Polyamide resin composition and sliding member

Abstract

The purpose of the present invention is to provide a polyamide resin composition (nylon composition) having excellent moldability and sliding properties, and a sliding member that uses said composition. The polyamide resin composition contains a polyamide resin as a main component, and as additives contains 5-20 wt% of a polyethylene resin, 5-30 wt% of a tetrafluoroethylene resin, 0.5-5 wt% of a modified polyolefin resin, and 1-5 wt% of a phosphate. The sliding member is produced by molding this polyamide resin composition.

Description

[Technical Field]

[0001] The present invention relates to a polyamide resin composition and a sliding member such as a bearing having excellent friction and wear properties. [Background technology]

[0002] Polyamide resin (hereafter abbreviated as "nylon") is widely used in fields such as machinery, automobiles, electrical and electronic components, and home appliances due to its excellent moldability, heat resistance, toughness, chemical resistance, and abrasion resistance. However, in sliding applications such as plain bearings, nylon alone does not provide sufficient friction and wear properties, so it is essential to blend it with solid lubricants such as graphite, molybdenum disulfide, and polytetrafluoroethylene resin (hereafter abbreviated as "PTFE"), or lubricants such as mineral oil and wax.

[0003] For the purpose of imparting sliding properties to nylon, for example, Patent Document 1 proposes a synthetic resin composition for sliding members in which PTFE is blended with nylon, and Patent Document 2 proposes a nylon composition in which molybdenum disulfide is blended with nylon.

[0004] However, while nylon containing PTFE suppresses the decrease in rigidity when absorbing water and improves friction and wear properties, it has the problem of significantly reducing heat resistance and mechanical strength.Furthermore, nylon containing molybdenum disulfide has the problem of reducing friction and wear properties due to the decrease in rigidity caused by water absorption.

[0005] To solve the problem of nylon itself, which is its poor dimensional accuracy due to its water absorption, a technique has been proposed in which inorganic fillers are blended into the nylon. However, when inorganic fillers are blended into nylon, the inorganic fillers wear down and become abrasive grains on the sliding surface when the nylon slides against the mating material, causing roughness and wear.

[0006] It has been proposed to blend nylon with a polyethylene resin in order to improve abrasive wear. For example, Patent Document 3 proposes a resin composition containing nylon, an inorganic filler (mica), and a high-density polyethylene resin having a molecular weight of 50,000 to 400,000, and Patent Document 4 proposes a nylon composition consisting of nylon, wollastonite, a modified styrene copolymer, and a modified high-density polyethylene having a molecular weight of 50,000 to 400,000.

[0007] However, in Patent Document 3, when a nylon containing polyethylene resin is blended, the polyethylene resin is easily peeled off from the surface of the molded product, which results in a narrow range of molding conditions for obtaining a molded product with a good appearance, and there is a risk that actual molding will be extremely difficult.In addition, in Patent Document 4, a modified styrene copolymer and a modified high-density polyethylene are blended, which results in a risk of deterioration in fluidity during molding, which may result in deterioration in moldability. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2-219849 [Patent Document 2] Japanese Patent Application Publication No. 63-207851 [Patent Document 3] Japanese Patent Application Publication No. 5-263560 [Patent Document 4] Japanese Patent Application Publication No. 6-345961 Summary of the Invention [Problem to be solved by the invention]

[0009] The nylon compositions proposed above require strict molding conditions, and molded articles (sliding members) made from these nylon compositions have insufficient friction and wear properties. The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a nylon composition (polyamide resin composition) and a sliding member that are excellent in moldability and sliding properties. [Means for solving the problem]

[0010] The present invention Polyamide resin The composition comprises: A polyamide resin composition having a polyamide resin matrix, As an additive, Relative to the mass of the polyamide resin composition, It contains 5 to 20 mass% of polyethylene resin, 5 to 30 mass% of tetrafluoroethylene resin, 0.5 to 5 mass% of modified polyolefin resin, and 1 to 5 mass% of phosphate. And, The polyethylene resin is selected from high-density polyethylene resin, ultra-high molecular weight polyethylene resin, and acid-modified ultra-high molecular weight polyethylene resin. .

[0011] According to the nylon composition of the present invention, a molding material made from the nylon composition has good bite into the screw of a molding machine, excellent moldability, and the surface of a molded product is free from peeling and has an excellent surface condition. Furthermore, a sliding member made from the nylon composition can significantly improve sliding characteristics, including low friction and wear resistance, in sliding friction with a mating member, without impairing the inherent mechanical properties of nylon.

[0012] The nylon composition of the present invention may contain, as additional components, a lubricant in an amount of 0.1 to 1 mass %, an antioxidant in an amount of 0.1 to 2 mass %, and organic particles or organic fibers in an amount of 1 to 40 mass %.

[0013] The lubricant as an additional component functions as a mold release agent that improves the releasability of the nylon composition from a mold during molding, the antioxidant functions to prevent oxidative degradation of the nylon composition during molding, and the organic particles or organic fibers function to significantly improve the sliding properties, including low friction and wear resistance, of a molded article (sliding member) made from the nylon composition without reducing the mechanical strength. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a nylon composition and a sliding member which have good molding processability, such as good bite into the screw of a molding machine, and which can significantly improve sliding properties, including low friction and wear resistance, without impairing the inherent mechanical properties of nylon. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view illustrating a thrust test method. DETAILED DESCRIPTION OF THE INVENTION

[0016] The nylon composition of the present invention contains, in addition to the polyamide resin as the main component, 5 to 20 mass% of polyethylene resin, 5 to 30 mass% of tetrafluoroethylene resin, 0.5 to 5 mass% of modified polyolefin resin, and 1 to 5 mass% of phosphate as additives.

[0017] In the nylon composition of the present invention, the nylon that constitutes the main component is a polymer having an amide bond (-NH-CO-) in the main chain, and is a polymer containing structural units derived from monomer components such as aminocarboxylic acid (amino acid), diamine, dicarboxylic acid, etc. Nylon may be composed of one type of structural unit (polymer of aminocarboxylic acid) or may be composed of multiple types of structural units (copolymer of diamine and dicarboxylic acid, copolymer of diamine, dicarboxylic acid and aminocarboxylic acid, etc.).

[0018] Examples of aminocarboxylic acids include 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid, 10-aminodecanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, p(para)-aminobenzoic acid, p(para)-aminomethylbenzoic acid, etc. Examples of lactams include ε-caprolactam, undecanelactam, ω-laurolactam, etc. These can be used alone or in combination of two or more.

[0019] Examples of diamines include ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine (1,7-diaminoheptane), octamethylenediamine (1,8-diaminooctane), nonamethylenediamine (1,9-diaminononane), decamethylenediamine (1,10-diaminodecane), undecamethylenediamine (1,11-diaminoundecane), dodecamethylenediamine (1,12-diaminododecane), tridecamethylenediamine (1,13-diaminododecane), and the like. aliphatic diamines such as hexamethylenediamine, tetradecamethylenediamine, pentadecamethylenediamine, hexadecamethylenediamine, heptadecamethylenediamine, octadecamethylenediamine, nonadecamethylenediamine, eicosamethylendiamine, 2-methyl-1,5-diaminopentane, 3-methyl-1,5-diaminopentane, 2-methyl-1,8-octanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, and 5-methyl-1,9-nonanediamine; ,2-Cyclohexanediamine, 1,3-Cyclohexanediamine, 1,4-Cyclohexanediamine, 1,3-Bis(aminomethyl)cyclohexane, 1,4-Bis(aminomethyl)cyclohexane, Bis(4-aminocyclohexyl)methane, Bis(4-aminocyclohexyl)propane, Bis(3-methyl-4-aminocyclohexyl)methane, Bis(3-methyl-4-aminocyclohexyl)propane, 1,3-Bisaminomethylcyclohexane, 1,4-Bisaminomethylcyclohexane, 5-amino-2, Examples include alicyclic diamines such as 2,4-trimethyl-1-cyclopentanemethylamine, 5-amino-1,3,3-trimethylcyclohexanemethylamine (isophoronediamine), bis(aminopropyl)piperazine, bis(aminoethyl)piperazine, norbornanedimethyleneamine, and tricyclodecanedimethylamine; and aromatic diamines such as p-phenylenediamine, o(ortho)-phenylenediamine, m-phenylenediamine, p-xylylenediamine, o-xylylenediamine, and m-xylylenediamine. These can be used alone or in combination of two or more.

[0020] Examples of dicarboxylic acids include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, and eicosanedioic acid; 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and dicyclohexanemethane-4,4 ’ and aromatic dicarboxylic acids such as isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. These can be used alone or in combination of two or more.

[0021] Specific examples of nylons that can be used in the present invention include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polytetramethylene adipamide (nylon 46), polytetramethylene sebacamide (nylon 410), polypentamethylene adipamide (nylon 56), polypentamethylene sebacamide (nylon 510), polyhexamethylene sebacamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polydecamethylene adipamide (nylon 106), and polydecamethylene sebacamide. Aliphatic nylons with excellent heat resistance and strength, such as polyamide (nylon 1010), polydecamethylene dodecamide (nylon 1012), polyundecaneamide (nylon 11), polydodecanamide (nylon 12), and polycaproamide / polyhexamethylene adipamide copolymer (nylon 6 / 66), have a melting point of 150°C or higher, and polyhexamethylene terephthalamide (nylon 6T), polycaproamide / polyhexamethylene terephthalamide copolymer (nylon 6 / 6T), and polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (nylon 6 / 6T). Polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6T), polyhexamethylene isophthalamide (nylon 6I), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6I), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6T / 6I), polyhexamethylene terephthalamide / polyundecane amide copolymer (nylon 6T / 11), polyhexamethylene terephthalamide / polydodecanamide copolymer (nylon 6T / 12), polyhexamethylene Poly(Nylon 66 / 6T / 6I), Poly(Nylon 6 ...Examples include semi-aromatic nylons such as polydodecamethylene terephthalamide (nylon 12T) that can be obtained by polymerizing aliphatic and / or alicyclic diamines with aromatic carboxylic acids, aromatic diamines with aliphatic and / or alicyclic dicarboxylic acids, mixtures thereof, or these with lactams or aminocarboxylic acids.

[0022] In the present invention, among the various nylons mentioned above, plant-derived nylons can be used. Plant-derived nylons are resins that use monomers obtained from components derived from plants, such as vegetable oil, and are therefore desirable from the viewpoint of environmental protection (carbon neutrality). Examples of plant-derived nylons include nylon 11, which has a structure in which a monomer having 11 carbon atoms (aminoundecanoic acid) is bonded via an amide bond; nylon 610, which has a structure in which a monomer having 6 carbon atoms (hexamethylenediamine) and a monomer having 10 carbon atoms (sebacic acid) are bonded via an amide bond; nylon 612, which has a structure in which a monomer having 6 carbon atoms (hexamethylenediamine) and a monomer having 12 carbon atoms (dodecanedioic acid) are bonded via an amide bond; Examples include nylon 1010, which has a structure in which a monomer having 10 carbon atoms (decamethylenediamine) and a monomer having 10 carbon atoms (sebacic acid) are bonded via an amide bond; nylon 1012, which has a structure in which a monomer having 10 carbon atoms (decamethylenediamine) and a monomer having 12 carbon atoms (dodecanedioic acid) are bonded via an amide bond; and nylon 10T, which has a structure in which a monomer having 10 carbon atoms (decamethylenediamine) and terephthalic acid are bonded via an amide bond.

[0023] The PTFE blended in the nylon composition of the present invention serves to impart low friction to sliding members made of the nylon composition. PTFE is available in two types: PTFE for molding (molding powder, fine powder) and PTFE for lubricating additives. PTFE for molding usually has a molecular weight of several million to 10 million (high molecular weight PTFE), and is prone to fibrous formation when force is applied before sintering. stomachTherefore, in the present invention, PTFE for lubricant additives such as low-molecular-weight PTFE in which the molecular weight is reduced to several hundred thousand or less to suppress the tendency to become fibrillated, or PTFE obtained by shaping, baking, and then pulverizing the above-mentioned high-molecular-weight PTFE, is used.

[0024] Examples of PTFE for lubricant additives include "TLP10F-1 (trade name)" manufactured by Mitsui-Chemours Fluoroproducts, Inc.; "Lubron L-5 (trade name)" manufactured by Daikin Industries, Ltd.; "Fluon L150J (trade name)," "Fluon L169J (trade name)," "Fluon L170J (trade name)" manufactured by AGC Corporation; "KTL620 (trade name)," "KTL610 (trade name)," "KT300M (trade name)," "KT400M (trade name)," "KT600M (trade name)" manufactured by Kitamura Co., Ltd.; and "TF9201Z (trade name)," "TF9202Z (trade name)," and "TF9027Z (trade name)" manufactured by 3M Limited.

[0025] The blending amount of this PTFE is 5 to 30% by mass, preferably 10 to 25% by mass. If the blending amount is less than 5% by mass, the low friction property is not sufficiently imparted, and if the blending amount is more than 30% by mass, the moldability of the resin composition for a sliding member may be deteriorated.

[0026] The polyethylene resin blended in the nylon composition of the present invention serves to improve the sliding properties, such as friction and wear, of a sliding member made of the nylon composition. Examples of polyethylene resins that can be used include high-density polyethylene resins, ultra-high molecular weight polyethylene resins, and acid-modified ultra-high molecular weight polyethylene resins. Preferred acid-modified ultra-high molecular weight polyethylene resins are maleic anhydride-modified ultra-high molecular weight polyethylene resins.

[0027] High density polyethylene resin (HDPE) is a homopolymer of ethylene produced by a medium to low pressure process, and its density is usually 0.940 to 0.970 g / cm 3Examples of such ultra-high molecular weight polyethylene resins include "Hi-Zex (trade name)" manufactured by Prime Polymer Co., Ltd. and "Novatec (trade name)" manufactured by Japan Polyethylene Corporation. The ultra-high molecular weight polyethylene resin (UHPE) can be one having an intrinsic viscosity [η] of 10 dL / g or more measured in decaphosphoric acid solvent at 135°C and a viscosity-average molecular weight of 500,000 to 6,000,000. Examples of such UHPE resins include "Hi-Zex Million (trade name)" manufactured by Mitsui Chemicals, Inc., "Mipelon (trade name)" manufactured by the same company, and "Sunfine (trade name)" manufactured by Asahi Kasei Chemicals Corporation. Furthermore, the ultra-high molecular weight polyethylene resin can also be one made up of an ultra-high molecular weight polyethylene resin having an intrinsic viscosity of 10 to 40 dL / g at 135°C and a low- or high-molecular weight polyethylene resin having the same intrinsic viscosity of 0.1 to 5 dL / g. Examples of such UHPE resins include "Lubmer (trade name)" manufactured by Mitsui Chemicals, Inc. An example of an acid-modified ultra-high molecular weight polyethylene resin is "Modified LUBMER (trade name)" manufactured by Mitsui Chemicals, Inc., which is modified with maleic anhydride.

[0028] Furthermore, in the present invention, the polyethylene resin can be a homopolymer of plant-derived ethylene derived from bioethanol obtained from plants such as sugarcane or corn, or a plant-derived polyethylene resin that is a copolymer of this plant-derived ethylene with other monomers. When a plant-derived nylon having a biomass content of 100% or less is used as the main component of the nylon, the plant-derived polyethylene resin acts to increase the biomass content of the nylon composition. Examples of this plant-derived polyethylene resin include green polyethylenes manufactured by Braskem, such as SLL118, SLL218, SGM9450F, SHA7260, SHE150, and SGF4950 (all trade names).

[0029] One or more of the polyethylene resins are selected, and the blending amount is 5 to 20 mass %, preferably 5 to 15 mass %. If the blending amount is less than 5 mass %, it is not effective in improving the sliding properties of the sliding member made of the nylon composition, while if the blending amount exceeds 20 mass %, the proportion of the resin dispersed in the nylon, which is the main component, increases, which may deteriorate the wear resistance.

[0030] The modified polyolefin resin blended into the nylon composition of the present invention is a modified polyolefin resin into which acid groups have been introduced that can interact with nylon, which is the main component of the nylon composition. The modified polyolefin resin acts as a compatibilizer that finely disperses the polyethylene resin, which is insoluble in nylon, within the nylon matrix, and significantly improves the sliding properties, including low friction and wear resistance, of molded articles (sliding parts) made from the nylon composition without reducing the mechanical strength.

[0031] The modified polyolefin resin is selected from polyolefin resins graft-modified with unsaturated carboxylic acids, their anhydrides, or derivatives, and saponified polyolefin resins obtained by saponifying polyolefin resins having acetoxy groups in the molecular chain with alkali. Examples of polyolefin resins include homopolymers of α-olefins, copolymers of two or more α-olefins, and copolymers of α-olefins with other compounds copolymerizable with the α-olefins. Examples of α-olefins include α-olefins having 2 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. Examples of other compounds include compounds having polyunsaturated bonds, such as conjugated dienes and non-conjugated dienes, vinyl acetate, and acrylic esters.

[0032] Examples of suitable polyolefin resins include low-density, medium-density, or high-density polyethylene, linear low-density polyethylene, polypropylene, α-olefin copolymers (ethylene-propylene copolymers (EPR), ethylene-vinyl acetate copolymers (EVA), ethylene-butene copolymers (EBR), ethylene-hexene copolymers, ethylene-octene copolymers, ionically crosslinked olefin copolymers (ionomers)), and the like.

[0033] Unsaturated carboxylic acids, their anhydrides, or derivatives thereof are compounds having an ethylenically unsaturated bond and a carboxyl group, an acid anhydride, or derivative group in one molecule. Specific examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, endo-cis-bicyclo[2.2.1]hept-2,3-dicarboxylic acid (Nadic acid), and methyl-endo-cis-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid (methylnadic acid); anhydrides of these unsaturated carboxylic acids; and derivatives such as unsaturated carboxylic acid halides, unsaturated carboxylic acid amides, and unsaturated carboxylic acid imides. More specifically, examples include malenyl chloride, maleimide, N-phenylmaleimide, maleic anhydride, itaconic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, glycidyl maleate, etc. Among these, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, and itaconic anhydride are preferred, with maleic anhydride being particularly preferred.

[0034] Examples of maleic anhydride-modified polyolefin resins include maleic anhydride-modified polyethylene resins, maleic anhydride-modified polypropylene resins, maleic anhydride-modified ethylene-α-olefin copolymers (ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ethylene-butene copolymers, ethylene-hexene copolymers, ethylene-octene copolymers, etc.), and maleic anhydride-modified styrene-ethylene / butylene-styrene copolymers (SEBS).

[0035] A preferred example of the saponified polyolefin resin is a saponified ethylene-vinyl acetate copolymer.

[0036] The modified polyolefin resin used in the present invention preferably has a melt flow rate (MFR) of 0.1 to 100 g / 10 min, more preferably 0.1 to 50 g / 10 min, measured in accordance with JIS K7210 (2014) at a temperature of 190°C or 230°C under a load of 2.16 kg. If the MFR is less than 0.1 g / 10 min, the viscosity will be too high, resulting in poor fluidity of the nylon composition and possibly worsening moldability in melt extrusion molding, etc. If the MFR exceeds 100 g / 10 min, moldability will become unstable and the mechanical strength and heat resistance of the molded product may be reduced.

[0037] Specific examples of modified polyolefin resins used in the present invention include maleic anhydride-modified polyethylene resins and maleic anhydride-modified polypropylene resins such as "ADMER (trade name) NF518, ADMER QE800" manufactured by Mitsui Chemicals, Inc., and "MODIC (trade name)" manufactured by Mitsubishi Chemical Corporation; maleic anhydride-modified ethylene-propylene copolymers such as "TAFMER (trade name) MP0610, MP0620" manufactured by Mitsui Chemicals, Inc.; and maleic anhydride-modified ethylene-butene copolymers such as "TAFMER (trade name)" manufactured by Mitsui Chemicals, Inc. Examples of maleic anhydride-modified styrene-ethylene / butylene-styrene copolymers include "TUFTECH (product name)" manufactured by Asahi Kasei Corporation, "SEPTON (product name)" manufactured by Kuraray Co., Ltd., and "KRATON (product name)" manufactured by Kraton Polymer Japan Co., Ltd. Examples of saponified ethylene-vinyl acetate copolymers include "TECHNOLINK (product name)" manufactured by Taoka Chemical Co., Ltd., "MERCENE (product name)" manufactured by Tosoh Corporation, "EVAL (product name)" manufactured by Kuraray Co., Ltd., and "SOARNOL (product name)" manufactured by Mitsubishi Chemical Corporation.

[0038] The amount of modified polyolefin resin blended is 0.5 to 5 mass %, preferably 1 to 3 mass %. If the blended amount is less than 0.5 mass %, the effect of improving the load resistance and sliding properties of a molded article made from the nylon composition will not be exhibited, and if the blended amount exceeds 5 mass %, there is a risk that the moldability of the nylon composition will be deteriorated.

[0039] The phosphates incorporated into the nylon composition of the present invention are not themselves substances that exhibit lubricity like solid lubricants such as graphite or molybdenum disulfide. However, when incorporated into the nylon composition, they promote the formation of a lubricating coating such as PTFE on the surface of the mating material (sliding surface) during sliding with the mating material, and are effective in improving the wear resistance of molded articles (sliding components) made from the nylon composition. Furthermore, molded articles made from nylon compositions incorporating phosphates are less susceptible to the surface roughness of the mating material, making them suitable for applications requiring abrasive wear resistance.

[0040] The effect of promoting the film-forming properties of the lubricating coating described above begins to appear when a small amount, for example 1% by mass, of phosphate is added, and this effect is maintained up to 5% by mass. However, if the amount exceeds 5% by mass, the amount of lubricating coating formed on the mating material surface becomes too large, which actually reduces wear resistance. Therefore, the amount of phosphate to be added is 1 to 5% by mass, and preferably 1 to 3% by mass.

[0041] Preferred examples of phosphates include metal salts selected from the group consisting of metal salts of orthophosphate, pyrophosphate, and metaphosphate, and mixtures thereof. Among these, orthophosphates (particularly diphosphate and triphosphate), pyrophosphate, and metaphosphate of alkali metals and alkaline earth metals are preferred. As alkali metals and alkaline earth metals, lithium, calcium, and magnesium are particularly preferred. Specific examples include lithium triphosphate, calcium triphosphate, calcium hydrogen phosphate or anhydrous, magnesium hydrogen phosphate or anhydrous, lithium pyrophosphate, calcium pyrophosphate, magnesium pyrophosphate, lithium metaphosphate, calcium metaphosphate, and magnesium metaphosphate.

[0042] The nylon composition of the present invention may contain additional components such as a lubricant and an antioxidant, as well as organic particles or organic fibers.

[0043] Lubricants are blended into nylon compositions to improve mold releasability during molding. Examples of lubricants include hydrocarbon waxes such as paraffin wax, microcrystalline wax, polyethylene wax, and oxidized polyethylene wax; higher fatty acid metal salts of higher fatty acids having 12 or more carbon atoms, such as lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, ricinoleic acid, and naphthenic acid, such as sodium, magnesium, aluminum, calcium, barium, and zinc; and higher fatty acid amides having 12 or more carbon atoms, such as stearamide, oleamide, erucamide, ethylene bisoleamide, ethylene bisstearamide, and methylene bisstearamide. From the viewpoint of mold releasability, lubricants with a melting point of 120°C to 155°C are particularly preferred. Examples of such lubricants include ethylene bisstearamide, zinc stearate, polyethylene wax, and oxidized polyethylene wax.

[0044] The amount of the lubricant to be added is 0.1 to 1% by mass, preferably 0.3 to 0.5% by mass. If the amount is less than 0.1% by mass, the effect as a release agent will not be exerted, and if the amount is added in excess of 1% by mass, no improvement in release properties will be observed.

[0045] Examples of the antioxidant as an additional component include phenol-based antioxidants and phosphite-based antioxidants. One type of antioxidant may be used alone, or two or more types may be used in combination. Phenol-based antioxidants not only improve antioxidant performance at high temperatures, but also have excellent antioxidant performance at low temperatures.

[0046] Phenolic antioxidants include 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4,4'-methylenebis(2,6-di-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 4,4'-thiobis(3-methyl-6-tert-butylphenol), n-octadecyl-3-(4'-hydroxy-3',5'-di-tert-butylphenyl)propionate, and n-octadecyl-3-(4'-hydroxy-3',5'-di-tert-butylphenyl)propionate. -Octadecyl-2-(4'-hydroxy-3',5'-di-tert-butylphenyl)propionate, 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane, 3,9-bis[1,1-dimethyl-2-[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]2,4,8,10-tetraoxaspiro[5,5]-undecane, 2-tert-butyl-6-(3'-tert-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenyl acrylate, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl) Ethyl]-4,6-di-tert-pentylphenyl acrylate, di-n-octadecyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-dihydrocinnamamide, N,N'-ethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], N,N'-tetramethylenebis[3-(3,5-di- tert-butyl-4-hydroxyphenyl)propionamide], N,N'-hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], N,N'-ethylenebis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionamide], N,N'-hexamethylenebis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionamide], N,N'-bis Examples include [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, N,N'-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionyl]hydrazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, and 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate.

[0047] Among these, 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane are preferably used.

[0048] Specific examples of phenolic antioxidants include "ADEKA STAB (trade name)" manufactured by ADEKA Corporation, "SUMIRAIZER (trade name)" manufactured by Sumitomo Chemical Co., Ltd., "IRGANOX (trade name)" manufactured by BASF, "KEMINOX (trade name)" manufactured by Chemipro Kasei Co., Ltd., and "TOMINOX (trade name)" manufactured by Yoshitomi Pharmaceutical Co., Ltd.

[0049] Phosphite antioxidants include triphenyl phosphite, tris(nonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, and monooctyl diphenyl phosphite. bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, bis(nonylphenyl)pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, distearyl-pentaerythritol-diphosphite, and the like.

[0050] Among these, tris(nonylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, and bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite are preferably used.

[0051] Specific examples of phosphite antioxidants include "Irgafos (trade name)" manufactured by BASF, "ADEKA STAB (trade name)" manufactured by ADEKA Corporation, "JP (trade name)" and "JPP (trade name)" manufactured by Johoku Chemical Co., Ltd., and "GSY (trade name)" manufactured by Osaki Kogyo Co., Ltd.

[0052] The blending amount of the antioxidant is 0.1 to 2 mass%, preferably 0.2 to 1.5 mass%. If the blending amount is less than 0.1 mass%, the antioxidant effect is not exerted, and even if the blending amount exceeds 2 mass%, no improvement in antioxidant performance is observed.

[0053] Examples of organic particles or organic fibers as additional components include meta-aramid particles, para-aramid particles, meta-aramid fibers, para-aramid fibers, PBO (polyparaphenylene benzobisoxazole) fibers, polyarylate fibers, novoloid fibers, etc. The organic particles and organic fibers significantly improve the sliding properties, including low friction and wear resistance, of molded articles (sliding members) made from the nylon composition without reducing the mechanical strength.

[0054] A specific example of meta-aramid particles is "Conex Powder (trade name)" manufactured by Teijin Limited, a specific example of para-aramid particles is "Twaron (registered trademark) 5011 (trade name)" manufactured by Teijin Limited, a specific example of meta-aramid fibers is "Conex Staple Fiber (trade name)" manufactured by Teijin Limited, a specific example of para-aramid fibers is "Twaron (registered trademark) 1088 (trade name)" manufactured by Teijin Limited, a specific example of PBO fibers is "ZYLOM-AS (trade name)" manufactured by Toyobo Co., Ltd., a specific example of polyarylate fibers is "Vectran HT (trade name)" manufactured by Kuraray Co., Ltd., and a specific example of novoloid fibers is "Kynol KF-10BT (trade name)" manufactured by Gun-ei Chemical Industry Co., Ltd.

[0055] The blending amount of the organic particles or organic fibers is 1 to 40% by mass, preferably 1 to 30% by mass, and more preferably 3 to 15% by mass. If the blending amount is less than 1% by mass, the effects of improving moldability, abrasion resistance, and sliding properties will not be exhibited, and if the blending amount exceeds 40% by mass, there is a risk that the moldability of the resin composition for sliding members will deteriorate and that the mechanical strength of molded articles made from the nylon composition will decrease.

[0056] The nylon composition of the present invention can be easily prepared by a known method commonly used for preparing conventional resin compositions. For example, a method may be used in which predetermined amounts of nylon, polyethylene resin, PTFE, modified polyolefin resin, and phosphate, or these, plus lubricant, antioxidant, and organic particles or organic fibers, are weighed and mixed in a mixer such as a Henschel mixer, super mixer, ball mill, or tumbler mixer to prepare a mixture, which is then fed into a single- or twin-screw extruder, melt-kneaded to form a strand, which is then cut into pellets, and the pellets are used as the molding material; or a method may be used in which predetermined amounts of polyethylene resin, PTFE, modified polyolefin resin, and phosphate, or these, plus lubricant, antioxidant, and organic particles or organic fibers, are weighed and mixed in a mixer similar to the above to prepare a mixture, which is then fed into a single- or twin-screw extruder, melt-kneaded to form a strand, which is then cut into pellets, and the pellets are then blended with nylon in a predetermined ratio to prepare the molding material.

[0057] The nylon composition of the present invention has good bite into the screw of a molding machine, excellent moldability, and the surface of molded articles is free of peeling and has an excellent surface condition. Sliding members made from this nylon composition can achieve significantly improved sliding characteristics, including low friction and wear resistance, in sliding friction with mating members, without impairing the inherent mechanical properties of nylon. [Example]

[0058] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention. Evaluation of the moldability of the nylon composition and evaluation of the friction and wear properties of sliding members made of the nylon composition were carried out by the following methods.

[0059] <Moldability (1)> The mixture (nylon composition) was melt-kneaded using an extruder to form a string-like molded product, which was then cut to produce pellets.The string-like molded product was visually inspected for breakage (disconnection), its ability to fit into the screw, and the surface condition of the pellets (occurrence of voids (air bubbles), etc.), and evaluated according to the evaluation criteria in Table 1.

[0060] [Table 1]

[0061] <Moldability (2)> The pellets were molded into molded articles (sliding members) using an injection molding machine, and the molded articles were visually inspected for releasability from the mold and surface condition (peeling, etc.) of the molded articles, and evaluated according to the evaluation criteria in Table 2.

[0062] [Table 2]

[0063] <Friction and wear characteristics> The friction coefficient and wear volume were measured using a thrust testing machine under the conditions shown in Table 3. The test method, as shown in Figure 1, involved fixing a rectangular bearing test piece (sliding component) 1, 30 mm on a side and 3 mm thick, to a test stand. A predetermined load was applied from a cylindrical body 2, which served as the mating material, to one surface 3 of the bearing test piece 1 in a direction X perpendicular to said surface 3, while the cylindrical body 2 was rotated in a direction Y around the axis 4 of the cylindrical body 2. The friction coefficient between the bearing test piece 1 and the cylindrical body 2 and the wear volume of surface 3 of the bearing test piece 1 after the test were measured. The friction coefficient was measured from one hour after the start of the test until the end of the test when stable, and the wear volume was measured as the amount of dimensional change of the sliding surface after 8 hours of testing.

[0064] [Table 3]

[0065] In the following examples, the nylon, polyethylene resin, PTFE, modified polyolefin resin, phosphate, lubricant, antioxidant, organic particles, and organic fibers used were as follows. Note that the following materials are all listed by their trade names. [A] Nylon (A-1) Nylon 6 "Nylon 6 A1030JR" manufactured by Unitika Ltd. (A-2) Nylon 66 "Ultramid A" manufactured by BASF (A-3) Nylon 12 "Daiamide X1988" manufactured by Daicel-Evonik (A-4) Nylon 46 "Stanyl" manufactured by DSM (A-5) Nylon 9T "Genesta" manufactured by Kuraray (A-6) Nylon 10T "Xecot" manufactured by Unitika Ltd. (biomass content 56.4%) (A-7) Nylon 11 "Rilsan" manufactured by Arkema (100% biomass) (A-8) Nylon 610 "Vestamid HS16" (60% biomass) manufactured by Daicel-Evok (A-9) Nylon 1010 "Vestamid DS12" manufactured by Daicel-Evok Co., Ltd. (100% biomass) [B] Polyethylene resin (B-1) High-density polyethylene resin "Hi-Zex" manufactured by Prime Polymer Co., Ltd. (B-2) Ultra-high molecular weight polyethylene resin "Mipelon" manufactured by Mitsui Chemicals (B-3) Maleic anhydride modified ultra-high molecular weight polyethylene resin "Modified LUBMER" manufactured by Mitsui Chemicals, Inc. (B-4) Plant-derived polyethylene resin "Green Polyethylene" manufactured by Braskem (biomass content 94.5%) [C] PTFE Kitamura's "KT300M" [D] Modified polyolefin resin (D-1) Saponified ethylene-vinyl acetate copolymer: "Technolink K431-80" manufactured by Taoka Chemical Co., Ltd. (vinyl acetate content before saponification: 28% by mass, degree of saponification: 80%, MFR: 4g / 10 min: 190°C, load: 2.16 kg) (D-2) Saponified ethylene-vinyl acetate copolymer: "MELTHEN H-6051" manufactured by Tosoh Corporation (vinyl acetate content before saponification: 28% by mass, degree of saponification: 100%, MFR: 5.5 g / 10 min: 190°C, load: 2.16 kg) (D-3) Maleic anhydride modified polyethylene resin "Admer NF518" manufactured by Mitsui Chemicals (MFR 2.2g / 10min: 230℃, load 2.16kg) (D-4) Maleic anhydride-modified ethylene-propylene copolymer "Tafmer MP0620" manufactured by Mitsui Chemicals (MFR 0.3 g / 10 min: 230°C, load 2.16 kg) (D-5) Maleic anhydride-modified ethylene-butene copolymer "Tafmer MH7020" manufactured by Mitsui Chemicals, Inc. (MFR 1.5g / 10 min: 230°C, load 2.16 kg) (D-6) Maleic anhydride-modified styrene-ethylene / butylene-styrene copolymer, "Tuftec H1517" manufactured by Asahi Kasei Corporation (MFR 3.0g / 10min: 230℃, load 2.16kg) [E] Phosphate (E-1) Calcium pyrophosphate (manufactured by Yoneyama Chemical Industry Co., Ltd.) (E-2) Magnesium metaphosphate (manufactured by Taihei Chemical Industry Co., Ltd.) [F] Lubricant (F-1) Ethylene bisstearic acid amide "Kaowax EB-P" manufactured by Kao Corporation (melting point 143°C) (F-2) Zinc stearate "Zinc stearate" manufactured by Nitto Kasei Kogyo Co., Ltd. (melting point 140°C) (F-3) Oxidized polyethylene wax "Licowax PED191" (melting point 123°C) manufactured by Clariant Chemicals [G] Antioxidants (G-1) Phenolic antioxidant: 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane, "ADEKA STAB AO-80" manufactured by ADEKA Corporation (G-2) Phosphite antioxidant: Bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, ADEKA "ADEKA STAB PEP-36" [H] Organic particles or organic fibers (H-1) Meta-aramid particles "Conex Powder" manufactured by Teijin Ltd. (H-2) Para-aramid particles "Twaron (registered trademark) 5011" manufactured by Teijin Limited (H-3) Meta-aramid fiber "Conex staple fiber" manufactured by Teijin (H-4) Para-aramid fiber "Twaron (registered trademark) 1088" manufactured by Teijin Limited (H-5) PBO fiber "ZYLOM-AS" manufactured by Toyobo Co., Ltd. (H-6) Polyarylate fiber "Vectran HT" manufactured by Kuraray Co., Ltd. (H-7) Novoloid fiber "Kynol KF-10BT" manufactured by Gunei Chemical Industry Co., Ltd.

[0066] Examples 1 to 15 The nylons constituting the main components were aliphatic nylons (A-1) to (A-4) and semi-aromatic nylon (A-5), and the additives were polyethylene resins (B-1) to (B-3), PTFE (C), modified polyolefin resins (D-1) to (D-6), phosphates (E-1) and (E-2), lubricants (F-1) to (F-3), and antioxidants (G-1) and (G-2). These were weighed out in the amounts shown in Tables 4 to 6 and mixed in a tumbler mixer to produce a mixture. The mixture was then fed into a twin-screw vent extruder, melt-kneaded to form a string-like molded product, and then cut into pellets. These pellets were used as the molding material. During this manufacturing process, the string-like moldings were visually observed for breakage (disconnection), their ability to fit into the screw, and the surface condition of the pellets (occurrence of voids, etc.), and the evaluation results are shown in the various properties (Moldability 1) in Tables 4 to 6.

[0067] This molding material was then fed into a screw-type injection molding machine and injection-molded to produce rectangular molded articles (sliding members) measuring 30 mm on a side and 3 mm thick. During this manufacturing process, the releasability of the rectangular molded articles from the mold and the surface condition of the molded articles (peeling, etc.) were visually observed, and the results are shown in Tables 4 to 6 under Properties (Moldability 2). The coefficient of friction and wear volume of the rectangular molded articles were also evaluated according to the evaluation methods described above. The results are shown in Tables 4 to 6 under Properties (Sliding Properties).

[0068] Examples 16 to 26 The main components were plant-derived nylons (A-6) to (A-9), polyethylene resins (B-2) to (B-4), PTFE (C), modified polyolefin resins (D-2) to (D-6), phosphates (E-1) and (E-2), lubricants (F-1) to (F-3), and antioxidants (G-1) and (G-2). These were weighed out in the amounts shown in Tables 7 and 8 and mixed in a tumbler mixer to form a mixture. The mixture was then fed into a twin-screw vent extruder, melt-kneaded to form a string-like molded product, and cut into pellets. The pellets were used as molding materials. During this process, the string-like molded product was visually inspected for breakage (disconnection), screw penetration, and pellet surface condition (void formation, etc.). The results are shown in Tables 7 and 8 under "Moldability 1."

[0069] This molding material was then fed into a screw-type injection molding machine and injection-molded to produce rectangular molded articles (sliding members) measuring 30 mm on a side and 3 mm thick. During this manufacturing process, the releasability of the rectangular molded articles from the mold and the surface condition of the molded articles (peeling, etc.) were visually observed, and the results are shown in Tables 7 and 8 under Properties (Moldability 2). The coefficient of friction and wear volume of the rectangular molded articles were also evaluated according to the evaluation methods described above. The results are shown in Tables 7 and 8 under Properties (Sliding Properties).

[0070] Examples 27 to 48 The main component, plant-derived nylon (A-6), was used, along with additives (B-3) and (B-4) polyethylene resins, (C) PTFE, (D-2) modified polyolefin resins, (E-2) phosphates, (F-3) lubricants, (G-1) and (G-2) antioxidants, and (H-1) to (H-7) organic particles or fibers. These were weighed out in the amounts shown in Tables 9 to 11 and mixed in a tumbler mixer to form a mixture. The mixture was then fed into a twin-screw vent extruder, melt-kneaded to form a string-like molded product, and then cut into pellets. These pellets were used as molding materials. During this manufacturing process, the string-like molded product was visually observed for breakage (disconnection), screw penetration, and pellet surface condition (void formation, etc.). The results are shown in Tables 9 to 11 under "Moldability 1."

[0071] This molding material was then fed into a screw-type injection molding machine and injection-molded to produce rectangular molded articles (sliding members) measuring 30 mm on a side and 3 mm thick. During this manufacturing process, the releasability of the rectangular molded articles from the mold and the surface condition of the molded articles (peeling, etc.) were visually observed, and the results are shown in Tables 9 to 11 under Properties (Moldability 2). The coefficient of friction and wear volume of the rectangular molded articles were also evaluated according to the evaluation methods described above. The results are shown in Tables 9 to 11 under Properties (Sliding Properties).

[0072] Comparative Examples 1 to 8 The nylons constituting the main components were the same as those in the previous Examples (A-1), (A-2), (A-4), (A-5), and (A-6), and the additives were the same as those in the previous Examples (B-1) to (B-4), PTFE (C), modified polyolefin resin (D-2), phosphate (E-2), lubricant (F-3), antioxidants (G-1) and (G-2), meta-aramid particles (H-1), and further molybdenum disulfide (Nichimori Molybdenum Disulfide, manufactured by Daizo Co., Ltd.). The following materials were prepared: "Buten powder," glass fiber ("03JAFT692" manufactured by Asahi Fiberglass Co., Ltd.), potassium titanate whiskers ("Tismo (trade name)" manufactured by Otsuka Chemical Co., Ltd.), and mica; these were weighed out in the amounts shown in Table 12; these were mixed in a tumbler mixer to produce a mixture; the mixture was then fed into a twin-screw vent extruder, melt-kneaded to form a string-like molded product, which was then cut into pellets; these pellets were used as the molding material. During this manufacturing process, the string-like molded product was visually observed for breaks (disconnections), its ability to fit into the screw, and the surface condition of the pellets (occurrence of voids, etc.); the evaluation results are shown in Table 12 for various properties.

[0073] This molding material was then fed into a screw-type injection molding machine and injection-molded to produce rectangular molded articles (sliding members) measuring 30 mm on a side and 3 mm thick. During this manufacturing process, the releasability of the rectangular molded articles from the mold and the surface condition of the molded articles (peeling, etc.) were visually observed, and the evaluation results are shown in the various properties in Table 12. In addition, the coefficient of friction and wear volume of the rectangular molded articles were evaluated according to the evaluation methods described above, and the results are shown in the various properties in Table 12.

[0074] [Table 4]

[0075] [Table 5]

[0076] [Table 6]

[0077] [Table 7]

[0078] [Table 8]

[0079] [Table 9]

[0080] [Table 10]

[0081] [Table 11]

[0082] [Table 12]

[0083] From the above test results, the nylon compositions of Examples 1 to 48 exhibited good screw bite during extrusion molding, and no breakage (cutting) of the string-like molded articles was observed during the molding process. Furthermore, the molding material (pellets) formed from the string-like molded articles also exhibited good screw bite during injection molding, resulting in excellent molding processability. It was also confirmed that the molded articles had excellent surface condition, with no peeling on the surface. On the other hand, the nylon compositions of Comparative Examples 1 to 6 presented no particular problems with moldability, but the nylon compositions of Comparative Examples 7 and 8 exhibited breakage (cutting) of the string-like molded articles during extrusion molding, making it impossible to obtain good string-like molded articles. Therefore, evaluation (moldability 2) using an injection molding machine was not performed for Comparative Examples 7 and 8.

[0084] Furthermore, all of the molded articles (sliding members) made from the nylon compositions of Examples 1 to 48 exhibited low coefficients of friction and small amounts of wear. In contrast, the molded articles (sliding members) made from the nylon compositions of Comparative Examples 1 and 4 exhibited high coefficients of friction and significantly large amounts of wear. The molded articles (sliding members) made from the nylon compositions of Comparative Examples 2, 3, 5, and 6 had elevated coefficients of friction during the test, so the test was discontinued. In the case of the nylon compositions of Comparative Examples 7 and 8, good molded articles could not be obtained, so friction and wear property tests were not conducted. From the above, it can be seen that the molded articles (sliding members) made from the nylon compositions of the Examples have superior sliding properties compared to the molded articles (sliding members) made from the nylon compositions of the Comparative Examples.

[0085] As explained above, the nylon composition and sliding member of the present invention have good bite into the screw of a molding machine, are excellent in molding processability, and the surface of the molded article has an excellent surface condition without peeling. Furthermore, the sliding member made of the nylon composition does not impair the inherent mechanical properties of nylon, and can provide a nylon composition and sliding member that can significantly improve sliding characteristics, including low friction and wear resistance, in sliding friction with a mating material. [Explanation of symbols]

[0086] 1. Bearing test piece (sliding component) 2 Cylinder (mating material) 4 axis center

Claims

1. In a polyamide resin composition having a polyamide resin as a matrix, As an additive, the polyamide resin composition contains, relative to the mass of the polyamide resin composition, 5 to 20 mass% of a polyethylene resin, 5 to 30 mass% of a tetrafluoroethylene resin, 0.5 to 5 mass% of a saponified ethylene-vinyl acetate copolymer, and 1 to 5 mass% of a phosphate; The polyethylene resin is a polyamide resin composition selected from high-density polyethylene resins, ultra-high molecular weight polyethylene resins, and acid-modified ultra-high molecular weight polyethylene resins.

2. The polyamide resin composition according to claim 1, wherein the polyamide resin is selected from the group consisting of an aliphatic polyamide resin, a semi-aromatic polyamide resin, and a plant-derived polyamide resin.

3. The polyamide resin composition according to claim 2, wherein the plant-derived polyamide resin is polydecamethylene terephthalamide.

4. The polyamide resin composition according to any one of claims 1 to 3, The tetrafluoroethylene resin is The polyamide resin composition is a polytetrafluoroethylene resin that functions as a lubricating additive to impart low friction to the polyamide resin composition.

5. The polyamide resin composition according to any one of claims 1 to 4, The polyamide resin composition, wherein the phosphate is selected from the group consisting of an alkali metal or alkaline earth metal orthophosphate, pyrophosphate, and metaphosphate.

6. 6. The polyamide resin composition according to claim 5, wherein the phosphate is selected from the group consisting of lithium triphosphate, calcium triphosphate, calcium hydrogen phosphate, magnesium hydrogen phosphate, lithium pyrophosphate, calcium pyrophosphate, magnesium pyrophosphate, lithium metaphosphate, calcium metaphosphate, and magnesium metaphosphate.

7. The polyamide resin composition according to any one of claims 1 to 6, A polyamide resin composition comprising, as an additional component, organic particles or organic fibers in an amount of 1 to 40% by mass relative to the mass of the polyamide resin composition.

8. The polyamide resin composition according to any one of claims 1 to 7, A polyamide resin composition comprising, as an additional component, a lubricant selected from a hydrocarbon wax, a higher fatty acid metal salt, and a higher fatty acid amide in an amount of 0.1 to 1 mass % relative to the mass of the polyamide resin composition.

9. The polyamide resin composition according to any one of claims 1 to 8, A polyamide resin composition comprising, as an additional component, an antioxidant consisting of a phenol-based antioxidant and / or a phosphite-based antioxidant in an amount of 0.1 to 2 mass % relative to the mass of the polyamide resin composition.

10. A sliding member comprising the polyamide resin composition according to any one of claims 1 to 9.

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