WO2000017273A1

WO2000017273A1 - Sliding member for conveyor apparatus

Info

Publication number: WO2000017273A1
Application number: PCT/JP1999/005008
Authority: WO
Inventors: Naomitsu Nishihata; Kiyomi Ohuchi; Masahito Tada
Original assignee: Kureha Kagaku Kogyo K.K.
Priority date: 1998-09-17
Filing date: 1999-09-14
Publication date: 2000-03-30
Also published as: JP4209974B2; JP2000086891A

Abstract

A sliding member for conveyor apparatuses which is obtained by molding a resin composition comprising 30 to 79 wt.% polyarylene sulfide having a melt viscosity of 20 Pa.s or higher as measured at 310 °C and a shear rate of 1,200 sec-1, 20 to 50 wt.% fluororesin, and 1 to 20 wt.% conductive carbon black. The member is excellent in heat resistance, sliding properties, frictional properties, wearing resistance, mechanical properties, and antistatic properties.

Description

Description Sliding member for conveyor equipment Field of technology

The present invention relates to a sliding member for a transfer device formed from a resin material, and more particularly, to a transfer device formed by molding a resin composition containing polyarylene sulfide, a fluororesin, and conductive carbon black. The present invention relates to a mounting sliding member. The sliding member for a transport device of the present invention is excellent in heat resistance, slidability, friction characteristics, abrasion resistance, mechanical properties, and the like. Therefore, it is particularly suitable for applications such as a rotary bearing of a semiconductor transfer device, a transfer roller, and a pulley. Background art

Polyarylene sulfide (hereinafter abbreviated as PAS) represented by polyphenylene sulfide (hereinafter abbreviated as PPS) is excellent in heat resistance, flame retardancy, chemical resistance, dimensional stability, mechanical properties, etc. It is an engineering plastic that has been widely used in electrical and electronic parts, precision machine parts, automotive parts, and so on.

In recent years, demand for PAS has been increasing even in applications as sliding members such as bearings and gears, taking advantage of the above-mentioned various properties. Generally, sliding members made of synthetic resin are excellent in heat resistance, sliding characteristics (sliding properties, low dynamic friction coefficient, wear resistance), mechanical properties, etc., and can be precision molded by injection molding. In addition, it is required that the partner material is not damaged. In addition, the synthetic resin sliding member generates static electricity, It may be required to have an insufficient conductivity. Furthermore, in applications such as rotating bearings, it is required that the rotating shaft does not vibrate or generate frictional noise due to sliding with the rotating shaft. However, it has been difficult for conventional sliding members made of PAS to sufficiently satisfy these characteristics. Hereinafter, these points will be specifically described.

In general, in a transfer device using belt transmission, the driving force of a motor is transmitted to a rotating shaft and a transfer roller via a belt, and the transfer force is obtained by rotating a transfer roller mounted on the rotation shaft. In such a transport device, sliding members such as a rotary bearing for fixing the rotary shaft, a transport roller mounted on the rotary shaft, and a pulley for transmitting the driving force of the motor to the rotary shaft are used. In other words, in such a transport device, the rotating shaft and the rotating bearing, the transport roller and the rotating shaft, the belt and the pulley, the belt and the transport opening roller slide, respectively, so that the rotating bearing, the transport roller, and the pulley It is necessary to select a material with excellent sliding characteristics. Also, in a transfer device of a type that transmits a driving force to a rotating shaft via a gear or the like instead of a belt, the gear also requires sliding characteristics.

Conventionally, when applying PAS to sliding members, lubricants such as fluoroplastics, fibers such as aramide fibers, potassium titanate fibers, and carbon fibers have been used to improve friction and wear characteristics and mechanical strength. It has been proposed to incorporate reinforced reinforcement. For example, Japanese Patent Application Laid-Open No. 3-292366 proposes a wear-resistant resin composition comprising a filler such as PPS, a fluororesin, and an aramide fiber. Japanese Patent Application Laid-Open No. Hei 6-168638 discloses a magnet for a developing apparatus in which PPS contains a reinforcing material such as aramid fiber and potassium titanate fiber, and a lubricant. A resin composition for a roll gap holding opening has been proposed. Japanese Unexamined Patent Publication No. 2-1875753 discloses a resin for a sliding member in which a heat-resistant thermoplastic resin such as PAS is mixed with polytetrafluoroethylene resin powder, pitch-based carbon fiber, and carbon beads. Japanese Patent Application Laid-Open No. H10-36669 describes a composition in which potassium titanate powder, carbon fiber, and polytetrafluoroethylene are blended in a thermoplastic resin such as PPS. A resin composition for a moving member has been proposed.

However, since fibrous reinforcing materials such as aramide fiber, potassium titanate fiber, and carbon fiber are all very hard materials, sliding materials formed from a PAS resin composition containing these fibrous reinforcing materials are used. The component has a problem that the sliding counterpart material is easily damaged, and the damage deteriorates the friction and wear characteristics. In addition, when a sliding member containing such a fiber-like reinforcing material is applied to a rotating bearing of a transport device or the like, a hard fibrous filler protrudes from a sliding surface between the rotating shaft and the rotating bearing. There were problems such as vibrating the rotating shaft and generating noise due to friction.

Japanese Patent Application Laid-Open No. Hei 5-1-117678 describes that a heat-resistant sliding bearing for an electrophotographic apparatus includes a PPS resin, a tetrafluoroethylene resin, a molten fluororesin, and an aromatic polyester resin. Heat-resistant sliding bearings composed of a resin composition containing, as an essential component, at least one heat-resistant synthetic resin selected from the group consisting of polyimide resins, polyimide resins, polyether ketone resins, aromatic polyamide resins, and phenolic resins Have been. Since this heat-resistant slide bearing does not contain a hard fiber-like filler such as carbon fiber, there is no problem such as damaging the mating material. However, this heat-resistant sliding bearing has poor compatibility of each component, poor mechanical properties, and poor sliding characteristics ゃ creep characteristics. In addition, it does not have an antistatic function.

On the other hand, in a transfer device for semiconductors (semiconductor elements, semiconductor components, integrated circuit components, mounted components, etc.), the static electricity generated by friction between the rotating shaft and the rotating bearing may destroy the semiconductor on the transfer device. There was a problem that the yield was poor. However, conventionally, it has an appropriate conductivity without generating static electricity, and at the same time, does not vibrate the rotating shaft or generate frictional noise due to sliding with the rotating shaft, and has excellent sliding characteristics. No synthetic resin sliding member is provided. Disclosure of the invention

An object of the present invention is to provide excellent heat resistance, slidability, friction characteristics, abrasion resistance, mechanical properties, and the like, and to provide an antistatic property by controlling the electrical resistivity within a desired range. An object of the present invention is to provide a sliding member for a transfer device.

Another object of the present invention is to provide a sliding member for a transfer device that does not damage a mating member, vibrate a rotating shaft, or generate noise due to friction.

The present inventors have conducted intensive studies to overcome the problems of the prior art, and as a result, by mixing polyarylene sulfide, fluororesin, and conductive carbon black in an appropriate amount ratio, fibrous reinforcement has been achieved. It has been found that a resin composition suitable for a resin material of a sliding member for a transport device can be obtained without containing any material. A sliding member formed from the resin composition has excellent heat resistance, sliding properties (sliding property, low dynamic friction coefficient, wear resistance), mechanical properties, and the like, and also has antistatic properties. I have. Therefore, this sliding member is connected to the rotating bearing of the transfer device, When applied to feed rollers, pulleys, etc., there is no risk of damaging the mating material, vibrating the rotating shaft, generating noise due to friction, and also causing the possibility of destruction of the semiconductor due to static electricity. .

The present invention has been completed based on these findings.

According to the present invention, at a temperature of 310: a polyarylene sulfide (A) having a melt viscosity of not less than 20 Pa · s measured at a shear rate of 1200 ns, 30 to 79% by weight The present invention provides a sliding member for a transfer device formed by molding a resin composition containing 20 to 50% by weight of a fluororesin (B) and 1 to 20% by weight of a conductive force pump rack (C). You. BEST MODE FOR CARRYING OUT THE INVENTION

Polyarylene Sulfide (P AS)

The PAS used in the present invention is mainly composed of an arylene sulfide repeating unit represented by the formula [-A r — S—] (where —A r — is an arylene group). It is an aromatic polymer.

If [Ar—S—] is defined as 1 mol (basic mol), the PAS used in the present invention usually contains at least 50 mol%, preferably at least 70 mol%, Preferably, the polymer contains 90 mol% or more.

Examples of the arylene group include p-phenylene group, m-phenylene group, and substituted phenylene group (the substituent is preferably an alkyl group having 1 to 6 carbon atoms, or a phenylene group. ), P, p 'diphenylene sulfone group, p, p'-biphenylene group, p, p '-diphenylene carbonyl group, naphthylene group and the like. As the PAS, polymers having mainly the same arylene groups are preferred. From the viewpoint of processability and heat resistance, a copolymer containing two or more arylene groups can also be used.

Among these PAS, PPS having a repeating unit of p-phenylene sulfide as a main component is particularly preferable because of excellent workability and easy industrial availability. In addition, polyarylene ketone sulfide, polyarylene ketone ketone sulfide, and the like can be used. Specific examples of the copolymer include a random or block copolymer having p-phenylene sulfide repeating units and m-phenylene sulfide repeating units, a phenylene sulfide repeating unit, and an arylene ketone ketone sulfide. Examples thereof include a random or block copolymer having a repeating unit of styrene and a repeating unit of arylene sulfone sulfide. These PASs are preferably crystalline polymers. In addition, it is preferable that PAS is a linear polymer from the viewpoint of toughness and strength.

Such a PAS can be obtained by a known method of polymerizing an alkali metal sulfide and a dihalogen-substituted aromatic compound in a polar solvent (for example, Japanese Patent Publication No. 63-33775). it can.

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 Na〇H in the reaction system can also be used. Examples of dihalogen-substituted aromatic compounds include p-dichlorobenzene, m-dichlorobenzene, 2,5-dichlorotoluene, p-dibromobenzene, 2,6-dichloronaphthalene, 1-methoxy2,5— Dichlorobenzene, 4, 4'-dichlorobiphenyl, 3, 5-Dichloro mouth benzoic acid, p, p '-Dichlorodiphenyl ether, 4, 4'-Dichlorodiphenyl sulfone, 4, 4 '-Dichlorophenyl sulphoxide, 4, 4'-Dichlorodiphenyl ketone, etc. Can be. These can be used alone or in combination of two or more.

A small amount of a polyhalogen-substituted aromatic compound having three or more halogen substituents per molecule can be used in order to introduce a slight branched or cross-linked structure into the PAS. Preferred examples of the polyhalogen-substituted aromatic compound include 1,2,3—trichlorobenzene, 1,2,3—tribromobenzene, 1,2,4_trichlorobenzene, 1,2,4— Trihalogen-substituted aromatic compounds such as tribromobenzene, 1,3,5-trichlorobenzene, 1,3,5-tribromobenzene, 1,3-dichloro-5-bromobenzene, and alkyl-substituted products thereof Can be mentioned. These can be used alone or in combination of two or more. Of these, 1,2,4-trichlorobenzene, 1,3,5-trichlorobenzene, and 1,2,3-trichlorobenzene are preferred from the viewpoints of economy, reactivity, and physical properties. More preferred.

Examples of the polar solvent include N-alkylpyrrolidone such as N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP), 1,3-dialkyl-1-imidazolidinone, tetraalkylurea, and trialkylhexaalkylphosphate. Aprotic organic amide solvents, such as amides, are preferred because of high stability of the reaction system and easy production of high molecular weight polymers.

The PAS used in the present invention has a melt viscosity measured at a temperature of 310 and a shear rate of 1200 seconds of 20 Pas or more, and is preferably Is 20 to 500 Pa * s, more preferably 25 to 450 Pa * s. If the melt viscosity of PAS is too low, the mechanical properties may be insufficient. If the melt viscosity of PAS is too high, the moldability in injection molding or extrusion molding may be insufficient.

The PAS used in the present invention can be used after it has been washed after polymerization, but may be further treated with an aqueous solution containing an acid such as hydrochloric acid or acetic acid or a mixed solution of water and an organic solvent; It is preferable to use one that has been treated with a salt solution such as ammonium. In particular, the use of PAS with a pH of 8 or less in a mixed solvent in which acetone and water are adjusted to a volume ratio of 1: 2 by post-treatment after polymerization will further improve fluidity and mechanical properties. Can be.

The PAS used in the present invention is desirably a granular material having an average particle diameter of 100 zm or more. If the average particle size of the PAS is too small, the amount of feed during melt extrusion by the extruder will be limited, and the residence time of the resin composition in the extruder will be prolonged, causing a problem of deterioration of the resin composition. There is a risk. It is also undesirable in terms of manufacturing efficiency. The upper limit of the average particle diameter is about 20000 im, and in most cases is about 1500; m.

The mixing ratio of PAS is 30 to 79% by weight, preferably 40 to 75% by weight, and more preferably 45 to 75% by weight, based on the total amount of the resin composition. If the proportion of PAS is too small, the mechanical strength may be reduced and the creep properties may be insufficient. If the blending ratio of PAS is too small, the injection moldability and extrusion moldability may be insufficient when polytetrafluoroethylene is used as the fluororesin. If the proportion of PAS is too large, good sliding characteristics cannot be obtained, and the conductivity may be insufficient. Fluororesin

The fluororesin used in the present invention is not particularly limited. For example, polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), tetrafluoroethylene Z Fluoroalkyl vinyl ether copolymer (PFA) Polychlorinated trifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), vinylidene fluoride / hexafluoropropylene tetrafluoroethylene copolymer, polyfluoroethylene Vinyl chloride, Ethylene Z tetrafluoroethylene copolymer (ETFE), Ethylene Z Chloro trifluoroethylene copolymer (ECTFE), Propylene Z Tetrafluoroethylene copolymer, Tetrafluoroethylene Z Perfluoroalkyl perfluorovinyl ether copolymer, vinylidene fluoride hexaf Fluoropropylene copolymer, vinylidene fluoride _ / black mouth Trifluoroethylene copolymer, tetrafluoroethylene ethylene isobutylene copolymer, ethylene hexafluoropropylene copolymer, tetrafluoroethylene / ethylvinyl One-ter copolymers and the like can be mentioned. Among these, PTFE, FEP, PFA, and the like are preferable in terms of heat resistance, sliding characteristics, and the like. These fluororesins can be used alone or in combination of two or more.

The mixing ratio of the fluororesin in the resin composition is 20 to 50% by weight, preferably 23 to 50% by weight, and more preferably 23 to 48% by weight. If the blending ratio of the fluororesin is too large, the creep characteristics and moldability will be insufficient, and if the blending ratio of the fluororesin is too small, the sliding characteristics may be insufficient.

Conductive carbon black The conductive carbon black used in the present invention is not particularly limited as long as it is a conductive force pump rack. For example, acetylene black, water black, thermal black, and channel black can be used. In order to minimize the deterioration of mechanical properties and formability due to the addition of a pump rack, it is preferable to develop conductivity or semi-conductivity with a small amount of addition. However, a conductive black having a conductivity of at least 360 m 1/100 g can be suitably used.

The DBP oil absorption of the conductive black can be measured by the method specified in ASTM D224. Specifically, a conductive force pump rack is put in one chamber of the measuring device (Absortpotmote ter), and DBP (n-dibutyl phthalate) is added at a constant speed into the one chamber. As the DBP is absorbed, the conductivity of the pump rack increases, and the amount of DBP absorbed is calculated from the amount of DBP absorbed up to a certain degree. Viscosity is detected by a torque sensor.

If the DBP oil absorption of conductive black is too small, it is necessary to mix a large amount of conductive carbon black in order to reduce the resistivity of the resin composition to a desired level. There is a risk that the physical properties may be reduced. The upper limit of the amount of DBP oil absorption of the conductive carbon black is usually about 75 Oml lO Og. The DBP oil absorption is preferably about 400 to 600 m1 / 100 g.

The ratio of the conductive force to the pump rack depends on the conductivity of the conductive carbon black, the structure, the DBP oil absorption, the melt viscosity of the PAS resin, the target resistivity of the resin composition, and the like. Considering these factors comprehensively, the mixing ratio of the conductive pump rack is 1 to 1 based on the total amount of the resin composition. 20% by weight, preferably about 2 to 10% by weight, and more preferably about 2 to 7% by weight. If the compounding ratio of the conductive carbon black is too large, the moldability and the mechanical properties are reduced, and if it is too small, it becomes difficult to achieve a desired resistivity.

The resin composition used in the present invention preferably has a resistivity (JISK 7194, 4 probe method) in the range of 1 XI00 to 1 XI 015 _Ω · _cm . The resistivity is more preferably in the range of 1 × 10 1 to 1 × 10 13 Ω · cm. If the resistivity of the resin composition is too high, the antistatic property becomes insufficient. It is possible to achieve a desired resistivity within the range of the mixing ratio of the conductive car pump rack.

filler

In the sliding member for a transporting device of the present invention, various fillers can be blended as required, in addition to the above components. Examples of fillers include myriki, silica, talc, alumina, kaolin, calcium sulfate, calcium carbonate, titanium oxide, ferrite, clay, graphite, glass powder, zinc oxide, nickel carbonate, iron oxide, and iron oxide. Granular or powdery fillers such as quartz powder, magnesium carbonate, barium sulfate and the like can be mentioned.

Among these fillers, those having cleavage properties, such as graphite, talc, my force, and clay, suppress the amount of abrasion while maintaining the excellent sliding characteristics of the sliding member for a transport device. This is preferable because the durability can be dramatically improved. Among them, graphite is particularly preferable because it has an effect of greatly suppressing abrasion. On the other hand, hard fillers such as carbon beads, like hard fibrous fillers, are not preferable because they vibrate the rotating shaft and generate noise due to friction.

These fillers can be used alone or in combination of two or more. Can be used together. These fillers are used in an amount of usually not more than 20% by weight, preferably not more than 15% by weight, more preferably not more than 10% by weight, based on the total amount of the resin composition. In many cases, the content of the cleaving filler or the like is 5% by weight or less, and typically, about 1 to 5% by weight, a sufficient effect of improving the wear resistance can be obtained.

The sliding member for a transport device of the present invention substantially does not contain a hard fibrous filler (fibrous reinforcing material), which damages the mating material, vibrates the rotating shaft, and generates noise due to friction. I like it because it doesn't let me. However, a small amount of a fibrous filler may be blended within a range that does not impair the object of the present invention. Examples of such a fibrous filler include glass fiber, carbon fiber, asbestos fiber, silica fiber, aluminum fiber, zirconium fiber, boron nitride, silicon nitride fiber, boron fiber, potassium titanate fiber, and the like. Inorganic fibrous materials; Metal fibrous materials such as stainless steel, aluminum, titanium, steel, and brass; High-melting organic fibrous materials such as polyamide, fluororesin, polyester resin, and acrylic resin; fibrous fillers such as Is mentioned. These fibrous fillers can be used alone or in combination of two or more.

The filler may be treated with a sizing agent or a surface treatment agent, if necessary. Examples of the sizing agent or the surface treatment agent include functional compounds such as epoxy compounds, isocyanate compounds, silane compounds, and titanate compounds. These compounds may be used after being subjected to a surface treatment or a sizing treatment on the filler in advance, or may be added at the same time when the composition is prepared. However, in applications where contamination by bleed components from sliding members is severely restricted, such as sliding members for semiconductor transport equipment, compounds that easily bleed may be added. Addition is not preferred.

Other additives

In the resin composition of the present invention, other additives other than the filler include, for example, an impact modifier such as an epoxy group-containing one-year-old olefin copolymer, and a resin modifier such as ethylene glycidyl methacrylate. Lubricants such as pen erythritol tetrastearate, thermosetting resins and antioxidants, UV absorbers, nucleating agents such as boron nitride, flame retardants, and coloring agents such as dyes and pigments Can be added. However, as described above, in applications where contamination by bleed components from the sliding member is severely limited, such as a sliding member for a semiconductor transfer device, it is preferable to use a low molecular weight material that is liable to be precluded. Absent.

Resin composition

In the present invention, a resin composition can be prepared by using equipment and a method generally used for preparing a thermoplastic resin composition, using a predetermined amount of each component as described above. For example, each raw material component is premixed using a mixer such as a Henschel mixer or a tumbler, and if necessary, additives such as fillers are added and further mixed, and then a single-screw or twin-screw extruder is used. It can be used, kneaded, and melt-extruded to form a molding pellet. It is also possible to adopt a method in which some of the necessary components are batched together and then mixed with the remaining components. Also, in order to enhance the dispersibility of each component, it is also possible to pulverize a part of the raw materials to be used, adjust the particle size, mix, and extrude. Further, the molding pellet can be formed into a sliding member for a transfer device by a general melt molding method such as injection molding or extrusion molding.

Sliding member for transfer device

The sliding member for the transfer device is not particularly limited. Rolling bearings, roller bearings, sliding bearings, transport rollers, pulleys, etc. can be mentioned. More specific applications include heat resistance, slidability, friction and abrasion characteristics, mechanical properties, and moderate resistivity, and are used in, for example, electrophotographic copying machines, laser-beam printers, electrostatic Various sliding members in an image forming apparatus such as a recording apparatus, for example, a bearing for holding a gap of a developing roll, a sliding bearing of a heating roller in a fixing unit, and a sliding bearing of a pressure roller can be exemplified. In addition, the sliding member for a transfer device of the present invention is excellent in antistatic properties, high-temperature rigidity, flame retardancy, heat resistance, chemical resistance, dimensional stability, creep resistance, etc., and is free from contamination by bleed components. Particularly, it is suitable for applications such as rotating bearings of semiconductor transfer devices, transfer rollers, and pulleys. Example

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to only these Examples.

The methods for measuring physical properties are as shown below.

(1) Resistivity

The resistivity was measured in accordance with JIS K 7194 (Testing method for measuring resistivity of conductive plastic by 4-probe method).

(2) Dynamic friction coefficient

The Suzuki friction and wear test was performed under the conditions of load = 5 X 105 p &, speed = 0 2 mZs, mating material = aluminum, and running time = 15 hours, and the dynamic friction coefficient was determined.

(3) Evaluation of sliding members for transfer equipment

A rotary bearing is created as a sliding member for transport, and this is assembled into a transport device. Slidability (smaller coefficient of dynamic friction and better sliding), abrasion resistance (smaller wear is better), vibration (smaller is better), and sound (smaller is better) Each was evaluated in the following four stages. The load on the sliding surface of the rotating bearing of the conveyor is about 4 kg, the relative speed of the sliding surface to the rotating shaft is 30 mZ s, and the material of the rotating shaft is SUS304.

A: Very good,

B: Good,

C: Somewhat bad

D: Bad.

(4) Melt viscosity

The melt viscosity of the PAS was measured using a capillary pyrograph (manufactured by Toyo Seiki Co., Ltd.) at a temperature of 310 and a shear rate of 1200 Z seconds.

(5) P A S pH

The pH of PAS was measured in a mixed solvent of acetone: water = 1: 2 (volume ratio). More specifically, to 20 g of the polymer, add 50 ml of acetone, mix well, add 100 ml of ion-exchanged water, shake for 30 minutes with a shaker, and then remove the supernatant. 60 mml was collected and its pH was measured.

[Synthesis Example 1] Synthesis of P AS (A T)

The polymerization vessel, N- methyl-2-pyrrolidone (NM P) 7 2 0 kg , and 4 6. sulfide sodium containing 2 1 wt% of sodium sulfide (N a ₂ S), 5-hydrate 4 2 0 kg After replacing with nitrogen gas, the temperature was gradually raised to 200 with stirring to distill out 160 kg of water. At this time, 62 mol of H 2 S volatilized at the same time.

After the above dehydration step, p-dichrobenzene (p DCB) 364 kg and NMP 250 kg were added, and the mixture was reacted at 220 ° C. for 4.5 hours with stirring. Thereafter, 59 kg of water was injected while stirring was continued, the temperature was raised to 255 ° C, and the reaction was carried out for 5 hours. After the reaction was completed, the content was cooled to around room temperature, and the content was passed through a 100-mesh screen to sieve the granular polymer, washed twice with acetone, and washed three times with water to obtain a washed polymer. Was. Further, the washed polymer was washed with a 3% aqueous solution of ammonium chloride, and then washed with water. After dehydration, the recovered granular polymer was dried at 105 for 3 hours. The polymer thus obtained (A yield was 89%, melt viscosity was 140 Pa's, pH was 6.5, and average particle diameter was about 90 Om.

[Synthesis example 2] Synthesis of P AS (A?)

In a polymerization vessel, charge 70 kg of NMP 72 and 420 kg of sodium sulfide pentahydrate containing 46.2% by weight of sodium sulfide, replace with nitrogen gas, and gradually stir with stirring. The temperature was raised to 0 * and 158 kg of water was distilled off. At this time, 62 mol of H ₂ S volatilized at the same time. After the dehydration step, 371 kg of pDCB and 189 kg of NMP were added to the polymerization vessel, and the mixture was reacted with 220: 4.5 for 4.5 hours with stirring. Thereafter, 49 kg of water was injected while stirring was continued, the temperature was raised to 255 ° C, and the reaction was performed for 5 hours. After the completion of the reaction, the content was cooled to around room temperature, and the contents were passed through a 100-mesh screen to sieved the granular polymer. . Further, the washed polymer was washed with a 0.6% aqueous solution of ammonium chloride, and then washed with water. After dehydration, the collected granular polymer was dried at 105 ° C for 3 hours. The yield of the polymer (A ₂ ) thus obtained was 92%, the melt viscosity was 55 Pa * s, the pH was 6.2, and the average particle diameter was about 500 m . [Examples 1 to 5, and Comparative Examples 1 to 6]

Each component having the composition shown in Table 1 was uniformly driven by a Henschel mixer, and then supplied to a 45 mm φ twin-screw kneading extruder (PCM-45, manufactured by Ikegai Iron & Steel Co., Ltd.). The mixture was kneaded at 34O 0 C to produce a pellet. After drying the obtained pellets at 150 ° C for 6 hours, the mold temperature was set to 144 t and the cylinder temperature was set to 300 to 3 ° C by an injection molding machine (IS-75 manufactured by Toshiba Machine Co., Ltd.). At 40, a cylindrical rotating bearing having an outer diameter of 12.5 mm, an inner diameter of 8.3 mm, and a width of 14 m, and a flat plate for measuring electrical resistivity were produced. Table 1 shows the results.

Table 1 Example Comparative example

1 2 3 4 5 1 2 3 4 5 6

PAS (Ai) 56.5 71.2 53.6 54.5 100.0 81.0 70.0 51.5 94.0 42.0

PAS A ₂ ) 49.0 pairs PTFE 40.0 48.0 25.0 40.0 40.0 15.0 40.0 55.0 Carbon black 3.5 3.0 3.8 3.4 3.5 4.0 3.5 6.0 3.0 Graphite 3.0

Talc one 2.0

One

CF 30.0

I Carbon beads 5.0

Resistivity Ωcm 2E + 01 4E + 01 1E + 12 3E + 01 5E + 01 1E + 16 3E + 01 8E + 00 1E + 12 8E + 01 Coefficient of friction 0.16 0.14 0.19 0.14 0.15 0.45 0.23 0.18 0.19 0.46

Sliding A A B A A D D B A D Appearance Abrasion resistance B B B A A B D C A A D Defect

Vibration A A A A A A B D D A

AAAAAABDCA

(Footnote)

(1) PTFE: polytetrafluoroethylene powder (Kitamura Co., Ltd., KT-400M)

(2) Power pump rack: Conductive carbon black, Ketjen black with a DBP oil absorption of 500 ml / 100 g, TME C 600 JD (Lion)

(3) Talc: Crown Talc D RTM (Matsumura Sangyo Co., Ltd.)

(4) CF: carbon fiber, carbon fiber M—107 T (manufactured by Kureha Chemical Industry Co., Ltd.)

(5) Carbon beads: Bellpearl ^™ C_800 (Kanebo)

As is clear from the experimental results shown in Table 1, a resin composition containing 30 to 79% by weight of PAS, 50 to 20% by weight of fluororesin, and 1 to 20% by weight of conductive carbon black. Rotary bearings for transfer devices made of an object (Examples 1 to 5) exhibit a sufficient antistatic effect due to low electrical resistivity, have a low dynamic friction coefficient, and have excellent sliding characteristics. Furthermore, even in practical tests, it has excellent slidability and wear resistance, and does not generate vibration or noise even when sliding on the rotating shaft. In the present invention, although it is not an essential component, it is for a transport device containing a small amount of a cleavable filler. The rotational bearing (Examples 4 and 5) can further improve the wear resistance and sliding characteristics. it can.

On the other hand, a PAS sliding member not filled with conductive carbon black and PTFE (Comparative Example 1) has poor slidability due to a high dynamic friction coefficient, and has no antistatic effect because it is an insulating material. . A sliding member with a low PTFE compounding ratio (Comparative Example 2) is inferior in sliding characteristics and abrasion resistance and cannot be used as a rotary bearing. A large amount of carbon fiber The sliding member filled with fiber (Comparative Example 3) and the sliding member in which part of PAS was replaced with carbon beads in Example 1 (Comparative Example 4) had a low resistance factor, and thus had a sufficient antistatic effect. While exhibiting low dynamic friction coefficient and excellent sliding characteristics, vibration and noise are generated by sliding with the rotating shaft, making it impractical. The sliding member not filled with fluororesin (Comparative Example 5) had a high coefficient of kinetic friction, and was insufficient in slidability and wear resistance even in a practical test. In the case of the sliding member in which the content of PTFE was increased to 55% (Comparative Example 6), the appearance of the member obtained by injection molding was significantly poor. Industrial applicability

ADVANTAGE OF THE INVENTION According to this invention, it is excellent in heat resistance, slidability, friction characteristics, abrasion resistance, mechanical physical properties, etc., and can provide an antistatic property by controlling the electrical resistivity in a desired range. A sliding member for a device is provided. The sliding member for conveyance of the present invention does not damage the mating member, vibrate the rotating shaft, or generate noise due to friction. The transfer sliding member of the present invention is particularly suitable for applications such as a rotary bearing of a semiconductor transfer device, a transfer roller, and a pulley.

Claims

The scope of the claims

1-Temperature 310 t: Polyarylene sulfide having a melt viscosity measured at a shear rate of 1200 seconds of 20 Pa's or more (A) 30 to 79% by weight, fluororesin (B ) A sliding member for a transfer device formed by molding a resin composition containing 20 to 50% by weight and conductive carbon black (C) 1 to 20% by weight.

2. The sliding member for a transport device according to claim 1, wherein the polyarylene sulfide (A) has a melt viscosity of 20 to 500 Pa's.

3. The slide for a transfer device according to claim 1, wherein the polyarylene sulfide (A) has a pH of 8 or less measured in a mixed solvent of acetone: water = 1: 2 (volume ratio). Element.

4. The sliding member according to claim 1, wherein the polyarylene sulfide (A) is a granular material having an average particle diameter of 100 zm or more.

5. When the fluororesin (B) is polytetrafluoroethylene, tetrafluoroethylene hexafluoropropylene copolymer, or tetrafluoroethylene perfluoroalkyl vinyl ether copolymer The sliding member for a transfer device according to claim 1, wherein

6. The transfer device according to claim 1, wherein the conductive force pump rack (C) has a DBP oil absorption of Se O ml Z l OO g or more. Sliding member.

7. The sliding member for a transfer device according to claim 1, wherein the resin composition further contains a particulate or powdered filler in a proportion of 20% by weight or less.

8. The sliding member for a transfer device according to claim 7, wherein the filler has a cleavage property.

9. The sliding member for a transport device according to claim 8, wherein the filler having a cleavage property is at least one kind of filler selected from the group consisting of graphite, talc, my force, and clay.

10. The sliding member for a transport device according to claim 8, wherein the content of the cleaving filler in the resin composition is 1 to 5% by weight.

1 1. Resin composition, lxl oO ~ l X 1 0 l5 Q ' conveying device for sliding member according to claim 1 having a resistivity in the range of cm.

1 2. The transport device sliding member according to claim 1, which is a rotary bearing, a roller bearing, a slide bearing, a transport roller, or a pulley.

1 3. The sliding member for a transfer device according to claim 1, which is a rotary bearing for a semiconductor transfer device.