Method for producing recycled polyarylene sulfide resin composition, and recycled polyarylene sulfide resin composition

Abstract

Provided are: a recycled polyarylene sulfide resin composition adhering little dirt to a metal mold during molding; and a method for producing the same. This method for producing a recycled polyarylene sulfide resin composition (Z) comprises: a preparation step for preparing a pulverized product (X) of an article containing 100 parts by mass of a polyarylene sulfide resin (P) and 1-20 parts by mass of an elastomer (Q); and a melt-kneading step for melt-kneading the pulverized product (X) and an antioxidant (Y), the blended amount of the antioxidant (Y) being 0.025-0.25 parts by mass per 1 part by mass of the elastomer (Q) contained in the pulverized product (X).

Description

Method for producing recycled polyarylene sulfide resin composition and recycled polyarylene sulfide resin composition

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

[0002] Toward the creation of a sustainable recycling-based society, technologies for recycling and utilizing plastic waste have been investigated (for example, Patent Document 1). Polyarylene sulfide resins have excellent heat resistance, mechanical properties, chemical resistance, dimensional stability, and flame retardancy, and are therefore widely used as materials for electrical and electronic equipment components, automobile components, chemical equipment components, etc. Therefore, recycling and utilizing materials containing polyarylene sulfide resins can help create a sustainable recycling-based society.

[0003] Japanese Patent Application Laid-Open No. 2022-103152

[0004] When recycling materials containing polyarylene sulfide resins, molded products and parts other than the molded products discarded during molding (hereinafter collectively referred to as "recycled products") are crushed and then re-pelletized into recycled pellets for molding. However, recycled pellets may suffer from matrix polymer decomposition, additive degradation, and filler refinement due to shear stress during crushing of the recycled products, thermal history due to having undergone one or more molding processes, and thermal history during the re-pelletization process. In such cases, changes in fluidity, crystallinity, polarity, etc. may occur compared to virgin materials that have not undergone a molding process. When such recycled pellets are used alone or as mixed pellets with virgin materials, mold deposits and mold fouling are more likely to occur during molding than when virgin materials are used alone. In particular, mold fouling is more likely to occur when the polyarylene sulfide resin contained in the recycled product contains an elastomer. Reducing the amount of recycled pellets used to prevent mold fouling means that only small amounts of recycled material can be effectively used.

[0005] An object of the present disclosure is to provide a recycled polyarylene sulfide resin composition that causes little mold contamination during molding, and a method for producing the same.

[0006] The present disclosure includes the following aspects: <1> A method for producing a recycled polyarylene sulfide resin composition (Z), comprising: preparing a pulverized product (X) of an article containing 100 parts by mass of a polyarylene sulfide resin (P) and 1 to 20 parts by mass of an elastomer (Q); and melt-kneading the pulverized product (X) with an antioxidant (Y) in an amount such that the blending amount of the antioxidant (Y) is 0.025 to 0.25 parts by mass per 1 part by mass of the elastomer (Q) contained in the pulverized product (X). <2> A recycled polyarylene sulfide resin composition (Z) comprising: a pulverized product (X) of an article containing a polyarylene sulfide resin (P) and an elastomer (Q); and an antioxidant (Y), wherein the content of the elastomer (Q) is 1 to 20 parts by mass per 100 parts by mass of the polyarylene sulfide resin (P); and the content of the antioxidant (Y) is 0.025 to 0.25 parts by mass per 1 part by mass of the elastomer (Q).

[0007] According to the present disclosure, it is possible to provide a recycled polyarylene sulfide resin composition that causes little mold contamination during molding, and a method for producing the same.

[0008] FIG. 1 is a schematic diagram of a molded body used in evaluating mold deposits, with the upper side being a top view and the lower side being a cross-sectional view.

[0009] An embodiment of the present disclosure will be described in detail below. However, the scope of the present disclosure is not limited to the embodiment described herein, and various modifications can be made without departing from the spirit of the present disclosure. Each aspect described in this disclosure can be combined with any other feature described in this disclosure. Furthermore, when multiple upper and lower limit values ​​are described for a specific parameter, any of these upper and lower limit values ​​can be combined to form a suitable numerical range. Furthermore, the lower and / or upper limit values ​​of a numerical range described in this disclosure are numerical values ​​within that numerical range and may be replaced with numerical values ​​shown in the examples. The expression "X to Y" indicating a numerical range means "X or more and Y or less." If a specific description described for one embodiment also applies to other embodiments, that description may be omitted in other embodiments.

[0010] [First embodiment: Method for producing recycled polyarylene sulfide resin composition (Z)] The production method according to this embodiment is a method for producing recycled polyarylene sulfide resin composition (Z), and includes the steps of: (1) preparing a pulverized product (X) of an article containing 100 parts by mass of polyarylene sulfide resin (P) and 1 to 20 parts by mass of elastomer (Q) (preparation step); and (2) melt-kneading the pulverized product (X) with an antioxidant (Y) in an amount such that the blending amount of the antioxidant (Y) is 0.025 to 0.25 parts by mass per 1 part by mass of the elastomer (Q) contained in the pulverized product (X) (melt-kneading step).

[0011] As mentioned above, recycled pellets often have changes in fluidity, crystallinity, polarity, etc. compared to virgin pellets. When recycled products contain elastomers, the changes in their physical properties tend to be particularly significant. Therefore, even if a known additive is used, it is difficult to predict its effect when it is added to recycled pellets. In particular, depending on the type and amount of additive, it may cause mold deposits during molding, so the additives to be added to recycled pellets must be carefully selected.

[0012] Therefore, the present inventors investigated using recycled raw materials that already contained an antioxidant as the recycled product in order to suppress mold deposits during recycling. However, the expected effect of suppressing mold fouling was not obtained. After further research, the present inventors discovered that by blending a predetermined amount of antioxidant into the recycled raw materials and melt-kneading them, mold fouling can be suppressed when the resulting recycled pellets are injection-molded, and have completed the present disclosure.

[0013] That is, in this embodiment, a pulverized product (X) of an article containing 100 parts by mass of polyarylene sulfide resin (P) and 1 to 20 parts by mass of elastomer (Q) and an antioxidant (Y) are melt-kneaded together in an amount such that the blending amount of antioxidant (Y) is 0.025 to 0.25 parts by mass per part by mass of elastomer (Q) contained in the pulverized product (X), thereby obtaining a recycled polyarylene sulfide resin composition (Z) that causes little mold contamination during molding.

[0014] In this specification, "recycle" means crushing an article such as a molded body (a recycled product) and recycling it as a raw material for use in manufacturing a molded body, "recycled material" means recycled material, and "recycled pellets" means pellets of recycled material. A "recycled polyarylene sulfide resin composition" is a recycled material containing a polyarylene sulfide resin composition. A "raw material for recycling" means a material (raw material) to be recycled; for example, a recycled product and its crushed material fall under the category of raw material for recycling. In contrast, raw materials not used in manufacturing a molded body (raw materials that have not undergone a molding process) are called "virgin material," pellets of virgin material are called "virgin pellets," and virgin material of polyarylene sulfide resin is called "virgin polyarylene sulfide resin."

[0015] <Preparation Step> In the preparation step, a pulverized product (X) of an article containing 100 parts by mass of a polyarylene sulfide resin (P) and 1 to 20 parts by mass of an elastomer (Q) is prepared. The "article" here refers to an article to be recycled (a recycled product), and may be a molded product or an article that was discharged after being retained in a cylinder for a long period of time during molding. Examples include defective products generated during the manufacturing process of molded products, parts other than the product obtained during injection molding (e.g., runners, sprues, etc.), unused products, and chunks of polyarylene sulfide resin material used as a purge during molding and then discharged. Preferably, the recycled product contains one or more selected from these. In one embodiment, the recycled molded product may be an injection molded product.

[0016] (Polyarylene sulfide resin (P)) The polyarylene sulfide resin (P) may be a virgin polyarylene sulfide resin, or a recycled polyarylene sulfide resin that has been reused one or more times. In one embodiment, the polyarylene sulfide resin (P) preferably comprises a virgin polyarylene sulfide resin. By using an article containing virgin polyarylene sulfide resin or a pulverized product thereof as a raw material for recycling, it is possible to further reduce mold contamination during molding. In one embodiment, the polyarylene sulfide resin (P) preferably comprises a recycled polyarylene sulfide resin. By using an article containing recycled polyarylene sulfide resin as a raw material for recycling, it is easier to create a sustainable recycling-based society.

[0017] The polyarylene sulfide resin is a resin having a repeating unit represented by the following general formula (I): -(Ar-S)- (I) (where Ar represents an arylene group).

[0018] The arylene group is not particularly limited, but examples thereof include a p-phenylene group, an m-phenylene group, an o-phenylene group, a substituted phenylene group, a p,p'-diphenylene sulfone group, a p,p'-biphenylene group, a p,p'-diphenylene ether group, a p,p'-diphenylene carbonyl group, and a naphthalene group.

[0019] The polyarylene sulfide resin can be a homopolymer using the same repeating unit represented by the general formula (I) above, or a copolymer containing different repeating units. A preferred homopolymer has a p-phenylene group as the arylene group, that is, a p-phenylene sulfide group as the repeating unit. This is because homopolymers having a p-phenylene sulfide group as the repeating unit have extremely high heat resistance and exhibit high strength, high rigidity, and high dimensional stability over a wide temperature range. By using such homopolymers, molded articles with excellent physical properties can be obtained.

[0020] As the copolymer, a combination of two or more different arylene sulfide groups among the above-mentioned arylene group-containing arylene sulfide groups can be used. Among these, a combination containing a p-phenylene sulfide group and an m-phenylene sulfide group is preferred from the viewpoint of obtaining a molded product with high physical properties such as heat resistance, moldability, and mechanical properties. A polymer containing 70 to 100 mol% of p-phenylene sulfide groups is more preferred, and a polymer containing 80 to 100 mol% is even more preferred. The polyarylene sulfide resin containing phenylene sulfide groups is a polyphenylene sulfide resin (PPS resin).

[0021] Polyarylene sulfide resins are generally known to have a substantially linear molecular structure without branching or crosslinking, or a structure with branching or crosslinking, depending on the production method thereof. In one embodiment, from the viewpoint of improving the toughness of a molded article, it is more preferable that the polyarylene sulfide resin does not contain a structure with a crosslinking structure.

[0022] In one embodiment, the content of the polyarylene sulfide resin (P) in the pulverized product (X) is preferably 30 to 99% by mass, and more preferably 50 to 95% by mass, based on the total amount of the pulverized product (X). In one embodiment, the total content of the polyarylene sulfide resin (P) and the elastomer (Q) in the resin component contained in the pulverized product (X) is preferably 80 to 100% by mass, and more preferably 90 to 100% by mass, based on the total amount of the resin component. In one embodiment, the resin component contained in the pulverized product (X) may consist only of the polyarylene sulfide resin (P) and the elastomer (Q).

[0023] (Elastomer (Q)) Examples of the elastomer (Q) include olefin-based elastomers, styrene-based elastomers, polyester-based elastomers, and the like, which may be grafted. Preferably, the elastomer (Q) contains at least one selected from these, and may contain, for example, an olefin-based elastomer. Even when the pulverized material (X) contains an elastomer, mold contamination can be suppressed when molding the resulting recycled polyarylene sulfide resin composition (Z).

[0024] The elastomer (Q) may be an elastomer having a reactive functional group, such as an acid-modified elastomer modified with an acid or an acid anhydride, such as (meth)acrylic acid or maleic anhydride; an elastomer using a copolymerizable monomer having a glycidyl group or an epoxy group (glycidyl (meth)acrylate, etc.); or an epoxy-modified elastomer obtained by epoxidizing the unsaturated bond of an elastomer.

[0025] Examples of olefin-based elastomers include copolymers of α-olefins and copolymers of α-olefins and copolymerizable monomers. The α-olefin is preferably one or more selected from α-olefins having 2 to 13 carbon atoms (e.g., ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, etc.). Examples of copolymers of α-olefins and copolymerizable monomers include, but are not limited to, α-olefin-unsaturated carboxylic acid alkyl ester copolymers and olefin-based copolymers containing structural units derived from α-olefins and structural units derived from glycidyl esters of α,β-unsaturated acids. Examples of glycidyl esters of α,β-unsaturated acids include, but are not limited to, acrylic acid glycidyl esters, methacrylic acid glycidyl esters, and ethacrylic acid glycidyl esters. The olefin-based copolymer may further contain structural units derived from (meth)acrylic acid esters. Specific preferred examples of the olefin-based elastomer include ethylene propylene rubber (EPR), ethylene-glycidyl methacrylate copolymer (E-GMA), ethylene-glycidyl methacrylate-methyl acrylate copolymer (E-GMA-MA), etc. The olefin-based elastomer may be contained alone or in combination of two or more kinds.

[0026] Examples of styrene-based elastomers include block copolymers composed of a polymer block mainly composed of a vinyl aromatic compound such as styrene and a polymer block mainly composed of an unhydrogenated and / or hydrogenated conjugated diene compound. Specific preferred examples of styrene-based elastomers include styrene-butadiene rubber (SBR) and styrene-ethylene-butylene-styrene block copolymer (SEBS). Furthermore, the styrene-based elastomer may be a modified copolymer into which a functional group (epoxy group, carboxy group, acid anhydride group, etc.) has been introduced. Examples of modified copolymers include epoxidized styrene-diene copolymers in which the unsaturated bond of the diene has been epoxidized (e.g., epoxidized styrene-diene-styrene block copolymers or hydrogenated polymers thereof). The styrene-based elastomers may be used alone or in combination of two or more.

[0027] Examples of polyester-based elastomers include block copolymers having an aromatic polyester such as polyethylene terephthalate or polybutylene terephthalate as a hard segment and a polyether such as polyethylene glycol or polytetramethylene glycol, or an aliphatic polyester such as polyethylene adipate, polybutylene adipate or polycaprolactone as a soft segment. One type of polyester-based elastomer may be contained alone, or two or more types may be contained in combination.

[0028] When the elastomer (Q) has a reactive functional group, it can enhance the impact resistance and high- and low-temperature impact properties of virgin materials, and can impart toughness. However, during recycling, mold deposits are more likely to occur, and mold contamination is more likely to occur. However, according to the method for producing the recycled polyarylene sulfide resin composition (Z) of this embodiment, even when the pulverized material (X) contains an elastomer (Q) having a reactive functional group, mold contamination during molding can be reduced. In one embodiment, the elastomer (Q) may have a reactive functional group. That is, preparing the pulverized material (X) may include preparing a pulverized material (X) of an article containing an elastomer (Q) having a reactive functional group.

[0029] The term "reactive functional group" as used herein refers to a functional group capable of reacting with an end group of a polyarylene sulfide resin to form a chemical bond at the melting temperature of the resin. Examples of the reactive functional group include a glycidyl group, an epoxy group, a carboxy group, a hydroxyl group, an acid anhydride group, a salt of a carboxy group, a carboxylic acid ester group, an amide group, an amino group, an isocyanate group, an isothiocyanate group, an acetoxy group, a silanol group, an alkoxysilane group, an alkynyl group, an oxazoline group, a thiol group, and a sulfonic acid group. In one embodiment, the elastomer (Q) may include an olefin-based elastomer, a styrene-based elastomer, or a polyester-based elastomer containing one or more groups selected from the group consisting of a glycidyl group, an epoxy group, a carboxy group, a hydroxyl group, an acid anhydride group, a salt of a carboxy group, a carboxylic acid ester group, an amide group, an amino group, an isocyanate group, an isothiocyanate group, an acetoxy group, a silanol group, an alkoxysilane group, an alkynyl group, an oxazoline group, a thiol group, and a sulfonic acid group.

[0030] In one embodiment, the elastomer (Q) may include one or more selected from an olefin-based elastomer including structural units derived from an α-olefin and structural units derived from a glycidyl ester of an α,β-unsaturated acid, and a styrene-based elastomer including an epoxidized styrene-diene copolymer in which the unsaturated bond of the diene has been epoxidized. In one embodiment, the elastomer (Q) may include an elastomer (Q) including structural units derived from an α-olefin and structural units derived from a glycidyl ester of an α,β-unsaturated acid. That is, preparing the ground product (X) may include preparing a ground product (X) of an article including the elastomer (Q) including structural units derived from an α-olefin and structural units derived from a glycidyl ester of an α,β-unsaturated acid.

[0031] In one embodiment, when the elastomer has a reactive functional group, the content of the reactive functional group may be 0.1 to 10 mass %, or may be 0.5 to 8 mass %, of the total amount of the elastomer. The content of the reactive functional group can be calculated from the manufacturer's catalog value of the copolymer composition and the molecular weight of the functional group.

[0032] The content of the elastomer (Q) in the pulverized material (X) is 1 to 20 parts by mass, preferably 2 to 15 parts by mass, more preferably 3 to 10 parts by mass, and even more preferably 3 to 8.5 parts by mass, per 100 parts by mass of the polyarylene sulfide resin (P). In one embodiment, the content of the elastomer (Q) in the pulverized material (X) may be 6.2 parts by mass per 100 parts by mass of the polyarylene sulfide resin (P). In all aspects, these values ​​may be combined to form the upper or lower limit of a numerical range. The elastomer content may be the value listed in the product manufacturer's catalog. The elastomer content may also be measured by thermogravimetry.

[0033] In one embodiment, the ground material (X) may contain 1 to 20% by mass, 2 to 18% by mass, or 3 to 16% by mass of the elastomer having a reactive functional group, based on the total amount of the ground material (X).

[0034] (Other Components) In addition to the polyarylene sulfide resin (P) and elastomer (Q), the pulverized material (X) may contain other components contained in the recycled molded article. Examples of other components that the pulverized material (X) may contain include organic or inorganic fillers, and other additives generally added to thermoplastic resins (e.g., flame retardants, colorants such as dyes and pigments, stabilizers such as UV absorbers, lubricants, crystallization accelerators, crystal nucleating agents, etc.).

[0035] Examples of organic or inorganic fillers include fibrous fillers such as glass fibers, carbon fibers, zinc oxide fibers, titanium oxide fibers, wollastonite, silica fibers, silica-alumina fibers, alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, boron fibers, potassium titanate fibers, stainless steel fibers, aluminum fibers, titanium fibers, copper fibers, brass fibers, polyamides, high molecular weight polyethylene, aramids, fluororesins, polyester resins, and acrylic resins, and other high-melting point organic fibrous substances; carbon black, graphite, silica, quartz powder, glass beads, Examples of fillers include milled glass fiber, glass balloons, glass powder, talc (granular), silicates such as calcium silicate, aluminum silicate, and diatomaceous earth, metal oxides such as iron oxide, titanium oxide, zinc oxide, and granular alumina, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, and powdery and granular fillers such as silicon carbide, silicon nitride, boron nitride, and various metal powders; and plate-like fillers such as mica, glass flakes, talc (plate-like), mica, kaolin, clay, alumina (plate-like), and various metal foils. In terms of mechanical strength, heat resistance, etc., it is preferable to contain an inorganic filler.

[0036] The content of the organic or inorganic filler in the pulverized material (X) is preferably from 10 to 70% by mass, more preferably from 15 to 65% by mass, and even more preferably from 20 to 60% by mass.

[0037] The pulverized material (X) may or may not contain an antioxidant. According to the production method of this embodiment, in either case, a recycled polyarylene sulfide resin composition can be obtained that causes less mold contamination during molding. When the pulverized material (X) contains an antioxidant, it may be the same type as the antioxidant (Y), or a different type. When the pulverized material (X) contains an antioxidant, the content thereof may be, for example, 0.05 to 2.0% by mass, 0.1 to 1.0% by mass, or 0.1 to 0.5% by mass, relative to the total amount (100% by mass) of the pulverized material (X).

[0038] (Pulverized Product (X)) From the viewpoint of reducing interference with the screw and / or torque of the extruder when producing recycled pellets, the average particle diameter of the pulverized product (X) is preferably 0.3 to 20 mm, more preferably 0.4 to 15 mm, even more preferably 1 to 10 mm, even more preferably 1 to 5 mm, and particularly preferably 1 to 3 mm. The average particle diameter of the pulverized product (X) is the volume-based cumulative 50% diameter (D50) measured by a laser diffraction scattering method. In one embodiment, preparing the pulverized product (X) preferably includes preparing a pulverized product (X) having an average particle diameter of 0.3 to 20 mm.

[0039] The melt viscosity of the pulverized material (X) is not limited as long as it does not impair the effects of the present disclosure, and is preferably 310°C and a shear rate of 1200 sec. －１ The melt viscosity may be 10 to 1000 Pa·s, or 30 to 700 Pa·s, for example, using a known capillary rheometer, using a 1 mmφ×20 mmL flat die as a capillary, at a barrel temperature of 310° C. and a shear rate of 1000 sec －１ It can be measured by

[0040] The method for pulverizing the article is not limited, and can be performed by a known method using, for example, a jet mill, a roller mill, a high-speed rotary pulverizer, a container-driven mill, etc. The preparation step may, if necessary, include classifying the pulverized product (X) by sieving or the like.

[0041] <Melt-Kneading Step> In the melt-kneading step, the pulverized material (X) and the antioxidant (Y) are melt-kneaded in an amount such that the blending amount of the antioxidant (Y) is 0.025 to 0.25 parts by mass per part by mass of the elastomer (Q) contained in the pulverized material (X). By melt-kneading the antioxidant (Y) with the pulverized material (X) in the above blending amount, it is possible to suppress mold fouling when molding the obtained recycled pellets.

[0042] (Antioxidant (Y)) Examples of the antioxidant (Y) include phenolic antioxidants, phosphorus-based antioxidants, and thioether-based antioxidants. The antioxidant (Y) preferably contains one or more selected from the group consisting of these, and more preferably contains a phenolic antioxidant. The antioxidant (Y) may be used alone or in combination of two or more. In one embodiment, the melt-kneading preferably includes melt-kneading the pulverized material (X) with one or more antioxidants (Y) selected from the group consisting of phenolic antioxidants, phosphorus-based antioxidants, and thioether-based antioxidants.

[0043] Examples of phenolic antioxidants include compounds having one or more alkylphenol groups in their molecular structure. Preferred phenolic antioxidants are compounds having a phenyl group substituted with a hydroxyl group (—OH) and a tert-butyl group. Among these, compounds having two or more tert-butyl groups per phenolic hydroxyl group are more preferred. Specific examples of phenolic antioxidants include 2,6-di-tert-butyl-p-cresol, stearyl-(3,5-dimethyl-4-hydroxybenzyl)thioglycolate, stearyl-β-(4-hydroxy-3,5-di-tert-butylphenyl)propionate, distearyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, and distearyl(4-hydroxy-3-methyl-5-tert-butyl)benzyl. malonate, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4,4'-methylenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol], bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butylic acid]glycol ester, 4,4'-butylidenebis(6-tert-butyl-m-cresol), 1,1,3- Tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris[(3,5-di-te tert-butyl-4-hydroxyphenyl)propionyloxyethyl] isocyanurate, 2-octylthio-4,6-di(4-hydroxy-3,5-di-tert-butyl)phenoxy-1,3,5-triazine, 4,4'-thiobis(6-tert-butyl-m-cresol), triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexyldiol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,4-bis-octylthio-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine, 2,2-thio-diethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 3,5-di-tert-butyl Examples of suitable phenolic antioxidants include isooctyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris-(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 2,4-bis[(octylthio)methyl]-o-cresol. Phenolic antioxidants may be used alone or in combination of two or more.

[0044] Examples of phosphorus-based antioxidants include tetrakis(2,4-di-tert-butylphenyl)-4,4'-bisphenylene phosphonite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,4-di-butylphenyl)pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl)phosphite, 4,4'-[bis(2,4-di-tert-butyl-5-methylphenoxy)-phosphino]biphenyl, tris(nonylphenyl)phosphite, and distearylpentaerythritol diphosphat. Examples of the phosphorus-based antioxidant include phosphate, triphenyl phosphite, diphenyl alkyl phosphite, tridecyl phosphite, trioctyl phosphite, cyclic neopentane tetrale-bis(octadecyl phosphite), 3,5-di-butyl-4-hydroxybenzyl phosphonate diethyl ester, triphenyl phosphine, tridodecyl phosphine, tripropyl phosphine, trioctyl phosphine, tetraalkyl phosphonium halides, tetraalkyl phosphonium sulfonate chlorides, bis(4-tert-butylphenyl) phosphate sodium salt, etc. One type of phosphorus-based antioxidant may be used alone, or two or more types may be used in combination.

[0045] The thioether antioxidants include compounds having at least one thioether bond in their molecular structure. Specific examples of the thioether antioxidants include tetrakis[methylene-3-(dodecylthio)propionate]methane, dilauryl-3,3'-thiodipropionate, and distearyl-3,3'-thiodipropionate. The thioether antioxidants may be used alone or in combination of two or more.

[0046] The amount of antioxidant (Y) blended is preferably 0.026 to 0.20 parts by mass, more preferably 0.027 to 0.15 parts by mass, even more preferably 0.028 to 0.10 parts by mass, and particularly preferably 0.030 to 0.085 parts by mass, per part by mass of elastomer (Q) contained in the pulverized material (X). In one embodiment, the amount of antioxidant (Y) blended may be 0.05 parts by mass per part by mass of elastomer (Q) contained in the pulverized material (X). In all aspects, these numerical values ​​may be combined to form the upper or lower limit of the above numerical range.

[0047] (Melt-Kneading) The melt-kneading temperature is a temperature equal to or higher than the melting point of the pulverized material (X), and is generally preferably 280 to 360°C, more preferably 290 to 350°C.

[0048] The mixing method is not particularly limited as long as it can uniformly mix the pulverized material (X) and the antioxidant (Y), and examples thereof include a melt-kneading method using a conventional melt-kneading device such as a single-screw or twin-screw extruder. After melt-kneading and extruding the components, the resulting recycled polyarylene sulfide resin composition (Y) can be processed into a desired form such as powder, flakes, or pellets.

[0049] [Second embodiment: Recycled polyarylene sulfide resin composition (Z)] The recycled polyarylene sulfide resin composition (Z) according to this embodiment comprises a pulverized product (X) of an article containing a polyarylene sulfide resin (P) and an elastomer (Q), and an antioxidant (Y), wherein the content of the elastomer (Q) is 1 to 20 parts by mass per 100 parts by mass of the polyarylene sulfide resin (P), and the content of the antioxidant (Y) is 0.025 to 0.25 parts by mass per part by mass of the elastomer (Q).

[0050] Since the content of the antioxidant (Y) is 0.025 to 0.25 parts by mass per part by mass of the elastomer (Q), mold contamination during molding is reduced. The types and contents of the polyarylene sulfide resin (P), elastomer (Q), pulverized material (X), and antioxidant (Y), as well as the method for producing the recycled polyarylene sulfide resin composition (Z), are as described above.

[0051] The content of the elastomer (Q) is 1 to 20 parts by mass, preferably 2 to 15 parts by mass, more preferably 3 to 10 parts by mass, and even more preferably 3 to 8.5 parts by mass, per 100 parts by mass of the polyarylene sulfide resin (P). In one embodiment, the content of the elastomer (Q) may be 6.2 parts by mass per 100 parts by mass of the polyarylene sulfide resin (P). In all aspects, these values ​​may be combined to form the upper or lower limit of the above numerical range. The content of the elastomer (Q) in the recycled polyarylene sulfide resin composition (Z) can be measured, for example, by thermogravimetry.

[0052] The content of the antioxidant (Y) is preferably 0.026 to 0.20 parts by mass, more preferably 0.027 to 0.15 parts by mass, even more preferably 0.028 to 0.10 parts by mass, and particularly preferably 0.030 to 0.085 parts by mass, per 100 parts by mass of the elastomer (Q). In one embodiment, the amount of the antioxidant (Y) may be 0.05 parts by mass per part by mass of the elastomer (Q) contained in the pulverized material (X). In all aspects, these values ​​may be combined to form the upper or lower limit of the above-mentioned numerical range. The content of the antioxidant (Y) in the recycled polyarylene sulfide resin composition (Z) can be measured, for example, by GC / MS, LC / MS, X-ray fluorescence analysis, etc.

[0053] In one embodiment, the elastomer (Q) may have a reactive functional group. In one embodiment, the elastomer (Q) may include an elastomer (Q) containing structural units derived from an α-olefin and structural units derived from a glycidyl ester of an α,β-unsaturated acid. The reactive functional group and the like are also as described above. The other descriptions regarding the elastomer (Q) in the first embodiment also apply here.

[0054] In one embodiment, the melt viscosity of the recycled polyarylene sulfide resin composition (Z) is not limited as long as it does not impair the effects of the present disclosure, and is preferably 310°C and a shear rate of 1200 sec.－１ The melt viscosity measured by the method may be 10 to 1000 Pa·s, or 30 to 700 Pa·s. The method for measuring the melt viscosity is as described in the section on the pulverized product (X).

[0055] The recycled polyarylene sulfide resin composition (Z) may contain other components that can generally be blended into thermoplastic resins. Examples of other components include organic or inorganic fillers, and other additives generally added to thermoplastic resins (e.g., flame retardants, colorants such as dyes and pigments, stabilizers such as UV absorbers, lubricants, crystallization accelerators, crystal nucleating agents, etc.). Examples of organic or inorganic fillers include those exemplified as organic or inorganic fillers that may be contained in the pulverized material (X).

[0056] The method for producing the recycled polyarylene sulfide resin composition (Z) is as described above. The form of the recycled polyarylene sulfide resin composition (Z) is not limited and may be in any desired form such as powder, flakes, pellets, etc.

[0057] In one embodiment, the recycled polyarylene sulfide resin composition (Z) has a mold deposit of preferably 0 to 45 μg, more preferably 0 to 40 μg, even more preferably 0 to 35 μg, and particularly preferably 0 to 30 μg, measured by the following method. <Measurement method> Using a nested mold with a detachable vent portion and cavity portion, the molded article shown in FIG. 1 is continuously molded for 4 hours (1,000 times) using an injection molding machine under the following conditions. Before and after continuous molding, the total weight of the vent portion and cavity portion removed from the mold is measured, and the total weight change of the vent portion and cavity portion before and after continuous molding is taken as the weight of the deposit on the mold. <Injection molding conditions> Cylinder temperature: 340°C Injection time: 2 seconds Cooling time: 10 seconds Mold temperature: 140°C

[0058] (Applications) The recycled polyarylene sulfide resin composition (Z) can suppress mold contamination during molding, so it can be suitably used as a resin composition for injection molding or a resin composition for extrusion molding. The above-mentioned recycled polyarylene sulfide resin composition (Z) can be mixed with other thermoplastic resins as needed and used as a molding material. Examples of other thermoplastic resins include virgin polyarylene sulfide resins, and preferably virgin polyarylene sulfide resins or virgin polyarylene sulfide resin compositions.

[0059] [Third embodiment: Manufacturing method of recycled material-virgin material mixed resin composition (W)] The manufacturing method according to this embodiment is a manufacturing method of recycled material-virgin material mixed resin composition (W), and includes mixing the recycled polyarylene sulfide resin composition (Z) manufactured by the manufacturing method of the recycled polyarylene sulfide resin composition (Z) described above with virgin polyarylene sulfide resin or its composition (V). By mixing with virgin polyarylene sulfide resin or its composition (V), the excellent physical properties of the polyarylene sulfide resin can be reinforced. The manufacturing method of the recycled polyarylene sulfide resin composition (Z) and the recycled polyarylene sulfide resin composition (Z) are as described above, so description will be omitted here.

[0060] As described above, virgin polyarylene sulfide resin is a virgin polyarylene sulfide resin. Examples of virgin polyarylene sulfide resin compositions include compositions containing virgin polyarylene sulfide resin and, if necessary, other components. Examples of polyarylene sulfide resins containing virgin polyarylene sulfide resins or their compositions (V) include those described for the recycled polyarylene sulfide resin composition (Z) above. From the perspective of quality control, it is preferable that the composition be the same as the polyarylene sulfide resin in the recycled polyarylene sulfide resin composition (Z). Examples of other components include compounds similar to the other components that may be contained in the recycled polyarylene sulfide resin composition (Z), elastomers, antioxidants, etc. If the virgin polyarylene sulfide resin or its composition (V) is a composition, it is preferable that the composition be the same as the recycled polyarylene sulfide resin composition (Z) from the perspective of quality control, etc. (for example, the type and content of additives are the same).

[0061] The amount of recycled polyarylene sulfide resin composition (Z) is preferably 50% by mass or more, more preferably 50 to 99.99% by mass, and even more preferably 60 to 100% by mass, relative to the total amount (100% by mass) of recycled polyarylene sulfide resin composition (Z) and virgin polyarylene sulfide resin or its composition (V), in order to increase the amount of recycled material used. Even if the amount of recycled polyarylene sulfide resin composition (Z) is increased, a recycled material-virgin material mixed resin composition (W) with less mold contamination during molding can be obtained.

[0062] The mixing method is not limited, and the recycled polyarylene sulfide resin composition (Z) and the virgin polyarylene sulfide resin or its composition (V) may be dry blended, melt-kneaded using a conventional melt-kneading device such as a single-screw or twin-screw extruder, or mixed in the hopper (material supply member) of an injection molding machine. The resulting recycled material-virgin material mixed resin composition (W) can be processed into a desired form such as powder, flakes, or pellets.

[0063] [Fourth embodiment: recycled material-virgin material mixed resin composition (W)] The recycled material-virgin material mixed resin composition (W) according to this embodiment contains the recycled polyarylene sulfide resin composition (Z) described above and a virgin polyarylene sulfide resin or composition thereof (V). By including the virgin polyarylene sulfide resin or composition thereof (V), the excellent physical properties of the polyarylene sulfide resin can be reinforced. The recycled polyarylene sulfide resin composition (Z) and the virgin polyarylene sulfide resin or composition thereof (V) are as described in the section on the manufacturing method of the recycled material-virgin material mixed resin composition (W) above.

[0064] In order to increase the amount of recycled material used, the content of the recycled polyarylene sulfide resin composition (Z) is preferably 50% by mass or more, more preferably 50 to 99.99% by mass, and even more preferably 60 to 100% by mass, based on the total amount of the recycled polyarylene sulfide resin composition (Z) and the virgin polyarylene sulfide resin or composition thereof (V). The recycled material-virgin material mixed resin composition (W) causes little mold contamination during molding, even when the content of the recycled polyarylene sulfide resin composition (Z) is high.

[0065] In one embodiment, the total content of the recycled polyarylene sulfide resin composition (Z) and the virgin polyarylene sulfide resin or a composition thereof is preferably 80 to 100% by mass, more preferably 90 to 100% by mass, even more preferably 95 to 100% by mass, and even more preferably 100% by mass, relative to the total amount (100% by mass) of resin components contained in the recycled material-virgin material mixed resin composition (W).

[0066] In one embodiment, the melt viscosity of the recycled material-virgin material mixed resin composition (W) is not limited as long as it does not impair the effects of the present disclosure, and is preferably 310°C and 1200 sec. －１ The melt viscosity measured by the method may be 10 to 1000 Pa·s, or 30 to 700 Pa·s. The method for measuring the melt viscosity is as described in the section on the pulverized product (X).

[0067] The recycled material-virgin material mixed resin composition (W) may contain other components that can generally be blended into thermoplastic resins. Examples of other components include organic or inorganic fillers, and other additives that are generally added to thermoplastic resins (e.g., flame retardants, colorants such as dyes and pigments, stabilizers such as UV absorbers, lubricants, crystallization accelerators, crystal nucleating agents, etc.). Examples of organic or inorganic fillers include those exemplified as organic or inorganic fillers that may be contained in the ground material (X). The form of the recycled material-virgin material mixed resin composition (W) is not limited and may be in any desired form, such as powder, flakes, or pellets.

[0068] (Uses) The recycled material-virgin material mixed resin composition (W) can suppress mold contamination during molding, and therefore can be suitably used as a resin composition for injection molding or a resin composition for extrusion molding.

[0069] [Fifth embodiment: recycled molded product] The recycled molded product according to this embodiment is a molded product containing the above-described recycled polyarylene sulfide resin composition (Z). The method for producing the recycled molded product is not limited, and the recycled polyarylene sulfide resin composition (Z) can be produced by using the recycled polyarylene sulfide resin composition (Z) together with other thermoplastic resins and additives as necessary, and performing known injection molding, profile / solidification extrusion processing, press molding, spinning, etc. The recycled polyarylene sulfide resin composition (Z) causes little mold contamination during molding, so the number of mold replacements can be reduced, and the productivity of recycled molded products can be improved.

[0070] Sixth Embodiment: Method for Suppressing Mold Fouling This embodiment of the method is a method for suppressing mold fouling during molding of a recycled polyarylene sulfide resin composition (Z) obtained from a pulverized product (X) containing 100 parts by mass of a polyarylene sulfide resin (P) and 1 to 20 parts by mass of an elastomer (Q). The method includes melt-kneading the pulverized product (X) with an antioxidant (Y) in an amount such that the antioxidant (Y) is present in an amount of 0.025 to 0.25 parts by mass per part by mass of the elastomer (Q) contained in the pulverized product (X). Melt-kneading the pulverized product (X) with the antioxidant (Y) in a predetermined amount suppresses mold fouling during molding. The polyarylene sulfide resin (P), elastomer (Q), pulverized product (X), and antioxidant (Y) are as described above.

[0071] [Seventh Embodiment: Use of Antioxidant (Y)] This embodiment uses an antioxidant (Y) to suppress mold fouling during molding of a recycled polyarylene sulfide resin composition (Z) obtained from a pulverized product (X) of an article containing 100 parts by mass of a polyarylene sulfide resin (P) and 1 to 20 parts by mass of an elastomer (Q). The method includes melt-kneading the antioxidant (Y) with the pulverized product (X) in an amount of 0.025 to 0.25 parts by mass of the antioxidant (Y) per part by mass of the elastomer (Q) contained in the pulverized product (X). Melting and kneading the antioxidant (Y) with the pulverized product (X) in a predetermined amount can suppress mold fouling during molding. The polyarylene sulfide resin (P), elastomer (Q), pulverized product (X), and antioxidant (Y) are as described above.

[0072] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of the present disclosure is disclosed below. [1] A method for producing a recycled polyarylene sulfide resin composition (Z), comprising: preparing a pulverized product (X) of an article containing 100 parts by mass of a polyarylene sulfide resin (P) and 1 to 20 parts by mass of an elastomer (Q); and melt-kneading the pulverized product (X) with an antioxidant (Y) in an amount such that the antioxidant (Y) is blended in an amount of 0.025 to 0.25 parts by mass per part by mass of the elastomer (Q) contained in the pulverized product (X). [2] The production method according to [1], wherein preparing the pulverized product (X) comprises preparing a pulverized product (X) of an article containing the elastomer (Q) having a reactive functional group. [3] The manufacturing method according to [1] or [2], wherein preparing the pulverized material (X) comprises preparing a pulverized material (X) of an article comprising the elastomer (Q) containing structural units derived from an α-olefin and structural units derived from a glycidyl ester of an α,β-unsaturated acid. [4] The manufacturing method according to any one of [1] to [3], wherein preparing the pulverized material (X) comprises preparing the pulverized material (X) having an average particle size of 0.3 to 20 mm. [5] The manufacturing method according to any one of [1] to [4], wherein the melt-kneading comprises melt-kneading the pulverized material (X) with one or more antioxidants (Y) selected from the group consisting of phenolic antioxidants, phosphorus-based antioxidants, and thioether-based antioxidants. [6] A method for producing a recycled material-virgin material mixed resin composition (W), comprising mixing a recycled polyarylene sulfide resin composition (Z) produced by the method according to any one of [1] to [5] with a virgin polyarylene sulfide resin or a composition thereof (V). [7] A recycled polyarylene sulfide resin composition (Z), comprising: a pulverized product (X) of an article comprising a polyarylene sulfide resin (P) and an elastomer (Q); and an antioxidant (Y), wherein the content of the elastomer (Q) is 1 to 20 parts by mass per 100 parts by mass of the polyarylene sulfide resin (P); and the content of the antioxidant (Y) is 0.025 to 0.25 parts by mass per part by mass of the elastomer (Q).[8] The recycled polyarylene sulfide resin composition (Z) according to [7], wherein the elastomer (Q) has a reactive functional group. [9] A recycled-virgin mixed resin composition (W) comprising the recycled polyarylene sulfide resin composition (Z) according to [7] or [8] and a virgin polyarylene sulfide resin or composition thereof (V).

[10] The recycled-virgin mixed resin composition (W) according to [9], wherein the content of the recycled polyarylene sulfide resin composition (Z) is 50% by mass or more relative to the total amount of the recycled polyarylene sulfide resin composition (Z) and the virgin polyarylene sulfide resin or composition thereof (V).

[11] A method for suppressing mold fouling during molding of a recycled polyarylene sulfide resin composition (Z) obtained from a pulverized product (X) of an article containing 100 parts by mass of a polyarylene sulfide resin (P) and 1 to 20 parts by mass of an elastomer (Q), the method comprising melt-kneading the pulverized product (X) with an antioxidant (Y) in an amount such that the blending amount of the antioxidant (Y) is 0.025 to 0.25 parts by mass per part by mass of the elastomer (Q) contained in the pulverized product (X).

[12] Use of an antioxidant (Y) for suppressing mold fouling during molding of a recycled polyarylene sulfide resin composition (Z) obtained from a pulverized product (X) of an article containing 100 parts by mass of a polyarylene sulfide resin (P) and 1 to 20 parts by mass of an elastomer (Q), the use comprising melt-kneading the antioxidant (Y) with the pulverized product (X) in an amount such that the blending amount of the antioxidant (Y) is 0.025 to 0.25 parts by mass per part by mass of the elastomer (Q) contained in the pulverized product (X).

[0073] The configurations and combinations thereof in the above-described embodiments are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible as appropriate within the scope that does not deviate from the gist of this disclosure.

[0074] The present disclosure will be explained in more detail below by showing examples, but interpretation of the present disclosure is not limited to these examples.

[0075] [Materials] (Pulverized product (X1): pulverized product of injection-molded product not containing antioxidant) Polyphenylene sulfide (PPS) resin (manufactured by Kureha Corporation, Fortron (registered trademark) KPS) 65% by mass, glass fiber (GF) 30% by mass, and elastomer (composition: E-GMA-MA (glycidyl methacrylate content: 3% by mass)) 4% by mass, the remainder is other additives containing resin composition A (however, an injection-molded product of not containing an antioxidant) was pulverized by a mechanical pulverizer to obtain a pulverized material (pulverized product (X1)) having an average particle diameter D50 of 3 mm. The content ratio of each component relative to 100 parts by mass of polyarylene sulfide resin in the pulverized product (X1) is shown in Table 1 as "Composition of Resin Composition A".

[0076] (Pulverized product (X2): pulverized product of injection-molded product containing antioxidant) Polyphenylene sulfide (PPS) resin (manufactured by Kureha Corporation, Fortron (registered trademark) KPS) 64.8% by mass, glass fiber (GF) 30% by mass, elastomer (composition: E-GMA-MA (glycidyl methacrylate content: 3% by mass)) 4% by mass, and antioxidant 0.2% by mass, the remainder was an injection-molded product of resin composition B containing other additives, was pulverized by a mechanical pulverizer to obtain a pulverized material (pulverized product (X2)) having an average particle diameter D50 of 3 mm. The content ratio of each component relative to 100 parts by mass of polyarylene sulfide resin in the pulverized product (X2) is shown in Table 1 as "Composition of resin composition B".

[0077] (Antioxidant (Y)) Tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, IRGANOX 1010 (product name), manufactured by BASF Japan Ltd.

[0078] [Example 1] 20 g of antioxidant (Y) (0.05 parts by mass per part by mass of the elastomer in the pulverized material (X1)) was added to 10 kg of the pulverized material (X1) and dry-blended. This mixture was fed into a twin-screw extruder with a cylinder temperature of 320°C and melt-kneaded to obtain pellets (recycled pellets) of the recycled polyarylene sulfide resin composition (Z) of Example 1.

[0079] Comparative Example 1 The pulverized material (X1) was charged into a twin-screw extruder having a cylinder temperature of 320°C and melt-kneaded to obtain pellets (recycled pellets) of the recycled polyarylene sulfide resin composition of Comparative Example 1.

[0080] [Comparative Example 2] The pulverized material (X2) was fed into a twin-screw extruder having a cylinder temperature of 320°C and melt-kneaded to obtain pellets (recycled pellets) of the recycled polyarylene sulfide resin composition of Comparative Example 2. [Reference Example 1] For Reference Example 1, virgin pellets of the above-mentioned polyarylene sulfide resin composition A (containing no antioxidant) were used.

[0081] Reference Example 2 In Reference Example 2, virgin pellets of the polyarylene sulfide resin composition B (containing an antioxidant) were used.

[0082] [Evaluation of Mold Adhesion] A nested mold with detachable vent and cavity sections was used. Each recycled pellet and the virgin pellets of the Reference Example were used in the injection molding machine and under the conditions below to continuously mold molded articles having the dimensions and shape shown in Figure 1 for 4 hours (1,000 times). The total weight of the vent and cavity sections removed from the mold was measured before and after continuous molding. The change in the total weight of the vent and cavity sections before and after continuous molding was calculated as the weight (μg) of the material adhering to the mold. The results are shown in Table 1. Injection molding machine: FANUC ROBOSHOT S2000i30A Cylinder temperature: 340°C Injection time: 2 seconds Cooling time: 10 seconds Mold temperature: 140°C

[0083]

[0084] As shown in Table 1, the amount of material adhering to the mold when the recycled pellets of Example 1 were used was 27 μg. In contrast, the amount of material adhering to the mold when the recycled pellets of Comparative Example 1 were used was 69 μg, and the amount of material adhering to the mold when the recycled pellets of Comparative Example 2 were used was 57 μg. The amount of material adhering to the mold when the virgin pellets of Reference Example 1 were used was 51 μg, and the amount of material adhering to the mold when the virgin pellets of Reference Example 2 were used was 31 μg.

[0085] The recycled pellets of Example 1 resulted in less mold fouling than the virgin pellets of Reference Examples 1 and 2, and were able to reduce mold fouling by about 40% compared to the recycled pellets of Comparative Example 1, which did not contain an antioxidant (i.e., reduced mold fouling by about 60%). Furthermore, compared to the recycled pellets of Comparative Example 2, mold fouling was reduced by about 47% (i.e., reduced mold fouling by about 53%). In contrast, the recycled pellets of Comparative Example 1 resulted in more mold fouling than the virgin pellets of Reference Example 1. The recycled pellets of Comparative Example 2 resulted in more mold fouling than the virgin pellets of Reference Example 2, and also more mold fouling than the virgin pellets of Reference Example 1. These results demonstrate that recycled pellets cause worse mold fouling than virgin pellets, and that even when the recycled product contains an antioxidant, the effect of reducing mold fouling is low.

[0086] The method for producing a recycled polyarylene sulfide resin composition of this embodiment can suppress mold contamination during molding, and therefore has industrial applicability as a method for producing a resin composition for injection molding or a resin composition for extrusion molding.

Claims

1. A method for producing a recycled polyarylene sulfide resin composition (Z), comprising: preparing a pulverized product (X) of an article containing 100 parts by mass of a polyarylene sulfide resin (P) and 1 to 20 parts by mass of an elastomer (Q); and melt-kneading the pulverized product (X) with an antioxidant (Y) in an amount such that the amount of the antioxidant (Y) is 0.025 to 0.25 parts by mass per 1 part by mass of the elastomer (Q) contained in the pulverized product (X).

2. The manufacturing method according to claim 1, wherein preparing the ground material (X) includes preparing a ground material (X) of an article comprising the elastomer (Q) having a reactive functional group.

3. The method according to claim 1 or 2, wherein preparing the pulverized material (X) includes preparing a pulverized material (X) of an article comprising the elastomer (Q) that contains structural units derived from an α-olefin and structural units derived from a glycidyl ester of an α,β-unsaturated acid.

4. The manufacturing method according to claim 1 or 2, wherein preparing the pulverized material (X) includes preparing the pulverized material (X) having an average particle size of 0.3 to 20 mm.

5. The method according to claim 1 or 2, wherein the melt-kneading step comprises melt-kneading the ground material (X) with one or more of the antioxidants (Y) selected from the group consisting of phenol-based antioxidants, phosphorus-based antioxidants, and thioether-based antioxidants.

6. A method for producing a recycled material-virgin material mixed resin composition (W), comprising mixing a recycled polyarylene sulfide resin composition (Z) produced by the method described in claim 1 or 2 with a virgin polyarylene sulfide resin or a composition thereof (V).

7. A recycled polyarylene sulfide resin composition (Z) comprising: a pulverized product (X) of an article containing a polyarylene sulfide resin (P) and an elastomer (Q); and an antioxidant (Y), wherein the content of the elastomer (Q) is 1 to 20 parts by mass per 100 parts by mass of the polyarylene sulfide resin (P); and the content of the antioxidant (Y) is 0.025 to 0.25 parts by mass per 1 part by mass of the elastomer (Q).

8. The recycled polyarylene sulfide resin composition (Z) according to claim 7, wherein the elastomer (Q) has a reactive functional group.

9. A recycled material-virgin material mixed resin composition (W) comprising the recycled polyarylene sulfide resin composition (Z) according to claim 7 or 8 and a virgin polyarylene sulfide resin or composition thereof (V).

10. The recycled material-virgin material mixed resin composition (W) according to claim 9, wherein the content of the recycled polyarylene sulfide resin composition (Z) is 50 mass% or more based on the total amount of the recycled polyarylene sulfide resin composition (Z) and the virgin polyarylene sulfide resin or composition thereof (V).

11. A method for suppressing mold contamination during molding of a recycled polyarylene sulfide resin composition (Z) obtained from a pulverized product (X) of an article containing 100 parts by mass of a polyarylene sulfide resin (P) and 1 to 20 parts by mass of an elastomer (Q), the method comprising melt-kneading the pulverized product (X) with an antioxidant (Y) in an amount such that the amount of the antioxidant (Y) is 0.025 to 0.25 parts by mass per part by mass of the elastomer (Q) contained in the pulverized product (X).

12. Use of an antioxidant (Y) for suppressing mold fouling during molding of a recycled polyarylene sulfide resin composition (Z) obtained from a pulverized product (X) of an article containing 100 parts by mass of a polyarylene sulfide resin (P) and 1 to 20 parts by mass of an elastomer (Q), the use comprising melt-kneading the antioxidant (Y) with the pulverized product (X) in an amount such that the blending amount of the antioxidant (Y) is 0.025 to 0.25 parts by mass per part by mass of the elastomer (Q) contained in the pulverized product (X).