Polyarylene sulfide resin composition, molded article, and method for producing the same

Abstract

The present invention provides a polyarylene sulfide (PAS) resin molded article that exhibits both excellent sliding properties and mechanical strength, and a resin composition capable of providing the molded article. More specifically, the present invention provides a PAS resin composition containing, as essential components, a PAS resin (A), a polytetrafluoroethylene resin (B), a fibrous filler (C), and a release agent (D), wherein the PAS resin (A) has a melt viscosity (V6) of 20 to 60 Pa s, the polytetrafluoroethylene resin (B) has a melt flow rate (MFR) of 1 g / 10 min or less, and the amounts of the polytetrafluoroethylene resin (B), the fibrous filler (C), and the release agent (D) are 20 to 40 parts by mass, 10 to 70 parts by mass, and 0.01 to 5 parts by mass per 100 parts by mass of the PAS resin (A), and a molded article and methods for producing the same.

Description

[Technical Field]

[0001] The present invention relates to a polyarylene sulfide resin composition, a molded article, and a method for producing the same. [Background technology]

[0002] In recent years, engineering plastics have been developed that offer excellent productivity and moldability, and because they are lightweight, they are widely used as alternatives to metal materials in components for electrical and electronic devices, automobiles, etc. Among these, polyarylene sulfide (PAS) resins, typified by polyphenylene sulfide (PPS), are increasingly being adopted, primarily for electrical and electronic device components and automobile components, due to their excellent mechanical strength, heat resistance, chemical resistance, moldability, dimensional stability, and flame retardancy.

[0003] As metal materials are increasingly being replaced by resin materials in various applications, the application of PAS resins to sliding parts such as valves, bearings, and gears is also being actively investigated. To meet the required characteristics of these parts, such as low friction coefficient and low wear, the demands for quality and processability of PAS resins are increasing year by year, making it necessary to improve their physical properties. For example, Patent Document 1 discloses a resin composition containing 100 parts by weight of PPS resin, 5 to 100 parts by weight of polytetrafluoroethylene, 20 to 200 parts by weight of an inorganic filler with a Mohs hardness of 3.5 or less, and 0.01 to 5 parts by weight of an olefin copolymer with a molecular weight of 1,000 to 10,000. Patent Document 2 also discloses a resin composition containing 100 parts by weight of PPS resin, 6 to 60 parts by weight of carbon fiber, 6 to 60 parts by weight of fluororesin, 6 to 40 parts by weight of graphite, and 1 to 20% by weight of a metal sulfide. As such, there is conventional technology for blending fluororesin, graphite, low-hardness fillers, etc. with PAS resin to impart sliding properties, but adding high-molecular-weight fluororesin with high sliding properties can lead to issues such as a decrease in moldability, and it is difficult to achieve both high levels of sliding properties and mechanical strength. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-332406 [Patent Document 2] Japanese Patent Application Publication No. 2019-85470 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present invention is to provide a PAS resin molded article that has both good sliding properties and mechanical strength, and a resin composition that can provide such a molded article. [Means for solving the problem]

[0006] As a result of various investigations, the inventors have completed the present invention having the following constituent features.

[0007] That is, the present invention includes the following aspects. [1] A PAS resin composition containing, as essential components, a PAS resin (A), a polytetrafluoroethylene resin (B) (hereinafter, sometimes simply referred to as "PTFE resin (B)"), a fibrous filler (C), and a release agent (D), the melt viscosity (V6) of the PAS resin (A) is 20 to 60 Pa s; The melt flow rate (MFR) of the PTFE resin (B) is 1 g / 10 min or less, A PAS resin composition comprising 20 to 40 parts by mass of the PTFE resin (B), 10 to 70 parts by mass of the fibrous filler (C), and 0.01 to 5 parts by mass of the release agent (D) relative to 100 parts by mass of the PAS resin (A). (However, the MFR of the PTFE resin (B) is a value measured at a temperature of 372°C and a load of 2.16 kg.) [2] The PAS resin composition according to [1], wherein the PTFE resin (B) has a perfluorooctanoic acid content of less than 25 ppb. [3] The PAS resin composition according to [1] or [2], wherein the PAS resin (A) has a weight average molecular weight of 20,000 to 40,000. [4] The PAS resin composition according to any one of [1] to [3], wherein the PTFE resin (B) has an average dispersed particle size of 1.0 to 10 μm. [5] The PAS resin composition according to any one of [1] to

[44] , wherein the fibrous filler (C) has a tensile modulus of elasticity of 200 to 300 GPa. [6] The PAS resin composition according to any one of [1] to [5], wherein the number average fiber length of the fibrous filler (C) is 150 to 250 μm. [7] The PAS resin composition according to any one of [1] to [6], wherein the release agent (D) is an olefin polymer or a fatty acid ester. [8] A molded article obtained by melt molding the PAS resin composition according to any one of [1] to [7]. [9] A method for producing a PAS resin composition, comprising a step of blending a PAS resin (A), a PTFE resin (B), a fibrous filler (C), and a release agent (D) as essential components, and melt-kneading the mixture at a temperature equal to or higher than the melting point of the PAS resin (A), the melt viscosity (V6) of the PAS resin (A) is 20 to 60 Pa s; The melt flow rate (MFR) of the PTFE resin (B) is 1 g / 10 min or less, A method for producing a PAS resin composition, wherein the PTFE resin (B) is 20 to 40 parts by mass, the fibrous filler (C) is 10 to 70 parts by mass, and the release agent (D) is 0.01 to 5 parts by mass relative to 100 parts by mass of the PAS resin (A). (However, the MFR of the PTFE resin (B) is a value measured at a temperature of 372°C and a load of 2.16 kg.)

[10] The method for producing a PAS resin composition according to [9], wherein the PTFE resin (B) has a perfluorooctanoic acid content of less than 25 ppb.

[11] The method for producing a PAS resin composition according to [9] or

[10] , wherein the PAS resin (A) has a weight average molecular weight of 20,000 to 40,000.

[12] The method for producing a PAS resin composition according to any one of [9] to

[11] , wherein the poly-PTFE resin (B) has an average dispersed particle size of 1.0 to 10 μm.

[13] The method for producing the PAS resin composition according to [9] to

[12] , wherein the tensile elastic modulus of the fibrous filler (C) is 200 to 300 GPa.

[14] The method for producing the PAS resin composition according to [9] to

[13] , wherein the number average fiber length of the fibrous filler (C) is 150 to 250 μm.

[15] The method for producing the PAS resin composition according to [9] to

[14] , wherein the mold release agent (D) is an olefin polymer or a fatty acid ester.

[16] The method for producing a PAS resin molded article, comprising a step of melt-molding the PAS resin composition according to [9] to

[15] .

Effect of the Invention

[0008] According to the present invention, it is possible to provide a PAS resin molded article having both sliding characteristics and mechanical strength, and a resin composition capable of providing the molded article.

Embodiments for Carrying out the Invention

[0009] Hereinafter, an embodiment of the present invention will be described in detail. However, 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. Also, when a plurality of upper limit values and lower limit values are described for specific parameters, any upper limit value and lower limit value can be combined to form a suitable numerical range.

[0010] <Method for Producing PAS Resin> The PAS resin composition according to this embodiment is a PAS resin composition in which a PAS resin (A), a PTFE resin (B), a fibrous filler (C), and a mold release agent (D) are blended as essential components, wherein the melt viscosity (V6) of the PAS resin (A) is 20 to 60 Pa·s, the MFR of the PTFE resin (B) is 1 g / 10 min or less, and the PAS resin composition is characterized in that, with respect to 100 parts by mass of the PAS resin (A), the PTFE resin (B) is 20 to 40 parts by mass, the fibrous filler (C) is 10 to 70 parts by mass, and the mold release agent (D) is 0.01 to 5 parts by mass. The following will be described.

[0011] <PAS resin (A)> The PAS resin composition according to this embodiment is prepared by blending PAS resin (A) as an essential component.

[0012] The PAS resin has a resin structure having a structure in which an aromatic ring and a sulfur atom are bonded as a repeating unit. Specifically, the following general formula (1)

[0013]

Chemical formula

[0014]

Chemical formula

[0015] Here, the structural site represented by the general formula (1) is such that R 1 and R 2 in the formula are preferably hydrogen atoms from the viewpoint of the mechanical strength of the PAS resin. In that case, 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) can be mentioned.

[0016]

Chemical formula

[0017] The PAS resin may contain not only the structural moieties represented by the general formulas (1) and (2) but also the structural moieties represented by the following structural formulas (5) to (8):

[0018] [ka] 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.

[0019] The PAS resin may also have naphthyl sulfide bonds or the like in its molecular structure, but the amount is preferably 3 mol % or less, and particularly preferably 1 mol % or less, of the total number of moles including other structural moieties.

[0020] 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.

[0021] (melt viscosity) The melt viscosity (V6) of the PAS resin (A) used in this embodiment is in the range of 20 to 60 Pa·s, preferably 25 to 50 Pa·s, measured at 300°C, in order to achieve a good balance between processability and toughness. The melt viscosity (V6) is measured using a Shimadzu CFT-500D flow tester at 300°C and a load of 1.96×10. 6 The melt viscosity is measured after holding the sample at a pressure of 10 Pa and L / D=10 (mm) / 1 (mm) for 6 minutes.

[0022] (Weight average molecular weight) The weight-average molecular weight of the PAS resin (A) used in this embodiment is 20,000 to 40,000, more preferably 25,000 to 35,000, from the viewpoints of mechanical strength and sliding properties. The weight-average molecular weight of the PAS resin (A) in this disclosure is the weight-average molecular weight measured using gel permeation chromatography under the following measurement conditions. Six types of monodisperse polystyrene are used for calibration. Equipment: Ultra-high temperature polymer molecular weight distribution measuring device (SSC-7000 manufactured by Senshu Scientific Co., Ltd.) Column: UT-805L (Showa Denko K.K.) Column temperature: 210℃ Solvent: 1-chloronaphthalene Measurement method: UV detector (360 nm)

[0023] (Non-Newtonian exponents) The non-Newtonian index of the PAS resin (A) used in this embodiment is not particularly limited, but is preferably in the range of 0.95 to 1.50. Within this range, the PAS resin composition has excellent mechanical strength. 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 is, and the higher the non-Newtonian index (N value), the more branched the structure is.

[0024]

number

[0025] (Manufacturing method) Methods for producing the PAS resin include, but are not limited to, (Production Method 1) polymerization of a dihalogenoaromatic compound in the presence of sulfur and sodium carbonate, optionally with a polyhalogenoaromatic compound or other copolymerization component; (Production Method 2) polymerization of a dihalogenoaromatic compound in a polar solvent, optionally with a polyhalogenoaromatic compound or other copolymerization component, in the presence of a sulfidizing agent or the like; (Production Method 3) self-condensation of p-chlorothiophenol, optionally with other copolymerization components; and (Production Method 4) melt polymerization of a diiodoaromatic compound and elemental sulfur 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. Among these methods, (Production Method 2) is preferred for its general utility. During the reaction, alkali metal salts of carboxylic acids or sulfonic acids or alkali hydroxides 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 adding a water-containing sulfidizing agent to 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 compound 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 WO2010 / 058713 pamphlet).Specific examples of dihalogenoaromatic compounds 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, 4,4'-di 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.

[0026] 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) a method in which, after the polymerization reaction is completed, the solvent is first distilled off under reduced pressure or normal pressure either as is or after adding an acid or base, and then the solid obtained after the solvent distillation is washed 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, filtration, and drying; or (post-treatment 2) a method in which, after the polymerization reaction is completed, the reaction mixture is treated with 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 PAS). Examples of post-treatment methods include adding a solvent (or an organic solvent with equivalent solubility to the low-molecular-weight polymer) as a precipitant to precipitate solid products such as PAS and inorganic salts, which are then filtered, washed, and dried; (post-treatment 3) adding the reaction solvent (or an organic solvent with equivalent solubility to the low-molecular-weight polymer) to the reaction mixture after the polymerization reaction is complete, stirring, filtering to remove the low-molecular-weight polymer, washing once or twice with a solvent such as water, acetone, methyl ethyl ketone, or alcohols, followed by neutralization, washing with water, filtering, and drying; (post-treatment 4) adding water to the reaction mixture after the polymerization reaction is complete, washing with water, filtering, optionally adding an acid during the water washing, and then drying; and (post-treatment 5) filtering the reaction mixture after the polymerization reaction is complete, washing once or twice or twice with the reaction solvent if necessary, followed by further washing with water, filtering, and drying. Among these methods, (post-treatment 4) is preferred because it yields a PAS resin having carboxyl groups at the molecular terminals.

[0027] 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.

[0028] In the PAS resin composition according to this 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, based on 100 parts by mass of the resin composition. In such a range, it is preferable because the resin composition is excellent in heat resistance and mechanical strength.

[0029] As the PAS resin used in this embodiment, a newly polymerized PAS resin by the above method can be used, or a recycled PAS resin (reclaimed PAS resin) can also be used. The raw material (history) of the recycled PAS resin is not particularly limited, and it may be a post-consumer recycled one (so-called PCR material), or a post-industry recycled one (so-called PIR material). Specifically, examples of the PCR material include molded products containing at least the PAS resin that has been used as a product once, and examples of the PIR material include dust and scraps generated during the production of the PAS resin, dust and scraps generated during the production of a composition containing at least the PAS resin, or sprues or runners generated during the production of a molded product containing at least the PAS resin and those recovered as off-specification molded products. As a method of using these as the recycled PAS resin, for example, a method of pulverizing or crushing the above PIR material or PCR material and using it, or a method of sieving and using it can be mentioned. Also, the PAS resin can be extracted from the above PIR material or PCR material and used. Specifically, in a solution obtained by heating the above PIR material or PCR material in an organic polar solvent to dissolve the contained PAS resin, the PAS resin obtained by performing the above post-treatment can be used. When using a recycled PAS resin, it may contain components other than the PAS resin. However, from the viewpoint of mechanical strength, in 100 parts by mass of the recycled PAS resin, it is preferable that the PAS resin is 90 parts by mass or more, more preferably 95 parts by mass or more, further preferably 98 parts by mass or more, and even more preferably 99 parts by mass or more.

[0030] <PTFE resin (B)> The PAS resin composition according to this embodiment contains a PTFE resin (B) as an essential component. The PTFE resin (B) that can be used in this embodiment has an MFR of 1 g / 10 min or less. The MFR of the PTFE resin (B) in this disclosure is a value measured at a temperature of 372°C and a load of 2.16 kg using a method in accordance with ASTM D1238.

[0031] From an environmental perspective, the PTFE resin (B) used in this embodiment preferably does not substantially contain perfluorooctanoic acid. The perfluorooctanoic acid content is preferably less than 25 ppb by mass per 100 parts by mass of the PTFE resin (B), more preferably 20 ppb by mass or less, even more preferably 15 ppb by mass or less, even more preferably 10 ppb by mass or less, even more preferably less than 10 ppb by mass, even more preferably 1 ppb by mass or less, even more preferably less than 1 ppb by mass, and particularly preferably below the lower limit of quantitation. The perfluorooctanoic acid content of the PTFE resin (B) can be measured by a known method. For example, the resin is crushed, then solvent extracted, and the content is detected by liquid chromatography. More specifically, the measurement can be performed in accordance with the European Committee for Standardization CEN Technical Specification CEN / TS15968.

[0032] The PTFE resin (B) used in this embodiment preferably does not substantially contain perfluorooctane sulfonic acid. "Substantially free of fluorine-containing compounds" means that the amount of perfluorooctane sulfonic acid is 25 mass ppb or less per 100 mass parts of the PTFE resin (B), preferably 20 mass ppb or less, more preferably 15 mass ppb or less, even more preferably 10 mass ppb or less, even more preferably less than 10 mass ppb, even more preferably 1 mass ppb or less, even more preferably less than 1 mass ppb, and particularly preferably less than the lower limit of quantitation. The amount of perfluorooctane sulfonic acid can be measured by a known, commonly used method.

[0033] In the PAS resin composition according to this embodiment, the blending amount of the PTFE resin (B) is 20 to 40 parts by mass, more preferably 20 to 35 parts by mass, and even more preferably 25 to 35 parts by mass, per 100 parts by mass of the PAS resin (A), from the viewpoint of achieving both mechanical strength and sliding properties.

[0034] <Fiber filler (C)> The PAS resin composition according to this embodiment further contains a fibrous filler (C) as an essential component. The fibrous filler (C) applicable to this embodiment is not particularly limited, and known fillers can be used. Examples of fibrous fillers that can be used include glass fiber, carbon fiber, silane glass fiber, ceramic fiber, aramid fiber, metal fiber, potassium titanate, silicon carbide, calcium silicate, wollastonite, and natural fibers.

[0035] From the viewpoint of mechanical strength and sliding properties, the fibrous filler (C) preferably has a tensile modulus of elasticity of 200 to 300 GPa, more preferably 220 to 280 GPa.

[0036] The fibrous filler (C) can also be treated with a surface treatment agent or a sizing agent, if necessary. This is preferable because it improves adhesion to the PAS resin (A) and improves the mechanical strength of the resulting resin composition and molded article. Examples of the surface treatment agent or sizing agent include at least one polymer selected from the group consisting of silane compounds having functional groups such as amino groups, epoxy groups, isocyanate groups, and vinyl groups, titanate compounds, acrylic resins, urethane resins, polyether resins, and epoxy resins. In particular, when glass fibers are used, a urethane resin is preferred in order to prevent excessive defibration during processing. When the surface treatment agent or sizing agent contains a urethane resin, its content is not particularly limited, but is preferably 35% by mass or less, and more preferably 20% by mass or less, in terms of moist heat resistance, etc.

[0037] In the PAS resin composition according to this embodiment, the blending amount of the fibrous filler (C) is 10 to 70 parts by mass, preferably 20 to 70 parts by mass, and more preferably 20 to 60 parts by mass, per 100 parts by mass of the PAS resin (A). This range is preferable because the resin composition has good processability and the molded article has excellent mechanical strength.

[0038] <Release agent (D)> The PAS resin composition according to this embodiment further contains a mold release agent (D) as an essential component.

[0039] As the mold release agent (D), any known material can be used as long as it has the function of accelerating the release of a resin molded article from a mold during melt molding, and examples thereof include olefin polymers such as polyethylene, fatty acid esters, and fatty acid metal salts.

[0040] In the PAS resin composition according to the present embodiment, the blending amount of the release agent (D) is 0.01 to 5 parts by mass, preferably 0.1 to 1.0 part by mass, per 100 parts by mass of the PAS resin (A), which is preferable because the resin composition has good processability and the molded article has excellent mechanical strength within this range.

[0041] In addition to the essential components described above, the PAS resin composition according to this embodiment may optionally contain a non-fibrous filler. Known and commonly used materials can be used as non-fibrous fillers as long as they do not impair the effects of the present invention. Specifically, non-fibrous fillers such as glass flakes, glass beads, barium sulfate, attapulgite, ferrite, boehmite, graphite, carbon black, calcium carbonate, magnesium carbonate, magnesium hydroxide, boron nitride, mica, talc, zeolite, hydrotalcite, silica gel, and alumina can also be used.

[0042] In this embodiment, the non-fibrous filler is not an essential component, but when it is added, its amount is not particularly limited as long as it does not impair the effects of the present invention. The amount of the other filler added is, for example, preferably 1 to 500 parts by mass, more preferably 10 to 400 parts by mass, per 100 parts by mass of the PAS resin (A). This range is preferable because the resin composition exhibits good moldability and the molded product has excellent mechanical properties.

[0043] In addition to the above essential components, the PAS resin composition according to this embodiment can optionally contain a silane coupling agent. The silane coupling agent is not particularly limited as long as it does not impair the effects of the present invention, but preferred examples include silane coupling agents having a functional group that reacts with a carboxy group, such as an epoxy group, an isocyanato group, an amino group, or a hydroxyl group. Examples of such silane coupling agents include epoxy group-containing alkoxysilane compounds such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; isocyanato group-containing alkoxysilane compounds such as γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanatopropylmethyldiethoxysilane, γ-isocyanatopropylethyldimethoxysilane, γ-isocyanatopropylethyldiethoxysilane, and γ-isocyanatopropyltrichlorosilane; amino group-containing alkoxysilane compounds such as γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, and γ-aminopropyltrimethoxysilane; and hydroxyl group-containing alkoxysilane compounds such as γ-hydroxypropyltrimethoxysilane and γ-hydroxypropyltriethoxysilane. Although a silane coupling agent is not an essential component in the present invention, when it is used, its amount is not particularly limited as long as it does not impair the effects of the present invention, and is preferably in the range of 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the PAS resin (A). This range is preferred because the resin composition has good moldability, particularly releasability, and the mechanical strength of the molded article is improved.

[0044] In addition to the essential components described above, the PAS resin composition according to this embodiment may optionally contain a thermoplastic elastomer. Examples of the thermoplastic elastomer 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 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the PAS resin (A). This range is preferred because it improves the impact resistance of the resulting molded article.

[0045] 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 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 the 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 α,β-unsaturated dicarboxylic acids (monoesters, diesters, and acid anhydrides). The thermoplastic elastomers described above may be used alone or in combination of two or more.

[0046] In addition to the essential components described above, the PAS resin composition according to this embodiment may further contain optional synthetic resins (hereinafter simply referred to as 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, polyaryletherketone resins, polyarylate resins, polyethylene resins, polypropylene resins, polystyrene resins, ABS resins, phenolic resins, urethane resins, and liquid crystal polymers, depending on the intended use. While the synthetic resins are not essential components in the present disclosure, when they are included, their proportions are not particularly limited as long as they do not impair the effects of the present invention. Furthermore, the proportions vary depending on the intended purpose and cannot be generally defined; however, examples include a range of 1 to 15 parts by mass per 100 parts by mass of the PAS resin (A).

[0047] The PAS resin composition according to this embodiment may optionally contain known and commonly used additives, such as colorants, antistatic agents, antioxidants, heat stabilizers, UV stabilizers, UV absorbers, foaming agents, flame retardants, flame retardant assistants, and rust inhibitors. These additives are not essential components, and may be used in an amount, for example, of 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 component (A), adjusted appropriately depending on the purpose and application so as not to impair the effects of the present invention.

[0048] In the PAS resin composition according to this embodiment, the average dispersed diameter of the PTFE resin (B) is preferably 1.0 to 10 μm, more preferably 1.2 to 5.0 μm. When the average dispersed diameter of the dispersed phase is 1.0 to 10 μm, the resin composition and its molded article exhibit excellent sliding properties and fluidity. The average dispersed diameter of the PTFE resin (B) in the resin composition according to the present disclosure is a value measured using the method described in the examples.

[0049] The PAS resin composition according to this embodiment preferably has an MFR measured at a temperature of 315°C and a load of 5 kg exceeding 25 g / 10 min, and more preferably 28 g / 10 min or more. In such a range, the resin composition has excellent moldability. From the viewpoint of sliding property, the PAS resin composition according to this embodiment preferably has a coefficient of kinetic friction of 0.30 or less. Also, from the same viewpoint, the specific wear rate is preferably 0.006 or less. The above values in this disclosure are the values measured by the methods described in the examples.

[0050] From the viewpoints of mechanical strength and sliding property, the PAS resin composition according to this embodiment preferably has a number average fiber length of the fibrous filler (C) in the range of 120 to 300 μm, and more preferably in the range of 150 to 250 μm. The number average fiber length of the fibrous filler (C) in the resin composition in this disclosure is the value measured by the method described in the examples.

[0051] <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 having a step of blending a PAS resin (A), a PTFE resin (B), a fibrous filler (C), and a mold release agent (D) as essential components and melt-kneading at a temperature not lower than the melting point of the PAS resin (A), the melt viscosity (V6) of the PAS resin (A) is 20 to 60 Pa·s, the MFR of the PTFE resin (B) is 1 g / 10 min or less, and it is characterized in that the PTFE resin (B) is 20 to 40 parts by mass, the fibrous filler (C) is 10 to 70 parts by mass, and the mold release agent (D) is 0.01 to 5 parts by mass with respect to 100 parts by mass of the PAS resin (A). The following will be described.

[0052] The method for producing a PAS resin composition according to this embodiment includes a step of blending the essential components and melt-kneading them at a temperature above the melting point of the PAS resin (A). More specifically, the PAS resin composition according to this embodiment is composed of 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 include a method of blending the essential components and, if necessary, optional components, and melt-kneading them; more specifically, a method of uniformly dry-mixing them, if necessary, using a tumbler or Henschel mixer, and then feeding them into a twin-screw extruder and melt-kneading them.

[0053] The melt-kneading can be carried out by heating the resin 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.

[0054] From the viewpoints of dispersibility and productivity, the melt-kneading machine 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 components may be added and mixed simultaneously or in portions into the melt-kneading extruder. For example, when adding the essential component PA fiber (B) or other optional fibrous fillers, it is preferable from the viewpoint of dispersibility to feed them into the twin-screw kneading extruder through a side feeder. Regarding the location of the side feeder, 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 preferably 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.

[0055] The PAS resin composition according to this embodiment obtained by melt-kneading as described above is a molten mixture containing the above essential components, optional components added as necessary, and their derived components. Therefore, the PAS resin composition 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. At this time, the average dispersion diameter of the PTFE resin (B) is preferably 1.0 to 10 μm, and more preferably 1.2 to 5.0 μm.

[0056] After the melt-kneading, the PAS resin composition according to this embodiment is processed into forms such as pellets, chips, granules, powders, etc. after extruding the molten resin composition into strands by a known method, for example, and then preferably pre-dried in a temperature range of 100 to 150 °C as necessary.

[0057] <PAS Resin Molded Article, Method for Producing PAS Resin Molded Article> The molded article according to this embodiment is obtained by melt-molding the PAS resin composition. Further, the method for producing 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. Since the PAS resin composition has such a morphology, a molded article excellent in thermal conductivity and mechanical strength can be obtained.

[0058] The PAS resin composition according to this embodiment can be subjected to various molding processes, such as injection molding, compression molding, extrusion molding (e.g., composite, sheet, pipe), 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 conventional methods. 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 above the melting point to 100°C above the melting point, and even more preferably in a range of 20°C above the melting point to 50°C above the melting point, and then injected into a mold through a resin outlet. 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.

[0059] 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 intended use or shape of the molded article. The annealing temperature is preferably in the range of the glass transition temperature of the PAS resin (A) or higher, preferably in the range of the glass transition temperature +10°C or higher, and more preferably in the range of the glass transition temperature +30°C or higher. The annealing time is preferably in the range of 260°C or lower, and more preferably in the range of 240°C or lower. The annealing time is not particularly limited, but is preferably in the range of 0.5 hours or higher, more preferably in the range of 1 hour or higher. The annealing time is preferably in the range of 10 hours or lower, and more preferably in the range of 8 hours or lower. This range is preferable because it reduces distortion in the resulting molded article, improves the crystallinity of the resin, and further improves the thermal conductivity, mechanical strength, and other properties. The annealing treatment may be performed in air, but is preferably performed in an inert gas such as nitrogen gas.

[0060] 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, examples include sprues or runners generated during the production of molded articles, recovered non-standard molded articles, and molded articles once used as products, which are cleaned as necessary, pulverized, and then remolded at a temperature above the melting point of the PAS resin. When recycling, it is preferable to mix the pulverized molded article with the PAS resin composition from the viewpoint of mechanical strength. The size of the pulverized molded article is not particularly limited, but from the viewpoints of mixability and processability, it is preferable that the size be similar to 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.

[0061] <Composition / Applications, etc.> The PAS resin molded articles according to this embodiment have an excellent balance of sliding properties and mechanical properties, making them suitable for use as drive and sliding parts for gears, pumps, valves, etc. Furthermore, the molded articles according to this embodiment can be used not only for the above-mentioned parts but also for the following general applications: For example, protective and support members for box-shaped integrated modules of electric 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 electric and electronic parts such as computer-related parts; VTR parts, television parts, irons, headsets, etc. 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, various valves such as exhaust gas valves, various pipes for fuel, exhaust and intake systems, 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 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 many other applications. [Example]

[0062] The present disclosure will be specifically described below with reference to examples. These examples are illustrative and not limiting. Note that, hereinafter, "%" and "parts" are based on mass unless otherwise specified.

[0063] <Examples 1 to 5 and Comparative Examples 1 to 6> The materials were blended according to the composition and 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 output 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. The fibrous filler 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 for 2 hours in a gear oven at 140°C and then injection-molded to prepare various test pieces, which were then subjected to the following tests.

[0064] <Evaluation>

[0065] (1) Evaluation of sliding characteristics 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 cylindrical test pieces with an inner diameter of 20 mm, an outer diameter of 25.6 mm, and a height of 15.0 mm were obtained using a mold temperature controlled at 140°C. The friction coefficient and specific wear rate [10 -3 [mm 3 The measurement results are shown in Table 1. Friction coefficient Pressure: 150kPa (load 30N) Rotation speed: 0.3 m / s Measurement time: 60 minutes Temperature environment: 23℃ Mating material: Carbon steel S45C Specific wear rate (JIS K7218 A method compliant) Pressure: 1500kPa (load 300N) Rotation speed: 0.5 m / s Measurement time: 100 minutes (sliding distance: 3 km) Temperature environment: 23℃ Mating material: Carbon steel S45C

[0066] (2) Melt viscosity (MFR) measurement (ISO1133-1 compliant) The melt viscosity of the resin compositions obtained in each of the Examples and Comparative Examples was measured using a Toyo Seiki Melt Indexer T-01 with an orifice having an inner diameter of 2.1 mm, an outer diameter of 9.5 mm, and a length of 8.0 mm at a temperature of 315°C and a load of 5 kg. The measurement results are shown in Table 1. The MFR of the polytetrafluoroethylene resin used in the present invention was measured at a temperature of 372°C under a load of 2.16 kg.

[0067] (3) 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 mold controlled at a mold temperature of 140°C to obtain ISO Type-A dumbbell specimens. The resin was injected from a single gate to ensure that the specimens did not contain welds. The tensile strength of the obtained specimens was measured using a measurement method in accordance with ISO 527-1 and 2. The results are shown in Table 1.

[0068] (4) Measurement of Charpy impact strength (3) The central part of the same test piece was cut into a bar of 80 mm in length, 10 mm in width, and 4 mm in thickness, and the Charpy impact strength (kJ / mm) of the test piece with and without notch was measured in accordance with ISO179-1 / 1eA and ISO179-1 / 1eU, respectively. 2 The results are shown in Table 1.

[0069] (5) Measurement of the number average fiber length of fibrous fillers 1 g of pellets of the resin composition obtained in each Example and Comparative Example was placed in a crucible and heated in a muffle furnace at 550°C for 3 hours to incinerate and ash the resin. The resulting ash was dispersed in 1 L of distilled water, and approximately 1 mL of the resulting dispersion was dropped onto a glass Petri dish. With a cover glass overlaid, images were taken at 200x magnification using a Keyence Corporation VHX-8000 video microscope to measure the fiber length. In each Example, the lengths of more than 1,000 fibers were measured to determine the number-average fiber length. The results are shown in Table 1.

[0070] (6) Measurement of the average dispersed diameter of PTFE resin in the resin composition The test piece obtained in (3) was cut perpendicular to the surface, and the exposed cut surface was polished to a smooth surface. It was then photographed at 300x magnification using a Hitachi S-2380N scanning electron microscope. The maximum and minimum diameters of 10 randomly selected PTFE resin dispersed phases were measured from the image, and the average diameter of each dispersed phase was calculated. The average diameter was then calculated to determine the average dispersed diameter. The results are shown in Table 1.

[0071] [Table 1]

[0072] The components in Table 1 were as follows:

[0073] ·PPS resin (A) A-1: DIC.PPS Melt viscosity (V6) 40 Pa·s, weight average molecular weight 30,000, non-Newtonian index 1.07 A-2: DIC.PPS Melt viscosity (V6) 20 Pa·s, weight average molecular weight 25,000, non-Newtonian index 1.05 A-3: DIC.PPS Melt viscosity (V6) 50 Pa·s, weight average molecular weight 33,000, non-Newtonian index 1.07 a-4: DIC.PPS melt viscosity (V6) 70 Pa·s, weight average molecular weight 38,000, non-Newtonian index 1.09 a-5: DIC.PPS melt viscosity (V6) 10 Pa·s, weight average molecular weight 23,000, non-Newtonian index 1.05

[0074] ·PTFE resin (B) B-1: Gujarat Fluorochemicals Limited "INOLUB T201F", MFR 0.5g / 10min (ASTM D1238 372℃ / 2.16kg / 2.095mm), PFOA content less than 25ppb b-2: Kitamura Co., Ltd. "SG-1000", MFR>1g / 10min, PFOA content over 25ppb

[0075] Fibrous filler (C) C-1: PAN-based carbon fiber "TR06YLB6R" manufactured by Mitsubishi Chemical Corporation, elastic modulus 250GPa

[0076] Release agent (D) D-1: Montan acid ester wax "Recorb WE40" manufactured by Clariant Japan Co., Ltd. D-2: High-density polyethylene wax "Luwax AH-6" manufactured by BASF

Claims

1. A polyarylene sulfide resin composition comprising, as essential components, a polyarylene sulfide resin (A), a polytetrafluoroethylene resin (B), a fibrous filler (C), and a release agent (D), The melt viscosity (V6) of the polyarylene sulfide resin (A) is 20 to 60 Pa s, the polytetrafluoroethylene resin (B) has a melt flow rate (MFR) of 1 g / 10 min or less; A polyarylene sulfide resin composition, comprising 20 to 40 parts by mass of the polytetrafluoroethylene resin (B), 10 to 70 parts by mass of the fibrous filler (C), and 0.01 to 5 parts by mass of the release agent (D) relative to 100 parts by mass of the polyarylene sulfide resin (A). (Note that the melt viscosity (V6) of the polyarylene sulfide resin (A) is a value measured after holding it at a temperature of 300°C under a load of 1.96 x 106 Pa for 6 minutes, and the MFR of the polytetrafluoroethylene resin (B) is a value measured at a temperature of 372°C under a load of 2.16 kg.)

2. 2. The polyarylene sulfide resin composition according to claim 1, wherein the polytetrafluoroethylene resin (B) has a perfluorooctanoic acid content of less than 25 ppb.

3. 3. The polyarylene sulfide resin composition according to claim 1, wherein the polyarylene sulfide resin (A) has a weight average molecular weight of 20,000 to 40,000.

4. 3. The polyarylene sulfide resin composition according to claim 1, wherein the polytetrafluoroethylene resin (B) has an average dispersed particle size of 1.0 to 10 μm.

5. 3. The polyarylene sulfide resin composition according to claim 1, wherein the fibrous filler (C) has a tensile modulus of elasticity of 200 to 300 GPa.

6. 3. The polyarylene sulfide resin composition according to claim 1, wherein the number average fiber length of the fibrous filler (C) is 150 to 250 μm.

7. 3. The polyarylene sulfide resin composition according to claim 1, wherein the release agent (D) is an olefin polymer or a fatty acid ester.

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

9. A method for producing a polyarylene sulfide resin composition, comprising a step of blending a polyarylene sulfide resin (A), a polytetrafluoroethylene resin (B), a fibrous filler (C), and a release agent (D) as essential components, and melt-kneading the blended components at a temperature equal to or higher than the melting point of the polyarylene sulfide resin (A), The melt viscosity (V6) of the polyarylene sulfide resin (A) is 20 to 60 Pa s, the polytetrafluoroethylene resin (B) has a melt flow rate (MFR) of 1 g / 10 min or less; A method for producing a polyarylene sulfide resin composition, wherein the polytetrafluoroethylene resin (B) is 20 to 40 parts by mass, the fibrous filler (C) is 10 to 70 parts by mass, and the release agent (D) is 0.01 to 5 parts by mass, relative to 100 parts by mass of the polyarylene sulfide resin (A). (Note that the melt viscosity (V6) of the polyarylene sulfide resin (A) is a value measured after holding it at a temperature of 300°C under a load of 1.96 x 106 Pa for 6 minutes, and the MFR of the polytetrafluoroethylene resin (B) is a value measured at a temperature of 372°C under a load of 2.16 kg.)

10. 10. The method for producing a polyarylene sulfide resin composition according to claim 9, wherein the polytetrafluoroethylene resin (B) has a perfluorooctanoic acid content of less than 25 ppb.

11. The method for producing a polyarylene sulfide resin composition according to claim 9 or 10, wherein the polyarylene sulfide resin (A) has a weight average molecular weight of 20,000 to 40,000.

12. The method for producing a polyarylene sulfide resin composition according to claim 9 or 10, wherein the polytetrafluoroethylene resin (B) has an average dispersed particle size of 1.0 to 10 μm.

13. The method for producing a polyarylene sulfide resin composition according to claim 9 or 10, wherein the fibrous filler (C) has a tensile modulus of elasticity of 200 to 300 GPa.

14. The method for producing a polyarylene sulfide resin composition according to claim 9 or 10, wherein the number average fiber length of the fibrous filler (C) is 150 to 250 μm.

15. The method for producing a polyarylene sulfide resin composition according to claim 9 or 10, wherein the release agent (D) is an olefin polymer or a fatty acid ester.

16. A method for producing a polyarylene sulfide resin molded article, comprising a step of melt-molding the polyarylene sulfide resin composition according to claim 9 or 10.

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