Crosslinked polyarylene sulfide resin composition and method for suppressing occurrence of die build-up

Abstract

The first problem addressed by the present invention is to provide a crosslinked polyarylene sulfide resin composition with which it is possible to suppress the occurrence of die build-up during pellet production.　This crosslinked polyarylene sulfide resin composition satisfies item (1) or item (2): (1) contains, with respect to 100 parts by mass of a crosslinked polyarylene sulfide resin (A), 0.04-3.0 parts by mass of a lubricant (B1) having a weight loss rate of 20% or less after heating from 50°C to 360°C at a temperature rise rate of 45°C per minute under a nitrogen atmosphere and maintaining 360°C for 30 minutes (2) contains, with respect to 100 parts by mass of the resin (A), 0.04-3.0 parts by mass of a lubricant (B2) other than the lubricant (B1), and 0.1-1.0 parts by mass of a silane coupling agent (C).

Description

Crosslinked polyarylene sulfide resin composition and method for suppressing the occurrence of blackening

[0001] The present disclosure relates to a crosslinked polyarylene sulfide resin composition and a method for suppressing the occurrence of blackening.

[0002] As one of the molding methods for thermoplastic resin compositions, there is extrusion molding using a screw extruder. Screw extruders include single-screw or multi-screw extruders. General ones are equipped with a screw, a cylinder (sometimes called a barrel), a driving device, a heating / cooling unit, etc., and a die plate according to the purpose is attached to the discharge hole part.

[0003] When producing pellets of a thermoplastic resin composition using an extruder, the thermoplastic resin composition may adhere and stay around the discharge holes of the die, forming a lump called "blackening". If this blackening adheres as a foreign object in the pellets, it may reduce the quality of the pellets. Also, strand breakage or the like caused by blackening may occur.

[0004] Japanese Patent Application Laid-Open No. 2003-136579

[0005] By the way, according to the study of the inventors of the present application, it has been found that blackening occurs significantly when producing pellets of a resin composition containing a crosslinked polyarylene sulfide resin.

[0006] As a method for suppressing the occurrence of blackening, for example, in Patent Document 1 and the like, a method of providing a protruding nozzle in the discharge hole of the die plate and extruding a strand-like object through the protruding nozzle has been proposed. However, in this method, equipment modification such as changing the die shape of the extruder is required. Also, a crosslinked polyarylene sulfide resin composition that can suppress the occurrence of blackening itself is not known.

[0007] The first problem of the present disclosure is to provide a crosslinked polyarylene sulfide resin composition capable of suppressing the occurrence of blackening during pellet production. The second problem of the present disclosure is to provide a method capable of suppressing the occurrence of blackening using existing equipment in the production of pellets of a crosslinked polyarylene sulfide resin composition.

[0008] As a result of diligent research, the inventors of the present invention have found that the first problem described above can be solved if a cross-linked polyarylene sulfide resin composition contains a specific amount of a specific lubricant (B1) with high thermal stability per 100 parts by mass of a cross-linked polyarylene sulfide resin (A), or contains a specific amount of a lubricant (B2) other than the lubricant (B1) and a silane coupling agent (C) per 100 parts by mass of the resin (A).

[0009] Furthermore, the inventors of the present invention have found that the second problem can be solved by a method that includes extruding a cross-linked polyarylene sulfide resin composition obtained by blending a specific amount of a specific lubricant (B1) with high thermal stability with 100 parts by mass of a cross-linked polyarylene sulfide resin (A), or by blending a specific amount of a lubricant (B2) other than the lubricant (B1) and a silane coupling agent (C) with 100 parts by mass of the resin (A), from a die.

[0010] In other words, the present disclosure includes the following embodiments: [1] A crosslinked polyarylene sulfide resin composition that satisfies the following (1): (1) per 100 parts by mass of a crosslinked polyarylene sulfide resin (A), the composition contains 0.04 to 3.0 parts by mass of a lubricant (B1) whose weight loss rate after heating from 50°C to 360°C at a heating rate of 45°C / min under a nitrogen atmosphere and holding at 360°C for 30 minutes is 20% or less, or (2): (2) per 100 parts by mass of the resin (A), the composition contains 0.04 to 3.0 parts by mass of a lubricant (B2) other than the lubricant (B1), and 0.1 to 1.0 parts by mass of a silane coupling agent (C). [2] A method for suppressing the generation of lint when manufacturing pellets of a cross-linked polyarylene sulfide resin composition, the method comprising: (1) (1) to obtain a cross-linked polyarylene sulfide resin composition by blending 0.04 to 3.0 parts by mass of a lubricant (B1) with a weight loss rate of 20% or less after heating from 50°C to 360°C at a heating rate of 45°C / min under a nitrogen atmosphere and holding at 360°C for 30 minutes, with 100 parts by mass of a cross-linked polyarylene sulfide resin (A); or (2) (2) to obtain a cross-linked polyarylene sulfide resin composition by blending 0.04 to 3.0 parts by mass of a lubricant (B2) other than the lubricant (B1) and 0.1 to 1.0 parts by mass of a silane coupling agent (C) with 100 parts by mass of the resin (A), further comprising: A method comprising extruding the crosslinked polyarylene sulfide resin composition obtained in (1) or (2) above from a die.

[0011] This disclosure can solve the first and second problems. Specifically, it can provide a cross-linked polyarylene sulfide resin composition that can suppress the generation of lint during pellet manufacturing. Furthermore, this disclosure can provide a method for suppressing the generation of lint in pellet manufacturing of a cross-linked polyarylene sulfide resin composition using existing equipment.

[0012] The following describes in detail one embodiment of the present disclosure. The present disclosure is not limited to the following embodiment and can be implemented with appropriate modifications, provided that these modifications do not impede the effects of the present disclosure. Each configuration and combination thereof in each embodiment is an example, and additions, omissions, substitutions, and other modifications can be made as appropriate, provided that these modifications do not deviate from the spirit of the present disclosure. The present disclosure is not limited by the embodiments. Each aspect disclosed herein can be combined with any other features disclosed herein. Where a particular description given for one embodiment also applies to another embodiment, that description may be omitted in the other embodiments. In this disclosure, the expression "X to Y" for numerical ranges means "X or greater and Y or less".

[0013] [Cross-linked polyarylene sulfide resin composition] The first embodiment of the present disclosure relates to a cross-linked polyarylene sulfide resin composition. That is, the first embodiment relates to a cross-linked polyarylene sulfide resin composition that satisfies the following (1): (1) per 100 parts by mass of a cross-linked polyarylene sulfide resin (A), the composition contains 0.04 to 3.0 parts by mass of a lubricant (B1) whose weight loss rate after heating from 50°C to 360°C at a heating rate of 45°C / min under a nitrogen atmosphere and holding at 360°C for 30 minutes is 20% or less, or (2): (2) per 100 parts by mass of the resin (A), the composition contains 0.04 to 3.0 parts by mass of a lubricant (B2) other than the lubricant (B1), and 0.1 to 1.0 parts by mass of a silane coupling agent (C).

[0014] According to the cross-linked polyarylene sulfide resin composition of the first embodiment (hereinafter simply referred to as "resin composition"), the generation of die residue during pellet manufacturing of the cross-linked polyarylene sulfide resin composition can be suppressed. In this specification, "die residue" refers to the lumpy resin composition formed near the discharge hole of the die, and includes not only those adhering to the vicinity of the discharge hole, but also lumpy foreign matter that falls from the discharge hole. Furthermore, in this disclosure, "the generation of die residue can be suppressed" may include reducing the amount of die residue generated during pellet manufacturing. The "amount of die residue generated" can be quantified, for example, by the number of lumpy foreign matter that fall from near the discharge hole of the die. By reducing the amount of die residue generated, strand breakage caused by die residue adhesion and quality degradation caused by die residue (lumpy foreign matter) mixing into the pellets can be prevented.

[0015] The following describes the details of the resin composition according to the first embodiment. For convenience, a resin composition that satisfies the configuration of (1) will be referred to as "resin composition (1)," and a resin composition that satisfies the configuration of (2) will be referred to as "resin composition (2)."

[0016] <Cross-linked polyarylene sulfide resin (A)> The resin composition according to the first embodiment includes a cross-linked polyarylene sulfide resin (A) (hereinafter also simply referred to as "resin (A)"). "Cross-linked polyarylene sulfide resin" refers to all polyarylene sulfide resins having a cross-linked structure. Examples of resin (A) include polyarylene sulfide resins containing the following constituent units of (I) or (II).

[0017]

[0018] In the above formula (I), Ar １ represents an arylene group which may have substituents other than S. Also, in formula (II) above, Ar ２ This represents an arylene group which may have substituents other than oxygen.

[0019] The -S- or -O- in formula (I) or (II) above crosslinks the molecular chain of the polyarylene sulfide resin to form a crosslinked polyarylene sulfide resin (A). Formula (I) or (II) represents a constituent unit that includes an example of the crosslinked structure of resin (A), and the constituent units of resin (A) may include a crosslinked structure in which two or more oxygen atoms and / or sulfur atoms are bonded.

[0020] The arylene group in formula (I) or (II) is not particularly limited, but examples include p-phenylene group, m-phenylene group, o-phenylene group, substituted phenylene group, p,p'-diphenylene sulfone group, p,p'-biphenylene group, p,p'-diphenylene ether group, p,p'-diphenylene carbonyl group, naphthalene group, etc. The resin (A) may be a resin that contains only the constituent units represented by the above formula (I) or (II) as repeating units, and may contain two or more types of constituent units (for example, a constituent unit represented by "-(Ar-S)-" that does not have a crosslinking structure of -S- or -O-). Furthermore, if it contains two or more types of constituent units, it may be a copolymer containing different types of arylene groups.

[0021] In one embodiment, the peak molecular weight (Mtop) of resin (A) is preferably 20,000 to 100,000, and more preferably 20,000 to 80,000. If Mtop is within the above range, it is easier to suppress the generation of resin buildup during pellet manufacturing. The inventors of this application have found that the gas generated during pellet manufacturing affects the generation of resin buildup. If Mtop is 20,000 or higher, it is easier to suppress the generation of gas derived from the cross-linked polyarylene sulfide resin during pellet manufacturing. Also, if Mtop is 100,000 or lower, shear heating during pellet manufacturing is less likely to increase, making it easier to suppress gas generation. The Mtop of resin (A) can be measured by the following method. Resin (A) may be used alone or in combination of two or more types, but if resin (A) is a mixture of two or more types, it is preferable that the Mtop of the mixture is within the above range.

[0022] (Method for measuring Mtop) The peak molecular weight (Mtop) of resin (A) can be measured as the peak molecular weight of the molecular weight distribution converted to standard polystyrene by high-temperature gel permeation chromatography. Mtop measured by high-temperature gel permeation chromatography can be measured using, for example, an instrument such as the SSC-7000 manufactured by Senshu Scientific Co., Ltd. (UV detector: detection wavelength 360 nm). For measurement, a sample prepared by dissolving resin (A) in 1-chloronaphthalene, the solvent, at 230°C for 10 minutes and adjusting the concentration to 0.05% by mass can be used.

[0023] In one embodiment, the measurement temperature of resin (A) was 310°C and the shear rate was 1200 sec. －１ The melt viscosity in is preferably 10 to 400 Pa·s, and more preferably 15 to 200 Pa·s. If the melt viscosity is within the above range, it is easier to suppress the generation of resin during pellet manufacturing. The melt viscosity of resin (A) can be measured using a capillary rheometer (for example, Capillograph 1D manufactured by Toyo Seiki Seisakusho Co., Ltd.).

[0024] (Method for producing resin (A)) The method for producing resin (A) is not particularly limited and can be prepared by conventionally known methods. For example, it may be prepared by polycondensation reaction of a sulfur-containing compound and an arylene compound having a halogen substituent. This step can produce resin (A) containing the constituent units of formula (I). Furthermore, the method for preparing resin (A) containing the constituent units of formula (II) is not particularly limited and typically, the resin obtained by the above polycondensation reaction may be further heated in an oxygen-containing atmosphere to undergo oxidative crosslinking.

[0025] Examples of sulfur-containing compounds include elemental sulfur, alkali metal sulfides, and alkali metal hydrosulfides.

[0026] Examples of arylene compounds having halogen substituents include arylene compounds having one to three halogen atoms selected from the group consisting of fluorine, chlorine, bromine, and iodine atoms. From the viewpoint of availability, it is preferable to include paradihalobenzene, and more preferable to include paradichlorobenzene.

[0027] The amount of sulfur-containing compounds and arylene compounds having halogen substituents used is not particularly limited, and the amount can be adjusted as appropriate depending on the physical properties required for the final resin composition.

[0028] <Lubricant (B1)> If the resin composition according to the first embodiment satisfies the requirement of (1), the resin composition (1) contains 0.04 to 3.0 parts by mass of lubricant (B1) per 100 parts by mass of resin (A).

[0029] Lubricant (B1) refers to a lubricant whose weight loss rate is 20% or less after being heated from 50°C to 360°C at a heating rate of 45°C / min under a nitrogen atmosphere and held at 360°C for 30 minutes. By blending a certain amount of such lubricant (B1) with resin (A), the generation of resin residue during the production of resin composition pellets can be suppressed.

[0030] In this disclosure, "weight loss rate" refers to the change in weight after heating from 50°C to 360°C at a heating rate of 45°C / min under a nitrogen atmosphere and holding at 360°C for 30 minutes, expressed as (weight of lubricant before heating (g) - weight of lubricant after heating (g)) ÷ weight of lubricant before heating (g) × 100 (%). Specifically, the weight loss rate can be measured by the following method. (Measurement conditions) Measuring instrument: TGA Q500 (manufactured by TA Instruments) Starting temperature: 50°C Heating rate: 45°C / min Holding temperature: 360°C Holding time: 30 minutes Carrier gas: N ２ Carrier gas flow rate: 60 mL / min

[0031] In one embodiment, the weight loss rate of the lubricant (B1) is preferably 15% or less, more preferably 10% or less, even more preferably 7% or less, and particularly preferably 5% or less, from the viewpoint of more effectively suppressing the generation of eye discharge. In a preferred embodiment, the weight loss rate of the lubricant (B1) may be 1 to 5%.

[0032] The lubricant (B1) is not particularly limited as long as it has a weight loss rate of 20% or less, and any lubricant can be used. From the viewpoint of ease of availability, heat resistance, or mold release properties, it is preferable that the lubricant (B1) contains a polyolefin wax or a fatty acid metal salt with 10 or more carbon atoms. These lubricants may be used individually or in combination of two or more. Examples of polyolefin waxes include polyethylene wax.

[0033] Examples of fatty acid metal salts having 10 or more carbon atoms include sodium, potassium, calcium, magnesium, or aluminum salts of fatty acids having 10 to 20 carbon atoms. Specifically, examples include sodium, potassium, calcium, magnesium, or aluminum salts of capric acid, lauric acid, myristic acid, palmitic acid, or stearic acid. Of these, from the viewpoint of heat resistance or mold release properties, it is more preferable to include a metal salt of stearic acid, and even more preferable to include calcium stearate or calcium hydroxystearate.

[0034] In one embodiment, the lubricant (B1) preferably contains one or more selected from polyethylene wax, calcium stearate, and calcium hydroxystearate, and is particularly preferably polyethylene wax.

[0035] In one embodiment, the ratio of lubricant (B1) to 100 parts by mass of resin (A) is preferably 0.1 to 2.0 parts by mass, more preferably 0.3 to 1.5 parts by mass, and particularly preferably 0.5 to 1.0 parts by mass, from the viewpoint of easily suppressing the generation of adhesive buildup.

[0036] The resin composition (1) may contain components other than the resin (A) and the lubricant (B1) described above, from the viewpoint of making it easier to suppress the generation of nail discharge. From the viewpoint of more effectively suppressing the generation of nail discharge, it is preferable to include the lubricant (B1) and the silane coupling agent (C) described later. That is, in one preferred embodiment of the resin composition (1), 0.1 to 1.0 parts by mass of the silane coupling agent (C) is further included with respect to 100 parts by mass of the resin (A). The ratio of the silane coupling agent (C) to 100 parts by mass of the resin (A) is more preferably 0.1 to 0.5 parts by mass, even more preferably 0.1 to 0.4 parts by mass, and particularly preferably 0.15 to 0.35 parts by mass. By including the lubricant (B1) and the silane coupling agent (C) within the above ranges relative to the resin (A), the generation of nail discharge can be more effectively suppressed.

[0037] When the resin composition (1) contains a lubricant (B1) and a silane coupling agent (C), the mass ratio of the lubricant (B1) to the silane coupling agent (C) in the resin composition (1) ((B1):(C)) is preferably 10:1 to 2.5:1, and more preferably 5:1 to 2.5:1. By setting the mass ratio of the lubricant (B1) to the silane coupling agent (C) within the above range, the generation of lint during pellet manufacturing can be more effectively suppressed.

[0038] If the resin composition according to the first embodiment satisfies the requirements of (2), the resin composition (2) contains, per 100 parts by mass of the resin (A), 0.04 to 3.0 parts by mass of a lubricant other than lubricant (B1) (B2) and 0.1 to 1.0 parts by mass of a silane coupling agent (C). The lubricant (B2) is a common lubricant blended into conventional cross-linked polyarylene sulfide resin compositions. By blending such a lubricant in combination with the silane coupling agent (C) described later, the generation of lint can be suppressed.

[0039] <Lubricant (B2)> The lubricant (B2) refers to all lubricants other than the aforementioned lubricant (B1). That is, the lubricant (B2) is a lubricant with a weight loss rate exceeding 20%. Such lubricants include, for example, fatty acid metal salts having 9 or less carbon atoms (e.g., sodium salts, potassium salts, calcium salts, magnesium salts, or aluminum salts of fatty acids having 1 to 9 carbon atoms, etc.); fatty acids (e.g., monovalent saturated or unsaturated fatty acids, divalent saturated or unsaturated fatty acids); fatty acid derivatives (esters of the aforementioned fatty acids, fatty acid amides, etc.); polyalkylene glycols [e.g., homopolymers or copolymers of alkylene glycols having 2 to 6 carbon atoms (e.g., ethylene glycol, propylene glycol, tetramethylene glycol, etc.), or derivatives thereof, etc.]; silicone-based compounds [e.g., monoorganosiloxanes such as dialkylsiloxane (e.g., dimethylsiloxane, etc.), alkylarylsiloxane (e.g., phenylmethylsiloxane, etc.), diarylsiloxane (e.g., diphenylsiloxane, etc.), or homopolymers or copolymers thereof (e.g., polyorganosiloxane); modified polyorganosiloxane, etc.]. These lubricants may be used alone or in combination of two or more. In the lubricants exemplified above, those with a weight loss rate of 20% or less may be included in the lubricant (B1). In the present embodiment, the lubricant (B2) is one of the lubricants exemplified above with a weight loss rate exceeding 20%.

[0040] Among the above lubricants, as the fatty acid, for example, fatty acids having 10 or more carbon atoms (e.g., saturated fatty acids having 10 to 34 carbon atoms such as capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, montanic acid, etc.; unsaturated fatty acids having 10 to 34 carbon atoms such as oleic acid, linoleic acid, linolenic acid, arachidonic acid, erucic acid, etc.) are preferred. Further, as the fatty acid derivative, it preferably contains esters of the aforementioned fatty acids having 10 or more carbon atoms.

[0041] In one embodiment, as the lubricant (B2), a lubricant with a weight loss rate of more than 20% is preferred, and it preferably contains one or more selected from fatty acid metal salts, fatty acids, and fatty acid derivatives having 9 or less carbon atoms, more preferably contains a fatty acid ester having 10 or more carbon atoms, and particularly preferably contains a stearic acid ester.

[0042] In one embodiment, the proportion of the lubricant (B2) in the resin composition (2) is preferably 0.1 to 2.0 parts by mass, more preferably 0.3 to 1.5 parts by mass, and particularly preferably 0.5 to 1.0 parts by mass with respect to 100 parts by mass of the resin (A).

[0043] <Silane coupling agent (C)> The resin composition (2) contains the lubricant (B2) and the silane coupling agent (C). By combining the lubricant (B2) and the silane coupling agent (C) with respect to the resin (A), it is possible to suppress the occurrence of meyan during the production of pellets of the resin composition (2).

[0044] The silane coupling agent (C) is not particularly limited as long as it can suppress the occurrence of meyan in combination with the lubricant (B2). For example, epoxy silane compounds, amino silane compounds, vinyl silane compounds, (meth)acrylic silane compounds, isocyanate silane compounds, mercapto silane compounds, etc. can be mentioned. The silane coupling agent (C) may be used alone or in combination of two or more.

[0045] As the above silane compound, an alkoxysilane having 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms in the alkoxy group is preferred.

[0046] For example, as the epoxy silane compound, epoxy alkoxysilane is preferred. For example, 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, etc. can be mentioned.

[0047] As aminosilane compounds, aminoalkoxysilanes are preferred, and examples include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, N-(β-aminoethyl)-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-diallylaminopropyltrimethoxysilane, and 3-diallylaminopropyltriethoxysilane.

[0048] Vinyl alkoxysilanes are preferred vinyl silane compounds, such as vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris(β-methoxyethoxy)silane.

[0049] (Meth)acrylic silane compounds are preferably (meth)acryloxysilanes, such as 3-acryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, and 3-methacryloxypropylmethyldiethoxysilane.

[0050] As isocyanate silane compounds, isocyanate alkoxysilanes are preferred, and examples include 3-isocyanate propyltriethoxysilane and 3-isocyanate propyltrimethoxysilane.

[0051] Preferred mercapto-silane compounds include mercaptoalkoxysilanes, such as 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane.

[0052] Of these, from the viewpoint of stability, heat resistance, or reactivity, it is preferable that the silane coupling agent (C) contains one or more selected from aminosilane compounds and epoxysilane compounds.

[0053] In one embodiment, the proportion of the silane coupling agent (C) in the resin composition (2) is preferably 0.1 to 1.0 parts by mass, more preferably 0.1 to 0.5 parts by mass, even more preferably 0.1 to 0.4 parts by mass, and particularly preferably 0.15 to 0.35 parts by mass, per 100 parts by mass of resin (A). By including the lubricant (B2) and the silane coupling agent (C) within the above range, the generation of lint can be suppressed more effectively.

[0054] When the resin composition (2) contains a lubricant (B2) and a silane coupling agent (C), the mass ratio of the lubricant (B2):(C) in the resin composition (2) is preferably 10:1 to 2.5:1, and more preferably 5:1 to 2.5:1. By setting the mass ratio of the lubricant (B2) to the silane coupling agent (C) within the above range, the generation of lint during pellet production can be more effectively suppressed.

[0055] <Inorganic Filler (D)> The resin composition according to the first embodiment may further contain an inorganic filler (D). The inorganic filler (D) may be included in both resin compositions (1) and (2). Including the inorganic filler (D) makes it easier to improve the mechanical strength of the resulting molded article.

[0056] The inorganic filler (D) can take any form, such as powder, granules, fibers, flakes, or whiskers, but it is preferable to include a fibrous inorganic filler (D1).

[0057] Examples of fibrous inorganic fillers (D1) include mineral fibers such as glass fibers, carbon fibers, zinc oxide fibers, titanium oxide fibers, wollastonite, silica fibers, silica-alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, boron fibers, and potassium titanate fibers; and metallic fibrous materials such as stainless steel fibers, aluminum fibers, titanium fibers, copper fibers, and brass fibers. These fibrous inorganic fillers may be used individually or in combination of two or more. Hollow fibers may also be used as the fibrous inorganic filler (D1) for purposes such as reducing the specific gravity of the resin composition. Of these, it is preferable to include glass fibers as the fibrous inorganic filler (D1) from the viewpoint of improving mechanical strength.

[0058] From the viewpoint of further increasing the bending strength and impact strength of the molded product, the average fiber length of the fibrous inorganic filler (D1) before melt-kneading into the resin composition is preferably 0.01 to 5 mm, more preferably 0.05 to 4 mm, even more preferably 0.1 to 3.5 mm, and particularly preferably 0.5 to 3 mm. The average fiber length can be calculated using a scanning electron microscope and image processing software, and the arithmetic mean measured for 1000 fibrous inorganic fillers (D1) is used. The average fiber length may also be the manufacturer's value (a value published by the manufacturer in their catalog, etc.).

[0059] When the resin composition according to the first embodiment contains an inorganic filler (D), the amount is preferably 5 to 300 parts by mass, more preferably 20 to 150 parts by mass, even more preferably 30 to 130 parts by mass, and particularly preferably 50 to 100 parts by mass, per 100 parts by mass of resin (A).

[0060] <Other Thermoplastic Resins> The resin compositions according to the first embodiment (i.e., resin compositions (1) and (2)) may include thermoplastic resins other than the resin (A) described above. Examples of other thermoplastic resins include polyarylene sulfide resins other than resin (A); aromatic polyester resins consisting of aromatic dicarboxylic acids and diols, or oxycarboxylic acids, such as polyethylene terephthalate resin and polybutylene terephthalate resin; polyamide resins; polycarbonate resins; ABS resins; polyphenylene oxide resins; polyalkyl acrylate resins; polysulfone resins; polyethersulfone resins; polyetherimide resins; polyetherketone resins; liquid crystal polymers; cyclic olefin copolymers, etc. Furthermore, two or more of these thermoplastic resins may be used in mixture form. The content of the other thermoplastic resins may be, for example, 20% by mass or less, 15% by mass or less, or 10% by mass or less, based on the total mass of the resin composition.

[0061] <Additives> The resin compositions according to the first embodiment (i.e., resin compositions (1) and (2)) may contain known additives generally added to thermoplastic resins and thermosetting resins in proportions corresponding to the required performance, in order to impart desired properties according to their purpose, to the extent that they do not impede the effects of the present disclosure. Examples of additives include burr inhibitors, mold release agents, lubricants (excluding the above-mentioned lubricants (B1) and (B2)), plasticizers, flame retardants, colorants such as dyes and pigments, crystallization accelerators, crystal nucleating agents, various antioxidants, heat stabilizers, weather stabilizers, and corrosion inhibitors. The content of the above additives may be 5% by mass or less of the total mass of the resin composition.

[0062] As described above, the resin composition according to the first embodiment may include the configuration of resin composition (1) or resin composition (2). Of these, the configuration of resin composition (1) is preferred from the viewpoint of more effectively suppressing the generation of lint. Furthermore, it is more preferable that the resin composition satisfies the configuration of resin composition (1) and further contains 0.1 to 1.0 parts by mass of the silane coupling agent (C) per 100 parts by mass of resin (A).

[0063] [Method for producing resin composition, pellets, and method for producing the same] The resin composition according to the first embodiment can be prepared by mixing resin (A) and lubricant (B1), or resin (A), lubricant (B2), and silane coupling agent (C) by any method. The resin composition according to the first embodiment can be obtained in the form of pellets by dry blending each component, melt-kneading using a single-screw or twin-screw extruder, and then extruding from a die.

[0064] In other words, a method for producing pellets containing the resin composition according to the first embodiment includes: (1) extruding a cross-linked polyarylene sulfide resin composition (i.e., resin composition (1)) from a die, wherein the composition contains 100 parts by mass of a cross-linked polyarylene sulfide resin (A), and 0.04 to 3.0 parts by mass of a lubricant (B1) having a weight loss rate of 20% or less after being heated from 50°C to 360°C at a heating rate of 45°C / min under a nitrogen atmosphere and held at 360°C for 30 minutes; or (2) extruding a cross-linked polyarylene sulfide resin composition (i.e., resin composition (2)) from a die, wherein the composition contains 100 parts by mass of the resin (A), 0.04 to 3.0 parts by mass of a lubricant (B2) other than the lubricant (B1), and 0.1 to 1.0 parts by mass of a silane coupling agent (C).

[0065] In the above method, the method for preparing resin composition (1) or resin composition (2) is not particularly limited, and equipment and methods generally used for mixing synthetic resin compositions can be employed. That is, as described above, resin composition (1) can be obtained by dry blending resin (A), lubricant (B1), and other thermoplastic resins and additives as needed, and then melt-kneading them using a single-screw or twin-screw extruder. The same applies to resin composition (2). The preferred temperature during mixing (or melt-kneading) is 250 to 360°C.

[0066] In one embodiment, the conditions for extruding the resin composition (1) or resin composition (2) from the die include, for example, adjusting the extrusion temperature to a range of 300 to 340°C, from the viewpoint of more effectively suppressing the generation of die residue.

[0067] As described above, when manufacturing pellets of resin compositions using a single-screw or twin-screw extruder, it is common practice to heat and knead the resin at a temperature above its melting point before extruding. During extrusion, the molten resin comes into contact with air, causing the monomers and various additives in the resin composition to oxidize, and a lumpy oxide called "die grease" is formed near the die's discharge hole. If extrusion continues for a long time, the die grease gradually adheres to and accumulates in the die's discharge hole. This die grease can adhere to the strand, causing strand breakage, or it can become a foreign substance mixed into the pellet. In addition, the discharge hole may become blocked with die grease, making extrusion impossible. Conventionally, these problems caused by die grease have generally been addressed by improving the extruder, such as by changing the die shape.

[0068] The inventors of the present invention noticed that cross-linked polyarylene sulfide resin compositions generated significantly more resin buildup during pellet manufacturing than linear polyarylene sulfide resin compositions. Investigating the reason for this phenomenon in cross-linked polyarylene sulfide resin compositions, the inventors discovered that the lubricant and low-molecular-weight components contained in the resin composition vaporized during melt-kneading, generating gas. This gas caused the strands to expand during extrusion, leading to the massive generation of resin buildup.

[0069] To solve this problem, the inventors of the present invention conducted further intensive studies and found that by blending a certain amount of a lubricant with a weight loss rate of 20% or less, i.e., a lubricant with high thermal stability (lubricant (B1)), into the cross-linked polyarylene sulfide resin, or, when using a normal lubricant (lubricant (B2)), controlling the amount of lubricant (B2) blended within a certain range and combining it with a silane coupling agent (C), the generation of lint during pellet manufacturing can be effectively suppressed in a resin composition containing a cross-linked polyarylene sulfide resin. It is presumed that the reason why resin composition (2) (containing lubricant (B2) and silane coupling agent (C)) can suppress the generation of lint is that the silane coupling agent (C) reacts with low molecular weight components (oligomers, etc.) in the cross-linked polyarylene sulfide resin composition to increase their molecular weight, thereby preventing gases originating from these low molecular weight components.

[0070] As described above, since the pellets according to this embodiment contain the resin composition according to the first embodiment, the generation of resin residue during pellet manufacturing can be effectively suppressed. Therefore, the generation of resin residue can be suppressed using existing equipment. Furthermore, strand breakage during pellet manufacturing is easily suppressed. In addition, foreign matter derived from resin residue is less likely to be mixed into the pellets. Therefore, pellets of the resin composition according to the first embodiment tend to have good manufacturability during molding. Specifically, foreign matter contamination and weighing errors during molding are less likely to occur.

[0071] <Applications> As described above, the resin composition according to the first embodiment can suppress the generation of resin residue during the manufacture of pellets containing the resin composition. Therefore, pellets containing the resin composition according to the first embodiment have less contamination from resin residue, are of good quality, and can be used for various applications such as various molded products.

[0072] [Molded article and method for manufacturing the same] A molded article according to this embodiment can be obtained by molding a pellet containing the resin composition according to the first embodiment. More specifically, this molding includes molding the pellet containing the resin composition according to the first embodiment using generally known molding methods for thermoplastic resins, such as injection molding, extrusion molding, vacuum molding, and compression molding.

[0073] [Method for suppressing the generation of adhesive residue] A second embodiment of the present disclosure relates to a method for suppressing the generation of adhesive residue when manufacturing pellets of a cross-linked polyarylene sulfide resin composition. The second embodiment is a method for suppressing the generation of lint when manufacturing pellets of a cross-linked polyarylene sulfide resin composition, the method comprising: (1) (1) obtaining a cross-linked polyarylene sulfide resin composition by blending 0.04 to 3.0 parts by mass of a lubricant (B1) with a weight loss rate of 20% or less after heating from 50°C to 360°C at a heating rate of 45°C / min under a nitrogen atmosphere and holding at 360°C for 30 minutes, with 100 parts by mass of a cross-linked polyarylene sulfide resin (A); or (2) (2) obtaining a cross-linked polyarylene sulfide resin composition by blending 0.04 to 3.0 parts by mass of a lubricant (B2) other than the lubricant (B1) and 0.1 to 1.0 parts by mass of a silane coupling agent (C) with 100 parts by mass of the resin (A); and further, This includes extruding the crosslinked polyarylene sulfide resin composition obtained in (1) or (2) above from a die.

[0074] According to the method of the second embodiment, the generation of lint can be suppressed in the production of pellets of a cross-linked polyarylene sulfide resin composition using existing equipment.

[0075] In the method according to the second embodiment, (1) includes obtaining resin composition (1), and (2) includes obtaining resin composition (2). As described above, resin compositions (1) and (2) can suppress the generation of die grease during pellet manufacturing. By a method that includes extruding such resin composition (1) or (2) from a die, the generation of die grease can be suppressed in pellet manufacturing using existing equipment. The method for obtaining resin compositions (1) and (2), and the method for extruding these resin compositions (1) or (2) from a die can be the method described in the pellet manufacturing method described above. Furthermore, the lubricants (B1), (B2), and silane coupling agent (C) described in the first embodiment can be suitably used.

[0076] Other embodiments of the present disclosure are crosslinked polyarylene sulfide resin compositions, the resin composition comprising a crosslinked polyarylene sulfide resin (A) and a lint inhibitor (M), wherein (1) the lint inhibitor (M) comprises a lubricant (B1) whose weight loss rate after heating from 50°C to 360°C at a heating rate of 45°C / min under a nitrogen atmosphere and holding at 360°C for 30 minutes is 20% or less, and the lubricant (B1) is present in an amount of 0.04 to 3.0 parts by mass per 100 parts by mass of the resin (A), or (2) the lint inhibitor (M) comprises a lubricant (B2) other than the lubricant (B1) and a silane coupling agent (C), This invention relates to a crosslinked polyarylene sulfide resin composition that satisfies the following conditions: per 100 parts by mass of the resin (A), it contains 0.04 to 3.0 parts by mass of the lubricant (B2) and 0.1 to 1.0 parts by mass of the silane coupling agent (C).

[0077] In the above embodiment, lubricant (B1), lubricant (B2), and silane coupling agent (C) are blended as a lint-reducing agent (M). Here, "lint-reducing agent" refers to an agent that has the function of suppressing the generation of lint (including reducing the amount of lint generated) when manufacturing pellets of the resin composition according to this embodiment. By combining the cross-linked polyarylene sulfide resin (A) and the lint-reducing agent (M), the generation of lint during the manufacturing of pellets of the cross-linked polyarylene sulfide resin composition can be effectively suppressed.

[0078] A non-limiting list of exemplary embodiments of the present disclosure and combinations of exemplary embodiments is given below. [1] A crosslinked polyarylene sulfide resin composition that satisfies the following (1): (1) 0.04 to 3.0 parts by mass of a lubricant (B1) per 100 parts by mass of a crosslinked polyarylene sulfide resin (A), wherein the lubricant has a weight loss rate of 20% or less after being heated from 50°C to 360°C at a heating rate of 45°C / min under a nitrogen atmosphere and held at 360°C for 30 minutes, or (2): (2) 0.04 to 3.0 parts by mass of a lubricant (B2) other than the lubricant (B1) per 100 parts by mass of the resin (A), and 0.1 to 1.0 part by mass of a silane coupling agent (C). [2] The crosslinked polyarylene sulfide resin composition according to [1], wherein the lubricant (B1) comprises one or more selected from polyolefin waxes and fatty acid metal salts having 10 or more carbon atoms. [3] The crosslinked polyarylene sulfide resin composition according to [1] or [2], wherein the silane coupling agent (C) comprises one or more selected from aminosilane compounds and epoxysilane compounds. [4] The crosslinked polyarylene sulfide resin composition according to any one of [1] to [3], wherein the lubricant (B2) comprises one or more selected from fatty acid metal salts having 9 or fewer carbon atoms, fatty acids, and fatty acid derivatives. [5] The crosslinked polyarylene sulfide resin composition according to any one of [1] to [4], satisfying (1) or (2) above, and further comprising an inorganic filler (D). [6] The crosslinked polyarylene sulfide resin composition according to [5], comprising 5 to 300 parts by mass of the inorganic filler (D) per 100 parts by mass of the resin (A). [7] A crosslinked polyarylene sulfide resin composition according to any one of [1] to [6] that satisfies (1) above. [8] A crosslinked polyarylene sulfide resin composition according to any one of [1] to [7] that satisfies (1) above and further comprises 0.1 to 1.0 parts by mass of the silane coupling agent (C) per 100 parts by mass of the resin (A). [9] A pellet comprising the crosslinked polyarylene sulfide resin composition according to any one of [1] to [8].

[10] A molded article comprising the crosslinked polyarylene sulfide resin composition according to any one of [1] to [8].

[11] A method for suppressing the generation of lint when manufacturing pellets of a cross-linked polyarylene sulfide resin composition, the method comprising: (1) (1) to obtain a cross-linked polyarylene sulfide resin composition by blending 0.04 to 3.0 parts by mass of a lubricant (B1) with a weight loss rate of 20% or less after heating from 50°C to 360°C at a heating rate of 45°C / min under a nitrogen atmosphere and holding at 360°C for 30 minutes, or (2) (2) to obtain a cross-linked polyarylene sulfide resin composition by blending 0.04 to 3.0 parts by mass of a lubricant (B2) other than the lubricant (B1) and 0.1 to 1.0 parts by mass of a silane coupling agent (C) with 100 parts by mass of the resin (A), further comprising: A method comprising extruding the crosslinked polyarylene sulfide resin composition obtained in (1) or (2) above from a die.

[0079] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following description.

[0080] [Materials] The materials used in the examples and comparative examples are as follows:

[0081] <Resin (A)> Cross-linked polyphenylene sulfide (PPS) resin: Zhejiang NHU, "20212C", melt viscosity: 104 Pa·s (shear rate: 1200 sec) －１ (at 310°C), peak molecular weight (Mtop): 43300

[0082] (Measurement of melt viscosity of resin (A)) The melt viscosity of resin (A) was measured as follows: A capillary tube manufactured by Toyo Seiki Seisakusho Co., Ltd. was used, with a flat die of 1 mmφ × 20 mmL as the capillary, at a barrel temperature of 310°C and a shear rate of 1200 sec. －１ The melt viscosity was measured.

[0083] (Measurement of peak molecular weight (Mtop) of resin (A)) The Mtop of the above resin (A) was measured as follows. Using 1-chloronaphthalene as the solvent, a 0.05 mass% solution was prepared by heating and dissolving it in an oil bath at 230°C for 10 minutes. High-temperature gel permeation chromatography (GPC) measurement was performed using an SSC-7000 manufactured by Senshu Scientific Co., Ltd., with a UV detector (detection wavelength: 360 nm), and the molecular weight of the peak top of the molecular weight distribution converted to standard polystyrene was calculated.

[0084] <Lubricant (B1)> Polyethylene wax: Sanyo Chemical Industries, Ltd., "Sunwax (registered trademark) 161-P", weight loss rate 5% <Lubricant (B2)> Pentaerythritol stearate: NOF Corporation, "Unistar (registered trademark) H476", weight loss rate 25% <Silane coupling agent (C)> (C1): γ-aminopropyltriethoxysilane, Shin-Etsu Chemical Co., Ltd., "KBE-903" (C2): 3-glycidoxypropyltrimethoxysilane, Shin-Etsu Chemical Co., Ltd., "KBM-403" <Inorganic filler (D)> (D1): Glass fiber, Taishan Glass Fiber Co., Ltd., "ECS13-3.0-T443R", average fiber length (cut length) 3 mm

[0085] The weight loss rates of the lubricants (B1) and (B2) in the above materials were measured using the following method.

[0086] <Measurement Method for Weight Loss Rate> Under the following measurement conditions, the lubricant was heated from 50°C to 360°C at a heating rate of 45°C / min in a nitrogen atmosphere, and the change in weight of the lubricant after holding it at 360°C for 30 minutes was measured. The weight loss rate was calculated as (weight of lubricant before heating (g) - weight of lubricant after heating (g)) ÷ weight of lubricant before heating (g) × 100 (%).

[0087] (Measurement conditions) Measuring instrument: TGA Q500 (manufactured by TA Instruments) Starting temperature: 50°C Heating rate: 45°C / min Holding temperature: 360°C Holding time: 30 minutes Carrier gas: N ２ Carrier gas flow rate: 60 mL / min

[0088] [Examples 1-8, Comparative Example 1] The materials shown in Table 1 were dry-blended in the proportions shown in Table 1. This was fed into a twin-screw extruder at a cylinder temperature of 320°C (fibrous inorganic filler (D1) was added separately from the side feed section of the extruder), melt-kneaded, and then extruded from the die to obtain resin composition pellets.

[0089] <Amount of Die Adhesive Generated> The amount of die adhesive generated during pellet manufacturing was measured using the following method. The state of the die discharge hole was recorded on video, and the number of die adhesive particles that fell from the die per minute was measured. This operation was performed for 3 minutes, and the average value was evaluated as the amount of die adhesive generated (number of particles / minute). The results are shown in Table 1.

[0090] <Pellet Volume Increase Rate> The pellet volume increase rate was measured using X-ray CT (Comscan Techno, ScanXmate-D90SS270). In addition, the volume increase rate of each example was calculated with the volume of the pellet in Comparative Example 1 set to 1. The results are shown in Table 1.

[0091]

[0092] As shown in Table 1, the resin compositions of Examples 1 to 8, which satisfy the configuration of the first embodiment, produced less resin during pellet manufacturing compared to the resin composition of Comparative Example 1. Furthermore, based on the pellet volume increase rate, the pellets of Examples 1 to 8 had a small volume increase rate, which suggests that gas generation during pellet manufacturing was suppressed, resulting in reduced resin generation. From these results, it was confirmed that the resin composition according to the first embodiment can suppress the generation of resin during pellet manufacturing. In addition, it was confirmed that the method according to the second embodiment can suppress the generation of resin during pellet manufacturing using existing equipment.

[0093] The resin composition according to the first embodiment can suppress the generation of lint during the manufacture of pellets containing the resin composition, resulting in less contamination from foreign matter derived from lint, allowing for the production of high-quality pellets, and thus having industrial applicability.

Claims

1. A cross-linked polyarylene sulfide resin composition that satisfies the following (1): (1) per 100 parts by mass of a cross-linked polyarylene sulfide resin (A), contains 0.04 to 3.0 parts by mass of a lubricant (B1) whose weight loss rate after heating from 50°C to 360°C at a heating rate of 45°C / min under a nitrogen atmosphere and holding at 360°C for 30 minutes is 20% or less, or (2): (2) per 100 parts by mass of the resin (A), contains 0.04 to 3.0 parts by mass of a lubricant (B2) other than the lubricant (B1), and contains 0.1 to 1.0 part by mass of a silane coupling agent (C).

2. The crosslinked polyarylene sulfide resin composition according to claim 1, wherein the lubricant (B1) comprises one or more selected from polyolefin waxes and fatty acid metal salts having 10 or more carbon atoms.

3. The crosslinked polyarylene sulfide resin composition according to claim 1 or 2, wherein the silane coupling agent (C) comprises one or more selected from aminosilane compounds and epoxysilane compounds.

4. The crosslinked polyarylene sulfide resin composition according to claim 1 or 2, wherein the lubricant (B2) comprises one or more selected from fatty acid metal salts, fatty acids, and fatty acid derivatives having 9 or fewer carbon atoms.

5. A crosslinked polyarylene sulfide resin composition according to claim 1 or 2, which satisfies (1) or (2) above and further comprises an inorganic filler (D).

6. The crosslinked polyarylene sulfide resin composition according to claim 5, comprising 5 to 300 parts by mass of the inorganic filler (D) per 100 parts by mass of the resin (A).

7. A crosslinked polyarylene sulfide resin composition according to claim 1 or 2, satisfying the above (1).

8. The crosslinked polyarylene sulfide resin composition according to claim 1 or 2, which satisfies (1) above and further comprises 0.1 to 1.0 parts by mass of the silane coupling agent (C) per 100 parts by mass of the resin (A).

9. A pellet comprising the crosslinked polyarylene sulfide resin composition according to claim 1 or 2.

10. A molded article comprising the crosslinked polyarylene sulfide resin composition according to claim 1 or 2.

11. A method for suppressing the generation of lint when manufacturing pellets of a cross-linked polyarylene sulfide resin composition, the method comprising: (1) (1) obtaining a cross-linked polyarylene sulfide resin composition by blending 0.04 to 3.0 parts by mass of a lubricant (B1) with a weight loss rate of 20% or less after heating from 50°C to 360°C at a heating rate of 45°C / min under a nitrogen atmosphere and holding at 360°C for 30 minutes, with 100 parts by mass of a cross-linked polyarylene sulfide resin (A); or (2) (2) obtaining a cross-linked polyarylene sulfide resin composition by blending 0.04 to 3.0 parts by mass of a lubricant (B2) other than the lubricant (B1) and 0.1 to 1.0 parts by mass of a silane coupling agent (C) with 100 parts by mass of the resin (A); further, A method comprising extruding the crosslinked polyarylene sulfide resin composition obtained in (1) or (2) above from a die.

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