JP3044491B2 - bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing made of a thermotropic liquid crystal polymer and spherical glassy carbon.

[0002]

2. Description of the Related Art In recent years, synthetic resin products have been widely used as mechanical parts in order to reduce the weight and cost of machines, and synthetic resin products have been widely used for bearings requiring slidability. I have. Conventionally, as a resin composition having good slidability, polyamide, polyacetal, polyphenylene sulfide, resin such as polytetrafluoroethylene,
Solid lubricants, lubricating oils and the like to which additives for improving sliding properties have been used have been used. These can be used without any particular problem in a relatively low load and low speed range, but become more susceptible to wear as the load increases and the speed increases, and they become unusable due to seizure or melting due to frictional heat. For this purpose, glass fiber, carbon fiber, various whiskers, etc. are added for the purpose of improving abrasion resistance and heat resistance.These fillers are used to wear metal and resin of mating materials used for sliding parts. There is a problem that it is.

[0003] In other words, the sliding characteristics required for bearings used under high loads and high speeds are different from those of conventional bearings in terms of wear resistance, heat resistance, and other physical properties rather than the coefficient of friction. The material must be selected from a completely different point of view.

[0004] On the other hand, thermotropic liquid crystal polymers having a high melting point have high heat resistance among many plastics, so that they hardly burn or melt due to frictional heat. However, the thermotropic liquid crystal polymer itself does not have abrasion resistance and has a disadvantage that the critical PV value is low, so that it is not suitable as a raw material for producing a bearing.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. In particular, the present invention is excellent in abrasion resistance, has a high limit PV value, and damages a mating material. Another object of the present invention is to provide a bearing having excellent heat resistance.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a thermotropic liquid crystal polymer (a) 90 to 50% by weight, and a spherical glassy carbon (b) 10 characterized by having a particle-like cross section having a glassy luster. It is a bearing characterized in that it comprises about 50% by weight.

The details will be described below.

The thermotropic liquid crystal polymer referred to in the present invention is a thermoplastic meltable polymer which exhibits optical anisotropy when melted. Such a polymer exhibiting optical anisotropy at the time of melting has a property that polymer molecular chains take a regular parallel arrangement in a molten state. The properties of the optically anisotropic molten phase can be confirmed by a normal polarization inspection method using an orthogonal polarizer.

For example, liquid crystalline polyester, liquid crystalline polycarbonate, liquid crystalline polyesterimide and the like can be mentioned. Specifically, (whole) aromatic polyester, polyester amide, polyamide imide, polyester carbonate, polyazomethine and the like are used.

[0010] Thermotropic liquid crystal polymers are generally made from monomers that are elongated, flat, rigid and have a plurality of chain-extended bonds in either a coaxial or parallel relationship along the long chain of the molecule. Is done.

The thermotropic liquid crystal polymer used in the present invention can be produced from the above compound by various ester forming methods such as a melt acidilysis method and a slurry polymerization method. In the thermotropic liquid crystal polymer used in the present invention, a thermoplastic resin in which a part of one polymer chain is composed of a polymer segment forming an anisotropic molten phase and the remaining part does not form an anisotropic molten phase And a polymer composed of the following segments. Further, a composite of a plurality of thermotropic liquid crystal polymers is also included.

As the polymer forming the optically anisotropic molten phase as described above, for example, a wholly aromatic polyester,
Examples thereof include wholly aromatic polyester amides and the constituent components thereof include at least one of (A) aromatic dicarboxylic acids.
Species, (B) at least one aromatic hydroxycarboxylic acid compound, (C) at least one aromatic diol compound, (D) (D1) aromatic dithiol, (D2) aromatic thiophenol, (D3 And (E) aromatic hydroxyamine, aromatic diamine-based compounds, and the like. Although these may be constituted singly, in many cases (A) and (C), (A) and (D), (A) (B) and (C), (A) (B) and ( E) or (A) (B)
(C) and (E) are combined.

The aromatic dicarboxylic acid compound (A) includes terephthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-triphenyldicarboxylic acid, 2,6-
Naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenylether-4,4'-dicarboxylic acid, diphenoxyethane-4,4'-dicarboxylic acid, diphenoxybutane-4,
4'-dicarboxylic acid, diphenylethane-4,4'-dicarboxylic acid, isophthalic acid, diphenyl ether-3,
3'-dicarboxylic acid, diphenoxyethane-3,3'-
Aromatic dicarboxylic acids such as dicarboxylic acid, diphenylethane-3,3′-dicarboxylic acid, 1,6-naphthalenedicarboxylic acid or chloroterephthalic acid, dichloroterephthalic acid, bromoterephthalic acid, methylterephthalic acid,
Alkyl, alkoxy or halogen-substituted aromatic dicarboxylic acids such as dimethyl terephthalic acid, ethyl terephthalic acid, methoxy terephthalic acid, ethoxy terephthalic acid and the like.

(B) The aromatic hydroxycarboxylic acid compounds include aromatic hydroxycarboxylic acids such as 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid and 6-hydroxy-1-naphthoic acid. Carboxylic 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, 3-chloro-4
-Hydroxybenzoic acid, 2,3-dichloro-4-hydroxybenzoic acid, 3,5-dichloro-4-hydroxybenzoic acid, 2,5-dichloro-4-hydroxybenzoic acid, 3
-Bromo-4-hydroxybenzoic acid, 6-hydroxy-5
Alkyl, alkoxy or halogen-substituted aromatic hydroxycarboxylic acids such as -chloro-2-naphthoic acid, 6-hydroxy-7-chloro-2-naphthoic acid and 6-hydroxy-5,7-dichloro-2-naphthoic acid Is mentioned.

(C) As the aromatic diol, 4,4 ′
-Dihydroxydiphenyl, 3,3'-dihydroxydiphenyl, 4,4'-dihydroxytriphenyl, hydroquinone, resorcinol, 2,6-naphthalenediol, 4,4'-dihydroxydiphenylether, bis (4-hydroxyphenoxy) ethane, Aromatic diols such as 3,3′-dihydroxydiphenyl ether, 1,6-naphthalenediol, 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) methane or chlorohydroquinone, methylhydroquinone, t-butyl Alkyl, alkoxy or halogen-substituted aromatic diols such as hydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4-chlororesorcin and 4-methylresorcin are exemplified.

(D1) Examples of the aromatic dithiol include benzene-1,4-dithiol, benzene-1,3-dithiol, 2,5-naphthalene-dithiol, and 2,7-naphthalene-dithiol.

(D2) As the aromatic thiophenol,
4-mercaptophenol, 3-mercaptophenol, 6-mercaptophenol and the like.

(D3) Examples of the aromatic thiolcarboxylic acid include 4-mercaptobenzoic acid, 3-mercaptobenzoic acid, 6-mercapto-2-naphthoic acid, and 7-mercapto-2-naphthoic acid.

(E) As aromatic hydroxyamine and aromatic diamine compounds, 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-amino-
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'-diaminodiphenyl sulfone, 2,5
-Diaminotoluene, 4,4'-ethylenedianiline,
4,4′-diaminodiphenoxyethane, 4,4′-diaminodiphenylmethane (methylenedianiline),
4'-diaminodiphenyl ether (oxydianiline) and the like.

Particularly preferred in the present invention is at least a compound represented by the general formula:

Embedded image

(Co) polymer containing a monomer unit represented by Specific examples of these are as follows.

Embedded image

That is, a particularly preferred wholly aromatic polyester of the present invention is a polyester having a repeating unit derived from each of three compounds of P-hydroxybenzoic acid, phthalic acid and biphenol, or p-hydroxybenzoic acid and hydroxy. It is a polyester having a repeating unit derived from each of two compounds of naphthoic acid.

The glassy carbon referred to in the present invention has a basic structure of a turbostratic structure having an extremely small crystal size, and has a non-oriented structure as a fine structure, such as a phenol resin, a furan resin, and an epoxy resin. , Unsaturated polyester resin, urea resin, melamine resin, alkyd resin,
It is manufactured by carbonizing a thermosetting resin such as a xylene resin at a high temperature.

The vitreous carbon is characterized by having a glassy gloss on its fractured surface, but also has a diffraction angle (2) of a spectrum in a normal X-ray diffraction method.
θ) It is also confirmed by having a broad peak around 23 to 25 degrees. The X-ray diffraction method is based on the usual method,
It is measured by the u-Kα ray (double line). A conventional carbon material such as graphite does not have such a broad peak, but shows a sharp _doo2 peak due to crystallinity at another diffraction angle (2θ = 26.4 ° C.). It is preferable that the glassy carbon of the present invention has substantially no peak characteristic of graphite. In addition, a mere organic carbonized material does not have a glassy gloss in its fractured surface, and of course, its X
In the X-ray diffraction spectrum, the glassy carbon does not have a specific diffraction angle peak characteristic of graphite, of course.

By the way, this glassy carbon sometimes contains an incompletely carbonized product or an uncarbonized product due to being produced by carbonizing a thermosetting resin such as a phenol resin as described above.

That is, even if the fractured surface has a vitreous gloss, or has a broad peak at a specific diffraction angle in the X-ray diffraction spectrum, the vitreous carbon is not recognized. It may contain fully or uncarbonized material.

When glassy carbon is blended with a thermoplastic resin, the presence of the incompletely carbonized or uncarbonized material as described above causes a problem in the molding process of the thermoplastic resin or the molded product itself. Often not. That is,
This is because these incompletely carbonized products or uncarbonized products are considered to be the thermosetting resin itself, which is the raw material resin of glassy carbon, or its thermally decomposed low polymer.

On the other hand, the forming temperature of the thermotropic liquid crystal polymer is extremely high because one of its features is a high melting point which can be said to be abnormal among polymers. In such a case, the above-mentioned incomplete carbonized material or uncarbonized material contained in the glassy carbon is decomposed and easily causes gas generation. At high temperatures, especially in molding under high pressure, such as compression or injection molding, the generation of gas, even in trace amounts, can be a fatal defect in the working process or in the molding. For example, in an extreme case, the molding itself is difficult due to gas generation, or blisters and flow marks are observed on the surface of the molded article, and the commercial value of the molded article is lost.

Here, even if the fracture surface is vitreous carbon characterized by having a vitreous luster, the type of raw material resin, its preparation method, raw material particle shape, carbonization temperature,
Products with different properties are produced depending on the carbonization time, the type of atmospheric gas, the pressure during carbonization, and other conditions. That is, the content and properties of the incompletely carbonized or uncarbonized material in the produced glassy carbon are different.

In the bearing of the present invention, spherical glassy carbon having a weight loss of 5% by weight or less under the conditions peculiar to the liquid crystal polymer is used in view of the fact that it is mixed with the thermotropic liquid crystal polymer having a high melting point as described above. It is preferred to use.

Here, the weight loss means that, for example, a thermobalance is used as a measuring device, and a heating rate of 35 ° C./min.
It is defined as the weight loss when heated to 0 ° C. and held at that temperature for 30 minutes.

Glassy carbon having a weight loss of more than 5% by weight under the above conditions, when combined with a thermotropic liquid crystal polymer having a high melting point, generates gas due to heating during molding and is difficult to mold as described above. Or blisters or flow marks on the molded product, resulting in a decrease in productivity and commercial value.

On the other hand, the shape is preferably spherical, and more preferably a true sphere. A non-spherical shape such as an irregular shape is not preferable when used for a member requiring slidability, such as the bearing of the present invention, because the metal and resin of the mating material are worn away.

The amount of the spherical glassy carbon added is 1
It is 0 to 50% by weight, preferably 25 to 40% by weight. In this range, the abrasion resistance and the like are sufficient, and the effects of the present invention can be exhibited.

The amount of spherical glassy carbon added is 10% by weight.
If the amount is less than 50%, the abrasion resistance is insufficient. Even if the amount exceeds 50% by weight, further improvement of the abrasion resistance cannot be expected. Further, the strength of the obtained molded article is also reduced.

Here, various additives can be added to the thermotropic liquid crystal polymer composition used for the bearing of the present invention.

The additives include inorganic fillers, organic fillers, stabilizers, ultraviolet absorbers, pigments, dyes, modifiers and the like. Of these, inorganic fillers are particularly important, and are often used for improving workability, physical properties, and the like.

Examples of the inorganic filler include graphite, molybdenum disulfide, bronze, talc, mica, clay, sericite, calcium carbonate, calcium silicate, calcium phosphate, calcium pyrophosphate, silica, alumina, aluminum hydroxide, calcium hydroxide, and calcium hydroxide. Graphite graphite, potassium titanate, etc., as well as glass fiber, carbon fiber,
Various whiskers can be added as long as the effects of the present invention are not impaired.

Examples of the organic filler include various thermoplastic and thermosetting resins. In particular, a fluororesin represented by polytetrafluoroethylene is preferably used. The method of mixing the thermotropic liquid crystal polymer and the spherical glassy carbon and the above-mentioned additives to be added thereto,
There is no particular limitation, and various means can be applied.
For example, they may be separately supplied to an extruder and melt-mixed, or may be preliminarily mixed by a mixer such as a Henschel mixer or a tumbler and then supplied to the extruder.

In addition, the glassy carbon used in the present invention can be added during the polymerization of the thermotropic liquid crystal polymer. Even in the case of a thermotropic liquid crystal polymer composition in which glassy carbon is blended at the time of polymerization as described above, naturally, when a processed product is produced therefrom, that is, the composition is formed by molding such as injection molding or compression molding. When molding, the thermotropic liquid crystal polymer is melt-molded and exposed to a high temperature. Therefore, even in such a case, the predetermined effect of the present invention is achieved.

Further, the composition thus obtained is molded into a bearing of the present invention by a method such as injection, compression, extrusion or the like. , May be molded.

In many cases, lubricating oils and the like are used as lubricants for bearings. These are inactive at normal temperature, but may exhibit corrosiveness to contact members other than at high temperatures due to frictional heat. is there. However, the resin composition comprising the thermotropic liquid crystal polymer and the spherical glassy carbon in the present invention has sufficient chemical resistance at high temperatures, so even under a high temperature atmosphere when lubricating oil is used for the sliding portion. It is not affected by lubricating oils or other chemicals.

In addition, bearings are required to have dimensional accuracy of products and dimensional stability against temperature changes due to their properties, but the bearing of the present invention is also excellent in this respect. That is, the thermotropic liquid crystal polymer exerts a shear force at the time of melting, whereby the molecular chains are oriented in the shearing direction and exhibit extremely good fluidity. And, since it shows a crystalline state at the time of melt flow, there is very little change in structure and change in specific volume when it is cooled and solidified in a mold. As a result, molding shrinkage is small and precision molding can be easily performed. Further, since the molecules are highly oriented and form a rigid molecular chain, the coefficient of linear expansion is small. Therefore, the processing accuracy can be maintained over a wide temperature range, and there is no malfunction due to a temperature change.

[0044]

The bearing according to the present invention has the following features, and is particularly suitable for use under high load, high speed and high temperature. (1) Since a polymer having a particularly high melting point is used among conventional plastics, melting, seizure, and the like due to frictional heat are less likely to occur. (2) Since a thermotropic liquid crystal polymer having a small linear expansion coefficient is used as a material, a processing temperature can be maintained over a wide temperature range. (3) At high temperatures due to frictional heat, lubricating oil or the like, which should normally be inert, may show corrosiveness to members in contact therewith. However, the bearings of the present invention are also stable against them.

[0045]

EXAMPLES The present invention will be described in more detail with reference to Examples, but these Examples do not limit the scope of the present invention, but show preferred embodiments of the present invention. First, raw materials used in Examples and Comparative Examples are collectively shown.

Thermotropic liquid crystal polymer A: A powder of a thermotropic liquid crystal polymer which is a terpolymer of terephthalic acid, 4-hydroxybenzoic acid and 4,4′-dihydroxydiphenyl. Melting point 42
0 ° C.

B: Powder of a thermotropic liquid crystal polymer which is a quaternary copolymer of terephthalic acid, isophthalic acid, 4-hydroxybenzoic acid, and 4,4'-dihydroxydiphenyl. Melting point 350 [deg.] C.

[0048] Spherical glassy carbons a to c are spherical glassy carbons obtained by firing and carbonizing a thermosetting resin. a: Univex GCP-50 (H) (trade name, manufactured by Unitika Ltd.) Weight loss 0.5% b: Bellpearl C-800 (trade name, Kanebo Co., Ltd.)
1.2% c: Univex GCP-50 (L) (trade name, manufactured by Unitika Ltd.) Weight loss 5.1%

All of these glassy carbons were confirmed to have a distinctly glassy luster at the particle fracture surface, and the X-ray diffraction spectrum measured by Cu-Kα ray (double line) showed a diffraction pattern. Similarly, a broad peak was similarly observed around 23 to 25 degrees at a bending angle (2θ), and a sharp peak unique to graphite was not substantially observed. Weight loss: Weight loss when the temperature is raised from room temperature to 350 ° C. at a rate of 10 ° C./min and held at this temperature for 30 minutes. (Thermobalance SSC-5020 T manufactured by Seiko Instruments Inc.
The measurement was performed by G / DTA200. )

Graphite ACP (trade name) flaky graphite manufactured by Nippon Graphite Co., Ltd., average particle size: 10 μm Polytetrafluoroethylene Daibron Lubron L5 (trade name), average particle size: 5 μm
m

Example 1 The above-mentioned raw materials were blended in the proportions shown in Table 1, mixed with a Henschel mixer, and then melt-kneaded with a twin-screw extruder (PCM-30, manufactured by Ikegai Iron Works Co., Ltd.). 420 ° C., screw rotation speed 200 rpm), and pelletized.

Next, the pellets were obtained using an injection molding machine (Nestal SG25 type, manufactured by Sumitomo Heavy Industries, Ltd.) at a cylinder temperature of 400 ° C., an injection pressure of 1000 kgf / cm ² , and a mold temperature of 150 ° C., with a diameter of 5 cm and a thickness of 5 mm. A 3 mm disk was formed. The wear coefficient of the obtained test piece was measured with a Suzuki friction and wear tester under the conditions of a pressure of 6 kgf / cm ² and a speed of 120 m / min, using a ring-shaped S45C steel having an outer diameter of 26 mm and an inner diameter of 20 mm as a mating material. did. Using the same testing machine, the speed was kept constant at 20 m / min, and the pressure was set at 50 k / min.
The product of the maximum pressure and the speed (20 m / min) at which the test piece did not melt and maintained a normal frictional state while increasing from gf / cm ² by 10 kgf / cm ² was determined as a maximum PV value.

Further, a bending test piece was molded under the same conditions using the above-mentioned injection molding machine, and AS
The bending strength was measured according to TM D-790. Also,
Ten test pieces were continuously formed, the moldability and the appearance were observed, and the number of blisters and flow marks generated was recorded.

A bearing as shown in FIG. 1 was molded using the same injection molding machine. An S45C steel shaft was inserted, rotated at 1,000 revolutions per minute, and the operation status was observed.

Examples 2 to 4 The above-mentioned various raw materials were blended in the proportions shown in Table 1 and mixed with a Henschel mixer, followed by a twin-screw extruder (Ikegai Iron Works:
(PCM-30 type), and the mixture was melt-kneaded (temperature: 350 ° C., screw rotation speed: 200 rpm) and pelletized.
Next, the pellets were subjected to an injection molding machine (manufactured by Sumitomo Heavy Industries Machinery, Ltd .: Nestal SG25 type) at a cylinder temperature of 340.
° C, injection pressure 1000kgf / cm ² , mold temperature 80 ° C
Under the conditions described above, a disk having a diameter of 5 cm and a thickness of 3 mm was formed.
Wear characteristics were measured in the same manner as in Example 1.

Further, bending test pieces and bearings were molded under the same conditions using the above-mentioned injection molding machine, and the same evaluation was performed.

In Example 3, graphite was used as the inorganic filler.
In Example 4, polytetrafluoroethylene was added as an organic filler.

Example 5 The above raw materials were mixed at the ratios shown in Table 1 and mixed with a Henschel mixer.
(PCM-30 type), and the mixture was melt-kneaded (temperature: 420 ° C., screw rotation speed: 200 rpm) and granulated into pellets.

Next, the pellet was compression-molded at a temperature of 420 ° C. and an injection pressure of 200 kgf / cm ² to prepare a test piece having a thickness of 3 mm and a size of 50 × 50 mm, and the wear characteristics were evaluated in the same manner as in Example 1. . Further, a flat plate having a thickness of 20 mm and a size of 40 × 40 mm was prepared, and the bearing of FIG. 1 was cut out from the flat plate and evaluated in the same manner as in Example 1. further,
A flat plate having a thickness of 3 mm and a size of 100 × 100 mm was prepared, a test piece having a width of 12.7 mm and a length of 100 mm was cut out, and the bending strength was measured by ASTM D-790.

Example 6 The above-mentioned various raw materials were blended at the ratios shown in Table 1 and mixed with a Henschel mixer, followed by a twin-screw extruder (Ikegai Iron Works:
(PCM-30 type), and the mixture was melt-kneaded (temperature: 350 ° C., screw rotation speed: 200 rpm) and granulated into pellets. Next, the pellets were heated at a temperature of 360 ° C. and an injection pressure of 200 kgf.
/ Compression molded at cm ^2, a thickness of 3 mm, size 50 × 50
mm test pieces were prepared, and the wear characteristics were evaluated in the same manner as in Example 1. In the same manner as in Example 5, evaluation as a bearing and measurement of bending strength were performed. The above results are summarized in Table 1.

Comparative Examples 1 and 2 The above-mentioned raw materials were blended in the proportions shown in Table 2, and pelletized granules, disks, bending test pieces and bearings were formed and evaluated in the same manner as in Example 1. The results are shown in Table 2, and Comparative Example 2
In this case, the bearing was not evaluated because blisters occurred.

Comparative Example 3 The above-mentioned various raw materials were blended in the proportions shown in Table 2, and pelletized and formed into a flat plate in the same manner as in Example 5, and evaluated. The results are shown in Table 2, but the moldability was poor and the physical properties could not be evaluated.

Comparative Example 4 The above-mentioned various raw materials were blended in the proportions shown in Table 2, and pelletized and formed into a flat plate in the same manner as in Example 6, and evaluated. The results are shown in Table 2, but the strength was significantly deteriorated, and other physical properties were not evaluated.

Here, in comparison with Examples 1 to 6 and Comparative Examples 1 to 4, Examples 1 to 6 show that the ratio of the thermotropic liquid crystal polymer to the vitreous carbon and the temperature of the glassy carbon at 350 ° C.
Because all of the weight loss in 30 minutes is in the desired range,
The wear characteristics, formability, and performance as a bearing were excellent. On the other hand, in Comparative Example 1, the wear coefficient was large due to the small amount of glassy carbon, and seizure occurred when used as a bearing. Further, in Comparative Examples 2 and 3, when the weight loss of glassy carbon in air at 350 ° C. for 30 minutes was out of the desired range, the moldability and the appearance of the molded product could not be satisfied. In Comparative Example 4,
Since it exceeded 50% by weight, moldability and product strength were poor.

[0065]

[Table 1]

[0066]

[Table 2]

[Brief description of the drawings]

FIG. 1 is a schematic view of a bearing and a shaft.

[Description of Signs] 1 Bearing 2 Shaft

Claims (4)

(57) [Claims] 1. Thermotropic liquid crystal polymer (a) 9
A bearing comprising from 0 to 50% by weight and from 10 to 50% by weight of a spherical glassy carbon (b) characterized by a particle fracture surface having a glassy luster. 2. The bearing according to claim 1, wherein the glassy carbon has a weight loss of 5% by weight or less when held in air at 350 ° C. for 30 minutes. 3. The bearing according to claim 1, wherein the thermotropic liquid crystal polymer is a wholly aromatic polyester. 4. The thermotropic liquid crystalline polymer contains at least a monomer unit represented by the following general formula (co)
The bearing according to any one of claims 1 to 3, which is a polymer. Embedded image