Polyphenylene sulfide resin composition, molded article, and production method

Abstract

The present invention addresses the problem of obtaining a polyphenylene sulfide resin composition which contains a large amount of a thermoplastic amorphous resin and achieves adequate fluidity and recycled material content at the same time. The present invention relates to a polyphenylene sulfide resin composition which is obtained by adding, if the polyphenylene sulfide resin composition is taken as 100 mass%, (A) 85-30 mass% of a polyphenylene sulfide resin and (B) 15-70 mass% of a thermoplastic amorphous resin, wherein: the thermoplastic amorphous resin (B) is a recycled thermoplastic amorphous resin; and the polyphenylene sulfide resin composition has a melt viscosity (v) of 10-500 Pa∙s at a shear rate of 1,216 / s as measured under the condition of (orifice length L (mm)) / (orifice diameter D (mm)) = 10 after retaining the polyphenylene sulfide resin composition at 310°C for 5 minutes with use of a capillary rheometer.

Description

Polyphenylene sulfide resin composition, molded article, and manufacturing method

[0001] The present invention relates to a polyphenylene sulfide resin composition that contributes to a circular economy, a molded article, and a method for producing the same.

[0002] In recent years, in order to realize a circular economy, the recycling of thermoplastic resins has been accelerating, and thermoplastic resin compositions containing recycled raw materials have been attracting attention.

[0003] Polyphenylene sulfide (hereinafter sometimes abbreviated as PPS) resin is an engineering plastic that has excellent heat resistance, chemical resistance, flame retardancy, and electrical properties. Many of them are used as fiber-reinforced PPS resin compositions mixed with inorganic fillers such as glass fiber, primarily in automotive parts, plumbing parts, and electrical and electronic parts.

[0004] Since PPS resin is mainly used as a fiber-reinforced PPS resin composition for molded articles obtained by injection molding, extrusion molding, etc., the absolute amount of easily recoverable recycled materials, such as process offcuts from fiber production and film production, is small, and there is a problem that PPS resin compositions containing recycled raw materials cannot be sufficiently produced. Therefore, a PPS resin composition has been proposed in which recycled polyamide is blended with PPS resin to increase the recycled material content (see, for example, Patent Document 1).

[0005] Furthermore, since PPS resin is brittle and has poor impact resistance and toughness, methods for improving the toughness of PPS resin have been proposed, including a resin composition comprising PPS resin and another thermoplastic resin (see, for example, Patent Document 2), a resin composition obtained by melt-kneading PPS resin and a thermoplastic resin selected from polycarbonate, polysulfone, and polyether ketone under specific conditions (see, for example, Patent Document 3), a resin composition comprising PPS resin and a thermoplastic amorphous resin selected from polyetherimide and polyethersulfone (see, for example, Patent Document 4), and a resin composition comprising PPS resin and polyallyl ether sulfone (see, for example, Patent Document 5).

[0006] JP 2023-60933 A JP 2003-113307 A JP 2000-248179 A International Publication No. 2007 / 108384 JP 2022-119844 A

[0007] However, since the PPS resin composition described in Patent Document 1 has an increased recycled material content by blending a recycled polyamide resin, if the blending amount of the recycled polyamide resin is increased, the heat resistance of the PPS resin composition cannot be maintained, and there is an upper limit to the recycled material content. Furthermore, there is no description of the case where a recycled thermoplastic amorphous resin, which has heat resistance close to that of PPS and is expected to be utilized toward realizing a circular economy, is included.

[0008] The PPS resin composition described in Patent Document 2 only describes the incorporation of polyamide, and does not describe the incorporation of a thermoplastic amorphous resin. Furthermore, the inventions relating to PPS resin compositions described in Patent Documents 3 to 5 are not based on the technical idea of ​​incorporating a high amount of recycled thermoplastic amorphous resin toward the realization of a circular economy. Therefore, there is no description of the problem of reduced fluidity of the resin composition when a large amount of recycled thermoplastic amorphous resin is incorporated.

[0009] Among these, polysulfone-based resins, typified by polysulfone, polyethersulfone, polyarylethersulfone, and the like, are amorphous super engineering plastics that have excellent heat resistance, flame retardancy, hydrolysis resistance, and transparency, and are suitable for applications in the automotive, food industry, medical equipment, etc., and are compatible with PPS resins. In recent years, process waste materials of hollow fiber membranes of polysulfone-based resins used in artificial kidneys, etc., have been attracting attention as a promising recycled material due to their stable quality and supply, but they are designed to have a high viscosity to improve spinnability, and there has been an issue of reduced fluidity when they are incorporated into resin compositions as recycled raw materials.

[0010] Therefore, the present inventors conducted extensive research to solve the above-mentioned problems, and as a result, they discovered that in a PPS resin composition using a specific recycled thermoplastic resin, it is possible to increase the recycled material content without impairing the inherent properties of PPS, such as mechanical properties and flowability, and thus arrived at the present invention.

[0011] That is, the present invention has the following configuration: (1) A polyphenylene sulfide resin composition comprising 85 to 30 mass % of (A) polyphenylene sulfide resin and 15 to 70 mass % of (B) thermoplastic amorphous resin, where the polyphenylene sulfide resin composition is 100 mass %, wherein the thermoplastic amorphous resin (B) is a recycled thermoplastic amorphous resin, and the polyphenylene sulfide resin composition has a melt viscosity (v) of 10 to 500 Pa s at a shear rate of 1216 / s, as measured using a capillary rheometer under the condition of orifice length L (mm) / orifice diameter D (mm) = 10 after retention at 310°C for 5 minutes. (2) The polyphenylene sulfide resin composition according to (1), wherein the melt viscosity (b) of the thermoplastic amorphous resin (B) is 1 to 1,000 Pa s at a shear rate of 1,216 / s when measured using a capillary rheometer under the conditions of orifice length L (mm) / orifice diameter D (mm) = 10 after 5 minutes of residence at a temperature 150°C above the glass transition temperature of the thermoplastic amorphous resin (B), and the ratio (b) / (a) of the melt viscosity (a) of the polyphenylene sulfide resin (A) to the melt viscosity (b) is within a range of 0.1 to 20 when measured using a capillary rheometer under the conditions of orifice length L (mm) / orifice diameter D (mm) = 10 after 5 minutes of residence at 310°C. (3) The polyphenylene sulfide resin composition according to (1) or (2) above, in which (A) the polyphenylene sulfide resin forms a continuous phase and (B) the thermoplastic amorphous resin forms a dispersed phase. (4) The polyphenylene sulfide resin composition according to any one of (1) to (3) above, in which (C) an inorganic filler is blended in an amount of 1 to 55 mass% relative to 100 mass% of the polyphenylene sulfide resin composition. (5) The polyphenylene sulfide resin composition according to any one of (1) to (4) above, in which the weight-average molecular weight of the (A) polyphenylene sulfide resin is 20,000 or more and 100,000 or less.(6) The polyphenylene sulfide resin composition according to any one of (1) to (5) above, wherein the polyphenylene sulfide resin (A) is a polyphenylene sulfide resin having a melt viscosity of 1 to 50 Pa s at a shear rate of 1216 / s when measured using a capillary rheometer under the conditions of orifice length L (mm) / orifice diameter D (mm) = 10 after 5 minutes of residence at 310°C. (7) The polyphenylene sulfide resin composition according to any one of (1) to (6) above, wherein the thermoplastic amorphous resin (B) has a glass transition temperature of 170°C or higher. (8) The polyphenylene sulfide resin composition according to (7) above, wherein the thermoplastic amorphous resin (B) is polysulfone, polyethersulfone, or polyetherimide. (9) The polyphenylene sulfide resin composition according to any one of (1) to (8) above, wherein the thermoplastic amorphous resin (B) has a melt viscosity (b) of 1 to 500 Pa s. (10) The polyphenylene sulfide resin composition according to any one of (1) to (9) above, wherein the thermoplastic amorphous resin (B) has a weight-average molecular weight of 10,000 or more and 100,000 or less. (11) The polyphenylene sulfide resin composition according to (10) above, wherein the thermoplastic amorphous resin (B) has a weight-average molecular weight of 10,000 or more and 60,000 or less. (12) The polyphenylene sulfide resin composition according to any one of (2) to (11) above, wherein the thermoplastic amorphous resin (B) is a recycled thermoplastic amorphous resin derived from hollow fiber process waste materials used in artificial kidneys. (13) The polyphenylene sulfide resin composition according to any one of (1) to (12) above, further comprising (X) a hydrophilic resin. (14) (X) The polyphenylene sulfide resin composition according to (13) above, wherein the hydrophilic resin is at least one selected from the group consisting of polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol. (15) A molded article made of the polyphenylene sulfide resin composition according to any one of (1) to (14) above. (16) The molded article according to (15) above, which is a plumbing part selected from toilet-related parts, water heater-related parts, bath-related parts, pump-related parts, and water meter-related parts.(17) A method for producing a polyphenylene sulfide resin composition, comprising contacting, in the absence of a solvent, a resin composition comprising (A) a polyphenylene sulfide resin, (B) at least one resin selected from the group consisting of polysulfone, polyethersulfone, and polyallyl ether sulfone, (X) a hydrophilic resin, and (Y) a metal alkoxide. (18) The method for producing a polyphenylene sulfide resin composition according to (17), wherein (X) the hydrophilic resin is at least one selected from the group consisting of polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol.

[0012] According to the present invention, a PPS resin composition having a high recycled material content, which contains a large amount of recycled thermoplastic amorphous resin, can be obtained without impairing the inherent properties of PPS such as mechanical properties and flowability.

[0013] The polyphenylene sulfide resin (A) used in the present invention (hereinafter sometimes abbreviated as PPS resin (A)) is a polymer having a repeating unit represented by the following structural formula.

[0014]

[0015] From the viewpoint of heat resistance, a polymer containing 70 mol % or more, and even more preferably 90 mol % or more, of a polymer containing a repeating unit represented by the above structural formula is preferred. Furthermore, the (A) PPS resin may be composed of at least one repeating unit represented by the following formula, with less than 30 mol % of the repeating units being approximately equal to or less than 100 mol %:

[0016]

[0017] The melt viscosity (a) of the (A) PPS resin used in the present invention is not particularly limited as long as it can achieve both the dispersibility of the (B) thermoplastic amorphous resin and the inherent properties of PPS. However, from the viewpoint of application to injection molding, where fluidity is required, the upper limit is preferably 1000 Pa s or less, more preferably 500 Pa s or less. When a fibrous filler is blended to obtain a composite material, from the viewpoint of suppressing breakage of the fibrous filler and improving mechanical properties, 400 Pa s or less is particularly preferred, and 300 Pa s or less is even more preferred. Furthermore, from the viewpoint of reducing the viscosity ratio with the (B) thermoplastic amorphous resin and improving the dispersibility of the (B) thermoplastic amorphous resin, 250 Pa s or less is even more preferred, and 200 Pa s or less is most preferred. Furthermore, from the viewpoint of expressing the properties of the PPS resin, the lower limit is preferably 1 Pa s or more, more preferably 10 Pa s or more. A PPS resin having such a melt viscosity can be obtained by adjusting the molar ratio of the polyhalogenated aromatic compound to the sulfidizing agent, which will be described later, or by adjusting the amount of polymerization aid added. The melt viscosity of the PPS resin (A) in the present invention is a value measured using a capillary rheometer (for example, "Capilograph" (registered trademark) manufactured by Toyo Seiki Seisaku-sho) under conditions of a shear rate of 1216 / s and an orifice length L (mm) / orifice diameter D (mm) = 10, after allowing the resin to dwell for 5 minutes at a test temperature of 310°C.

[0018] The weight-average molecular weight of the (A) PPS resin used in the present invention is preferably 20,000 to 100,000 in order to achieve both the dispersibility of the (B) thermoplastic amorphous resin and the inherent properties of PPS. A PPS resin with such a weight-average molecular weight can be obtained by adjusting the molar ratio of the polyhalogenated aromatic compound to the sulfidizing agent, as described below, or by adjusting the amount of polymerization aid added. The weight-average molecular weight here is a value calculated in terms of polystyrene by gel permeation chromatography (GPC).

[0019] The PPS resin (A) used in the present invention can be a PPS resin obtained by a known method, such as a method of desalting polycondensation using a polyhalogenated aromatic compound and a sulfidizing agent in an organic polar solvent, or a method of synthesis under melt conditions using diiodobenzene and sulfur. Representative raw materials and post-treatment processes for the PPS resin are described in detail below.

[0020] [Polyhalogenated Aromatic Compound] The polyhalogenated aromatic compound refers to an aromatic compound having two or more halogen atoms per molecule. Specific examples include dihaloaromatic compounds such as p-dichlorobenzene, m-dichlorobenzene, o-dichlorobenzene, 1,3,5-trichlorobenzene, 1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene, hexachlorobenzene, 2,5-dichlorotoluene, 2,5-dichloro-p-xylene, 1,4-dibromobenzene, 1,4-diiodobenzene, and 1-methoxy-2,5-dichlorobenzene, with p-dichlorobenzene being preferred.

[0021] The amount of the polyhalogenated aromatic compound added is, for example, in the range of 0.9 to 2.0 mol, preferably 0.95 to 1.5 mol, and more preferably 1.005 to 1.2 mol per mol of the sulfidizing agent, from the viewpoint of obtaining a PPS resin with an appropriate weight-average molecular weight.

[0022] [Sulfidizing agent] Examples of sulfidizing agents include alkali metal sulfides and alkali metal hydrosulfides.Specific examples of alkali metal sulfides include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and mixtures of two or more of these, and sodium sulfide is particularly preferred.These alkali metal sulfides can be used as hydrates or aqueous mixtures, or in the form of anhydrides.

[0023] Specific examples of alkali metal hydrosulfides include sodium hydrosulfide, potassium hydrosulfide, lithium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide, and mixtures of two or more of these, with sodium hydrosulfide being preferred. These alkali metal hydrosulfides can be used as hydrates, aqueous mixtures, or anhydrous forms.

[0024] [Polymerization Aid] To obtain a PPS resin with a relatively high degree of polymerization in a shorter time, the use of a polymerization aid is one preferred embodiment. Here, the polymerization aid refers to a substance that has the effect of increasing the viscosity of the resulting PPS resin. Specific examples of such polymerization aids include organic carboxylates, water, alkali metal chlorides, organic sulfonates, alkali metal sulfates, alkaline earth metal oxides, alkali metal phosphates, and alkaline earth metal phosphates. These can be used alone or in combination of two or more. Among these, organic carboxylates, water, and alkali metal chlorides are preferred, with alkali metal carboxylates being preferred as the organic carboxylates and lithium chloride being preferred as the alkali metal chlorides.

[0025] The alkali metal carboxylate is a salt of a carboxylate represented by the general formula R(COOM) ｎ (wherein R is an alkyl group, cycloalkyl group, aryl group, alkylaryl group, or arylalkyl group having 1 to 20 carbon atoms; M is an alkali metal selected from lithium, sodium, potassium, rubidium, and cesium; and n is an integer of 1 to 3). The alkali metal carboxylate can also be used as a hydrate, anhydrous form, or aqueous solution. Specific examples of the alkali metal carboxylate include lithium acetate, sodium acetate, potassium acetate, sodium propionate, lithium valerate, sodium benzoate, sodium phenylacetate, potassium p-toluate, and mixtures thereof.

[0026] When these alkali metal carboxylates are used as polymerization aids, the amount used is usually in the range of 0.01 mol to 2 mol per mol of the charged alkali metal sulfide. In terms of obtaining a higher degree of polymerization, the amount used is preferably in the range of 0.1 mol to 0.6 mol, and more preferably in the range of 0.2 mol to 0.5 mol.

[0027] [Post-treatment step of PPS resin] The PPS resin is preferably subjected to an acid treatment after polymerization in order to obtain a PPS resin having enhanced reactivity with the (B) thermoplastic amorphous resin.

[0028] The acid used in the acid treatment of the PPS resin is not particularly limited as long as it does not have the effect of decomposing the PPS resin, and examples thereof include acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid, and propylic acid, with acetic acid and hydrochloric acid being more preferably used.

[0029] The acid treatment can be carried out by immersing the PPS resin in an acid or an aqueous solution of an acid, with stirring or heating as necessary. For example, when using acetic acid, a sufficient effect can be obtained by immersing the PPS resin powder in an aqueous solution of pH 4 heated to 80°C to 200°C and stirring for 30 minutes. The pH after treatment may be 4 or higher, for example, about pH 4 to 8. The acid-treated PPS resin is preferably washed several times with water or warm water to remove residual acid or salt. The water used for washing is preferably distilled water or deionized water, so as not to impair the desired chemical modification effect of the PPS resin by the acid treatment.

[0030] The (B) thermoplastic amorphous resin of the present invention is a recycled thermoplastic amorphous resin and can contribute to the realization of a circular economy. By blending the recycled thermoplastic amorphous resin with the PPS resin to a high degree, the recycled material content of the PPS resin composition can be increased without impairing the inherent properties of PPS. The "recycled material content" in the present invention refers to the blending ratio of recycled material contained in the PPS resin composition, and is calculated by the formula: (mass of recycled thermoplastic amorphous resin in the (B) thermoplastic amorphous resin) / (mass of PPS resin composition) × 100 [%]. Furthermore, recycled PPS resin is treated as (A) PPS resin, and the recycled material content in this case is calculated by the formula: (mass of recycled PPS resin in the (A) PPS resin + mass of recycled thermoplastic amorphous resin in the (B) thermoplastic amorphous resin) / (mass of PPS resin composition) × 100 [%]. Furthermore, when a (C) inorganic filler described below is contained and the (C) inorganic filler is a recycled inorganic filler containing recycled material, it can be calculated by (mass of recycled PPS resin in (A) PPS resin + mass of recycled thermoplastic amorphous resin in (B) thermoplastic amorphous resin + mass of recycled inorganic filler in (C) inorganic filler) / mass of PPS resin composition × 100 [%]. Furthermore, when a (D) thermoplastic elastomer described below is contained and the (D) thermoplastic elastomer is a thermoplastic elastomer containing recycled material, it can be calculated by (mass of recycled PPS resin in (A) PPS resin + mass of recycled thermoplastic amorphous resin in (B) thermoplastic amorphous resin + mass of recycled inorganic filler in (C) inorganic filler + mass of recycled thermoplastic elastomer in (D) thermoplastic elastomer) / mass of PPS resin composition × 100 [%]. Here, recycled material refers to process residues or molded articles collected after use in the market.

[0031] The process waste is, for example, process waste generated in a process for producing a thermoplastic amorphous resin, a process for producing a thermoplastic amorphous resin composition, or a process for molding a molded article made from a thermoplastic amorphous resin composition, and includes, for example, crushed process waste generated in an extrusion molding process such as a blow molding process, a membrane forming process, or a spinning process, and crushed sprues, runners, and the like recovered during molding in an injection molding process, etc. Among these, from the viewpoint of availability of recycled materials and stability of quality, process waste derived from a spinning process is preferred, and process waste generated in the production of hollow fiber membranes for artificial kidneys is particularly preferred.

[0032] From the perspective of realizing a circular economy, molded products that have been collected after use in the market are more preferable. In this case, performance tends to be reduced due to components that adhere during use in the market. Therefore, it is preferable to wash with a solvent to remove the adhered components. Examples of solvents include water and organic solvents. Water is preferred from the perspective of cost, and organic solvents are preferred from the perspective of efficiently removing contaminant components. Multiple solvents may be used in combination.

[0033] (B) The thermoplastic amorphous resin is a molded product recovered after use in the market as process offcuts or products, and it is preferable that traceability to prove its origin is ensured. This may be certification by a certification body, or traceability using a blockchain system.

[0034] The melt viscosity (b) of the thermoplastic amorphous resin (B) used in the present invention is preferably 1 to 1,000 Pa·s. From the viewpoint of improving handleability at the processing temperature of PPS, it is preferably 850 Pa·s or less, more preferably 700 Pa·s or less. Furthermore, from the viewpoint of application to injection molding, which requires fluidity, it is preferably 500 Pa·s or less, more preferably 450 Pa·s or less. When blending a fibrous filler to obtain a composite material, from the viewpoint of suppressing breakage of the fibrous filler and improving mechanical properties, it is particularly preferably 350 Pa·s or less, and even more preferably 300 Pa·s or less. Furthermore, from the viewpoint of reducing the viscosity ratio with the PPS resin (A) and improving dispersibility, it is more preferably 250 Pa·s or less, and most preferably 200 Pa·s or less. Furthermore, from the viewpoint of expressing the properties of the thermoplastic amorphous resin (B), it is preferably 10 Pa·s or more, more preferably 50 Pa·s or more. The melt viscosity (b) of the thermoplastic amorphous resin (B) in the present invention is a value measured using a capillary rheometer (for example, "Capilograph" (registered trademark) manufactured by Toyo Seiki Seisaku-sho) under conditions of a shear rate of 1216 / s and an orifice length L (mm) / orifice diameter D (mm) = 10 after allowing the resin to dwell for 5 minutes at a test temperature of Tg+150°C of the thermoplastic amorphous resin (B).

[0035] Specific examples of the thermoplastic amorphous resin (B) include vinyl chloride resin, vinylidene chloride resin, polystyrene, AS resin, ABS resin, methacrylic resin, polycarbonate, polyphenylene ether, polyarylate, polysulfone, polyethersulfone, polyallyl ether sulfone, polyetherimide, and copolymers thereof, as well as polymer alloys made of a plurality of these resins.From the viewpoint of compatibility with PPS resin, such as compatibility and processing temperature, it is preferable that the glass transition temperature of the thermoplastic amorphous resin (B) is 170 ° C. or higher, and among these, polyphenylene ether, polyarylate, polysulfone, polyethersulfone, polyetherimide, and polyallyl ether sulfone are more preferable, and polysulfone-based resins represented by polysulfone and polyethersulfone are particularly preferable.The thermoplastic amorphous resin (B) may be used alone or in combination of two or more types.

[0036] Specific examples of polysulfone-based resins include "Udel" (registered trademark) P-1700 and P-3500 manufactured by Solvay, and "Ultrason" (registered trademark) S3010, S6010, and E6020P manufactured by BASF.

[0037] Such polysulfone resins and polyetherimide resins have heat resistance and processing temperatures similar to those of PPS, resulting in less degradation and excellent mechanical properties when alloyed with PPS. On the other hand, because they are amorphous super engineering plastics with high glass transition temperatures, their melt viscosities are 500 Pa·s to 2000 Pa·s, which is significantly higher than that of PPS resin. Therefore, there was a problem of reduced fluidity when alloyed with (A) PPS resin. In particular, hollow fiber membranes for artificial kidneys made of polysulfone resins have stable quality and availability, and are expected to be used as promising recycled resources. However, they are designed with a high viscosity to enhance spinnability, which poses a problem of significantly reduced fluidity when alloyed with (A) PPS resin.

[0038] The weight average molecular weight of the thermoplastic amorphous resin (B) used in the present invention is preferably 10,000 or more and 100,000 or less from the viewpoint of improving dispersibility in the PPS resin (A). From the viewpoint of improving handleability at the processing temperature of PPS, it is preferably 90,000 or less, more preferably 80,000 or less, and even more preferably 60,000 or less.

[0039] The weight-average molecular weight of the thermoplastic amorphous resin (B) in the present invention is a value measured in polystyrene equivalent terms using gel permeation chromatography (GPC), a type of size exclusion chromatography (SEC). In particular, polysulfone-based resins are usually designed to have a weight-average molecular weight of 60,000 or more and 100,000 or less to ensure the toughness of the resin itself. Therefore, there is a problem of reduced fluidity when alloyed with PPS resin (A). To address this problem, the inventors discovered that blending a hydrophilic resin (X) and a metal alkoxide (Y) with a polysulfone-based resin enables depolymerization in a short time despite contact in a non-solvent environment, allowing for adjustment of the molecular weight and viscosity to be favorable for alloying with PPS resin (A). They also discovered that a PPS resin composition with a high recycled content, containing a large amount of recycled thermoplastic amorphous resin, can be obtained without impairing the inherent properties of PPS, such as mechanical properties and fluidity.

[0040] The hydrophilic resin (X) is a resin that is soluble in water or ethanol, and preferably dissolves in these at a concentration of 0.1 g / mL or more.

[0041] Specific examples of the hydrophilic resin (X) include polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, and copolymers thereof. Examples of the copolymer include, but are not limited to, copolymers of vinylpyrrolidone with a component selected from vinyl acetate, vinyl propionate, and vinyl butanoate. Among these, polyvinylpyrrolidone or its copolymers are preferred from the viewpoint of compatibility with the polysulfone-based resin and the metal alkoxide (Y) described below.

[0042] The (Y) metal alkoxide used in the present invention is a salt of a metal ion and an aliphatic or aromatic alkoxide. The metal species is preferably an alkali metal or alkaline earth metal, and metal species with low electronegativity are more preferred to achieve excellent reactivity. From the standpoints of availability and economy, sodium or potassium is more preferred, with potassium being particularly preferred. The valence of the (Y) metal alkoxide is preferably monovalent or divalent. Using a monovalent alkoxide can inactivate the terminals of the polysulfone-based resin, improving retention stability. Using a divalent alkoxide results in excellent terminal reactivity, resulting in a polysulfone-based resin suitable for polymer alloys; therefore, it is desirable to select the valence depending on the purpose. The (Y) metal alkoxide is preferably an aliphatic or aromatic metal alkoxide having 1 to 30 carbon atoms. Specific examples of the (Y) metal alkoxide include sodium phenoxide, sodium methoxide, sodium ethoxide, potassium phenoxide, potassium methoxide, potassium ethoxide, and potassium t-butoxide. Furthermore, from the viewpoint of heat resistance, it is preferable that the compound has a bisphenol skeleton. Specific examples include alkali metal salts or alkaline earth metal salts of bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, and bisphenol PH. Metal salts of bisphenol A or bisphenol S, which are the basic skeletons of polysulfone-based resins, are preferred because they allow for the production of polysulfone-based resins with reduced viscosity without impairing the properties of the polysulfone-based resin.

[0043] The amount of the hydrophilic resin (X) is preferably 0.1 to 100 parts by mass per 100 parts by mass of the polysulfone-based resin, and from the viewpoint of expressing the properties of the polysulfone-based resin, the upper limit is more preferably 50 parts by mass or less, and particularly preferably 30 parts by mass or less, and from the viewpoint of suppressing gas generation during processing, the upper limit is particularly preferably 10 parts by mass or less, and most preferably 5 parts by mass or less. Furthermore, from the viewpoint of efficiently lowering the viscosity of the polysulfone-based resin, the lower limit is more preferably 0.5 parts by mass or more, and particularly preferably 1 part by mass or more.

[0044] The (X) hydrophilic resin may be intentionally blended into the polysulfone-based resin, or, when the polysulfone-based resin is a process residue or a molded article recovered after use on the market as a finished product, the hydrophilic resin may be blended into the polysulfone-based resin by being mixed in or remaining in the polysulfone-based resin during the manufacturing process or use. In particular, when the polysulfone-based resin is derived from a process residue in the manufacture of hollow fiber membranes for artificial kidneys, the hydrophilic resin blended in during the process remains, making it possible to omit the addition of a hydrophilic resin when reducing the viscosity of the polysulfone-based resin, which is preferred.

[0045] The blending amount of the (Y) metal alkoxide is preferably 0.1 to 20 mol % per mole of the polysulfone resin, more preferably 15 mol % or less from the viewpoint of expressing the properties of the polysulfone resin, particularly preferably 10 mol % or less, even more preferably 5 mol % or less from the viewpoint of ensuring the toughness of the polysulfone resin, and most preferably 3 mol % or less. Also, from the viewpoint of efficiently lowering the viscosity of the polysulfone resin, it is more preferably 0.5 mol % or more, particularly preferably 1 mol % or more.

[0046] The metal alkoxide (Y) may be produced in situ by blending an alcohol and a metal compound and contacting them with the polysulfone resin in the absence of a solvent.

[0047] In the present invention, 1 mole of the polysulfone resin is a value calculated by dividing the molecular weight (g / mol) of the unit structure of the polysulfone resin by the mass (g) of the polysulfone resin.

[0048] Contact in a non-solvent state can be achieved by any means as long as the components come into contact and the reaction proceeds, but it is preferable to increase the contact frequency by heating to a molten state. Representative examples of heating include supplying raw materials to a known autoclave in a batchwise manner and melt-kneading them, or supplying raw materials to a known melt-kneader such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll in a continuous manner and melt-kneading them so that the resin temperature is the glass transition temperature of the polysulfone-based resin + 100°C to 200°C. A continuous method is preferred from the viewpoint of low-cost and simple viscosity reduction, and melt-kneading using a twin-screw extruder is preferred from the viewpoint of efficient viscosity reduction. The resin temperature here is a value obtained by directly measuring the temperature of the resin discharged from the device.

[0049] Even when a high-viscosity recycled polysulfone resin is blended using the above method, the melt viscosity can be reduced to within a range of 1 to 500 Pa·s as needed, making it suitable for use as the (B) thermoplastic amorphous resin of the present invention. From the viewpoint of application to injection molding, where fluidity is required, the upper limit is preferably 450 Pa·s or less, more preferably 400 Pa·s or less. When blending a fibrous filler to obtain a composite material, from the viewpoint of suppressing breakage of the fibrous filler and improving mechanical properties, 350 Pa·s or less is particularly preferred, and 300 Pa·s or less is even more preferred. Furthermore, from the viewpoint of reducing the viscosity ratio with the (A) PPS resin and improving dispersibility when alloyed with the (A) PPS resin, 250 Pa·s or less is even more preferred, and 200 Pa·s or less is most preferred. Furthermore, from the viewpoint of expressing the properties of the polysulfone resin, the lower limit is preferably 10 Pa·s or more, more preferably 50 Pa·s or more.

[0050] In order to obtain a polysulfone-based resin having such a low viscosity, it is preferable to adjust the depolymerization reaction by changing the melt viscosity of the polysulfone-based resin or by changing the blending amount or type of the (Y) metal alkoxide.

[0051] The weight-average molecular weight of the polysulfone-based resin whose viscosity has been reduced by the above-mentioned method is preferably 10,000 or more and 60,000 or less. From the viewpoint of application to injection molding, where fluidity is required, the upper limit is preferably 55,000 or less, more preferably 50,000 or less. From the viewpoint of suppressing breakage of the fibrous filler and improving mechanical properties when blending a fibrous filler to obtain a composite material, 45,000 or less is particularly preferred, and 40,000 or less is even more preferred. From the viewpoint of reducing the viscosity ratio with the (A) PPS resin and improving dispersibility when alloyed with the (A) PPS resin, 35,000 or less is even more preferred. From the viewpoint of expressing the properties of the polysulfone-based resin, the lower limit is preferably 15,000 or more, more preferably 20,000 or more, and particularly preferably 25,000 or more. To obtain a polysulfone-based resin having such a weight-average molecular weight, it is preferable to adjust the depolymerization reaction by changing the amount or type of the (Y) metal alkoxide.

[0052] Here, an example of a method for obtaining a weight average molecular weight of 10,000 or more and 60,000 or less for a polysulfone-based resin has been described, but it is also preferable that the weight average molecular weight of the thermoplastic amorphous resin (B) other than a polysulfone-based resin is 10,000 or more and 60,000 or less.

[0053] When the polysulfone-based resin (B) depolymerized by the above-mentioned method is alloyed with the PPS resin (A), a two-stage process may be carried out in which the polysulfone-based resin (B), the hydrophilic resin (X), and the metal alkoxide (Y) are first brought into contact with each other in a non-solvent, and the depolymerized polysulfone-based resin (B) is then blended with the PPS resin (A), or the PPS resin (A), the polysulfone-based resin (B), the hydrophilic resin (X), and the metal alkoxide (Y) may all be brought into contact with each other in a non-solvent.

[0054] The thermoplastic amorphous resin (B) of the present invention must be contained in an amount of 15 to 70% by mass relative to 85 to 30% by mass of the PPS resin (A), taking the polyphenylene sulfide resin composition as 100% by mass, and from the viewpoint of contributing to a circular economy, the lower limit is preferably 20% by mass or more, and even more preferably 25% by mass or more. The upper limit is preferably 60% by mass or less, and more preferably 50% by mass or less, from the viewpoint of achieving compatibility with the properties of PPS.

[0055] The PPS resin composition of the present invention is prone to problems such as high melt viscosity (v) of the PPS resin composition and reduced fluidity when the thermoplastic amorphous resin (B) is incorporated at a high concentration to increase the recycled content. Therefore, the present inventors discovered that controlling the viscosity ratio of the PPS resin (A) to the thermoplastic amorphous resin (B) can achieve both good fluidity and mechanical properties. The ratio (b) / (a) of the melt viscosity (a) of the PPS resin (A) to the melt viscosity (b) of the thermoplastic amorphous resin (B) is preferably within the range of 0.1 to 20. The upper limit of the melt viscosity ratio (b) / (a) is preferably 15 or less, more preferably 10 or less, particularly preferably 7 or less, and even more preferably 5 or less. The lower limit is preferably 0.3 or more, more preferably 0.5 or more. Furthermore, from the viewpoint of enhancing the dispersibility of the thermoplastic amorphous resin (B), the melt viscosity ratio (b) / (a) is preferably as close to 1 as possible.

[0056] For the purpose of adjusting the viscosity ratio, it is preferable to use multiple PPS resins in combination to adjust the melt viscosity (a) of the (A) PPS resin. From the viewpoint of achieving both mechanical strength and fluidity, it is particularly preferable to use a PPS resin having a melt viscosity of 1 to 50 Pa·s and a PPS resin having a melt viscosity of 50 to 200 Pa·s in combination. When multiple PPS resins are used in combination, the melt viscosity (a) of the (A) PPS resin can be calculated from the melt viscosity of each PPS resin component in the PPS resin multiplied by the sum of the masses of each PPS resin in the PPS resin and the ratio of the mass of the PPS resin. Furthermore, for the purpose of adjusting the viscosity ratio, when the (B) thermoplastic amorphous resin is a (B) polysulfone-based resin, it is preferable that the (B) polysulfone-based resin be obtained by contacting the aforementioned (B) polysulfone-based resin with the (X) hydrophilic resin and the (Y) metal alkoxide in a non-solvent to depolymerize them.

[0057] The mechanical strength of the PPS resin composition of the present invention can be improved by blending (C) an inorganic filler such as a fibrous filler such as glass fiber, carbon fiber, carbon nanotube, carbon nanohorn, potassium titanate whisker, zinc oxide whisker, calcium carbonate whisker, wollastonite whisker, or aluminum borate whisker, as well as aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, gypsum fiber, or metal fiber. From the viewpoints of performance and cost, glass fiber and carbon fiber are particularly preferred.

[0058] The fiber diameter of the fibrous filler is preferably 1 to 50 μm, more preferably 3 to 30 μm, and even more preferably 5 to 20 μm. The smaller the fiber diameter of the fibrous filler, the more improved the tensile strength and flexural strength can be obtained. The larger the fiber diameter, the less likely the glass fibers are to break during molding, and the more improved the impact strength can be obtained. In addition, the increased voids between the fibers tend to improve the resin impregnation ability. By setting the fiber diameter within the above range, both mechanical strength and impregnation ability can be achieved, which is preferable.

[0059] (C) Inorganic fillers may include non-fibrous fillers such as fullerene, talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, silica, bentonite, asbestos, silicates such as alumina silicate, metal compounds such as silicon oxide, magnesium oxide, alumina, zirconium oxide, titanium oxide, and iron oxide, carbonates such as calcium carbonate, magnesium carbonate, and dolomite, sulfates such as calcium sulfate and barium sulfate, hydroxides such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide, glass beads, glass flakes, glass powder, ceramic beads, boron nitride, silicon carbide, carbon black, silica, and graphite. These inorganic fillers may be hollow, and two or more types may be used in combination. These inorganic fillers may also be pre-treated with coupling agents such as isocyanate compounds, organic silane compounds, organic titanate compounds, organic borane compounds, and epoxy compounds before use. Among these, magnesium hydroxide, calcium carbonate, silica, and carbon black are preferred in terms of electrical properties, corrosion prevention, lubricating properties, and conductivity-imparting effects.

[0060] By incorporating the inorganic filler, the interface between the resin and the inorganic filler becomes a bottleneck in the expression of the properties of the PPS resin composition, and deterioration in properties due to the incorporation of the thermoplastic amorphous resin (B) can be suppressed, and therefore, it is preferable to incorporate the inorganic filler.

[0061] The inorganic filler (C) is preferably blended in an amount of 1 to 55% by mass, based on 100% by mass of the PPS resin composition. From the viewpoint of ensuring that the PPS resin composition exhibits sufficient strength, the lower limit is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more. From the viewpoint of the fluidity of the PPS resin composition, the upper limit is preferably 50% by mass or less, more preferably 45% by mass or less.

[0062] Although the incorporation of (C) inorganic filler can impart favorable mechanical properties, the melt viscosity of the PPS resin composition tends to increase. On the other hand, since the (B) thermoplastic amorphous resin has a high viscosity, if a high amount is incorporated to increase the recycled material content, the melt viscosity (v) of the PPS resin composition tends to increase, resulting in a problem of reduced fluidity. Therefore, when the (C) inorganic filler is incorporated, it is preferable to adjust the ratio (b) / (a) of the melt viscosity (a) of the PPS resin to the melt viscosity (b) of the (B) thermoplastic amorphous resin.

[0063] In order to impart desired functions to the PPS resin composition of the present invention, it is preferable to blend (D) a thermoplastic elastomer. As the (D) thermoplastic elastomer, any of those generally called thermoplastic elastomers may be used, including olefin copolymers, styrene copolymers, urethane copolymers, ester copolymers, and amide copolymers, and two or more of these may also be used in combination.

[0064] Olefin copolymers are preferred from the viewpoint of imparting excellent toughness and heat cycle resistance due to stress relaxation to the PPS resin molding material, etc. Examples of the olefin copolymer include olefin copolymers having at least one functional group selected from the group consisting of epoxy groups, carboxyl groups, acid anhydride groups, amino groups, hydroxyl groups, and mercapto groups, which can improve compatibility with the PPS resin, and unmodified olefin copolymers, which can dramatically improve toughness, and their combined use is also effective.

[0065] The thermoplastic elastomer (D) is preferably blended in an amount of 1 to 50% by mass, based on 100% by mass of the PPS resin composition. From the viewpoint of imparting excellent toughness, the lower limit is preferably 3% by mass or more, more preferably 5% by mass or more, and from the viewpoint of imparting various functions, even more preferably 10% by mass or more. From the viewpoint of achieving both heat resistance and chemical resistance of the PPS resin composition, the upper limit is preferably 40% by mass or less, more preferably 30% by mass or less.

[0066] Although the incorporation of a (D) thermoplastic elastomer can impart desirable properties, it tends to increase the melt viscosity of the PPS resin composition. On the other hand, because the (B) thermoplastic amorphous resin has a high viscosity, incorporating a large amount of it to increase the recycled content can easily result in an increase in the melt viscosity (v) of the PPS resin composition, resulting in reduced fluidity. Therefore, when incorporating a (D) thermoplastic elastomer, it is preferable to adjust the ratio (b) / (a) of the melt viscosity (a) of the PPS resin to the melt viscosity (b) of the (B) thermoplastic amorphous resin. The PPS resin composition of the present invention can be formulated with conventional additives such as functional alkoxysilanes, phenolic antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, plasticizers such as organophosphorus compounds, organophosphorus compounds, Montan acid waxes, metal soaps such as lithium stearate and aluminum stearate, release agents such as ethylenediamine-stearic acid-sebacic acid polycondensates and silicone compounds, as well as water, lubricants, UV inhibitors, colorants, and foaming agents. Such additives are preferably blended in an amount of 0.01 to 5 parts by mass per 100 parts by mass of the PPS resin (A).

[0067] In particular, alkoxysilanes having a functional group are preferred because they have the function of adjusting the viscosity of the (A) PPS resin, the function of acting as a compatibilizer between the (A) PPS resin and the (B) thermoplastic amorphous resin, the function of improving the adhesion between the (A) PPS resin and the (C) inorganic filler, and the function of capturing silicone impurities and the like that have contaminated the recycled materials. The functional group is preferably at least one selected from an epoxy group, an amino group, and an isocyanate group.

[0068] The melt viscosity (v) of the PPS resin composition of the present invention must be 10 to 500 Pa s from the viewpoint of achieving both mechanical strength and fluidity. From the viewpoint of application to injection molding, which requires fluidity, it is preferably 400 Pa s or less, and more preferably 350 Pa s or less. From the viewpoint of moldability, it is preferably 30 Pa s or more, and more preferably 50 Pa s or more.

[0069] The melt viscosity (v) of the PPS resin composition in the present invention is a value measured using a capillary rheometer (for example, "Capilograph" (registered trademark) manufactured by Toyo Seiki Seisaku-sho) under conditions of a shear rate of 1216 / s and an orifice length L (mm) / orifice diameter D (mm) = 10 after allowing the composition to retain for 5 minutes at a test temperature of 310°C.

[0070] In order to obtain a PPS resin composition having such a melt viscosity, it is preferable to adjust the viscosity of the (A) PPS resin as described above, or to adjust the melt viscosity ratio (b) / (a) of the (B) thermoplastic amorphous resin using the depolymerization method described above.

[0071] The gas generation rate of the PPS resin composition of the present invention is preferably 2.0% by mass or less from the viewpoint of suppressing gas burning of a molded article during molding, more preferably 1.5% by mass or less from the viewpoint of suppressing mold fouling, particularly preferably 1.0% by mass or less from the viewpoint of increasing the strength of welds in the molded article, and even more preferably 0.5% by mass or less.

[0072] The gas generation rate of the PPS resin composition in the present invention is a mass reduction rate (%), which is the ratio of the mass change before and after drying treatment of PPS resin composition pellets at a test temperature of 320° C. for 2 hours.

[0073] In order to obtain a PPS resin composition having such a gas generation rate, a (B) thermoplastic amorphous resin having heat resistance similar to that of the PPS resin is selected. In addition, when the (B) thermoplastic amorphous resin is a molded article recovered after use in the market as process offcuts or a product, a preferred method is to remove impurities by subjecting the resin to appropriate washing or heat history during recycling.

[0074] In the PPS resin composition of the present invention, from the viewpoint of exhibiting the heat resistance and chemical resistance of the PPS resin, it is preferable that, in the phase structure observed by transmission electron microscopy of pellets or molded articles of the resin composition, the (A) PPS resin forms a continuous phase and the (B) thermoplastic amorphous resin forms a dispersed phase. To obtain such a phase structure, it is effective to set the volume fraction of the (A) PPS resin equal to or greater than the volume fraction of the (B) thermoplastic resin. On the other hand, by setting the melt viscosity of the (A) PPS resin equal to or less than the melt viscosity of the (B) thermoplastic amorphous resin, it is also possible to make the (A) PPS resin a continuous phase even if the volume fraction of the (A) PPS resin is equal to or less than the volume fraction of the (B) thermoplastic amorphous resin. Making the phase structure of the PPS resin composition a phase inversion structure as described above is preferable because it allows the amount of the (B) thermoplastic amorphous resin to be increased while exhibiting the heat resistance and chemical resistance of the (A) PPS resin. In particular, when the thermoplastic amorphous resin (B) is a recycled thermoplastic amorphous resin derived from fibers, it tends to exhibit a high melt viscosity. In such a case, it is preferable to form a phase inversion structure by using, for example, a PPS resin (A) having a lower melt viscosity than the thermoplastic amorphous resin (B).

[0075] The continuous phase and the dispersed phase can be identified by the following method: an ultrathin section is cut from a pellet of the PPS resin composition using an ultramicrotome, and an unstained sample of the ultrathin section is observed under a transmission electron microscope at a magnification of 2,000 to 10,000 times. The components constituting the dispersed phase can be identified by the difference in phase contrast in the unstained sample.

[0076] From the viewpoint of ensuring excellent mechanical properties and flowability, the PPS resin composition of the present invention preferably has a tensile strength of 80 MPa or more and 250 MPa or less, as measured in accordance with ISO 527-1, -2 (2012). From the viewpoint of obtaining even better mechanical properties, a tensile strength of 120 MPa or more is more preferable, and from the viewpoint of use as a metal replacement, a tensile strength of 150 MPa or more is particularly preferable. Furthermore, from the viewpoint of obtaining even better flowability, a tensile strength of 200 MPa or less is preferable. The tensile strength can be adjusted by (A) adjusting the melt viscosity of the PPS resin, (B) adjusting the type and amount of the thermoplastic amorphous resin, or (C) blending an inorganic filler. Since the tensile strength of a PPS resin that has sufficiently exhibited toughness is approximately 80 MPa, for example, blending a thermoplastic resin such as recycled polyamide to result in a tensile strength of less than 80 MPa is not preferred, as this does not utilize the inherent properties of the PPS resin.

[0077] From the viewpoint of ensuring excellent mechanical properties and flowability, the PPS resin composition of the present invention preferably has a weld tensile strength of 20 MPa or more and 150 MPa or less, as measured according to ASTM D638 (2010). From the viewpoint of obtaining even better mechanical properties, 30 MPa or more is more preferable, and 40 MPa or more is particularly preferable. From the viewpoint of obtaining practical physical properties such as water pressure burst strength, 50 MPa or more is particularly preferable, and 60 MPa or more is most preferable. Furthermore, from the viewpoint of obtaining even better flowability, 100 MPa or less is preferable. The weld tensile strength is the tensile strength of the weld joint of a molded product. Since weld joints are difficult to reinforce with inorganic fillers, the properties of the thermoplastic resin are easily expressed at these joints. Therefore, the weld tensile strength can be adjusted by adjusting the melt viscosity of (A) the PPS resin or the type and amount of (B) the thermoplastic amorphous resin. The weld tensile strength of a PPS resin alone that has fully exhibited toughness is about 80 MPa. Therefore, if a thermoplastic resin such as recycled polyamide is blended with the resin and this significantly reduces the weld tensile strength to 80 MPa or less, this is not preferable as it prevents the inherent properties of the PPS resin from being utilized.

[0078] The PPS resin composition of the present invention retains the inherent mechanical properties and fluidity of PPS, and therefore, even with a high recycled content, a weld strength retention of 20% or more can be achieved. From the viewpoint of obtaining better mechanical properties, 30% or more is preferred, and 40% or more is preferable. From the viewpoint of obtaining practical physical properties such as water pressure burst strength, 50% or more is particularly preferable, and 70% or more is most preferable. The weld strength retention in the present invention is a value calculated by dividing the weld tensile strength by the tensile strength x 100 (%).

[0079] From the viewpoint of ensuring excellent mechanical properties and flowability, the PPS resin composition of the present invention has a Charpy impact strength (notched) of 3 kJ / m as measured in accordance with ISO 179 (2010). ２ Above, 40kJ / m ２ From the viewpoint of obtaining better mechanical properties, it is preferably 5 kJ / m or less. ２ More than 7 kJ / m is preferable. ２ More preferably, it is 10 kJ / m or more from the viewpoint of using it as a metal replacement. ２ More preferably, the amount is 30 kJ / m or more. ２ The following is preferred. The Charpy impact strength (notched) can be adjusted by (A) adjusting the melt viscosity of the PPS resin, (B) adjusting the type and amount of the thermoplastic amorphous resin, or (C) blending an inorganic filler. For example, if the toughness of the (A) PPS resin is reduced by blending a thermoplastic resin such as recycled polyamide, the test piece may break during notching, and the inherent properties of the PPS resin may not be utilized, which is not preferred.

[0080] When the PPS resin composition of the present invention is applied to plumbing components such as piping components for housing facilities and water heaters, the water pressure fracture strength of the molded product is important. The water pressure fracture strength is preferably 7 MPa or more, more preferably 8 MPa or more, and even more preferably 9 MPa or more. A water pressure fracture strength of 7 MPa or more is preferable because it improves durability and can withstand use in hot water environments. The water pressure fracture strength in the present invention was measured by connecting one end of a T-shaped pipe fitting having an outer diameter of 21.7 mm and a wall thickness of 2.8 mm as specified in JIS G 3452 to a Kiyowa pump (T-300N), passing water through a test specimen with the ball valve open, purging the air from inside the test specimen, closing the ball valve, and then applying water pressure using the pump. The pressure indicated by the pressure gauge at the time of test specimen fracture was the water pressure fracture strength. The water pressure fracture strength can be improved by increasing the weld tensile strength and Charpy impact strength (notched).

[0081] When the PPS resin composition of the present invention is used in plumbing applications such as piping components for housing facilities and water heaters, it is important that the amount of contaminants leaching from the molded article into water is low. The amount of contaminants leaching from the molded article into water is determined by the total organic carbon (TOC) content of the Water Supply Method Test (JIS S 3200-7:2010, "Plumbing Appliances - Leaching Performance Test"). TOC content is an indicator of water contamination, and JIS S 3200-7:2010 specifies a standard value of 3 mg / L or less. Therefore, the TOC content in the present invention is preferably 3 mg / L or less, more preferably 2 mg / L or less, and even more preferably 1 mg / L or less. The TOC content in the present invention is determined by treating a molded square plate measuring 80 mm x 80 mm x 3 mm in water under the conditions specified in JIS S 3200-7:2010, 7.1.2a), and measuring the resulting leachate using a total organic carbon meter. The TOC content can be reduced by reducing the amount of organic substances in the PPS resin composition or by using a PPS resin with high heat resistance and chemical resistance as the continuous phase. In particular, even if the PPS resin composition contains a hydrophilic resin (X) or a metal alkoxide (Y), using a PPS resin as the continuous phase is preferred because it allows for a reduction in the TOC content.

[0082] There are no particular limitations on the method for producing the PPS resin composition of the present invention, and a representative example is a method in which raw materials are fed into a known melt-kneader such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll, and melt-kneaded so that the resin temperature is the peak melting temperature of the PPS resin (A) + 5°C to 100°C. Among these, melt-kneading using a twin-screw extruder is preferred. The resin temperature here is a value obtained by directly measuring the temperature of the resin discharged from the extruder.

[0083] The PPS resin composition of the present invention, like known PPS resin compositions, can be applied to various molding methods, such as extrusion molding, injection molding, blow molding, calendar molding, compression molding, vacuum molding, foam molding, blow molding, and rotational molding, and is particularly suitable for injection molding.

[0084] Molded articles obtained by molding the PPS resin composition of the present invention, like known PPS resin compositions, can be used in the known applications described in many patents relating to PPS resin compositions. In particular, they are preferably used in automotive components, where demand for a circular economy is increasing. Because the elution of contaminants into water from the molded articles is minimal, they are also preferably used in plumbing applications such as toilet-related parts, water heater-related parts, bath-related parts, pump-related parts, and water meter-related parts.

[0085] The effects of the present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0086] (1) Melt Viscosity The PPS resin compositions obtained in each Example and Comparative Example were measured using a Toyo Seiki "Capilograph" (registered trademark) under the conditions of a temperature of 310°C, a shear rate of 1216 / s, and an orifice length L (mm) / orifice diameter D (mm) = 10 after 5 minutes of residence at 310°C. The thermoplastic amorphous resins obtained in each raw material, Reference Example, and Comparative Example were measured using a Toyo Seiki "Capilograph" (registered trademark) under the conditions of a temperature of 310°C, a shear rate of 1216 / s, and an orifice length L (mm) / orifice diameter D (mm) = 10 after 5 minutes of residence at Tg of the thermoplastic amorphous resin + 150°C.

[0087] (2) Preparation of test pieces by injection molding The PPS resin compositions obtained in each example and comparative example were dried in a hot air dryer at 130°C for 3 hours, and then injection-molded into ISO (1A) dumbbell test pieces using an injection molding machine SE75-DUZ manufactured by Sumitomo Heavy Industries, Ltd., under conditions of a cylinder temperature of 310°C, a mold temperature of 140°C, and a screw rotation speed of 100 rpm. Next, ASTM No. 4 dumbbell test pieces (1.6 mm thick) with gates on both ends and a weld line near the center of the test piece were injection-molded.

[0088] (3) Mechanical Properties: The ISO (1A) dumbbell test specimens obtained in (2) above were evaluated for tensile strength at 23°C using an Autograph AG-Xplus 20kN testing machine in accordance with ISO 527-1, -2 (2012), with a support distance of 114 mm and a tensile speed of 5 mm / min. Next, the ASTM No. 4 dumbbell test specimens with weld lines obtained in (2) above were evaluated for weld tensile strength at 23°C using an Autograph AG-Xplus 20kN testing machine in accordance with ASTM-D638 (2010), with a support distance of 64 mm and a tensile speed of 10 mm / min. The weld strength retention (%) was then calculated based on the formula: weld tensile strength / tensile strength x 100%. Next, the ISO (1A) dumbbell obtained in the above (2) was cut to obtain a test piece, and the Charpy impact strength (with notch) was evaluated in accordance with ISO 179 (2010).

[0089] (4) Observation of Phase Structure Ultrathin sections were cut from the ISO(1A) dumbbell test specimens obtained in (2) above using an ultramicrotome, and the unstained samples of the ultrathin sections were observed under a transmission electron microscope at magnifications of 5,000 to 10,000. The components constituting the dispersed phase were identified by comparing the contrast difference of the phases in the unstained samples.

[0090] (5) Gas Generation Rate 10 g of the PPS resin composition pellets obtained in each Example and Comparative Example were weighed into an aluminum cup, treated for 2 hours in an Espec PHH202 hot air dryer heated to 320° C., and allowed to cool at room temperature. The mass was then measured, and the mass reduction rate (%), which is the ratio of the mass after drying to the mass before drying, was taken as the gas generation rate.

[0091] (6) Measurement of Water Pressure Burst Strength The PPS resin compositions obtained in each Example and Comparative Example were dried for 3 hours in a 130°C hot air dryer and injection molded using a Sumitomo Heavy Industries injection molding machine (SE100DU) at a cylinder temperature of 305°C, a mold temperature of 130°C, a filling time of 1 s, and a holding pressure of 50% of the filling pressure to obtain a T-shaped pipe joint test piece with an outer diameter of 21.7 mm and a wall thickness of 2.8 mm. One end of this test piece was connected to a rubber pipe connected to a Kyowa pump (T-300N), and the remaining two ends were connected to ball valves. Water was passed through the test piece with the ball valve open, and the air inside the test piece was purged, after which the ball valve was closed. Water pressure was applied using the pump, and the pressure indicated by the pressure gauge at the time of test piece failure was taken as the water pressure burst strength.

[0092] (7) Measurement of TOC Amount The PPS resin compositions obtained in Reference Example 7 and Example 15 were dried in a 130°C hot air dryer for 3 hours, and injection-molded using an injection molding machine (SE75-DUZ) manufactured by Sumitomo Heavy Industries under conditions of a cylinder temperature of 310°C, a mold temperature of 140°C, and a screw rotation speed of 100 rpm to obtain 80 x 80 x 3 mm square plates. These were treated in water under the conditions specified in JIS S 3200-7:2010 7.1.2a), and the TOC amount of the resulting leachate was measured using a total organic carbon meter measurement method.

[0093] (8) Molecular Weight Measurement of PPS Resin The weight average molecular weight (Mw) was calculated in terms of polystyrene using gel permeation chromatography (GPC), a type of size exclusion chromatography (SEC). The GPC measurement conditions are as follows: Apparatus: Senshu Scientific SSC-7110 Column name: "Shodex" (registered trademark) UT806M x 2 Eluent: 1-chloronaphthalene Detector: Differential refractive index detector Column temperature: 210 ° C. Pre-thermostat temperature: 250 ° C. Pump thermostat temperature: 50 ° C. Detector temperature: 210 ° C. Flow rate: 1.0 mL / min (9) Molecular Weight Measurement of Polysulfone Resin The weight average molecular weight (Mw) was calculated in terms of polystyrene using gel permeation chromatography (GPC), a type of size exclusion chromatography (SEC). The GPC measurement conditions are as follows: Apparatus: Resonac "Shodex" (registered trademark) GPC-101 Column name: Resonac "Shodex" (registered trademark) KF806L Eluent: THF Sample concentration: 1 mg / ml Detector: Differential refractive index detector Column temperature: 40°C Detector temperature: 35°C Flow rate: 1.0 mL / min When measuring the molecular weight of the polysulfone resin in the PPS resin composition, 10 g of THF was added to 20 mg of the PPS resin composition, and the extract was subjected to two 45-minute ultrasonic extractions. The solution obtained was filtered through a microfilter with a pore size of 0.45 μm and used for measurement. (10) Molecular Weight Measurement of Polyetherimide Resin and Polyethersulfone Resin The weight average molecular weight (Mw) was calculated in terms of polystyrene using gel permeation chromatography (GPC), a type of size exclusion chromatography (SEC). The GPC measurement conditions are described below. Apparatus: "Shodex" (registered trademark) GPC-101 manufactured by Resonac Column name: "Shodex" (registered trademark) KF805L manufactured by Resonac Eluent: DMF / LiCl (0.5 wt%) Sample concentration: 1 mg / ml Detector: differential refractive index detector Column temperature: 40°C Detector temperature: 35°C The raw materials used in each example and comparative example are shown below.

[0094] [Reference Example 1] (A-1) An autoclave equipped with a polyphenylene sulfide resin stirrer and a bottom stop valve was charged with 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.91 kg (69.80 mol) of 96% sodium hydroxide, 11.45 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), 1.89 kg (23.10 mol) of sodium acetate, and 10.5 kg of ion-exchanged water. The mixture was gradually heated to 245°C over approximately 3 hours under atmospheric pressure while passing nitrogen through it. 14.78 kg of water and 0.28 kg of NMP were distilled off, and the reaction vessel was then cooled to 200°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.06 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.02 mol per mole of charged alkali metal sulfide.

[0095] The mixture was then cooled to 200°C, and 10.45 kg (71.07 mol) of p-dichlorobenzene and 9.37 kg (94.50 mol) of NMP were added. The reaction vessel was sealed under nitrogen gas and heated from 200°C to 270°C at a rate of 0.6°C / min while stirring at 240 rpm. After reacting at 270°C for 100 minutes, the bottom stopper valve of the autoclave was opened, and the contents were flushed into a vessel equipped with a stirrer over 15 minutes while pressurizing with nitrogen, and the mixture was stirred for a while at 250°C to remove most of the NMP.

[0096] The obtained solid and 76 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer, washed at 70°C for 30 minutes, and then suction-filtered through a glass filter. Next, 76 liters of ion-exchanged water heated to 70°C was poured into the glass filter and suction-filtered to obtain a cake.

[0097] The obtained cake and 90 liters of ion-exchanged water were charged into an autoclave equipped with a stirrer, and acetic acid was added to adjust the pH to 7. After the inside of the autoclave was purged with nitrogen, the temperature was raised to 192°C and maintained at that temperature for 30 minutes. Thereafter, the autoclave was cooled, and the contents were removed.

[0098] The contents were filtered with a glass filter under suction, and then 76 liters of ion-exchanged water at 70°C was poured into the filter and filtered under suction to obtain a cake. The obtained cake was dried at 120°C under a nitrogen stream to obtain a dried PPS.

[0099] The PPS obtained above was placed in a heating device equipped with a stirrer and subjected to heat treatment under the conditions of an oxygen concentration of 2% and 200°C for 2 hours. Note that, for the heat treatment at an oxygen concentration of 2%, 0.18 L / min of air and 1.78 L / min of nitrogen were introduced into the heating device, and an oxygen concentration meter was installed in the heating device to measure the oxygen concentration.

[0100] The resulting PPS resin (A-1) had a melt viscosity of 110 Pa·s at 310° C. and a weight average molecular weight of 60,000.

[0101] [Reference Example 2] (A-2) An autoclave equipped with a polyphenylene sulfide resin stirrer and a bottom stop valve was charged with 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.91 kg (69.80 mol) of 96% sodium hydroxide, 11.45 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), and 10.5 kg of ion-exchanged water, and the mixture was gradually heated to 245°C over approximately 3 hours under atmospheric pressure while passing nitrogen through it. 14.78 kg of water and 0.28 kg of NMP were distilled off, and the reaction vessel was then cooled to 200°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.06 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.02 mol per mole of charged alkali metal sulfide.

[0102] The mixture was then cooled to 200°C, and 10.48 kg (71.27 mol) of p-dichlorobenzene and 9.37 kg (94.50 mol) of NMP were added. The reaction vessel was sealed under nitrogen gas and heated from 200°C to 270°C at a rate of 0.6°C / min while stirring at 240 rpm. After reacting for 100 minutes at 270°C, the bottom stopper valve of the autoclave was opened, and the contents were flushed into a vessel equipped with a stirrer over 15 minutes while pressurizing with nitrogen, and the contents were stirred for a while at 250°C to remove most of the NMP.

[0103] The obtained solid and 76 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer, washed at 70°C for 30 minutes, and then suction-filtered through a glass filter. Next, 76 liters of ion-exchanged water heated to 70°C was poured into the glass filter and suction-filtered to obtain a cake.

[0104] The obtained cake and 90 liters of ion-exchanged water were charged into an autoclave equipped with a stirrer, and acetic acid was added to adjust the pH to 7. After the inside of the autoclave was purged with nitrogen, the temperature was raised to 192°C and maintained at that temperature for 30 minutes. Thereafter, the autoclave was cooled, and the contents were removed.

[0105] The contents were filtered with a glass filter under suction, and then 76 liters of ion-exchanged water at 70°C was poured into the filter and filtered under suction to obtain a cake. The obtained cake was dried at 120°C under a nitrogen stream to obtain a dried PPS.

[0106] The PPS obtained above was placed in a heating device equipped with a stirrer and subjected to heat treatment under the conditions of 2% oxygen concentration and 220°C x 12 hours. For the heat treatment at 2% oxygen concentration, 0.18 L / min of air and 1.78 L / min of nitrogen were introduced into the heating device, and an oxygen concentration meter was installed in the heating device to measure the oxygen concentration. The resulting PPS resin (A-2) had a melt viscosity of 20 Pa s at 310°C and a weight average molecular weight of 25,000.

[0107] [Reference Example 3] (A-3) An autoclave equipped with a polyphenylene sulfide resin stirrer and a bottom stop valve was charged with 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.94 kg (70.63 mol) of 96% sodium hydroxide, 11.45 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), 2.24 kg (27.3 mol) of sodium acetate, and 5.50 kg of ion-exchanged water. The mixture was gradually heated to 245°C over approximately 3 hours under atmospheric pressure while passing nitrogen through it. 9.77 kg of water and 0.28 kg of NMP were distilled off, and the reaction vessel was then cooled to 200°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.06 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.02 mol per mole of charged alkali metal sulfide.

[0108] After that, it was cooled to 200 ° C., 10.32 kg (70.20 mol) of p-dichlorobenzene and 9.37 kg (94.50 mol) of NMP were added, the reaction vessel was sealed under nitrogen gas, and the temperature was raised from 200 ° C. to 235 ° C. at a rate of 0.8 ° C. / min while stirring at 240 rpm, and the reaction was carried out at 235 ° C. for 40 minutes. Thereafter, the temperature was raised to 270 ° C. at a rate of 0.8 ° C. / min, and the reaction was carried out at 270 ° C. for 70 minutes. After that, 2.40 kg (133 mol) of water was injected while cooling from 270 ° C. to 250 ° C. over 15 minutes. Then, it was gradually cooled from 250 ° C. to 220 ° C. over 75 minutes, and then rapidly cooled to near room temperature and the contents were removed.

[0109] The contents were diluted with approximately 35 liters of NMP to form a slurry, which was stirred at 85°C for 30 minutes and then filtered through an 80-mesh wire mesh (opening 0.175 mm) to obtain a solid. The resulting solid was similarly washed and filtered with approximately 35 liters of NMP. The resulting solid was diluted with 70 liters of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh to recover the solid. This operation was repeated three times. The resulting solid and 32 g of acetic acid were diluted with 70 liters of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh. The resulting solid was further diluted with 70 liters of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh to recover the solid. The solid thus obtained was dried at 120°C under a nitrogen stream to obtain dried PPS.

[0110] The resulting PPS resin (A-3) had a melt viscosity of 170 Pa·s at 310° C. and a weight average molecular weight of 70,000.

[0111] (B-1) Recycled polysulfone resin (thermoplastic amorphous resin) This polysulfone resin was derived from hollow fiber process waste materials used in artificial kidneys. Its Tg was 190°C, melt viscosity at 340°C was 580 Pa s, weight average molecular weight was 62,000, and the content of the hydrophilic resin polyvinylpyrrolidone was approximately 2% as a result of elemental analysis.

[0112] (B-2) Recycled polyethersulfone resin (thermoplastic amorphous resin) This polyethersulfone resin was derived from hollow fiber process waste materials used in artificial kidneys. Its Tg was 220°C, its melt viscosity at 370°C was 900 Pa s, its weight-average molecular weight was 72,000, and its content of the hydrophilic resin polyvinylpyrrolidone was approximately 2% as determined by elemental analysis.

[0113] (B-3) Recycled polysulfone resin (thermoplastic amorphous resin) This polysulfone resin originating from a sprue runner generated during injection molding was used. It had a Tg of 190°C, a melt viscosity of 550 Pa s at 340°C, a weight-average molecular weight of 29,000, and a hydrophilic resin content of 0%.

[0114] (B-4) Recycled polyethersulfone resin (thermoplastic amorphous resin) This polyethersulfone resin originating from a sprue runner generated during injection molding was used. It had a Tg of 220°C, a melt viscosity at 370°C of 300 Pa s, a weight-average molecular weight of 40,000, and a hydrophilic resin content of 0%.

[0115] (B-5) Recycled polyetherimide resin (thermoplastic amorphous resin) This polyetherimide resin originated from a sprue runner generated during injection molding. It had a Tg of 220°C, a melt viscosity of 600 Pa s at 370°C, a weight-average molecular weight of 61,000, and a hydrophilic resin content of 0%.

[0116] (B'-1) Recycled Polyamide 6 Resin (Thermoplastic Crystalline Resin) As the recycled polyamide 6, "Reamide" (registered trademark) RA6H00 manufactured by Refinverse was used.

[0117] (B'-2) Recycled Polyamide 66 Resin (Thermoplastic Crystalline Resin) As the recycled polyamide 66, "Reamide" (registered trademark) RA7C00 manufactured by Refinverse was used.

[0118] (C-1) Chopped glass bundled with an epoxy compound having an inorganic filler fiber length of 3 mm and an average fiber diameter of 10.5 μm was used (T760H manufactured by Nippon Electric Glass Co., Ltd.).

[0119] (D-1) Olefin copolymer: An ethylene-glycidyl methacrylate copolymer was used ("Bondfast" (registered trademark) E, manufactured by Sumitomo Chemical).

[0120] (D-2) Olefin copolymer: An ethylene / 1-octene copolymer was used (Dow Chemical's "Engage" (registered trademark) 8842).

[0121] [Reference Examples 4 to 7, Comparative Examples 1 to 4, Examples 1 to 16] To obtain a PPS resin composition, the raw materials, excluding (C) inorganic filler, were dry-blended in the proportions shown in Tables 1 to 3 to form a main-feed raw material blend. The main-feed raw material blend was then charged from the base charging position into a TEX30α twin-screw extruder (L / D = 45, 3 kneading sections) manufactured by The Japan Steel Works, Ltd., equipped with a vacuum vent, so as to achieve the mass percentages shown in Tables 1 to 3. The (C) inorganic filler was charged using a side feeder manufactured by The Japan Steel Works, Ltd., so as to achieve the mass percentages shown in Tables 2 and 3. After charging, the mixture was melt-kneaded at a cylinder temperature of 300°C and a screw rotation speed of 200 rpm to obtain pellets of the PPS resin composition, and the pellet evaluations (1) and (5) above were carried out.

[0122] The pellets were then injection molded under the conditions described in (2) above to obtain ISO (1A) dumbbell test pieces and ISO (1A) welded dumbbell test pieces. The mechanical properties of the test pieces were measured.

[0123] The pellets thus obtained were then injection molded under the conditions described in (6) and (7) above, and the resulting molded articles were measured for water pressure burst strength and TOC content.

[0124]

[0125] A comparison of Table 1 above reveals the following.

[0126] A comparison of Reference Example 4 with Comparative Examples 1 and 2 showed that when a large amount of recycled polyamide 6,66 was blended, the gas generation rate increased, and the tensile strength and weld tensile strength decreased, as well as the Charpy impact strength decreased. On the other hand, a comparison of Reference Example 4 with Examples 1 to 5 showed that blending a thermoplastic amorphous resin improved the recycled content while maintaining the inherent mechanical strength and fluidity of PPS. A comparison of Example 1 with Examples 6 and 7 showed that even when the blending amount of (B) recycled thermoplastic amorphous resin was increased, the recycled content was improved while maintaining the inherent mechanical strength and fluidity of PPS. A comparison of Example 1 with Example 8 also showed that by using (A) PPS resins of different viscosities in combination and adjusting the viscosity ratio of (A) PPS resin and (B) thermoplastic amorphous resin, the recycled content could be improved while maintaining the inherent mechanical strength and fluidity of PPS.

[0127]

[0128] Comparing the data in Table 2 reveals the following.

[0129] A comparison of Reference Example 4 and Reference Example 5 shows that the incorporation of (C) inorganic filler increases the melt viscosity (v) of the PPS resin composition, making it more difficult to design a desirable melt viscosity. On the other hand, a comparison of Reference Example 5 and Examples 9 to 13 shows that even if the amount of (B) thermoplastic amorphous resin is increased in a resin composition containing (C) inorganic filler, the recycled material content can be increased while maintaining the inherent mechanical strength and fluidity of PPS by using (A) PPS resins of different viscosities in combination and adjusting the viscosity ratio of (A) PPS resin to (B) thermoplastic amorphous resin within a specified range.

[0130]

[0131] Comparing the data in Table 3 reveals the following.

[0132] A comparison of Reference Examples 6 and 7 reveals that the incorporation of the thermoplastic elastomer (D) increases the melt viscosity (v) of the PPS resin composition, making it even more difficult to design a desirable melt viscosity.

[0133] A comparison of Reference Example 7 with Comparative Examples 3 and 4 reveals that blending a large amount of recycled polyamide 6,66 results in an increase in the gas generation rate, a decrease in tensile strength and weld tensile strength, and a decrease in Charpy impact strength. On the other hand, a comparison of Reference Example 7 with Examples 14 to 16 reveals that even if the blending amount of (B) thermoplastic amorphous resin is increased in a resin composition blended with (C) inorganic filler and (D) thermoplastic elastomer, by combining (A) PPS resins of different viscosities and adjusting the viscosity ratio of (A) PPS resin to (B) thermoplastic amorphous resin within a specified range, it is possible to improve the recycled material content while maintaining both the inherent mechanical strength and fluidity of PPS.

[0134] Furthermore, the water pressure breakdown strength was 7 MPa or more, making it suitable for use in wet areas. Furthermore, the TOC amount of Reference Example 7 was 0.14 mg / L, and that of Example 15 was 0.10 mg / L. Even when a large amount of (B) thermoplastic amorphous resin was blended, the TOC amount was equivalent to that of a PPS resin composition consisting of PPS alone, inorganic filler, and thermoplastic elastomer, demonstrating its suitability for use in wet areas. Meanwhile, comparing Reference Example 7 with Examples 14 to 16, decreasing the viscosity ratio of (A) PPS resin to (B) thermoplastic amorphous resin improved weld strength and weld strength retention to the same level as Reference Example 7, but also increased melt viscosity (v) and reduced fluidity. Increasing the viscosity ratio showed the opposite trend, indicating a trade-off between these properties. This is because (B) recycled thermoplastic amorphous resin has a high viscosity, which makes it necessary to lower the molecular weight and viscosity of (A) PPS resin, and at the same time, the toughness of the PPS resin decreases. This is a problem specific to the use of (B) recycled thermoplastic amorphous resin.

[0135] Therefore, it is preferable to further improve the weld strength and fluidity by lowering the viscosity of the (B) recycled thermoplastic amorphous resin by depolymerization to reduce the viscosity ratio between the (A) PPS and the (B) thermoplastic amorphous resin, as exemplified below.

[0136] (B-6) Recycled polysulfone resin (thermoplastic amorphous resin) This polysulfone resin originating from a sprue runner generated during injection molding was used. It had a Tg of 190°C, a melt viscosity at 340°C of 690 Pa s, a weight-average molecular weight of 69,000, and a hydrophilic resin content of 0%.

[0137] (X-1) As the hydrophilic resin, polyvinylpyrrolidone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., Polyvinylpyrrolidone K90) was used.

[0138] (X-2) Polyethylene glycol (PEG20000, manufactured by Sanyo Chemical Industries, Ltd.) was used as the hydrophilic resin.

[0139] (Y-1) Bisphenol A disodium salt, a metal alkoxide: 40 g of water, 0.96 g (0.02 mol) of sodium hydroxide, and 2.51 g (0.01 mol) of bisphenol A (Tokyo Chemical Industry Co., Ltd., special grade reagent) were charged into a 100 ml recovery flask and mixed and stirred using a stirrer at room temperature and atmospheric pressure. After the bisphenol A was completely dissolved, water was removed using an evaporator. The resulting sample was then vacuum dried overnight at 60°C to obtain bisphenol A disodium salt.

[0140] (Y-2) Bisphenol A dipotassium salt, a metal alkoxide: 40 g of water, 1.45 g (0.02 mol) of potassium hydroxide, and 2.51 g (0.01 mol) of bisphenol A (Tokyo Chemical Industry Co., Ltd., special grade reagent) were charged into a 100 ml recovery flask and mixed and stirred at 50°C using a stirrer. After the bisphenol A was completely dissolved, water was removed using an evaporator. The resulting sample was then vacuum dried overnight at 60°C to obtain bisphenol A dipotassium salt.

[0141] [Reference Examples 8 to 15, Comparative Examples 5 to 6] The raw materials were dry-blended in the proportions shown in Table 4. The raw material blend was then charged into a ThermoFisher "HAAKE" MiniLab twin-screw extruder and melt-kneaded at a cylinder temperature of 340°C and a screw rotation speed of 200 rpm. The mixture was discharged after a kneading time of 2 minutes to obtain a polysulfone-based resin composition. The obtained polysulfone-based resin composition was then subjected to the analyses described in (1) and (9) above.

[0142] [Reference Example 16] The raw materials were dry-blended in the proportions shown in Table 4. Next, the raw material blend was charged from the base charging position into a TEX30α twin-screw extruder (L / D = 45, 3 kneading sections) manufactured by The Japan Steel Works, Ltd., equipped with a vacuum vent, and melt-kneaded at a cylinder temperature of 340°C and a screw rotation speed of 150 rpm to obtain pellets of a polysulfone-based resin composition, which were subjected to the above-mentioned analyses (1) and (9).

[0143]

[0144] The parts by mass of the (X) hydrophilic resin in Reference Examples 11 to 16 are values ​​calculated from the content of polyvinylpyrrolidone already contained in the (B-1) polysulfone resin derived from hollow fiber process waste materials used in artificial kidneys, and no additional (X) hydrophilic resin was added.

[0145] From these comparisons, it was found that when the three components (B) polysulfone-based resin, (X) hydrophilic resin, and (Y) metal alkoxide were simultaneously contacted in the presence of a non-solvent, the melt viscosity and the molecular weight of the polysulfone-based resin were significantly reduced. Furthermore, as in Reference Example 10, it was found that the melt viscosity and the molecular weight of the polysulfone-based resin were significantly reduced when polyethylene glycol was added as the hydrophilic resin (X).

[0146] It is presumed that the high compatibility between the polysulfone resin (B) and the hydrophilic resin (X), and the high compatibility between the hydrophilic resin (X) and the metal alkoxide (Y) increased the frequency of contact between the polysulfone resin (B) and the metal alkoxide (Y), resulting in efficient depolymerization in a short time even in the presence of a non-solvent.

[0147] Comparison of Reference Examples 11 to 16 revealed that even if the polysulfone resin (B) was derived from process waste materials of hollow fiber membranes and contained the hydrophilic resin (X) derived from the process, the addition of the metal alkoxide (Y) reduced the melt viscosity and the molecular weight of the polysulfone resin. Thus, process waste materials of hollow fiber membranes used in artificial kidneys are suitable because they contain the hydrophilic resin derived from the process.

[0148] The recycled polysulfone resin (B-7) obtained in Reference Example 16 was used to carry out the following investigation.

[0149] Examples 17 to 20 Pellets of the PPS resin composition were obtained and evaluated in the same manner as in Example 1, except that the raw materials used were changed to those shown in Table 5.

[0150]

[0151] The following is clear from a comparison of Table 5 above.

[0152] A comparison of Reference Example 7 with Examples 14 and 17 reveals that by lowering the melt viscosity (b) of the thermoplastic amorphous resin (B), it is possible to reduce the melt viscosity (v) of the PPS resin composition while decreasing the viscosity ratio between the PPS resin (A) and the thermoplastic amorphous resin (B), and that it is possible to achieve a high degree of compatibility between the inherent mechanical properties and fluidity of PPS and a high recycled material content.

[0153] Comparison of Examples 14 and 18 to 20 revealed that even when a resin composition comprising (A) PPS resin, (B) polysulfone-based resin, (X) hydrophilic resin, and (Y) metal alkoxide was contacted together in the presence of a non-solvent, the melt viscosity (v) of the PPS resin composition was reduced, and the inherent mechanical properties and fluidity of PPS, as well as a high recycled material content, could be achieved at the same time.

Claims

1. A polyphenylene sulfide resin composition comprising 85 to 30% by mass of (A) polyphenylene sulfide resin and 15 to 70% by mass of (B) thermoplastic amorphous resin, where the polyphenylene sulfide resin composition is 100% by mass, wherein the thermoplastic amorphous resin (B) is a recycled thermoplastic amorphous resin, and wherein the polyphenylene sulfide resin composition is retained using a capillary rheometer at 310°C for 5 minutes and then measured under the condition of orifice length L (mm) / orifice diameter D (mm) = 10, and the melt viscosity (v) at a shear rate of 1216 / s is 10 to 500 Pa s.

2. The polyphenylene sulfide resin composition according to claim 1, wherein the thermoplastic amorphous resin (B) has a melt viscosity (b) of 1 to 1,000 Pa·s at a shear rate of 1,216 / s when measured using a capillary rheometer under the conditions of orifice length L (mm) / orifice diameter D (mm) = 10 after 5 minutes of residence at a temperature 150°C above the glass transition temperature of the thermoplastic amorphous resin (B), and wherein the ratio (b) / (a) of the melt viscosity (a) to the melt viscosity (b) of the polyphenylene sulfide resin (A) is within the range of 0.1 to 20 when measured using a capillary rheometer under the conditions of orifice length L (mm) / orifice diameter D (mm) = 10 after 5 minutes of residence at 310°C.

3. A polyphenylene sulfide resin composition according to claim 1 or 2, wherein (A) the polyphenylene sulfide resin forms a continuous phase, and (B) the thermoplastic amorphous resin forms a dispersed phase.

4. The polyphenylene sulfide resin composition according to claim 1 or 2, which contains 1 to 55 mass% of (C) inorganic filler, based on 100 mass% of the polyphenylene sulfide resin composition.

5. A polyphenylene sulfide resin composition according to claim 1 or 2, wherein the weight average molecular weight of the polyphenylene sulfide resin (A) is 20,000 or more and 100,000 or less.

6. The polyphenylene sulfide resin composition according to claim 1 or 2, wherein (A) the polyphenylene sulfide resin is a combination of a polyphenylene sulfide resin having a melt viscosity of 1 to 50 Pa·s and a polyphenylene sulfide resin having a melt viscosity of 50 to 200 Pa·s at a shear rate of 1216 / s when measured using a capillary rheometer under the condition of orifice length L (mm) / orifice diameter D (mm) = 10 after retention at 310°C for 5 minutes.

7. A polyphenylene sulfide resin composition according to claim 1 or 2, wherein the thermoplastic amorphous resin (B) has a glass transition temperature of 170°C or higher.

8. The polyphenylene sulfide resin composition according to claim 7, wherein the thermoplastic amorphous resin (B) is polysulfone, polyethersulfone or polyetherimide.

9. A polyphenylene sulfide resin composition according to claim 1 or 2, wherein the melt viscosity (b) of the thermoplastic amorphous resin (B) is 1 to 500 Pa·s.

10. A polyphenylene sulfide resin composition according to claim 1 or 2, wherein the weight average molecular weight of the thermoplastic amorphous resin (B) is 10,000 or more and 100,000 or less.

11. The polyphenylene sulfide resin composition according to claim 10, wherein the weight average molecular weight of the thermoplastic amorphous resin (B) is 10,000 or more and 60,000 or less.

12. A polyphenylene sulfide resin composition according to claim 1 or 2, wherein (B) the thermoplastic amorphous resin is a recycled thermoplastic amorphous resin derived from leftover materials from the hollow fiber process used in artificial kidneys.

13. The polyphenylene sulfide resin composition according to claim 1 or 2, further comprising (X) a hydrophilic resin.

14. The polyphenylene sulfide resin composition according to claim 13, wherein the hydrophilic resin (X) is at least one selected from the group consisting of polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol.

15. A molded article made from the polyphenylene sulfide resin composition according to claim 1 or 2.

16. The molded product according to claim 15, which is any one plumbing part selected from toilet-related parts, water heater-related parts, bath-related parts, pump-related parts, and water meter-related parts.

17. A method for producing a polyphenylene sulfide resin composition, comprising contacting a resin composition comprising (A) a polyphenylene sulfide resin, (B) at least one resin selected from the group consisting of polysulfone, polyethersulfone, and polyallyl ether sulfone, (X) a hydrophilic resin, and (Y) a metal alkoxide in the presence of a non-solvent.

18. A method for producing a polyphenylene sulfide resin composition according to claim 17, wherein the hydrophilic resin (X) is at least one selected from the group consisting of polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol.

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