JP2019151802A - Resin composition - Google Patents

Abstract

To provide a resin composition that has excellent mechanical characteristics and abrasion properties, as well as low aggression to an opposite material at the time of sliding.SOLUTION: The present invention provides a resin composition containing, relative to (A) polyamide resin (component A) 100 pts.wt., (B) wholly aromatic polyamide fiber (component B) 10-20 pts.wt. and (C) zinc oxide whisker (component C) 10-30 pts.wt.SELECTED DRAWING: None

Description

  The present invention relates to a resin composition comprising a polyamide resin, a wholly aromatic polyamide fiber, and zinc oxide whisker, and having both excellent mechanical characteristics and wear characteristics, and low attack to a mating material during sliding. .

  Polyamide resins typified by polyamide 6 and polyamide 66 have excellent heat resistance, chemical resistance, mechanical properties, wear characteristics, and moldability, so they are used as engineering plastics for electrical / electronic parts, automobile-related parts, housing equipment parts, etc. Widely used in In recent years, electronic devices such as digital cameras and tablets have been made thinner as products become smaller, and vehicle-related parts such as automobiles have become lighter due to energy savings. Electrification of self-propelled vehicles such as hybrid vehicles and electric vehicles for the purpose of fossil and fossil fuel reduction is progressing. In these related applications, resin conversion from conventional metals has been studied for the purpose of reducing the weight of products, and in particular, replacement of metals used for applications such as gears and bearings in resin conversion of these mechanical parts. The resin material to be used is required to have high wear characteristics and rigidity, and low aggression property that does not damage the counterpart material when sliding.

  In order to satisfy the above characteristics, Patent Document 1 proposes a sliding member composition comprising a specific amount of zinc oxide whisker, aromatic polyamide fiber, solid lubricant, and synthetic resin. Although there is a description regarding the shaving of the material, there is no description regarding the rigidity. Patent Document 2 proposes a polyamide resin composition for gears containing a specific amount of aluminum borate whisker or zinc oxide whisker. However, although there is a description regarding wear characteristics, there is no description regarding rigidity. Further, Patent Document 3 proposes a fiber reinforced resin gear made of a resin in which a para-type aromatic polyamide fiber having a prescribed tensile modulus is reinforced with para-type aromatic polyamide fibers having different characteristics. Although improvement in strength is described, there is no description regarding wear characteristics. Patent Document 4 proposes a zinc oxide whisker having a tetrapod structure composed of a core part and needle-like crystal parts extending in different four-axis directions from the core part, but specific wear characteristics and other reinforcements are proposed. There is no description about combined use with materials.

JP-A-3-239756 JP 2003-268230 A JP 2010-249195 A Japanese Patent No. 2600761

  An object of the present invention is to provide a resin composition having both excellent mechanical characteristics and wear characteristics, and low attacking property against a mating material during sliding.

  As a result of intensive studies, the present inventors have found that a resin composition comprising polyamide resin, wholly aromatic polyamide fiber and zinc oxide whisker has excellent mechanical characteristics and wear characteristics, and low attacking property against a mating material during sliding. It has been found out that it has both, and has led to the present invention.

Specifically, (1) (A) polyamide resin (component A) 100 parts by weight, (B) wholly aromatic polyamide fiber (component B) 10-20 parts by weight and (C) zinc oxide This is achieved by a resin composition containing 10 to 30 parts by weight of whisker (component C).
One of the preferred embodiments of the present invention is the resin composition according to the above constitution 1, wherein the component (2) is polyamide 66.
One of the preferred embodiments of the present invention is the resin composition according to the above configuration 1 or 2, wherein the (3) B component is a para-type wholly aromatic polyamide fiber.
One of the preferred embodiments of the present invention is (4) wholly aromatic polyamide fiber in which the component B is bundled with at least one sizing agent selected from the group consisting of polyester, polyurethane and polyethersulfone resin. It is a resin composition in any one of the said structures 1-3 characterized by having.
One of the preferred embodiments of the present invention is the resin composition according to the above constitution 4, wherein the component (5) is a wholly aromatic polyamide fiber bundled with polyurethane.
One of the preferred embodiments of the present invention is (6) a molded article comprising the resin composition according to any one of the above configurations 1 to 5.
One of the preferred embodiments of the present invention is (7) the molded product according to the above-described configuration 6, which is a sliding component.

Details of the present invention will be described below.
(A component: polyamide resin)
The polyamide resin of the present invention is a thermoplastic polymer having an amide bond mainly composed of amino acids, lactams, diamines and dicarboxylic acids or amide-forming derivatives thereof. A polycondensate obtained by condensing a diamine with a dicarboxylic acid or an acyl activator thereof can be used. Further, a polymer obtained by polycondensation of aminocarboxylic acid, lactam or amino acid can be used. Moreover, these copolymers can be used.

  Examples of the diamine include aliphatic diamines and aromatic diamines. Examples of the aliphatic diamine include tetramethylene diamine, hexamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2,4-trimethylhexamethylene diamine, 2,4,4-trimethylhexamethylene diamine, and 5-methylnona. Methylenediamine, 2,4-dimethyloctamethylenediamine, metaxylylenediamine, paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane 3,8-bis (aminomethyl) tricyclodecane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (Aminopropyl) pipette Jin, and amino ethyl piperazine.

  As aromatic diamines, p-phenylenediamine, m-phenylenediamine, 2,6-naphthalenediamine, 4,4′-diphenyldiamine, 3,4′-diphenyldiamine, 4,4′-diaminodiphenyl ether, 3,4 '-Diaminodiphenyl ether, 4,4' sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ketone, 3,4'-diaminodiphenyl ketone, 2,2-bis (4-aminophenyl) propane Etc.

  Dicarboxylic acids include adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanoic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium Examples include sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, and diglycolic acid.

  Specifically, as the polyamide resin, polycaproamide (nylon 6), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebacamide (nylon 610), poly Aliphatic polyamides such as hexamethylene dodecanamide (nylon 612), polyundecane adipamide (nylon 116), polyundecanamide (nylon 11), polydodecanamide (nylon 12) and the like can be mentioned. Polytrimethylhexamethylene terephthalamide, polyhexamethylene isophthalamide (nylon 6I), polyhexamethylene terephthalamide / isophthalamide (nylon 6T / 6I), polybis (4-aminocyclohexyl) methane dodecamide (nylon PACM12), polybis (3 -Methyl-4-aminocyclohexyl) methane dodecamide (nylon dimethyl PACM12), polymetaxylylene adipamide (nylon MXD6), polyundecamethylene terephthalamide (nylon 11T), polyundecamethylene hexahydroterephthalamide (nylon 11T) (H)) and aliphatic-aromatic polyamides such as these copolyamides. Moreover, these copolymers, mixtures, poly (p-phenylene terephthalamide), poly (p-phenylene terephthalamide-co-isophthalamide) and the like can be mentioned. Among them, polyamide 66 is preferable.

(B component: wholly aromatic polyamide fiber)
As the wholly aromatic polyamide fiber used as the component B of the present invention, any fiber may be used as long as it belongs to the category called aramid fiber. Examples of the wholly aromatic aramid fiber include meta-type wholly aromatic aramid fiber and para-type wholly aromatic aramid fiber, among which para-type wholly aromatic aramid fiber is preferable.

  The wholly aromatic polyamide constituting the fiber of the present invention is substantially obtained from one or more aromatic diamines and one or more aromatic dicarboxylic acid halides. However, for example, a condensing agent represented by a triphenyl phosphite and pyridine system may be added to one or more aromatic diamines and one or more aromatic dicarboxylic acids. Preferred aromatic diamines include p-phenylenediamine, benzidine, 4,4 "-diamino-p-terphenyl, 2,7-diaminofluorene, 3,4-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 1, 4-bis- (4-aminophenoxy) benzene, 4,4′-bis- (4-aminophenoxy) biphenyl, 9,10-bis- (4-aminophenyl) anthracene, etc. Aromatic dicarboxylic acid halides. Are particularly preferably acid chlorides, such as terephthalic acid chloride, 2,6-naphthalenedicarboxylic acid chloride, 4,4′-diphenyldicarboxylic acid chloride, and one or more lower alkyl groups, lower alkoxy groups, halogeno groups on the aromatic ring thereof. And those containing non-reactive functional groups such as nitro groups Further, when an aromatic dicarboxylic acid is used, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, and one or more lower alkyl groups and lower alkoxy groups in the aromatic ring And those containing non-reactive functional groups such as halogeno groups, nitro groups, etc. Further, the structure of the wholly aromatic polyamide preferred in the present invention has a main skeleton represented by the following formula.

（但し、Ａｒ_１、Ａｒ_２は下記一般式［Ｉ］〜［ＩＶ］からなる群より選ばれる少なくとも１種類の芳香族残基を示す。なおＡｒ_１、Ａｒ_２は互いに同一であっても異なるものであってもよい。また、これらの芳香族残基は、その水素原子の一部がハロゲン原子または低級アルキル基で置換されていてもよい。）

(However, Ar ₁ and Ar ₂ represent at least one aromatic residue selected from the group consisting of the following general formulas [I] to [IV]. Ar ₁ and Ar ₂ may be the same or different. In addition, in these aromatic residues, a part of the hydrogen atoms may be substituted with a halogen atom or a lower alkyl group.)

Among them, when the total of Ar ₁ and Ar ₂ is 100 mol%, the total of general formula [I] and general formula [II], the total of general formula [I] and general formula [III], The total of the general formula [I] and the general formula [IV] or the general formula [I] is preferably 80 mol% or more. More preferably, the total of the general formula [I] and the general formula [II] or the total of the general formula [I] and the general formula [III] is 80 mol% or more. More preferably, the total of the general formula [I] and the general formula [II], or the total of the general formula [I] and the general formula [III] is 80 mol% or more, and the general formula [II] or the general formula [III] is from 1 to 20 mol%.

  The aromatic polyamide dope used as the spinning dope may be solution-polymerized or may be obtained by dissolving a separately obtained wholly aromatic polyamide in a solvent, but is preferably subjected to a solution polymerization reaction. Further, a small amount of an inorganic salt may be added as a solubilizer in order to improve solubility. Examples of such inorganic salts include lithium chloride and calcium chloride.

  As a polymerization solvent or a redissolving solvent, generally known aprotic organic polar solvents are used. For example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N, N-dimethylformamide, N , N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylpropionamide, N, N-butyramide, N, N-dimethylisobutyramide, N-methylcaprolactam, N, N-dimethylmethoxyacetamide, N- Acetylpyrrolidine, N-acetylpiperidine, N-methylpiperidone-2, N, N′-dimethylethyleneurea, N, N′-dimethylpropyleneurea, N, N, N ′, N′-tetramethylmalonamide, N-acetyl Pyrrolidone, N, N, N ′, N′-tetramethylurea, dimethyl sulfoxide, etc. Ri, as a further re-dissolving solvent include strong acid such as concentrated sulfuric acid or methanesulfonic acid.

  The degree of polymerization of the wholly aromatic polyamide is not particularly limited, but it is preferable that the degree of polymerization is large if it dissolves in a solvent. When solution polymerization of a wholly aromatic polyamide is carried out, the ratio of the acid component to the diamine component is made to react in substantially equimolar amounts, but either component can be used in excess to control the degree of polymerization. Moreover, you may use a monofunctional acid component and an amine component as a terminal blocker.

  In the case of forming a wholly aromatic polyamide into a fiber, a method of wet molding a wholly aromatic polyamide dope is usually used. A method of directly discharging the dope into a coagulation bath or an air gap is provided to provide a coagulation bath. There is a method of discharging inside. A poor solvent for wholly aromatic polyamide is used for the coagulation bath. Usually, a good solvent is added to coagulate so that the solvent for the wholly aromatic polyamide dope quickly escapes and no defect occurs in the wholly aromatic polyamide fiber. Adjust the speed. In general, it is preferable to use water as a poor solvent and a solvent of wholly aromatic polyamide dope as a good solvent. The ratio of good solvent / poor solvent is preferably 15/85 to 40/60, although it depends on the solubility and coagulability of the wholly aromatic polyamide.

  The fiber length of the wholly aromatic polyamide fiber is preferably 0.1 mm to 6 mm, and more preferably 0.5 mm to 3 mm. If the thickness is less than 0.1 mm, the reinforcing effect may not be sufficient, and the impact resistance may not be sufficiently improved. If the thickness exceeds 6 mm, handling during production becomes difficult and the fluidity of the composition is inferior, and the moldability is low. It may become defective.

  Such wholly aromatic polyamide fibers exhibit an effect regardless of the presence or absence of bundling, but those that are bundled are preferred because they are easy to handle. Examples of the binder for bundling include polyester, polyurethane, polyethersulfone resin and the like. Among them, polyurethane is preferable. In the present invention, such heat-resistant organic fibers can be used alone or as a mixture of two or more.

  Content of B component is 10-20 weight part with respect to 100 weight part of A component, Preferably it is 13-20 weight part, More preferably, it is 15-20 weight part. If the content of the B component is less than 10 parts by weight, the mechanical properties such as rigidity are not sufficiently improved, and if it exceeds 20 parts by weight, strand breakage or surging occurs during kneading extrusion, resulting in reduced productivity or workability. In the worst case, extrusion is impossible.

(C component: zinc oxide whisker)
The zinc oxide whisker used as the C component of the present invention increases the c-axis direction crystal growth of zinc oxide as compared to the a-axis direction crystal growth by, for example, heat oxidation of metallic zinc in an oxidizing atmosphere such as oxygen. Manufactured so as to be acicular crystals with different direction crystal growth, for example, based on the method described in the example of Japanese Patent No. 2600761.

  The zinc oxide whisker used as component C is preferably a needle-like crystal grown in a different direction in zinc oxide having a hexagonal wurtzite crystal structure. In particular, a zinc oxide-based whisker having a three-dimensional shape such as a so-called tetrapod having a core located at the center of a regular tetrahedron and four needle-like parts extending from the core toward the apex of the regular tetrahedron is provided. Preferably used. The zinc oxide-based whisker having such a three-dimensional shape may have a single structure formed entirely by zinc oxide, or a core part that becomes the nucleus of crystal growth is formed by another substance, The surface may have a composite structure covered with crystal-grown zinc oxide. Further, the surface of the zinc oxide-based whisker may be surface-treated with a coupling agent or the like.

  Content of C component is 10-30 weight part with respect to 100 weight part of A component, Preferably it is 10-20 weight part, More preferably, it is 15-20 weight part. When the content of component C is less than 10 parts by weight, the wear characteristics are not sufficiently improved, and when it exceeds 30 parts by weight, production or moldability is deteriorated, and in the worst case, extrusion cannot be performed.

(Other ingredients)
The resin composition in the present invention can contain an elastomer component as long as the effects of the present invention are not impaired. Suitable elastomer components include core-shells such as acrylonitrile-butadiene-styrene copolymer (ABS resin), methyl methacrylate-butadiene-styrene copolymer (MBS resin), and silicone-acrylic composite rubber-based graft copolymer. Examples of the graft copolymer resin include thermoplastic elastomers such as silicone-based thermoplastic elastomers, olefin-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and polyurethane-based thermoplastic elastomers.

  The resin composition in the present invention can contain other thermoplastic resins as long as the effects of the present invention are not impaired. Other thermoplastic resins include, for example, general-purpose plastics represented by polyethylene resin, polypropylene resin, polyalkyl methacrylate resin, polyphenylene ether resin, polyacetal resin, aromatic polyester resin, liquid crystalline polyester resin, cyclic polyolefin resin, Engineering plastics represented by polyarylate resin (amorphous polyarylate, liquid crystalline polyarylate), so-called super engineering plastics such as polyetheretherketone, polyetherimide, polysulfone, polyphenylene sulfide, and polyethersulfone Can be mentioned.

  The resin composition in the present invention can contain fillers other than wholly aromatic polyamide fibers and zinc oxide whiskers as long as the effects of the present invention are not impaired. The material is not particularly limited, and fillers such as fibrous, plate-like, powdery, and granular can be used. Specifically, for example, fibrous fillers such as carbon fiber, glass fiber, potassium titanate whisker, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, masonry fiber, metal fiber, wollastonite, sericite, kaolin , Silicates such as mica, clay, bentonite, asbestos, talc and alumina silicate, swellable layered silicates such as montmorillonite and synthetic mica, metals such as alumina, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide and iron oxide Non-fibrous fillers such as compounds, carbonates such as calcium carbonate, magnesium carbonate and dolomite, sulfates such as calcium sulfate and barium sulfate, glass beads, ceramic beads, boron nitride, silicon carbide, calcium phosphate and silica Even though these are hollow Ku, can be further used together these fillers 2 or more.

  In addition, these fillers are pretreated with an organic onium ion in the case of coupling agents such as isocyanate compounds, organosilane compounds, organic titanate compounds, organoborane compounds, and epoxy compounds, and swellable layered silicates. The use is preferable in terms of obtaining a higher mechanical strength.

  In order to impart further conductivity to the resin composition of the present invention, a conductive filler can be contained as a filler. The material is not particularly limited, but the conductive filler is not particularly limited as long as it is a conductive filler that is usually used for conducting a resin. Specific examples thereof include carbon fiber, metal powder, and metal flake. , Metal ribbon, metal fiber, metal oxide, carbon fiber coated with a conductive substance, inorganic filler, carbon powder, graphite, carbon flake, scaly carbon, and the like.

  Specific examples of metal species of metal powder, metal flakes, and metal ribbons include silver, nickel, copper, zinc, aluminum, stainless steel, iron, brass, chromium, and tin. Specific examples of the metal species of the metal fiber include iron, copper, stainless steel, aluminum, and brass. Such metal powders, metal flakes, metal ribbons, and metal fibers may be surface-treated with a surface treatment agent such as titanate, aluminum, or silane.

Specific examples of the metal oxide include SnO ₂ (antimony dope), In ₂ O ₃ (antimony dope), ZnO (aluminum dope), etc., and these include the surface of titanate, aluminum, and silane coupling agents. Surface treatment may be performed with a treating agent.

Specific examples of the conductive material in the inorganic filler coated with the conductive material include aluminum, nickel, silver, carbon, SnO ₂ (antimony doped), and In ₂ O ₃ (antimony doped). Examples of the inorganic filler to be coated include mica, glass beads, glass fiber, potassium titanate whisker, barium sulfate, zinc oxide, titanium oxide, aluminum borate whisker, titanate whisker, and silicon carbide whisker. Examples of the coating method include vacuum deposition, sputtering, electroless plating, and baking. These may be subjected to a surface treatment with a surface treatment agent such as a titanate, aluminum or silane coupling agent.

  Carbon powders are classified into acetylene black, gas black, oil black, naphthalene black, thermal black, furnace black, lamp black, channel black, roll black, disc black, and the like, depending on the raw materials and production method. The carbon powder that can be used in the present invention is not particularly limited in its raw material and production method, but acetylene black and furnace black are particularly preferably used.

  The resin composition in the present invention is an antioxidant, a heat resistance stabilizer (hindered phenol type, hydroquinone type, phosphite type and substituted products thereof), a weather resistance agent (resorcinol type, Salicylates, benzotriazoles, benzophenones, hindered amines, etc.), mold release agents and lubricants (montanic acid and its metal salts, its esters, their half esters, stearyl alcohol, stearamide, various bisamides, bisureas, polyethylene waxes, etc.) , Pigments (cadmium sulfide, phthalocyanine, carbon black, etc.), dyes (nigrosine, etc.), crystal nucleating agents (talc, silica, kaolin, clay, etc.), plasticizers (octyl p-oxybenzoate, N-butylbenzenesulfonamide, etc.) ), Antistatic agent (alkyl resin) Fate type anionic antistatic agent, quaternary ammonium salt type cationic antistatic agent, nonionic antistatic agent such as polyoxyethylene sorbitan monostearate, betaine amphoteric antistatic agent, etc.), flame retardant (red phosphorus) , Phosphate esters, melamine cyanurate, magnesium hydroxide, aluminum hydroxide and other hydroxides, ammonium polyphosphate, brominated polystyrene, brominated polyphenylene ether, brominated polycarbonate, brominated epoxy resins or their brominated flame retardants And a combination of antimony trioxide and the like and other polymers can be added.

(Manufacture of resin composition)
The resin composition of the present invention can be produced by mixing the above components simultaneously or in any order with a mixer such as a tumbler, V-type blender, nauter mixer, Banbury mixer, kneading roll, or extruder. Preferably, melt kneading by a twin screw extruder is preferable, and if necessary, it is preferable to supply arbitrary components from the second supply port into other melt-mixed components using a side feeder or the like. As the extruder, one having a vent capable of degassing moisture in the raw material and volatile gas generated from the melt-kneaded resin can be preferably used. From the vent, a vacuum pump is preferably installed for efficiently discharging generated moisture and volatile gas to the outside of the extruder. It is also possible to remove a foreign substance from the resin composition by installing a screen for removing the foreign substance mixed in the extrusion raw material in the zone in front of the extruder die. Examples of such a screen include a wire mesh, a screen changer, a sintered metal plate (such as a disk filter), and the like.

The screw used in the twin-screw extruder is configured as a single screw by inserting and complexly combining screw pieces of various shapes between the forward flight pieces for transportation, and integrating them as a single screw. Examples include a combination of screw pieces such as a forward kneading piece, a reverse kneading piece, and a reverse flight piece arranged in an appropriate order and position in consideration of the characteristics of the raw material to be processed.
Examples of the melt kneader include a banbury mixer, a kneading roll, a single screw extruder, a multi-screw extruder having three or more axes, in addition to a twin screw extruder.

  The resin extruded as described above is directly cut into pellets, or after forming strands, the strands are cut with a pelletizer to be pelletized. When it is necessary to reduce the influence of external dust during pelletization, it is preferable to clean the atmosphere around the extruder. Although the shape of the obtained pellet can take general shapes, such as a cylinder, a prism, and a spherical shape, it is more preferably a cylinder. The diameter of such a cylinder is preferably 1 to 5 mm, more preferably 1.5 to 4 mm, and still more preferably 2 to 3.5 mm. On the other hand, the length of the cylinder is preferably 1 to 30 mm, more preferably 2 to 5 mm, and still more preferably 2.5 to 4 mm.

(About molded products)
A molded product using the resin composition of the present invention can be obtained by molding the pellets produced as described above. Preferably, it is obtained by injection molding or extrusion molding. In injection molding, not only ordinary molding methods, but also injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including the method of injecting supercritical fluid), insert molding, in-mold coating molding, and heat insulation gold Examples thereof include mold molding, rapid heating / cooling mold molding, two-color molding, multicolor molding, sandwich molding, and ultrahigh-speed injection molding. In addition, either a cold runner method or a hot runner method can be selected for molding. In extrusion molding, various shaped extrusion molded products, sheets, films and the like are obtained. For forming sheets and films, an inflation method, a calendar method, a casting method, or the like can be used. It is also possible to form a heat-shrinkable tube by applying a specific stretching operation. The resin composition of the present invention can also be formed into a molded product by rotational molding, blow molding or the like.

  The resin composition of the present invention is a resin composition having both excellent mechanical characteristics and wear characteristics, and low attacking property against a mating material during sliding. It is useful for bearings and gears, packing, sliding parts related to guide rails, wiring covers around automobile engines (corrugated tubes), etc., and the industrial effects that it plays are exceptional.

  The form of the present invention considered to be the best by the present inventor is a collection of the preferable ranges of the above requirements. For example, typical examples are described in the following examples. Of course, the present invention is not limited to these forms.

[Evaluation of resin composition]
(1) Flexural modulus Measured according to ISO 178 (measurement condition 23 ° C.). The test piece was molded by an injection molding machine (EC160NII manufactured by Toshiba Machine Co., Ltd.). The larger this value, the higher the rigidity of the resin composition and the better the mechanical properties.
(2) Specific wear amount Using a hollow cylindrical test piece having an outer diameter of 25.6 mm, an inner diameter of 20 mm, and a height of 15 mm in accordance with JIS K7218 A method, a test piece of the same shape and slide made of stainless steel (SUS304) The specific wear amount was calculated from the change in weight of the test piece before and after the test when moved. The test was performed using a friction and wear tester (EFM-III-EN, manufactured by Orientec Co., Ltd.) under the conditions of a load of 150 N, a sliding speed of 500 mm / s, and a sliding distance of 3 km. The test piece was molded by an injection molding machine (EC160NII manufactured by Toshiba Machine Co., Ltd.). The smaller this value, the better the wear characteristics of the resin composition.
(3) Aggressiveness According to JIS K7218 A method, a hollow cylindrical test piece having an outer diameter of 25.6 mm, an inner diameter of 20 mm, and a height of 15 mm is used and slides with a test piece of the same shape made of stainless steel (SUS304). When the specific wear amount is calculated from the change in weight of the stainless steel before and after the test, and the value is less than 0.5 (× 10 ⁻³ mm ³ / N · km) Was marked with x. The test was performed under the same conditions as in (2). 〇 means low aggression.

[Examples 1-4, Comparative Examples 1-4]
Polyamide resin, wholly aromatic polyamide fiber, and zinc oxide whisker were melt-kneaded in the respective compounding amounts shown in Table 1 using a vent type twin screw extruder to obtain pellets. The vent type twin screw extruder used was TEX-30XSST (completely meshed, rotating in the same direction) manufactured by Nippon Steel Works. Extrusion conditions were a discharge rate of 14 kg / h, a screw rotation speed of 150 rpm, a vent vacuum of 3 kPa, and an extrusion temperature of 290 ° C. from the first supply port to the die part. The polyamide resin, the wholly aromatic polyamide fiber, and the zinc oxide whisker were supplied to the extruder from the first supply port farthest from the die. The obtained pellets were dried at 80 ° C. for 24 hours in a vacuum dryer at a vacuum degree of about −76 cmHg, and thereafter, test pieces for various evaluations were molded by an injection molding machine at a cylinder temperature of 280 ° C. and a mold temperature of 100 ° C. . In addition, each component of the symbol description in Table 1 is as follows.

<A component>
A-1: Polyamide 66 (manufactured by Unitika Ltd .: Maranyl nylon 66 A127 number average molecular weight 18,000)
<B component>
B-1: Totally aromatic polyamide fiber (manufactured by Teijin Limited: Para-type aramid fiber T322UR, long diameter 12 μm, cut length 3 mm, urethane-based sizing agent)
B-2: Totally aromatic polyamide fiber (manufactured by Teijin Limited: Para-type aramid fiber T322EH major axis 12 μm, cut length 3 mm, polyester-based sizing agent)
B-3: Totally aromatic polyamide fiber (manufactured by Teijin Limited: para-aramid fiber T324, long diameter 12 μm, cut length 3 mm, polyethersulfone-based sizing agent)
<C component>
C-1: Zinc oxide whisker (WZ-0511 manufactured by Amtec Co., Ltd. Surface treatment: aminosilane treatment average fiber length 10 μm)

Claims (7)

  (A) 100 parts by weight of polyamide resin (component A), (B) 10-20 parts by weight of wholly aromatic polyamide fiber (component B) and (C) 10-30 parts by weight of zinc oxide whisker (component C) Resin composition.   The resin composition according to claim 1, wherein the component A is polyamide 66.   The resin composition according to claim 1 or 2, wherein the B component is a para-type wholly aromatic polyamide fiber.   The B component is a wholly aromatic polyamide fiber bundled with at least one sizing agent selected from the group consisting of polyester, polyurethane and polyethersulfone resin. The resin composition described in 1.   The resin composition according to claim 4, wherein the component B is a wholly aromatic polyamide fiber bundled with polyurethane.   A molded article comprising the resin composition according to claim 1.   The molded article according to claim 6, which is a sliding part.