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

Abstract

To provide PAS resin molded articles with excellent wear resistance and moldability, PAS resin compositions capable of producing such molded articles, and methods for manufacturing them. [Solution] A polyarylene sulfide resin composition for sliding members, comprising 100 parts by mass of a polyarylene sulfide resin having a V6 viscosity of 250 to 3000 Pa·s at 300°C, and 0.01 to 1 part by mass of an organic crystallization accelerator having a melting point of 300°C or higher and an average particle diameter of 100 μm or less; a molded article made therefrom; and a method for producing the same.

Description

Technical Field

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

Background Art

[0002] Polyarylene sulfide resins (hereinafter sometimes referred to as PAS resins), typified by polyphenylene sulfide resin (hereinafter sometimes referred to as PPS resin), are excellent in mechanical strength, heat resistance, chemical resistance, molding processability, dimensional stability, flame retardancy, etc., and are thus widely used mainly for electrical and electronic equipment parts, automotive part materials, etc. Conventionally, when developing PAS resins for sliding applications, designs have been made in which additives and fillers are dispersed in the PAS resin. For example, Patent Document 1 discloses a PPS resin composition containing a PPS resin, PAN-based carbon fibers having a tensile strength of 3000 MPa or more, and isotropic pitch-based carbon fibers.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in order to be used in sliding applications in a strict environment such as a semiconductor manufacturing line where product management is strict, in order to avoid the filler that has fallen off due to sliding from damaging the product, it is difficult to use a conventional inorganic filler design, and there has been a demand for a material that is excellent in slidability and moldability using only a soft organic material.

[0005] Therefore, the problem to be solved by the present invention is to provide a PAS resin molded product excellent in abrasion resistance and moldability, a PAS resin composition capable of providing the molded product, and methods for producing them. [Means for solving the problem]

[0006] The inventors of the present invention have discovered that by incorporating an organic crystallization accelerator having a specific melting point and particle size, a PAS resin composition with excellent P abrasion resistance and moldability can be obtained, thus completing the present invention.

[0007] In other words, the present invention encompasses the following aspects. [1] A polyarylene sulfide resin composition for sliding members, comprising 100 parts by mass of a polyarylene sulfide resin (A) having a V6 viscosity of 400 to 3000 Pa·s at 300°C, and 0.01 to 1 part by mass of an organic crystallization accelerator (B) having a melting point of 300°C or higher and an average particle size of 100 μm or less. [2] The polyarylene sulfide resin composition for sliding members according to [1], wherein the organic crystallization accelerator (B) is at least one selected from the group consisting of aromatic polyether ketone resins, metal benzoate salts, and metal phosphate ester salts. [3] The polyarylene sulfide resin composition for sliding members according to [1] or [2], wherein the non-Newtonian exponent of the polyarylene sulfide resin (A) is 1.1 to 1.7. [4] The polyarylene sulfide resin composition for sliding members according to [1] to [3] above, wherein the inorganic filler (C) is less than 1 part by mass per 100 parts by mass of the resin composition. [5] A polyarylene sulfide resin composition for sliding members according to [1] to [4] above, wherein the cooling crystallization temperature is 200°C or higher. (However, the cooling crystallization temperature was measured by differential thermal analysis at a cooling rate of 20°C / min.) [6] A polyarylene sulfide resin molded article for a sliding member, obtained by melt-molding the resin composition described in [1] to [5] above. [7] A method for producing a polyarylene sulfide resin composition comprising the step of melt-kneading a polyarylene sulfide resin (A) having a V6 viscosity of 400 to 3000 Pa·s at 300°C and an organic crystallization accelerator (B) having a melting point of 300°C or higher and an average particle size of 100 μm or less, A method for producing a polyarylene sulfide resin composition for sliding members, wherein the amount of the organic crystallization accelerator (B) is 0.01 to 1 part by mass per 100 parts by mass of the polyarylene sulfide resin (A). [8] A method for producing the polyarylene sulfide resin composition for sliding members according to [7], wherein the non-Newtonian exponent of the polyarylene sulfide resin (A) is 1.1 to 1.7. [9] A method for producing a polyarylene sulfide resin composition for sliding members according to [7] or [8], wherein the amount of inorganic filler (C) is less than 1 part by mass per 100 parts by mass of the resin composition.

[10] A method for producing the polyarylene sulfide resin composition for sliding members according to [7] to [9] above, wherein the cooling crystallization temperature is 200°C or higher. (However, the cooling crystallization temperature was measured by differential thermal analysis at a cooling rate of 20°C / min.)

[11] A method for producing a polyarylene sulfide resin molded article for a sliding member, comprising the steps of producing a polyarylene sulfide resin composition by the manufacturing method described in [7] to

[10] above, and melt-molding the obtained polyarylene sulfide resin composition. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide PAS resin molded articles that have excellent wear resistance and moldability, PAS resin compositions capable of providing such molded articles, and methods for producing them. [Modes for carrying out the invention]

[0009] The embodiments of the present invention will be described in detail below, but the scope of the present invention is not limited to the embodiments described herein, and various modifications can be made without departing from the spirit of the invention. Furthermore, if multiple upper and lower limits are given for a particular parameter, any combination of these upper and lower limits can be used to create a suitable numerical range.

[0010] The PAS resin composition according to this embodiment is characterized in that 0.01 to 1 part by mass of an organic crystallization accelerator (B) having a melting point of 300°C or higher and an average particle diameter of 100 μm or less (hereinafter sometimes simply referred to as "organic crystallization accelerator (B)") is blended with 100 parts by mass of a PAS resin (A) having a V6 viscosity at 300°C of 400 to 3000 Pa·s. This will be described below.

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

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

[0013]

Chemical formula

[0014]

Chemical formula

[0015] Here, the structural part represented by the general formula (1) is such that, particularly from the viewpoint of the mechanical strength of the PAS resin, R 1 and R 2 are preferably hydrogen atoms. In that case, examples include those bonded at the para position represented by the following formula (3) and those bonded at the meta position represented by the following formula (4).

[0016]

Chem.

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

[0018]

Chem.

[0019] Further, the PAS resin may have a naphthyl sulfide bond or the like in its molecular structure, but it is preferably 3 mol% or less, particularly preferably 1 mol% or less, based on the total number of moles with other structural parts.

[0020] Also, the physical properties of the PAS resin (A) are not particularly limited as long as the effects of the present invention are not impaired, but are as follows.

[0021] (V6 viscosity) The PAS resin (A) used in this embodiment has a good balance of moldability and mechanical strength, so a V6 viscosity measured at 300°C is preferably 250 to 3000 Pa·s, more preferably 300 to 2500 Pa·s, and even more preferably 400 to 2000 Pa·s. However, the V6 viscosity in this disclosure is measured using a Shimadzu flow tester, CFT-500D, at 300°C and a load of 1.96 × 10⁻⁶. 6 The measured melt viscosity was obtained after holding the mixture at Pa and L / D = 10(mm) / 1(mm) for 6 minutes.

[0022] (Non-Newtonian exponents) The non-Newtonian index of the PAS resin (A) used in this embodiment is not particularly limited, but from the viewpoint of processability and mechanical strength, it is preferably in the range of 1.1 to 1.7, and more preferably in the range of 1.2 to 1.6. However, in this disclosure, the non-Newtonian index (N value) is a value calculated using the following formula by measuring the shear rate (SR) and shear stress (SS) using a capillary graph under the conditions of melting point +20°C and the ratio of orifice length (L) to orifice diameter (D), L / D = 40. The closer the non-Newtonian index (N value) is to 1, the closer the structure is to linear, and the higher the non-Newtonian index (N value), the more branched the structure is.

[0023]

number

[0024] (Manufacturing method) The method for producing the PAS resin is not particularly limited, but examples include: (Method 1) polymerizing a dihalogeno-aromatic compound in the presence of sulfur and sodium carbonate, with the addition of a polyhalogeno-aromatic compound or other copolymerizing component if necessary; (Method 2) polymerizing a dihalogeno-aromatic compound in a polar solvent in the presence of a sulfidating agent, with the addition of a polyhalogeno-aromatic compound or other copolymerizing component if necessary; (Method 3) self-condensing p-chlorthiophenol, with the addition of other copolymerizing components if necessary; (Method 4) melt-polymerizing a diiodo-aromatic compound and elemental sulfur under reduced pressure in the presence of a polymerization inhibitor which may have functional groups such as carboxyl groups or amino groups. Among these methods, Method 2 is the most versatile and preferred. During the reaction, alkali metal salts of carboxylic acids or sulfonic acids, or alkali hydroxides may be added to adjust the degree of polymerization. Among the above (manufacturing method 2) methods, there is a method for producing PAS resin by introducing a hydrated sulfidating agent into a mixture containing a heated organic polar solvent and a dihalogeno-aromatic compound at a rate at which water can be removed from the reaction mixture, and reacting the dihalogeno-aromatic compound and the sulfidating agent in the organic polar solvent with a polyhalogeno-aromatic compound as needed, and controlling the amount of water in the reaction system to be in the range of 0.02 to 0.5 moles per mole of the organic polar solvent (see Japanese Patent Publication No. 07-228699), and solid A Particularly preferred is a product obtained by adding a dihalogeno-aromatic compound and, if necessary, a polyhalogeno-aromatic compound or other copolymerizing component in the presence of a rucali metal sulfide and an aprotic polar organic solvent, and reacting the alkali metal hydrosulfide and the alkali metal salt of an organic acid while controlling the amount of alkali metal salt of the organic acid in the range of 0.01 to 0.9 moles per mole of sulfur source and the amount of water in the reaction system to be 0.02 moles or less per mole of aprotic polar organic solvent (see WO2010 / 058713 pamphlet).Specific examples of dihalogenoaromatic compounds include p-dihalobenzene, m-dihalobenzene, o-dihalobenzene, 2,5-dihalotoluene, 1,4-dihalonaphthalene, 1-methoxy-2,5-dihalobenzene, 4,4'-dihalobiphenyl, 3,5-dihalobenzoic acid, 2,4-dihalobenzoic acid, 2,5-dihalonitrobenzene, 2,4-dihalonitrobenzene, 2,4-dihaloanisole, p,p'-dihalodiphenyl ether, 4,4'-dihalobenzophenone, 4,4'-di Examples include halodiphenylsulfones, 4,4'-dihalodiphenyl sulfoxides, 4,4'-dihalodiphenyl sulfides, and compounds having an alkyl group with 1 to 18 carbon atoms in the aromatic ring of each of the above compounds. Examples of polyhalogenoaromatic compounds include 1,2,3-trihalobenzene, 1,2,4-trihalobenzene, 1,3,5-trihalobenzene, 1,2,3,5-tetrahalobenzene, 1,2,4,5-tetrahalobenzene, and 1,4,6-trihalonaphthalene. Furthermore, it is desirable that the halogen atoms contained in each of the above compounds be chlorine atoms and bromine atoms.

[0025] The post-treatment method for the reaction mixture containing the PAS resin obtained by the polymerization step is not particularly limited, but for example, (post-treatment 1) after the polymerization reaction is completed, first the reaction mixture is treated as is, or an acid or base is added, and the solvent is removed under reduced pressure or atmospheric pressure, and then the solid after solvent removal is washed once or twice or more with a solvent such as water, the reaction solvent (or an organic solvent having equivalent solubility to the low molecular weight polymer), acetone, methyl ethyl ketone, or alcohols, and then neutralized, washed with water, filtered and dried, or (post-treatment 2) after the polymerization reaction is completed, the reaction mixture is treated with a solvent such as water, acetone, methyl ethyl ketone, alcohols, ethers, halogenated hydrocarbons, aromatic hydrocarbons, or aliphatic hydrocarbons (solubilable in the polymerization solvent used and poorly soluble in at least PAS). Methods include adding a solvent (as a medium) as a precipitating agent to precipitate solid products such as PAS and inorganic salts, then filtering, washing, and drying them; (post-treatment 3) after the polymerization reaction is complete, adding a reaction solvent (or an organic solvent having equivalent solubility to the low molecular weight polymer) to the reaction mixture and stirring, then filtering to remove the low molecular weight polymer, washing once or twice or more with a solvent such as water, acetone, methyl ethyl ketone, or alcohols, then neutralizing, washing with water, filtering, and drying; (post-treatment 4) after the polymerization reaction is complete, adding water to the reaction mixture and washing with water, filtering, adding acid during water washing as needed for acid treatment, and then drying; (post-treatment 5) after the polymerization reaction is complete, filtering the reaction mixture, washing once or twice or more with the reaction solvent as needed, and then further washing with water, filtering, and drying. Among these methods, method (post-treatment 4) is preferred because it yields a PAS resin having carboxyl groups at the molecular ends of the PAS resin.

[0026] Furthermore, in the post-treatment methods exemplified above (Post-treatment 1) to (Post-treatment 5), the drying of the PAS resin may be carried out in a vacuum, in air, or in an inert gas atmosphere such as nitrogen.

[0027] In the PAS resin composition according to this embodiment, the amount of PAS resin (A) blended is preferably 97 parts by mass or more, more preferably 98 parts by mass or more, and even more preferably 99 parts by mass or more, per 100 parts by mass of the resin composition. Within this range, the resin composition has good processability and the molded product has excellent chemical resistance, heat resistance, etc., so it is preferable.

[0028] Furthermore, the PAS resin used in this embodiment may be newly polymerized PAS resin using the method described above, or recycled PAS resin (recycled PAS resin) may be used. The raw materials (history) of the recycled PAS resin are not particularly limited and may be post-consumer recycled materials (so-called PCR materials) or post-industry recycled materials (so-called PIR materials). Specifically, PCR materials include molded articles containing at least PAS resin that have been used as products once, and PIR materials include dust and chips generated when manufacturing PAS resin, dust and chips generated when manufacturing compositions containing at least PAS resin, or sprues or runners or off-spec molded articles recovered when manufacturing molded articles containing at least PAS resin. Methods for using these as recycled PAS resin include, for example, crushing or shredding the above-mentioned PIR materials or PCR materials, or sieving them. Furthermore, PAS resin can be extracted from the above-mentioned PIR material or PCR material and used. Specifically, the PAS resin obtained by performing the above-mentioned post-treatment on a solution obtained by heating the above-mentioned PIR material or PCR material in an organic polar solvent to dissolve the contained PAS resin can be used. When using recycled PAS resin, other components besides PAS resin may be included, but from the viewpoint of mechanical strength, it is preferable that the PAS resin is 90 parts by mass or more, more preferably 95 parts by mass or more, even more preferably 98 parts by mass or more, and most preferably 99 parts by mass or more per 100 parts by mass of recycled PAS resin.

[0029] <Organic crystallization accelerator (B)> The PAS resin composition according to this embodiment is formulated with an organic crystallization accelerator (B) as an essential component for the purpose of adjusting the crystallization behavior. Specifically, it may be at least one organic crystallization accelerator selected from the group consisting of aromatic polyetherketone resins, metal benzoate salts, and metal phosphate ester salts.

[0030] The organic crystallization accelerator (B) used in this embodiment has a melting point of 300°C or higher, and more preferably 320°C or higher, from the viewpoint of moldability. In this disclosure, the melting point refers to the melting peak temperature measured by differential scanning calorimetry (DSC) in accordance with the method of JIS 7121 (1999) 9.1(1).

[0031] The organic crystallization accelerator (B) used in this embodiment preferably has an average particle diameter of 100 μm or less, and more preferably 50 μm or less, from the viewpoint of mechanical strength and moldability. In this disclosure, the average particle diameter is determined based on the particle size distribution measured according to a conventional method using a laser diffraction scattering particle size distribution analyzer (Microtrac MT3300EXII). 50 )

[0032] The structure of the aromatic polyetherketone resin is not particularly limited, and any known and publicly available structure in which a benzene group is bonded with an ether group and a ketone group can be used. Examples include polyetherketone resins, polyetheretherketone resins, polyetherketone ketone resins, polyetheretherketone ketone resins, polyetherketone etherketone ketone resins, polyetherketone ester resins, etc., which can be used individually or as mixtures of two or more.

[0033] Examples of commercially available aromatic polyetherketone resins include "150PF" and "450PF" from Victrex, and "Vestakeep 2000UPF10" from Polypla Evonik. If the average particle size of these commercially available aromatic polyetherketone resins differs from the preferred range described above, they can be adjusted to that range by grinding, sieving, or other means before use.

[0034] The metals contained in the aforementioned benzoate metal salts and phosphate ester metal salts include lithium, sodium, potassium, rubidium, cesium, boron, magnesium, aluminum, calcium, manganese, cobalt, nickel, iron, tin, antimony, copper, silver, zinc, molybdenum, vanadium, strontium, zirconium, barium, bismuth, gold, platinum, and rare earth elements. From the viewpoint of avoiding concerns such as toxicity, lithium, sodium, potassium, manganese, iron, bismuth, zirconium, barium, calcium, strontium, copper, zinc, rare earth elements, or vanadium are preferred. In this disclosure, "rare earth elements" means one or more elements selected from scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

[0035] In the PAS resin composition according to this embodiment, the amount of organic crystallization accelerator (B) is 0.01 to 1 part by mass, preferably 0.05 to 0.5 parts by mass, and more preferably 0.08 to 0.3 parts by mass, per 100 parts by mass of PAS resin (A). Within this range, excellent moldability and mechanical strength are obtained.

[0036] <Inorganic filler (C)> From the viewpoint of improving abrasion resistance, the PAS resin composition according to this embodiment preferably contains substantially no inorganic filler (C), and more preferably less than 1 part by mass, and even more preferably 0.5 parts by mass or less, per 100 parts by mass of the resin composition.

[0037] Examples of inorganic fillers (C) include fillers in various forms such as fibrous, plate-like, and granular forms. Specifically, examples include fibers such as glass fibers, carbon fibers, silane glass fibers, ceramic fibers, aramid fibers, metal fibers, potassium titanate, silicon carbide, calcium silicate, and wollastonite; natural fibers; glass flakes; clay; pyrophyllite; bentonite; sericite; mica; attapulgite; ferrite; calcium silicate; zeolite; boehmite; silica; quartz powder; glass beads; glass powder; silicates such as calcium silicate, aluminum silicate, and diatomaceous earth; metal oxides such as iron oxide, titanium oxide, zinc oxide, and alumina; metal carbonates such as calcium carbonate and magnesium carbonate; metal sulfates such as calcium sulfate and barium sulfate; fumed silica; and other plant-derived fillers such as silicon carbide, silicon nitride, boron nitride, various metal powders, cocoa husk, and cellulose.

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

[0039] Furthermore, in addition to the above components, the PAS resin composition according to this embodiment may optionally contain synthetic resins (hereinafter simply referred to as "synthetic resins") such as polyester resin, polyamide resin, polyimide resin, polyetherimide resin, polycarbonate resin, polyphenylene ether resin, polysulfone resin, polyethersulfone resin, polyarylate resin, polyethylene resin, polypropylene resin, polytetrafluoroethylene resin, polydifluoroethylene resin, polystyrene resin, ABS resin, epoxy resin, phenolic resin, urethane resin, liquid crystal polymer, thermoplastic elastomer, etc., depending on the application. Although the above synthetic resins are not essential components in the present invention, if they are included, for example, the amount can range from 0.01 to 5 parts by mass per 100 parts by mass of PAS resin (A), and should be adjusted appropriately according to the purpose and application so as not to impair the effects of the present invention.

[0040] Furthermore, the PAS resin composition according to this embodiment may also contain, as necessary, other known and conventional additives such as colorants, antistatic agents, antioxidants, heat stabilizers, UV stabilizers, UV absorbers, foaming agents, flame retardants, flame retardant aids, rust inhibitors, and mold release agents (such as metal salts or esters of fatty acids with 18 to 30 carbon atoms, including stearic acid and montanic acid, and polyolefin waxes such as polyethylene), antibacterial agents, and antiviral agents as optional components. These additives are not essential components, and for example, they can be used in amounts ranging from 0.01 to 10 parts by mass per 100 parts by mass of PAS resin (A), and should be adjusted appropriately according to the purpose and application so as not to impair the effects of the present invention.

[0041] The physical properties of the PAS resin composition disclosed herein are not particularly limited as long as they do not impair the effects of the present invention, but are as follows.

[0042] (cooling down crystallization temperature) The temperature of the PAS resin composition according to this embodiment during cooling crystallization is preferably 200°C or higher, more preferably 210°C or higher, from the viewpoint of moldability. In order to achieve such a range of the temperature of cooling crystallization, for example, a method of adjusting the molecular structure of the PAS resin in the resin composition can be mentioned. For example, it tends to increase by reducing the branching of the polymer chain of the PAS resin. Note that the method of adjusting the temperature of cooling crystallization is not limited to the above method. Further, the cooling crystallization rate in the present disclosure is a value obtained by measuring the temperature at the peak top of the exothermic peak derived from the crystallization of the resin at a cooling rate of 20°C / min by differential scanning calorimetry (DSC), and can be measured by the method described in the examples.

[0043] <Method for producing PAS resin composition> The method for producing a PAS resin composition according to this embodiment is a method for producing a PAS resin composition having a step of melt-kneading a PAS resin (A) having a V6 viscosity at 300°C of 400 to 3000 Pa·s and an organic crystallization accelerator (B) having a melting point of 300°C or higher and an average particle diameter of 100 μm or less. It is characterized in that the blending amount of the organic crystallization accelerator (B) is 0.01 to 1 part by mass with respect to 100 parts by mass of the PAS resin (A). Details will be described below.

[0044] The method for producing a PAS resin composition according to this embodiment has a step of blending the above essential components and melt-kneading them in a temperature range not lower than the melting point of the PAS resin (A). More specifically, the PAS resin composition according to this embodiment is obtained by blending each essential component and, if necessary, other optional components. The method for producing the resin composition used in the present invention is not particularly limited, but a method of blending essential components and optional components as necessary and melt-kneading them, more specifically, a method of uniformly dry-blending with a tumbler or a Henschel mixer as necessary and then charging them into a twin-screw extruder for melt-kneading can be mentioned. <000The temperature of the PAS resin composition according to this embodiment during cooling crystallization is preferably 200°C or higher, more preferably 210°C or higher, from the viewpoint of moldability. In order to achieve such a range of the temperature of cooling crystallization, for example, a method of adjusting the molecular structure of the PAS resin in the resin composition can be mentioned. For example, it tends to increase by reducing the branching of the polymer chain of the PAS resin. Note that the method of adjusting the temperature of cooling crystallization is not limited to the above method. Further, the cooling crystallization rate in the present disclosure is a value obtained by measuring the temperature at the peak top of the exothermic peak derived from the crystallization of the resin at a cooling rate of 20°C / min by differential scanning calorimetry (DSC), and can be measured by the method described in the examples.

[0043] <Method for producing PAS resin composition> The method for producing a PAS resin composition according to this embodiment is a method for producing a PAS resin composition having a step of melt-kneading a PAS resin (A) having a V6 viscosity at 300°C of 400 to 3000 Pa·s and an organic crystallization accelerator (B) having a melting point of 300°C or higher and an average particle diameter of 100 μm or less. It is characterized in that the blending amount of the organic crystallization accelerator (B) is 0.01 to 1 part by mass with respect to 100 parts by mass of the PAS resin (A). Details will be described below.

[0044] The method for producing a PAS resin composition according to this embodiment has a step of blending the above essential components and melt-kneading them in a temperature range not lower than the melting point of the PAS resin (A). More specifically, the PAS resin composition according to this embodiment is obtained by blending each essential component and, if necessary, other optional components. The method for producing the resin composition used in the present invention is not particularly limited, but a method of blending essential components and optional components as necessary and melt-kneading them, more specifically, a method of uniformly dry-blending with a tumbler or a Henschel mixer as necessary and then charging them into a twin-screw extruder for melt-kneading can be mentioned.

[0045] Melt mixing can be carried out by heating to a temperature range in which the resin temperature is equal to or greater than the melting point of the PAS resin (A), preferably a temperature range of 10°C or more above the melting point, more preferably 10°C or more above the melting point, even more preferably 20°C or more above the melting point, preferably 100°C or less above the melting point, and more preferably 50°C or less above the melting point.

[0046] As the melting and mixing machine, a twin-screw extruder is preferred from the viewpoint of dispersibility and productivity. For example, it is preferable to melt and mix while appropriately adjusting the discharge rate of the resin component in the range of 5 to 500 kg / hr and the screw rotation speed in the range of 50 to 500 rpm, and it is even more preferable to melt and mix under conditions where the ratio of these (discharge rate / screw rotation speed) is in the range of 0.02 to 5 kg / hr / rpm. In addition, the addition and mixing of each component to the melting and mixing machine may be done simultaneously or in stages. For example, if other fibrous fillers are added as needed from among the components, it is preferable from the viewpoint of dispersibility to introduce them into the extruder from the side feeder of the twin-screw extruder. The position of such a side feeder is preferably such that the ratio of the distance from the extruder resin input section (top feeder) to the total length of the screw of the twin-screw extruder to the side feeder is 0.1 or more, and more preferably 0.3 or more. Furthermore, this ratio is preferably 0.9 or less, and more preferably 0.7 or less.

[0047] The PAS resin composition according to this embodiment, obtained by melt-kneading in this manner, is a molten mixture containing the essential components, optional components added as needed, and their derived components. Therefore, the PAS resin composition according to this embodiment has a morphology in which the PAS resin (A) forms a continuous phase and the organic crystallization accelerator (B) and other optional components are dispersed.

[0048] In this embodiment, the PAS resin composition is preferably processed after melt kneading by a known method, for example, by extruding the molten resin composition into strands, then into the form of pellets, chips, granules, powder, etc., and then pre-dried at a temperature range of 100 to 150°C as needed.

[0049] <PAS resin molded product, method for producing PAS resin molded product> The molded product according to the present embodiment is obtained by melt-molding a PAS resin composition. Further, the method for producing a molded product according to the present embodiment includes a step of melt-molding the PAS resin composition. Therefore, the molded product according to the present embodiment has a morphology in which the PAS resin (A) forms a continuous phase and other essential components and optional components are dispersed. By having such a morphology, a molded product excellent in thermal conductivity and mechanical strength can be obtained.

[0050] The PAS resin composition according to the present embodiment can be used for various moldings such as injection molding, compression molding, composite molding, sheet molding, pipe extrusion molding, drawing molding, blow molding, and transfer molding. In particular, it is suitable for injection molding applications because of its excellent mold release properties. When molding by injection molding, various molding conditions are not particularly limited, and molding can be performed by a generally common method. For example, in an injection molding machine, after passing through a step of melting the PAS resin composition in a temperature range of the melting point or higher of the PAS resin (A), preferably in a temperature range of the melting point + 10°C or higher, more preferably in a temperature range of melting point + 10°C to melting point + 100°C, and even more preferably in a temperature range of melting point + 20 to melting point + 50°C, it may be injected into a mold from a resin discharge port and molded. At that time, the mold temperature may also be set within a known temperature range, for example, room temperature (23°C) to 300°C, preferably 130 to 190°C.

[0051] The method for manufacturing a molded article according to this embodiment may include a step of annealing the molded article. The optimal conditions for annealing are selected depending on the application or shape of the molded article, but the annealing temperature is in a temperature range above the glass transition temperature of the PAS resin (A), preferably in a temperature range of the glass transition temperature + 10°C or higher, and more preferably in a temperature range of the glass transition temperature + 30°C or higher. On the other hand, it is preferably in a range of 260°C or lower, and more preferably in a range of 240°C or lower. The annealing time is not particularly limited, but is preferably in a range of 0.5 hours or more, and more preferably in a range of 1 hour or more. On the other hand, it is preferably in a range of 10 hours or less, and more preferably in a range of 8 hours or less. Within this range, the strain of the resulting molded article is reduced, the crystallinity of the resin is improved, and the thermal conductivity and mechanical strength are further improved, which is preferable. The annealing treatment may be carried out in air, but it is preferable to carry it out in an inert gas such as nitrogen gas.

[0052] The molded articles according to this embodiment include remolded articles obtained by reusing molded articles made by melt-molding the PAS resin composition. Specifically, this includes, for example, molded articles obtained by washing, if necessary, sprues or runners generated during the manufacture of molded articles, molded articles recovered as off-spec products, or molded articles that have been used as products, crushing them, and then melt-molding them again at a temperature above the melting point of the PAS resin. When reusing, it is preferable from the viewpoint of mechanical strength to mix the crushed molded articles with the PAS resin composition. The size of the crushed molded articles is not particularly limited, but from the viewpoint of mixability and processability, it is preferable that the size is about the same as that of the PAS resin composition being mixed. Furthermore, the mixing ratio is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 20 parts by mass or less, of the crushed molded articles per 100 parts by mass of the PAS resin composition. Within this range, it is possible to improve recyclability without impairing the effects exhibited by the PAS resin composition of this disclosure.

[0053] <Application> The PAS resin molded product according to this embodiment is particularly suitable for sliding member applications due to its excellent moldability and wear resistance. Specifically, it can be suitably used for sliding members such as gears, bearings, blades, vanes, seal rings, packings, guides, retainers, and washers. Furthermore, the molded product according to this embodiment can be used not only for sliding members but also for the following common applications: for example, protective and support members for box-shaped electrical and electronic component integrated modules; multiple individual semiconductors or modules; sensors; LED lamps; connectors; sockets; resistors; relay cases; switches; coil bobbins; capacitors; variable capacitor cases; optical pickups; oscillators; various terminal boards; transformers; plugs; printed circuit boards; tuners; speakers; microphones; headphones; small motors; magnetic head bases; power modules; terminal blocks; semiconductors; liquid crystal displays; FDD carriages; FDD chassis; motor brush holders; parabolic antennas; computer-related parts; and electrical and electronic components such as VTR parts, television parts, irons, and helmets. Parts for household and office electrical appliances, such as dryers, rice cooker parts, microwave oven parts, audio parts, audio and video equipment parts (including audio, laser discs, compact discs, DVDs, Blu-ray discs, etc.), lighting parts, refrigerator parts, air conditioner parts, typewriter parts, word processor parts, and plumbing equipment parts such as water heaters and bath water volume and temperature sensors; parts for office computers, telephones, facsimile machines, photocopiers, cleaning jigs, motor parts, writers, typewriters, and other mechanical parts; and parts for optical instruments and precision machinery, such as microscopes, binoculars, cameras, and watches.Alternator terminals, alternator connectors, brush holders, slip rings, IC regulators, potentiometer bases for light dimmers, relay blocks, inhibitor switches, various valves such as exhaust gas valves, various pipes for fuel, exhaust, and intake systems, air intake nozzle snorkels, intake manifolds, engine coolant joints, carburetor main bodies, carburetor spacers, exhaust gas sensors, coolant sensors, oil temperature sensors, brake pad wear sensors, throttle position sensors, crankshaft position sensors, temperature sensors, air flow meters, brake pad wear sensors, thermostat bases for air conditioners, heating hot air flow control valves, radiators Examples of automotive and vehicle-related parts include motor brush holders, water pump impellers, turbine vanes, wiper motor components, distributors, starter switches, ignition coils and their bobbins, motor insulators, motor rotors, motor cores, starter relays, transmission wire harnesses, windshield washer nozzles, air conditioning panel switch boards, fuel-related solenoid valve coils, fuse connectors, horn terminals, electrical component insulating plates, stepper motor rotors, lamp sockets, lamp reflectors, lamp housings, brake pistons, solenoid bobbins, engine oil filters, ignition system cases, and other various applications. [Examples]

[0054] The present invention will be described below using examples and comparative examples, but it is not limited to these examples. Unless otherwise specified, "%" and "parts" refer to mass.

[0055] <Examples 1-8 and Comparative Examples 1-4> Each material was blended according to the composition and proportions listed in Table 1. These blended materials were then fed into a vented twin-screw extruder "TEX-30α" manufactured by Japan Steel Works Ltd., and melt-kneaded at a resin component discharge rate of 30 kg / hr, a screw rotation speed of 200 rpm, and a set resin temperature of 310°C to obtain resin composition pellets. The materials were pre-mixed uniformly in a tumbler and fed through a top feeder. After drying the obtained resin composition pellets in a 140°C gear oven for 2 hours, various test pieces were prepared by injection molding, and the following tests were performed.

[0056] <Rating>

[0057] (1) Measurement of crystallization temperature The recrystallization temperature for each example and comparative example resin composition was evaluated using a differential scanning calorimetry analyzer (Perkin Elmer "DSC8500") by raising the temperature from 40°C to 350°C, holding it for 3 minutes, and then cooling it down to 120°C at a rate of 20°C / min. The peak temperature of the exothermic peak resulting from resin crystallization was measured. The results are shown in Table 1. Note that the lower the crystallization temperature, the longer the time required for the molten state to solidify completely, and therefore the poorer the moldability tends to be.

[0058] (2) Evaluation of moldability (evaluation of gate seal time) The moldability of each example and comparative example resin composition was evaluated based on the gate sealing time when injection-molded using a single-gate ISO TYPE-A dumbbell mold. The injection molding machine cylinder temperature was set to 310°C and the mold temperature to 140°C. For evaluation, resin composition pellets were injected into the mold, and the internal pressure was measured using an internal pressure sensor installed near the mold gate. The time from completion of filling until the gate completely solidified was measured as the gate sealing time. Injection molding was performed 20 times, and the gate sealing time was taken as the average value (seconds). The results are shown in Table 1. Note that the longer the gate sealing time, the longer the molding cycle, and therefore the worse the moldability tends to be.

[0059] (3) Abrasion resistance evaluation The resin compositions of each example and comparative example were molded into test specimens measuring 100 mm in length, 100 mm in width, and 2 mm in thickness using an injection molding machine. The cylinder temperature of the injection molding machine was set to 310°C and the mold temperature to 140°C. The test specimens were subjected to a Taber abrasion tester (Rotary Abrasion Tester 403, manufactured by Toyo Seiki Seisakusho). The measurement conditions were as follows: CS-17 was used as the abrasion wheel, the load was 9.8 N, and the amount of abrasion after 3000 cycles was evaluated. The results are shown in Table 1. Note that a larger amount of abrasion tends to indicate poorer sliding properties.

[0060] [Table 1]

[0061] The following ingredient ratios were used for the ingredients listed in Table 1. ·PAS resin A-1: PPS resin (melt viscosity (V6) 600 Pa·s, non-Newtonian index 1.5) A-2: PPS resin (melt viscosity (V6) 300 Pa·s, non-Newtonian index 1.2) A-3: PPS resin (melt viscosity (V6) 2000 Pa·s, non-Newtonian index 1.6) a-1: PPS resin (melt viscosity (V6) 200 Pa·s, non-Newtonian index 1.3)

[0062] • Organic crystallization accelerator B-1: Aromatic polyether ketone resin (Victrex Co., Ltd. "150PF", average particle size 50 μm, melting point 340°C) B-2: Metal benzoate salt (AL-PTBBA, manufactured by Kyodo Yakuhin Co., Ltd., average particle size 2 μm, no melting point) B-3: Phosphate ester metal salt (ADEKA Corporation's "ADEKA Stab NA-11", average particle size 0.5 μm, melting point 400°C or higher) b-1: Dibenzylidene sorbitol (“(1-3-2-4) dibenzylidene sorbitol” manufactured by Shandong Shangcheng Chemical Co., Ltd., average particle size 20μm, melting point 220℃)

[0063] Comparing the examples and comparative examples in Table 1, it was shown that when the melt viscosity of the PAS resin is lower than that of Comparative Example 1, the wear resistance is poor; when there is less organic crystallization accelerator than that of Comparative Example 2, the processability is poor; when there is more organic crystallization accelerator than that of Comparative Example 3, the wear resistance is poor; and when the melting point of the organic crystallization accelerator is too low compared to that of Comparative Example 4, the processability is poor.

Claims

1. A polyarylene sulfide resin composition for sliding members, comprising 100 parts by mass of a polyarylene sulfide resin (A) having a V6 viscosity of 250 to 3000 Pa·s at 300°C, and 0.01 to 1 part by mass of an organic crystallization accelerator (B) having a melting point of 300°C or higher and an average particle size of 100 μm or less.

2. The polyarylene sulfide resin composition for sliding members according to claim 1, wherein the organic crystallization accelerator (B) is at least one selected from the group consisting of aromatic polyether ketone resins, metal benzoate salts, and metal phosphate ester salts.

3. The polyarylene sulfide resin composition for sliding members according to claim 1, wherein the non-Newtonian exponent of the polyarylene sulfide resin (A) is 1.1 to 1.

7.

4. The polyarylene sulfide resin composition for sliding members according to claim 1 or 2, wherein the inorganic filler (C) is less than 1 part by mass per 100 parts by mass of the resin composition.

5. A polyarylene sulfide resin composition for sliding members according to claim 1 or 2, wherein the cooling crystallization temperature is 200°C or higher. (However, the cooling crystallization temperature was measured by differential scanning calorimetry at a cooling rate of 20°C / min.)

6. A polyarylene sulfide resin molded article for a sliding member, obtained by melt-molding the resin composition according to claim 1 or 2.

7. A method for producing a polyarylene sulfide resin composition comprising the step of melt-kneading a polyarylene sulfide resin (A) having a V6 viscosity of 400 to 3000 Pa·s at 300°C and an organic crystallization accelerator (B) having a melting point of 300°C or higher and an average particle size of 100 μm or less, A method for producing a polyarylene sulfide resin composition for sliding members, wherein the amount of the organic crystallization accelerator (B) is 0.01 to 1 part by mass per 100 parts by mass of the polyarylene sulfide resin (A).

8. A method for producing a polyarylene sulfide resin composition for a sliding member according to claim 6, wherein the non-Newtonian exponent of the polyarylene sulfide resin (A) is 1.1 to 1.

7.

9. A method for producing a polyarylene sulfide resin composition for sliding members according to claim 6 or 7, wherein the amount of inorganic filler (C) is less than 1 part by mass per 100 parts by mass of the resin composition.

10. A method for producing a polyarylene sulfide resin composition for sliding members according to claim 6 or 7, wherein the cooling crystallization temperature is 200°C or higher. (However, the cooling crystallization temperature was measured by differential scanning calorimetry at a cooling rate of 20°C / min.)

11. A method for producing a polyarylene sulfide resin molded article for a sliding member, comprising the steps of: producing a polyarylene sulfide resin composition by the manufacturing method described in claim 6 or 7; and melt-molding the obtained polyarylene sulfide resin composition.

Images