JP4041206B2 - Sliding member in an electrophotographic image forming apparatus formed by molding a polyarylene sulfide resin composition - Google Patents

Description

【００３４】
（脚注）
（１）ＰＴＦＥ：ポリテトラフルオロエチレン粉末（喜多村社製、商品名ＫＴＬ−６１０）
（２）ＦＥＰ：テトラフルオロエチレン／ヘキサフルオロプロピレン共重合体（三井・デュポンフロロケミカル社製、商品名テフロン１００−Ｊ）
（３）エポキシ基含有α−オレフィン共重合体：モデイパーＡ４４００（日本油脂社製）
（４）導電性カーボンブラック（ＤＢＰ吸油量５００ｍｌ／１００ｇ）：ケッチェンブラックＥＣ６００ＪＤ（ライオン社製）
（５）アミノアルコキシシラン：γ−アミノプロピルトリエトキシシラン
（６）測定値中、Ｅの表記は、常法に従って、例えば、３Ｅ＋１２の場合、３×１０¹²を表し、また、２．１Ｅ−０６は、２．１×１０^-6を表すものとする。
【００３５】
考察
表１に示された実験結果から明らかなように、ＰＡＳ、フッ素樹脂、導電性カーボンブラックにアミノアルコキシシラン化合物を添加した樹脂組成物（実施例１〜６）は、それぞれに対応する、フッ素樹脂、カーボンブラック、アミノアルコキシシラン化合物未充填樹脂組成物（比較例１）、カーボンブラック、アミノアルコキシシラン化合物未充填樹脂組成物（比較例２）、フッ素樹脂、アミノアルコキシシラン化合物未充填樹脂組成物（比較例３）に比べて、動摩擦係数及び比摩耗量は低く、摺動特性に優れる。また、アミノアルコキシシラン化合物未添加の樹脂組成物（比較例４）は、引張強さ、引張伸び、曲げ強さが、対応するアミノアルコキシシラン化合物添加の樹脂組成物と比較して低い。さらに、本発明においては、必須成分ではないが、エポキシ基含有α−オレフィン共重合体を充填することで、引張伸びが改善される（実施例６）。
【００３６】
【発明の効果】
本発明によれば、耐熱性、摺動特性（摩擦・摩耗特性）、機械的物性、溶融流動性に優れ、かつ、体積抵抗率が所望の範囲内に制御されたポリアリーレンスルフィド樹脂組成物を成形してなる電子写真方式の画像形成装置における摺動部材が提供される。本発明の摺動部材は、帯電防止の機能を有し、かつ、軟質金属部品などの相手材を傷つけることがないので、電子写真方式の画像形成装置における摺動部材、例えば、現像ロールのギャップ保持コロ軸受、加熱ロールの滑り軸受、加圧ロールの滑り軸受などとして特に好適である。[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a polyarylene sulfide resin compositionMember in an electrophotographic image forming apparatus formed by moldingMore specifically, a polyarylene sulfide resin composition having excellent heat resistance, sliding characteristics (friction / wear characteristics), mechanical properties, melt flowability, and volume resistivity controlled within a desired range.Member in an electrophotographic image forming apparatus formed by moldingAbout. Of the present inventionSliding memberIs suitable for applications such as a sliding member using a soft metal part such as an aluminum alloy as a counterpart.
[0002]
[Prior art]
Polyarylene sulfide (hereinafter abbreviated as PAS), represented by polyphenylene sulfide (hereinafter abbreviated as PPS), is an engineering plastic that excels in heat resistance, flame retardancy, chemical resistance, dimensional stability, mechanical properties, etc. Yes, it is used in a wide range of applications such as electrical / electronic parts, precision equipment parts, and automobile parts. In recent years, the demand for PAS has been increased in applications as materials for sliding members such as bearings and gears.
In general, sliding members made of synthetic resin are excellent in heat resistance, sliding characteristics (low dynamic friction coefficient, wear resistance), mechanical properties, etc., and can be precisely molded by injection molding, and can be slid. It is required not to damage the material. Furthermore, the sliding member made of synthetic resin often requires an antistatic function depending on the application field.
[0003]
Conventionally, when applying PAS to sliding member applications, in order to improve friction and wear characteristics, mechanical strength, etc., lubricants such as fluororesin, aramid fibers, potassium titanate fibers, carbon fibers, etc. It has been proposed to incorporate a reinforcing material. For example, JP-A-3-292366 proposes an abrasion-resistant resin composition containing a filler such as PPS, fluororesin, and aramid fiber. JP-A-4-63866 discloses a resin for a magnet roll gap retaining roller of a developing device containing an organic reinforcing material such as PPS and aramid fiber and / or an inorganic reinforcing material such as potassium titanate fiber, and a lubricant. Compositions have been proposed. Japanese Patent Laid-Open No. 2-287553 proposes a resin composition for a sliding member in which polytetrafluoroethylene resin powder, pitch-based carbon fibers, and carbon beads are blended with PAS or polyarylene thioether ketone. Japanese Patent Laid-Open No. 10-36679 proposes a resin composition for a sliding member in which a potassium titanate whisker, carbon fiber, and polytetrafluoroethylene are blended with a thermoplastic resin such as PPS.
[0004]
However, since reinforcing materials such as aramid fiber, potassium titanate fiber (or whisker), and carbon fiber are all hard materials, a sliding member formed from a PAS resin composition containing these reinforcing materials is made of aluminum. When a part made of a soft metal such as an alloy or a soft alloy is the counterpart material, there is a problem that the counterpart material is damaged.
On the other hand, sliding members used in electrophotographic copying machines, laser beam printers, electrostatic recording devices, and other image forming apparatuses have excellent heat resistance, friction / wear characteristics, mechanical characteristics, etc., such as aluminum alloys In addition to not damaging the soft metal parts, an antistatic function is required. For example, a sliding member such as a developing roller gap holding roller bearing (for example, a magnet roll gap holding roller) in a developing unit of an image forming apparatus or a sliding roller of a heating roll or a pressure roll in a fixing unit has a constant voltage. Since there is a possibility of charging due to contact with an applied member or friction, it is required to have an antistatic function. If the sliding member is charged, for example, when the sliding member is in contact with the photosensitive drum, the charging characteristics of the photosensitive drum are affected, and the image quality is degraded. Further, when the sliding member is charged, the toner adheres and becomes dirty, the sliding property is lowered, or in some cases, sparks are generated. However, it has both an antistatic function with strictly controlled electrical resistivity (volume resistivity) and excellent slidability that does not damage the mating material even when the soft metal part is the mating material. Resin materials have not yet been provided.
[0005]
Conventionally, for example, as a heat-resistant sliding bearing for a heat fixing part of an electrophotographic apparatus, JP-A-5-117678 discloses PPS resin, tetrafluoroethylene resin, molten fluororesin, aromatic polyester resin, A heat-resistant plain bearing made of a resin composition in which one or more heat-resistant synthetic resins selected from the group consisting of a polyimide resin, a polyether ketone resin, an aromatic polyamide resin and a phenol resin are added as essential components has been proposed. However, this plain bearing does not have an antistatic function. In addition, this resin composition has problems such as poor compatibility of each resin component, insufficient mechanical properties, and insufficient creep characteristics.
[0006]
[Problems to be solved by the invention]
  The object of the present invention is excellent in heat resistance, sliding properties, mechanical properties, melt fluidity, etc.WhenBoth polyarylene sulfide resin compositions whose volume resistivity is controlled within a desired rangeMember in an electrophotographic image forming apparatus formed by moldingIs to provide. MaAnother object of the present invention is to provide a sliding member that is excellent in the above-mentioned various characteristics and that does not damage a counterpart material such as a soft metal part.
[0007]
As a result of diligent research to overcome the problems of the prior art, the present inventors have formulated PAS by adding a fluororesin and conductive carbon black to PAS and further adding an aminoalkoxysilane compound. Resin composition capable of controlling frictional resistance within a desired low range while maintaining the inherent properties such as heat resistance, flame retardancy, and chemical resistance, and having remarkably improved friction and wear characteristics. I found out that In the resin composition of the present invention, a reinforcing material such as aramid fiber may be added depending on the use, but since such a reinforcing material is not essential, in addition to excellent sliding characteristics and antistatic properties, A sliding member that does not damage a mating member such as a soft metal part can be provided. The resin composition of the present invention is particularly suitable as a resin material for various sliding members such as a bearing disposed in an electrophotographic image forming apparatus. The present invention has been completed based on these findings.
[0008]
[Means for Solving the Problems]
  According to the present invention, (A) polyarylene sulfide70-89% By weight, (B) Fluororesin8-20% By weight and (C) conductive carbon black3-10(D) aminoalkoxysilane compound with respect to 100 parts by weight of the resin component containing wt%0.1-5Including part by weight, Volume resistivity is 1 × 10 ⁵ ~ 1x10 ¹⁵ Ω · cmPolyarylene sulfide resin compositionMember in an electrophotographic image forming apparatus formed by moldingIs provided.Furthermore, according to the present invention, (1) according to the Suzuki friction and wear test, a load of 5 × 10 ⁵ The specific wear amount of the polyarylene sulfide resin composition measured under the conditions of Pa, speed 0.2 m / s, counterpart material aluminum, and travel time 15 hours is 2.1 × 10 ^-6 mm ³ / Nm or less of the sliding member, (2) (C) the conductive carbon black has a DBP oil absorption of 360 ml / 100 g or more, (3) the sliding member is an electrophotographic There is provided the above-mentioned sliding member which is a gap maintaining roller bearing of a developing roll, a sliding bearing of a heating roll, or a sliding bearing of a pressure roll in an image forming apparatus of the type.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Polyarylene sulfide (PAS)
The PAS used in the present invention is an aromatic polymer mainly composed of an arylene sulfide repeating unit represented by the formula [—Ar—S—] (wherein —Ar— is an arylene group). is there. 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.
[0010]
Among these PASs, PPS having a repeating unit of p-phenylene sulfide as a main constituent element is particularly preferable since it is excellent in processability and easily industrially available. 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 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 a random or block copolymer having a repeating unit of arylene ketone ketone sulfide and a random or block copolymer having a repeating unit of phenylene sulfide and 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 a PAS can be obtained by a known method (for example, Japanese Patent Publication No. 63-33775) in which an alkali metal sulfide and a dihalogen-substituted aromatic compound are subjected to a polymerization reaction in a polar solvent.
[0011]
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 4,4'-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.
[0012]
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.
[0013]
  As the polar solvent, N-alkylpyrrolidone such as N-methyl-2-pyrrolidone, 1,3-dialkyl-2-imidazolidinone, tetraalkylurea, aprotic organic amide solvent typified 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 50 to 550 Pa · s, more preferably 70 to 550 Pa · s, measured at a temperature of 310 ° C. and a shear rate of 1200 / sec.sIt is. When two or more kinds of PASs having different melt viscosities are blended and used, it is preferable that the melt viscosity of the blend is within the above range. In addition, it is particularly desirable that the PAS has a melt viscosity of 100 Pa · s or more from the viewpoint of mechanical strength and toughness. If the melt viscosity of PAS is too small, mechanical 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.
[0014]
The PAS used in the present invention can be washed after the completion of the polymerization, and further treated with an aqueous solution containing an acid such as hydrochloric acid or acetic acid, or a water-organic solvent mixed solution, or ammonium chloride. It is preferable to use those treated with a salt solution such as 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.
[0015]
  The PAS used in the present invention 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 feed amount is limited during melt extrusion by the extruder, so the residence time of the resin composition in the extruder becomes long, and problems such as deterioration of the resin composition occur. There is a fear. Further, it is not desirable in terms of manufacturing efficiency.
  The blending ratio of PAS in the resin component is, 70 to 89% by weight. If the blending ratio of PAS is excessive, good sliding characteristics cannot be obtained and the antistatic property is insufficient. If the blending ratio of PAS is too small, the creep characteristics may be insufficient, and if polytetrafluoroethylene is used as the fluororesin, the moldability will be insufficient.
[0016]
Fluorine resin
  The fluororesin used in the present invention is not particularly limited. For example, polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer ( PFA), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), vinylidene fluoride / hexafluoropropylene / tetrafluoroethylene copolymer, polyvinyl fluoride, ethylene / tetrafluoroethylene copolymer (ETFE), Ethylene / chlorotrifluoroethylene copolymer (ECTFE), propylene / tetrafluoroethylene copolymer, tetrafluoroethylene / perfluoroalkyl perfluorovinyl ether copolymer, vinylide fluoride / Hexafluoropropylene copolymer, vinylidene fluoride / chlorotrifluoroethylene copolymer, tetrafluoroethylene / ethylene / isobutylene copolymer, ethylene / hexafluoropropylene copolymer, tetrafluoroethylene / ethyl vinyl ether copolymer, etc. Can be mentioned. Among these, PTFE, FEP, PFA, and the like are preferable in terms of heat resistance and slidability.
  The blending ratio of fluororesin in the resin component is, 8-20% by weight. If the blending ratio of the fluororesin is excessive, the creep characteristics are insufficient, and if it is excessive, the sliding characteristics may be insufficient.
[0017]
Conductive carbon black
The conductive carbon black used in the present invention is not particularly limited, and various conductive carbon blacks such as acetylene black, oil furnace black, thermal black, and channel black can be used. In order to minimize the deterioration of mechanical properties and moldability due to the addition of conductive carbon black, it is preferable to develop the volume resistivity of the conductive or semiconductive region with a small addition amount. Conductive carbon black having an oil absorption of 360 ml / 100 g or more can be suitably used.
[0018]
The DBP oil absorption of the conductive carbon black is measured by the method specified in ASTM D2414. That is, carbon black is put in a chamber of a measuring device (Absorpotometer), and DBP (n-dibutyl phthalate) is added into the chamber at a constant rate. As the DBP is absorbed, the viscosity of the conductive carbon black increases, and the DBP oil absorption is calculated from the amount of DBP absorbed up to a certain point. The viscosity is detected with a torque sensor. If the DBP oil absorption of the conductive carbon black is too small, it is necessary to add a large amount of conductive carbon black to reduce the volume resistivity of the resin composition to a desired level. May cause a decrease. The upper limit of the DBP oil absorption is usually about 750 ml / 100 g. The DBP oil absorption is preferably about 400 to 600 ml / g.
[0019]
  The blending ratio of the conductive carbon black depends on the conductivity of the conductive carbon black, the structure, the DBP oil absorption, the melt viscosity of the PAS, and the target volume resistivity of the resin composition. To achieve the purpose, the blending ratio of conductive carbon black in the resin component is3-10% by weight. If the blending ratio of the conductive carbon black is excessive, the moldability and mechanical properties are lowered, and if it is too small, it is difficult to achieve a desired volume resistivity.DesiredVolume resistivityIs 1× 10⁵~ 1x10¹⁵Ω · cm.
[0020]
Aminoalkoxysilane compounds
The aminoalkoxysilane compound used in the present invention is not particularly limited, but is an amino group having 1 to 4 carbon atoms in the alkyl group and 1 to 4 carbon atoms in the alkoxy group (C₁~ C_Four) Alkyl (C₁~ C_Four) Alkoxysilane compounds are preferred, and among them, γ-aminopropyltrialkoxysilane compounds are particularly preferred because they are excellent in addition effect and easily available.
Specific examples of the aminoalkoxysilane compound include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethoxysilane, γ-phenyl-γ-aminopropyltrimethoxysilane, and γ-ureidopropyltri An ethoxysilane etc. are mentioned.
[0021]
  The compounding ratio of the aminoalkoxysilane compound is based on 100 parts by weight of the resin component containing PAS, fluororesin, and conductive carbon black., 0. 1 to 5 parts by weight. If the compounding ratio of the aminoalkoxysilane compound is too small, the effect of improving the mechanical properties due to the addition is small, and if it is too large, gas is likely to be generated during the molding process, and voids are likely to occur in the molded product.
[0022]
Filler
The resin composition of this invention can mix | blend various fillers in the range which does not impair the objective of this invention. Examples of the filler include inorganic fibers such as glass fiber, carbon fiber, asbestos fiber, silica fiber, alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber; stainless steel, aluminum And fibrous fillers such as metal fibrous materials such as titanium, steel and brass; high melting point organic fibrous materials such as polyamide, fluororesin, polyester resin and acrylic resin; Examples of the filler include mica, silica, talc, alumina, kaolin, calcium sulfate, calcium carbonate, titanium oxide, ferrite, clay, glass powder, zinc oxide, nickel carbonate, iron oxide, quartz powder, magnesium carbonate, Particulate or powder fillers such as barium sulfate can be mentioned.
[0023]
These fillers can be used alone or in combination of two or more. Further, the filler may be treated with a sizing agent or a surface treatment agent as 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 subjecting the filler to a surface treatment or a focusing treatment in advance, or may be added simultaneously with the preparation of the composition.
In addition, when applying the sliding member made of the resin composition of the present invention to an application in contact with a soft metal part or the like, the fibrous filler with high hardness is not blended or the blending ratio is set. It is preferable to reduce it.
[0024]
Other additives
In the resin composition of the present invention, as other additives than the above, for example, an impact modifier such as an epoxy group-containing α-olefin copolymer, a resin modifier such as ethylene glycidyl methacrylate, pentaerythritol Lubricants such as tetrastearate, thermosetting resins, antioxidants, ultraviolet absorbers, nucleating agents such as poron nitride, flame retardants, colorants such as dyes and pigments, and the like can be appropriately added.
Among these, an epoxy group-containing α-olefin copolymer is preferable for increasing the toughness (tensile elongation) of the resin composition. Examples of the epoxy group-containing α-olefin copolymer include a copolymer of an α-olefin and an unsaturated glycidyl group-containing monomer, and a copolymer of an α-olefin and an unsaturated glycidyl group-containing monomer. Grafting precursors obtained by polymerizing a vinyl monomer in the presence of (JP-A-1-131220, JP-A-1-138214) and the like. The epoxy group-containing α-olefin copolymer is usually used in a proportion of 0 to 30% by weight in the resin component.
[0025]
Resin composition
The resin composition of the present invention can be prepared by facilities and methods generally used for preparing a synthetic resin composition. For example, each raw material component is premixed with a Henschel mixer, tumbler, etc., and if necessary, a filler such as glass fiber is added and further mixed, then kneaded using a single or twin screw extruder and extruded. To form a pellet for molding. A method of mixing a part of the required components into a master batch and then mixing with the remaining components. In addition, in order to improve the dispersibility of each component, a part of the raw materials to be used is pulverized, mixed with a uniform particle size, and melt extruded It is also possible to do.
Since the resin composition of the present invention is excellent in melt fluidity, it is precisely applied to, for example, a sheet, a film, a tube, a pipe, and other molded articles by a general melt molding processing method such as injection molding or extrusion molding. It can be molded. Molded products have excellent antistatic properties, high-temperature rigidity, flame resistance, heat resistance, chemical resistance, dimensional stability, creep resistance, friction and wear characteristics, etc. Can be used in the field.
[0026]
The resin composition of the present invention can be preferably used particularly as a sliding member. As a sliding member, it can be used in fields that require high heat resistance, friction / wear characteristics, mechanical properties, etc., but the volume resistivity can be controlled to be low within a predetermined range. It can be suitably used as various sliding members in image forming apparatuses such as electrophotographic copying machines (electrophotographic copying machines), laser beam printers, and electrostatic recording apparatuses. Various sliding members in the image forming apparatus include a developing roller gap holding roller bearing (for example, a magnet roll gap holding roller) in the developing unit, a heating roller (fixing roller) sliding bearing and a pressure roller sliding bearing in the fixing unit. Etc. can be illustrated.
[0027]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited only to these examples.
In addition, the measuring method of a physical property is as showing below.
(1) Tensile properties (tensile strength, tensile elongation)
The tensile strength and tensile elongation (tensile elongation at break) of the resin composition were measured at a measurement temperature of 23 ° C., a distance between gauge points of 50 mm, and a crosshead speed of 5 mm / min in accordance with ASTM D638.
(2) Bending properties (flexural modulus, bending strength)
The flexural modulus and flexural strength of the resin composition were measured at a measurement temperature of 23 ° C., a support distance of 80 mm, and a crosshead speed of 3.5 mm / min according to ASTM D790.
(3) Volume resistivity
The volume resistivity of the resin composition was measured according to JIS K6911.
(4) Coefficient of dynamic friction and amount of wear
The dynamic friction coefficient and the amount of wear of the resin composition were determined according to the Suzuki type friction and wear test.^FiveThe measurement was performed under the conditions of Pa, a speed of 0.2 m / s, an aluminum counterpart, and a travel time of 15 hours.
(5) Melt viscosity
The melt viscosity of PAS was measured using a capillograph (manufactured by Toyo Seiki Co., Ltd.) under conditions of a temperature of 310 ° C. and a shear rate of 1200 / sec.
(6) pH of PAS
The pH of PAS was measured in a mixed solvent of acetone: water = 1: 2 (volume ratio).
More specifically, to 20 g of polymer, 50 ml of acetone was added and mixed well. Further, 100 ml of ion-exchanged water was added, and after shaking for 30 minutes with a shaker, 60 ml of the supernatant was separated to obtain its pH. Was measured.
[0028]
[Synthesis Example 1]Synthesis of PAS (A)
In a polymerization can, 720 kg of N-methylpyrrolidone (NMP) and 46.21 wt% sodium sulfide (Na₂Sodium sulfide and pentahydrate 420 kg containing S) were charged, and after substitution with nitrogen gas, the temperature was gradually raised to 200 ° C. while stirring to distill 160 kg of water. At this time, 62 mol of H at the same time₂S volatilized.
After the dehydration step, 364 kg of p-dichlorobenzene (pDCB) and 250 kg of NMP were added to the polymerization can and reacted at 220 ° C. for 4.5 hours while stirring. Thereafter, 59 kg of water was injected while stirring, and the temperature was raised to 255 ° C. and reacted for 5 hours. After completion of the reaction, the mixture was cooled to near room temperature, and the contents were passed through a 100-mesh screen, the granular polymer was sieved, and washed twice with acetone and three times with water to obtain a washed polymer. Further, the washed polymer was washed with a 3% aqueous ammonium chloride solution and then washed with water. After dehydration, the recovered granular polymer was dried at 105 ° C. for 3 hours. The yield of the polymer (A) thus obtained was 89%, the melt viscosity was 140 Pa · s, the pH was 6.5, and the average particle size was about 900 μm.
[0029]
[Synthesis Example 2]Synthesis of PAS (B)
In a polymerization can, 800 kg of NMP and 46.10 wt% Na₂When 373 kg of S was charged and dehydration was performed in the same manner as in Synthesis Example 1, 142 kg of water and 54 mol of H were added.₂S distills. Next, 320 kg of pDCB, 0.79 kg of 1,2,4-trichlorobenzene, 274 kg of NMP, and 0.9 kg of water were added to the polymerization vessel, and reacted at 220 ° C. for 1 hour and then at 230 ° C. for 3 hours. Next, 77 kg of water was injected while continuing stirring, the temperature was raised to 255 ° C. and reacted for 1 hour, and then the reaction was continued at 245 ° C. for 3 hours. After completion of the reaction, the mixture was cooled to near room temperature, and the contents were passed through a 100-mesh screen, the granular polymer was sieved, washed with acetone twice and further washed with water four times to obtain a washed polymer. After dehydration, the recovered granular polymer was dried at 105 ° C. for 3 hours. The yield of the polymer (B) thus obtained was 90%, the melt viscosity was 517 Pa · s, the pH was 7.5, and the average particle size was about 800 μm.
[0030]
[Synthesis Example 3]Synthesis of PAS (C)
In a polymerization can, 720 kg of N-methylpyrrolidone (NMP) and 46.21 wt% sodium sulfide (Na₂Sodium sulfide and pentahydrate 420 kg containing S) were charged, replaced with nitrogen gas, and gradually heated to 200 ° C. with stirring to distill 158 kg of water. At this time, 62 moles of H₂S volatilized.
After the dehydration step, 371 kg of p-dichlorobenzene (pDCB) and 189 kg of NMP were added to the polymerization can and reacted at 220 ° C. for 4.5 hours while stirring. Thereafter, 49 kg of water was injected while continuing stirring, and the temperature was raised to 255 ° C. and reacted for 5 hours. After completion of the reaction, the mixture was cooled to near room temperature, and the contents were passed through a 100-mesh screen, the granular polymer was sieved, washed with acetone twice and further washed with water three times to obtain a washed polymer. Further, the washed polymer was washed with a 0.6% aqueous ammonium chloride solution and then washed with water. After dehydration, the recovered granular polymer was dried at 105 ° C. for 3 hours. The yield of the polymer (C) thus obtained was 92%, the melt viscosity was 55 Pa · s, the pH was 6.2, and the average particle size was about 500 μm.
[0031]
[Example 1]
Each polymer component shown in Table 1 is uniformly dry blended with a Henschel mixer, supplied to a 46 mmφ twin-screw kneading extruder (PCM-46 manufactured by Ikekai Tekko Co., Ltd.), kneaded at a cylinder temperature of 260 to 340 ° C., and pellets. Got. The obtained pellet-like product was dried at 150 ° C. for 6 hours, and then subjected to a tensile test piece and a bending test at an injection molding machine (IS-75 manufactured by Toshiba Machine Co., Ltd.) at a mold temperature of 145 ° C. and a cylinder temperature of 300 to 340 ° C. A piece and a flat plate for volume resistivity measurement were prepared. The results are shown in Table 1.
[0032]
[Examples 2 to 6 and Comparative Examples 1 to 4]
Each test piece was prepared in the same manner as in Example 1 except that the types and blending ratios of the components were changed as shown in Table 1. The results are shown in Table 1.
[0033]
[Table 1]

[0034]
(footnote)
(1) PTFE: polytetrafluoroethylene powder (Kitamura Co., Ltd., trade name KTL-610)
(2) FEP: Tetrafluoroethylene / hexafluoropropylene copolymer (Mitsui / Dupont Fluoro Chemical Co., Ltd., trade name: Teflon 100-J)
(3) Epoxy group-containing α-olefin copolymer: Modeler A4400 (manufactured by NOF Corporation)
(4) Conductive carbon black (DBP oil absorption 500 ml / 100 g): Ketjen black EC600JD (manufactured by Lion)
(5) Aminoalkoxysilane: γ-aminopropyltriethoxysilane
(6) In the measured value, the notation of E follows a conventional method, for example, 3 × 10 in the case of 3E + 12¹²And 2.1E-06 is 2.1 × 10^-6.
[0035]
Consideration
As is clear from the experimental results shown in Table 1, the resin compositions (Examples 1 to 6) obtained by adding an aminoalkoxysilane compound to PAS, fluororesin, and conductive carbon black correspond to the fluororesin corresponding to each. , Carbon black, aminoalkoxysilane compound unfilled resin composition (Comparative Example 1), carbon black, aminoalkoxysilane compound unfilled resin composition (Comparative Example 2), fluororesin, aminoalkoxysilane compound unfilled resin composition ( Compared with Comparative Example 3), the dynamic friction coefficient and the specific wear amount are low, and the sliding characteristics are excellent. Moreover, the resin composition not added with the aminoalkoxysilane compound (Comparative Example 4) has lower tensile strength, tensile elongation, and bending strength than the corresponding resin composition with the aminoalkoxysilane compound added. Furthermore, in the present invention, although it is not an essential component, the tensile elongation is improved by filling the epoxy group-containing α-olefin copolymer (Example 6).
[0036]
【The invention's effect】
  According to the present invention, a polyarylene sulfide resin composition having excellent heat resistance, sliding properties (friction / wear properties), mechanical properties, melt fluidity, and volume resistivity controlled within a desired range.Member in an electrophotographic image forming apparatus formed by moldingWill be provided. BookThe sliding member of the invention has an antistatic function and does not damage a counterpart material such as a soft metal part. Therefore, the sliding member in an electrophotographic image forming apparatus, for example, maintaining a gap of a developing roll Particularly suitable as a roller bearing, a sliding bearing for a heating roll, a sliding bearing for a pressure roll, and the like.

Claims (4)

With respect to 100 parts by weight of a resin component containing (A) 70 to 89 % by weight of polyarylene sulfide, (B) 8 to 20 % by weight of fluororesin, and (C) 3 to 10 % by weight of conductive carbon black, (D ) An electrophotographic system obtained by molding a polyarylene sulfide resin composition having a volume resistivity of 1 × 10 ⁵ to 1 × 10 ¹⁵ Ω · cm, containing 0.1 to 5 parts by weight of an aminoalkoxysilane compound. Member in the image forming apparatus . According to Suzuki friction and wear test, load 5 × 10 ⁵ The specific wear amount of the polyarylene sulfide resin composition measured under the conditions of Pa, speed 0.2 m / s, counterpart material aluminum, and travel time 15 hours is 2.1 × 10 ^-6 mm ³ The sliding member according to claim 1, which is / Nm or less. (C) The sliding member according to claim 1 or 2 , wherein the conductive carbon black has a DBP oil absorption of 360 ml / 100 g or more. The sliding member according to any one of claims 1 to 3, wherein the sliding member is a gap maintaining roller bearing of a developing roll, a sliding bearing of a heating roll, or a sliding bearing of a pressure roll in an electrophotographic image forming apparatus. Moving member.