Polyamide resin composition and molded article

Abstract

The present invention relates to a polyamide resin composition and a molded article. The present invention provides a polyamide resin composition which is excellent in flame retardancy, extrusion processability and molding processability, particularly in flow properties and welding strength at the time of molding, when the thickness is thin. A polyamide resin composition comprising 20 to 70 mass% of (A) a polyamide, 10 to 35 mass% of (B) brominated polystyrene, 1 to 15 mass% of (C) a flame retardant aid, and 10 to 60 mass% of (D) an inorganic filler, wherein the bromine content in the (B) brominated polystyrene is 64 to 71 mass%, and the (B) brominated polystyrene contains a component having a weight average molecular weight of 1,000 to 5,000 and a component having a weight average molecular weight of 150,000 to 200,000.

Description

Technical Field

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

[0002] Polyamides, such as polyamide 6 (hereinafter sometimes referred to as "PA6") and polyamide 66 (hereinafter sometimes referred to as "PA66"), are widely used in automotive parts, mechanical parts, and electrical and electronic components due to their excellent mechanical strength and heat resistance. Particularly in electrical and electronic component applications, high levels of flame retardancy are required, demanding flame retardancy properties that are even higher than the self-extinguishing properties of traditional polyamide resins. Therefore, extensive research is underway to meet the V-0 evaluation standard of Underwriters Laboratories' UL94 standard.

[0003] As representative examples of such flame-retardant polyamide resins, flame-retardant polyamide materials using brominated polystyrene can be cited. For instance, Patent Document 1 discloses a polyamide resin composition that exhibits excellent heat resistance, flame retardancy, and flowability during reflow soldering, and good thermal stability during molding. Patent Document 2 discloses a polyamide resin composition that significantly reduces gas generation during molding and exhibits minimal mold corrosion. Patent Document 3 discloses a polyamide resin composition that imparts both high flame retardancy and high weld strength while also providing toughness.

[0004] However, recently, due to the increasing complexity of the structure of electrical and electronic components, there is a trend towards thinner materials. In addition to the generally required flame retardancy and mechanical strength (tensile strength, impact strength), there is a further requirement for the strength of welded parts and materials with excellent forming fluidity. The materials mentioned above may not be able to meet these requirements.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. 2006 / 123469

[0008] Patent Document 2: Japanese Patent Application Publication No. 10-168307

[0009] Patent Document 3: Japanese Patent Application Publication No. 2007-291249 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] The purpose of this invention is to provide a polyamide resin composition with excellent flame retardancy, extrusion processability and molding processability when thin, and especially excellent flow characteristics and weld strength during molding.

[0012] means for solving problems

[0013] The present invention was made in view of the above circumstances, and its object is to stably provide polyamide resin compositions and molded articles with excellent mechanical properties (especially weld strength), molding flowability, flame retardancy, etc.

[0014] In order to solve the above-mentioned problems, the inventors conducted repeated and in-depth research and found that a polyamide resin composition containing brominated polystyrene with a specific molecular weight can solve the above-mentioned problems, thereby completing the present invention.

[0015] That is, the present invention is as follows.

[0016] (1) A polyamide resin composition comprising 20% ​​to 70% by mass of (A) polyamide, 10% to 35% by mass of (B) brominated polystyrene, 1% to 15% by mass of (C) flame retardant additive and 10% to 60% by mass of (D) inorganic filler, wherein the bromine content in the (B) brominated polystyrene is 64% to 71% by mass, and the (B) brominated polystyrene contains components with a weight average molecular weight of 1,000 to 5,000 and components with a weight average molecular weight of 150,000 to 200,000.

[0017] (2) The polyamide resin composition as described in (1), wherein, in the (B) brominated polystyrene 100% by mass, the proportion of the component with a weight average molecular weight of 1,000 to 5,000 is more than 1% by mass and less than 50% by mass, and the proportion of the component with a weight average molecular weight of 150,000 to 200,000 is more than 50% by mass and less than 99% by mass.

[0018] (3) The polyamide resin composition as described in (1) or (2), wherein, in the (B) brominated polystyrene 100% by mass, the proportion of the component with a weight average molecular weight of 1,000 to 5,000 is 1% by mass or more and 20% by mass or less, and the proportion of the component with a weight average molecular weight of 150,000 to 200,000 is 80% by mass or more and 99% by mass or less.

[0019] (4) The polyamide resin composition as described in any one of (1) to (3), wherein in the brominated polystyrene of (B), the molecular weight distribution Mw / Mn of the component with a weight average molecular weight of 1,000 to 5,000 is 1.0 to 2.0, and the molecular weight distribution Mw / Mn of the component with a weight average molecular weight of 150,000 to 200,000 is 1.1 to 3.0.

[0020] (5) The polyamide resin composition as described in any one of (1) to (4), wherein the flame retardant additive (C) is selected from at least one of antimony oxides, tin oxides, iron oxides, and metal borates.

[0021] (6) The polyamide resin composition as described in any one of (1) to (5), wherein the flame retardant additive (C) is antimony trioxide.

[0022] (7) The polyamide resin composition as described in any one of (1) to (6), wherein the polyamide resin composition further comprises (E) a compatibilizer, said (E) being at least one selected from copolymers of aromatic vinyl compounds and α,β-unsaturated dicarboxylic anhydrides, and polymers modified with α,β-unsaturated dicarboxylic anhydrides.

[0023] (8) The polyamide resin composition as described in (7), wherein the (E) compatibilizer is at least one selected from styrene-maleic anhydride copolymer and polyphenylene ether resin modified with α,β-unsaturated dicarboxylic anhydride.

[0024] (9) A molded article, wherein the molded article is obtained by molding the polyamide resin composition of any one of (1) to (8).

[0025] Invention Effects

[0026] According to the present invention, a polyamide resin composition is provided that exhibits excellent flame retardancy, extrusion processability and molding processability at thin thicknesses, and particularly excellent flow characteristics and weld strength during molding. Detailed Implementation

[0027] The following describes in detail the method for carrying out the present invention (hereinafter referred to as "this embodiment"). It should be noted that the present invention is not limited to the following embodiment, and can be implemented with various modifications within its scope. It should be noted that, in this specification, "polyamide" refers to a polymer having an amide (-NHCO-) ​​group in its main chain.

[0028] [(A) Polyamide]

[0029] Examples of the polyamides used in embodiment (A) include: condensation polymers of dicarboxylic acids and diamines, ring-opening polymers of cyclic lactams, and condensation polymers of aminocarboxylic acids. Specifically, examples include: polycaprolactam (hereinafter referred to as polyamide 6), polyhexamethylene adipamide (hereinafter referred to as polyamide 66), polybutylene adipamide (hereinafter referred to as polyamide 46), polyhexamethylene sebacate (hereinafter referred to as polyamide 610), polyhexamethylene dodecyl diamide (hereinafter referred to as polyamide 612), polyundecyl diamide (hereinafter referred to as polyamide 116), polyundecyl lactam (hereinafter referred to as polyamide 11), and polydodecyl lactam (hereinafter referred to as polyamide 12). Aliphatic polyamides; poly(m-phenylene adipamide) (hereinafter referred to as polyamide MXD6), poly(hexamethylene terephthalamide) (hereinafter referred to as polyamide 6T), poly(hexamethylene terephthalamide) (hereinafter referred to as polyamide 6I), poly(nonadiamine terephthalamide) (hereinafter referred to as polyamide 9T), poly(dodecanediamine terephthalamide) (hereinafter referred to as polyamide 12T), poly(butylene terephthalamide) (hereinafter referred to as polyamide 4I) and other polyamides containing aromatic components; as well as copolymers or mixtures of the above-mentioned aliphatic polyamides, copolymers or mixtures of polyamides containing aromatic components, and copolymers or mixtures of aliphatic polyamides and polyamides containing aromatic components.

[0030] When the melting point of (A) polyamide is too high, the flame retardant decomposes and the gas content increases during melt processing, thus reducing melt processability and decreasing flame retardant efficiency. Furthermore, when the melting point of (A) polyamide is too low, the heat resistance of the molded article, such as the HDT (highest temperature under load), decreases. Therefore, the melting point of the (A) polyamide used in this embodiment is preferably 240°C or higher and 270°C or lower. Examples of such (A) polyamides include: polyamide 66, polyamide MXD6, 66 / 6I copolymer polyamide, 66 / 6 copolymer polyamide, 6I / 6T copolymer polyamide, 66 / 6I / 6T ternary copolymer polyamide, 66 / 6I / 6 ternary copolymer polyamide, and 6 / 6I / 6T ternary copolymer polyamide. Additionally, polyamide resins that are mixed with these polyamides, polyamide 6, and other low-melting-point polyamides and have a melting point of 240°C or higher and 270°C or lower are also included.

[0031] Further preferred options include polyamide 66, 66 / 6 copolyamide, and 66 / 6I copolyamide, which exhibit excellent moldability and physical properties. Additionally, polyamide resins that are mixed with these polyamides, polyamide 6I, and polyamide 6 and have a melting point of 240°C or higher and 270°C or lower are also included. Polyamide 66 is the most preferred.

[0032] In this embodiment (A), the molecular weight of the polyamide only needs to be within the range that allows for molding. Polyamides with a relative viscosity (RV) in the range of 10 to 70, as determined according to ASTM D789, are particularly preferred because they exhibit good molding flowability and maintain a high level of flame retardancy. A relative viscosity (RV) in the range of 30 to 60 is further preferred, and a range of 35 to 55 is most preferred. The relative viscosity (RV) is measured using 90% formic acid as a solvent, at a concentration of 3 g (polyamide) sample / 30 ml formic acid, and at a temperature of 25°C.

[0033] Amino or carboxyl groups are typically present in the terminal groups of (A) polyamides.

[0034] (A) The ratio of the amount of amino-terminal groups to the total molar amount of amino-terminal groups and carboxyl-terminal groups in the polyamide [amount of amino-terminal groups / (amount of amino-terminal groups + amount of carboxyl-terminal groups)] is preferably greater than or equal to 0.2 and less than 1.0, more preferably 0.2 or more and 0.5 or less, and even more preferably 0.2 or more and 0.4 or less. When the ratio of the amount of terminal groups is within the above range, the molded articles obtained from the polyamide resin composition tend to have better color tone, mechanical strength, and flowability.

[0035] [(B) Brominated polystyrene]

[0036] In this embodiment, (B) brominated polystyrene is added to improve flame retardant properties. To impart flame retardancy, flowability, and mechanical properties to the polyamide resin composition of this embodiment, brominated polystyrene with a specific bromine content and a specific molecular weight is required.

[0037] There are no particular limitations on the manufacturing method of (B) brominated polystyrene. For example, the following methods can be listed: manufacturing polystyrene by polymerizing styrene monomers and then brominating the benzene ring of the polystyrene to manufacture brominated polystyrene; manufacturing brominated polystyrene by polymerizing brominated styrene monomers (bromostyrene, dibromostyrene, tribromostyrene, etc.).

[0038] (B) The bromine content in the 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 met with a small amount of (B) brominated polystyrene, and a polyamide resin composition with excellent heat resistance, flowability, toughness, low water absorption, rigidity, and flame retardancy can be obtained without compromising the properties of (A) polyamide. Furthermore, by setting the bromine content to 71% by mass or less, thermal decomposition is less likely to occur during melt processing such as extrusion and molding, gas generation can be suppressed, and a polyamide resin composition with excellent heat resistance and colorfastness can be obtained. When considering the balance of these properties, a bromine content of 65% to 69% by mass is further preferred.

[0039] Furthermore, (B) brominated polystyrene preferably contains a component with a specific molecular weight, more preferably a first component with a high weight-average molecular weight and a second component with a low weight-average molecular weight, and may also contain two components consisting of the first and second components. The weight-average molecular weight of the first component can be 150,000 to 200,000, and the weight-average molecular weight of the second component can be 1,000 to 5,000. It should be noted that the weight-average molecular weight in this specification can be determined by GPC (gel permeation chromatography). The first and second components preferably have sharp peaks, but even in the case of overlapping peaks, the weight-average molecular weight and weight ratio can be calculated by assuming that each peak exhibits a Gaussian distribution and separating the peaks. Generally, when the value of the molecular weight distribution (Mw / Mn) is small, there is a tendency to show sharp peaks.

[0040] (B) Brominated polystyrene preferably contains a component with a weight average molecular weight of 1,000 to 5,000 in order to improve flowability, and from the viewpoint of flame retardancy and weldability, contains a component with a weight average molecular weight of 150,000 to 200,000. More preferably, the proportion of the component with a weight average molecular weight of 1,000 to 5,000 is 1% to 50% by mass and less than 50% by mass, and the proportion of the component with a weight average molecular weight of 150,000 to 200,000 is 50% to 99% by mass and less than 99% by mass. From the viewpoint of inhibiting mold fouling, it is even more preferable that the proportion of the component with a weight average molecular weight of 1,000 to 5,000 is 1% to 20% by mass and less than 80% by mass and less than 99% by mass. When (B) brominated polystyrene contains only components with a weight-average molecular weight of less than 5000, it sometimes exhibits poor compatibility with (A) polyamide, resulting in noticeable fuzzing of the extruded filament and easy breakage of the filament midway, thus reducing productivity. Alternatively, it may show poor interfacial adhesion with (D) inorganic filler materials, leading to reduced strength. When (B) brominated polystyrene is composed only of components with a weight-average molecular weight greater than 150,000, the melt viscosity becomes very high, increasing torque during extrusion and causing decreased productivity. It also tends to exhibit reduced flowability during molding.

[0041] (B) The molecular weight distribution (Mw / Mn) of the brominated polystyrene component with a weight average molecular weight of 1000 to 5000 is preferably 1.0 to 2.0, more preferably 1.05 to 1.30. Furthermore, the molecular weight distribution (Mw / Mn) of the brominated polystyrene component with a weight average molecular weight of 150000 to 200000 is preferably 1.1 to 3.0, more preferably 1.5 to 2.5. By satisfying the above molecular weight distribution, higher fluidity during molding and improved mechanical properties of the welded parts can be obtained.

[0042] [(C) Flame retardant additives]

[0043] The polyamide resin composition of this embodiment also contains (C) a flame retardant additive. Therefore, it is possible to produce a polyamide resin composition with even better flame retardancy.

[0044] The flame retardant additive (C) used in this embodiment is not particularly limited, and examples include: antimony oxides such as antimony trioxide, antimony tetroxide, antimony pentoxide, and sodium antimonate; tin oxides such as tin monoxide and tin dioxide; iron oxides such as iron oxide and γ-iron oxide; and metal oxides such as zinc oxide, calcium oxide, zirconium oxide, manganese oxide, molybdenum oxide, cobalt oxide, bismuth oxide, chromium oxide, nickel oxide, copper oxide, and tungsten oxide; metal hydroxides such as magnesium hydroxide and aluminum hydroxide; metal borates such as zinc borate, magnesium borate, calcium borate, and aluminum borate; and organosilicon; etc. One of these flame retardant additives (C) may be used, or two or more may be used in combination.

[0045] As the flame retardant additive (C) used in this embodiment, from the perspective of flame retardant effect, it is preferably selected from at least one of antimony oxides, tin oxides, iron oxides, and metal borates, and is more preferably antimony oxides, especially antimony trioxide.

[0046] To improve the flame retardant effect, it is preferable to use (C) flame retardant additives with an average particle size of 0.01 μm to 10 μm. The average particle size can be determined using a laser diffraction scattering particle size distribution measuring device or a precision particle size distribution measuring device.

[0047] [(D) Inorganic filler materials]

[0048] The polyamide resin composition of this embodiment also contains (D) an inorganic filler. Therefore, it is possible to produce a polyamide resin composition with superior mechanical properties such as toughness and rigidity.

[0049] There are no particular limitations on the inorganic filler material (D) used in this embodiment. Examples include: glass fiber, carbon fiber, calcium silicate fiber, potassium titanate fiber, flake glass, talc, kaolin, mica, hydrotalcite, calcium carbonate, zinc carbonate, dicalcium phosphate, wollastonite, silica, zeolite, alumina, boehmite, titanium dioxide, silicon dioxide, 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, swelling fluoromica, and apatite, etc.

[0050] As an inorganic filler material (D), one type or two or more types can be used in combination.

[0051] As (D) inorganic filler materials, from the viewpoint of rigidity and strength, glass fiber, carbon fiber, flake glass, talc, kaolin, mica, calcium carbonate, dicalcium phosphate, wollastonite, silica, carbon nanotubes, graphite, calcium fluoride, montmorillonite, swelling fluoromica, and apatite are preferred.

[0052] As the inorganic filler material (D), glass fiber or carbon fiber is preferred. From the viewpoint of exhibiting high properties, glass fiber or carbon fiber with a number-average fiber diameter of 3 μm to 30 μm, a weight-average fiber length of 100 μm to 750 μm, and an aspect ratio (L / D) of weight-average fiber length (L) to number-average fiber diameter (D) of 10 to 100 is even more preferred.

[0053] Furthermore, glass fiber is preferred as the (D) inorganic filler material. Among the glass fibers, glass fibers with a number-average fiber diameter of 3 μm to 30 μm, a weight-average fiber length of 10 μm to 500 μm, and an aspect ratio (L / D) of 3 to 100 are even more preferred.

[0054] (D) The number-average fiber diameter and weight-average fiber length of inorganic filler materials can be determined by the following method: the molded polyamide resin composition is dissolved in a solvent such as formic acid that can dissolve polyamide, and more than 100 inorganic filler materials are randomly selected from the obtained insoluble components. The inorganic filler materials are observed using an optical microscope, scanning electron microscope, etc., and the number-average fiber diameter and weight-average fiber length are determined.

[0055] [(E) Compatibilizer]

[0056] The polyamide resin composition of this embodiment preferably further contains (E) a compatibilizer. This allows for the production of polyamide resin compositions with superior flame retardancy, as well as improved mechanical properties such as toughness and rigidity.

[0057] As the compatibilizer (E) used in this embodiment, a polymer containing α,β-unsaturated dicarboxylic anhydride is preferred. Examples include polymers containing α,β-unsaturated dicarboxylic anhydride as a copolymer component, polymers modified with α,β-unsaturated dicarboxylic anhydride, etc. Preferably, at least one is selected from copolymers of aromatic vinyl compounds and α,β-unsaturated dicarboxylic anhydride, polymers modified with α,β-unsaturated dicarboxylic anhydride.

[0058] Examples of α,β-unsaturated dicarboxylic acid anhydrides include compounds represented by the following general formula (1).

[0059]

[0060] In general formula (1), R 1 and R 2 Each is independently a hydrogen or an alkyl group having 1 to 3 carbon atoms.

[0061] Examples of α,β-unsaturated dicarboxylic acid anhydrides include maleic anhydride and methylmaleic anhydride, with maleic anhydride being preferred. Examples of polymers containing α,β-unsaturated dicarboxylic acid anhydrides as copolymerizing components include copolymers of aromatic vinyl compounds and α,β-unsaturated dicarboxylic acid anhydrides.

[0062] Examples of polymers modified with α,β-unsaturated dicarboxylic anhydrides include: polyphenylene ether resins modified with α,β-unsaturated dicarboxylic anhydrides, and polypropylene resins modified with α,β-unsaturated dicarboxylic anhydrides.

[0063] From the viewpoint of improving the efficiency of flame retardancy (exhibiting flame retardant effect with a small amount of addition), copolymers of aromatic vinyl compounds and α,β-unsaturated dicarboxylic anhydrides are preferred as polymers containing α,β-unsaturated dicarboxylic anhydrides.

[0064] As an aromatic vinyl compound used in this embodiment, compounds represented by the following general formula (2) can be listed as examples.

[0065]

[0066] In general formula (2), R 3 and R 4 Each is independently a hydrogen or an alkyl group having 1 to 3 carbon atoms, and k is an integer from 1 to 5.

[0067] Examples of aromatic vinyl compounds include styrene, α-methylstyrene, p-methylstyrene, etc., with styrene being preferred.

[0068] In this embodiment, when the polymer containing α,β-unsaturated dicarboxylic anhydride contains aromatic vinyl compound components, it can be considered that: the aromatic vinyl compound components are affinity for (B) brominated polystyrene, and the α,β-unsaturated dicarboxylic anhydride portion is affinity for or reacts with (A) polyamide, thereby facilitating the dispersion of (B) brominated polystyrene in the polyamide matrix, enabling its fine dispersion.

[0069] Regarding the ratio of aromatic vinyl compound to α,β-unsaturated dicarboxylic anhydride in the copolymer of aromatic vinyl compound and α,β-unsaturated dicarboxylic anhydride, from the viewpoints of flame retardancy, flowability, and thermal decomposition resistance, it is preferable that the aromatic vinyl compound content is 50% to 99% by mass and the α,β-unsaturated dicarboxylic anhydride content is 1% to 50% by mass. The proportion of α,β-unsaturated dicarboxylic anhydride is more preferably 5% to 20% by mass, and even more preferably 8% to 15% by mass.

[0070] By setting the proportion of α,β-unsaturated dicarboxylic anhydride in the above copolymer to 1% by mass or more, a polyamide resin composition with excellent mechanical properties such as toughness and rigidity, as well as flame retardancy, can be obtained. Furthermore, by setting the proportion of α,β-unsaturated dicarboxylic anhydride in the above copolymer to 50% by mass or less, the deterioration of the polyamide resin composition caused by α,β-unsaturated dicarboxylic anhydride can be prevented.

[0071] (E) The compatibilizer is preferably selected from at least one of styrene-maleic anhydride copolymer and polyphenylene ether resin modified with α,β-unsaturated dicarboxylic anhydride.

[0072] (Content of each component)

[0073] Relative to 100% by mass of the polyamide resin composition, the content of (A) polyamide in the polyamide resin composition of this embodiment can be set to 20% by mass or more and 70% by mass or less, for example, 23% by mass or more and 65% by mass or less, for example, 25% by mass or more and 60% by mass or less.

[0074] In the polyamide resin composition of this embodiment, the content of the above-mentioned (B) brominated polystyrene is preferably 10% to 35% by mass, more preferably 15% to 30% by mass, and even more preferably 17% to 25% by mass, relative to 100% by mass of the above-mentioned polyamide resin composition.

[0075] 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, the generation of decomposition gases during melt mixing, the reduction in fluidity during molding, and the adhesion of contaminating substances to the molding die can be suppressed. In addition, the reduction in mechanical properties such as toughness and rigidity, as well as the appearance of the molded product, can also be suppressed.

[0076] The content of (C) flame retardant in the polyamide resin composition is preferably 1% to 15% by mass, more preferably 2% to 10% by mass, relative to 100% by mass of the polyamide resin composition. By containing (C) flame retardant within the above range, a polyamide resin composition with superior flame retardancy can be obtained. Furthermore, by setting the content of (C) flame retardant to 15% by mass or less, the viscosity during melt processing can be controlled within an appropriate range, suppressing increases in torque during extrusion, decreases in moldability during molding, and reductions in the appearance of the molded article. Additionally, a polyamide resin composition with excellent toughness and other properties can be obtained without compromising the excellent mechanical properties of the polyamide resin composition, such as toughness and rigidity.

[0077] The content of (D) inorganic filler in the polyamide resin composition is preferably 10% to 60% by mass, more preferably 13% to 50% by mass, and even more preferably 15% to 40% by mass, relative to 100% by mass of the polyamide resin composition.

[0078] By containing 10% by mass or more of (D) inorganic filler, the mechanical properties of the polyamide resin composition, such as strength and rigidity, are significantly improved. Furthermore, by setting the content of inorganic filler to 60% by mass or less, a polyamide resin composition with excellent extrusion processability and moldability can be obtained.

[0079] The content of (E) compatibilizer in the polyamide resin composition is preferably 0.1% to 20% by mass relative to 100% by mass, more preferably 0.5% to 20% by mass, even more preferably 1% to 15% by mass, and particularly preferably 2% to 10% by mass. By containing a (E) compatibilizer within the above range, the micro-dispersion effect of (B) brominated polystyrene generated by compatibilization in the polyamide resin composition can be improved, resulting in a polyamide resin composition with excellent flame retardancy and strength enhancement. Furthermore, by setting the content of (E) compatibilizer to 20% by mass or less, a polyamide resin composition with excellent strength and other properties can be obtained without compromising the excellent mechanical properties of the polyamide resin composition, such as toughness and rigidity.

[0080] In this embodiment, the total amount of (B) brominated polystyrene, (C) flame retardant, (D) inorganic filler, and (E) compatibilizer relative to 100% by mass of the polyamide resin composition is 30% to 80% by mass, preferably 40% to 80% by mass. By setting the total amount of (B) to (E) to 30% by mass or more, a polyamide resin composition with excellent processability, such as excellent strength, rigidity, and flame retardancy, and with appropriate melt viscosity, can be obtained.

[0081] (Molding modifier)

[0082] In the polyamide resin composition of this embodiment, a molding modifier may be added as needed without compromising the purpose of this embodiment.

[0083] As a molding modifier, there are no particular limitations, and examples include: higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, and higher fatty acid amides.

[0084] Examples of the aforementioned higher fatty acids include, for example, stearic acid, palmitic acid, behenic acid, erucic acid, oleic acid, lauric acid, and linoleic acid, which are saturated or unsaturated straight-chain or branched aliphatic monocarboxylic acids with 8 to 40 carbon atoms. Among these substances, stearic acid and linoleic acid are preferred.

[0085] The aforementioned higher fatty acid metal salts refer to the metal salts of the aforementioned higher fatty acids.

[0086] The preferred metal elements for metal salts are elements from Groups 1, 2, and 3 of the periodic table, zinc, and aluminum, with more preferred elements being elements from Groups 1 and 2 such as calcium, sodium, potassium, and magnesium, as well as aluminum.

[0087] Examples of high-grade fatty acid metal salts include: calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, calcium lignite, sodium lignite, and calcium palmitate.

[0088] Among these substances, metal salts of lycine and metal salts of stearic acid are preferred.

[0089] The aforementioned higher fatty acid esters refer to the esterifications of the aforementioned higher fatty acids with alcohols.

[0090] The preferred esters are aliphatic carboxylic acids with 8 to 40 carbon atoms and aliphatic alcohols with 8 to 40 carbon atoms.

[0091] Examples of aliphatic alcohols include stearyl alcohol, behenyl alcohol, and lauryl alcohol.

[0092] Examples of high-grade fatty acid esters include stearate stearate and behenate behenate.

[0093] The aforementioned higher fatty acid amides refer to amide compounds of the aforementioned higher fatty acids.

[0094] Examples of high-grade fatty acid amides include: stearamide, oleamide, mustardamide, ethylene bis-stearamide, ethylene bis-oleamide, N-stearyl stearamide, N-stearyl mustardamide, etc.

[0095] As a higher fatty acid amide, stearamide, mustardamide, ethylene bis-stearamide and N-stearyl mustardamide are preferred, and ethylene bis-stearamide and N-stearyl mustardamide are more preferred.

[0096] These higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, and higher fatty acid amides can each be used alone or in combination of two or more.

[0097] (Deterioration inhibitor)

[0098] In the polyamide resin composition of this embodiment, degradation inhibitors may be added as needed to prevent thermal degradation and discoloration, and to improve heat aging resistance and weather resistance, without compromising the purpose of this embodiment.

[0099] There are no particular limitations on what can be used as a degradation inhibitor. Examples include: copper compounds such as copper acetate and cuprous iodide; phenolic stabilizers such as hindered phenolic compounds; phosphite stabilizers; hindered amine stabilizers; triazine stabilizers; and sulfur-containing stabilizers.

[0100] These degradation inhibitors can be used alone or in combination of two or more.

[0101] (Other resins)

[0102] In the polyamide resin composition of this embodiment, other resins may be added as needed without compromising the purpose of this embodiment.

[0103] There are no particular limitations on such resins; thermoplastic resins, rubber components, etc., which will be listed later, are examples.

[0104] Examples of the aforementioned thermoplastic resins include: atactic polystyrene, isotactic polystyrene, syndiotactic polystyrene, AS resin, ABS resin, and other polystyrene-based resins; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; other polyamides (excluding the polyamides used in this embodiment) such as nylon 6, nylon 66, and nylon 612; polyether resins such as polycarbonate, polyphenylene ether, polysulfone, and polyethersulfone; condensation resins such as polyphenylene sulfide and polyoxymethylene; acrylic resins such as polyacrylic acid, polyacrylate, and polymethyl methacrylate; polyolefin resins such as polyethylene, polypropylene, polybutene, and ethylene-propylene copolymer; halogenated vinyl compound resins such as polyvinyl chloride and polyvinylidene chloride; phenolic resins; and epoxy resins.

[0105] These thermoplastic resins can be used alone or in combination of two or more.

[0106] Examples of rubber components mentioned above include: natural rubber, polybutadiene, polyisoprene, polyisobutylene, chloroprene rubber, vulcanized rubber, polysulfide rubber, acrylic rubber, polyurethane 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. Element-ethylene-propylene random copolymers, styrene-ethylene-butene random copolymers, ethylene-propylene copolymers (EPR), ethylene-(1-butene) copolymers, ethylene-(1-hexene) copolymers, ethylene-(1-octene) copolymers, ethylene-propylene-diene copolymers (EPDM), 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 core-shell rubbers containing siloxanes, represented by methyl methacrylate-butyl acrylate siloxane, etc.

[0107] These rubber components can be used alone or in combination of two or more.

[0108] [Method for manufacturing polyamide resin composition]

[0109] As for the method of manufacturing the polyamide resin composition of this embodiment, there are no particular limitations as long as it is a method of mixing (A) polyamide, (B) brominated polystyrene, (C) flame retardant additive, and (D) inorganic filler material.

[0110] Methods for mixing (A) polyamide, (B) brominated polystyrene, (C) flame retardant, and (D) inorganic filler can include, for example, a method of mixing at least one of the group consisting of (A) polyamide, (B) brominated polystyrene, (C) flame retardant, and (D) inorganic filler using a Henschel mixer or similar equipment, and then feeding the mixture into a melt mixer for mixing; or a method of feeding a mixture obtained by pre-mixing (A) polyamide, (B) brominated polystyrene, (C) flame retardant, (D) inorganic filler, and optionally (E) compatibilizer in a single-screw or twin-screw extruder into a melt mixer for mixing, and then optionally feeding (D) inorganic filler into the mixture from a side feeder, etc.

[0111] Regarding the method of supplying the components constituting the polyamide resin composition to the melt mixer, all the components can be supplied at once from the same supply port, or the components can be supplied separately from different supply ports.

[0112] The preferred temperature for melt mixing is about 1°C to about 100°C higher than the melting point of (A) polyamide, and more preferably about 10°C to about 50°C higher than the melting point of (A) polyamide.

[0113] The preferred shearing speed in the mixer is approximately 100 seconds. -1 The preferred average residence time during mixing is approximately 0.5 minutes to approximately 5 minutes.

[0114] As the apparatus for performing melt mixing, known apparatuses are preferred, such as single-screw or twin-screw extruders, Banbury internal mixers, and melt mixing mills such as mixing rollers.

[0115] The proportions of each component in the polyamide resin composition of this embodiment are the same as the proportions of each component in the polyamide resin composition described above.

[0116] [Molded articles of polyamide resin compositions]

[0117] The specified molded article is obtained by molding the polyamide resin composition of this embodiment.

[0118] There are no particular restrictions on the method for obtaining the molded article; well-known molding methods can be used.

[0119] Examples of molding methods include: extrusion molding, injection molding, vacuum molding, blow molding, injection compression molding, decorative molding, heterogeneous 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, injection molding on substrate), etc.

[0120] [use]

[0121] The molded article of this embodiment comprises the above-described polyamide resin composition. It exhibits excellent surface appearance stability, welded mechanical properties, and flame retardancy under harsh molding conditions, making it suitable for various applications. For example, it can be appropriately used in the automotive, electrical and electronic, machinery and industrial, office equipment, and aerospace industries.

[0122] [Example]

[0123] The present invention will now be described in detail with specific embodiments and comparative examples, but the present invention is not limited to the following embodiments.

[0124] First, the following shows the constituent elements of polyamide, the methods for measuring its physical properties, and the methods for evaluating its characteristics.

[0125] [Determination Method]

[0126] <Viscosity RV of polyamide in formic acid solution>

[0127] The polyamide was dissolved in formic acid and tested according to ASTM D789.

[0128] <End ratio of polyamide>

[0129] Ammonia terminal content ([NH2])

[0130] The amount of amino-terminal bonds at the polymer ends in the polyamides obtained in the Examples and Comparative Examples was determined by neutralization titration in the following manner.

[0131] Dissolve 3.0 g of polyamide in 100 ml of 90% (w / w) aqueous phenol solution. Use the resulting solution to titrate with 0.025 N hydrochloric acid to determine the amount of amino-terminated molecules (µequivalents / g). The endpoint is determined by the pH meter reading.

[0132] Carboxyl terminus amount ([COOH])

[0133] The amount of carboxyl-terminal groups bonded to the polymer ends in the polyamides obtained in the Examples and Comparative Examples was determined by neutralization titration in the following manner.

[0134] Dissolve 4.0 g of polyamide in 50 mL of benzyl alcohol. Use the resulting solution to titrate with 0.1 N NaOH to determine the amount of carboxyl-terminated groups (microequivalents / g). The endpoint is determined by the color change of phenolphthalein indicator.

[0135] The total amount of active terminals ([NH2] + [COOH]) and the ratio of the amount of amino-terminal group to the total amount of active terminals ([NH2] / ([NH2] + [COOH])) are calculated based on the measured amount of amino-terminal group ([NH2]) and carboxyl-terminal group ([COOH]).

[0136] <Determination of Molecular Weight of Brominated Polystyrene>

[0137] GPC determination conditions

[0138] GPC Unit: HLC-8320GPC (Manufactured by Tosoh Corporation)

[0139] Column: TSKgel GMHHR-H (inner diameter 7.8 mm × 30 cm) × 2 (manufactured by Tosoh Corporation)

[0140] Eluent: Chloroform (pentene additive for HPLC manufactured by Fujifilm and Kazumitsu Chemical Co., Ltd.)

[0141] Detector: Differential refractometer (RI detector), polarity = (+)

[0142] Flow rate: 1.0 mL / min

[0143] Column temperature: 40℃

[0144] Sample concentration: 2 mg / mL

[0145] Injection volume: 100 μL

[0146] Sample pretreatment: Weigh the sample, add the specified amount of eluent, let stand overnight at room temperature, and heat at 50°C for 1 hour to dissolve. Then, slowly shake to mix and filter using a 0.45 μm PTFE cartridge filter. It should be noted that no insoluble matter was observed in the entire sample solution upon visual inspection.

[0147] Calibration curve: A cubic approximation curve was obtained using standard polystyrene (PS) (manufactured by Tosoh Corporation). Therefore, the values ​​obtained are molecular weight converted from PS.

[0148] <Tensile Strength>

[0149] The apparatus used was an "FN3000" manufactured by Nissei Resin Kogyo Co., Ltd. The barrel temperature was set to 290°C and the mold temperature to 80°C. Various polyamide resin compositions were used for injection molding under injection conditions of 10 seconds injection followed by 10 seconds cooling, resulting in molded products (ISO test pieces). The tensile strength was determined using the ISO test pieces according to ISO 527. The measured values ​​were set as the average of n=6.

[0150] <Welding strength>

[0151] Test pieces were obtained by molding using an injection molding machine (PS40E manufactured by Nissei Resin Kogyo Co., Ltd.) equipped with a mold having molten resin flowing into it from both ends along its length (127 mm in length, 12.7 mm in width, and 1.6 mm in thickness), forming a weld seam at the center along its length. Tensile tests were performed on the molded test pieces according to ISO 527, except that the clamp spacing was set to 50 mm and the tensile speed to 50 mm / min. The tensile strength was determined. The measured values ​​were set as the average of n = 6.

[0152] <Evaluation of Flame Retardancy>

[0153] The test was conducted using the UL 94 method (a standard established by Underwriters Laboratories, Inc.). It should be noted that the test piece (127 mm in length, 12.7 mm in width, and 0.75 mm or 0.3 mm in thickness) was manufactured by molding a polyamide resin composition in an injection molding machine (PS40E manufactured by Nissei Resin Kogyo Co., Ltd.) with a mold containing the UL test piece (mold temperature = 80°C) and a barrel temperature = 300°C. The injection pressure was set at the full filling pressure during UL test piece molding + 2%. The flame retardancy rating was determined according to the UL 94 standard (vertical burning test).

[0154] As an evaluation criterion for V-0, a short total flaming time (t1+t2) after two exposures (a total of 10 exposures) for each of the five test pieces, with no flame spread to the fixture holding the test piece, is considered excellent flame retardancy. It should be noted that to obtain a V-0 rating in UL94, the total flaming time must be less than 50 seconds, and the flame must not spread to the fixture.

[0155] <Liquidity>

[0156] The polyamide resin composition was injection molded under the following conditions, and the flow length (spiral flow value) was determined by measuring the length of the molded sheet. It should be noted that before measuring the spiral flow value, the particles were dried at 100°C for 16 to 24 hours to confirm that the particle moisture content was less than 300 ppm, and then the measurement was performed under the following conditions.

[0157] Injection molding machine: EC75S manufactured by Toshiba Machine Co., Ltd.

[0158] Test mold: Spiral mold with an internal groove width (mold cavity) of 10mm and a thickness of 1mm; mold temperature: 80℃

[0159] Set temperature: 285℃

[0160] Injection pressure: 60MPa (injection speed is controlled by pressure within the range set by Max)

[0161] Injection time: 10 seconds

[0162] Cooldown: 10 seconds

[0163] [raw material]

[0164] <(A) Polyamide resin>

[0165] Polyamide 66 with the terminal group concentrations shown in (A-1) and (A-2) below was obtained by polymerization using a 40L autoclave. The terminal groups were adjusted by the type and amount of added terminal group modifier, and the polyamide obtained by melt polymerization was taken out in a linear fashion from the lower nozzle to obtain polyamide particles.

[0166] (A-1) Polyamide 66: Formic acid relative viscosity (RV) = 41, terminal amino concentration (ratio) = 75.5 mEq / kg (59%), terminal carboxyl concentration (ratio) = 52.1 mEq / kg (41%)

[0167] (A-2) Polyamide 66: Formic acid relative viscosity (RV) = 36, terminal amino concentration (ratio) = 38 milliequivalents / kg (30%), terminal carboxyl concentration (ratio) = 90 milliequivalents / kg (70%), otherwise the same as (A-1).

[0168] (A-3) Polyamide 6 (manufactured by Ube Industries, Ltd., model: SF1013A, relative viscosity of formic acid (RV) = 36.0)

[0169] (A-4): Polyamide 6I (formic acid relative viscosity RV: 14.0)

[0170] The polymerization reaction of polyamide 66 is carried out by the "thermal melt polymerization method" in the following manner.

[0171] An equimolar 50% by mass aqueous solution of the raw material monomers was prepared by dissolving 1500g of isophthalic acid and an equimolar salt of hexamethylenediamine, along with an excess of 1.5 mol% adipic acid relative to the total equimolar salt composition, in 1500g of distilled water.

[0172] While stirring at 110℃~150℃, water vapor is slowly extracted to concentrate the solution to a concentration of 70% by mass. Then, the internal temperature is raised to 220℃. At this point, the autoclave is pressurized to 1.8MPa. This state is maintained for 1 hour, and the reaction is allowed to proceed for another hour while slowly extracting water vapor and maintaining the pressure at 1.8MPa, until the internal temperature reaches 245℃.

[0173] Next, the pressure was reduced over 30 minutes. Then, the autoclave was maintained at a reduced pressure of 650 Torr for 10 minutes using a vacuum device. At this point, the final internal temperature of the polymerization was 265°C.

[0174] Then, using nitrogen pressure, the material is made into a thread from the lower spinning nozzle, water-cooled, cut, and discharged as granules. It is then dried at 100°C in a nitrogen atmosphere for 12 hours to obtain polyamide 66.

[0175] <(B) Brominated Polystyrene>

[0176] (B-1) Brominated polystyrene (manufactured by Shandong Sunris New Materials, trade name SR-7010 (component 1: Mw = 178551, Mn = 103616, Mw / Mn = 1.72, content 92%; component 2: Mw = 4443, Mn = 4078, Mw / Mn = 1.09, content 8%)

[0177] (B-2) Brominated polystyrene (manufactured by GBR SVEN INDUSTRIAL, trade name BPS-7010, first component: Mw = 167640, Mn = 94629, Mw / Mn = 1.77, content 53%; second component: Mw = 3808, Mn = 2844, Mw / Mn = 1.34, content 47%)

[0178] (B-3) Brominated polystyrene (manufactured by ALBEMARLE, trade name SAYTEX (registered trademark) HP-7010G (Mw=147109, Mn=55982, Mw / Mn=2.63)

[0179] (B-4) Brominated polystyrene (manufactured by ALBEMARLE, trade name SAYTEX (registered trademark) HP-3010PST (Mw=3557, Mn=2978, Mw / Mn=1.16)

[0180] <(C) Flame retardant additives>

[0181] (C) Antimony trioxide: Manufactured by Campine Company, trade name: Antimony trioxide

[0182] <(D) Inorganic filler materials>

[0183] (D) Glass fiber (GF) (manufactured by PFG, trade name HP3540, average fiber diameter 10μmφ, cut length 3mm)

[0184] <(E) Compatibilizer>

[0185] (E) Copolymer of styrene and maleic anhydride (manufactured by Polyscope, trade name SZ15170, Mw=170000, copolymer of 85% by mass of styrene and 15% by mass of maleic anhydride)

[0186] [Preparation of the composition]

[0187] <Preparation of Polyamide Resin Compositions>

[0188] [Examples 1-7 and Comparative Examples 1-7]

[0189] (Preparation of polyamide resin compositions PA-a1~PA-a7 and PA-b1~PA-b7)

[0190] In addition to combining the raw materials in the manner described in Tables 1 and 2, the various polyamide resin compositions were manufactured using the following methods.

[0191] As a method for manufacturing the polyamide resin composition, a twin-screw extruder (manufactured by Coperon GmbH (Germany), ZSK-26MC) is used. The temperature from the upstream feed port to the die is set to 280°C, the screw speed is set to 300 rpm, and the discharge rate is set to 25 kg / h. The twin-screw extruder has an upstream feed port on the first barrel from the upstream side of the extruder, a downstream feed port on the fourth barrel, and a vacuum devouring port on the eleventh barrel. The L / D ratio (barrel length of the extruder / barrel diameter of the extruder) is 48 (number of barrels: 12). (A) polyamide resin, (B) brominated polystyrene, (C) flame retardant, and (E) compatibilizer are supplied from the upstream feed port, and (D) inorganic filler (glass fiber) is supplied from the downstream feed port. The mixture is then depressurized and melt-blended from the vacuum devouring port to produce granules of the polyamide resin composition.

[0192] Specifically, the polymer is discharged in a linear fashion from the nozzle at the front end of the extruder, the resin temperature is measured, and then it is water-cooled and cut to obtain granules of the polyamide resin composition.

[0193] Furthermore, using the obtained polyamide resin composition, molded articles were manufactured by the method described above, and the moldability, weld strength, and flame retardancy during molding were evaluated. The evaluation results are shown in Tables 1 and 2 below.

[0194] [Table 1]

[0195]

[0196] [Table 2]

[0197]

[0198] As shown in Table 1, in Examples 1 to 7, which contain components (A) to (D) and meet the specified range, the flowability, flame retardancy, tensile properties, and weld strength are all good.

[0199] On the other hand, as shown in Table 2, in Comparative Examples 1 to 7, when the weight-average molecular weight ratio of (B) brominated polystyrene was outside the range, or when the ratio of components (A) to (D) did not meet the specified range, compositions with good flowability, flame retardancy, tensile properties, and weld strength were not obtained.

[0200] Industrial practicality

[0201] The polyamide resin composition according to this embodiment can stably provide polyamide resin compositions and molded articles with excellent mechanical properties, molding flowability, and flame retardancy. In particular, despite its thinness, it exhibits excellent flame retardancy and weld strength, making it more suitable for use in dense electrical and electronic component applications.

Claims

1. A polyamide resin composition comprising 20% ​​to 70% by mass of (A) polyamide, 20% to 35% by mass of (B) brominated polystyrene, 1% to 15% by mass of (C) a flame retardant additive, and 10% to 60% by mass of (D) an inorganic filler, wherein the sum of the contents of all components in the polyamide resin composition is 100% by mass, wherein... The brominated polystyrene (B) contains 64% to 71% bromine by mass, and contains components with a weight-average molecular weight of 1,000 to 5,000 and components with a weight-average molecular weight of 150,000 to 200,000. In (B) brominated polystyrene, the proportion of components with a weight average molecular weight of 1000-5000 is 1%-20% by mass, and the proportion of components with a weight average molecular weight of 150,000-200,000 is 80%-99% by mass. The flame retardant additive (C) is selected from at least one of antimony oxides, tin oxides, iron oxides, and metal borates.

2. The polyamide resin composition according to claim 1, wherein, In the brominated polystyrene described in (B), the molecular weight distribution Mw / Mn of the component with a weight average molecular weight of 1000-5000 is 1.0-2.0, and the molecular weight distribution Mw / Mn of the component with a weight average molecular weight of 150000-200000 is 1.1-3.

0.

3. The polyamide resin composition according to claim 2, wherein, In the brominated polystyrene described in (B), the molecular weight distribution Mw / Mn of the component with a weight average molecular weight of 1000 to 5000 is 1.05 to 1.

30.

4. The polyamide resin composition according to claim 2, wherein, In the (B) brominated polystyrene, the molecular weight distribution Mw / Mn of the component with a weight-average molecular weight of 150,000 to 200,000 is 1.5 to 2.

5.

5. The polyamide resin composition according to claim 1 or 2, wherein, The bromine content in (B) brominated polystyrene is 65% to 69% by mass.

6. The polyamide resin composition according to claim 1 or 2, wherein, The flame retardant additive (C) is antimony trioxide.

7. The polyamide resin composition according to claim 1 or 2, wherein, The average particle size of the flame retardant additive (C) is 0.01 μm to 10 μm.

8. The polyamide resin composition according to claim 1 or 2, wherein, The inorganic filler material (D) is selected from one or more of the following: glass fiber, carbon fiber, calcium silicate fiber, potassium titanate fiber, flake glass, talc, kaolin, mica, hydrotalcite, calcium carbonate, zinc carbonate, dicalcium phosphate, wollastonite, silica, zeolite, alumina, boehmite, titanium dioxide, silicon dioxide, 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, swelling fluoromica, and apatite.

9. The polyamide resin composition according to claim 1 or 2, wherein, The polyamide resin composition further comprises (E) a compatibilizer, wherein the (E) compatibilizer is at least one selected from copolymers of aromatic vinyl compounds and α,β-unsaturated dicarboxylic anhydrides, and polymers modified with α,β-unsaturated dicarboxylic anhydrides.

10. The polyamide resin composition of claim 9, wherein, The aromatic vinyl compound is a compound represented by the following general formula (2). In general formula (2), R 3 and R 4 Each is independently a hydrogen or an alkyl group having 1 to 3 carbon atoms, and k is an integer from 1 to 5.

11. The polyamide resin composition of claim 9, wherein, The aromatic vinyl compound is styrene, α-methylstyrene, or p-methylstyrene.

12. The polyamide resin composition of claim 9, wherein, The α,β-unsaturated dicarboxylic anhydride is a compound represented by the following general formula (1). In general formula (1), R 1 and R 2 Each is independently a hydrogen or an alkyl group having 1 to 3 carbon atoms.

13. The polyamide resin composition of claim 9, wherein, The α,β-unsaturated dicarboxylic acid anhydride is maleic anhydride or methylmaleic anhydride.

14. The polyamide resin composition of claim 9, wherein, The compatibilizer (E) is selected from at least one of styrene-maleic anhydride copolymers and polyphenylene ether resins modified with α,β-unsaturated dicarboxylic anhydrides.

15. The polyamide resin composition of claim 9, wherein, In the copolymer of the aromatic vinyl compound and α,β-unsaturated dicarboxylic anhydride, the aromatic vinyl compound content is 50% to 99% by mass, and the α,β-unsaturated dicarboxylic anhydride content is 1% to 50% by mass.

16. The polyamide resin composition of claim 15, wherein, The proportion of the α,β-unsaturated dicarboxylic anhydride component is 5% to 20% by mass.

17. The polyamide resin composition of claim 15 or 16, wherein, The proportion of the α,β-unsaturated dicarboxylic anhydride component is 8% to 15% by mass.

18. The polyamide resin composition according to claim 1 or 2, wherein, The polyamide (A) is an aliphatic polyamide, a polyamide containing an aromatic component, a copolymer or mixture of aliphatic polyamides, a copolymer or mixture of polyamides containing aromatic components, or a copolymer or mixture of an aliphatic polyamide and a polyamide containing an aromatic component.

19. The polyamide resin composition according to claim 1 or 2, wherein, The polyamide (A) is selected from one or more of the following: polyamide 6, polyamide 66, polyamide 46, polyamide 610, polyamide 612, polyamide 116, polyamide 11, polyamide 12, polyamide MXD6, polyamide 6T, polyamide 6I, polyamide 9T, polyamide 12T, polyamide 4I, 66 / 6I copolyamide, 66 / 6 copolyamide, 6I / 6T copolyamide, 66 / 6I / 6T ternary copolyamide, 66 / 6I / 6 ternary copolyamide, and 6 / 6I / 6T ternary copolyamide.

20. The polyamide resin composition according to claim 1 or 2, wherein, The polyamide (A) has a melting point above 240°C and below 270°C.

21. The polyamide resin composition according to claim 1 or 2, wherein, The relative viscosity of the polyamide (A) as determined by ASTM D789 is in the range of 10 to 70.

22. The polyamide resin composition of claim 21, wherein, The relative viscosity of the polyamide (A) as determined by ASTM D789 is in the range of 30 to 60.

23. The polyamide resin composition of claim 21, wherein, The relative viscosity of the polyamide (A) as determined by ASTM D789 is in the range of 35 to 55.

24. The polyamide resin composition according to claim 1 or 2, wherein, The ratio of the amount of amino-terminal groups to the total molar amount of amino-terminal groups and carboxyl-terminal groups in the polyamide (A) [Amount of amino-terminal groups / (Amount of amino-terminal groups + Amount of carboxyl-terminal groups)] is greater than or equal to 0.2 and less than 1.

0.

25. The polyamide resin composition of claim 24, wherein, The ratio of the amount of amino-terminal groups to the total molar amount of amino-terminal groups and carboxyl-terminal groups in the polyamide (A) [Amount of amino-terminal groups / (Amount of amino-terminal groups + Amount of carboxyl-terminal groups)] is 0.2 or more and 0.5 or less.

26. The polyamide resin composition of claim 24, wherein, The ratio of the amount of amino-terminal groups to the total molar amount of amino-terminal groups and carboxyl-terminal groups in the polyamide (A) [Amount of amino-terminal groups / (Amount of amino-terminal groups + Amount of carboxyl-terminal groups)] is 0.2 or more and 0.4 or less.

27. The polyamide resin composition according to claim 1 or 2, wherein, The content of polyamide (A) is 23% by mass or more and 65% by mass or less relative to 100% by mass of the polyamide resin composition.

28. The polyamide resin composition according to claim 1 or 2, wherein, The content of polyamide (A) is 25% by mass or more and 60% by mass or less relative to 100% by mass of the polyamide resin composition.

29. The polyamide resin composition according to claim 1 or 2, wherein, The content of (B) brominated polystyrene is 20% to 30% by mass relative to 100% by mass of the polyamide resin composition.

30. The polyamide resin composition according to claim 1 or 2, wherein, The content of (B) brominated polystyrene is 20% to 25% by mass relative to 100% by mass of the polyamide resin composition.

31. The polyamide resin composition according to claim 1 or 2, wherein, The content of the flame retardant (C) is 2% to 10% by mass relative to 100% by mass of the polyamide resin composition.

32. The polyamide resin composition according to claim 1 or 2, wherein, The content of the inorganic filler (D) is 13% to 50% by mass relative to 100% by mass of the polyamide resin composition.

33. The polyamide resin composition according to claim 1 or 2, wherein, The content of the inorganic filler (D) is 15% to 40% by mass relative to 100% by mass of the polyamide resin composition.

34. The polyamide resin composition of claim 9, wherein, The content of the (E) compatibilizer is 0.1% to 20% by mass relative to 100% by mass of the polyamide resin composition.

35. The polyamide resin composition of claim 9, wherein, The content of the (E) compatibilizer is 0.5% to 20% by mass relative to 100% by mass of the polyamide resin composition.

36. The polyamide resin composition of claim 9, wherein, The content of the (E) compatibilizer is 1% to 15% by mass relative to 100% by mass of the polyamide resin composition.

37. The polyamide resin composition of claim 9, wherein, The content of the (E) compatibilizer is 2% to 10% by mass relative to 100% by mass of the polyamide resin composition.

38. A molded article, wherein, The molded article is obtained by molding the polyamide resin composition according to any one of claims 1 to 37.

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