WO2025187661A1 - Poly(arylene sulfide) resin composition for recycle materials - Google Patents

Abstract

Provided is a poly(arylene sulfide) resin composition which, during recycling, can be inhibited from forming burrs. The poly(arylene sulfide) resin composition (X) for recycle materials comprises (A) 100 parts by mass of a linear poly(arylene sulfide) resin having a carboxy group and (B) 0.3-10 parts by mass of an alkoxysilane compound.

Description

Polyarylene sulfide resin composition for recycled materials

This disclosure relates to a polyarylene sulfide resin composition for recycled materials.

In order to build a sustainable, circular society, technologies are being considered to recycle and utilize plastic waste.
Polyarylene sulfide resins, typified by polyphenylene sulfide resins, are excellent in 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 build a sustainable recycling-oriented society.
However, polyarylene sulfide resins have a problem in that burrs are frequently generated during injection molding, even when virgin pellets that have never been subjected to a molding process are used (for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2006-45451

When recycling materials containing polyarylene sulfide resin, molded products and items that were ejected after remaining in the cylinder for a long time during molding (hereinafter collectively referred to as "recycled products") are crushed and used as recycled material, and if necessary, further re-pelletized before being injection molded again. However, recycled materials may have decomposed matrix polymers, deteriorated additives, and pulverized fillers due to shearing when crushing the recycled products and the thermal history caused by having been through the molding process one or more times. In such cases, flashing is more pronounced than when virgin pellets that have not been through the molding process are injection molded.

The objective of the present disclosure is to provide a polyarylene sulfide resin composition that can suppress the generation of burrs during recycling.

The present disclosure includes the following aspects.
(1) (A) 100 parts by mass of a linear polyarylene sulfide resin having a carboxy group;
(B) A polyarylene sulfide resin composition (X) for recycled materials, comprising: 0.3 to 10 parts by mass of an alkoxysilane compound.
(2) (A) 100 parts by mass of a polyarylene sulfide resin having a carboxy group;
(B) A recycled material (R) of a polyarylene sulfide resin composition containing 0.3 to 10 parts by mass of an alkoxysilane compound.
(3) obtaining a pulverized product of a molded product of a polyarylene sulfide resin composition (X) containing (A) 100 parts by mass of a polyarylene sulfide resin having a carboxy group and (B) 0.3 to 10 parts by mass of an alkoxysilane compound;
and melt-kneading the recycled material containing the pulverized material at 260 to 380°C to obtain a recycled material.

This disclosure provides a polyarylene sulfide resin composition that can suppress the generation of burrs during recycling.

One embodiment of the present disclosure will be described in detail below, but the scope of the present disclosure is not limited to the embodiment described herein, and various modifications may be made without departing from the spirit of the present disclosure. Each aspect disclosed in this specification can be combined with any other feature disclosed in this specification. Furthermore, when multiple upper and lower limit values are listed for a particular 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 "greater than or equal to X and less than or equal to Y." If a specific description given for one embodiment also applies to other embodiments, that description may be omitted in other embodiments.

[Polyarylene sulfide resin composition (X)]
The polyarylene sulfide resin composition (X) according to the present disclosure (hereinafter also simply referred to as "resin composition (X)") is a polyarylene sulfide resin composition (X) for recycled materials, and contains (A) 100 parts by mass of a linear polyarylene sulfide resin having a carboxy group, and (B) 0.3 to 10 parts by mass of an alkoxysilane compound. The "polyarylene sulfide resin composition" means a composition containing a polyarylene sulfide resin.

Among polyarylene sulfide resins, linear polyarylene sulfide resins that do not have branches in their chemical structure are susceptible to decomposition of the main chain and a decrease in molecular weight when heated and melted in a pelletizing process or molding process. Therefore, when an article containing a linear polyarylene sulfide resin is crushed and then re-injected into injection molding or the like as a recycled material, the burrs tend to become longer than when virgin pellets that have never been subjected to a molding process are used.
On the other hand, branched polyarylene sulfide resins having branches in their chemical structure are expected to be able to suppress burrs during molding because they tend to maintain a high molecular weight even when heated. Therefore, a small amount of ultra-high molecular weight gel-like branched polyarylene sulfide resin, which tends to maintain a high molecular weight, is sometimes added to linear polyarylene sulfide resins as a burr suppressant. However, even when a branched polyarylene sulfide resin is added as a burr suppressant, it was found that although burrs were suppressed in injection-molded virgin materials, the burr length increased when the product was crushed after one molding process and then injection-molded again. Therefore, the present inventors conducted extensive research into polyarylene sulfide resin compositions that can suppress burrs even during recycling. The present inventors were surprised to find that by adding a predetermined amount of (B) an alkoxysilane compound to (A) a linear polyarylene sulfide resin having carboxy groups, burrs can be suppressed even when the product is crushed after a molding process and then injection-molded again, resulting in the completion of the present invention. Although the mechanism is not clear at this stage, one non-limiting mechanism is that by incorporating a predetermined amount of an alkoxysilane compound, when the polyarylene sulfide resin is heated and melted in the re-pelletizing process or the injection molding process during recycling, the main chain of the polyarylene sulfide resin is decomposed and, in parallel, the reaction between the carboxy groups of the polyarylene sulfide resin and the alkoxysilane compound proceeds, thereby increasing the degree of crosslinking of the polyarylene sulfide resin. It is believed that the increased degree of crosslinking of the polyarylene sulfide resin increases or maintains the molecular weight of the polyarylene sulfide resin, thereby suppressing burrs.

"Recycled material" means a material obtained by crushing an article such as a molded body (a recycled product) and recycling it as a material for use in manufacturing molded bodies. The term "recycled material of a polyarylene sulfide resin composition" can include crushed articles containing a polyarylene sulfide resin composition, as well as repelletized materials made by crushing crushed articles. "For recycled material" means that the material is used to manufacture recycled material.

In contrast, raw materials not used in the production of molded products (raw materials that have not undergone the molding process) are called "virgin materials," virgin materials for polyarylene sulfide resin are called "virgin polyarylene sulfide resin," and virgin materials for polyarylene sulfide resin compositions are called "virgin polyarylene sulfide resin compositions."

((A) Linear Polyarylene Sulfide Resin Having Carboxy Group)
The polyarylene sulfide resin is a resin having a repeating unit represented by the following general formula (I).
-(Ar-S)-...(I)
(wherein Ar represents an arylene group.)

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

Polyarylene sulfide resins can be homopolymers using the same repeating units represented by the general formula (I) above, or copolymers containing different types of repeating units. Homopolymers with a p-phenylene sulfide group as the repeating unit, which has a p-phenylene group as the arylene group, are preferred. This is because homopolymers with 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. Using such homopolymers makes it possible to obtain molded articles with excellent physical properties.

For copolymers, a combination of two or more different arylene sulfide groups containing the above-mentioned arylene groups can be used. Of these, a combination containing a p-phenylene sulfide group and an m-phenylene sulfide group is preferred from the perspective of obtaining a molded product with excellent physical properties such as heat resistance, moldability, and mechanical properties. Polymers containing 70 mol% or more of p-phenylene sulfide groups are more preferred, and polymers containing 80 mol% or more are even more preferred. A polyarylene sulfide resin containing phenylene sulfide groups is a polyphenylene sulfide resin (PPS resin).

Polyarylene sulfide resins are generally known to have a substantially linear molecular structure without branching or crosslinking (hereinafter referred to as "straight-chain"), or a structure with branching or crosslinking (hereinafter referred to as "branched"), depending on the manufacturing method. The polyarylene sulfide resin composition (X) for recycled materials according to the present disclosure contains at least (A) a linear polyarylene sulfide resin having a carboxy group.

By including (A) a linear polyarylene sulfide resin having a carboxy group, the carboxy group reacts with the (B) alkoxysilane compound described below when the resin is re-pelletized and/or re-injection molded, thereby suppressing the occurrence of burrs during recycling. The presence of carboxy groups in the linear polyarylene sulfide resin can be confirmed by FT-IR measurement.

The carboxy group content in (A) linear polyarylene sulfide resin having carboxy groups is preferably 5 to 100 μmol/g, more preferably 7 to 70 μmol/g, and even more preferably 10 to 50 μmol/g. By having a carboxy group content of 5 to 100 μmol/g in (A) linear polyarylene sulfide resin having carboxy groups, the reaction with (B) alkoxysilane compound, described below, proceeds more easily, making it easier to suppress the generation of burrs during recycling.

The amount of carboxy groups can be measured as follows. That is, using FT-IR, the peak heights of the absorption peak of the benzene ring of benzoic acid and the absorption peak of the carboxy group are measured, and the relative intensity of the absorption peak of the carboxy group to the C-H bond of the benzene ring is measured. From the relative intensity, the content (mol %) of carboxy groups relative to the benzene ring is calculated. The amount of carboxy groups contained in 1 kg of resin composition is calculated from the amount of repeating units -(Ar-S)- (Ar is a benzene ring) contained in 1 kg of resin composition.

(A) A method for producing a linear polyarylene sulfide resin having carboxy groups includes, for example, polymerizing a linear polyarylene sulfide resin using a monomer capable of constituting the above structural unit, followed by washing with an acidic aqueous solution of appropriate acidity. In this case, acids used in the acidic aqueous solution include inorganic acids such as hydrochloric acid, sulfuric acid, and ammonium chloride; saturated fatty acids such as acetic acid, formic acid, propionic acid, butyric acid, valeric acid, and caproic acid; unsaturated fatty acids such as acrylic acid, crotonic acid, and oleic acid; aromatic carboxylic acids such as benzoic acid, phthalic acid, and salicylic acid; dicarboxylic acids such as oxalic acid, maleic acid, and fumaric acid; methanesulfonic acid and paratoluenesulfonic acid. Among these, hydrochloric acid, acetic acid, and ammonium chloride are preferred. Before or after washing with the acidic aqueous solution, the resin may be washed with an organic solvent such as acetone or with water, as needed.

(A) Another example of a method for producing a linear polyarylene sulfide resin having a carboxy group is a method in which a linear polyarylene sulfide resin is polymerized using a monomer having a carboxy group as a monomer that can constitute the above-mentioned structural unit. In this case, too, washing with an acidic aqueous solution of appropriate acidity after polymerization is preferable. For example, a method in which the polymerized monomer is one or more monomers having one or more carboxy groups selected from p-phenylene group, m-phenylene group, o-phenylene group, substituted phenylene group, p,p'-diphenylene sulfone group, p,p'-biphenylene group, p,p'-diphenylene ether group, p,p'-diphenylenecarbonyl group, and naphthalene group is used.

The polyarylene sulfide resin composition (X) for recycled materials may contain a linear polyarylene sulfide resin other than the linear polyarylene sulfide resin (A) having a carboxy group, or may contain a branched polyarylene sulfide resin.
In one embodiment, from the viewpoint of increasing the reactivity with the (B) alkoxysilane compound, from the viewpoint of easily obtaining a molded article having excellent appearance, and/or from the viewpoint of preventing a decrease in moldability due to the incorporation of the (B) alkoxysilane compound, the content of the (A) linear polyarylene sulfide resin having a carboxy group in the total amount (100% by mass) of the polyarylene sulfide resin contained in the polyarylene sulfide resin composition for recycled material (X) is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 95% by mass or more, and particularly preferably 98% by mass or more. In one embodiment, the polyarylene sulfide resin contained in the polyarylene sulfide resin composition for recycled material (X) preferably consists solely of the (A) linear polyarylene sulfide resin having a carboxy group.

The content of (A) linear polyarylene sulfide resin having carboxy groups in the resin components (100% by mass) contained in polyarylene sulfide resin composition (X) for recycled materials is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 95% by mass or more, and particularly preferably 98% by mass or more. In one embodiment, the resin components contained in polyarylene sulfide resin composition (X) for recycled materials preferably consist solely of (A) linear polyarylene sulfide resin having carboxy groups.

The content of the linear polyarylene sulfide resin having a carboxy group (A) in the polyarylene sulfide resin composition for recycled materials (X) (100% by mass) is preferably 30% by mass or more, and more preferably 35% by mass or more.
In one embodiment, from the viewpoint of further shortening the burr length during recycling, the content of the linear polyarylene sulfide resin (A) having a carboxy group in the polyarylene sulfide resin composition (X) for recycled material (100% by mass) is preferably 30 to 50% by mass, more preferably 35 to 45% by mass.
In another embodiment, from the viewpoint of further suppressing the occurrence of burrs compared to injection-molded articles made of virgin material, the content of the linear polyarylene sulfide resin (A) having a carboxy group in the polyarylene sulfide resin composition (X) for recycled material (100% by mass) is preferably 50% by mass or more, more preferably more than 50% by mass, and even more preferably 55 to 70% by mass.

From the viewpoint of improving moldability and toughness, the melt viscosity of the polyarylene sulfide resin composition (X) for recycled materials is preferably 20 to 600 Pa·s, more preferably 50 to 500 Pa·s, and even more preferably 100 to 400 Pa·s.

The temperature-decreasing crystallization temperature (Tc) of the (A) linear polyarylene sulfide resin having a carboxy group is preferably 215° C. or higher, more preferably greater than 215° C., even more preferably 216° C. or higher, still more preferably 217° C. or higher, and particularly preferably 218° C. or higher. When the (A) polyarylene sulfide resin has a temperature-decreasing crystallization temperature (Tc) of 215° C. or higher, the impact strength of the molded article can be further increased.
The upper limit of the temperature-lowering crystallization temperature (Tc) of the polyarylene sulfide resin (A) is preferably 260°C or lower, more preferably 250°C or lower, and particularly preferably 240°C or lower.

The cooling crystallization temperature (Tc) is the peak exothermic temperature associated with crystallization observed when (A) a linear polyarylene sulfide resin having carboxy groups is heated to 340°C using a differential scanning calorimeter, melted, and then cooled at a rate of 10°C/min.

Methods for increasing the temperature-decreasing crystallization temperature (Tc) of (A) linear polyarylene sulfide resin having carboxy groups include, but are not limited to, adjusting the molecular weight of (A) linear polyarylene sulfide resin having carboxy groups, and washing the polymer after polymerization with an acidic aqueous solution of appropriate acidity. In this case, examples of the acid used in the acidic aqueous solution include those described above in the method for introducing carboxy groups. If the molecular weight of (A) linear polyarylene sulfide resin having carboxy groups is low, the temperature-decreasing crystallization temperature (Tc) is likely to be high. Therefore, if the temperature-decreasing crystallization temperature (Tc) is too low, the temperature-decreasing crystallization temperature (Tc) can be increased by blending (A) linear polyarylene sulfide resin having carboxy groups with a low molecular weight.

((B) Alkoxysilane Compound)
The polyarylene sulfide resin composition (X) for recycled materials contains an alkoxysilane compound (B). By containing the alkoxysilane compound (B), it is possible to obtain a polyarylene sulfide resin composition that can suppress the generation of burrs during recycling.

(B) The alkoxysilane compound preferably contains one or more alkoxysilane compounds having one or more groups selected from the group consisting of an epoxy group, an amino group, a vinyl group, a (meth)acrylic group, an isocyanate group, and a mercapto group.

In one embodiment, the alkoxysilane compound (B) is preferably represented by the following formula (II):
R ¹ _n Si(OR ² ) _4-n (II)
In formula (II), ^R1 is an alkyl group having 1 to 18 carbon atoms (preferably 1 to 10 carbon atoms) and having an epoxy group, an amino group, a vinyl group, a (meth)acrylic group, an isocyanate group, or a mercapto group; ^R2 is an alkyl group having 1 to 4 carbon atoms; and n is an integer of 1 to 3.

(B) Examples of alkoxysilane compounds include alkoxysilanes such as epoxyalkoxysilanes, aminoalkoxysilanes, vinylalkoxysilanes, (meth)acrylicalkoxysilanes, isocyanatealkoxysilanes, and mercaptoalkoxysilanes, and it is preferable to include one or more of these. The alkoxy group preferably contains 1 to 10 carbon atoms, and particularly preferably 1 to 4 carbon atoms.

Examples of epoxyalkoxysilanes include γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and γ-glycidoxypropyltriethoxysilane.

Examples of aminoalkoxysilanes include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-diallylaminopropyltrimethoxysilane, and γ-diallylaminopropyltriethoxysilane.

Examples of vinylalkoxysilanes include vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris(β-methoxyethoxy)silane.

(Meth)acrylalkoxysilanes include, for example, gamma-acryloxypropyltriethoxysilane, gamma-acryloxypropyltrimethoxysilane, gamma-methacryloxypropyltriethoxysilane, gamma-methacryloxypropyltrimethoxysilane, gamma-methacryloxypropylmethyldimethoxysilane, and gamma-methacryloxypropylmethyldiethoxysilane.

Examples of isocyanate alkoxysilanes include gamma-isocyanate propyl triethoxysilane and gamma-isocyanate propyl trimethoxysilane.

Examples of mercaptoalkoxysilanes include γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane.

Of these, epoxyalkoxysilanes and aminoalkoxysilanes are more preferred, with gamma-aminopropyltriethoxysilane being particularly preferred.

The content of the (B) alkoxysilane compound is 0.3 to 10 parts by mass, preferably 0.6 to 8 parts by mass, and more preferably 0.7 to 4.5 parts by mass, per 100 parts by mass of the (A) linear polyarylene sulfide resin having a carboxy group. By having the (B) alkoxysilane compound content of 0.3 to 10 parts by mass per 100 parts by mass of the (A) linear polyarylene sulfide resin having a carboxy group, a polyarylene sulfide resin composition can be obtained that can suppress the generation of burrs during recycling. Furthermore, a polyarylene sulfide resin composition with excellent moldability during recycling can be obtained.

In one embodiment, from the viewpoint of further shortening the length of burrs generated during recycling, the content of the (B) alkoxysilane compound is preferably more than 1.0 part by mass and not more than 10 parts by mass, more preferably 1.1 to 4.5 parts by mass, even more preferably 1.3 to 2.0 parts by mass, and particularly preferably 1.4 to 1.8 parts by mass, per 100 parts by mass of the (A) linear polyarylene sulfide resin having carboxy groups.

In another embodiment, from the viewpoint of further suppressing the occurrence of burrs compared to virgin material, the content of the (B) alkoxysilane compound is preferably 0.3 to 1.4 parts by mass, more preferably 0.6 to 1.3 parts by mass, even more preferably 0.7 to 1.2 parts by mass, and particularly preferably 0.8 to 1.1 parts by mass per 100 parts by mass of the (A) linear polyarylene sulfide resin having a carboxy group.

((C) Inorganic Filler)
The polyarylene sulfide resin composition (X) for recycled materials preferably contains an inorganic filler (C). By containing the inorganic filler (C), the mechanical strength of a recycled product obtained by injection molding the recycled material can be increased.

(C) Examples of inorganic fillers include (C1) fibrous inorganic fillers, (C2) plate-like inorganic fillers, and (C3) granular inorganic fillers, and it is preferable to include one or more selected from these.

(C1) Examples of fibrous inorganic fillers include glass fiber, carbon fiber, zinc oxide fiber, titanium oxide fiber, wollastonite, silica fiber, silica-alumina fiber, alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, stainless steel fiber, aluminum fiber, titanium fiber, copper fiber, and brass fiber. (C1) Fibrous inorganic fillers may be used alone or in combination of two or more.

(C2) Examples of plate-like inorganic fillers include mica, glass flakes, talc (plate-like), mica, kaolin, clay, alumina (plate-like), and various metal foils. (C2) Plate-like inorganic fillers may be used alone or in combination of two or more.

(C3) Examples of granular inorganic fillers include carbon black, graphite, silica, quartz powder, glass beads, 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 alumina (granular), metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, as well as silicon carbide, silicon nitride, boron nitride, and various metal powders. (C3) granular inorganic fillers may be used alone or in combination of two or more.

In one embodiment, the (C) inorganic filler preferably contains (C1) a fibrous inorganic filler, from the viewpoint of easily increasing the impact strength of a recycled product obtained by injection molding the recycled material.
Examples of the (C1) fibrous inorganic filler include (C1a) a fibrous inorganic filler having a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of 3.0 or more (hereinafter, also referred to simply as "(C1a) fibrous inorganic filler"), and (C1b) a fibrous inorganic filler having a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of less than 3.0, less than 2.0, or 1.5 or less (hereinafter, also referred to simply as "(C1b) fibrous inorganic filler").

The "major axis of a cross section perpendicular to the longitudinal direction" is the longest linear distance in a cross section perpendicular to the longitudinal direction of the fiber, and the "minor axis of a cross section perpendicular to the longitudinal direction" is the longest linear distance in a direction perpendicular to the major axis in that cross section. The diameter difference ratio refers to the diameter difference ratio of the initial shape (the shape before melt-kneading). The diameter difference ratio can be calculated using a scanning electron microscope and image processing software, and is the arithmetic average value measured for 10 (C1a) fibrous inorganic fillers. The diameter difference ratio can also be the manufacturer's value (a value published by the manufacturer in a catalog, etc.).

In one embodiment, the inorganic filler (C) preferably includes, as the fibrous inorganic filler (C1), a fibrous inorganic filler (C1a) having a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of 3.0 or more. By including the fibrous inorganic filler (C1a) in the polyarylene sulfide resin composition (X) for recycled materials, the impact strength of recycled products obtained by injection molding the recycled materials can be increased.

The diameter ratio of the (C1a) fibrous inorganic filler is 3.0 or more, preferably 3.5 or more, and more preferably 3.8 or more. The upper limit of the diameter ratio is 10.0 or less, preferably 8.0 or less, and more preferably 6.0 or less.

(C1a) Examples of fibrous inorganic fillers include fibrous inorganic fillers whose cross-sectional shape perpendicular to the longitudinal direction of the fiber is oval, semicircular, cocoon-shaped (an oval shape with a portion of the longitudinal direction recessed inward), rectangular, or similar shapes.

The major axis of the cross section perpendicular to the longitudinal direction of the fibrous inorganic filler (C1a) is preferably 10 to 40 μm, more preferably 20 to 30 μm.
The minor axis of the cross section perpendicular to the longitudinal direction of the fibrous inorganic filler (C1a) is preferably 1 to 20 μm, more preferably 3 to 10 μm.
The major axis and minor axis of the cross section perpendicular to the longitudinal direction can be calculated using a scanning electron microscope and image processing software, and are the arithmetic mean values measured for 10 pieces of (C1a) fibrous inorganic filler. Furthermore, the major axis and minor axis of the cross section perpendicular to the longitudinal direction can also be manufacturer values (values published by the manufacturer in a catalogue or the like).

In one embodiment, the content of (C1a) fibrous inorganic filler in the (C) inorganic filler, which has a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of 3.0 or more, is preferably 50 to 100 mass %, more preferably 80 to 100 mass % or more, and even more preferably 90 to 100 mass % or more, based on the total amount (100 mass %) of the (C) inorganic filler. In one embodiment, the (C) inorganic filler can also be configured to consist solely of (C1a) fibrous inorganic filler, which has a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of 3.0 or more.

From the perspective of further increasing the impact strength of recycled products obtained by injection molding recycled materials, the average fiber length (cut length) of (C1) fibrous inorganic filler before melt-kneading into the resin composition is preferably 0.01 to 3.5 mm, more preferably 0.05 to 3.5 mm, even more preferably 0.1 to 3.5 mm, and particularly preferably 0.5 to 3 mm. The average fiber length can be calculated using a scanning electron microscope and image processing software, and is the arithmetic average value measured for 1,000 pieces of (C1) fibrous inorganic filler. The average fiber length can also be determined by the manufacturer (a value published by the manufacturer in a catalog, etc.).

From the viewpoint of ease of production, the cross-sectional area of the (C1) fibrous inorganic filler is preferably 1×10 ⁻⁵ to 1×10 ⁻³ mm ² , and more preferably 1×10 ⁻⁴ to 5×10 ⁻⁴ mm ^2. The "cross-sectional area" can be calculated by multiplying the value obtained by dividing the longest linear distance of the cross section of the (C1) fibrous inorganic filler by 2, where the longest linear distance is the major axis and the shortest linear distance is the minor axis, and then multiplying the value obtained by dividing the minor axis by 2 by pi. The cross-sectional area is the arithmetic average value measured for 10 pieces of (C1) fibrous inorganic filler.

(C) The inorganic filler may be surface-treated with various commonly known surface treatment agents such as epoxy compounds, isocyanate compounds, silane compounds, titanate compounds, and fatty acids. Surface treatment can improve adhesion to (A) the linear polyarylene sulfide resin having a carboxy group. The surface treatment agent may be applied to (C) the inorganic filler in advance to perform surface treatment or convergence treatment before preparing the material, or may be added simultaneously during material preparation. If (C) the inorganic filler has been surface-treated with an alkoxysilane compound, the content of (B) the alkoxysilane compound described above does not include the content of the alkoxysilane compound derived from the surface treatment agent.

From the viewpoint of making it easier to increase the mechanical strength of recycled products obtained by injection molding recycled materials, the content of (C) inorganic filler is preferably 30 to 250 parts by mass, more preferably 35 to 200 parts by mass, even more preferably 38 to 180 parts by mass, and particularly preferably 40 to 160 parts by mass per 100 parts by mass of (A) polyarylene sulfide resin having carboxy groups.

In one embodiment, from the viewpoint of increasing mechanical strength while also making it easier to shorten the length of burrs generated during recycling, the content of (C) inorganic filler is preferably 90 to 250 parts by mass, more preferably 100 to 200 parts by mass, even more preferably 120 to 180 parts by mass, and particularly preferably 130 to 170 parts by mass per 100 parts by mass of (A) linear polyarylene sulfide resin having carboxy groups.

In another embodiment, from the viewpoint of increasing mechanical strength while further suppressing the occurrence of burrs compared to virgin material, the content of (C) inorganic filler is preferably 30 to 90 parts by mass, more preferably 35 to 85 parts by mass, even more preferably 38 to 80 parts by mass, and particularly preferably 40 to 75 parts by mass per 100 parts by mass of (A) linear polyarylene sulfide resin having carboxy groups.

(Other ingredients)
The polyarylene sulfide resin composition (X) for recycled materials can contain known additives generally added to thermoplastic resins and thermosetting resins to impart desired properties according to the intended purpose, as long as the effects of the present invention are not impaired. Examples of additives include burr inhibitors, release agents, lubricants, plasticizers, flame retardants, colorants such as dyes and pigments, crystallization accelerators, crystal nucleating agents, various antioxidants, heat stabilizers, weathering stabilizers, and corrosion inhibitors. The content of these other components is preferably 5% by mass or less of the total resin composition.

The polyarylene sulfide resin composition (X) for recycled materials can also be used in small amounts of other auxiliary thermoplastic resin components depending on the purpose. The other thermoplastic resins used here can be any resin stable at high temperatures. Examples include aromatic polyesters composed of aromatic dicarboxylic acids and diols or oxycarboxylic acids, such as polyethylene terephthalate and polybutylene terephthalate, polyamides, polycarbonates, ABS, polyphenylene oxide, polyalkyl acrylates, polysulfones, polyethersulfones, polyetherimides, polyether ketones, fluororesins, liquid crystal polymers, and cyclic olefin copolymers. Two or more of these thermoplastic resins can also be used in combination. The content of the other thermoplastic resin components is preferably 20% by mass or less of the total amount (100% by mass) of the polyarylene sulfide resin composition (X) for recycled materials. The content of other thermoplastic resin components in the resin components constituting the polyarylene sulfide resin composition (X) for recycled materials is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

(Method for producing polyarylene sulfide resin composition (X) for recycled materials)
The method for producing the polyarylene sulfide resin composition (X) for recycled materials is not particularly limited, and it can be produced by melt-kneading the above-mentioned components by a known method. For example, any of a method in which the components are mixed and then kneaded and extruded in an extruder to prepare pellets, a method in which pellets with different compositions are first prepared, a predetermined amount of the pellets are mixed, and molded to obtain a molded product of the desired composition after molding, and a method in which one or more of the components are directly charged into a molding machine can be used.

The polyarylene sulfide resin composition (X) for recycled materials is an injection-molded product having dimensions of 80 mm length x 80 mm width x 1.0 mm thickness, which is injection-molded at a cylinder temperature of 320°C and a mold temperature of 150°C, and mechanically pulverized until the average particle diameter (D50) is 3 mm. The pulverized product (recycled material) has a burr length (L _R ) measured under the following condition (1) of preferably 140 μm or less, more preferably 130 μm or less, even more preferably 110 μm or less, and particularly preferably 100 μm or less.
<Condition (1)>
Using a mold with a disk-shaped cavity and a flash measurement section with a mold gap of 20 μm provided on the periphery, injection molding is performed at a cylinder temperature of 320° C., a mold temperature of 150° C., and the minimum pressure required to completely fill the cavity. The length of the flash generated in the flash measurement section is measured under magnification using an image projector.
The average particle size (D50) is the volume-based average particle size (D50) measured by a laser diffraction scattering method. When the burr length (L _R ) is 140 μm or less, the generation of burrs during recycling is further suppressed.

The polyarylene sulfide resin composition (X) for recycled materials has a ratio (LR/Lv) of the burr length ( _LR ) measured under the above condition (1) to the burr length ( _LV ) measured under the above condition (1) for a virgin material ( _V ) having the same composition, of preferably 1.20 or less, more preferably 1.10 or less, and even more preferably 1.0 or less. When the burr length ratio _LR / _Lv is 1.20 or less, the burr length during recycling can be kept to the same level as that of virgin material. In one embodiment, the _burr length ratio _LR / _Lv may be less than 1.0. When the burr length ratio _LR / _Lv is less than 1.0, the burr length during recycling can be shorter than that when virgin material is injection molded.

[Recycled material (R)]
The recycled material (R) according to the present disclosure is a recycled material (R) of a polyarylene sulfide resin composition containing (A) 100 parts by mass of a polyarylene sulfide resin having a carboxy group and (B) 0.3 to 10 parts by mass of an alkoxysilane compound. The recycled material (R) may also contain (C) an inorganic filler. The (C) inorganic filler preferably contains (C1) a fibrous inorganic filler, and more preferably contains (C1a) a fibrous inorganic filler having a diameter ratio, which is the ratio of the major axis to the minor axis of a cross section perpendicular to the longitudinal direction, of 3.0 or more. The (A) polyarylene sulfide resin having a carboxy group, the (B) alkoxysilane compound, the (C) inorganic filler that may be contained as needed, the (C1) fibrous inorganic filler, the (C1a) fibrous inorganic filler having a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of 3.0 or more, and other components, as well as their contents, are as described above and therefore will not be described here.

As mentioned above, "recycled material" refers to a material (recycled material) that has been produced by crushing an item such as a molded body (a recycled product) and regenerating it into a material for use in manufacturing molded bodies. It is preferable that the recycled material (R) is a recycled material for injection molding.

The recycled material (R) preferably comprises or consists solely of a pulverized product of an article containing the above-mentioned polyarylene sulfide resin composition (X) for recycled materials, and/or a repelletized material obtained by repelleting the pulverized product.

The items (recycled items) that are used as raw materials for recycled material (R) may be molded products, or may be items that were ejected after remaining in the cylinder for a long period of time during molding. Examples include defective products generated during the manufacturing process of molded products, non-product parts obtained during injection molding (e.g., runners, sprues, etc.), unused products, and chunks of polyethylene sulfide resin material used for purging during molding.

In one embodiment, the recycled material (R) may be a pulverized product of an article containing the polyarylene sulfide resin composition (X) for recycled materials. When the recycled material (R) is a pulverized product, the average particle size of the pulverized product is not limited. For example, the volume-based cumulative 50% diameter (D50) measured by the laser diffraction scattering method is preferably 0.3 to 20 mm, more preferably 0.4 to 15 mm, even more preferably 1 to 10 mm, and particularly preferably 1 to 3 mm.

In one embodiment, the recycled material (R) may be a repelletized material. When the recycled material (R) is a repelletized material, the reaction between the carboxyl groups of the polyarylene sulfide resin and the alkoxysilane compound (B) has progressed, making it easier to maintain or produce a high molecular weight polymer. In one embodiment, in the molecular weight distribution of the repelletized material measured by gel permeation chromatography (GPC), the area at molecular weights of 700,000 or more preferably accounts for 1 to 20% of the total.

In one embodiment, the recycled material (R) has a burr length (L _R ) measured under the following condition (1) of preferably 140 μm or less, more preferably 130 μm or less, even more preferably 110 μm or less, and particularly preferably 100 μm or less.
<Condition (1)>
Using a mold with a disk-shaped cavity and a flash measurement section with a mold gap of 20 μm provided on the periphery, injection molding is performed at a cylinder temperature of 320° C., a mold temperature of 150° C., and the minimum pressure required to completely fill the cavity. The length of the flash generated in the flash measurement section is measured under magnification using an image projector.
When the burr length (L _R ) is 140 μm or less, the generation of burrs during recycling is further suppressed.

In one embodiment, the ratio (LR/Lv) of the burr length (LR) measured under the above condition (1) of the recycled material (R) to the burr length ( _LV ) measured under the above condition ( ₁ ) for a virgin material _{( V} ) having the same composition is preferably 1.20 or less, more preferably 1.10 or less, and even more preferably 1.0 or less. When the burr length ratio _LR / _Lv is 1.20 or less, the burr length during recycling can be kept to the same level as that of virgin material. In one embodiment, the burr length ratio _LR / _Lv may be less than 1.0. When the burr length ratio _LR / _Lv is less than 1.0, the burr length during recycling can be shorter than that when virgin material is injection molded.

Recycled material (R) can be reused as a molding material (preferably injection molding material) either alone or as a mixture with virgin material. When used as a mixture with virgin material, the content of recycled material (R) in the mixture is preferably 30% by mass or more, and more preferably 50% by mass or more, of the total amount of the mixture (100% by mass). Recycled material (R) can suppress the occurrence of burrs during recycling, so even when the content of recycled material (R) in the mixture is high, burrs can be suppressed to the same extent (or better) as with virgin material.

[Method of manufacturing repellet material]
The method for producing a repellet material according to the present disclosure includes obtaining a pulverized product of a molded product of a polyarylene sulfide resin composition (X) containing (A) 100 parts by mass of a polyarylene sulfide resin having a carboxy group and (B) 0.3 to 10 parts by mass of an alkoxysilane compound; and
and melt-kneading the recycled material containing the pulverized material at 260 to 380°C to obtain a repellet material. The polyarylene sulfide resin composition (X) may contain (C) an inorganic filler. The (C) inorganic filler preferably contains (C1) a fibrous inorganic filler, and more preferably contains (C1a) a fibrous inorganic filler having a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of 3.0 or more. The (A) polyarylene sulfide resin having a carboxy group, the (B) alkoxysilane compound, the (C) inorganic filler that may be contained as needed, the (C1) fibrous inorganic filler, the (C1a) fibrous inorganic filler having a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of 3.0 or more, and other components, as well as their contents, are as described above and therefore will not be described here.

The pulverized material may be, for example, a molded product of the polyarylene sulfide resin composition (X) for recycled materials described above that has been pre-pulverized, or may be obtained by mechanically pulverizing the product using a pulverizer, a crusher, or the like. The average particle size of the pulverized material is not limited, and for example, the volume-based cumulative 50% diameter (D50) measured by a laser diffraction scattering method is preferably 0.3 to 20 mm, more preferably 0.4 to 15 mm, even more preferably 1 to 10 mm, and particularly preferably 1 to 3 mm. The molded product of the polyarylene sulfide resin composition (X) for recycled materials may be a molded product, or may be a product that has been retained in a cylinder for a long period of time during molding and then discharged. 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 for purging during molding.

The recycled material containing the ground material is melt-kneaded preferably at 260-380°C, more preferably 280-340°C, to obtain a re-pellet material. The re-pellet material can then be used again as material for injection molding. By re-pelletizing, the reaction between the carboxy groups of (A) the carboxy-containing linear polyarylene sulfide resin and (B) the alkoxysilane compound can be promoted during the re-pelletization process, making it easier to suppress the occurrence of burrs during recycling. It also makes the material easier to handle during recycling.

[Method for suppressing burrs during recycling]
In one embodiment, there is provided a method for suppressing burrs during recycling of a polyarylene sulfide resin composition, comprising blending 0.3 to 10 parts by mass of (B) an alkoxysilane compound per 100 parts by mass of (A) a linear polyarylene sulfide resin having a carboxy group. This method can suppress burrs when the polyarylene sulfide resin composition is injection-molded at least once, the resulting molded article is pulverized to produce a recycled material, and then injection-molded again. In one embodiment, this method can shorten the burr length generated when the polyarylene sulfide resin composition is injection-molded at least once, the resulting molded article is pulverized to produce a recycled material, and then injection-molded again.

(A) Polyarylene sulfide resin having a carboxy group, (B) Alkoxysilane compound, (C) Inorganic filler, (C1) Fibrous inorganic filler, (C1a) Fibrous inorganic filler having a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of 3.0 or more that may be contained as needed, and other components, as well as their contents, are as described above and therefore will not be described here.

[Use of alkoxysilane compounds to suppress burrs during recycling]
In one embodiment, there is provided a use of an alkoxysilane compound for suppressing burrs during recycling of a polyarylene sulfide resin composition, the use comprising blending 0.3 to 10 parts by mass of (B) an alkoxysilane compound per 100 parts by mass of (A) a linear polyarylene sulfide resin having a carboxy group. This use can suppress burrs when the polyarylene sulfide resin composition is injection-molded at least once, the resulting molded article is crushed, and, if necessary, re-pelletized to produce a recycled material, and then injection-molded again. In one embodiment, this use can reduce the burr length generated when the polyarylene sulfide resin composition is injection-molded at least once, the resulting molded article is crushed to produce a recycled material, and then injection-molded again, compared to the burr length generated when a virgin material having the same composition is injection-molded.

(A) Polyarylene sulfide resin having a carboxy group, (B) Alkoxysilane compound, (C) Inorganic filler, (C1) Fibrous inorganic filler, (C1a) Fibrous inorganic filler having a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of 3.0 or more that may be contained as needed, and other components, as well as their contents, are as described above and therefore will not be described here.

[Use of polyarylene sulfide resin composition as recycled material]
In one embodiment, there is provided use of a polyarylene sulfide resin composition comprising (A) 100 parts by mass of a linear polyarylene sulfide resin having a carboxy group and (B) 0.3 to 10 parts by mass of an alkoxysilane compound as a recycled material. This use can produce a recycled material that can suppress burrs when re-injection molding. In one embodiment, this use can produce a recycled material in which the length of burrs generated when re-injection molding is shorter than the length of burrs generated when injection molding a virgin material having the same composition.

(A) Polyarylene sulfide resin having a carboxy group, (B) Alkoxysilane compound, (C) Inorganic filler, (C1) Fibrous inorganic filler, (C1a) Fibrous inorganic filler having a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of 3.0 or more that may be contained as needed, and other components, as well as their contents, are as described above and therefore will not be described here.

A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of the present disclosure are disclosed below.
[1] (A) 100 parts by mass of a linear polyarylene sulfide resin having a carboxy group;
(B) A polyarylene sulfide resin composition (X) for recycled materials, comprising: 0.3 to 10 parts by mass of an alkoxysilane compound.
[2] The polyarylene sulfide resin composition (X) for recycled materials according to [1], wherein the (B) alkoxysilane compound contains one or more alkoxysilane compounds having one or more selected from an epoxy group, an amino group, a vinyl group, a (meth)acrylic group, an isocyanate group, and a mercapto group.
[3] The polyarylene sulfide resin composition (X) for recycled materials according to [1] or [2], which contains 30 to 250 parts by mass of (C) inorganic filler per 100 parts by mass of (A) polyarylene sulfide resin having a carboxy group.
[4] The polyarylene sulfide resin composition (X) for recycled materials according to [3], wherein the inorganic filler (C) contains a fibrous inorganic filler (C1).
[5] The polyarylene sulfide resin composition (X) for recycled materials according to [4], wherein the fibrous inorganic filler (C1) contains a fibrous inorganic filler (C1a) having a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of 3.0 or more.
[6] The polyarylene sulfide resin composition (X) for recycled materials according to [5], wherein the content of (C1a) a fibrous inorganic filler having a diameter ratio, which is the ratio of the major axis to the minor axis of a cross section perpendicular to the longitudinal direction, of 3.0 or more is 50 to 100 mass% of the total amount of (C1) the fibrous inorganic filler.
[7] (A) 100 parts by mass of a polyarylene sulfide resin having a carboxy group;
(B) A recycled material (R) of a polyarylene sulfide resin composition containing 0.3 to 10 parts by mass of an alkoxysilane compound.
[8] A recycled material (R) of the polyarylene sulfide resin composition according to [7], which is a repellet material.
[9] A recycled material (R) of the polyarylene sulfide resin composition according to [7], wherein the burr length (L _R ) measured under the following condition (1) is 140 μm or less.
[Condition (1):
Using a mold with a disk-shaped cavity, the outer periphery of which is provided with a burr measurement section with a 20 μm mold gap, injection molding is performed at a cylinder temperature of 320°C, a mold temperature of 150°C, and the minimum pressure required to completely fill the cavity. The length of the burr generated at the burr measurement section is measured under magnification using an image projector.
[10] Obtaining a pulverized product of a molded product of a polyarylene sulfide resin composition (X) containing (A) 100 parts by mass of a polyarylene sulfide resin having a carboxy group and (B) 0.3 to 10 parts by mass of an alkoxysilane compound;
and melt-kneading the recycled material containing the pulverized material at 260 to 380°C to obtain a recycled material.
The configurations and combinations thereof in each embodiment 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.

The following examples further illustrate the present disclosure, but the interpretation of the present disclosure is not limited to these examples.

[Raw materials]
The raw materials used in the examples and comparative examples are as follows.
(Polyarylene sulfide resin)
PPS1: Linear polyphenylene sulfide resin, manufactured by Kureha Corporation, Fortron (registered trademark) KPS, melt viscosity 30 Pa·s (shear rate 1200 sec ⁻¹ , 310° C.), Tc: 219° C., carboxy group content: 35 μmol/g

(Method for measuring melt viscosity of PPS resin)
The melt viscosity of the PPS resin was measured as follows.
Using a Capillograph manufactured by Toyo Seiki Seisakusho Co., Ltd. and a flat die of 1 mmφ×20 mmL as a capillary, the melt viscosity was measured at a barrel temperature of 310° C. and a shear rate of 1200 sec ⁻¹ .

(Method for measuring Tc)
The Tc of the polyarylene sulfide resin was measured as follows.
Approximately 5 mg of polyarylene sulfide resin was weighed, and using a PerkinElmer DSC-8500 differential scanning calorimeter, the temperature was increased at a rate of 10°C/min, held at 340°C for 5 minutes, and then decreased at a rate of 10°C/min. The crystallization peak (exothermic peak) temperature was read from the obtained DSC chart to determine Tc.

(Method for measuring the amount of carboxyl groups)
The carboxy group content of the polyarylene sulfide resin was measured as follows.
(i) By FT-IR measurement, the peak heights of the absorption peak of the benzene ring of benzoic acid at 3065 cm ^-1 and the absorption peak of the carboxy group at 1704 cm ^-1 are measured. They are 0.023 and 0.293, respectively. Therefore, the relative intensity of the absorption peak of the carboxy group to the C-H bond of the benzene ring is 63.7.
(ii) The resin composition was pressed and subjected to FT-IR measurement, where the peak height (absorption intensity) was 0.049 at 3065 cm ⁻¹ and 0.003 at 1704 ^{cm −1} .
(iii) For the resin composition to be measured, the relative intensity of the absorption peak of one carboxy group relative to one C—H bond on the benzene ring was calculated from the peak heights (3065 cm ⁻¹ and 1704 cm ⁻¹ ) in the same manner as above, and was found to be 0.24. From the relative intensity of the absorption peak of benzoic acid in which one carboxy group is substituted on the benzene ring, it was determined that the carboxy group content was 0.38 mol % relative to the benzene ring.
(iv) The amount of the repeating unit -(Ar-S)- (Ar is a benzene ring) contained in 1 kg of the resin was 9.3 mol/kg, and the amount of the carboxyl group contained in 1 kg of the resin composition was 35 μmol/g.

(Alkoxysilane Compound)
Alkoxysilane compound: γ-aminopropyltriethoxysilane, "KBE-903P" manufactured by Shin-Etsu Chemical Co., Ltd.
(burr suppressant)
Branched PPS resin: A branched PPS resin produced by pre- and post-polymerization of monomers in the same manner as in Synthesis Example 3 described in WO 2006/068161.

(fibrous inorganic filler)
GF1: Chopped strand ECS03T-747H manufactured by Nippon Electric Glass Co., Ltd., approximately circular cross section, average fiber diameter 10.5 μm, major axis/minor axis ratio 1.0, average fiber length 3 mm
GF2: Chopped strand ECS03T-747N manufactured by Nippon Electric Glass Co., Ltd., approximately circular cross section, average fiber diameter 17 μm, major axis/minor axis ratio 1.0, average fiber length 3 mm
GF3: Nippon Electric Glass Co., Ltd., flat glass fiber ESC03T-760-FGF, oval cross section, major axis 28 μm, minor axis 7 μm, major axis/minor axis ratio 4.0, average fiber length 3 mm

[Examples 1 to 9, Comparative Examples 1 to 9]
Using the above materials, a polyarylene sulfide resin, an alkoxysilane compound, and a fibrous inorganic filler were dry-blended in the compositions and content ratios shown in Tables 1 and 2. This was fed into a twin-screw extruder at a cylinder temperature of 320°C and melt-kneaded to obtain virgin pellets. The obtained virgin pellets were injection-molded at a cylinder temperature of 320°C and a mold temperature of 150°C to obtain an injection-molded product measuring 80 mm long x 80 mm wide x 1.0 mm thick.
The obtained injection-molded article was pulverized in a mechanical pulverizer until the average particle diameter (D50) was 3 mm, and the pulverized injection-molded article (recycled material) was obtained. The pulverized material was fed into a twin-screw extruder at a cylinder temperature of 320°C and melt-kneaded to obtain the repelletized material (recycled material) of the examples and comparative examples.

[evaluation]
The repellet materials obtained in the examples and comparative examples were injection molded by the following method, and the flash length and Charpy impact strength were measured and evaluated. The results are shown in Tables 1 and 2.

(Evaluation of burr occurrence)
The repellet materials obtained in the examples and comparative examples were injection molded using a disk-shaped cavity mold having a burr measurement section on the outer periphery with a mold gap of 20 μm, at a cylinder temperature of 320° C., a mold temperature of 150° C., and the minimum pressure required to completely fill the cavity.
The burr length (L _R ) generated at the burr measurement section was enlarged and measured using an image projector. When the burr length (L _R ) is 140 μm or less, burr generation can be suppressed during recycling. When the burr length (L _R ) is 130 μm or less, burr generation can be further suppressed during recycling. When the burr length (L _R ) is 100 μm or less, burr generation can be further suppressed during recycling. When the burr length (L _R ) is 90 μm or less, burr generation can be particularly suppressed during recycling.

Using the virgin pellets used in the examples and comparative examples, injection molding was performed in the same manner as above, and the burr length (L _v ) was measured in the same manner as above. Using the obtained values, the ratio (L _R /L _v ) of the burr length (L _R ) of the repellet material to the burr length (L _v ) of the injection-molded product made from virgin pellets was calculated. When the burr length ratio (L _R /L _v ) is 1.40 or less, burr generation can be significantly suppressed compared to virgin pellets, and when it is 1.20 or less, burr generation can be kept to the same level as virgin pellets. When the burr length ratio (L _R /L _v ) is less than 1.0, burr generation is suppressed more effectively with the repellet material than with virgin pellets.

(Charpy impact strength (notched))
The repellet materials obtained in the examples and comparative examples were dried at 140°C for 3 hours, and then injection molded into test pieces (width 10 mm, thickness 4 mm) in accordance with ISO 316 at a molding cylinder temperature of 320°C and a mold temperature of 150°C. Using these test pieces, the Charpy impact strength (notched) (kJ/ ^m2 ) was measured in accordance with ISO 179-1.

As shown in Table 1, the repellet materials of Examples 1 to 9 had a burr length (L _R ) of 130 μm or less, thereby further suppressing burr generation during recycling. The repellet materials of Examples 1, 2, 7, and 8 had a burr length ratio (L _R /L _v ) of less than 1.0, which not only prevented burr generation during recycling, but also demonstrated that the repellet materials suppressed burr generation more effectively than virgin pellets. The repellet materials of Examples 4 and 5 had a burr length ratio (L _R /L _v ) of 1.10 or less, thereby limiting burr generation to the same level as virgin pellets. The repellet materials of Examples 3, 6, 8, and 9 had a burr length (L _R ) of 90 μm or less, thereby particularly suppressing burr generation during recycling. The repellet materials of Examples 7 to 9, which used a fibrous inorganic filler with a flat cross-sectional shape as the inorganic filler, were able to produce recycled molded products with high Charpy impact strength.
In contrast, as shown in Table 2, when a branched polyarylene sulfide resin was blended as a burr suppressant (Comparative Examples 1 to 9), burrs could be suppressed when virgin pellets were injection molded, but since no alkoxysilane compound was included, a large amount of burrs were generated when repellet material was injection molded.

The polyarylene sulfide resin composition for recycled materials of this embodiment can suppress the generation of burrs during recycling, making it suitable for use as a resin composition for recyclable injection-molded products. Specifically, it has industrial applicability as a material for electrical and electronic equipment parts, automotive parts, chemical equipment parts, etc.

Claims (10)

(A) 100 parts by mass of a linear polyarylene sulfide resin having a carboxy group;
(B) A polyarylene sulfide resin composition (X) for recycled materials, comprising: 0.3 to 10 parts by mass of an alkoxysilane compound. The polyarylene sulfide resin composition (X) for recycled materials according to claim 1, wherein the (B) alkoxysilane compound includes one or more alkoxysilane compounds having one or more groups selected from an epoxy group, an amino group, a vinyl group, a (meth)acrylic group, an isocyanate group, and a mercapto group. The polyarylene sulfide resin composition (X) for recycled materials according to claim 1 or 2, comprising 30 to 250 parts by mass of (C) inorganic filler per 100 parts by mass of (A) polyarylene sulfide resin having a carboxy group. The polyarylene sulfide resin composition (X) for recycled materials described in claim 3, wherein the inorganic filler (C) includes a fibrous inorganic filler (C1). The polyarylene sulfide resin composition (X) for recycled materials described in claim 4, wherein the (C1) fibrous inorganic filler includes (C1a) a fibrous inorganic filler having a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of 3.0 or more. The polyarylene sulfide resin composition (X) for recycled materials described in claim 5, wherein the content of (C1a) fibrous inorganic filler having a diameter ratio, which is the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction, of 3.0 or more is 50 to 100 mass% of the total amount of (C1) fibrous inorganic filler. (A) 100 parts by mass of a polyarylene sulfide resin having a carboxy group;
(B) A recycled material (R) of a polyarylene sulfide resin composition containing 0.3 to 10 parts by mass of an alkoxysilane compound. Recycled material (R) of the polyarylene sulfide resin composition described in claim 7, which is a repellet material. The recycled material (R) of polyarylene sulfide resin composition according to claim 7, wherein the burr length (L _R ) measured under the following condition (1) is 140 μm or less.
[Condition (1):
Using a mold with a disk-shaped cavity and a flash measurement section with a mold gap of 20 μm provided on the outer periphery, injection molding is performed at a cylinder temperature of 320°C, a mold temperature of 150°C, and the minimum pressure required to completely fill the cavity. The length of the flash generated at the flash measurement section is measured under magnification using an image projector. obtaining a pulverized product of a molded product of a polyarylene sulfide resin composition (X) containing (A) 100 parts by mass of a polyarylene sulfide resin having a carboxy group and (B) 0.3 to 10 parts by mass of an alkoxysilane compound;
and melt-kneading the recycled material containing the pulverized material at 260 to 380°C to obtain a recycled material.