Resin composition, pellet, and molded article

Abstract

To provide a resin composition which is excellent in electromagnetic wave shielding property and flame retardance, and a pellet and a molded article which are formed of the resin composition.SOLUTION: A resin composition contains (A) a polybutylene terephthalate resin, (B) a thermoplastic resin having an SP value lower than that of the polybutylene terephthalate resin, (C) a carbon fiber, and (D) a bromine-based flame retardant having a weight average molecular weight (Mw) of 200 to 20,000, wherein in the resin composition, the content of (C) the carbon fiber is 5 to 30 mass%, and (B) / (A), which is a mass ratio of (B) to (A), is more than 0.1 and less than 1.0.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resin composition, a pellet, and a molded article, and in particular to a resin composition containing a polybutylene terephthalate resin as a main component. [Background technology]

[0002] Polybutylene terephthalate resin has excellent mechanical properties, electrical properties, and heat resistance, and is therefore used in a wide range of applications, including electrical, electronic, and office automation equipment parts and machine parts.

[0003] Although polybutylene terephthalate has excellent properties, its high electrical resistivity means that it is easily charged, which can cause various problems due to static electricity. For example, when a resin molded product becomes charged with static electricity, dust and dirt adhere to the surface, causing a deterioration in appearance and a decrease in commercial value. In particular, when used for electrical, electronic, and office automation equipment components, the charging of the resin molded product can cause incorrect operation and serious problems in functionality, so there is a demand for resin materials that prevent charging and have excellent conductivity.

[0004] On the other hand, in electric / electronic / OA equipment, since the electronic components inside the resin molded product that is the housing generate electromagnetic waves, a metal coating is usually formed on the surface of the housing as an electromagnetic wave shielding layer by a method such as plating or deposition in order to prevent the electromagnetic waves from leaking outside the equipment. In recent years, due to the simplification of product manufacturing processes and the diversification of product designs, there is a demand for the resin material of the housing itself to have this electromagnetic wave shielding property, that is, a resin composition with excellent electromagnetic wave shielding properties.

[0005] As an example of such a resin composition having excellent electromagnetic wave shielding properties, Patent Document 1 discloses a thermoplastic resin composition consisting of 50 to 95% by weight of a polycarbonate resin (A1) and / or a polyester-based resin (A2) and 50 to 5% by weight of graphite (B), characterized in that the polycarbonate resin (A1) and / or the polyester-based resin (A2) are blended with graphite (B) having a moisture content of 0.2% or less. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2008-163270 A Summary of the Invention [Problem to be solved by the invention]

[0007] Here, in the above Patent Document 1, only the embodiment using polycarbonate resin as the resin component is specifically considered. However, it would be beneficial to have a resin composition having excellent electromagnetic wave shielding properties that utilizes the performance of polybutylene terephthalate resin. In addition, in a resin composition containing polybutylene terephthalate resin, flame retardancy is required depending on the application. The present invention aims to solve these problems, and has an object to provide a resin composition having excellent electromagnetic shielding properties and flame retardancy, as well as pellets and molded articles formed from the resin composition. [Means for solving the problem]

[0008] In light of the above-mentioned problems, the present inventors have conducted research and found that the above-mentioned problems can be solved by using, in addition to polybutylene terephthalate resin, a thermoplastic resin (e.g., a polystyrene-based resin) having a lower SP value than polybutylene terephthalate resin, and further employing a bromine-based flame retardant having a predetermined molecular weight as the flame retardant. Specifically, the above problems were solved by the following means. <1> (A) polybutylene terephthalate resin; (B) a thermoplastic resin having a lower SP value than the polybutylene terephthalate resin; (C) carbon fiber; (D) a brominated flame retardant having a weight average molecular weight (Mw) of 200 to 20,000; A resin composition comprising: The content of (C) carbon fiber in the resin composition is 5 to 30 mass %, The mass ratio of (A) to (B), (B) / (A), is greater than 0.1 and less than 1.0; Resin composition. <2> The intrinsic viscosity of the (A) polybutylene terephthalate resin is 0.80 dL / g or less. <1> The resin composition according to claim 1. <3> The (B) thermoplastic resin includes recycled products, <1> or <2> The resin composition according to claim 1. <4> The (B) thermoplastic resin includes a polystyrene-based resin. <1> ~ <3> 10. The resin composition according to claim 9 . <5> The (D) brominated flame retardant contains at least one of brominated poly(meth)acrylate, brominated polycarbonate, and brominated phthalimide. <1> ~ <4> 10. The resin composition according to claim 9 . <6> The (D) brominated flame retardant does not have a functional group capable of reacting with the (A) polybutylene terephthalate resin. <1> ~ <5> 10. The resin composition according to claim 9 . <7> Further, antimony compounds, <1> ~ <6> 10. The resin composition according to claim 9 . <8> Further comprising a compatibilizer, <1> ~ <7> 10. The resin composition according to claim 9 . <9> the compatibilizer comprises a polycarbonate resin; <8> The resin composition according to claim 1. <10> the compatibilizer comprises recycled polycarbonate resin; <8> or <9> The resin composition according to claim 1. <11> For electromagnetic wave shielding, <1> ~ <10> 10. The resin composition according to claim 9 . <12> The (A) polybutylene terephthalate resin has an intrinsic viscosity of 0.80 dL / g or less, the (B) thermoplastic resin contains a polystyrene-based resin, the (D) brominated flame retardant contains at least one of a brominated poly(meth)acrylate, a brominated polycarbonate, and a brominated phthalimide; the (D) brominated flame retardant does not have a functional group capable of reacting with the (A) polybutylene terephthalate resin, Further, antimony compounds are included. Further comprising a compatibilizer, The compatibilizer contains a polycarbonate resin and is for electromagnetic wave shielding. <1> ~ <11> 10. The resin composition according to claim 9 . <13> The polycarbonate resin and / or the polystyrene resin contain recycled products; <12> The resin composition according to claim 1. <14> <1> ~ <13> 2. A pellet of the resin composition according to claim 1. <15> <1> ~ <13> 2. A molded article molded from the resin composition according to claim 1. <16> <14> A molded article molded from the pellets according to claim 1. Effect of the Invention

[0009] According to the present invention, it is possible to provide a resin composition having excellent electromagnetic wave shielding properties and flame retardancy, as well as pellets and molded articles formed from the resin composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to the present embodiment. In this specification, the use of "to" means that the numerical values ​​before and after it are included as the lower limit and upper limit. In this specification, various physical properties and characteristic values ​​are those at 23° C. unless otherwise specified. In this specification, unless otherwise specified, the weight average molecular weight and the number average molecular weight are values ​​calculated as polystyrene standards measured by GPC (gel permeation chromatography). If the measurement methods, etc. described in the standards shown in this specification vary from year to year, they will be based on the standards as of January 1, 2023, unless otherwise stated.

[0011] In this specification, unless otherwise specified, the weight average molecular weight and number average molecular weight are polystyrene-equivalent values ​​measured by GPC (gel permeation chromatography) using a Tosoh HLC-8320GPC EcoSEC with tetrahydrofuran as a solvent and Shodex KF-G, KF-805L x 3, KF-800D columns at a column temperature of 40°C and a flow rate of 1.2 mL / min, and detected at a detection wavelength of 254 nm.

[0012] The resin composition of the present embodiment is a resin composition including (A) a polybutylene terephthalate resin, (B) a thermoplastic resin having a lower SP value than the polybutylene terephthalate resin, (C) carbon fiber, and (D) a brominated flame retardant having a weight average molecular weight (Mw) of 200 to 20,000, wherein the content of the carbon fiber (C) in the resin composition is 5 to 30 mass%, and the mass ratio of (A) to (B), (B) / (A), is greater than 0.1 and less than 1.0. By adopting such a constitution, a resin composition having excellent electromagnetic wave shielding properties and flame retardancy can be obtained. By using a flame retardant having a relatively small weight-average molecular weight, the viscosity of the resulting resin composition does not become too high. As a result, the carbon fibers are less likely to break during melt-kneading, etc., and the electromagnetic shielding properties of the resulting molded product can be maintained at a high level. Moreover, recycled products may be used as the thermoplastic resin (B) and the compatibilizer described below.

[0013] <(A) Polybutylene terephthalate resin> The resin composition of the present embodiment contains (A) a polybutylene terephthalate resin. The polybutylene terephthalate resin used in the resin composition of this embodiment is a polyester resin having a structure in which terephthalic acid units and 1,4-butanediol units are ester-bonded, and includes, in addition to polybutylene terephthalate resin (homopolymer), a polybutylene terephthalate copolymer containing other copolymerization components other than terephthalic acid units and 1,4-butanediol units, and a mixture of a homopolymer and a polybutylene terephthalate copolymer.

[0014] The (A) polybutylene terephthalate resin may contain one or more types of dicarboxylic acid units other than terephthalic acid. Specific examples of other dicarboxylic acids include aromatic dicarboxylic acids such as isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2,2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, bis(4,4'-carboxyphenyl)methane, anthracenedicarboxylic acid, and 4,4'-diphenyletherdicarboxylic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and 4,4'-dicyclohexyldicarboxylic acid; and aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, and dimer acid. In the polybutylene terephthalate resin (A) used in this embodiment, terephthalic acid units preferably account for 80 mol % or more, and more preferably 90 mol % or more, of all dicarboxylic acid units.

[0015] The diol unit may contain one or more other diol units in addition to 1,4-butanediol. Specific examples of other diol units include aliphatic or alicyclic diols having 2 to 20 carbon atoms, bisphenol derivatives, etc. Specific examples include ethylene glycol, propylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, decamethylene glycol, cyclohexanedimethanol, 4,4'-dicyclohexylhydroxymethane, 4,4'-dicyclohexylhydroxypropane, and ethylene oxide adduct diol of bisphenol A. In addition to the above-mentioned bifunctional monomers, a small amount of a trifunctional monomer such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, or trimethylolpropane can be used in combination to introduce a branched structure, or a monofunctional compound such as a fatty acid can be used in combination to adjust the molecular weight. In the polybutylene terephthalate resin (A) used in this embodiment, 1,4-butanediol units preferably account for 80 mol % or more, and more preferably 90 mol % or more, of all diol units.

[0016] As described above, the (A) polybutylene terephthalate resin is preferably a polybutylene terephthalate homopolymer obtained by polycondensation of terephthalic acid and 1,4-butanediol. The carboxylic acid unit may be a polybutylene terephthalate copolymer containing at least one dicarboxylic acid other than the above-mentioned terephthalic acid and / or at least one diol other than the above-mentioned 1,4-butanediol as a diol unit. When the (A) polybutylene terephthalate resin is a polybutylene terephthalate resin modified by copolymerization, specific preferred copolymers include polyester ether resins copolymerized with polyalkylene glycols, particularly polytetramethylene glycol, dimer acid copolymerized polybutylene terephthalate resins, and isophthalic acid copolymerized polybutylene terephthalate resins. Among them, it is preferable to use a polyester ether resin copolymerized with polytetramethylene glycol. Incidentally, these copolymers refer to those in which the copolymerization amount is 1 mol% or more and less than 50 mol% in the total segments of the polybutylene terephthalate resin. In particular, the copolymerization amount is preferably 2 mol% or more and less than 50 mol%, more preferably 3 to 40 mol%, and further preferably 5 to 20 mol%. By setting the copolymerization ratio in this range, there is a tendency that the fluidity, toughness, and tracking resistance are easily improved, which is preferable.

[0017] The amount of terminal carboxyl groups in the polybutylene terephthalate resin (A) may be appropriately selected and determined, but is usually 60 eq / ton or less, preferably 50 eq / ton or less, and more preferably 30 eq / ton or less. By setting it to the above upper limit or less, the alkali resistance and hydrolysis resistance tend to be improved. The lower limit of the amount of terminal carboxyl groups is not particularly set, but is usually 10 eq / ton or more, taking into consideration the productivity of the production of the polybutylene terephthalate resin (A).

[0018] The amount of terminal carboxyl groups in the polybutylene terephthalate resin (A) is a value measured by dissolving 0.5 g of the polybutylene terephthalate resin (A) in 25 mL of benzyl alcohol and titrating it with a 0.01 mol / L benzyl alcohol solution of sodium hydroxide. The amount of terminal carboxyl groups may be adjusted by any conventionally known method, such as adjusting the polymerization conditions, such as the raw material charge ratio during polymerization, the polymerization temperature, and the pressure reduction method, or by reacting a terminal blocking agent.

[0019] The intrinsic viscosity of the polybutylene terephthalate resin (A) is preferably 0.80 dL / g or less, more preferably 0.75 dL / g or less, and more preferably 0.72 dL / g or less. By making it equal to or less than the upper limit, damage to the carbon fiber in a molten state can be effectively suppressed, and electromagnetic wave shielding properties tend to be improved. The lower limit is, for example, preferably 0.4 dL / g or more, more preferably 0.5 dL / g or more, and even more preferably 0.6 dL / g or more. By making it equal to or more than the lower limit, mechanical properties tend to be improved. (A) The intrinsic viscosity of the polybutylene terephthalate resin is a value measured at 30° C. in a mixed solvent of tetrachloroethane and phenol in a 1:1 (mass ratio). When the resin composition of the present embodiment contains two or more types of (A) polybutylene terephthalate resins, the intrinsic viscosity is the intrinsic viscosity of the mixture.

[0020] (A) Polybutylene terephthalate resin can be produced by batch or continuous melt polymerization of a dicarboxylic acid component mainly composed of terephthalic acid or an ester derivative thereof and a diol component mainly composed of 1,4-butanediol. In addition, after producing a low molecular weight polybutylene terephthalate resin by melt polymerization, the degree of polymerization (or molecular weight) can be increased to a desired value by further solid-phase polymerization under a nitrogen gas flow or reduced pressure. The (A) polybutylene terephthalate resin is preferably one obtained by a production method in which a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of 1,4-butanediol are subjected to continuous melt polycondensation.

[0021] The catalyst used in carrying out the esterification reaction may be a conventionally known catalyst, and examples thereof include titanium compounds, tin compounds, magnesium compounds, calcium compounds, etc. Among these, titanium compounds are particularly preferred. Specific examples of titanium compounds as esterification catalysts include titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate.

[0022] The content of the polybutylene terephthalate resin (A) in the resin composition of this embodiment is preferably 20% by mass or more, more preferably 25% by mass or more, even more preferably 30% by mass or more, and even more preferably 32% by mass or more in the resin composition. The content of the polybutylene terephthalate resin (A) is preferably 55% by mass or less, more preferably 52% by mass or less, even more preferably 50% by mass or less, even more preferably 45% by mass or less, and even more preferably 40% by mass or less.

[0023] <(B) Thermoplastic resin with a lower SP value than polybutylene terephthalate resin> The resin composition of this embodiment contains a thermoplastic resin (sometimes referred to as "thermoplastic resin (B)" in this specification) having a lower SP value than polybutylene terephthalate resin. By blending a resin composition having a lower SP value than polybutylene terephthalate resin into the alloy, the carbon fiber (C) is relatively unevenly distributed in the polybutylene terephthalate resin region (A) rather than in the thermoplastic resin region (B) in the resin composition or molded product, and the carbon fiber (C) is more effectively dispersed in the resin composition or molded product, resulting in improved electromagnetic wave shielding. In addition, the flowability of the resin composition can be improved. Furthermore, the thermoplastic resin (B) used in this embodiment may contain a recycled product (recycled thermoplastic resin). In the resin composition of this embodiment, even though a recycled product is used as the thermoplastic resin (B) (e.g., polystyrene-based resin (PS)), it is possible to achieve performance comparable to that of a virgin thermoplastic resin (B) (e.g., polystyrene-based resin (PS)). In addition, in the present invention, resins that fall under (B) thermoplastic resin and also fall under (D) bromine-based flame retardants and compatibilizers, which will be described later, are referred to as (D) halogen-based flame retardants and compatibilizers, respectively.

[0024] In this embodiment, the SP value is a solubility parameter, and the solubility in a solvent having a known SP value is obtained, and calculation can be performed using Hansen Solubility Parameter in Practice ver. 5.0 based on the obtained solubility.

[0025] The (B) thermoplastic resin can be used without particular limitation as long as it has a lower SP value than the polybutylene terephthalate resin. In this embodiment, the SP value difference between the polybutylene terephthalate resin (A) and the thermoplastic resin (B) (the SP value of (A) - the SP value of (B)) is preferably 0.1 or more, more preferably 1.0 or more, and even more preferably 2.0 or more, and is preferably 10.0 or less, more preferably 5.0 or less, and may be 3.0 or less. By making it equal to or more than the lower limit, the carbon fibers are effectively unevenly distributed in the polybutylene terephthalate resin, and the electromagnetic shielding property tends to be further improved. Also, by making it equal to or less than the upper limit, the compatibility between the polymers tends to be further improved. When the resin composition of the present embodiment contains two or more types of (B) thermoplastic resins, it is preferable that the sum (weighted average value) of the SP value of each (B) thermoplastic resin multiplied by the mass fraction of each (B) thermoplastic resin falls within the above range.

[0026] In the present embodiment, the mass ratio of (A) to (B), that is, (B) / (A), is greater than 0.1 and less than 1.0. By keeping it within this range, the electromagnetic wave shielding property tends to be improved. The X / PBT is preferably 0.2 or more, more preferably 0.3 or more, even more preferably 0.4 or more, may be 0.5 or more, or may be 0.7 or more, and is preferably 0.9 or less, and may be less than 0.9.

[0027] Preferred examples of the thermoplastic resin (B) used in this embodiment include polyester resins (thermoplastic polyester resins); polyamide resins; polycarbonate resins; polystyrene-based resins; polyolefin resins such as polyethylene resins, polypropylene resins, and cyclic cycloolefin resins; polyacetal resins; polyimide resins; polyetherimide resins; polyurethane resins; polyphenylene ether resins; polyphenylene sulfide resins; polysulfone resins; polymethacrylate resins; and the like, and it is more preferable to select the thermoplastic resin (B) from polyester resins, polystyrene-based resins, and polyolefin resins. An example of the thermoplastic resin (B) used in this embodiment is selected from polyester resins and polystyrene-based resins. Another example of the thermoplastic resin (B) used in this embodiment is selected from polyolefin resins and polystyrene-based resins, and is preferably selected from polyolefin-based elastomers and styrene-based elastomers. In this embodiment, the (B) thermoplastic resin more preferably contains a polystyrene-based resin, and even more preferably contains HIPS (preferably butadiene rubber-containing polystyrene).

[0028] Examples of the polystyrene-based resin include homopolymers of styrene-based monomers, copolymers of styrene-based monomers and monomers copolymerizable with styrene-based monomers, etc. Examples of the styrene-based monomers include styrene, α-methylstyrene, chlorostyrene, methylstyrene, and tert-butylstyrene. In the polystyrene-based resin of the present embodiment, 50 mol % or more of the monomer units are styrene-based monomers. A preferred example of the polystyrene-based resin used in this embodiment is a styrene-based elastomer. More specifically, examples of polystyrene resins include polystyrene resin, acrylonitrile-styrene copolymer (AS resin), high impact polystyrene resin (HIPS), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), acrylonitrile-ethylene propylene rubber-styrene copolymer (AES resin), and styrene-IPN type rubber copolymer. In this embodiment, the polystyrene resin is preferably an acrylonitrile-styrene copolymer (AS resin), general-purpose polystyrene (GPPS), high impact polystyrene resin (HIPS), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), acrylonitrile-ethylene propylene rubber-styrene copolymer (AES resin), or a styrene-IPN type rubber copolymer, more preferably general-purpose polystyrene (GPPS) or high impact polystyrene resin (HIPS), and even more preferably general-purpose polystyrene (GPPS).

[0029] When the polystyrene resin contains a rubber component, the content of the rubber component in the polystyrene resin is preferably 3 to 70 mass%, more preferably 5 to 50 mass%, and even more preferably 7 to 30 mass%. By making the content of the rubber component 3 mass% or more, impact resistance tends to be improved, and by making it 50 mass% or less, flame retardancy tends to be improved, which is preferable. In addition, the average particle size of the rubber component is preferably 0.05 to 10 μm, more preferably 0.1 to 6 μm, and even more preferably 0.2 to 3 μm. When the average particle size is 0.05 μm or more, impact resistance tends to be improved, and when it is 10 μm or less, appearance tends to be improved, which is preferable.

[0030] The weight average molecular weight of the polystyrene resin is usually 50,000 or more, preferably 100,000 or more, more preferably 150,000 or more, and usually 500,000 or less, preferably 400,000 or less, more preferably 300,000 or less. The number average molecular weight is usually 10,000 or more, preferably 30,000 or more, more preferably 50,000 or more, and preferably 500,000 or less, more preferably 300,000 or less.

[0031] The melt flow rate (MFR) of the polystyrene resin measured in accordance with JIS K7210 (temperature 200°C, load 5 kgf) is preferably 0.1 to 30 g / 10 min, more preferably 0.5 to 25 g / 10 min. If the MFR is 0.1 g / 10 min or more, the fluidity tends to be improved, and if it is 30 g / 10 min or less, the impact resistance tends to be improved.

[0032] Examples of methods for producing such polystyrene resins include known methods such as emulsion polymerization, solution polymerization, suspension polymerization, and bulk polymerization.

[0033] The polyolefin resin is preferably a resin in which olefins such as ethylene, propylene, and 1-butene account for 50% by mass or more (preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass). More specifically, examples of the polyolefin resin include polyethylene, polypropylene, and ethylene-propylene copolymers. Alternatively, the polyolefin resin may be a polyolefin-based elastomer.

[0034] Examples of recycled thermoplastic resins (e.g., recycled polystyrene-based resins and / or recycled polystyrene resins, preferably recycled polystyrene-based resins) include those obtained by material recycling in which recovered used thermoplastic resin (e.g., used polystyrene-based resin) molded articles are crushed, washed, and reused, those obtained by chemical recycling (chemical decomposition method), and those obtained by mechanical recycling. Chemical recycling involves chemically breaking down recovered used thermoplastic resin (e.g., used polystyrene resin) molded products, returning them to their raw material level, and resynthesizing thermoplastic resin (e.g., recycled polystyrene resin).Mechanical recycling, on the other hand, is a method that makes it possible to remove dirt from thermoplastic resin (e.g., polystyrene resin) molded products more reliably than material recycling by carrying out alkaline washing more strictly than in the above-mentioned material recycling, or by vacuum drying at high temperatures. For example, after foreign matter is removed from a used thermoplastic resin (e.g., used polystyrene-based resin) molded product, the product is crushed and washed, and then pelletized using an extruder to obtain a recycled thermoplastic resin (e.g., recycled polystyrene-based resin).

[0035] The resin composition of the present embodiment may contain only virgin products, only recycled products, or both recycled products and virgin products as the (B) thermoplastic resin (preferably a polystyrene-based resin). In the present embodiment, when the resin composition contains virgin (B) thermoplastic resin, the content is such that 50 to 100 parts by mass of recycled product is per 100 parts by mass of (B) thermoplastic resin, 80 to 100 parts by mass of recycled product may be, or 90 to 100 parts by mass of recycled product may be.

[0036] The total content of the polybutylene terephthalate resin (A) and the thermoplastic resin (B) (preferably a polystyrene-based resin) in the resin composition of this embodiment is preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more in the resin composition. By making it equal to or more than the lower limit, the flowability of the resin composition tends to be further improved. In addition, the total content of the polybutylene terephthalate resin (A) and the thermoplastic resin (B) (preferably a polystyrene-based resin) in the resin composition of this embodiment is preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 83% by mass or less, even more preferably 80% by mass or less, even more preferably 75% by mass or less, and even more preferably 70% by mass or less. By making it equal to or less than the upper limit, the mechanical strength tends to be further improved.

[0037] The resin composition of the present embodiment may contain only one kind or two or more kinds of (A) polybutylene terephthalate resin and (B) thermoplastic resin (preferably polystyrene-based resin).

[0038] <(C) Carbon fiber> The resin composition of the present embodiment contains (C) carbon fibers, which can improve the electromagnetic wave shielding properties of the resulting molded article. The type of (C) carbon fiber is not particularly limited, and either polyacrylonitrile-based carbon fiber (PAN-based fiber) or pitch-based carbon fiber using pitch is preferably used, with polyacrylonitrile-based carbon fiber (PAN-based fiber) being more preferred. The (C) carbon fiber may have a tensile strength of 5.0 GPa or less (preferably 3.5 to 5.0 GPa) measured at 23° C. in accordance with JIS R7601.

[0039] The (C) carbon fibers are preferably chopped strands. The lower limit of the number average fiber length (cut length) of the (C) carbon fiber is preferably 2 mm or more, more preferably 3 mm or more, and the upper limit of the number average fiber length is preferably 10 mm or less, more preferably 8 mm or less, and even more preferably 7 mm or less. The carbon fibers (C) preferably have a number average fiber diameter of 3 to 20 μm, more preferably 5 to 15 μm. By using the carbon fibers (C) in such a range, the molded product obtained can have an excellent balance between mechanical strength and appearance. Specific examples of the carbon fiber (C) include Torayca manufactured by Toray Industries, Inc., Besfight Filament manufactured by Toho Tenax Co., Ltd., and Pyrofil manufactured by Mitsubishi Chemical Corporation.

[0040] The content of the (C) carbon fiber in the resin composition of this embodiment is 5% by mass or more in the resin composition, preferably 10% by mass or more, more preferably 11% by mass or more, and even more preferably 12% by mass or more. By making it equal to or more than the lower limit, the electromagnetic wave shielding property tends to be further improved. In addition, the upper limit of the content of the (C) carbon fiber in the resin composition is 30% by mass or less, preferably 26% by mass or less, more preferably 23% by mass or less, even more preferably 20% by mass or less, even more preferably 18% by mass or less, and even more preferably 16% by mass or less. By making it equal to or less than the upper limit, the flowability during molding tends to be improved. The resin composition of the present embodiment may contain only one type of (C) carbon fiber, or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0041] <(D) Brominated flame retardant having a weight average molecular weight (Mw) of 200 to 20,000> The resin composition of the present embodiment contains (D) a brominated flame retardant having a weight average molecular weight (Mw) of 200 to 20000. By containing (D) a brominated flame retardant, flame retardancy can be achieved. In addition, by using a flame retardant having a weight average molecular weight (Mw) of 200 to 20000, electromagnetic wave shielding properties can be improved. The weight average molecular weight of the (D) bromine-based flame retardant is preferably 210 or more, more preferably 220 or more, even more preferably 400 or more, even more preferably 500 or more, even more preferably 550 or more, and is preferably 20000 or less, more preferably 18000 or less, even more preferably 15000 or less, even more preferably 10000 or less, even more preferably 8000 or less, and may be 6000 or less, 4000 or less, 2000 or less, or 1500 or less. By making it equal to or more than the lower limit, there is a tendency that flame retardancy can be effectively obtained. Also, by making it equal to or less than the upper limit, there is a tendency that the flowability and electromagnetic wave shielding property of the resin composition are further improved. When the resin composition of the present embodiment contains two or more types of (D) brominated flame retardants, it is sufficient that the weight average molecular weight of at least one of the brominated flame retardants is within the above range, and it is more preferable that 80 mass% or more of the brominated flame retardants contained in the resin composition are within the above range, even more preferable that 90 mass% or more of the brominated flame retardants contained in the resin composition are within the above range, still more preferable that 95 mass% or more of the brominated flame retardants contained in the resin composition are within the above range, and 100 mass% of the brominated flame retardants contained in the resin composition may be within the above range.

[0042] The brominated flame retardant (D) used in this embodiment preferably does not have a functional group capable of reacting with the polybutylene terephthalate resin (A). By adopting such a configuration, the reaction between the brominated flame retardant (D) and the polybutylene terephthalate resin (A) can be effectively suppressed, and the viscosity of the resin composition can be effectively suppressed from increasing. As a result, the carbon fiber (C) can be made less likely to break during melt-kneading or injection molding of the resin composition, and the electromagnetic wave shielding property of the obtained molded product can be maintained at a higher level. (A) Examples of the functional group capable of reacting with the polybutylene terephthalate resin include an epoxy group, a carboxyl group, an isocyanate group, a carbodiimide group, an aldehyde group, and an amide group.

[0043] The type of the (D) brominated flame retardant is not particularly limited, but at least one of brominated poly(meth)acrylate, brominated polycarbonate, and brominated phthalimide is preferable.

[0044] The brominated poly(meth)acrylate is preferably a polymer obtained by polymerizing a bromine atom-containing (meth)acrylate monomer, particularly benzyl (meth)acrylate, alone or by copolymerizing two or more kinds of the monomers, or by copolymerizing the monomers with other vinyl monomers. The bromine atoms are added to the benzene ring, and the number of added bromine atoms is preferably 1 to 5, more preferably 4 to 5, per benzene ring.

[0045] As the brominated poly(meth)acrylate, pentabromobenzyl poly(meth)acrylate is preferred due to its high bromine content.

[0046] The molecular weight of the brominated poly(meth)acrylate is arbitrary and may be appropriately selected and determined, but the weight average molecular weight (Mw) is preferably 3,000 or more, more preferably 10,000 or more, even more preferably 15,000 or more, even more preferably 20,000 or more, and even more preferably 25,000 or more. By making it equal to or greater than the lower limit, a molded product having higher mechanical strength tends to be obtained. In addition, the upper limit of the weight average molecular weight (Mw) is preferably equal to or less than 100,000, more preferably equal to or less than 80,000, even more preferably equal to or less than 60,000, even more preferably equal to or less than 50,000, and even more preferably equal to or less than 35,000. By making it equal to or less than the upper limit, the flowability of the resin composition tends to be further improved.

[0047] The brominated polycarbonate preferably has a free bromine content of 0.05% by mass or more, and preferably 0.20% by mass or less. By setting the content within such a range, the heat resistance stability of the resin composition tends to be further improved. The brominated polycarbonate also preferably has a chlorine atom content of 0.001% by mass or more, and preferably 0.20% by mass or less. By setting the content within such a range, the mold corrosion resistance during molding tends to be further improved. Specifically, the brominated polycarbonate is preferably a brominated polycarbonate obtained from, for example, brominated bisphenol A, particularly tetrabromobisphenol A. Examples of the terminal structure include a phenyl group, a 4-t-butylphenyl group, and a 2,4,6-tribromophenyl group, and in particular, one having a 2,4,6-tribromophenyl group in the terminal group structure is preferred.

[0048] The average number of carbonate constituent units in the brominated polycarbonate may be appropriately selected and determined, but is preferably 2-30, more preferably 3-15, and even more preferably 3-10.

[0049] The molecular weight of the brominated polycarbonate is optional and may be appropriately selected and determined, but it is preferably from 1,000 to 20,000, more preferably from 2,000 to 10,000, in terms of viscosity average molecular weight.

[0050] The brominated polycarbonate obtained from the above brominated bisphenol A can be obtained, for example, by a conventional method of reacting brominated bisphenol with phosgene. The end-capping agent includes an aromatic monohydroxy compound, which may be substituted with a halogen or an organic group.

[0051] The brominated phthalimide is preferably one represented by formula (1), and more preferably N-bromophthalimide. [ka] (In formula (1), D represents an alkylene group, an arylene group, -S(=O)2-, -C(=O)-, and a group formed by combining two or more of -O-. i is an integer of 1 to 4.)

[0052] In formula (1), D represents a group consisting of a combination of two or more of an alkylene group, an arylene group, -S(=O)2-, -C(=O)-, and -O-. A group consisting of a combination of an alkylene group or an arylene group and at least one of -S(=O)2-, -C(=O)-, and -O- is preferable, a group consisting of a combination of an alkylene group or an arylene group and one of -S(=O)2-, -C(=O)-, and -O- is more preferable, and an alkylene group is further preferable. The group consisting of a combination of an alkylene group and -O- is intended to include, for example, a combination of two alkylene groups and one -O- (the same applies to other combinations). The alkylene group represented by D is preferably an alkylene group having 1 to 6 carbon atoms, more preferably a methylene group, an ethylene group, a propylene group, or a butylene group. The arylene group is preferably a phenylene group. "i" is an integer of 1 to 4, and is preferably 4.

[0053] Examples of the brominated phthalimide represented by formula (1) include N,N'-(bistetrabromophthalimide)ethane, N,N'-(bistetrabromophthalimide)propane, N,N'-(bistetrabromophthalimide)butane, N,N'-(bistetrabromophthalimide)diethyl ether, N,N'-(bistetrabromophthalimide)dipropyl ether, N,N'-(bistetrabromophthalimide)dibutyl ether, N,N'-(bistetrabromophthalimide)diphenyl sulfone, N,N'-(bistetrabromophthalimide)diphenyl ketone, and N,N'-(bistetrabromophthalimide)diphenyl ether.

[0054] The brominated phthalimide represented by formula (1) is preferably a brominated phthalimide represented by formula (2). [ka] (In formula (2), i is an integer of 1 to 4.) "i" is an integer of 1 to 4, and is preferably 4.

[0055] The brominated poly(meth)acrylate is preferably a polymer obtained by polymerizing a bromine atom-containing benzyl (meth)acrylate alone, copolymerizing two or more kinds of the bromine atom-containing benzyl (meth)acrylate, or copolymerizing the bromine atom with another vinyl monomer, and the bromine atoms are added to a benzene ring with 1 to 5 bromine atoms, preferably 4 to 5 bromine atoms, added per benzene ring.

[0056] Examples of the benzyl acrylate containing a bromine atom include pentabromobenzyl acrylate, tetrabromobenzyl acrylate, tribromobenzyl acrylate, and mixtures thereof. Examples of the benzyl methacrylate containing a bromine atom include methacrylates corresponding to the above-mentioned acrylates.

[0057] Specific examples of other vinyl monomers that can be copolymerized with the bromine atom-containing benzyl (meth)acrylate include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and benzyl acrylate; methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and benzyl methacrylate; unsaturated carboxylic acids or anhydrides thereof, such as styrene, acrylonitrile, fumaric acid, and maleic acid; vinyl acetate, and vinyl chloride.

[0058] These are usually used in an equimolar amount or less, particularly preferably 0.5 times the molar amount or less, relative to the bromine atom-containing benzyl (meth)acrylate.

[0059] Furthermore, examples of vinyl monomers that can be used include xylylene diacrylate, xylylene dimethacrylate, tetrabromo xylylene diacrylate, tetrabromo xylylene dimethacrylate, butadiene, isoprene, and divinylbenzene. These can usually be used in an amount of 0.5 or less by mole relative to the bromine atom-containing benzyl acrylate or benzyl methacrylate.

[0060] The (D) brominated flame retardant may be brominated polystyrene. In this specification, a compound that corresponds to the (D) brominated flame retardant and also corresponds to the (B) thermoplastic resin is classified as the (D) brominated flame retardant. The brominated polystyrene preferably includes a brominated polystyrene containing a constitutional unit represented by the formula (3). [ka] (In formula (3), t is an integer of 1 to 5, and n is the number of constitutional units.)

[0061] Brominated polystyrene may be produced by brominating polystyrene or by polymerizing brominated styrene monomer, but the polymerized brominated styrene has a smaller amount of free bromine (atoms), and is therefore preferred. In formula (3), the CH group to which the brominated benzene is bonded may be substituted with a methyl group. Brominated polystyrene may also be a copolymer in which other vinyl monomers are copolymerized. Examples of the vinyl monomer in this case include styrene, α-methylstyrene, (meth)acrylonitrile, (meth)methyl acrylate, butadiene, and vinyl acetate. Brominated polystyrene may be used alone or as a mixture of two or more types with different structures, and may contain units derived from styrene monomers with different bromine numbers in a single molecular chain.

[0062] Specific examples of brominated polystyrene include poly(4-bromostyrene), poly(2-bromostyrene), poly(3-bromostyrene), poly(2,4-dibromostyrene), poly(2,6-dibromostyrene), poly(2,5-dibromostyrene), poly(3,5-dibromostyrene), poly(2,4,6-tribromostyrene), poly(2,4,5-tribromostyrene), poly(2,3,5-tribromostyrene), and poly(4-bromo-α-methylstyrene). Examples of suitable styrene copolymers include poly(2,4-dibromostyrene), poly(2,5-dibromo-α-methylstyrene), poly(2,4,6-tribromo-α-methylstyrene) and poly(2,4,5-tribromo-α-methylstyrene), of which poly(2,4,6-tribromostyrene), poly(2,4,5-tribromostyrene) and polydibromostyrene and polytribromostyrene containing an average of 2 to 3 bromine groups in the benzene ring are particularly preferred.

[0063] (D) The brominated flame retardant may be a brominated epoxy. Specific preferred examples of the brominated epoxy include bisphenol A type brominated epoxy compounds, such as tetrabromobisphenol A epoxy compounds and glycidyl brominated bisphenol A epoxy compounds.

[0064] In addition, a brominated epoxy oligomer can be used in combination as the brominated epoxy. In this case, for example, by using an oligomer having Mw of 5,000 or less at a ratio of about 50 mass% or less, the flame retardancy, releasability, and flowability can be appropriately adjusted. The bromine atom content in the brominated epoxy compound is arbitrary, but in order to impart sufficient flame retardancy, it is usually 10 mass% or more, preferably 20 mass% or more, and particularly preferably 30 mass% or more, with the upper limit being 60 mass%, and preferably 55 mass% or less.

[0065] The bromine concentration in the (D) bromine-based flame retardant is preferably 45% by mass or more, more preferably 48% by mass or more, and even more preferably 50% by mass or more. By making it equal to or more than the lower limit, the flame retardancy of the molded article tends to be effectively improved. The upper limit of the bromine concentration is preferably 75% by mass or less, more preferably 73% by mass or less, even more preferably 71% by mass or less, and may be 65% by mass or less.

[0066] The content of the (D) bromine-based flame retardant in the resin composition of the present embodiment is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, and even more preferably 10 parts by mass or more, relative to 100 parts by mass of the total of the (A) polybutylene terephthalate resin and the (B) thermoplastic resin. By making it equal to or more than the lower limit, the flame retardancy of the obtained molded article tends to be further improved. The upper limit of the content of the (D) bromine-based flame retardant is 50 parts by mass or less, preferably 45 parts by mass or less, more preferably 40 parts by mass or less, even more preferably 35 parts by mass or less, even more preferably 30 parts by mass or less, even more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less, relative to 100 parts by mass of the total of the (A) polybutylene terephthalate resin and the (B) thermoplastic resin. By making it equal to or less than the upper limit, the decrease in the mechanical strength of the obtained molded article can be more effectively suppressed. The resin composition of the present embodiment may contain only one type of (D) brominated flame retardant, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0067] The resin composition of the present embodiment may or may not contain a flame retardant other than the (D) bromine-based flame retardant, for example, a phosphorus-based flame retardant. An example of the resin composition of the present embodiment is one that is substantially free of phosphorus-based flame retardants. Substantially free means that the content of the phosphorus-based flame retardant contained in the resin composition is less than 10% by mass of the content of the (D) bromine-based flame retardant, preferably less than 5% by mass, more preferably less than 3% by mass, and may be less than 1% by mass. Another example of the resin composition of the present embodiment is that it is substantially free of flame retardants other than the (D) brominated flame retardant. Substantially free means that the content of flame retardants other than the (D) brominated flame retardant contained in the resin composition is less than 10 mass%, preferably less than 5 mass%, more preferably less than 3 mass%, and may be less than 1 mass% of the (D) brominated flame retardant. Another example of the resin composition of the present embodiment is that it is substantially free of brominated polystyrene and brominated epoxy. Substantially free of brominated polystyrene and brominated epoxy contained in the resin composition means that the total content of brominated polystyrene and brominated epoxy contained in the resin composition is less than 10% by mass of the total amount of (D) brominated flame retardant, preferably less than 5% by mass, more preferably less than 3% by mass, and may be less than 1% by mass.

[0068] <Flame retardant synergist> The resin composition of the present embodiment may contain a flame retardant auxiliary. By containing the flame retardant auxiliary, the flame retardancy of the molded article can be further improved. The flame retardant auxiliary is particularly preferably used when a halogen-based flame retardant is contained. The flame retardant auxiliary used in the present embodiment is exemplified by antimony compounds, such as antimony trioxide (Sb2O3), antimony tetraoxide (Sb2O4), antimony pentoxide (Sb2O5), and sodium antimonate. In particular, antimony oxide, and particularly antimony trioxide, is preferred from the viewpoint of impact resistance. When a flame retardant auxiliary is blended, it may be blended as a master batch. The content of the antimony compound in the master batch is preferably 30 to 90 mass%, more preferably 40 to 85 mass%, further preferably 50 to 85 mass%, even more preferably 60 to 85 mass%, and still more preferably 70 to 85 mass%. The resin used in the master batch is preferably a polyester resin or a polystyrene resin, and more preferably a polystyrene resin.

[0069] When the resin composition of the present embodiment contains a flame retardant auxiliary (for example, an antimony compound), the content is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, even more preferably 2 parts by mass or more, and even more preferably 4 parts by mass or more, relative to 100 parts by mass of the total of the polybutylene terephthalate resin (A) and the thermoplastic resin (B). By making the content equal to or more than the lower limit, the flame retardancy tends to be more effectively exhibited. In addition, the upper limit of the content of the antimony compound is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, even more preferably 10 parts by mass or less, and even more preferably 8 parts by mass or less, relative to 100 parts by mass of the total of the polybutylene terephthalate resin (A) and the thermoplastic resin (B). By making the content equal to or less than the upper limit, the mold release property and impact resistance of the obtained molded product tend to be improved. The resin composition of the present embodiment may contain only one type of flame retardant auxiliary, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0070] <Compatibilizer> The resin composition of the present embodiment preferably further contains a compatibilizer, which can promote compatibility between the polybutylene terephthalate resin (A) and the thermoplastic resin (preferably a polystyrene-based resin) (B), making it easier to obtain excellent mechanical strength and excellent appearance.

[0071] The compatibilizer is not particularly limited as long as it can perform the function of compatibilizing the (A) polybutylene terephthalate resin and the (B) thermoplastic resin (preferably a polystyrene-based resin). In the present embodiment, a polymeric compound-based compatibilizer is preferred from the viewpoint of heat resistance.

[0072] The compatibilizer is preferably a polycarbonate resin and / or a styrene-maleic acid copolymer, more preferably a polycarbonate resin. The polycarbonate resin may be a recycled product (recycled polycarbonate resin).

[0073] Polycarbonate resins are thermoplastic polymers or copolymers, which may be branched, obtained by reacting a dihydroxy compound or a small amount of a polyhydroxy compound with phosgene or a carbonic acid diester.

[0074] The dihydroxy compound as the raw material is one that does not substantially contain bromine atoms, and is preferably an aromatic dihydroxy compound.Specific examples include 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), tetramethylbisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4-dihydroxydiphenyl, and the like, and preferably bisphenol A.Also, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compound can be used.

[0075] As the polycarbonate resin, among the above, aromatic polycarbonate resin derived from 2,2-bis(4-hydroxyphenyl)propane, or aromatic polycarbonate copolymer derived from 2,2-bis(4-hydroxyphenyl)propane and other aromatic dihydroxy compounds is preferable. Also, it may be a copolymer mainly composed of aromatic polycarbonate resin, such as a copolymer with a polymer or oligomer having a siloxane structure. Furthermore, two or more of the above polycarbonate resins may be mixed and used.

[0076] In order to adjust the molecular weight of the polycarbonate resin, a monovalent aromatic hydroxy compound may be used, such as m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, p-long-chain alkyl-substituted phenol, and the like.

[0077] The viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 10,000 or more, more preferably 12,000 or more, even more preferably 13,000 or more, and particularly preferably more than 14,000. If a viscosity average molecular weight lower than 10,000 is used, the resulting resin composition tends to have low mechanical strength such as impact resistance. In addition, Mv is preferably 60,000 or less, more preferably 40,000 or less, even more preferably 35,000 or less, and even more preferably 30,000 or less, and may be 25,000 or less, or 20,000 or less. If it is higher than 60,000, the flowability of the resin composition may be poor, and moldability may be deteriorated.

[0078] In the present invention, the viscosity average molecular weight (Mv) of a polycarbonate resin is a value calculated from the intrinsic viscosity ([η]) obtained by measuring the viscosity of a methylene chloride solution of the polycarbonate resin at 25° C. using an Ubbelohde viscometer, and then calculating the viscosity from the following Schnell viscosity formula: [η]=1.23×10 -4 Mv 0.83

[0079] The melt mass flow rate (MFR) of the polycarbonate resin measured in accordance with JIS K7210 (temperature 300°C, load 1.20 kgf) is preferably 3 g / 10 min or more, more preferably 6 g / 10 min or more, and is preferably 100 g / 10 min or less, more preferably 70 g / 10 min or less. When the MFR is within the above range, the effects of the present invention tend to be more effectively exhibited.

[0080] The melt volume rate (MVR) of polycarbonate resin, measured according to JIS K7210 (temperature 300°C, load 1.20kgf), is 0.5 to 20cm. 3 g / 10 min., and 1 to 10 cm 3 When the MVR is within the above range, the effects of the present invention tend to be more effectively exhibited.

[0081] The method for producing the polycarbonate resin is not particularly limited, and polycarbonate resins produced by either the phosgene method (interfacial polymerization method) or the melting method (ester exchange method) can be used. In addition, polycarbonate resins produced by the melting method and then subjected to post-treatment to adjust the amount of OH groups at the terminals are also preferred.

[0082] Examples of recycled polycarbonate resin include those obtained by material recycling in which recovered used polycarbonate resin molded products are crushed, washed, and reused, those obtained by chemical recycling (chemical decomposition method), and those obtained by mechanical recycling. Chemical recycling involves chemically breaking down the collected used polycarbonate resin molded products, returning them to their raw material level and resynthesizing the polycarbonate resin.Mechanical recycling, on the other hand, is a method that makes it possible to remove dirt from polycarbonate resin molded products more reliably than material recycling by carrying out alkaline washing more strictly than in the above-mentioned material recycling, or by vacuum drying at high temperatures. For example, after foreign matter is removed from used polycarbonate resin molded products, the products are crushed and washed, and then pelletized using an extruder to obtain recycled polycarbonate resin.

[0083] The resin composition of the present embodiment may contain only recycled products as the polycarbonate resin, or may contain both recycled products and virgin products. In the present embodiment, the recycled product is preferably 50 to 100 parts by mass, more preferably 80 to 100 parts by mass, and even more preferably 90 to 100 parts by mass, of 100 parts by mass of the polycarbonate resin contained in the resin composition.

[0084] For the styrene-maleic acid copolymer, the description in paragraphs 0048 to 0050 of JP 2020-176159 A can be referred to, the contents of which are incorporated herein by reference.

[0085] When the resin composition of the present embodiment contains a compatibilizer, the content is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, even more preferably 7 parts by mass or more, and even more preferably 8 parts by mass or more, relative to 100 parts by mass of the total of (A) polybutylene terephthalate resin and (B) thermoplastic resin (preferably polystyrene-based resin). By making the content equal to or more than the lower limit, the compatibility of (A) polybutylene terephthalate resin and (B) thermoplastic resin (preferably polystyrene-based resin) is improved, and mechanical properties and appearance tend to be excellent. In addition, the upper limit of the content of the compatibilizer is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 18 parts by mass or less, even more preferably 15 parts by mass or less, and even more preferably 12 parts by mass or less, relative to 100 parts by mass of the total of (A) polybutylene terephthalate resin and (B) thermoplastic resin (preferably polystyrene-based resin). By making the content equal to or less than the upper limit, electromagnetic wave shielding properties and flowability can be further improved. The resin composition of the present embodiment may contain only one type of compatibilizer, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0086] <Other ingredients> The resin composition of the present embodiment may contain other components in addition to those described above, as necessary, as long as the desired physical properties are not significantly impaired. Examples of other components include (C) reinforcement materials other than carbon fiber (glass fiber, etc.), various resin additives, etc. Note that the other components may be contained alone or in any combination and ratio of two or more.

[0087] Examples of various resin additives include stabilizers, release agents, anti-dripping agents, reactive compounds, pigments, dyes, UV absorbers, antistatic agents, antifogging agents, antiblocking agents, flow improvers, plasticizers, dispersants, antibacterial agents, etc. The resin composition of the present embodiment preferably contains at least one of stabilizers and release agents. The resin composition of this embodiment is adjusted so that the total of (A) polybutylene terephthalate resin, (B) thermoplastic resin (preferably polystyrene resin), (C) carbon fiber, (D) bromine-based flame retardant, and other components that are selectively blended is 100% by mass. In one example of the resin composition of this embodiment, the total of (A) polybutylene terephthalate resin, (B) thermoplastic resin (preferably polystyrene resin), (C) carbon fiber, (D) bromine-based flame retardant, flame retardant assistant, compatibilizer, stabilizer, and release agent accounts for 95% by mass or more (preferably 99% by mass or more) of the resin composition.

[0088] <<Stabilizer>> The resin composition of the present embodiment may contain a stabilizer (a heat stabilizer, a light stabilizer, an antioxidant, etc.). The stabilizer preferably contains one or more compounds selected from the group consisting of thioether compounds, hindered phenol compounds, and phosphite compounds, and more preferably contains two or more compounds including hindered phenol compounds and phosphite compounds. By using two or more stabilizers in this way, the stability is further improved and tends to continue for a long period of time.

[0089] As the thioether-based compound, any conventionally known sulfur atom-containing compound can be used, and among them, thioethers are preferred. By including the thioether-based compound in the resin composition of the present embodiment, the appearance of the molded product tends to be improved and color change tends to be suppressed. Specific examples include didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis(3-dodecylthiopropionate), 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diylbis[3-(dodecylthio)propionate], thiobis(N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropylxanthate, and trilauryltrithiophosphite. Among these, 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diylbis[3-(dodecylthio)propionate] is preferable. Commercially available products include "Seenox 412S" manufactured by Shipro Chemical Co., Ltd. and "Adekastab AO-412S" manufactured by ADEKA Corporation.

[0090] Examples of hindered phenol compounds include pentaerythritol tetrakis (3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, thiodiethylene bis (3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate), pentaerythritol tetrakis (3-(3,5-di-neopentyl-4-hydroxyphenyl) propionate), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, etc. Among these, pentaerythritol tetrakis (3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate) and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate are preferred. Commercially available products include those manufactured by ADEKA Corporation under the trade names "ADEKA STAB AO-60" and "ADEKA STAB AO-330."

[0091] Any known phosphorus-based compound can be used. Specific examples include phosphorus oxoacids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; metal acid pyrophosphates such as sodium acid pyrophosphate, potassium acid pyrophosphate, and calcium acid pyrophosphate; phosphates of Group 1 or Group 2B metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds, with organic phosphite compounds and organic phosphate compounds being particularly preferred.

[0092] Examples of organic phosphite compounds include triphenyl phosphite, tris(mononylphenyl)phosphite, tris(mononyl / dinonyl phenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, monooctyl diphenyl phosphite, dioctyl monophenyl phosphite, monodecyl diphenyl phosphite, didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, and 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite. Specific examples of such organic phosphite compounds include "ADK STAB 1178", "ADK STAB 2112", and "ADK STAB HP-10" manufactured by ADEKA CORPORATION, "JP-351", "JP-360", and "JP-3CP" manufactured by Johoku Chemical Industry Co., Ltd., and "IRGAFOS 168" manufactured by BASF.

[0093] As the organic phosphate compound, organic phosphate metal salts can be suitably used, specifically, a mixture of zinc salt of distearyl acid phosphate and zinc salt of monostearyl acid phosphate, mono- and di-stearyl acid phosphate, etc. can be mentioned. Specific examples of such organic phosphate metal salts include "JP-518Zn" manufactured by Johoku Chemical Industry Co., Ltd. and "AX-71" manufactured by ADEKA Corporation.

[0094] Other examples of stabilizers include the following: JP 2021-063196 A, paragraphs 0067 to 0075; JP 2018-070722 A, paragraphs 0046 to 0057; JP 2019-056035 A, paragraphs 0030 to 0037; and WO 2017 / 038949 A, paragraphs 0066 to 0078. The contents of these are incorporated herein by reference.

[0095] The resin composition of the present embodiment preferably contains 0.01 parts by mass or more of the stabilizer relative to 100 parts by mass of the total of the polybutylene terephthalate resin (A) and the thermoplastic resin (preferably a polystyrene-based resin) (B). The upper limit of the amount of the stabilizer is preferably 3 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less relative to 100 parts by mass of the total of the polybutylene terephthalate resin (A) and the thermoplastic resin (preferably a polystyrene-based resin). The resin composition of the present embodiment may contain only one type of stabilizer, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0096] <<Release agent>> The resin composition of the present embodiment preferably contains a release agent. As the release agent, a wide variety of known release agents can be used, and examples thereof include aliphatic carboxylic acid amides, aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, and polysiloxane-based silicone oils. Esters of aliphatic carboxylic acids, paraffin wax, polystyrene wax, and polyolefin wax are preferred, and polyethylene wax is more preferred.

[0097] Examples of the aliphatic carboxylic acid amide include compounds obtained by a dehydration reaction between a higher aliphatic monocarboxylic acid and / or a polybasic acid and a diamine. As the higher aliphatic monocarboxylic acid, saturated aliphatic monocarboxylic acids and hydroxycarboxylic acids having 16 or more carbon atoms are preferred, and examples thereof include palmitic acid, stearic acid, behenic acid, montanic acid, and 12-hydroxystearic acid. Examples of polybasic acids include aliphatic dicarboxylic acids such as malonic acid, succinic acid, adipic acid, sebacic acid, pimelic acid, and azelaic acid; aromatic dicarboxylic acids such as phthalic acid and terephthalic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and cyclohexylsuccinic acid. Examples of diamines include ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, hexamethylenediamine, metaxylylenediamine, tolylenediamine, paraxylylenediamine, phenylenediamine, and isophoronediamine. As the carboxylic acid amide compound, a compound obtained by polycondensation of stearic acid, sebacic acid, and ethylenediamine is preferred, and a compound obtained by polycondensation of 2 moles of stearic acid, 1 mole of sebacic acid, and 2 moles of ethylenediamine is more preferred. In addition to bisamide compounds obtained by reacting diamines and aliphatic carboxylic acids, such as N,N'-methylenebisstearamide and N,N'-ethylenebisstearamide, dicarboxylic acid amide compounds, such as N,N'-dioctadecylterephthalamide, can also be suitably used.

[0098] Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic mono-, di- or tri-carboxylic acids. Here, the aliphatic carboxylic acid also includes alicyclic carboxylic acids. Among these, preferred aliphatic carboxylic acids are mono- or di-carboxylic acids having 6 to 36 carbon atoms, and more preferred are saturated aliphatic mono-carboxylic acids having 6 to 36 carbon atoms. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetralinic acid, montanic acid, adipic acid, and azelaic acid.

[0099] In the ester of an aliphatic carboxylic acid and an alcohol, the aliphatic carboxylic acid may be the same as the aliphatic carboxylic acid. On the other hand, the alcohol may be, for example, a saturated or unsaturated monohydric or polyhydric alcohol. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, a monohydric or polyhydric saturated alcohol having 30 or less carbon atoms is preferred, and an aliphatic or alicyclic saturated monohydric alcohol or an aliphatic saturated polyhydric alcohol having 30 or less carbon atoms is more preferred. Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, and dipentaerythritol. Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture mainly composed of myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate, and esters of montanic acid and polyfunctional alcohols.

[0100] Examples of the aliphatic hydrocarbons having a number average molecular weight of 200 to 15,000 include liquid paraffin, paraffin wax, microwax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomers having 3 to 12 carbon atoms. The aliphatic hydrocarbons herein also include alicyclic hydrocarbons. The number average molecular weight of the aliphatic hydrocarbons is preferably 5,000 or less.

[0101] Examples of polyolefin waxes include polyethylene wax, polypropylene wax, and polyethylene propylene wax, with polyethylene wax being preferred. The polyolefin wax may be unmodified or modified. Examples of modified polyolefin waxes include vinyl ester modified polyolefin wax, acid modified polyolefin wax, and oxidized polyolefin wax, and oxidized polyolefin wax is preferred. Oxidized polyolefin wax has excellent compatibility with polyalkylene terephthalate resins and tends to effectively suppress mold deposits in the resulting resin composition.

[0102] The oxidized polyolefin wax can be obtained by oxidizing the corresponding unmodified polyolefin wax. Examples of the oxidized polyethylene wax include Licowax (registered trademark) PED521, PED522, and PED121 manufactured by Clariant Chemicals; Ceridust (registered trademark) 3715, and the like. In addition to the above, commercially available polyolefin waxes can be found in paragraph 0028 of JP-A-2022-140470, the contents of which are incorporated herein by reference.

[0103] The weight average molecular weight of the polyolefin wax is preferably 800 or more, more preferably 1,000 or more, even more preferably 1,500 or more, even more preferably 2,000 or more, and even more preferably 2,500 or more. By making it equal to or greater than the lower limit, the glowing time tends to be further shortened. In addition, the weight average molecular weight of the polyolefin wax is preferably 30,000 or less, more preferably 20,000 or less, even more preferably 15,000 or less, and even more preferably 10,000 or less. By making it equal to or less than the upper limit, the flowability of the resin composition during molding tends to be further improved. In the case where the resin composition in the present embodiment contains two or more types of polyolefin waxes, the weight average molecular weight is the weight average molecular weight of the mixture.

[0104] The dropping point of the polyolefin wax is preferably 165°C or lower, more preferably 160°C or lower, even more preferably 155°C or lower, even more preferably 150°C or lower, even more preferably 145°C or lower, even more preferably 140°C or lower, even more preferably 135°C or lower, particularly more preferably 130°C or lower, and preferably 80°C or higher, more preferably 85°C or higher, even more preferably 85°C or higher, even more preferably 90°C or higher, and even more preferably 95°C or higher. The dropping point is determined by heating a polyolefin wax until it changes from a solid to a liquid state and the temperature at which the first drop of molten material falls from a standard cup having an opening of 2.8 mm.

[0105] As for the release agent, in addition to the above, the descriptions in paragraphs 0063 to 0077 of JP 2018-070722 A, the descriptions in paragraphs 0090 to 0098 of JP 2019-123809 A, and the descriptions in paragraphs 0115 to 0120 of JP 2013-007058 A can be referred to, the contents of which are incorporated herein by reference.

[0106] The resin composition of the present embodiment preferably contains 0.01 parts by mass or more of the release agent relative to 100 parts by mass of the total of (A) polybutylene terephthalate resin and (B) thermoplastic resin (preferably polystyrene-based resin), more preferably 0.08 parts by mass or more, and even more preferably 0.2 parts by mass or more. The upper limit of the content of the release agent is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, even more preferably 1 part by mass or less, and even more preferably 0.8 parts by mass or less relative to 100 parts by mass of the total of (A) polybutylene terephthalate resin and (B) thermoplastic resin (preferably polystyrene-based resin). The resin composition may contain only one type of release agent, or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0107] <Physical Properties> The resin composition of the present embodiment has excellent electromagnetic wave shielding properties. Specifically, the electromagnetic wave shielding properties of the resin composition of the present embodiment at a frequency of 100 MHz are preferably -30.0 or less, more preferably -33.0 or less, and even more preferably -35.0 or less. The lower limit of the electromagnetic wave shielding properties is not particularly determined, but -55.0 or more is practical. The electromagnetic shielding property of the resin composition of the present embodiment at a frequency of 200 MHz is preferably −29.0 or less, and more preferably −30.0 or less. The lower limit of the electromagnetic shielding property is not particularly set, but −51.0 or more is practical. The resin composition of the present embodiment has an electromagnetic shielding property at a frequency of 800 MHz of preferably −24.0 or less, more preferably −25.0 or less. The lower limit of the electromagnetic shielding property is not particularly set, but is practically −51.0 or more.

[0108] The resin composition of the present embodiment has excellent flame retardancy. Specifically, when the resin composition of the present embodiment is molded into a thickness of 1.6 mm, the flame retardancy according to the UL94 test preferably satisfies V-0 or V-1, and more preferably satisfies V-0. The electromagnetic wave shielding property and flame retardancy are measured according to the description in the examples described later.

[0109] <Method of producing resin composition> The resin composition of the present embodiment can be produced by a conventional method for producing a resin composition containing a thermoplastic resin. (A) polybutylene terephthalate resin, (B) thermoplastic resin (preferably polystyrene-based resin), (C) carbon fiber, and (D) bromine-based flame retardant, as well as other components that are mixed as necessary, are put into an extruder and melt-kneaded to produce the resin composition. One form formed from such a resin composition is pellets. The components may be mixed in advance and fed to the extruder at once, or the components may not be mixed in advance or only a portion of the components may be mixed in advance and fed to the extruder using a feeder. The extruder may be a single-screw extruder or a twin-screw extruder. When a flame retardant auxiliary is added, it is preferable to prepare a master batch with a thermoplastic resin in advance and then charge the master batch into the extruder. The (C) carbon fiber may be fed from a side feeder midway through the cylinder of the extruder. The heating temperature during melt kneading can usually be appropriately selected from the range of 150 to 350°C.

[0110] <Method of manufacturing molded products> The molded article of the present embodiment is formed from the resin composition or pellets of the present embodiment. The manufacturing method of the molded product in this embodiment is not particularly limited, and any molding method generally used for resin compositions containing thermoplastic resins can be used. Examples of such methods include injection molding, ultra-high speed injection molding, injection compression molding, two-color molding, gas-assisted hollow molding, molding using a heat-insulating mold, molding using a rapid heating mold, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, press molding, blow molding, etc., among which injection molding is preferred.

[0111] <Field of use> The application field of the molded product formed from the resin composition or pellets of this embodiment is not particularly limited, but it is preferably used for applications requiring electromagnetic wave shielding properties (electromagnetic wave shielding). Examples of applications requiring electromagnetic wave shielding properties include casing applications for office automation equipment, audiovisual equipment, connector parts, air purifiers, IoT home appliances (internet-enabled home appliances), mobile communication devices such as smartphones, radio base stations, measuring equipment, transport equipment, communication devices, radar devices, connectors, packaging materials, etc. In particular, examples of applications for automobiles include electronic control unit casings, power control unit casings, camera casings, and battery covers for electric automobiles. In addition, examples of applications for automobiles requiring high rigidity include. EXAMPLES

[0112] The present invention will be described in more detail below with reference to examples. The materials, amounts, ratios, processing contents, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

[0113] 1.Raw materials The following raw materials were used: [Table 1]

[0114] [Table 2] In the above table, "PBT" means polybutylene terephthalate resin.

[0115] 2. Examples 1 to 5 and Comparative Examples 1 to 4 <Production of Resin Composition (Pellets)> The components shown in Table 1 or Table 2 were placed in a stainless steel tumbler in the amounts shown in Table 3 or Table 4 (the amounts of each component are mass ratios), and mixed by stirring for 1 hour. The resulting mixture was fed to a co-rotating intermeshing twin screw extruder (Japan Steel Works, Ltd., "TEX-30α", screw diameter 32 mm, L / D=42) from the main feed port. The barrel temperature of the first kneading section was set to 270°C, and melt kneaded under conditions of a discharge rate of 30 kg / h and a screw rotation speed of 200 rpm, and extruded as strands under conditions of a nozzle number of 5 holes (circular (φ4 mm), length 1.5 cm). The extruded strands were introduced into a water tank to cool, and then inserted into a pelletizer and cut to obtain a resin composition (pellets).

[0116] <Electromagnetic wave shielding> The resin pellets obtained above were dried at 120°C for 5 hours, and then flat test pieces of 150 x 150 x 2 mm were injection molded using an injection molding machine (Shibaura Machine Co., Ltd., "EC160") under conditions of a cylinder temperature of 260°C and a mold temperature of 80°C. The electromagnetic wave shielding properties (electric field) of the molded flat test pieces were measured using the KEC method at frequencies of 100 MHz, 200 MHz, and 800 MHz. The measurements were performed using the Agilent Technologies network analyzer "N5230A." The electromagnetic shielding effect is expressed in dB. The lower the value, the better the electromagnetic shielding effect.

[0117] <Flame retardancy> The resin composition pellets obtained above were dried at 110°C for 5 hours, and then injection molded into combustion test specimens (12.7 mm width x 127 mm length x 1.6 mm thickness) using an injection molding machine (Japan Steel Works, Ltd., "J-50AD") under conditions of a cylinder temperature of 250°C and a mold temperature of 80°C. The obtained combustion test specimens were left to stand in an atmosphere of 70°C for one week, and then the flame retardancy was evaluated according to the Underwriters Laboratories Subject 94 (UL94) method.

[0118] <Tensile strength and tensile strain> The resin pellets obtained above were dried at 120°C for 5 hours, and then ISO multipurpose test pieces (thickness 4 mm) were injection molded using an injection molding machine (Japan Steel Works, Ltd., "J85AD") under conditions of a cylinder temperature of 250°C and a mold temperature of 80°C. The molded multipurpose ISO multipurpose test pieces were used to measure the tensile strength (unit: MPa) and tensile strain (unit: %) in accordance with ISO527-1 and ISO527-2.

[0119] <Flexural strength and flexural modulus> From the obtained resin composition (pellets), an ISO tensile test piece having a thickness of 4 mm was produced using an injection molding machine (Model SE50 manufactured by Sumitomo Heavy Industries, Ltd.) at an injection molding speed of 30 mm / sec, a screw diameter of 28 mm (injection rate: 18.5 cm3 / sec), a resin temperature of 260°C, and a mold temperature of 80°C. In accordance with ISO178, the flexural strength (unit: MPa) and flexural modulus (unit: MPa) were measured at a temperature of 23°C using the above ISO tensile test pieces (4 mm thick).

[0120] [Table 3]

[0121] [Table 4]

[0122] As is clear from the above results, the molded article formed from the resin composition of the present invention had excellent electromagnetic wave shielding properties and flame retardancy, as well as excellent mechanical strength. Furthermore, even when some of the resin was replaced with recycled materials, the same performance as virgin products was achieved.

Claims

1. (A) a polybutylene terephthalate resin; (B) a thermoplastic resin having a SP value lower than that of the polybutylene terephthalate resin; (C) carbon fibers; (D) a brominated flame retardant having a weight average molecular weight (Mw) of 200 to 20,000; A resin composition comprising: The content of (C) carbon fiber in the resin composition is 5 to 30 mass %, The mass ratio of (A) to (B), (B) / (A), is greater than 0.1 and less than 1.0; Resin composition.

2. The resin composition according to claim 1, wherein the intrinsic viscosity of the polybutylene terephthalate resin (A) is 0.80 dL / g or less.

3. The resin composition according to claim 1 or 2, wherein the thermoplastic resin (B) includes a recycled product.

4. The resin composition according to claim 1 or 2, wherein the thermoplastic resin (B) comprises a polystyrene-based resin.

5. The resin composition according to claim 1 or 2, wherein the (D) brominated flame retardant comprises at least one of a brominated poly(meth)acrylate, a brominated polycarbonate, and a brominated phthalimide.

6. The resin composition according to claim 1 or 2, wherein the (D) bromine-based flame retardant has no functional group capable of reacting with the (A) polybutylene terephthalate resin.

7. The resin composition according to claim 1 or 2, further comprising an antimony compound.

8. The resin composition according to claim 1 or 2, further comprising a compatibilizer.

9. The resin composition of claim 8 , wherein the compatibilizer comprises a polycarbonate resin.

10. 9. The resin composition of claim 8, wherein the compatibilizer comprises recycled polycarbonate resin.

11. The resin composition according to claim 1 or 2, which is used for electromagnetic wave shielding.

12. The intrinsic viscosity of the polybutylene terephthalate resin (A) is 0.80 dL / g or less, The (B) thermoplastic resin includes a polystyrene-based resin, the (D) brominated flame retardant contains at least one of a brominated poly(meth)acrylate, a brominated polycarbonate, and a brominated phthalimide; the (D) brominated flame retardant does not have a functional group capable of reacting with the (A) polybutylene terephthalate resin, Further, antimony compounds are included. Further comprising a compatibilizer, The resin composition according to claim 1 , wherein the compatibilizer comprises a polycarbonate resin and is for electromagnetic wave shielding.

13. The resin composition according to claim 12, wherein the polycarbonate resin and / or the polystyrene resin comprises recycled products.

14. A pellet of the resin composition according to claim 1, 2, 12 or 13.

15. A molded article molded from the resin composition according to claim 1, 2, 12 or 13.

16. A molded article made from the pellets according to claim 14.

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