Polyamide resin composition and molded article

Abstract

To provide a polyamide resin composition that allows enhanced extrusion workability, molding workability, and flame retardancy in thin-wall portions.SOLUTION: A polyamide resin composition comprising (A) a polyamide, (B) brominated polystyrene, and (C) a flame retardant aid, wherein a number-average area (B-na) of domains of the dispersed (B) brominated polystyrene is 1.3 μm2 or more and 2.2 μm2 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyamide resin composition and a molded article containing the polyamide resin composition. [Background technology]

[0002] Polyamide resins are used in a variety of fields, including automobile parts, machine parts, and electrical and electronic components, due to their excellent strength, heat resistance, and chemical resistance, as well as their excellent specific gravity. Electrical and electronic component applications, in particular, require a high level of flame retardancy, requiring even higher levels of flame retardancy than the self-extinguishing properties inherent to polyamide resins. For this reason, numerous studies have been conducted to achieve compliance with the V-0 rating of the Underwriters Laboratories UL94 standard.

[0003] A typical example of such a flame-retardant polyamide resin is a flame-retardant polyamide material using brominated polystyrene. For example, Patent Document 1 discloses a polyamide resin composition that is excellent in heat resistance, flame retardancy, and flowability in a reflow soldering process, and also has good thermal stability during molding. Patent Document 2 discloses a polyamide resin composition that generates significantly less gas during molding and is extremely less corrosive to molds. Patent Document 3 discloses a polyamide resin composition that is endowed with high flame retardancy, high weld strength, and toughness. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-239842 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-154107 [Patent Document 3] Japanese Patent Application Laid-Open No. 2007-291249 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in recent years, the trend toward thinner walls has been driven by the increasingly complex structures of electrical and electronic components, and there is an increasing demand for materials that have excellent moldability, such as flowability during molding and mold deposit (MD), in addition to the conventional properties of tensile strength and flame retardancy. However, the above-mentioned documents do not necessarily satisfy these requirements.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polyamide resin composition which is excellent in extrusion processability, molding processability, and flame retardancy even when thin-walled. Another object of the present invention is to provide a molded article containing the polyamide resin composition, which has excellent flame retardancy. [Means for solving the problem]

[0007] As a result of extensive research to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by setting the unit area of ​​the domain of the brominated polystyrene contained in the polyamide resin composition within a specific range, and have thus completed the present invention. That is, the present invention includes the following aspects.

[0008] [1] (A) polyamide, (B) brominated polystyrene, and (C) a flame retardant synergist, A polyamide resin composition comprising: The number average area (B-na) of the dispersed brominated polystyrene domains (B) is 1.30 μm 2 More than 2.20μm 2 A polyamide resin composition comprising:

[0009] [2] Of the total domains of the dispersed (B) brominated polystyrene, 0.8 μm 2 The polyamide resin composition according to [1], wherein the proportion of domains of (B) brominated polystyrene having the following area is less than 30%.

[0010] [3] Of the total domains of the dispersed brominated polystyrene (B), 3.0 μm 2 The polyamide resin composition according to [1] or [2], wherein the proportion of domains of (B) brominated polystyrene having an area of ​​at least 10% is less than 20%.

[0011] [4] The polyamide resin composition according to any one of [1] to [3], wherein the viscosity number (VN) of the polyamide (A) is 90 or more and 200 or less.

[0012] [5] The polyamide resin composition according to any one of [1] to [4], wherein the melting point of the (A) polyamide is 200°C or higher and 270°C or lower.

[0013] [6] Furthermore, (D) Inorganic filler, (E) a copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride, and (F) polyphenylene ether modified with an α,β-unsaturated dicarboxylic acid anhydride; The polyamide resin composition according to any one of [1] to [5], comprising:

[0014] [7] Based on 100% by mass of the polyamide resin composition, 20 to 70 mass % of the (A) polyamide, 10 to 35 mass% of the (B) brominated polystyrene, 1 to 15 mass % of the (C) flame retardant synergist, 10 to 60 mass % of the (D) inorganic filler, 0.1 to 1.5 mass % of the (E) copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride, and (F) 1 to 5 mass % of polyphenylene ether modified with an α,β-unsaturated dicarboxylic acid anhydride, A polyamide resin composition comprising: The polyamide resin composition according to [6], wherein the (B) brominated polystyrene has a bromine content of 64 to 71 mass % and a weight average molecular weight of 1,000 to 10,000.

[0015] [8] The polyamide resin composition according to [6] or [7], wherein the ratio Ew / Aw of the mass (Ew) of the (E) copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride to the mass (Aw) of the (A) polyamide is 0.0050 or more and 0.050 or less.

[0016] [9] The polyamide resin composition according to any one of [6] to [8], wherein the α,β-unsaturated dicarboxylic acid anhydride component contained in the (E) copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride is 1 to 40 mass % relative to the total mass of the (E) copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride.

[0017]

[10] The polyamide resin composition according to any one of [6] to [9], wherein the weight average molecular weight of the (E) copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride is 10,000 or more and 250,000 or less.

[0018]

[11] The polyamide resin composition according to any one of [6] to

[10] , wherein the α,β-unsaturated dicarboxylic anhydride component contained in the (F) polyphenylene ether modified with an α,β-unsaturated dicarboxylic anhydride is 0.2 to 1.0 mass% based on the total mass of the (F) polyphenylene ether modified with an α,β-unsaturated dicarboxylic anhydride.

[0019]

[12] A molded article comprising the polyamide resin composition according to any one of [1] to

[11] . [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a polyamide resin composition that is excellent in extrusion processability, molding processability, and flame retardancy even when thin-walled. Furthermore, according to the present invention, it is possible to provide a molded article containing the polyamide resin composition, which has excellent flame retardancy. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention (hereinafter abbreviated as "the present embodiment") will be described in detail. Note that the present invention is not limited to the following embodiment, and various modifications can be made within the scope of the gist of the present invention.

[0022] In this specification, the term "polyamide" refers to a polymer having an amide (-NHCO-) ​​group in the main chain.

[0023] <Polyamide resin composition> The polyamide resin composition of the present embodiment is (A) polyamide, (B) brominated polystyrene, and (C) a flame retardant synergist, A polyamide resin composition comprising: The number-average area (B-na) of the dispersed brominated polystyrene domains is 1.30 μm 2 More than 2.20μm 2 The present invention is characterized by the following: The polyamide resin composition of this embodiment has excellent extrusion processability, molding processability, and flame retardancy even in thin walls. In particular, the polyamide resin composition of this embodiment has excellent flowability during molding, mold deposit (MD), and drip suppression during combustion tests. Furthermore, because the flame retardancy is stable over a wide range of polyamide viscosity, it can also solve the problem of unstable flame retardancy that occurs when using recycled polyamide raw materials.

[0024] ((A) Polyamide) Specific examples of (A) polyamides include, but are not limited to, (a) polyamides obtained by ring-opening polymerization of lactams, (b) polyamides obtained by self-condensation of ω-aminocarboxylic acids, (c) polyamides obtained by condensing diamines and dicarboxylic acids, and copolymers thereof. These polyamides may be used singly or as a mixture of two or more.

[0025] (a) Examples of lactams include, but are not limited to, pyrrolidone, caprolactam, undecalactam, and dodecalactam.

[0026] (b) ω-aminocarboxylic acids include, but are not limited to, ω-amino fatty acids, which are ring-opened compounds of the lactams described above with water. Two or more monomers of each of the lactams and ω-aminocarboxylic acids may be condensed in combination.

[0027] (c) Examples of diamines (monomers) in polyamides obtained by condensing diamines and dicarboxylic acids include, but are not limited to, linear saturated aliphatic diamines having 2 to 20 carbon atoms, such as ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, and tridecamethylenediamine.

[0028] Examples of diamines constituting diamine units having a substituent branched from the main chain include, but are not limited to, branched saturated aliphatic diamines having 3 to 20 carbon atoms, such as 2-methylpentamethylenediamine (also referred to as 2-methyl-1,5-diaminopentane), 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 2-methyl-1,8-octanediamine (also referred to as 2-methyloctamethylenediamine), and 2,4-dimethyloctamethylenediamine. Among these, 2-methylpentamethylenediamine or 2-methyl-1,8-octanediamine is preferred, and 2-methylpentamethylenediamine is more preferred. By including such an aliphatic diamine, the polyamide resin composition tends to have better heat resistance, rigidity, etc.

[0029] The diamine unit preferably has a carbon number of 4 or more and 12 or less, and more preferably 4 or more and 10 or less. When the carbon number is 4 or more, the heat resistance is superior, while when the carbon number is 12 or less, the crystallinity and releasability are superior.

[0030] The aliphatic diamine may further contain a trivalent or higher polyvalent aliphatic amine such as bishexamethylenetriamine, if necessary.

[0031] The diamine may be used alone or in combination of two or more kinds.

[0032] (c) Examples of dicarboxylic acids (monomers) in polyamides obtained by condensing diamines and dicarboxylic acids include, but are not limited to, aliphatic dicarboxylic acids such as succinic acid, adipic acid, pimelic acid, sebacic acid, dodecanedioic acid, and tetradecanedioic acid; aromatic dicarboxylic acids such as isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, and 5-sodiumsulfoisophthalic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid.

[0033] The diamine and dicarboxylic acid as the monomers may be condensed either individually or in combination of two or more.

[0034] The polyamide (A) may further contain, as necessary, units derived from a trivalent or higher polycarboxylic acid such as trimellitic acid, trimesic acid, or pyromellitic acid. The trivalent or higher polycarboxylic acid may be used alone or in combination of two or more.

[0035] In the (A) polyamide, the dicarboxylic acid constituting the dicarboxylic acid unit is not limited to the compounds described above as the dicarboxylic acid, but may be a compound equivalent to the above dicarboxylic acid. Here, the term "compound equivalent to a dicarboxylic acid" refers to a compound that can have a dicarboxylic acid structure similar to the dicarboxylic acid structure derived from the dicarboxylic acid. Examples of such compounds include, but are not limited to, anhydrides and halides of dicarboxylic acids.

[0036] Specific examples of the polyamide (A) used in the polyamide resin composition of this embodiment include polyamide 4 (poly-α-pyrrolidone), polyamide 6 (polycaproamide), polyamide 11 (polyundecaneamide), polyamide 12 (polydodecanamide), polyamide 46 (polytetramethylene adipamide), polyamide 56 (polypentamethylene adipamide), polyamide 66 (polyhexamethylene adipamide), polyamide 610 (polyhexamethylene sebacamide), polyamide 612 (polyhexamethylene dodecamide), polyamide 4T (polytetramethylene terephthalamide), polyamide 6T (polyhexamethylene terephthalamide), polyamide 6I (polyhexamethylene isophthalamide), and polyamide 9T (polynonamethylene terephthalamide), as well as copolymer polyamides containing these as constituent components.

[0037] If the melting point of the polyamide (A) is too high, the flame retardant will decompose during melt processing, resulting in an increase in char (hereinafter referred to as black spots) in the pellets and an increase in gas components, which will reduce melt processability and flame retardancy. If the melting point is too low, the heat resistance of the molded article, such as HDT (deflection temperature under load), will be reduced. Therefore, the melting point (TmA2) of the polyamide (A) used in this embodiment is preferably 180°C or higher and 330°C or lower, and more preferably 200°C or higher and 270°C or lower. Examples of polyamide (A) having such a melting point include polyamide 66, polyamide MXD6, 66 / 6I copolymer polyamide, 66 / 6 copolymer polyamide, 6I / 6T copolymer polyamide, 66 / 6I / 6T terpolymer polyamide, 66 / 6I / 6 terpolymer polyamide, and 6 / 6I / 6T terpolymer polyamide. Also included are polyamide resins having a melting point of 200°C or higher and 270°C or lower that are mixed with low-melting point polyamides such as these polyamides and polyamide 6.

[0038] The (A) polyamide is more preferably polyamide 66, 66 / 6 copolymer polyamide, or 66 / 6I copolymer polyamide, which have excellent moldability and physical properties, and also includes polyamide resins having a melting point (TmA2) of 240° C. or higher and 270° C. or lower that are blended with these polyamides, polyamide 6I, or polyamide 6. The (A) polyamide is most preferably polyamide 66. The melting point can be measured using a Diamond-DSC manufactured by Perkin-Elmer in accordance with JIS-K7121.

[0039] The molecular weight of the polyamide (A) of this embodiment may be within a moldable range. For example, the viscosity number (VN) determined according to ISO 307 is preferably in the range of 90 to 200, more preferably 100 to 185, even more preferably 110 to 160, and even more preferably 130 to 150. From the viewpoint of the balance of fluidity during molding, MD, and flame retardancy, the viscosity number is preferably within the above range. The viscosity number (VN) is measured using 90% formic acid as a solvent at a concentration of 0.5 g (polyamide) sample / 100 ml formic acid at a temperature of 25°C.

[0040] The content of the (A) polyamide in the polyamide resin composition of this embodiment can be 20% by mass or more and 70% by mass or less, for example, 23% by mass or more and 65% by mass or less, or 25% by mass or more and 60% by mass or less, relative to 100% by mass of the polyamide resin composition.

[0041] ((B) Brominated polystyrene) The brominated polystyrene (B) used in this embodiment is added to improve flame retardancy. In order to impart flame retardancy, flowability, and mechanical properties of welds to the polyamide resin composition of this embodiment, it is preferable to use a brominated polystyrene having a specific bromine content and a specific molecular weight. (B) The method for producing brominated polystyrene is not particularly limited, and examples thereof include a method in which styrene monomers are polymerized to produce polystyrene, and then the benzene rings of the polystyrene are brominated, and a method in which brominated styrene monomers (bromostyrene, dibromostyrene, tribromostyrene, etc.) are polymerized to produce the brominated polystyrene.

[0042] The bromine content in (B) brominated polystyrene is preferably 64 to 71% by mass. By setting the bromine content to 64% by mass or more, the amount of bromine required for flame retardancy can be satisfied with a small amount of (B) brominated polystyrene blended, resulting in a polyamide resin composition that is excellent in heat resistance, flowability, toughness, low water absorption, and rigidity, as well as excellent flame retardancy, without impairing the properties of (A) polyamide. Furthermore, by setting the bromine content to 71% by mass or less, a polyamide resin composition that is less likely to undergo thermal decomposition during melt processing such as extrusion or molding, can be suppressed in gas generation, and also has excellent heat discoloration resistance can be obtained. Considering these balances, the bromine content is more preferably 65 to 69% by mass.

[0043] Furthermore, (B) brominated polystyrene is preferably composed of a specific molecular weight, and in order to improve fluidity, the weight average molecular weight (Mw) is preferably 1,000 to 10,000, more preferably 1,000 to 5,000. The weight-average molecular weight (Mw) in this specification can be determined by measurement using GPC (gel permeation chromatography). When the weight-average molecular weight of (B) brominated polystyrene is 1,000 or more, it is less susceptible to thermal decomposition during extrusion processing, improving productivity and flame retardancy after molding. On the other hand, when the weight-average molecular weight (Mw) of (B) brominated polystyrene is 10,000 or less, compatibility with (A) polyamide, (E) copolymer of aromatic vinyl compound and α,β-unsaturated dicarboxylic acid anhydride, and (F) polyphenylene ether modified with α,β-unsaturated dicarboxylic acid anhydride is improved, resulting in a good dispersion state of (B) brominated polystyrene, which tends to improve flame retardancy and toughness.

[0044] The component of (B) brominated polystyrene having a weight average molecular weight (Mw) of 1,000 to 10,000 preferably has a molecular weight distribution (Mw / Mn) of 1.0 to 2.0, more preferably 1.05 to 1.30. By satisfying the above molecular weight distribution, higher fluidity during molding and better mechanical properties of the welds can be obtained.

[0045] In the polyamide resin composition of the present embodiment, the content of (B) brominated polystyrene is preferably 10 to 35 mass %, more preferably 15 to 30 mass %, and even more preferably 17 to 25 mass %, relative to 100 mass % of the polyamide resin composition. By setting the content of (B) brominated polystyrene to 10% by mass or more, a polyamide resin composition with excellent flame retardancy can be obtained. Furthermore, by setting the content of (B) brominated polystyrene to 35% by mass or less, it is possible to suppress the generation of decomposition gases during melt-kneading, the decrease in fluidity during molding, and the adhesion of contaminants to molding dies. Furthermore, it is possible to suppress the deterioration of mechanical properties such as toughness and rigidity, and the appearance of molded articles.

[0046] In the polyamide resin composition of the present embodiment, the number average area (B-na) of the domains of the dispersed (B) brominated polystyrene is 1.30 μm 2 More than 2.20μm 2 Less than or equal to 1.40 μm 2 More than 2.00μm 2 More preferably, it is 1.50 μm or less. 2 More than 1.90μm 2 The number average area (B-na) of the dispersed brominated polystyrene (B) domains is more preferably 1.30 μm or less. 2 By satisfying this requirement, dripping is suppressed and a dispersion layer of (B) brominated polystyrene with sufficient fire-extinguishing properties can be formed, which tends to improve flame retardancy. Furthermore, the contact area between the dispersion layer and the mold is reduced, and the friction coefficient can be reduced, which prevents the resin flow from being impeded, which tends to suppress the occurrence of mold deposits (MD). In addition, the number average area (B-na) of (B) brominated polystyrene is 2.20 μm 2 By ensuring that the brominated polystyrene (B) is sufficiently dispersed, flame retardancy tends to improve. Furthermore, the resin flows uniformly during molding, which tends to suppress the occurrence of MD.

[0047] In the polyamide resin composition of the present embodiment, the dispersed brominated polystyrene (B) has a domain size of 0.8 μm or less. 2The proportion of (B) brominated polystyrene domains having an area of ​​less than 0.8 μm is preferably less than 30%, more preferably less than 25%, and even more preferably less than 20%. 2 When the proportion of domains of (B) brominated polystyrene having the following area is less than 30%, the induction of dripping is suppressed and a dispersed layer of (B) brominated polystyrene with sufficient fire extinguishing ability can be formed, which tends to improve flame retardancy.

[0048] The polyamide resin composition of the present embodiment is characterized in that, of the total domains of the dispersed brominated polystyrene (B), 3.0 μm 2 The proportion of domains of (B) brominated polystyrene having an area of ​​3.0 μm or more is preferably less than 20%, more preferably less than 15%, and even more preferably less than 10%. 2 When the proportion of (B) brominated polystyrene domains having an area of ​​this magnitude or greater is less than 20%, dripping is suppressed and a dispersed layer of (B) brominated polystyrene with sufficient fire extinguishing ability can be formed, which tends to improve flame retardancy.

[0049] In the present embodiment, the method for adjusting the dispersion state of the (B) brominated polystyrene as described above is not particularly limited, and examples thereof include adjusting the weight average molecular weight of the (B) brominated polystyrene to an appropriate range, using in combination (E) a copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic anhydride, and (F) a polyphenylene ether modified with an α,β-unsaturated dicarboxylic anhydride, adjusting the contents of the (E) copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic anhydride and (F) a polyphenylene ether modified with an α,β-unsaturated dicarboxylic anhydride to appropriate ranges, and adjusting the ratio Ew / Aw of the mass (Ew) of the (E) copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic anhydride to the mass (Aw) of the (A) polyamide to an appropriate range. The dispersion state of (B) brominated polystyrene can be determined by observing it with a scanning electron microscope (SEM) to obtain an image of the dispersion state, and then separating the domains of each component from the obtained image by multi-level processing, thereby determining the area per (B) brominated polystyrene domain. Specifically, the dispersion state of (B) brominated polystyrene can be determined by the method described in the Examples below.

[0050] ((C) Flame retardant synergist) The polyamide resin composition of the present embodiment contains a flame retardant aid (C), which allows the polyamide resin composition to have even more excellent flame retardancy.

[0051] The flame retardant aid (C) used in this embodiment is not particularly limited, and examples thereof include antimony oxides such as diantimony trioxide, diantimony tetroxide, diantimony pentoxide, and sodium antimonate; tin oxides such as tin monoxide and tin dioxide; iron oxides such as ferric oxide and γ-iron oxide; metal hydroxides such as magnesium hydroxide and aluminum hydroxide; metal borates such as zinc borate, magnesium borate, calcium borate, and aluminum borate; and silicones. These flame retardant aids (C) may be used alone or in combination of two or more. The flame retardant aid (C) used in this embodiment is preferably at least one selected from antimony oxides, tin oxides, iron oxides, and metal borates, from the viewpoint of flame retardancy effect, more preferably antimony oxides, and particularly preferably diantimony trioxide.

[0052] To improve the flame retardancy, it is preferable to use a flame retardant auxiliary (C) having an average particle size of 0.01 to 10 μm. The average particle size can be measured using a laser diffraction scattering particle size distribution analyzer or a precision particle size distribution analyzer.

[0053] To improve the ease of handling, it is preferable to use the flame retardant synergist (C) as a masterbatch by impregnating the resin with the flame retardant synergist (C). The resin to be impregnated can be freely selected within the range that does not impair the effects of the invention, but polyamide is preferable.

[0054] The content of the (C) flame retardant synergist in the polyamide resin composition is preferably 1 to 15 mass %, more preferably 1.5 to 9 mass %, based on 100 mass % of the polyamide resin composition. By adjusting the content of the (C) flame retardant synergist to 1 mass % or more, a polyamide resin composition with even better flame retardancy can be obtained. Furthermore, by adjusting the content of the (C) flame retardant synergist to 15 mass % or less, a decrease in flowability during molding and a decrease in the appearance of the molded product can be suppressed. Furthermore, a polyamide resin composition with excellent toughness and other properties can be obtained without impairing the properties of the polyamide resin composition, which have excellent mechanical properties such as toughness and rigidity.

[0055] ((D) Inorganic filler) The polyamide resin composition of the present embodiment preferably further contains (D) an inorganic filler, which allows the polyamide resin composition to have even more excellent mechanical properties such as toughness and rigidity. The (D) inorganic filler used in the present embodiment is not particularly limited, and examples thereof include glass fibers, carbon fibers, calcium silicate fibers, potassium titanate fibers, glass flakes, talc, kaolin, mica, hydrotalcite, calcium carbonate, zinc carbonate, calcium hydrogen phosphate, wollastonite, silica, zeolite, alumina, boehmite, titanium oxide, silicon oxide, magnesium oxide, calcium silicate, sodium aluminosilicate, magnesium silicate, ketjen black, acetylene black, furnace black, carbon nanotubes, graphite, brass, copper, silver, aluminum, nickel, iron, calcium fluoride, montmorillonite, swellable fluoromica, and apatite. The (D) inorganic filler may be used alone or in combination of two or more.

[0056] Among the above-mentioned inorganic fillers, glass fiber, carbon fiber, glass flake, talc, kaolin, mica, calcium carbonate, calcium hydrogen phosphate, wollastonite, silica, carbon nanotubes, graphite, calcium fluoride, montmorillonite, swellable fluoromica, and apatite are preferred as the (D) inorganic filler from the viewpoints of rigidity and strength.

[0057] As the (D) inorganic filler, glass fiber and carbon fiber are more preferred, and among glass fiber and carbon fiber, those having a number average fiber diameter of 3 to 30 μm, a weight average fiber length of 100 to 750 μm, and an aspect ratio (L / D) of the weight average fiber length (L) to the number average fiber diameter (D) of 10 to 100 are more preferably used from the viewpoint of exhibiting high properties.

[0058] Furthermore, as the (D) inorganic filler, glass fibers are more preferred, and among glass fibers, those having a number average fiber diameter of 3 to 30 μm, a weight average fiber length of 10 to 500 μm, and an aspect ratio (L / D) of 3 to 100 are even more preferably used.

[0059] The number-average fiber diameter and weight-average fiber length of the (D) inorganic filler can be measured by dissolving a molded product of a polyamide resin composition in a solvent in which polyamide is soluble, such as formic acid, and then arbitrarily selecting, for example, 100 or more inorganic fillers from the insoluble components obtained, and observing them with an optical microscope, a scanning electron microscope, or the like.

[0060] The content of (D) inorganic filler in the polyamide resin composition is preferably 10 to 60 mass%, more preferably 13 to 50 mass%, and even more preferably 15 to 40 mass%, based on 100 mass% of the polyamide resin composition. By containing 10 mass% or more of (D) inorganic filler, the mechanical properties such as strength and rigidity of the polyamide resin composition are improved favorably, and by keeping the content of inorganic filler at 60 mass% or less, an increase in resin temperature is suppressed, and a polyamide resin composition with excellent extrusion processability and moldability can be obtained.

[0061] ((E) Copolymer of aromatic vinyl compound and α,β-unsaturated dicarboxylic acid anhydride) The polyamide resin composition of the present embodiment preferably further contains (E) a copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride. (E) Examples of the α,β-unsaturated dicarboxylic acid anhydride in the copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride include compounds represented by the following general formula (1). [ka]

[0062] In general formula (1), R 1 and R 2 each independently represents hydrogen or an alkyl group having 1 to 3 carbon atoms.

[0063] (E) Examples of the α,β-unsaturated dicarboxylic anhydride in the copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic anhydride include maleic anhydride and methylmaleic anhydride, with maleic anhydride being preferred. Examples of the polymer containing an α,β-unsaturated dicarboxylic anhydride as a copolymerization component include copolymers of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic anhydride.

[0064] (E) Examples of the aromatic vinyl compound in the copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride include compounds represented by the following general formula (2). [ka]

[0065] In general formula (2), R 3 and R 4 each independently represents hydrogen or an alkyl group having 1 to 3 carbon atoms; and k is an integer of 1 to 5.

[0066] Examples of aromatic vinyl compounds include styrene, α-methylstyrene, and p-methylstyrene, with styrene being preferred among these.

[0067] In this embodiment, when the polymer containing an α,β-unsaturated dicarboxylic acid anhydride contains an aromatic vinyl compound component, it is believed that the aromatic vinyl compound component has affinity with the brominated polystyrene (B), and the α,β-unsaturated dicarboxylic acid anhydride portion has affinity with or reacts with the polyamide (A), thereby helping to disperse and finely disperse the brominated polystyrene (B) in the polyamide matrix.

[0068] The proportions of the aromatic vinyl compound component and the α,β-unsaturated dicarboxylic anhydride component in the (E) copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic anhydride are preferably 60 to 99 mass% for the aromatic vinyl compound component and 1 to 40 mass% for the α,β-unsaturated dicarboxylic anhydride component, from the viewpoints of flame retardancy, extrusion processability, flowability, thermal decomposition resistance, etc. The proportion of the α,β-unsaturated dicarboxylic anhydride component in the (E) copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic anhydride component is more preferably 5 to 30 mass%, and even more preferably 8 to 20 mass%.

[0069] The weight average molecular weight of the (E) copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride is preferably 10,000 or more and 250,000 or less from the viewpoints of flame retardancy, extrusion processability, etc., and more preferably 80,000 or more and 200,000 or less from the viewpoints of flowability and thermal decomposition resistance.

[0070] The content of (E) the copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride in the polyamide resin composition is preferably 0.1 to 1.5 mass%, more preferably 0.15 to 1 mass%, and even more preferably 0.2 to 0.7 mass%, based on 100 mass% of the polyamide resin composition, from the viewpoints of strand stability and flowability during extrusion. By including (E) the copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride in the range of 0.1 to 1.5 mass%, the effect of finely dispersing (B) the brominated polystyrene in the polyamide resin composition due to compatibilization can be enhanced, and a polyamide resin composition can be obtained that is excellent in the effects of improving flame retardancy and strength due to its drip-suppressing effect.

[0071] In particular, setting the ratio Ew / Aw of the mass (Ew) of the copolymer of (E) an aromatic vinyl compound and an α,β-unsaturated dicarboxylic anhydride to the mass (Aw) of the polyamide in the polyamide resin composition within a specific range is an effective method for controlling the dispersion area of ​​the brominated polystyrene (B). The ratio Ew / Aw of the mass (Ew) of the copolymer of (E) an aromatic vinyl compound and an α,β-unsaturated dicarboxylic anhydride to the mass (Aw) of the polyamide (A) is preferably 0.0050 or more and 0.050 or less, more preferably 0.0060 or more and 0.0150 or less, and even more preferably 0.0070 or more and 0.010 or less. By setting Ew / Aw to 0.0050 or more and 0.050 or less, the dispersion area can be made uniform, which can be expected to further improve flame retardancy and strength, and tends to further suppress MD generation during molding.

[0072] ((F) Polyphenylene ether modified with α,β-unsaturated dicarboxylic acid anhydride) The polyamide resin composition of the present embodiment preferably further contains polyphenylene ether modified with an α,β-unsaturated dicarboxylic acid anhydride. (F) Polyphenylene ether modified with an α,β-unsaturated dicarboxylic acid anhydride is a polyphenylene ether based on a polyphenylene ether represented by general formula (3) (wherein R5 and R6 represent alkyl groups having 1 to 4 carbon atoms, and n is 60 to 300), and having an α,β-unsaturated dicarboxylic acid anhydride structure as part of the substituent. [ka]

[0073] Preferred specific examples of the polyphenylene ether represented by the above general formula (3) include poly(2,6-dimethylphenylene-1,4-ether), poly(2-methyl-6-ethylphenylene-1,4-ether), poly(2,6-diethylphenylene-1,4-ether), poly(2-methyl-6-n-propylphenylene-1,4-ether), etc. Examples of the α,β-unsaturated dicarboxylic acid anhydride include maleic anhydride and methylmaleic anhydride, with maleic anhydride being preferred.

[0074] Furthermore, the modification rate of (F) α,β-unsaturated dicarboxylic acid anhydride-modified polyphenylene ether with α,β-unsaturated dicarboxylic acid anhydride is preferably 0.2 to 1.0%, more preferably 0.3 to 0.6%, from the viewpoints of flame retardancy and weld strength.

[0075] The α,β-unsaturated dicarboxylic anhydride component contained in (F) α,β-unsaturated dicarboxylic anhydride-modified polyphenylene ether is preferably 0.2 to 1.0 mass % based on the total mass of (F) α,β-unsaturated dicarboxylic anhydride-modified polyphenylene ether.

[0076] The content of (F) polyphenylene ether modified with an α,β-unsaturated dicarboxylic acid anhydride in the polyamide resin composition is preferably 1.0 to 5.0 mass%, more preferably 2.0 to 3.0 mass%, based on 100 mass% of the polyamide resin composition. By including (F) in the range of 1.0 to 5.0 mass%, the effect of finely dispersing (B) brominated polystyrene in the polyamide resin composition due to compatibilization can be enhanced, and a polyamide resin composition can be obtained that is excellent in improving flame retardancy and strength due to its drip-suppressing effect.

[0077] (Other ingredients) The polyamide resin composition of the present embodiment may further contain, in addition to the above-mentioned (A) polyamide, (B) brominated polystyrene, (C) flame retardant aid, (D) inorganic filler, (E) copolymer of aromatic vinyl compound and α,β-unsaturated dicarboxylic acid anhydride, and (F) α,β-unsaturated dicarboxylic acid anhydride-modified polyphenylene ether, one or more components selected from the group consisting of (G) lubricant, (H) heat stabilizer, (I) other resin, and (J) other additive.

[0078] [(G) Lubricant] The (G) lubricant is not particularly limited, and examples thereof include higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, and higher fatty acid amides. The lubricant can also be used as a molding improver. By adding a (G) lubricant to the polyamide resin composition of the present embodiment, which is dispersed in the (A) polyamide to form domains, molecular mobility can be further improved, and plasticization properties, mold releasability, and impact resistance under low-temperature conditions can be further improved. The lubricant (G) may be used alone or in combination of two or more.

[0079] -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 the linear saturated aliphatic monocarboxylic acid having from 8 to 40 carbon atoms include lauric acid, palmitic acid, stearic acid, behenic acid, and montanic acid. Examples of branched saturated aliphatic monocarboxylic acids having 8 to 40 carbon atoms include isopalmitic acid and isostearic acid. Examples of the linear unsaturated aliphatic monocarboxylic acid having from 8 to 40 carbon atoms include oleic acid and erucic acid. Examples of branched unsaturated aliphatic monocarboxylic acids having 8 to 40 carbon atoms include isooleic acid. Among these, stearic acid or montanic acid is preferred as the higher fatty acid.

[0080] -Higher fatty acid metal salts- The higher fatty acid metal salt is a metal salt of a higher fatty acid. Examples of the metal element of the metal salt include Group 1 elements, Group 2 elements, and Group 3 elements of the periodic table, zinc, aluminum, and the like. 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. Among these, Group 1 and Group 2 elements of the periodic table, or aluminum are preferred, and sodium, potassium, calcium, magnesium, or aluminum is more preferred. Examples of higher fatty acids include the higher fatty acids described above in the section on higher fatty acids. Specific examples of higher fatty acid metal salts include calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, calcium montanate, sodium montanate, calcium palmitate, and the like. Among these, metal salts of higher fatty acids are preferably metal salts of montanic acid or metal salts of stearic acid.

[0081] -Higher fatty acid esters- The higher fatty acid ester is an ester of a higher fatty acid and an alcohol. The higher fatty acid ester is preferably an ester of an aliphatic carboxylic acid having 8 to 40 carbon atoms and an aliphatic alcohol having 8 to 40 carbon atoms. Examples of the aliphatic alcohol having 8 to 40 carbon atoms include stearyl alcohol, behenyl alcohol, and lauryl alcohol. Specific examples of higher fatty acid esters include stearyl stearate and behenyl behenate.

[0082] -Higher fatty acid amide- Higher fatty acid amides are amide compounds of higher fatty acids. The higher fatty acid amide is not particularly limited, but examples thereof include stearic acid amide, oleic acid amide, erucic acid amide, ethylene bisstearylamide, ethylene bisoleylamide, N-stearyl stearic acid amide, and N-stearyl erucic acid amide. These higher fatty acids, higher fatty acid metal salts, higher fatty acid esters and higher fatty acid amides may be used singly or in combination of two or more.

[0083] The content of the (G) lubricant is preferably 0.01% by mass or more and 1% by mass or less, more preferably 0.05% by mass or more and 0.5% by mass or less, and even more preferably 0.08% by mass or more and 0.2% by mass or less, based on the total mass of the polyamide resin composition. By setting the content of the lubricant in the range of 0.01 mass % or more and 1 mass % or less relative to the total amount of the polyamide resin composition, the effect of further improving the mold releasability, surface appearance, and impact resistance of the obtained molded body is exerted.

[0084] Furthermore, when a higher fatty acid metal salt and a higher fatty acid amide are combined as the lubricant (G), the dispersibility of the lubricants is improved, thereby further improving molecular mobility and impact resistance at low temperatures. The mass ratio of the higher fatty acid metal salt to the higher fatty acid amide (mass% of higher fatty acid metal salt / mass% of higher fatty acid amide) is preferably 0.3 to 5.0, more preferably 0.5 to 4.0, even more preferably 1.0 to 3.5, even more preferably 1.5 to 3.4, and particularly preferably 2.0 to 3.0. By setting the mass ratio of the higher fatty acid metal salt to the higher fatty acid amide within the above upper and lower limits, the mold releasability, surface appearance, and impact resistance of the resulting molded article are further improved.

[0085] [(H) Heat stabilizer] (H) Heat stabilizers include, but are not limited to, phenol-based heat stabilizers, phosphorus-based heat stabilizers, amine-based heat stabilizers, metal salts of elements of Groups 3, 4, and 11 to 14 of the periodic table, and alkali metal and alkaline earth metal halides.

[0086] -Phenol-based heat stabilizer- Examples of phenol-based heat stabilizers include, but are not limited to, hindered phenol compounds, etc. Hindered phenol compounds have the property of imparting excellent heat resistance and light resistance to resins such as polyamides and fibers.

[0087] Examples of the hindered phenol compound include, but are not limited to, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide], pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionamide], and methyl ... nate], 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid, and the like. These hindered phenol compounds may be used alone or in combination of two or more. In particular, from the viewpoint of improving heat aging resistance, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)] is preferred as the hindered phenol compound.

[0088] When a phenolic heat stabilizer is used, the content of the phenolic heat stabilizer 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. When the content of the phenolic heat stabilizer is within the above range, the heat aging resistance of the polyamide resin composition can be further improved, and the amount of gas generation can be further reduced.

[0089] -Phosphorus-based heat stabilizer- Examples of phosphorus-based heat stabilizers include, but are not limited to, pentaerythritol-type phosphite compounds, trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl diphenyl phosphite, trisisodecyl phosphite, phenyl diisodecyl phosphite, phenyl di(tridecyl) phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, diphenyl (tridecyl) phosphite, triphenyl phosphite, tris(nonyl) phosphite, tris(2,4-di-tert-butylphenyl)phosphite, tris(2,4-di-tert-butyl-5-methylphenyl)phosphite, tris(butoxyethyl)phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenyl-tetra-tridecyl)diphosphite, tetra(C12-C15 mixed alkyl)-4,4'-isopropylidenediphenyldiphosphite, 4,4'-isopropylidenebis(2-tert-butylphenyl)-di(no tris(biphenyl)phosphite, tetra(tridecyl)-1,1,3-tris(2-methyl-5-tert-butyl-4-hydroxyphenyl)butane diphosphite, tetra(tridecyl)-4,4'-butylidenebis(3-methyl-6-tert-butylphenyl)diphosphite, tetra(C1-C15 mixed alkyl)-4,4'-isopropylidenediphenyl diphosphite, tris(mono- and di-mixed nonylphenyl)phosphite, 4,4'-isopropylidenebis(2 -tert-butylphenyl)-di(nonylphenyl)phosphite, 9,10-di-hydro-9-oxa-9-oxa-10-phosphaphenanthrene-10-oxide, tris(3,5-di-tert-butyl-4-hydroxyphenyl)phosphite, hydrogenated-4,4'-isopropylidenediphenyl polyphosphite, bis(octylphenyl)-bis(4,4'-butylidenebis(3-methyl-6-tert-butylphenyl))-1,6-hexanol diphosphite, hexatridecyl-1,1,Examples of such phosphite include 3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)diphosphite, tris(4,4'-isopropylidenebis(2-tert-butylphenyl))phosphite, tris(1,3-stearoyloxyisopropyl)phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octylphosphite, 2,2-methylenebis(3-methyl-4,6-di-tert-butylphenyl)2-ethylhexylphosphite, tetrakis(2,4-di-tert-butyl-5-methylphenyl)-4,4'-biphenylene diphosphite, and tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphite. These phosphorus-based heat stabilizers may be used alone or in combination of two or more. Among these, from the viewpoint of further improving the heat aging resistance of the polyamide resin composition and reducing the amount of gas generated, the phosphorus-based heat stabilizer is preferably at least one selected from the group consisting of pentaerythritol-type phosphite compounds and tris(2,4-di-tert-butylphenyl)phosphite.

[0090] Examples of the pentaerythritol phosphite compound include, but are not limited to, 2,6-di-tert-butyl-4-methylphenyl-phenyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-methyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-2-ethylhexyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-isodecyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-isodecyl-pentaerythritol diphosphite, 6-di-tert-butyl-4-methylphenyl-lauryl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-isotridecyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-stearyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-cyclohexyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-benzyl-pentaerythritol diphosphite, 2,6-Di-tert-butyl-4-methylphenyl ethyl cellosolve-pentaerythritol diphosphite, 2,6-Di-tert-butyl-4-methylphenyl-butylcarbitol-pentaerythritol diphosphite, 2,6-Di-tert-butyl-4-methylphenyl-octylphenyl-pentaerythritol diphosphite, 2,6-Di-tert-butyl-4-methylphenyl-nonylphenyl pentaerythritol diphosphite, Bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-ethylphenyl)pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-2,6-di-tert-butylphenyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-2,4-di-tert-butylphenyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-2,4-di-tert-octylphenyl-pentaerythritol diphosphite, 2,Examples include 6-di-tert-butyl-4-methylphenyl-2-cyclohexylphenyl-pentaerythritol diphosphite, 2,6-di-tert-amyl-4-methylphenyl-phenyl pentaerythritol diphosphite, bis(2,6-di-tert-amyl-4-methylphenyl)pentaerythritol diphosphite, and bis(2,6-di-tert-octyl-4-methylphenyl)pentaerythritol diphosphite. These pentaerythritol-type phosphite compounds may be used alone or in combination of two or more. Among these, from the viewpoint of reducing the amount of gas generated from the polyamide resin composition, the pentaerythritol phosphite compound is preferably one or more selected from the group consisting of bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-ethylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-amyl-4-methylphenyl)pentaerythritol diphosphite, and bis(2,6-di-tert-octyl-4-methylphenyl)pentaerythritol diphosphite, and more preferably bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite.

[0091] When a phosphorus-based heat stabilizer is used, the content of the phosphorus-based heat stabilizer in the polyamide resin composition is preferably 0.01% 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. When the content of the phosphorus-based heat stabilizer is within the range of 0.01% by mass or more and 1% by mass or less, the heat aging resistance of the polyamide resin composition can be further improved and the amount of gas generation can be further reduced.

[0092] -Amine-based heat stabilizer- Examples of the amine-based heat stabilizer include, but are not limited to, 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(phenylacetoxy)-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-methoxy-2,2,6,6-tetramethylpiperidine, and 4-stearyloxy-2,2,6,6-tetramethylpiperidine. 4-cyclohexyloxy-2,2,6,6-tetramethylpiperidine, 4-benzyloxy-2,2,6,6-tetramethylpiperidine, 4-phenoxy-2,2,6,6-tetramethylpiperidine, 4-(ethylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(cyclohexylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(phenylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, bis(2,2,6,6-tetramethyl-4-piperidyl)-carbonate, bis( 2,2,6,6-tetramethyl-4-piperidyl)-oxalate, bis(2,2,6,6-tetramethyl-4-piperidyl)-malonate, bis(2,2,6,6-tetramethyl-4-piperidyl)-sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl)-adipate, bis(2,2,6,6-tetramethyl-4-piperidyl)-terephthalate, 1,2-bis(2,2,6,6-tetramethyl-4-piperidyloxy)-ethane, α,α'-bis(2,2,6,6-tetramethyl-4-piperidyloxy)-p-xylene, biphenyl Bis(2,2,6,6-tetramethyl-4-piperidyl)tolylene-2,4-dicarbamate, bis(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylene-1,6-dicarbamate, tris(2,2,6,6-tetramethyl-4-piperidyl)-benzene-1,3,5-tricarboxylate, tris(2,2,6,6-tetramethyl-4-piperidyl)-benzene-1,3,4-tricarboxylate, 1-[2-{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy}butyl]-4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]2,2,6,6-tetramethylpiperidine, a condensation product of 1,2,3,4-butanetetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinol, and β,β,β',β'-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro(5,5)undecane]diethanol, etc. These amine-based heat stabilizers may be used alone or in combination of two or more.

[0093] When an amine-based heat stabilizer is used, the content of the amine-based heat stabilizer in the polyamide resin composition is preferably 0.01% 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. When the content of the amine-based heat stabilizer is in the range of 0.01% by mass or more and 1% by mass or less, the heat aging resistance of the obtained molded body can be further improved, and the amount of gas generation can be further reduced.

[0094] -Metal salts of elements in groups 3, 4, and 11 to 14 of the periodic table- There are no particular limitations on the metal salts of elements in Groups 3, 4, and 11 to 14 of the periodic table, as long as they are salts of metals belonging to these groups. Among these, copper salts are preferred from the viewpoint of further improving the heat aging resistance of the resulting molded article. Examples of such copper salts include, but are not limited to, copper halides, copper acetate, copper propionate, copper benzoate, copper adipate, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate, copper stearate, and copper complex salts in which copper is coordinated with a chelating agent. Examples of copper halides include copper iodide, copper (I) bromide, copper (II) bromide, and copper (I) chloride. Examples of the chelating agent include ethylenediamine and ethylenediaminetetraacetic acid. These copper salts may be used alone or in combination of two or more. Among them, the copper salt is preferably at least one selected from the group consisting of copper iodide, copper (I) bromide, copper (II) bromide, copper (I) chloride, and copper acetate, and more preferably at least one selected from the group consisting of copper iodide and copper acetate. When the above-mentioned preferred copper salts are used, a polyamide resin composition can be obtained that is more excellent in heat aging resistance and can more effectively suppress metal corrosion of the screw and cylinder during extrusion (hereinafter, sometimes simply referred to as "metal corrosion").

[0095] When a copper salt is used as the (H) heat stabilizer, the content of the copper salt in the polyamide resin composition is preferably 0.01 parts by mass or more and 0.60 parts by mass or less, and more preferably 0.02 parts by mass or more and 0.40 parts by mass or less, per 100 parts by mass of the (A) polyamide. When the content of the copper salt is within the above range, the heat aging resistance of the polyamide resin composition tends to be further improved, and copper precipitation and metal corrosion tend to be more effectively suppressed.

[0096] In addition, the content of copper element derived from the copper salt is set to be 100% or less of (A) polyamide 10 from the viewpoint of improving the heat aging resistance of the polyamide resin composition. 6 The amount is preferably 10 to 2000 parts by mass, more preferably 30 to 1500 parts by mass, and even more preferably 50 to 500 parts by mass, per 1 million parts by mass.

[0097] (Alkali metal and alkaline earth metal halides) Halides of alkali metals and alkaline earth metals include, but are not limited to, potassium iodide, potassium bromide, potassium chloride, sodium iodide, sodium chloride, and the like. These alkali metal and alkaline earth metal halides may be used alone or in combination of two or more. Among these, from the viewpoint of improving heat aging resistance and suppressing metal corrosion, the alkali metal and alkaline earth metal halides are preferably at least one selected from the group consisting of potassium iodide and potassium bromide, and more preferably potassium iodide.

[0098] When alkali metal and alkaline earth metal halides are used, the content of the alkali metal and alkaline earth metal halides in the polyamide resin composition is preferably 0.05 parts by mass or more and 20 parts by mass or less, and more preferably 0.2 parts by mass or more and 10 parts by mass or less, per 100 parts by mass of the total mass of the (A) polyamide and the (B) crystalline semi-aromatic polyamide. By ensuring that the content of alkali metal and alkaline earth metal halides is within the above range, the heat aging resistance of the resulting molded body is further improved, and copper precipitation and metal corrosion can be more effectively suppressed.

[0099] The components of the heat stabilizer (H) explained above may be used alone or in combination of two or more. Among these, the heat stabilizer (H) is preferably a mixture of a copper salt and a halide of an alkali metal or alkaline earth metal, from the viewpoint of further improving the heat aging resistance of the resulting molded article.

[0100] The content ratio of the copper salt and the alkali metal and alkaline earth metal halides is preferably 2 / 1 or more and 40 / 1 or less, more preferably 5 / 1 or more and 30 / 1 or less, in terms of the molar ratio of halogen to copper (halogen / copper). When the molar ratio of halogen to copper (halogen / copper) is within the above range, the heat aging resistance of the resulting molded article tends to be further improved. Furthermore, when the molar ratio of halogen to copper (halogen / copper) is equal to or greater than the above lower limit, copper precipitation and metal corrosion tend to be more effectively inhibited. On the other hand, when the molar ratio of halogen to copper (halogen / copper) is equal to or less than the above upper limit, corrosion of the screw and the like of the molding machine tends to be more effectively prevented without substantially impairing the mechanical properties (toughness, etc.) of the molded article.

[0101] [(I) Other resins] If necessary, (I) other resins may be added to the polyamide resin composition of the present embodiment, as long as the object of the present embodiment is not impaired. (I) Other resins are not particularly limited, but examples thereof include thermoplastic resins and rubber components, which will be described later.

[0102] Examples of the thermoplastic resin include polystyrene-based resins such as atactic polystyrene, isotactic polystyrene, syndiotactic polystyrene, AS resin, and ABS resin; polyester-based resins such as polyethylene terephthalate and polybutylene terephthalate; other polyamides such as nylon 6, 66, and 612 (polyamides other than the (A) polyamide used in this embodiment); polyether-based resins such as polycarbonate, polyphenylene ether, polysulfone, and polyethersulfone; condensation-based resins such as polyphenylene sulfide and polyoxymethylene; acrylic-based resins such as polyacrylic acid, polyacrylic acid ester, and polymethyl methacrylate; polyolefin-based resins such as polyethylene, polypropylene, polybutene, and ethylene-propylene copolymer; halogen-containing vinyl compound-based resins such as polyvinyl chloride and polyvinylidene chloride; phenolic resins; and epoxy resins. These thermoplastic resins may be used singly or in combination of two or more.

[0103] Examples of the rubber component include natural rubber, polybutadiene, polyisoprene, polyisobutylene, neoprene, polysulfide rubber, thiokol rubber, acrylic rubber, urethane rubber, silicone rubber, epichlorohydrin rubber, styrene-butadiene block copolymer (SBR), hydrogenated styrene-butadiene block copolymer (SEB), styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), styrene-isoprene block copolymer (SIR), hydrogenated styrene-isoprene block copolymer (SEP), styrene-isoprene-styrene block copolymer (SIS), hydrogenated styrene-isoprene-styrene block copolymer (SEPS), styrene-butadiene random copolymer, hydrogenated styrene-butadiene random copolymer, and styrene-ethylene-propylene random copolymer. , styrene-ethylene-butylene random copolymer, ethylene-propylene copolymer (EPR), ethylene-(1-butene) copolymer, ethylene-(1-hexene) copolymer, ethylene-(1-octene) copolymer, ethylene-propylene-diene copolymer (EPDM), as well as core-shell types such as butadiene-acrylonitrile-styrene-core-shell rubber (ABS), methyl methacrylate-butadiene-styrene-core-shell rubber (MBS), methyl methacrylate-butyl acrylate-styrene-core-shell rubber (MAS), octyl acrylate-butadiene-styrene-core-shell rubber (MABS), alkyl acrylate-butadiene-acrylonitrile-styrene-core-shell rubber (AABS), butadiene-styrene-core-shell rubber (SBR), and siloxane-containing core-shell rubbers such as methyl methacrylate-butyl acrylate siloxane. These rubber components may be used singly or in combination of two or more.

[0104] [(J) Other additives] In addition to the above components, the polyamide resin composition of this embodiment may contain (J) other additives commonly used in polyamide resin compositions, provided that the effects of the present invention are not impaired. Examples of (J) other additives include colorants such as pigments and dyes (including colored masterbatches), flame retardants (excluding (B) brominated polystyrene), fibrillating agents, fluorescent bleaching agents, plasticizers, antioxidants, ultraviolet absorbers, antistatic agents, flow improvers, and spreading agents.

[0105] When the polyamide resin composition of the present embodiment contains other additives, the content of the (J) other additives varies depending on the type of additive and the intended use of the polyamide resin composition, and is not particularly limited as long as it is within a range that does not impair the effects of the present invention.

[0106] (Method of producing polyamide resin composition) The method for producing the polyamide resin composition of this embodiment is not particularly limited as long as it is a method of mixing (A) polyamide, (B) brominated polystyrene, and (C) a flame retardant aid, and optionally (D) an inorganic filler, (E) a copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride, and (F) a polyphenylene ether modified with an α,β-unsaturated dicarboxylic acid anhydride.

[0107] As a method for mixing (A) polyamide, (B) brominated polystyrene, (C) flame retardant synergist, (D) inorganic filler, (E) copolymer of aromatic vinyl compound and α,β-unsaturated dicarboxylic anhydride, and (F) α,β-unsaturated dicarboxylic anhydride-modified polyphenylene ether, for example, a method for mixing (A) polyamide, (B) brominated polystyrene, (C) flame retardant synergist, and (D) inorganic filler, (E) copolymer of aromatic vinyl compound and α,β-unsaturated dicarboxylic anhydride, and (F) polyphenylene ether modified with α,β-unsaturated dicarboxylic anhydride is used. and a method in which at least one of the above-mentioned compounds is mixed using a Henschel mixer or the like, and the mixture is fed to a melt kneader and kneaded; or a method in which (A) polyamide, (B) brominated polystyrene, (C) flame retardant aid, (D) inorganic filler, (E) copolymer of aromatic vinyl compound and α,β-unsaturated dicarboxylic anhydride, and (F) α,β-unsaturated dicarboxylic anhydride-modified polyphenylene ether are mixed in advance using a Henschel mixer or the like in a single-screw or twin-screw extruder, and the mixture is fed to a melt kneader and kneaded, and then, optionally, (D) inorganic filler is added from a side feeder.

[0108] The components constituting the polyamide resin composition may be supplied to the melt kneader by supplying all of the components to the same supply port at once, or by supplying each component from a different supply port.

[0109] The melt-kneading temperature is preferably about 1 to 100° C. higher than the melting point of the (A) polyamide, and more preferably about 10 to 50° C. higher than the melting point of the (A) polyamide. The shear rate in the mixer is 100 sec -1 The average residence time during kneading is preferably about 0.5 to 5 minutes. As the melt-kneading device, known devices such as a single-screw or twin-screw extruder, a Banbury mixer, and a mixing roll are preferably used.

[0110] The amount of each component blended when producing the polyamide resin composition of the present embodiment is the same as the content of each component in the polyamide resin composition described above.

[0111] <Molded body> The molded article of this embodiment contains the polyamide resin composition of this embodiment. The molded article of this embodiment can suppress the occurrence of MD during molding, and further has excellent toughness, heat resistance, and flame retardancy, and can be used in a variety of applications. The molded article of this embodiment can be suitably used in, for example, the automotive field, the electrical and electronic field, the mechanical and industrial field, the office equipment field, and the aerospace field.

[0112] (Method of manufacturing a molded body) By molding the polyamide resin composition of the present embodiment, a molded article containing a predetermined polyamide resin composition can be obtained. The method for obtaining the molded body is not particularly limited, and any known molding method can be used. Examples of molding methods include extrusion molding, injection molding, vacuum molding, blow molding, injection compression molding, decorative molding, other material molding, gas-assisted injection molding, foam injection molding, low-pressure molding, ultra-thin-wall injection molding (ultra-high-speed injection molding), and in-mold composite molding (insert molding, outsert molding). [Example]

[0113] 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.

[0114] First, the components, measurement methods, and evaluation methods used in the examples and comparative examples are shown below. 2 means 0.098 MPa.

[0115] <Components> [(A) Polyamide] A-1: Polyamide 66 (VN=140, TmA2=265°C) A-2: Polyamide 66 (VN=130, TmA2=265°C) A-3: Polyamide 66 (VN=120, TmA2=265°C) A-4: Polyamide 66 (VN=195, TmA2=265°C)

[0116] [(B) Brominated polystyrene] B-1: Brominated polystyrene (manufactured by ALBEMARLECORPORATION, trade name SAYTEX (registered trademark) HP-3010PST (Mw=3557, Mn=2978, Mw / Mn=1.16) B-2: Brominated polystyrene (manufactured by ALBEMARLE CORPORATION, trade name SAYTEX (registered trademark) HP-7010G (Mw=147109, Mn=55982, Mw / Mn=2.63)

[0117] [(C) Flame retardant synergist] C-1: Antimony trioxide (manufactured by Campine, trade name: Antimony trioxide)

[0118] [(D) Inorganic filler] D-1: Glass fiber (GF) (manufactured by Megashi Group Co., Ltd., product name ECS10-03-568H, average fiber diameter 10 μmφ, cut length 3 mm)

[0119] [(E) Copolymer of aromatic vinyl compound and α,β-unsaturated dicarboxylic acid anhydride] E-1: Styrene and maleic anhydride copolymer (manufactured by Polyscope, trade name SZ15170, Mw=170000, copolymer of 85% by mass of styrene and 15% by mass of maleic anhydride) E-2: Styrene and maleic anhydride copolymer (manufactured by Polyscope, trade name XIBOND220, Mw=15000, copolymer of 89% by mass of styrene and 11% by mass of maleic anhydride) E-3: Styrene and maleic anhydride copolymer (manufactured by Polyscope, trade name XIBOND280, Mw=5000, copolymer of 57% by mass of styrene and 43% by mass of maleic anhydride)

[0120] [(F) Polyphenylene ether modified with α,β-unsaturated dicarboxylic acid anhydride] F-1: Modified polyphenylene ether (maleic anhydride addition rate = 0.5%) F-2: Modified polyphenylene ether (maleic anhydride addition rate = 0.1%)

[0121] [Antioxidants] Irganox 1098 (BASF)

[0122] (A) Polyamide and (F) polyphenylene ether modified with an α,β-unsaturated dicarboxylic acid anhydride were produced by the following method. [Manufacturing Example 1] (Production of Polyamide A-1 (Polyamide 66)) The polymerization reaction of polyamide was carried out by the "hot melt polymerization method" as follows. 1500 g of an equimolar salt of adipic acid and hexamethylenediamine was dissolved in 1500 g of distilled water to prepare a homogeneous aqueous solution containing 50% by weight of the raw material monomers. This aqueous solution was placed in a 5.4 L autoclave and purged with nitrogen. Next, the solution was concentrated by gradually removing water vapor to a solution concentration of 70% by weight while stirring at a temperature of 110°C to 150°C. The internal temperature was then raised to 220°C. The autoclave was then pressurized to 1.8 MPa. The reaction was continued for 1 hour while gradually removing water vapor to maintain the pressure at 1.8 MPa until the internal temperature reached 245°C. The pressure was then reduced over 1 hour. The autoclave was then maintained at a reduced pressure of 650 torr (86.66 kPa) for 10 minutes using a vacuum device. The final internal temperature of the polymerization was 265°C. The mixture was then pressurized with nitrogen to form strands from the lower spinneret (nozzle), cooled with water, cut, and discharged as pellets, which were then dried at 100°C in a nitrogen atmosphere for 12 hours to obtain Polyamide A-1 (Polyamide 66). Polyamide A-1 (Polyamide 66) had a VN of 140 and a TmA2 of 265°C.

[0123] [Manufacturing Example 2] (Production of Polyamide A-2 (Polyamide 66)) Polyamide polymerization reaction was carried out in the same manner as in Production Example 1 ("melt polymerization method"), except that the autoclave was maintained under a reduced pressure of 650 torr (86.66 kPa) for 20 minutes using a vacuum device, to obtain polyamide A-2 (polyamide 66) pellets. Polyamide A-2 (polyamide 66) had a VN of 130 and a TmA2 of 265°C.

[0124] [Manufacturing Example 3] (Production of Polyamide A-3 (Polyamide 66)) Polyamide polymerization reaction was carried out in the same manner as in Production Example 1 ("melt polymerization method"), except that the autoclave was maintained under a reduced pressure of 300 torr (39.99 kPa) for 10 minutes using a vacuum device, to obtain pellets of polyamide A-3 (polyamide 66). Polyamide A-3 (polyamide 66) had a VN of 120 and a TmA2 of 265°C.

[0125] [Manufacturing Example 4] (Production of Polyamide A-4 (Polyamide 66)) Polyamide polymerization was carried out in the same manner as in Production Example 1, except that the autoclave was maintained under a reduced pressure of 650 torr (86.66 kPa) for 30 minutes using a vacuum device ("hot melt polymerization method"), to obtain pellets of polyamide A-4 (polyamide 66). Polyamide A-4 (polyamide 66) had a VN of 195 and a TmA2 of 265°C.

[0126] [Manufacturing Example 5] (Production of modified polyphenylene ether F-1) Poly(2,6-dimethyl-1,4-phenylene ether) (hereinafter sometimes abbreviated as "polyphenylene ether"), obtained by oxidative polymerization of 2,6-dimethylphenol and having a reduced viscosity of 0.52 dL / g (0.5 dL / g chloroform solution, measured at 30°C), was used in a mixture of 100 parts by mass, 0.1 parts by mass of a radical initiator, and 1.5 parts by mass of maleic anhydride as a compatibilizer. The mixture was melt-kneaded under conditions of a cylinder set temperature of 320°C, a screw rotation of 300 rpm, and a discharge rate of 20.15 kg / hr, and discharged into strand form. The mixture was then cooled in a strand bath. The mixture was then granulated using a cutter to obtain pellets of maleic anhydride-modified polyphenylene ether. The maleic anhydride addition rate was 0.5%.

[0127] [Manufacturing Example 6] (Production of Modified Polyphenylene Ether F-2) Pellets of maleic anhydride-modified polyphenylene ether were obtained by the same method as in the above (F-1) except that the amount of maleic anhydride was 0.3 parts by mass. The maleic anhydride addition rate was 0.1%.

[0128] <Production of Polyamide Resin Composition> [Examples 1 to 11 and Comparative Examples 1 to 5] Each polyamide resin composition was produced using the following method, except that the raw materials were blended to obtain the composition shown in Table 1. Each polyamide obtained in the above Production Examples was dried in a nitrogen stream to adjust the moisture content to about 0.2% by mass before being used as a raw material for the polyamide resin composition.

[0129] A twin-screw extruder [ZSK-26MC: manufactured by Coperion (Germany)] was used as the apparatus for producing the polyamide resin composition. In the twin-screw extruder, the temperature from the upstream supply port to the die was set to the melting point TmA2 of each (A) polyamide produced in the above production examples + 30°C, the screw rotation speed was set to 300 rpm, and the discharge rate was set to 30 kg / h.

[0130] (A) Polyamide, (B) Brominated polystyrene, (C) Flame retardant aid, (E) Copolymer of aromatic vinyl compound and α,β-unsaturated dicarboxylic anhydride, and (F) α,β-unsaturated dicarboxylic anhydride-modified polyphenylene ether were dry-blended so as to obtain the types and proportions shown in Table 1, and then fed into the upstream feed port of a twin-screw extruder. (D) Glass fiber D-1 as an inorganic filler was fed into the downstream feed port of the twin-screw extruder. The molten mixture extruded from the die head was cooled in the form of strands and pelletized to obtain pellets of a polyamide resin composition. The resulting pellets of the polyamide resin composition were dried in a nitrogen stream to reduce the water content in the polyamide resin composition to 500 ppm or less.

[0131] <Measurement and evaluation methods> The following physical properties were measured and various evaluations were carried out using (A) polyamide, (B) brominated polystyrene, and the polyamide resin composition after adjusting the water content. The measurement results of the physical properties and the evaluation results are shown in Table 1 below.

[0132] [(A) Melting point of polyamide (TmA2)] The melting point (TmA2) of the polyamide (A) was measured in accordance with JIS-K7121 using a Diamond-DSC manufactured by Perkin-Elmer Co., Ltd. Specifically, the measurement was performed as follows. First, in a nitrogen atmosphere, approximately 10 mg of sample was heated from room temperature to 300°C at a heating rate of 20°C / min. The highest peak temperature of the endothermic peak (melting peak) that appeared at this time was designated Tm1 (°C). Next, the temperature was maintained at the highest peak temperature Tm1 for 2 minutes. At this highest peak temperature Tm1, the polyamide was in a molten state. The temperature was then lowered to 30°C at a heating rate of 20°C / min. After holding at 30°C for 2 minutes, the temperature was raised from 30°C to 300°C at a heating rate of 20°C / min. The highest peak temperature of the endothermic peak (melting peak) that appeared at this time was designated the melting point Tm2 (°C).

[0133] [(A) Viscosity number of polyamide (VN)] The polyamide was dissolved in formic acid and measured according to ISO 307.

[0134] [(B) Weight-average molecular weight, number-average molecular weight, and molecular weight distribution of brominated polystyrene] (B) The weight-average molecular weight and number-average molecular weight of brominated polystyrene were measured using GPC (HLC-8320GPC, manufactured by Tosoh Corporation) and standard polystyrene (PS) (manufactured by Tosoh Corporation) as a solvent. The molecular weight distribution was calculated from these values.

[0135] [Extrusion processability] When a polyamide resin composition was produced according to the above-mentioned method for producing a polyamide resin composition, the composition was taken out in the form of a strand, and the surface of the strand was visually observed to evaluate the extrusion processability according to the following criteria. A: Smooth and free of fluffing, with no strand breakage for 15 minutes or more B: There is some fluffing, but no strand breakage occurs for 15 minutes or more. C: The hair became fuzzy and strands broke within 15 minutes.

[0136] [(B) Number average area and abundance ratio of brominated polystyrene] The pellets obtained according to the above-mentioned method for producing a polyamide resin composition were stained with Ru, and then the cross section was observed with a scanning electron microscope (SEM) at a magnification of 500x to obtain an image of the dispersed state. From the obtained image, domains of (A) polyamide, (B) brominated polystyrene, (C) flame retardant aid, and (D) inorganic filler were separated by multi-value processing, and the area per (B) brominated polystyrene domain was calculated. The number average area was calculated from all domains of (B) brominated polystyrene. Furthermore, the area of ​​0.8 μm 2 (B) Brominated polystyrene domain number with an area of ​​3.0 μm 2 The number of (B) brominated polystyrene domains was calculated, and the number of 0.8 μm domains of the total brominated polystyrene domains was calculated. 2 (B) a brominated polystyrene domain having an area of ​​3.0 μm 2The abundance ratio of (B) brominated polystyrene domains having an area of ​​at least this value was calculated.

[0137] [Moldability] As an index of moldability, MD (mold deposit) during molding was evaluated. For each polyamide resin composition, a flat plate specimen (6 cm x 9 cm x 3 mm thick) was produced using an injection molding machine (NEX50III-5EG, manufactured by Nissei Plastic Industrial Co., Ltd.). The injection time was 10 seconds, the cooling time was 10 seconds, the screw rotation speed was 200 rpm, the mold temperature was 80°C, and the cylinder temperature was set to the melting point of (A) polyamide, TmA2 + 20. The injection pressure and injection rate were appropriately adjusted so that the filling time was within the range of 1.0 ± 0.1 seconds. One hundred consecutive molding shots were performed, and gas vents were visually inspected after completion of molding. The evaluation criteria for gas generation during molding were as follows, rated on a three-point scale, with A > B > C being the most favorable, with A and B being considered to be the most favorable. A: No adhesions are found in the gas vent area. B: There is something stuck to the gas vent C: There is adhesion in the gas vent and it is starting to clog.

[0138] [Tensile strength] For each polyamide resin composition, a 4 mm thick ISO dumbbell was prepared as a test specimen using an injection molding machine [PS-40E, manufactured by Nissei Plastics Co., Ltd.]. The specific molding conditions were set as follows: injection + pressure holding time 25 seconds, cooling time 15 seconds, mold temperature 80°C, and molten resin temperature (melting point TmA2 of polyamide (A) + 20°C). Using the obtained test pieces, a tensile test was carried out in accordance with ISO527 at a temperature of 23°C and a tensile speed of 5 mm / min, and the tensile yield stress was measured and taken as the tensile strength (MPa). A sample having a tensile strength of 135 MPa or more under a temperature condition of 23°C was evaluated as having good tensile strength.

[0139] [Notched Charpy impact strength] Using the same method as for tensile strength, 4 mm thick ISO dumbbells were prepared for each polyamide resin composition and used as test specimens. Using the obtained test specimens, notched Charpy impact strength (kJ / m) was measured at a temperature of 23°C in accordance with ISO 179. 2 ) was measured. Notched Charpy impact strength at 23°C is 10.0kJ / m 2 Those having the above mentioned properties were evaluated as having good notched Charpy impact strength.

[0140] [Liquidity] Each polyamide resin composition was used to produce a spiral molded article with a cavity width of 10 mm and a thickness of 1 mm using an injection molding machine (NEX50III-5EG, manufactured by Nissei Plastic Industrial Co., Ltd.). The injection time was 10 seconds, the cooling time was 10 seconds, the screw rotation speed was 200 rpm, the mold temperature was 80°C, the cylinder temperature was set to the melting point (TmA2) of polyamide (A) + 20°C, the injection speed was set to Max, and the injection pressure was 70 MPa. The flow length (spiral flow value) was measured by measuring the length of the molded article. Prior to measuring the spiral flow value, the pellets were dried at 80°C for 48 hours, and after confirming that the moisture content of the pellets was less than 300 ppm, the measurement was performed under the following conditions. A flow length of 145 mm or greater was considered to have good fluidity.

[0141] [Flame retardant] Measurements were carried out using the UL94 method (a standard established by Underwriters Laboratories Inc., USA). Test specimens (127 mm long, 12.7 mm wide, and 0.3 mm thick) were prepared by molding a polyamide resin composition using an injection molding machine (PS40E, manufactured by Nissei Kogyo Co., Ltd.) with a UL test specimen mold (mold temperature = glass transition temperature of polyamide + 20°C) attached, and a cylinder temperature of 20°C + the melting point of polyamide. The injection pressure was set to a pressure of 2% + the full filling pressure when molding the UL test specimen. Flame retardancy ratings were determined in accordance with the UL94 standard (vertical flame test). To obtain a V-0 rating under UL94, the total flame burning time must be 50 seconds or less, the maximum burning time must be 10 seconds or less, the cotton placed directly under the test specimen must not ignite, and the flame must not reach the clamp. Tests that obtained a V-0 rating were judged to have passed, and those that did not obtain a V-0 rating were judged to have failed. Furthermore, as an index for evaluation within the V-0 grade, the shorter the total flaming burning time (t1 + t2) after two flame applications for each of the five test specimens (a total of 10 applications), and the lower the risk of the cotton placed directly below the test specimen igniting due to drips and the lower the risk of the flame reaching the clamp, the better the flame retardancy was evaluated. Specifically, the better the flame retardancy was evaluated when the total flaming burning time (t1 + t2) was shorter than 25 seconds, the number of cotton pieces igniting due to drips (number of drips) was one or less, and the number of pieces of flame reaching the clamp (whether or not the clamp burned) was one or less.

[0142] [Table 1]

[0143] As shown in Table 1, the polyamide resin compositions of Examples 1 to 11, which contain components (A) to (C) and have a number-average area (B-na) of brominated polystyrene (B) that falls within the specified range, are all excellent in tensile properties, Charpy notched impact strength, fluidity, flame retardancy, extrusion processability, and molding processability.

[0144] On the other hand, as shown in Table 1, in Comparative Examples 1 to 5, even though the components (A) to (C) were contained, when the number average area (B-na) of the brominated polystyrene (B) did not satisfy the predetermined range, it was not possible to obtain a composition having good flame retardancy, extrusion processability, and molding processability. [Industrial Applicability]

[0145] The polyamide resin composition of the present embodiment can provide a polyamide composition that is excellent in extrusion processability, molding processability, flame retardancy, etc. In particular, the material is thin-walled yet has excellent flame retardancy and toughness, and can be more suitably used in electrical and electronic component applications with dense structures.

Claims

1. (A) polyamide, (B) brominated polystyrene, and (C) a flame retardant synergist, A polyamide resin composition comprising: The number average area (B-na) of the dispersed brominated polystyrene domains (B) is 1.30 μm ２ 2.20 μm or more ２ A polyamide resin composition comprising:

2. Of the total domains of the dispersed brominated polystyrene (B), 0.8 μm ２ 2. The polyamide resin composition according to claim 1, wherein the proportion of domains of (B) brominated polystyrene having the following area is less than 30%.

3. Of the total domains of the dispersed brominated polystyrene (B), 3.0 μm ２ 2. The polyamide resin composition according to claim 1, wherein the proportion of domains of the brominated polystyrene (B) having an area of ​​at least 100 nm is less than 20%.

4. 2. The polyamide resin composition according to claim 1, wherein the viscosity number (VN) of the polyamide (A) is 90 or more and 200 or less.

5. 2. The polyamide resin composition according to claim 1, wherein the melting point of the polyamide (A) is 200°C or higher and 270°C or lower.

6. moreover, (D) inorganic filler, (E) a copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride, and (F) polyphenylene ether modified with an α,β-unsaturated dicarboxylic acid anhydride; The polyamide resin composition according to claim 1, comprising:

7. With respect to 100% by mass of the polyamide resin composition, 20 to 70% by mass of the (A) polyamide, (B) 10 to 35 mass% of brominated polystyrene, 1 to 15 mass % of the (C) flame retardant aid, 10 to 60 mass% of the (D) inorganic filler, (E) 0.1 to 1.5 mass % of a copolymer of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride, and (F) 1 to 5 mass % of polyphenylene ether modified with an α,β-unsaturated dicarboxylic acid anhydride, A polyamide resin composition comprising:

7. The polyamide resin composition according to claim 6, wherein the brominated polystyrene (B) has a bromine content of 64 to 71% by mass and a weight average molecular weight of 1,000 to 10,000.

8. 8. The polyamide resin composition according to claim 6, wherein the ratio Ew / Aw of the mass (Ew) of the copolymer of the aromatic vinyl compound and the α,β-unsaturated dicarboxylic acid anhydride (E) to the mass (Aw) of the polyamide (A) is 0.0050 or more and 0.050 or less.

9. The polyamide resin composition according to claim 6 or 7, wherein the α,β-unsaturated dicarboxylic acid anhydride component contained in the copolymer of (E) an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride is 1 to 40 mass% based on the total mass of the copolymer of (E) an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride.

10. 8. The polyamide resin composition according to claim 6, wherein the weight average molecular weight of the copolymer (E) of an aromatic vinyl compound and an α,β-unsaturated dicarboxylic acid anhydride is 10,000 or more and 250,000 or less.

11. The polyamide resin composition according to claim 6 or 7, wherein the α,β-unsaturated dicarboxylic anhydride component contained in the polyphenylene ether modified with the α,β-unsaturated dicarboxylic anhydride (F) is 0.2 to 1.0 mass% relative to the total mass of the polyphenylene ether modified with the α,β-unsaturated dicarboxylic anhydride (F).

12. A molded article comprising the polyamide resin composition according to claim 1.

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