JPH05202225A - Bearing - Google Patents

Abstract

PURPOSE:To provide a bearing having excellent abrasion resistance and a high critical PV value, not damaging a mating material, and also excellent in heat resistance. CONSTITUTION:A bearing wherein the main body comprises 90-50wt.% thermotropic liquid crystal polymer and 10-50wt.% spherical glassy carbon having a fractured surface of a glassy gloss.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a bearing consisting 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 machine parts in order to reduce the weight of machines and reduce product costs, and synthetic resin products are also often used for bearings that are required to have slidability. There is. Conventionally, as a resin composition having good slidability, a resin such as polyamide, polyacetal, polyphenylene sulfide, or polytetrafluoroethylene,
Those to which additives such as solid lubricants and lubricating oils for improving sliding characteristics have been added have been used. These can be used without any particular problems in a relatively low load and low speed region, but are easily worn at higher load and high speed, and cannot be used because they are seized or melted due to frictional heat. Therefore, for the purpose of improving wear resistance and heat resistance, glass fiber, carbon fiber, various whiskers, etc. are added, but these fillers wear metal and resin of the mating material used for the sliding part. There is a problem that it ends up.

That is, unlike the conventional sliding characteristics, the sliding characteristics required for a bearing used under a high load and a high speed are abrasion resistance, heat resistance, and other physical properties rather than a friction coefficient. The material must be selected from a completely different viewpoint from that of the sliding member.

On the other hand, the thermotropic liquid crystal polymer having a high melting point has high heat resistance among many plastics, and therefore it is less likely to be seized or melted by frictional heat. However, the thermotropic liquid crystal polymer itself is not suitable as a raw material for manufacturing a bearing because it has the drawbacks of no abrasion resistance and a low limit PV value.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the above-mentioned conventional techniques. In particular, it has excellent wear resistance, a high limit PV value, and damages the mating material. First, to provide a bearing with excellent heat resistance.

[0006]

The present invention is directed to 90-50% by weight of the thermotropic liquid crystal polymer (a) and a spherical glassy carbon (b) 10 characterized by a particle fracture surface having a glassy luster. It is a bearing characterized in that it is made up of 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 when melted has the property that the polymer molecular chains take a regular parallel arrangement in the melted state. The properties of the optically anisotropic molten phase can be confirmed by a usual polarization inspection method using a crossed polarizer.

Examples thereof include liquid crystalline polyester, liquid crystalline polycarbonate, liquid crystalline polyester imide and the like. Specifically, (all) aromatic polyesters, polyester amides, polyamide imides, polyester carbonates, polyazomethines, and the like.

Thermotropic liquid crystal polymers are generally made of elongated, flat, and rigid monomers along the long chain of the molecule which have a plurality of chain extension bonds, either coaxial or parallel. To be done.

The thermotropic liquid crystal polymer used in the present invention can be produced by various ester forming methods such as the melt acidolysis method and the slurry polymerization method. The thermotropic liquid crystal polymer used in the present invention is a thermoplastic resin in which one polymer chain is composed of a segment of a polymer forming an anisotropic melt phase and the remaining part is not forming an anisotropic melt phase. Also included are polymers composed of Further, it also includes a composite of a plurality of thermotropic liquid crystal polymers.

As the polymer forming the optically anisotropic melt phase as described above, for example, wholly aromatic polyester,
Examples thereof include wholly aromatic polyester amides and the like. As its constituent component, at least one of (A) aromatic dicarboxylic acid is used.
Species, (B) at least one kind of aromatic hydroxycarboxylic acid compound, (C) at least one kind of aromatic diol compound, (D) (D1) aromatic dithiol, (D2) aromatic thiophenol, (D3) ) At least one kind of aromatic thiolcarboxylic acid compound, at least one kind of (E) aromatic hydroxyamine, aromatic diamine compound and the like. Although these may be configured independently, most of them are (A) and (C), (A) and (D), (A) (B) and (C), (A) (B) and ( E) or (A) (B)
(C) and (E) are combined and configured.

The above-mentioned (A) aromatic dicarboxylic acid type compounds include terephthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-triphenyldicarboxylic acid and 2,6-
Naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenyl ether-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,
Examples thereof include alkyl, alkoxy or halogen substitution products of the above aromatic dicarboxylic acids such as dimethyl terephthalic acid, ethyl terephthalic acid, methoxy terephthalic acid and ethoxy terephthalic acid.

(B) Aromatic hydroxycarboxylic acid compounds include aromatic hydroxy 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 substitution products of 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.

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

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

Examples of the aromatic thiophenol (D2) include
4-mercaptophenol, 3-mercaptophenol, 6-mercaptophenol and the like can be mentioned.

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

Examples of (E) aromatic hydroxyamine and aromatic diamine compounds include 4-aminophenol and 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,
4'-diamino diphenyl ether (oxydianiline) etc. are mentioned.

Particularly preferred in the present invention is at least the general formula

[Chemical 2]

It is a (co) polymer containing a monomer unit represented by: Specific examples of these are as follows.

[Chemical 3]

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

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

This glassy carbon is characterized in that its fracture surface has a glassy luster, but in addition to this, the diffraction angle (2) of the spectrum in the usual X-ray diffraction method is used.
It is also confirmed by having a broad peak around θ) of 23 to 25 degrees. The X-ray diffraction method is a conventional method, and C
It is measured by u-Kα ray (double line). Conventional carbon materials such as graphite do not have such a broad peak and show a sharp d _oo2 peak due to crystallinity at other diffraction angles (2θ = 26.4 ° C.). It is preferable that the glassy carbon of the present invention has substantially no peak characteristic of this graphite. Further, a mere organic carbonized material does not have a glassy luster on the fracture surface, and of course, X
In the line diffraction spectrum, it does not have the peak of a specific diffraction angle characteristic of graphite as well as glassy carbon.

By the way, the glassy carbon may contain an incomplete 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 glassy carbon is confirmed to have a glassy luster on the fracture surface or has a wide peak at a specific diffraction angle in the X-ray diffraction spectrum, the glassy carbon is not It may include completely carbonized or uncarbonized materials.

When glassy carbon is blended with a thermoplastic resin, the presence of the incomplete carbonized product or uncarbonized product 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 materials or uncarbonized materials are considered to be the thermosetting resin itself which is the raw material resin for glassy carbon, or the thermally decomposed low polymer thereof.

On the other hand, one of the characteristics of the thermotropic liquid crystal polymer is a high melting point which can be said to be anomalous among the polymers, so that the molding temperature is extremely high. In such a case, the above-mentioned incompletely carbonized material or uncarbonized material contained in the glassy carbon is decomposed and is likely to cause gas generation. At high temperatures, especially in compression or molding under high pressure such as injection molding, the generation of gas, even in a small amount, becomes a fatal defect in a processing step or a molded product. For example, in an extreme case, molding itself is difficult due to gas generation, or blisters and flow marks are generated on the surface of the molded product, resulting in loss of the commercial value of the molded product.

Here, even if the glassy carbon is characterized in that the fracture surface has a glassy luster, the kind of the raw material resin, its adjusting method, the raw material particle shape, the carbonization temperature,
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 material or the uncarbonized material in the produced glassy carbon are different.

In the bearing of the present invention, in consideration of blending with the thermotropic liquid crystal polymer having a high melting point as described above, spherical glassy carbon having a weight loss of 5% by weight or less under the conditions peculiar to the liquid crystal polymer is used. Preference is given to using.

Here, the weight reduction means that, for example, a thermobalance is used as a measuring instrument, and the weight is reduced from room temperature to 10 ° C./min at a heating rate of 35.
It is defined as the weight loss when heated to 0 ° C and held at that temperature for 30 minutes.

When the glassy carbon whose weight loss is more than 5% by weight under the above conditions is combined with the thermotropic liquid crystal polymer having a high melting point, gas is generated due to heating during molding, and as described above, molding is difficult. It may cause blister and flow marks on molded products, resulting in reduced productivity and commercial value.

On the other hand, the shape is preferably spherical, and more preferably close to a true sphere. A non-spherical shape such as an irregular shape is not preferable when it is used for a member such as the bearing of the present invention that is required to have slidability, because it causes abrasion of the metal or resin of the mating material.

The addition amount of spherical glassy carbon 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 addition amount of spherical glassy carbon is 10% by weight.
If it is less than the above range, the abrasion resistance is insufficient, and even if the amount exceeds 50% by weight, further improvement of the abrasion resistance cannot be expected. In addition, the strength of the obtained molded product also decreases.

Various additives may 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. Among them, the inorganic filler is particularly important and is often used for improving workability and physical properties.

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, fluorine. Graphite, potassium titanate and the like, glass fiber, carbon fiber,
It is possible to add various whiskers and the like as long as the effects of the present invention are not impaired.

As the organic filler, various thermoplastic and thermosetting resins can be mentioned, and a fluororesin typified by polytetrafluoroethylene is particularly preferably used. The method of mixing the thermotropic liquid crystal polymer, spherical glassy carbon and the above additives added to these are
There is no particular limitation, and various means can be applied.
For example, they may be separately supplied to the extruder for melt mixing, or may be premixed with 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. Thus, even if the thermotropic liquid crystal polymer composition in which glassy carbon is blended at the time of polymerization is used, it goes without saying that when a processed product is produced, that is, the composition is prepared by molding such as injection molding or compression molding. In the case of molding, the thermotropic liquid crystal polymer is melt-molded and exposed to high temperature. Therefore, even in such a case, the predetermined effects of the present invention can be obtained.

Further, the composition thus obtained is used to form the bearing of the present invention by a method such as injection, compression or extrusion. In the case of compression molding, it is dry blended in powder form. , May be molded.

In many cases, lubricating oil or the like is used as a lubricant for bearings, which are inactive at room temperature, but exhibit corrosiveness to contact members in addition to high temperature due to frictional heat. is there. However, since the resin composition comprising the thermotropic liquid crystal polymer and spherical glassy carbon in the present invention has sufficient chemical resistance at high temperatures, even in a high temperature atmosphere when a lubricating oil is used for the sliding portion. Not affected by lubricating oil or other chemicals.

In addition to the above, the bearing is required to have dimensional accuracy of the product and dimensional stability against changes in temperature due to its property, and the bearing of the present invention is also excellent in this respect. That is, the thermotropic liquid crystal polymer exhibits extremely good fluidity because the molecular chains are oriented in the shearing direction when a shearing force is applied during melting. Since it exhibits a crystalline state during melt flow, there is very little change in structure and specific volume when it is cooled and solidified in the mold, and as a result, the molding shrinkage law is small and precision molding can be easily performed. In addition, 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 temperature change.

[0044]

The bearing according to the present invention has the following features and is most suitable for use under high load, high speed and high temperature. (1) Among the conventional plastics, since a polymer having a particularly high melting point is used, it is less likely to cause melting and seizing due to frictional heat. (2) Since the thermotropic liquid crystal polymer having a small linear expansion coefficient is used as the material, the processing temperature can be maintained over a wide temperature range. (3) At high temperatures due to frictional heat, lubricating oil, which should normally be inactive, may show corrosive properties to the members in contact with it. However, the bearing of the present invention is stable against them.

[0045]

EXAMPLES The present invention will be described in more detail by way of examples, which should not be construed as limiting the scope of the present invention, but showing preferred embodiments of the present invention. First, the raw materials used in Examples and Comparative Examples are collectively shown.

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

B: Powder of 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.

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

It was confirmed that the broken surface of each of these glassy carbon particles had a clear glassy luster, and the X-ray diffraction spectrum measured by Cu-Kα ray (double line) showed Similarly, it had a clear broad peak near a bending angle (2θ) of 23 to 25 degrees, and virtually no sharp peak peculiar to graphite was observed. Weight loss: The weight loss when the temperature is raised from room temperature to 350 ° C. at a rate of 10 ° C./min and kept at this temperature for 30 minutes. (Thermal balance SSC-5020T made by Seiko Instruments Inc.
The measurement was performed by G / DTA200. )

Graphite Nippon Graphite Co., Ltd. ACP (trade name) scaly graphite, average particle size 10 μm Polytetrafluoroethylene Daikin Lubron L5 (trade name) average particle size 5 μm
m

Example 1 The above raw materials were blended in the proportions shown in Table 1, mixed with a Henschel mixer, and then melted and kneaded with a twin-screw extruder (PCM-30 type manufactured by Ikegai Tekko KK) (temperature). Granules were formed into pellets at 420 ° C. and screw rotation speed 200 rpm).

Next, the pellets were put into an injection molding machine (manufactured by Sumitomo Heavy Industries Machinery Co., Ltd .: Nestal SG25 type) under conditions of a cylinder temperature of 400 ° C., an injection pressure of 1000 kgf / cm ² and a mold temperature of 150 ° C., a diameter of 5 cm and a thickness. A 3 mm disc was molded. The obtained test piece was measured with a Suzuki type friction and wear tester under the conditions of pressure of 6 kgf / cm ² and speed of 120 m / min using a mating material of ring-shaped S45C steel with an outer diameter of 26 mm and an inner diameter of 20 mm to measure the wear coefficient did. Also, using the same tester, the speed was kept constant at 20 m / min and the pressure was 50 k.
The maximum PV value was determined as the product of the maximum pressure and the speed (20 m / min) at which the test piece did not melt and gradually increased from gf / cm ² by 10 kgf / cm ² .

Further, a bending test piece was formed under the same conditions by using the above-mentioned injection molding machine, and the obtained test piece was used for AS.
Bending strength was measured by TM D-790. Also,
Ten test pieces were continuously molded, the moldability and the appearance thereof were observed, and the number of blister and flow mark generated was recorded.

A bearing as shown in FIG. 1 was molded using the same injection molding machine. The S45C steel shaft was inserted, and the operating condition was observed by rotating the shaft at 1000 rpm.

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

Further, using the above-mentioned injection molding machine, bending test pieces and bearings were molded under the same conditions, 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 betting raw materials were blended in the proportions shown in Table 1 and mixed in a Henschel mixer, and then a twin-screw extruder (manufactured by Ikegai Tekko KK:
It was melt-kneaded with a PCM-30 type (temperature 420 ° C., screw rotation speed 200 rpm) and granulated into pellets.

Next, the pellets were 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 abrasion property was 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 this 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 from the flat plate, and the bending strength was measured by ASTM D-790.

Example 6 The above raw materials were blended in the proportions shown in Table 1, mixed with a Henschel mixer, and then twin-screw extruder (manufactured by Ikegai Tekko KK:
It was melt-kneaded with PCM-30 type (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.
/ Cm ² compression molding, thickness 3mm, size 50 x 50
mm test pieces were prepared and the wear characteristics were evaluated in the same manner as in Example 1. In addition, as in Example 5, the bearing was evaluated and the bending strength was measured. The above results are summarized in Table 1.

Comparative Examples 1 and 2 The raw materials were mixed in the proportions shown in Table 2, and pellet granulation, a disk, a bending test piece and a bearing were molded and evaluated in the same manner as in Example 1. The results are shown in Table 2, and Comparative Example 2
However, since the blister occurred, the bearing was not evaluated.

Comparative Example 3 The above raw materials were blended in the proportions shown in Table 2, pelletized and molded into flat plates 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 raw materials were blended in the proportions shown in Table 2, pelletized and molded into flat plates 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, comparing Examples 1 to 6 and Comparative Examples 1 to 4, Examples 1 to 6 show that the ratio of thermotropic liquid crystal polymer to glassy carbon and 350 ° C. of glassy carbon,
Because all of the weight loss in 30 minutes is in the desired range,
It was excellent in wear characteristics, formability, and performance as a bearing. On the other hand, in Comparative Example 1, since the glassy carbon was in a small amount, the wear coefficient was large, and it burned 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 desirable range, the moldability and the appearance of the molded product could not be satisfied. In Comparative Example 4,
Since it exceeds 50% by weight, moldability and product strength are poor.

[0065]

[Table 1]

[0066]

[Table 2]

[Brief description of drawings]

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

[Explanation of symbols] 1 bearing 2 shaft

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location F16C 33/24 Z 6814-3J

Claims (4)

[Claims] 1. Thermotropic liquid crystal polymer (a) 9
A bearing, characterized in that it comprises 0 to 50% by weight and 10 to 50% by weight of spherical glassy carbon (b) characterized by a glass 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 kept 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. [Chemical 1]