride, talc, boron nitride, fluorine oil, silicone resin or oil, etc. Industrial lubricants and the like can also be selected and used as appropriate depending on the purpose of use. In either case, it is of course possible to modify the intermediate or final product to improve its properties by chemical or physical treatment, as long as the lubricity of the lubricating resin composition of the present invention is not impaired.

(Function) The lubricating resin composition of the present invention has aromatic polyamide particles with excellent heat resistance and mechanical properties finely dispersed to form a sliding contact surface, resulting in a small coefficient of friction and resistance to friction in the high-speed range. At the same time, as the thermoplastic resin of the base material is reinforced, wear is small (stable sliding characteristics can be obtained for a long time).

(Examples) Hereinafter, the present invention will be explained in more detail and concretely using Examples.

The thermoplastic resins used in the examples are as shown below, and are indicated by abbreviations in brackets in the examples.

(11 Polyacetal (POM) (Manufactured by Asahi Kasei Corporation: Tenasoku 5010) (2) Nylon 66 (Ny66) (Manufactured by Asahi Kasei Corporation; Leona 1300S) (3) Polyethersulfone (PES) (Manufactured by Sumitomo Chemical Corporation; Pictrex 300 P) (4) Polyetherimide (PEI) (manufactured by GE; Ultem 1000) (5) Aromatic polyester (ArES) (manufactured by Sumitomo Chemical Co., Ltd.; Econol E2000) Evaluation friction coefficient of abrasion resistance; Precious wood formula 15! Surface pressure 10 by abrasion tester
Kg/cm”, linear velocity 60cm/sec, mating material 345C
Measured without lubrication.

Wear coefficient; surface pressure 2Kg/by precious wood type friction and wear tester
cm", a linear velocity of 60 cm/sec, and a mating material of 345G without lubrication.

Melting limit PV value; When the material is under a constant load (P), When the circumferential speed (V) exceeds a certain value, Limit of load that melts or seizes It is the product of the limit value P and ■.

Reference Example 8.5 kg of lithium chloride and 10.8 kg of phenylenediamine were added and dissolved in 250 kg of N-methyl-2-pyrrolidone in a polymerization vessel equipped with a stirrer, and then 20.3 kg of powdered terephthalic acid chloride was added once. and polymerization was carried out. About 3 minutes after the addition, stirring became difficult, so stirring was stopped and the mixture was allowed to stand for 30 minutes, to obtain a polymerized and solidified dope that solidified into a cheese shape.

Next, this polymerized and solidified dope was placed in a Henschel mixer together with water and stirred for 30 minutes to perform pulverization. This Henschel mixer is equipped with a vertical blade located at a distance of 5 mm from the vessel wall. After the grinding operation was completed, the contents were taken out, the polymer particles were washed with water, and then dried.

The obtained dry particles were put into a Huiley type pulverizer and pulverized to obtain particles of poly-varophenylene terephthalamide having average particle diameters of 54 μm and 125 μm, respectively.

Logarithmic viscosity η1nh (=lnηr/C) of the obtained particles
(Measured in 30'C, 0.2g/100cc, 98% sulfuric acid) was 4.78.

Examples 1 to 3 The polyparaphenylene terephthalamide particles obtained in the reference examples and POM powder were mixed in the proportions shown in Table 1, then melt-kneaded and extruded using a twin-screw presser to form pellet-like compositions. Obtained. Next, using this pellet, a test piece was prepared by injection molding, and the friction and abrasion properties were evaluated.

For comparison, samples without particles were also evaluated in the same manner, and the results are also listed in Table 1.

As is clear from Table 1, it was observed that the molded products obtained from the resin compositions of the present invention had excellent sliding properties. Furthermore, while the molded product shown in the comparative example that did not contain aromatic polyamide particles suffered from seizure under the test conditions, the molded product made from the resin composition of the present invention could not be used under even harsher conditions. It has been proven that this method is also possible and has excellent heat resistance.

Examples 4 to 10 The compositions shown in Table 2 were obtained in the same manner as in Examples 1 to 3, and the results of the same evaluations are shown in Table 2. All of them were found to have extremely high sliding properties.

(The following is a blank space) (Effects of the invention) As is clear from the above explanation and examples, by blending a specific amount of aromatic polyamide particles into a thermoplastic resin, sliding properties in high load and high speed regions can be improved. As a result, a lightweight and high-performance sliding member can be obtained. Furthermore, the composition of the present invention has excellent heat resistance and mechanical properties, and has excellent and well-balanced properties.

Claims (1)

[Claims] (1) A lubricating resin composition containing 1 to 100 parts by weight of aromatic polyamide particles to 100 parts by weight of a thermoplastic resin.