JPH0359068A - Sliding resin composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a resin composition having excellent sliding properties. In particular, the present invention relates to a sliding resin composition that can be used under severe conditions, such as when the mating material is a metal material and the sliding part is subjected to high-speed, high-load sliding (of course, the temperature becomes high due to frictional heat).

(Conventional technology) In recent years, synthetic resin products have come into widespread use as machine parts to make machines lighter and reduce product costs.
Synthetic resin products are also often used for parts that require sliding properties.

Conventionally, resin compositions with good sliding properties are made by adding additives such as solid lubricants and lubricating oils to resins such as polyamide, polyacetal, polyphenylene sulfide, and polytetrafluoroethylene to improve sliding properties. Things are being used
&Ta.

These can be used without any particular problems under relatively low loads and low speeds, but as the loads and high speeds increase, they tend to wear out and become unusable due to frictional heat and seizing or melting. . For this reason, it has been proposed to add glass fiber, carbon fiber, various types of whiskers, etc. to improve wear resistance and heat resistance, but these do not wear out the metal of the filter used in sliding parts. There is a problem with this.

In other words, the sliding characteristics required for high-load, high-speed sliding parts are #4 wear resistance, heat resistance, and other physical properties rather than friction coefficients, unlike conventional ones. Materials must be selected from a completely different perspective than for moving parts.

On the other hand, thermotropic liquid crystal polymers with high melting points have high heat resistance among many plastics, and therefore are less likely to seize or melt due to wa heat.

However, the mating material of the sliding part is usually made of metal such as aluminum alloy or steel, but thermotropic liquid crystal polymer itself has inferior wear resistance to these metals, so conventionally There were no examples of it being used as a sliding material.

(Problems to be Solved by the Invention) The purpose of the present invention is to solve the above-mentioned problems of the prior art. An object of the present invention is to provide a slidable resin composition.

(Means for Solving the Problems) The sliding resin composition of the present invention comprises at least 95 to 30 parts by weight of a thermotropic liquid crystal polymer, which is a (co)polymer containing at least the following monomer units: It consists of 5 to 70 parts by weight of spherical glassy carbon having an average particle size of 10 to 5002 chrome meters obtained by carbonizing a curable resin at a temperature range of 420 to 800°C.

- maximum The details are described below.

First, the thermotropic liquid crystal polymer, which is a (co)polymer containing at most the above-mentioned monomer units in the present invention, is a thermoplastic meltable polymer that exhibits optical anisotropy when melted. Such polymers exhibiting optical anisotropy when melted have a property in which polymer molecular chains are regularly arranged in parallel in the melted state. The nature of the optically anisotropic melt phase can be confirmed by conventional polarization testing using crossed polarizers.

Thermotropic liquid crystal polymers are generally made from monomers that are elongated, flat, and have a plurality of chain extension bonds in either rigid, coaxial or parallel relationships along the long chains of the molecules.

The constituent components of the polymer that form an optically anisotropic melt phase as described above include (A) at least one of aromatic dicarboxylic acids and alicyclic dicarboxylic acid compounds; (B) aromatic hydroxycarboxylic acid compounds; (C) at least one of aromatic diols, alicyclic diols, and aliphatic diol compounds; (1) at least one of aromatic dithiols, aromatic thiophenols, and aromatic thiol carboxylic acid compounds; seed,(
E) At least one of aromatic hydroxyamine and aromatic diamine compounds. These may be composed of one individual, but most are (A) and (C), (A) and (D), and (A).
(B) and (C), (A) (B) and (E), or (
It is constructed by combining A), (B), (C) and (E), etc.

Examples of the aromatic dicarboxylic acid compound (AI) include terephthalic acid, 4,4'-diphenyldicarboxylic acid, 4.
4'-triphenyldicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 2.
7-naphthalene dicarboxylic acid, Schiffpentyl ether 4
, 4'-dicarboxylic acid, diphenoxyethane-4゜4'
-dicarboxylic acid, diphenoxybutane-4,4'-dicarboxylic acid, diphenylethane-4,4'-dicarboxylic acid, isophthalic acid, diphenylether-3,3'-dicarboxylic acid, diphenoxyethane-3,3'-dicarboxylic acid acid, diphenylethane-3,3'-dicarboxylic acid, 1,
Aromatic dicarboxylic acids such as 6-naphthalene dicarboxylic acid or chloroterephthalic acid, dichloroterephthalic acid,
Examples include alkyl, alkoxy or halogen substituted products of the above aromatic dicarboxylic acids, such as bromo terephthalic acid, methyl terephthalic acid, dimethyl terephthalic acid, ethyl terephthalic acid, methoxyterephthalic acid, and ethoxyterephthalic acid.

(Person 2) Alicyclic dicarboxylic acids include trans-1,
Alicyclic dicarboxylic acids such as 4-cyclohexanedicarboxylic acid, cis-1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, or trans-1,
Examples include alkyl, alkoxy or halogen substituted products of the above alicyclic dicarboxylic acids, such as 4-(2-methyl)cyclohexanedicarboxylic acid and trans-1,4-(2-chloro)cyclohexanedicarboxylic acid.

(As a B1M aromatic hydroxycarboxylic acid compound,
4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6
-Hydroxy-2-naphthoic acid, 6-hydroxy-1-
Aromatic hydroxycarboxylic acids such as naphthoic acid or 3-
Methyl-4-hydroxybenzoic acid, 3,5-dimethyl-
4-hydroxybenzoic acid, 2,6-dimethyl-4-hydroxybenzoic acid, 3-methoxy-4-hydroxybenzoic acid, 3,5-dimethoxy-4-hydroxybenzoic acid, 6
-Hydroxy-5-methyl-2-naphthoic acid, 6-hydroxy-5-methoxy-2-naphthoic acid, 2-chloro-
4-Hydroxybenzoic acid 11.3-Chloro-4-hydroxybenzoic acid, 2,3-dichloro-4-hydroxybenzoic acid, 3,5-dichloro-4-hydroxybenzoic acid, 2゜5-dichloro-4-hydroxybenzoic acid ! 11.3-bromo-4-hydroxybenzoic acid, 6-hydroxy-5-chloro0-2-naphthoic acid, 6-hydroxy-7-chloro-2-naphthoic acid, 6-hydroxy-5゜7-dichloro-
Examples include alkyl, alkoxy or halogen substituted aromatic hydroxycarboxylic acids such as 2-naphthoic acid.

(CI) Aromatic diols include 4.4'-dihydroxydiphenyl, 3.3'-dihydroxydiphenyl,
4.4'-dihydroxytriphenyl, hydroquinone, resorcinol, 2,6-naphthalene diol, 4.4
'-dihydroxydiphenyl ether, bis(4-hydroxyphenylcy)ethane, 3.3'-dihydroxydiphenyl ether, 1,6-naphthalenediol, 2,
2-bis(4-hydroxyphenyl)propane, bis(
Aromatic diols such as 4-hydroxyphenyl)methane or chlorohydroquinone, methylhydroquinone, t
-Butylhydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4
Examples include alkyl, alkoxy or halogen substituted aromatic diols such as -chlororesorcin and 4-methylresorcin.

(C2) As the alicyclic diol, trans-1,4-
Cyclohexanediol, cis-1,4-cyclohexanediol, trans-1,4-cyclohexane dimetatool, cis-1,4-cyclohexane dimetatool,
trans-1,3-cyclohexanediol, cis-1
, 2-cyclohexanediol, trans-3,3-cyclohexane dimetatool or alicyclic diols such as trans-1,4-(2-methyl)cyclohexanediol, trans-1,←(2-chloro)cyclohexanediol Mention may be made of alkyl-, alkoxy- or halogen-substituted NR-group diols such as.

(cs)IN1 aliphatic diols include linear or C-branched aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, and neopentyl glycol.

(Dl) As the aromatic dithiol, benzene-1,4
-dithiol, benzene-1,3-dithiol, 2,6
-naphthalene-dithiol, 2,7-naphthalene-dithiol, and the like.

(D2) Aromatic mercaptocarboxylic acids include 4-mercaptobenzoic acid, 3-mercaptobenzoic acid, 6-mercapto-2-naphthoic acid, 7-mercapto-2-naphthoic acid, and the like.

(D3) As aromatic mercaptophenol [yo, 4-
Mercaptophenol, 3-mercaptophenol, 6
-mercaptophenol and the like.

(E) Aromatic hydroxyamine and aromatic diamine compounds include 4-aminophenol, N-methyl-4-
Aminophenol, 1,4-phenylenediamine, N-
Methyl-1,4-phenylenediamine, N,N'-dimethyl-1,4-phenylenediamine, 3-aminophenol, 3-methyl-4-aminophenol, 2-chloro-4-aminophenol, 4-aminophenol -1-naphthol, 4-amino-4'-hydroxydiphenyl, 4-amino-4'-hydroxydiphenyl ether, 4-amino-4'-hydroxydiphenylmethane, 4-amino-
4'-hydroxydiphenyl sulfide, 4.4'-diaminophenyl sulfide (thiodianiline), 4.4
'-Diamino phenyl sulfone, 2,5-diaminotoluene, 4,4'-ethylene dianiline, 4,4'-diaminodiphenoxyethane, 4,4'-diaminodiphenylmethane (methylene dianiline L 4,4'-diamino Examples include diphenyl ether (oxydianiline).

The thermotropic liquid crystal polymer ζ used in the present invention can be produced by various ester forming methods such as melt acidolysis and slurry polymerization.

The thermotropic liquid crystal polymer used in the present invention includes a thermoplastic resin in which a part of one polymer chain is composed of a polymer segment that forms an anisotropic melt phase, and the remaining part is a thermoplastic resin that does not form an anisotropic melt phase. Also included are polymers composed of segments. Also included are composites of multiple thermotropic liquid crystal polymers.

Among these thermotropic liquid crystal polymers, preferred are (co)polymers containing at least a monomer unit represented by the general formula, specifically (I), etc., especially those having high heat resistance, low shrinkage rate, etc. It has excellent properties and has good workability.

In addition, the spherical glassy carbon referred to in the present invention has a basic structure of a turbostratic structure with extremely small crystal size, and a non-oriented microstructure, and is a material that is made of thermosetting materials such as phenolic resins and furan resins. It is obtained by carbonizing the resin very slowly at a specific temperature.

This glassy carbon is clearly distinguishable from conventional carbon materials such as graphite and carbon fiber in terms of physical properties and the like.

In the present invention, spherical glassy carbon having an average particle size in the range of 10 to 500 micrometers is used, which is carbonized at a temperature in the range of 420 to 800°C.

If carbonized at less than 420°C, uncarbonized resin tends to remain, and this uncarbonized thermosetting resin will decompose during heating to melt and mix the high melting point thermotropic liquid crystal polymer. , which is not preferable because it has an adverse effect on the composition. In order to completely eliminate the uncarbonized resin at a temperature below 420°C, it is necessary to perform long firing, but since the firing is already long, it is not practical to fire for any longer time.

Further, carbonized at a temperature exceeding 800°C: This is not preferable because it damages the mating material at the sliding part. Furthermore, such glassy carbon fired at a high temperature becomes hard and tends to become brittle. Therefore, when this is blended, the amount of wear tends to increase.

Furthermore, if the average particle size is less than 10 micrometers, wear resistance will be insufficient. On the other hand, if it exceeds 500 micrometers, the physical properties of the high melting point thermotropic liquid crystal polymer will seriously deteriorate, making it undesirable.

The shape is preferably spherical, and more preferably close to a true sphere. A non-spherical shape such as an amorphous shape is not preferable because it may wear out the metal or resin of the mating material used in the sliding part, for example.

Further, the amount of spherical glassy carbon added is 5 parts by weight based on 95 to 30 parts by weight of thermotropic liquid crystal polymer having a true melting point.
~70 parts by weight. Within this range, moldability, abrasion resistance, etc. are sufficient, and the effects of the present invention can be exhibited. That is, if the amount of spherical glassy carbon added is less than 5 parts by weight, the abrasion resistance is insufficient, and if it exceeds 70 parts by weight, moldability deteriorates and a good molded product cannot be obtained. Moreover, the strength of the molded product also decreases.

Furthermore, lubricating oil is often used as a lubricant for sliding parts, and although these are inert at room temperature, they can unexpectedly become corrosive to contact members at high temperatures due to frictional heat. . In addition, compressors are also exposed to chemicals such as chlorofluorocarbon gas, and resistance to these chemicals is also an issue.

However, the resin composition made of the thermotropic liquid crystal polymer and spherical glassy carbon in the present invention has sufficient chemical resistance at high temperatures, so even in a high temperature atmosphere when lubricating oil is used in sliding parts, it can be lubricated. It is not affected by oil or other chemicals.

Various additives can also be blended into the composition of the present invention.

Such additives include inorganic fillers, organic fillers,
Examples include stabilizers, ultraviolet absorbers, pigments, dyes, and modifiers. Among these, inorganic fillers are particularly important and are often used to improve processability, physical properties, etc.

Inorganic fillers include molybdenum disulfide, bronze, talc, mica, clay, sericite, calcium carbonate,
Calcium silicate, calcium phosphate, calcium birophosphate, silica, alumina, aluminum hydroxide, calcium hydroxide, graphite, graphite fluoride, potassium titanate, calcium phosphate, calcium birophosphate, etc.
Furthermore, glassy carbon, carbon fibers, various whiskers, etc. can also be added to the extent that they do not impair the effects of the present invention.

Thermotropic liquid crystal polymer and spherical glassy carbon,
Alternatively, the method of mixing the above-mentioned additives further added thereto is not particularly limited, and various means can be applied.

For example, they may be supplied separately to an extruder and melt-mixed, or they may be premixed in a mixer such as a Henschel mixer or a tumbler, and then supplied to the extruder.

Furthermore, the composition 1 of the present invention obtained in this way,
Generally, it is molded by injection molding, but it can also be molded into a sliding member of an appropriate shape by other methods such as extrusion molding and compression molding.

The composition of the present invention has excellent sliding properties and abrasion resistance, so it can be used in shafts and bearings of electrical appliances, office equipment, and power equipment, various gears, cams, bearings, guide rolls for video tapes and cassette tapes, and mechanical parts. Seal end materials, valve seats, V-rings, rod seals, piston rings, rider rings, etc., compressor rotation shafts,
It can be used for sliding members in rotating sleeves, pistons, impellers, vanes, rotors, etc.

(Effects of the Invention) The composition of the present invention has the following characteristics and is therefore most suitable as a sliding material for use in high-load, high-speed sliding parts where the mating material is a metal material.

(1) Since it uses a polymer with a particularly high melting point among conventional plastics, it is unlikely to melt or seize due to frictional heat.

(2) Since a specific glassy carbon is used, a product with less wear is obtained, and there is less damage to metal materials such as iron materials such as steel, which are the mating members of the sliding material.

(3) Since it is a thermotropic liquid crystal polymer, it has good fluidity when melted despite its high melting point, making it easy to mold into sliding members.

(4) Under high temperatures due to frictional heat, lubricating oil, fluorocarbon gas, etc., which are normally inert, may become corrosive to the members that come into contact with them. However, since the composition of the present invention is stable against these, it is suitable as a sliding material.

(Example) The present invention will be explained in more detail by *Examples, but these Examples do not limit the scope of the present invention.
This figure shows a preferred embodiment of the present invention.

First, the raw materials used in the Examples and Comparative Examples are collectively shown.

■ Synthetic resins terephthalic acid, 4-hydroxybenzoic acid, and 4,4
-dihydroxydiphenyl (molar ratio 1:2:1
) powder of thermotropic liquid crystal polymer (trade name: Xydar, manufactured by Amoco Performance Products, Inc., USA), which is a terpolymer of Melting point: 420 DEG C. ■ Spherical carbon, etc. A-E are obtained by firing spherical phenol resin as a raw material under a nitrogen atmosphere at the carbonization temperature shown below.

A: Carbonization temperature 480℃, average particle size 50 micrometers B: 0 400℃, 0 50 micrometers C: 1 1000℃, 〃
50 micron meter D: 0 480℃,
l 100i: Rionme) le E: /l
480℃, // 5 micrometers F: The same spherical phenolic resin as the raw material used in A was sintered at 500℃ and then crushed (non-spherical) Average particle size 50 < micrometers Examples 1 to 4 The above raw materials were blended in the proportions shown in Table 1, mixed in a Henschel mixer, and then melted and kneaded in a twin-screw extruder (manufactured by Ikegai Tekko Co., Ltd.: PCI-30 type) at a temperature of 420°C and a screw rotation speed of 200 rpm. ), granulated into pellets. Next, this pellet was molded into an injection molding machine (Sumitomo Heavy Industries, Ltd.!)
I: Nestal SG 25 type), cylinder temperature 4
00℃, injection pressure 100100O/cIl, mold temperature 1
A tensile test piece (TYPE 1) specified in ASTM D-838 was molded at 50°C.

The tensile strength was measured using the obtained test piece.

In addition, a sample was cut out from this test piece and tested with a Chimken friction and wear tester at a pressure of 10 kgf/a/, 1 m/
s@e, 54SC steel plated with hard chrome was used as the mating material, and the wear coefficient was determined after 24 hours had elapsed.

Furthermore, the same test piece was placed in a 500cc pressure container with lubricating oil (
Product name: Suniso 5GS oil) 150■j and sealed, and while cooling, add 50% of Freon gas R-22.
0g was injected. This pressure-resistant container was immersed in silicone oil at 150° C. for 48 hours, and after cooling for 4 hours, the gas was removed, the sample was taken out, and dimensional changes in the length direction and weight changes were measured. Furthermore, this sample was placed in an oven at 200° C. for 4 hours, and the presence or absence of blisters on the surface was observed.

Furthermore, using the injection molding machine described above, under the same conditions, a diameter of 5 cm was made.
m.

A disk with a thickness of 3 m was formed, and a pressure of I was measured using a Suzuki friction tester.
The llIwA coefficient was measured under the conditions of C1kg f/ed and speed of 20m/m111.

The above results are summarized in Table 1.

Comparative Examples 1 to 6 The above raw materials were blended in the proportions shown in Table 2, and evaluated by pelletizing, forming tensile test pieces, and disks in the same manner as in the examples. The results are shown in Table 2.

Comparing Examples 1 to 4 and Comparative Examples 1 to 6, Example 1
-4 has a good wear coefficient, heat resistance, and
It has excellent chemical resistance.

On the other hand, in Comparative Example 1, the content of spherical carbon in the resin composition is small, resulting in a high wear coefficient, and in Comparative Example 2, the content of spherical carbon exceeds 70 parts by weight, resulting in a decrease in mechanical strength.

Furthermore, in Comparative Examples 3 to 5, when the carbonization temperature and average particle size of the spherical carbon are out of the range of the present invention, the wear coefficient,
This indicates that it is not possible to satisfy all chemical resistance requirements.

Furthermore, Comparative Example 6 shows that it is not desirable when the carbon shape is non-spherical.

Claims (2)

[Claims] (1) 95 to 30 parts by weight of a thermotropic liquid crystal polymer, which is a (co)polymer containing at least monomer units represented by the following general formula, and 420 to 30 parts by weight of a thermosetting resin.
The average particle size obtained by carbonization in a temperature range of 800°C is 1
A slidable resin composition comprising 5 to 70 parts by weight of spherical glassy carbon having a size in the range of 0 to 500 micrometers. General formulas ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (2) The sliding resin composition according to claim 1, wherein the thermotropic liquid crystal polymer is a wholly aromatic polyester.