Polyamide resin composition and molded article

Abstract

The object of the present invention is to provide a polyamide resin composition that exhibits excellent color stability, flame retardancy, tracking resistance, and moldability. [Solution] The polyamide resin composition of the present invention comprises a polyamide resin (A), at least one primary antioxidant (B) selected from the group consisting of hindered phenol antioxidants, amine antioxidants, and sulfur antioxidants, and a secondary antioxidant (C) which is a phosphorus compound, wherein the mass ratio of the primary antioxidant (B) to the secondary antioxidant (C) is in the range of 50:50 to 5:95, and the mass ratio of the primary antioxidant (B) to 100 parts by mass of the polyamide resin (A) is 0.01 to 2.0 parts by mass, and the mass ratio of the secondary antioxidant (C) is 0.01 to 3.0 parts by mass.

Description

[Technical Field]

[0001] This invention relates to polyamide resin compositions and molded articles. [Background technology]

[0002] Polyamides, such as polyamide 66 (hereinafter also referred to as "PA66"), are used in a variety of industrial fields, taking advantage of their characteristics such as good fluidity, high heat resistance, and mechanical properties.

[0003] Polyamide, in particular, has been used as a component material for internal combustion engines (ICE) in automobiles, but with the recent proliferation of electric vehicles (EVs), its excellent electrical properties, heat resistance, and chemical resistance are being increasingly utilized in components around high voltages.

[0004] With the adoption of polyamides in EVs, new material requirements have arisen, necessitating the meeting of stringent design requirements such as flame retardancy and tracking resistance. Furthermore, color stability of polyamides is also important for EV and high-voltage applications. Polyamides have a long-standing problem of discoloration to brown due to thermal oxidative degradation caused by thermal aging. Generally, this problem has been solved by coloring polyamides black with carbon pigments or nigrosine dyes to conceal the discoloration in polyamide materials for ICEs.

[0005] On the other hand, in EVs, polyamide is often colored in various colors, including chromatic colors such as orange, which are warning colors other than black. Because it is not possible to conceal brown discoloration by coloring it black, brown discoloration of polyamide has become a problem.

[0006] Known color stabilization techniques for polyamides include the use of hindered phenol antioxidants, sulfur-based antioxidants, amine-based antioxidants, or phosphate ester antioxidants, or optionally a combination of these with hindered phenol antioxidants. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Specification of Chinese Patent Application Publication No. 106916444 [Patent Document 2] Specification of Chinese Patent Application Publication No. 104804416 [Patent Document 3] Specification of Chinese Patent Application Publication No. 114605817 [Patent Document 4] Specification of European Patent Application Publication No. 3919561 [Summary of the Invention] [Problems to be Solved by the Invention]

[0008] However, although the known technology has a certain effect on the color stability of polyamide, it is still not at a satisfactory level, and further improvement is required. In addition, in the known technology, there are insufficient considerations regarding the flame retardancy, tracking resistance required for EV applications, and further the moldability regarding mold contamination and fluidity.

[0009] The object of the present application is to provide a polyamide resin composition excellent in color stability, flame retardancy, tracking resistance, and moldability. The present invention has been made in view of the above circumstances, and an object thereof is to provide a polyamide resin composition excellent in color stability, flame retardancy, and tracking resistance, and excellent in moldability, and a molded product using the above polyamide resin composition. [Means for Solving the Problems]

[0010] As a result of intensive studies to solve the above problems, the present inventor has found that a polyamide resin composition can solve the above problems by setting a specific additive at a specific addition ratio, and has completed the present invention.

[0011] That is, the present invention is as follows. [1] · Polyamide resin (A), · At least one primary antioxidant (B) selected from the group consisting of hindered phenol antioxidants, amine antioxidants, and sulfur antioxidants, and • Contains a phosphorus-based secondary antioxidant (C), The mass ratio of the primary antioxidant (B) and the secondary antioxidant (C) when the total mass of the primary antioxidant (B) and the secondary antioxidant (C) is set to 100 (primary antioxidant (B): secondary antioxidant (C)) is within the range of 50:50 to 5:95. The mass ratio of the primary antioxidant (B) to 100 parts by mass of the polyamide resin (A) is 0.01 to 2.0 parts by mass, and the mass ratio of the secondary antioxidant (C) is 0.01 to 3.0 parts by mass. Polyamide resin composition. [2] The polyamide resin composition according to [1], wherein the primary antioxidant (B) is at least one selected from the group consisting of ethylenebis(oxyethylene)bis-(3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate, N,N'-hexane-1,6-diylbis(3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)), pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 2',3-bis[[3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyl]]propionohydrazide, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, and bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate. [3] The polyamide resin composition according to [1] or [2], wherein the secondary antioxidant (C) is a metal hypophosphite salt. [4] The polyamide resin composition according to any one of [1] to [3], wherein the secondary antioxidant (C) is selected from the group consisting of calcium hypophosphate, magnesium hypophosphate, and hydrates thereof. [5] The polyamide resin composition according to any one of [1] to [4], wherein the tanδ peak temperature of the polyamide resin composition is 80°C or higher. [6] The polyamide resin (A) contains an aliphatic polyamide (A1) and a semi-aromatic polyamide (A2) containing diamine units and dicarboxylic acid units. The aliphatic polyamide (A1) is polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 611, polyamide 612, polyamide 1010, or polyamide 66 / 6 copolymer. The polyamide resin composition according to any one of [1] to [5], wherein the semi-aromatic polyamide (A2) is polyamide 66 / 6I, polyamide 6T, polyamide 6I, polyamide 6I / 6T, polyamide 4T, polyamide 4T / 6T, polyamide 9T, or polyamide MXD6. [7] The polyamide resin composition according to any one of [1] to [6], further comprising at least one selected from the group consisting of a flame retardant (E), a reinforcing agent (F), and a coloring agent (G). [8] The polyamide resin composition according to [7], which is colored with the coloring agent (G). [9] The polyamide resin composition according to [7], wherein the reinforcing material (F) is glass fiber, the boron content in the glass fiber is 1.0% by mass or less relative to the total mass of the glass fiber, and the mass ratio (Mg / Si) of magnesium (Mg) and silicon (Si) elements contained in the glass fiber is 0.01 to 0.2.

[10] The polyamide resin composition according to any one of [1] to [9], wherein the mass ratio of copper elements contained in the polyamide resin composition is 0 to 0.001 parts by mass per 100 parts by mass of the polyamide resin (A).

[11] A molded article comprising a polyamide resin composition as described in any of [1] to

[10] .

[12] A high-voltage component comprising the molded product described in

[11] .

[13] The high-voltage component described in

[12] is selected from the group consisting of covers, housings, relays, battery cell modules, fuse holders, fuse plugs, terminals, cable holders, sheathings, connectors, breaker boxes and high-voltage busbars for hybrid vehicles, electric vehicles or electronic equipment. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a polyamide resin composition that is excellent in color stability, flame retardancy, tracking resistance, and moldability, as well as a molded article using the same. [Modes for carrying out the invention]

[0013] The following describes in detail embodiments for carrying out the present invention (hereinafter simply referred to as "this embodiment"). This embodiment is illustrative for explaining the present invention and is 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.

[0014] In this specification, "polyamide" means a polymer having an amide (-NHCO-) ​​group in its main chain.

[0015] ≪Polyamide resin composition≫ The polyamide resin composition of this embodiment contains a polyamide resin (A), a primary antioxidant (B), and a secondary antioxidant (C). The polyamide resin composition of this embodiment may consist only of the polyamide resin (A), the primary antioxidant (B), and the secondary antioxidant (C), or it may further contain other additives.

[0016] [Physical properties of polyamide resin compositions] The tanδ peak temperature of the polyamide resin composition of this embodiment is preferably 60°C or higher, more preferably 70°C to 130°C, even more preferably 80°C to 120°C, and even more preferably 90°C to 115°C. It is also preferable that it be 80°C or higher. In this embodiment, the tanδ peak temperature of the polyamide resin composition is above the lower limit, which tends to result in a polyamide resin composition with superior mechanical properties when molded, particularly color stability, mechanical strength in hot and wet conditions, and fluidity. On the other hand, when the tanδ peak temperature of the polyamide resin composition is below the upper limit, and a component such as the reinforcing material (F) is further included, the molded article obtained from the polyamide resin composition tends to have superior properties such as impact resistance under low-temperature conditions. The tanδ peak temperature of the polyamide resin composition can be measured, for example, using a viscoelasticity analyzer (DVE-V4 manufactured by Rheology Corporation), and specifically, it can be measured by the method described in the examples below.

[0017] The molecular weight of a polyamide resin composition can be measured by GPC (gel permeation chromatography). GPC provides the number-average molecular weight (Mn), weight-average molecular weight (Mw), and molecular weight distribution (Mw / Mn). Larger Mw and Mn values ​​indicate a higher molecular weight polyamide resin composition, while smaller values ​​indicate a lower molecular weight polyamide resin composition. The weight-average molecular weight (Mw) can be used as an indicator of the molecular weight of the polyamide resin composition. The weight-average molecular weight (Mw) of the polyamide resin composition is preferably 20,000 to 40,000, more preferably 22,000 to 35,000, even more preferably 25,000 to 33,000, and still more preferably 26,000 to 32,000. By having a weight-average molecular weight (Mw) within the above range, a polyamide resin composition with superior fluidity during molding and excellent mechanical properties when formed into a molded article can be obtained.

[0018] (A) Polyamide resin The polyamide resin (A) contained in the polyamide resin composition of this embodiment preferably contains an aliphatic polyamide (A1) and a semi-aromatic polyamide (A2) containing diamine units and dicarboxylic acid units, from the viewpoint of flame retardancy, color stability, and tracking resistance.

[0019] [Aliphatic polyamide (A1)] The constituent units of the aliphatic polyamide (A1) preferably satisfy at least one of the following conditions (1) and (2). (1) Contains (A1-a) aliphatic dicarboxylic acid units and (A1-b) aliphatic diamine units. (2) (A1-c) Contains at least one constituent unit selected from the group consisting of lactam units and aminocarboxylic acid units.

[0020] The polyamide resin composition of this embodiment may contain, as aliphatic polyamide (A1), one or more polyamides that satisfy at least one of the conditions (1) and (2) above.

[0021] ((A1-a) Aliphatic dicarboxylic acid unit) (A1-a) Examples of aliphatic dicarboxylic acids that constitute an aliphatic dicarboxylic acid unit include linear or branched saturated aliphatic dicarboxylic acids having 3 to 20 carbon atoms. Examples of linear saturated aliphatic dicarboxylic acids having 3 to 20 carbon atoms include, but are not limited to, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanediic acid, tetradecanediic acid, hexadecanedioic acid, octadecanediic acid, eicosanedioic acid, and diglycolic acid. Examples of branched-chain saturated aliphatic dicarboxylic acids having 3 to 20 carbon atoms include, but are not limited to, dimethylmalonic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylglutaric acid, 2,2-diethylsuccinic acid, 2,3-diethylglutaric acid, 2,2-dimethylglutaric acid, 2-methyladipic acid, trimethyladipic acid, and the like. These (A1-a) aliphatic dicarboxylic acid units may be used individually or in combination of two or more types. In particular, polyamide resin compositions tend to have superior heat resistance, fluidity, toughness, low water absorption, and rigidity, so linear saturated aliphatic dicarboxylic acids having 6 or more carbon atoms are preferred as the aliphatic dicarboxylic acids constituting the (A1-a) aliphatic dicarboxylic acid unit.

[0022] Preferred linear saturated aliphatic dicarboxylic acids having 6 or more carbon atoms include, for example, adipic acid, sebacic acid, dodecanediic acid, tetradecanediic acid, hexadecanedioic acid, octadecanediic acid, and eicosanedioic acid. Among these, adipic acid, sebacic acid, or dodecanediic acid are preferred as linear saturated aliphatic dicarboxylic acids having 6 or more carbon atoms, from the viewpoint of the heat resistance of the polyamide resin composition.

[0023] Furthermore, the aliphatic polyamide (A1) may optionally contain units derived from a trivalent or higher polycarboxylic acid, to the extent that it does not impair the effects of the polyamide resin composition of this embodiment. Examples of trivalent or higher polycarboxylic acids include trimellitic acid, trimesic acid, and pyromellitic acid. These trivalent or higher polycarboxylic acids may be used individually or in combination of two or more types.

[0024] ((A1-b) Aliphatic diamine units) (A1-b) Examples of aliphatic diamines that constitute an aliphatic diamine unit include linear saturated aliphatic diamines having 2 to 20 carbon atoms, or branched saturated aliphatic diamines having 3 to 20 carbon atoms. Examples of straight-chain saturated aliphatic diamines having 2 to 20 carbon atoms include, but are not limited to, ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, and tridecamethylenediamine. Branched-chain saturated aliphatic diamines having 3 to 20 carbon atoms are not limited to the following, but examples include 2-methylpentamethylenediamine (also known as 2-methyl-1,5-diaminopentane), 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 2-methyl-1,8-octanediamine (also known as 2-methyloctamethylenediamine), and 2,4-dimethyloctamethylenediamine. These (A1-b) aliphatic diamine units may be used individually or in combination of two or more aliphatic diamines. In particular, the number of carbon atoms in the aliphatic diamine constituting the (A1-b) aliphatic diamine unit is preferably 6 to 12, and more preferably 6 to 10. When the number of carbon atoms in the aliphatic diamine constituting the (A1-b) aliphatic diamine unit is above the lower limit, the heat resistance of the resulting molded article is better. On the other hand, when the number of carbon atoms is below the upper limit, the crystallinity and release properties of the resulting molded article are better.

[0025] Preferred linear or branched saturated aliphatic diamines having 6 to 12 carbon atoms include, for example, hexamethylenediamine, 2-methylpentamethylenediamine, and 2-methyl-1,8-octanediamine. In particular, hexamethylenediamine or 2-methylpentamethylenediamine are preferred as linear or branched saturated aliphatic diamines having 6 to 12 carbon atoms. Including such (A1-b) aliphatic diamine units improves the heat resistance and rigidity of molded articles obtained from the polyamide resin composition.

[0026] Furthermore, the aliphatic polyamide (A1) may optionally contain units derived from a trivalent or higher polyhydric aliphatic amine, to the extent that it does not impair the effects of the polyamide resin composition of this embodiment. Examples of a trivalent or higher polyhydric aliphatic amine include bishexamethylenetriamine.

[0027] ((A1-c) At least one constituent unit selected from the group consisting of lactam units and aminocarboxylic acid units) Aliphatic polyamide (A1) may contain at least one constituent unit selected from the group consisting of (A1-c) lactam units and aminocarboxylic acid units. The inclusion of such units tends to result in polyamides with excellent toughness. In this context, "lactam unit" and "aminocarboxylic acid unit" refer to the polymerized (condensed) lactam and aminocarboxylic acid units.

[0028] The lactams that make up the lactam unit are not limited to the following, but examples include butyrolactam, pivalolactam, ε-caprolactam, capryloractam, enantractam, undecanolactam, and laurolactam (dodecanolactam). In particular, ε-caprolactam or laurolactam are preferred as the lactam constituting the lactam unit, with ε-caprolactam being more preferred. Including such lactams tends to result in better toughness of molded articles obtained from the polyamide resin composition.

[0029] The aminocarboxylic acids that constitute the aminocarboxylic acid unit are not limited to those listed below, but examples include ω-aminocarboxylic acids and α,ω-amino acids, which are compounds in which a lactam ring has been opened. The aminocarboxylic acid constituting the aminocarboxylic acid unit is preferably a linear or branched saturated aliphatic carboxylic acid having 4 to 14 carbon atoms, with the ω position substituted with an amino group. Examples of such aminocarboxylic acids, though not limited to those listed below, include 6-aminocaproic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Other examples of aminocarboxylic acids include para-aminomethylbenzoic acid.

[0030] The lactam and aminocarboxylic acid constituting at least one constituent unit selected from the group consisting of (A1-c) lactam units and aminocarboxylic acid units may be one or more types of either lactam or aminocarboxylic acid, or one type each of lactam and aminocarboxylic acid, a combination of one and two or more types, or a combination of two or more types each.

[0031] Among these, as aliphatic polyamide (A1), polyamides containing dicarboxylic acid units and diamine units are preferred from the viewpoint of mechanical properties, heat resistance, moldability and toughness, polyamides containing (A1-a) aliphatic dicarbanic acid units and (A1-b) aliphatic diamine units are more preferred, and polyamide 66 (PA66) is even more preferred. PA66 is considered a suitable material for automotive parts because of its excellent mechanical properties, heat resistance, moldability and toughness.

[0032] The content of aliphatic polyamide (A1) can be, for example, 50% to 100% by mass, 60% to 100% by mass, or 70% to 100% by mass, based on the total mass of polyamide resin (A) in the polyamide resin composition.

[0033] [Semi-aromatic polyamide (A2)] Semi-aromatic polyamide (A2) is a polyamide resin containing diamine units and dicarboxylic acid units. The semi-aromatic polyamide (A2) preferably contains 20 mol% to 80 mol% of aromatic constituent units, more preferably 30 mol% to 70 mol% of aromatic constituent units, and even more preferably 40 mol% to 60 mol% of aromatic constituent units, relative to the total constituent units of the semi-aromatic polyamide (A2). Here, "aromatic constituent units" means aromatic diamine units and aromatic dicarboxylic acid units. The aliphatic polyamide (A1) preferably does not contain aromatic constituent units.

[0034] Furthermore, the semi-aromatic polyamide (A2) is preferably a polyamide resin containing dicarboxylic acid units that include 50 mol% or more of terephthalic acid or isophthalic acid units, and diamine units that include diamine units having 4 to 10 carbon atoms, relative to the total dicarboxylic acid units of the semi-aromatic polyamide (A2). Furthermore, the total content of terephthalic acid or isophthalic acid units and diamine units having 4 to 10 carbon atoms in the semi-aromatic polyamide (A2) is preferably 50 mol% or more, more preferably 80 mol% to 100 mol%, even more preferably 90 mol% to 100 mol%, and particularly preferably 100 mol% relative to the total constituent units of the (A2) semi-aromatic polyamide.

[0035] The proportion of specific monomer units constituting the semi-aromatic polyamide (A2) can be measured by nuclear magnetic resonance spectroscopy (NMR) or the like.

[0036] ((A2-a) dicarboxylic acid unit) (A2-a) The dicarboxylic acid unit is not particularly limited and includes, for example, aromatic dicarboxylic acid units, aliphatic dicarboxylic acid units, alicyclic dicarboxylic acid units, etc. In particular, the (A2-a)dicarboxylic acid unit preferably contains 50 mol% or more of terephthalic acid or isophthalic acid relative to the total number of moles of (A2-a)dicarboxylic acid, more preferably contains 65 mol% or more and 100 mol% or less of terephthalic acid or isophthalic acid, even more preferably contains 75 mol% or more and 100 mol% or less, particularly preferably contains 80 mol% or more and 100 mol% or less, and most preferably contains 100 mol%. (A2-a) When the proportion of terephthalic acid or isophthalic acid units in the dicarboxylic acid units is above the above lower limit, a polyamide resin composition that can simultaneously satisfy mechanical properties, particularly water absorption stiffness, thermal stiffness, and fluidity, tends to be obtained. Furthermore, molded articles obtained from the polyamide resin composition tend to have excellent tensile strength and flexural modulus when water is absorbed.

[0037] (1) Aromatic dicarboxylic acid unit Aromatic dicarboxylic acids constituting aromatic dicarboxylic acid units other than terephthalic acid or isophthalic acid units are not limited to the following, but examples include dicarboxylic acids having aromatic groups such as a phenyl group or a naphthyl group. The aromatic group of the aromatic dicarboxylic acid may be unsubstituted or may have substituents.

[0038] The substituents are not particularly limited, but examples include alkyl groups having 1 to 4 carbon atoms, aryl groups having 6 to 10 carbon atoms, arylalkyl groups having 7 to 10 carbon atoms, alkylaryl groups having 7 to 10 carbon atoms, halogen groups, silyl groups having 1 to 6 carbon atoms, sulfonic acid groups and their salts (such as sodium salts). Examples of alkyl groups having 1 to 4 carbon atoms include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl groups. Examples of aryl groups having 6 to 10 carbon atoms include, but are not limited to, phenyl groups and naphthyl groups. Examples of arylalkyl groups having 7 to 10 carbon atoms include, but are not limited to, the benzyl group. Examples of alkylaryl groups having 7 to 10 carbon atoms include, but are not limited to, tolyl groups and xylyl groups. Examples of halogen groups include, but are not limited to, fluoro groups, chloro groups, bromo groups, and iodo groups. Silyl groups having 1 to 6 carbon atoms are not limited to the following, but examples include trimethylsilyl group and tert-butyldimethylsilyl group. In particular, among the aromatic dicarboxylic acids that constitute aromatic dicarboxylic acid units other than isophthalic acid units, aromatic dicarboxylic acids having 8 to 20 carbon atoms that are unsubstituted or substituted with a predetermined substituent are preferred.

[0039] Examples of unsubstituted or substituted aromatic dicarboxylic acids having 8 to 20 carbon atoms include, but are not limited to, terephthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, and 5-sodium sulfoisophthalic acid. The aromatic dicarboxylic acid that constitutes the aromatic dicarboxylic acid unit may be used individually or in combination of two or more types.

[0040] (2) Aliphatic dicarboxylic acid units Examples of aliphatic dicarboxylic acids that constitute an aliphatic dicarboxylic acid unit include linear or branched saturated aliphatic dicarboxylic acids having 3 to 20 carbon atoms.

[0041] Examples of linear saturated aliphatic dicarboxylic acids having 3 to 20 carbon atoms include, but are not limited to, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanediic acid, tetradecanediic acid, hexadecanedioic acid, octadecanediic acid, eicosanedioic acid, and diglycolic acid. Examples of branched-chain saturated aliphatic dicarboxylic acids having 3 to 20 carbon atoms include, but are not limited to, dimethylmalonic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylglutaric acid, 2,2-diethylsuccinic acid, 2,3-diethylglutaric acid, 2,2-dimethylglutaric acid, 2-methyladipic acid, trimethyladipic acid, and the like.

[0042] (3) Alicyclic dicarboxylic acid units The alicyclic dicarboxylic acids that constitute the alicyclic dicarboxylic acid unit (hereinafter sometimes referred to as "alicyclic dicarboxylic acid unit") are not limited to the following, but examples include alicyclic dicarboxylic acids with 3 to 10 carbon atoms in the alicyclic structure. Among these, alicyclic dicarboxylic acids with 5 to 10 carbon atoms in the alicyclic structure are preferred.

[0043] 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. Among these, 1,4-cyclohexanedicarboxylic acid is preferred as the alicyclic dicarboxylic acid. Furthermore, the alicyclic dicarboxylic acid that constitutes the alicyclic dicarboxylic acid unit may be used alone or in combination of two or more types.

[0044] The alicyclic group of an alicyclic dicarboxylic acid may be unsubstituted or substituted. Examples of substituents include alkyl groups having 1 to 4 carbon atoms. Examples of alkyl groups having 1 to 4 carbon atoms are the same as those exemplified in the "aromatic dicarboxylic acid unit" above.

[0045] Dicarboxylic acid units other than terephthalic acid or isophthalic acid units preferably include aromatic dicarboxylic acid units, and more preferably include aromatic dicarboxylic acids having 6 or more carbon atoms. By using such dicarboxylic acids, polyamide resin compositions that simultaneously satisfy mechanical properties, particularly water absorption stiffness, thermal stiffness, and fluidity, tend to be obtained. Furthermore, molded articles obtained from these polyamide resin compositions tend to exhibit superior tensile strength, flexural modulus under water absorption, long-term heat resistance, and tracking resistance.

[0046] In the semi-aromatic polyamide (A2), the dicarboxylic acid constituting the (A2-a) dicarboxylic acid unit is not limited to the compounds described above as dicarboxylic acids, but may be equivalent compounds to the dicarboxylic acids. In this context, "compounds equivalent to dicarboxylic acids" refers to compounds that can have a dicarboxylic acid structure similar to the dicarboxylic acid structure derived from the above-mentioned dicarboxylic acid. Examples of such compounds, though not limited to those listed below, include anhydrides of dicarboxylic acids and halides of dicarboxylic acids.

[0047] Furthermore, the semi-aromatic polyamide (A2) may optionally contain units derived from trivalent or higher polycarboxylic acids, to the extent that it does not impair the effects of the polyamide resin composition of this embodiment. Examples of polycarboxylic acids with a valency of three or more include trimellitic acid, trimesic acid, and pyromellitic acid. These polycarboxylic acids with a valency of three or more may be used individually or in combination of two or more types.

[0048] ((A2-b) diamine unit) The (A2-b) diamine units constituting the semi-aromatic polyamide (A2) are not particularly limited, and examples include aromatic diamine units, aliphatic diamine units, alicyclic diamine units, etc. Among these, the (A2-b) diamine units constituting the (A2) semi-aromatic polyamide preferably include diamine units having 4 to 10 carbon atoms, and more preferably include diamine units having 6 to 10 carbon atoms.

[0049] (1) Aliphatic diamine units Examples of aliphatic diamines that constitute an aliphatic diamine unit include linear saturated aliphatic diamines having 4 to 20 carbon atoms. Examples of linear saturated aliphatic diamines having 4 to 20 carbon atoms include, but are not limited to, ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, and tridecamethylenediamine.

[0050] (2) Alicyclic diamine units The alicyclic diamines that constitute the alicyclic diamine unit (hereinafter sometimes referred to as "alicyclic diamines") are not limited to the following, but examples include 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, and 1,3-cyclopentanediamine.

[0051] (3) Aromatic diamine units The aromatic diamines that constitute the aromatic diamine unit are not limited to those listed below, as long as they contain an aromatic compound. Specific examples of aromatic diamines include, for example, metaxylylenediamine.

[0052] Furthermore, each of these diamine units may be composed of only one type of diamine, or two or more types may be used in combination. Among these, (A2-b) diamine units are preferably aliphatic diamine units, more preferably linear saturated aliphatic diamine units having 4 to 10 carbon atoms, even more preferably linear saturated aliphatic diamine units having 6 to 10 carbon atoms, and particularly preferably hexamethylenediamine units. By using such diamines, polyamide resin compositions that simultaneously satisfy mechanical properties, particularly water absorption rigidity, thermal rigidity, and fluidity, tend to be obtained. Furthermore, molded articles obtained from these polyamide resin compositions tend to exhibit superior tensile strength, flexural modulus of elasticity during water absorption, long-term heat resistance, and tracking resistance.

[0053] The semi-aromatic polyamide (A2) is preferably polyamide 4T, polyamide 4T / 6T, polyamide 6T, polyamide 9T, polyamide 6I, polyamide 9I, or polyamide 10I, with polyamide 4T or 6I being more preferred.

[0054] The content of semi-aromatic polyamide (A2) can be 0% by mass or more and 50.0% by mass or less, preferably 5.0% by mass or more and 45.0% by mass or less, more preferably 7.0% by mass or more and 35.0% by mass or less, and even more preferably 10.0% by mass or more and 25.0% by mass or less, based on the total mass of polyamide resin (A) in the polyamide resin composition. By setting the content of semi-aromatic polyamide (A2) within the above range, the color stability of molded articles obtained from the polyamide resin composition is improved. Furthermore, by including components such as reinforcing material (F), the tensile strength, flexural modulus when water is absorbed, long-term heat resistance, and tracking resistance of molded articles obtained from the polyamide resin composition tend to be improved.

[0055] The above aliphatic polyamide (A1) is preferably polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 611, polyamide 612, polyamide 1010, or polyamide 66 / 6 copolymer. The above-mentioned semi-aromatic polyamide (A2) is preferably polyamide 66 / 6I, polyamide 6T, polyamide 6I, polyamide 6I / 6T, polyamide 4T, polyamide 4T / 6T, polyamide 9T, or polyamide MXD6. The polyamide resin (A) is preferably a combination of the aliphatic polyamide (A1) and the semi-aromatic polyamide (A2), and more preferably a combination of an aliphatic polyamide (A1) which is polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 611, polyamide 612, polyamide 1010, or polyamide 66 / 6 copolymer, and a semi-aromatic polyamide (A2) which is polyamide 66 / 6I, polyamide 6T, polyamide 6I, polyamide 6I / 6T, polyamide 4T, polyamide 4T / 6T, polyamide 9T, or polyamide MXD6.

[0056] [End-capsulation agent] The ends of the (A) polyamide resin contained in the polyamide resin composition of this embodiment may be end-sealed with a known end-sealing agent. Such end-capturing agents can also be added as molecular weight modifiers when producing polyamide resins, either from the above-mentioned dicarboxylic acid and the above-mentioned diamine, or from at least one selected from the group consisting of the above-mentioned lactam and the above-mentioned aminocarboxylic acid.

[0057] Examples of end-captive agents include, but are not limited to, monocarboxylic acids, monoamines, acid anhydrides (such as phthalic anhydride), monoisocyanates, monoesters, and monoalcohols. End-captive agents may be used individually or in combination of two or more types. Among these, monocarboxylic acids or monoamines are preferred as end-capping agents. When the ends of the polyamide resin are sealed with an end-capping agent, the thermal stability of molded articles obtained from the polyamide resin composition tends to be better.

[0058] Any monocarboxylic acid that can be used as a terminal encapsulant is acceptable as long as it has reactivity with amino groups that may be present at the ends of the polyamide resin. Examples of monocarboxylic acids are not limited to those listed below, but include aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, aromatic monocarboxylic acids, etc. Examples of aliphatic monocarboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecyl acid, myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutyric acid. Examples of alicyclic monocarboxylic acids include cyclohexanecarboxylic acid. Examples of aromatic monocarboxylic acids include benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid. These monocarboxylic acids may be used individually or in combination of two or more types. In particular, it is preferable that the ends of the semi-aromatic polyamide (A2) are sealed with acetic acid from the viewpoint of fluidity and mechanical strength.

[0059] Any monoamine that can be used as a terminal encapsulant is one that is reactive with carboxyl groups that may be present at the ends of a polyamide. Examples of monoamines, but not limited to those listed below, include aliphatic monoamines, alicyclic monoamines, and aromatic monoamines. Examples of aliphatic monoamines include methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, and dibutylamine. Examples of alicyclic monoamines include cyclohexylamines and dicyclohexylamines. Examples of aromatic monoamines include aniline, toluidine, diphenylamine, and naphthylamine. These monoamines may be used individually or in combination of two or more types.

[0060] Polyamide resin compositions containing polyamide resins encapsulated with end-captives tend to exhibit superior heat resistance, fluidity, toughness, low water absorption, and rigidity.

[0061] ≪Primary antioxidant (B)≫ The primary antioxidant is an antioxidant that plays a role in stopping the chain reaction by donating hydrogen atoms to radicals generated in the oxidation process, and is at least one selected from the group consisting of hindered phenol antioxidants, amine antioxidants, and sulfur antioxidants. The primary antioxidant (B) may be one type or more types. Preferably, the primary antioxidant (B) is not a phosphorus compound, and more preferably does not contain the element phosphorus.

[0062] [Hindered phenol antioxidants] The above hindered phenol antioxidants are not limited to the following, but include, for example, N,N'-hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanamide], triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate, 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,4-bis- (n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine, pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,2-thiobis(4-methyl-6-tert-butylphenol), N,N'-hex Smethylenebis(3,5-di-tert-butyl-4-hydroxy-hydroxynamamide), 3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-butyl-4-hydroxybenzyl)benzene, bis(3,5-di-tert-butyl-4-hydroxybenzylsulfonate ethylcalcium), tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate, 2,6-di-tert-butyl-p-cresol , butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, stearyl-β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis-(4-methyl-6-tert-butylphenol), 2,2'-methylene-bis-(4-ethyl-6-tert-butylphenol), 4,4'-thiobis-(3-methyl-6-tert-butylphenol), octylated diphenylamine, 2,4-bis[(octylthio)methyl]-o-cresol, isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 4,4'-butylidenebis(3-methyl-6-tert-butylphenol, 3,9-bis[1,1-dimethyl-2-[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane Examples include 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, bis[3,3'-bis-(4'-hydroxy-3'-tert-butylphenyl)butyric acid] glycol ester, 1,3,5-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-sec-triazine-2,4,6-(1H,3H,5H)trione, and d-α-tocopherol. These may be used individually as hindered phenol antioxidants, or in combination of two or more types. In particular, from the viewpoint of color stability of polyamides, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)] is more preferred.

[0063] [Amine-based antioxidants] Amine-based antioxidants are not limited to the following, but include, for example, 2',3-bis[[3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyl]]propionohydrazide, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, 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, 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-tetramethyl Piperidine, 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, bis(2,2,6,6-tetramethyl-4-piperidyltrylene-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,Examples include 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, condensates 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, etc. These amine-based antioxidants may be used individually or in combination of two or more. In particular, from the viewpoint of color stability of polyamides, 2',3-bis[[3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyl]]propionohydrazide and 4,4'-bis(α,α-dimethylbenzyl)diphenylamine are preferred.

[0064] [Sulfur-based antioxidants] Examples of sulfur-based antioxidants, though not limited to those listed below, include dilaurylthiodipropionate, distearylthiodipropionate, and dioctylthiodipropionate.

[0065] The primary antioxidant (B) is preferably at least one selected from the group consisting of ethylenebis(oxyethylene)bis-(3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate), N,N'-hexane-1,6-diylbis(3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)), pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 2',3-bis[[3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyl]]propionohydrazide, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, and bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate.

[0066] The mass ratio of the primary antioxidant (B) to 100 parts by mass of the polyamide resin (A) is preferably 0.01 to 2.0 parts by mass, more preferably 0.03 to 1.0 parts by mass, and even more preferably 0.03 to 0.60 parts by mass.

[0067] Secondary antioxidant (C) Secondary antioxidants are phosphorus-based compounds that reduce and decompose the peroxides remaining after the primary antioxidant has reacted into stable alcohols. These secondary antioxidants are selected from phosphinate ester compounds and hypophosphate metal salts, although they are not limited to those listed below. From the viewpoint of color stability, flame retardancy, and tracking properties of polyamides, hypophosphate metal salts are the most preferred.

[0068] [Metal hypophosphate salts] Specific examples of hypophosphate metal salts include sodium hypophosphate, calcium hypophosphate, magnesium hypophosphate, and their hydrates. From the viewpoint of color stability, flame retardancy, tracking resistance, and moldability of the polyamide resin composition, it is preferable to select from the group consisting of magnesium hypophosphate, calcium hypophosphate, and their hydrates, with magnesium hypophosphate and calcium hypophosphate being the most preferred.

[0069] The mass ratio of the secondary antioxidant (C) to 100 parts by mass of the polyamide resin (A) is preferably 0.01 to 3.0 parts by mass, more preferably 0.1 to 2.5 parts by mass, and even more preferably 0.2 to 2.0 parts by mass.

[0070] The mass ratio of primary antioxidant (B) to secondary antioxidant (C) (primary antioxidant (B):secondary antioxidant (C)) is preferably 50:50 to 1:99, more preferably 50:50 to 5:95, even more preferably 40:60 to 5:95, and particularly preferably 30:70 to 7:93, assuming the total of primary antioxidant (B) and secondary antioxidant (C) is 100.

[0071] <Flame retardant (E)> The polyamide resin composition of this embodiment preferably further contains at least one selected from the group consisting of a flame retardant (E), a reinforcing agent (F), and a coloring agent (G). The flame retardant (E), reinforcing agent (F), and coloring agent (G) are compounds other than the polyamide resin (A), primary antioxidant (B), and secondary antioxidant (C) described above. The flame retardant is not particularly limited, but is selected from at least one of the group consisting of phosphazenes, aliphatic or aromatic esters of phosphoric acid or polyphosphate, metal phosphinates or phosphinates, phosphinic acid-phosphonic acid complex metals, salt bromine-containing flame retardants, chlorine-containing flame retardants, flame retardant melamine compounds, benzoguanidine compounds or their salts, allantoin compounds or their salts, glycoluryl or its salts, cyanoguanidine, antimony trioxide, antimony pentoxide and other metal oxides, and / or phosphorus such as sodium antimonate and red phosphorus. Among these, it is preferable to select one or more from phosphinates and phosphinic acid-phosphonic acid complex metal salts.

[0072] [Phosphinate (E1)] The above flame retardant (E) may include, for example, at least one phosphinate selected from the group consisting of a phosphinate represented by the following general formula (1) (hereinafter sometimes abbreviated as "phosphinate (1)"), a diphosphinate represented by the following general formula (2) (hereinafter sometimes abbreviated as "diphosphinate (2)"), and condensates thereof.

[0073] [ka] [ka] (In general formula (1), R 11 and R 12 Each of these is independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. n11+is an n11-valent metal ion. M is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc or aluminum. n11 is 2 or 3. When n11 is 2 or 3, multiple R 11 and R 12 may be the same or different from each other. In the general formula (2), R 21 and R 22 are each independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. Y 21 is an alkylene group having 1 to 10 carbon atoms or an arylene group having 6 to 10 carbon atoms. M’ m21+ is an m21-valent metal ion. M’ is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc or aluminum. n21 is an integer of 1 or more and 3 or less. When n21 is 2 or 3, multiple R 21 、R 22 and Y 21 may be the same or different from each other. m21 is 2 or 3. x is 1 or 2. When x is 2, multiple M’s may be the same or different from each other. n21, x and m21 are integers satisfying the relational expression of 2×n21 = m21×x.)

[0074] [R 11 、R 12 、R 21 and R 22 R 11 、R 12 、R 21 and R 22 ​​​​​​​​​These may be identical or different, but it is preferable that they be identical because it is easier to manufacture. The alkyl group may be linear or cyclic, but it is preferably linear. The linear alkyl group may be linear or branched. Examples of linear alkyl groups include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, and n-hexyl group. Examples of branched alkyl groups include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1,1-dimethylethyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 1,3-dimethylbutyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, 3,3-dimethylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, and 1,1,2-trimethylpropyl group. Examples of aryl groups include phenyl groups and naphthyl groups. Alkyl and aryl groups may have substituents. Examples of substituents on alkyl groups include aryl groups having 6 to 10 carbon atoms. Examples of substituents on aryl groups include alkyl groups having 1 to 6 carbon atoms. Examples of alkyl groups having substituents include, for instance, the benzyl group. Examples of substituted aryl groups include tolyl groups and xylyl groups. Among them, R 11 , R 12 , R 21 and R 22 Preferably, the alkyl group has 1 to 6 carbon atoms, and more preferably, a methyl group or an ethyl group.

[0075] [Y 21 ] Y 21This is an alkylene group having 1 to 10 carbon atoms or an arylene group having 6 to 10 carbon atoms. If n21 is 2 or 3, there are multiple Y groups. 21 These may be identical or different, but it is preferable that they be identical because it is easier to manufacture. The alkylene group may be linear or cyclic, but it is preferable to be linear. The linear alkylene group may be straight or branched. Examples of straight alkylene groups include methylene, ethylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene groups. Examples of branched alkylene groups include 1-methylethylene and 1-methylpropylene groups. Examples of arylene groups include phenylene groups and naphthylene groups. The alkylene group and the arylene group may have substituents. Examples of substituents on the alkylene group include aryl groups having 6 to 10 carbon atoms. Examples of substituents on the arylene group include alkyl groups having 1 to 6 carbon atoms. Examples of alkylene groups having substituents include, for example, phenylmethylene group, phenylethylene group, phenyltrimethylene group, and phenyltetramethylene group. Examples of substituent arylene groups include methylphenylene group, ethylphenylene group, tert-butylphenylene group, methylnaphthylene group, ethylnaphthylene group, and tert-butylnaphthylene group. Among them, Y 21 Preferably, the alkylene group has 1 to 10 carbon atoms, and more preferably, a methylene group or an ethylene group.

[0076] [M and M'] M and M' are, independently, ions of elements belonging to Group 2 or Group 15 of the periodic table, ions of transition elements, zinc ions, or aluminum ions. Examples of ions of elements belonging to Group 2 of the periodic table include calcium ions and magnesium ions. Examples of ions of elements belonging to Group 15 of the periodic table include bismuth ions. Furthermore, when x is 2, the multiple M' elements may be the same or different, but it is preferable that they be the same because it is easier to manufacture. In particular, calcium, zinc, or aluminum are preferred for M and M', with calcium or aluminum being more preferred.

[0077] [x] x represents the number of M' molecules and is either 1 or 2. x can be appropriately selected depending on the type of M' and the number of diphosphinic acids.

[0078] [n11 and n21] n11 represents the number of phosphinic acid molecules and the valency of M, and is either 2 or 3. n11 can be appropriately selected depending on the type and valency of M. n21 represents the number of diphosphinic acid molecules and is an integer between 1 and 3. n21 can be appropriately selected depending on the type and number of M' molecules.

[0079] [m21] m21 represents the valence of M', which is either 2 or 3. n21, x, and m21 are integers that satisfy the relationship 2 × n21 = m21 × x.

[0080] Preferred phosphinates (1) specifically include, for example, calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, magnesium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, aluminum methyl-n-propylphosphinate, zinc methyl-n-propylphosphinate, methane (methylphosphinate) Examples include calcium, magnesium methanedi(methylphosphinate), aluminum methanedi(methylphosphinate), zinc methanedi(methylphosphinate), calcium benzene-1,4-(dimethylphosphinate), magnesium benzene-1,4-(dimethylphosphinate), aluminum benzene-1,4-(dimethylphosphinate), zinc benzene-1,4-(dimethylphosphinate), calcium methylphenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate, and zinc diphenylphosphinate. Among these, calcium diethylphosphinate or aluminum diethylphosphinate are particularly preferred as the phosphinate (1) due to their excellent flame retardancy.

[0081] Preferred diphosphinates (2) specifically include, for example, calcium methanedi(methylphosphinate), magnesium methanedi(methylphosphinate), aluminum methanedi(methylphosphinate), zinc methanedi(methylphosphinate), calcium benzene-1,4-di(methylphosphinate), magnesium benzene-1,4-di(methylphosphinate), aluminum benzene-1,4-di(methylphosphinate), and zinc benzene-1,4-di(methylphosphinate).

[0082] There are no particular limitations on the method for producing phosphinates, but examples include the methods described in Japanese Patent Application Publication No. 2005-179362, European Patent Application Publication No. 699708, and Japanese Patent Application Publication No. 08-073729. Specifically, they are produced in aqueous solution using phosphinic acid and a metal carbonate, metal hydroxide, or metal oxide. These are essentially monomeric compounds, but depending on the reaction conditions, polymeric phosphinates, which are condensates with a degree of condensation of 1 to 3, may also be included depending on the environment.

[0083] Specific examples of phosphinate products include, for example, Clariant's "Exolit OP1230," "Exolit OP1240," "Exolit OP1312," "Exolit OP1314," and "Exolit OP1400."

[0084] [Phosphinic acid-phosphonic acid bimetallic salt (E2)] For example, it may include at least one phosphinate selected from the group consisting of phosphinates represented by the following general formula (3) (hereinafter sometimes abbreviated as "phosphinate (3)"), diphosphinates represented by the following general formula (4) (hereinafter sometimes abbreviated as "diphosphinate (4)"), and condensates thereof.

[0085] [ka] In general formula (3), R 1 , R 2 and R 3 Each of these is independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. m+ R is a metal ion. M is an element belonging to group 2 or group 15 of the periodic table, a transition element, zinc, or aluminum. m is 2 or 3. If m is 2 or 3, there are multiple R 1 and R 2 These may be the same or different.

[0086] Preferably, the resin composition consists of a polyamide resin composition in which the median diameter (D50) of component (E2) observed from the pellets and molded articles is 2.5 to 6.0 μm, and the ratio (d75 / d25) of the particle diameter of the 25% of particles with the smallest particle size (d25) to the particle diameter of the 75% of particles (d75) is less than 2.0.

[0087] [R 1 , R 2 , and R 3 ] R 1 , R 2 , and R 3 Each of these is independently an alkyl group having 1 to 6 carbon atoms and an aryl group having 6 to 10 carbon atoms. When m+ is 2 or 3, there are multiple R 1 and R 2 These may be identical or different, but it is preferable that they be identical because it is easier to manufacture.

[0088] The alkyl group may be linear or cyclic, but it is preferably linear. The linear alkyl group may be linear or branched. Examples of linear alkyl groups include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, and n-hexyl group. Examples of branched alkyl groups include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1,1-dimethylethyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 1,3-dimethylbutyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, 3,3-dimethylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, and 1,1,2-trimethylpropyl group.

[0089] Examples of aryl groups include phenyl groups and naphthyl groups. Alkyl and aryl groups may have substituents. Examples of substituents on alkyl groups include aryl groups having 6 to 10 carbon atoms. Examples of substituents on aryl groups include alkyl groups having 1 to 6 carbon atoms.

[0090] [M] M is independently an ion of an element belonging to Group 2 or Group 15 of the periodic table, an ion of a transition element, a zinc ion, or an aluminum ion. Examples of ions of elements belonging to Group 2 of the periodic table include calcium ions and magnesium ions. Examples of ions of elements belonging to Group 15 of the periodic table include bismuth ions. Among these, aluminum is preferred for material M.

[0091] [m+] m+ represents the number of M molecules, which is either 2 or 3. The number of m+ molecules can be appropriately selected depending on the type of M and the number of diphosphinic acid molecules.

[0092] [a and b] 'a' represents the number of phosphinic acid molecules. It can be selected appropriately depending on the type and number of M molecules. b represents the number of phosphonic acids. It can be selected appropriately depending on the type and number of M.

[0093] Furthermore, among phosphinates, the flame retardant represented by chemical formula (4), which is a composite salt of a phosphinate and a phosphonate, is preferred from the viewpoint of heat resistance, flame retardancy, and metal corrosion resistance. [ka] Most preferably, the flame retardant is represented by formula (4) as a hexavalent anion having R1=ethyl group, R2=ethyl group, R3=ethyl group, a=4, b=1 and a hexavalent cation having M=aluminum and two m=3 groups, and an aluminum composite salt of diethylphosphinic acid and ethylphosphonic acid is preferred, and specific product examples include "HR8900", "MADP8900SP", "MADP8900BS", and "HR8966" manufactured by Weihai Hairun Co., Ltd.

[0094] The amount of flame retardant (E) is preferably 20 parts by mass or more and 80 parts by mass or less, more preferably 25 parts by mass or more and 70 parts by mass or less, and particularly preferably 30 parts by mass or more and 60 parts by mass or less, per 100 parts by mass of polyamide resin (A). By setting the content of the flame retardant (E) to above the lower limit, a polyamide resin composition with superior flame retardancy can be obtained. On the other hand, by setting the amount of flame retardant to below the upper limit, a polyamide resin composition with superior flame retardancy can be obtained without impairing the properties of the polyamide resin.

[0095] ≪Reinforcement material (F)≫ The polyamide resin composition of this embodiment may further contain a reinforcing material (F) in addition to the above components (A) to (E).

[0096] The reinforcing material (F) is not limited to the following, but examples include glass fiber, carbon fiber, calcium silicate fiber, potassium titanate fiber, aluminum borate fiber, clay, flake glass, talc, kaolin, mica, hydrotalcite, calcium carbonate, magnesium carbonate, zinc carbonate, zinc oxide, monocalcium phosphate, wollastonite, silica, zeolite, alumina, boehmite, aluminum hydroxide, titanium oxide, silicon oxide, magnesium oxide, calcium silicate, sodium aluminosilicate, magnesium silicate, Ketjenblack, acetylene black, furnace black, carbon nanotubes, graphite, brass, copper, silver, aluminum, nickel, iron, calcium fluoride, montmorillonite, swelling fluoromica, apatite, etc. These reinforcing materials may be used individually or in combination of two or more types.

[0097] In particular, from the viewpoint of further improving mechanical strength, one or more selected from the group consisting of glass fiber, carbon fiber, wollastonite, kaolin, mica, talc, calcium carbonate, magnesium carbonate, potassium titanate fiber, aluminum borate fiber, and clay is preferred. More preferably, one or more selected from the group consisting of glass fiber, carbon fiber, wollastonite, kaolin, mica, talc, calcium carbonate, and clay is preferred. Glass fiber is the most preferred.

[0098] When the reinforcing material is glass fiber or carbon fiber, the number-average fiber diameter (d) is preferably 3 μm or more and 30 μm or less, more preferably 3 μm or more and 20 μm or less, even more preferably 3 μm or more and 12 μm or less, particularly preferably 3 μm or more and 9 μm or less, and most preferably 4 μm or more and 6 μm or less.

[0099] By setting the number-average fiber diameter to below the above upper limit, a polyamide resin composition with superior toughness and surface appearance of molded products can be obtained. On the other hand, by setting the number-average fiber diameter to above the above lower limit, a polyamide resin composition with a good balance between cost, powder handling, and physical properties (flowability, etc.) can be obtained. Furthermore, by setting the number-average fiber diameter to 3 μm or more and 9 μm or less, a polyamide resin composition with superior vibration fatigue characteristics and sliding properties can be obtained.

[0100] When the reinforcing material is glass fiber or carbon fiber, its cross-section may be circular or flattened. Examples of such flattened cross-sections are, but are not limited to, rectangular, oblong, elliptical, and cocoon-shaped with a constriction in the middle along the longitudinal direction. Here, "flatness ratio" as used herein refers to the value expressed as d2 / d1, where d2 is the major axis of the fiber cross-section and d1 is the minor axis of the fiber cross-section (for a circular cross-section, the flatness ratio is approximately 1).

[0101] When the reinforcing material is glass fiber or carbon fiber, in particular, from the viewpoint of imparting excellent mechanical strength to the polyamide resin composition, it is preferable that the number-average fiber diameter (d) is 3 μm or more and 30 μm or less, the weight-average fiber length (l) is 100 μm or more and 750 μm or less, and the ratio of the weight-average fiber length (l) to the number-average fiber diameter (d), i.e., the aspect ratio (l / d), is 10 or more and 100 or less. The "number-average fiber diameter (d)" referred to here is the average value of the major axis (d2 above) of the fiber cross-section, and is determined using the calculation method described later.

[0102] Furthermore, from the viewpoint of reducing warping of the plate-shaped molded product and improving heat resistance, toughness, low water absorption, and heat aging resistance, the flatness ratio is preferably 1.5 or more, more preferably 1.5 to 10.0, even more preferably 2.5 to 10.0, particularly preferably greater than 3.0 and 6.0 or less, and most preferably 3.1 to 6.0 or less. By having the flatness ratio within the above range, crushing can be more effectively prevented during processing such as mixing with other components, kneading, and molding, and the desired effects for the molded product can be obtained more fully.

[0103] The thickness of glass fibers or carbon fibers with an aspect ratio of 1.5 or more is not limited to the following, but it is preferable that the minor axis d1 of the fiber cross-section is 0.5 μm or more and 25 μm or less, and the major axis d2 of the fiber cross-section is 1.25 μm or more and 250 μm or less. It is more preferable that the minor axis d1 of the fiber cross-section is 3.0 μm or more and 25 μm or less, and the major axis d2 of the fiber cross-section is 1.25 μm or more and 250 μm or less. By having the minor axis (d1) and major axis (d2) within the above range, the difficulty of spinning the fibers can be more effectively avoided, and the strength of the molded product can be further improved without reducing the contact area with the resin (polyamide).

[0104] Glass fibers or carbon fibers with an aspect ratio of 1.5 or more are preferably manufactured using either an orifice plate having multiple orifice holes on its bottom surface, with a convex edge surrounding multiple orifice outlets and extending downward from the bottom surface, or a nozzle tip for spinning glass fibers with a deformed cross-section having one or more orifice holes and multiple convex edges extending downward from the outer tip of the nozzle tip. These fibrous reinforcing materials may be used as rovings in the form of fiber strands, or they may be further cut and used as chopped glass strands.

[0105] Furthermore, the "number-average fiber diameter (d)" and "weight-average fiber length (l)" in this specification can be determined by the following method. First, the polyamide resin composition is placed in an electric furnace to incinerate the organic matter contained therein. From the residue after this treatment, 100 or more glass fibers (or carbon fibers) are arbitrarily selected and observed with a scanning electron microscope (SEM). The number-average fiber diameter can be determined by measuring the fiber diameter (longest diameter) of these glass fibers (or carbon fibers). In addition, the weight-average fiber length can be determined by measuring the fiber length using SEM images of the above 100 or more glass fibers (or carbon fibers) taken at a magnification of 1000x.

[0106] Furthermore, glass fibers or carbon fibers may be surface-treated with a silane coupling agent or the like. Examples of silane coupling agents include, but are not limited to, aminosilanes, mercaptosilanes, epoxysilanes, vinylsilanes, and the like. Examples of aminosilanes include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane.

[0107] Examples of mercaptosilanes include γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane. These silane coupling agents may be used individually or in combination of two or more. Among these, aminosilanes are preferred as silane coupling agents.

[0108] Furthermore, glass fibers or carbon fibers may also contain a sizing agent. Examples of sizing agents include copolymers containing carboxylic acid anhydride-containing unsaturated vinyl monomers and unsaturated vinyl monomers excluding carboxylic acid anhydride-containing unsaturated vinyl monomers as constituent units, epoxy compounds, polyurethane resins, acrylic acid homopolymers, copolymers of acrylic acid and other copolymerizable monomers, and salts thereof with primary, secondary, and tertiary amines. These sizing agents may be used individually or in combination of two or more.

[0109] In particular, from the viewpoint of the mechanical strength of the resulting polyamide resin composition, it is preferable to use one or more sizing agents selected from the group consisting of copolymers containing carboxylic acid anhydride-containing unsaturated vinyl monomers and unsaturated vinyl monomers other than carboxylic acid anhydride-containing unsaturated vinyl monomers as constituent units, epoxy compounds, and polyurethane resins. More preferably, it is preferable to use one or more sizing agents selected from the group consisting of copolymers containing carboxylic acid anhydride-containing unsaturated vinyl monomers and unsaturated vinyl monomers other than carboxylic acid anhydride-containing unsaturated vinyl monomers and polyurethane resins.

[0110] Glass fibers or carbon fibers are obtained by continuously reacting them in a known fiber manufacturing process by applying the above-mentioned sizing agent to the fibers using a known method such as a roller-type applicator, and then drying the resulting fiber strands. The fiber strands may be used as roving as is, or they may be further cut and used as chopped glass strands.

[0111] The sizing agent is preferably added in an amount of 0.2% to 3% by mass as a solid content ratio relative to the total mass of the glass fibers or carbon fibers, and more preferably in an amount of 0.3% to 2% by mass. By adding a sizing agent in an amount equal to or greater than the lower limit in terms of solid content relative to the total mass of glass fibers or carbon fibers, the filaments can be more effectively maintained. On the other hand, by adding a sizing agent in an amount equal to or less than the upper limit in terms of solid content relative to the total mass of glass fibers or carbon fibers, the thermal stability of the resulting polyamide resin composition is further improved. The strands may be dried after the cutting process, or they may be cut after drying.

[0112] The boron content in the glass fibers is preferably 1.0% by mass or less, more preferably 0.5% by mass or less, and even more preferably absent. When the boron content is within the above range, the molded articles obtained from the polyamide resin composition tend to have superior mechanical strength, rigidity, dimensional accuracy, and appearance.

[0113] The mass ratio (Mg / Si) of magnesium (Mg) and silicon (Si) elements contained in the glass fiber is preferably 0.01 to 0.2, more preferably 0.01 to 0.1, even more preferably 0.01 to 0.05, and still more preferably 0.01 to 0.025. Alternatively, the ratio (Mg / Si) of magnesium (Mg) and silicon (Si) elements contained in component (C) is preferably 0 to 0.025. When the above Mg / Si ratio is within the above range, a polyamide resin composition with excellent color stability tends to be obtained.

[0114] As reinforcing materials other than glass fibers and carbon fibers, wollastonite, kaolin, mica, talc, calcium carbonate, magnesium carbonate, potassium titanate fibers, aluminum borate fibers, or clay are preferred from the viewpoint of improving the strength, rigidity, and surface appearance of the molded product. Wollastonite, kaolin, mica, talc, calcium carbonate, or clay are more preferred. Wollastonite, kaolin, mica, or talc are even more preferred. Wollastonite, mica, or talc are particularly preferred. These inorganic fillers may be used individually or in combination of two or more types.

[0115] The average particle size of reinforcing materials other than glass fibers and carbon fibers is preferably 0.01 μm to 38 μm, more preferably 0.03 μm to 30 μm, even more preferably 0.05 μm to 25 μm, even more preferably 0.10 μm to 20 μm, and particularly preferably 0.15 μm to 15 μm, from the viewpoint of improving toughness and the surface appearance of the molded product.

[0116] By setting the average particle size of reinforcing materials other than glass fibers and carbon fibers to below the above upper limit, a polyamide resin composition with superior toughness and surface appearance of molded products can be obtained. On the other hand, by setting the average particle size to above the above lower limit, a polyamide resin composition with a superior balance between cost, powder handling, and physical properties (flowability, etc.) can be obtained.

[0117] For needle-shaped inorganic fillers other than glass fibers and carbon fibers, such as wollastonite, the number-average particle diameter (hereinafter sometimes simply referred to as "average particle diameter") shall be used as the average particle size. Furthermore, if the cross-section is not circular, the maximum length of that cross-section shall be used as the (number-average) fiber diameter.

[0118] The number-average particle length of the needle-shaped reinforcing material (hereinafter sometimes simply referred to as "average particle length") is preferably a numerical range calculated from the preferred range of the number-average particle diameter described above and the preferred range of the aspect ratio (l / d) of the number-average particle length (l) to the number-average particle diameter (d) described below.

[0119] Although the particles have a needle-like shape, the aspect ratio (l / d) of the number-average particle length (l) to the number-average particle diameter (d) is preferably 1.5 to 10, more preferably 2.0 to 5, and even more preferably 2.5 to 4, from the viewpoint of improving the surface appearance of the molded product and preventing wear of metallic parts such as injection molding machines.

[0120] Furthermore, reinforcing materials other than glass fibers and carbon fibers may be surface-treated using silane coupling agents, titanate-based coupling agents, etc. Examples of silane coupling agents include those similar to those exemplified above for glass fibers and carbon fibers. Among these, aminosilanes are preferred as silane coupling agents. Such surface treatment agents may be applied to the surface of the reinforcing material in advance, or they may be added when mixing the polyamide and the inorganic filler. The amount of surface treatment agent added is preferably 0.05% by mass or more and 1.5% by mass or less, relative to the total mass of the inorganic filler.

[0121] [Content of reinforcing material (F)] The content of the reinforcing material (F) is preferably 10 parts by mass or more and 150 parts by mass or less, more preferably 40 parts by mass or more and 150 parts by mass or less, and even more preferably 40 parts by mass or more and 14 parts by mass or less, per 100 parts by mass of polyamide resin (A). When the reinforcing material content is above the lower limit, the strength and rigidity of the resulting polyamide resin composition are further improved. On the other hand, when the reinforcing material content is below the upper limit, a polyamide resin composition with better extrudeability and moldability can be obtained.

[0122] ≪Coloring agent (G)≫ The polyamide resin composition of this embodiment may further contain a coloring agent (G) in addition to the above components (A) to (F).

[0123] As colorants (G), one or more inorganic pigments and / or organic dyes are selected and used to color the material to any desired color, although this is not limited to the following. Specific examples of inorganic pigments, though not limited to the following, include sodium aluminosilicate, cobalt aluminate, bismuth vanadate, iron oxide, titanium dioxide, zinc sulfide, zinc oxide, cerium sulfide, lanthanum sulfide, barium sulfide, cerium sulfide, lanthanum sulfide, and titanium tin oxide. Specific organic dyes, though not limited to those listed below, include phthalocyanine, benzimidazole, 14H-benzo[4,5]isoquino[2,1-a]perimidine-14-one, 2-octadecyl-1H-thioxantheno[2,1,9-def]isoquinoline-1,3(2H)-dione, 3,9-perienedicarboxylate diisobutyl, hydroxynaphthyl-benzimidazole, pyridinium-azo-benzimidazole, 5,6-diamino-1,3-dihydro-2H-benzimidazole-2-one, condensation products with anthraquinone, 1,8-dichloroanthracene-9, benzenethiol, 10,10'-oxybis-12H-phthaloperin-12-one, 14H-anthra(2,1,9-mna)thioxanthene-14-one, and 2-octadecyl-1 Examples include H-thioxantheno[2,1,9-def]isoquinoline 1,3(2H)-dione and 12H-phthaloperine-12-one.

[0124] While there are no particular limitations on the form in which colorants are used, they can be used as liquids, powders, pastes, or masterbatches.

[0125] The colors used to color the material with coloring agent (G) are preferably chromatic colors, and while chromatic colors are not limited to the following, they include red, blue, orange, and green. Among these, orange is preferred, and it is preferable to color the material to the orange color standards RAL2001, RAL2003, RAL2007, RAL2009, RAL2010, and RAL2011.

[0126] ≪Other components (H)≫ The polyamide resin composition of this embodiment may also contain, in addition to the above components (A) to (G), one or more other components (H) selected from the group consisting of flame retardants, lubricants, heat stabilizers, nucleating agents, other polymers, and other additives.

[0127] [Flame retardant] Anhydrous zinc borate can be used as a flame retardant. When selecting anhydrous zinc borate, from the viewpoint of flame retardancy efficiency, a mass ratio of anhydrous zinc borate to flame retardant (E) of 2:98 to 10:90 is preferable.

[0128] [Lubricant] Lubricants are not particularly limited, but examples include higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, and higher fatty acid amides. Lubricants can also be used as molding modifiers.

[0129] [Higher fatty acids] Examples of higher fatty acids include linear or branched saturated or unsaturated aliphatic monocarboxylic acids having 8 to 40 carbon atoms. Examples of linear or branched saturated or unsaturated aliphatic monocarboxylic acids having 8 to 40 carbon atoms include lauric acid, palmitic acid, stearic acid, behenic acid, and montanic acid. Examples of branched-chain saturated aliphatic monocarboxylic acids having 8 to 40 carbon atoms include isopalmitic acid and isostearic acid. Examples of linear unsaturated aliphatic monocarboxylic acids having 8 to 40 carbon atoms include oleic acid and erucic acid. Examples of branched-chain unsaturated aliphatic monocarboxylic acids having 8 to 40 carbon atoms include isoleic acid. Among these, stearic acid or montanic acid are preferred as higher fatty acids.

[0130] [Higher fatty acid metal salts] Metal salts of higher fatty acids are metal salts of higher fatty acids. Examples of metallic elements in metal salts include the elements of Group 1, Group 2, and Group 3 of the periodic table, as well as zinc and aluminum. Examples of Group 1 elements in the periodic table include sodium and potassium. Examples of Group 2 elements in the periodic table include calcium and magnesium. Examples of Group 3 elements in the periodic table include scandium and yttrium. In particular, elements from groups 1 and 2 of the periodic table, or aluminum, are preferred, and sodium, potassium, calcium, magnesium, or aluminum are more preferred.

[0131] Examples of higher fatty acid metal salts include calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, calcium montana, sodium montana, and calcium palmitate. Among these, metal salts of montanic acid or stearic acid are preferred as higher fatty acid metal salts.

[0132] [High-grade fatty acid esters] Higher fatty acid esters are esterified products of higher fatty acids and alcohols. As higher fatty acid esters, esters of an aliphatic carboxylic acid having 8 to 40 carbon atoms and an aliphatic alcohol having 8 to 40 carbon atoms are preferred. Examples of aliphatic alcohols with 8 to 40 carbon atoms include stearyl alcohol, behenyl alcohol, and lauryl alcohol. Examples of higher fatty acid esters include stearyl stearate and behenyl behenate.

[0133] [High-grade fatty acid amides] Higher fatty acid amides are amide compounds of higher fatty acids. Examples of higher fatty acid amides include stearic acid amide, oleic acid amide, erucic acid amide, ethylenebisstearyl amide, ethylenebisoleyl amide, N-stearylstearate amide, and N-stearylerucic acid amide.

[0134] These higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, and higher fatty acid amides may be used individually or in combination of two or more types.

[0135] The lubricant content in the polyamide resin composition is preferably 0.01% by mass or more and 1% by mass or less, and more preferably 0.1% by mass or more and 1% by mass or less, relative to the total mass of the polyamide resin composition. By having a lubricant content above the lower limit, the moldability of the polyamide resin composition can be improved, while by having a lubricant content below the upper limit, the rigidity of the molded product can be improved.

[0136] [Nucleoforming agent] A nucleating agent is a substance that, when added, produces at least one of the following effects (1) to (3). (1) Effect of increasing the crystallization peak temperature of the polyamide resin composition. (2) The effect of reducing the difference between the extrapolation start temperature and the extrapolation end temperature of the crystallization peak. (3) The effect of making the spherulites of the resulting molded product finer or more uniform in size.

[0137] Examples of nucleating agents include, but are not limited to, talc, boron nitride, mica, kaolin, silicon nitride, potassium titanate, and molybdenum disulfide. The nucleating agent may be used alone or in combination of two or more types. In particular, talc or boron nitride is preferred as a nucleating agent from the viewpoint of its nucleating effect.

[0138] Furthermore, because the nucleating agent is highly effective, the number-average particle size of the nucleating agent is preferably 0.01 μm or more and 10 μm or less. The number-average particle size of the nucleating agent can be measured using the following method. First, the molded product is dissolved in a solvent that is soluble in polyamide, such as formic acid. Next, for example, 100 or more nucleating agents are arbitrarily selected from the resulting insoluble components. Then, the particle size can be determined by observing them with an optical microscope or scanning electron microscope.

[0139] The content of the nucleating agent in the polyamide resin composition of this embodiment is preferably 0.001% by mass or more and 1% by mass or less, more preferably 0.001% by mass or more and 0.5% by mass or less, and even more preferably 0.001% by mass or more and 0.09% by mass or less, based on the total mass of the polyamide resin composition. By setting the nucleating agent content above the lower limit, the heat resistance of the polyamide resin composition tends to improve further. Conversely, by setting the nucleating agent content below the upper limit, a polyamide resin composition with superior toughness can be obtained.

[0140] [Copper compound] Copper compounds are preferable to be omitted from polyamide resin compositions because they worsen the color stability of the polyamide resin. However, a certain amount of copper compounds may be included to improve the heat retention and heat aging properties of the polyamide resin composition. Examples of copper compounds, though not limited to those listed below, include copper halides, copper acetate, copper propionate, copper benzoate, copper adipate, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate, copper stearate, and copper complex salts coordinated to chelating agents such as ethylenediamine and ethylenediaminetetraacetic acid. These copper compounds may be used individually or in combination of two or more. Among these, copper iodide, cuprous bromide, cupric bromide, cuprous chloride, and copper acetate are preferred from the viewpoint of suppressing molecular weight reduction during melt kneading and improving heat aging resistance, with copper iodide and copper acetate being more preferred.

[0141] The polyamide resin composition of this embodiment may or may not contain copper. Preferably, the mass ratio of copper in the copper compound per 100 parts by mass of polyamide resin (A) is 0.0 to 0.05 parts by mass, more preferably 0 to 0.01 parts by mass, and even more preferably 0.0 to 0.001 parts by mass. By keeping the copper content within the above range, deterioration of the color stability of the polyamide resin composition can be suppressed. The mass ratio of copper elements contained in the polyamide resin composition of this embodiment is preferably 0 to 0.001 parts by mass per 100 parts by mass of polyamide resin (A).

[0142] [Other polymers] Other polymers are not limited to polyamide resin (A), but include, for example, polyester, liquid crystal polyester, polyphenylene sulfide, polyphenylene ether, polycarbonate, polyarylate, phenolic resin, epoxy resin, etc. Polyesters are not limited to the following, but include, for example, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, etc.

[0143] The content of other polymers is preferably 1% to 30% by mass, more preferably 5% to 20% by mass, and even more preferably 5% to 15% by mass, based on the total amount of polyamide resin in the polyamide resin composition. By having the content of other polymers within the above range, a polyamide resin composition with superior heat resistance and mold release properties can be obtained.

[0144] In addition to the components described above, the polyamide resin composition of this embodiment may also contain additives commonly used in polyamide resin compositions as other components (H), to the extent that they do not impair the effects of the polyamide resin composition of this embodiment. Examples of additives include flame retardants, fibrillating agents, fluorescent bleaching agents, plasticizers, ultraviolet absorbers, antistatic agents, flow improvers, spreading agents, and the like.

[0145] If the polyamide resin composition of this embodiment contains other components (H), the amount of these components varies depending on their type and the intended use of the polyamide resin composition. Therefore, there are no particular limitations as long as the effects of the polyamide resin composition of this embodiment are not impaired.

[0146] The total mass ratio of the polyamide resin (A), the primary antioxidant (B), and the secondary antioxidant (C) in 100% by mass of the polyamide resin composition of this embodiment may be 40% by mass or more, or 50% by mass or more. It may also be 90% by mass or less, or 80% by mass or less. The mass percentage of the polyamide resin (A) in 100% by mass of the polyamide resin composition of this embodiment may be 40% by mass or more, or 50% by mass or more. Alternatively, it may be 90% by mass or less, or 80% by mass or less. The total mass ratio of the primary antioxidant (B) and the secondary antioxidant (C) in 100% by mass of the polyamide resin composition of this embodiment may be 0.01 to 10% by mass, or 0.1 to 5% by mass.

[0147] <Method for producing polyamide resin composition> The method for producing the polyamide resin composition of this embodiment is not particularly limited, as long as it includes a step of melting and kneading raw material components including the polyamide (A), the primary antioxidant (B), the secondary antioxidant (C), and optionally a flame retardant (E), a reinforcing agent (F), a coloring agent (G), and other components (H). For example, a method is preferred in which the raw material components including A to H are melted and kneaded in an extruder, and the set temperature of the extruder is set to be 30°C or lower than or equal to the melting peak temperature Tm of the polyamide resin composition.

[0148] Methods for melt-kneading raw material components including polyamide resin (A) include, for example, mixing polyamide resin (A) with a primary antioxidant (B) and a secondary antioxidant (C) using a tumbler, Henschel mixer, etc., and supplying the mixture to a melt-kneading machine for kneading, or adding other raw materials including a flame retardant (E) and a reinforcing agent (F) to the molten polyamide resin (A) using a single-screw or twin-screw extruder via a side feeder.

[0149] The method for supplying the components constituting the polyamide resin composition to a melt kneader is to supply all components at once to the same supply port, or to supply each component from different supply ports.

[0150] <Molded products> The molded article of this embodiment is a molded article formed from the polyamide resin composition of this embodiment described above. The molded article of this embodiment may contain the polyamide resin composition of this embodiment described above, or it may consist only of the polyamide resin composition of this embodiment. According to the polyamide resin composition of this embodiment, molded articles can be obtained using various conventionally known methods, such as press molding, injection molding, gas-assisted injection molding, welding, extrusion molding, blow molding, film molding, hollow molding, multilayer molding, melt spinning, etc.

[0151] The polyamide resin composition of this embodiment can be used in applications where color stability, flame retardancy, and tracking resistance are particularly important, and is suitable for use in electrical and electronic components and automotive electrical and electronic components. The above electrical components can be used as industrial equipment such as office machines, measuring instruments, chassis, internal parts of electrical equipment, power adapters for home appliances, recording media and their drives, sensor equipment, terminal blocks, secondary batteries in the energy and environment field, electrical and electronic components used in fuel cells, solar cells, solar thermal power generation, geothermal power generation, wind power generation, smart meters, etc., electrical components that make up power transmission equipment, cable terminals, automotive parts, in particular connection structures for solar power generation modules such as solar power generation module connectors and solar cell junction boxes, and parts for hybrid and electric vehicles. More preferably used applications include covers for electrical or electronic equipment, control devices, covers / housings for fuses, relays, battery cell modules, fuse holders, fuse plugs, terminals, cable holders or sheathings, connectors, especially sheathings for high-voltage busbars and high-voltage distribution busbars. The molded article of this embodiment is preferably a molded article selected from the group consisting of covers, housings, relays, battery cell modules, fuse holders, fuse plugs, terminals, cable holders, sheathings, connectors, and high-voltage busbars for hybrid vehicles, electric vehicles, or electronic equipment.

[0152] The high-voltage component of this embodiment preferably includes the molded product of this embodiment described above, or it may consist only of the molded product of this embodiment described above. The high-voltage components mentioned above are preferably selected from the group consisting of covers, housings, relays, battery cell modules, fuse holders, fuse plugs, terminals, cable holders, sheathings, connectors, breaker boxes, and high-voltage busbars for hybrid vehicles, electric vehicles, or electronic equipment. [Examples]

[0153] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

[0154] 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.

[0155] <Components> [Polyamide resin (A)] [Aliphatic polyamide (A1)] A1-1: Polyamide 66 (synthesized by the synthesis method described later, Cu content 1 ppm or less) [Semi-aromatic polyamide (A2)] A2-1: Polyamide 6I (synthesized by the synthesis method described later, Cu content less than 1 ppm) A2-2: Polyamide 4T / 6T (synthesized by the synthesis method described later, Cu content less than 1 ppm) A2-3: Polyamide 6T / 6I (Manufactured by Ms. Co., Ltd., Model No.: G21, Cu content less than 1 ppm)

[0156] [Primary antioxidant (B)] B-1: N,N'-Hexane-1,6-diyrbis(3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)) (Basf, trade name "Irganox 1098") B-2: Pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (Basf, brand name "Irganox 1010") B-3: 4,4'-Bis(α,α-dimethylbenzyl)diphenylamine (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., product name "Nocrac CD")

[0157] [Secondary antioxidant] (C)) C-1: Phosphite ester C-2: Sodium hypophosphate C-3: Magnesium hypophosphate C-4: Calcium hypophosphate

[0158] [Flame retardant (E)] E-1: Phosphinic acid-based flame retardant, aluminum diethylphosphinate (manufactured by Clariant, product name: "Exolit OP1400") E-2: Phosphinic acid-based flame retardant: Aluminum composite salt of diethylphosphinic acid and ethylphosphonic acid (manufactured by Wei Hui Jun Co., Ltd., product name "MADP8900SP")

[0159] [Reinforcement material (F)] F-1: Glass fiber (GF) (manufactured by Jushi Group Co., Ltd., product name "ECS10-03-568H", boron element: 0.0 mass%, Mg / Si ratio: 0.02, Fe element: 0.34 mass%, Na element: 1.03 mass%) F-2: Glass fiber (GF) (manufactured by Nippon Electric Glass, product name "ECS03T275H") Boron: 2.0% by mass, Mg / Si ratio: 0.03, Fe: 0.17% by mass, Na: 1.8% by mass

[0160] [Coloring agent (G)] G-1: Orange pigment (Milliken & Company, product name "RESIST XTR Orange 9798")

[0161] [Other components (H)] H-1: Copper iodide (manufactured by Wako Pure Chemical Industries, Ltd.)

[0162] <Manufacturing of polyamide resin> The production methods for A1-1 aliphatic polyamide and A2-1 and A2-2 semi-aromatic polyamides are described in detail below. The A1-1 aliphatic polyamide and A2-1 and A2-2 semi-aromatic polyamides obtained by the production methods described below were dried in a nitrogen stream to adjust the moisture content to approximately 0.2% by mass, and then used as raw materials for the polyamide resin compositions in the examples and comparative examples described later.

[0163] [Synthesis Example 1] (Synthesis of A1-1 Aliphatic Polyamide (Polyamide 66)) The polymerization reaction of polyamide was carried out using the "thermal fusion polymerization method" as follows. First, 1500g of an equimolar salt of adipic acid and hexamethylenediamine was dissolved in 1500g of distilled water to prepare a homogeneous aqueous solution of 50% by mass of the starting monomers. This aqueous solution was placed in a 5.4L autoclave and purged with nitrogen. Next, the solution was concentrated by gradually removing water vapor while stirring at a temperature of approximately 110°C to 150°C until the solution concentration reached 70% by mass. Then, the internal temperature was raised to 220°C. At this time, the autoclave was pressurized to 1.8 MPa. The reaction was allowed to continue for 1 hour, while gradually removing water vapor and maintaining the pressure at 1.8 MPa until the internal temperature reached 245°C. Next, the pressure was reduced over 1 hour. Finally, the autoclave was maintained under reduced pressure of 650 torr (86.66 kPa) for 10 minutes using a vacuum device. At this time, the final internal temperature of polymerization was 265°C. Next, the material was pressurized with nitrogen and formed into strands from the lower spindle (nozzle), then water-cooled and cut to discharge it in pellet form. The pellets were then dried at 100°C under a nitrogen atmosphere for 12 hours to obtain A1-1 aliphatic polyamide (polyamide 66).

[0164] [Synthesis Example 2] (A2-1 Synthesis of semi-aromatic polyamides (polyamide 6I)) The polymerization reaction of polyamide was carried out using the "thermal fusion polymerization method" as follows. First, 1500 g of an equimolar salt of isophthalic acid and hexamethylenediamine, along with 1.5 mol% excess adipic acid and 0.5 mol% acetic acid relative to the total equimolar salt components, were dissolved in 1500 g of distilled water to prepare a homogeneous aqueous solution of 50% by mass of the raw material monomers. Next, the solution was concentrated by gradually removing water vapor while stirring at a temperature of approximately 110°C to 150°C until the solution concentration reached 70% by mass. Then, the internal temperature was raised to 220°C. At this time, the autoclave was pressurized to 1.8 MPa. The reaction was carried out for 1 hour, while gradually removing water vapor and maintaining the pressure at 1.8 MPa until the internal temperature reached 245°C. Next, the pressure was reduced over 30 minutes. Then, the autoclave was maintained under reduced pressure of 650 torr (86.66 kPa) for 10 minutes using a vacuum device. At this time, the final internal temperature of polymerization was 265°C. Next, the material was pressurized with nitrogen and formed into strands from the lower spindle (nozzle), then water-cooled and cut to discharge it in pellet form. The pellets were then dried at 100°C under a nitrogen atmosphere for 12 hours to obtain amorphous polyamide A2-1 (polyamide 6I).

[0165] [Synthesis Example 3] (Synthesis of A2-2 semi-aromatic polyamides (polyamide 4T / 6T)) 1500g of 4T / 6T salt (38 mol% / 62 mol%) was added to a 50-liter rotary dryer, the rotary dryer was evacuated to 50 mbar, and then filled with nitrogen. After repeating the above procedure five times, the mixture was heated to 220°C over 5 hours while draining the reaction water from the system, and then heated to 255°C over 15 hours. Under nitrogen purging, 65g of 1,6-hexamethylenediamine, 30g of 1,4-butanediamine, and 100g of water were added to the mixture over 7 hours at 1.0 hour. The mixture was then reacted for 29 hours at 235°C under a nitrogen atmosphere, and the material was cooled to room temperature to obtain a white powder A2-2 (polyamide 4T / 6T).

[0166] <Physical properties and evaluation methods of molded products> [Manufacturing of molded products] The polyamide resin composition pellets obtained in the examples and comparative examples were dried at 80°C for 16 to 24 hours to reduce the moisture content of the polyamide resin composition to 500 ppm by mass or less. Next, pellets of each polyamide resin composition with adjusted moisture content were used in injection molding to produce ASTM D1822 TYPE L test specimens (length 15 mm, width 3.1 mm, thickness 2.9 mm), multi-purpose test specimens (Type A, dumbbell-shaped tensile test specimen, total length ≥ 170 mm, tab distance 109.3 ± 3.2 mm, parallel section length 80 ± 2 mm, shoulder radius 24 ± 1 mm, end width 20 ± 0.2 mm, central parallel section width 10 ± 0.2 mm, thickness 4 ± 0.2 mm) and UL test specimens (length 127 mm, width 12.7 mm, thickness 0.75 mm) and flat molded products (length 6 cm, width 9 cm, thickness 2 mm) in accordance with ISO 3167. The specific injection molding conditions were as follows: injection and holding pressure time: 25 seconds, cooling time: 15 seconds, mold temperature: 80°C, and cylinder temperature: melting point of the polyamide resin composition + 35°C.

[0167] [tanδ] The temperature dispersion spectrum of the dynamic viscoelasticity of specimens obtained by cutting the parallel section of a prepared ASTM D1822 TYPE L test specimen into strips was measured under the following conditions. In this specification, the tanδ peak temperature of the polyamide resin composition refers to the value measured by the method described in this paragraph using an ASTM D1822 TYPE L test specimen prepared by the method described above. (Measurement conditions) Measurement mode: Tensile Waveform: Sine wave Frequency: 3.5Hz Temperature range: 0°C to 180°C Heating step: 2°C / min Static load: 400g Displacement amplitude: 0.75 μm The ratio of the loss modulus E2 to the storage modulus E1 (E2 / E1) is defined as tanδ, and the highest temperature is defined as the tanδ peak temperature (°C).

[0168] [Evaluation 1] Color stability The hue of each multipurpose test specimen (Type A) was measured using a colorimeter (Nippon Denshoku Co., Ltd., ZE6000). Next, these multipurpose test specimens (Type A) were placed in a gear oven (ESPEC, Model: PHH-201, damper opening: 25%) and heated at 120°C or 130°C for 1000 hours to perform thermal aging. After 1000 hours, each multipurpose test specimen (Type A) was removed from the oven and cooled at 23°C for 24 hours before measuring the hue. The amount of hue change due to thermal aging, ΔL*, Δa*, and Δb*, were determined from the L, a, and b values ​​obtained from the measurements before and after thermal aging. These values ​​were substituted into equation (5) below to obtain the color difference ΔE, which represents the hue change before and after thermal aging. ΔE=[(ΔL*) 2 +(Δa*) 2 +(Δb*) 2 ] 1 / 2 (5) A smaller ΔE indicates better color stability, meaning the polyamide resin composition does not discolor due to thermal aging.

[0169] [Evaluation 2] Flame retardant Measurements were performed using the UL94 method (a standard established by Under Writers Laboratories Inc. in the United States). UL test specimens were used, and the flame retardancy rating was evaluated according to the UL94 standard (vertical combustion test), determining whether it fell into one of three categories: V-0, V-1, or V-2. A lower rating indicates higher flame retardancy.

[0170] [Evaluation 3] Tracking resistance Using flat molded plates, tests were conducted in accordance with IEC 60112 using a tracking resistance tester (manufactured by Yamayo Testing Equipment Co., Ltd.) to calculate the tracking resistance index (CTI). A higher tracking resistance index (CTI) was considered to indicate superior electrical properties.

[0171] [Evaluation 4] Moldability: Mold contamination Using an injection molding machine [NEX50III-5EG: manufactured by Nissei Plastic Co., Ltd.], a cooling time of 25 seconds, screw rotation speed of 200 rpm, mold temperature of 80°C, and molten resin temperature of the polyamide resin composition were set to the melting point (Tm) + 35°C. The injection pressure and injection speed were adjusted as appropriate so that the filling time was within the range of 1.6 ± 0.1 seconds to produce a flat plate molded piece (6 cm × 9 cm, thickness 2 mm). The above molding process was performed 100 times consecutively, and the mold gas vent was visually inspected after the molding was complete. The evaluation criteria for gas generation during molding were as follows. The successful acquisition of molded products without problems was evaluated as contributing to improved productivity. (Evaluation Criteria) A: No deposits were found on the gas vent. B: There is residue on the gas vent. C: There is deposits in the gas vent area, causing it to become clogged. D: There is deposits in the gas vent and it is completely clogged.

[0172] [Evaluation 5] Moldability: Spiral flow length; SFD Pellets of each polyamide resin composition were injection molded using an injection molding machine (Nissei Plastic Industrial Co., Ltd. NEX50IV) with the cylinder temperature set to the melting point of the polyamide resin composition + 35°C and the mold temperature to 80°C. The injection molding was performed under the conditions of 10 seconds of injection, 10 seconds of cooling, and an injection speed of 100 mm / s. The molded material was then placed in a spiral flow mold with a width of 10 mm and a thickness of 2 mm, and the flow length (spiral flow length; SFD) was measured when the limit pressure was set to 70 MPa. A longer SFD indicates better molding fluidity.

[0173] <Manufacturing of polyamide resin compositions> [Example 1] Using a Toshiba Machine Co., Ltd. TEM35mm two - screw extruder (set temperature: 295°C, screw rotation speed 330 rpm), a blend of aliphatic polyamide (A1), semi - aromatic polyamide (A2), primary antioxidant (B), and secondary antioxidant (C) was supplied from the top feed port provided at the uppermost stream part of the extruder. Further, a flame retardant (E) and a reinforcing material (F) were supplied from separate side feed ports, and the melt - kneaded material extruded from the die head was cooled in strand form and pelletized to obtain a polyamide resin composition PA - a1. The mass ratios of each constituent component were as described in Tables 1 and 2.

[0174] [Examples 2 - 23 and Comparative Examples 1 - 10] A polyamide resin composition was obtained in the same manner as in Example 1 except that the constituent components were changed to the configurations described in Tables 1 and 2. In Example 23, coloring was performed using an orange pigment, and it was confirmed by a color sample that it was colored to RAL2003.

[0175] Using the above method, various evaluations were carried out. The evaluation results are shown in Tables 1 and 2 below.

[0176] As shown in the above results, it was confirmed that the polyamide resin composition of this embodiment is excellent in color stability, tracking resistance, flame retardancy, and molding processability after heat aging.

[0177] [Table 1][[ID=%]] °

[0178] [Table 2]

Claims

1. • Polyamide resin (A), - At least one primary antioxidant (B) selected from the group consisting of hindered phenol antioxidants, amine antioxidants, and sulfur antioxidants, and • Contains a phosphorus-based compound as a secondary antioxidant (C), The mass ratio of the primary antioxidant (B) and the secondary antioxidant (C), when the total mass of the primary antioxidant (B) and the secondary antioxidant (C) is set to 100, is within the range of 50:50 to 5:

95. The mass ratio of the primary antioxidant (B) to 100 parts by mass of the polyamide resin (A) is 0.01 to 2.0 parts by mass, and the mass ratio of the secondary antioxidant (C) is 0.01 to 3.0 parts by mass. Polyamide resin composition.

2. The polyamide resin composition according to claim 1, wherein the primary antioxidant (B) is at least one selected from the group consisting of ethylenebis(oxyethylene)bis-(3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate), N,N'-hexane-1,6-diylbis(3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)), pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 2',3-bis[[3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyl]]propionohydrazide, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, and bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate.

3. The polyamide resin composition according to claim 1 or 2, wherein the secondary antioxidant (C) is a metal hypophosphate salt.

4. The polyamide resin composition according to claim 1 or 2, wherein the secondary antioxidant (C) is selected from the group consisting of calcium hypophosphate, magnesium hypophosphate, and hydrates thereof.

5. The polyamide resin composition according to claim 1 or 2, wherein the tanδ peak temperature of the polyamide resin composition is 80°C or higher.

6. The polyamide resin (A) contains an aliphatic polyamide (A1) and a semi-aromatic polyamide (A2) containing diamine units and dicarboxylic acid units. The aliphatic polyamide (A1) is polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 611, polyamide 612, polyamide 1010, or polyamide 66 / 6 copolymer. The polyamide resin composition according to claim 1 or 2, wherein the semi-aromatic polyamide (A2) is polyamide 66 / 6I, polyamide 6T, polyamide 6I, polyamide 6I / 6T, polyamide 4T, polyamide 4T / 6T, polyamide 9T, or polyamide MXD6.

7. The polyamide resin composition according to claim 1 or 2, wherein the polyamide resin composition further comprises at least one selected from the group consisting of a flame retardant (E), a reinforcing agent (F), and a coloring agent (G).

8. The polyamide resin composition according to claim 7, which is colored with the coloring agent (G).

9. The polyamide resin composition according to claim 7, wherein the reinforcing material (F) is glass fiber, the boron content in the glass fiber is 1.0% by mass or less relative to the total mass of the glass fiber, and the mass ratio (Mg / Si) of magnesium (Mg) and silicon (Si) elements contained in the glass fiber is 0.01 to 0.

2.

10. The polyamide resin composition according to claim 1 or 2, wherein the mass ratio of copper elements contained in the polyamide resin composition is 0 to 0.001 parts by mass per 100 parts by mass of the polyamide resin (A).

11. A molded article comprising the polyamide resin composition described in claim 1 or 2.

12. A high-voltage component comprising a molded article as described in claim 11.

13. The high-voltage component according to claim 12, wherein the high-voltage component is selected from the group consisting of covers, housings, relays, battery cell modules, fuse holders, fuse plugs, terminals, cable holders, sheathings, connectors, breaker boxes and high-voltage busbars for hybrid vehicles, electric vehicles or electronic equipment.

Images