Resin composition, pellet and molded article

Abstract

To provide a resin composition capable of providing a molded article excellent in mechanical strength and conductivity, and to provide a pellet and a molded article.SOLUTION: A resin composition which contains a polyamide resin (A), a flat glass fiber (B) and a pitch-based carbon fiber (C) is such that: the polyamide resin (A) includes a constitutional unit derived from diamine, and a constitutional unit derived from dicarboxylic acid; 70 mol% or more of the constitutional unit derived from diamine is derived from xylylenediamine; 70 mol% or more of the constitutional unit derived from dicarboxylic acid includes a polyamide resin derived from 4 to 20C α,ω-direct chain aliphatic dicarboxylic acid; a content of (A) is 40 to 70 pts.mass, a content of (B) is 1.4 to 43 pts.mass, and a content of (C) is 8.6 to 58.6 pts.mass in the total amount of 100 pts.mass of (A), (B) and (C); the total content of (B) and (C) is 30 to 60 pts.mass; and a mass ratio (C) / (B) of the glass fiber (B) to the pitch-based carbon fiber (C) is 0.4 or more and 5 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition, a pellet, and a molded article, and more particularly to a resin composition containing a polyamide resin as a main component. [Background technology]

[0002] Polyamide resin, a typical engineering plastic, is easy to process and has excellent mechanical properties, electrical properties, heat resistance, and other physical and chemical properties, making it widely used in vehicle parts, electrical and electronic equipment parts, and other precision equipment parts. Furthermore, polyamide resin molded articles with excellent electrical conductivity are required depending on the application, etc. Patent Documents 1 and 2 disclose polyamide resin compositions with such excellent electrical conductivity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-277730 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-132550 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the increasing demand for polyamide resins and conductive members, new polyamide resin materials are being sought. In particular, there is a demand for polyamide resin molded articles that are excellent in mechanical strength and electrical conductivity. The present invention aims to solve the above problems, and to provide a resin composition, pellets, and molded articles that can provide molded articles having excellent mechanical strength and excellent electrical conductivity. [Means for solving the problem]

[0005] 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 flat glass fibers and pitch-based carbon fibers in combination with a xylylenediamine-based polyamide resin and precisely adjusting the amounts of these fibers blended. Specifically, the above problems were solved by the following means. [1] A composite material comprising a polyamide resin (A), a flat glass fiber (B), and a pitch-based carbon fiber (C), the polyamide resin (A) comprises a polyamide resin containing diamine-derived structural units and dicarboxylic acid-derived structural units, in which 70 mol % or more of the diamine-derived structural units are derived from xylylenediamine and 70 mol % or more of the dicarboxylic acid-derived structural units are derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms; In a total of 100 parts by mass of (A), (B) and (C), The content of (A) is 40 to 70 parts by mass, The content of (B) is 1.4 to 43 parts by mass, The content of (C) is 8.6 to 58.6 parts by mass, The total content of (B) and (C) is 30 to 60 parts by mass, and the mass ratio of the flat glass fiber (B) to the pitch-based carbon fiber (C), (C) / (B), is 0.4 or more and 5 or less. Resin composition. [2] The resin composition according to [1], wherein the total content of the flat glass fibers (B) and the pitch-based carbon fibers (C) in the resin composition is 25 to 60 mass %. [3] The resin composition according to [1] or [2], wherein the mass ratio of the flat glass fiber (B) to the pitch-based carbon fiber (C), (C) / (B), is 0.5 or more and 2 or less. [4] The resin composition is molded into a test piece of 100 mm × 100 mm and 2 mm thick, and the surface resistance measured at a voltage of 1.0 V in accordance with ASTM D257 is 1.0 × 10 7 The resin composition according to any one of [1] to [4], which has a modulus of elasticity of Ω or less. [5] The total content of the flat glass fiber (B) and the pitch-based carbon fiber (C) in the resin composition is 25 to 60 mass%, The mass ratio of the flat glass fiber (B) to the pitch-based carbon fiber (C), (C) / (B), is 0.5 or more and 2 or less, The resin composition was molded into a test piece of 100 mm × 100 mm and 2 mm thick, and the surface resistance measured at a voltage of 1.0 V in accordance with ASTM D257 was 1.0 × 10 7 The resin composition according to any one of [1] to [4] below: [6] Pellets of the resin composition according to any one of [1] to [5]. [7] A molded article formed from the resin composition according to any one of [1] to [5]. [8] A molded article formed from the pellets according to [6]. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a resin composition, pellets, and molded articles that are capable of providing molded articles that are excellent in mechanical strength and electrical conductivity. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, an embodiment for carrying out 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 only this embodiment. In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as upper and lower limits. "A to B" means that the range is A or more and B or less. In addition, any combination of the upper and lower limit values ​​of the numerical values ​​in this specification is an example of this embodiment. If the measurement methods, etc. described in the standards shown in this specification change from year to year, they will be based on the standards in effect as of January 1, 2024, unless otherwise specified. If the measurement methods, etc. described in the standards shown in this specification are abolished as of January 1, 2024, they will be based on the standards in effect at the time of abolition.

[0008] The resin composition of the present embodiment comprises a polyamide resin (A), flat glass fibers (B), and pitch-based carbon fibers (C), wherein the polyamide resin (A) comprises diamine-derived structural units and dicarboxylic acid-derived structural units, and 70 mol % or more of the diamine-derived structural units are derived from xylylenediamine, and 70 mol % or more of the dicarboxylic acid-derived structural units are derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms (referred to herein as "xylylenediamine"). The fiber reinforced plastic (hereinafter referred to as "polyamide resin") is characterized in that, out of a total of 100 parts by mass of (A), (B), and (C), the content of (A) is 40 to 70 parts by mass, the content of (B) is 1.4 to 43 parts by mass, the content of (C) is 8.6 to 58.6 parts by mass, the total content of (B) and (C) is 30 to 60 parts by mass, and the mass ratio of the flat glass fiber (B) to the pitch-based carbon fiber (C), (C) / (B), is 0.4 or more and 5 or less. By adopting such a constitution, a resin composition can be obtained that can provide a molded article having excellent mechanical strength and excellent electrical conductivity. That is, the inventors have conducted research and found that conductivity is improved by setting the mass ratio of the flat glass fiber (B) to the pitch-based carbon fiber (C), (C) / (B), to 0.4 or more. They also found that conductivity is improved by using flat glass fiber (B) as the glass fiber. It is presumed that the use of flat glass (B) facilitates orientation of the flat glass (B), making it easier to form conductive paths for the pitch-based carbon fiber (C). On the other hand, it was found that various mechanical strengths can be improved by using flat glass fiber (B) in addition to pitch-based carbon fiber (C), by using xylylenediamine-based polyamide resin as polyamide resin (A), and by adjusting the content and content ratio of flat glass fiber (B) and pitch-based carbon fiber (C).

[0009] Hereinafter, the embodiments of the present invention will be described in detail. However, the explanation of the constituent elements described below is an example of an embodiment of the present invention, and the present invention is not limited to these contents.

[0010] <Polyamide resin (A)> The resin composition of the present embodiment contains a polyamide resin (A). The polyamide resin (A) contains diamine-derived structural units and dicarboxylic acid-derived structural units, and contains a polyamide resin in which 70 mol % or more of the diamine-derived structural units are derived from xylylenediamine and 70 mol % or more of the dicarboxylic acid-derived structural units are derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms (sometimes referred to as a "xylylenediamine-based polyamide resin" in this specification).

[0011] The diamine-derived structural units of the xylylenediamine-based polyamide resin are more preferably 75 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more, and particularly preferably 99 mol% or more, derived from xylylenediamine (preferably paraxylylenediamine and / or metaxylylenediamine).

[0012] The xylylenediamine is preferably paraxylylenediamine and / or metaxylylenediamine. The xylylenediamine preferably contains 0 to 100 mol% of metaxylylenediamine and 100 to 0 mol% of paraxylylenediamine (however, the total of metaxylylenediamine and paraxylylenediamine does not exceed 100 mol%), more preferably 10 to 100 mol% of metaxylylenediamine and 90 to 0 mol% of paraxylylenediamine, even more preferably 30 to 100 mol% of metaxylylenediamine and 70 to 0 mol% of paraxylylenediamine, and even more preferably 50 to 100 mol% of metaxylylenediamine and 50 to 0 mol% of paraxylylenediamine. In the xylylenediamine-based polyamide resin, the total of the constitutional units derived from paraxylylenediamine and the constitutional units derived from metaxylylenediamine preferably accounts for 80 mol % or more, more preferably 85 mol % or more, even more preferably 90 mol % or more, still more preferably 95 mol % or more, still more preferably 98 mol % or more, and still more preferably 99 mol % or more of the constitutional units derived from diamine. The upper limit of the total of the constitutional units derived from paraxylylenediamine and the constitutional units derived from metaxylylenediamine is 100 mol %.

[0013] Diamines other than metaxylylenediamine and paraxylylenediamine that can be used as raw diamine components for xylylenediamine-based polyamide resins include aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine; 1,3-bis( Examples of the diamine include alicyclic diamines such as bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminomethyl)decalin, and bis(aminomethyl)tricyclodecane; and diamines having an aromatic ring such as bis(4-aminophenyl)ether, paraphenylenediamine, and bis(aminomethyl)naphthalene. These diamines can be used alone or in combination of two or more.

[0014] On the other hand, the dicarboxylic acid-derived structural units of the xylylenediamine-based polyamide resin are preferably derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms (preferably sebacic acid) at 70 mol% or more, preferably 75 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more, and particularly preferably 99 mol% or more.

[0015] Examples of α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms that are suitable for use as the raw dicarboxylic acid component of xylylenediamine-based polyamide resins include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, undecanedioic acid, and 1,12-dodecanedioic acid. These can be used alone or in combination of two or more. Among these, at least one of adipic acid, sebacic acid, and 1,12-dodecanedioic acid is preferred, as this ensures that the melting point of the polyamide resin falls within a range suitable for molding and processing. Adipic acid and / or sebacic acid is more preferred, and adipic acid is even more preferred.

[0016] Examples of dicarboxylic acid components other than those mentioned above include phthalic acid compounds such as isophthalic acid, terephthalic acid, and orthophthalic acid, and isomers of naphthalenedicarboxylic acid such as 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid, and these can be used alone or in combination of two or more.

[0017] In this embodiment, it is particularly preferred that the polyamide resin contains diamine-derived structural units and dicarboxylic acid-derived structural units, with 90 mol % or more of the diamine-derived structural units being derived from xylylenediamine and 90 mol % or more of the dicarboxylic acid-derived structural units being derived from adipic acid and / or sebacic acid. Such xylylenediamine-based polyamide resins are preferred because they have a high degree of crystallization, a high melting point, and excellent dimensional stability.

[0018] Although the xylylenediamine-based polyamide resin is primarily composed of diamine-derived structural units and dicarboxylic acid-derived structural units, other structural units are not completely excluded, and it goes without saying that it may contain structural units derived from lactams such as ε-caprolactam and laurolactam, and aliphatic aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid. Here, "major component" refers to the structural units constituting the xylylenediamine-based polyamide resin in which the total number of diamine-derived structural units and dicarboxylic acid-derived structural units is the largest among all structural units. In this embodiment, the total of the diamine-derived structural units and dicarboxylic acid-derived structural units in the xylylenediamine-based polyamide resin preferably accounts for 90% by mass or more of all structural units, more preferably 95% by mass or more, even more preferably 97% by mass or more, and even more preferably 99% by mass or more.

[0019] It is also preferable to use a polyamide resin produced using biomass raw materials (biomass polyamide resin) as the xylylenediamine-based polyamide resin, which can reduce the environmental impact. In the polyamide resin of this embodiment, bio-dodecanedioic acid and xylylenediamine can be used as biomass raw materials. Mass balance certified (ISCC PLUS) adipic acid and xylylenediamine can also be used. Mass balance certification means that the amount of renewable raw materials and bio-based raw materials used at each factory or production facility and the amount of products produced and shipped are quantified and guaranteed along with their quality. The xylylenediamine-based polyamide resin used in this embodiment may be a recycled polyamide resin product (including recovered products, material recycled products, chemical recycled products, etc.), a rejected product, or scrap material generated when molding a molded product from a resin composition.

[0020] The polyamide resin (A) used in this embodiment may or may not contain a polyamide resin other than a xylylenediamine-based polyamide resin. The polyamide resin other than the xylylenediamine-based polyamide resin may be an aliphatic polyamide resin or a semi-aromatic polyamide resin, but an aliphatic polyamide resin is preferred. Specific examples of polyamide resins other than xylylenediamine-based polyamide resins include polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 66, polyamide 610, polyamide 612, polyamide 6I, polyamide 6 / 66, polyamide 6T / 6I, polyamide 6 / 6T, polyamide 66 / 6T, polyamide 66 / 6T / 6I, polytrimethylhexamethylene terephthalamide, polybis(4-aminocyclohexyl)methanedodecamide, polybis(3-methyl-4-aminocyclohexyl)methanedodecamide, and polyundecamethylenehexahydroterephthalamide. The "I" in the above text indicates an isophthalic acid component, and the "T" indicates a terephthalic acid component. Regarding polyamide resins, the description in paragraphs 0011 to 0013 of JP 2011-132550 A can be referenced, the contents of which are incorporated herein by reference.

[0021] When the polyamide resin (A) contains other polyamide resins, aliphatic polyamide resins are preferred, polyamide 6 and / or polyamide 66 are preferred, and polyamide 66 is more preferred.

[0022] An example of a blend form of the polyamide resin (A) in this embodiment is one containing 90 to 100 parts by mass of a xylylenediamine-based polyamide resin and 10 to 0 parts by mass of an aliphatic polyamide resin (preferably polyamide 6 and / or polyamide 66, more preferably polyamide 66). In addition, in the polyamide resin (A) of this embodiment, the total of the xylylenediamine-based polyamide resin and the aliphatic polyamide resin preferably accounts for 90% by mass or more of the polyamide resin (A), more preferably 95% by mass or more, even more preferably 97% by mass or more, and even more preferably 99% by mass or more.

[0023] The melting point of the polyamide resin (A) is preferably 150°C or higher, more preferably 250°C or higher, and even more preferably 280°C or higher, and is preferably 350°C or lower, and more preferably 330°C or lower.

[0024] The lower limit of the number average molecular weight (Mn) of the polyamide resin (A) is preferably 6,000 or more, more preferably 8,000 or more, and even more preferably 10,000 or more, and is preferably 100,000 or less, more preferably 50,000 or less. Within such ranges, the heat resistance, elastic modulus, dimensional stability, and moldability are improved.

[0025] The content of polyamide resin (A) in the resin composition of this embodiment is 40 parts by mass or more and 70 parts by mass or less, preferably 65 parts by mass or less, and more preferably 60 parts by mass or less, per 100 parts by mass of the total of (A), (B), and (C). By ensuring that the content is equal to or greater than the lower limit, production stability during extrusion kneading of the resin composition and fluidity during injection molding tend to be sufficiently ensured. Meanwhile, by ensuring that the content is equal to or less than the upper limit, molded products with superior mechanical strength tend to be obtained.

[0026] Furthermore, the content of polyamide resin (A) in the resin composition of this embodiment is preferably 40% by mass or more, and is preferably 70% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less, based on 100% by mass of the resin composition. The resin composition of the present embodiment may contain only one type of polyamide resin (A), or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0027] <Flat glass fiber (B)> The resin composition of the present embodiment contains flat glass fibers (B). By containing the flat glass fibers (B), the bending properties can be improved. The flat glass fibers (B) that can be used in the resin composition of this embodiment are composed of glass compositions such as A-glass, C-glass, E-glass, S-glass, R-glass, M-glass, and D-glass, and E-glass (alkali-free glass) is particularly preferred.

[0028] The flat glass fiber (B) used in the resin composition of this embodiment may be a single fiber or a plurality of single fibers twisted together. The flat glass fiber (B) may be in the form of a "glass roving" in which a single fiber or a plurality of single fibers twisted together is continuously wound, a "chopped strand" in which the fiber is cut to a length of 1 to 10 mm, or a "milled fiber" in which the fiber is pulverized to a length of 10 to 500 μm. Such glass fibers are readily available and are commercially available under the trade names "Glaslon Chopped Strand" and "Glaslon Milled Fiber" from Asahi Fiber Glass Co., Ltd. and "E Glass Fiber Chopped Strand" from Nippon Electric Glass Co., Ltd. In this embodiment, the flat glass fiber (B) is preferably a "chopped strand" in which the fiber is cut to a length of 1 to 10 mm. It is more preferable to use flat glass fibers (B) that have been surface-treated with a surface treatment agent such as a coupling agent. Glass fibers with a surface treatment agent attached thereto are preferred because they have excellent durability, moist heat resistance, hydrolysis resistance, and heat shock resistance.

[0029] The content of the flat glass fiber (B) in the resin composition of this embodiment is 1.4 parts by mass or more, preferably 3 parts by mass or more, more preferably 6 parts by mass or more, even more preferably 8 parts by mass or more, even more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, per 100 parts by mass of the total of (A), (B), and (C). It is also 43 parts by mass or less, preferably 40 parts by mass or less, more preferably 37 parts by mass or less, and even more preferably 35 parts by mass or less. Depending on the application, it may be 30 parts by mass or less, 26 parts by mass or less, 22 parts by mass or less, or 18 parts by mass or less. By setting the content at or above the lower limit, molded articles with better impact resistance tend to be obtained. By setting the content at or below the upper limit, molded articles with better elastic modulus tend to be obtained. The resin composition of the present embodiment may contain only one type of flat glass fiber (B), or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0030] <Pitch-based carbon fiber (C)> The resin composition of this embodiment contains pitch-based carbon fiber (C). By containing pitch-based carbon fiber (C), the electrical conductivity of the resulting molded article can be improved. Pitch-based carbon fiber (C) is a fiber made by carbonizing at high temperature a by-product (pitch) of coal, petroleum, or coal tar. The pitch-based carbon fiber (C) used in this embodiment is preferably a carbon fiber bundle formed by bundling a plurality of pitch-based carbon fibers (C) and processing the bundle into an arbitrary length.

[0031] The average fiber length (cut length) of the pitch-based carbon fiber (C) used in this embodiment is preferably 1 to 20 mm, more preferably 1 to 15 mm, even more preferably 2 to 15 mm, particularly preferably 3 to 10 mm, and even more preferably 4 to 10 mm.

[0032] The pitch-based carbon fiber (C) used in this embodiment is preferably surface-treated with a treatment agent. The treatment agent preferably functions to bundle the pitch-based carbon fiber (C) into a fiber bundle. Specifically, preferred examples include epoxy resins such as bisphenol A epoxy resins, and vinyl ester resins such as epoxy acrylate resins having an acrylic or methacrylic group per molecule, including bisphenol A vinyl ester resins, novolac vinyl ester resins, and brominated vinyl ester resins. Urethane-modified epoxy resins and vinyl ester resins may also be used. The amount of the treatment agent is preferably 0.001 to 1.5% by mass of the pitch-based carbon fiber (C).

[0033] The content of pitch-based carbon fiber (C) in the resin composition of this embodiment is 8.6 parts by mass or more, preferably 10 parts by mass or more, more preferably 12 parts by mass or more, even more preferably 16 parts by mass or more, even more preferably 18 parts by mass or more, still more preferably 20 parts by mass or more, or may be 22 parts by mass or more, and is 58.6 parts by mass or less, preferably 39 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 28 parts by mass or less, per 100 parts by mass of the total of (A), (B), and (C). By setting the content at or above the lower limit, molded products with better electrical conductivity tend to be obtained. By setting the content at or below the upper limit, production stability during extrusion kneading and flowability during injection molding tend to be sufficiently ensured. The resin composition of the present embodiment may contain only one kind of pitch-based carbon fiber (C), or may contain two or more kinds. When two or more kinds are contained, the total amount is preferably in the above range.

[0034] <Blend of flat glass fiber (B) and pitch-based carbon fiber (C)> Next, the blending form of the flat glass fiber (B) and the pitch-based carbon fiber (C) will be described. The total content of (B) and (C) in the resin composition of this embodiment is 30 parts by mass or more, preferably 35 parts by mass or more, and more preferably 38 parts by mass or more, per 100 parts by mass of the total of (A), (B), and (C). It is also 60 parts by mass or less, preferably 56 parts by mass or less, more preferably 50 parts by mass or less, even more preferably 45 parts by mass or less, and even more preferably 42 parts by mass or less. By ensuring that the content is equal to or greater than the lower limit, molded products with superior bending strength and heat resistance tend to be obtained. By ensuring that the content is equal to or less than the upper limit, production stability during extrusion kneading and fluidity during injection molding tend to be better secured and improved.

[0035] The mass ratio (C) / (B) of the flat glass fiber (B) to the pitch-based carbon fiber (C) in the resin composition of this embodiment is 0.4 or more, preferably 0.5 or more, more preferably 0.8 or more, even more preferably 1.2 or more, and even more preferably 1.4 or more, and is 5 or less, preferably 4 or less, more preferably 3 or less, and even more preferably 2 or less. By setting it to be equal to or greater than the lower limit, molded articles tend to have better electrical conductivity. By setting it to be equal to or less than the upper limit, molded articles tend to have better impact resistance.

[0036] Furthermore, in the resin composition of this embodiment, the total content of the flat glass fiber (B) and pitch-based carbon fiber (C) in the resin composition is preferably 25 to 60 mass%, more preferably 30 to 60 mass%, even more preferably 35 to 60 mass%, and even more preferably 35 to 57 mass%.

[0037] <Impact modifier> The resin composition of this embodiment may contain an impact modifier. By incorporating an impact modifier, the impact resistance of the resulting molded article can be improved. In particular, this embodiment is highly valuable in that electrical conductivity can be maintained even when an impact modifier is incorporated. There are no limitations on the type of impact modifier, and any rubbery polymer (including thermoplastic elastomers) can be used. For example, known elastomers such as polyolefin elastomers, diene elastomers, polystyrene elastomers, polyamide elastomers, polyester elastomers, polyurethane elastomers, and silicone elastomers can be used.

[0038] Examples of polyolefin elastomers include polyisobutylene, ethylene-propylene copolymer (EPR), ethylene-propylene-butadiene copolymer (EPDM), ethylene-propylene-non-conjugated diene copolymer, ethylene-butene-1 copolymer, ethylene-propylene-butene-1 copolymer, ethylene-hexene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-glycidyl acrylate copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, ethylene-maleic acid copolymer, and ethylene-maleic anhydride copolymer.

[0039] Examples of the diene elastomer include polybutadiene and hydrogenated products thereof, polyisoprene and hydrogenated products thereof, butadiene-styrene random copolymers and hydrogenated products thereof, and the like.

[0040] Examples of polystyrene-based elastomers include block copolymers of vinyl aromatic compounds, conjugated diene compounds, and olefin compounds, or hydrogenated products of these block copolymers (hereinafter abbreviated as hydrogenated block copolymers).Specific examples include block copolymers consisting of at least one polymer block mainly made of a vinyl aromatic compound and at least one polymer block mainly made of a conjugated diene compound, and hydrogenated block copolymers obtained by hydrogenating these block copolymers to hydrogenate 80% or more of the aliphatic double bonds based on the conjugated diene compound in the block copolymer.

[0041] The vinyl aromatic compound constituting the polystyrene-based elastomer can be one or more selected from styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, 1,1-diphenylethylene, etc., with styrene being preferred. The conjugated diene compound can be one or more selected from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, etc., with butadiene, isoprene, and combinations thereof being preferred. These can also be copolymerized with olefin compounds, with hydrogenated block copolymers (SEBS) combining styrene, ethylene, and butadiene being preferred.

[0042] Of these, preferred elastomers include polyolefin-based elastomers, diene-based elastomers, and polystyrene-based elastomers, and further include elastomers having functional groups such as carboxyl groups, acid anhydride groups, and epoxy groups as described below.

[0043] When the impact resistance improver used in this embodiment does not have a functional group, it is preferable to introduce a functional group (by chemical modification or modification by copolymerization, etc.) to impart better compatibility.

[0044] The introduction of a functional group can be achieved, for example, by reacting an impact modifier (e.g., a polyolefin elastomer or a styrene elastomer) that does not have a functional group with one or more compounds selected from α,β-unsaturated carboxylic acids, acrylamides, epoxy compounds, and derivatives thereof in an amount of, for example, 0.01 to 10 parts by mass per 100 parts by mass of the impact modifier, in the presence or absence of a radical initiator. Specific examples of α,β-unsaturated carboxylic acids and derivatives thereof include maleic acid, maleic anhydride, fumaric acid, itaconic acid, acrylic acid, glycidyl acrylate, 2-hydroxyethyl acrylate, methacrylic acid, glycidyl methacrylate, 2-hydroxyethyl methacrylate, crotonic acid, cis-4-cyclohexene-1,2-dicarboxylic acid and its anhydride, endo-cis-bicyclo{2.2.1}-5-heptene-2,3-dicarboxylic acid and its anhydride, and maleimide compounds.

[0045] Furthermore, the radical initiator used as needed when introducing a functional group is not particularly limited, and examples thereof include organic peroxide initiators such as dicumyl peroxide, di-tert-butyl peroxide, tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane-3, n-butyl-4,4-bis(tert-butylperoxy)valerate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, tert-butylperoxytriphenylsilane, and tert-butylperoxytrimethylsilane, as well as 2,3-dimethyl-2,3-diphenylbutane, 2,3-diethyl-2,3-diphenylbutane, 2,3-dimethyl-2,3-bis(p-methylphenyl)butane, and 2,3-dimethyl-2,3-bis(bromophenyl)butane. The amount of the radical initiator used is usually 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, per 100 parts by mass of the impact modifier into which the functional group is to be introduced. The reaction for introducing the functional group can be carried out according to a known method, such as melt-kneading or solution mixing.

[0046] <Nucleating agent> The resin composition of the present embodiment may contain a nucleating agent, which can increase the crystallization rate.

[0047] The nucleating agent is not particularly limited as long as it remains unmelted during melt processing and can serve as a nucleus for crystals during the cooling process. Either an organic or inorganic nucleating agent may be used, with an inorganic nucleating agent being preferred. Examples of inorganic nucleating agents include graphite, molybdenum disulfide, barium sulfate, talc, calcium carbonate, sodium phosphate, mica, and kaolin, and at least one selected from talc and calcium carbonate is more preferred, with talc being even more preferred. The organic nucleating agent is not particularly limited, and any known nucleating agent can be used. For example, the nucleating agent is preferably at least one selected from dibenzylidene sorbitol-based nucleating agents, nonitol-based nucleating agents, phosphate ester salt-based nucleating agents, rosin-based nucleating agents, and metal benzoate salt-based nucleating agents. The lower limit of the number average particle size of the nucleating agent is preferably 0.1 μm or more. The upper limit of the number average particle size of the nucleating agent is preferably 40 μm or less, more preferably 30 μm or less, even more preferably 28 μm or less, even more preferably 15 μm or less, and even more preferably 10 μm or less. By setting the number average particle size to 40 μm or less, the number of nucleating agents that become nuclei increases compared to the amount of nucleating agent blended, which tends to make the crystal structure more stable.

[0048] The content of the nucleating agent in the resin composition of this embodiment is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.3 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of the polyamide resin (A). By setting the content at or above the lower limit, the crystalline state of the resin composition can be more sufficiently stabilized. Furthermore, the content of the nucleating agent in the resin composition of this embodiment is 10 parts by mass or less, preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and may be 2 parts by mass or less, per 100 parts by mass of the polyamide resin. When the resin composition of the present embodiment contains a nucleating agent, it may contain only one type of nucleating agent or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0049] <Release agent> The resin composition of the present embodiment may contain a release agent. Examples of the release agent include aliphatic carboxylic acids, fatty acid metal salts, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, polysiloxane-based silicone oils, ketone wax, and light amides. Of these, aliphatic carboxylic acids, fatty acid metal salts, and esters of aliphatic carboxylic acids and alcohols are preferred, and aliphatic fatty acid metal salts are more preferred.

[0050] The fatty acid metal salt is preferably a fatty acid metal salt having a carbon chain length of 20 to 40. The fatty acid constituting the fatty acid metal salt is preferably a fatty acid having a carbon chain length of 21 or more, more preferably a fatty acid having a carbon chain length of 22 to 35, and even more preferably a fatty acid having a carbon chain length of 25 to 30. Specific examples of the fatty acid constituting the fatty acid metal salt include stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid, and ricinoleic acid, with montanic acid being preferred. Examples of metals constituting fatty acid metal salts include calcium, magnesium, zinc, aluminum, barium, and lithium, with calcium being preferred. For details of the release agent, in addition to the above, reference can be made to the descriptions in paragraphs 0055 to 0061 of JP 2018-095706 A, the contents of which are incorporated herein by reference.

[0051] The content of the mold release agent (preferably a fatty acid metal salt having 20 to 40 carbon chains) in the resin composition of this embodiment is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.3 parts by mass or more, and even more preferably 0.5 parts by mass or more, relative to 100 parts by mass of the polyamide resin. By ensuring that the content is above the lower limit, the mold release resistance during mold release can be reduced and ejection deformation of the molded product can be effectively suppressed. Furthermore, the content of the mold release agent (preferably a fatty acid metal salt having 20 to 40 carbon chains) in the resin composition of this embodiment is preferably 2.0 parts by mass or less, more preferably 1.4 parts by mass or less, even more preferably 1.1 parts by mass or less, and even more preferably 0.9 parts by mass or less, relative to 100 parts by mass of the polyamide resin. By ensuring that the content is below the upper limit, bleeding out of the fatty acid metal salt and gas generation during molding can be effectively suppressed. The resin composition of the present embodiment may contain only one type of release agent (preferably a fatty acid metal salt having a carbon chain number of 20 to 40) or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0052] <Coloring agent> The resin composition of the present embodiment may contain a colorant. By containing a colorant, it is possible to impart color to the resulting molded article. The colorant may be a pigment or a dye, but is preferably a pigment. The colorant may be either an achromatic colorant or a chromatic colorant, with an achromatic colorant being preferred. Also preferred is a black colorant composed of two or more chromatic colorants. In this embodiment, preferred examples of the colorant include a black colorant (preferably a black pigment) and / or a white colorant (preferably a white pigment). An example of a black pigment is carbon black. An example of the white pigment is titanium oxide. It is preferable to use a pigment such as carbon black in the form of a masterbatch made with a thermoplastic resin (preferably a polyamide resin).

[0053] The content of the colorant (preferably carbon black) in the resin composition of this embodiment is preferably 0.0005 parts by mass or more, more preferably 0.001 parts by mass or more, even more preferably 0.005 parts by mass or more, even more preferably 0.01 parts by mass or more, even more preferably 0.05 parts by mass or more, and even more preferably 0.10 parts by mass or more, relative to 100 parts by mass of the polyamide resin (A). By ensuring that the content is equal to or greater than the lower limit, color development can be fully achieved. Furthermore, the content of the colorant in the resin composition of this embodiment is preferably 10.00 parts by mass or less, more preferably 5.00 parts by mass or less, even more preferably 3.00 parts by mass or less, even more preferably 1.00 parts by mass or less, and even more preferably 0.50 parts by mass or less, relative to 100 parts by mass of the polyamide resin (A). By ensuring that the content is equal to or less than the upper limit, problems such as mold contamination during injection molding can be effectively suppressed. The resin composition of the present embodiment may contain only one type of colorant, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0054] <Other ingredients> The resin composition of this embodiment may contain other components in addition to those described above. Examples of other components include thermoplastic resins other than polyamide resins, antioxidants such as heat stabilizers and weather stabilizers, flame retardants, flame retardant assistants, anti-dripping agents, delustering agents, UV absorbers, plasticizers, antistatic agents, coloring inhibitors, and anti-gelling agents, as needed. These additives may each be used alone or in combination of two or more. Details of these components include additives described in paragraphs 0047 to 0103 of International Publication No. 2021 / 241471, the contents of which are incorporated herein. The total amount of these components in the resin composition of this embodiment is preferably less than 5% by mass of the resin composition, more preferably less than 3% by mass, and even more preferably less than 1% by mass. In the resin composition of this embodiment, the polyamide resin (A), the flat glass fiber (B), and the pitch-based carbon fiber (C) preferably account for 90% by mass or more of the resin composition, more preferably 93% by mass or more, and even more preferably 95% by mass or more, and may even be 100% by mass. Furthermore, in the resin composition of this embodiment, the polyamide resin (A), the flat glass fiber (B), and the pitch-based carbon fiber (C), as well as the impact resistance improver, nucleating agent, release agent, and colorant (masterbatch) that are blended as needed, preferably account for 90% by mass or more of the resin composition, more preferably 95% by mass or more, and even more preferably 97% by mass or more, and may even account for 99% by mass or more, or even 100% by mass.

[0055] <Physical properties of resin composition> The resin composition of the present embodiment preferably has excellent electrical conductivity. Specifically, the resin composition was molded into a test piece of 100 mm × 100 mm and 2 mm thick, and the surface resistance measured at 1.0 V in accordance with ASTM D257 was 1.0 × 10 7 Ω or less is preferable, and 5.0×10 6 Ω or less is more preferable, and 2.0×10 6 Ω or less is more preferable, and 5.0×10 5 Ω or less is more preferable, and 2.0×10 5 Ω or less is even more preferable, and 6.0×10 4 The lower limit of the surface resistance is not particularly limited, but is preferably 1.0×10 1 Even if it is Ω or more, it satisfies the required performance.

[0056] <Method of manufacturing resin composition> In the present embodiment, the method for producing the resin composition is not particularly limited, and a wide variety of known methods for producing thermoplastic resin compositions can be employed. Specifically, the resin composition can be produced by pre-mixing the components using various mixers such as a tumbler or a Henschel mixer, and then melt-kneading them using a Banbury mixer, a roll, a Brabender mixer, a single-screw extruder, a twin-screw extruder, a kneader, or the like.

[0057] Alternatively, for example, the resin composition can be produced by not mixing the components in advance, or by mixing only some of the components in advance, feeding the mixture into an extruder using a feeder, and melt-kneading the mixture. Furthermore, for example, some of the components such as a colorant may be mixed in advance, fed to an extruder, and melt-kneaded to obtain a masterbatch composition, which may then be mixed again with the remaining components and melt-kneaded to produce pellets. The flat glass fibers (B) and the pitch-based carbon fibers (C) are preferably side-fed. Examples of the side feed method in the extruder include a method in which flat glass fibers and pitch-based carbon fibers are simultaneously fed from two or more upstream and downstream locations, and a method in which flat glass fibers (B) and pitch-based carbon fibers (C) are fed in any ratio from one side feed port. It is also preferable to provide a kneading section between the upstream and downstream locations. In this embodiment, it is more preferable to simultaneously feed the flat glass fibers (B) and the pitch-based carbon fibers (C) through one side feed port.Furthermore, it is preferable to use a side feed port downstream of the kneading section for feeding the flat glass fibers (B) and the pitch-based carbon fibers (C).

[0058] <Molded products> The molded article of this embodiment is formed from the resin composition or pellets of this embodiment. The pellets obtained by pelletizing the resin composition of this embodiment are molded into a molded article by various molding methods. Alternatively, a resin composition melt-kneaded in an extruder can be directly molded into a molded article without going through pelletization. The shape of the molded article is not particularly limited and can be appropriately selected depending on the application and purpose of the molded article. Examples of the shape of the molded article include plate-like, plate-like, rod-like, sheet-like, film-like, cylindrical, ring-like, circular, elliptical, gear-like, polygonal, irregular-shaped, hollow, frame-like, box-like, and panel-like shapes. The molded article of this embodiment may be a finished product or a part.

[0059] The method for molding the molded article is not particularly limited, and any conventionally known molding method can be used, such as injection molding, injection compression molding, extrusion molding, profile extrusion, transfer molding, blow molding, gas-assisted blow molding, blow molding, extrusion blow molding, IMC (in-mold coating molding), rotational molding, multilayer molding, two-color molding, insert molding, sandwich molding, foam molding, and pressure molding.

[0060] <Application> The resin composition, pellets, and molded articles of this embodiment can be used for various storage containers, electrical and electronic equipment parts, office automation (OA) equipment parts, home appliance parts, mechanical components, and vehicle components. In particular, materials for transporting and packaging electrical and electronic components, electrostatically coated automotive parts, and automotive fuel components are preferred. Examples of materials for transporting and packaging electrical and electronic components include IC chip trays, IC component boxes, wafer trays, circuit board storage boxes, substrates for optical and magnetic recording media such as hard disks, CDs, DVDs, and MOs, trays and storage boxes for components such as housings and heads, and gas detector housings. Examples of automotive parts that can be electrostatically coated include bumpers, fenders, door panels, wheel caps, and door handles, whose painting process includes electrostatic painting. Examples of automotive fuel components include fuel hose connectors, fuel filters, filler necks, and tank valves attached to fuel tanks. [Example]

[0061] The present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, processing details, 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.

[0062] 1. Raw materials The following raw materials were used: [Table 1]

[0063] <Synthesis Example 1: Synthesis of MP6> A reaction vessel equipped with a stirrer, partial condenser, total condenser, thermometer, dropping funnel, nitrogen inlet tube, and strand die was charged with 7220 g (49.4 mol) of adipic acid (Roadia) and 11.66 g of sodium acetate / sodium hypophosphite monohydrate (molar ratio = 1 / 1.5). After thorough nitrogen replacement, the system was heated to 170°C and melted while stirring under a small nitrogen stream. 6647 g of mixed xylylenediamine (34.16 mol metaxylylenediamine, 14.64 mol paraxylylenediamine, manufactured by Mitsubishi Gas Chemical Co., Inc.) with a molar ratio of metaxylylenediamine to paraxylylenediamine of 70 / 30 was added dropwise to the molten mixture in the reaction vessel with stirring. The resulting condensed water was discharged from the system while the internal temperature was continuously raised to 260°C over 150 minutes. After the dropwise addition, the internal temperature was increased, and when it reached 270°C, the pressure in the reaction vessel was continuously reduced to 600 Torr over 10 minutes. The internal temperature was then further increased to 280°C, and the melt polycondensation reaction was continued for 20 minutes. The system was then pressurized to 0.2 MPa with nitrogen gas, and the resulting polymer was removed from the strand die and pelletized to obtain a polyamide resin. Hereinafter, this will be referred to as "MP6."

[0064] <Synthesis Example 2: Synthesis of MP10> A precisely weighed 60.00 mol of sebacic acid was placed in a jacketed reactor equipped with a stirrer, partial condenser, condenser, thermometer, dropping tank, and nitrogen gas inlet tube. The contents were thoroughly purged with nitrogen and heated to 170°C under a small nitrogen stream to dissolve the sebacic acid and achieve a uniform flow. 60 mol of para / meta-xylylenediamine, consisting of 30 mol% para-xylylenediamine and 70 mol% meta-xylylenediamine as diamine components, was added dropwise over 160 minutes with stirring. During this time, the internal pressure of the reaction system was maintained at atmospheric pressure, and the internal temperature was continuously raised to 235°C. Water distilled during the dropwise addition of para / meta-xylylenediamine was removed from the system via the partial condenser and condenser. After the dropwise addition of para / meta-xylylenediamine, the liquid temperature was maintained at 235°C and the reaction was continued for 10 minutes. The internal pressure of the reaction system was then continuously reduced to 600 Torr over 10 minutes, after which the reaction was continued for another 20 minutes. During this time, the reaction temperature was continuously raised to 245°C. Thereafter, the system was pressurized to 0.2 MPa with nitrogen gas, and the resulting polymer was removed from the strand die and pelletized to obtain a polyamide resin. Hereinafter, this may be referred to as "MP10."

[0065] 2. Examples 1 to 8 and Comparative Examples 1 to 6 <Compound> Each component was weighed to obtain the composition shown in Tables 2 to 4 below, and the components except for the glass fiber and carbon fiber were blended in a tumbler. The blend was then fed into the base of a twin-screw extruder (Shibaura Machine Co., Ltd., TEM26SS). After melting, the glass fiber and carbon fiber were side-fed into pellets. The temperature of the twin-screw extruder was set to 300°C. The components in Tables 2 to 4 are shown in mass%.

[0066] <Flexural strength and flexural modulus> The pellets obtained by the above manufacturing method were dried at 120°C for 4 hours, and then injection-molded into ISO tensile test specimens (4 mm thick) using an injection molding machine (Nissei Plastic Industrial Co., Ltd., "NEX-140III") under conditions of a cylinder temperature of 300°C, a mold temperature of 130°C, and a molding cycle of 50 seconds. The flexural strength (unit: MPa) and flexural modulus (unit: MPa) were measured at a temperature of 23°C in accordance with ISO178.

[0067] <Charpy impact strength> The pellets obtained by the above manufacturing method were dried at 120°C for 4 hours, and then injection-molded into ISO tensile test specimens (4 mm thick) using an injection molding machine (Nissei Plastic Industrial Co., Ltd., "NEX-140III") under conditions of a cylinder temperature of 300°C, a mold temperature of 130°C, and a molding cycle of 50 seconds. Charpy impact strength (notched and unnotched) was measured at a temperature of 23°C according to ISO 179 standard. The unit is kJ / m 2 As shown.

[0068] <Deflection temperature under load (DTUL)> In accordance with ISO75-1 and 2, the deflection temperature under load (unit: °C) was measured using the above ISO tensile test piece (thickness: 4 mm) under a bending stress of 1.80 MPa.

[0069] <Surface resistance value> The pellets obtained by the above manufacturing method were dried at 120°C for 4 hours and then injection-molded into test pieces measuring 100 mm x 100 mm and 2 mm thick using an injection molding machine (Nissei Plastic Industrial Co., Ltd., "NEX-140III") under conditions of a cylinder temperature of 300°C, a mold temperature of 130°C, and a molding cycle of 50 seconds. In accordance with ASTM D257, the surface resistance of the test piece was measured using an Advantest R8340 ultra insulation resistance meter with an applied voltage set to 1.0 V. The unit is ohms.

[0070] [Table 2]

[0071] [Table 3]

[0072] [Table 4]

[0073] In the above table, CF / GF indicates the mass ratio of carbon fiber (CF) to glass fiber (GF). In the above table, the units of flexural strength are MPa, the units of flexural modulus are MPa, and the units of Charpy impact strength (notched and unnotched) are kJ / m 2 The unit of the deflection temperature under load is ° C., and the unit of the surface resistance value is Ω. In the table above, E+06 is 10 6 For example, the surface resistance value of Example 1, "1.6.E+06", means 1.6×10 6 This means that it is Ω.

[0074] As is clear from the above results, the molded articles formed from the resin compositions of the present embodiment were excellent in mechanical properties and had low surface resistance values ​​(Examples 1 to 8). In contrast, when no carbon fiber was included or when the carbon fiber content was low (Comparative Examples 1, 2, and 4), the surface resistance was high. Also, when the glass fiber had a round cross section (Comparative Example 5), the surface resistance was high. On the other hand, when no glass fiber was included (Comparative Example 3) or when the polyamide resin did not include a xylylenediamine-based polyamide resin (Comparative Example 6), the mechanical properties were poor.

[0075] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.

Claims

1. The composite material comprises a polyamide resin (A), a flat glass fiber (B), and a pitch-based carbon fiber (C), the polyamide resin (A) comprises diamine-derived structural units and dicarboxylic acid-derived structural units, in which 70 mol % or more of the diamine-derived structural units are derived from xylylenediamine, and 70 mol % or more of the dicarboxylic acid-derived structural units are derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms; In a total of 100 parts by mass of (A), (B) and (C), The content of (A) is 40 to 70 parts by mass, The content of (B) is 1.4 to 43 parts by mass, The content of (C) is 8.6 to 58.6 parts by mass, The total content of (B) and (C) is 30 to 60 parts by mass, and the mass ratio of the flat glass fiber (B) to the pitch-based carbon fiber (C), (C) / (B), is 0.4 or more and 5 or less. Resin composition.

2. The resin composition according to claim 1, wherein the total content of the flat glass fiber (B) and the pitch-based carbon fiber (C) in the resin composition is 25 to 60 mass%.

3. The resin composition according to claim 1 or 2, wherein the mass ratio of the flat glass fiber (B) to the pitch-based carbon fiber (C), (C) / (B), is 0.5 or more and 2 or less.

4. The resin composition was molded into a test piece of 100 mm × 100 mm and 2 mm thick, and the surface resistance measured at a voltage of 1.0 V in accordance with ASTM D257 was 1.0 × 10 ７ The resin composition according to claim 1 or 2, having a modulus of elasticity of Ω or less.

5. The total content of the flat glass fiber (B) and the pitch-based carbon fiber (C) in the resin composition is 25 to 60 mass%, The mass ratio of the flat glass fiber (B) to the pitch-based carbon fiber (C), (C) / (B), is 0.5 or more and 2 or less; The resin composition was molded into a test piece of 100 mm x 100 mm and 2 mm thick, and the surface resistance measured at a voltage of 1.0 V in accordance with ASTM D257 was 1.0 x 10 ７ The resin composition according to claim 1, wherein:

6. A pellet of the resin composition according to claim 1 , 2 or 5 .

7. A molded article formed from the resin composition according to claim 1 , 2 or 5 .

8. A molded article formed from the pellets of claim 6.

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