Polyamide resin composition for extrusion molding and molded article

Abstract

To provide a polyamide resin composition for extrusion molding which is excellent in extrusion processability and extrusion moldability, and is excellent in flexibility, chemical resistance and fading resistance when formed into a molded article.SOLUTION: A polyamide resin composition for extrusion molding contains, with respect to 100 pts.mass of the total mass of (A) a polyamide resin and (B) an impact-resistant material, 55 pts.mass or more and 85 pts.mass or less of (A) the polyamide resin, 15 pts.mass or more and 45 pts.mass or less of (B) the impact-resistant material, 0.01 pt.mass or more and 0.50 pt.mass or less of (C) a black dye, and 0.05 pt.mass or more and 0.50 pt.mass or less of (D) carbon black, and contains 60 pts.mass or more of a polyamide resin having an average carbon number of more than 6 and 10 or less per monomer unit with respect to 100 pts.mass of (A) the polyamide resin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyamide resin composition for extrusion molding and a molded article. [Background technology]

[0002] Polyamide resins have properties suitable for use as engineering plastics, such as excellent mechanical properties, thermal properties, and chemical resistance, and are therefore widely used in a wide range of applications, including injection molding, machine parts, automobile parts, and various electrical and electronic parts. Meanwhile, electric vehicles (EVs), which are expected to see rapid growth in the future, require long, thin-diameter molded products as cooling pipes through which refrigerants pass to cool batteries. The mainstream method for producing long, thin-diameter molded products is to bend a straight tubular primary molded body obtained by extrusion molding and use it as a component. However, polyamide resins generally have low melt viscosity and only a small change in melt viscosity with respect to shear rate, making them difficult to extrude.

[0003] It is known that polyamide resins for extrusion molding, which are obtained by adding an impact-resistant material and a metal halide to polyamide 6, have excellent extrusion moldability, retention stability, and thickness unevenness of molded products (see, for example, Patent Document 1). It is also known that polyamide resins obtained by adding maleic anhydride-grafted ethylene-propylene copolymer or maleic anhydride-grafted SEBS (styrene-ethylene / 1-butene-styrene block copolymer) to polyamide 12 can be extrusion molded and have excellent flexibility and chemical resistance (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6690785 [Patent Document 2] Patent No. 3850608 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the technology described in Patent Document 1, even if an extrusion-moldable polyamide resin composition is used, it is difficult to sufficiently improve the chemical resistance, productivity during melt processing, and discoloration resistance of molded articles required for cooling pipes. With Patent Document 2, even if an extrusion-moldable polyamide resin composition has excellent chemical resistance, it is difficult to sufficiently improve the productivity during melt processing and discoloration resistance of molded articles.

[0006] The present invention has been made in view of the above circumstances, and provides a polyamide resin composition for extrusion molding that has excellent extrusion processability and extrusion moldability, and that, when formed into a molded article, has excellent flexibility, chemical resistance, and discoloration resistance, and a molded article made using the polyamide resin composition for extrusion molding. [Means for solving the problem]

[0007] That is, the present invention includes the following aspects. (1) For every 100 parts by mass of the total mass of (A) polyamide resin and (B) impact-resistant material, 55 parts by mass or more and 85 parts by mass or less of the (A) polyamide resin; 15 parts by mass or more and 45 parts by mass or less of the impact-resistant material (B); 0.01 parts by mass or more and 0.50 parts by mass or less of (C) a black dye; (D) carbon black in an amount of 0.05 parts by mass or more and 0.50 parts by mass or less; A polyamide resin composition for extrusion molding, comprising: The polyamide resin composition for extrusion molding comprises 60 parts by mass or more of a polyamide resin having an average carbon number per monomer unit of more than 6 and not more than 10, relative to 100 parts by mass of the (A) polyamide resin. (2) The polyamide resin composition for extrusion molding according to (1), wherein the impact-resistant material (B) is a maleic acid-grafted ethylene-α-olefin copolymer. (3) The polyamide resin composition for extrusion molding according to (1) or (2), wherein the total mass of the (C) black dye and the (D) carbon black is more than 0.10 parts by mass per 100 parts by mass of the total of the (A) polyamide resin and the (B) impact-resistant material. (4) Carboxy group concentration (COOH) of the impact-resistant material (B) EL and the amino terminal group concentration NH of the (A) polyamide resin 2PA Ratio of COOH EL / NH 2PA The polyamide resin composition for extrusion molding according to any one of (1) to (3), wherein the value is 0.30 or more and 1.50 or less. (5) Carboxy group concentration (COOH) of the impact-resistant material (B) EL and the amino terminal group concentration NH of the (A) polyamide resin 2PA Ratio of COOH EL / NH 2PA The polyamide resin composition for extrusion molding according to any one of (1) to (4), wherein the value is 0.30 or more and 1.20 or less. (6) Carboxy group concentration (COOH) of the impact-resistant material (B) EL and the amino terminal group concentration NH of the (A) polyamide resin 2PA Ratio of COOH EL / NH 2PA The polyamide resin composition for extrusion molding according to any one of (1) to (5), wherein the value is 0.30 or more and 1.00 or less. (7) The polyamide resin composition for extrusion molding according to any one of (1) to (6), further comprising 0.01 to 3.00 parts by mass of a heat-resistant agent (E) relative to 100 parts by mass of the total of the polyamide resin (A) and the impact-resistant material (B). (8) A molded article obtained by molding the polyamide resin composition for extrusion molding according to any one of (1) to (7). (9) The molded article according to (8), wherein the molded article is hollow. (10) The molded article according to (8), wherein the molded article has a shape of a pipe, a tube, a hose, or a film. (11) The molded article according to any one of (8) to (10), which is an automobile material part. (12) The molded product according to (11), wherein the automotive material part is an air conditioning hose or a battery cooling pipe. [Effects of the Invention]

[0008] The polyamide resin composition for extrusion molding of the above aspect can provide a polyamide resin composition for extrusion molding that has excellent extrusion processability and extrusion moldability, and that, when formed into a molded article, has excellent flexibility, chemical resistance, and resistance to fading. The molded article of the above aspect is obtained by molding the polyamide resin composition for extrusion molding and has excellent flexibility, chemical resistance, and resistance to fading. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following embodiments are merely examples for explaining the present invention, and are not intended to limit the present invention to the following content. The present invention can be implemented by modifying it as appropriate within the scope of its gist.

[0010] In this specification, the term "polyamide" refers to a polymer having an amide (-NHCO-) ​​group in the main chain.

[0011] <Polyamide resin composition for extrusion molding> The polyamide resin composition for extrusion molding of this embodiment (hereinafter, sometimes simply referred to as "the polyamide resin composition of this embodiment") contains, per 100 parts by mass of the total mass of (A) polyamide resin and (B) impact-resistant material, 55 parts by mass or more and 85 parts by mass or less of the (A) polyamide resin; 15 parts by mass or more and 45 parts by mass or less of the impact-resistant material (B); 0.01 parts by mass or more and 0.50 parts by mass or less of (C) a black dye; (D) carbon black in an amount of 0.05 parts by mass or more and 0.50 parts by mass or less; Includes.

[0012] The polyamide resin composition of the present embodiment contains 60 parts by mass or more of a polyamide resin having an average carbon number per monomer unit of more than 6 and not more than 10, relative to 100 parts by mass of the (A) polyamide resin.

[0013] The polyamide resin composition of the present embodiment has the above-described configuration, and thus (A) the polyamide resin and (B) the impact-resistant material can be crosslinked appropriately, and the composition has excellent extrusion processability and extrusion moldability, and when molded, a molded article having excellent flexibility, chemical resistance, and discoloration resistance can be obtained.

[0014] Hereinafter, each of the constituent components of the polyamide resin composition of the present embodiment will be described in detail. Hereinafter, (A) polyamide resin, (B) impact-resistant material, (C) black dye, and (D) carbon black may be referred to as component (A), component (B), component (C), and component (D), respectively.

[0015] <(A) Polyamide resin> The polyamide resin composition of the present embodiment contains, per 100 parts by mass of (A) polyamide resin, 60 parts by mass or more, preferably 70 parts by mass or more, more preferably 80 parts by mass or more, even more preferably 90 parts by mass or more, particularly preferably 95 parts by mass or more, of a polyamide resin having an average carbon number per monomer unit of more than 6 and not more than 10, and most preferably 100 parts by mass, i.e., (A) polyamide resin is most preferably made of a polyamide resin having an average carbon number per monomer unit of more than 6 and not more than 10. When the polyamide resin having an average carbon number per monomer unit of more than 6 and not more than 10 is at least the above lower limit, the polyamide resin tends to have excellent chemical resistance.

[0016] The term "average number of carbon atoms per monomer unit (φ)" refers to the number of carbon atoms calculated by dividing the total number of carbon atoms in the monomers used to produce the polyamide resin by the number of monomers used. Examples include: PA6 φ Average number of carbon atoms per monomer unit: 6 (6÷1=6) PA66 φ Average number of carbon atoms per monomer unit: 6 ((6 + 6) ÷ 2 = 6) PA612 φ Average number of carbon atoms per monomer unit: 9 ((6 + 12) ÷ 2 = 9) PA66 / 6I φ Average number of carbon atoms in the monomer unit: 6.5 ({(6+6)+(6+8)}÷4=6.5)

[0017] Examples of (A) polyamide resins include, but are not limited to, polyamide resins obtained by condensation polymerization of diamines and dicarboxylic acids, polyamide resins obtained by ring-opening polymerization of lactams, polyamide resins obtained by self-condensation of aminocarboxylic acids, and copolymers obtained by copolymerization of two or more types of monomers that constitute these polyamide resins. These (A) components may be used alone or in combination of two or more.

[0018] [Polymerization monomer] (A) Polymerization monomers that are raw materials for polyamide resins will be described in detail below.

[0019] (diamine) The diamine is not limited to the following, but examples thereof include aliphatic diamines, alicyclic diamines, and aromatic diamines.

[0020] The aliphatic diamine may be a linear saturated aliphatic diamine or a branched saturated aliphatic diamine. Examples of the branched saturated aliphatic diamine include diamines having a substituent branched from the main chain.

[0021] The linear saturated aliphatic diamine preferably has 2 to 20 carbon atoms, and examples thereof include ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, and tridecamethylenediamine.

[0022] The branched saturated aliphatic diamine preferably has 3 to 20 carbon atoms, and examples thereof include 2-methylpentamethylenediamine (also written as "2-methyl-1,5-diaminopentane"), 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 2-methyloctamethylenediamine, and 2,4-dimethyloctamethylenediamine.

[0023] Examples of alicyclic diamines (also referred to as alicyclic diamines) include, but are not limited to, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 1,3-cyclopentanediamine, and the like.

[0024] Examples of aromatic diamines include, but are not limited to, metaxylylenediamine, paraxylylenediamine, metaphenylenediamine, orthophenylenediamine, and paraphenylenediamine.

[0025] These diamines may be used alone or in combination of two or more.

[0026] (dicarboxylic acid) The dicarboxylic acid is not limited to the following, but examples thereof include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and aromatic dicarboxylic acids.

[0027] The aliphatic dicarboxylic acid may be a linear saturated aliphatic dicarboxylic acid or a branched saturated aliphatic dicarboxylic acid, and preferably has a carbon number of 3 to 20. Examples of such aliphatic dicarboxylic acids include, but are not limited to, malonic acid, dimethylmalonic acid, succinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylglutaric acid, 2,2-diethylsuccinic acid, 2,3-diethylglutaric acid, glutaric acid, 2,2-dimethylglutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, eicosane diacid, and diglycolic acid.

[0028] The number of carbon atoms in the alicyclic structure of the alicyclic dicarboxylic acid (also referred to as alicyclic dicarboxylic acid) is not particularly limited, but from the viewpoint of the balance between the water absorption and crystallinity of the resulting component (A), it is preferably 3 or more and 10 or less, and more preferably 5 or more and 10 or less.

[0029] The alicyclic dicarboxylic acid may be unsubstituted or may have a substituent. The substituent is preferably an alkyl group having 1 to 4 carbon atoms. Examples of the substituent include, but are not limited to, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group.

[0030] Examples of such alicyclic dicarboxylic acids include, but are not limited to, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,3-cyclopentanedicarboxylic acid.

[0031] Examples of aromatic dicarboxylic acids include, but are not limited to, unsubstituted or substituted aromatic dicarboxylic acids having from 8 to 20 carbon atoms. Examples of substituents include, but are not limited to, alkyl groups having from 1 to 6 carbon atoms, aryl groups having from 6 to 12 carbon atoms, arylalkyl groups having from 7 to 20 carbon atoms, halogen groups, alkylsilyl groups having from 3 to 10 carbon atoms, sulfonic acid groups, and groups having sulfonate salts. Examples of halogen groups include chloro groups and bromo groups. Examples of salts constituting groups having sulfonate salts include sodium salts.

[0032] Examples of such aromatic dicarboxylic acids include, but are not limited to, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, and 5-sodium sulfoisophthalic acid.

[0033] These dicarboxylic acids may be used alone or in combination of two or more.

[0034] (lactam) Examples of lactams include, but are not limited to, butyrolactam, pivalolactam, ε-caprolactam, caprylolactam, enantholactam, undecanelactam, laurolactam (dodecanelactam), etc. Among them, ε-caprolactam, undecanelactam, or laurolactam (dodecanelactam) is preferred from the viewpoint of polymerization production. These lactams may be used alone or in combination of two or more.

[0035] (aminocarboxylic acid) Examples of aminocarboxylic acids include, but are not limited to, compounds in which the above-mentioned lactams are ring-opened, more specifically ω-aminocarboxylic acids, α,ω-aminocarboxylic acids, and the like.

[0036] The aminocarboxylic acid may be an aliphatic aminocarboxylic acid or an aromatic aminocarboxylic acid. Examples of the aromatic aminocarboxylic acid include, but are not limited to, para-aminomethylbenzoic acid.

[0037] From the viewpoint of increasing the degree of crystallinity, the aminocarboxylic acid is preferably a linear or branched saturated aliphatic aminocarboxylic acid having from 4 to 14 carbon atoms and substituted with an amino group at the ω-position. Specific examples of preferred aminocarboxylic acids include, but are not limited to, 6-aminocaproic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

[0038] These aminocarboxylic acids may be used alone or in combination of two or more.

[0039] Examples of (A) polyamide resins include, but are not limited to, polyamide 610 (polyhexamethylene sebacamide), polyamide 612 (polyhexamethylene dodecamide), polyamide 116 (polyundecamethylene adipamide), polyamide MXD6 (polymetaxylylene adipamide), polyamide 66 / 6I (polyhexamethylene adipamide / polyisophthaladipamide copolymer), polyamide 6I / 6T (polyisophthaladipamide / polytetrafluoroethylene copolymer), and polyamide 6I / 6T (polyisophthaladipamide / polytetrafluoroethylene copolymer). Polyamide 6 / 11 (caprolactam / aminoundecanoic acid copolymer), polyamide 6 / 12 (caprolactam / laurolactam copolymer), polyamide 6 / 66 / 12 (caprolactam / polyhexamethylene adipamide / laurolactam copolymer), polyamide TMHT (trimethylhexamethylene terephthalamide), polyamide 6T (polyhexamethylene terephthalamide), polyamide 2Me-5T (poly2-methylpentene Polyamide 9T (Polynonamethylene terephthalamide), 2Me-8T (Poly 2-methyloctamethylene terephthalamide), Polyamide 6C (Polyhexamethylenecyclohexanedicarboxamide), Polyamide 2Me-5C (Poly 2-methylpentamethylenecyclohexanedicarboxamide), Polyamide 9C (Polynonamethylenecyclohexanedicarboxamide), 2Me-8C (Poly 2-methyloctamethylenecyclohex Examples of suitable polyamides include polyamide 10T (polydecamethylene terephthalamide), polyamide 11T (polyundecamethylene terephthalamide), polyamide 12T (polydodecamethylene terephthalamide), polyamide 10C (polydecamethylene cyclohexanedicarboxamide), polyamide 11C (polyundecamethylene cyclohexanedicarboxamide), and polyamide 12C (polydodecamethylene cyclohexanedicarboxamide).

[0040] Among these, from the viewpoints of flexibility and chemical resistance, polyamide 610, polyamide 612, polyamide 116, polyamide 6 / 11, polyamide 6 / 12, polyamide 6 / 66 / 12, polyamide 9T, 2Me-8T, polyamide 9C, 2Me-8C, polyamide 10T, polyamide 11T, polyamide 12T, polyamide 10C, polyamide 11C, or polyamide 12C is preferred as the (A) polyamide resin, and from the viewpoint of processability during melt processing, polyamide 610, polyamide 612, polyamide 116, polyamide 6 / 11, polyamide 6 / 12, or polyamide 6 / 66 / 12 is more preferred.

[0041] The average number of carbon atoms per monomer unit of the (A) polyamide resin is preferably more than 6, and more preferably 8 or more. On the other hand, the upper limit of the average number of carbon atoms per monomer unit is preferably 10. That is, the number of carbon atoms per monomer unit of the (A) polyamide resin is preferably more than 6 and 10 or less, and more preferably 8 or more and 10 or less. When the average number of carbon atoms per monomer unit is equal to or greater than the above lower limit, the chemical resistance of a molded article tends to be improved. On the other hand, when the average number of carbon atoms per monomer unit is equal to or less than the above upper limit, the crystallization temperature of the polyamide resin composition tends to be higher, and productivity tends to be improved.

[0042] [(A) Characteristics of polyamide resin] (terminal group concentration) The terminal amino group concentration of the (A) polyamide resin is not particularly limited, but is preferably 10 μmol / g or more in order to facilitate reaction with the (B) impact-resistant material. The upper limit of the terminal amino group concentration of the (A) polyamide resin is not particularly limited, but can be, for example, 100 μmol / g.

[0043] The terminal carboxyl group concentration of the (A) polyamide resin is not particularly limited, but is preferably 100 μmol / g or less in order to provide excellent hydrolysis resistance and metal corrosion resistance. The lower limit of the terminal carboxyl group concentration of the (A) polyamide resin is not particularly limited, but can be, for example, 10 μmol / g.

[0044] The terminal group concentration of the (A) polyamide resin can be measured by neutralization titration, specifically by the method described in the examples below.

[0045] (Relative viscosity of sulfuric acid) The relative viscosity in sulfuric acid of the (A) polyamide resin is preferably 4.5 or less, more preferably 1.7 to 4.5, even more preferably 1.9 to 4.0, and particularly preferably 1.9 to 3.5. When the relative viscosity in sulfuric acid is equal to or greater than the above lower limit, a polyamide resin composition having excellent extrusion moldability and mechanical properties when molded into a molded article can be obtained. On the other hand, when the relative viscosity in sulfuric acid is equal to or less than the above upper limit, a polyamide resin composition having excellent extrusion processability and extrusion moldability tends to be obtained. The sulfuric acid relative viscosity can be measured by a method in accordance with ISO 307. The relative viscosity of sulfuric acid can be controlled by adjusting the pressure during polymerization of the (A) polyamide resin.

[0046] [End-capping agent] In the production of (A) polyamide resin, when polymerizing the polymerization monomer, an end-capping agent may be further added to adjust the molecular weight. The end-capping agent is not particularly limited, and known end-capping agents may be used.

[0047] Examples of the terminal blocking agent include, but are not limited to, monocarboxylic acids, monoamines, acid anhydrides, monoisocyanates, monoacid halides, monoesters, and monoalcohols. Among these, monocarboxylic acids and monoamines are preferred from the viewpoint of thermal stability. These terminal blocking agents may be used alone or in combination of two or more.

[0048] The monocarboxylic acid may be any one that is reactive with an amino group, and examples thereof include aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, and aromatic monocarboxylic acids. Examples of aliphatic monocarboxylic acids include, but are not limited to, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutyric acid. Examples of alicyclic monocarboxylic acids include, but are not limited to, cyclohexanecarboxylic acid. Examples of aromatic monocarboxylic acids include, but are not limited to, benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid. These monocarboxylic acids may be used alone or in combination of two or more.

[0049] The monoamine may be any monoamine that is reactive with a carboxy group, and examples thereof include aliphatic monoamines, alicyclic monoamines, and aromatic monoamines. Examples of aliphatic monoamines include, but are not limited to, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, and dibutylamine. Examples of alicyclic monoamines include, but are not limited to, cyclohexylamine and dicyclohexylamine. Examples of aromatic monoamines include, but are not limited to, aniline, toluidine, diphenylamine, naphthylamine, and the like. These monoamines may be used alone or in combination of two or more.

[0050] Examples of acid anhydrides include, but are not limited to, phthalic anhydride, maleic anhydride, benzoic anhydride, acetic anhydride, and hexahydrophthalic anhydride. These acid anhydrides may be used alone or in combination of two or more.

[0051] Examples of monoisocyanates include, but are not limited to, phenyl isocyanate, tolyl isocyanate, dimethylphenyl isocyanate, cyclohexyl isocyanate, butyl isocyanate, and naphthyl isocyanate. These monoisocyanates may be used alone or in combination of two or more.

[0052] Examples of monoacid halides include, but are not limited to, halogen-substituted monocarboxylic acids such as benzoic acid, diphenylmethanecarboxylic acid, diphenylsulfonecarboxylic acid, diphenylsulfoxidecarboxylic acid, diphenylsulfidecarboxylic acid, diphenylethercarboxylic acid, benzophenonecarboxylic acid, biphenylcarboxylic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, and anthracenecarboxylic acid. These monoacid halides may be used alone or in combination of two or more.

[0053] Examples of monoesters include, but are not limited to, glycerin monopalmitate, glycerin monostearate, glycerin monobehenate, glycerin monomontanate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol monobehenate, pentaerythritol monomontanate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monobehenate, sorbitan monomontanate, sorbitan dimontanate, sorbitan trimontanate, sorbitol monopalmitate, sorbitol monostearate, sorbitol monobehenate, sorbitol tribehenate, sorbitol monomontanate, and sorbitol dimontanate. These monoesters may be used alone or in combination of two or more.

[0054] Examples of monoalcohols include, but are not limited to, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, docosanol, tricosanol, tetracosanol, hexacosanol, heptacosanol, octacosanol, and triacontanol (these monoalcohols may be linear or branched), oleyl alcohol, behenyl alcohol, phenol, cresol (o-, m-, or p-isomer), biphenol (o-, m-, or p-isomer), 1-naphthol, and 2-naphthol. These monoalcohols may be used alone or in combination of two or more.

[0055] [(A) Method for producing polyamide resin] In producing the (A) polyamide resin, the amount of dicarboxylic acid and the amount of diamine added are preferably approximately the same molar amount. Taking into consideration the amount of diamine that escapes to the outside of the reaction system during the polymerization reaction, the molar amount of all diamines relative to the molar amount of all dicarboxylic acids is preferably 0.9 to 1.2, more preferably 0.95 to 1.1, and even more preferably 0.98 to 1.05.

[0056] The method for producing a polyamide resin includes, but is not limited to, the following polymerization step (1) or (2). (1) A step of polymerizing one or more members selected from the group consisting of lactams constituting lactam units and aminocarboxylic acids constituting aminocarboxylic acid units to obtain a polymer. (2) A step of polymerizing a combination of a dicarboxylic acid constituting the dicarboxylic acid unit and a diamine constituting the diamine unit to obtain a polymer.

[0057] The method for producing a polyamide resin preferably further comprises, after the polymerization step, an increasing step of increasing the degree of polymerization of the polyamide resin. If necessary, the method may further comprise, after the polymerization step and the increasing step, a capping step of capping the ends of the resulting polymer with an end-capping agent.

[0058] Specific methods for producing polyamide resins include various methods such as those exemplified in the following 1) to 4). 1) A method in which an aqueous solution or suspension of a lactam and one or more members selected from the group consisting of an aminocarboxylic acid, a dicarboxylic acid-diamine salt, and a mixture of a dicarboxylic acid and a diamine is heated and polymerized while maintaining the molten state (hereinafter, this may be referred to as "thermal melt polymerization"). 2) A method in which the degree of polymerization of polyamide obtained by the hot melt polymerization method is increased while maintaining the solid state at a temperature below the melting point (hereinafter sometimes referred to as "hot melt polymerization / solid state polymerization method"). 3) A method in which one or more members selected from the group consisting of dicarboxylic acid-diamine salts, mixtures of dicarboxylic acids and diamines, lactams, and / or aminocarboxylic acids are polymerized while maintaining the solid state (hereinafter, this may be referred to as "solid-state polymerization method"). 4) A method of polymerizing a dicarboxylic acid halide component equivalent to a dicarboxylic acid and a diamine component (hereinafter, sometimes referred to as a "solution method").

[0059] Among these, a specific method for producing a polyamide resin is preferably a production method including a hot melt polymerization method. When producing a polyamide by the hot melt polymerization method, it is preferable to maintain the molten state until the polymerization is completed. In order to maintain the molten state, it is necessary to produce the polyamide resin composition under polymerization conditions suitable for the polyamide resin composition. Examples of the polymerization conditions include the following conditions. First, the polymerization pressure in the hot melt polymerization method is set to 14 kg / cm. 2 More than 25kg / cm 2 Heating is continued while controlling the pressure in the vessel to atmospheric pressure (gauge pressure is 0 kg / cm 2 ) over 30 minutes or more until the blood pressure drops.

[0060] In the method for producing a polyamide resin, the polymerization mode is not particularly limited, and may be a batch system or a continuous system. The polymerization apparatus used for producing the polyamide resin is not particularly limited, and known apparatuses can be used. Specific examples of the polymerization apparatus include an autoclave reactor, a tumbler reactor, and an extruder reactor (e.g., a kneader).

[0061] Hereinafter, as a method for producing a polyamide resin, a method for producing a polyamide resin by a batch-type hot melt polymerization method will be specifically shown, but the method for producing a polyamide resin is not limited to this. First, an aqueous solution containing about 40% to 60% by weight of raw materials for polyamide resin (lactam and / or aminocarboxylic acid, dicarboxylic acid, diamine) is prepared. Next, the aqueous solution is concentrated to about 65% to 90% by weight in a concentration tank operated at a temperature of 110°C to 180°C and a pressure of about 0.035 MPa to 0.6 MPa (gauge pressure) to obtain a concentrated solution. The resulting concentrated solution is then transferred to an autoclave, and heating is continued until the pressure in the autoclave reaches about 1.2 MPa or more and 2.2 MPa or less (gauge pressure). Next, the pressure in the autoclave is maintained at about 1.2 MPa to 2.2 MPa (gauge pressure) while at least one of water and gas components is removed. Next, when the temperature reaches about 220°C to 260°C, the pressure is reduced to atmospheric pressure (gauge pressure: 0 MPa). After the pressure in the autoclave is reduced to atmospheric pressure, the pressure can be reduced as needed to effectively remove the by-product water. The autoclave is then pressurized with an inert gas such as nitrogen, and the polyamide melt is extruded from the autoclave as a strand. The extruded strand is cooled and cut to obtain polyamide pellets.

[0062] [(A) Polyamide resin content] In the polyamide resin composition of this embodiment, the content of the (A) polyamide resin is 55 to 85 parts by mass, preferably 60 to 80 parts by mass, and more preferably 65 to 75 parts by mass, per 100 parts by mass of the total mass of the (A) polyamide resin and the (B) impact-resistant material. When the content of the (A) polyamide resin is equal to or greater than the lower limit, the composition can have excellent extrusion processability and extrusion moldability, while when the content is equal to or less than the upper limit, a molded product with excellent flexibility can be obtained.

[0063] <(B) Impact-resistant material> The polyamide resin composition of the present embodiment contains (B) an impact-resistant material. Examples of the impact-resistant material include rubber-like polymers.

[0064] Specific examples of the (B) impact-resistant material include (ethylene and / or propylene) / α-olefin copolymers, (ethylene and / or propylene) / (α,β-unsaturated carboxylic acid and / or α,β-unsaturated carboxylic acid ester) copolymers, SEBS (styrene-ethylene / 1-butene / styrene) copolymers, etc. These can be used alone or in combination of two or more.

[0065] [(Ethylene and / or Propylene) / α-Olefin Copolymer] The (ethylene and / or propylene) / α-olefin copolymer is a polymer obtained by copolymerizing ethylene and / or propylene with an α-olefin having 3 or more carbon atoms or 4 or more carbon atoms.

[0066] Examples of the α-olefins having 3 or more carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, and 12-ethyl-1-tetradecene. These may be used alone or in combination of two or more.

[0067] The copolymer may also be one obtained by copolymerizing a polyene such as a non-conjugated diene. Non-conjugated dienes include 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 4,8-dimethyl-1,4,8-decatriene (DMDT), and dicyclopentadiene. Examples of the alkyl acrylate include butyl acrylate, butyl acrylate, butyl acrylate, butyl acrylate, butyl acrylate (VBAC), ...

[0068] [(Ethylene and / or Propylene) / (α,β-Unsaturated Carboxylic Acid and / or α,β-Unsaturated Carboxylic Acid Ester) Copolymer] The (ethylene and / or propylene) / (α,β-unsaturated carboxylic acid and / or α,β-unsaturated carboxylic acid ester) copolymer is a polymer obtained by copolymerizing ethylene and / or propylene with an α,β-unsaturated carboxylic acid and / or α,β-unsaturated carboxylic acid ester monomer. Examples of the α,β-unsaturated carboxylic acid monomer include acrylic acid and methacrylic acid. Examples of the α,β-unsaturated carboxylic acid ester monomer include methyl esters, ethyl esters, propyl esters, butyl esters, pentyl esters, hexyl esters, heptyl esters, octyl esters, nonyl esters, decyl esters, etc. of these α,β-unsaturated carboxylic acids, which may be used alone or in combination of two or more.

[0069] [SEBS (styrene-ethylene / 1-butene / styrene) copolymer] SEBS (styrene-ethylene / 1-butene / styrene) copolymers are preferably based on styrene monomers (styrene and styrene derivatives) and other vinyl aromatic monomers. Examples include block copolymers synthesized from alkenyl-aromatic compounds and conjugated dienes, and hydrogenated block copolymers of alkenyl-aromatic compounds and conjugated dienes. The block copolymers contain at least one block derived from an alkenyl-aromatic compound and at least one block derived from a conjugated diene. In the case of hydrated block polymers, the proportion of aliphatic unsaturated carbon-carbon double bonds is reduced by hydrogenation. Polyblock copolymers with diblock, triblock, tetrablock, and linear structures are suitable as block copolymers. However, branched and star structures can also be used. Branched block copolymers obtained by known methods, such as grafting side chains onto the polymer backbone, can also be used. These may be used alone or in combination.

[0070] The (B) impact-resistant material preferably contains a functional group in its molecule that has affinity for the polyamide resin (A). The (ethylene and / or propylene) / α-olefin copolymer and the SEBS copolymer can be modified with a carboxylic acid and / or a derivative thereof, and / or an unsaturated carboxylic acid and / or a derivative thereof, thereby containing a functional group in its molecule that has affinity for the polyamide resin (A). The (ethylene and / or propylene) / (α,β-unsaturated carboxylic acid and / or α,β-unsaturated carboxylic acid ester) copolymer contains a carboxy group and / or a carboxylic acid ester group, and therefore contains a functional group in its molecule that has affinity for the polyamide resin (A), and may be further modified with a carboxylic acid and / or a derivative thereof, and / or an unsaturated carboxylic acid and / or a derivative thereof.

[0071] (A) Examples of functional groups having affinity for polyamide resins include carboxyl groups, acid anhydride groups, carboxylic acid ester groups, metal carboxylic acid salts, carboxylic acid imide groups, carboxylic acid amide groups, and epoxy groups.

[0072] Examples of compounds containing these functional groups include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, mesaconic acid, citraconic acid, glutaconic acid, cis-4-cyclohexene-1,2-dicarboxylic acid, endo-bicyclo-[2.2.1]-5-heptene-23-carboxylic acid, and metal salts of these carboxylic acids, monomethyl maleate, monomethyl itaconate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 2-methyl-2-propanol, and the like. N-ethylhexyl, hydroxyethyl methacrylate, aminoethyl methacrylate, dimethyl maleate, dimethyl itaconate, maleic anhydride, itaconic anhydride, citraconic anhydride, endobicyclo-[2.2.1J-5-heptene-2,3-dicarboxylic anhydride], maleimide, N-ethylmaleimide, N-butylmaleimide, N-phenylmaleimide, acrylamide, methacrylamide, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, glycidyl citraconate, etc. These may be used alone or in combination of two or more. Of these, maleic anhydride is preferred.

[0073] Methods for introducing these functional groups into a resin include (i) copolymerizing a copolymerizable monomer having a functional group during polymerization of the resin, (ii) introducing a functional group into the molecular chain or molecular end of the resin using a polymerization initiator, a chain transfer agent, etc., and (iii) grafting a compound (graft compound) having a functional group and a graftable functional group onto the resin, etc. These introduction methods can be used alone or in appropriate combination.

[0074] Among these, the (B) impact-resistant material is preferably a polymer acid-modified with an unsaturated carboxylic acid or its acid anhydride, and more preferably an (ethylene and / or propylene) / (α,β-unsaturated carboxylic acid and / or α,β-unsaturated carboxylic acid ester) copolymer that is acid-modified with an unsaturated carboxylic acid or its acid anhydride in addition to the functional groups already present. When the (B) impact-resistant material contains acid anhydride groups, the content of the acid anhydride groups in the (B) impact-resistant material is preferably 0.3% by mass or more and 3.0% by mass or less, more preferably 0.4% by mass or more and 2.0% by mass or less, and even more preferably 0.4% by mass or more and 1.5% by mass or less. Having the acid anhydride group content within the above range increases affinity with the (A) polyamide resin, and tends to result in better extrusion processability and flexibility.

[0075] The impact-resistant material (B) is preferably a maleic acid-grafted ethylene-α-olefin copolymer.

[0076] The (B) impact-resistant material preferably has a melt mass-flow rate (MFR) of 0.5 g / 10 min to 20 g / 10 min, measured at a temperature of 190°C and a load of 2.16 kg in accordance with ASTMD1238. By keeping the MFR in this range, drawdown of the molten resin during extrusion molding is further suppressed, and the molded body tends to have a more uniform thickness.

[0077] [(B) Impact-resistant material content] The content of the (B) impact-resistant material is 15 to 45 parts by mass, preferably 20 to 35 parts by mass, and more preferably 30 to 40 parts by mass, per 100 parts by mass of the total mass of the (A) polyamide resin and the (B) impact-resistant material. When the content of the (A) polyamide resin is equal to or greater than the lower limit, a molded product with excellent flexibility can be obtained, while when the content is equal to or less than the upper limit, a molded product with excellent extrusion processability can be obtained.

[0078] [(B) Carboxylic acid group concentration of impact-resistant material COOH ELand (A) the amino end group concentration of polyamide resin, NH 2PA Ratio of COOH EL / NH 2PA ] (B) Carboxylic acid group concentration of impact-resistant material (COOH) EL and the amino terminal group concentration NH of the (A) polyamide resin 2PA Ratio of COOH EL / NH 2PA is preferably 0.30 or more and 1.50 or less, more preferably 0.30 or more and 1.20 or less, even more preferably 0.30 or more and 1.00 or less, and particularly preferably 0.40 or more and 0.70 or less. EL / NH 2PA By ensuring that the (A) polyamide resin composition is at or above the lower limit, the thickness of the molded article can be maintained more uniformly even when the discharge rate during extrusion molding is increased. This is thought to be because the adhesive strength between the polyamide resin composition and the die can be adjusted so as not to become too strong. On the other hand, by ensuring that the (B) polyamide resin composition is at or below the upper limit, the thickness of the molded article can be maintained more uniformly while maintaining better retention stability during melt processing. This is thought to be because decomposition of the functional groups of the (B) impact-resistant material that did not react with the (A) polyamide resin and uneven distribution of the impact-resistant material on the surface layer of the molded article can be suppressed. ratio COOH EL / NH 2PA can be calculated, for example, by neutralization titration. Specifically, it can be measured by the method described in the Examples below.

[0079] <(C) Black dye> Examples of black dyes include nigrosine and aniline black, and although similar effects can be obtained using either, nigrosine is preferred from the standpoints of cost and moldability.

[0080] Nigrosine is not particularly limited, but examples include black azine condensation mixtures such as triphenazine oxazine and phenazine azine, which are described in COLORINDE X as CISOLVENT BLACK 5 and CISOLVENT BLACK 7. Partially modified nigrosines may also be used. Examples of commercially available nigrosine include Nubian® Black PA-9801, Nubian® Black PA-9800, Nubian® Black PA-0800, and Nubian® Black TN-870.

[0081] [(C) Black dye content] The content of the (C) black dye is 0.01 to 0.50 parts by mass, preferably 0.05 to 0.50 parts by mass, and more preferably 0.10 to 0.50 parts by mass, per 100 parts by mass of the combined weight of the (A) polyamide resin and the (B) impact-resistant material. By ensuring that the content of the (C) black dye is equal to or greater than the lower limit, a sufficient coloring effect can be achieved. On the other hand, by ensuring that the content is equal to or less than the upper limit, the amount used can be reduced while still achieving a sufficient coloring effect.

[0082] <(D) Carbon Black> Examples of carbon black include furnace black obtained by the furnace method, channel black obtained by the channel method, acetylene black obtained by the acetylene method, thermal black obtained by the thermal method, and lamp black.

[0083] The average primary particle size of the carbon black is preferably 10 to 40 nm, more preferably 10 to 30 nm, and particularly preferably 10 to 20 nm. When the average primary particle size of the carbon black is equal to or greater than the lower limit, the dispersibility in the composition can be improved, while when the average primary particle size is equal to or less than the upper limit, the flexibility and elongation of the molded product can be improved.

[0084] Here, the average primary particle size refers to the average value calculated by obtaining a magnified image of an aggregate according to the procedure described in ASTM D3849 (Standard Test Method for Carbon Black - Morphological Characterization by Electron Microscopy), measuring the particle diameters of 3,000 unit constituent particles from this aggregate image.

[0085] In addition, the specific surface area measured by the BET adsorption method is 50m 2 / g or more 300m 2 / g or less, and an oil absorption using dibutyl phthalate in the range of 50 mL / 100 g or more and 150 mL / 100 g or less can be preferably used.

[0086] [(D) Carbon black content] The content of (D) carbon black is 0.05 to 0.50 parts by mass, preferably 0.10 to 0.50 parts by mass, and more preferably 0.15 to 0.25 parts by mass, per 100 parts by mass of the combined mass of (A) polyamide resin and (B) impact-resistant material. By having the content of (D) carbon black equal to or greater than the lower limit, a sufficient coloring effect can be obtained. On the other hand, by having the content equal to or less than the upper limit, the flexibility and tensile elongation of a molded article can be excellent.

[0087] [Total mass of (C) black dye and (D) carbon black] The total mass of the (C) black dye and the (D) carbon black is preferably greater than 0.10 parts by mass, more preferably greater than 0.10 parts by mass and not greater than 1.00 parts by mass, even more preferably 0.20 parts by mass to 1.00 parts by mass, and particularly preferably 0.40 parts by mass to 0.80 parts by mass, per 100 parts by mass of the total mass of the (A) polyamide resin and the (B) impact-resistant material. When the total mass of the (C) black dye and the (D) carbon black is equal to or greater than the above-mentioned lower limit, the molded article has excellent resistance to fading when immersed in water. On the other hand, when the total mass is equal to or greater than the above-mentioned lower limit, the molded article has excellent flexibility and elongation while maintaining good resistance to fading.

[0088] <(E) Heat-resistant material> The polyamide resin composition of this embodiment may further contain (E) a heat-resistant agent in addition to the above components (A) to (D). The heat-resistant agent (E) can be one that can improve the heat resistance of the polyamide resin, and either an organic heat-resistant material or an inorganic heat-resistant material can be used depending on the purpose. By including the heat-resistant agent in the polyamide resin composition of this embodiment, thermal decomposition and deterioration of the polyamide resin and impact-resistant material during melt processing can be more effectively suppressed, and a polyamide resin composition can be obtained that is superior in extrusion processability and extrusion moldability, as well as in flexibility when formed into a molded product.

[0089] From the viewpoint of thermal welding properties and heat resistance, the polyamide resin composition preferably contains at least one organic heat-resistant agent as a heat-resistant agent. By including an organic heat-resistant agent, normal heat aging properties, physical properties, melt viscosity, etc. can be maintained even when the residence time during extrusion molding is long. This is thought to be because, for example, the addition of the organic heat-resistant agent suppresses gelation due to thermal degradation of the polyamide resin and impact resistance agent, thereby suppressing nucleation.

[0090] [(E) Content of heat-resistant agent] In the polyamide resin composition of this embodiment, the content of the (E) heat-resistant agent is preferably 0.01 parts by mass or more and 3.00 parts by mass or less, more preferably 0.05 parts by mass or more and 2.00 parts by mass or less, and even more preferably 0.10 parts by mass or more and 1.00 parts by mass or less, relative to 100 parts by mass of the total mass of the (A) polyamide resin and the (B) impact-resistant material.

[0091] [Organic heat-resistant material] Examples of organic heat-resistant materials (referred to as "organic antioxidants") include phenol-based antioxidants, phosphorus-based antioxidants, and amine-based antioxidants.

[0092] (Phenol-based antioxidant) Examples of phenolic heat stabilizers include, but are not limited to, hindered phenol compounds, which have the property of imparting excellent heat resistance to resins such as polyamides and fibers.

[0093] Examples of the hindered phenol compound include, but are not limited to, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide), pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionamide], 2,2'-bis[2 ... 1,1'-[2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2,2-dimethyl-2,1-ethanediyl)]isocyanuric acid.

[0094] These may be used alone or in combination of two or more.

[0095] In particular, from the viewpoint of preventing deterioration of polyamide resins and impact-resistant materials during melt processing, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)], pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 3-(1,1-dimethylethyl)-4-hydroxy-5-methylbenzenepropanoic acid 1,1'-[2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2,2-dimethyl-2,1-ethanediyl)]isocyanuric acid are preferred.

[0096] When a phenolic heat stabilizer is used, the content of the phenolic heat stabilizer in the polyamide resin composition is preferably 0.01 to 1.00 parts by mass, and more preferably 0.10 to 1.00 parts by mass, per 100 parts by mass of the total mass of the (A) polyamide resin and the (B) impact-resistant material. When the content of the phenolic heat stabilizer is within the above range, thermal degradation of the polyamide resin and the impact-resistant material can be further suppressed, the heat resistance of the polyamide resin composition can be further improved, and the amount of gas generated can be further reduced.

[0097] (phosphorus antioxidant) Examples of phosphorus-based heat stabilizers include, but are not limited to, pentaerythritol-type phosphite compounds, trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl diphenyl phosphite, trisisodecyl phosphite, phenyl diisodecyl phosphite, phenyl di(tridecyl) phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, diphenyl (tridecyl) phosphite, triphenyl phosphite, tris(nonyl) phosphite, tris(2,4-di-tert-butylphenyl)phosphite, tris(2,4-di-tert-butyl-5-methylphenyl)phosphite, tris(butoxyethyl)phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenyl-tetra-tridecyl)diphosphite, tetra(C12-C15 mixed alkyl)-4,4'-isopropylidenediphenyldiphosphite, 4,4'-isopropylidenebis(2-tert-butylphenyl)-di(no tris(biphenyl)phosphite, tetra(tridecyl)-1,1,3-tris(2-methyl-5-tert-butyl-4-hydroxyphenyl)butane diphosphite, tetra(tridecyl)-4,4'-butylidenebis(3-methyl-6-tert-butylphenyl)diphosphite, tetra(C1-C15 mixed alkyl)-4,4'-isopropylidenediphenyl diphosphite, tris(mono- and di-mixed nonylphenyl)phosphite, 4,4'-isopropylidenebis(2 -tert-butylphenyl)-di(nonylphenyl)phosphite, 9,10-di-hydro-9-oxa-9-oxa-10-phosphaphenanthrene-10-oxide, tris(3,5-di-tert-butyl-4-hydroxyphenyl)phosphite, hydrogenated-4,4'-isopropylidenediphenyl polyphosphite, bis(octylphenyl)-bis(4,4'-butylidenebis(3-methyl-6-tert-butylphenyl))-1,6-hexanol diphosphite, hexatridecyl-1,1,3-Tris(2-methyl-4-hydroxy-5-tert-butylphenyl)diphosphite, tris(4,4'-isopropylidenebis(2-tert-butylphenyl))phosphite, tris(1,3-stearoyloxyisopropyl)phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octylphosphite, 2,2-methylenebis(3-methyl-4,6-di-tert-butylphenyl)2-ethylhexylphosphite, tetrakis(2,4-di-tert-butyl-5- Examples of suitable phosphite compounds include tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphite, 3,9-bis[2,6-bis(1,1-dimethylethyl)-4-methylphenoxy]-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]undecane, and 3,9-bis[2,4-bis(1-methyl-1phenylethyl)phenoxy]-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]undecane.

[0098] These may be used alone or in combination of two or more.

[0099] Among those listed above, from the viewpoint of further improving the heat aging resistance of the polyamide resin composition and reducing the amount of gas generated, pentaerythritol-type phosphite compounds and / or tris(2,4-di-tert-butylphenyl)phosphite, 3,9-bis[2,6-bis(1,1-dimethylethyl)-4-methylphenoxy]-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]undecane, and 3,9-bis[2,4-bis(1-methyl-1phenylethyl)phenoxy]-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]undecane are preferred. Examples of the pentaerythritol phosphite compound include, but are not limited to, 2,6-di-tert-butyl-4-methylphenyl-phenyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-methyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-2-ethylhexyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-isodecyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-lauryl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-isotridecyl-pentaerythritol diphosphite, 2,6-di-tert -butyl-4-methylphenyl-stearyl pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-cyclohexyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-benzyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-ethylcellosolve-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-butylcarbitol-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-octylphenyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-nonylphenyl-pentaerythritol diphosphite, Bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-ethylphenyl)pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-2,6-di-tert-butylphenyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-2,4-di-tert-butylphenyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-2,4- Examples include di-tert-octylphenyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-2-cyclohexylphenyl-pentaerythritol diphosphite, 2,6-di-tert-amyl-4-methylphenyl-phenyl pentaerythritol diphosphite, bis(2,6-di-tert-amyl-4-methylphenyl)pentaerythritol diphosphite, and bis(2,6-di-tert-octyl-4-methylphenyl)pentaerythritol diphosphite. These may be used alone or in combination of two or more.

[0100] Among the pentaerythritol phosphite compounds listed above, from the viewpoint of reducing the amount of gas generated from the polyamide resin composition, one or more compounds selected from the group consisting of bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-ethylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-amyl-4-methylphenyl)pentaerythritol diphosphite, and bis(2,6-di-tert-octyl-4-methylphenyl)pentaerythritol diphosphite are preferred, and bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is more preferred.

[0101] When a phosphorus-based heat stabilizer is used, the content of the phosphorus-based heat stabilizer in the polyamide resin composition is preferably 0.01 to 1.00 parts by mass, and more preferably 0.10 to 1.00 parts by mass, per 100 parts by mass of the total mass of the (A) polyamide resin and the (B) impact-resistant material. When the content of the phosphorus-based heat stabilizer is within the above range, thermal degradation of the polyamide resin and the impact-resistant material can be suppressed, the heat resistance of the polyamide resin composition can be further improved, and the amount of gas generated can be reduced.

[0102] Examples of the amine-based heat stabilizer include, but are not limited to, 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(phenylacetoxy)-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-methoxy-2,2,6,6-tetramethylpiperidine, and 4-stearyloxy-2,2,6,6-tetramethylpiperidine. 4-cyclohexyloxy-2,2,6,6-tetramethylpiperidine, 4-benzyloxy-2,2,6,6-tetramethylpiperidine, 4-phenoxy-2,2,6,6-tetramethylpiperidine, 4-(ethylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(cyclohexylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(phenylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, bis(2,2,6,6-tetramethyl-4-piperidyl)-carbonate, bis( 2,2,6,6-tetramethyl-4-piperidyl)-oxalate, bis(2,2,6,6-tetramethyl-4-piperidyl)-malonate, bis(2,2,6,6-tetramethyl-4-piperidyl)-sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl)-adipate, bis(2,2,6,6-tetramethyl-4-piperidyl)-terephthalate, 1,2-bis(2,2,6,6-tetramethyl-4-piperidyloxy)-ethane, α,α'-bis(2,2,6,6-tetramethyl-4-piperidyloxy)-p-xylene, biphenyl Bis(2,2,6,6-tetramethyl-4-piperidyl)tolylene-2,4-dicarbamate, bis(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylene-1,6-dicarbamate, tris(2,2,6,6-tetramethyl-4-piperidyl)-benzene-1,3,5-tricarboxylate, tris(2,2,6,6-tetramethyl-4-piperidyl)-benzene-1,3,4-tricarboxylate, 1-[2-{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy}butyl]-4-[3-(3,[5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]2,2,6,6-tetramethylpiperidine, and a condensation product of 1,2,3,4-butanetetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinol, and β,β,β',β'-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro(5,5)undecane]diethanol. These may be used alone or in combination of two or more.

[0103] When an amine-based heat stabilizer is used, the content of the amine-based heat stabilizer in the polyamide resin composition is preferably 0.01 to 1.00 parts by mass, and more preferably 0.10 to 1.00 parts by mass, per 100 parts by mass of the total mass of the (A) polyamide resin and the (B) impact-resistant material. When the content of the amine-based heat stabilizer is within the above range, thermal degradation of the polyamide resin and the impact-resistant material can be suppressed, the heat resistance of the polyamide resin composition can be further improved, and the amount of gas generated can be reduced.

[0104] [Inorganic heat-resistant agent] The inorganic heat-resistant agent may be copper salt, alkali metal halide, alkaline earth metal halide, or the like.

[0105] (copper salts) Among the copper salts listed above, one or more selected from the group consisting of copper iodide, copper (I) bromide, copper (II) bromide, copper (I) chloride, and copper acetate are preferred, and copper iodide or copper acetate is more preferred. When the more preferred copper salts are used, a polyamide resin composition can be obtained that further suppresses thermal degradation of the polyamide resin, has more excellent heat aging resistance, and can more effectively suppress metal corrosion of the screw and cylinder during processing (hereinafter also simply referred to as "metal corrosion").

[0106] (Copper salt content) When a copper salt is used, the content of the copper salt in the polyamide resin composition is preferably 0.01 to 1.00 parts by mass, and more preferably 0.02 to 0.60 parts by mass, per 100 parts by mass of the total mass of the (A) polyamide resin and the (B) impact-resistant material. When the content of the copper salt is within this range, the heat resistance of the polyamide resin composition can be further improved, and copper precipitation and metal corrosion can be more effectively suppressed.

[0107] In addition, the content of copper element derived from the copper salt is set to 100% by weight of polyamide 10 from the viewpoint of improving the heat resistance of the polyamide resin composition. 6 The amount is preferably 10 parts by mass or more and 2000 parts by mass or less, more preferably 30 parts by mass or more and 1500 parts by mass or less, and even more preferably 50 parts by mass or more and 500 parts by mass or less.

[0108] Halides of alkali metals and alkaline earth metals include, but are not limited to, potassium iodide, potassium bromide, potassium chloride, sodium iodide, sodium chloride, and mixtures thereof. Among these, potassium iodide or potassium bromide is preferred, and potassium iodide is more preferred, from the viewpoints of improving heat aging resistance and suppressing metal corrosion.

[0109] When alkali metal and alkaline earth metal halides are used, the content of the alkali metal and alkaline earth metal halides in the polyamide resin composition is preferably 0.05 to 20.00 parts by mass, and more preferably 0.10 to 10.00 parts by mass, per 100 parts by mass of the total mass of the (A) polyamide resin and the (B) impact-resistant material. When the content of the alkali metal and alkaline earth metal halides is within the above range, the heat aging resistance of the polyamide resin composition is further improved, and copper precipitation and metal corrosion can be more effectively suppressed.

[0110] The stabilizer components described above may be used alone or in combination of two or more. Among them, a mixture of a copper salt with a halide of an alkali metal and an alkaline earth metal is preferred from the viewpoint of further improving the heat aging resistance of the polyamide resin composition.

[0111] The ratio of the copper salt to the alkali metal and alkaline earth metal halides is preferably 2 / 1 or more and 40 / 1 or less, and more preferably 5 / 1 or more and 30 / 1 or less, in terms of the molar ratio of halogen to copper (halogen / copper).Within the above range, the heat aging resistance of the polyamide resin composition can be further improved. When the halogen / copper ratio is equal to or greater than the lower limit, copper deposition and metal corrosion can be more effectively suppressed, whereas when the halogen / copper ratio is equal to or less than the upper limit, corrosion of the screw of the molding machine and the like can be more effectively prevented without substantially impairing mechanical properties (such as toughness).

[0112] <(F) Other Ingredients> In addition to the components (A) to (C), the polyamide resin composition of the present embodiment may further contain (F) other components, as needed, within a range that does not impair the effects of the present embodiment.

[0113] (F) Other components include, but are not limited to, ultraviolet absorbers, photodegradation inhibitors, plasticizers, lubricants, release agents, nucleating agents, flame retardants, colorants, dyes other than black dyes, pigments other than carbon black, other thermoplastic resins, and the like.

[0114] Since the properties of the (F) other components are significantly different, there are various suitable contents for each component that do not substantially impair the effects of the present embodiment. A person skilled in the art can easily determine the suitable contents for each of the above-mentioned other components.

[0115] <Method of producing polyamide resin composition> The polyamide resin composition of the present embodiment can be produced by mixing (A) a polyamide resin, (B) an impact-resistant material, (C) a black dye, (D) carbon black, and, as necessary, the components (E) to (F).

[0116] Examples of a method for mixing the components (A) to (D) and, if necessary, the components (E) to (F) include the following method (1) or (2). (1) A method in which the components (A) to (D) and, if necessary, the components (E) to (F) are mixed using a Henschel mixer or the like, and then fed to a melt kneader and kneaded. (2) A method in which the components (A) to (D) and, if necessary, the components (E) to (F) are mixed in advance in a single-screw or twin-screw extruder using a Henschel mixer or the like to prepare a mixture containing the components (A) to (D) and, if necessary, the components (E) to (F), and then the mixture is supplied to a melt kneader and kneaded.

[0117] The components constituting the polyamide resin composition may be supplied to the melt kneader by supplying all of the components to the same supply port at once, or by supplying each component from a different supply port.

[0118] The melt-kneading temperature is preferably about 1° C. to 100° C. higher than the melting point of the (A) polyamide resin, and more preferably about 10° C. to 70° C. higher than the melting point of the (A) polyamide resin.

[0119] The shear rate in the mixer is 100 sec -1 The average residence time during kneading is preferably about 0.5 minutes or more and 5 minutes or less.

[0120] Any known device may be used for melt-kneading, and for example, a single-screw or twin-screw extruder, a Banbury mixer, a melt-kneader (mixing roll, etc.), etc. are preferably used.

[0121] The amount of each component blended when producing the polyamide resin composition of the present embodiment is the same as the content of each component in the polyamide resin composition described above.

[0122] ≪Molded products≫ The molded article of the present embodiment is obtained by molding the above-described polyamide resin composition for extrusion molding.

[0123] The molded article of this embodiment is excellent in flexibility, chemical resistance, and colorfastness.

[0124] The molded article of the present embodiment can be obtained by extrusion molding the above-described polyamide resin composition for extrusion molding using a known device.

[0125] The shape of the extruded product may be, for example, pellets, plates, fibers, strands, films or sheets, or hollow shapes, with hollow or film-shaped extruded products being preferred, and hollow extruded products being more preferred, such as pipes, tubes, and hoses.

[0126] More specifically, examples of hollow molded articles include, but are not limited to, material parts for various applications such as automobiles, machinery, electrical and electronics, industrial materials, industrial materials, and daily necessities and household goods. The molded article of the present embodiment can also be suitably used for molded articles for extrusion applications (extrusion molded articles). In particular, the molded article of the present embodiment is suitably used for automotive material parts or extrusion molded articles.

[0127] Automotive material parts are not particularly limited, but examples include intake system parts, cooling system parts, and fuel system parts.

[0128] The automobile intake system parts are not particularly limited, but examples thereof include air intake manifolds and intercooler inlets.

[0129] The automotive cooling system parts are not particularly limited, but examples thereof include outlet pipes, air conditioner hoses, and battery cooling pipes.

[0130] Examples of automobile fuel system parts include, but are not limited to, fuel delivery pipes, fuel tubes, and gasoline tank cases.

[0131] The extrusion molded product is not particularly limited, but examples thereof include hollow molded products such as rods, tubes, and hoses. [Example]

[0132] The present invention will be described in detail below with reference to specific examples and comparative examples, but the present invention is not limited to the following examples.

[0133] <Components> Each of the components of the polyamide resin composition will be described below.

[0134] [(A) Polyamide resin] A-1: Polyamide 612 (PA612) (manufactured by Asahi Kasei Corporation, model number: Leona 4102, melting point 215°C, relative viscosity in sulfuric acid 2.2, amino group terminal concentration 40 μmol / g, carboxyl group terminal concentration 93 μmol / g) A-2: Polyamide 612 (PA612) (manufactured by Asahi Kasei Corporation, model number: Leona 4400, melting point 215°C, relative viscosity in sulfuric acid 3.6, amino group terminal concentration 14 μmol / g, carboxyl group terminal concentration 52 μmol / g) A-3: Polyamide 610 (PA610) (manufactured by Asahi Kasei Corporation, model number: Leona 3100, melting point 225°C, relative viscosity in sulfuric acid 2.3, amino group terminal concentration 41 μmol / g, carboxyl group terminal concentration 86 μmol / g) A-4: Polyamide 6 (PA6) (manufactured by Ube Industries, Ltd., model number: SF1013A, melting point 225°C, relative viscosity in sulfuric acid 2.4, amino group terminal concentration 41 μmol / g, carboxyl group terminal concentration 78 μmol / g) A-5: Polyamide 6 (PA6) (manufactured by Ube Industries, Ltd., model number: 1030, melting point 225°C, relative viscosity in sulfuric acid 4.0, amino group terminal concentration 32 μmol / g, carboxyl group terminal concentration 46 μmol / g) A-6: Polyamide 12 (PA12) (melting point 175°C, relative viscosity in sulfuric acid 1.9, amino terminal group concentration 33 μmol / g, carboxy terminal group concentration 45 μmol / g) *A-6 was synthesized by a known method to achieve the above physical properties.

[0135] The melting point of each polyamide resin was measured in accordance with ISO 11357 using a Diamond DSC manufactured by PERKIN-ELMER.

[0136] The relative viscosity of each polyamide resin in 96% sulfuric acid was measured in accordance with ISO 307.

[0137] The amino group terminal concentration of each polyamide resin was measured by neutralization titration as follows. First, 3.0 g of the obtained polyamide was dissolved in 100 mL of 90% by mass aqueous phenol solution. Next, the obtained solution was titrated with 0.025 N hydrochloric acid to determine the amino terminal concentration (μmol / g). The endpoint was determined from the indicated value of the pH meter.

[0138] The carboxyl group terminal concentration of each polyamide resin was measured by neutralization titration as follows. First, 4.0 g of the obtained polyamide was dissolved in 50 mL of benzyl alcohol. Next, the obtained solution was titrated with 0.1 N NaOH to determine the carboxyl end group concentration (μmol / g). The endpoint was determined from the color change of the phenolphthalein indicator.

[0139] [(B) Impact-resistant material] B-1: Maleic anhydride grafted ethylene-butene copolymer (Mitsui Chemicals, Inc., trade name "Tafmer MD715", acid modification rate 0.75%) B-2: Maleic anhydride grafted ethylene-butene copolymer (Mitsui Chemicals, Inc., trade name "Tafmer MH5040", acid modification rate 2.0%) B-3: Maleic anhydride grafted ethylene-propylene diene copolymer (manufactured by DuPont, product name "Fusabond N416", acid modification rate 0.9%) B-4: Ethylene-butene copolymer (manufactured by Mitsui Chemicals, Inc., product name "TafmerDF605") B-5: Ethylene-propylene diene copolymer (Mitsui Chemicals, Inc., product name "Mitsui EPT3092PM")

[0140] [(C) Black dye] C-1: Nigrosine (manufactured by Orient Chemical Industry Co., Ltd., product name "Nubian Black TN-870")

[0141] [(D) Carbon black] D-1: Carbon black (primary particle diameter: 13 nm)

[0142] [(E) Heat-resistant agent] E-1: Cuprous iodide (Wako Pure Chemical Industries, Ltd.) E-2: Potassium iodide (Wako Pure Chemical Industries, Ltd.) E-3: Irganox 1098 (BASF)

[0143] <Methods for measuring physical properties> [Physical Properties 1] (ratio COOH EL / NH 2PA ) Carboxylic group concentration of impact-resistant material COOH EL was measured by neutralization titration as follows: 4.0 g of impact-resistant material was dissolved in 50 mL of toluene. The resulting solution was then titrated with a 0.1 N KOH ethanol solution to determine the carboxyl end group concentration (μmol / g). The endpoint was determined from the color change of the phenolphthalein indicator.

[0144] Amino end group concentration of polyamide resin NH 2PA was measured by neutralization titration as follows: First, 3.0 g of the obtained polyamide was dissolved in 100 mL of 90% by mass aqueous phenol solution. Next, the obtained solution was titrated with 0.025 N hydrochloric acid to determine the amino terminal concentration (μmol / g). The endpoint was determined from the indicated value of the pH meter.

[0145] The carboxyl group concentration of the obtained impact-resistant material is COOH EL The amino end group concentration of the polyamide resin, NH 2PA By dividing by COOH EL / NH 2PA was calculated.

[0146] <Evaluation method> [Rating 1] (Extrusion processability) Using a twin-screw extruder TEM26SX manufactured by Shibaura Machine Co., Ltd., a pre-blended mixture of (A) polyamide resin, (B) impact-resistant material, (C) black dye, and (D) carbon black, and optionally (E) heat-resistant material, was fed through the top feed port located at the most upstream portion of the extruder. The molten mixture was then extruded from the die head and formed into strands. The strands were cooled by immersing 1.5 m in 30°C water and pelletized using a pelletizer to obtain polyamide resin compositions. In the polyamide production process, extrusion processability was evaluated for the following evaluation items.

[0147] 1. Number of strand breaks 10 kg of a polyamide resin composition was produced under the conditions of a twin-screw extruder temperature set at the melting point of the polyamide + 40°C and a discharge rate of 25 kg / hr, and the number of strand breaks during extrusion processing was measured and evaluated according to the following evaluation criteria. A composition with zero strand breaks was evaluated as having excellent extrusion processability.

[0148] (Evaluation criteria) ○: No strand breakage △: Strand breakage occurred once ×: Strand breakage occurred more than twice

[0149] 2. Strand cut defect The shape of the pellets obtained when the polyamide resin composition was produced under the above conditions was measured and evaluated according to the following evaluation criteria: When the mass of the polyamide resin composition with poor cutting was 0 mass %, the composition was evaluated as having excellent extrusion processability.

[0150] (Evaluation criteria) ○: The mass of the polyamide resin composition that was poorly cut was 0 mass% △: The mass of the polyamide resin composition with poor cutting is more than 0 mass% and less than 5 mass% ×: The mass of the polyamide resin composition with poor cutting is more than 5 mass%

[0151] [Rating 2] (Extrusion moldability) The polyamide resin compositions obtained in the examples and comparative examples were dried at 80°C for 8 hours, and extrusion molded into hollow pipes with an outer diameter of 16 mm and an inner diameter of 13 mm using an extrusion molding machine (BELLAFORM, BH45-25D) with a cylinder temperature of 240°C to 260°C and a take-up speed of 7.0 m / min. The cross-sectional wall thickness of the molded product was measured with a vernier caliper, and the maximum value (T max ) and minimum (T min The ratio of the maximum and minimum wall thickness (T max / T min ) was calculated and the thickness uniformity was judged according to the following criteria: max / T min The smaller the value, the smaller the variation in wall thickness, and the better the extrusion moldability.

[0152] (Evaluation criteria) 5:(T max / T min )≦1.05 4:1.05<(T max / T min )≦1.10 3:1.10<(T max / T min )≦1.15 2:1.15<(T max / T min )≦1.20 1:1.20<(T max / T min )

[0153] [Molded product manufacturing] Pellets of the polyamide resin compositions obtained in the examples and comparative examples were dried in a nitrogen stream to reduce the moisture content in the polyamide resin compositions to 500 ppm or less. Next, the pellets of each polyamide resin composition with the adjusted moisture content were molded into multipurpose test specimens (A-type, dumbbell-shaped tensile test specimens) in accordance with ISO 3167 using an injection molding machine (NEX-50IV, manufactured by Nissei Plastics Co., Ltd.). The dimensions of the multipurpose test specimens were: total length ≥ 170 mm, distance between tabs 109.3 ± 3.2 mm, parallel portion length 80 ± 2 mm, shoulder radius 24 ± 1 mm, end width 20 ± 0.2 mm, central parallel portion width 10 ± 0.2 mm, and thickness 4 ± 0.2 mm. Specific injection molding conditions were: injection and dwell time: 25 seconds, cooling time: 15 seconds, mold temperature: 80°C, and cylinder temperature: 280°C.

[0154] [Rating 3] (flexural modulus) Using a multipurpose test piece (Type A), a tensile test was performed in accordance with ISO 527 to measure the flexural modulus (GPa). The bending speed was 2 mm / min. A flexural modulus of 1.5 GPa or less was evaluated as having excellent flexibility and secondary processability.

[0155] [Rating 4] (Fading resistance) The multipurpose test piece (Type A) was immersed in 80°C warm water for 2 weeks, and the change in color difference ΔE before and after the test was measured. 00 was measured using a colorimeter (ZE6000, manufactured by Nippon Denshoku Co., Ltd.), and ΔE 00 was judged according to the following criteria: ΔE 00 When the value is 5.5 or less, the change in color difference is small and the colorfastness is excellent.

[0156] [Rating 5] (Chemical resistance: Resistant to 40% by mass calcium chloride aqueous solution) A multipurpose test piece (Type A) was cut into a Φ16 mm x 100 mm test piece. The cut test piece was immersed in a 40 mass % calcium chloride solution (water:ethanol = 1:1 (mass ratio), 40 mass % anhydrous calcium chloride). After 15 minutes, the test piece was removed, washed with water, and air-dried. The appearance of the test piece was evaluated visually. The smaller the area of ​​the whitened portion of the test piece, the better the resistance to the calcium chloride aqueous solution.

[0157] (Evaluation criteria) ◎: The area of ​​the whitened part of the test piece is 25% or less ○: The area of ​​the whitened part of the test piece is more than 25% and 50% or less △: The area of ​​the whitened part of the test piece is more than 50% and less than 75% ×: The area of ​​the whitened part of the test piece is more than 75%

[0158] <Production of Polyamide Resin Composition> [Example 1] (Production of polyamide resin composition P-a1) Using a twin-screw extruder TEM26SX manufactured by Shibaura Machine Co., Ltd., a pre-blended mixture of (A) polyamide resin, (B) impact-resistant material, (C) black dye, (D) carbon black, and (E) heat-resistant material was fed through the top feed port located at the most upstream end of the extruder. The molten mixture extruded from the die head was cooled in the form of strands and pelletized to obtain pellets of polyamide resin composition P-a1. The type and content of each component were as shown in Table 1.

[0159] [Examples 2 to 13 and Comparative Examples 1 to 5] (Production of Polyamide Resin Compositions P-a2 to P-a13 and P-b1 to P-b5) Pellets of polyamide resin compositions P-a2 to P-a13 and P-b1 to P-b5 were obtained in the same manner as in Example 1, except that the type and content of each constituent component was as shown in each table.

[0160] Using the pellets of the polyamide resin compositions obtained in the examples and comparative examples, various physical properties were measured, and molded articles were produced by the above-mentioned methods and evaluated. The evaluation results are shown in the following table.

[0161] [Table 1]

[0162] [Table 2]

[0163] [Table 3]

[0164] As can be seen from Tables 1 and 2, the polyamide resin compositions P-a1 to P-a13 (Examples 1 to 13) were excellent in all respects: extrusion processability and extrusion moldability, as well as flexibility, discoloration resistance, and chemical resistance when molded into molded articles. Furthermore, in a comparison of polyamide resin compositions P-a1, P-a6, and P-a7 (Examples 1, 6, and 7) with different compounding ratios of the (A) component and the (B) component, it was found that the higher the compounding ratio of the (A) component, the better the extrusion moldability and the colorfastness when molded into a molded product. On the other hand, the higher the compounding ratio of the (B) component, the better the flexibility. Furthermore, in a comparison of polyamide resin compositions PA-a3 to PA-a5 (Examples 3 to 5) with different total amounts of the (C) component and the (D) component, it was found that the greater the total amount of the (C) component and the (D) component, the better the colorfastness of the molded product. In addition, in a comparison of polyamide resin compositions P-a4 and PA-a9 (Examples 4 and 9), which differ in whether or not they contain heat-resistant material, it was found that the incorporation of heat-resistant material tended to result in better flexibility when molded into a product. Furthermore, in a comparison of polyamide resin compositions PA-a4, PA-a11, and PA-a12 (Examples 4, 11, and 12) containing different types of component (A), polyamide resin compositions PA-a4 and PA-a11 (Examples 4 and 11), which contain polyamide resins with an average carbon number of 9 per monomer unit, tended to have better extrusion moldability and discoloration resistance when molded into molded articles, while polyamide resin composition PA-a12 (Example 12), which contains polyamide resins with an average carbon number of 8 per monomer unit, tended to have better flexibility when molded into molded articles. Furthermore, in a comparison of polyamide resin compositions PA-a4, PA-a10, and PA-a13 (Examples 4, 10, and 13) with different blending ratios of polyamide resins A-1 and A-4 in component (A), it was observed that the flexibility tended to be better as the blending ratio of polyamide resin A-1 increased.

[0165] On the other hand, as can be seen from Table 3, the polyamide resin compositions P-b1 to P-b5 (Comparative Examples 1 to 5) did not provide excellent extrusion processability and extrusion moldability, nor did they provide excellent flexibility, discoloration resistance, and chemical resistance when molded into molded products.

[0166] Specifically, a polyamide resin composition P-b1 (Comparative Example 1) containing a polyamide resin having an average carbon number of 6 per monomer unit and not containing a polyamide resin having an average carbon number of more than 6 and not more than 10 per monomer unit and not containing component (D) had poor extrusion processability. Furthermore, although extrusion molding itself was possible, the thickness uniformity was insufficient, the extrusion moldability was poor, and the molded product had poor flexibility, discoloration resistance, and chemical resistance. Polyamide resin composition P-b2 (Comparative Example 2), which contained a polyamide resin having an average carbon number of 12 per monomer unit and did not contain a polyamide resin having an average carbon number of more than 6 and 10 or less per monomer unit and component (C), suffered from poor strand cutting and exhibited poor extrusion processability. Furthermore, although extrusion molding itself was possible, the thickness was not sufficiently uniform and extrusion moldability was also poor. Polyamide resin compositions P-b3 and P-b4 (Comparative Examples 3 and 4) were prepared by removing (D) carbon black or (C) black dye from the formulation of polyamide resin composition P-a12 (Example 12), respectively, and showed poor colorfastness. Comparing polyamide resin compositions P-a1, P-a6, and P-a7 (Examples 1, 6, and 7) with P-b5 (Comparative Example 5), it was found that by containing appropriate amounts of (A) polyamide resin and (B) impact-resistant material, the compositions have excellent extrusion processability and extrusion moldability.

[0167] From the above, it has become clear that only polyamide resin compositions containing specific amounts of components (A) to (D) and specific amounts of polyamide resins having an average carbon number per monomer unit of more than 6 and not more than 10 are excellent in extrusion processability and extrusion moldability, as well as in flexibility, discoloration resistance, and chemical resistance when formed into molded articles. [Industrial Applicability]

[0168] The polyamide resin composition for extrusion molding of this embodiment can provide a polyamide resin composition for extrusion molding that has excellent extrusion processability and extrusion moldability, and that, when formed into a molded article, has excellent flexibility, chemical resistance, and discoloration resistance. The molded article of this embodiment is obtained by molding the polyamide resin composition for extrusion molding and has excellent flexibility, chemical resistance, and discoloration resistance. The molded article of this embodiment can be used as a material for various parts for automobiles, the machinery industry, electrical and electronics, industrial materials, industrial materials, daily necessities, household goods, etc.

Claims

1. (A) Polyamide resin and (B) Impact-resistant material (total 100 parts by mass) 55 parts by mass or more and 85 parts by mass or less of the polyamide resin (A); 15 parts by mass or more and 45 parts by mass or less of the impact-resistant material (B); 0.01 parts by mass or more and 0.50 parts by mass or less of a black dye (C); 0.05 parts by mass or more and 0.50 parts by mass or less of (D) carbon black; A polyamide resin composition for extrusion molding, comprising: A polyamide resin composition for extrusion molding, comprising 60 parts by mass or more of a polyamide resin having an average carbon number per monomer unit of more than 6 and not more than 10, relative to 100 parts by mass of the polyamide resin (A).

2. 2. The polyamide resin composition for extrusion molding according to claim 1, wherein the impact-resistant material (B) is a maleic acid-grafted ethylene-α-olefin copolymer.

3. 3. The polyamide resin composition for extrusion molding according to claim 1, wherein the total mass of the black dye (C) and the carbon black (D) is more than 0.10 parts by mass relative to 100 parts by mass of the polyamide resin (A) and the impact-resistant material (B).

4. (B) Carboxy group concentration of the impact-resistant material (COOH) ＥＬ and the amino terminal group concentration NH of the (A) polyamide resin ２ＰＡ Ratio of COOH ＥＬ / NH ２ＰＡ The polyamide resin composition for extrusion molding according to any one of claims 1 to 3, wherein the σ is 0.30 or more and 1.50 or less.

5. (B) Carboxy group concentration of the impact-resistant material (COOH) ＥＬ and the amino terminal group concentration NH of the (A) polyamide resin ２ＰＡ Ratio of COOH ＥＬ / NH ２ＰＡ The polyamide resin composition for extrusion molding according to any one of claims 1 to 4, wherein the σ is 0.30 or more and 1.20 or less.

6. (B) Carboxy group concentration of the impact-resistant material (COOH) ＥＬ and the amino terminal group concentration NH of the (A) polyamide resin ２ＰＡ Ratio of COOH ＥＬ / NH ２ＰＡ The polyamide resin composition for extrusion molding according to any one of claims 1 to 5, wherein the σ is 0.30 or more and 1.00 or less.

7. The polyamide resin composition for extrusion molding according to any one of claims 1 to 6, further comprising 0.01 parts by mass or more and 3.00 parts by mass or less of (E) a heat-resistant agent relative to a total of 100 parts by mass of the (A) polyamide resin and the (B) impact-resistant material.

8. A molded article obtained by molding the polyamide resin composition for extrusion molding according to any one of claims 1 to 7.

9. The molded article according to claim 8, wherein the molded article is hollow.

10. The molded article according to claim 8 , wherein the molded article has a shape of a pipe, a tube, a hose, or a film.

11. The molded article according to any one of claims 8 to 10, wherein the molded article is an automotive material part.

12. The molded article according to claim 11, wherein the automotive material part is an air conditioning hose or a battery cooling pipe.

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