Resin composition and molded article thereof

Abstract

The present invention relates to a resin composition comprising: a styrene resin (A); a polyamide elastomer (B); and at least one antistatic aid (C) which is selected from the group consisting of salts (C1) of an inorganic fluorine compound and a compound having a imidazole skeleton, salts (C2) of a compound having a sulfonyl group or a sulfo group and a compound having an imidazole skeleton, salts (C3) of an inorganic fluorine compound and a compound having a pyridine skeleton, salts (C4) of a compound having a sulfonyl group or a sulfo group and a compound having a pyridine skeleton, and organic sulfonic acid metal salts (C5), and which does not contain a carbon-fluorine bond.

Description

Resin composition and molded article thereof

[0001] The present invention relates to an antistatic resin composition comprising a styrene-based resin, a polyamide elastomer, and an antistatic additive, and to a molded article made from the antistatic resin composition.

[0002] In recent years, thermoplastic resin molded products have been used in a wide range of fields, including parts for household electrical appliances, office automation equipment, and automobiles. However, since most thermoplastic resins that make up thermoplastic resin molded products are electrically insulating, there has been a problem where the static electricity generated on these resin molded products can cause malfunctions in the control devices when they are used in various devices equipped with precision electrical and electronic control products.

[0003] As a method for solving these problems caused by static charge, Patent Document 1 describes an antistatic ABS resin composition comprising an antistatic polymer such as acrylonitrile-butadiene-styrene resin (ABS resin) and polyether ester amide, and an antistatic additive having a carbon-fluorine bond.

[0004] Patent Document 2 describes an antistatic styrene resin composition comprising a styrene resin, polyoxyalkylene glycol, and an organic sulfonic acid metal salt.

[0005] International Publication No. 2007 / 094195, Japanese Patent Publication No. 2006-89544

[0006] However, the composition described in Patent Document 1 contains an antistatic agent having a carbon-fluorine bond, and because these substances are persistent, highly bioaccumulative, and capable of long-distance transport, efforts to regulate and manage risks are underway in Japan.

[0007] Furthermore, the composition described in Patent Document 2 uses polyalkylene glycol as an antistatic polymer, making it prone to bleed-out and preventing sufficient antistatic properties from being exhibited depending on the usage environment.

[0008] The present invention provides a resin composition that does not contain compounds containing carbon-fluorine bonds and exhibits stable antistatic properties.

[0009] To solve the above problems, the present invention is as follows: (1) A resin composition comprising a styrene resin (A), a polyamide elastomer (B), and an antistatic agent (C) selected from the group consisting of a salt of a compound having an imidazole skeleton and an inorganic fluorine compound (C1), a salt of a compound having an imidazole skeleton and a compound having a sulfonyl group or a sulfo group (C2), a salt of a compound having a pyridine skeleton and an inorganic fluorine compound (C3), a salt of a compound having a pyridine skeleton and a compound having a sulfonyl group or a sulfo group (C4), and an organosulfonic acid metal salt (C5), which does not contain a carbon-fluorine bond. (2) The resin composition according to (1), wherein the styrene-based resin (A) comprises at least one selected from the group consisting of polystyrene, high-impact polystyrene, acrylonitrile-butadiene-styrene (ABS) resin, methyl methacrylate-acrylonitrile-butadiene-styrene (MABS) resin, acrylonitrile-styrene-acrylic acid ester (ASA) resin, acrylonitrile-styrene (AS) resin, methacrylic-styrene (MS) resin, methyl methacrylate-butadiene-styrene (MBS) resin, acrylonitrile-ethylene-propylene-diene-styrene (AES) resin, and methyl methacrylate-acrylic rubber-styrene (MAS) resin. (3) The resin composition according to (1) or (2), wherein the resin composition further comprises at least one selected from the group consisting of polyolefin resin, polyester resin, polyamide resin, modified polyphenylene ether resin, polycarbonate resin, and polyacetal resin. (4) The resin composition according to any one of (1) to (3), wherein the polyamide elastomer (B) is at least one compound selected from the group consisting of polyetheramide elastomers or polyether ester amide elastomers. (5) The resin composition according to any one of (1) to (4), wherein the compound having an imidazole skeleton is a compound represented by the following general formula (1).

[0010]

[0011] (R1 and R2 are independently alkyl groups having 1 to 8 carbon atoms) (6) The resin composition according to any one of (1) to (5), wherein the compound having the imidazole skeleton is at least one compound selected from the group consisting of 1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, 1-pentyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, 1-heptyl-3-methylimidazolium, and 1-methyl-3-octylimidazolium. (7) The resin composition according to any one of (1) to (6), wherein the compound having a sulfonyl group or a sulfo group is at least one compound selected from the group consisting of methyl sulfate, ethyl sulfate, and compounds represented by the following general formula (2).

[0012]

[0013] (R3 is hydrogen or an alkyl group having 1 to 3 carbon atoms) (8) The resin composition according to any one of (1) to (7), wherein the compound having a pyridine skeleton is at least one compound selected from the group consisting of 1-ethyl-3-methylpyridinium, 1-propyl-3-methylpyridinium, 1-butyl-3-methylpyridinium, 1-pentyl-3-methylpyridinium, 1-hexyl-3-methylpyridinium, 1-heptyl-3-methylpyridinium, and 1-octyl-3-methylpyridinium. (9) The resin composition according to any one of (1) to (8), wherein the organosulfonic acid metal salt (C5) is lithium bis(fluorosulfonyl)imide. (10) The resin composition according to any one of (1) to (9), wherein the styrene resin (A) is a transparent styrene resin (A') selected from the group consisting of polystyrene, methyl methacrylate-acrylonitrile-butadiene-styrene (MABS) resin, acrylonitrile-styrene (AS) resin, methacrylic-styrene (MS) resin, methyl methacrylate-butadiene-styrene (MBS) resin, and methyl methacrylate-acrylic rubber-styrene (MAS) resin. (11) The resin composition according to (10), wherein the salt (C2) of a compound having an imidazole skeleton and a compound having a sulfonyl group or a sulfo group is a salt (C2') of a compound represented by the following general formula (1) and a compound represented by the following general formula (2).

[0014]

[0015] (R1 and R2 are independently alkyl groups having 1 to 8 carbon atoms)

[0016]

[0017] (R3 is hydrogen or an alkyl group having 1 to 3 carbon atoms) A molded article comprising any of the resin compositions described in (1) to (11) (12)

[0018] The present invention provides a resin composition that does not contain compounds having carbon-fluorine bonds and exhibits excellent mechanical properties and antistatic properties.

[0019] The 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, respectively.

[0020] Styrene-based resin (A) The resin composition of the present invention uses a styrene-based resin. The styrene-based resin used in the present invention consists of a polymer in which an aromatic vinyl monomer is included as a component. Examples of this aromatic vinyl monomer include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, t-butylstyrene, o-ethylstyrene, o-chlorostyrene, and o,p-dichlorostyrene, but styrene or α-methylstyrene is preferred. One or more aromatic vinyl monomers may be used in combination.

[0021] Furthermore, the styrene-based resin may contain a vinyl copolymer obtained by copolymerizing an aromatic vinyl monomer with another vinyl monomer that can copolymerize with the aromatic vinyl monomer, for the purpose of imparting properties such as chemical resistance and heat resistance. These vinyl monomers include, for example, acrylonitrile, methacrylonitrile, ethacrylonitrile, (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, n-hexyl (meth)acrylate, glycidyl (meth)acrylate, allyl glycidyl ether, styrene-p-glycidyl ether, p-glycidylstyrene, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2,3,4,5,6-pentahydroxyhexyl (meth)acrylate, 2,3,4,5,6-pentahydroxyhexyl (meth)acrylate, 2,3,4,5-tetrahydroxypentyl acrylate, maleic acid, maleic anhydride, maleic acid Examples include monoethyl iodine, itaconic acid, itaconic anhydride, phthalic acid, n-methylmaleimide, n-ethylmaleimide, n-cyclohexylmaleimide, n-phenylmaleimide, acrylamide, methacrylamide, n-methylacrylamide, butoxymethylacrylamide, n-propylmethacrylamide, aminoethyl acrylate, propylaminoethyl acrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, phenylaminoethyl methacrylate, cyclohexylaminoethyl methacrylate, n-vinyldiethylamine, n-acetylvinylamine, allylamine, methallylamine, n-methylallylamine, p-aminostyrene, 2-isopropenyl-oxazoline, 2-vinyl-oxazoline, 2-acryloyl-oxazoline, and 2-styryl-oxazoline. Among these, acrylonitrile or methyl methacrylate is particularly preferred.

[0022] The proportion of aromatic vinyl monomers contained in the styrene resin is preferably 10 to 100% by weight, and more preferably 20 to 90% by weight, from the viewpoint of moldability.

[0023] For styrene-based resins, the weight-average molecular weight in polystyrene equivalent is preferably between 50,000 and 300,000 in order to maintain a balance of physical properties. The weight-average molecular weight can be measured using a generally known method by gel permeation chromatography (GPC).

[0024] There are no particular restrictions on the method for producing styrene-based resins; conventional methods such as bulk polymerization, suspension polymerization, emulsion polymerization, and bulk-suspension polymerization can be used. Alternatively, one or more styrene-based resins obtained by any of these methods may be melt-kneaded to produce the resin.

[0025] When the objective is to dramatically improve properties such as impact resistance of styrene-based resins, it is preferable to use a rubber-modified styrene-based resin in which a rubbery polymer is dispersed in a matrix made of aromatic vinyl (co)polymer. That is, as the styrene-based resin, a rubber-modified styrene-based resin containing a graft copolymer obtained by graft polymerization of an aromatic vinyl monomer and other vinyl monomers copolymerizable with the aromatic vinyl monomer in a rubbery polymer can be preferably used. Furthermore, rubber-modified styrene-based resins containing an aromatic vinyl monomer, a vinyl copolymer obtained by copolymerizing the aromatic vinyl monomer and other vinyl monomers copolymerizable with the aromatic vinyl monomer, and a graft copolymer obtained by graft polymerization of an aromatic vinyl monomer and other vinyl monomers copolymerizable with the aromatic vinyl monomer in a rubbery polymer can also be preferably used.

[0026] Examples of rubbery polymers include diene rubbers such as polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, styrene-butadiene block copolymer, and butyl acrylate-butadiene copolymer; acrylic rubbers such as polybutyl acrylate; polyisoprene; and ethylene-propylene-diene ternary copolymers. Among these, polybutadiene or butadiene copolymers are preferred.

[0027] From the viewpoint of excellent impact resistance, the weight-average particle size of the rubber polymer is preferably 0.1 μm or more, more preferably rubber particles in the range of 0.15 to 0.60 μm, and even more preferably rubber particles in the range of 0.20 to 0.55 μm. Among these, a rubber polymer in which the weight ratio of rubber particles with a weight-average particle size in the range of 0.20 to 0.25 μm to rubber particles in the range of 0.50 to 0.65 μm is 90:10 to 60:40 is particularly preferred because it exhibits remarkably excellent impact resistance and drop weight impact strength of thin-walled molded products.

[0028] Here, the weight-average particle diameter of rubber particles can be measured by the method described in "Rubber Age, Vol. 88, pp. 484-490, (1960), by E. Schmidt, P.H. Biddison," which determines the particle diameter at a cumulative weight fraction of 50% from the cumulative weight fraction of sodium alginate concentration.

[0029] When using the above-mentioned rubber-modified styrene resin as the styrene resin, the rubbery polymer and the styrene resin matrix are immiscible. Therefore, grafting a component that is compatible with the matrix onto the rubbery polymer can further improve impact resistance. In other words, it is preferable to use a graft copolymer obtained by graft polymerization of an aromatic vinyl monomer or monomer mixture onto a rubbery polymer. As the monomer used in graft polymerization, it is preferable to use monomer components similar to those in the aromatic vinyl (co)polymer matrix mentioned above, in the same proportions. There are no particular restrictions on the composition and graft amount, but it is preferable to adjust the composition and graft amount so as not to impair the dispersibility of the rubbery polymer. The graft rate is preferably 5 to 200% by weight, and more preferably 20 to 100% by weight. The graft rate here is the value calculated by the following formula 1.

[0030] Grafting rate (%) = (Amount of vinyl polymer grafted onto rubbery polymer) / (Rubber content of graft copolymer) × 100 (Equation 1)

[0031] From the viewpoint of obtaining a resin composition having excellent impact resistance regarding the properties of ungrafted (co)polymer, the intrinsic viscosity [η] (measured at 30°C) of the methyl ethyl ketone soluble component is preferably in the range of 0.25 to 0.60 dl / g, more preferably in the range of 0.25 to 0.50 dl / g.

[0032] As a specific method for producing a rubber-modified styrenic resin, a method of producing a rubber-modified styrenic resin by melt-kneading a graft copolymer obtained by graft-polymerizing a monomer or monomer mixture containing an aromatic vinyl monomer onto a rubbery polymer with a styrenic (co)polymer obtained by polymerizing a monomer or monomer mixture containing an aromatic vinyl monomer is industrially and economically preferred.

[0033] The graft copolymer contained in the above rubber-modified styrenic resin can be obtained by known polymerization methods such as emulsion polymerization and bulk polymerization. Among these, a method of performing emulsion polymerization by continuously supplying a mixture of a monomer or monomer mixture, a radical generator and a chain transfer agent to a polymerization vessel in the presence of a rubbery polymer latex is operationally preferred.

[0034] Specific examples of the styrenic resin used in the present invention include polystyrene, high-impact polystyrene, acrylonitrile-butadiene-styrene (ABS) resin, methyl methacrylate-acrylonitrile-butadiene-styrene (MABS) resin, acrylonitrile-styrene-acrylate (ASA) resin, acrylonitrile-styrene (AS) resin, methacryl-styrene (MS) resin, methyl methacrylate-butadiene-styrene (MBS) resin, acrylonitrile-ethylene-propylene-diene-styrene (AES) resin, and methyl methacrylate-acrylic rubber-styrene (MAS) resin. Two or more of these may be contained. Among these, ABS resin is particularly preferable. In the present invention, a transparent resin composition can be obtained by using a transparent styrenic resin (A') selected from the group consisting of polystyrene, methyl methacrylate-acrylonitrile-butadiene-styrene (MABS) resin, acrylonitrile-styrene (AS) resin, methacryl-styrene (MS) resin, methyl methacrylate-butadiene-styrene (MBS) resin, and methyl methacrylate-acrylic rubber-styrene (MAS) resin as the styrenic resin (A).

[0035] A transparent styrenic resin (A') can be obtained by using a mixture of a vinyl copolymer and a graft copolymer described below as the styrenic resin.

[0036] The difference in refractive index between the vinyl copolymer used in the transparent resin composition and the rubbery polymer (r) described later is preferably 0.03 or less, more preferably 0.01 or less. By setting the difference in refractive index between the vinyl copolymer and the rubbery polymer (r) to 0.03 or less, the transparency of a molded article obtained from the resin composition can be improved.

[0037] The weight-average particle diameter of the rubbery polymer (r) is not particularly limited, but from the viewpoint of improving the transparency of the molded article, it is preferably 0.15 to 1.50 µm, more preferably 0.20 to 0.50 µm.

[0038] The refractive index of a vinyl copolymer mainly depends on the composition of the vinyl monomers used as raw materials. Therefore, by appropriately selecting the type and composition ratio of the vinyl monomers, the refractive index can be brought within a desired range. The refractive index of a vinyl copolymer can be estimated from the refractive index and content of the vinyl monomers. For example, in the case of a copolymer of styrene, acrylonitrile, and methyl methacrylate, the refractive index of the vinyl copolymer can be estimated using the following formula.

[0039] nD(A) = (1.510 × MA / 100) + (1.595 × MS / 100) + (1.490 × MM / 100) Here, nD(A) is the refractive index of the vinyl copolymer, MA is the acrylonitrile content (weight %), MS is the styrene content (weight %), and MM is the methyl methacrylate content (weight %). Also, 1.510 is the refractive index of acrylonitrile, 1.595 is the refractive index of styrene, and 1.490 is the refractive index of methyl methacrylate. These can be calculated by measuring the refractive indices of polyacrylonitrile, polystyrene, and polymethyl methacrylate, respectively, using an Abbe refractometer.

[0040] There are no particular restrictions on the grafting ratio of the graft copolymer used in the transparent resin composition, but from the viewpoint of further improving the impact resistance of the molded product, 10 to 100% is preferred.

[0041] In the present invention, the graft component (acetone-insoluble portion) of the graft copolymer preferably has a refractive index difference of 0.03 or less from that of the rubbery polymer (r), and more preferably 0.01 or less. By making the difference between the refractive index of the graft copolymer and the refractive index of the graft component and the rubbery polymer (r) 0.03 or less, the transparency of the molded article made of the resin composition can be improved.

[0042] The refractive index of the graft component of a graft copolymer mainly depends on the composition of the vinyl monomers used as raw materials. Therefore, by appropriately selecting the type and composition ratio of the vinyl monomers, the refractive index can be brought within a desired range. The refractive index of the graft component of a graft copolymer can be estimated from the refractive index and content of the vinyl monomers. For example, in the case of a copolymer of styrene, acrylonitrile, and methyl methacrylate, the refractive index of the graft component of the graft copolymer can be estimated using the following formula.

[0043] nD(G) = (1.510 × MA / 100) + (1.595 × MS / 100) + (1.490 × MM / 100) Here, nD(G) is the refractive index of the graft component of the graft copolymer, MA is the acrylonitrile content (weight %), MS is the styrene content (weight %), and MM is the methyl methacrylate content (weight %). Also, 1.510 represents the refractive index of acrylonitrile, 1.595 represents the refractive index of styrene, and 1.490 represents the refractive index of methyl methacrylate. These can be calculated by measuring the refractive indices of polyacrylonitrile, polystyrene, and polymethyl methacrylate, respectively, using an Abbe refractometer.

[0044] Furthermore, the refractive index of the rubbery polymer (r) is generally shown in the literature; for example, in the case of polybutadiene rubber, it is 1.516. When copolymerized rubber is used, the refractive index of the copolymerized rubber can be estimated from the refractive index and content of the copolymerized components. For example, in the case of styrene-butadiene rubber, the refractive index of the copolymerized rubber (nD(r)) can be estimated using the following formula. Note that the copolymerized components can be identified by FT-IR, viscoelasticity measurement, etc.

[0045] nD(r) = (1.516 × MB / 100) + (1.595 × MS / 100) Here, nD(r) is the refractive index of the rubbery polymer (r), MB is the butadiene content (weight %), and MS is the styrene content (weight %). Also, 1.516 is the refractive index of butadiene and 1.595 is the refractive index of styrene.

[0046] Furthermore, the refractive index of the graft component of a graft copolymer can be measured for the graft component obtained by dissolving the graft copolymer in acetone, filtering out the acetone-soluble components, and drying the resulting residue. A film with a thickness of 30 ± 5 μm obtained by heating and pressing the graft copolymer at 230°C can be used as a measurement sample. A small amount of 1-bromonaphthalene is added dropwise, and the refractive index can be measured using an Abbe refractometer under the conditions of a sodium lamp D line light source and a measurement temperature of 23°C.

[0047] By using a styrene-based resin (A') consisting of a mixture of vinyl copolymer and graft copolymer with the refractive index adjusted in this manner, a transparent resin composition can be obtained.

[0048] Polyamide Elastomer (B) The resin composition of the present invention contains a polyamide elastomer to exhibit antistatic properties. Polyetheramide elastomers or polyether ester amide elastomers are preferably used as the polyamide elastomer. Those composed of poly(alkylene oxide) glycols or diol compounds to which alkylene oxides are added are preferred, and copolymers in which these are block-bonded or graft-bonded are preferred.

[0049] The copolymer containing alkylene oxide units as a constituent component is preferably a copolymer containing poly(alkylene oxide) glycol and one or more diol compounds selected from the group consisting of the following general formulas (I) to (III) as constituent components.

[0050]

[0051] Here, in general formulas (I) to (III), R ７ , R ８ Each of these independently represents an ethylene group or a propylene group, Y is a covalent bond, an alkylene group with 1 to 6 carbon atoms, an alkylidene group with 2 to 6 carbon atoms, a cycloalkylidene group with 7 to 17 carbon atoms, an arylalkylidene group with 7 to 17 carbon atoms, O, SO, SO ２ , represents CO, S, or NH, X １ ~X １２each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, halogen, SO ３ H or a metal salt thereof (SO ３ Na, SO ３ K, etc.).

[0052] In general formulas (I) to (III), m and n respectively represent the degree of polymerization of "-(R ７ O)-" and "-(R ８ O)-". The sum (m+n) depends on the diol compound of general formulas (I) to (III) used, and is preferably in the range of 8 to 65. The average value of (m+n) can be obtained by calculation from the structure (molecular weight of the monomer) and the number average molecular weight of the diol compound of general formulas (I) to (III).

[0053] In the present invention, the number average molecular weight is determined as follows: 1 g of a sample is heated with an excess acetylating agent, for example, acetic anhydride, to perform acetylation; let G be the amount (in mg) of potassium hydroxide required to neutralize the generated acetylated product, and H be the amount (in mg) of potassium hydroxide required to neutralize 1 g of the sample before acetylation. The number average molecular weight can be calculated by the following (Formula 2).

[0054] Number average molecular weight = 11200 / [G / (1 - 0.00075 × G) - H] (Formula 2)

[0055] As the poly(alkylene oxide) glycol, polyethylene oxide glycol, poly(1,2-propylene oxide) glycol, poly(1,3-propylene oxide) glycol, poly(tetramethylene oxide) glycol, poly(hexamethylene oxide) glycol, block or random copolymers of ethylene oxide and propylene oxide, and block or random copolymers of ethylene oxide and tetrahydrofuran are preferably used; among these, polyethylene oxide glycol is more preferred. The number average molecular weight of the poly(alkylene oxide) glycol is preferably in the range of 200 to 6000, and particularly preferably in the range of 300 to 4000. Further, if necessary, both terminals of the poly(alkylene oxide) glycol component may be aminated or carboxylated.

[0056] Diol compounds selected from the group consisting of general formulas (I) to (III) include R ７ , R ８ Each is independently either an ethylene group or a propylene group, where Y is an alkylene with 1 to 6 carbon atoms, X １ ~X １２ Diol compounds in which each is independently hydrogen or an alkyl group having 1 to 6 carbon atoms are preferred, and among these, X １ ~X １２ A diol compound in which hydrogen is present is preferred.

[0057] Specific examples of diol compounds include ethylene oxide and / or propylene oxide adducts such as bisphenol A, tetrabromobisphenol A, dimethylbisphenol A, tetramethylbisphenol A, 2,2-bis(4,4'-hydroxyphenyl-3,3'-sodium sulfonate)propane, bisphenol S, dimethylbisphenol S, tetramethylbisphenol S, 4,4'-(hydroxy)biphenyl, bis(4-hydroxyphenyl) sulfide, bis(4-hydroxyphenyl) sulfoxide, bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl) ether, bis(4-hydroxyphenyl)amine, 2,2-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-dihydroxybenzophenone, hydroquinone, and sodium 1,4-dihydroxybenzenesulfonate, as well as dihydroxynaphthalene or block copolymers thereof. Among these, the more preferred diol compounds are ethylene oxide adducts of hydroquinone, ethylene oxide adducts of bisphenol A, ethylene oxide adducts of bisphenol S, ethylene oxide adducts of dihydroxynaphthalene, and their block copolymers. In particular, ethylene oxide adducts of bisphenol A or their block copolymers are preferred in terms of polymerizability and economic efficiency.

[0058] The number-average molecular weight of these diol compounds selected from the group consisting of general formulas (I) to (III) is preferably 1,000 to 3,000. When the number-average molecular weight is within this range, it is possible to improve the antistatic properties of the resulting polyether ester amide and shorten the polymerization time.

[0059] The copolymer containing alkylene oxide units as a constituent component used in the present invention is preferably a polyether ester amide (polyamide elastomer) containing the above-mentioned poly(alkylene oxide) glycol and one or more diol compounds selected from the group consisting of general formulas (I) to (III) as constituent components.

[0060] As the polyether ester amide, a graft or block copolymer containing as a component a reaction product of an aminocarboxylic acid having 6 or more carbon atoms, a lactam having 6 or more carbon atoms, or a diamine having 6 or more carbon atoms and a dicarboxylic acid having 6 or more carbon atoms, the above-mentioned poly(alkylene oxide) glycol, and a diol compound selected from the group consisting of general formulas (I) to (III) is preferred.

[0061] As the aminocarboxylic acid having 6 or more carbon atoms that constitutes the polyether ester amide, aminocarboxylic acids having 6 to 20 carbon atoms are preferred, specifically, aminocarboxylic acids such as ω-aminocaproic acid, ω-aminoenanthic acid, ω-aminocaprylic acid, ω-aminopergonic acid, ω-aminocapric acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Furthermore, as the lactam having 6 or more carbon atoms, lactams having 6 to 20 carbon atoms are preferred, specifically, ε-caprolactam, enantractam, capryllactam, and laurolactam. Furthermore, as reaction products of a diamine having 6 or more carbon atoms and a dicarboxylic acid having 6 or more carbon atoms, reaction products of a diamine having 6 to 20 carbon atoms and a dicarboxylic acid having 6 to 20 carbon atoms are preferred. Specifically, examples include reaction products of salts (nylon salts) of diamines and dicarboxylic acids, such as hexamethylenediamine-adipate, hexamethylenediamine-sebacate, and hexamethylenediamine-isophthalate.

[0062] In polyether ester amides, the bond between the reaction product of an aminocarboxylic acid having 6 or more carbon atoms, a lactam having 6 or more carbon atoms, or a diamine having 6 or more carbon atoms and a dicarboxylic acid having 6 or more carbon atoms, and the diol compound is preferably an ester bond or an amide bond.

[0063] Furthermore, the polyether ester amide may also contain a third component such as a dicarboxylic acid or diamine as a reaction component. In this case, the dicarboxylic acid component is preferably a carboxylic acid having 4 to 20 carbon atoms. Examples include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4-dicarboxylic acid, diphenoxyethanedicarboxylic acid, and sodium 3-sulfoisophthalate; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and dicyclohexyl-4,4-dicarboxylic acid; and aliphatic dicarboxylic acids such as succinic acid, oxalic acid, adipic acid, sebacic acid, and 1,10-decanedicarboxylic acid, which are preferred in terms of polymerizability, color, and physical properties. On the other hand, as the diamine component, aromatic, alicyclic, or aliphatic diamines can be used, and among these, hexamethylenediamine, which is an aliphatic diamine, is preferred.

[0064] The method for producing the polyamide elastomer used in the present invention is not particularly limited, and known production methods can be used. For example, in the case of polyether ester amide, a method can be applied in which an aminocarboxylic acid, lactam, or a salt of a diamine having 6 or more carbon atoms and a dicarboxylic acid having 6 or more carbon atoms is reacted with a dicarboxylic acid that can be contained as the above-mentioned third component to produce a polyamide prepolymer with carboxylic acid groups at both ends, and this prepolymer is reacted with poly(alkylene oxide) glycol and a diol compound selected from the group consisting of general formulas (I) to (III) under vacuum. Alternatively, a method can be applied in which three compounds—an aminocarboxylic acid, lactam, or a salt of a diamine having 6 or more carbon atoms and a dicarboxylic acid having 6 or more carbon atoms, a dicarboxylic acid that can be contained as the above-mentioned third component, poly(alkylene oxide) glycol, and a diol compound selected from the group consisting of general formulas (I) to (III)—are charged into a reaction vessel, and a polyamide elastomer with carboxylic acid ends is produced by heating at a high temperature in the presence or absence of water, and then polymerization is carried out under atmospheric pressure or reduced pressure. Furthermore, a method can also be applied in which these three compounds are simultaneously placed in a reaction vessel, melt-polymerized, and then polymerized rapidly under high vacuum.

[0065] Antistatic additive (C) In the present invention, the antistatic additive used is selected from the group consisting of a salt of a compound having an imidazole skeleton and an inorganic fluorine compound (C1), a salt of a compound having an imidazole skeleton and a compound having a sulfonyl group or a sulfo group (C2), a salt of a compound having a pyridine skeleton and an inorganic fluorine compound (C3), a salt of a compound having a pyridine skeleton and a compound having a sulfonyl group or a sulfo group (C4), and an organic sulfonic acid metal salt (C5). Compounds that do not have a carbon-fluorine bond can be used. Here, it is preferable that the compound having an imidazole skeleton is a compound represented by the following general formula (1).

[0066]

[0067] (R1 and R2 are independently alkyl groups having 1 to 8 carbon atoms, with R1 preferably being an alkyl group having 3 to 8 carbon atoms and R2 preferably being an alkyl group having 1 to 3 carbon atoms.) Furthermore, it is preferable that the compound having the imidazole skeleton is at least one compound selected from the group consisting of 1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, 1-pentyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, 1-heptyl-3-methylimidazolium, and 1-methyl-3-octylimidazolium. Furthermore, it is preferable that the compound having the sulfonyl group or sulfo group is at least one compound selected from the group consisting of methyl sulfate, ethyl sulfate, and compounds represented by the following general formula (2).

[0068]

[0069] (R3 is hydrogen or an alkyl group having 1 to 3 carbon atoms) Furthermore, it is preferable that the compound having the pyridine skeleton is at least one compound selected from the group consisting of 1-ethyl-3-methylpyridinium, 1-propyl-3-methylpyridinium, 1-butyl-3-methylpyridinium, 1-pentyl-3-methylpyridinium, 1-hexyl-3-methylpyridinium, 1-heptyl-3-methylpyridinium, and 1-octyl-3-methylpyridinium.

[0070] As the salt (C1) of the compound having an imidazole skeleton and the inorganic fluorine compound, the imidazole skeleton compounds are preferably 1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, 1-pentyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, 1-heptyl-3-methylimidazolium, and 1-methyl-3-octylimidazolium, and as the inorganic fluorine compound, hexafluorophosphate that is not designated as a hazardous substance is preferred.

[0071] As the salt (C2) of a compound having an imidazole skeleton and a compound having a sulfonyl group or a sulfo group, the imidazole skeleton compound is preferably 1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, 1-pentyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, 1-heptyl-3-methylimidazolium, and 1-methyl-3-octylimidazolium, similar to (C1), and as the salt having a sulfonyl group or a sulfo group, methyl sulfate, ethyl sulfate, and methylbenzenesulfonic acid are preferred.

[0072] The salt (C3) of a compound having a pyridine skeleton and an inorganic fluorine compound is preferably such as 1-ethyl-3-methylpyridinium, 1-propyl-3-methylpyridinium, 1-butyl-3-methylpyridinium, 1-pentyl-3-methylpyridinium, 1-hexyl-3-methylpyridinium, 1-heptyl-3-methylpyridinium, and 1-octyl-3-methylpyridinium as the compound having a pyridine skeleton, and the inorganic fluorine compound is preferably such as hexafluorophosphate, which, like (C1), is not designated as a hazardous substance.

[0073] As the salt (C4) of a compound having a pyridine skeleton and a compound having a sulfonyl group or a sulfo group, the compound having a pyridine skeleton is preferably 1-ethyl-3-methylpyridinium, 1-propyl-3-methylpyridinium, 1-butyl-3-methylpyridinium, 1-pentyl-3-methylpyridinium, 1-hexyl-3-methylpyridinium, 1-heptyl-3-methylpyridinium, and 1-octyl-3-methylpyridinium, similar to (C3), and as the salt having a sulfonyl group or a sulfo group, is preferably methylsulfuric acid, ethylsulfuric acid, and methylbenzenesulfonic acid, similar to (C2).

[0074] As the organic sulfonic acid metal salt (C5), an organic sulfonic acid metal salt containing lithium, such as lithium bis(fluorosulfonyl)imide, is preferred.

[0075] Since this invention does not use compounds containing carbon-fluorine bonds as antistatic additives, it is possible to provide an antistatic resin composition with low health risks, such as accumulation in the human body.

[0076] In this case, when a transparent styrene-based resin (A') is used as the styrene-based resin, it is preferable to use a salt (C2') of the compound represented by general formula (1) and the compound represented by general formula (2) as an antistatic additive, in order to obtain a transparent resin composition. As such an antistatic additive (C'), 3-butyl-1-methyl-1H-imidazolium / 4-methylbenzenesulfonate is preferably used.

[0077] Resin Composition The blending ratio of the styrene resin (A), polyamide elastomer (B), and antistatic additive (C) of the present invention is as follows: 100 parts by weight of styrene resin (A), the polyamide elastomer (B) is preferably added in the range of 5 to 80 parts by weight, more preferably 10 to 40 parts by weight, and even more preferably 10 to 20 parts by weight; the antistatic additive (C) is preferably added in the range of 0.01 to 30 parts by weight, more preferably 0.1 to 5 parts by weight. When the total of styrene resin (A), polyamide elastomer (B), and antistatic additive (C) is 100 parts by weight, the styrene resin (A) is preferably added in the range of 5 to 95 parts by weight, more preferably 10 to 90 parts by weight; the polyamide elastomer (B) is preferably added in the range of 5 to 70 parts by weight, more preferably 10 to 40 parts by weight; and the antistatic additive (C) is preferably added in the range of 0.01 to 30 parts by weight, more preferably 0.1 to 5 parts by weight.

[0078] Other Components: The resin composition of the present invention may also contain thermoplastic resins other than styrene-based resins. Examples include polyolefin resins, polyester resins, polyamide resins, polyphenylene ether resins, polycarbonate resins, polyacetal resins, polyimide resins, vinyl halogenated resins, polyacrylate resins, polyoxymethylene resins, polyamide-imide resins, polyarylsulfone resins, polyarylketone resins, polyarylene ether resins, polyarylene sulfide resins, polyaryletherketone resins, polyethersulfone resins, polyetherimide resins, polyetherketone resins, polyetheretherketone resins, polyarylate resins, and modifiers thereof. Two or more of these may be included.

[0079] Examples of olefin resins include polypropylene, polyethylene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / propylene / non-conjugated diene copolymer, ethylene / ethyl acrylate copolymer, ethylene / glycidyl methacrylate copolymer, ethylene / vinyl acetate / glycidyl methacrylate copolymer, ethylene / propylene-g-maleic anhydride copolymer, and methacrylic acid / methyl methacrylate / glutaric acid anhydride copolymer, and two or more of these may be included. Among these, polypropylene is particularly preferred from the viewpoint of further improving fluidity and the mechanical strength of the molded product.

[0080] As polyester resins, polymers or copolymers having residues of dicarboxylic acid or its ester-forming derivative and diol or its ester-forming derivative as the main structural units are preferred. Among these, aromatic polyester resins such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polycyclohexanedimethylene terephthalate, polyethylene naphthalate, polypropylene naphthalate, polybutylene naphthalate, polyethylene isophthalate / terephthalate, polypropylene isophthalate / terephthalate, polybutylene isophthalate / terephthalate, polyethylene terephthalate / naphthalate, polypropylene terephthalate / naphthalate, and polybutylene terephthalate / naphthalate are particularly preferred, with polybutylene terephthalate being the most preferred. Two or more of these may be contained. In these polyesters, the ratio of terephthalic acid residues to total dicarboxylic acid residues is preferably 30 mol% or more, and more preferably 40 mol% or more.

[0081] Furthermore, the polyester resin may contain one or more residues selected from hydroxycarboxylic acids or their ester-forming derivatives and lactones. Examples of hydroxycarboxylic acids include glycolic acid, lactic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, hydroxybenzoic acid, p-hydroxybenzoic acid, and 6-hydroxy-2-naphthoic acid. Examples of lactones include caprolactone, valerolactone, propiolactone, undecalactone, and 1,5-oxepan-2-one. Examples of polymers or copolymers using these residues as structural units include aliphatic polyester resins such as polyglycolic acid, polylactic acid, polyglycolic acid / lactic acid, and polyhydroxybutyric acid / β-hydroxybutyric acid / β-hydroxyvaleric acid. Two or more of these may be contained.

[0082] Polyamide resins are not particularly limited as long as they have amide bonds in their repeating structure and are obtained by ring-opening polymerization of lactams, polycondensation of diamines and dicarboxylic acids, polycondensation of aminocarboxylic acids, etc. Examples of lactams include ε-caprolactam, enantractam, and ω-laurolactam. Examples of diamines include aliphatic diamines such as tetramethylenediamine, hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecamethylenediamine, 1,9-nonanediamine, 1,10-decanediamine, 2-methyl-1,8-octanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, and 5-methylnonamethylenediamine; alicyclic diamines such as 1,3-bisaminomethylcyclohexane and 1,4-bisaminomethylcyclohexane; and aromatic diamines such as m-phenylenediamine, p-phenylenediamine, m-xylylenediamine, and p-xylylenediamine. Examples of dicarboxylic acids include aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, dimer acid, dodecanediic acid, and 1,1,3-tridecanediic acid; alicyclic dicarboxylic acids such as 1,3-cyclohexanedicarboxylic acid; and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid. Examples of aminocarboxylic acids include ε-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and 13-aminotridecanoic acid.

[0083] Specific examples of polyamide resins include, for example, nylon 6, nylon 46, nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6 / 66, nylon 6 / 612, nylon MXD (m-xylylenediamine) 6, nylon 9T, nylon 10T, nylon 6T / 66, nylon 6T / 6I, nylon 6T / M5T, nylon 6T / 12, nylon 66 / 6T / 6I, nylon 6T / 6, and others. Two or more of these may be included. Among these, nylon 6, nylon 66, nylon 610, and nylon 9T are preferred.

[0084] Polycarbonate resins can be obtained by methods such as the phosgene method, in which phosgene is blown into a difunctional phenolic compound in the presence of a caustic alkali and a solvent, and the transesterification method, in which a difunctional phenolic compound and diethyl carbonate are transesterified in the presence of a catalyst. Examples of polycarbonates include aromatic homopolycarbonates and aromatic copolycarbonates. The viscosity-average molecular weight of these aromatic polycarbonates is preferably 10,000 or more, and more preferably 15,000 or more. The upper limit is preferably 100,000 or less, and more preferably 50,000 or less, from the perspective of reducing fracture of fibrous fillers and ensuring production stability. Examples of difunctional phenolic compounds include 2,2'-bis(4-hydroxyphenyl)propane, 2,2'-bis(4-hydroxy-3,5-dimethylphenyl)propane, bis(4-hydroxyphenyl)methane, 1,1'-bis(4-hydroxyphenyl)ethane, 2,2'-bis(4-hydroxyphenyl)butane, 2,2'-bis(4-hydroxy-3,5-diphenyl)butane, 2,2'-bis(4-hydroxy-3,5-dipropylphenyl)propane, 1,1'-bis(4-hydroxyphenyl)cyclohexane, and 1-phenyl-1,1'-bis(4-hydroxyphenyl)ethane. Two or more of these may be used.

[0085] Among these thermoplastic resins, polyolefin resins, polyester resins, polyamide resins, polycarbonate resins, modified polyphenylene ether resins, and polyacetal resins are preferred.

[0086] To the extent that the objectives of the present invention are not impaired, antioxidants such as hindered phenols, sulfur-containing compounds, or phosphorus-containing organic compounds; heat stabilizers such as phenols and acrylates; ultraviolet absorbers such as benzotriazoles, benzophenones, or salicylates; light stabilizers such as organonickels and hindered amines; lubricants such as metal salts of higher fatty acids and higher fatty acid amides; plasticizers such as phthalates and phosphate esters; various flame retardants such as brominated compounds, phosphate esters, or red phosphorus; flame retardant additives such as antimony trioxide and antimony pentoxide; metal salts of alkyl carboxylic acids and alkyl sulfonic acids; carbon black; pigments; dyes; and the like may be added as needed. In addition, various reinforcing materials, fillers, and neutralizing agents in cases where any of the components are acidic or basic may be added.

[0087] Method for Manufacturing the Resin Composition Regarding the method for melt-mixing each component constituting the thermoplastic resin composition of the present invention, methods such as using a heating device and a cylinder with a vent, and melt-mixing using a single-screw or twin-screw method 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.

[0088] The antistatic thermoplastic resin composition of the present invention can be molded into a molded article by known molding methods currently used for molding thermoplastic resins, such as injection molding, extrusion molding, blow molding, vacuum molding, compression molding, and gas-assisted molding.

[0089] Molded articles made from the antistatic resin composition of the present invention have a low surface resistivity, stable and sustained antistatic properties, and excellent moldability, surface appearance, and mechanical properties. Taking advantage of these characteristics, molded articles of the present invention can be suitably used as electrical and electronic components, transport components for electrical and electronic components, and transport components for display-related components.

[0090] Electrical and electronic equipment components refer to parts of various devices equipped with precision electrical and electronic control devices, such as car navigation systems, car audio systems, automotive electrical components such as fuel cell peripherals installed in electric vehicles, and IC peripheral components or enclosures on which ICs are mounted. Components for transporting electrical and electronic components include, for example, photomask cases, IC chip trays, IC transport trays, and silicone wafer transport boxes. Components for transporting display-related components include, for example, carrier reels, TAB tape reels, COF tape reels, liquid crystal display transport trays, and plasma display transport trays.

[0091] Furthermore, since the composition of the present invention does not contain carbon-fluorine bonds, the health risk to the human body is reduced, and therefore it is preferably used in household electrical components, household electronic toys, electronic game devices, and other commercial amusement and entertainment equipment components that may come into contact with the human body.

[0092] To further illustrate the present invention, examples are given below, but the present invention is not limited to these examples. In the following examples and comparative examples, unless otherwise specified, "parts" and "%" represent parts by weight and weight percent, respectively. First, the evaluation methods for various physical properties of the antistatic resin composition are described below.

[0093] (1) Charpy impact strength The pellets obtained in the Charpy impact strength examples, reference examples and comparative examples 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, multipurpose test specimens of type A1 as specified in JIS K 7139:2009 were molded using a Sumitomo Heavy Industries, Ltd. SE50EV injection molding machine set to a cylinder temperature of 230°C and a mold temperature of 60°C. The molded multipurpose test specimens of type A1 were processed to 80 × 10 × 4 mm with a type A notch in accordance with the provisions of ISO 179 (2023), and the Charpy impact strength was measured at a temperature of 23°C. Six test specimens were used, and the arithmetic mean was used for evaluation.

[0094] (2) The pellets obtained in the tensile strain examples, reference examples, and comparative examples 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, multipurpose test specimens of type A1 as specified in JIS K 7139:2009 were molded using a Sumitomo Heavy Industries, Ltd. SE50EV injection molding machine set to a cylinder temperature of 230°C and a mold temperature of 60°C. The tensile strain was evaluated in accordance with the provisions of ISO 527 (2019). Five test specimens were used, and the arithmetic mean was used for evaluation.

[0095] (3) 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 more than 8 hours 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 a Sumitomo Heavy Industries, Ltd. SE50EV injection molding machine set to a cylinder temperature of 230°C and a mold temperature of 60°C. The flexural modulus was evaluated in accordance with the provisions of ISO 178 (2019). Three test specimens were used, and the arithmetic mean was used for evaluation.

[0096] (4) Melt flow rate 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 more than 8 hours using a vacuum pump connected to the dryer and a cooling / trapping device. The melt flow rate was evaluated according to ISO 1133 (2011) (temperature: 220°C, load: 98N). The test was performed three times and evaluated using the arithmetic mean.

[0097] (5) Surface resistivity was measured for 40 x 50 x 3 mm thick rectangular plate molded products obtained from a Sumitomo Heavy Industries, Ltd. SE50EV injection molding machine with the cylinder temperature set to 230°C and the mold temperature to 60°C. The products were left for 24 hours at a temperature of 23°C and a humidity of 50% Rh, and the surface resistivity was measured in accordance with ASTM D257 (2021). An applied voltage of 500V was applied, and the surface resistivity was read after 1 minute. Four test pieces were used, and the arithmetic mean was used for evaluation.

[0098] (6) Light transmittance and haze (cloudiness) The total light transmittance (%) and haze (cloudiness) (%) of the square plate molded product obtained in (5) above were measured in accordance with JIS K7136 (2000) using a DIRECT READING HAZE METER manufactured by Toyo Seiki Seisakusho Co., Ltd. Four test pieces were used.

[0099] (Reference example) A styrene-based resin (A) was made up of a graft copolymer (A-1) and a vinyl copolymer (A-3), and a transparent styrene-based resin (A') was made up of a graft copolymer (A-2) and a vinyl copolymer (A-4).

[0100] The grafting rate of each graft copolymer was determined by the following method: A predetermined amount (m) of graft copolymer was added to acetone and refluxed for 4 hours. This solution was then subjected to centrifugal force of 10,000 G (approximately 100 × 10⁻¹⁶) at 8,000 rpm. ３ m / s ２ After centrifuging for 30 minutes at a rotation of )), the insoluble matter was filtered out. This insoluble matter was dried under reduced pressure at 70°C for 5 hours, and its weight (n) was measured. The graft rate was calculated using the following formula.

[0101] Graft rate = [(n) - (m) × L] / [(m) × L] × 100 where L is the rubber content of the graft copolymer.

[0102] Preparation of graft copolymer (A-1): 50 parts (on a solids basis) of polybutadiene latex (average rubber particle size 0.2 μm) were added to 50 parts of a monomer mixture consisting of 70% methyl methacrylate, 25% styrene, and 5% acrylonitrile, and emulsion polymerization was carried out. After coagulation of the obtained graft copolymer with sulfuric acid, it was neutralized with sodium hydroxide, washed, filtered, and dried to obtain powdered graft copolymer (A-1). The grafting rate of the obtained graft copolymer (A-1) was 45%. The intrinsic viscosity of the methyl ethyl ketone soluble portion was 0.32 dl / g.

[0103] Preparation of graft copolymer (A-2): 50 parts (on a solids basis) of polybutadiene latex (average rubber particle size 0.15 μm) were added to 50 parts of a monomer mixture consisting of 72% methyl methacrylate, 24% styrene, and 4% acrylonitrile, and emulsion polymerization was carried out. The resulting graft copolymer was coagulated with sulfuric acid, neutralized with sodium hydroxide, washed, filtered, and dried to obtain powdered graft copolymer (A-2). The grafting rate of the obtained graft copolymer (A-2) was 47%.

[0104] Preparation of vinyl copolymer (A-3): A monomer mixture consisting of 70% methyl methacrylate, 25% styrene, and 5% acrylonitrile was subjected to suspension polymerization to obtain vinyl copolymer (A-3). The intrinsic viscosity of the N,N-dimethylformamide-soluble portion of the obtained vinyl copolymer (A-3) was 0.42 dl / g.

[0105] Vinyl copolymer (A-4): A monomer mixture consisting of 63% methyl methacrylate, 22% styrene, and 15% acrylonitrile was subjected to suspension polymerization to obtain vinyl copolymer (A-4).

[0106] Preparation of Polyether Esteramide (B): 45 parts ε-caprolactam, 45 parts ethylene oxide adduct of bisphenol A with a number average molecular weight of 1,800, 5 parts polyethylene glycol with a number average molecular weight of 1,800, 5.2 parts terephthalic acid, and 0.2 parts "Irganox" (registered trademark) 1098 (antioxidant) were charged into a reaction vessel, purged with nitrogen, and heated and stirred at 260°C for 60 minutes to obtain a clear homogeneous solution. The pressure was then reduced to 0.07 kPa or less. 0.1 parts tetrabutyl titanate was added, and the mixture was reacted for 2 hours under conditions of a pressure of 0.07 kPa or less and a temperature of 260°C. The resulting polymer was extruded in strand form and cut to obtain pellet-shaped polyether ester amide elastomer (B).

[0107] Antistatic additive (C) Antistatic additive (C-1) 1-hexyl-3-methylimidazolium / hexafluorophosphate (manufactured by Nippon Carlit Co., Ltd.) was used.

[0108] The antistatic agent (C-2) used was 1-ethyl-3-methylimidazolium-p-toluenesulfonate (manufactured by Nippon Carlit Co., Ltd.).

[0109] The antistatic agent (C-3) used was 1-butyl-3-methylpyridinium / p-toluenesulfonate (manufactured by Nippon Carlit Co., Ltd.).

[0110] The antistatic agent (C-4) 1-butyl-3-methylpyridinium / hexafluorophosphate (manufactured by Nippon Carlit Co., Ltd.) was used.

[0111] The antistatic agent (C-5) used was 2,5,8,11-tetraoxadodecane (55 wt%) / lithium-bis(fluorosulfonyl)imide (45 wt%) (registered name "FSITGL", manufactured by Kaken Sangyo Co., Ltd.).

[0112] The antistatic agent (C-6) lithium trifluoromethanesulfonate (manufactured by Morita Chemical Industries, Ltd.) was used.

[0113] The antistatic agent (C-7) 3-butyl-1-methyl-1H-imidazolium / 4-methylbenzenesulfonate (Tokyo Chemical Industries, Ltd.) was used.

[0114] [Examples 1-5, Comparative Example 1] The graft copolymer (A-1) was blended in an amount of 27.7 parts by weight, vinyl copolymer (A-3) in an amount of 72.3 parts by weight, polyether ester amide (B) in an amount of 15 parts by weight, and antistatic additive (C) in an amount of 0.6 parts by weight. The antistatic additive (C) was changed as shown in Table 1. The mixture was mixed at 23°C using a Henschel mixer. The obtained mixture was melt-kneaded at a cylinder setting temperature of 230°C using a twin-screw extruder with a screw diameter of 30 mm and a vent (PCM30, manufactured by Ikegai Co., Ltd.) to obtain pellets of thermoplastic resin composition. The evaluation results of various physical properties obtained in each example and comparative example are shown in Table 1.

[0115]

[0116] As shown in Table 1, the surface resistivity is 1.0 × 10 for both the examples and the comparative example. １１ The static charge ratio was less than or equal to Ω / □, indicating excellent antistatic properties. Furthermore, it exhibits excellent mechanical properties and formability.

[0117] However, in Comparative Example 1, the antistatic additive (C6) has a carbon-fluorine bond, which means it may cause health problems in humans due to its resistance to degradation, high bioaccumulation potential, and long-distance transport, making its use problematic.

[0118] [Example 6, Comparative Example 2] 27.7 parts by weight of the graft copolymer (A-2), 72.3 parts by weight of the vinyl copolymer (A-4), 15 parts by weight of the polyether ester amide (B), and 0.6 parts by weight of the antistatic additive (C) were blended. The antistatic additive (C) was changed as shown in Table 2. The mixture was mixed at 23°C using a Henschel mixer. The resulting mixture was melt-kneaded at a cylinder setting temperature of 230°C using a twin-screw extruder with a screw diameter of 30 mm (PCM30, manufactured by Ikegai Co., Ltd.) to obtain pellets of thermoplastic resin composition. The various physical properties, haze, and total light transmittance obtained in Example 6 and Comparative Example 2 are shown in Table 2.

[0119]

[0120] As shown in Table 2, the surface resistivity is 1.0 × 10 for both the examples and the comparative example. １１ The electrostatic discharge ratio was less than Ω / □, indicating excellent antistatic properties. Good results were also obtained for haze and total light transmittance.

[0121] However, in Comparative Example 2, the antistatic additive (C6) has a carbon-fluorine bond, which means it may cause health problems in humans due to its resistance to degradation, high bioaccumulation potential, and long-distance transport, making its use problematic.

[0122] The resin composition of the present invention does not contain compounds having carbon-fluorine bonds, has a low surface resistivity, and possesses stable, long-lasting antistatic properties, as well as excellent moldability, surface appearance, and mechanical properties. Therefore, because the composition of the present invention does not contain carbon-fluorine bonds, there is less concern about health damage such as accumulation in the human body, and health risks are reduced, making it suitable for use in household electrical components, household electronic toys, electronic game devices, and other commercial amusement and entertainment equipment components that may come into contact with the human body.

[0123] 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.

[0124] This application is based on Japanese Patent Application No. 2025-053277 filed on March 27, 2025, and Japanese Patent Application No. 2026-011014 filed on January 27, 2026, the contents of which are incorporated by reference in this application.

Claims

1. A resin composition comprising a styrene-based resin (A), a polyamide elastomer (B), and an antistatic agent (C) selected from the group consisting of a salt of a compound having an imidazole skeleton and an inorganic fluorine compound (C1), a salt of a compound having an imidazole skeleton and a compound having a sulfonyl group or a sulfo group (C2), a salt of a compound having a pyridine skeleton and an inorganic fluorine compound (C3), a salt of a compound having a pyridine skeleton and a compound having a sulfonyl group or a sulfo group (C4), and an organosulfonic acid metal salt (C5), the antistatic agent not containing a carbon-fluorine bond.

2. The resin composition according to claim 1, wherein the styrene-based resin (A) comprises at least one selected from the group consisting of polystyrene, high-impact polystyrene, acrylonitrile-butadiene-styrene (ABS) resin, methyl methacrylate-acrylonitrile-butadiene-styrene (MABS) resin, acrylonitrile-styrene-acrylic acid ester (ASA) resin, acrylonitrile-styrene (AS) resin, methacrylic-styrene (MS) resin, methyl methacrylate-butadiene-styrene (MBS) resin, acrylonitrile-ethylene-propylene-diene-styrene (AES) resin, and methyl methacrylate-acrylic rubber-styrene (MAS) resin.

3. The resin composition according to claim 1, further comprising at least one selected from the group consisting of polyolefin resin, polyester resin, polyamide resin, modified polyphenylene ether resin, polycarbonate resin, and polyacetal resin.

4. The resin composition according to claim 1, wherein the polyamide elastomer (B) is at least one compound selected from the group consisting of polyetheramide elastomers or polyether ester amide elastomers.

5. The resin composition according to claim 1, wherein the compound having an imidazole skeleton is a compound represented by the following general formula (1). (R1 and R2 are each independently an alkyl group having 1 to 8 carbon atoms) 6. The resin composition according to claim 1, wherein the compound having an imidazole skeleton is at least one compound selected from the group consisting of 1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, 1-pentyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, 1-heptyl-3-methylimidazolium, and 1-methyl-3-octylimidazolium.

7. The resin composition according to claim 1, wherein the compound having a sulfonyl group or a sulfo group is at least one compound selected from the group consisting of methyl sulfate, ethyl sulfate, and compounds represented by the following general formula (2). (R3 is hydrogen or an alkyl group having 1 to 3 carbon atoms) 8. The resin composition according to claim 1, wherein the compound having a pyridine skeleton is at least one compound selected from the group consisting of 1-ethyl-3-methylpyridinium, 1-propyl-3-methylpyridinium, 1-butyl-3-methylpyridinium, 1-pentyl-3-methylpyridinium, 1-hexyl-3-methylpyridinium, 1-heptyl-3-methylpyridinium, and 1-octyl-3-methylpyridinium.

9. The resin composition according to claim 1, wherein the organosulfonic acid metal salt (C5) is lithium bis(fluorosulfonyl)imide.

10. The resin composition according to claim 1, wherein the styrene resin (A) is a transparent styrene resin (A') selected from the group consisting of polystyrene, methyl methacrylate-acrylonitrile-butadiene-styrene (MABS) resin, acrylonitrile-styrene (AS) resin, methacrylic-styrene (MS) resin, methyl methacrylate-butadiene-styrene (MBS) resin, and methyl methacrylate-acrylic rubber-styrene (MAS) resin.

11. The resin composition according to claim 10, wherein the salt (C2) of a compound having an imidazole skeleton and a compound having a sulfonyl group or a sulfo group is a salt (C2') of a compound represented by the following general formula (1) and a compound represented by the following general formula (2). (R1 and R2 are independently alkyl groups having 1 to 8 carbon atoms) (R3 is hydrogen or an alkyl group having 1 to 3 carbon atoms) 12. A molded article comprising the resin composition according to any one of claims 1 to 11.

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