Polyamide resin composition

Abstract

To provide a polyamide resin composition having excellent mechanical properties and slidability.SOLUTION: A polyamide resin composition comprises an aliphatic polyamide resin (A) of 50.00-85.00 mass%, an acid-modified polyolefin (B) of 2.00-6.00 mass%, a glass fiber (C) coated with a sizing agent comprising a polyurethane resin and an acid copolymer of 10.00-45.00 mass%, and a component (D) other than the components (A)-(C), of 0-38.00 mass%.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Polyamide resins have excellent properties as engineering plastics and are widely used in various industrial fields, including automobiles, machinery, and electrical and electronics. Furthermore, a technique for blending inorganic fillers such as glass fibers or modified polyethylene with polyamide resins to improve mechanical properties such as sliding properties is known. Patent Document 1 discloses a polyamide resin composition containing polyamide resin and modified polyethylene. Patent Document 2 discloses a polyamide resin composition containing an aliphatic polyamide resin, a polyethylene resin, and a fibrous inorganic filler. Patent Document 3 discloses a glass fiber-reinforced polyamide resin obtained by combining glass fibers treated with a glass fiber sizing agent containing a copolymer compound, an aminosilane, and a polyurethane resin with polyamide resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-199789 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-28231 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-231452 Summary of the Invention [Problem to be solved by the invention]

[0004] However, it has been found that the compositions containing polyamide resins as disclosed in Patent Documents 1 to 3 have room for further improvement in terms of mechanical properties and sliding properties.

[0005] Therefore, an object of the present invention is to provide a polyamide resin composition that is excellent in mechanical properties and sliding properties. [Means for solving the problem]

[0006] The present invention relates to the following [1] to [4]. [1] 50.00 to 85.00 mass% of an aliphatic polyamide resin (A), 2.00 to 6.00 mass% of an acid-modified polyolefin (B), 10.00 to 45.00 mass% of glass fibers (C) coated with a sizing agent containing a polyurethane resin and an acid copolymer, and Contains 0 to 38.00 mass% of a component (D) other than (A) to (C), Polyamide resin composition. [2] The polyamide resin composition according to [1], wherein the aliphatic polyamide resin (A) has a number average molecular weight of 10,000 to 30,000. [3] The polyamide resin composition according to [1] or [2], wherein the acid-modified polyolefin (B) has an average intrinsic viscosity [η] of 10 to 40 dl / g as measured in decaphosphoric acid solvent at 135°C. [4] A molded article comprising the polyamide resin composition according to any one of [1] to [3]. [Effects of the Invention]

[0007] According to the present invention, a polyamide resin composition having excellent mechanical properties and sliding properties can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0008] In this specification, the content of each component in a composition means the total amount of the multiple substances present in the composition when multiple substances corresponding to each component are present in the composition, unless otherwise specified. In this specification, the use of "to" to indicate a range of values ​​means that the values ​​before and after it are included as the lower and upper limits. For example, "2.00 to 6.00% by mass" means "2.00% by mass or more and 6.00% by mass or less."

[0009] [Polyamide resin composition] The polyamide resin composition contains 50.00 to 85.00 mass% of an aliphatic polyamide resin (A), 2.00 to 6.00 mass% of an acid-modified polyolefin (B), 10.00 to 45.00 mass% of surface-treated and / or bundled glass fibers (C) of a polyurethane resin and an acid copolymer, and 0 to 38.00 mass% of a component (D) other than (A) to (C). The polyamide resin composition has excellent mechanical properties, particularly excellent fatigue properties.

[0010] [Aliphatic polyamide resin (A)] The aliphatic polyamide resin (A) is an aliphatic polyamide resin having no aromatic ring or alicyclic group. Examples of the aliphatic polyamide resin (A) include an aliphatic homopolyamide resin (A-1) and an aliphatic copolyamide resin (A-2).

[0011] <Aliphatic homopolyamide resin (A-1)> The aliphatic homopolyamide resin (A-1) refers to a polyamide resin containing one type of monomer component. Examples of the monomer component constituting the aliphatic polyamide resin include a combination of an aliphatic diamine and an aliphatic dicarboxylic acid, a lactam, or an aminocarboxylic acid. When the monomer component constituting the aliphatic polyamide resin is a combination of an aliphatic diamine and an aliphatic dicarboxylic acid, the combination of one type of aliphatic diamine and one type of aliphatic dicarboxylic acid is considered to be one type of monomer component.

[0012] The aliphatic diamine preferably has 2 to 20 carbon atoms, and more preferably 4 to 12. The aliphatic dicarboxylic acid preferably has 2 to 20 carbon atoms, and more preferably 6 to 12. The lactam preferably has 6 to 12 carbon atoms. The aminocarboxylic acid preferably has 6 to 12 carbon atoms.

[0013] Examples of aliphatic diamines include ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, hexadecanediamine, heptadecanediamine, octadecanediamine, nonadecanediamine, and eicosanediamine. Examples of aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedionic acid, dodecanedionic acid, tridecanedionic acid, tetradecanedionic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, and eicosanedionic acid.

[0014] Examples of combinations of aliphatic diamines and aliphatic dicarboxylic acids include a combination of hexamethylenediamine and adipic acid, a combination of hexamethylenediamine and sebacic acid, and a combination of hexamethylenediamine and dodecanedioic acid, and equimolar salts of these combinations are preferably used.

[0015] Examples of lactams include ε-caprolactam, enantholactam, undecane lactam, dodecane lactam, α-pyrrolidone, and α-piperidone. Examples of aminocarboxylic acids include 6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. From the viewpoint of productivity, the lactam is preferably ε-caprolactam, undecane lactam, or dodecane lactam.

[0016] Specific examples of the aliphatic homopolyamide resin (A-1) include polycaprolactam (polyamide 6), polyenantholactam (polyamide 7), polyundecane lactam (polyamide 11), polylauryl lactam (polyamide 12), polyhexamethylene adipamide (polyamide 66), polytetramethylene dodecamide (polyamide 412), polypentamethylene azelamide (polyamide 59), polypentamethylene sebacamide (polyamide 510), polypentamethylene dodecamide (polyamide 512), polyhexamethylene azelamide (polyamide 69), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polynonamethylene adipamide polyamide 96), polynonamethylene azelamide (polyamide 99), polynonamethylene sebacamide (polyamide 910), polynonamethylene dodecamide (polyamide 912), polydecamethylene adipamide (polyamide 106), polydecamethylene azelamide (polyamide 109), polydecamethylene decamide (polyamide 1010), polydecamethylene dodecamide (polyamide 1012), polydodecamethylene adipamide (polyamide 126), polydodecamethylene azelamide (polyamide 129), polydodecamethylene sebacamide (polyamide 1210), polydodecamethylene dodecamide (polyamide 1212), polydodecamethylene oxamide (polyamide 122), and the like.

[0017] <Aliphatic copolyamide resin (A-2)> The aliphatic copolyamide resin (A-2) is an aliphatic polyamide resin that contains two or more kinds of monomer components constituting the aliphatic polyamide resin and does not have an aromatic ring or an alicyclic group. Therefore, the aliphatic copolyamide resin (A-2) may be a combination of an aliphatic diamine and an aliphatic dicarboxylic acid, or an aliphatic copolyamide resin that is a copolymer of two or more kinds of monomers selected from the group consisting of lactam and aminocarboxylic acid.

[0018] Specific examples of the aliphatic copolymer polyamide resin (A-2) include caprolactam / hexamethylenediaminoadipic acid copolymer (polyamide 6 / 66), caprolactam / hexamethylenediaminoazelaic acid copolymer (polyamide 6 / 69), caprolactam / hexamethylenediaminosebacic acid copolymer (polyamide 6 / 610), caprolactam / hexamethylenediaminoundecanoic acid copolymer (polyamide 6 / 611), caprolactam / hexamethylenediaminododecanoic acid copolymer (polyamide 6 / 612), caprolactam / aminoundecanoic acid copolymer (polyamide 6 / 11), caprolactam / lauryllactam copolymer (polyamide 6 / 12), caprolactam / hexamethylenediaminoadipic acid / lauryllactam copolymer (polyamide 6 / 66 / 12), caprolactam / hexamethylenediaminoadipic acid / hexamethylenediaminosebacic acid copolymer (polyamide 6 / 66 / 610), caprolactam / hexamethylenediaminoadipic acid / hexamethylenediaminododecanedicarboxylic acid copolymer (polyamide 6 / 66 / 612), hexamethylenediaminoadipic acid / caprolactam copolymer (polyamide 66 / 6), etc.

[0019] <Preferred embodiment> From the viewpoint of productivity, the aliphatic polyamide resin (A) is preferably an aliphatic homopolyamide resin (A-1), more preferably one or more 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.

[0020] <Number average molecular weight> From the viewpoint of sliding properties, the number average molecular weight of the aliphatic polyamide resin (A) is preferably 10,000 to 30,000, more preferably 13,000 to 29,000, and even more preferably 22,000 to 29,000. The number average molecular weight is a value calculated from the relative viscosity (JIS K 6920).

[0021] The aliphatic polyamide resin (A) may be one kind of component or a combination of two or more kinds of components.

[0022] [Acid-modified polyolefin (B)] The acid-modified polyolefin (B) is a polyolefin modified with a compound containing an acid-modifying group. The acid-modified polyolefin (B) may be further modified with a compound containing a modifying group other than the acid-modifying group.

[0023] <Polyolefin> Polyolefins are homopolymers or copolymers of olefins. Examples of olefins include α-olefins such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene. Polyolefins are preferably homopolymers of ethylene or copolymers of ethylene and α-olefins other than ethylene.

[0024] <Modifying group> Examples of the acid-modified group of the polyolefin include a carboxyl group, a carboxyl metal salt, an acid anhydride group, and a sulfonic acid group. The acid-modified group is preferably a carboxyl group. Examples of the modifying group other than the acid-modified group include an amino group, a hydroxyl group, a silanol group, an alkoxy group, an epoxy group, an isocyanate group, a mercapto group, and an oxazoline group.

[0025] <Method for producing acid-modified polyolefin (B)> The acid-modified polyolefin (B) can be obtained by melt-kneading a polyolefin and a compound containing an acid-modified group, and graft-modifying the polyolefin to introduce the acid-modified group. Alternatively, the acid-modified polyolefin (B) can be produced by reacting a polyolefin with a compound containing an acid-modified group in the absence of a solvent using an extruder, a twin-screw kneader, or the like.

[0026] Examples of compounds containing an acid-modified group include unsaturated carboxylic acids or derivatives thereof, hydroxyl group-containing ethylenically unsaturated compounds, amino group-containing ethylenically unsaturated compounds, and vinyl group-containing organosilicon compounds. Examples of unsaturated carboxylic acids or derivatives thereof include unsaturated compounds having one or more carboxyl groups, esters of compounds having carboxyl groups with alkyl alcohols, and unsaturated compounds having one or more carboxyl anhydride groups. Examples of unsaturated groups include vinyl groups, vinylene groups, and unsaturated cyclic hydrocarbon groups. From the viewpoint of reactivity, the compound containing an acid-modified group is preferably an unsaturated carboxylic acid or a derivative thereof.

[0027] Specific examples of unsaturated carboxylic acids include unsaturated dicarboxylic acids such as acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, mesaconic acid, citraconic acid, crotonic acid, isocrotonic acid, and endo-cis-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid. Derivatives of unsaturated carboxylic acids include acid halides, amides, imides, anhydrides, and esters of the unsaturated carboxylic acids, with malenyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, and glycidyl maleate being preferred. 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-modifiable group may be one component or two or more components.

[0028] The compound containing a modifying group other than the acid-modifying group can be appropriately selected from the compounds containing the modifying group described above.

[0029] When the polyolefin is acid-modified, the amounts of the compound containing the acid-modifying group and the compound containing a modifying group other than the acid-modifying group to be added can be appropriately set depending on the desired degree of modification of the polyolefin.

[0030] When the acid-modified polyolefin (B) is obtained by melt-kneading a polyolefin and a compound containing an acid-modifying group, and then graft-modifying the polyolefin to introduce the modifying group, the graft-modification of the polyolefin can be carried out, for example, by dissolving the polyolefin in an organic solvent, then adding the compound containing an acid-modifying group and a radical initiator to the solution, and allowing the reaction to proceed. The reaction temperature is preferably 70°C to 200°C, and particularly preferably 80°C to 190°C. The reaction time is preferably 0.5 to 15 hours, and particularly preferably 1 to 10 hours.

[0031] When the acid-modified polyolefin (B) is obtained by reacting a polyolefin with a compound containing a modifying group without using a solvent, such as an extruder or a twin-screw kneader, the reaction is preferably carried out at a temperature equal to or higher than the melting point of the polyolefin, particularly preferably from 160 to 330° C. The reaction is preferably carried out by melt-kneading for 0.5 to 10 minutes.

[0032] <Preferred embodiment> The acid-modified polyolefin (B) preferably has an average intrinsic viscosity [η] of 10 to 40 dL / g, more preferably 15 to 35 dL / g, and even more preferably 20 to 30 dL / g, as measured in decacarboxylic acid solvent at 135°C. When the average intrinsic viscosity [η] is 10 or more, the dynamic friction coefficient of the polyamide resin composition tends to be low, and the sliding properties tend to be further improved. The average intrinsic viscosity [η] of the acid-modified polyolefin (B) can be adjusted by the polymerization conditions.

[0033] In addition to the above, 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) may be one kind of component or a combination of two or more kinds of components.

[0034] [Glass fiber (C) coated with a sizing agent containing a polyurethane resin and an acid copolymer] The glass fibers (C) coated with a sizing agent containing a polyurethane resin and an acid copolymer are a component that imparts excellent sliding properties and mechanical properties to the polyamide resin composition.

[0035] <Glass fiber> Examples of glass constituting the glass fiber include those having compositions such as A glass, AR glass, C glass, D glass, E glass, H glass, S glass, T glass, M glass, and NE glass.

[0036] The shape of the glass fiber is not particularly limited, and examples thereof include flat fiber, chopped strand, etc. The cross-sectional shape of the glass fiber is not particularly limited, and examples thereof include a perfect circle, a cocoon, an oval, a rectangle, or shapes similar thereto.

[0037] The average fiber diameter of the glass fibers is not particularly limited. The average fiber diameter of the glass fibers is preferably 2 μm to 15 μm, and particularly preferably 5 μm to 12 μm. When the cross section of the glass fibers is rectangular or a similar shape, the length of one side of the cross section is preferably 0.5 μm to 50 μm, and particularly preferably 1 to 40 μm. The number average fiber length of the glass fibers is preferably 250 μm to 400 μm, and particularly preferably 300 μm to 360 μm. The weight average fiber length of the glass fibers is preferably 350 μm to 550 μm, and particularly preferably 380 μm to 500 μm. The number average fiber length and weight average fiber length of the glass fibers are values ​​measured by the method described in the Examples. The aspect ratio, obtained by dividing the number average fiber length by the average fiber diameter of the glass fibers, is preferably 10 or more, and particularly preferably 15 to 100, from the viewpoints of rigidity, mechanical strength, and fluidity.

[0038] <Polyurethane resin> The polyurethane resin is a resin obtained by subjecting a polyol component and a polyisocyanate component to a urethane reaction.

[0039] <Polyol component> Examples of the polyol component include polyester polyols (condensation polyester polyols, lactone polyester polyols), polycarbonate polyols, and polyether polyols.

[0040] Condensation polyester polyols include those obtained by reacting dicarboxylic acids or lower alkyl esters thereof with aliphatic diols. Examples of dicarboxylic acids or lower alkyl esters thereof include adipic acid, succinic acid, azelaic acid, pimelic acid, sebacic acid, and phthalic acid. Examples of aliphatic diols include aliphatic diols without side chains, such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, and 1,10-decamethylene glycol, and aliphatic diols with side chains, such as 1,2-propylene glycol, 1,3-butanediol, 2,5-dimethyl-2,5-hexanediol, 2,2-diethyl-1,3-propanediol, and neopentyl glycol.

[0041] Examples of lactone-based polyester polyols include those obtained by reacting a lactone compound such as β-propiolactone, pivalolactone, δ-valerolactone, ε-caprolactone, methyl-ε-caprolactone, dimethyl-ε-caprolactone, or trimethyl-ε-caprolactone with a hydroxy compound such as a short-chain polyol.

[0042] Polycarbonate polyols are typically obtained by transesterification of a hydroxy compound such as a short-chain polyol with diallyl carbonate, dialkyl carbonate, or ethylene carbonate. For example, poly-1,6-hexamethylene carbonate and poly-2,2'-bis(4-hydroxyhexyl)propane carbonate are industrially produced and readily available. Another method for obtaining polycarbonate polyols is the so-called phosgene method (or solvent method).

[0043] Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyoxypropylene glycol, and glycerin-based polyalkylene ether glycol.

[0044] <Polyisocyanate component> Examples of polyisocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates.

[0045] Examples of aliphatic polyisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis(2-isocyanatoethyl) fumarate, bis(2-isocyanatoethyl) carbonate, and 2-isocyanatoethyl-2,6-diisocyanatohexanoate.

[0046] Examples of alicyclic polyisocyanates 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, and 2,6-norbornane diisocyanate.

[0047] Examples of aromatic polyisocyanates include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenyl, Phenylmethane, 1,5-naphthylene diisocyanate, 4,4',4''-triphenylmethane triisocyanate, m-isocyanatophenylsulfonyl isocyanate, p-isocyanatophenylsulfonyl 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-dinaphthyl-2,2'-diisocyanate, biphenyl-2,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 2,2'-diphenylmethane diisocyanate, and the like.

[0048] The polyisocyanate is preferably a diisocyanate having two isocyanato groups per molecule.

[0049] In the urethane reaction, a chain extender such as a polyhydric alcohol or a polyhydric amine may also be used.

[0050] <Acid copolymer> Examples of the acid copolymer include a copolymer of a monomer having an acid group, and a copolymer of a monomer having an acid group and a monomer not having an acid group.

[0051] Examples of monomers having an acid group include unsaturated carboxylic acids, carboxylic anhydrides, methyl acrylate, and methyl methacrylate. The unsaturated carboxylic acids are as described above in the compound containing a modifying group. Examples of carboxylic anhydrides include dicarboxylic anhydrides such as maleic anhydride, itaconic anhydride, succinic anhydride, phthalic anhydride, glutaric anhydride, dodecenylsuccinic anhydride, and chlorendic anhydride. The carboxylic anhydride is preferably maleic anhydride because it has little steric hindrance during copolymerization and has low polarity.

[0052] Examples of the monomer having no acid group include styrene, ethylene, and acetylene.

[0053] The acid copolymer may be an unsaturated dicarboxylic acid and / or carboxylic acid anhydride, acrylic acid, or the like. It is preferable that the copolymer is a copolymer compound in which methyl acrylate and methyl methacrylate are copolymerized.

[0054] The copolymerization ratio of the unsaturated dicarboxylic acid and / or carboxylic anhydride is preferably 20 to 60% by mass, and particularly preferably 25 to 55% by mass, from the viewpoints of reactivity and mechanical properties when producing the copolymer. The copolymerization ratio of methyl acrylate is preferably 20 to 75% by mass, and particularly preferably 30 to 65% by mass, from the viewpoints of reactivity and mechanical properties when producing the copolymer. Furthermore, the copolymerization ratio of methyl methacrylate is preferably 5 to 20% by mass, and particularly preferably 7 to 17% by mass, from the viewpoints of reactivity and mechanical properties when producing the copolymer. The copolymerization ratio of the monomer not having an acid group is preferably 10% by mass or less, and particularly preferably 1% by mass or less.

[0055] From the viewpoints of reactivity during copolymer production and mechanical properties, the weight-average molecular weight of the copolymer compound is preferably 10,000 to 60,000, and particularly preferably 20,000 to 50,000. The weight-average molecular weight of the copolymer compound is a molecular weight measured by gas permeation chromatography (GPC).

[0056] <Other ingredients in the sizing agent> The sizing agent may contain additional components in addition to the polyurethane resin and the acid copolymer. Examples of the additional components include lubricants, nonionic surfactants, antistatic agents, water, organic solvents, etc. Examples of lubricants include fatty acid amides and quaternary ammonium salts. Examples of nonionic surfactants include synthetic alcohols, natural alcohols, and fatty acid esters. The water and organic solvents are components that dissolve the lubricants, nonionic surfactants, antistatic agents, etc. Examples of organic solvents include ethanol.

[0057] The content of each component in the sizing agent can be appropriately set depending on the properties of the glass fibers to be obtained.

[0058] [Coating] The glass fibers are coated with a sizing agent containing a polyurethane resin and an acid copolymer. The glass fibers are surface-treated by coating them with the sizing agent. The glass fibers may also be subjected to a bundling treatment in which two or more glass fibers are bundled into one by coating the sizing agent. The bundling treatment can also be performed by coating a plurality of glass fiber monofilaments formed by drawing molten glass from a plurality of nozzles with the sizing agent, bundling the monofilaments into a single glass fiber strand, and then winding the monofilaments into a cake.

[0059] The glass fibers (C) coated with the sizing agent may be surface-treated with an additional component, such as the additional component contained in the sizing agent.

[0060] In addition to the above, the glass fibers (C) coated with a sizing agent containing a polyurethane resin and an acid copolymer may contain components described in JP-A-2014-231452. The glass fibers (C) coated with a sizing agent containing a polyurethane resin and an acid copolymer may be one type of component or a combination of two or more types of components.

[0061] [Component (D) other than (A) to (C)] The polyamide resin composition may contain a component (D) other than components (A) to (C) as long as the effects of the present invention are not impaired. Component (D) may include other resins and functionality-imparting agents. Examples of other resins include 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; polyurethane resin; acrylic resin; polycarbonate; polyacetal; polyvinyl alcohol; and rosin-based resins.

[0062] Examples of the functionality-imparting agent include various additives that are usually blended into polyamide resin compositions. Specific examples of the functionality-imparting agent include plasticizers, heat resistance agents, foaming agents, weather resistance agents, crystal nucleating agents, antioxidants, crystallization accelerators, mold release agents, lubricants, antistatic agents, flame retardants, flame retardant assistants, pigments, dyes, etc. Here, when the functionality-imparting agent is a heat resistance agent, the heat resistance agent is preferably a combination of an inorganic compound and a nitrogen-containing compound.

[0063] The inorganic compounds include metal halides and inorganic compounds other than metal halides.

[0064] Metal halides are compounds of halogens and metals. Examples of halogens include fluorine, chlorine, bromine, and iodine. Examples of metals include Group 1 elements (alkali metals), Group 2 elements (alkaline earth metals), and Group 3 to Group 12 elements (e.g., transition metals). The metal in the metal halide is preferably a Group 1 element (alkali metal) or a Group 11 element (copper group). Examples of metal halides when the metal is a Group 1 element (alkali metal) include potassium iodide, potassium bromide, potassium chloride, sodium iodide, and sodium chloride. Examples of metal halides when the metal is a Group 11 element (copper group) include cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cuprous iodide, and cupric iodide. The metal halide is particularly preferably potassium iodide and / or cuprous iodide.

[0065] Examples of inorganic compounds other than metal halides include metals, metal oxides, metal hydroxides, metal nitrides, metal phosphates, metal phosphites, metal carbonates, metal silicates, metal titanates, metal borates, metal sulfates, metal nitrates, etc. 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 foil, ceramic beads, clay, sericite, zeolite, bentonite, aluminum hydroxide, dolomite, kaolin, silica, finely powdered silicic acid, feldspar powder, potassium titanate, shirasu balloons, calcium carbonate, magnesium carbonate, barium sulfate, calcium oxide, aluminum oxide, titanium oxide, acid Examples of such fibers include magnesium nitride, aluminum silicate, silicon oxide, magnesium hydroxide, gypsum, novaculite, dawsonite, clay, glass fiber, carbon fiber, graphite fiber, metal fiber, potassium titanate whisker, aluminum borate whisker, magnesium-based whisker, silicon-based whisker, wollastonite, sepiolite, slag fiber, zonolite, elastadite, gypsum fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, and boron fiber.

[0066] Examples of the nitrogen-containing compound include melamine, benguanamine, dimethylol urea, and cyanuric acid.

[0067] Examples of functionality-imparting agents other than those mentioned above include the components described in JP-A No. 2002-370551.

[0068] Component (D) may be one kind of component or a combination of two or more kinds of components.

[0069] ≪Content≫ The content of each component relative to the total mass of the polyamide resin composition is as follows: In the polyamide resin composition, the total of (A) to (D) is 100 mass %.

[0070] The content of the aliphatic polyamide resin (A) is 50.00 to 85.00% by mass. From the viewpoints of mechanical properties and moldability, the content of the aliphatic polyamide resin (A) is preferably 55.00 to 80.00% by mass, and more preferably 55.00 to 70.00% by mass.

[0071] The content of the acid-modified polyolefin (B) is 2.00 to 6.00% by mass. If the content of the acid-modified polyolefin (B) is outside the above range, the sliding properties and mechanical strength tend to be inferior.

[0072] The content of glass fiber (C) is 10.00 to 45.00% by mass. If the content of glass fiber (C) is outside this range, the mechanical properties tend to be inferior. If the content of glass fiber (C) exceeds 45.00% by mass, there is a risk of damaging the mating surface. From the viewpoints of moldability and mechanical strength, the content of glass fiber (C) is preferably 20.00 to 40.00% by mass, and particularly preferably 25.00 to 35.00% by mass.

[0073] The content of component (D) other than components (A) to (C) is 0 to 38.00% by mass. From the viewpoints of mechanical properties and moldability, it is preferably 0 to 20.00% by mass, more preferably 0 to 15.00% by mass, and particularly preferably 0 to 5.00% by mass.

[0074] <Method for producing polyamide resin composition> The method for producing the polyamide resin composition is not particularly limited as long as it is a method that can knead each component, and examples thereof include methods using a twin-screw extruder, a single-screw extruder, a multi-screw extruder, etc.

[0075] [Uses of polyamide resin compositions, etc.] The polyamide resin composition can be used to produce molded articles using known methods without any particular limitations. Furthermore, molded articles containing the polyamide resin composition can be used for sliding parts. Examples of sliding parts include gears, cams, pulleys, bearings, bearing retainers, door checks, timing chain guides, and cable / hose support / guiding devices and other devices intended for dynamic applications. Molded articles containing the polyamide resin composition can be obtained by molding the polyamide resin composition into molded articles of desired shapes. For example, they can be produced by injection molding. Molding methods include extrusion molding, blow molding, and injection molding. Molded articles containing the polyamide resin composition are used for gears, pulleys, cams, bearings, cable housings, and the like for automobiles and machines, but they may also be used for other components requiring similar functions. [Example]

[0076] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. The components used in the examples and comparative examples and the methods for measuring the physical properties of the molded articles are shown below.

[0077] [Ingredients used] 1. Aliphatic polyamide resin (A) PA66-1: Polyamide 66 with a number average molecular weight of 20,000 PA66-2: Polyamide 66 with a number average molecular weight of 29,000 2. Acid-modified polyolefin (B) Maleic anhydride-modified ultra-high molecular weight polyethylene (Mitsui Chemicals, Inc., LUBMER (registered trademark) LY1040 (intrinsic viscosity [η] measured in decaphosphoric acid solvent at 135°C: 25 dL / g)) 3. Glass fiber coated with a sizing agent containing polyurethane resin and acid copolymer (C) Round chopper NEG T-275H Φ10.5 microns (manufactured by Nippon Electric Glass Co., Ltd., diameter 10.5 μm) Round chopper NEG T-211H Φ10.5 microns (manufactured by Nippon Electric Glass Co., Ltd., diameter 10.5 μm) Flat fiber NEG 920EW (7 x 28 μm) (manufactured by Nippon Electric Glass Co., Ltd., cross section 7 μm x 28 μm) 4. Glass fiber other than (C) (C') Round chopped NEG T-249H Φ10.5 microns (Nippon Electric Glass Co., Ltd., glass fiber coated with a sizing agent containing polyurethane resin and not containing acid copolymers. Diameter 10.5 μm) Flat fiber CSG-3PE-820S (manufactured by Nitto Boseki Co., Ltd.; glass fiber coated with a sizing agent containing polyurethane resin and not containing acid copolymers; cross section 7 μm x 28 μm) 5. Ingredients other than (A) to (C) (D) Heat-resistant agent: CuI / KI=1 / 6 (mass ratio) CuI: Cuprous iodide (Ise Chemical Industry Co., Ltd.) KI: Powdered potassium iodide (Mitsui Fine Co., Ltd.)

[0078] [Mechanical properties] (1) Tensile stress, tensile strain at break, and tensile modulus Using the pellets, Type A test pieces were prepared in accordance with ISO294-1, and tensile tests were carried out in an atmosphere of 23°C in accordance with ISO527-1,2. (2) Flexural strength and flexural modulus Using the pellets, Type B test pieces were prepared in accordance with ISO294-1, and bending tests were carried out in an atmosphere of 23°C in accordance with ISO178. (3) Charpy impact strength Using the pellets, Type B test pieces were prepared in accordance with ISO 294-1, and V-notched in accordance with ISO 179 / 1eA in post-processing. A Charpy impact test was carried out using a hammer capacity of 1 J in an atmosphere at 23°C. (4) Fatigue limit Using the pellets, a FANUC FAS-T100D injection molding machine was used to prepare cantilever bending fatigue test pieces according to JIS K 7118 III. In accordance with JIS K 7119, a cyclic vibration fatigue tester (Toyo Seiki B50) equipped with a humidity chamber was set at 90°C. An arbitrary stress was applied to the cantilever bending fatigue test pieces according to JIS K 7118 III at 1,800 cycles / min, and the number of cycles until failure was measured. The number of cycles until failure occurred (10 to the power of 7) was determined as the fatigue limit (stress amplitude).

[0079] The tensile stress is 140 MPa or more, the tensile breaking strain is 3.5% or more, the tensile modulus is 8,000 MPa or more, the flexural strength is 260 MPa or more, the flexural modulus is 5,000 MPa or more, and the Charpy impact strength is 14 KJ / m 2 If the fatigue limit was 30 MPa or more, the specimen was judged to have excellent "mechanical properties and fatigue properties."

[0080] [Slidability] (1) Limit PV test value Using the pellets, 60 mm x 40 mm x 3 mm test specimens were prepared using a FANUC FAS-T100D injection molding machine. According to JIS K7218A, the limiting PV values ​​of the prepared test specimens were measured using a Suzuki friction and wear tester (Orientec, EFM-III-EN) using a ring-on-disk type S45C carbon steel ring with an outer diameter of 25.6 mm, an inner diameter of 20 mm, and a height of 15 mm. The material was S45C carbon steel as specified in JIS standard G4051. The test speed (circumferential speed) was 700 mm / s, and the test load was 25 kgf (245 N) at the start of the test, increasing by 25 kgf (245 N) every 5 minutes. The limiting PV value was determined from the load just before the load at which the test specimen melted and the test speed (circumferential speed) of 700 mm / s. Limit PV value = (pressure applied to test piece) x test speed (circumferential speed)

[0081] (2) Coefficient of kinetic friction Using the pellets, 60mm x 40mm x 3mm test specimens were prepared using a FANUC FAS-T100D injection molding machine. Using a Suzuki friction and wear tester (Orientec EFM-III-EN) with a ring-on-disc system, the test speed (circumferential speed) was set to 700mm / s, and a test load of 25kgf (245N) was applied at the start of the test, increasing by 25kgf (245N) every 10 minutes. The frictional resistance of the prepared test specimens was measured just before their limiting PV value. The dynamic friction coefficient was calculated using the following equation (1): Coefficient of dynamic friction = (frictional resistance force) / (load applied to test piece) (1)

[0082] Furthermore, when the dynamic friction coefficient was 0.20 or less and the limit PV test value was 170 MPa·cm / sec or more, the "slidability" was judged to be excellent.

[0083] [Fiber length of component (C) or component (C')] <Number average fiber length> The pellets were dissolved in sulfuric acid, and the precipitated glass fibers were dropped onto a slide glass, which was then sandwiched between a cover glass and observed under a transmission microscope. The image was then photographed using Olympus image processing software. The glass fiber length in the photographed image was measured using Asahi Engineering's image analysis software, A-Zou-kun, to measure the number-average fiber length.

[0084] <Weight average fiber length> The pellets were dissolved in sulfuric acid, and the precipitated glass fibers were dropped onto a slide glass, sandwiched between cover glasses, observed under a transmission microscope, and photographed using Olympus image processing software. The glass fiber length in the photographed image was measured using Asahi Engineering's image analysis software, A-Zou-kun.

[0085] Examples 1 to 8, Comparative Examples 1 to 10 The components listed in Table 1 were melt-kneaded in a Coperion ZSK32Mc twin-screw kneader to prepare pellets of the desired polyamide resin composition. The pellets were then injection-molded at a cylinder temperature of 290°C and a mold temperature of 80°C to prepare various test pieces, and their physical properties were evaluated.

[0086] [Table 1]

[0087] [Table 2]

[0088] As is clear from the results in Table 1, the polyamide resin compositions of the Examples were excellent in mechanical properties and sliding properties, and in particular in fatigue properties. On the other hand, the resin compositions of Comparative Examples 1 to 9 were composed of a polyurethane resin and an acid copolymer and did not contain surface-treated and / or bundled glass fibers (C), and therefore were inferior in either mechanical properties or sliding properties. Here, the resin composition of Comparative Example 7 also did not contain an acid-modified polyolefin (B), and therefore had poor sliding properties. Furthermore, the resin composition of Comparative Example 10 also did not contain an acid-modified polyolefin (B), and therefore had poor sliding properties.

Claims

1. 50.00 to 85.00 mass% of an aliphatic polyamide resin (A), 2.00 to 6.00 mass% of acid-modified polyolefin (B), 10.00 to 45.00 mass% of glass fibers (C) coated with a sizing agent containing a polyurethane resin and an acid copolymer, and Contains 0 to 38.00 mass% of a component (D) other than (A) to (C), A polyamide resin composition, wherein the cross-sectional shape of the glass fiber (C) is oval or rectangular.

2. 2. The polyamide resin composition according to claim 1, wherein the aliphatic polyamide resin (A) has a number average molecular weight of 10,000 to 30,000.

3. 3. The polyamide resin composition according to claim 1, wherein the acid-modified polyolefin (B) has an average intrinsic viscosity [η] of 10 to 40 dl / g, as measured in a decacarboxylic acid solvent at 135°C.

4. A molded article comprising the polyamide resin composition according to any one of claims 1 to 3.

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