Thermoplastic resin composition and molded article

Abstract

The present invention relates to a thermoplastic resin composition which contains, when the total amount of components (A) to (E) is 100 parts by weight: 20-80 parts by weight of a polyamide (A) that includes a recycled polyamide; 10-30 parts by weight of a graft copolymer (B) that is obtained by the graft copolymerization of a vinyl-based monomer mixture containing an aromatic vinyl-based monomer (b2) and a vinyl cyanide-based monomer (b3) in the presence of a rubbery polymer (b1); 1-20 parts by weight of a vinyl-based copolymer (C) that is obtained by the copolymerization of a vinyl-based monomer mixture containing an aromatic vinyl-based monomer (c1) and a vinyl cyanide monomer (c2); 1-10 parts by weight of a modified vinyl-based copolymer (D) that is obtained by the copolymerization of at least one monomer (d1) selected from the group consisting of unsaturated carboxylic acids and α,β-unsaturated carboxylic anhydrides, an aromatic vinyl-based monomer (d2), and a vinyl cyanide-based monomer (d3); and 1-10 parts by weight of an acid-modified polyolefin (E).

Description

Thermoplastic resin composition and molded article

[0001] The present invention relates to thermoplastic resin compositions containing polyamide resins and graft copolymers, typically acrylonitrile butadiene styrene resins (hereinafter referred to as ABS resins), and molded articles made therefrom.

[0002] Patent Document 1 proposes blending ABS resin, which has excellent impact strength and paint adhesion, with polyamide, and discloses a technique for blending two types of ABS resin with different fluidity (ABS resin with a high melt flow rate and ABS resin with a low melt flow rate) with polyamide in order to improve paint adhesion.

[0003] Furthermore, since conventional automotive applications require mechanical properties and heat resistance, Patent Document 2 proposes a resin composition in which a styrene-acrylonitrile-methacrylic acid copolymer having a specific reduced viscosity and an inorganic filler are added to polyamide and ABS resin.

[0004] Patent Document 3 proposes a resin composition comprising polyamide, graft copolymer, vinyl copolymer, modified vinyl copolymer, thermoplastic resin composition, and fiber reinforcement material for improving the rigidity, impact ductility, moldability, paint appearance, and paint adhesion of injection molded products. It describes conditions in which the melt viscosity ratio is defined within the shear rate range of injection molding in which the polyamide is a continuous phase.

[0005] Japanese Patent Publication No. 2002-302603, Japanese Patent Publication No. 2004-149791, Japanese Patent Publication No. 2009-256647

[0006] The inventions described in Patent Documents 1, 2, and 3 all use virgin resin materials, resulting in a significant environmental impact and posing a challenge to the environmental impact reduction goals advocated by the automotive industries in Japan and Europe in recent years. Furthermore, since recycled materials are collected after long-term use and manufactured through various recycling processes, their properties may have changed from those of the virgin material before use. Therefore, when recycled materials are used, qualities such as mechanical strength and heat resistance deteriorate, and in particular, if the recycled materials have high viscosity, moldability is impaired, making it necessary to improve fluidity.

[0007] The objective of this invention is to provide mechanical strength, heat resistance, and impact resistance comparable to virgin resin materials while utilizing recycled resources.

[0008] To solve the above problems, the present invention has the following configuration.

[0009] (1) A thermoplastic resin composition comprising, with a total of 100 parts by weight of (A) to (E) below, 20 to 80 parts by weight of polyamide (A) containing recycled polyamide, 10 to 30 parts by weight of graft copolymer (B) obtained by graft copolymerizing a vinyl monomer mixture containing an aromatic vinyl monomer (b2) and a vinyl cyanide monomer (b3) in the presence of a rubbery polymer (b1), 1 to 20 parts by weight of vinyl copolymer (C) obtained by copolymerizing a vinyl monomer mixture containing an aromatic vinyl monomer (c1) and a vinyl cyanide monomer (c2), 1 to 10 parts by weight of modified vinyl copolymer (D) obtained by copolymerizing at least one monomer (d1) selected from the group consisting of unsaturated carboxylic acids and α,β-unsaturated carboxylic acid anhydrides, an aromatic vinyl monomer (d2), and a vinyl cyanide monomer (d3), and 1 to 10 parts by weight of acid-modified polyolefin (E).

[0010] (2) The thermoplastic resin composition according to (1), further comprising 0.01 to 1 part by weight of acid anhydride (F) with a total of 100 parts by weight of (A) to (E).

[0011] (3) The thermoplastic resin composition according to (2), wherein the acid anhydride (F) is at least one selected from the group consisting of succinic anhydride, phthalic anhydride, benzoic anhydride, isobutyric anhydride, itaconic anhydride, octanoic anhydride, glutaric anhydride, acetic anhydride, dimethylmaleic anhydride, decanoic anhydride, trimellitic anhydride, 1,8-naphthalic anhydride, and maleic anhydride.

[0012] (4) The thermoplastic resin composition according to any one of (1) to (3), wherein the graft copolymer (B) is obtained by graft copolymerizing 20 to 60% by weight of the vinyl monomer mixture in the presence of 40 to 80% by weight of the rubbery polymer (b1), with a total of 100% by weight of the rubbery polymer (b1) and the vinyl monomer mixture.

[0013] (5) The thermoplastic resin composition according to (4), wherein the vinyl monomer mixture comprises 5 to 45% by weight of an aromatic vinyl monomer (b2), 5 to 30% by weight of a vinyl cyanide monomer (b3), and 0 to 50% by weight of other monomers copolymerizable thereto (b4), based on 100% by weight of the total of the rubbery polymer (b1) and the vinyl monomer mixture.

[0014] (6) The vinyl copolymer (C) is obtained by copolymerizing 70 to 80% by weight of an aromatic vinyl monomer (c1), 20 to 30% by weight of a vinyl cyanide monomer (c2), and 0 to 10% by weight of another monomer (c3) copolymerizable with these, according to any one of (1) to (5).

[0015] (7) The thermoplastic resin composition according to any one of (1) to (6), wherein the weight-average molecular weight of the vinyl copolymer (C) is 80,000 to 130,000.

[0016] (8) The thermoplastic resin composition according to any one of (1) to (7), further comprising 5 to 40 parts by weight of inorganic reinforcing material (G), with the total of (A) to (E) being 100 parts by weight.

[0017] (9) A molded article obtained by molding any of the thermoplastic resin compositions described in (1) to (8).

[0018] According to the present invention, by utilizing polyamide derived from recycled materials, it is possible to reduce the environmental burden and obtain thermoplastic resin compositions and molded articles with mechanical properties and heat resistance comparable to virgin resin materials. Furthermore, by incorporating acid anhydrides, the moldability of the thermoplastic resin composition can be improved, and molded articles obtained from these thermoplastic resin compositions are useful for automotive interior and exterior parts, motorcycle exterior parts, and the like.

[0019] The thermoplastic resin composition and molded article of the present invention will be described in detail below. In this specification, the "~" indicating a numerical range is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0020] It is important that the polyamide (A) used in the present invention includes recycled polyamide obtained from material recycling or chemical recycling. As recycled polyamide, material recycling materials can be used, which are obtained by melting and reusing industrial waste such as polymer scraps of polyamide, fiber scraps, and molded product scraps, or chemical recycling materials, which are obtained by depolymerizing such industrial waste or used waste, and then repolymerizing the monomers obtained. Among these, as material recycled polyamide resin, recycled polyamide resin obtained by chipping process scraps, polymer scraps, and fiber scraps generated in the manufacturing process of polyamide fibers is preferred in terms of quality stability. As chemical recycled resin, recycled polyamide resin obtained by depolymerizing waste fishing nets to monomers and then repolymerizing them is preferred.

[0021] The proportion of polyamide (A) used in the present invention is 20 to 80 parts by weight, preferably 30 to 70 parts by weight, more preferably 40 to 60 parts by weight, and more preferably 45 to 60 parts by weight, based on a total of 100 parts by weight of (A) to (E). In particular, by using 40 parts by weight or more of polyamide, it becomes possible to make polyamide (A) a continuous phase, resulting in a resin composition with excellent heat resistance. If the proportion of polyamide (A) used is less than 20 parts by weight, impact ductility, moldability, and paint appearance are insufficient. On the other hand, if the proportion used is more than 80 parts by weight, impact ductility and paint adhesion are insufficient, and dimensional changes during water absorption become large, which hinders part assembly.

[0022] Furthermore, the recycled polyamide contained in polyamide (A) in the present invention may be the entire amount of polyamide (A) or a portion thereof. A higher recycled polyamide content is advantageous in terms of environmental impact, but virgin polyamide may also be included to control the properties of the composition. The ratio of recycled polyamide to polyamide (A) is preferably 20% to 100% by weight, more preferably 40% to 100% by weight, and particularly preferably 50% to 100% by weight.

[0023] In the present invention, a particularly useful polyamide (A) is a resin made of a polymer having amide bonds, and is mainly made from amino acids, lactams or diamines and dicarboxylic acids. Typical examples of these raw materials include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and para-aminomethylbenzoic acid; lactams such as ε-caprolactam and ω-laurolactam; aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, and 5-methylnonamethylenediamine; aromatic diamines such as metaxylylenediamine and paraxylylenediamine; and 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, and 1-amino- Examples include alicyclic diamines such as 3-aminomethyl-3,5,5-trimethylcyclohexane, bis(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminopropyl)piperazine, and aminoethylpiperazine; aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. In the present invention, two or more polyamide homopolymers or copolymers derived from these raw materials may be blended.

[0024] In the present invention, the particularly useful polyamide (A) is a polyamide with excellent heat resistance and strength, having a crystal melting temperature of 150°C or higher. From the viewpoint of heat resistance and moldability, the crystal melting temperature is preferably 320°C or lower, and more preferably 300°C or lower.Specific examples of polyamides having a crystal melting temperature of 150°C to 320°C include polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), polypentamethylene adipamide (polyamide 56), polytetramethylene adipamide (polyamide 46), polyhexamethylene sevacamide (polyamide 610), polypentamethylene sevacamide (polyamide 510), polytetramethylene sevacamide (polyamide 410), polyhexamethylene dodecamide (polyamide 612), and polyundecane. Polyamide (Polyamide 11), Polydodecanamide (Polyamide 12), Polycaproamide / Polyhexamethylene adipamide copolymer (Polyamide 6 / 66), Polycaproamide / Polyhexamethylene terephthalamide copolymer (Polyamide 6 / 6T), Polyhexamethylene adipamide / Polyhexamethylene terephthalamide copolymer (Polyamide 66 / 6T), Polyhexamethylene adipamide / Polyhexamethylene isophthalamide copolymer (Polyamide 66 / 6I), Polyhexamethylene adipamide / Polyhexa Methylene isophthalamide / polycaproamide copolymer (polyamide 66 / 6I / 6), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 6T / 6I), polyhexamethylene terephthalamide / polydecaneamide copolymer (polyamide 6T / 12), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6T / 6I), polyxylylene adipamide (polyamide XD6), poly Examples include hexamethylene terephthalamide / poly-2-methylpentamethylene terephthalamide copolymer (polyamide 6T / M5T), polyhexamethylene terephthalamide / polypentamethylene terephthalamide copolymer (polyamide 6T / 5T), polypentamethylene terephthalamide / polypentamethylene adipamide copolymer (5T / 56), polynonamethylene terephthalamide (polyamide 9T), polydecamethylene terephthalamide (polyamide 10T), and mixtures or copolymers thereof. Here, " / " indicates a copolymer, and the same applies hereafter.

[0025] Particularly preferred examples include polyamide 6, polyamide 66, polyamide 56, polyamide 610, polyamide 510, polyamide 410, polyamide 612, polyamide 11, polyamide 12, polyamide 6 / 66, polyamide 66 / 6T, polyamide 6T / 6I, polyamide 66 / 6I / 6, polyamide 6T / 5T, etc. It is also practically preferable to blend two or more of these polyamides according to required properties such as moldability, heat resistance, toughness and surface properties. Among these, polyamide 6, polyamide 66, polyamide 610, polyamide 11, polyamide 12, and polyamide 66 / 6T are excellent in the balance of strength, rigidity, heat resistance and injection moldability, and in high-speed compression of a prismatic molded article obtained by melt-molding a thermoplastic resin composition using these polyamides, the displacement until the load becomes zero and the load at the rising edge can be further increased, and thus these are most preferred.

[0026] There are no particular restrictions on the amount of terminal groups of these polyamides (A), but the amount of amino terminal groups is 2×10 －６ mol / g or more, which is preferable from the viewpoint of reactivity with the graft copolymer (B) having a reactive functional group, and on the other hand, from the viewpoint of suppressing a decrease in molding processability due to excessive reaction, it is 1×10 －４ mol / g or less. The amount of amino terminal groups as referred to herein can be measured by dissolving a polyamide resin in an 85% by weight phenol-ethanol solution, using thymol blue as an indicator, and performing titration with an aqueous hydrochloric acid solution.

[0027] There are no particular restrictions on the degree of polymerization of these polyamides, but the relative viscosity is preferably 1.8 to 7.0, more preferably 2.0 to 4.0. The relative viscosity as referred to herein means a value measured at 25°C in a 98% concentrated sulfuric acid solution having a polyamide resin concentration of 0.01 g / ml. In the present invention, the relative viscosity can also be adjusted by blending and adding two or more types of polyamides (A) having different relative viscosities. By using a polyamide having a relative viscosity of 1.8 or more, the impact properties of the composition can be improved; and by setting the relative viscosity of the polyamide to 7.0 or less, a composition excellent in molding processability can be obtained, which not only provides a molded article excellent in appearance, but also can improve the chemical resistance of the molded article.

[0028] The graft copolymer (B) in the present invention is a graft copolymer (B) obtained by graft-copolymerizing a vinyl monomer mixture containing at least an aromatic vinyl monomer (b2), a vinyl cyanide monomer (b3), and optionally another monomer (b4) copolymerizable therewith, in the presence of a rubbery polymer (b1).

[0029] The graft copolymer referred to herein includes, in addition to the product obtained by graft-copolymerizing the vinyl monomer mixture onto the rubbery polymer (b1), a copolymer produced from a non-grafted vinyl mixture soluble in acetone, and these are collectively referred to as the graft copolymer (B). Further, the graft ratio is preferably 5 to 60%, more preferably 10 to 50%, from the viewpoint of the balance between impact ductility morphology and molding processability. The graft ratio (%) is represented by the following formula. Graft ratio (%) = [Amount of vinyl polymer graft-polymerized onto rubbery polymer] / [Rubber content of graft copolymer] × 100. Furthermore, as the above rubbery polymer (b1), those having a glass transition temperature of 0°C or lower are suitable, and the lower limit thereof is practically about -80°C.

[0030] Examples of rubbery polymers (b1) include diene-based rubbery polymers such as polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, styrene-butadiene block copolymer, and butyl acrylate-butadiene copolymer. Among these, polybutadiene is preferably used as the rubbery polymer (b1).

[0031] Examples of the above-mentioned aromatic vinyl monomer (b2) include styrene, α-methylstyrene, vinyltoluene, o-ethylstyrene, p-methylstyrene, chlorostyrene, and bromostyrene, but styrene is particularly preferred.

[0032] Furthermore, examples of the vinyl cyanide monomer (b3) mentioned above include acrylonitrile, methacrylonitrile, and ethacrylonitrile, but acrylonitrile is particularly preferred.

[0033] Furthermore, the graft copolymer (B) in the present invention may be replaced with other copolymerizable monomers (b4) to the extent that the effects of the present invention are not lost. Examples include N-phenylmaleimide, N-methylmaleimide, and methyl methacrylate, which can be selected according to the purpose. These can be used individually or in combination. If the intention is to improve heat resistance or flame retardancy, N-phenylmaleimide is preferred. Also, if the emphasis is on improving hardness or transparency, methyl methacrylate is preferably used.

[0034] The rubber particle diameter of the rubbery polymer (b1) used in the present invention is preferably 0.10 to 0.50 μm, and more preferably 0.18 to 0.40 μm, from the viewpoint of impact ductility. This weight-average particle diameter can be measured by the sodium alginate method described in "Rubbaer Age Vol. 88 pp. 484-490 (1960) by E. Schmidt, P.H. Biddison" (determining the particle diameter at a cumulative weight fraction of 50% from the concentration ratio of sodium alginate and the cumulative weight fraction of sodium alginate concentration).

[0035] The proportion of rubber polymer (b1) used in the total 100% by weight of the rubber polymer (b1) and vinyl monomer mixture is preferably adjusted to 40 to 80% by weight. The proportion of rubber polymer (b1) used is preferably 45 to 75% by weight, and more preferably 50 to 70% by weight. A usage proportion of 40% by weight or more improves impact ductility, and a usage proportion of 80% by weight or less improves moldability and the surface appearance of the molded product.

[0036] The proportion of the vinyl monomer mixture used in the total 100% by weight of the rubbery polymer (b1) and the vinyl monomer mixture is preferably adjusted to 20 to 60% by weight, more preferably 25 to 55% by weight, more preferably 25 to 50% by weight, and particularly preferably 25 to 45% by weight. A proportion of 20% by weight or more improves the moldability of the composition and results in a good surface appearance. A proportion of 60% by weight or less results in good impact ductility of the composition.

[0037] The composition ratio of aromatic vinyl monomer (b2), vinyl cyanide monomer (b3), and other monomers copolymerizable with these (b4) is preferably designed such that, for example, in a total of 100% by weight of the rubbery polymer (b1) and vinyl monomer mixture, the aromatic vinyl monomer (b2) is 5 to 45% by weight, the vinyl cyanide monomer (b3) is 5 to 30% by weight, and the other monomers copolymerizable with these (b4) is 0 to 50% by weight.

[0038] The amount of graft copolymer (B) in the present invention is 10 to 30 parts by weight, where the total of (A) to (E) is 100 parts by weight. By using this range, a composition with well-balanced mechanical properties can be obtained. Preferably, the amount of graft copolymer (B) is 15 to 20 parts by weight.

[0039] In the present invention, the vinyl copolymer (C) refers to a copolymer obtained by copolymerizing a vinyl monomer mixture containing an aromatic vinyl monomer (c1), a vinyl cyanide monomer (c2), and optionally other monomers copolymerizable with these (c3).

[0040] Examples of the above-mentioned aromatic vinyl monomer (c1) include styrene, α-methylstyrene, vinyltoluene, o-ethylstyrene, p-methylstyrene, chlorostyrene, and bromostyrene, but styrene is particularly preferred.

[0041] Furthermore, examples of the vinyl cyanide monomer (c2) mentioned above include acrylonitrile, methacrylonitrile, and ethacrylonitrile, but acrylonitrile is particularly preferred.

[0042] Other copolymerizable monomers (c3) include, for example, N-phenylmaleimide, N-methylmaleimide, and methyl methacrylate, which can be selected according to the purpose. These can be used individually or in combination. If the intention is to improve heat resistance or flame retardancy, N-phenylmaleimide is preferred. If the emphasis is on improving hardness or transparency, methyl methacrylate is preferred.

[0043] Preferably, the monomer composition ratio of the vinyl copolymer (C) is that of a copolymer obtained by copolymerizing a monomer mixture consisting of 10 to 85% by weight of an aromatic vinyl monomer (c1), 10 to 85% by weight of a vinyl cyanide monomer (c2), and 0 to 80% by weight of another monomer copolymerizable with these (c3). More preferably, the monomer composition ratio of the vinyl copolymer (C) is that of a copolymer obtained by copolymerizing a monomer mixture consisting of 70 to 80% by weight of an aromatic vinyl monomer (c1), 20 to 30% by weight of a vinyl cyanide monomer (c2), and 0 to 10% by weight of another monomer copolymerizable with these (c3).

[0044] The intrinsic viscosity of the vinyl copolymer (C) is preferably 0.1 to 1.0 dl / g, and more preferably 0.3 to 0.8 dl / g.

[0045] This intrinsic viscosity can be measured by dissolving the vinyl copolymer in a methyl ethyl ketone solvent and measuring it at a temperature of 30°C. In this invention, it is necessary to adjust the melt viscosity ratio with polyamide, so the intrinsic viscosity of the vinyl copolymer (C) should be adjusted to satisfy the conditions described later.

[0046] The weight-average molecular weight of the vinyl copolymer (C) is preferably 80,000 to 130,000. The weight-average molecular weight can be measured by the method described in the examples below.

[0047] The amount of vinyl copolymer (C) in the present invention is 1 to 20 parts by weight, where the total of (A) to (E) is 100 parts by weight. By using this range, a composition with well-balanced mechanical properties can be obtained. The amount of vinyl copolymer (C) is preferably 5 to 15 parts by weight, and more preferably 10 to 15 parts by weight.

[0048] The modified vinyl copolymer (D) in the present invention is a modified vinyl copolymer (D) obtained by copolymerizing at least one monomer (d1) selected from the group consisting of unsaturated carboxylic acids and α,β-unsaturated carboxylic acid anhydrides, an aromatic vinyl monomer (d2), and a vinyl cyanide monomer (d3). Preferably, a copolymer obtained by copolymerizing 0.1 to 10% by weight of at least one monomer (d1) selected from the group consisting of unsaturated carboxylic acids and α,β-unsaturated carboxylic acid anhydrides with a total of 90 to 99.9% by weight of the aromatic vinyl monomer (d2) and the vinyl cyanide monomer (d3) is used.

[0049] The modified vinyl copolymer (D) referred to herein is composed of at least one monomer (d1) selected from the group consisting of the above-mentioned unsaturated carboxylic acids and α,β-unsaturated carboxylic acid anhydrides. Examples include unsaturated carboxylic acids such as methacrylic acid, maleic acid, fumaric acid, itaconic acid, methylmaleic acid, methylfumaric acid, and glutaconic acid, and α,β-unsaturated carboxylic acid anhydrides such as maleic anhydride, phthalic anhydride, itaconic anhydride, methylmaleic anhydride, and methylfumaric anhydride. Among these, methacrylic acid, maleic acid, and maleic anhydride are preferred, and methacrylic acid is more preferably used. These may be used individually or in combination of two or more.

[0050] Furthermore, examples of the aromatic vinyl monomer (d2) constituting the modified vinyl copolymer (D) include styrene, α-methylstyrene, vinyltoluene, o-ethylstyrene, p-methylstyrene, chlorostyrene, and bromostyrene, but styrene is particularly preferred.

[0051] Furthermore, examples of the vinyl cyanide monomer (d3) constituting the modified vinyl copolymer (D) include acrylonitrile, methacrylonitrile, and ethacrylonitrile, but acrylonitrile is particularly preferred.

[0052] The proportion of at least one monomer (d1) selected from the group consisting of unsaturated carboxylic acids and α,β-unsaturated carboxylic acid anhydrides in the overall modified vinyl copolymer (D) is preferably 0.1 to 10% by weight. A proportion of 0.1% by weight or more provides excellent compatibility and reactivity with polyamide (A), improves impact ductility and paint adhesion, and prevents problems such as paint peeling. Furthermore, a proportion of 10% by weight or less provides improved moldability and prevents the occurrence of flow marks.

[0053] Furthermore, it is preferable to adjust the proportion of the vinyl monomer mixture containing aromatic vinyl monomer (d2) and vinyl cyanide monomer (d3) in the modified vinyl copolymer (D) to 90 to 99.9% by weight. By setting the proportion to 90% by weight or more, it is possible to obtain a composition with improved moldability and no flow marks. Alternatively, setting the proportion to 99.9% by weight or less is preferable because it provides excellent compatibility and reactivity with polyamide (A), and improves impact ductility and paint adhesion.

[0054] The monomer composition ratio of the aromatic vinyl monomer (d2) and the vinyl cyanide monomer (d3) constituting the modified vinyl copolymer (D) is preferably 15:85 to 85:15 for aromatic vinyl monomer (d2) and vinyl cyanide monomer (d3). For example, the copolymer may be obtained by copolymerizing a monomer mixture consisting of 15 to 85% by weight of aromatic vinyl monomer (d2) and 15 to 85% by weight of vinyl cyanide monomer (d3).

[0055] The amount of modified vinyl copolymer (D) in the present invention is 1 to 10 parts by weight, where the total of (A) to (E) is 100 parts by weight. By setting the amount within this range, a composition with excellent paint adhesion and other properties can be obtained. Preferably, the amount of modified vinyl copolymer (D) is 5 to 8 parts by weight.

[0056] In the present invention, acid-modified polyolefin (E) refers to a polyolefin-based rubber modified with carboxyl groups, anhydrous carboxyl groups, epoxy groups, oxazoline groups, and the like.

[0057] The above-mentioned acid-modified polyolefin (E) polyolefin rubber can be selected from polyolefin rubbers such as ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / ethyl acrylate / carbon monoxide copolymer, ethylene / glycidyl methacrylate copolymer, ethylene / methyl acrylate / glycidyl methacrylate copolymer, ethylene / butyl acrylate / glycidyl methacrylate copolymer, ethylene / octene-1 copolymer, and ethylene / butene-1 copolymer. These do not necessarily have to be used individually; two or more types can be mixed and used together.

[0058] The amount of acid-modified polyolefin (E) added is in the range of 1 to 10 parts by weight, with the total of (A) to (E) being 100 parts by weight. The preferred lower limit is 2 parts by weight or more, more preferably 5 parts by weight or more, and the preferred upper limit is 8 parts by weight or less. If the amount of acid-modified polyolefin (E) added is less than 1 part by weight, the impact ductility of the molded product is impaired. On the other hand, if an amount exceeding 10 parts by weight is added, the impact ductility becomes very high, but the moldability, especially the fluidity during injection molding, decreases, and in some cases the molded product may not be able to be completely filled, which is undesirable.

[0059] In the present invention, an acid anhydride (F) may be added to improve the fluidity of the thermoplastic resin composition. The acid anhydride (F) can sequester the amino-terminated groups of the polyamide, thereby improving the fluidity when the thermoplastic resin composition is injection molded. Examples of acid anhydrides include benzoic acid anhydride, isobutyric acid anhydride, itaconic acid anhydride, octanoic acid anhydride, glutaric acid anhydride, succinic acid anhydride, acetic acid anhydride, dimethylmaleic anhydride, decanoic acid anhydride, trimellitic acid anhydride, 1,8-naphthalic acid anhydride, phthalic acid anhydride, maleic acid anhydride and its derivatives. Two or more of these may be added, with succinic acid anhydride and phthalic acid anhydride being preferred, and succinic acid anhydride being particularly preferred.

[0060] The amount of acid anhydride (F) added is preferably 0.01 to 1 part by weight, more preferably 0.03 to 1 part by weight, and even more preferably 0.05 to 0.5 parts by weight, based on 100 parts by weight of the total of (A) to (E). By adding 0.01 parts by weight or more of acid anhydride (F), the fluidity during injection molding can be further improved. Furthermore, by adding 1 part by weight or less of acid anhydride (F), the mechanical properties of the thermoplastic resin composition can be maintained.

[0061] In this invention, inorganic reinforcing materials (G) can be incorporated for purposes such as improving mechanical properties. Examples of inorganic reinforcing materials (G) that can be used include carbon fibers, glass fibers, stainless steel fibers, whiskers, and wollastonite. To maintain a glossy and good appearance, carbon fibers or glass fibers are preferred, with glass fibers being particularly preferred.

[0062] When using a fibrous filler as an inorganic reinforcing material (G), the fiber length (weight-average fiber length) is preferably 2 to 15 mm, and the fiber diameter is preferably 2 to 20 μm. By setting the fiber length to 2 mm or more, sufficient mechanical properties can be obtained, and by setting it to 15 mm or less, the appearance of the molded product obtained from the composition can be improved. Furthermore, by using a fiber diameter of 2 μm or more, sufficient mechanical properties can be obtained, and by setting it to 20 μm or less, a molded product with an excellent appearance can be obtained.

[0063] Furthermore, it is preferable that the inorganic reinforcing material (G) used in the present invention is treated with a coupling agent or a converging agent. Examples of treatment methods include treatment by introducing functional groups such as isocyanate compounds, organosilane compounds, organotitanate compounds, organoborane compounds, acrylic compounds, and epoxy compounds. In particular, if the inorganic reinforcing material (G) is treated with an acrylic compound, the adhesion to the polyamide (A) and the modified vinyl compound (D) is improved, which is highly preferable in terms of mechanical properties, impact ductility, and painted appearance.

[0064] The amount of inorganic reinforcing material (G) used in the thermoplastic resin composition of the present invention is preferably 5 to 40 parts by weight, more preferably 5 to 30 parts by weight, and even more preferably 10 to 20 parts by weight, per 100 parts by weight of the total of (A) to (E). By adding 5 to 40 parts by weight of inorganic reinforcing material (G), impact ductility and heat resistance can be improved.

[0065] The thermoplastic resin composition of the present invention may contain components other than those described in (A) to (G) above, as necessary, as long as their properties are not impaired. For example, the thermoplastic resin composition of the present invention may contain rubbers other than the graft copolymer (B), as necessary, as long as their properties are not impaired. Examples of such rubbers include those exemplified as rubbery polymers in the graft copolymer (B) having reactive functional groups, but without reactive functional groups. Two or more of these may be blended. When using such rubbers, there are no particular restrictions on the amount blended, but 0.1 to 400 parts by weight is preferred per 100 parts by weight of the thermoplastic resin composed of (A) to (E).

[0066] Furthermore, various additives may be added to the thermoplastic resin composition of the present invention as needed, to the extent that they do not impair its properties. Examples of such additives include crystal nucleating agents, color inhibitors, antioxidants (heat stabilizers), ultraviolet absorbers (light stabilizers), antibacterial agents, antifungal agents, mold release agents, plasticizers, lubricants, dye-based colorants, pigment-based colorants, antistatic agents, flame retardants / flame retardant aids, and foaming agents. Two or more of these may be added. There are no particular restrictions on the amount added, but 0.01 to 20 parts by weight is preferred per 100 parts by weight of the thermoplastic resin composition comprising (A) to (E). However, adding fatty acid-based materials such as higher fatty acid amides, higher fatty acid esters, and higher fatty acid metal salts as lubricants may worsen the paintability.

[0067] A nucleating agent that promotes the crystallization of polyamide can be used. Examples of such nucleating agents include inorganic fine particles such as talc, silica, and graphite; metal oxides such as magnesium oxide and aluminum oxide; high-melting-point polyamides such as polyhexamethylene terephthalate (nylon 6T) and polyhexamethylene adipamide / hexamethylene terephthalate copolymer (nylon 66 / 6T). Among these, inorganic fine particles are preferred, and talc is particularly preferred.

[0068] Preferred antioxidants (heat stabilizers) include hindered phenol compounds, hindered amine compounds, hydroquinone compounds, phosphorus compounds and their substituted derivatives, copper halides, and iodide compounds.

[0069] Specific examples of hindered phenol compounds include triethylene glycol-bis[3-t-butyl-(5-methyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxyhydrocinnamide), tetrakiss[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, pentaerythrityltetrakiss[3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate], and 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)-s-triazine-2,4,6-(1H,3 Examples include H,5H)-trione, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 4,4'-butylidenebis(3-methyl-6-t-butylphenol), n-octadecyl-3-(3,5-di-t-butyl-4-hydroxy-phenyl)propionate, 3,9-bis[2-(3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy)-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, and 1,3,5-trimethyl-2,4,6-tris-(3,5-di-t-butyl-4-hydroxybenzyl)benzene.

[0070] Among these, ester-type polymer hindered phenol types are preferred, and specifically, tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, pentaerythrityltetrakis[3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate], 3,9-bis[2-(3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy)-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane are preferred.

[0071] Specific examples of phosphorus compounds include phosphite compounds such as bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol-diphosphite, bis(2,4-di-t-butylphenyl)pentaerythritol-diphosphite, bis(2,4-di-cumylphenyl)pentaerythritol-diphosphite, tris(2,4-di-t-butylphenyl)phosphite, tetrakis(2,4-di-t-butylphenyl)-4,4'-bisphenylenephosphite, distearylpentaerythritol-diphosphite, and triphenyl phosphite; and 3,5-di-butyl-4-hydroxybenzylphosphonate diethyl ester.

[0072] Preferred ultraviolet absorbers (light stabilizers) include resorcinol compounds, salicylate compounds, benzotriazole compounds, benzophenone compounds, and hindered amine compounds.

[0073] As release agents, aliphatic alcohols, aliphatic amides, aliphatic bisamides, ethylenebisstearylamides, and the like are preferably used.

[0074] As plasticizers, octyl p-oxybenzoate and N-butylbenzenesulfonamide are preferably used.

[0075] As dye-based colorants, nigrosine and aniline black are preferably used.

[0076] Preferred pigment-based colorants include cadmium sulfide, phthalocyanine, and carbon black.

[0077] Preferred antistatic agents include alkyl sulfate-type anionic antistatic agents, quaternary ammonium salt-type cationic antistatic agents, nonionic antistatic agents such as polyoxyethylene sorbitan monostearate, and betaine-type amphoteric antistatic agents.

[0078] As flame retardants and flame retardant assistants, melamine cyanurate, hydroxides such as magnesium hydroxide and aluminum hydroxide, ammonium polyphosphate, brominated polystyrene, brominated polyphenylene oxide, brominated polycarbonate, brominated epoxy resins, or combinations of these brominated flame retardants with antimony trioxide are preferably used.

[0079] The thermoplastic resin composition used in the present invention has improved heat resistance because polyamide (A) forms a continuous phase. The term "continuous phase" refers to a phase constituting the outer periphery when a plurality of resin materials are mixed.

[0080] In the present invention, for polyamide (A) to form a continuous phase, it is required to satisfy the following formula: ・W ＡＢＳ ≦(η ＡＢＳ / η ＰＡ )×(1.04 / 1.13)×W ＰＡ (wherein ABS: graft copolymer (B)+vinyl copolymer (C)+modified vinyl copolymer (D), PA: polyamide (A), W ＡＢＳ : parts by weight of ABS, W ＰＡ : parts by weight of polyamide, η ＡＢＳ / η ＰＡ : the melt viscosity ratio of ABS to PA at a shear rate within the range of 200s －１ to 1000s －１ ).

[0081] η ＡＢＳ / η ＰＡ is measured as the melt viscosity ratio within the range of 200s －１ to 1000s －１ , which is the shear rate during molding under the molding temperature conditions of the thermoplastic resin composition obtained by the method disclosed in the present specification. For example, when the thermoplastic resin composition is molded at 250°C, the shear rate is 200s －１ or 1000s －１The melt viscosity ratio of ABS and polyamide (A) is measured, and if the thermoplastic resin composition is configured to satisfy the above formula under all measurement conditions, it is determined that the formula is satisfied. A capillary graph measuring device is used to measure the melt viscosity. Furthermore, when the thermoplastic resin composition satisfies the above formula and polyamide (A) becomes a continuous phase, impact ductility, chemical resistance, and appearance are improved.

[0082] Furthermore, the thermoplastic resin composition used in the present invention is η ＡＢＳ / η ＰＡ It is preferable to design it so that it is in the range of 0.1 to 20, and furthermore η ＡＢＳ / η ＰＡ It is preferable to design the material so that the melt viscosity ratio r is in the range of 0.5 to 15. By setting the melt viscosity ratio r within this range, good impact ductility, chemical resistance, and paint adhesion are achieved.

[0083] In the thermoplastic resin composition used in the present invention, η ＡＢＳ / η ＰＡ There are no limitations on the method for setting the value to 0.1 to 20. The molding temperature conditions of the thermoplastic resin composition finally obtained by the method disclosed herein are 200 s. －１ and 1000s －１ The melt viscosity ratio of ABS and polyamide (A) at each shear rate should be calculated and set so that the melt viscosity ratio is in the range of 0.1 to 20 under all measurement conditions. For example, when molding the thermoplastic resin composition finally obtained by the method disclosed herein at 250°C, the melt temperature is 250°C and the shear rate is 200 s. －１ or 1000s －１ The melt viscosity ratio of ABS and polyamide (A) should be measured and set to a range of 0.1 to 20. A capillary graph measuring device can be used to measure the melt viscosity.

[0084] Also, shear rate 200 s －１ and 1000s －１It is preferable to design the composition such that the difference in the melt viscosity ratio between ABS and polyamide (A) is within 10. By using recycled polyamide as polyamide (A), it becomes easier to control the difference in the melt viscosity ratio between ABS and polyamide (A) to within 10. Furthermore, it is preferable to design the composition so that this difference in melt viscosity ratio is within 7. By setting the shear rate within these ranges, the dispersion form of the polyamide (A), graft copolymer (B), vinyl copolymer (C), modified vinyl copolymer (D), acid-modified polyolefin (E), acid anhydride (F), and inorganic reinforcing material (G) constituting the thermoplastic resin composition becomes stable, resulting in good impact ductility, moldability, paint appearance, and paint adhesion.

[0085] Shear rate 200 s －１ and 1000s －１ A method for designing such a condition that the difference in the melt viscosity ratio between ABS and polyamide (A) is within 10 is η ＡＢＳ / η ＰＡ Similar to the method of setting the value in the range of 0.1 to 20, the injection molding temperature is 200 s. －１ and 1000s －１ The melt viscosity ratio of ABS and polyamide (A) at each shear rate can be determined by applying the following formula: Difference in melt viscosity ratio = (200 s) －１ (Melting viscosity ratio) - (1000s) －１ (Melting viscosity ratio).

[0086] In the present invention, there are no particular restrictions on the method for producing the graft copolymer (B), and methods such as bulk polymerization, suspension polymerization, bulk suspension polymerization, solution polymerization, emulsion polymerization, precipitation polymerization, and combinations thereof can be used. There are also no particular restrictions on the method of preparing the monomers; they may be added all at once at the beginning, or the addition method may be divided into several steps in order to establish or prevent a specific compositional distribution of the copolymer.

[0087] In the present invention, there are no particular restrictions on the method for producing the vinyl copolymer (C), and methods such as bulk polymerization, solution polymerization, bulk suspension polymerization, suspension polymerization, emulsion polymerization, precipitation polymerization, and combinations thereof can be used. There are also no particular restrictions on the method of adding the monomers; they may be added all at once at the beginning, or the addition method may be divided into several steps in order to establish or prevent a specific compositional distribution of the copolymer.

[0088] In the present invention, there are no particular restrictions on the method for producing the modified vinyl copolymer (D), and methods such as solution polymerization, suspension polymerization, emulsion polymerization, precipitation polymerization, and combinations thereof can be used. There are also no particular restrictions on the method of preparing the monomers; they may be added all at once at the beginning, or the addition method may be divided into several steps to establish or prevent a specific compositional distribution of the copolymer. In the present invention, peroxides or azo compounds are preferably used as initiators for the polymerization of the graft copolymer (B), vinyl copolymer (C), and modified vinyl copolymer (D).

[0089] Specific examples of peroxides include, for example, benzoyl peroxide, cumene hydroperoxide, dicumyl peroxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide, t-butylcumyl peroxide, t-butyl peroxyacetate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, di-t-butyl peroxide, t-butyl peroctate, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, and t-butylperoxy-2-ethylhexanoate. Among these, cumene hydroperoxide and 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane are particularly preferred.

[0090] Specific examples of azo compounds include, for example, azobisisobutyronitrile, azobis(2,4-dimethylvaleronitrile), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2-cyano-2-propylazoformamide, 1,1'-azobiscyclohexane-1-carbonitride, azobis(4-methoxy-2,4-dimethylvaleronitrile), dimethyl2,2'-azobisisobutyrate, 1-t-butylazo-1-cyanocyclohexane, 2-t-butylazo-2-cyanobutane, and 2-t-butylazo-2-cyano-4-methoxy-4-methylpentane. Among these, azobisisobutyronitrile is particularly preferred. When using these initiators, one or more are used in combination.

[0091] When carrying out polymerization, chain transfer agents such as mercaptans and terpenes can be used to adjust the degree of polymerization of the graft copolymer (B), vinyl copolymer (C), and modified vinyl copolymer (D). Specific examples of chain transfer agents include n-octyl mercaptan, t-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, and terpinolene. Among these, n-octyl mercaptan, t-dodecyl mercaptan, and n-dodecyl mercaptan are preferred. When using these chain transfer agents, one or more can be used in combination.

[0092] The thermoplastic resin composition of the present invention can be obtained by melting each copolymer component constituting the thermoplastic resin composition and mixing each component.

[0093] Regarding the method for melt-mixing each component constituting the thermoplastic resin composition of the present invention, methods such as melt-mixing using a single-screw or twin-screw method in a cylinder having a heating device and vents can be employed. The heating temperature during melt-mixing is usually selected from the range of 210 to 320°C, but it is also possible to freely set the temperature gradient during melt-mixing within a range that does not impair the objective of the present invention. Furthermore, when using twin-screw, they may be rotated in the same direction or in different directions.

[0094] The order in which each component is melted and mixed can be as follows: one method involves simultaneously blending and then melting and mixing polyamide (A), graft copolymer (B), vinyl copolymer (C), modified vinyl copolymer (D), and acid-modified polyolefin (E); or one method involves pre-melting and mixing graft copolymer (B) and vinyl copolymer (C) to obtain a resin composition, and then subsequently mixing and melting polyamide (A), modified vinyl copolymer (D), and acid-modified polyolefin (E).

[0095] The acid anhydride (F) may be melt-mixed together with the polyamide (A), graft copolymer (B), vinyl copolymer (C), modified vinyl copolymer (D), and acid-modified polyolefin (E). Alternatively, the acid anhydride (F) may be melt-mixed together with the graft copolymer (B) and vinyl copolymer (C), which have been melt-mixed beforehand, along with the polyamide (A), modified vinyl copolymer (D), and acid-modified polyolefin (E).

[0096] In terms of rigidity and appearance, it is preferable to first melt and mix the inorganic reinforcing material (G) with polyamide (A), graft copolymer (B), vinyl copolymer (C), modified vinyl copolymer (D), and acid-modified polyolefin (E) to form a thermoplastic resin composition before mixing. In particular, when using a fibrous filler as the inorganic reinforcing material (G), it is preferable to add the inorganic reinforcing material by side feed.

[0097] The thermoplastic resin composition of the present invention obtained as described above can be molded into a molded product by injection molding. Injection molding can preferably be carried out in the normal molding temperature range of 220 to 300°C. The mold temperature during injection molding is preferably in the normal molding temperature range of 30 to 80°C. However, since polyamide is a crystalline resin, it is preferable to carry out the injection molding at a temperature lower than the crystallization transition temperature, i.e., in the range of 30 to 60°C.

[0098] The thermoplastic resin composition of the present invention is characterized by its ability to produce excellent thermoplastic resins and molded products that are effective in designing injection molded products with good rigidity, impact ductility, moldability, paint appearance, and paint adhesion, without differences between parts. The thermoplastic resin composition of the present invention can be usefully used for various automobile exterior and interior parts, motorcycle exterior materials, and housings for electrical and electronic equipment.

[0099] To further illustrate the present invention, examples are given below, but these examples do not limit the present invention in any way. Next, a method for analyzing the resin properties of a thermoplastic resin composition is described below.

[0100] First, the evaluation methods in the examples, reference examples, and comparative examples are described below.

[0101] (1) Weight-average rubber particle diameter: Measured according to the sodium alginate method described in "Rubber Age Vol. 88 pp. 484-490 (1960) by E. Schmidt, P.H. Biddison" (which utilizes the fact that the particle diameter of polybutadiene that becomes creamy differs depending on the concentration of sodium alginate, and determines the particle diameter at a cumulative weight fraction of 50% from the weight percentage of creamy material and the accumulated weight fraction of sodium alginate concentration).

[0102] (2) Graft rate A predetermined amount of graft copolymer (m: approximately 1 g) was mixed with 200 ml of acetone and refluxed in a water bath at 70°C for 3 hours. The solution was then centrifuged at 880 rpm (10,000 G) for 40 minutes, the insoluble matter was filtered out, and the insoluble matter was dried under reduced pressure at 60°C for 5 hours. Its weight (n) was measured. The graft rate was calculated using the following formula, where L is the rubber content of the graft copolymer. Graft rate (%) = {[(n) - (m) × L] / [(m) × L]} × 100.

[0103] (3) Approximately 0.03 g of weight-average molecular weight vinyl copolymer was weighed and dissolved in approximately 15 g of tetrahydrofuran to obtain a solution of approximately 0.2% by mass. The weight-average molecular weight was determined from the GPC chromatogram using this solution by converting it to a polystyrene standard substance. The GPC measurement was performed under the following conditions: Instrument: Waters2695 Column temperature: 40°C Detector: RI2414 (differential refractive index system) Carrier eluent flow rate: 0.3 ml / min (solvent: tetrahydrofuran) Column: TSKgel SuperHZM-M (6.0 mm I.D. × 15 cm), TSKgel SuperHZM-N (6.0 mm I.D. × 15 cm) in series (both manufactured by Tosoh Corporation). Standard sample: Monodisperse polystyrene manufactured by Tosoh.

[0104] (4) Bending strength The pellets obtained in the examples, reference examples and comparative examples were placed in a box-type hot air dryer set to 80°C and vacuum-dried for 8 hours or more using a vacuum pump and cooling / trapping device connected to the dryer. Then, multipurpose test specimens of type A1 as specified in JIS K 7139:2009 were molded using an injection molding machine set to a cylinder temperature of 250°C and a mold temperature of 60°C, and measured in accordance with ISO 178:2010.

[0105] (5) Flexural modulus The pellets obtained in the examples, reference examples and comparative examples were placed in a box-type hot air dryer set to 80°C and vacuum-dried for 8 hours or more using a vacuum pump and cooling / trapping device connected to the dryer. Then, multipurpose test specimens of type A1 as specified in JIS K 7139:2009 were molded using an injection molding machine set to a cylinder temperature of 250°C and a mold temperature of 60°C, and measured in accordance with ISO 178:2010.

[0106] (6) Load deflection temperature The pellets obtained in the examples, reference examples and comparative examples were placed in a box-type hot air dryer set to 80°C and vacuum dried for 8 hours or more using a vacuum pump and cooling / trapping device connected to the dryer. Then, multipurpose test specimens of type A1 as specified in JIS K 7139:2009 were molded using an injection molding machine set to a cylinder temperature of 250°C and a mold temperature of 60°C, and measurements were taken in accordance with ISO 75-1:2011 using type B2 test specimens cut from these A1 specimens.

[0107] (7) Charpy impact strength The pellets obtained in the examples, reference examples and comparative examples were placed in a box-type hot air dryer set to 80°C and vacuum-dried for 8 hours or more using a vacuum pump and cooling / trapping device connected to the dryer. Then, multipurpose test specimens of type A1 as specified in JIS K 7139:2009 were molded using an injection molding machine set to a cylinder temperature of 250°C and a mold temperature of 60°C, and the type B2 test specimens cut out from these were measured in accordance with ISO 179-1:2010.

[0108] (8) The pellets obtained in the moldability examples, reference examples and comparative examples were placed in a box-type hot air dryer set to 80°C, and vacuum dried for 8 hours or more using a vacuum pump and cooling / trapping device connected to the dryer. The MFR (melt flow rate) was then measured in accordance with ISO 1133-1:2011.

[0109] Next, the raw materials used in the examples, reference examples, and comparative examples are shown below.

[0110] [Polyamide (A)] (A-1) Recycled polyamide 6 resin with a viscosity number VN of 120 to 125 ml / g obtained by the 96% sulfuric acid method (25°C). (A-2) Virgin polyamide 6 resin with a viscosity number VN of 95 to 120 ml / g obtained by the 98% sulfuric acid method (25°C). (A-3) Virgin polyamide 6 resin with a viscosity number VN of 122 to 142 ml / g obtained by the 98% sulfuric acid method (25°C).

[0111] [Preparation of Graft Copolymer (B)] (B-1) A monomer mixture consisting of 32% by weight of styrene and 13% by weight of acrylonitrile was emulsion polymerized using potassium stearate in the presence of 55% by weight (on a solids basis) of polybutadiene latex (weight-average rubber particle size 0.21 μm, gel content 80%) to obtain a rubber-reinforced graft copolymer. This was added to a 0.3% dilute sulfuric acid aqueous solution at 90°C to agglomerate, then neutralized with sodium hydroxide aqueous solution, followed by washing, dehydration, and drying steps to prepare the product. The graft rate was 42%.

[0112] (B-2) In the presence of 55% by weight (on a solids basis) of polybutadiene latex (weight-average rubber particle size 0.21 μm, gel content 80%), a monomer mixture consisting of 9% by weight of styrene, 9% by weight of acrylonitrile, and 27% by weight of methyl methacrylate was emulsion polymerized using potassium stearate to obtain a rubber-reinforced graft copolymer. This was added to a 0.3% dilute sulfuric acid aqueous solution at 90°C to agglomerate, then neutralized with sodium hydroxide aqueous solution, followed by washing, dehydration, and drying to prepare the graft copolymer (B-2). The grafting rate was 45%.

[0113] (B-3) In the presence of 40% by weight (on a solids basis) of polybutadiene latex (weight-average rubber particle size 0.21 μm, gel content 80%), a monomer mixture consisting of 42% by weight of styrene and 18% by weight of acrylonitrile was emulsion polymerized using potassium stearate to obtain a rubber-reinforced graft copolymer. This was added to a 0.3% dilute sulfuric acid aqueous solution at 90°C to agglomerate, then neutralized with sodium hydroxide aqueous solution, followed by washing, dehydration, and drying to prepare the graft copolymer (B-3). The grafting rate was 42%.

[0114] [Production of vinyl copolymer (C)] A monomer mixture consisting of (C-1) 76% by weight of styrene and 24% by weight of acrylonitrile was suspended and polymerized to obtain a slurry. This slurry was then washed, dehydrated, and dried to prepare vinyl copolymer (C-1). The weight-average molecular weight was 100,000, and the intrinsic viscosity, measured in methyl ethyl ketone solvent (at 30°C), was 0.42 dl / g.

[0115] A monomer mixture consisting of (C-2) 72% by weight of styrene and 28% by weight of acrylonitrile was suspended and polymerized to obtain a slurry. This slurry was then washed, dehydrated, and dried to prepare a vinyl copolymer (C-2). The weight-average molecular weight was 351,000, and the intrinsic viscosity, measured in methyl ethyl ketone solvent (at 30°C), was 0.9 dl / g.

[0116] A monomer mixture consisting of (C-3) 69% by weight of styrene and 31% by weight of acrylonitrile was subjected to suspension polymerization to obtain a slurry, which was then washed, dehydrated, and dried to prepare a vinyl monomer (C-3). The weight-average molecular weight was 130,000, and the intrinsic viscosity measured in methyl ethyl ketone solvent (at 30°C) was 0.54 dl / g.

[0117] [Production of Modified Vinyl Copolymer (D)] A slurry obtained by suspension polymerization of a monomer mixture consisting of 70% by weight of styrene, 25% by weight of acrylonitrile, and 5% by weight of methacrylic acid was washed, dehydrated, and dried to prepare Modified vinyl copolymer (D-1).

[0118] (D-2) A monomer mixture consisting of 67% by weight of styrene, 30% by weight of acrylonitrile, and 3% by weight of maleic anhydride was suspended and polymerized to obtain a slurry. This slurry was then washed, dehydrated, and dried to prepare a modified vinyl copolymer (D-2).

[0119] [Acid-modified polyolefins (E)] (E-1) Ethylene / butene-1 / maleic anhydride "Tafmer (registered trademark) MH7020" manufactured by Mitsui Chemicals, Inc. (E-2) Ethylene / ethyl acrylate / glycidyl methacrylate "Bondfast (registered trademark) 7M" manufactured by Sumitomo Chemical Co., Ltd. (E-3) Ethylene / butene-1 "Tafmer (registered trademark) A4085" manufactured by Mitsui Chemicals, Inc. (E-4) Ethylene / ethyl acrylate / carbon monoxide copolymer "Elbaroy (registered trademark) HP4051" manufactured by The Dow Chemical Company.

[0120] [Acid anhydride (F)] (F-1) Succinic anhydride "Ricacid (registered trademark) SA-25" manufactured by Shin Nippon Rika Co., Ltd.

[0121] [Inorganic Reinforced Materials (G)] (G-1) Glass fibers (G-1) with a glass fiber length of 12.0 to 14.0 mm and a diameter of 2.0 to 4.0 μm, measured according to JIS R 3420, and surface-treated with an acrylic compound. (G-2) Glass fibers (G-2) with a glass fiber length of 12.0 to 14.0 mm and a diameter of 2.0 to 4.0 μm, measured according to JIS R 3420, and surface-treated with an isocyanate compound. (G-3) Glass fibers (G-3) with a glass fiber length of 9.0 to 11.0 mm and a diameter of 7.0 to 9.0 μm, measured according to JIS R 3420, and surface-treated with an isocyanate compound.

[0122] Examples, reference examples, and comparative examples are described below.

[0123] (Examples 1-15, Reference Examples 1 and 2, Comparative Examples 1-15) The polyamide (A), graft copolymer (B), vinyl copolymer (C), modified vinyl copolymer (D), acid-modified polyolefin (E), and acid anhydride (F) were blended in parts by weight as shown in Tables 1, 2, 3, and 4, and mixed at 23°C using a Henschel mixer. The resulting mixture was melt-kneaded at a cylinder setting temperature of 300°C using a twin-screw extruder with a vent and a screw diameter of 30 mm (PCM30, manufactured by Ikegai Co., Ltd.), and the inorganic reinforcing material (G) was added from the side feeder in parts by weight as shown in Tables 1, 2, 3, and 4 to obtain pellets of thermoplastic resin composition.

[0124] The obtained thermoplastic resin composition pellets were placed in a box-type hot air dryer set to 80°C and vacuum-dried for more than 8 hours using a vacuum pump and cooling / trapping device connected to the dryer. Then, various test pieces were prepared using an injection molding machine at a cylinder temperature of 250°C and a mold temperature of 60°C, and various evaluations were performed. The molded articles obtained from the thermoplastic compositions of Examples 1 to 15, Reference Examples 1 and 2, and Comparative Examples 6, 7, and 9 to 15 showed polyamide as a continuous phase. The evaluation results are shown in Tables 1, 2, 3, and 4.

[0125]

[0126]

[0127]

[0128]

[0129] By comparing Example 14 with Reference Example 1, and Example 2 with Reference Example 2, it can be seen that the composition of the present invention provides mechanical properties and heat resistance comparable to those obtained when virgin polyamide is used. By comparing Examples 1 to 15 and Comparative Examples 1 to 15, it can be seen that the composition of the present invention has excellent mechanical properties and heat resistance. Furthermore, by adding acid anhydride, the fluidity is improved, resulting in a thermoplastic resin composition with good moldability.

[0130] Although various embodiments have been described above, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. Furthermore, the components in the above embodiments may be combined in any way without departing from the spirit of the invention.

[0131] This application is based on Japanese Patent Application No. 2025-051455 filed on March 26, 2025, and its contents are incorporated herein by reference.

Claims

1. A thermoplastic resin composition comprising, with a total of 100 parts by weight of (A) to (E) below, 20 to 80 parts by weight of polyamide (A) containing recycled polyamide, 10 to 30 parts by weight of graft copolymer (B) obtained by graft copolymerizing a vinyl monomer mixture containing an aromatic vinyl monomer (b2) and a vinyl cyanide monomer (b3) in the presence of a rubbery polymer (b1), 1 to 20 parts by weight of vinyl copolymer (C) obtained by copolymerizing a vinyl monomer mixture containing an aromatic vinyl monomer (c1) and a vinyl cyanide monomer (c2), 1 to 10 parts by weight of modified vinyl copolymer (D) obtained by copolymerizing at least one monomer (d1) selected from the group consisting of unsaturated carboxylic acids and α,β-unsaturated carboxylic acid anhydrides, an aromatic vinyl monomer (d2), and a vinyl cyanide monomer (d3), and 1 to 10 parts by weight of acid-modified polyolefin (E).

2. The thermoplastic resin composition according to claim 1, further comprising 0.01 to 1 part by weight of acid anhydride (F), with the total of (A) to (E) being 100 parts by weight.

3. The thermoplastic resin composition according to claim 2, wherein the acid anhydride (F) is at least one selected from the group consisting of succinic anhydride, phthalic anhydride, benzoic anhydride, isobutyric anhydride, itaconic anhydride, octanoic anhydride, glutaric anhydride, acetic anhydride, dimethylmaleic anhydride, decanoic anhydride, trimellitic anhydride, 1,8-naphthalic anhydride, and maleic anhydride.

4. The thermoplastic resin composition according to claim 1, wherein the graft copolymer (B) is obtained by graft copolymerizing 20 to 60% by weight of the vinyl monomer mixture in the presence of 40 to 80% by weight of the rubbery polymer (b1), with the total of the rubbery polymer (b1) and the vinyl monomer mixture being 100% by weight.

5. The thermoplastic resin composition according to claim 4, wherein the vinyl monomer mixture comprises 5 to 45% by weight of an aromatic vinyl monomer (b2), 5 to 30% by weight of a vinyl cyanide monomer (b3), and 0 to 50% by weight of other monomers copolymerizable therewith (b4), based on 100% by weight of the total of the rubbery polymer (b1) and the vinyl monomer mixture.

6. The thermoplastic resin composition according to claim 1, wherein the vinyl copolymer (C) is obtained by copolymerizing 70 to 80% by weight of an aromatic vinyl monomer (c1), 20 to 30% by weight of a vinyl cyanide monomer (c2), and 0 to 10% by weight of another monomer (c3) copolymerizable with these.

7. The thermoplastic resin composition according to claim 5, wherein the weight-average molecular weight of the vinyl copolymer (C) is 80,000 to 130,000.

8. The thermoplastic resin composition according to claim 1, further comprising 5 to 40 parts by weight of inorganic reinforcing material (G), with the total of (A) to (E) being 100 parts by weight.

9. A molded article obtained by molding a thermoplastic resin composition according to any one of claims 1 to 8.

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