JP5071133B2 - Bearing for motor - Google Patents

Description

  The present invention relates to a motor bearing using a resin composition having excellent wear resistance.

  In recent years, the capacity of information recording media such as hard disks and DVD disks has been increasing. In order to read and write information at high speed, motor bearings used in these disk drives are required to have wear resistance under high speed and high load conditions.

Conventionally, high heat-resistant and high-sliding resins such as polyetheretherketone have been used for these bearing applications (see Patent Document 1). However, these resins are expensive, and further material cost reduction is required. Yes. Further, with the increase in rotational speed, further improvement in wear resistance is required.
JP 2001-40225 A

  An object of the present invention is to solve the above-described problems and provide a motor bearing having excellent frictional wear resistance under high speed and high load.

In order to solve these problems, the present inventors have conducted extensive research,
(A) A resin composition containing 1 to 50 parts by weight of a spherical filler and (C) 1 to 50 parts by weight of a solid lubricant with respect to 100 parts by weight of a thermoplastic resin, The present invention has been completed by finding that it is excellent in frictional wear resistance and suitable for use as a motor bearing.

That is, this invention relates to the bearing for motors shown below.

(1) (A) A resin composition containing 1 to 50 parts by weight of a spherical filler and (C) 1 to 50 parts by weight of a solid lubricant is molded with respect to 100 parts by weight of a thermoplastic resin. Bearing for motor.

(2) The motor bearing according to (1), wherein the thermoplastic resin (A) is a polyarylene sulfide resin.

(3) The motor bearing according to (1), wherein the thermoplastic resin (A) is a polyarylene sulfide resin and an aromatic polyamideimide resin.

(4) (B) The motor bearing according to (1), wherein the spherical filler has an average particle diameter of 10 to 200 μm.

(5) The motor bearing according to (1), wherein the spherical filler (B) is a hollow filler and / or a particulate filler.

(6) The motor bearing according to (5), wherein the hollow filler is at least one selected from ceramic balloons, shirasu balloons, glass balloons, and metal balloons.

(7) The motor bearing according to (5), wherein the particulate filler is at least one selected from ceramic powder, silica, glass beads, and metal powder.

(C) The motor bearing according to (1), wherein the solid lubricant is a fluororesin or graphite.

    A bearing using a resin composition comprising (A) a thermoplastic resin, (B) a spherical filler, and (C) a solid lubricant component of the present invention is excellent in frictional wear resistance and is therefore preferably used as a motor bearing. In addition, the price can be kept lower than that of conventionally used materials.

(A) The thermoplastic resin is preferably a so-called engineering plastic in terms of strength and heat resistance. For example, crystalline resins such as polyarylene sulfide, polyetheretherketone, polyamide, polyester, polyacetal, and aromatic polyamideimide, polyether Examples thereof include amorphous resins such as imide, polyether sulfone, polycarbonate, and modified polyphenylene ether. Among these, polyarylene sulfide resins and aromatic polyamideimide resins are particularly preferable from the balance of strength, heat resistance, and moldability.

  The polyarylene sulfide resin (hereinafter abbreviated as PAS) is an arylene sulfide repeating unit represented by the formula [—Ar—S—] (wherein —Ar— is an arylene group). Is an aromatic polymer. When [—Ar—S—] is defined as 1 mol (basic mol), the PAS used in the present invention usually has this repeating unit of 50 mol% or more, preferably 70 mol% or more, more preferably 90 mol% or more. It is a polymer to contain. Examples of the arylene group include a p-phenylene group, an m-phenylene group, a substituted phenylene group (the substituent is preferably an alkyl group having 1 to 6 carbon atoms, or a phenyl group), p, p′-di. Examples thereof include a phenylene sulfone group, p, p′-biphenylene group, p, p′-diphenylenecarbonyl group, and naphthylene group. As the PAS, a polymer mainly having the same arylene group can be preferably used, but from the viewpoint of processability and heat resistance, a copolymer containing two or more arylene groups can also be used.

Among these PASs, polyphenylene sulfide (PPS) having a repeating unit of p-phenylene sulfide as a main constituent element is particularly preferable because of excellent processability and industrial availability. In addition, polyarylene ketone sulfide and the like can be used. Specific examples of the copolymer include a random or block copolymer having a repeating unit of p-phenylene sulfide and a repeating unit of m-phenylene sulfide, a random or block copolymer having a repeating unit of phenylene sulfide and a repeating unit of arylene ketone sulfide, and phenylene sulfide. And random or block copolymers having a repeating unit of arylene sulfone sulfide. These PAS are preferably crystalline polymers. PAS is preferably a linear polymer from the viewpoint of toughness and strength. Such PAS can be obtained by a known method (for example, described in JP-B-63-33775) in which an alkali metal sulfide and a dihalogen-substituted aromatic compound are subjected to a polymerization reaction in a polar solvent.

  Examples of the alkali metal sulfide include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, and cesium sulfide. Sodium sulfide produced by reacting NaSH and NaOH in the reaction system can also be used. Examples of the dihalogen-substituted aromatic compound include p-dichlorobenzene, m-dichlorobenzene, 2,5-dichlorotoluene, p-dibromobenzene, 2,6-dichloronaphthalene, 1-methoxy-2,5-dichlorobenzene, 4 , 4'-dichlorobiphenyl, 3,5-dichlorobenzoic acid, p, p'-dichlorodiphenyl ether, 4,4'-dichlorodiphenyl sulfone, 4,4'-dichlorodiphenyl sulfoxide, 4,4'-dichlorodiphenyl ketone, etc. Can be mentioned. These can be used alone or in combination of two or more.

  In order to introduce some branched structure or crosslinked structure into PAS, a small amount of polyhalogen-substituted aromatic compound having 3 or more halogen substituents per molecule can be used together. Preferred examples of the polyhalogen-substituted aromatic compound include 1,2,3-trichlorobenzene, 1,2,3-tribromobenzene, 1,2,4-trichlorobenzene, 1,2,4-tribromobenzene, Examples include trihalogen-substituted aromatic compounds such as 1,3,5-trichlorobenzene, 1,3,5-tribromobenzene, 1,3-dichloro-5-bromobenzene, and alkyl-substituted products thereof. These can be used alone or in combination of two or more. Among these, 1,2,4-trichlorobenzene, 1,3,5-trichlorobenzene, and 1,2,3-trichlorobenzene are more preferable from the viewpoints of economy, reactivity, and physical properties.

  As the polar solvent, N-alkylpyrrolidone such as N-methyl-2-pyrrolidone, 1,3-dialkyl-2-imidazolidinone, tetraalkylurea, aprotic organic amide solvent represented by hexaalkylphosphate triamide, It is preferable because the stability of the reaction system is high and a high molecular weight polymer is easily obtained. The PAS used in the present invention has a melt viscosity of usually 10 to 600 Pa · s, preferably 40 to 550 Pa · s, more preferably 50 to 550 Pa · s, measured at a temperature of 310 ° C. and a shear rate of 1200 / sec. . When two or more kinds of PAS having different melt viscosities are blended and used, it is preferable that the melt viscosity of the blend is in the above range. If the melt viscosity of PAS is too small, physical properties such as mechanical strength and toughness may be insufficient. If the melt viscosity of PAS is too large, the melt fluidity will be insufficient, and the injection moldability and extrusion moldability may be insufficient.

  In addition, the PAS can be used after washing after the completion of the polymerization. Further, the PAS is treated with an aqueous solution containing an acid such as hydrochloric acid or acetic acid, or a water-organic solvent mixed solution, or a salt such as ammonium chloride. It is preferable to use a solution treated with a solution. In particular, when PAS washed until the pH in a mixed solvent adjusted to acetone: water = 1: 2 (volume ratio) is 8 or less is used, the melt fluidity and mechanical properties of the resin composition are used. Can be further improved.

  The PAS is preferably a granular material having an average particle diameter of 100 μm or more. If the average particle size of the PAS is too small, the amount of feed is limited during melt extrusion by the extruder, so that the residence time of the resin composition in the extruder becomes longer, causing problems such as deterioration of the resin composition. There is a fear. Further, it is not desirable in terms of manufacturing efficiency.

In addition, the aromatic polyamideimide resin is synthesized from an aromatic tricarboxylic acid anhydride (including some cases including an aromatic tetracarboxylic acid anhydride) and a diisocyanate compound. In general, it can be performed by controlling the amidation reaction and imidization reaction by appropriately performing the polymerization temperature, reaction time, and catalyst addition method, but basically the formation reaction of the amide group is substantially completed. Until then, the amidation reaction is carried out under the condition that the imide group formation reaction does not occur, and then the imidation reaction is carried out.

In order to obtain an aromatic polyamideimide resin, a method of controlling the polymerization temperature is simple as a method for carrying out the imidation reaction after completion of the amidation reaction. That is, an aromatic tricarboxylic acid anhydride (including a case where some aromatic tetracarboxylic acid anhydrides are included) and a diisocyanate compound are contained in a solvent at 50 to 100 ° C, preferably 60 to 100 ° C, and more preferably 80 to 100 ° C. The amidation reaction is 70% or more, preferably 80%, more preferably 90%, most preferably 95% or more after completion of the reaction, usually at 100 to 200 ° C., preferably 105 to 180. It is a method in which the imidization reaction is carried out at a temperature range of 10 ° C, more preferably 110 to 180 ° C.

The reaction temperature of the aromatic tricarboxylic acid anhydride (including some cases including aromatic tetracarboxylic acid anhydride) and the diisocyanate compound is an important condition, and it is used in the present invention by controlling this. An aromatic polyamideimide resin constituting the resin composition to be produced can be produced. The temperature in each stage may be set in any way as long as it is within the temperature range. For example, the temperature may be raised, kept at a constant temperature, or a combination thereof, but it is desirable to keep the temperature constant. When the temperature of each stage is lower than the above range, the formation reaction of amide and imide groups is not completed, and as a result, the polymerization degree of the obtained aromatic polyamideimide resin is not increased. Becomes brittle.
When the amidation temperature is higher than the above range, the amide group formation reaction and the imide group formation reaction occur at the same time, so the obtained aromatic polyamide-imide resin has poor melt fluidity and residence stability. become.

    The reaction time between the aromatic tricarboxylic acid anhydride and the diisocyanate compound is 40 minutes to 5 hours, preferably 40 minutes to 2 hours for the amidation reaction, and 40 minutes to 10 hours, preferably 1 hour for the imidation reaction. 8 hours. If the reaction time is too short, the degree of polymerization of the resulting aromatic polyamideimide will not increase, and the resin composition of the present invention will become brittle. On the other hand, when the reaction time is too long, the obtained aromatic polyamideimide resin is inferior in melt fluidity. The amide group component and the imide group component must be traced during the polymerization reaction. This method can be performed by a known infrared spectroscopy method, gas chromatogram method, or the like.

  The aromatic tricarboxylic acid used for producing the aromatic polyamideimide resin is a compound represented by the following general formula.

（式中のＡｒは、少なくとも１つの炭素６員環を含む３価の芳香族基を示す。）

(Ar in the formula represents a trivalent aromatic group containing at least one carbon 6-membered ring.)

上記のうち、芳香族トリカルボン酸無水物としては、トリメリット酸無水物が好ましい。 Specific examples of Ar include the following, but two or more kinds of compounds may be mixed and used.

Among the above, trimellitic anhydride is preferable as the aromatic tricarboxylic acid anhydride.

  It is also possible to replace 0 to 50 mol% of the aromatic tricarboxylic acid anhydride with an aromatic tetracarboxylic acid anhydride. However, if the amount of aromatic tetracarboxylic acid anhydride is larger than the above range, the resulting aromatic polyamideimide resin tends to be brittle. The aromatic tetracarboxylic acid anhydride is a compound represented by the following general formula.

（式中、Ａｒ１は、少なくとも１つの炭素６員環を含む３価の芳香族基を示す。）

(In the formula, Ar1 represents a trivalent aromatic group containing at least one carbon 6-membered ring.)

    Specific examples of the aromatic tetracarboxylic acid anhydride include the following.

  The diisocyanate compound used for producing the aromatic polyamideimide resin is a compound represented by the following general formula.

(Chemical 5)
O = C = N-R-N = C = O
(Wherein R is a divalent aromatic and / or aliphatic group)

  Specific examples include the following, but two or more kinds of compounds may be mixed and used.

  Among these, m-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and methylene di (4-phenyl isocyanate) are particularly preferable.

  In order to produce an aromatic polyamideimide resin, the aromatic tricarboxylic acid anhydride component (which can include the above-mentioned dicarboxylic acid and tetracarboxylic acid anhydride) and the diisocyanate component have their respective molar numbers A, B, In this case, the molar ratio between the two is desirably maintained at 0.9 <A / B <1.1, and more preferably is maintained at 0.99 <A / B <1.01.

  In the present invention, a solvent is used to smoothly produce an aromatic polyamideimide resin. The solvent used is not particularly limited as long as it is inactive with respect to the diisocyanate compound, and specifically, a solvent having compatibility with the produced aromatic polyamideimide such as N-methylpyrrolidone and dimethylformamide. And polar solvents that are not compatible with the aromatic polyamideimide produced, such as nitrobenzene and nitrotoluene. These may be used alone or in combination. Preferred are solvents such as N-methylpyrrolidone and dimethylformamide that are compatible with polyamideimide. These solvents are used at a ratio of 0.1 to 4 mol / liter with respect to the solvent of the monomer raw material.

  Various catalysts can be used in the production of aromatic polyamideimide resin, but the amount used should be kept to a minimum and the polymerization rate is at a sufficient level so as not to impair the moldability during melting. As long as it is not desirable to use it. Specific examples of the catalyst include tertiary amines such as pyridine, quinoline, isoquinoline, trimethylamine, N, N-diethylamine, and triethylamine, weak acid metal salts such as cobalt acetate and cobalt naphthenate, heavy metal salts, alkalis A metal salt etc. can be mentioned.

  The water content of the polymerization system composed of a solvent, a monomer, etc. is desirably kept at 500 ppm or less, more preferably 100 ppm or less, and most preferably 50 ppm or less. If the water content in the system exceeds 500 ppm, the degree of polymerization of the aromatic polyamideimide of the present invention does not increase, which is not preferable.

  Aromatic polyamide-imide resin is recovered as a powder by precipitation and washing with alcohols such as methanol and isopropanol, ketones such as acetone and methyl ethyl ketone, aliphatics such as heptane and toluene, and aromatic hydrocarbons. The polymerization solvent may be concentrated directly. Furthermore, after concentrating to a certain extent, it is possible to remove the solvent under reduced pressure using an extruder or the like and pelletize it.

  The degree of polymerization of the aromatic polyamide-imide resin is preferably 0.15 dl / g to 10 dl / g when expressed in terms of reduced viscosity measured in dimethylformamide at a concentration of 1 g / dl at 40 ° C., more preferably, 0.2 dl / g to 0.6 dl / g is most preferably 0.2 to 0.5 dl / g.

In the present invention, the polyarylene sulfide resin and the aromatic polyamideimide resin may be used alone, or the polyarylene sulfide resin and the aromatic polyamideimide resin may be used in combination.
When the polyarylene sulfide resin and the aromatic polyamideimide resin are used in combination, the aromatic polyamideimide resin is preferably 60 parts by weight or less with respect to the total of 100 parts by weight of both. When there is more aromatic polyamideimide resin than this quantity, the fluidity | liquidity at the time of a fusion | melting will fall, and moldability will be inferior.

Examples of the spherical filler as the component (B) include hollow fillers such as ceramic balloons, shirasu balloons, glass balloons, and metal balloons, and particulate fillers such as ceramic powders, silica, glass beads, and metal powders. However, in order to maintain the strength at the time of load application, those having a compressive strength of 30 MPa or more are preferable.
The average particle size is preferably in the range of 10 to 200 μm, more preferably 10 to 100 μm.
The presence of these fillers on the surface of the molded body has the effect of reducing friction and reducing the true contact surface in contact with the metal shaft.

  The mixing ratio of these spherical fillers is preferably 1 to 50 parts by weight, more preferably 1 to 30 parts by weight with respect to 100 parts by weight of the component (A). If the amount is less than 1 part by weight, the desired frictional wear resistance cannot be obtained, and if it exceeds 50 parts by weight, the toughness and fluidity of the molded product are deteriorated.

These spherical fillers can be used alone or in combination of two or more. In particular, it is preferable to use a hollow filler and a particulate filler in combination since both strength and slidability can be obtained.

  Furthermore, the surface of these spherical fillers can be subjected to surface treatment using organosilane, organic borane, organic titanate, or the like for the purpose of improving the interfacial adhesion with the resin.

  (C) Fluororesin, which is one of the solid lubricants, is an additive for the purpose of imparting lubricity, and is a heavy polymer having a carbon chain in the main chain and a fluorine atom bond in the side chain. Or a copolymer having such a polymer. Specific examples include polytetrafluoroethylene (hereinafter abbreviated as PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (hereinafter abbreviated as PFA), and tetrafluoroethylene-hexafluoropropylene copolymer. (Hereinafter abbreviated as FEP), ethylene-tetrafluoroethylene copolymer (hereinafter abbreviated as ETFE), tetrafluoroethylene-fluoroalkyl vinyl ether-fluoroolefin copolymer (hereinafter abbreviated as EPE). And ethylene-trichlorofluoroethylene copolymer (hereinafter abbreviated as ECTFE).

  As the fluororesin, PTFE in which the carbon chain is completely fluorinated is particularly preferable since it has excellent lubricity, and as a commercially available PTFE, a powder for molding or a powder for dispersion can be used. As the molecular weight, both a high molecular weight type and a low molecular weight type can be used. It is preferable to use a low molecular weight type when fluidity is required, and a high molecular weight type when mechanical strength is required.

  Graphite may be used as the solid lubricant. As for the shape of graphite, scaly, lump, flat, spherical, etc. are used, but scaly is preferred. A particle size of 1 to 100 μm is used, but a particle size of 10 to 40 μm is preferable.

    Moreover, as a ratio which mix | blends these solid lubricants, it is preferable that it is 1-50 weight part with respect to 100 weight part of (A) component. If the amount is less than the predetermined amount, the desired lubricity cannot be obtained, and if the amount exceeds the predetermined amount, the mechanical strength and fluidity of the molded product are lowered, which is not preferable.

  It is also effective to add a lubricant to the resin composition of the present invention for the purpose of improving frictional wear resistance. Representative examples of the lubricant include mineral oil, silicone oil, ethylene wax, polypropylene wax, stearic acid or a metal salt of montanic acid, stearic acid or a montanic acid ester, stearic acid or a montanic acid amide, and the like. It is assumed that these lubricants exist on the surface of the molded body and are liquefied by frictional heat on the sliding surface, and friction is reduced by forming an oil film between the shaft and the bearing.

    Moreover, as a ratio which mix | blends these lubricants, it is preferable that it is 0.1-10 weight part with respect to 100 weight part of (A) component. If the amount is less than the predetermined amount, the desired lubricity cannot be obtained. If the amount exceeds the predetermined amount, the mechanical strength of the molded body is lowered and the lubricant bleeds out to the surface of the molded product.

    The resin composition of the present invention may contain various fillers other than those described in the claims for the purpose of improving mechanical strength. Examples of the filler include wollastonite, mica, talc, kaolin. Mineral fillers such as silicon dioxide, clay, asbestos, calcium carbonate, magnesium hydroxide, diatomaceous earth; fiber forms such as glass fiber, carbon fiber, milled fiber, potassium titanate fiber, boron fiber, silicon carbide fiber A filler can be mentioned. The filler can be used in an amount of 1 to 70% by weight based on the entire resin composition. Preferred fillers are glass fiber, milled fiber, carbon fiber, and potassium titanate fiber, but mica, talc, etc. that have low hardness when selected in terms of wear resistance.

  Moreover, an elastomer can be mix | blended in order to provide impact resistance to the resin composition of this invention. Examples of the elastomer include polysulfide rubber, polyester elastomer, polyamide elastomer, polyesteramide elastomer, polyolefin elastomer, silicon rubber, fluororubber and the like.

  Examples of additives other than the above include colorants. Examples of the colorant include carbon black, titanium oxide, zinc sulfide, and zinc oxide.

  In the present invention, a resin composition containing (B) 1 to 50 parts by weight of a spherical filler and (C) 1 to 50 parts by weight of a solid lubricant with respect to (A) 100 parts by weight of the thermoplastic resin as described above. The molding is performed by a normal injection molding method, the cylinder temperature is in the range of 290 to 320 ° C., and the mold is desirably 120 to 160 ° C. in order to obtain sufficient heat resistance. Further, it is desirable to perform heat treatment after molding for the purpose of improving heat resistance and removing residual stress. In particular, when molding is performed at a mold temperature lower than 120 ° C., heat treatment is preferable. The method for the heat treatment is not particularly limited. For example, a normal hot air oven is used. The heat treatment temperature is preferably 180 to 280 ° C., and most preferably 200 to 260 ° C. for 1 hour to 36 hours under normal pressure or reduced pressure.

    The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

<Synthesis Example 1>
(Manufacture of aromatic polyamideimide resin)
N-methylpyrrolidone with a water content of 15 ppm, 3 liters were charged into a reactor equipped with a 5 liter stirrer, thermometer, and reflux condenser fitted with a drying tube filled with calcium chloride at the tip. To this, 555 g (50 mol%) of trimellitic anhydride was added, followed by 503.3 g (50 mol%) of 2,4-tolylene diisocyanate. The water content in the system when trimellitic anhydride was added was 40 ppm. Initially, it took 20 minutes from room temperature to bring the content temperature to 90 ° C., and polymerization was carried out at this temperature for 50 minutes. While polymerizing, the amount of isocyanate groups decreased and the amount of imide groups formed in 2,4-tolylene diisocyanate were measured. The measuring method was performed by sampling a small amount of the reaction solution with a syringe and quantifying the absorption at 2276 cm ⁻¹ of the isocyanate group by infrared spectroscopy. When polymerization was carried out for 50 minutes, the amount of isocyanate groups was reduced to 50 mol%. At this time, no imide group absorption was observed. This confirmed that the amidation reaction was completed before the imidation reaction occurred. Thereafter, the temperature was raised to 115 ° C. in 15 minutes, and the polymerization was continued for 8 hours while maintaining this temperature.
After completion of the polymerization, the polymer solution was dropped into 6 liters of methanol under strong stirring. The precipitated polymer was filtered off with suction, re-dispersed in methanol, washed well, filtered, and dried at 135 ° C. for 6 hours to obtain polyamideimide powder. When the reduced viscosity at 40 ° C. of this product was measured with a dimethylformamide solution (concentration: 10 g / dl), it was 0.25 dl / g.

<Examples 1-4>
Aromatic polyamide-imide resin and PPS resin produced in Synthesis Example 1 (melting point: 285 ° C., melt viscosity of 50 Pa · s measured at a shear rate of 1200 / second at 310 ° C.) and polytetrafluoroethylene (medium molecular weight unfired product, Average particle size 17 μm), ceramic balloon (E-SPHERES SL75 made by Taiheiyo Cement: SiO ₂ / Al ₂ O ₃ = 6/4 ratio, average particle size 45 μm, compressive strength 70 MPa), glass balloon (EGB731D manufactured by Potters Ballotini) A particle size of 13 μm and a compressive strength of 69 MPa) were blended at a ratio shown in Table 1, and melt-kneaded at 320 ° C. using a biaxial extruder to be pelletized to produce a resin composition. A bearing disc having a diameter of 5 mm and a thickness of 0.8 mm was formed using the pellets, and the amount of wear (the amount of depressions) was measured. For the evaluation, a self-made bearing tester was used and evaluated under the following conditions.
(Test conditions)
Shaft shape and material: 3mmφ steel (SUS420)
Test temperature: room temperature, test speed: 7,200 rpm, load: 1 kgf
Test environment: Oil immersion test time: 1 hr

<Comparative example 1>
A PEEK sheet (manufactured by Sumitomo Bakelite) was cut out, and the amount of wear (the amount of depression) was evaluated in the same manner as in other examples.

<Comparative Examples 2 and 3>
Aromatic polyamide-imide resin and PPS resin produced in Synthesis Example 1 (melting point: 285 ° C., melt viscosity of 50 Pa · s measured at a shear rate of 1200 / second at 310 ° C.) and polytetrafluoroethylene (medium molecular weight unfired product, Average particle diameter 17 μm), carbon fiber (pitch system, average fiber diameter 13 μm), glass fiber (chopped strand, average fiber diameter 10 μm) are blended in the proportions shown in Table 2, and melted at 320 ° C. using a twin screw extruder. The resin composition was manufactured by kneading and pelletizing. Using this pellet, a disk similar to that of Example 1 was molded, and the amount of wear (the amount of depression) was measured.

ＰＡＩ：芳香族ポリアミドイミド樹脂
ＰＰＳ：ポリフェニレンスルフィド樹脂
ＳＢ：セラミックバルーン
ＧＢ：ガラスバルーン
ＰＴＦＥ：ポリテトラフルオロエチレン

PAI: aromatic polyamideimide resin PPS: polyphenylene sulfide resin SB: ceramic balloon GB: glass balloon PTFE: polytetrafluoroethylene

ＰＡＩ：芳香族ポリアミドイミド樹脂
ＰＰＳ：ポリフェニレンスルフィド樹脂
ＰＡＩ：芳香族ポリアミドイミド樹脂
ＣＦ：炭素繊維
ＧＦ：ガラス繊維
ＰＥＥＫ：ポリエーテルエーテルケトン樹脂

PAI: aromatic polyamideimide resin PPS: polyphenylene sulfide resin PAI: aromatic polyamideimide resin CF: carbon fiber GF: glass fiber PEEK: polyetheretherketone resin

    As is clear from the results in Table 1, the resin compositions of Examples 1 to 4 showed a small amount of wear. On the other hand, in the case of the resin compositions shown in Comparative Examples 1 to 3, an increase in the amount of wear was recognized as compared with the Examples.

Claims (6)

(A) 1 to 50 parts by weight of a spherical filler and (C) 1 to 50 parts by weight of a solid lubricant with respect to 100 parts by weight of a thermoplastic resin, and (A) the thermoplastic resin is polyarylene A bearing for a motor formed by molding a resin composition which is a sulfide resin and an aromatic polyamideimide resin . (B) The motor bearing according to claim 1, wherein the spherical filler has an average particle size of 10 to 200 μm. The motor bearing according to claim 1, wherein the spherical filler is a hollow filler and / or a particulate filler. 4. The motor bearing according to claim 3, wherein the hollow filler is at least one selected from ceramic balloons, shirasu balloons, glass balloons, and metal balloons. 4. The motor bearing according to claim 3, wherein the particulate filler is at least one selected from ceramic powder, silica, glass beads, and metal powder. (C) The motor bearing according to claim 1, wherein the solid lubricant is a fluororesin or graphite.