Polyarylene sulfide resin composition and method for producing resin composition

Abstract

To provide: a polyarylene sulfide (PAS) resin molded article the resistance of which in the semiconducting region is easily controlled; a PAS resin composition capable of providing the molded article; and methods for producing these. More specifically, a PAS resin composition in which a PAS resin and carbon fibers are blended as essential components, wherein the weight loss rate of the carbon fibers is 5-25% and the blending amount of the carbon fibers is 15-50 mass parts per 100 mass parts of the PAS resin; a molded article; and methods for producing these.

Description

Polyarylene sulfide resin composition and method for producing the resin composition

[0001] The present invention relates to a polyarylene sulfide resin composition and a method for producing the resin composition.

[0002] Secondary batteries, such as lithium-ion batteries (LIBs), are increasingly being used in a wide range of applications, from small consumer electronics to automotive applications, and demand for them is increasing year by year. Materials for the electrode components of these secondary batteries require resin materials that have a certain level of conductivity, toughness, and flame retardancy, as well as minimal quality variation.

[0003] On the other hand, polyarylene sulfide (hereinafter sometimes abbreviated as PAS) resins, typified by polyphenylene sulfide (hereinafter sometimes abbreviated as PPS) resins, are widely used mainly in electrical and electronic equipment parts, automotive part materials, etc., due to their properties such as high mechanical strength, heat resistance, excellent chemical resistance, ease of processing, dimensional stability, and flame retardancy.

[0004] Since PAS resin is an insulating material by itself, it needs to be made conductive in order to be used in safety components for the anode of a secondary battery. A common method is to compound it with a conductive material such as carbon fiber or carbon black. For example, Patent Document 1 discloses a PPS resin composition containing PAS resin, graphite, carbon fiber, and polyolefin wax. Patent Document 2 discloses a PAS resin composition containing PAN-based carbon fiber whose sizing agent is a polyimide resin.

[0005] JP 2006-19227 A JP 2021-116355 A

[0006] However, the method of adding carbon black has the problem that the flammability of the molded product worsens as the amount of carbon black added increases, because the carbon black itself is flammable. Also, carbon fibers, such as PAN-based carbon fibers, have few resin / filler interfaces that cause resistance to conductivity, so they can reach a semiconductive region with a small amount added. However, because they lack stability, even slight variations in the content cause large fluctuations in resistance, making it difficult to control the resistance in the semiconductive region.

[0007] Therefore, the problem to be solved by the present invention is to provide a PAS resin molded article in which the resistance value in the semiconductive region can be easily controlled, a PAS resin composition capable of providing such a molded article, and a method for producing the same.

[0008] That is, the present disclosure encompasses the following aspects. [1] A PAS resin composition containing PAS resin (A) and carbon fiber (B) as essential components, wherein the weight loss rate of the carbon fiber (B) is 5 to 25%, and the amount of the carbon fiber (B) is 15 to 50 parts by mass per 100 parts by mass of the PAS resin (A). (Note that the weight loss rate is a value measured by thermogravimetric analysis in an air atmosphere at a temperature range of 400 to 600°C.) [2] The PAS resin composition according to [1] above, wherein the carbon fiber (B) contains a surface treatment agent. [3] The PAS resin composition according to [1] or [2] above, wherein the carbon fiber (B) is recycled carbon fiber, and the recycling method is a method of isolating the carbon fiber by thermally decomposing the resin from a carbon fiber-blended resin composition or a molded article. [4] The PAS resin composition according to [1] to [3] above, further containing a silane coupling agent. [5] The PAS resin composition according to any one of [1] to [4] above, further comprising a filler. [6] A molded product obtained by melt-molding the PAS resin composition according to any one of [1] to [5] above. [7] A method for producing a PAS resin composition, comprising a step of blending a PAS resin (A) and a carbon fiber (B) as essential components and melt-kneading them at a temperature equal to or higher than the melting point of the PAS resin (A), wherein the weight loss rate of the carbon fiber (B) is 5 to 25%, and the blending amount of the carbon fiber (B) is 15 to 50 parts by mass per 100 parts by mass of the PAS resin (A). (Note that the weight loss rate is a value measured by thermogravimetric analysis in a temperature range of 400°C to 600°C under an air atmosphere.) [8] The method for producing a PAS resin composition according to any one of [7] above, wherein the carbon fiber (B) contains a surface treatment agent. [9] The method for producing a PAS resin composition according to [7] or [8] above, wherein the carbon fiber (B) is recycled carbon fiber, and the recycling method is a method of isolating the carbon fiber by thermally decomposing a resin from a carbon fiber-blended resin composition or a molded article.

[10] The method for producing a PAS resin composition according to [7] to [9] above, further comprising blending a silane coupling agent.

[11] The method for producing a PAS resin composition according to [7] to

[10] above, further comprising blending a filler.

[12] A method for producing a molded article, comprising the steps of producing a PAS resin composition by the method according to any one of [7] to

[11] above, and melt-molding the obtained PAS resin composition.

[0009] In the present disclosure, the semiconductive region is defined as a region having a thickness of 1.0×10 ０～５ Refers to Ω·cm.

[0010] According to the present invention, it is possible to provide a PAS resin molded article in which the resistance value in the semiconductive region is easily controlled, a PAS resin composition capable of providing such a molded article, and a method for producing the same.

[0011] Hereinafter, an embodiment of the present invention will be described in detail, but the scope of the present invention is not limited to the embodiment described here, and various modifications can be made without departing from the spirit of the present invention. Furthermore, when multiple upper and lower limit values ​​are specified for a specific parameter, any upper and lower limit values ​​can be combined to form a suitable numerical range.

[0012] The PAS resin composition according to this embodiment is a PAS resin composition containing PAS resin (A) and carbon fiber (B) as essential components, characterized in that the weight loss rate of the carbon fiber (B) is 5 to 25%, and the blending amount of the carbon fiber (B) is 15 to 50 parts by mass per 100 parts by mass of the PAS resin (A). This will be explained below.

[0013] <PAS Resin (A)> The PAS resin composition according to this embodiment contains a PAS resin (A) as an essential component.

[0014] The PAS resin has a resin structure having a repeating unit in which an aromatic ring and a sulfur atom are bonded, and specifically, a PAS resin represented by the following general formula (1):

[0015] (In the formula, R １ and R ２ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a nitro group, an amino group, a phenyl group, a methoxy group, or an ethoxy group, and, if necessary, a structural portion represented by the following general formula (2):

[0016] The trifunctional structural moiety represented by formula (2) is preferably present in an amount of 0.001 to 3 mol %, particularly preferably 0.01 to 1 mol %, based on the total number of moles of the trifunctional structural moiety and other structural moieties.

[0017] Here, the structural moiety represented by the general formula (1) is particularly R １ and R ２ is preferably a hydrogen atom from the viewpoint of the mechanical strength of the PAS resin, and in that case, examples include those bonded at the para position represented by the following formula (3) and those bonded at the meta position represented by the following formula (4).

[0018] Among these, a structure in which the bond between the sulfur atom and the aromatic ring in the repeating unit is at the para position represented by the general formula (3) is particularly preferred in terms of the heat resistance of the PAS resin.

[0019] The PAS resin may contain not only the structural moieties represented by the general formula (1) or (2) but also the structural moieties represented by the following structural formulae (5) to (8):

[0020] The structural moieties represented by the general formula (1) and the general formula (2) may be contained in an amount of 30 mol % or less of the total of the structural moieties represented by the general formula (1) and the general formula (2). In particular, in the present disclosure, it is preferable that the structural moieties represented by the general formulas (5) to (8) be 10 mol % or less from the viewpoint of the heat resistance and mechanical strength of the PAS. When the structural moieties represented by the general formulas (5) to (8) are contained in the PAS resin, the bonding mode thereof may be either a random copolymer or a block copolymer.

[0021] The PAS resin may also have naphthyl sulfide bonds or the like in its molecular structure, but the amount of such bonds is preferably 3 mol % or less, and particularly preferably 1 mol % or less, relative to the total number of moles including other structural moieties.

[0022] The physical properties of the PAS resin (A) are not particularly limited as long as they do not impair the effects of the present invention, but are as follows.

[0023] (Melt Viscosity) The melt viscosity of the PAS resin (A) used in this embodiment is not particularly limited, but the melt viscosity (V6) measured at 300°C is preferably 1 to 200 Pa s, more preferably 5 to 150 Pa s, and even more preferably 10 to 120 Pa s, in order to achieve a good balance between processability and toughness. The melt viscosity (V6) is measured using a flow tester, CFT-500D, manufactured by Shimadzu Corporation, at 300°C and a load of 1.96 × 10 ６ The melt viscosity is measured after holding the sample at a temperature of 10 Pa and L / D=10 (mm) / 1 (mm) for 6 minutes.

[0024] (Carboxyl group content) The carboxyl group content of the PAS resin (A) used in this embodiment is not particularly limited, but is preferably in the range of 10 to 200 μmol / g or less, more preferably in the range of 20 to 180 μmol / g, and even more preferably in the range of 40 to 180 μmol / g. Note that the carboxyl group content in the present disclosure is a value measured by the method described in the examples.

[0025] (Non-Newtonian Index) The non-Newtonian index of the PAS resin (A) used in this embodiment is not particularly limited, but is preferably in the range of 0.90 or more and 2.00 or less. When a linear PAS resin is used, the non-Newtonian index is preferably in the range of 0.90 or more, more preferably 0.95 or more, and preferably 1.50 or less, more preferably 1.20 or less. Such a PAS resin has excellent mechanical strength and fluidity. However, in this disclosure, the non-Newtonian index (N value) is a value calculated using the following formula after measuring the shear rate (SR) and shear stress (SS) using a capillograph under conditions of a melting point of +20°C and an orifice length (L) to orifice diameter (D) ratio of L / D = 40. The closer the non-Newtonian index (N value) is to 1, the more linear the structure, and the higher the non-Newtonian index (N value), the more branched the structure.

[0026] [where SR is the shear rate (sec －１ ), SS is the shear stress (dyne / cm ２ ), and K denotes a constant.

[0027] (Production Method) The method for producing the PAS resin is not particularly limited, but examples thereof include (Production Method 1) a method in which a dihalogenoaromatic compound is polymerized in the presence of sulfur and sodium carbonate, and if necessary, a polyhalogenoaromatic compound or other copolymerization component is added; (Production Method 2) a method in which a dihalogenoaromatic compound is polymerized in a polar solvent in the presence of a sulfidizing agent or the like, and if necessary, a polyhalogenoaromatic compound or other copolymerization component is added; (Production Method 3) a method in which p-chlorothiophenol is added, and if necessary, other copolymerization components are added, and then self-condensed; and (Production Method 4) a method in which a diiodoaromatic compound and elemental sulfur are melt-polymerized under reduced pressure in the presence of a polymerization inhibitor that may have a functional group such as a carboxyl group or an amino group. Of these methods, (Production Method 2) is preferred because it is versatile. During the reaction, an alkali metal salt of a carboxylic acid or sulfonic acid or an alkali hydroxide may be added to adjust the degree of polymerization. Among the above-mentioned (Production Method 2) methods, there is a method for producing a PAS resin by introducing a water-containing sulfidizing agent into a mixture containing a heated organic polar solvent and a dihalogeno aromatic compound at a rate at which water can be removed from the reaction mixture, and then adding the dihalogeno aromatic compound and the sulfidizing agent, and optionally a polyhalogeno aromatic compound, in the organic polar solvent to react with each other, and controlling the amount of water in the reaction system to be in the range of 0.02 to 0.5 moles per mole of the organic polar solvent (see JP-A-07-228699). Particularly preferred is a copolymer obtained by a method in which a dihalogenoaromatic compound and, if necessary, a polyhalogenoaromatic compound or other copolymerization component are added in the presence of an alkali metal sulfide and an aprotic polar organic solvent, and an alkali metal hydrosulfide and an organic acid alkali metal salt are reacted while controlling the amount of organic acid alkali metal salt in the range of 0.01 to 0.9 mol per mol of the sulfur source and the amount of water in the reaction system to 0.02 mol or less per mol of the aprotic polar organic solvent (see WO 2010 / 058713 pamphlet).Specific examples of the dihalogeno aromatic compound include p-dihalobenzene, m-dihalobenzene, o-dihalobenzene, 2,5-dihalotoluene, 1,4-dihalonaphthalene, 1-methoxy-2,5-dihalobenzene, 4,4'-dihalobiphenyl, 3,5-dihalobenzoic acid, 2,4-dihalobenzoic acid, 2,5-dihalonitrobenzene, 2,4-dihalonitrobenzene, 2,4-dihaloanisole, p,p'-dihalodiphenyl ether, 4,4'-dihalobenzophenone ... Examples of the polyhalogenoaromatic compounds include 1,2,3-trihalobenzene, 1,2,4-trihalobenzene, 1,3,5-trihalobenzene, 1,2,3,5-tetrahalobenzene, 1,2,4,5-tetrahalobenzene, 1,4,6-trihalonaphthalene, etc. The halogen atoms contained in the above compounds are preferably chlorine atoms or bromine atoms.

[0028] The method for post-treating the reaction mixture containing the PAS resin obtained by the polymerization step is not particularly limited, and examples thereof include: (post-treatment 1) after the completion of the polymerization reaction, first, distilling off the solvent from the reaction mixture either as is or after adding an acid or a base under reduced pressure or normal pressure, and then washing the solid obtained after the solvent distillation once or twice or more times with a solvent such as water, the reaction solvent (or an organic solvent having a similar solubility to the low-molecular-weight polymer), acetone, methyl ethyl ketone, or alcohols, followed by neutralization, washing with water, filtering, and drying; or (post-treatment 2) after the completion of the polymerization reaction, adding a solvent such as water, acetone, methyl ethyl ketone, alcohols, ethers, halogenated hydrocarbons, aromatic hydrocarbons, or aliphatic hydrocarbons (soluble in the polymerization solvent used and poorly soluble in at least the PAS) to the reaction mixture. Examples of such methods include: (1) adding a solvent (which is a solvent for polymerization) as a precipitant to the reaction mixture, allowing solid products such as PAS and inorganic salts to precipitate, followed by filtration, washing, and drying; (2) adding a reaction solvent (or an organic solvent having equivalent solubility to the low-molecular-weight polymer) to the reaction mixture after the polymerization reaction is complete, stirring the mixture, filtering to remove the low-molecular-weight polymer, washing once or twice or more times with a solvent such as water, acetone, methyl ethyl ketone, or an alcohol, followed by neutralization, washing with water, filtering, and drying; (3) adding water to the reaction mixture after the polymerization reaction is complete, washing with water, filtering, and optionally adding an acid during the water washing step to perform an acid treatment, followed by drying; and (4) filtering the reaction mixture after the polymerization reaction is complete, and optionally washing once or twice or more times with the reaction solvent, followed by further washing with water, filtering, and drying. Among these methods, (4) is preferred because it enables the production of a PAS resin having carboxyl groups at the molecular terminals of the PAS resin.

[0029] In the post-treatment methods exemplified above as (Post-treatment 1) to (Post-treatment 5), the PAS resin may be dried in a vacuum, in air, or in an inert gas atmosphere such as nitrogen.

[0030] In the PAS resin composition according to the present embodiment, the blending amount of the PAS resin (A) is preferably 30 to 80 parts by mass, more preferably 40 to 70 parts by mass, per 100 parts by mass of the resin composition. This range is preferable because the resin composition has good processability and the molded article has excellent chemical resistance, toughness, etc.

[0031] The PAS resin (A) used in this embodiment can be a PAS resin newly polymerized by the above method, or a recycled PAS resin. For example, PAS resin recovered from a PAS resin composition or a PAS resin molded article can be used. Specifically, a PAS resin obtained by heating a PAS resin composition or a PAS resin molded article in an organic polar solvent to dissolve the PAS contained therein and then performing the above-described post-treatment can be used. Mechanically pulverized PAS resin compositions or PAS resin molded articles can also be used as PAS resins. Specifically, sprues or runners generated during the production of molded articles, recovered non-standard molded articles, or pulverized molded articles once used as products can be used. In this case, pulverized PAS resin compositions or PAS resin molded articles containing components other than PAS resin can also be used. However, from the perspective of mechanical strength, the PAS resin content is preferably 90 parts by mass or more, more preferably 95 parts by mass or more, and even more preferably 98 parts by mass or more.

[0032] <Carbon Fiber (B)> The PAS resin composition according to this embodiment contains carbon fiber (B) as an essential component.

[0033] The carbon fiber (B) used in this embodiment has a weight loss rate of 5 to 25% from the viewpoint of achieving both moldability and conductivity. A weight loss rate of 8 to 20% is preferred, and 10 to 18% is more preferred. The weight loss rate is a value measured by thermogravimetric analysis in an air atmosphere at a temperature range of 400 to 600°C, and is a value measured by the method described in the Examples. Components that thermally decompose in this temperature range are expected to include impurities, carbides, and surface treatment agents on the carbon fiber surface, but other components may also be used. When recycled carbon fiber is used, carbides such as resins may remain on the carbon fiber surface, making it easier to meet this condition, but this is not limited to this, and virgin carbon fiber may also be used.

[0034] In the PAS resin composition according to this embodiment, the blending amount of the carbon fiber (B) is 15 to 50 parts by mass, preferably 20 to 40 parts by mass, and more preferably 25 to 40 parts by mass, per 100 parts by mass of the PAS resin (A). Within this range, the electrical resistance of the molded article can be controlled to a small variation in the semiconductive region.

[0035] The shape of the carbon fiber (B) is not particularly limited as long as it is fibrous, and the fiber diameter, fiber length, aspect ratio, and the like can be appropriately adjusted depending on the application of the molded body, etc., but from the viewpoint of being able to exhibit better mechanical strength, the average fiber length is preferably 0.5 mm or more, more preferably 1 mm or more, and is preferably 6 mm or less, more preferably 5 mm or less.

[0036] The carbon fiber (B) used in this embodiment preferably contains a surface treatment agent (sizing agent). The type of surface treatment agent is not particularly limited as long as it does not impair the effects of the present invention. Examples include silane compounds having functional groups such as amino groups, epoxy groups, isocyanate groups, and vinyl groups, titanate compounds, and at least one polymer selected from the group consisting of acrylic resins, urethane resins, polyether resins, and epoxy resins. From the viewpoint of achieving both ease of handling and moldability of the carbon fiber (B), the amount of the surface treatment agent applied is preferably 1 to 10 parts by mass, and more preferably 1 to 5 parts by mass. In this embodiment, either PAN (polyacrylonitrile)-based carbon fiber or pitch-based carbon fiber can be used as the carbon fiber (B).

[0037] The carbon fiber (B) used in this embodiment preferably contains recycled, regenerated carbon fiber. The method for recycling carbon fiber is not particularly limited, and known methods and devices can be used. For example, carbon fiber (B) recycled by removing resin components from a carbon fiber-blended resin composition or molded article can be used. Examples of carbon fiber-blended resin compositions or molded articles to be recycled include sprues or runners generated during the production of molded articles, those recovered as non-standard molded articles, and crushed molded articles that have been used as products. Methods for removing resin components include dissolving the carbon fiber in a solvent and performing solid-liquid separation, and pyrolysis. Pyrolysis is preferred because it can form charcoal on the surface of the carbon fiber.

[0038] The PAS resin composition according to this embodiment may contain a silane coupling agent as an optional component in order to improve mechanical strength. The amount of the silane coupling agent is not particularly limited as long as it does not impair the effects of the present invention. For example, the amount is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, per 100 parts by mass of the PAS resin (A). This range is preferable for achieving both moldability and mechanical strength.

[0039] The PAS resin composition according to this embodiment may contain a thermoplastic elastomer as an optional component to improve toughness and impact resistance. Examples of thermoplastic elastomers that can be used in this embodiment include polyolefin elastomers, fluorine elastomers, and silicone elastomers, with polyolefin elastomers being preferred. When these elastomers are added, their amount is not particularly limited as long as it does not impair the effects of the present invention. However, it is preferably in the range of 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, to 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the PAS resin (A). This range is preferred because it improves the impact resistance of the resulting PAS resin composition.

[0040] Examples of the polyolefin elastomer include a homopolymer of an α-olefin, a copolymer of two or more α-olefins, and a copolymer of one or more α-olefins with a vinyl polymerizable compound having a functional group. Examples of the α-olefin include α-olefins having 2 or more to 8 carbon atoms, such as ethylene, propylene, and 1-butene. Examples of the functional group include a carboxyl group, an acid anhydride group (—C(═O)OC(═O)—), an epoxy group, an amino group, a hydroxyl group, a mercapto group, an isocyanate group, and an oxazoline group. Examples of the vinyl polymerizable compound having a functional group include one or more of vinyl acetate; α,β-unsaturated carboxylic acids such as (meth)acrylic acid; alkyl esters of α,β-unsaturated carboxylic acids such as methyl acrylate, ethyl acrylate, and butyl acrylate; metal salts of α,β-unsaturated carboxylic acids such as ionomers (metals include alkali metals such as sodium, alkaline earth metals such as calcium, and zinc); glycidyl esters of α,β-unsaturated carboxylic acids such as glycidyl methacrylate; α,β-unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; and derivatives of the above α,β-unsaturated dicarboxylic acids (monoesters, diesters, and acid anhydrides). The above-mentioned thermoplastic elastomers may be used alone or in combination of two or more.

[0041] From the viewpoint of improving mechanical strength, the PAS resin composition according to the present embodiment may contain fillers other than the carbon fiber (B) (hereinafter referred to as "other fillers") as optional components within a range that does not impair the effects of the present invention. Examples of such fillers include fillers of various shapes, such as fibrous, plate-like, and granular. Specific examples include glass fiber, silane glass fiber, ceramic fiber, aramid fiber, metal fiber, fibers such as potassium titanate, silicon carbide, calcium silicate, and wollastonite, natural fibers, glass flakes, clay, pyrophyllite, bentonite, sericite, mica, attapulgite, ferrite, calcium silicate, zeolite, boehmite, silica, quartz powder, glass beads, glass powder, silicates such as calcium silicate, aluminum silicate, and diatomaceous earth, metal oxides such as iron oxide, titanium oxide, zinc oxide, and alumina, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, fumed silica, silicon carbide, silicon nitride, boron nitride, various metal powders, cocoa husk, plant-derived fillers such as cellulose, and the like.

[0042] In this embodiment, other fillers are not essential components, but when blended, the blending amount is not particularly limited as long as it does not impair the effects of the present invention. The blending amount of other fillers is, for example, preferably 1 part by mass or more, more preferably 5 parts by mass or more, to preferably 600 parts by mass or less, more preferably 200 parts by mass or less, per 100 parts by mass of the PAS resin (A). Within such a range, the resin composition exhibits good moldability and the molded product has excellent mechanical strength, which is preferable.

[0043] Furthermore, in addition to the above components, the PAS resin composition according to this embodiment can further contain, as an optional component, synthetic resins such as polyester resins, polyamide resins, polyimide resins, polyetherimide resins, polycarbonate resins, polyphenylene ether resins, polysulfone resins, polyethersulfone resins, polyetheretherketone resins, polyetherketone resins, polyarylate resins, polyethylene resins, polypropylene resins, polyethylenetetrafluoroethylene resins, polyethylenedifluoroethylene resins, polystyrene resins, ABS resins, epoxy resins, phenolic resins, urethane resins, and liquid crystal polymers, depending on the application. In particular, the incorporation of fluorine-based resins is preferred because it further improves sliding properties. While the synthetic resin is not an essential component in the present invention, when it is incorporated, it can be incorporated in an amount of, for example, 5 to 15 parts by mass per 100 parts by mass of the PAS resin (A).

[0044] The PAS resin composition according to the present embodiment may also contain other known and commonly used additives as optional components, as needed, such as colorants, antistatic agents, antioxidants, heat stabilizers, UV stabilizers, UV absorbers, foaming agents, flame retardants, flame retardant assistants, rust inhibitors, mold release agents (metal salts or esters of fatty acids having 18 to 30 carbon atoms, including stearic acid or montanic acid, and polyolefin waxes such as polyethylene), antibacterial agents, and antiviral agents. These additives are not essential components, and may be used in an amount, for example, preferably 0.01 part by mass or more, and preferably 1,000 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of the PAS resin (A), as appropriate for the purpose and application so as not to impair the effects of the present invention.

[0045] <Method for producing PAS resin composition> The method for producing a PAS resin composition according to this embodiment is a method for producing a PAS resin composition, comprising a step of blending PAS resin (A) and carbon fiber (B) as essential components and melt-kneading the blended PAS resin (A) or higher at a temperature equal to or higher than the melting point of the PAS resin (A), characterized in that the weight loss rate of the carbon fiber (B) is 5 to 25%, and the blending amount of the carbon fiber (B) is 15 to 50 parts by mass per 100 parts by mass of the PAS resin (A). This will be described in detail below.

[0046] The method for producing a PAS resin composition according to this embodiment includes a step of blending the essential components and melt-kneading them in a temperature range equal to or higher than the melting point of the PAS resin (A). More specifically, the PAS resin composition according to this embodiment is obtained by blending the essential components and, if necessary, other optional components. The method for producing the resin composition used in the present invention is not particularly limited, but examples thereof include a method of blending the essential components and, if necessary, optional components, and melt-kneading them, and more specifically, a method of uniformly dry-mixing them in a tumbler or Henschel mixer, if necessary, and then feeding them into a twin-screw extruder and melt-kneading them.

[0047] The melt-kneading can be carried out by heating to a temperature range in which the resin temperature is equal to or higher than the melting point of the PAS resin (A), preferably equal to or higher than the melting point + 10°C, more preferably equal to or higher than the melting point + 10°C, even more preferably equal to or higher than the melting point + 20°C, to a temperature range in which the resin temperature is equal to or lower than the melting point + 100°C, more preferably equal to or lower than the melting point + 50°C.

[0048] From the viewpoint of dispersibility and productivity, the melt kneader is preferably a twin-screw kneading extruder. For example, it is preferable to melt knead while appropriately adjusting the resin component discharge rate in the range of 5 to 500 (kg / hr) and the screw rotation speed in the range of 50 to 500 (rpm). It is even more preferable to melt knead under conditions where the ratio (discharge rate / screw rotation speed) is in the range of 0.02 to 5 (kg / hr / rpm). Furthermore, the addition and mixing of the components to the melt kneader may be carried out simultaneously or in portions. For example, when adding the essential component carbon fiber (B) or other fibrous fillers as needed, it is preferable from the viewpoint of dispersibility to feed them into the twin-screw kneading extruder through a side feeder. The position of the side feeder is preferably such that the ratio of the distance from the extruder's resin input section (top feeder) to the side feeder to the total screw length of the twin-screw kneading extruder is 0.1 or more, more preferably 0.3 or more. Moreover, the ratio is preferably 0.9 or less, and more preferably 0.7 or less.

[0049] The PAS resin composition according to the present embodiment obtained by melt-kneading in this manner is a molten mixture containing the essential components, optional components added as needed, and components derived therefrom. Therefore, the PAS resin composition according to the present embodiment has a morphology in which the PAS resin (A) forms a continuous phase and the other essential components and optional components are dispersed.

[0050] After the melt-kneading, the PAS resin composition according to the present embodiment is preferably processed into a form such as pellets, chips, granules, or powder by a known method, for example, by extruding the molten resin composition into a strand shape, and then pre-dried at a temperature in the range of 100 to 150°C as needed.

[0051] <PAS resin molded article, manufacturing method of PAS resin molded article> The molded article according to this embodiment is obtained by melt-molding a PAS resin composition. Furthermore, the manufacturing method of the molded article according to this embodiment includes a step of melt-molding the PAS resin composition. Therefore, the molded article according to this embodiment has a morphology in which the PAS resin (A) forms a continuous phase and other essential components and optional components are dispersed. Because the PAS resin composition has such a morphology, a molded article having excellent thermal conductivity and mechanical strength can be obtained.

[0052] The PAS resin composition according to this embodiment can be subjected to various molding processes, such as injection molding, compression molding, extrusion molding of composites, sheets, and pipes, pultrusion molding, blow molding, and transfer molding. However, due to its excellent mold releasability, it is particularly suited to injection molding applications. When molding by injection molding, the molding conditions are not particularly limited, and molding can be performed using a typical method. For example, the PAS resin composition can be melted in an injection molding machine at a resin temperature in a range equal to or higher than the melting point of the PAS resin (A), preferably in a range of 10°C above the melting point, more preferably in a range of 10°C to 100°C above the melting point, and even more preferably in a range of 20°C to 50°C above the melting point, and then the resulting resin can be injected into a mold through a resin discharge port and molded. The mold temperature can also be set within a known temperature range, for example, from room temperature (23°C) to 300°C, preferably 130°C to 190°C.

[0053] The method for producing a molded article according to this embodiment may include a step of annealing the molded article. The optimal conditions for the annealing treatment are selected depending on the application or shape of the molded article. The annealing temperature is in a temperature range above the glass transition temperature of the PAS resin (A), preferably in a temperature range above the glass transition temperature + 10°C, and more preferably in a temperature range above the glass transition temperature + 30°C. The annealing time is preferably in the range of 260°C or less, and more preferably in the range of 240°C or less. The annealing time is not particularly limited, but is preferably in the range of 0.5 hours or more, more preferably in the range of 1 hour or more. The annealing time is preferably in the range of 10 hours or less, and more preferably in the range of 8 hours or less. This range is preferable because it reduces distortion in the resulting molded article, improves the crystallinity of the resin, and further improves thermal conductivity and mechanical strength. The annealing treatment may be performed in air, but is preferably performed in an inert gas such as nitrogen gas.

[0054] The molded article according to this embodiment includes a remolded article obtained by reusing a molded article obtained by melt-molding the PAS resin composition. Specifically, the molded article includes, for example, a sprue or runner generated during the production of a molded article, a recovered non-standard molded article, or a molded article once used as a product, which is cleaned as necessary, pulverized, and then melt-molded again at a temperature equal to or higher than the melting point of the PAS resin. When reusing, it is preferable to mix the pulverized molded article with the PAS resin composition from the viewpoint of mechanical strength. The size of the molded article to be pulverized is not particularly limited, but from the viewpoints of mixability and processability, it is preferable that the size be approximately the same as that of the PAS resin composition to be mixed. Furthermore, the mixing ratio of the pulverized molded article to 100 parts by mass of the PAS resin composition is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 20 parts by mass or less. Within this range, recyclability can be improved without impairing the effects of the PAS resin composition of the present disclosure.

[0055] <Applications> The PAS resin molded article according to this embodiment has excellent conductivity and is therefore particularly suitable for use in conductive parts. Specifically, it can be suitably used for conductive parts such as electrode peripheral parts for lithium ion batteries, carrier trays, battery parts, conductive reels, and conductive pallets. Furthermore, the molded article according to this embodiment can be used not only for conductive parts but also for general applications such as the following: For example, protective and support members for box-shaped integrated modules of electrical and electronic components, multiple individual semiconductors or modules, sensors, LED lamps, connectors, sockets, resistors, relay cases, switches, coil bobbins, capacitors, variable capacitor cases, optical pickups, oscillators, various terminal boards, transformers, plugs, printed circuit boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, power modules, terminal blocks, semiconductors, liquid crystal displays, FDD carriages, FDD chassis, motor brush holders, parabolic antennas, and electrical and electronic parts such as computer-related parts; VTR parts, television parts, irons, and headsets. Home and office electrical appliance parts such as air dryers, rice cooker parts, microwave oven parts, audio parts, audio / visual equipment parts such as laser discs, compact discs, DVD discs, and Blu-ray discs, lighting parts, refrigerator parts, air conditioner parts, typewriter parts, word processor parts, and plumbing equipment parts such as water heaters, bath water volume and temperature sensors; machine-related parts such as office computer-related parts, telephone-related parts, facsimile-related parts, copier-related parts, cleaning jigs, motor parts, lighters, and typewriters; optical equipment and precision machinery-related parts such as microscopes, binoculars, cameras, and watches;Alternator terminals, alternator connectors, brush holders, slip rings, IC regulators, light dimmer potentiometer bases, relay blocks, inhibitor switches, exhaust gas valves and other valves, fuel-related, exhaust system and intake system pipes, air intake nozzle snorkels, intake manifolds, engine coolant joints, carburetor main bodies, carburetor spacers, exhaust gas sensors, coolant sensors, oil temperature sensors, brake pad wear sensors, throttle position sensors, crankshaft position sensors, temperature sensors, air flow meters, brake pad wear sensors, air conditioner thermostat bases, heating hot air flow control valves, radiators Examples of automotive and vehicle related parts include brush holders for motor motors, water pump impellers, turbine vanes, wiper motor related parts, distributors, starter switches, ignition coils and bobbins, motor insulators, motor rotors, motor cores, starter relays, transmission wire harnesses, windshield washer nozzles, air conditioner panel switch boards, fuel-related electromagnetic valve coils, fuse connectors, horn terminals, electrical component insulating plates, step motor rotors, lamp sockets, lamp reflectors, lamp housings, brake pistons, solenoid bobbins, engine oil filters, ignition device cases, and various other applications are also possible;

[0056] The present invention will be described below using examples and comparative examples, but is not limited to these examples. Unless otherwise specified, "%" and "parts" are based on mass.

[0057] Examples and Comparative Examples Materials were blended according to the composition and blending amounts listed in Table 1. These blended materials were then fed into a vented twin-screw extruder "TEX-30α (product name)" manufactured by The Japan Steel Works, Ltd., and melt-kneaded at a resin component discharge rate of 30 kg / hr, a screw rotation speed of 200 rpm, and a set resin temperature of 310°C to obtain pellets of the resin composition. Glass fiber was fed through a side feeder (S / T ratio 0.5), and the other materials were pre-mixed uniformly in a tumbler and then fed through the top feeder. The resulting pellets of the resin composition were dried in a gear oven at 140°C for 2 hours and then injection-molded to prepare various test pieces, which were then subjected to the following tests.

[0058] <Evaluation>

[0059] (1) Volume resistivity measurement Volume resistivity was measured using the "Loresta AX MCP-T370" manufactured by Nitto Seiko Analytech Co., Ltd. (upper limit of measurement: 10 ６ The volume resistivity of each test piece was measured using a resistivity tester (Ω) under conditions of room temperature 21°C and humidity 67% RH in accordance with JIS K 7194 "Testing method for resistivity of conductive plastics using the four-probe method." Ten test pieces were measured, and the standard deviation divided by the average value was evaluated as the variation. The test pieces were prepared by feeding the pellets obtained in each example and comparative example into a Sumitomo Heavy Industries injection molding machine (SE-75D-HP) set at a cylinder temperature of 310°C, and injection molding using a plate molding mold temperature-controlled at 140°C to form a plate shape (80 mm x 50 mm x 2 mmt). The results are shown in Table 1.

[0060] (2) Measurement of Tensile Strength The pellets obtained in each Example and Comparative Example were fed into a Sumitomo Heavy Industries injection molding machine (SE-75D-HP) set at a cylinder temperature of 310°C, and injection molding was carried out using an ISO Type-A dumbbell specimen molding die controlled at a die temperature of 140°C to obtain ISO Type-A dumbbell specimens. The resin was injected from a single gate to produce test specimens that did not include welds. The tensile strength of the obtained test specimens was measured using a measurement method in accordance with ISO 527-1 and 2. The results are shown in Table 1.

[0061] (3) Flammability Evaluation Flammability was evaluated by a 20 mm vertical flame burning test (V test) using 125 mm × 13 mm × 1.5 mm bar-shaped test pieces prepared from the resin compositions of the Examples and Comparative Examples in accordance with the UL94 V test method. The results are shown in Table 1.

[0062] (4) Measurement of Weight Loss Rate The weight loss rate of each carbon fiber was measured using a thermal analyzer "DTG-60" manufactured by Shimadzu Corporation. Approximately 8 mg of a sample was heated in an air atmosphere from room temperature (23°C) to 600°C at a temperature increase rate of 20°C / min, and the weight loss rate in the temperature range from 400°C to 600°C was calculated.

[0063]

[0064] The blending ratios of the blending components in Table 1 are as follows: PAS resin A: PPS resin (melt viscosity (V6) 30 Pa s, zeta potential -64 mV, carboxyl group amount 30 μmol / g) Carbon fiber B-1: Carbon fiber, "T8S103CD0P" manufactured by Carbon Fiber Recycle Industry Co., Ltd., average fiber length 3 mm, weight reduction rate 15% B-2: Carbon fiber, "T8S103CD0E" manufactured by Carbon Fiber Recycle Industry Co., Ltd., average fiber length 3 mm, weight reduction rate 12% B-3: Carbon fiber, "HT C702" manufactured by Teijin Limited, average fiber length 6 mm, weight reduction rate 2% Optional components B-4: Carbon black, "#4400" manufactured by Tokai Carbon Co., Ltd. C: Olefin-based elastomer, "Bondfast 7M" manufactured by Sumitomo Chemical Co., Ltd. D: Glass fiber, "T-717H" manufactured by Nippon Electric Glass Co., Ltd., fiber length 3 mm, average diameter 10 μm E: Silane coupling agent, epoxy silane 3-glycidoxypropyltrimethoxysilane "SH-6040" manufactured by Dow Corning Co., Ltd.

[0065] Comparing the Examples and Comparative Examples in Table 1, Comparative Example 1 showed excellent flammability but poor conductivity due to the low carbon fiber content. Comparative Example 2 showed poor processability and difficult molding due to the high carbon fiber content. Comparative Example 3 used carbon fiber that did not satisfy the weight loss rate requirement, resulting in large variations in volume resistivity. Comparative Example 4 showed poor flammability when carbon black was used instead of carbon fiber.

Claims

1. A polyarylene sulfide resin composition containing polyarylene sulfide resin (A) and carbon fiber (B) as essential components, wherein the weight loss rate of the carbon fiber (B) is 5 to 25%, and the blending amount of the carbon fiber (B) is 15 to 50 parts by mass per 100 parts by mass of the polyarylene sulfide resin (A). (However, the weight loss rate is a value measured by thermogravimetric analysis in an air atmosphere in the temperature range of 400 to 600°C.) 2. The polyarylene sulfide resin composition according to claim 1, wherein the carbon fibers (B) contain a surface treatment agent.

3. The polyarylene sulfide resin composition according to claim 1, wherein the carbon fiber (B) is recycled carbon fiber, and the recycling method is a method of isolating the carbon fiber by thermally decomposing the resin from a carbon fiber-blended resin composition or a molded article.

4. The polyarylene sulfide resin composition according to claim 1, further comprising a silane coupling agent.

5. The polyarylene sulfide resin composition according to claim 1, further comprising a filler.

6. A molded article obtained by melt molding the polyarylene sulfide resin composition according to claim 1 or 2.

7. A method for producing a polyarylene sulfide resin composition, comprising a step of blending polyarylene sulfide resin (A) and carbon fiber (B) as essential components and melt-kneading the blended polyarylene sulfide resin (A) at a temperature equal to or higher than the melting point of the polyarylene sulfide resin (A), wherein the weight loss rate of the carbon fiber (B) is 5 to 25%, and the blending amount of the carbon fiber (B) is 15 to 50 parts by mass per 100 parts by mass of the polyarylene sulfide resin (A). (However, the weight loss rate is a value measured by thermogravimetric analysis in an air atmosphere at a temperature range of 400 to 600°C.) 8. The method for producing a polyarylene sulfide resin composition according to claim 7, wherein the carbon fiber (B) contains a surface treatment agent.

9. The method for producing a polyarylene sulfide resin composition according to claim 7, wherein the carbon fiber (B) is recycled carbon fiber, and the recycling method is a method of isolating the carbon fiber by thermally decomposing the resin from a carbon fiber-blended resin composition or a molded article.

10. The method for producing a polyarylene sulfide resin composition according to claim 7, further comprising blending a silane coupling agent.

11. The method for producing a polyarylene sulfide resin composition according to claim 7, further comprising blending a filler.

12. A method for producing a molded article, comprising the steps of producing a polyarylene sulfide resin composition by the method of claim 7, and melt-molding the polyarylene sulfide resin composition obtained.

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