Polyamide resin composition

Abstract

The present invention relates to a polyamide resin composition obtained by blending (A) an aliphatic polyamide resin, (B) an acid-modified polyolefin, and (C) a glass fiber coated with a bundling agent, the polyamide resin composition comprising 100 parts by mass of the polyamide resin composition, the polyamide resin composition is characterized in that: 50.00-90.00 parts by mass of an aliphatic polyamide resin (A), 2.00-15.00 parts by mass of an acid-modified polyolefin (B), and 6.00-14.00 parts by mass of glass fibers (C) coated with a bundling agent are blended, the intrinsic viscosity [eta] of the acid-modified polyolefin (B) measured in a decalin solvent at 135 DEG C is 10-40 dl / g, and the average fiber diameter of the glass fibers (C) is 10.0 [mu] m or less; the bundling agent contains a polyurethane resin and a copolymer having an acidic group.

Description

Technical Field

[0001] The present invention relates to a polyamide resin composition. Background Art

[0002] Polyamide resins have excellent properties as engineering plastics and are widely used in various industrial fields such as automobiles, machinery, and electrical and electronics. Among them, polyamide resins have advantages in terms of rigidity and toughness, and are therefore used for sliding parts used under friction conditions such as gears, cams, pulleys, bearings, bearing retainers, door checks, and timing chain guides.

[0003] In order to improve the slidability, particularly the abrasion resistance, of such sliding parts, polyamide resins containing polyolefin components have been developed. It is described in Patent Documents 1 and 3 that a polyamide resin composition using an ultra-high molecular weight substance as a polyolefin component has excellent slidability. In Patent Documents 1 and 2, an acid-modified substance is used as the polyolefin component. Furthermore, in Patent Document 4, glass fibers treated with a glass fiber sizing agent containing a copolymer compound, an aminosilane, and a polyurethane resin and glass fiber-reinforced polyamide resins in which polyamide resins are compounded are disclosed. [Prior Art Documents] [Patent Documents]

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-199789 Patent Document 2: Japanese Patent Application Laid-Open No. 2018-119018 Patent Document 3: Japanese Patent Application Laid-Open No. 10-60269 Patent Document 4: Japanese Patent Application Laid-Open No. 2014-231452 Summary of the Invention Problems to be Solved by the Invention

[0005] For sliding parts, in addition to requiring that the sliding parts themselves do not wear due to repeated use, it is also required that they do not deteriorate the contact object. Regarding the polyamide resin compositions of Patent Documents 1 to 3, although their slidability has been confirmed, further improvement is required to make them compositions that meet the above requirements. In the polyamide resin of Patent Document 4, only the mechanical strength has been confirmed.

[0006] An object of the present invention is to provide a polyamide resin composition having excellent mechanical properties, slidability, and abrasion resistance. Means for Solving the Problems

[0007] The present invention is, for example, the following [1] to [6]. [1] A polyamide resin composition is a polyamide resin composition prepared by compounding an aliphatic polyamide resin (A), an acid-modified polyolefin (B), and glass fibers (C) coated with a sizing agent. In 100 parts by mass of the polyamide resin composition, 50.00 to 90.00 parts by mass of the aliphatic polyamide resin (A), 2.00 to 15.00 parts by mass of the acid-modified polyolefin (B), and 6.00 to 14.00 parts by mass of the glass fibers (C) coated with a sizing agent are compounded. The intrinsic viscosity [η] of the acid-modified polyolefin (B) measured in a decalin solvent at 135 °C is 10 to 40 dl / g. The average fiber diameter of the glass fibers is 10.0 μm or less. The sizing agent contains a polyurethane resin and a copolymer having an acidic group. [2] The polyamide resin composition according to [1], wherein, in 100 parts by mass of the polyamide resin composition, at least one higher fatty acid compound (D) selected from the group consisting of higher fatty acid amides (D1) and higher fatty acid salts (D2) is further compounded in an amount of 0.05 to 0.50 parts by mass. [3] The polyamide resin composition according to [1] or [2], wherein the aliphatic polyamide resin (A) has a structural unit derived from an aminocarboxylic acid or a lactam. [4] The polyamide resin composition according to any one of [1] to [3], wherein the number average molecular weight of the aliphatic polyamide resin (A) is 10,000 to 35,000. [5] A molded article is a molded article of the polyamide resin composition according to any one of [1] to [4]. [6] The molded article according to [5], which is used for applications requiring slidability. Effects of the Invention

[0008] The polyamide resin composition of the present invention has excellent mechanical properties, slidability, and abrasion resistance. Detailed Description

[0009] The present invention relates to a polyamide resin composition which is a polyamide resin composition prepared by compounding an aliphatic polyamide resin (A), an acid-modified polyolefin (B), and glass fibers (C) coated with a sizing agent. In 100 parts by mass of the polyamide resin composition, 50.00 to 90.00 parts by mass of the aliphatic polyamide resin (A), 2.00 to 15.00 parts by mass of the acid-modified polyolefin (B), and 6.00 to 14.00 parts by mass of the glass fibers (C) coated with a sizing agent are compounded. The intrinsic viscosity [η] of the above-mentioned acid-modified polyolefin (B) measured in a decalin solvent at 135 °C is 10 to 40 dl / g. The average fiber diameter of the above-mentioned glass fibers is less than 10.0 μm. The above-mentioned sizing agent contains a polyurethane resin and a copolymer having an acidic group.

[0010] <Aliphatic polyamide resin (A)> An aliphatic polyamide resin (A) is compounded in the polyamide resin composition. Examples of the aliphatic polyamide resin (A) include an aliphatic homopolyamide resin (A-1) and an aliphatic copolyamide resin (A-2). They can be used alone as one kind, or two or more kinds can be used in combination.

[0011] (A-1) Aliphatic homopolyamide resin The aliphatic homopolyamide resin (A-1) refers to a polyamide resin in which the monomer component constituting the aliphatic polyamide resin is one kind. Here, as the monomer component constituting the aliphatic polyamide resin, a combination of an aliphatic diamine and an aliphatic dicarboxylic acid, a lactam, or an aminocarboxylic acid can be cited. The combination of an aliphatic diamine and an aliphatic dicarboxylic acid is a monomer component composed of a condensate of an aliphatic diamine and an aliphatic dicarboxylic acid. When the monomer component constituting the aliphatic polyamide resin is a combination of an aliphatic diamine and an aliphatic dicarboxylic acid, a combination of one kind of aliphatic diamine and one kind of aliphatic dicarboxylic acid is regarded as one kind of monomer component.

[0012] The number of carbon atoms of the aliphatic diamine is preferably 2 to 20, particularly preferably 4 to 12. The number of carbon atoms of the aliphatic dicarboxylic acid is preferably 2 to 20, particularly preferably 6 to 12. The number of carbon atoms of the lactam is preferably 4 to 12. The number of carbon atoms of the aminocarboxylic acid is preferably 4 to 12.

[0013] Examples of the lactam include ε-caprolactam, heptalactam, undecalactam, α-pyrrolidone, α-piperidone, laurolactam, etc. Among them, from the viewpoint of polymerization production, it is preferably one kind selected from the group consisting of ε-caprolactam, undecalactam, and laurolactam. In addition, examples of the aminocarboxylic acid include 6-aminohexanoic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Among them, from the viewpoint of polymerization production, one selected from the group consisting of 6-aminohexanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid is preferred.

[0014] Examples of the aliphatic diamine include aliphatic diamines other than alicyclic ones such as ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, hexadecanediamine, heptadecanediamine, octadecanediamine, nonadecanediamine, eicosanediamine, 2-methyl-1,8-octanediamine, 2,2,4 / 2,4,4-trimethylhexamethylenediamine; alicyclic diamines such as 1,3- / 1,4-cyclohexanediamine, bis(4-aminocyclohexyl)methane, bis(4-aminocyclohexyl)propane, bis(3-methyl-4-aminocyclohexyl)methane, (3-methyl-4-aminocyclohexyl)propane, 1,3- / 1,4-bis(aminomethyl)cyclohexane, 5-amino-2,2,4-trimethyl-1-cyclopentanemethanamine, 5-amino-1,3,3-trimethylcyclohexanemethanamine, bis(aminopropyl)piperazine, bis(aminoethyl)piperazine, norbornanedimethyleneamine, etc. Among them, from the viewpoint of polymerization productivity, aliphatic diamines other than alicyclic ones are preferred, and hexamethylenediamine is more preferred.

[0015] Examples of the aliphatic dicarboxylic acid include aliphatic dicarboxylic acids other than alicyclic ones such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, eicosanedioic acid; alicyclic dicarboxylic acids such as 1,3- / 1,4-cyclohexanedicarboxylic acid, dicyclohexylmethane-4,4'-dicarboxylic acid, norbornanedicarboxylic acid, etc. Among them, aliphatic dicarboxylic acids other than alicyclic ones are preferred, one selected from the group consisting of adipic acid, sebacic acid, and dodecanedioic acid is more preferred, and adipic acid or dodecanedioic acid is further preferred.

[0016] Examples of the combination of the aliphatic diamine and the aliphatic dicarboxylic acid include the combination of hexamethylenediamine and adipic acid, the combination of hexamethylenediamine and sebacic acid, the combination of hexamethylenediamine and dodecanedioic acid, etc., and equimolar salts of these combinations are preferably used.

[0017] As the aliphatic homopolyamide resin (A-1), specifically, polybutyrolactam (polyamide 4), polybutylene adipamide (polyamide 46), polybutylene azelate (polyamide 49), polybutylene sebacamide (polyamide 410), polypentrolactam (polyamide 5), polycaprolactam (polyamide 6), polyheptolactam (polyamide 7), polyundecanolactam (polyamide 11), polylaurolactam (polyamide 12), pentamethylene adipamide (polyamide 56), hexamethylene adipamide (polyamide 66), dodecamethylene adipamide (polyamide 412), pentamethylene azelate (polyamide 59), pentamethylene sebacamide (polyamide 510), dodecamethylene sebacamide (polyamide 512), tridecamethylene sebacamide (polyamide 513), hexamethylene azelate (polyamide 69), hexamethylene sebacamide (polyamide 610), dodecamethylene sebacamide (polyamide 612), adipic acid nonanediamide (polyamide 96), azelaic acid nonanediamide (polyamide 99), sebacic acid nonanediamide (polyamide 910), dodecanedioic acid nonanediamide (polyamide 912), adipic acid decanediamide (polyamide 106), azelaic acid decanediamide (polyamide 109), sebacic acid decanediamide (polyamide 1010), dodecanedioic acid decanediamide (polyamide 1012), adipic acid dodecanediamide (polyamide 126), azelaic acid dodecanediamide (polyamide 129), sebacic acid dodecanediamide (polyamide 1210), dodecanedioic acid dodecanediamide (polyamide 1212), ethylenedioic acid dodecanediamide (polyamide 122), etc. can be mentioned. The aliphatic homopolyamide resin (A-1) can be used alone as 1 kind, or can be used in the form of a mixture combining 2 or more kinds.

[0018] Among them, from the viewpoint of polymerization productivity, the aliphatic homopolyamide resin (A-1) is preferably at least 1 kind selected from the group consisting of polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, and polyamide 612, more preferably at least 1 kind selected from polyamide 6, polyamide 11, polyamide 12, polyamide 610, and polyamide 612, and further preferably polyamide 6.

[0019] (A-2) Aliphatic copolyamide resin The aliphatic copolyamide resin (A-2) is an aliphatic polyamide resin having two or more monomer components that make up the aliphatic polyamide resin and having no aromatic ring. Therefore, examples of the aliphatic copolyamide resin (A-2) include aliphatic copolyamide resins that are copolymers of two or more monomers selected from the group consisting of combinations of aliphatic diamines and aliphatic dicarboxylic acids, lactams, and aminocarboxylic acids. Here, the combination of an aliphatic diamine and an aliphatic dicarboxylic acid is a monomer component composed of a condensate of an aliphatic diamine and an aliphatic dicarboxylic acid. For the combination of an aliphatic diamine and an aliphatic dicarboxylic acid, the combination of one diamine and one dicarboxylic acid is regarded as one monomer component.

[0020] Examples of the aliphatic diamine include the same aliphatic diamines as those exemplified as raw materials for the aliphatic homopolyamide resin (A-1). The diamine may be used alone or two or more thereof may be used in appropriate combination. Among them, from the viewpoint of polymerization productivity, at least one selected from the group consisting of aliphatic diamines other than alicyclic aliphatic diamines is preferred, at least one selected from the group consisting of linear aliphatic diamines is more preferred, and hexamethylenediamine is further preferred.

[0021] Examples of the aliphatic dicarboxylic acid include the same aliphatic dicarboxylic acids as those exemplified as raw materials for the aliphatic homopolyamide resin (A-1). The dicarboxylic acid may be used alone or two or more thereof may be used in appropriate combination. Among them, an aliphatic dicarboxylic acid other than alicyclic aliphatic dicarboxylic acids is preferred, at least one selected from the group consisting of adipic acid, sebacic acid, and dodecanedioic acid is more preferred, and at least one selected from the group consisting of adipic acid and dodecanedioic acid is further preferred.

[0022] Examples of the lactam include the same lactams as those exemplified as raw materials for the aliphatic homopolyamide resin (A-1). The lactam may be used alone or two or more thereof may be used in appropriate combination. Among them, from the viewpoint of polymerization production, at least one selected from the group consisting of ε-caprolactam, undecanolactam, and laurolactam is preferred.

[0023] In addition, examples of the aminocarboxylic acid include the same aminocarboxylic acids as those exemplified as raw materials for the aliphatic homopolyamide resin (A-1). The aminocarboxylic acid may be used alone or two or more thereof may be used in appropriate combination. Among them, from the viewpoint of polymerization production, at least one selected from the group consisting of 6-aminohexanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid is preferred.

[0024] As the aliphatic copolyamide resin (A-2), specifically, examples thereof include caprolactam / hexamethylenediamine adipate copolymer (polyamide 6 / 66), caprolactam / hexamethylenediamine azelate copolymer (polyamide 6 / 69), caprolactam / hexamethylenediamine sebacate copolymer (polyamide 6 / 610), caprolactam / hexamethylenediamine undecanoate copolymer (polyamide 6 / 611), caprolactam / hexamethylenediamine dodecanoate copolymer (polyamide 6 / 612), caprolactam / aminoundecanoic acid copolymer (polyamide 6 / 11), caprolactam / lauryllactam copolymer (polyamide 6 / 12), caprolactam / hexamethylenediamine adipate / lauryllactam copolymer (polyamide 6 / 66 / 12), caprolactam / hexamethylenediamine adipate / hexamethylenediamine sebacate copolymer (polyamide 6 / 66 / 610), caprolactam / hexamethylenediamine adipate / hexamethylenediamine dodecanedicarboxylate copolymer (polyamide 6 / 66 / 612), hexamethylenediamine adipate / caprolactam copolymer (polyamide 6 / 66), and other aliphatic copolyamides. The aliphatic copolyamide resin (A-2) can be used alone as 1 type, or can be used in the form of a mixture of 2 or more types combined.

[0025] Among them, from the viewpoints of suppressing the water absorption rate of the molded product and maintaining mechanical strength, at least 1 type selected from the group consisting of polyamide 6 / 66, polyamide 6 / 12, and polyamide 6 / 66 / 12 is preferred, at least 1 type selected from the group consisting of polyamide 6 / 66 and polyamide 6 / 66 / 12 is more preferred, and polyamide 6 / 66 is particularly preferred.

[0026] From the viewpoint of productivity, the aliphatic polyamide resin (A) preferably has a structural unit derived from an aminocarboxylic acid or a lactam, is preferably an aliphatic homopolyamide resin (A-1), more preferably 1 or more types selected from the group consisting of polyamide 6, polyamide 46, polyamide 66, polyamide 610, polyamide 612, polyamide 11, and polyamide 12, and particularly preferably polyamide 6, polyamide 46, and / or polyamide 66.

[0027] From the viewpoint of slidability, the number average molecular weight of the aliphatic polyamide resin (A) is preferably 10,000 to 35,000, more preferably 10,000 to 32,000, and further preferably 11,000 to 30,000. The number average molecular weight is a value calculated from the relative viscosity. The relative viscosity is a value measured by dissolving 1 g of polyamide in 100 ml of 96% sulfuric acid at 25°C in accordance with JIS K6920-2.

[0028] Regarding the terminal amino group concentration of the aliphatic polyamide resin (A), in terms of the terminal amino group concentration determined by dissolving it in a mixed solvent of phenol and methanol and performing neutralization titration, it is preferably in the range of 30 μmol / g or more, more preferably in the range of 30 μmol / g or more and 50 μmol / g or less. If it is within the above range, sufficient moldability and mechanical properties can be obtained.

[0029] When the aliphatic polyamide resin (A) contains two or more kinds of polyamide resins with different terminal amino group concentrations (for example, at least one aliphatic homopolyamide resin (A-1) and at least one aliphatic copolyamide resin (A-2)), the terminal amino group concentration in the aliphatic polyamide resin (A) is preferably measured by the above-mentioned neutralization titration. However, when the terminal amino group concentration and the mixing ratio of each polyamide resin are clear, the average value calculated by summing up the values obtained by multiplying each terminal amino group concentration by its mixing ratio can be used as the terminal amino group concentration of the aliphatic polyamide resin (A). In the present invention, the value measured by neutralization titration is adopted. The aliphatic polyamide resin (A) can be one component or a combination of two or more components.

[0030] The blending amount of the aliphatic polyamide resin (A) is 50.00 to 90.00 parts by mass, preferably 65.00 to 87.00 parts by mass, more preferably 75.00 to 85.00 parts by mass in 100 parts by mass of the polyamide resin composition. When the blending amount of the aliphatic polyamide resin (A) is within the above range, the mechanical properties and moldability are good.

[0031] <Acid-modified polyolefin (B)> An acid-modified polyolefin (B) is blended in the polyamide resin composition. The acid-modified polyolefin (B) is a polyolefin modified with a compound containing an acid-modifying group. The acid-modified polyolefin (B) can be modified not only with a compound containing an acid-modifying group but also with a compound containing a modifying group other than the acid-modifying group. By modifying the polyolefin with a compound containing an acid-modifying group, the affinity with the aliphatic polyamide resin (A) is improved.

[0032] Polyolefins are homopolymers or copolymers of olefins. Examples of olefins include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc. They can be used alone or in combination of two or more.

[0033] In addition, the copolymer can also be a copolymer copolymerized with polyenes such as non-conjugated dienes. Examples of non-conjugated dienes include 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 4,8-dimethyl-1,4,8-decatriene (DMDT), dicyclopentadiene, cyclohexadiene, cyclooctadiene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,5-norbornadiene, etc. They can be used alone or in combination of two or more. The polyolefin is preferably a homopolymer of ethylene and a copolymer of ethylene and an α-olefin other than ethylene. Examples of commercially available polyolefins include products sold as ultra-high molecular weight polyolefins.

[0034] Examples of acid-modifying groups of polyolefins include carboxyl group, carboxyl metal salt, acid anhydride group, sulfonic acid group, etc. The acid-modifying group is preferably carboxyl group and acid anhydride group. In addition, examples of modifying groups other than acid-modifying groups include amino group, hydroxyl group, silanol group, alkoxy group, epoxy group, isocyanate group, mercapto group, oxazoline group, etc.

[0035] The acid-modified polyolefin (B) can be obtained by melt-kneading a polyolefin and a compound containing an acid-modifying group or graft-modifying the polyolefin to introduce an acid-modifying group. In addition, the acid-modified polyolefin (B) can also be prepared by reacting a polyolefin and a compound containing an acid-modifying group in the absence of a solvent using an extruder or a twin-screw kneader, etc.

[0036] Examples of the compound containing an acid-modified group include unsaturated carboxylic acids or their derivatives, olefinically unsaturated compounds containing a hydroxyl group, olefinically unsaturated compounds containing an amino group, organosilicon compounds containing a vinyl group, and the like. Examples of the unsaturated carboxylic acid or its derivative include unsaturated compounds having one or more carboxyl groups, esters of compounds having a carboxyl group and an alkyl alcohol, unsaturated compounds having one or more carboxylic anhydride groups, and the like. Examples of the unsaturated group include a vinyl group, a vinylene group, an unsaturated cyclic hydrocarbon group, and the like. From the viewpoint of reactivity, the compound containing an acid-modified group is preferably an unsaturated carboxylic acid or its derivative.

[0037] Specific examples of the unsaturated carboxylic acid include unsaturated dicarboxylic acids such as acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, mesaconic acid, citraconic acid, crotonic acid, isocrotonic acid, endo-cis-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid. In addition, examples of the derivative of the unsaturated carboxylic acid include acid halides, amides, imides, acid anhydrides, esters, etc. of the above unsaturated carboxylic acids, and preferably include maleoyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, glycidyl maleate, etc. From the viewpoint of reactivity, the unsaturated carboxylic acid or its derivative is more preferably maleic anhydride and / or acrylic acid, and particularly preferably maleic anhydride. The compound containing an acid-modified group may be one component or two or more components.

[0038] The compound containing a modifying group other than the acid-modified group can be appropriately selected from the compounds containing a modifying group other than the above acid-modified group.

[0039] The addition amounts of the compound containing the above acid-modified group and the compound containing a modifying group other than an arbitrary acid-modified group during the acid modification of the polyolefin can be appropriately set according to the desired modification amount of the polyolefin.

[0040] In the case of obtaining the acid-modified polyolefin (B) by melt-kneading a polyolefin and a compound containing an acid-modified group and graft-modifying the polyolefin to introduce an acid-modified group, the graft modification of the polyolefin can be carried out, for example, by dissolving the polyolefin in an organic solvent and then adding a compound containing an acid-modified group, a radical initiator, etc. to the solution to react. The reaction temperature is preferably 70°C to 200°C, particularly preferably 80°C to 190°C. In addition, the reaction time is preferably 0.5 hour to 15 hours, particularly preferably 1 to 10 hours.

[0041] When producing an acid-modified polyolefin (B) by reacting a polyolefin with a compound containing an acid-modifying group using an extruder or a twin-screw kneader without a solvent, the reaction temperature is preferably above the melting point of the polyolefin, particularly preferably 160°C to 330°C. In addition, the reaction is preferably carried out by melt-kneading for 0.5 minutes to 10 minutes.

[0042] The intrinsic viscosity [η] of the acid-modified polyolefin (B) measured in a decalin solvent at 135°C is 10 to 40 dl / g, preferably 15 to 35 dl / g, more preferably 20 to 30 dl / g. When the intrinsic viscosity [η] is 10 or more, the coefficient of kinetic friction of the polyamide resin composition tends to be lower and the slidability is further improved. The intrinsic viscosity [η] of the acid-modified polyolefin (B) can be adjusted by the polymerization conditions.

[0043] Examples of the acid-modified polyolefin (B) include the components described in JP-A-2018-199789 and JP-A-2006-28231. The acid-modified polyolefin (B) can be one component or a combination of two or more components.

[0044] The blending amount of the acid-modified polyolefin (B) is 2.00 to 15.00 parts by mass, preferably 2.00 to 13.00 parts by mass, more preferably 4.00 to 11.00 parts by mass, per 100 parts by mass of the polyamide resin composition. When the blending amount of the acid-modified polyolefin (B) is within the above range, the slidability and mechanical strength are good.

[0045] <Glass fiber (C) coated with a sizing agent containing a polyurethane resin and a copolymer having an acidic group> Glass fiber (C) coated with a sizing agent is incorporated into the polyamide resin composition, and the sizing agent contains a polyurethane resin and a copolymer having an acidic group. Glass fiber (C) coated with a sizing agent containing a polyurethane resin and a copolymer having an acidic group (hereinafter also referred to as "glass fiber (C) coated with a sizing agent") is a component that imparts excellent slidability and mechanical properties to the polyamide resin composition.

[0046] [Glass fiber] Examples of the glass constituting the glass fiber include glass made from the compositions of A glass, AR glass, C glass, D glass, E glass, H glass, S glass, T glass, M glass, NE glass, etc.

[0047] A fiber refers to a shape with an aspect ratio (ratio of major axis to minor axis) of 10 or more. Glass fibers sometimes break during melt compounding with other components. Therefore, the glass fibers only need to meet the definition of "fibers" in this specification during compounding, and also include glass fibers that no longer meet the definition of "fibers" in this specification in the polyamide composition due to breakage during melt compounding.

[0048] The shape of the glass fibers is not particularly limited, and examples include flat fibers and chopped fibrils. The shape of the cross-section of the glass fibers is not particularly limited, and examples include a perfect circle, a crescent shape, an ellipse, a rectangle, or a similar shape thereof.

[0049] The average fiber diameter of the glass fibers is 10.0 μm or less, preferably 5.0 μm to 10.0 μm, more preferably 5.0 μm to 8.0 μm. When the average fiber diameter of the glass fibers is within the above range, the sliding property is excellent and the amount of wear is suppressed. The average fiber diameter of the glass fibers is a value obtained by measurement with an optical microscope, and in the case of using a commercially available product, it can also be a catalog value. The average fiber diameter of the glass fiber (C) coated with a sizing agent is also preferably in the same range.

[0050] In the case where the cross-section of the glass fibers is a rectangle or a similar shape, the length of one side of the cross-section is preferably 0.5 μm to 50 μm, particularly preferably 1 to 40 μm. The number-average fiber length of the glass fibers is preferably 250 μm to 400 μm, particularly preferably 300 μm to 360 μm. The weight-average fiber length of the glass fibers is preferably 350 μm to 550 μm, particularly preferably 380 μm to 500 μm. The number-average fiber length and the weight-average fiber length of the glass fibers can be obtained from an image taken with a transmission microscope using image analysis software. From the viewpoints of rigidity, mechanical strength, and fluidity, the aspect ratio obtained by dividing the average fiber diameter of the glass fibers by the number-average fiber length is preferably 10 or more, particularly preferably 15 to 100.

[0051] [Polyurethane resin] The polyurethane resin is a resin obtained by subjecting a polyol component and a polyisocyanate component to a urethane reaction.

[0052] [[Polyol component]] Examples of the polyol component include polyester polyols (condensation polyester polyols, lactone polyester polyols), polycarbonate polyols, polyether polyols, and the like.

[0053] As the condensation polyester polyol, substances obtained by reacting a dicarboxylic acid or its lower alkyl ester with an aliphatic diol can be cited, etc. Here, as the dicarboxylic acid or its lower alkyl ester, adipic acid, succinic acid, azelaic acid, pimelic acid, sebacic acid, phthalic acid, etc. can be cited. As the aliphatic diol, aliphatic diols without side chains such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, etc.; and aliphatic diols with side chains such as 1,2-propanediol, 1,3-butanediol, 2,5-dimethyl-2,5-hexanediol, 2,2-diethyl-1,3-propanediol, neopentyl glycol, etc. can be cited.

[0054] As the lactone polyester polyol, substances obtained by reacting lactone compounds such as β-propiolactone, pivalolactone, δ-valerolactone, ε-caprolactone, methyl-ε-caprolactone, dimethyl-ε-caprolactone, trimethyl-ε-caprolactone, etc. with hydroxy compounds such as short-chain polyols can be cited, etc.

[0055] As the polycarbonate polyol, substances obtained by the transesterification reaction of hydroxy compounds such as short-chain polyols with diallyl carbonate, dialkyl carbonate or ethylene carbonate can be used. For example, poly-1,6-hexamethylene carbonate, poly-2,2'-bis(4-hydroxyhexyl) propane carbonate, etc. can be industrially produced and are thus easily obtainable. As other methods for obtaining polycarbonate polyols, the so-called phosgene method (or solvent method) can be adopted.

[0056] As the polyether polyol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyoxypropylene glycol, polyalkylene ether diols based on glycerol, etc. can be cited.

[0057] <<Polyisocyanate component>> As the polyisocyanate, aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, etc. can be cited.

[0058] As the aliphatic polyisocyanate, for example, ethylenediisocyanate, tetramethylenediisocyanate, hexamethylenediisocyanate (HDI), dodecamethylenediisocyanate, 1,6,11-undecanetriisocyanate, 2,2,4-trimethylhexamethylenediisocyanate, lysine diisocyanate, methyl 2,6-diisocyanatohexanoate, bis(2-isocyanatoethyl) fumarate, bis(2-isocyanatoethyl) carbonate, 2-isocyanatoethyl 2,6-diisocyanatohexanoate can be cited.

[0059] As alicyclic polyisocyanates, examples include isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate.

[0060] As aromatic polyisocyanates, examples include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate (TDI), 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, 1,5-naphthalene diisocyanate, 4,4',4”-triphenylmethane triisocyanate, m-isocyanatobenzenesulfonyl isocyanate, p-isocyanatobenzenesulfonyl isocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-2,5-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-3,5-phenylene diisocyanate, 1-ethyl-2,4-phenylene diisocyanate, 1-isopropyl-2,4-phenylene diisocyanate, 1,3-dimethyl-2,4-phenylene diisocyanate, 1,3-dimethyl-4,6-phenylene diisocyanate, 1,4-dimethyl-2,5-phenylene diisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl-3,5-diethylbenzene diisocyanate, 3-methyl-1,5-diethylbenzene-2,4-diisocyanate, 1,3,5-triethylbenzene-2,4-diisocyanate, naphthalene-1,4-diisocyanate, 1-methyl-naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1-binaphthyl-2,2'-diisocyanate, biphenyl-2,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 2,2'-diphenylmethane diisocyanate, etc.

[0061] The polyisocyanate is preferably a diisocyanate having two isocyanate groups per molecule.

[0062] In the urethanization reaction, chain extenders such as polyols and polyamines can also be used.

[0063] [Copolymer having an acidic group] As the copolymer having an acidic group, a copolymer of monomers having an acidic group, or a copolymer of monomers having an acidic group and monomers not having an acidic group can be cited.

[0064] Examples of the monomer having an acidic group include unsaturated carboxylic acids, carboxylic anhydrides, etc. Examples of the unsaturated carboxylic acid include acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, mesaconic acid, citraconic acid, crotonic acid, isocrotonic acid, endo-cis-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid, etc. Examples of the carboxylic anhydride include dicarboxylic anhydrides such as maleic anhydride, itaconic anhydride, succinic anhydride, phthalic anhydride, glutaric anhydride, dodecenyl succinic anhydride, chlorendic anhydride, citraconic anhydride, etc. Since the steric hindrance during copolymerization is small and the polarity of the compound is small, maleic anhydride is preferably used as the carboxylic anhydride. In addition, the monomer having an acidic group may also be a monomer having a functional group with the same function as the acidic group. Examples of such a functional group include acid halides, amides, imides, and esters of the above unsaturated carboxylic acids. Examples of the monomer having a functional group with the same function as the acidic group include maleoyl chloride, maleimide, monomethyl maleate, dimethyl maleate, glycidyl maleate, etc. They may be used alone or in combination of two or more kinds.

[0065] Examples of the monomer not having an acidic group include styrene, ethylene, acetylene, etc.

[0066] As the copolymer having an acidic group, a copolymer compound obtained by copolymerizing an unsaturated dicarboxylic acid and / or a carboxylic anhydride, methyl acrylate, and methyl methacrylate is preferred.

[0067] From the viewpoints of reactivity and mechanical properties during the production of the copolymer, the copolymerization ratio of the unsaturated dicarboxylic acid and / or the carboxylic anhydride is preferably 20 to 60% by mass, particularly preferably 25 to 55% by mass. From the viewpoints of reactivity and mechanical properties during the production of the copolymer, the copolymerization ratio of methyl acrylate is preferably 20 to 75% by mass, particularly preferably 30 to 65% by mass. In addition, from the viewpoints of reactivity and mechanical properties during the production of the copolymer, the copolymerization ratio of methyl methacrylate is preferably 5 to 20% by mass, particularly preferably 7 to 17% by mass. The copolymerization ratio of the monomer not having an acidic group is preferably 10% by mass or less, particularly preferably 1% by mass or less.

[0068] From the viewpoints of reactivity and mechanical properties during the production of the copolymer, the weight-average molecular weight of the copolymer compound is preferably 10,000 to 60,000, particularly preferably 20,000 to 50,000. The weight-average molecular weight of the copolymer compound is the molecular weight measured by gel permeation chromatography (GPC).

[0069] [Other components of the bundling agent] The sizing agent may contain other components in addition to the polyurethane resin and the copolymer having an acidic group. Examples of other components include coupling agents, lubricants, nonionic surfactants, antistatic agents, water, organic solvents, etc. Examples of lubricants include fatty acid amides, quaternary ammonium salts, etc. In addition, examples of nonionic surfactants include synthetic alcohol-based, natural alcohol-based, fatty acid ester-based, etc. Water and organic solvents are components that dissolve lubricants, nonionic surfactants, antistatic agents, etc. Examples of organic solvents include ethanol, etc.

[0070] The content of each component in the sizing agent can be appropriately set according to the properties of the obtained glass fiber.

[0071] 〔Coating〕 The glass fiber is coated with a sizing agent containing a polyurethane resin and a copolymer having an acidic group. "Coating" means attaching the sizing agent to at least a part of the surface of the glass fiber. The glass fiber is surface-treated by coating the above sizing agent. In addition, the glass fiber can also be subjected to a bundling treatment in which two or more glass fibers are bundled into one by coating the above sizing agent. In addition, the bundling treatment can also be carried out by the following method: after coating the above sizing agent on a plurality of glass fiber filaments formed by drawing molten glass from a plurality of nozzles, bundling them into a single glass fiber bundle, and then winding them into a cake.

[0072] The glass fiber (C) coated with the above sizing agent can also be surface-treated with other components. Examples of such components include other components contained in the sizing agent.

[0073] For the glass fiber (C) coated with a sizing agent containing a polyurethane resin and a copolymer having an acidic group, in addition to the above, components described in JP-A-2014-231452 can also be mentioned. The glass fiber (C) coated with a sizing agent containing a polyurethane resin and a copolymer having an acidic group can be one component or a combination of two or more components.

[0074] The compounding amount of the glass fiber (C) coated with the sizing agent is 6.00 to 14.00 parts by mass. When the compounding amount of the glass fiber (C) is outside the above range, the mechanical properties tend to deteriorate. In addition, when the compounding amount of the glass fiber (C) exceeds 14.00 parts by mass, the wear amount of the sliding member and the object contacted by the sliding member increases. From the viewpoints of moldability and mechanical strength, the compounding amount of the glass fiber (C) coated with the sizing agent is preferably 7.00 to 13.00 parts by mass, and particularly preferably 8.00 to 12.00 parts by mass.

[0075] <Higher fatty acid compound (D)> In the polyamide resin composition, it is preferable to incorporate at least one higher fatty acid compound (D) selected from the group consisting of higher fatty acid amides (D1) and higher fatty acid salts (D2). Among the higher fatty acid compounds (D), higher fatty acid amides are preferred. Further, from the viewpoint of suppressing the amount of wear, it is preferable to use a higher fatty acid amide and a higher fatty acid salt in combination.

[0076] Examples of the higher fatty acid include fatty acids having 12 or more carbon atoms, and specifically, lauric acid, stearic acid, myristic acid, erucic acid, palmitic acid, behenic acid, oleic acid, arachidic acid, ricinoleic acid, behenic acid, etc. can be mentioned. Examples of the higher fatty acid salt (D2) include metal salts of higher fatty acids. Examples of the metal include Group 1 elements (alkali metals), Group 2 elements (alkaline earth metals), Group 12 elements, and Group 13 elements. Specifically, for example, magnesium stearate, zinc stearate, lithium stearate, calcium stearate, aluminum palmitate, lithium behenate, calcium behenate, etc. can be mentioned.

[0077] As the higher fatty acid amide (D1), for example, there may be mentioned: aliphatic mono-higher fatty acid amides such as lauric acid amide, palmitic acid amide, oleic acid amide, stearic acid amide, erucic acid amide, behenic acid amide, ricinoleic acid amide, 12-hydroxystearic acid amide; N-substituted aliphatic mono-carboxylic acid amides such as N-lauryl lauric acid amide, N-palmityl palmitic acid amide, N-oleyl palmitic acid amide, N-oleyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-stearyl erucic acid amide, N-stearyl-12-hydroxystearic acid amide, N-oleyl-12-hydroxystearic acid amide, hydroxymethyl stearic acid amide, hydroxymethyl behenic acid amide, 12-hydroxystearic acid monoethanolamide; aliphatic dicarboxylic acid amides such as methylene bis-stearic acid amide, methylene bis-lauric acid amide, methylene bis-12-hydroxystearic acid amide, ethylene bis-decanoic acid amide, ethylene bis-lauric acid amide, ethylene bis-oleic acid amide, ethylene bis-stearic acid amide, ethylene bis-erucic acid amide, ethylene bis-behenic acid amide, ethylene bis-isostearic acid amide, ethylene bis-12-hydroxystearic acid amide, butylene bis-stearic acid amide, hexamethylene bis-oleic acid amide, hexamethylene bis-stearic acid amide, hexamethylene bis-behenic acid amide, hexamethylene bis-12-hydroxystearic acid amide, N,N'-dioleyl sebacic acid amide, N,N'-dioleyl adipic acid amide, N,N'-distearyl adipic acid amide, N,N'-distearyl sebacic acid amide; alicyclic carboxylic acid amides such as N,N'-dicyclohexanecarbonyl-1,4-diaminocyclohexane, 1,4-cyclohexanedicarboxamide, 1,4-cyclohexanedicarboxylic acid diaminocyclohexane, 1,2,3,4-butane tetracarboxylic acid tetracyclohexylamide, N,N'-bis(3-hydroxypropyl)-1,4-cubanedicarboxamide, N,N'-(1,4-cyclohexanediyl)bisacetamide, tris(methylcyclohexyl)propane trimethylamide; aromatic carboxylic acid amides such as 1,4-cyclohexanedicarboxylic acid dianilide, 1,4-cyclohexanedicarboxylic acid dibenzylamide, trimesic acid tris(tert-butylamide), trimesic acid tricyclohexylamide, trimesic acid tris(2-methylcyclohexylamide), trimesic acid tris(4-cyclohexylamide), 2,6-naphthalenedicarboxylic acid dicyclohexylamide, N,N'-dibenzylcyclohexane-1,4-dicarboxamide, N,N'-distearyl isophthalamide, N,N'-distearyl terephthalamide, m-phenylene dimethylene bis-stearic acid amide, m-phenylene dimethylene bis-12-hydroxystearic acid amide. Among them, the aliphatic carboxylic acid amide selected from the group consisting of aliphatic mono-carboxylic acid amides, N-substituted aliphatic mono-carboxylic acid amides and aliphatic dicarboxylic acid amides is preferred, and the aliphatic dicarboxylic acid amide is more preferred. The higher fatty acid compound (D) may be one component or a combination of two or more components.

[0078] The compounding amount of the higher fatty acid compound (D) is preferably 0.05 to 0.50 parts by mass, more preferably 0.10 to 0.50 parts by mass, and still more preferably 0.15 to 0.45 parts by mass per 100 parts by mass of the polyamide resin composition. When the compounding amount of the higher fatty acid compound (D) is within the above range, it will not exude from the molded article, and while improving the mold release property, it contributes well to crystallization.

[0079] <Components other than (A) to (D)> The polyamide resin composition may contain components other than (A) to (D) within the range that does not impair the effects of the present invention. As components other than (A) to (D), resins other than component (A) and component (B), and functional imparting agents can be cited.

[0080] As resins other than component (A) and component (B), semi-aromatic polyamide resins, aromatic polyamide resins, unmodified polyolefin resins such as low-density, medium-density, and high-density polyethylene, polypropylene, and polybutene, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyester-based elastomers, vinyl aromatic resins such as polystyrene, ABS resin, and AS resin, polyether resins, polyurethane resins, acrylic resins, polyimide resins, polycarbonate resins, polyacetals, polyvinyl alcohol, rosin resins, etc. can be cited.

[0081] Functional imparting agents can include various additives usually compounded in polyamide resin compositions. Specific examples of functional imparting agents include plasticizers, heat-resistant agents, foaming agents, weather-resistant agents, crystal nucleating agents, antioxidants, crystal growth promoters, mold release agents, lubricants, antistatic agents, dispersants, flame retardants, flame retardant aids, pigments, dyes, etc.

[0082] Here, when the functional imparting agent is a heat-resistant agent, as the heat-resistant agent, organic or inorganic heat-resistant agents can be used according to the purpose, and they can be used alone as 1 type, or 2 or more types can be used in combination. As organic heat-resistant agents, phenolic compounds, phosphorus compounds, sulfur compounds, nitrogen compounds, etc. can be cited. They can be used alone as 1 type, or 2 or more types can be used in combination. As phenolic compounds, hindered phenolic organic compounds can be preferably cited. In this specification, hindered phenols refer to compounds having substituents at the ortho position of the hydroxyl group of phenols. As phosphorus compounds, hindered phenolic phosphite compounds and hindered phenolic hypophosphite compounds can be preferably cited.

[0083] The heat-resistant agent is preferably a combination of an inorganic compound and a nitrogen-containing compound or an inorganic compound. As inorganic compounds, metal halides and inorganic compounds other than metal halides can be cited.

[0084] Metal halides are compounds of halogens and metals. As halogens, fluorine, chlorine, bromine, iodine, etc. can be cited. As metals, Group 1 elements (alkali metals), Group 2 elements (alkaline earth metals), Group 3 elements to Group 12 elements (e.g., transition metals), etc. can be cited. The metal in the metal halide is preferably a metal of Group 1 element (alkali metal) or Group 11 element (copper group). As metal halides when the metal is a Group 1 element (alkali metal), potassium iodide, potassium bromide, potassium chloride, sodium iodide, sodium chloride, etc. can be cited. In addition, as metal halides when the metal is a Group 11 element (copper group), cuprous chloride, copper chloride, cuprous bromide, copper bromide, cuprous iodide, copper iodide, etc. can be cited. The metal halide is particularly preferably potassium iodide and / or cuprous iodide.

[0085] As inorganic compounds other than metal halides, metals, metal oxides, metal hydroxides, metal nitrides, metal phosphates, metal phosphites, metal carbonates, metal silicates, metal titanates, metal borates, metal sulfates, metal nitrates, etc. can be cited. Specific examples of inorganic compounds other than metal halides include talc, mica, synthetic mica, glass flakes, non-swelling mica, fullerene, carbon nanotubes, carbon black, graphite, metal foils, ceramic beads, clay, sericite, zeolite, bentonite, aluminum hydroxide, dolomite, kaolin, silica, microsilica, feldspar powder, potassium titanate, hollow volcanic ash spheres, calcium carbonate, magnesium carbonate, barium sulfate, calcium oxide, alumina, titanium oxide, magnesium oxide, aluminum silicate, silica, magnesium hydroxide, gypsum, novaculite, dawsonite, clay, glass fiber, carbon fiber, graphite fiber, metal fiber, potassium titanate whiskers, aluminum borate whiskers, magnesium-based whiskers, silicon-based whiskers, wollastonite, sepiolite, slag fiber, calcined vermiculite (zonolite), silicon apatite, gypsum fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, and boron fiber, etc.

[0086] As nitrogen-containing compounds, melamine, benzoguanamine, dimethylolurea, cyanuric acid, etc. can be cited.

[0087] When a heat-resistant agent is compounded, the compounding amount of the heat-resistant agent is preferably 0.01 to 2.00 parts by mass, more preferably 0.05 to 1.00 parts by mass, and still more preferably 0.10 to 0.50 parts by mass in 100 parts by mass of the polyamide resin composition.

[0088] As functional imparting agents other than the above, for example, the components described in JP-A-2002-370551 can be cited. The components other than (A) to (D) may each be one component or a combination of two or more components.

[0089] <Method for producing polyamide resin composition> As a method for producing a polyamide resin composition, there is no particular limitation as long as it is a method capable of kneading each component. For example, methods of production using a twin-screw kneader, a twin-screw extruder, a single-screw extruder, a multi-screw extruder, etc. may be mentioned. For example, any of the following methods may be used: a method of using a twin-screw extruder to melt-knead all the raw materials after blending; a method of melt-kneading after blending some of the raw materials and then blending the remaining raw materials and melt-kneading them; or a method of using a side feeder to mix the remaining raw materials during the process of melt-kneading after blending some of the raw materials.

[0090] In the polyamide resin composition, a part of the aliphatic polyamide resin (A) and the acid-modified polyolefin (B) may react. As a reaction mode, a mode in which the terminal amino group of the aliphatic polyamide resin (A) reacts with the acid-modified group of the acid-modified polyolefin (B) may be mentioned. Therefore, the blending amounts of the respective components at the time of preparing the polyamide resin composition and the contents of the respective components in the prepared polyamide resin composition may sometimes not match.

[0091] [Uses of polyamide resin composition, etc.] The polyamide resin composition can be used without particular limitation for the production of molded articles by known methods such as injection molding, extrusion molding, blow molding, rotational molding, vacuum molding, pressure-air molding, etc. In addition, a molded article containing the polyamide resin composition can be used for components that require slidability. As components that require slidability, for example, components targeted for dynamic uses such as gears, cams, pulleys, bearings, bearing retainers, door opening limiters, timing chain guides, and support and guiding devices for cables and hoses can be mentioned. In addition, it can also be used for other components that require the same function. Examples

[0092] Hereinafter, the present invention will be described in more detail by way of examples and comparative examples, but the present invention is not limited to these examples.

[0093] [Measurement methods and evaluations] [Mechanical properties] (1) Tensile stress, tensile fracture strain Based on ISO294-1, a Type A test piece was produced, and a tensile test was carried out at 23 °C and 50% RH atmosphere based on ISO527-1,2.

[0094] (2) Flexural strength and flexural modulus A B-type test piece was produced based on ISO294-1, and a bending test was carried out at 23 °C and 50% RH atmosphere based on ISO178 (Method A).

[0095] (3) Charpy impact strength A B-type test piece was produced based on ISO294-1, and V-notch machining was carried out based on ISO 179 / 1eA by post-processing. A Charpy impact test was carried out at an impact hammer capacity of 1 J, 23 °C, and 50% RH atmosphere.

[0096] It should be noted that when the tensile stress is 110 - 130 MPa, the tensile fracture strain is 3.0 - 5.0%, the bending strength is 160 - 200 MPa, the bending elastic modulus is 4,500 - 5,000 MPa, and the Charpy impact strength is 4.0 KJ / m 2 In the above cases, it is judged that the "mechanical properties" are excellent.

[0097] [Hardness] (1) Rockwell hardness (M scale) Based on the ISO 6508-1 standard, using the electric digital Rockwell hardness tester ARD-P manufactured by Akashi Seisakusho Co., Ltd., the measurement was carried out at 23 °C and 50% RH. It should be noted that when the Rockwell hardness is 80 - 92, it is judged that the "hardness" is an appropriate hardness as a material for sliding parts.

[0098] [Sliding property] The sliding property between the polyamide resin composition and carbon steel was measured as follows. (1) Limiting PV value Using the SE100D-C160S injection molding machine manufactured by Sumitomo Heavy Industries, Ltd., test pieces of 60 mm × 40 mm × 3 mm of the polyamide resin composition of the examples and comparative examples were produced. According to the JISK7218A method, using the Suzuki type friction and wear testing machine (manufactured by Orientec Co., Ltd., EFM-III-EN), with a ring made of S45C carbon steel described in JIS standard G4051 with an outer diameter of 25.6 mm, an inner diameter of 20 mm, and a height of 15 mm, in a ring-disk contact mode, with the test speed (circumferential speed) set to 500 mm / s, a test load of 25 kgf (245 N) was applied at the start of the test and the load was increased by 25 kgf (245 N) every 5 minutes, the limiting PV value of the produced test pieces was measured. Based on the load just before the test piece melted and the test speed (circumferential speed) of 500 mm / s, the limiting PV test value was calculated by the following formula (I). Formula (I) Limiting PV value = Pressure applied to the test piece just before the test piece melts × Test speed (circumferential speed)

[0099] (2) Coefficient of kinetic friction Using a Sumitomo Heavy Industries, Ltd. SE100D-C160S injection molding machine, test pieces of 60 mm × 40 mm × 3 mm of the polyamide resin compositions of the examples and comparative examples were produced. According to the JIS K7218A method, using a Suzuki friction and wear testing machine (manufactured by Orientec Corporation, EFM-III-EN), a ring with an outer diameter of 25.6 mm, an inner diameter of 20 mm, and a height of 15 mm made of S45C carbon steel described in JIS standard G4051 was used. In a ring-disk contact mode, with the test speed (circumferential speed) set to 500 mm / s, a test load of 25 kgf (245 N) applied at the start of the test and the load increased by 25 kgf (245 N) every 5 minutes, the frictional resistance of the produced test piece just before reaching the limit PV value was measured. The coefficient of kinetic friction is the value calculated according to the following formula (II). Formula (II) Coefficient of kinetic friction = (Frictional resistance just before reaching the limit PV value) / (Vertical load applied to the specimen)

[0100] It should be noted that when the limit PV value is 400 MPa·cm / sec or more and the coefficient of kinetic friction (polyamide against carbon steel) is 0.10 or less, it is considered that the "sliding property" is excellent.

[0101] [Wear amount] (1) Polyamide wear amount To confirm the wear amount of the sliding member, the following measurement was made on the wear amount of the polyamide resin composition against carbon steel. Using a Sumitomo Heavy Industries, Ltd. SE100D-C160S injection molding machine, test pieces of 60 mm × 40 mm × 3 mm of the polyamide resin compositions of the examples and comparative examples were produced. According to the JIS K7218A method, using a Suzuki friction and wear testing machine (manufactured by Orientec Corporation, EFM-III-EN), a ring with an outer diameter of 25.6 mm, an inner diameter of 20 mm, and a height of 15 mm made of S45C carbon steel described in JIS standard G4051 was used. In a ring-disk contact mode, with the test speed (circumferential speed) set to 300 mm / s, the sliding surface pressure set to 4.4 MPa, and the sliding distance set to 3.24 km, the wear depth of the polyamide sliding surface of the test piece was measured. The wear amount is the value calculated according to the following formula (III). Formula (III) Polyamide wear amount = (Sliding area × Wear depth of the test piece of the polyamide resin composition) / (Sliding surface pressure × Sliding distance)

[0102] (2) Polyacetal wear amount In order to confirm the wear amount of the object contacted by the sliding member, polyoxymethylene resin was used as the object contacted by the sliding member, and the following measurement was carried out on the wear amount of polyoxymethylene resin by the polyamide resin composition. Using a SE100D-C160S injection molding machine manufactured by Sumitomo Heavy Industries, Ltd., test pieces of 60 mm × 40 mm × 3 mm of the polyamide resin composition of the examples and comparative examples were produced. Similarly, the polyoxymethylene resin was made into an annular test piece with an outer diameter of 25.6 mm, an inner diameter of 20 mm, and a height of 15 mm. According to the JIS K7218A method, using a Suzuki type friction and wear testing machine (manufactured by Orientec Corporation, EFM-III-EN), using the test piece of the above polyamide resin composition and the annular test piece of the above polyoxymethylene resin, in a ring-disk contact mode, with the test speed (circumferential speed) set to 100 mm / s, the sliding surface pressure set to 1.25 MPa, and the sliding distance set to 1.08 km, the wear depth of the sliding surface of the test piece of polyoxymethylene resin was measured. The polyoxymethylene wear amount is the value calculated according to the following formula (IV). Formula (IV) Polyoxymethylene wear amount = (sliding area × wear depth of the test piece of polyoxymethylene resin) / (sliding surface pressure × sliding distance)

[0103] (3) Dynamic friction coefficient The following measurement was carried out on the dynamic friction coefficient between the polyamide resin composition and the polyoxymethylene resin. Using a SE100D-C160S injection molding machine manufactured by Sumitomo Heavy Industries, Ltd., test pieces of 60 mm × 40 mm × 3 mm of the polyamide resin composition of the examples and comparative examples were produced. Similarly, the polyoxymethylene resin was made into an annular test piece with an outer diameter of 25.6 mm, an inner diameter of 20 mm, and a height of 15 mm. According to the JIS K7218A method, using a Suzuki type friction and wear testing machine (manufactured by Orientec Corporation, EFM-III-EN), using the test piece of the above polyamide resin composition and the annular test piece of the above polyoxymethylene resin, in a ring-disk contact mode, with the test speed (circumferential speed) set to 100 mm / s, the sliding surface pressure set to 1.25 MPa, the sliding distance 1.08 km, and the sliding surface test load 25 kg, the measurement of the frictional resistance was carried out. The dynamic friction coefficient is the value calculated according to the following formula (V). Dynamic friction coefficient = (frictional resistance) / (sliding surface test load) (V)

[0104] It should be noted that when the polyamide wear amount is 5.0 mm 3 / MPa·km or less and the polyoxymethylene wear amount is 1.7 mm 3When the friction coefficient (polyamide to polyacetal) is 0.018 or less and the wear amount is determined to be small, the wear amount is determined to be small.

[0105] [Comprehensive evaluation] Examples that were judged to be excellent in "mechanical properties", excellent in "sliding properties", and small in "wear amount" were rated as 0 (passed), and examples that did not meet at least one of the criteria were rated as x (failed).

[0106] The components used in Examples and Comparative Examples are shown below. Polyamide 6: manufactured by UBE Co., Ltd., number average molecular weight 15,000, terminal amino group concentration 40 μmol / g LY1040: maleic anhydride-modified ultrahigh molecular weight polyethylene, product name "Lubmer (registered trademark) LY1040", manufactured by Mitsui Chemicals, Inc., intrinsic viscosity [η] = 25 dl / g Glass fiber (1): Maruchop NEG T-211DE Φ6.5 μm (manufactured by Nippon Electric Glass Co., Ltd., average fiber diameter 6.5 μm, coated with a sizing agent containing a polyurethane resin and a copolymer having an acidic group) Glass fiber (2): round-cut NEG T-211H Φ10.5 μm (manufactured by Nippon Electric Glass Co., Ltd., average fiber diameter 10.5 μm, coated with a sizing agent comprising a polyurethane resin and a copolymer having an acidic group) Glass fiber (3): round cut 456S Φ6.5 μm (manufactured by Nitto Bosho Co., Ltd., average fiber diameter 6.5 μm, coated with a sizing agent containing a polyurethane resin) Ethylene bisstearamide: Product name "Light amide WH-255", manufactured by Kyoeisha Chemical Co., Ltd. Calcium stearate: NOF Co., Ltd. calcium stearate U Magnesium stearate: NOF Co., Ltd. magnesium stearate Carbon black:Cabot corporation VALCAN P CuI / KI: Cuprous iodide / potassium iodide = 1 / 6 (mixture) Dispersant: Nonionic surfactant, product name "Bal-7220", manufactured by Marubishi Industry Co., Ltd. Polyacetal resin used for measurement: Product name "Duracon M90-40", manufactured by Polyplastics The number average molecular weight of polyamide 6 is a value obtained from relative viscosity. The relative viscosity is a value measured at 25° C. by dissolving 1 g of polyamide in 100 ml of 96% concentrated sulfuric acid in accordance with JIS K6920-2. The terminal amino group concentration of polyamide 6 is a value obtained by dissolving it in a mixed solvent of phenol and methanol and performing neutralization titration. The intrinsic viscosity [η] of the acid-modified polyolefin is a value measured in a decalin solvent at 135 °C. The average fiber diameter of the glass fiber is the catalog value.

[0107] [Examples 1 to 4, Comparative Examples 1 to 4] The respective components described in Table 1 were melt-kneaded using a ZSK32Mc twin-screw kneader manufactured by Coperion to produce target polyamide resin composition pellets. When not particularly described in the evaluation method, the obtained pellets were injection molded at a cylinder temperature of 290 °C and a mold temperature of 80 °C to manufacture various test pieces, and various physical properties were evaluated.

[0108] [Table 1]

[0109] From the results in Table 1, it can be seen that the polyamide resin compositions of the examples have excellent mechanical properties and slidability, and a small amount of wear. In Comparative Example 1 where the amount of the bundled glass fiber (C) is below the scope of the present invention, the mechanical properties are poor. In Comparative Example 2 where the average fiber diameter of the glass fiber is higher than the scope of the present invention, the slidability is poor, and the wear amount of the sliding member is large. In Comparative Example 3 where the bundling agent for the glass fiber does not contain a copolymer having an acidic group, the mechanical properties are poor, and the wear amount of the sliding member is large. In Comparative Example 4 where the amount of the bundled glass fiber (C) is higher than the scope of the present invention, both the mechanical properties and the slidability are poor, and the hardness is high, and the wear amounts of both the sliding member and the contact object of the sliding member are large. Industrial Applicability

[0110] The polyamide resin composition of the present invention is suitable as a molded article for components requiring slidability.

Claims

1. A polyamide resin composition, which is a polyamide resin composition prepared by blending an aliphatic polyamide resin (A), an acid-modified polyolefin (B), and glass fibers (C) coated with a sizing agent. In 100 parts by mass of the polyamide resin composition, 50.00 to 90.00 parts by mass of the aliphatic polyamide resin (A), 2.00 to 15.00 parts by mass of the acid-modified polyolefin (B), and 6.00 to 14.00 parts by mass of the glass fibers (C) coated with a sizing agent are blended. The intrinsic viscosity [η] of the acid-modified polyolefin (B) measured in a decalin solvent at 135 °C is 10 to 40 dl / g. The average fiber diameter of the glass fibers is 10.0 μm or less. The sizing agent contains a polyurethane resin and a copolymer having an acidic group.

2. The polyamide resin composition according to claim 1, wherein, In 100 parts by mass of the polyamide resin composition, 0.05 to 0.50 parts by mass of a higher fatty acid compound (D) selected from at least one of the group consisting of a higher fatty acid amide (D1) and a higher fatty acid salt (D2) is further blended.

3. The polyamide resin composition according to claim 1, wherein, The aliphatic polyamide resin (A) has a structural unit derived from an aminocarboxylic acid or a lactam.

4. The polyamide resin composition according to claim 1, wherein The number-average molecular weight of the aliphatic polyamide resin (A) is 10,000 to 35,000.

5. A molded article, which is a molded article of the polyamide resin composition according to any one of claims 1 to 4.

6. The molded article according to claim 5, which is used for applications requiring slidability.

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