Polyamide resin composition, molded article, and method for producing the same

Abstract

To provide a fiber-reinforced polyamide resin composition with imparted sufficient mechanical properties and enhanced durability, and a molded article, a sliding member, a gear, and a worm wheel using the same.SOLUTION: A fiber-reinforced polyamide resin composition contains a crystalline polyamide (A) and glass fibers (B). The formic acid relative viscosity of the fiber-reinforced polyamide resin composition is 90 or more. A number average fiber length of the glass fibers (B) contained in the fiber-reinforced polyamide resin composition is 300 μm or more.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a fiber-reinforced polyamide resin composition excellent in mechanical properties and durability, a molded article made therefrom, and a method for producing the same. More specifically, the present invention relates to a fiber-reinforced polyamide resin composition characterized by containing a polyamide having a specific viscosity and glass fibers having a specific fiber length, a molded article made therefrom, and a method for producing the same.

Background Art

[0002] Since polyamide resins are excellent in slidability, moldability, mechanical properties, and chemical resistance, they have been widely used as various component materials for industrial materials, automobiles, electric and electronic devices, or industrial use. From the viewpoint of particularly excellent slidability and mechanical properties, polyamide resins are often used as sliding members such as automotive gears and worms.

[0003] For the purpose of enhancing these performances, compositions having a higher viscosity than ordinary polyamides or composites with inorganic compound fillers such as glass fibers, glass flakes, alumina fibers, or layered inorganic compounds have been studied. Among these, glass fiber-reinforced polyamide resin compositions containing high molecular weight polyamide and using glass fibers as inorganic compound fillers have attracted particular attention because of their high effect of improving slidability and mechanical properties.

[0004] On the other hand, since weight reduction of automobiles themselves from the viewpoint of environmental consideration is required, miniaturization is also required for sliding members such as automotive gears and worms. Along with this, high durability of the material itself of the sliding member is required.

[0005] Regarding glass fiber-reinforced polyamide resin compositions containing high molecular weight polyamide compositions, for example, Patent Documents 1 and 2 disclose compositions capable of improving slidability, mechanical properties, and productivity by blending specific glass fibers and coupling agents.

Prior Art Documents

Patent Document

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the above-described conventional technology, sufficient mechanical properties and durability have not been achieved in polyamides in the high molecular weight region where the formic acid relative viscosity is 90 or more, and further improvement is desired.

[0008] The present invention has been made in view of the above problems, and aims to provide a fiber-reinforced polyamide resin composition having sufficient mechanical properties and improved durability, a molded article using the same, a sliding member, a gear, a worm wheel, and a method for producing the same.

Means for Solving the Problems

[0009] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved with a fiber-reinforced polyamide resin composition having predetermined conditions, and have completed the present invention.

[0010] That is, the fiber-reinforced polyamide resin composition and molded article of the present invention are as follows. [1] A fiber-reinforced polyamide resin composition containing crystalline polyamide (A) and glass fiber (B), wherein the formic acid relative viscosity of the fiber-reinforced polyamide resin composition is 90 or more, and the number average fiber length of the glass fiber (B) contained in the fiber-reinforced polyamide resin composition is 300 μm or more. ​Fiber-reinforced polyamide resin composition. [2] The fiber-reinforced polyamide resin composition according to [1], characterized in that it contains 1 to 100 parts by weight of the glass fiber (B) with respect to 100 parts by weight of the crystalline polyamide (A). [3] The fiber-reinforced polyamide resin composition according to [1] or [2], characterized in that the relative viscosity of the crystalline polyamide (A) in formic acid is 130 or more. [4] A fiber-reinforced polyamide resin molded article comprising the fiber-reinforced polyamide resin composition according to any one of [1] to [3]. [5] The fiber-reinforced polyamide resin molded article according to [4], characterized in that the relative viscosity of the fiber-reinforced polyamide resin molded article in formic acid is 90 or more. [6] The fiber-reinforced polyamide resin molded article according to [4] or [5], characterized in that the number average fiber length of the glass fiber (B) contained in the fiber-reinforced polyamide resin molded article is 300 μm or more. [7] The fiber-reinforced polyamide resin molded article according to any one of [4] to [6], characterized in that the yellowness index (YI) of the fiber-reinforced polyamide resin molded article is 0 or more and 50 or less. [8] A melt-kneading step of adding 5 to 100 parts by mass of glass fiber having an average fiber diameter of 3 μm or more and 20 μm or less to 100 parts by mass of a crystalline polyamide having a relative viscosity in formic acid of 30 or more and 90 or less, and melt-kneading to obtain a melt-kneaded product; A molding step of molding the melt-kneaded product to obtain a fiber-reinforced polyamide resin pre-molded article; A heating step of heating the fiber-reinforced polyamide resin pre-molded article at a temperature T represented by the following general formula (I) to obtain a fiber-reinforced polyamide resin molded article; A method for producing a fiber-reinforced polyamide resin composition, characterized by including the above steps. Tm - 130°C ≤ T ≤ Tm - 10°C (I) (In the formula, Tm is the melting point of the thermoplastic resin.) [9] A fiber-reinforced polyamide resin molded article according to any one of [4] to [7], which is a sliding member.

[10] A fiber-reinforced polyamide resin molded article according to any one of [4] to [7], which is a gear. [Advantages of the Invention]

[0011] According to the present invention, it is possible to obtain a fiber-reinforced polyamide resin composition having sufficient mechanical properties imparted and improved durability, a molded article, a sliding member, a gear, and a worm wheel using the same. [Modes for Carrying Out the Invention]

[0012] Hereinafter, modes for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail. The present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.

[0013] [Fiber-Reinforced Polyamide Resin Composition] The fiber-reinforced polyamide resin composition of the present embodiment contains a crystalline polyamide (A) and glass fibers (B). Hereinafter, the "fiber-reinforced polyamide resin composition" may be abbreviated as "polyamide composition".

[0014] The formic acid relative viscosity VR of the fiber-reinforced polyamide resin composition is 90 or more. When the formic acid relative viscosity is 90 or more, a fiber-reinforced polyamide resin molded body having more excellent mechanical properties and sliding characteristics tends to be obtained.

[0015] The formic acid relative viscosity VR of the fiber-reinforced polyamide resin composition is preferably 110 or more, and more preferably 130 or more.

[0016] The above formic acid relative viscosity can be measured by the method according to ASTM D789 shown in the examples.

[0017] By satisfying a specific composition, the fiber-reinforced polyamide resin composition of the present embodiment can impart sufficient mechanical properties to the resulting molded article, reduce property variations, and further impart sliding characteristics.

[0018] Hereinafter, each component of the fiber-reinforced polyamide resin composition according to the present embodiment will be described in detail.

[0019] ≪Component (A): Crystalline polyamide≫ In this specification, the "crystalline polyamide" is a polyamide having a heat of fusion of crystals of 4 J / g or more when measured at 20 °C / min by a differential scanning calorimeter.

[0020] The terminal amino group concentration [NH2] of the crystalline polyamide contained in the fiber-reinforced polyamide resin composition is preferably 1 milliequivalent / kg or more and 100 milliequivalents / kg or less, more preferably 3 milliequivalents / kg or more and 90 milliequivalents / kg or less, and even more preferably 5 milliequivalents / kg or more and 80 milliequivalents / kg or less. When the terminal amino group concentration is within the above range, the color tone of the polyamide resin composition is more excellent, and yellowing due to deterioration is more suppressed.

[0021] As a method for measuring the terminal amino group concentration, a method of dissolving a predetermined amount of a polyamide sample in a 90% aqueous phenol solution and titrating with 1 / 50 normal hydrochloric acid at 25 °C to calculate is exemplified.

[0022] The terminal carboxyl group concentration [COOH] of the crystalline polyamide contained in the fiber-reinforced polyamide resin composition is preferably 10 milliequivalents / kg or more and 150 milliequivalents / kg or less, more preferably 20 milliequivalents / kg or more and 140 milliequivalents / kg or less, and even more preferably 30 milliequivalents / kg or more and 130 milliequivalents / kg or less. When the terminal carboxyl group concentration is within the above range, the appearance of the molded article of the fiber-reinforced polyamide resin composition tends to be more excellent.

[0023] As a method for measuring the terminal carboxyl group concentration, for example, a method may be mentioned in which a predetermined amount of a polyamide sample is dissolved in benzyl alcohol at 160°C and titrated and calculated using a 1 / 10 normal potassium hydroxide ethylene glycol solution with phenolphthalein as an indicator.

[0024] The ratio of the terminal carboxyl group to the terminal amino group (terminal carboxyl group / terminal amino group) in the crystalline polyamide contained in the fiber-reinforced polyamide resin composition is 0.1 or more, preferably 0.5 or more, and more preferably 1 or more. The upper limit value of the ratio (terminal carboxyl group / terminal amino group) is, for example, 20 or less, 15 or less, or 10 or less. The above upper and lower limit values of the ratio (terminal carboxyl group / terminal amino group) can be arbitrarily combined. Examples of combinations are 0.1 or more and 20 or less, 0.5 or more and 15 or less, and 1 or more and 10 or less.

[0025] When the ratio (terminal carboxyl group / terminal amino group) is within the above range, a molded article having excellent fatigue characteristics and gear durability is easily obtained.

[0026] Here, the ratio of the terminal carboxyl group to the terminal amino group means a value obtained by dividing the terminal carboxyl group concentration [COOH] by the terminal amino group concentration [NH2].

[0027] Examples of the crystalline polyamide include, but are not limited to, polyamides obtained by ring-opening polymerization of (A-a) lactams, polyamides obtained by self-condensation of (A-b) ω-aminocarboxylic acids, polyamides obtained by condensing (A-c) diamines and dicarboxylic acids, and copolymers thereof. The crystalline polyamide may be used alone or in combination of two or more.

[0028] Examples of the lactam used for the production of (A-a) polyamide include, but are not limited to, pyrrolidone, caprolactam, undecalactam, dodecalactam, etc.

[0029] (A-b) Examples of the ω-aminocarboxylic acid used in the production of polyamide include, but are not limited to, ω-amino fatty acids which are ring-opening compounds of the above lactam with water, etc. In addition, as the above lactam or the above ω-aminocarboxylic acid, two or more kinds of monomers may be used in combination for condensation.

[0030] (A-c) Examples of the diamine (monomer) used in the production of polyamide include, but are not limited to, linear aliphatic diamines, branched aliphatic diamines, alicyclic diamines, aromatic diamines, etc.

[0031] Examples of the linear aliphatic diamine include, but are not limited to, hexamethylenediamine, pentamethylenediamine, etc.

[0032] Examples of the branched aliphatic diamine include, but are not limited to, 2-methylpentanediamine, 2-ethylhexamethylenediamine, etc.

[0033] Examples of the alicyclic diamine include, but are not limited to, cyclohexanediamine, cyclopentanediamine, cyclooctanediamine, etc.

[0034] Examples of the aromatic diamine include, but are not limited to, p-phenylenediamine, m-phenylenediamine, etc.

[0035] (A-c) Examples of the dicarboxylic acid (monomer) used in the production of polyamide include, but are not limited to, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, etc.

[0036] Examples of the aliphatic dicarboxylic acid include, but are not limited to, adipic acid, pimelic acid, sebacic acid, etc.

[0037] Examples of the alicyclic dicarboxylic acid include, but are not limited to, cyclohexanedicarboxylic acid and the like.

[0038] Examples of the aromatic dicarboxylic acid include, but are not limited to, phthalic acid, isophthalic acid and the like.

[0039] The diamine and dicarboxylic acid as the above-mentioned monomers may be condensed alone or in combination of two or more.

[0040] The crystalline polyamide may further contain units derived from polyvalent carboxylic acids having a valence of 3 or more, such as trimellitic acid, trimesic acid, pyromellitic acid, etc., if necessary. The polyvalent carboxylic acids having a valence of 3 or more may be used alone or in combination of two or more.

[0041] Specific examples of the crystalline polyamide contained in the fiber-reinforced polyamide resin composition of the present embodiment include, for example, polyamide 4 (poly-α-pyrrolidone), polyamide 6 (polycaproamide), polyamide 11 (polyundecanamide), polyamide 12 (polydodecanamide), polyamide 46 (polytetramethylene adipamide), polyamide 56 (polypentamethylene adipamide), polyamide 66 (polyhexamethylene adipamide), polyamide 610 (polyhexamethylene sebacamide), polyamide 612 (polyhexamethylene dodecamide), polyamide 6T (polyhexamethylene terephthalamide), polyamide 9T (polynonamethylene terephthalamide), and copolyamides containing these as constituent components.

[0042] Among them, as the crystalline polyamide, polyamide 66 (PA66), polyamide 46 (PA46), or polyamide 610 (PA610) is preferable from the viewpoint of sliding characteristics. In particular, PA66 is most preferable because it is excellent in heat resistance, moldability, and toughness and is a suitable material for automotive parts.

[0043] The method for polymerizing polyamide is not particularly limited, and examples thereof include melt polycondensation method, solid-phase polymerization method, and solution method. The melt polycondensation method is, for example, a method in which hexamethylene adipamide, which is a raw material of polyamide 66, is blended with an antifoaming agent or the like as necessary, heated and concentrated at a temperature of 40 to 300°C, the generated water vapor pressure is maintained at a pressure between normal pressure and 20 atmospheres, and finally the pressure is released to normal pressure or reduced pressure to perform polycondensation. The solid-phase polymerization method is a method in which polymerization is carried out at a temperature below the melting point of a diamine or a dicarboxylic acid salt solid salt or a polycondensate. Further, the solution method is a method in which a dicarboxylic acid halide component and a diamine component are polycondensed in a solution. These methods may be combined as necessary. Also, the polymerization form may be batch type or continuous type. The polymerization apparatus is not particularly limited, and for example, an autoclave type reactor, a tumbler type reactor, an extruder type reactor such as a kneader, etc. can be used.

[0044] In order to obtain a polyamide having a predetermined formic acid relative viscosity VR, for example, general methods such as adjusting the polymerization time by the above melt polycondensation method, solid-phase polymerization below the melting point of the polycondensate, etc. can be used, and it is not particularly limited.

[0045] The fiber-reinforced polyamide resin composition of this embodiment contains glass fibers. The glass fiber (B) contained in the polyamide resin composition preferably has a number average fiber length of 300 μm or more, more preferably 320 μm or more.

[0046] The fiber length of the glass fiber (B) contained in the polyamide resin composition is measured by the following method. The fiber length of the glass fiber is determined by burning or dissolving and removing only the polyamide of the polyamide composition, observing with an optical microscope, measuring the lengths of 400 reinforcing fibers arbitrarily selected using an image analyzer, and calculating the number average fiber length.

[0047] The above glass fiber is preferably such that at least a part of the surface is coated with a surface treatment agent. By including glass fiber having at least a part of the surface coated with a surface treatment agent, the fiber-reinforced polyamide resin composition is excellent in the defibratability of the glass fiber in the fiber-reinforced polyamide resin composition and excellent in processability.

[0048] The average fiber diameter of the glass fiber is not particularly limited, but is preferably 4 to 30 μm, more preferably 5 to 9 μm, and particularly preferably 5 to 8 μm. Here, the average fiber diameter is a value observed by an electron microscope or the like. When the average fiber diameter is within the above range, it tends to be possible to achieve better mechanical strength, rigidity, imparting of moldability, and reduction of variations in mechanical properties in the polyamide resin composition. As the glass fiber, any commercially available glass fiber such as chopped glass, roving glass, and milled glass can be used.

[0049] The surface treatment agent for the glass fiber may contain a sizing agent and is not particularly limited. For example, urethane resin, polycarbodiimide compound, homopolymer of acrylic acid, copolymer of acrylic acid and copolymerizable monomer, salt of homopolymer (homopolymer of acrylic acid) or copolymer (copolymer of acrylic acid and copolymerizable monomer) and amine, epoxy resin, and copolymer of carboxylic anhydride-containing unsaturated vinyl monomer and unsaturated vinyl monomer, etc. may be mentioned. These may be used alone or in combination of two or more.

[0050] The above urethane resin is not particularly limited as long as it is generally used as a surface treatment agent or sizing agent for glass fiber. For example, those synthesized from isocyanates such as m-xylylene diisocyanate (XDI), 4,4'-methylenebis(cyclohexyl isocyanate) (HMDI), and isophorone diisocyanate (IPDI), and polyester-based or polyether-based diols can be preferably used.

[0051] The above polycarbodiimide compound is not particularly limited, and examples thereof include those obtained by condensing a compound containing one or more carbodiimide groups (-N=C=N-).

[0052] The weight average molecular weight of the above homopolymer of acrylic acid is preferably from 1,000 to 90,000, more preferably from 1,000 to 50,000, and still more preferably from 1,000 to 25,000. The weight average molecular weight in this specification can be determined by measurement using GPC (gel permeation chromatography).

[0053] The copolymerizable monomer constituting the copolymer of the above acrylic acid and the copolymerizable monomer is not particularly limited, and examples thereof include monomers having a hydroxyl group and / or a carboxyl group, and ester monomers. Such copolymerizable monomers are not particularly limited, and examples thereof include one or more selected from the group consisting of acrylic acid, maleic acid, methacrylic acid, vinylacetic acid, crotonic acid, isocrotonic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, and ester compounds thereof (however, the case of only acrylic acid is excluded). It is preferable to have one or more ester monomers among the above-mentioned monomers.

[0054] The amine that forms a salt with the above homopolymer or copolymer of acrylic acid is not particularly limited, and it may be a primary, secondary, or tertiary amine. Specifically, examples thereof include triethylamine, triethanolamine, and glycine. From the viewpoints of improving the stability of the mixed solution with other co-used agents (such as silane coupling agents) and reducing the amine odor, the degree of neutralization is preferably from 20 to 90%, more preferably from 30 to 80%, and still more preferably from 40 to 60%.

[0055] The weight average molecular weight of the homopolymer or copolymer of acrylic acid that forms the above salt is not particularly limited, but is preferably 3,000 to 50,000. When the weight average molecular weight is 3,000 or more, the bundling property of the glass fiber tends to be further improved. Also, when the weight average molecular weight is 50,000 or less, the mechanical properties of the resulting molded body tend to be further improved.

[0056] The above epoxy resin is not particularly limited, but for example, it is preferable to use a compound having at least two or more glycidyl groups, and among them, an epoxy resin obtained by reacting bisphenol with epihalohydrin is suitable. In consideration of the bundling property of the glass fiber, the epoxy equivalent of the epoxy resin is preferably 180 g / equivalent or more, and more preferably 450 to 1900 g / equivalent.

[0057] In the glass fiber reinforced polyamide resin composition of the present embodiment, as the above glass fiber surface treatment agent or bundling agent, it is preferable to include a copolymer of a carboxylic acid anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer. By including such a copolymer, the resulting molded body tends to be more excellent in mechanical properties. The carboxylic acid anhydride-containing unsaturated vinyl monomer is not particularly limited, and examples thereof include maleic anhydride, itaconic anhydride, and citraconic anhydride. Among these, maleic anhydride is preferable. On the other hand, the unsaturated vinyl monomer is not particularly limited, and examples thereof include styrene, α-methylstyrene, ethylene, propylene, butadiene, isoprene, chloroprene, 2,3-dichlorobutadiene, 1,3-pentadiene, cyclooctadiene, methyl methacrylate, methyl acrylate, ethyl acrylate, and ethyl methacrylate. Among these, ethylene, styrene, and butadiene are preferable.

[0058] Among the combinations of the carboxylic acid anhydride-containing unsaturated vinyl monomer and the unsaturated vinyl monomer, copolymers of maleic anhydride and butadiene, copolymers of maleic anhydride and ethylene, copolymers of maleic anhydride and styrene, and mixtures thereof are more preferable.

[0059] Also, the weight average molecular weight of the copolymer containing the carboxylic anhydride-containing unsaturated vinyl monomer and the unsaturated vinyl monomer is preferably 2,000 or more, more preferably 2,000 to 1,000,000, and even more preferably 5,000 to 500,000. When the weight average molecular weight is within the above range, the fluidity of the glass fiber-reinforced polyamide resin composition tends to be further improved.

[0060] It is also preferable to use a silane coupling agent as the surface treatment agent for the glass fiber. The silane coupling agent is not particularly limited. For example, aminosilanes such as γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane; mercaptosilanes such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane; epoxysilanes; vinylsilanes. Among them, it is preferably one or more selected from the above-listed components, and aminosilanes are more preferable.

[0061] When preparing the surface treatment agent for the glass fiber, it is preferable to use a lubricant. The lubricant is not particularly limited. For example, any ordinary liquid or solid lubricant material suitable for the purpose can be used. Such lubricants are not particularly limited. For example, waxes of animal or plant origin or mineral origin such as carnauba wax and lanolin wax; surfactants such as fatty acid amides, fatty acid esters, or fatty acid ethers, or aromatic esters or aromatic ethers.

[0062] (Method for Coating the Surface of Glass Fiber with a Surface Treatment Agent) In this embodiment, it is preferable that at least a part of the surface of the glass fiber is coated with a surface treatment agent. The coating method of the surface treatment agent is not particularly limited. For example, in a known glass fiber manufacturing process, a known method such as a roller-type applicator is used to apply the surface treatment agent to the glass fiber to produce a glass fiber strand, and the produced glass fiber strand is dried to continuously react to obtain it.

[0063] The state of the glass fiber is not particularly limited. For example, the above glass fiber strand may be used as roving as it is, or further through a cutting process, it may be used as chopped glass strands. Note that the drying of the strand may be performed after the cutting process, or the strand may be cut after drying.

[0064] The adhesion amount of such a surface treatment agent for the glass fiber is preferably 0.1 to 1.0 parts by mass, more preferably 0.2 to 1.0 parts by mass, still more preferably 0.2 to 0.8 parts by mass, and most preferably 0.2 to 0.6 parts by mass as a solid content ratio with respect to 100 parts by mass of the glass fiber. When the adhesion amount of the surface treatment agent for the glass fiber is 0.1 part by mass or more as a solid content ratio with respect to 100 parts by mass of the glass fiber, the coating of the surface treatment agent on the glass fiber tends to be better maintained. On the other hand, when the usage amount is 1.0 part by mass or less as a solid content ratio with respect to 100 parts by mass of the glass fiber, the thermal stability of the fiber-reinforced polyamide resin composition tends to be further improved.

[0065] The polyamide resin composition of this embodiment preferably contains 1 part by weight or more and 100 parts by weight or less of glass fiber (B) with respect to 100 parts by weight of crystalline polyamide (A).

[0066] ≪Copper compound≫ It is preferable to add a copper compound to the polyamide resin composition. The copper compound may be described as the “(C) component”. Examples of the (C) component include, but are not limited to, copper halides, copper acetate, copper propionate, copper benzoate, copper adipate, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate, copper stearate, etc., and copper complex salts coordinated with chelating agents such as ethylenediamine and ethylenediaminetetraacetic acid. These copper compounds may be used alone or in combination of two or more. Among these, copper halides are preferable, and further, copper iodide, cuprous bromide, cupric bromide, cuprous chloride, and copper acetate are preferable from the viewpoints of suppressing the decrease in molecular weight during melt-kneading and / or heat aging resistance.

[0067] ≪Either one or both of the halides of alkali metals and alkaline earth metals≫ It is preferable to add either one or both of the halides of alkali metals and alkaline earth metals to the polyamide resin composition. Either one or both of the halides of alkali metals and alkaline earth metals may be described as the “(D) component”.

[0068] Examples of the (D) component include, but are not limited to, potassium iodide, potassium bromide, potassium chloride, sodium iodide, sodium chloride, and mixtures thereof. These may be used alone or in combination of two or more.

[0069] As the (D) component, only an alkali metal halide may be used, only an alkaline earth metal halide may be used, or both an alkali metal halide and an alkaline earth metal halide may be used. Among these, from the viewpoints of improving heat aging resistance and suppressing metal corrosion, potassium iodide and / or potassium bromide are preferable, and potassium iodide is more preferable.

[0070] (C) component and (D) component, when used in combination, not only provide a better heat stability effect, but also are more preferable from the viewpoints of suppressing the variation in mechanical properties and improving the wear characteristics. It is preferable to incorporate the (C) component and the (D) component into the polyamide resin composition at a ratio such that the molar ratio of the halogen content to the copper content (halogen / copper) is from 3 / 1 to 50 / 1 when used in combination.

[0071] The molar ratio of the halogen content to the copper content (halogen / copper) is more preferably from 4 / 1 to 40 / 1, and even more preferably from 5 / 1 to 30 / 1. Here, the "halogen" means "halogen elements" such as Br and I. Further, when copper halide is used as the copper compound, it means the total of the halogen derived from the copper halide and the halogen derived from the (D) component. When the molar ratio of the halogen content to the copper content is within the above range, it is preferable from the viewpoints of suppressing copper precipitation and metal corrosion, and suppressing the variation in mechanical strength and improving the wear characteristics.

[0072] ≪Heat stabilizer≫ It is preferable to add a heat stabilizer to the polyamide resin composition. The heat stabilizer is not particularly limited, and examples thereof include phenolic stabilizers such as hindered phenol compounds, phosphite stabilizers, hindered amine stabilizers, triazine stabilizers, and sulfur stabilizers. The above heat stabilizers may be used alone or in combination of two or more. When containing a heat stabilizer, it tends to be able to suppress deterioration due to heat. In this embodiment, the content of the heat stabilizer is not particularly limited, but from the viewpoints of effectively suppressing deterioration due to heat, preventing coloring, and maintaining mechanical properties, it is preferably from 0.005 to 5 parts by mass, more preferably from 0.1 to 3 parts by mass, and even more preferably from 0.015 to 2 parts by mass with respect to 100 parts by mass of the polyamide resin.

[0073] The phenolic stabilizer is a molecule containing a phenol group, and is not particularly limited, and examples thereof include Irganox (registered trademark) 1098 (manufactured by BASF).

[0074] The phosphite stabilizer is a molecule containing a phosphorus element, and although not particularly limited, for example, PEP(trademark registration)36 (manufactured by ADEKA Corporation) can be mentioned.

[0075] <<Other Additives>> In the polyamide resin composition, other additives may be added as necessary within a range that does not impair the object of the present embodiment. The above-mentioned other additives are not particularly limited, and for example, inorganic fillers other than glass fibers, antioxidants, ultraviolet absorbers, light degradation inhibitors, plasticizers, lubricants, mold release agents, nucleating agents, flame retardants, and colorants may be added, or other thermoplastic resins may be mixed. Here, since the properties of the above-mentioned additives are greatly different from each other, suitable content ratios that hardly impair the effects of the present embodiment for each component are various and can be appropriately set for each.

[0076] <Method for Producing Fiber-Reinforced Polyamide Resin Composition> The method for producing the fiber-reinforced polyamide resin composition of the present embodiment is not particularly limited, and it can be produced by mixing and kneading (A) crystalline polyamide and (B) glass fiber and other components blended as necessary in an arbitrary order.

[0077] The fiber-reinforced polyamide resin composition is preferably melt-kneaded using various commonly used extruders such as single-screw or twin-screw extruders, and the method using a twin-screw extruder is particularly preferred from the viewpoints of productivity, versatility, etc. Specifically, when using glass chopped strands as the (B) glass fiber, it is preferable to use a twin-screw extruder equipped with an upstream supply port and a downstream supply port, and supply the glass chopped strands from the upstream supply port for melt-kneading. When using a high-molecular-weight polyamide, the molecular weight may decrease due to melt-kneading using a twin-screw extruder. Therefore, it is preferable to use a method in which a low-molecular-weight polyamide and the (B) glass fiber are melt-kneaded in advance and then solid-phase polymerized below the melting point to obtain a high-molecular-weight fiber-reinforced polyamide resin composition. Also, when molding the molded article described later, the molecular weight may similarly decrease. Therefore, it is more preferable to use a method in which a low-molecular-weight polyamide and the (B) glass fiber are melt-kneaded in advance, molded using the molding method described later, and then the molded article is solid-phase polymerized below the melting point to obtain a high-molecular-weight fiber-reinforced polyamide resin composition.

[0078] <Molded article using fiber-reinforced polyamide resin composition> The molded body of the present embodiment contains the fiber-reinforced polyamide resin composition according to the above embodiment. Although not particularly limited, for example, it can be a molded body of various parts by injection molding of the fiber-reinforced polyamide resin composition according to the above embodiment.

[0079] And the above molded body in the present embodiment is not particularly limited, and can be applied to various parts such as for automobiles, for the machine industry, for electric and electronic products, for industrial materials, for industrial materials, and for daily and household products, for example. Thus, the molded body of the present embodiment can impart sufficient mechanical properties and durability to the above various parts.

[0080] The above molded body preferably has a yellowness index (YI) measured in accordance with ISO17223 of 2 or less. More preferably, it is preferably 0 or less. When the YI of the molded body is within the above range, it can be said that the appearance is excellent.

[0081] The fiber-reinforced polyamide resin composition according to this embodiment can be suitably used particularly for automotive parts due to its excellent mechanical properties and durability, and can be suitably used particularly for sliding members such as automotive gears, worms, and worm wheels.

Examples

[0082] 〔Raw materials〕 (A) Crystalline polyamide Production Example 1 (A)-1: Polyamide 66-1 15,000 g of an equimolar salt of adipic acid and hexamethylenediamine, and 0.5 mol% excess adipic acid with respect to the equimolar salt component were dissolved in 15,000 g of distilled water to obtain a 50 mass% aqueous solution of the raw material monomers. The obtained aqueous solution was charged into an autoclave with an internal volume of 40 L, and the inside of the autoclave was replaced with nitrogen. While stirring this aqueous solution at a temperature of 110 to 150°C, water vapor was gradually removed to concentrate the solution to a concentration of 70 mass%. Then, the internal temperature was raised to 220°C. At this time, the pressure in the autoclave increased to 1.8 MPa. While gradually removing water vapor and maintaining the pressure at 1.8 MPa, the reaction was carried out for 1 hour until the internal temperature reached 270°C. Thereafter, the pressure was reduced to atmospheric pressure over about 1 hour. After reaching atmospheric pressure, it was discharged in a strand form from the lower nozzle, cooled with water, and cut to obtain pellets of crystalline polyamide. The obtained pellets were dried in a nitrogen stream at 90°C for 4 hours. The formic acid relative viscosity of the pellets of this crystalline polyamide was 45, the melting point was 265°C, and the crystallization temperature was 220°C.

[0083] Production Example 2 (A)-2: Polyamide 66-2 10 kg of the pellets of the above polyamide 66-1 were placed in a conical ribbon vacuum dryer (manufactured by Okawara Seisakusho Co., Ltd., trade name Ribocone RM-10V), and sufficient nitrogen substitution was performed. While flowing nitrogen at 1 L / min and stirring, heating was carried out at a pellet temperature of 190 °C for 6 hours. Then, while nitrogen was flowing, the temperature was lowered, and when it reached about 50 °C, the pellets were taken out from the apparatus as they were. The formic acid relative viscosity of the pellets of this crystalline polyamide was 130.

[0084] (B) Glass fiber (B)-1: Glass chopped strand-1 Manufactured by Nitto Boseki Co., Ltd., trade name "CS-3DE-456S" (average glass fiber diameter 7 μm, average glass fiber length 3 mm, loss on ignition 36.5, boron content 13,000 ppm) (B)-2: Glass chopped strand-2 Manufactured by Nippon Electric Glass Co., Ltd., trade name "ECS03T-289DE" (average glass fiber diameter 7 μm, average glass fiber length 3 mm, loss on ignition 13.9, boron content 14,000 ppm) (B)-3: Glass chopped strand-3 Manufactured by Nitto Boseki Co., Ltd., trade name "CS-3PE-454" (average glass fiber diameter 13 μm, average glass fiber length 3 mm, loss on ignition 29.2, boron content 13,000 ppm) (B)-4: Glass chopped strand-4 The glass fiber adjusted in Production Example 4 described below (average glass fiber diameter 7 μm, average glass fiber length 3 mm, loss on ignition 32.7, boron content 0 ppm)

[0085] Production Example 4: Glass chopped strand-4 In terms of solid content, 2% by mass of a polyurethane resin (trade name: Bondic (registered trademark) 1050, an aqueous solution with a solid content rate of 50% by mass (manufactured by Dainippon Ink and Chemicals, Inc.)), 0.6% by mass of γ-aminopropyltriethoxysilane (trade name: KBE-903, (manufactured by Shin-Etsu Chemical Co., Ltd.)), and 0.1% by mass of a lubricant [trade name: carnauba wax (manufactured by Kato Yoko Co., Ltd.)] were diluted with water in such proportions that the total mass was adjusted to 100% by mass to obtain a glass fiber sizing agent.

[0086] The glass raw materials were blended at a ratio of SiO2: 58% by mass, Al2O3: 14% by mass, CaO: 21% by mass, MgO: 2% by mass, and Na2O + K2O: 5% by mass. After obtaining glass long fibers with an average fiber diameter of 7 μm by melt spinning this blend, the above-mentioned glass fiber sizing agent was attached. That is, the glass fiber sizing agent was applied to the glass fiber being wound around a rotating drum using an applicator installed at a predetermined position.

[0087] Next, this was dried to obtain rovings (glass rovings) of a glass fiber bundle surface-treated with the above-mentioned glass fiber sizing agent. At that time, the glass fibers were in a form of bundles of 1000 fibers. This was cut into lengths of 3 mm to obtain glass chopped strands - 4. These chopped strands were used as glass fibers.

[0088] (Component (C)) Copper(I) iodide (manufactured by Fujifilm Wako Pure Chemical Corporation)

[0089] (Component (D)) Potassium iodide (manufactured by Fujifilm Wako Pure Chemical Corporation)

[0090] Other components Antioxidant: Irganox (registered trademark) 1098 (manufactured by BASF) Colorant: Mitsubishi (registered trademark) Carbon Black #2600 (manufactured by Mitsubishi Chemical Corporation)

[0091] [Example 1] As an extruder, a twin-screw extruder (ZSK-40MC: manufactured by Coperion GmbH (Germany)) was used. This twin-screw extruder has an upstream supply port provided in the first barrel from the upstream side and a downstream supply port provided in the eighth barrel. And, L / D (length of the extruder cylinder / diameter of the extruder cylinder) = 48 (number of barrels: 12). In this twin-screw extruder, the temperature from the upstream supply port to the barrel immediately before the barrel having the downstream supply port was set to 310 to 320 °C, the temperature from the barrel having the downstream supply port to the final barrel was set to 290 °C, the screw rotation speed was set to 200 rpm, the discharge amount was set to 80 kg / hour, and the degree of vacuum was set to -0.08 MPa, respectively.

[0092] Under such conditions, (A) crystalline polyamide, (C) component, (D) component, and other components were supplied from the upstream supply port at the ratios shown in Table 1, and (B) glass fiber was supplied from the downstream supply port at the composition shown in Table 1, and the resin composition pellets were produced by melt-kneading.

[0093] More than 11 kg of the obtained pellets were put into a thermostat (manufactured by Espec Corporation, trade name Perfect Oven PHH-202M), and sufficient nitrogen substitution was performed. While flowing nitrogen at 1 L / min, post-extrusion solid-phase polymerization was carried out by heating at a pellet temperature of 210 °C for 2 hours. Then, while nitrogen was flowing, the temperature was lowered, and when it reached about 50 °C, the pellets were taken out from the apparatus as they were.

[0094] Using the obtained pellets and an injection molding machine PS-40E [manufactured by Nissei Plastic Industrial Co., Ltd.], the mold temperature was set to 80 °C and the cylinder temperature was set to 290 °C, and test pieces of ISO 3167, multi-purpose test piece A type were molded. Using the molded pieces, various mechanical properties and the like were evaluated. Also, the molar ratio of the copper element content to the halogen element content was calculated as I / Cu from the usage ratios of copper(I) iodide and potassium iodide.

[0095] [Examples 2 to 9] (A) Crystalline polyamide, (B) glass fiber, and pellets and test pieces of the resin compositions of Examples 2 to 9 were prepared in the same manner as in Example 1, except that the solid-phase polymerization time or the solid-phase polymerization temperature was changed as shown in Table 1, and each was subjected to various tests.

[0096] [Example 10] As the extruder, a twin-screw extruder (ZSK-40MC: manufactured by Coperion GmbH (Germany)) was used. This twin-screw extruder has an upstream supply port provided in the first barrel from the upstream side and a downstream supply port provided in the eighth barrel. And, L / D (length of the extruder cylinder / diameter of the extruder cylinder) = 48 (number of barrels: 12). In this twin-screw extruder, the temperature from the upstream supply port to the barrel immediately before the barrel having the downstream supply port was set to 310 to 320 °C, the temperature from the barrel having the downstream supply port to the final barrel was set to 290 °C, the screw rotation speed was set to 200 rpm, the discharge amount was set to 80 kg / hour, and the degree of vacuum was set to -0.08 MPa.

[0097] Under such conditions, (A) crystalline polyamide, (C) component, (D) component, and other components were supplied from the upstream supply port at the ratios shown in Table 1, and (B) glass fiber was supplied from the downstream supply port at the composition shown in Table 1, and the resin composition pellets were produced by melt-kneading.

[0098] Using the obtained pellets and an injection molding machine PS-40E [manufactured by Nissei Plastic Industrial Co., Ltd.], the mold temperature was set to 80 °C and the cylinder temperature was set to 290 °C, and test pieces of ISO 3167, multi-purpose test piece A type were molded.

[0099] The obtained multi-purpose test piece A type test pieces were placed in a thermostat (manufactured by Espec Corporation, trade name Perfect Oven PHH-202M), and sufficiently purged with nitrogen. While flowing nitrogen at 1 L / min, post-molding solid-phase polymerization was carried out by heating at a pellet temperature of 210 °C for 2 hours. Then, the temperature was lowered while nitrogen was flowing, and the test pieces were taken out of the apparatus when it reached about 50 °C. Using the molded pieces, various mechanical properties and the like were evaluated.

[0100] [Examples 11 to 20] (A) Crystalline polyamide, (B) glass fiber, components (C) and (D), and other components were changed in terms of type or content and solid-phase polymerization time or solid-phase polymerization temperature as shown in Table 1. Except for this, pellets and test pieces of the resin compositions of Examples 11 to 20 were prepared in the same manner as in Example 10 and subjected to each test. In Table 1, the masterbatch containing components (C) and (D) was abbreviated as "C·D masterbatch".

[0101] [Comparative Examples 1 to 2] As an extruder, a twin-screw extruder (ZSK-40MC: manufactured by Coperion GmbH (Germany)) was used. This twin-screw extruder has an upstream supply port provided in the first barrel from the upstream side and a downstream supply port provided in the eighth barrel. And L / D (length of the extruder cylinder / diameter of the extruder cylinder) = 48 (number of barrels: 12). In this twin-screw extruder, the temperature from the upstream supply port to the barrel immediately before the barrel having the downstream supply port was set to 310 to 320 °C, the temperature from the barrel having the downstream supply port to the final barrel was set to 290 °C, the screw rotation speed was set to 200 rpm, the discharge amount was set to 80 kg / hour, and the degree of vacuum was set to -0.08 MPa, respectively.

[0102] Under such conditions, (A) crystalline polyamide, components (C) and (D), and other components were supplied from the upstream supply port at the ratios shown in the composition in Table 1, and (B) glass fiber was supplied from the downstream supply port so as to have the composition shown in Table 1, and the resin composition pellets were produced by melt-kneading.

[0103] The obtained pellets were used in an injection molding machine PS-40E [manufactured by Nissei Plastic Industrial Co., Ltd.], the mold temperature was set to 80 °C, the cylinder temperature was set to 290 °C, and test pieces of ISO 3167, multi-purpose test piece A type were molded. Using the molded pieces, various mechanical physical properties, etc. were evaluated.

[0104] [Comparative Example 3] As an extruder, a twin-screw extruder (ZSK-40MC: manufactured by Coperion GmbH (Germany)) was used. This twin-screw extruder has an upstream supply port provided in the first barrel from the upstream side and a downstream supply port provided in the eighth barrel. And, L / D (length of the extruder cylinder / diameter of the extruder cylinder) = 48 (number of barrels: 12). In this twin-screw extruder, the temperature from the upstream supply port to the barrel immediately before the barrel having the downstream supply port was set to 310 to 320 °C, the temperature from the barrel having the downstream supply port to the final barrel was set to 290 °C, the screw rotation speed was set to 200 rpm, the discharge amount was set to 80 kg / hour, and the degree of vacuum reduction was set to -0.08 MPa, respectively.

[0105] Under such conditions, (A) crystalline polyamide, (C) component, (D) component, and other components were supplied from the upstream supply port at the ratios shown in Table 1, and (B) glass fiber was supplied from the downstream supply port so as to have the composition shown in Table 1, and the resin composition pellets were produced by melt-kneading.

[0106] 11 kg of the obtained pellets were put into a conical ribbon vacuum dryer (manufactured by Okawara Seisakusho Co., Ltd., trade name Ribocone RM-10V), and sufficient nitrogen replacement was performed. While flowing nitrogen at 1 L / min and stirring, post-extrusion solid-phase polymerization was carried out by heating at a pellet temperature of 210 °C for 5 hours. Then, the temperature was lowered while nitrogen was flowing, and when it reached about 50 °C, the pellets were taken out from the apparatus.

[0107] Using an injection molding machine PS-40E [manufactured by Nissei Plastic Industrial Co., Ltd.], the mold temperature was set to 80 °C and the cylinder temperature was set to 290 °C, and test pieces of ISO 3167, multi-purpose test piece A type were molded. Using the molded pieces, various mechanical properties and the like were evaluated.

[0108] [Measurement method] <Loss on ignition of glass fiber (amount of surface treatment agent adhered)> After precisely weighing 10 g of glass fiber, it was heated in an electric furnace at 650 °C for 1 hour. The mass loss during this period was defined as the ignition loss of the glass fiber. This operation was carried out 10 times with 10 g of different glass fibers each time, and the average value M and standard deviation σ of the ignition loss were calculated.

[0109] <Relative viscosity VR of formic acid> The relative viscosity of formic acid (VR) was obtained by comparing the viscosity of a solution (soluble component) prepared by dissolving the fiber-reinforced polyamide resin compositions obtained in the examples and comparative examples in formic acid with the viscosity of formic acid itself. Specifically, it was carried out in accordance with ASTM-D789. More specifically, VR was measured at 25 °C using a solution prepared by dissolving the soluble component in the fiber-reinforced polyamide resin composition at a ratio such that it was 8.4% by mass in 90% by mass formic acid (10% by mass water).

[0110] <Fiber length> The fiber-reinforced polyamide resin compositions obtained in the examples and comparative examples were heated at 650 °C for 2 hours to burn and remove only the polyamide, and then observed using an optical microscope. The lengths of 400 randomly selected glass fibers were measured using an image analyzer, and the number-average fiber length was calculated.

[0111] <Tensile test> Using the Type A test pieces obtained in Examples 1 to 20 and Comparative Examples 1 to 3, in accordance with ISO527, tensile tests were carried out on 5 pieces each at a test temperature of 23 °C and 120 °C at a test speed of 50 mm / min, and the average value of the tensile strength (MPa) of each 5 pieces was calculated.

[0112] <Charpy impact value> The Type A test pieces obtained in Examples 1 to 20 and Comparative Examples 1 to 3 were used. They were processed into notched test pieces in accordance with ISO2818, and for the obtained notched test pieces, the Charpy impact strength was measured in accordance with JIS K7111 (ISO179).

[0113] <Black dot foreign matter> Using the Type A test pieces obtained in Examples 1 to 20 and Comparative Examples 1 to 3, a visual inspection for black dot foreign matters was carried out. Based on the standard spot size gauge of the Wireless Communications and Electronics Industries Association, the diameter of the black dots was measured, digitized, and less than 3 points was rated as A, 4 to 10 points as B, 11 to 100 points as C, and 101 points or more as D.

[0114] <Yellowness Index (YI)> Using the Type A test pieces obtained in Examples 1 to 20 and Comparative Examples 1 to 3, the yellowness index YI was calculated in accordance with ISO 17223 using a spectrocolorimeter [ZE6000: manufactured by Nippon Denshoku Industries Co., Ltd.]. The higher the YI value, the more yellow the coloring indicates.

[0115] <Gear Durability Test> The pellets obtained through the post-extrusion solid-phase polymerization process in Examples 1 to 9 and Comparative Example 3 and the pellets obtained through melt kneading in Comparative Examples 1 to 2 were injection molded using an injection molding machine α50i-A [manufactured by Fanuc Corporation] at a cylinder temperature of 290 °C, a mold temperature of 80 °C, a maximum injection pressure of 120 MPa, an injection time of 10 seconds, and a cooling time of 60 seconds to obtain a worm wheel gear with a module of 3.0, 50 teeth, a tooth thickness of 5 mm, and a tooth width of 15 mm. Also, the pellets obtained through the post-extrusion solid-phase polymerization process in Examples 10 to 20 were used to obtain a worm wheel gear in the same manner as above, and then post-molding solid-phase polymerization was carried out under the conditions described in Table 1. Using the obtained worm wheel gear, a test was carried out on a gear durability tester manufactured by Toshiba Machine Co., Ltd. A SUS304 worm was combined with a resin-made worm wheel gear, with the driving side being the worm wheel gear and the driven side being the worm. Also, grease (Martemp CPL manufactured by Kyodo Yushi Co., Ltd.) was applied to the meshing part and rotated by hand so that the grease would conform to the entire worm and worm wheel gear. Next, the gear on the driving side was rotated under the following conditions, and the number of rotations (durability number of rotations) until the gear broke was measured. Test conditions: Temperature 23 °C, humidity 50%, torque 25 N / m, rotational speed 30 rpm After one rotation in each of the forward and reverse paths, after a 1-second interval, rotation in the opposite direction was carried out. The test was carried out 5 times each, and the average value was calculated.

[0116] <Weight reduction rate at 100,000 rotations> Using the worm wheel gear obtained by the method described in the gear durability test, after rotating it 100,000 times (1.0×10 5 rotations) with the above gear durability tester, the mass W1 of the worm wheel gear was measured, and the weight reduction rate (mass %) with respect to the mass W0 before the start of the test was calculated by the following formula. Weight reduction rate = [(W0 - W1) / W0]×100 The test was carried out 5 times each, and the average value was calculated.

[0117]

Table 1

[0118] In Examples 1 to 20 that satisfy a predetermined range, sufficient mechanical properties were imparted and durability was improved. On the other hand, in Comparative Examples 1 to 3, sufficient mechanical properties were not imparted to the molded product, and durability was not improved.

Industrial Applicability

[0119] Since the fiber-reinforced polyamide resin composition and the molded product of the present invention have excellent mechanical properties and durability, they have industrial applicability in the fields of automobiles, electric and electronic fields, mechanical and industrial fields, office equipment fields, aviation and space fields, etc.

Claims

1. A fiber-reinforced polyamide resin composition containing crystalline polyamide (A) and glass fiber (B), wherein the relative viscosity of the fiber-reinforced polyamide resin composition in formic acid is 90 or more, and the number average fiber length of the glass fiber (B) contained in the fiber-reinforced polyamide resin composition is 300 μm or more.

2. The fiber-reinforced polyamide resin composition according to claim 1, characterized in that it contains 1 to 100 parts by weight of the glass fiber (B) with respect to 100 parts by weight of the crystalline polyamide (A).

3. The fiber-reinforced polyamide resin composition according to claim 1, characterized in that the relative viscosity of the crystalline polyamide (A) in formic acid is 130 or more.

4. A fiber-reinforced polyamide resin molded article comprising the fiber-reinforced polyamide resin composition according to claim 1.

5. The fiber-reinforced polyamide resin molded article according to claim 4, characterized in that the relative viscosity of the fiber-reinforced polyamide resin molded article in formic acid is 90 or more.

6. The fiber-reinforced polyamide resin molded article according to claim 4, characterized in that the number average fiber length of the glass fiber (B) contained in the fiber-reinforced polyamide resin molded article is 300 μm or more.

7. The fiber-reinforced polyamide resin molded article according to claim 4, characterized in that the yellowness index (YI) of the fiber-reinforced polyamide resin molded article is 0 or more and 50 or less.

8. A melting and kneading step of adding 5 to 100 parts by mass of glass fiber having an average fiber diameter of 3 μm or more and 20 μm or less to 100 parts by mass of crystalline polyamide having a relative viscosity in formic acid of 30 or more and 90 or less, and melting and kneading to obtain a melt-kneaded product; A molding step of molding the melt-kneaded product to obtain a fiber-reinforced polyamide resin pre-molded article; A heating step of heating the fiber-reinforced polyamide resin pre-molded article at a temperature T represented by the following general formula (I) to obtain a fiber-reinforced polyamide resin molded article. Tm - 130°C ≤ T ≤ Tm - 10°C (I) (In the formula, Tm is the melting point of the thermoplastic resin.)

9. The fiber-reinforced polyamide resin molded article according to claim 4, which is a sliding member.

10. The fiber-reinforced polyamide resin molded article according to claim 4, which is a gear. ​ ​ ​ ​

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