Polyamide resin composition

Abstract

The present invention relates to a polyamide resin composition comprising, based on 100% by mass of the polyamide resin composition, (A) 55.0%-96.0% by mass of an aliphatic polyamide resin, (B) 1.0%-10.0% by mass of a cross-linking agent, and (C) 3.0%-28.0% by mass of glass fibers, wherein the aliphatic polyamide resin (A) is at least one selected from the group consisting of (A-1) polycondensation products of a diamine having 4-6 carbon atoms and a dicarboxylic acid having 8-13 carbon atoms, and (A-2) polycondensation products of a diamine having 8-13 carbon atoms and a dicarboxylic acid having 4-6 carbon atoms. The polyamide resin composition can contribute to the achievement of Goals 12, 13, 15, and the like of sustainable development goals (SDGs) from the viewpoints of reducing the amounts of resin components, metal components, or retrograded components thereof discharged due to abrasion, and enabling the use as a member having high reliability over a long period of time.

Description

Polyamide resin composition

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

[0002] BACKGROUND ART Polyamide resins have excellent mechanical properties, heat resistance, and chemical resistance, and are therefore widely used as engineering plastics in automobile parts, machine parts, sliding parts, electric and electronic parts, and the like.

[0003] In order to improve the sliding properties and strength when used for these purposes, polyamide resin compositions in which a crosslinking agent is blended with a polyamide resin are known (Patent Documents 1 to 3).

[0004] In Patent Document 1, polyamide 12 or the like is used as the polyamide resin. In Patent Document 2, polyamide 46, polyamide 66, polyamide 6, polyamide 9T, polyamide 6 / 11 or the like is used as the polyamide resin. Furthermore, Example 15 of Patent Document 2 describes a polyamide resin composition containing 30 mass% of a glass filler. In Patent Document 3, polyamide 46, polyamide 66 or the like is used as the polyamide resin. In the Examples of Patent Document 3, a polyamide resin composition containing no glass filler is described. Furthermore, in Patent Documents 1 to 3, the polyamide resin composition is irradiated with active energy rays to crosslink the crosslinking agent, thereby improving the sliding properties and strength.

[0005] International Publication No. 2023 / 032780 Patent No. 6283453 JP 2015-209512 A

[0006] The molded article of the polyamide resin composition as described in Patent Document 1 still has room for improvement in mechanical properties. The molded article of the polyamide resin composition containing 30 mass % of a glass filler as described in Example 15 of Patent Document 2 has a problem of high density. Furthermore, the molded article of the polyamide resin composition not containing a glass filler as described in Patent Document 3 has a problem in mechanical properties.

[0007] An object of the present invention is to provide a polyamide resin composition that has good mechanical properties such as tensile properties, flexural properties, and impact resistance, and that has low water absorption and density.

[0008] The present invention relates to the following items [1] to

[14] . [1] A polyamide resin composition comprising, based on 100% by mass of the polyamide resin composition, 55.0 to 96.0% by mass of an aliphatic polyamide resin (A), 1.0 to 10.0% by mass of a crosslinking agent (B), and 3.0 to 28.0% by mass of glass fiber (C), wherein the aliphatic polyamide resin (A) is at least one selected from the group consisting of (A-1) a polycondensate of a diamine having 4 to 6 carbon atoms and a dicarboxylic acid having 8 to 13 carbon atoms, and (A-2) a polycondensate of a diamine having 8 to 13 carbon atoms and a dicarboxylic acid having 4 to 6 carbon atoms. [2] The polyamide resin composition according to item [1], wherein the aliphatic polyamide resin (A) has a relative viscosity of 2.0 to 4.0. [3] The polycondensate (A-1) is selected from the group consisting of polytetramethylene suberamide (polyamide 48), polytetramethylene azelamide (polyamide 49), polytetramethylene sebacamide (polyamide 410), polytetramethylene undecamide (polyamide 411), polytetramethylene dodecamide (polyamide 412), polytetramethylene tridecamide (polyamide 413), polyhexamethylene suberamide (polyamide 58), polypentamethylene azelamide (polyamide 59), polypentamethylene sebacamide (polyamide 510), polypentamethylene undecamide (polyamide 511), polypentamethylene dodecamide (polyamide 512), polypentamethylene tridecamide (polyamide 513), The polyamide resin composition according to [1] or [2], wherein the polyamide resin is at least one selected from the group consisting of polyhexamethylene suberamide (polyamide 68), polyhexamethylene azelamide (polyamide 69), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene undecamide (polyamide 611), polyhexamethylene dodecamide (polyamide 612), and polyhexamethylene tridecamide (polyamide 613).[4] The polycondensate (A-2) is selected from the group consisting of polyoctamethylene succinamide (polyamide 84), polyoctamethylene glutaramide (polyamide 85), polyoctamethylene adipamide (polyamide 86), polynonamethylene succinamide (polyamide 94), polynonamethylene glutaramide (polyamide 95), polynonamethylene adipamide (polyamide 96), polydecamethylene succinamide (polyamide 104), polydecamethylene glutaramide (polyamide 105), polydecamethylene adipamide (polyamide 106), polyundecamethylene succinamide (polyamide 114), polyundecamethylene glutaramide (polyamide 115), polyundecamethylene adipamide (polyamide 116), The polyamide resin composition according to any one of [1] to [3], wherein the crosslinking agent (B) is at least one selected from the group consisting of polydodecamethylene succinamide (polyamide 124), polydodecamethylene glutaramide (polyamide 125), polydodecamethylene adipamide (polyamide 126), polytridecamethylene succinamide (polyamide 134), polytridecamethylene glutaramide (polyamide 135), and polytridecamethylene adipamide (polyamide 136). [5] The polyamide resin composition according to any one of [1] to [4], wherein the crosslinking agent (B) is at least one selected from the group consisting of triallyl cyanurate, triallyl isocyanurate, trimethallyl isocyanurate, diallyl phthalate, and diallyl benzene phosphonate. [6] The polyamide resin composition according to any one of [1] to [5], which contains 0.1 to 1.5 mass% of a heat stabilizer based on 100 mass% of the polyamide resin composition. [7] The polyamide resin composition according to any one of [1] to [6], which is for sliding applications. [8] A molded article comprising the polyamide resin composition according to any one of [1] to [7]. [9] A molded article obtained by molding the polyamide resin composition according to any one of [1] to [7], followed by irradiating with active energy rays.

[10] A molded article obtained by irradiating the polyamide resin composition according to any one of [1] to [7], followed by molding.

[11] A density of 1.10 to 1.25 g / cm. ３

[12] The molded article according to any one of [8] to

[11] , which is a sliding member.

[13] A method for producing a molded article, comprising the steps of: molding the polyamide resin composition according to any one of [1] to [7] to obtain a molded article of the polyamide resin composition; and irradiating the molded article of the polyamide resin composition obtained in the step with active energy rays.

[14] A method for producing a molded article, comprising the steps of irradiating the polyamide resin composition according to any one of [1] to [7] with active energy rays to obtain a polyamide resin composition irradiated with activation energy; and molding the polyamide resin composition irradiated with activation energy obtained in the step.

[0009] The present invention provides a polyamide resin composition that has good mechanical properties such as tensile properties, flexural properties, and impact resistance, and has low water absorption and density.

[0010] In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. Furthermore, when a composition contains multiple substances corresponding to each component, the amount of each component in the composition means the total amount of the multiple substances present in the composition, unless otherwise specified. In this specification, the term "process" does not only include independent processes, but also includes processes that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved. In this specification, the content is a value obtained by rounding off the stated value to one digit.

[0011] [Polyamide Resin Composition] The polyamide resin composition contains, based on 100% by mass of the polyamide resin composition, 55.0 to 96.0% by mass of an aliphatic polyamide resin (A), 1.0 to 10.0% by mass of a crosslinking agent (B), and 3.0 to 28.0% by mass of glass fiber (C), wherein the aliphatic polyamide resin (A) is at least one selected from the group consisting of polycondensates (A-1) of diamines having 4 to 6 carbon atoms and dicarboxylic acids having 8 to 13 carbon atoms, and polycondensates (A-2) of diamines having 8 to 13 carbon atoms and dicarboxylic acids having 4 to 6 carbon atoms.

[0012] In addition to having good mechanical properties and low water absorption and density, polyamide resin compositions exhibit low resin wear when molded articles (resin molded articles) containing the polyamide resin composition are used as sliding members, and low metal wear when molded articles (metal molded articles) made of metal come into contact with the resin molded articles. Here, "low wear" refers to low wear on each molded article when the resin molded article and the metal molded article are slid against each other, and low wear on the molded articles is preferred to maintain a good sliding condition. Furthermore, polyamide resin compositions reduce the amount of resin and metal components (including those that have deteriorated) discharged due to wear, allowing them to be used as highly reliable components over a long period of time, which can contribute to the achievement of Goals 12, 13, 15, etc. of the Sustainable Development Goals (SDGs).

[0013] [Aliphatic Polyamide Resin (A)] The polyamide resin composition contains an aliphatic polyamide resin (A), which is at least one selected from the group consisting of polycondensates (A-1) of diamines having 4 to 6 carbon atoms and dicarboxylic acids having 8 to 13 carbon atoms, and polycondensates (A-2) of diamines having 8 to 13 carbon atoms and dicarboxylic acids having 4 to 6 carbon atoms.

[0014] <Polycondensation product (A-1) of diamine having 4 to 6 carbon atoms and dicarboxylic acid having 8 to 13 carbon atoms> Examples of diamine having 4 to 6 carbon atoms include tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine. Examples of dicarboxylic acids having 8 to 13 carbon atoms include suberic acid, azelaic acid, sebacic acid, undecanedionic acid, dodecanedionic acid, and tridecanedionic acid.

[0015] Examples of the polycondensate (A-1) of a diamine having 4 to 6 carbon atoms and a dicarboxylic acid having 8 to 13 carbon atoms include polytetramethylene suberamide (polyamide 48), polytetramethylene azelamide (polyamide 49), polytetramethylene sebacamide (polyamide 410), polytetramethylene undecamide (polyamide 411), polytetramethylene dodecamide (polyamide 412), polytetramethylene tridecamide (polyamide 413), polyhexamethylene suberamide (polyamide 58), polypentamethylene azelamide (polyamide 59), polypentamethylene sebacamide (polyamide 59), and polytetramethylene undecamide (polyamide 411).

[0049] The polyimide polymer is preferably at least one selected from the group consisting of polypentamethylene undecamide (polyamide 510), polypentamethylene dodecamide (polyamide 511), polypentamethylene tridecamide (polyamide 512), polypentamethylene tridecamide (polyamide 513), polyhexamethylene suberamide (polyamide 68), polyhexamethylene azelamide (polyamide 69), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene undecamide (polyamide 611), polyhexamethylene dodecamide (polyamide 612), and polyhexamethylene tridecamide (polyamide 613).

[0016] <Polycondensation product (A-2) of diamine having 8 to 13 carbon atoms and dicarboxylic acid having 4 to 6 carbon atoms> Examples of diamine having 8 to 13 carbon atoms include octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, and tridecanediamine. Examples of dicarboxylic acid having 4 to 6 carbon atoms include succinic acid, glutaric acid, and adipic acid.

[0017] Examples of the polycondensate (A-2) of a diamine having 8 to 13 carbon atoms and a dicarboxylic acid having 4 to 6 carbon atoms include polyoctamethylene succinamide (polyamide 84), polyoctamethylene glutaramide (polyamide 85), polyoctamethylene adipamide (polyamide 86), polynonamethylene succinamide (polyamide 94), polynonamethylene glutaramide (polyamide 95), polynonamethylene adipamide (polyamide 96), polydecamethylene succinamide (polyamide 104), polydecamethylene glutaramide (polyamide 105), polydecamethylene adipamide (polyamide 106), poly It is preferably at least one selected from the group consisting of undecamethylene succinamide (polyamide 114), polyundecamethylene glutalamide (polyamide 115), polyundecamethylene adipamide (polyamide 116), polydodecamethylene succinamide (polyamide 124), polydodecamethylene glutalamide (polyamide 125), polydodecamethylene adipamide (polyamide 126), polytridecamethylene succinamide (polyamide 134), polytridecamethylene glutalamide (polyamide 135), and polytridecamethylene adipamide (polyamide 136).

[0018] <Preferred Aspects of Aliphatic Polyamide Resin (A)> From the viewpoint of easy availability of raw materials, the aliphatic polyamide resin (A) is preferably a polycondensate (A-1) of a diamine having 4 to 6 carbon atoms and a dicarboxylic acid having 8 to 13 carbon atoms, and particularly preferably polytetramethylene sebacamide (polyamide 410), polypentamethylene sebacamide (polyamide 510), polypentamethylene dodecamide (polyamide 512), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polydecamethylene succinamide (polyamide 104), polydecamethylene adipamide (polyamide 106), or polydodecamethylene adipamide (polyamide 126).

[0019] From the viewpoint of further reducing the amount of wear of the polyamide resin from a molded article using the polyamide resin composition described below, the relative viscosity of the aliphatic polyamide resin (A) is preferably 2.0 to 4.0, more preferably 2.1 to 3.8, and particularly preferably 2.5 to 3.5. The relative viscosity can be measured in accordance with JIS K 6920 by dissolving 1 g of the aliphatic polyamide resin (A) in 100 ml of 96% sulfuric acid at 25°C.

[0020] From the viewpoint of moldability and mechanical properties, the melting point of the aliphatic polyamide resin (A) is preferably 180 to 250° C., more preferably 200 to 230° C. The melting point can be determined by measuring the peak temperature of a melting curve measured in accordance with ISO 11357-3 using a differential scanning calorimeter, by heating a sample to a temperature equal to or higher than the expected melting point, then lowering the temperature of the sample at a rate of 10° C. per minute to 30° C., leaving the sample as is for about 1 minute, and then raising the temperature at a rate of 20° C. per minute.

[0021] The terminal amino group concentration of the aliphatic polyamide resin (A), as determined by dissolving the resin in a mixed solvent of phenol and methanol and subjecting it to neutralization titration, is preferably in the range of 10 μmol / g or more, more preferably in the range of 15 μmol / g to 50 μmol / g, inclusive, in order to obtain sufficient moldability and mechanical properties.

[0022] The aliphatic polyamide resin (A) may be a single component or a combination of two or more components.

[0023] <Crosslinking Agent (B)> Examples of the crosslinking agent (B) include polyfunctional (meth)allylic monomers, polyfunctional (meth)acrylic monomers, and mixed monomers thereof. The polyfunctional (meth)allylic monomers are polyfunctional allylic monomers and polyfunctional methallylic monomers. The polyfunctional (meth)acrylic monomers are polyfunctional acrylic monomers and polyfunctional methacrylic monomers.

[0024] Examples of the polyfunctional (meth)allyl monomer include triallyl cyanurate, triallyl isocyanurate, trimethallyl isocyanurate, diallyl phthalate, diallyl benzene phosphonate, and mixtures thereof. From the viewpoint of ease of crosslinking by electron beam irradiation, the polyfunctional (meth)allyl monomer is preferably at least one selected from the group consisting of triallyl cyanurate, triallyl isocyanurate, trimethallyl isocyanurate, diallyl phthalate, and diallyl benzene phosphonate.

[0025] Examples of polyfunctional (meth)acrylic monomers include ethylene oxide-modified bisphenol A di(meth)acrylate, 1,4-butanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, caprolactone-modified dipentaerythritol hexaacrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane triacrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl)isocyanurate, tris(methacryloxyethyl)isocyanurate, and mixtures thereof. From the viewpoint of low skin irritation, the polyfunctional (meth)acrylic monomer is preferably tris(acryloxyethyl)isocyanurate (triacrylic acid ester of tris(2-hydroxyethyl)isocyanuric acid).

[0026] The crosslinking agent (B) is preferably a polyfunctional (meth)allylic monomer. The crosslinking agent (B) may be a single component or a combination of two or more components. The crosslinking agent (B) may be supported on a carrier (e.g., an inorganic filler such as silicon dioxide) or dissolved in a solvent, to the extent that the effects of the present invention are not impaired.

[0027] <Glass fiber (C)> The term "fiber" in glass fiber (C) refers to a shape having a fiber length of 0.3 mm or more and an aspect ratio (ratio of fiber length / diameter) of 10 or more. As described below, the glass fiber (C) in the polyamide resin composition includes glass fiber (C) that has been broken by melt-kneading. Therefore, the content of glass fiber (C) in the polyamide resin composition also includes glass fiber (C) that has been broken and therefore no longer meets the definition of "fiber" in this specification. The content of glass fiber (C) in the polyamide resin composition corresponds to the blending amount of glass fiber in the raw material.

[0028] The glass fiber (C) may be surface-treated with a surface treatment agent and / or a binder. Furthermore, to improve workability, the glass fiber (C) may be aggregated or granulated with these surface treatment agents. Examples of the surface treatment agent and binder include various coupling agents such as silane coupling agents, titanium-based coupling agents, aluminum-based coupling agents, and zirconia-based coupling agents; water glass, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, starch, polyvinyl alcohol, acrylic resins, epoxy resins, phenolic resins, polyvinyl acetate, polyurethane resins, epoxy compounds, isocyanate compounds, colloidal silica, colloidal alumina, fatty acids, and surfactants. The surface treatment agent and binder may be used alone or in combination of two or more.

[0029] The surface treatment agent and binder may be applied to the glass fiber (C) in advance, dried, and subjected to a surface treatment or a binder treatment, or may be added simultaneously with the glass fiber (C) during preparation of the resin composition.

[0030] Examples of the glass constituting the glass fiber (C) include those having compositions such as A-glass, C-glass, E-glass, and R-glass. From the viewpoint of the thermal stability of the polyamide resin, the glass constituting the glass fiber (C) is preferably E-glass and / or R-glass.

[0031] The glass fibers used as the raw material may have an average fiber diameter of 3 to 40 μm. From the viewpoint of the dimensional stability and mechanical properties of the molded article made from the composition, the average fiber diameter is preferably 5 to 35 μm.

[0032] The cross section of the raw material glass fiber is not particularly limited and can be circular or noncircular (for example, flat). When the cross section of the glass fiber is noncircular, the aspect ratio of the cross section (ratio of the major axis of the cross section to the minor axis of the cross section) is preferably more than 1 and not more than 8, particularly preferably 2 to 6. Furthermore, when the cross section of the raw material glass fiber is noncircular, the average fiber diameter can be the average value of the major axis of the cross section and the minor axis of the cross section.

[0033] The glass fibers may be used alone or in combination of two or more. Two or more types of glass fibers having different average fiber diameters may be used. An example of a combination of glass fiber diameters is a combination of (C1) glass fibers having an average fiber diameter of 5 to 11 μm and (C2) glass fibers having an average fiber diameter of 13 to 35 μm.

[0034] The length (cut length) of the raw glass fibers is not particularly limited, but is preferably 1 mm to 50 mm, and from the viewpoint of productivity, it is particularly preferably 3 mm to 10 mm. Chopped strands having such a cut length are preferably used as the raw glass fibers. The average fiber length of the glass fibers in the polyamide resin composition is not particularly limited, but is preferably 50 μm to 1,000 μm, and more preferably 100 μm to 700 μm from the viewpoints of mechanical properties and of sufficiently defibrating the glass fibers and dispersing them uniformly in the material.

[0035] The values ​​of the average fiber diameter of the glass fibers and the glass fiber length (cut length) of the raw material described above are values ​​before melt-kneading with the aliphatic polyamide resin (A), etc. The value of the average fiber length of the glass fibers in the polyamide resin composition is a value after melt-kneading with the aliphatic polyamide resin (A), etc. The value after melt-kneading takes into account the case where at least a part of the glass fibers (C) are broken and dispersed in the polyamide composition during melt-kneading of the raw materials in the production process of the polyamide composition.

[0036] The average fiber diameter and the cut length of the raw glass fibers can be observed using an optical microscope. The average fiber diameter and the cut length of the raw glass fibers (C) may be catalog values.

[0037] The average fiber length of the glass fibers (C) in the polyamide resin composition can be observed under an optical microscope after dissolving the polyamide resin in a solvent and separating it from the glass fibers. The lengths of approximately 1,000 arbitrarily selected glass fibers are measured from the observed image using image analysis software, and the average value is calculated to be the average fiber length.

[0038] Commercially available glass fibers (C) include those manufactured by Nippon Electric Glass Co., Ltd. under the product names ECS 03T-211DE, ECS 03T-249, ECS 03T-249H, ECS 03T-275, ECS 03T-275H, ECS 03T-289, ECS 03T-289H, ECS 03T-289DE, ECS 03T-920EW, and HP3610XM; and those manufactured by Nitto Boseki Co., Ltd. under the product names CS 3DE-456S, CSG 3J-820, CSG 3PA-820S, CS 3SH-223, and CS 3PE-454.

[0039] The glass fiber (C) may be one component or a combination of two or more components.

[0040] <Optional Additives (D)> The polyamide resin composition may contain, as optional components, optional additives (D) such as heat resistance agents, inorganic fillers other than the glass fibers (C), thermoplastic resins other than the aliphatic polyamide resins (A), initiators, catalysts, stabilizers, dyes, pigments, particulate reinforcing materials, plasticizers, antioxidants, foaming agents, weather resistance agents, crystal nucleating agents, crystallization accelerators, lubricants, antistatic agents, flame retardants, flame retardant assistants, colorants, and functionality-imparting agents such as solvents.

[0041] Among the optional additives (D), those that also function as inorganic fillers are included in the inorganic fillers in the present invention. Among the optional additives (D), those that function as heat resistance agents are included in the heat resistance agents. Among the optional additives (D), initiators, catalysts and / or stabilizers may be contained in the aliphatic polyamide resin (A) and / or crosslinking agent (B).

[0042] <Heat Resistant> The heat resistant is a component that can improve the heat resistance and antioxidant properties of the molded body. Examples of the heat resistant include inorganic heat resistants and / or organic heat resistants, and inorganic heat resistants are preferred.

[0043] Inorganic Heat Resistant Agents Examples of inorganic heat resistance agents include copper compounds, potassium halides, and combinations of copper compounds and potassium halides. The inorganic heat resistance agent is preferably a combination of copper compounds and potassium halides.

[0044] Examples of the copper compound include copper (I) iodide, copper (I) bromide, copper (II) bromide, and copper acetate. From the viewpoints of heat resistance and inhibition of metal corrosion, the copper compound is preferably copper (I) iodide. Examples of the potassium halide include potassium iodide, potassium bromide, and potassium chloride. From the viewpoints of heat resistance and long-term stability of the inorganic heat-resistant agent, the potassium halide is preferably potassium iodide and / or potassium bromide. Examples of the combination of the copper compound and the potassium halide include a combination of copper (I) iodide and potassium iodide and / or potassium bromide.

[0045] Organic Heat Resistant Examples of the organic heat resistant include phenolic compounds, phosphorus-based compounds, sulfur-based compounds, nitrogen-based compounds, etc. From the viewpoint of coloring of the molded product, the organic heat resistant is preferably one or more selected from the group consisting of phenolic compounds and phosphorus-based compounds, and particularly preferably a hindered phenolic compound.

[0046] A phenolic compound is a compound having a phenol structure in the molecule. The phenolic compound is preferably a hindered phenolic compound or the like. In this specification, "hindered phenol" refers to a compound having a substituent at the ortho-position (hereinafter also referred to as "o-position") of the phenolic hydroxyl group. The substituent at the o-position is not particularly limited, but examples thereof include alkyl groups, alkoxy groups, amino groups, and halogens. Among these, alkyl groups such as methyl groups, ethyl groups, n-propyl groups, i-propyl groups, n-butyl groups, sec-butyl groups, i-butyl groups, and t-butyl groups are preferred, with bulky i-propyl groups, sec-butyl groups, i-butyl groups, and t-butyl groups being more preferred, and t-butyl groups being most preferred. Furthermore, with regard to the o-position, it is preferable that both of the two o-positions relative to the phenolic hydroxyl group have a substituent.

[0047] Examples of hindered phenols having a t-butyl group at the o-position include N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)-propionate, ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], and 3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane. Commercially available phenolic compounds include "Irganox (registered trademark) 1010" (BASF) and "Sumilizer (registered trademark) GA-80" (Sumitomo Chemical Co., Ltd.).

[0048] The phosphorus-based compound is a compound having a phosphorus atom in the molecule. Examples of the phosphorus-based compound include a phosphite ester compound of a hindered phenol and a hypophosphite ester compound of a hindered phenol. The phosphorus-based compound is preferably a phosphite ester compound of a hindered phenol having a t-butyl group at the o-position or a hypophosphite ester compound of a hindered phenol having a t-butyl group at the o-position, and a phosphite ester compound of a hindered phenol having a t-butyl group at the o-position is particularly preferred. Examples of the phosphite ester compound of a hindered phenol having a t-butyl group at the o-position include tris(2,4-di-t-butylphenyl)phosphite and bis(2,6-di-t-butyl-4-methylphenyl)pentaerthritol diphosphite. Examples of hypophosphite ester compounds of hindered phenols having a t-butyl group at the o-position include reaction products of biphenyl, phosphorus trichloride, and 2,4-di-tert-butylphenol, the main component of which is p,p,p',p'-tetrakis(2,4-di-tert-butylphenoxy)-4,4-biphenyldiphosphine. Commercially available phosphorus-based compounds include "Irgafos (registered trademark) 168" (BASF) and "Hostanox (registered trademark) P-EPQ" (Clariant Chemicals).

[0049] Sulfur-based compounds are compounds that contain sulfur atoms in the molecule, such as distearyl-3,3-thiodipropionate, pentaerythrityl tetrakis(3-laurylthiopropionate), and didodecyl(3,3′-thiodipropionate).

[0050] Examples of the nitrogen-based compound include melamine, melamine cyanurate, benguanamine, dimethylol urea, and cyanuric acid.

[0051] Combination of inorganic heat-resistant agent and organic heat-resistant agent An example of a combination of an inorganic heat-resistant agent and an organic heat-resistant agent is a combination of an inorganic heat-resistant agent and a nitrogen-based compound. The combination of an inorganic heat-resistant agent and a nitrogen-based compound can more efficiently exhibit the heat resistance effect.

[0052] <<Other Inorganic Fillers>> In the present invention, inorganic fillers other than the glass fiber (C) can be present to the extent that the effects of the present invention are not impaired. Examples of such components include inorganic fibers such as wollastonite, potassium titanate whiskers, zinc oxide whiskers, carbon fibers, alumina fibers, silicon carbide fibers, ceramic fibers, asbestos fibers, gypsum fibers, and metal fibers; silicates such as sericite, kaolin, mica, clay, bentonite, asbestos, talc, and alumina silicates; swellable layered silicates such as montmorillonite and synthetic mica; metal compounds such as alumina, silicon dioxide, magnesium oxide, zirconium oxide, titanium oxide, and iron oxide; carbonates such as calcium carbonate, magnesium carbonate, and dolomite; sulfates such as calcium sulfate and barium sulfate; glass flakes, glass beads, ceramic beads, boron nitride, silicon carbide, and calcium phosphate.

[0053] <<Thermoplastic Resin Other than Aliphatic Polyamide Resin (A)>> In the present invention, a thermoplastic resin other than the aliphatic polyamide resin (A) can be present to the extent that the effects of the present invention are not impaired. Examples of such a resin include semi-aromatic polyamide, polyolefin, halogenated polyolefin, polystyrene, polyvinyl acetate, polyurethane, ABS resin, acrylic resin, polyacetal, polycarbonate, polyester, etc.

[0054] Each of the optional additives (D) may be a single component or a combination of two or more components.

[0055] [Content of each component] The content of each component in 100% by mass of the polyamide resin composition is preferably as follows. The content of the aliphatic polyamide resin (A) is 55.0 to 96.0% by mass. If the content of the aliphatic polyamide resin (A) is less than 55.0% by mass, molding processing tends to be difficult. If the content of the aliphatic polyamide resin (A) is more than 96.0% by mass, mechanical properties tend to be insufficient. The content of the aliphatic polyamide resin (A) is preferably 68.0 to 90.0% by mass, and particularly preferably 72.0 to 90.0% by mass.

[0056] The content of the crosslinking agent (B) is 1.0 to 10.0% by mass. If the content of the crosslinking agent (B) is less than 1.0% by mass, strength such as tensile strength and tensile modulus tends to be inferior. If the content of the crosslinking agent (B) exceeds 10.0% by mass, impact resistance such as elongation and impact strength tends to be adversely affected. The content of the crosslinking agent (B) is preferably 2.0 to 8.0% by mass, and particularly preferably 3.5 to 6.5% by mass.

[0057] The content of glass fiber (C) is 3.0 to 28.0% by mass. If the content of glass fiber (C) is less than 3.0% by mass, the mechanical properties are inferior. If the content of glass fiber (C) exceeds 28.0% by mass, the density of the molded body increases, which may make molding processability difficult. Furthermore, when a polyamide resin composition with such a content is used as a sliding member, the amount of metal wear and the amount of resin wear tend to increase. The content of glass fiber (C) is preferably 4.0 to 24.0% by mass, and particularly preferably 5.0 to 22.0% by mass.

[0058] The content of optional additive (D) is 0 to 41.0% by mass. That is, in the composition, the remainder of components (A), (B), and (C) is optional additive (D). The content of optional additive (D) is preferably 0 to 30.0% by mass, and particularly preferably 0 to 20.0% by mass.

[0059] The content of the heat-resistant agent is optional as long as it does not exceed the content of the optional additives described above. The content of the heat-resistant agent is preferably 0.1 to 1.5 mass%, more preferably 0.1 to 1.2 mass%, and particularly preferably 0.1 to 1.0 mass%. When the content of the heat-resistant agent is 0.1 mass% or more, the effect of the stabilizer against thermal degradation of the molded body tends to be fully exhibited. When the content of the heat-resistant agent is 1.5 mass% or less, bleed-out from the molded body tends to be reduced as much as possible. Furthermore, when the inorganic heat-resistant agent is a combination of a copper compound and potassium halide, the mass ratio of the copper compound to the potassium halide is preferably 0.1:10 to 10:0.1, and particularly preferably 0.1:5 to 5:0.1.

[0060] Therefore, the total content of components (A), (B), and (C) in 100% by mass of the polyamide resin composition is 59.0 to 100% by mass, preferably 70.0 to 100% by mass, and particularly preferably 80.0 to 100% by mass. Furthermore, the total content of components (A), (B), and (C) in 100% by mass of the polyamide resin composition may be 98.5% by mass or less, 98.8% by mass or less, or 99.0% by mass or less.

[0061] [Method for producing polyamide resin composition] The method for producing a polyamide resin composition is not particularly limited, and a method including a step of mixing the respective components can be applied. Here, the optional additive (D) may be contained in the aliphatic polyamide resin (A) and / or the crosslinking agent (B) and then used for mixing the respective components. For example, the initiator, catalyst, and / or stabilizer may be contained in the aliphatic polyamide resin (A) and / or the crosslinking agent (B) and then used for mixing the respective components. The crosslinking agent (B) may be dissolved in a solvent and then used for mixing the respective components. Furthermore, the crosslinking agent (B) may be supported on an inorganic filler that functions as a carrier and then used for mixing the respective components.

[0062] A known melt kneader can be used to mix the aliphatic polyamide resin (A), the crosslinking agent (B), the glass fiber (C), and the optional additive (D). Examples of known melt kneaders include a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneader, and a mixing roll. Specific methods for mixing the components include a method in which all raw materials are blended and then melt-kneaded using a twin-screw extruder; a method in which some raw materials are blended and then melt-kneaded, and then the remaining raw materials are blended and melt-kneaded; or a method in which some raw materials are blended and then the remaining raw materials are mixed using a side feeder during melt-kneading.

[0063] [Molded Articles Using Polyamide Resin Composition] The polyamide resin composition can be used to produce molded articles. Furthermore, molded articles using the polyamide resin composition may be irradiated with active energy rays. It is believed that irradiating the polyamide resin composition with active energy rays causes the crosslinking agent (B) to crosslink, resulting in a composition of a crosslinked product of the crosslinking agent (B) and the aliphatic polyamide resin (A). Furthermore, if the crosslinked product has functional groups, it is believed that it may interact with the terminal functional groups or amide groups of the aliphatic polyamide to form a composite. Therefore, examples of molded articles using the polyamide resin composition include the following first molded article, second molded article, and third molded article (hereinafter, these are also collectively referred to as "molded articles using the polyamide resin composition").

[0064] The first molded article is a molded article containing a polyamide resin composition.

[0065] The second molded article is a molded article obtained by molding a polyamide resin composition and then irradiating the molded article with active energy rays.

[0066] The third molded article is a molded article obtained by irradiating a polyamide resin composition with active energy rays and then molding the same.

[0067] [First Molded Article] The first molded article is a molded article containing a polyamide resin composition. The first molded article may be a molded article obtained by molding a polyamide resin composition. The first molded article may also be a multilayer structure comprising a layer of the polyamide resin composition (i.e., a molded article made of the polyamide resin composition) and a layer of a polyolefin such as polyethylene or another thermoplastic resin. In this case, an adhesive layer may be provided between the layer of the polyamide resin composition and the layer of the other thermoplastic resin such as polyolefin. In the case of a multilayer structure, the polyamide resin composition of the present invention may be used in either an outer layer or an inner layer.

[0068] <Characteristics of the first molded body> In the first molded body, the molded body made of the polyamide resin composition has a density of 1.10 to 1.25 g / cm ３ When the density of the first molded body is within the above range, the molded body has good mechanical properties.

[0069] <Method for producing first molded article> The method for producing the first molded article includes a step of molding a polyamide resin composition to obtain a molded article of the polyamide resin composition. In the method for producing the first molded article, the polyamide resin composition is as described above.

[0070] <Molding Method> Examples of methods for molding the polyamide resin composition include injection molding, extrusion molding, blow molding, and rotational molding.

[0071] The method for producing an injection-molded article from the polyamide resin composition by injection molding is not particularly limited, and any known method can be used, for example, a method conforming to ISO 294-1.

[0072] The method for producing an extrusion molded article from the polyamide resin composition by extrusion molding is not particularly limited, and known methods can be used. It is also possible to obtain a multilayer structure by co-extrusion with a polyolefin such as polyethylene or another thermoplastic resin, followed by blow molding. In this case, an adhesive layer can be provided between the polyamide resin composition layer and the other thermoplastic resin layer such as polyolefin. In the case of a multilayer structure, the polyamide resin composition of the present invention can be used in either the outer layer or the inner layer.

[0073] The method for producing a blow-molded article from a polyamide resin composition by blow molding is not particularly limited, and known methods can be used. Generally, a parison is formed using a conventional blow molding machine, and then blow molding is carried out. The resin temperature during parison formation is preferably in the range of 10°C to 70°C higher than the melting point of the polyamide resin composition.

[0074] The method for producing a rotational molded article from the polyamide resin composition by rotational molding is not particularly limited, and any known method can be used. For example, the method described in WO 2019 / 054109 can be taken into consideration.

[0075] From the viewpoint that the polyamide resin composition has good injection moldability, the method for molding the polyamide resin composition is preferably injection molding.

[0076] Furthermore, when the first molded body is a multilayer structure of a layer of a polyamide resin composition and a layer of a polyolefin or other thermoplastic resin, the method for producing the first molded body can include a step of co-extruding the polyamide resin composition with the polyolefin or other thermoplastic resin, followed by blow molding to obtain a molded body.

[0077] [Second Molded Article] The second molded article is a molded article obtained by molding a polyamide resin composition and then irradiating the molded article with active energy rays.

[0078] In the second molded body, the method for molding the polyamide resin composition is the same as that described above for the first molded body. The second molded body may be a molded body obtained by irradiating the first molded body with active energy rays. The second molded body may be a layer of the polyamide resin composition in the multilayer structure described above for the first molded body.

[0079] <Active energy rays> Examples of active energy rays include ultraviolet rays, electron beams, α rays, β rays, ion rays, particle rays, X-rays, γ rays, etc. The active energy rays are preferably ultraviolet rays or electron beams.

[0080] Examples of light sources for ultraviolet rays include xenon lamps, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, carbon arc lamps, and tungsten lamps. The irradiation time of the active energy rays can be appropriately set depending on conditions such as the type of (B) crosslinking agent, the type of photopolymerization initiator, the thickness of the molded body, and the ultraviolet light source. From the viewpoint of workability, the irradiation time of the active energy rays is preferably 1 to 60 seconds. From the viewpoints of fast curing and workability, the irradiation dose of the active energy rays is 300 to 3,000 mJ / cm. ２ Furthermore, for the purpose of completing the crosslinking reaction of the crosslinking agent (B), a heat treatment may be carried out after the ultraviolet irradiation.

[0081] When an electron beam or the like is used as the active energy ray, the polyamide resin composition does not need to contain a photopolymerization initiator. When an electron beam is used as the active energy ray, it is preferable to use an electron beam accelerator having an energy of 100 to 500 eV.

[0082] <Characteristics of the second molded body> The density of the second molded body is 1.10 to 1.25 g / cm ３ When the density of the second molded body is within the above range, the mechanical properties of the second molded body are good.

[0083] <Method for producing second molded article> The method for producing the second molded article includes a step of molding a polyamide resin composition to obtain a molded article of the polyamide resin composition, and a step of irradiating the molded article of the polyamide resin composition obtained in the above step with active energy rays. In the method for producing the second molded article, the polyamide resin composition, the method for molding the polyamide resin composition, and the energy rays are as described above.

[0084] [Third Molded Article] The third molded article is a molded article obtained by irradiating a polyamide resin composition with active energy rays and then molding the same.

[0085] In the third molded body, the method for molding the polyamide resin composition is as described above for the first molded body. In addition, in the third molded body, the active energy rays are as described above for the second molded body. In addition, the third molded body may be a layer of the polyamide resin composition in the multilayer structure described above for the first molded body.

[0086] <Characteristics of the Third Molded Product> The density of the third molded product, including the preferred embodiment, is as described above for the second molded product.

[0087] <Third method for producing a molded article> The third method for producing a molded article includes a step of irradiating a polyamide resin composition with active energy rays to obtain a polyamide resin composition irradiated with activation energy, and a step of molding the polyamide resin composition irradiated with activation energy obtained in the step. In the third method for producing a molded article, the polyamide resin composition, the method for molding the polyamide resin composition, and the energy rays are as described above.

[0088] [Uses of Polyamide Resin Composition and Uses of Molded Article] The polyamide resin composition and / or molded articles of the polyamide resin composition can be used in various applications. Examples of such applications include sliding components for dynamic sliding properties, such as gears, cams, pulleys, bearings, bearing retainers, door checks, timing chain guides, and cable / hose support / guiding devices; automotive components, such as spoilers, air intake ducts, intake manifolds, resonators, fuel tanks, gas tanks, hydraulic oil tanks, fuel filler tubes, fuel delivery pipes, and various other hoses, tubes, and tanks; machine components, such as power tool housings and pipes; electric and electronic components, such as tanks, tubes, hoses, and films; household and office supplies; building materials; and furniture components.

[0089] Molded articles using the polyamide resin composition are preferably used as components that are used in environments where the temperature environment fluctuates greatly, such as heat resistance, cold resistance, etc., for example, driving components such as gears and belts in the field of vehicles such as automobiles, and sliding components such as tire sidewalls and belts.

[0090] Furthermore, since molded articles using the polyamide resin composition have excellent gas barrier properties, they are also preferably molded articles that come into contact with high-pressure gas. Examples of molded articles that come into contact with high-pressure gas include tanks, tubes, hoses, films, etc. that come into contact with high-pressure gas. The type of gas is not particularly limited, and examples include hydrogen, nitrogen, oxygen, helium, methane, butane, propane, etc., with low polarity gases being preferred, and hydrogen, nitrogen, and methane being particularly preferred.

[0091] The polyamide resin composition is particularly preferably used for sliding applications. Furthermore, a molded article using the polyamide resin composition is more preferably an automobile part, a sliding part, or an electric / electronic part, and is particularly preferably a sliding part.

[0092] 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 values ​​of the examples, comparative examples, and raw materials were measured by the following methods.

[0093] <Relative Viscosity> This is a value measured at 25°C in accordance with JIS K6920-2 by dissolving 1 g of polyamide resin in 100 ml of 96% concentrated sulfuric acid.

[0094] <Density> The density was measured in accordance with ISO 1183-3 (gas pycnometer method) using an ISO TYPE-B test piece obtained from the polyamide resin composition. ３ The following were considered successful:

[0095] <Water absorption rate> An ISO TYPE-A test piece obtained from the polyamide resin composition was immersed in water at 80°C for 24 hours, and the water absorption rate was calculated from the difference in mass of the test piece before and after immersion. A value of 1.7% or less was considered to be acceptable.

[0096] <Mechanical Properties> The following mechanical properties were measured using ISO TYPE-A test pieces and ISO TYPE-B test pieces obtained from the polyamide resin compositions.

[0097] (1) Tensile strength, tensile breaking strain, and tensile modulus ISO TYPE-A test pieces were prepared based on ISO 294-1, and tensile tests were carried out in a 23°C atmosphere based on ISO 527-1, 2. A tensile strength of 90 MPa or more was considered acceptable. A tensile breaking strain of 4.0% or more was considered acceptable. A tensile modulus of 3,500 MPa or more was considered acceptable.

[0098] (2) Flexural Strength and Flexural Modulus ISO TYPE-B test pieces were prepared based on ISO 294-1, and a flexural test was carried out in a 23°C atmosphere based on ISO 178. A flexural strength of 130 MPa or more was considered acceptable, and a flexural modulus of 3,500 MPa or more was considered acceptable.

[0099] (3) Charpy impact strength ISO TYPE-B test pieces were prepared based on ISO 294-1, and V-notched based on ISO 179 / 1eA in post-processing. Charpy impact tests were conducted with a hammer capacity of 0.5 to 5 J in an atmosphere of 23°C. ２ The above is considered a pass.

[0100] (4) Rockwell hardness (M scale) Measured at 23°C in accordance with ISO 6508-1 using an electric digital Rockwell hardness tester model ARD-P manufactured by Akashi Seisakusho Co., Ltd. A value of 80 or more was considered to be acceptable.

[0101] (5) Storage Modulus Using a dynamic viscoelasticity measuring device RSA G-2 manufactured by TA Instruments, the storage modulus at 80°C was measured in a three-point bending mode with a span of 40 mm, a temperature range of 30°C to 220°C, a frequency of 1 Hz, a strain of 0.1%, and a heating rate of 3°C / min. A value of 1,200 MPa or more was considered acceptable.

[0102] <Wear resistance> Using a 3 mm thick injection-molded plate, an EFM-III-EN manufactured by Orientec Co., Ltd. was used to measure the plate resin wear amount and pin metal wear amount (for 3 pins) calculated from the weight difference before and after the test using the pin-on-disk method (3 pins, hemispherical tip), a load of 57.7 kg (19.2 kg per pin), a sliding speed of 2.2 cm / sec, 23°C, and a sliding distance of 200 m. A resin wear amount of 45 mg or less was considered acceptable. A metal wear amount of 1.0 mg or less was considered acceptable.

[0103] From the above measured values, a comprehensive evaluation was made according to the following criteria: ◯: Meets all of the pass criteria for each of the above measured values. ×: Does not meet one or more of the pass criteria for each of the above measured values.

[0104] [Examples 1 to 8, Comparative Examples 1 and 3 to 6] The components listed in Table 1 were melt-kneaded in a twin-screw kneader ZSK32-Mc with a cylinder diameter of 32 mm and L / D of 47 at a cylinder temperature of 240°C, a screw rotation of 200 rpm, and a discharge rate of 40 kg / hr to produce the desired polyamide resin composition pellets. Test piece 1 having the shape used in each test was prepared by injection molding from the obtained polyamide resin composition pellets. The obtained test piece 1 was irradiated with an electron beam of 100 kGy and electron beam energy of 4.8 MeV to produce test piece 2. Test piece 2 was used for the evaluation of each test.

[0105] [Comparative Example 2] The target polyamide resin composition pellets were prepared in the same manner as in Example 1. Test pieces 3 having the shapes used in each test were prepared from the obtained polyamide resin composition pellets by injection molding. The obtained test pieces 3 were used for evaluation of each test without being irradiated with an electron beam.

[0106] The results are shown in Table 1. The units of composition in the table are % by mass, with the entire resin composition being 100% by mass.

[0107] The following components were used as shown in Table 1: PA610(1): Polyamide 610, F170, relative viscosity 3.4, melting point 220°C, amino group concentration 30 μmol / g, manufactured by Shangdong Guangyin New Materials Co., Ltd. PA610(2): Polyamide 610, F120, relative viscosity 2.4, melting point 223°C, amino group concentration 35 μmol / g, manufactured by Shangdong Guangyin New Materials Co., Ltd. PA612(1): Polyamide 612, A170, relative viscosity 3.3, melting point 215°C, amino group concentration 20 μmol / g, manufactured by Shangdong Guangyin New Materials Co., Ltd. PA612 (2): Polyamide 612, A120, relative viscosity 2.2, melting point 217 ° C, amino group concentration 25 μmol / g, manufactured by Shangdong Guangyin New Materials Co., Ltd. PA12: Polyamide 12, UBESTA (registered trademark), relative viscosity 2.3, melting point 178 ° C, amino group concentration 22 μmol / g, manufactured by UBE Co., Ltd. Crosslinker: triallyl isocyanurate, TAICROS (registered trademark), manufactured by Evonic Glass fiber (1): E-glass, chopped strand ECS 03T-211DE, circular cross section, average diameter 6 μm, manufactured by Nippon Electric Glass Co., Ltd. Glass fiber (2): E-glass, chopped strand ECS 03T-920EW, flat cross section, minor axis 7 μm × major axis 28 μm, manufactured by Nippon Electric Glass Co., Ltd. Glass fiber (3): R-glass, chopped strand HP3610XM, circular cross section, average diameter 10.5 μm, manufactured by Nippon Electric Glass Co., Ltd. Heat-resistant agent: mixture of cuprous iodide and potassium iodide (CuI:KI = 1:6 (mass ratio))

[0108]

[0109] Comparing Examples 1 to 6 with Examples 7 to 8, it can be seen that resin abrasion was reduced when the relative viscosity of the aliphatic polyamide resin (A) was 2.5 to 3.5. The composition of Comparative Example 1 contained polyamide 12 as the aliphatic polyamide resin. Compared to Comparative Example 1, Examples 1 to 8 had superior mechanical strength. The composition of Comparative Example 2 did not contain a crosslinking agent. The molded article of Comparative Example 2 had inferior mechanical strength. The compositions of Comparative Examples 3 to 5 contained glass fiber in an amount exceeding 28.0% by mass. Therefore, the molded articles of Comparative Examples 3 to 5 had high densities and were too hard. Furthermore, the molded articles of Comparative Examples 3 to 5 had higher metal abrasion and resin abrasion. The composition of Comparative Example 6 contained glass fiber less than 3.0% by mass. Therefore, the molded article of Comparative Example 6 had inferior mechanical strength. These results demonstrate that the polyamide resin composition of the present invention is suitable for sliding applications. It can also be seen that molded articles obtained by molding the polyamide resin composition of the present invention are suitable for use as sliding members.

Claims

1. The polyamide resin composition contains 55.0 to 96.0 mass% of an aliphatic polyamide resin (A), 1.0 to 10.0 mass% of a crosslinking agent (B), and 3.0 to 28.0 mass% of a glass fiber (C), based on 100 mass% of the polyamide resin composition; the aliphatic polyamide resin (A) is at least one selected from the group consisting of polycondensates (A-1) of diamines having 4 to 6 carbon atoms and dicarboxylic acids having 8 to 13 carbon atoms and polycondensates (A-2) of diamines having 8 to 13 carbon atoms and dicarboxylic acids having 4 to 6 carbon atoms; The polyamide resin composition, wherein the crosslinking agent (B) is at least one selected from the group consisting of triallyl cyanurate, triallyl isocyanurate, trimethallyl isocyanurate, diallyl phthalate, and diallyl benzene phosphonate.

2. 2. The polyamide resin composition according to claim 1, wherein the aliphatic polyamide resin (A) has a relative viscosity of 2.0 to 4.

0.

3. The polycondensate (A-1) is selected from the group consisting of polytetramethylene suberamide (polyamide 48), polytetramethylene azelamide (polyamide 49), polytetramethylene sebacamide (polyamide 410), polytetramethylene undecamide (polyamide 411), polytetramethylene dodecamide (polyamide 412), polytetramethylene tridecamide (polyamide 413), Polypentamethylene suberamide (polyamide 58), polypentamethylene azelamide (polyamide 59), polypentamethylene sebacamide (polyamide 510), polypentamethylene undecamide (polyamide 511), polypentamethylene dodecamide (polyamide 512), polypentamethylene tridecamide (polyamide 513), Polyhexamethylene suberamide (polyamide 68), polyhexamethylene azelamide (polyamide 69), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene undecamide (polyamide 611), polyhexamethylene dodecamide (polyamide 612) and polyhexamethylene tridecamide (polyamide 613), The polyamide resin composition according to claim 1, wherein the polyamide resin composition is at least one selected from the group consisting of:

4. The polycondensate (A-2) is selected from the group consisting of polyoctamethylene succinamide (polyamide 84), polyoctamethylene glutaramide (polyamide 85), polyoctamethylene adipamide (polyamide 86), Polynonamethylene succinamide (polyamide 94), polynonamethylene glutaramide (polyamide 95), polynonamethylene adipamide (polyamide 96), Polydecamethylene succinamide (polyamide 104), polydecamethylene glutaramide (polyamide 105), polydecamethylene adipamide (polyamide 106), Polyundecamethylene succinamide (polyamide 114), polyundecamethylene glutaramide (polyamide 115), polyundecamethylene adipamide (polyamide 116), Polydodecamethylene succinamide (polyamide 124), polydodecamethylene glutaramide (polyamide 125), polydodecamethylene adipamide (polyamide 126), Polytridecamethylene succinamide (polyamide 134), polytridecamethylene glutaramide (polyamide 135), and polytridecamethylene adipamide (polyamide 136) The polyamide resin composition according to claim 1, wherein the polyamide resin composition is at least one selected from the group consisting of:

5. The polyamide resin composition according to claim 1, comprising 0.1 to 1.5% by mass of a heat-resistant agent based on 100% by mass of the polyamide resin composition.

6. The polyamide resin composition according to claim 1 for sliding applications.

7. A molded article comprising the polyamide resin composition according to any one of claims 1 to 6.

8. A molded article obtained by molding the polyamide resin composition according to any one of claims 1 to 6 and then irradiating it with active energy rays.

9. A molded article obtained by irradiating the polyamide resin composition according to any one of claims 1 to 6 with active energy rays and then molding the same.

10. Density is 1.10 to 1.25 g / cm ３ The molded article according to claim 8, wherein

11. Density is 1.10 to 1.25 g / cm ３ The molded article according to claim 9,

12. The molded article according to claim 7, which is a sliding member.

13. The molded article according to claim 8, which is a sliding member.

14. The molded article according to claim 9, which is a sliding member.

15. The molded article according to claim 10, which is a sliding member.

16. The molded article according to claim 11, which is a sliding member.

17. A method for producing a molded article, comprising: a step of molding the polyamide resin composition according to any one of claims 1 to 6 to obtain a molded article of the polyamide resin composition; and a step of irradiating the molded article of the polyamide resin composition obtained in the step with active energy rays.

18. A method for producing a molded article, comprising: a step of irradiating the polyamide resin composition according to any one of claims 1 to 6 with active energy rays to obtain an active energy ray-irradiated polyamide resin composition; and a step of molding the active energy ray-irradiated polyamide resin composition obtained in the step.