JP2023066346A - Polyphenylene sulfide resin composition, molded article, and method for manufacturing molded article - Google Patents

Abstract

To provide a polyphenylene sulfide resin composition which achieves high flexibility, high toughness, thermal aging resistance and chemical resistance, and is excellent in moldability, and a molded article using the same.SOLUTION: A polyphenylene sulfide resin composition is obtained by blending (A) a polyphenylene sulfide resin, (B) a modified diene-based copolymer, and (C) an elastomer containing an epoxy group, wherein when the total of the component (A), the component (B) and the component (C) is 100 mass%, the component (A) is 20 mass% or more and 60 mass% or less, and in a morphology when a molded article formed of the polyphenylene sulfide resin composition is observed by a transmission electron microscope, (A) the polyphenylene sulfide resin forms a continuous phase, and (B) the modified diene-based copolymer and (C) the elastomer containing the epoxy group form a dispersion phase.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a polyphenylene sulfide resin composition having high flexibility, high toughness, resistance to heat aging and chemical resistance, and excellent moldability, a molded article using the same, and a method for producing a molded article. be.

BACKGROUND ART In recent years, a method of making piping such as ducts, tubes, etc. in an engine room as automobile parts from resin to reduce weight and thereby improve fuel efficiency has become widespread. Polyamide-based materials are currently mainly used as materials for such pipes. However, in recent years, from the viewpoint of minimizing the space in the engine room and optimizing the layout, pipes are required to have better assembly and vibration absorption than ever before. In order to meet these demands, it is important to design piping by combining molding methods such as blow molding and extrusion molding, which have a high degree of freedom in designing molded products, with highly flexible resins. In addition, the closer the distance between the pipes and the heat source, the higher the temperature of the external environment.

Under such circumstances, resins used for automobile piping are required to satisfy not only heat resistance and chemical resistance, but also high flexibility and blow moldability or extrusion moldability.

Polyphenylene sulfide (hereinafter sometimes abbreviated as PPS) resin has properties suitable as an engineering plastic, such as excellent heat resistance, chemical resistance, flame resistance, electrical insulation, and heat and humidity resistance.・Widely used for electronic parts, communication equipment parts, automobile parts, etc. On the other hand, in order to apply the PPS resin to piping based on the above concept, there is a problem of poor flexibility and toughness, and poor blow moldability or extrusion moldability.

In order to solve the problem of flexibility and toughness of such a PPS resin composition, a PPS resin and a modified conjugated diene polymer having an affinity group or a reactive group for the PPS resin are used to improve impact resistance, elongation, and flexibility. A PPS resin composition with improved properties (see, for example, Patent Document 1) or a PPS resin, a polyamide, and an epoxy group-containing elastomer are blended to exhibit high toughness while improving heat aging resistance and chemical resistance. A PPS resin composition has been studied (see, for example, Patent Document 2).

JP 2021-42357 A WO2018/003700

However, the resin composition described in Patent Document 1 cannot be said to have sufficient flexibility because the amount of the elastomer compounded is small.

Although the resin composition described in Patent Document 2 has excellent toughness and a certain degree of flexibility, there is a need for further softening in order to expand its use as a flexible material in which the molded product is freely bent and used. there were.

Therefore, as a result of intensive studies to solve the above problems, the present inventors have found that a resin composition obtained by blending a polyphenylene sulfide resin, a modified diene copolymer, and an elastomer containing an epoxy group, wherein the polyphenylene By blending sulfide resins in a specific ratio, polyphenylene sulfide resin forms a continuous phase, and a modified diene copolymer and an epoxy group-containing elastomer form a dispersed phase. The present inventors have found that the properties can be obtained, and have arrived at the present invention.

That is, the present invention has the following configurations.
1. A polyphenylene sulfide resin composition comprising (A) a polyphenylene sulfide resin, (B) a modified diene copolymer, and (C) an elastomer containing an epoxy group, comprising (A) a polyphenylene sulfide resin, ( When the total of B) the modified diene copolymer and (C) the epoxy group-containing elastomer is 100% by mass, (A) the polyphenylene sulfide resin is 20% by mass or more and 60% by mass or less, and In the morphology of a molded article made of a polyphenylene sulfide resin composition observed with a transmission electron microscope, (A) the polyphenylene sulfide resin forms a continuous phase, (B) the modified diene copolymer and (C) the epoxy group A polyphenylene sulfide resin composition in which an elastomer containing: forms a dispersed phase.
2. The polyphenylene sulfide resin composition according to item 1, wherein the modifying group of the modified diene copolymer (B) is an amino group.
3. The polyphenylene sulfide resin composition according to item 1 or 2, wherein the (B) modified diene copolymer is a modified conjugated diene copolymer.
4. The polyphenylene sulfide resin composition according to any one of items 1 to 3, wherein the epoxy group-containing elastomer (C) is an epoxy group-containing polyolefin copolymer.
5. The polyphenylene sulfide resin according to any one of items 1 to 4, wherein the dispersed phase comprises a co-continuous structure of (B) a modified diene copolymer and (C) an epoxy group-containing elastomer. Composition.
6. An ISO (1A) dumbbell test piece obtained by injection molding the polyphenylene sulfide resin composition has a flexural modulus measured according to ISO 178 (2010) of 1.0 MPa or more and 1500 MPa or less. The polyphenylene sulfide resin composition according to 1.
7. The polyphenylene sulfide resin composition according to any one of items 1 to 6, wherein the polyphenylene sulfide resin composition is a polyphenylene sulfide resin composition for piping that comes into contact with cooling water for automobiles.
8. A molded article made of the polyphenylene sulfide resin composition according to any one of items 1 to 7.
9. The molded article according to item 8, wherein the molded article is a hollow molded article.
10. The molded product according to item 9, wherein the hollow molded product is a pipe that comes into contact with cooling water for automobiles.
11. A method for producing a molded article, comprising extruding the polyphenylene sulfide resin composition according to any one of 1 to 7.

According to the present invention, it is possible to obtain a polyphenylene sulfide resin composition that exhibits a very low elastic modulus, is flexible and exhibits high toughness, and has dramatically improved heat aging resistance and chemical resistance. Molded articles made from these resin compositions are suitable for tubes and hoses that are used by fitting or bent, especially molded articles such as ducts and hoses around automobile engines that are used at high temperatures and under vibration.

The present invention will now be described in more detail.

The (A) PPS resin used in the present invention is a polymer having a repeating unit represented by the following structural formula.

(A) PPS resin is preferably a polymer containing 70 mol % or more, more preferably 90 mol % or more of a polymer containing repeating units represented by the above structural formula, from the viewpoint of heat resistance. In the (A) PPS resin, 30 mol % or less of the repeating units may be composed of at least one repeating unit represented by the following formula.

The melt viscosity of the (A) PPS resin used in the present invention is not particularly limited, but from the viewpoint of obtaining more excellent toughness, a higher melt viscosity is preferred. For example, the melt viscosity is preferably over 30 Pa·s, more preferably 50 Pa·s or more, and even more preferably 100 Pa·s or more. The upper limit is preferably 600 Pa·s or less from the viewpoint of maintaining melt fluidity.

The melt viscosity of the (A) PPS resin in the present invention was measured using a capillary rheometer (for example, Capilograph (registered trademark) manufactured by Toyo Seiki Co., Ltd.) under the conditions of a test temperature of 300°C, a residence time of 5 minutes, and a shear rate of 1216/s. It is a value measured using

The blending amount of (A) PPS resin in the polyphenylene sulfide resin composition is the total blending amount of (A) PPS resin, (B) modified diene-based copolymer, and (C) epoxy group-containing elastomer to 100 mass. %, it must be 20% by mass or more and 60% by mass or less. If the blending amount is less than 20% by mass, it is difficult to make (A) PPS a continuous phase. From the viewpoint of obtaining heat resistance and chemical resistance, the blending amount is more preferably 25% by mass or more, and particularly preferably 30% by mass or more. In addition, the upper limit of the compounding amount is preferably 50% by mass or less, more preferably 40% by mass or less. If the blending amount exceeds 60% by mass, the contribution of rigidity derived from the PPS resin increases, resulting in a decrease in flexibility.

(A) As a method for producing the PPS resin, a known method can be used. For example, a method of desalting polycondensation with a polyhalogenated aromatic compound and a sulfidating agent in an organic polar solvent described in Patent Document 2 (International Publication No. 2018/003700), or a method of melting using diiodobenzene and sulfur. Examples include a method of synthesizing under certain conditions.

The (B) modified diene-based copolymer used in the present invention is a polymer containing, as a constituent component, a conjugated diene compound having a pair of conjugated double bonds. Representative examples of conjugated diene compounds include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1 -3-pentadiene, 1,3-hexadiene. Among these, 1,3-butadiene and isoprene are preferred from the viewpoint of availability and productivity.

The (B) modified diene copolymer used in the present invention may be composed of one type of conjugated diene compound unit, or may be composed of two or more types of conjugated diene compound units. Here, the conjugated diene compound unit represents a structural unit derived from a conjugated diene compound. (B) In the modified diene copolymer, part or all of the conjugated diene compound units may be hydrogenated. That is, the modified diene-based copolymer (B) also includes a polymer containing a structure in which structural units derived from a conjugated diene compound are hydrogenated. Examples of structures in which a structural unit derived from a conjugated diene compound is hydrogenated include 1-butene, 2-methyl-1-butene, 2,3-dimethyl-1-butene, 1-pentene, 2- Examples include structural units derived from methyl 1-pentene, 1-hexene, and the like. From the viewpoint of reactivity and compatibility between (B) the modified diene-based copolymer and (C) the epoxy group-containing elastomer, it is preferable that at least a portion thereof has a conjugated double bond.

In the present invention, (B) the modified diene-based copolymer has modifying groups in addition to the conjugated diene compound units described above. Examples of modifying groups constituting the modified diene copolymer (B) include a hydroxyl group, a carbonyl group, a thiocarbonyl group, an acid halide group, a carboxyl group, an acid anhydride group, a thiocarboxyl group, an aldehyde group, a thio Aldehyde group, carboxylate group, amide group, sulfone group, sulfonate ester group, phosphoric acid group, phosphate group, amino group, imino group, cyano group, urethane group, urea group, pyridyl group, quinoline group, epoxy group, thioepoxy group, sulfide group, isocyanate group, isothiocyanate group, silicon halide group, silanol group, alkoxysilane group, tin halide group, alkoxytin group, phenyltin group, etc. groups.

Among the functional groups, at least one functional group selected from a hydroxyl group, a carboxyl group, an acid anhydride group, an epoxy group, an amino group, a urethane group and an isocyanate group is preferable from the viewpoint of hydrolysis resistance of the functional group. . Among them, from the viewpoint of thickening by reacting with an elastomer containing (C) an epoxy group and making it easier for the (A) polyphenylene sulfide resin to form a continuous phase in the polyphenylene sulfide resin composition, a carboxyl group and an acid anhydride group and an amino group are preferable, and an amino group is particularly preferable from the viewpoint of selective reactivity. The amino group may be a primary, secondary or tertiary amino group, but a primary or secondary amino group is preferred from the viewpoint of reactivity.

The (B) modified diene copolymer used in the present invention comprises (a) a vinyl aromatic polymer block, (b) a conjugated diene polymer block, and (c) a random copolymer of a conjugated diene compound and a vinyl aromatic compound. Block copolymers having two or more polymer blocks selected from the group consisting of polymer blocks are preferred.

Examples of the vinyl aromatic compound constituting the (a) vinyl aromatic polymer block include, but are not limited to, styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenyl vinyl aromatic compounds such as ethylene, N,N-dimethyl-p-aminoethylstyrene, N,N-diethyl-p-aminoethylstyrene; Among these, styrene is preferred from the viewpoint of availability and productivity.

The (a) vinyl aromatic polymer block may be composed of one kind of vinyl aromatic monomer unit, or may be composed of two or more kinds of vinyl aromatic monomer units.

Examples of the conjugated diene compound constituting the (b) conjugated diene polymer block include, but are not limited to, 1,3-butadiene, 2-methyl-1,3 butadiene (isoprene), 2,3- Dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1-3pentadiene, 1,3-hexadiene. Among these, 1,3-butadiene and isoprene are preferred from the viewpoint of availability and productivity. (b) The conjugated diene polymer block may be composed of one type of conjugated diene monomer unit, or may be composed of two or more types of conjugated diene monomer units. As described above, some or all of the conjugated diene units may be hydrogenated, but from the viewpoint of reactivity and compatibility with (C) the epoxy group-containing elastomer, It is preferred to have conjugated double bonds in at least a portion of the coalescence.

As the conjugated diene compound and the vinyl aromatic compound constituting the (c) random copolymer block of the conjugated diene compound and the vinyl aromatic compound, the (a) vinyl aromatic polymer block and (b) the conjugated diene polymer block The compounds exemplified as compounds that can be used for the coalescing block can be used.

(c) The vinyl aromatic units derived from the vinyl aromatic compound in the random copolymer block of the conjugated diene compound and the vinyl aromatic compound may be uniformly distributed, or may be distributed in a stepwise tapered shape. You may have

The blending amount of (B) the modified diene copolymer in the polyphenylene sulfide resin composition depends on the type of modifying group constituting the (B) modified diene copolymer, (a) the vinyl aromatic polymer block, ( b) the conjugated diene polymer block and (c) the random copolymer block of the conjugated diene compound and the vinyl aromatic compound. From the viewpoint of expression, the range of 1 part by mass or more and 200 parts by mass or less is preferable with respect to 100 parts by mass of the (A) PPS resin. (B) When the modified diene-based copolymer is added in an amount of 1 part by mass or more, the toughness and flexibility are excellent, which is preferable. By setting the blending amount of (B) the modified diene copolymer to 200 parts by mass or less, the reaction with (C) the epoxy group-containing elastomer can be controlled, and the formation of gelled products can be suppressed, thereby reducing toughness. It is preferable because it does not occur. The lower limit of the amount to be blended is more preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and particularly preferably 30 parts by mass or more from the viewpoint of obtaining the assembly property of the molded product. The upper limit of the blending amount is more preferably 150 parts by mass or less, more preferably 140 parts by mass or less, particularly preferably 130 parts by mass or less, particularly preferably 120 parts by mass or less from the viewpoint of obtaining heat resistance and chemical resistance.

The (C) elastomer containing an epoxy group used in the present invention specifically means a thermoplastic elastomer containing an epoxy group. Specific examples of thermoplastic elastomers include polyolefin copolymers, diene copolymers, polyurethane copolymers, polyamide copolymers, and polyester copolymers. However, among elastomers containing epoxy groups, elastomers containing epoxy groups having a structure derived from a conjugated diene compound also correspond to (B) a modified diene copolymer. treated as a system copolymer. The (C) epoxy group-containing elastomer used in the present invention is particularly preferably an epoxy group-containing polyolefin copolymer from the viewpoint of compatibility with the (B) modified diene copolymer. Polyolefin copolymers containing epoxy groups include olefin copolymers in which monomers having epoxy groups such as glycidyl esters, glycidyl ethers and glycidyl diamines are copolymerized in side chains, and olefin copolymers having double bonds. Examples thereof include those obtained by epoxy-oxidizing the double bond portion of the copolymer. Among them, an olefin copolymer obtained by copolymerizing a monomer having an epoxy group is preferable, and in particular an olefin copolymer (C1) mainly composed of an α-olefin and a glycidyl ester of an α,β-unsaturated acid. (hereinafter sometimes abbreviated as an olefinic copolymer (C1) containing an epoxy group) is preferably used.

Specific examples of α-olefins include ethylene, propylene, butene-1, 4-methylpentene-1, hexene-1, decene-1, octene-1, etc. Among them, ethylene is preferably used. Moreover, these can also use 2 or more types simultaneously.

On the other hand, a glycidyl ester of an α,β-unsaturated acid is a compound represented by the following general formula (3), where R is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. .

Specific examples of the α,β-unsaturated acid glycidyl ester represented by the above general formula (3) include glycidyl acrylate, glycidyl methacrylate, and glycidyl ethacrylate, among which glycidyl methacrylate is preferred. Used.

The olefin-based copolymer (C1) mainly composed of an α-olefin and a glycidyl ester of an α,β-unsaturated acid is a random copolymer of the α-olefin and the glycidyl ester of an α,β-unsaturated acid. Copolymerization methods such as coalescence, block copolymer, and graft copolymer may be used.

In the present invention, (C) the epoxy group-containing elastomer is derived from a monomer represented by the following general formula (4) in addition to a structure derived from an α-olefin and a glycidyl ester of an α,β-unsaturated acid. An epoxy group-containing olefinic copolymer (C2) (hereinafter sometimes abbreviated as an epoxy group-containing olefinic copolymer (C2)) having a structure as an essential component is also preferably used.

In the above general formula (4), R ¹ represents hydrogen or an alkyl group having 1 to 5 carbon atoms, X is a group selected from —COOR ² groups, —CN groups and aromatic groups, and R ² has 1 carbon atom. -10 alkyl groups are shown.

The details of the α-olefin and glycidyl ester of α,β-unsaturated acid used in the epoxy group-containing olefin copolymer (C2) are described in the above-mentioned epoxy group-containing olefin polymer (C1). and glycidyl esters of α-olefins and α,β-unsaturated acids.

Specific examples of the monomer represented by formula (4) include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, and isobutyl acrylate. , methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, isobutyl methacrylate and other α,β-unsaturated carboxylic acid alkyl esters; acrylonitrile, styrene , α-methylstyrene, styrene in which the aromatic ring is substituted with an alkyl group, acrylonitrile-styrene copolymer, and the like. Two or more of these can be used simultaneously.

The olefinic copolymer (C2) containing an epoxy group has a structure derived from an α-olefin, a structure derived from a glycidyl ester of an α,β-unsaturated acid represented by general formula (3), and a general formula ( 4) Random copolymers, block copolymers, graft copolymers, and copolymers obtained by copolymerizing these copolymers with structures derived from the monomers shown in 4). may For example, a random copolymer of an α-olefin and a glycidyl ester of an α,β-unsaturated acid represented by the general formula (3) is graft-copolymerized with a monomer represented by the general formula (4). A copolymer in which the above copolymerization modes are combined may also be used.

The copolymerization ratio of each component constituting the olefinic copolymer (C1) containing an epoxy group has an effect on the intended effect, polymerizability, gelation, heat resistance, fluidity, strength, and the like. From the point of view, the total amount of α-olefin and glycidyl ester of α,β-unsaturated acid is 100% by mass, α-olefin / glycidyl ester of α,β-unsaturated acid = 60/40 to 99/1 (mass ratio) range is preferably selected. The copolymerization amount of the α,β-unsaturated acid glycidyl ester is preferably 3% by mass or more, particularly preferably 5% by mass or more. In addition, the upper limit of the copolymerization amount of the glycidyl ester of α,β-unsaturated acid is 40% by mass or less from the viewpoint of reducing entanglement of molecular chains and obtaining excellent melt toughness of the PPS resin composition. It is preferably 15% by mass or less, more preferably 10% by mass or less. Further, in the epoxy group-containing olefin copolymer (C2), the copolymerization ratio of the α-olefin and the α,β-unsaturated acid glycidyl ester is the same as that of the epoxy group-containing olefin copolymer (C1). is similar to The copolymerization ratio of the monomer represented by the general formula (4) is 95% by mass to 40% by mass of the total amount of the α-olefin and the glycidyl ester of the α,β-unsaturated acid, represented by the general formula (4). A range of 5% to 60% by weight of the monomer is preferably selected.

The amount of (C) the epoxy group-containing elastomer compounded in the polyphenylene sulfide resin composition depends on the amount of copolymerization of each component constituting the elastomer, and cannot be generally defined. ) the modified diene-based copolymer and (C) the epoxy group-containing elastomer in total is 100% by mass, the blending amount of (C) the epoxy group-containing elastomer is preferably 20% by mass or more, and 25% by mass. % or more is more preferable. By setting the blending amount of (C) the epoxy group-containing elastomer to 20% by mass or more, sufficient flexibility can be obtained and a desired phase structure can be obtained. In addition, the upper limit of the compounding amount is preferably 70% by mass or less, more preferably 60% by mass or less, and particularly preferably 50% by mass or less from the viewpoint of obtaining an appropriate viscosity. By setting the content of (C) the epoxy group-containing elastomer to 70% by mass or less, it is possible to suppress excessive shear heat generation due to a marked increase in viscosity and thermal decomposition of the polymer.

In addition, as the epoxy group-containing elastomer (C), two or more elastomers having different copolymerization amounts of glycidyl esters of α,β-unsaturated acids in the epoxy group-containing olefin copolymer (C1) are used in combination. You can also This makes it possible to adjust the reaction between (C) the epoxy group-containing elastomer and (B) the modified diene-based copolymer and control the melt viscosity of the polyphenylene sulfide resin composition.

In the present invention, by blending (B) a modified diene-based copolymer, (C) an epoxy group-containing elastomer, and (D) an elastomer containing no functional group, better toughness and flexibility can be obtained. can. (D) Specific examples of elastomers containing no functional groups include polyolefin copolymers, diene copolymers, silicone rubbers, fluororubbers, and urethane rubbers.

Specific examples of polyolefin copolymers include ethylene-propylene copolymers, ethylene-butene copolymers, ethylene-hexene copolymers, ethylene-octene copolymers, polybutene, ethylene-propylene-diene copolymers, and the like. is mentioned. Among them, ethylene-propylene copolymers, ethylene-butene copolymers, ethylene-hexene copolymers, ethylene-octene copolymers, and ethylene-propylene-diene copolymers are particularly preferred. (D) Elastomers containing no functional groups may be used in combination of two or more.

From the viewpoint of exhibiting excellent toughness and flexibility, the blending amount of (D) the elastomer containing no functional group in the polyphenylene sulfide resin composition is (B) the modified diene system per 100 parts by mass of the (A) PPS resin. The total amount of the copolymer, (C) the epoxy group-containing elastomer, and (D) the functional group-free elastomer is preferably in the range of 1 part by mass or more and 200 parts by mass or less. When the total amount of (B) the modified diene copolymer, (C) the epoxy group-containing elastomer, and (D) the functional group-free elastomer is 1 part by mass or more, the toughness and flexibility are excellent. By setting the total amount to be 200 parts by mass or less, it is possible to suppress the increase in viscosity and the formation of a gelled product, which is preferable because a decrease in toughness does not occur. The lower limit of the total compounding amount is more preferably 10 parts by mass or more, more preferably 30 parts by mass or more, and particularly preferably 50 parts by mass or more, particularly preferably 70 parts by mass or more from the viewpoint of obtaining the assembly property of the molded product. . The upper limit of the total compounding amount is more preferably 150 parts by mass or less, more preferably 140 parts by mass or less, particularly preferably 130 parts by mass or less, particularly preferably 120 parts by mass or less from the viewpoint of obtaining heat resistance and chemical resistance. .

The polyphenylene sulfide resin composition of the present invention comprises (A) a PPS resin, (B) a modified diene copolymer, (C) an epoxy group-containing elastomer, and (D) a functional group-free elastomer. is 100% by mass, the total amount (unit: % by mass) of the elastomer (component (B) + component (C) + component (D)) is set within a specific range to dramatically improve flexibility. can be improved. Specifically, the total amount of elastomer compounded is preferably 70% by mass or less, more preferably 60% by mass or less, and further preferably 55% by mass or less from the viewpoint of moldability. From the viewpoint of obtaining flexibility, the lower limit of the total amount of elastomer compounded is preferably 20% by mass or more, more preferably 25% by mass or more, and particularly preferably 30% by mass or more.

In the present invention, (X) at least one compound having a molecular weight of 1000 or less selected from carboxylic acids and acid anhydrides (hereinafter sometimes abbreviated as component (X)) may be added. By adding the component (X) to the polyphenylene sulfide resin composition of the present invention, the reactivity of the epoxy group remaining in the elastomer containing (C) the epoxy group and the reactivity of the modified diene copolymer (B) By adjusting the (B) modified diene copolymer and (C) the epoxy group-containing elastomer while maintaining appropriate reactivity, by suppressing retention thickening, excellent rheological properties and moldability is obtained.

The molecular weight of component (X) is 1,000 or less from the viewpoint of efficiently reacting component (X) with (A) the PPS resin, (B) the modified diene-based copolymer, and (C) the epoxy group-containing elastomer. is preferred, and 500 or less is more preferred. The lower limit of the molecular weight is preferably 100 or more from the viewpoint of chemical and physical stability.

Although the structure of the component (X) is not limited as long as the above effects are exhibited, it is preferably a compound containing an aromatic ring in terms of chemical and physical stability. In particular, from the viewpoint of preferably adjusting the reactivity of (A) the reactive group of the PPS resin, (B) the modified diene copolymer, and (C) the epoxy group of the epoxy group-containing elastomer, tetracarboxylic acid and tetracarboxylic acid It is preferably at least one compound selected from carboxylic acid dianhydrides. Further, the tetracarboxylic acid preferably has a structure capable of intramolecularly dehydrating and condensing to form a tetracarboxylic dianhydride. These compounds may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, the tetracarboxylic acid may be a tetracarboxylic dianhydride in which a part thereof is dehydrated and condensed in the molecule, or these may be used in combination.

Specific examples of the component (X) include pyromellitic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 2,2′,3,3′-biphenyltetracarboxylic dianhydride, anhydride, 4,4′-(hexafluoroisopropylidene)diphthalic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-cyclohexene-1,2 dicarboxylic anhydride, 1 ,2,3,4-benzenetetracarboxylic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 2,2′,3,3′-benzophenonetetracarboxylic dianhydride , 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride, methylene-4,4′-diphthalic dianhydride, 1,1-ethylidene-4,4′-diphthalic dianhydride, 2,2-propylidene-4,4'-diphthalic dianhydride, 1,2-ethylene-4,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride , 1,4-tetramethylene-4,4′-diphthalic dianhydride, 1,5-pentamethylene-4,4′-diphthalic dianhydride, 4,4′-oxydiphthalic dianhydride, p- phenylene bis(trimellitate anhydride), thio-4,4'-diphthalic dianhydride, sulfonyl-4,4'-diphthalic dianhydride, 1,3-bis(3,4-dicarboxyphenyl)benzene dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,3-bis[2- (3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, 1,4-bis[2-(3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, bis[3- (3,4-dicarboxyphenoxy)phenyl]methane dianhydride, bis[4-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, 2,2-bis[3-(3,4-di Carboxyphenoxy)phenyl]propane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, bis(3,4-dicarboxyphenoxy)dimethylsilane dianhydride, 1,3-bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4 ,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6 Tetracarboxylic dianhydrides such as ,7-anthracenetetracarboxylic dianhydride and 1,2,7,8-phenanthrenetetracarboxylic dianhydride, and tetracarboxylic dianhydrides obtained by ring-opening these dianhydrides with water Carboxylic acids are mentioned. From the viewpoint of industrial availability and cost, pyromellitic dianhydride or pyromellitic acid is preferred.

The amount of component (X) to be blended depends on the type of component (X) used and the type and amount of epoxy group-containing elastomer (C), so it cannot be generally defined. On the other hand, it is preferably added in an amount of 0.01 parts by mass or more and 3 parts by mass or less, preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, from the viewpoint of obtaining excellent moldability. The upper limit of the compounding amount is preferably 2 parts by mass or less from the viewpoint of obtaining excellent heat resistance and chemical resistance.

In the present invention, according to Patent Document 2 (International Publication No. 2018/003700), if necessary, (A) PPS resin, (B) modified diene-based copolymer, (C ) an epoxy group-containing elastomer, component (X), and component (D) other than the functional group-free elastomer.

From the viewpoint of obtaining flexibility, the polyphenylene sulfide resin composition of the present invention has a bending elastic modulus of 1.0 MPa or more and 1500 MPa or less measured according to ISO 178 (2010) for an ISO dumbbell test piece (1A) obtained by injection molding. Preferably. The bending elastic modulus is preferably 1200 MPa or less, more preferably 1000 MPa or less from the viewpoint of obtaining vibration absorbency, and particularly preferably 800 MPa or less from the viewpoint of obtaining particularly excellent vibration absorbency. Furthermore, the bending elastic modulus is preferably 600 MPa or less from the viewpoint of obtaining excellent assemblability of the molded product. From the viewpoint of obtaining high flexibility, the lower the bending elastic modulus is, the better. When the bending elastic modulus is 1.0 MPa or more, deformation is suppressed even when the molded product is used in a high-temperature environment, and the shape can be maintained, which is preferable.

In the present invention, a modified diene-based copolymer is used, and (C) an elastomer containing an epoxy group undergoes an appropriate reaction, thereby lowering the flexural modulus and providing excellent flexibility compared to the method described in Patent Document 2. is obtained. The flexural modulus of the polyphenylene sulfide resin composition of the present invention can be adjusted by adjusting the flexural modulus of each of the constituent components of the resin composition and their blending amounts. When the total amount of the coalescence and (C) the epoxy group-containing elastomer is 100% by mass, the (A) PPS resin is 20% by mass or more and 60% by mass or less to obtain the above bending elastic modulus range. can be done. By increasing the blending amounts of (B) the modified diene copolymer, (C) the epoxy group-containing elastomer, and (D) the functional group-free elastomer, the flexural modulus can be lowered.

From the viewpoint of obtaining toughness, the polyphenylene sulfide resin composition of the present invention has a tensile elongation of 50% or more when an ISO dumbbell test piece (1A) obtained by injection molding is measured according to ISO527-1,-2 (2012). It is preferably 200% or less. The tensile elongation is preferably 60% or more, more preferably 70% or more from the viewpoint of obtaining practical toughness of the molded product, and especially 80% or more from the viewpoint of ensuring toughness even after deterioration in heat aging resistance tests and chemical resistance tests. preferable. From the viewpoint of obtaining high toughness, the higher the tensile elongation, the better, but if the tensile elongation exceeds 200%, the flexibility becomes too high, and it is difficult to maintain the shape when the molded product is used in a high temperature environment. It is not preferable because it may become

The tensile elongation of the polyphenylene sulfide resin composition can be adjusted by using (C) an epoxy group-containing elastomer and (D) a functional group-free elastomer in combination. It can also be adjusted by appropriately reacting (B) the modified diene copolymer and (C) the epoxy group-containing elastomer.

The melt viscosity of the polyphenylene sulfide resin composition of the present invention is preferably greater than 500 Pa·s, more preferably 700 Pa·s or more, from the viewpoint of take-up properties of the molten resin during extrusion molding. Moreover, from the viewpoint of suppressing drawdown during blow molding, the melt viscosity is particularly preferably 900 Pa·s or more, and particularly preferably 1300 Pa·s or more. The upper limit of the melt viscosity is preferably 3000 Pa s or less from the viewpoint of maintaining melt fluidity, preferably 2500 Pa s or less from the viewpoint of improving the toughness during melting and obtaining moldability, and 2000 Pa s or less. Especially preferred. When the melt viscosity exceeds 500 Pa·s, extrusion molding becomes possible and heat aging resistance can be maintained, which is preferable.

The melt viscosity of the polyphenylene sulfide resin composition in the present invention was measured using a capillary rheometer (for example, Capilograph (registered trademark) manufactured by Toyo Seiki Co., Ltd.) under the conditions of a test temperature of 300°C, a residence time of 5 minutes, and a shear rate of 122/s. It is a value measured using

In the polyphenylene sulfide resin composition of the present invention, the morphology of the molded article observed with a transmission electron microscope shows that (A) the PPS resin forms a continuous phase, (B) the modified diene copolymer and (C) the epoxy An elastomer containing groups must form the dispersed phase. The amount of (A) PPS resin compounded in the polyphenylene sulfide resin composition is the total amount of (A) PPS resin, (B) modified diene-based copolymer, and (C) epoxy group-containing elastomer compounded to 100 mass. %, the polyphenylene sulfide resin composition of the present invention has a high It is possible to exhibit not only flexibility and high toughness, but also excellent heat aging resistance and chemical resistance derived from the PPS resin. Here, "(B) the modified diene copolymer and (C) the epoxy group-containing elastomer form a dispersed phase" means that (B) the modified diene copolymer and (B) the modified diene copolymer are contained in one dispersed phase. (C) represents the formation of a dispersed phase containing together with an elastomer containing epoxy groups. As long as both the (B) component and the (C) component are contained in one dispersed phase, other components may be contained, for example, a reaction in which the (B) component and the (C) component react substance may be contained, and a part of the component (A) may be contained. Further, if there is a dispersed phase containing both the component (B) and the component (C), there may be a dispersed phase containing only the component (B), or a dispersed phase containing only the component (C) may further exist. May be present. Further, the dispersed phase may have a co-continuous structure of components (B) and (C). In addition, (C) an elastomer containing an epoxy group forms a primary dispersed phase, and (B) a modified diene-based copolymer forms a secondary dispersed phase therein, or (B) a modified diene-based The structure may be such that (C) the epoxy group-containing elastomer forms the secondary dispersed phase in the primary dispersed phase of the copolymer. Such distributed structures are also called sea/island/lake structures or salami structures. In particular, it is preferable that the dispersed phase has a co-continuous structure of (B) the modified diene copolymer and (C) the epoxy group-containing elastomer because the toughness of the polyphenylene sulfide resin composition is improved.

In order to form such a phase structure, it is necessary to appropriately react (B) the modified diene copolymer and (C) the epoxy group-containing elastomer. By undergoing this reaction, the melt viscosity of (A) the PPS resin in the polyphenylene sulfide resin composition is compared with that of the component in which (B) the modified diene copolymer and (C) the epoxy group-containing elastomer have reacted. Melt viscosity increases. As a result, even when the mass fraction of the (A) PPS resin in the polyphenylene sulfide resin composition is small, the (A) PPS resin can be used as a continuous phase.

When the reaction between (B) the modified diene copolymer and (C) the epoxy group-containing elastomer is not appropriate, for example, gelation occurs due to excessive reaction of these components, resulting in poor melt processability. In addition to marked deterioration in molding processability, (B) the modified diene copolymer and (C) the epoxy group-containing elastomer may not be able to form a dispersed phase. If so, the heat resistance and chemical resistance of the polyphenylene sulfide resin composition may be deteriorated. In order to suppress this excessive reaction, it is necessary to adjust the reactivity of (C) the epoxy group-containing elastomer by adding component (X), and to optimize the cylinder temperature of the extruder during melt-kneading, which will be described later. It is effective to use a stirring screw with a notch.

In other cases where the reaction between (B) the modified diene copolymer and (C) the epoxy group-containing elastomer is not appropriate, for example, the reaction between these components is insufficient and the (A) PPS resin is not continuous. There are cases where phases cannot be formed. Examples of inadequate reaction include performing kneading in multiple steps during melt kneading, and using a side feeder or the like to mix (B) the modified diene copolymer and (C) the epoxy group-containing elastomer. Intentional avoidance of the reaction or the action of the additive may reduce the reactivity of (C) the epoxy group-containing elastomer, thereby preventing it from reacting with the (B) modified diene-based copolymer.

When the compatibility between (B) the modified diene copolymer and (C) the epoxy group-containing elastomer is high, it becomes easier to obtain a phase structure in which the dispersed phase has a co-continuous structure. In order to improve the compatibility, the proportion of (b) conjugated diene polymer block among (a) vinyl aromatic polymer block and (b) conjugated diene polymer block constituting (B) modified diene copolymer and using a polyolefin copolymer containing an epoxy group as (C) an epoxy group-containing elastomer.

In the polyphenylene sulfide resin composition of the present invention, the number average dispersed particle size of the dispersed phase containing (B) the modified diene copolymer is preferably 2000 nm or less in order to exhibit excellent toughness and heat aging resistance. It is preferably 1500 nm or less, particularly preferably 1000 nm or less, and even more preferably 700 nm or less. The lower limit of the number average dispersed particle size of the dispersed phase is preferably 10 nm or more.

In the polyphenylene sulfide resin composition of the present invention, the dispersed phase containing (C) an epoxy group-containing elastomer preferably has a number average dispersed particle size of 1000 nm or less in order to exhibit excellent toughness and flexibility. , 700 nm or less. The lower limit of the number average dispersed particle size of the dispersed phase is preferably 5 nm or more. In order to obtain such a dispersion diameter, it is effective to appropriately react (A) the PPS resin and (C) the epoxy group-containing elastomer.

Moreover, as described above, the polyphenylene sulfide resin composition of the present invention can be blended with (D) an elastomer containing no functional group together with (C) an epoxy group-containing elastomer. In this case, the elastomer containing no (D) functional groups also forms the dispersed phase. The number average dispersed particle size of the dispersed phase is preferably 2000 nm or less, more preferably 1500 nm or less, in order to exhibit excellent toughness and flexibility. The lower limit of the number average dispersed particle size of the dispersed phase is preferably 10 nm or more. In order to obtain such a dispersion diameter, it is effective to appropriately react (A) the PPS resin and (C) the epoxy group-containing elastomer.

The number average dispersed particle size of each dispersed phase in these phase separation structures is obtained by the following method. For example, from a polyphenylene sulfide resin composition pellet, blow molded product, injection molded product, etc., an ultra-thin section is cut out using an ultramicrotome, and the ultra-thin section is stained with ruthenium tetroxide or the like. The stained samples are observed with a transmission electron microscope at a magnification of 5000-10000. Select 10 arbitrarily different dispersed phases from the obtained image, calculate the major diameter and minor diameter of each dispersed phase, take the average value, and use the number average value of the average values as the number average dispersed particle size of the dispersed phase. can be calculated. The components constituting the dispersed phase can be identified by comparing the phase contrast difference in an unstained sample with the phase contrast difference in a sample stained with ruthenium tetroxide or the like.

The polyphenylene sulfide resin composition of the present invention having the above-described phase structure has a flexural modulus of 1.0 MPa or more and 1500 MPa or less from the viewpoint of exhibiting high flexibility, high toughness, and excellent heat aging resistance, In addition, it is preferable that the tensile elongation retention rate after durability treatment at 170° C.×1000 hr in air is 40% or more. The tensile elongation retention is more preferably 50% or more, still more preferably 60% or more, and even more preferably 70% or more. The tensile elongation retention rate is the ratio of the tensile elongation after 170° C.×1000 hr durability treatment to the tensile elongation before 170° C.×1000 hr durability treatment.

Furthermore, the polyphenylene sulfide resin composition of the present invention is characterized by excellent chemical resistance. Therefore, for example, it can be suitably used as a pipe that comes into contact with a cooling liquid containing ethylene glycol as a main component, which is used for cooling automobile engines and motors. LLC (Long Life Coolant), for example, Toyota Super Long Life Coolant (product number 08889-01005) manufactured by Toyota Motor Corporation and ion-exchanged water are mixed at a mass ratio of 1:1, and the polyphenylene sulfide resin composition is injection molded. It is preferable that the tensile elongation retention rate of the ISO (1A) dumbbell test piece obtained by the method is 80% or more after being completely immersed under the conditions of 150° C.×1000 hr. Tensile elongation retention can be exemplified as a more preferable range of 90% or more. The tensile elongation retention rate is the ratio of the tensile elongation after the above immersion treatment to the tensile elongation before immersion treatment in LLC of a test piece obtained by injection molding a polyphenylene sulfide resin composition. That is.

The method for producing the polyphenylene sulfide resin composition of the present invention is not particularly limited. A typical example is a method of melt kneading such that (A) the melting peak temperature of the PPS resin is +5°C to 100°C. Among them, melt-kneading by a twin-screw extruder is preferable. The resin temperature here may be a value obtained by directly measuring the temperature of the resin discharged from the extruder, or may be the temperature at the tip of the die.

The ratio (L/D) of the screw length L (mm) to the screw diameter D (mm) of the twin-screw extruder is desirably 10 or more, more preferably 20 or more, and even more preferably 30 or more. The upper limit of L/D for twin screw extruders is usually 60. When L/D is less than 10, kneading is insufficient, and it tends to be difficult to obtain the above-described desired phase structure in the polyphenylene sulfide resin composition.

In melt-kneading, the order of mixing raw materials is not particularly limited. Any method may be used, such as a method of blending raw materials and melt-kneading, or a method of melt-kneading a part of raw materials with an extruder and simultaneously mixing the remaining raw materials using a side feeder from the middle of the extruder. . When using a side feeder, from the viewpoint of obtaining an excellent phase structure, the reaction between (B) a modified diene copolymer and (C) an epoxy group-containing elastomer or (A) a PPS resin and (C) an epoxy group is performed. It is preferable to select the position where the raw materials are supplied so that the elastomer contained therein reacts appropriately.

(B) Modified diene-based copolymer and (C) epoxy group-containing elastomer are preferably suppressed from gelling of the extruded gut and the accompanying decrease in toughness due to excessive reaction. As a configuration, it is preferable to use a stirring screw having a notch. Here, the "notch" refers to a part of the crest portion of the screw flight that is cut away. Stirring screws with notches can increase the resin filling rate. Molten resin is susceptible to extruder cylinder temperature when passing through a kneading section to which a stirring screw is connected. By using a stirring screw having a notch, the molten resin that has generated heat due to shearing during kneading is efficiently cooled, so that the resin temperature during kneading can be lowered. In addition, unlike the conventional method of grinding resin, the agitating screw having a notch can perform kneading mainly by stirring and stirring, so that shear heat generation during kneading can be suppressed, and the above-mentioned desired It becomes easier to obtain a phase structure.

As a stirring screw having a notch, the length of the screw pitch is 0.1D to 0.3D where the screw diameter is D (mm) from the viewpoint of improving the cooling efficiency of the molten resin and improving the kneading property by filling with the resin. It is preferable that the agitating screw has a notch portion in which the number of notches is within the range and the number of notches is 10 to 15 per pitch. Here, the "screw pitch length" refers to the screw length between crest portions of the screw when the screw rotates 360 degrees.

For the agitating screw having a notch, it is preferably introduced so as to account for 3% or more of the total length L (mm) of the screw, more preferably 5% or more. The upper limit is preferably 20% or less, more preferably 15% or less, of the total length of the screw.

In addition, (B) the modified diene copolymer and (C) the epoxy group-containing elastomer are excessively reacted to cause gelation of the extruded gut and the accompanying decrease in toughness. (A) A method of melting and kneading by lowering to a temperature lower than the melting point of the PPS resin can be preferably exemplified. By lowering the cylinder temperature of the extruder to a temperature lower than the melting point of (A) the PPS resin in this way, the excessive reaction between (B) the modified diene copolymer and (C) the epoxy group-containing elastomer is suppressed. At the same time, the melt viscosity during melt-kneading can be increased, and stirring can be efficiently performed. As a result, the reaction between (B) the modified diene copolymer and (C) the epoxy group-containing elastomer can be efficiently carried out, and the (A) PPS resin forms the continuous phase, and the (B) modified diene copolymer Coalescence and (C) a phase structure in which the epoxy group-containing elastomer forms the dispersed phase are likely to be obtained.

Specifically, the cylinder temperature of the extruder depends on the melting point of the (A) PPS resin used, so it cannot be generalized, but a preferable range is 230° C. or higher and 285° C. or lower. It is preferable that 30 to 80% of the cylinder block of the extruder is within the above temperature range, and 50 to 80% is more preferably within the above temperature range. Furthermore, from the viewpoint of efficient cooling and stirring by the agitating screw having the notch described above, the temperature of the cylinder block corresponding to the location where the agitating screw having the notch is incorporated should be within the above temperature range. is particularly preferred.

Examples of methods for molding the polyphenylene sulfide resin composition of the present invention include extrusion molding, injection molding, hollow molding, calendar molding, compression molding, vacuum molding, foam molding, blow molding, and rotational molding. In particular, the polyphenylene sulfide resin composition of the present invention is useful for extrusion molding or blow molding because it has good take-up properties of molten resin and easy control of thickness.

The polyphenylene sulfide resin composition of the present invention is suitable for many molded articles described in Patent Document 2 (International Publication No. 2018/003700), taking advantage of its excellent toughness, flexibility, heat resistance and chemical resistance. be. Among them, hybrid vehicles, electric vehicles, railways, coated moldings for motor coil windings of power generation equipment, and various pipes, ducts, and tubes for fuel, exhaust, intake, and cooling systems of automobiles exposed to high temperature environments. It is also useful as piping used in gas water heaters, heat pump water heaters, hot water heaters, and the like. In particular, the molded article made of the resin composition of the present invention has excellent chemical resistance compared to polyamide resin, so it is used for cooling automobile engines and motors. Also useful as In addition, molded products made from the resin composition of the present invention are useful as cooling pipes for fuel cell vehicles because they release less metal ions than rubber pipes reinforced with glass fibers or the like. Furthermore, since the polyphenylene sulfide resin composition of the present invention has excellent flexibility, it can be used as piping that requires bending workability during product assembly, piping that requires assembly performance, and piping that requires vibration absorption. is particularly suitable for

EXAMPLES Hereinafter, the effects of the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples. Evaluation in each example and comparative example was performed by the following method.

(1) Injection molding For the resin composition pellets obtained in each example and comparative example, using an injection molding machine SE75-DUZ manufactured by Sumitomo Heavy Industries, set the cylinder temperature to 310 ° C. and the mold temperature to 140 ° C. ISO ( 1A) Dumbbell specimens were injection molded.

(2) Initial mechanical properties For the ISO (1A) dumbbell test piece injection-molded in (1), using a Tensilon UTA2.5T tensile tester at a temperature of 23 ° C., according to ISO527-1,-2 (2012) , the distance between fulcrums was 114 mm and the tensile speed was 50 mm/min. Then, according to ISO 178 (2010), bending properties were evaluated under the conditions of a distance between fulcrums of 64 mm and a speed of 2 mm/min.

(3) Mechanical properties after 170°C x 1000hr durability treatment (heat aging resistance)
An ISO (1A) dumbbell test piece injection-molded in (1) was subjected to endurance treatment in a hot air dryer (PHH202 manufactured by Espec Co., Ltd.) heated to 170° C. for 1000 hours, and then allowed to cool at room temperature for 24 hours.

Then, under conditions of 23 ° C., using a Tensilon UTA 2.5T tensile tester, according to ISO 527-1, -2 (2012), under the conditions of a distance between fulcrums of 114 mm and a tensile speed of 50 mm / min, the dumbbell test piece after the durability treatment was evaluated for tensile properties. The ratio of the tensile elongation after the 170° C.×1000 hr durability treatment to the initial tensile elongation was taken as the tensile elongation retention rate (%).

(4) Mechanical properties (chemical resistance) after 150°C x 1000hr LLC immersion treatment
For the ISO (1A) dumbbell test piece injection-molded in section (1), commercially available LLC ("Toyota Super Long Life Coolant (product number 08889-01005)" manufactured by Toyota Motor Corporation) and ion-exchanged water at a mass ratio of 1:1 After being completely immersed in the liquid mixed in (1) at a temperature of 150° C. for 1000 hours, it was allowed to cool at room temperature for 24 hours.

Then, under conditions of 23 ° C., using a Tensilon UTA 2.5T tensile tester, according to ISO 527-1, -2 (2012), under the conditions of a distance between fulcrums of 114 mm and a tensile speed of 50 mm / min, the dumbbell test piece after the immersion Tensile properties were evaluated. The ratio of the tensile elongation after the LLC immersion treatment to the initial tensile elongation was taken as the tensile elongation retention rate (%).

(5) Observation of phase structure Cut the center of the ISO (1A) dumbbell test piece injection molded in (1) in the direction perpendicular to the flow direction of the resin, and from the center of the cross section, at -20 ° C. A thin piece with a thickness of 0.1 μm or less was cut using an ultramicrotome. After that, a sample stained with ruthenium tetroxide and an unstained sample were prepared. These samples were photographed using a Hitachi H-7100 type transmission electron microscope (resolution (particle image): 0.38 nm, magnification of 500,000 to 600,000 times) at magnifications of 1,000 to 10,000 times. The identification of the components constituting the dispersed phase was determined by comparing the phase contrast difference of the unstained sample with the phase contrast difference of the ruthenium tetroxide-stained sample.

(6) Melt viscosity measurement For the resin composition pellets obtained in each example and comparative example, using Capilograph (registered trademark) manufactured by Toyo Seiki Co., Ltd., after residence at a test temperature of 300 ° C. for 5 minutes, a shear rate of 122 / s, capillary The melt viscosity was measured under conditions of a length of 10 mm and a capillary diameter of 1 mm.

Raw materials used in Examples and Comparative Examples are shown below.

[Reference Example 1] (A) PPS resin: A-1
8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.94 kg (70.63 mol) of 96% sodium hydroxide, N-methyl-2 were added to a 70 liter autoclave equipped with stirrer and bottom valve. -Pyrrolidone (NMP) 11.45 kg (115.50 mol), sodium acetate 2.24 kg (27.3 mol), and ion-exchanged water 5.50 kg were charged, and heated to 245°C over about 3 hours while passing nitrogen under normal pressure. After 9.77 kg of water and 0.28 kg of NMP were distilled off, the reactor was cooled to 200°C. The amount of water remaining in the system per 1 mol of the charged alkali metal sulfide was 1.06 mol including the water consumed for hydrolysis of NMP. The amount of hydrogen sulfide scattered was 0.02 mol per 1 mol of the charged alkali metal sulfide.

After cooling to 200° C., 10.32 kg (70.20 mol) of p-dichlorobenzene and 9.37 kg (94.50 mol) of NMP are added, the reaction vessel is sealed under nitrogen gas and stirred at 240 rpm while stirring at 0.5 rpm. The temperature was raised from 200°C to 235°C at a rate of 8°C/min, and the reaction was carried out at 235°C for 40 minutes. After that, the temperature was raised to 270°C at a rate of 0.8°C/min, and after reacting at 270°C for 70 minutes, 2.40 kg (133 mol) of water was injected while cooling from 270°C to 250°C over 15 minutes. . After gradually cooling from 250° C. to 220° C. over 75 minutes, it was rapidly cooled to near room temperature and the contents were taken out.

The content was diluted with about 35 liters of NMP to form a slurry, stirred at 85° C. for 30 minutes, and then filtered through an 80-mesh wire mesh (opening 0.175 mm) to obtain a solid. The solid obtained was likewise washed with about 35 liters of NMP and filtered off. The obtained solid matter was diluted with 70 liters of deionized water, stirred at 70° C. for 30 minutes, filtered through an 80-mesh wire mesh to recover the solid matter, and the operation was repeated three times in total. The resulting solid matter and 32 g of acetic acid were diluted with 70 liters of ion-exchanged water, stirred at 70° C. for 30 minutes, filtered through an 80-mesh wire mesh, and the obtained solid matter was further diluted with 70 liters of ion-exchanged water. After stirring at 70° C. for 30 minutes, the mixture was filtered through an 80-mesh wire mesh to recover a solid. Dry PPS was obtained by drying the solid thus obtained at 120° C. under a nitrogen stream. A PPS resin produced by such a method was designated as A-1. Further, after staying at a test temperature of 300° C. for 5 minutes, the melt viscosity determined at a shear rate of 1216/s was 170 Pa·s.

(B) Modified diene-based copolymer B-1: Amine-modified styrene-butylene/butadiene-styrene block copolymer (styrene-based thermoplastic elastomer "Tuftec (registered trademark)" MP10 manufactured by Asahi Kasei) was used.
B-2: A maleic anhydride-modified styrene-ethylene/butylene-styrene block copolymer (hydrogenated styrene thermoplastic elastomer “Tuftec (registered trademark)” M1943 manufactured by Asahi Kasei) was used.

(B') Unmodified diene-based copolymer B'-1: A styrene-ethylene/butylene-styrene block copolymer (hydrogenated styrene-based thermoplastic elastomer "Tuftec (registered trademark)" P1083 manufactured by Asahi Kasei) was used.

(C) Elastomer Containing Epoxy Groups C-1: An ethylene/glycidyl methacrylate copolymer ("Bondfast (registered trademark)" 7M manufactured by Sumitomo Chemical Co., Ltd.) having a glycidyl methacrylate copolymerization amount of 6% by mass was used.

(D) Elastomer D-1 containing no functional group: Ethylene/1-butene copolymer (“Tafmer (registered trademark)” TX-610 manufactured by Mitsui Chemicals) was used.

(E) Polyamide resin E-1: Nylon 610 with a relative viscosity of 2.7 (98% concentrated sulfuric acid solution (1 g of polymer, 100 ml of concentrated sulfuric acid), measured at 25° C.) (“Amilan (registered trademark)” manufactured by Toray) ) was used.

[Examples 1 to 5, Comparative Examples 1 to 7] (When the raw material addition method is batch loading)
After dry blending the raw materials in the ratios shown in Tables 1 and 2, a TEX30α type twin-screw extruder manufactured by Japan Steel Works, Ltd. (L / D = 45, 3 kneading parts, a screw with a notch) equipped with a vacuum vent 0%), and melt-kneaded at a cylinder temperature shown in Tables 1 and 2 at a screw rotation speed of 300 rpm. The strand extruded from the tip of the extruder was pelletized by a strand cutter. After that, the pellets were dried overnight at 120° C. and various characteristics were evaluated by the method described above.

[Examples 6 to 9] (when side feed is used as a raw material addition method)
The components for the main feed shown in Table 3 are introduced from the main loading position into a TEX30α twin-screw extruder (L/D = 45) manufactured by Japan Steel Works, Ltd. equipped with a vacuum vent, and the components for the side feed are added to the components manufactured by Japan Steel Works, Ltd. It was charged using a side feeder, melted and kneaded at a screw rotation speed of 300 rpm at the cylinder temperature and screw arrangement shown in Table 3, and pelletized with a strand cutter. In the table, the "normal" screw arrangement is an arrangement with 3 kneading portions and 0% screw having notches. The "notched" screw arrangement is an arrangement with three kneading portions and 10% of the screws having notched portions. After that, the pellets were dried overnight at 120° C. and various characteristics were evaluated by the method described above.

Focusing on the composition, the results of Examples and Comparative Examples shown in Table 1 will be compared and explained.

In Comparative Examples 1 and 3, although the (A) PPS resin formed a continuous phase, the blending amount of the (A) PPS resin was large, the flexural modulus exceeded 1500 MPa, and the flexibility was insufficient.

In Comparative Examples 2 and 4, as compared with Comparative Examples 1 and 3, the blending amount of (A) the PPS resin was reduced, and the blending amounts of (B) the modified diene copolymer and (C) the epoxy group-containing elastomer were increased. As a result of the increase, the initial flexibility was improved, but (A) the PPS resin formed a dispersed phase, so the heat aging resistance represented by the tensile elongation retention after treatment at 170°C for 1000 hours was remarkably lowered.

In Comparative Examples 5 and 6, as a result of forming a continuous phase in spite of the small amount of (A) the PPS resin blended, the heat aging resistance and chemical resistance were excellent, but (B) the modified diene copolymer It is hard to say that flexibility is sufficient because coalescence is not included.

In Examples 1 and 2, (B) the modified diene copolymer and (C) the epoxy group-containing elastomer were used in combination. It formed and had excellent heat aging resistance and chemical resistance. In addition, since the reactivity and compatibility between (B) the modified diene copolymer and (C) the epoxy group-containing elastomer are good, the dispersed phase of the obtained PPS resin composition is the (B) modified diene copolymer. A co-continuous structure of the polymer and (C) the epoxy group-containing elastomer was formed, and excellent flexibility with a flexural modulus of 500 MPa was obtained.

Focusing on the types and composition ratios of the elastomers used, the results of Examples and Comparative Examples shown in Table 2 above will be compared and explained.

In Example 3, excellent properties were obtained as compared with Example 2 even when the type of the modified diene copolymer (B) was changed.

In Examples 4 and 5, excellent properties similar to those in Example 2 were obtained even when the ratio of the elastomer used was changed.

In Comparative Example 7, as compared with Example 2, (B') unmodified diene copolymer was used instead of (B) modified diene copolymer. As a result, (C) epoxy group-containing elastomer and did not proceed, and (B') the unmodified diene copolymer and (C) the epoxy group-containing elastomer formed a continuous phase. , the heat aging resistance and chemical resistance were also significantly reduced. In addition, (B') unmodified diene-based copolymer is the total blending of component (B) + component (C) + component (D) with respect to the total blending amount of components (A) to (D) of 100% by mass. When calculating the ratio of the amount (unit: % by mass), it is calculated as component (D).

Focusing on the production method, the results of the examples in Table 3 are compared and explained.

In Example 6, as compared with Example 2, the modified diene polymer (B) was added by side feeding and melt-kneaded, and as a result, the dispersed phase contained the modified diene polymer (B) and the epoxy group (C). In Example 7, as compared with Example 2, (A) PPS resin was added by side feed and melt-kneaded, and as a result, (B) modified diene polymer and ( C) The reaction of the epoxy group-containing elastomer was further accelerated, and the tensile elongation, which is an initial mechanical property, was improved.

In Examples 8 and 9, by changing the cylinder temperature and screw arrangement compared to Example 7, (B) the modified diene polymer and (C) the epoxy group-containing elastomer were properly reacted. Tensile elongation, which is an initial mechanical property, improved dramatically.

Claims (11)

A polyphenylene sulfide resin composition comprising (A) a polyphenylene sulfide resin, (B) a modified diene copolymer, and (C) an epoxy group-containing elastomer, comprising (A) a polyphenylene sulfide resin, (B) (A) polyphenylene sulfide resin is 20% by mass or more and 60% by mass or less, and the polyphenylene In the morphology of a molded article made of the sulfide resin composition observed with a transmission electron microscope, (A) the polyphenylene sulfide resin forms a continuous phase, (B) the modified diene copolymer and (C) the epoxy group A polyphenylene sulfide resin composition in which an elastomer contained forms a dispersed phase. 2. The polyphenylene sulfide resin composition according to claim 1, wherein the modifying group of the modified diene copolymer (B) is an amino group. 3. The polyphenylene sulfide resin composition according to claim 1, wherein the modified diene polymer (B) is a modified conjugated diene polymer. 4. The polyphenylene sulfide resin composition according to any one of claims 1 to 3, wherein (C) the elastomer containing epoxy groups is a polyolefin copolymer containing epoxy groups. The polyphenylene sulfide resin composition according to any one of claims 1 to 4, wherein the dispersed phase comprises a co-continuous structure of (B) a modified diene copolymer and (C) an epoxy group-containing elastomer. thing. Any one of claims 1 to 5, wherein an ISO (1A) dumbbell test piece obtained by injection molding the polyphenylene sulfide resin composition has a flexural modulus of 1.0 MPa or more and 1500 MPa or less measured according to ISO 178 (2010). The polyphenylene sulfide resin composition according to . The polyphenylene sulfide resin composition according to any one of claims 1 to 6, wherein the polyphenylene sulfide resin composition is a polyphenylene sulfide resin composition for piping coming into contact with cooling water for automobiles. A molded article made of the polyphenylene sulfide resin composition according to any one of claims 1 to 7. The molded article according to claim 8, wherein the molded article is a hollow molded article. 10. The molded article according to claim 9, wherein the hollow molded article is a pipe that comes into contact with cooling water for automobiles. A method for producing a molded article, comprising extruding the polyphenylene sulfide resin composition according to any one of claims 1 to 7.