Polyphenylene sulfide resin composition and molded article formed from the same

Abstract

The objective of this invention is to obtain a polyphenylene sulfide resin composition possessing flame retardancy, flexibility, and toughness, and a molded article formed from the polyphenylene sulfide resin composition. The polyphenylene sulfide resin composition comprises (a) a polyphenylene sulfide resin and (b) an organosilicon polymer compound, wherein the content of component (b) is 3 parts by weight or more and 40 parts by weight or less relative to 100 parts by weight of component (a). In the morphology (phase structure) of the polyphenylene sulfide resin composition, component (a) forms a continuous phase, and component (b) forms a dispersed phase with a number-average particle size of 3.0 μm or less. In a bending test according to ISO 178, a test piece obtained by injection molding of the polyphenylene sulfide resin composition at a barrel temperature of 310°C and a mold temperature of 145°C has a flexural modulus of 3.0 GPa or less. In a test using the UL 94 standard, the flame retardancy measured in a test piece with a thickness of 1.6 mm or less is V-0.

Description

Technical Field

[0001] This invention relates to polyphenylene sulfide resin compositions and molded articles using the polyphenylene sulfide resin compositions. Background Technology

[0002] Polyphenylene sulfide (hereinafter, sometimes abbreviated as "PPS") resin is a super engineering plastic with a good balance of heat resistance, chemical resistance, and flame retardancy. Furthermore, due to its cost advantage compared to other super engineering plastics, PPS resin is a highly versatile resin material, second only to the top five engineering plastics, and is used in a wide range of applications, including automotive, residential equipment, and electrical / electronic applications.

[0003] In recent years, in response to social issues such as the SDGs, there has been a strong demand for energy conservation through lightweighting in automotive applications and for the reduction of greenhouse gas emissions due to electrification. PPS resin has been increasingly used in automotive applications because it can achieve lightweighting based on replacing metals and exhibits high insulation and heat resistance for electrification.

[0004] On the other hand, when expanding the applications of PPS resin, an essential issue is that, compared with other resins, it has low toughness, represented by the elongation at break during tensile testing, and is brittle.

[0005] Therefore, in applications requiring toughness, as described in Patent Document 1, PPS resin compositions blended with olefin-based elastomers have been developed and put into practical use. In this composition, by blending PPS resin with olefin-based elastomers, which are softer materials, improved toughness can be achieved along with softness.

[0006] Patent document 2 discloses a heat-shrinkable tube formed from a PPS resin composition that is made flexible by adding a thermoplastic elastomer and a plasticizer to the PPS resin.

[0007] Furthermore, Patent Documents 3 and 4 describe a method for softening PPS resin by adding an organosilicon elastomer.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 61-21156

[0011] Patent Document 2: Japanese Patent Application Publication No. 2013-6919

[0012] Patent Document 3: Japanese Patent Application Publication No. 2017-222867

[0013] Patent Document 4: Japanese Patent Application Publication No. 2017-214586 Summary of the Invention

[0014] The problem that the invention aims to solve

[0015] However, the inventors evaluated the flame retardancy of the resin composition consisting of PPS resin and an olefin-based elastomer described in Patent Document 1 and found that the flame retardancy of the resin composition was significantly reduced compared to PPS resin alone. This can be attributed to the fact that PPS resin alone has high flame retardancy, while the flame retardancy of the composition is reduced by blending it with an olefin-based elastomer, which has significantly poor flame retardancy. This composition suffers from the problem that while it possesses advantages of softness and toughness, it does not exhibit the excellent flame retardancy inherent in PPS resin, thus limiting its applications.

[0016] Regarding the heat-shrinkable tube formed from a PPS resin composition as described in Patent Document 2, in order to impart flexibility, plasticizers as low molecular weight compounds are added in addition to thermoplastic elastomers. However, due to the addition of these compounds, the flame retardancy is reduced, and therefore the flame retardancy V-0 of the UL94 standard cannot be obtained.

[0017] Furthermore, the PPS resin composition described in Patent Document 3, as described in the examples of Patent Document 3, has poor flexibility, low elongation at break, and insufficient toughness, and cannot achieve a PPS resin composition that combines flame retardancy with flexibility and toughness.

[0018] The PPS resin composition described in Patent Document 4, as illustrated in the examples of Patent Document 4, exhibits excellent flexibility and elongation at break, but does not possess excellent flame retardancy in addition to these two properties.

[0019] Therefore, the objective of this invention is to obtain a polyphenylene sulfide resin composition that maintains the flame retardancy of PPS resin while also possessing flexibility and toughness.

[0020] Methods for solving problems

[0021] The inventors conducted research to address this problem and discovered a polyphenylene sulfide resin composition containing (a) a polyphenylene sulfide resin (hereinafter, sometimes referred to as "component (a)") and (b) an organosilicon polymer compound (hereinafter, sometimes referred to as "component (b)") in a specific composition, wherein component (b) is in a specific dispersion state, and in a composition that substantially does not contain inorganic fillers such as glass fibers and has a flexural modulus of less than a specific value, this resin composition possesses excellent flexibility, exhibits flame retardancy (UL94 standard V-0 (1.6 mmt or less)) in thin-walled molded articles, and also possesses toughness. In other words, the present invention is made to solve at least a portion of the aforementioned problems.

[0022] (1) A polyphenylene sulfide resin composition comprising (a) a polyphenylene sulfide resin and (b) an organosilicon polymer compound, wherein the content of component (b) is 3 parts by weight or more and 40 parts by weight or less relative to 100 parts by weight of component (a), and the polyphenylene sulfide resin composition has a phase separation structure in which the above-mentioned component (a) forms a continuous phase and the above-mentioned component (b) forms a dispersed phase with a number-uniformly dispersed particle size of 3.0 μm or less, and in a flexural test according to ISO 178 (2010) of a test piece obtained by injection molding of the polyphenylene sulfide resin composition at a barrel temperature of 310°C and a mold temperature of 145°C, it has a flexural modulus of elasticity of 3.0 GPa or less, and in a test piece with a thickness of 1.6 mmt or less, the flame retardancy measured according to UL94 standard is V-0.

[0023] (2) According to the polyphenylene sulfide resin composition of (1), 1 part by weight and 40 parts by weight of olefin elastomer (c) are mixed in relative to 100 parts by weight of component (a) above.

[0024] (3) The polyphenylene sulfide resin composition according to (1) or (2) has a flame retardancy of V-0 in a test piece with a thickness of less than 1.0 mmt as determined by UL94 standard.

[0025] (4) The polyphenylene sulfide resin composition according to any one of (1) to (3) has an elongation at break of 10% or more in a tensile test in accordance with ISO 527-1, 2 (2012).

[0026] (5) The polyphenylene sulfide resin composition according to any one of (1) to (4) has a phase separation structure in which the above-mentioned component (a) forms a continuous phase and the above-mentioned component (b) forms a dispersed phase with a number-average particle size of 1.0 μm or less.

[0027] (6) The polyphenylene sulfide resin composition according to any one of (1) to (5), wherein the shear rate of component (a) is measured using a capillary rheometer with the trade name Capilograf at 300°C and pore length L (mm) / pore diameter D (mm) = 10, with a shear rate of 60 to 6080 s. -1 The non-Newtonian index N calculated by substituting the shear rate-shear stress relationship into the following equation (1) is 1.30 or higher.

[0028] SR = K·SS N ···(1)

[0029] (Here, N represents the non-Newtonian exponent, SR represents the shear rate (1 / second), and SS represents the shear stress (dynes / cm). 2 (where K represents a constant.)

[0030] (7) The polyphenylene sulfide resin composition according to any one of (1) to (6), wherein the shear rate of the polyphenylene sulfide resin composition is measured using a capillary rheometer with the trade name Capilograf at 300°C and a pore length L (mm) / pore diameter D (mm) = 10, is 122 s. -1 The melt viscosity is above 400 Pa·s.

[0031] (8) The polyphenylene sulfide resin composition according to any one of (1) to (7), wherein component (b) is an organosilicon core-shell rubber.

[0032] (9) A molded article formed from any one of the polyphenylene sulfide resin compositions (1) to (8).

[0033] (10) A molded article formed from the polyphenylene sulfide resin composition according to (9), which is a molded article for piping with a hollow shape.

[0034] The effects of the invention

[0035] According to the present invention, a polyphenylene sulfide resin composition and a molded article formed from the polyphenylene sulfide resin composition can be obtained, which have excellent flame retardancy, flexibility and toughness. Detailed Implementation

[0036] The embodiments of the present invention will be described in detail below.

[0037] (1)(a) Polyphenylene sulfide resin ((a) composition)

[0038] The polyphenylene sulfide resin used in this invention (a) is based on a polymer having repeating units as shown in the following structural formula.

[0039]

[0040] From the viewpoint of heat resistance, it is preferable to have a polymer containing 70 mol% or more, and more preferably 90 mol% or more, repeating units as shown in the above structural formula. Furthermore, the repeating units of the PPS resin constituting component (a) may be composed of repeating units having the following structure, etc., with less than 30 mol% of the repeating units.

[0041]

[0042] Some PPS copolymers with such a structure have a lower melting point than the typical melting point of PPS (280°C), thus making such resin compositions advantageous in terms of molding processability.

[0043] There are no particular limitations on the number-average molecular weight of the PPS resin used in this invention. However, for the purpose of obtaining superior mechanical properties, a number-average molecular weight of 10,000 to 60,000 is preferred, more preferably 12,000 to 50,000, even more preferably 14,000 to 40,000, and even more preferably 16,000 to 35,000. When the number-average molecular weight is low, the mechanical properties of the PPS resin itself decrease; therefore, a number-average molecular weight of 10,000 or higher is preferred. On the other hand, when the number-average molecular weight exceeds 60,000, the melt viscosity increases significantly, which is undesirable for molding and processing.

[0044] The weight-average molecular weight of the PPS resin constituting component (a) used in this invention is preferably 40,000 to 100,000, more preferably 50,000 to 95,000, and even more preferably 70,000 to 90,000. When the weight-average molecular weight is low, the melt viscosity of the PPS resin composition is considered insufficient, resulting in insufficient mixing strength during melt mixing. There is a tendency for the number-average particle size of the organosilicon polymer compound (b) in the PPS resin composition to become coarse, leading to reduced toughness and flame retardancy of the PPS resin composition. Therefore, a weight-average molecular weight of 40,000 or higher is preferred. On the other hand, when the weight-average molecular weight exceeds 100,000, the melt viscosity becomes excessive, which is undesirable in molding and processing. Here, the number-average particle size is determined by the method described in the examples.

[0045] In addition, the number-average molecular weight and weight-average molecular weight of component (a) in this invention are values ​​calculated using GPC (Gel Permeation Chromatography) prepared by Senshur Science and converted to polystyrene.

[0046] The non-Newtonian index N of the PPS resin constituting component (a) used in this invention is preferably 1.30 or higher, more preferably 1.35 or higher, more preferably 1.40 or higher, and particularly preferably 1.50 or higher. When the non-Newtonian index is less than 1.30, the PPS resin has a lower viscosity in a low-shear flow field, thus reducing dripping during molding and flame retardancy tests and decreasing flame retardancy due to surface renewal, which is undesirable. On the other hand, there is no particular upper limit to the non-Newtonian index, but when it exceeds 5, the melt viscosity tends to increase significantly due to the highly formed branched and cross-linked structure, which is undesirable in molding and processing. Methods for obtaining PPS resin with a non-Newtonian index of 1.30 or higher include: using a polyhalogenated aromatic compound having three or more halogen atoms per molecule as a polymerization raw material to introduce a branched structure into the polymer; and performing thermal oxidative cross-linking by heating under an oxygen atmosphere and adding a cross-linking agent such as a peroxide after the polymerization of the PPS resin.

[0047] Furthermore, the non-Newtonian index in this invention was measured using a capillary rheometer at 300°C and with a pore length L (mm) / pore diameter D (mm) = 10, with shear rates ranging from 60 to 6080 s. -1 The shear stress is calculated by substituting the relationship between shear rate and shear stress into the following equation (1).

[0048] SR = K·SS N ···(1)

[0049] (Here, N represents the non-Newtonian exponent, SR represents the shear rate (1 / second), and SS represents the shear stress (dynes / cm). 2 (where K represents a constant.)

[0050] The melt viscosity of the PPS resin constituting component (a) used in this invention is preferably 50–3000 Pa·s, more preferably 150–2500 Pa·s, even more preferably 300–2000 Pa·s, and particularly preferably 500–1500 Pa·s. Even more preferably, it is 800–1200 Pa·s. When the melt viscosity of the PPS resin is low, it can be considered that the melt viscosity of the PPS resin composition has not been sufficiently increased, resulting in insufficient mixing strength during melt mixing. The number-average particle size of the organosilicon polymer compound (b) in the PPS resin composition tends to become coarser, and the toughness and flame retardancy of the PPS resin composition decrease. Therefore, the melt viscosity of the PPS resin is preferably 50 Pa·s or higher. On the other hand, when the melt viscosity of the PPS resin exceeds 3000 Pa·s, the melt viscosity becomes excessive, which is undesirable in molding and processing.

[0051] Furthermore, the melt viscosity of the PPS resin in this invention is measured using a capsule at 300°C with a pore length L (mm) / pore diameter D (mm) = 10, and the shear rate is 122 s. -1 The value below.

[0052] Hereinafter, a method for manufacturing the PPS resin of component (a) used in this invention will be described, but the method is not limited to the following method as long as a PPS resin having the above-described characteristics can be obtained.

[0053] First, the contents of the polyhalogenated aromatic compounds, vulcanizing agents, polymerization solvents, molecular weight regulators, polymerization aids, and polymerization stabilizers used in the manufacturing method will be explained.

[0054] [Polyhalogenated aromatic compounds]

[0055] Polyhalogenated aromatic compounds are defined as compounds having two or more halogen atoms in one molecule. Specific examples include p-dichlorobenzene, m-dichlorobenzene, o-dichlorobenzene, 1,3,5-trichlorobenzene, 1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene, hexachlorobenzene, 2,5-dichlorotoluene, 2,5-dichloro-p-xylene, 1,4-dibromobenzene, 1,4-diiodobenzene, and 1-methoxy-2,5-dichlorobenzene, with p-dichlorobenzene being preferred. In addition, for the purpose of introducing carboxyl groups, it is also a preferred option to use dihaloaromatic compounds containing carboxyl groups, such as 2,4-dichlorobenzoic acid, 2,5-dichlorobenzoic acid, 2,6-dichlorobenzoic acid, and 3,5-dichlorobenzoic acid, and mixtures thereof as comonomers. Furthermore, it is also possible to combine two or more different polyhaloaromatic compounds to form copolymers, but it is preferred to use a dihaloaromatic compound as the main component.

[0056] From the perspective of obtaining a PPS resin with a viscosity suitable for processing, the amount of polyhalogenated aromatic compounds used can be exemplified as 0.9 to 2.0 moles per mole of vulcanizing agent, preferably 0.95 to 1.5 moles, and more preferably 1.005 to 1.2 moles.

[0057] [Vulcanizing agent]

[0058] Examples of sulfiding agents include alkali metal sulfides, alkali metal hydrogen sulfides, and hydrogen sulfide.

[0059] Specific examples of alkali metal sulfides include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and mixtures of two or more thereof, with sodium sulfide being preferred. These alkali metal sulfides can be used as hydrates or aqueous mixtures, or in the form of anhydrides.

[0060] Specific examples of alkali metal hydrosulfides include sodium hydrosulfide, potassium hydrosulfide, lithium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide, and mixtures of two or more thereof, with sodium hydrosulfide being preferred. These alkali metal hydrosulfides can be used as hydrates or aqueous mixtures, or in the form of anhydrides.

[0061] Alternatively, alkali metal sulfides prepared in situ within the reaction system from alkali metal hydrogen sulfides and alkali metal hydroxides can be used. Furthermore, alkali metal sulfides prepared from alkali metal hydrogen sulfides and alkali metal hydroxides can be transferred to a polymerization tank for use.

[0062] Alternatively, alkali metal sulfides can be prepared in situ using alkali metal hydroxides such as lithium hydroxide and sodium hydroxide, along with hydrogen sulfide, within the reaction system. Furthermore, alkali metal sulfides can be prepared from alkali metal hydroxides such as lithium hydroxide and sodium hydroxide, along with hydrogen sulfide, and then transferred to a polymerization tank for use.

[0063] In cases where a portion of the vulcanizing agent is lost before the polymerization reaction begins due to dehydration operations, the amount of vulcanizing agent added refers to the remaining amount obtained by subtracting the lost portion from the actual amount added.

[0064] Alternatively, it can be used in combination with alkali metal hydroxides and / or alkaline earth metal hydroxides. Specific examples of alkali metal hydroxides include, for example, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, and mixtures of two or more thereof. Specific examples of alkaline earth metal hydroxides include, for example, calcium hydroxide, strontium hydroxide, barium hydroxide, etc., with sodium hydroxide being preferred.

[0065] When using alkali metal hydrogen sulfide as a sulfiding agent, it is particularly preferred to use alkali metal hydroxide simultaneously. The amount used can be exemplified as 0.95 to 1.20 moles relative to 1 mole of alkali metal hydrogen sulfide, preferably 1.00 to 1.15 moles, and more preferably in the range of 1.005 to 1.100 moles.

[0066] [Polymerization solvent]

[0067] As a polymerization solvent, a polar organic solvent is preferred. Specific examples include N-alkylpyrrolidones such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, caprolactams such as N-methyl-ε-caprolactam, 1,3-dimethyl-2-imidazolinone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric triamine, dimethyl sulfone, tetramethylene sulfoxide, and mixtures thereof. These solvents exhibit high reaction stability and are therefore preferred. Among these, N-methyl-2-pyrrolidone (hereinafter sometimes abbreviated as "NMP") is particularly preferred.

[0068] The amount of organic polar solvent used is selected relative to 1 mole of vulcanizing agent, ranging from 2.0 moles to 10 moles, preferably from 2.25 moles to 6.0 moles, and more preferably from 2.5 moles to 5.5 moles.

[0069] [Molecular weight regulator]

[0070] To induce end formation in the generated PPS resin, or to adjust the polymerization reaction, molecular weight, etc., a monohalogen compound (which may not necessarily be an aromatic compound) can be used in combination with the aforementioned polyhalogenated aromatic compounds.

[0071] [Polymerization aids]

[0072] To obtain PPS resin with a higher degree of polymerization in a shorter time, the use of polymerization aids is also a preferred option. Here, polymerization aids refer to substances that increase the viscosity of the resulting (a)PPS resin. Specific examples of such polymerization aids include organic carboxylates, water, alkali metal chlorides, organic sulfonates, alkali metal sulfates, alkaline earth metal oxides, alkali metal phosphates, and alkaline earth metal phosphates. They can be used alone, or two or more can be used simultaneously. Among these, organic carboxylates, water, and alkali metal chlorides are preferred; more specifically, alkali metal carboxylates are preferred as organic carboxylates, and lithium chloride is preferred as an alkali metal chloride.

[0073] The aforementioned alkali metal carboxylates have the general formula R(COOM). n (In the formula, R is an aliphatic hydrocarbon group, an alicyclic hydrocarbon group that can be substituted by an aliphatic hydrocarbon group, or an aromatic hydrocarbon group that can be substituted by an aliphatic hydrocarbon group, with 1 to 20 carbon atoms and an n-valence. M is an alkali metal selected from lithium, sodium, potassium, rubidium, and cesium. n is an integer from 1 to 3.) The compound shown is an alkali metal carboxylate. Alkali metal carboxylates can also be used as hydrates, anhydrides, or aqueous solutions. Specific examples of alkali metal carboxylates include, for example, lithium acetate, sodium acetate, potassium acetate, sodium propionate, lithium valerate, sodium benzoate, sodium phenylacetate, potassium p-methylbenzoate, and mixtures thereof.

[0074] Alkali metal carboxylates can be formed by reacting an organic acid with one or more compounds selected from alkali metal hydroxides, alkali metal carbonates, and alkali metal bicarbonates in substantially stoichiometric amounts. Among the aforementioned alkali metal carboxylates, lithium salts have high solubility in the reaction system and are highly effective auxiliaries but are expensive. Potassium, rubidium, and cesium salts are considered to have insufficient solubility in the reaction system. Therefore, sodium acetate, which is inexpensive and has moderate solubility in the polymerization system, is the most preferred choice.

[0075] When using these alkali metal carboxylates as polymerization aids, the amount used is typically in the range of 0.01 mol to 2 mol relative to 1 mol of the added alkali metal sulfide. For the purpose of obtaining a higher degree of polymerization, the range of 0.1 mol to 0.6 mol is preferred, and the range of 0.2 mol to 0.5 mol is more preferred.

[0076] Furthermore, when water is used as a polymerization aid, the amount added is typically in the range of 0.3 to 15 moles relative to 1 mole of the added alkali metal sulfide. For the purpose of obtaining a higher degree of polymerization, the range of 0.6 to 10 moles is preferred, and more preferably the range of 1 to 5 moles.

[0077] These polymerization aids can, of course, be used in combination with more than one type. For example, if an alkali metal carboxylate is used in combination with water, each can be used in smaller quantities to increase the molecular weight.

[0078] There is no specific designation regarding the timing of adding these polymerization aids. They can be added at any time, either during the preceding steps (described later), at the start of polymerization, or during polymerization. They can also be added in multiple stages. However, when using alkali metal carboxylates as polymerization aids, adding them simultaneously at the start of the preceding steps or at the start of polymerization is preferable from an ease-of-addition perspective. Furthermore, when using water as a polymerization aid, adding it during the polymerization reaction after the addition of a polyhalogenated aromatic compound is effective.

[0079] [Polymerization stabilizer]

[0080] To stabilize the polymerization reaction system and prevent side reactions, polymerization stabilizers can also be used. Polymerization stabilizers help stabilize the polymerization reaction system and suppress undesirable side reactions. A standard example of a side reaction is the formation of thiophenol, which can be suppressed by adding a polymerization stabilizer. Specific examples of polymerization stabilizers include compounds such as alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, and alkaline earth metal carbonates. Among these, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide are preferred. The aforementioned alkali metal carboxylates also function as polymerization stabilizers. Furthermore, when using alkali metal hydrogen sulfides as vulcanizing agents, it has been explained above that the simultaneous use of alkali metal hydroxides is particularly preferred; here, an excess of alkali metal hydroxide relative to the vulcanizing agent can also serve as a polymerization stabilizer.

[0081] These polymerization stabilizers can be used individually or in combination of two or more. The polymerization stabilizer is preferably used at a ratio of 0.02 to 0.2 moles relative to 1 mole of the added alkali metal sulfide, typically 0.03 to 0.1 moles, and more preferably 0.04 to 0.09 moles. If the ratio is too low, the stabilizing effect will be insufficient; conversely, even an excessive amount is economically disadvantageous and may tend to reduce polymer yield.

[0082] There is no specific designation for the timing of adding the polymerization stabilizer. It can be added at any time during the preceding process, at the start of polymerization, or during polymerization. Alternatively, it can be added in multiple steps. However, adding it at the start of the preceding process or at the start of polymerization is preferred from an ease of consideration.

[0083] Next, a preferred method for manufacturing the PPS resin used in this invention will be described in detail, including the pre-processing step, the polymerization reaction step, the recycling step, and the post-processing step, but it is not limited to this method.

[0084] [Previous Process]

[0085] In the manufacturing process of PPS resin, the vulcanizing agent is usually used in the form of a hydrate, but it is preferable to heat the mixture containing the organic polar solvent and the vulcanizing agent before adding the polyhalogenated aromatic compound to remove excess water from the system.

[0086] Furthermore, as described above, vulcanizing agents can also be derived from alkali metal hydrogen sulfides and alkali metal hydroxides, either in situ within the reaction system or in a tank separate from the polymerization tank. There are no particular limitations to this method; examples include adding alkali metal hydrogen sulfides and alkali metal hydroxides to an organic polar solvent under an inert gas atmosphere, at a temperature range of room temperature to 150°C, preferably room temperature to 100°C, and then heating the mixture under atmospheric or reduced pressure to at least 150°C, preferably 180 to 260°C, to remove water by distillation. Polymerization aids can be added at this stage. Additionally, to facilitate water distillation, toluene or similar substances can be added to promote the reaction.

[0087] The amount of water in the polymerization reaction and within the polymerization system is preferably 0.3 to 10.0 mol per 1 mole of added vulcanizing agent. The amount of water in the polymerization system referred to here is the amount obtained by subtracting the amount of water removed from the polymerization system from the amount of water added to the polymerization system. Furthermore, the added water can be in any form, such as water, aqueous solution, or water of crystallization.

[0088] [Polymerization reaction process]

[0089] PPS resin is manufactured by reacting a vulcanizing agent with a polyhalogenated aromatic compound in an organic polar solvent at a temperature range of above 200°C and below 290°C.

[0090] At the start of the polymerization reaction, it is desirable to mix the organic polar solvent, the vulcanizing agent, and the polyhalogenated aromatic compound under an inert gas atmosphere and at a temperature range of room temperature to 240°C, preferably 100°C to 230°C. Polymerization aids can be added at this stage. These raw materials can be added in different orders or simultaneously.

[0091] Such mixtures are typically heated to a temperature range of 200°C to less than 290°C. There are no particular restrictions on the heating rate, but a rate of 0.01 to 5°C / min is usually chosen, and more preferably, a rate of 0.1 to 3°C / min.

[0092] Generally, the temperature is eventually raised to 250 to less than 290°C, and the reaction is usually carried out at this temperature for 0.25 to 50 hours, preferably 0.5 to 20 hours.

[0093] In the stage before reaching the final temperature, for example, after reacting at 200°C to 260°C for a certain time, raising the temperature to 270°C to less than 290°C is effective in obtaining a higher degree of polymerization. At this time, the reaction time at 200°C to 260°C is usually selected in the range of 0.25 hours to 20 hours, preferably in the range of 0.25 hours to 10 hours.

[0094] Furthermore, to obtain polymers with higher degrees of polymerization, it is sometimes effective to perform polymerization in multiple stages. When performing polymerization in multiple stages, it is effective when the conversion rate of polyhalogenated aromatic compounds in the system at 245°C reaches 40 mol% or more, preferably 60 mol%.

[0095] In addition, the conversion rate of polyhalogenated aromatic compounds (hereinafter referred to as "PHA") is calculated using the following formula. The residual amount of PHA can usually be determined by gas chromatography.

[0096] (A) The case of adding polyhalogenated aromatic compounds in excess relative to alkali metal sulfides in a molar ratio.

[0097] Conversion rate = [PHA added (moles) - PHA remaining (moles)] / [PHA added (moles) - PHA excess (moles)].

[0098] (B) Other than those mentioned in (A) above

[0099] Conversion rate = [PHA added (moles) - PHA remaining (moles)] / [PHA added (moles)].

[0100] [Recycling Process]

[0101] In the manufacturing process of PPS resin, after polymerization, solid substances are recovered from the polymerization reactants, which include polymers and solvents. Regarding the recovery method, it is essential to employ a method that involves slow cooling after the polymerization reaction to recover the particulate polymer. There are no particular restrictions on the slow cooling rate at this stage, but it is typically around 0.1°C / min to 3°C / min. It is not necessary to maintain the same slow cooling rate throughout the entire slow cooling process; methods such as cooling at 0.1 to 1°C / min until the polymer particles crystallize and precipitate, followed by slow cooling at a rate of 1°C / min or higher, are acceptable.

[0102] [Post-processing steps]

[0103] PPS resin can be produced through the above polymerization and recycling processes, and then subjected to acid treatment, hot water treatment, washing with organic solvents, and treatment with alkali metals and alkaline earth metals.

[0104] The acid treatment process is described below. There are no particular restrictions on the acid used for PPS resin acid treatment, as long as it does not decompose the PPS resin. Examples include acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid, and propionic acid. Acetic acid and hydrochloric acid are preferred, but substances such as nitric acid that decompose or degrade PPS resin are not preferred.

[0105] Acid treatment methods include immersing PPS resin in acid or an aqueous solution of acid, and stirring or heating may be applied as needed. For example, when using acetic acid, immersing PPS resin powder in an aqueous solution at pH 4 heated to 80–200°C and stirring for 30 minutes can achieve sufficient results. The pH after treatment can be above 4, for example, around pH 4–8. To remove residual acid or salts, the acid-treated PPS resin is preferably washed several times with water or warm water. Distilled water or deionized water is preferred for washing, provided it does not impair the preferred chemical modification effect of the acid treatment on the PPS resin.

[0106] The hot water treatment process is as follows. When treating the PPS resin with hot water, it is preferable that the water temperature is 100°C or higher, more preferably 120°C or higher, even more preferably 150°C or higher, and particularly preferably 170°C or higher. If the temperature is lower than 100°C, the preferred chemical modification effect on the PPS resin is small, and therefore it is not preferred.

[0107] To demonstrate the superior chemical modification effect of PPS resin brought about by hot water washing, distilled or deionized water is preferred. There are no particular restrictions on the hot water treatment operation; it can be carried out by adding a specified amount of PPS resin to a specified amount of water, heating and stirring in a pressure vessel, or by continuously performing the hot water treatment. The ratio of PPS resin to water is preferably more water, but a bath ratio of less than 200g of PPS resin per liter of water is typically chosen.

[0108] Furthermore, regarding the processing atmosphere, since the decomposition of end groups is undesirable, a non-reactive atmosphere is desirable to avoid it. Further, after completing this hot water treatment operation, the PPS resin is preferably washed several times with warm water to remove residual components.

[0109] The use of organic solvents for washing PPS resin is as follows. There are no particular restrictions on the organic solvents used for washing PPS resin, as long as they do not decompose the resin. Examples include nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, 1,3-dimethylimidazolinone, hexamethylphosphoramide, and piperazine; sulfoxide / sulfone solvents such as dimethyl sulfoxide, dimethyl sulfone, and sulfolane; ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, and acetophenone; and solvents such as dimethyl ether, dipropyl ether, etc. Ether solvents such as alkanes and tetrahydrofuran; halogen solvents such as chloroform, dichloromethane, trichloroethylene, 1,2-dichloroethane, perchloroethylene, monochloroethane, dichloroethane, tetrachloroethane, perchloroethane, and chlorobenzene; alcohol / phenol solvents such as methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, phenol, cresol, polyethylene glycol, and polypropylene glycol; and aromatic hydrocarbon solvents such as benzene, toluene, and xylene. Among these organic solvents, the use of N-methyl-2-pyrrolidone, acetone, dimethylformamide, and chloroform is particularly preferred. Furthermore, these organic solvents may be used in mixtures of one or more.

[0110] As a washing method using organic solvents, one method involves impregnating PPS resin in the organic solvent, and stirring or heating can be applied as needed. There are no particular restrictions on the washing temperature when washing PPS resin with organic solvents; any temperature from room temperature to approximately 300°C can be selected. Higher washing temperatures tend to result in higher washing efficiency, but generally, a washing temperature of room temperature to 150°C is sufficient to achieve adequate results. Washing can also be performed under pressure in a pressure vessel at a temperature above the boiling point of the organic solvent. Furthermore, there are no particular restrictions on the washing time. Although it depends on the washing conditions, in the case of intermittent washing, washing for 5 minutes or more is generally sufficient to obtain adequate results. Continuous washing is also possible.

[0111] Methods for treating PPS with alkali metals and alkaline earth metals include: adding alkali metal salts or alkaline earth metal salts before, during, or after the aforementioned preceding steps; adding alkali metal salts or alkaline earth metal salts into the polymerization reactor before, during, or after the polymerization step; or adding alkali metal salts or alkaline earth metal salts at the beginning, middle, or end of the aforementioned washing step. The easiest method is to add alkali metal salts or alkaline earth metal salts after removing residual oligomers or residual salts by washing with organic solvents, warm water, or hot water. The alkali metals or alkaline earth metals are preferably introduced into PPS in the form of alkali metal ions such as acetates, hydroxides, or carbonates. Furthermore, excess alkali metal salts or alkaline earth metal salts are preferably removed by washing with warm water, etc. The concentration of alkali metal ions or alkaline earth metal ions when introducing the aforementioned alkali metals or alkaline earth metals is preferably 0.001 mmol or more, more preferably 0.01 mmol or more, relative to 1 g of PPS. The preferred temperature is 50°C or higher, more preferably 75°C or higher, and particularly preferably 90°C or higher. There is no particular limitation on the upper limit temperature, but from an operational point of view, 280°C or lower is generally preferred. The preferred liquor ratio (weight of detergent relative to the weight of dried PPS) is 0.5 or higher, more preferably 3 or higher, and even more preferably 5 or higher.

[0112] In this invention, from the viewpoint of obtaining a polyphenylene sulfide resin composition with excellent retention stability, it is preferable to remove residual oligomers and residual salts by repeatedly washing with organic solvents and warm water at about 80°C or the above-mentioned hot water, followed by treatment with acid or alkali metal salts or alkaline earth metal salts, and more preferably by treatment with alkali metal salts or alkaline earth metal salts.

[0113] In addition, PPS resin can also be used by increasing its molecular weight through thermal oxidative crosslinking treatment after polymerization by heating under an oxygen atmosphere and adding crosslinking agents such as peroxides.

[0114] When dry heat treatment is performed for the purpose of increasing molecular weight through thermal oxidative crosslinking, the temperature is preferably in the range of 160–260°C, more preferably in the range of 170–250°C. Furthermore, an oxygen concentration of 5% by volume or more is desirable, and more preferably 8% by volume or more. There is no particular upper limit to the oxygen concentration, but approximately 50% by volume is a limit. The treatment time is preferably 0.5–100 hours, more preferably 1–50 hours, and more preferably 2–25 hours. The heat treatment apparatus can be a conventional hot air dryer, or a rotary or stirring-blade heating device; however, a rotary or stirring-blade heating device is more preferred for better efficiency and more uniform treatment.

[0115] Furthermore, dry heat treatment can also be performed to inhibit thermal oxidative crosslinking and remove volatile components. The preferred temperature is 130–250°C, more preferably 160–250°C. Furthermore, it is desirable that the oxygen concentration under these conditions be less than 5% by volume, and more preferably less than 2% by volume. The treatment time is preferably 0.5–50 hours, more preferably 1–20 hours, and more preferably 1–10 hours. The heat treatment apparatus can be a conventional hot air dryer, or a rotary or stirring-blade heating device; however, a rotary or stirring-blade heating device is more preferred for better efficiency and more uniform treatment.

[0116] From the viewpoint of improving reactivity with (c) olefin-based elastomers and other additives, the PPS resin constituting component (a) of the present invention can have functional groups such as carboxyl groups and amino groups introduced into the PPS resin terminals and side chains. A preferred amount of functional groups is 25 to 400 μmol / g, more preferably 25 to 250 μmol / g, more preferably 30 to 150 μmol / g, and even more preferably 30 to 80 μmol / g. A functional group amount of 25 μmol / g or more is preferred, as it provides good reactivity with (c) olefin-based elastomers and other additives. On the other hand, a functional group amount of 400 μmol / g or less in the PPS resin is preferred, as it helps to suppress the decrease in processability, flame retardancy, and chemical resistance associated with an increase in the amount of volatile components.

[0117] Methods for introducing functional groups such as carboxyl and amino groups into PPS resin include copolymerizing a polyhalogenated aromatic compound containing carboxyl and amino groups with a vulcanizing agent, and adding compounds containing carboxyl and amino groups, such as maleic anhydride and sorbic acid, and reacting them with PPS resin while melt-blending to introduce the functional groups. The preferred types of functional groups are carboxyl or amino groups.

[0118] Furthermore, in this invention, various PPS resins with different melt viscosities, non-Newtonian indices, and functional group contents can be mixed and used.

[0119] (2)(c) Olefin-based elastomers

[0120] From the viewpoint of obtaining excellent softness and toughness of the resin composition, the addition of (c) an olefin-based elastomer to the polyphenylene sulfide resin composition of the present invention is preferred. Furthermore, the increased melt viscosity of the resin composition leads to improved dispersibility of (b) the organosilicon polymer, thus improving toughness and flame retardancy. Moreover, from the viewpoint of cost advantage compared to other soft materials, olefin-based elastomers are also selected.

[0121] Examples of such (c) olefin-based elastomers include ethylene-butene copolymers, ethylene-propylene copolymers, ethylene-hexene copolymers, ethylene-octene copolymers, ethylene-vinyl acetate copolymers, ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, ethylene-glycidyl methacrylate copolymers, ethylene-butyl acrylate copolymers, ethylene-methyl acrylate copolymers, ethylene-styrene copolymers, ethylene-methyl acrylate-glycidyl methacrylate copolymers, ethylene-ethyl acrylate-glycidyl methacrylate copolymers, and ethylene-vinyl acetate-glycidyl methacrylate copolymers. From the viewpoint of compatibility and dispersibility with PPS resins, ethylene-butene copolymers, ethylene-propylene copolymers, ethylene-glycidyl methacrylate copolymers, ethylene-methyl acrylate-glycidyl methacrylate copolymers, ethylene-ethyl acrylate-glycidyl methacrylate copolymers, and ethylene-vinyl acetate-glycidyl methacrylate copolymers are preferred. Particularly preferred are olefin-based elastomers containing glycidyl groups, with ethylene-glycidyl methacrylate copolymer and ethylene-methyl acrylate-glycidyl methacrylate copolymer being the most preferred.

[0122] From the viewpoint of forming intermolecular bonds with PPS resin, the (c) olefin elastomer used in this invention may also include reactive functional groups as a preferred option.

[0123] (c) The reactive functional groups of olefin elastomers are not particularly limited. Specifically, examples include vinyl, epoxy, carboxyl, acid anhydride, ester, aldehyde, carbonyl dioxy, haloformyl, alkoxy carbonyl, amino, hydroxyl, styryl, methacryl, acryloyl, urea, mercapto, thioether, isocyanate, hydrolyzable silyl, etc. Azoline groups, etc., preferably hydroxyl, epoxy, carboxyl, amino, acid anhydride, amino, hydroxyl, isocyanate groups, etc. The zoline group can contain more than two of these reactive functional groups.

[0124] Examples of methods for introducing reactive functional groups into (c) olefin-based elastomers include: blending compounds or resins compatible with olefin-based elastomers and containing the aforementioned functional groups; copolymerizing polymerizable monomers containing the aforementioned functional groups or functional groups capable of being transformed into the aforementioned functional groups in the main chain, side chain, or terminal chain during the polymerization of olefin-based elastomers; using an initiator containing the aforementioned functional groups or functional groups capable of being transformed into the aforementioned functional groups during the polymerization of olefin-based elastomers; reacting olefin-based elastomers with polymerizable monomers containing the aforementioned functional groups or functional groups capable of being transformed into the aforementioned functional groups in the presence of a free radical initiator; and modifying olefin-based elastomers by oxidation, thermal decomposition, or other methods. From the perspectives of quality, cost, and dosage control, the preferred methods for polymerizing olefin-based elastomers include copolymerizing polymerizable monomers containing the aforementioned functional groups or functional groups capable of being transformed into the aforementioned functional groups in the main chain, side chain, or terminal chain, and reacting the olefin-based elastomer with polymerizable monomers containing the aforementioned functional groups or functional groups capable of being transformed into the aforementioned functional groups in the presence of a free radical initiator.

[0125] Polymerizable monomers containing the above-mentioned functional groups are not particularly limited, and examples include acrylic acid, methacrylic acid, maleic acid, itaconic acid, citraconic acid, crotonic acid, norborneol edioic acid, their anhydrides, glycidyl acrylate, glycidyl methacrylate, glycidyl ethyl acrylate, glycidyl itaconic acid, vinyl acetate, vinyl propionate, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, etc.

[0126] From the viewpoint of ensuring sufficient reaction with (a) the PPS resin, the amount of functional groups contained in (c) the olefin elastomer relative to the weight of the olefin elastomer is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and even more preferably 1% by weight or more. It is also expected that with increased reactivity with the PPS resin, compatibility will improve, leading to microdispersion of the olefin elastomer in the PPS resin, and consequently, improvements in impact properties, toughness, etc. Regarding the upper limit of the amount of functional groups, there is no particular limitation as long as it does not impair the inherent properties of the olefin elastomer. However, considering factors such as deterioration in flowability, it is preferably 40% by weight or less, and 30% by weight or less is a more preferred range.

[0127] In embodiments of the present invention, the amount of olefin elastomer in (c) relative to 100 parts by weight of PPS resin constituting component (a) is preferably 1 part by weight or more and 40 parts by weight or less, preferably 3 parts by weight or more and 35 parts by weight or less, more preferably 5 parts by weight or more and 30 parts by weight, more preferably 5 parts by weight or more and 25 parts by weight or less, and particularly preferably 5 parts by weight or more and 15 parts by weight or less. If the amount of olefin elastomer relative to 100 parts by weight of PPS resin exceeds 40 parts by weight, there is a tendency for the toughness to decrease due to the coarsening of the olefin elastomer in the PPS resin. In addition, there is also a tendency for the flame retardancy to decrease. On the other hand, when the amount of olefin elastomer relative to 100 parts by weight of PPS resin is less than 1 part by weight, the improvement effect on the softness and toughness of the resin composition is small, and therefore it is not preferred.

[0128] Furthermore, from the perspective of improving dispersibility, it is also suitable to use two or more olefin-based elastomers together.

[0129] In the case of blending (c) olefin-based elastomers into the polyphenylene sulfide resin composition of the present invention, from the viewpoint of minimizing the reduction in flame retardancy caused by the blending of (c) olefin-based elastomers while obtaining excellent improvements in softness and toughness, it is preferable that in the phase structure of the PPS resin composition, the PPS resin forms a continuous phase, and the (c) olefin-based elastomer forms a dispersed phase with a number-uniform particle size of 1.0 μm or less, more preferably 0.5 μm or less, and particularly preferably 0.3 μm or less. As a lower limit, the finer the dispersion diameter, the more preferred; an example is a dispersion diameter of about 1 nm, which is substantially incompatible with the system. In order for the (c) olefin-based elastomer to form a dispersed phase with a number-uniform particle size of 1.0 μm or less, it is preferable, for example, that the (c) olefin-based elastomer has reactive functional groups.

[0130] In addition, (c) the number-average particle size of the olefin elastomers was determined by molding ISO527-1-1A test pieces at a molding temperature of +20 to 40°C, where the PPS resin constituting component (a) was at its melting peak temperature. Thin sheets less than 0.1 μm were cut from the center of the test piece at room temperature along a cross-sectional direction perpendicular to the resin flow direction during the molding of the dumbbell-shaped sheet. The results were observed using a Hitachi High Tech Noroze field emission scanning electron microscope SU8220, magnified to 1000 to 5000 times. For any 100 olefin elastomers at this time, the maximum and minimum diameters of each were first measured, and the average value was taken as the particle size. Then, the average value of these values ​​was calculated.

[0131] (3)(b) Organosilicon polymers ((b) components)

[0132] In order to achieve both excellent softness and toughness as well as flame retardancy in the resin composition, it is necessary to contain (b) an organosilicon polymer compound in the PPS resin composition of the embodiments of the present invention.

[0133] Such so-called (b) organosilicon polymers are high molecular weight compounds whose main chain structure contains siloxane bonds. Specifically, examples include silicone gum, silicone elastomers, silicone resins, copolymers containing organopolysiloxanes, and composites containing organopolysiloxanes. Furthermore, the term "polymer" here refers to compounds with an organopolysiloxane degree of polymerization of 100 or higher and a weight-average molecular weight of approximately 10,000 or higher.

[0134] Organosilicon rubber, organosilicon elastomer, and organosilicon resin are all high-molecular-weight organosilicones with organopolysiloxanes as the basic framework. Based on the degree of their 3D network structure, substances without a 3D network structure are called organosilicon rubber, substances with a slight 3D network structure are called organosilicon elastomers, and substances with a high degree of 3D network structure are called organosilicon resins. As a copolymer containing organopolysiloxanes, it is a copolymer of the organopolysiloxane component and one or more copolymerizing components selected from polyolefins (polyethylene, polypropylene, polybutene, etc.), polycarbonate, polyamide, polybutylene terephthalate, polyester elastomers, polystyrene, polyetherimide, polyketone, liquid crystal polymers, polyetherketone, polyetheretherketone, polyacrylate (polymethyl methacrylate, etc.), etc., with more preferred copolymerizing components being polyolefins, polycarbonate, polyetherimide, and polyacrylate. Examples of composites containing organopolysiloxanes include core-shell rubbers (organosilicone acrylic core-shell rubbers) in which organosilicone elastomer particles are coated with acrylic components, and composite powders in which organosilicone elastomers are coated with organosilicone resins.

[0135] As the aforementioned organosilicone rubber, organosilicone elastomer, organosilicone resin, copolymer containing organopolysiloxane, core-shell compound containing organopolysiloxane, and composite containing organopolysiloxane, the organopolysiloxane structure preferably has one or more hydrocarbon groups selected from alkyl (methyl, ethyl, propyl, butyl, 2-ethylbutyl, octyl, etc.), cycloalkyl (cyclohexyl, cyclopentyl, etc.), alkenyl (vinyl, propenyl, butenyl, heptenyl, hexenyl, allyl, etc.), and aryl (phenyl, tolyl, xylyl, naphthyl, diphenyl, etc.), wherein methyl and phenyl are preferred.

[0136] Furthermore, from the viewpoint of improving compatibility with PPS resin or olefin-based elastomers, it is preferable that the organopolysiloxane structure contains one or more functional groups selected from alkoxy (methoxy, ethoxy, propoxy, butoxy, etc.), amino, epoxy, methanol, methacryloyl, ether, mercapto, carboxyl, phenol, silanol, acryloyl, carboxylic anhydride, polyether, aralkyl, fluoroalkyl, long-chain alkyl, higher fatty acid ester, higher fatty acid amide, etc., at the molecular chain end or side chain. Among these, alkoxy, amino, epoxy, methacryloyl, mercapto, carboxyl, and acryloyl are preferred, and alkoxy, epoxy, and methacryloyl are particularly preferred.

[0137] The shape of organosilicon polymers is not limited, and can be granules, blocks, powders, aggregates of powders, flakes, liquids, gels, etc. From the viewpoints of operability, processability and dispersibility, granules, powders, aggregates of powders and flakes are preferred.

[0138] Among these (b) organosilicon polymers, from the viewpoint of excellent flexibility, flame retardancy, and dispersibility in resin compositions, substances with a three-dimensional network structure are preferred, namely organosilicon elastomers and organosilicon resins. From the perspective of balancing flexibility and flame retardancy, organosilicon elastomers are particularly preferred. Among these, organosilicon core-shell rubbers are preferred, and organosilicon acrylic core-shell rubbers are particularly preferred.

[0139] From the viewpoints of dispersibility, flame retardancy, and the toughness of the PPS resin composition, (b) the average primary particle size of the organosilicon polymer itself is preferably 3.0 μm or less, more preferably 2.0 μm or less, even more preferably 1.0 μm or less, and particularly preferably 0.5 μm or less. Furthermore, the average primary particle size (number-average particle size) of (b) the organosilicon polymer itself can be calculated by taking the arithmetic mean of the diameters of 100 randomly selected particles from a scanning electron microscope image. In the aforementioned image, in the case where the particles are not perfectly spherical, i.e., elliptical, the maximum diameter of the particles is taken as its particle size.

[0140] When using organosilicon polymers (b) with an average primary particle size of 3.0 μm or less, for example, by combining them with olefin elastomers (c) or by using PPS resin with high melt viscosity, the melt viscosity of the PPS resin composition is increased. As a result, in the phase structure of the PPS resin composition, the aforementioned component (b) can form a dispersed phase with a number-uniformly dispersed particle size of 3.0 μm or less, thus improving toughness and flame retardancy. Furthermore, in melt compounding using a twin-screw extruder, achieving a L / D ratio of 20 or higher, providing two or more kneading sections, and maintaining a screw speed of 200 to 500 rpm can also yield the desired number-uniformly dispersed particle size of the aforementioned component (b), and these conditions can be exemplified as preferred conditions. Combinations of these methods are particularly preferred.

[0141] On the other hand, even when using organosilicon polymers (b) with an average primary particle size of 3.0 μm or less, if the melt viscosity of the resin composition is low and the mixing strength is insufficient during melt mixing in a twin-screw extruder, it is sometimes difficult to obtain the desired number-average particle size due to the aggregation of component (b), resulting in reduced toughness and flame retardancy. Furthermore, in the morphology (phase structure) of the PPS resin composition of the present invention, if component (b) is present due to aggregation, this aggregated portion is considered as a dispersed phase.

[0142] The content of the organosilicon polymer used in this invention (b) must be 3 parts by weight or more and 40 parts by weight or less relative to 100 parts by weight of the PPS resin constituting component (a), preferably 5 parts by weight or more and 37 parts by weight or less, more preferably 7.5 parts by weight or more and 35 parts by weight, more preferably 8 parts by weight or more and 30 parts by weight or less, and particularly preferably 9 parts by weight or more and 25 parts by weight or less. If the content of the organosilicon polymer exceeds 40 parts by weight relative to 100 parts by weight of the PPS resin, there is a tendency for the toughness and flame retardancy to decrease due to the coarsening of the organosilicon polymer in the PPS resin. On the other hand, if the content of the organosilicon polymer is less than 3 parts by weight relative to 100 parts by weight of the PPS resin, sufficient softness, toughness, and flame retardancy of the resin composition cannot be obtained, and therefore it is not preferred.

[0143] Furthermore, considering the good balance of softness, toughness, and flame retardancy, as well as improved dispersibility, it is also suitable to use two or more organosilicon polymers together.

[0144] (4)(d) Other additives

[0145] Furthermore, in the PPS resin composition of the embodiments of the present invention, resins other than components (a), (b), and (c) olefin-based elastomers may be added and blended, without impairing the effects of the present invention. Specific examples include polyamides, polyamide elastomers, polybutylene terephthalate, polyethylene terephthalate, polyester elastomers, polyetherimides, polyketones, liquid crystal polymers, polyetherketones, polyetheretherketones, ethylene-tetrafluoroethylene copolymers (ETFE), tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymers (PFA), tetrafluoroethylene-hexafluoropropylene copolymers (FEP), ethylene-tetrafluoroethylene-hexafluoropropylene copolymers, poly(1,1-difluoroethylene) (PVDF), poly(trifluoroethylene chloride) (PCTFE), and styrene-based elastomers, but are not limited to these. The amount of such resin added relative to 100 parts by weight of PPS resin is preferably less than 20 parts by weight, more preferably less than 15 parts by weight, and more preferably less than 10 parts by weight. Furthermore, as a lower limit, it is preferable that these resins are not included, i.e., 0 parts by weight.

[0146] Regarding the blending of other resins, since it can be considered that the formation of a phase-separated structure with PPS resin leads to a decrease in toughness accompanied by a decrease in adhesion, the blending amount of other resins is preferably within the above range.

[0147] In the PPS resin composition of the embodiments of the present invention, phosphorus-based flame retardants, halogen-based flame retardants, and inorganic flame retardants can be added for the purpose of improving flame retardancy. Examples of phosphorus-based flame retardants, which are flame retardants containing phosphorus, include aromatic phosphate ester compounds, phosphazene compounds, phenanthrene phosphate compounds, phosphonic acid metal salts, phosphonic acid polymers, ammonium polyphosphate, melamine polyphosphate, phosphate ester amides, and red phosphorus. Examples of halogen-based flame retardants include brominated epoxy resins, brominated polystyrene, brominated polycarbonate, and brominated polyphenylene ethers. Examples of inorganic flame retardants include aluminum hydroxide, magnesium hydroxide, zinc hydroxide, and titanium hydroxide. Furthermore, flame retardant additives can be used in conjunction with these flame retardants to improve their flame retardant properties. Specifically, antimony compounds or nitrogen-containing compounds can be used.

[0148] In the PPS resin composition of the embodiments of the present invention, compounds such as the following can be added for modification purposes. Plasticizers such as polyalkylene oxide oligomers, thioether compounds, ester compounds, and organophosphorus compounds, organophosphorus compounds, crystallizing nucleating agents such as polyether ether ketone, lignite waxes, lithium stearate, aluminum stearate, ethylenediamine / stearic acid / sebacic acid condensates, mold release agents such as organosilicon compounds, and common additives such as water, lubricants, UV inhibitors, colorants, colorants, and foaming agents can be mixed in. If any of the above compounds exceeds 10 parts by weight of the total composition, it will impair the original properties of the PPS resin composition of the present invention, and therefore is not preferred; adding 5 parts by weight or less, more preferably 1 part by weight or less, is preferable.

[0149] Furthermore, in this invention, compatibilizers can be used together to improve the compatibility between the resins. Specifically, organosilane compounds and epoxy resins can be examples.

[0150] As specific examples of organosilane compounds, organosilane compounds having at least one functional group selected from isocyanate group, epoxy group, amino group, hydroxyl group, mercapto group, urea group, and alkoxy group are preferred. Specific examples include 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropyltriethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-aminopropylmethyldiethoxysilane. N-phenylaminomethyltrimethoxysilane, N-phenylaminopropyltrimethoxysilane, dimethoxymethyl-3-piperazinylpropylsilane, 3-piperazinylpropyltrimethoxysilane, 3-isocyanate-propyltrimethoxysilane, 3-isocyanate-propyltriethoxysilane, 3-isocyanate-propylmethyldimethoxysilane, 3-isocyanate-propylmethyldiethoxysilane, 3-isocyanate-propylethyldimethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptomethyldimethoxysilane, γ-ureopropyltrimethoxysilane, etc.

[0151] From the viewpoints of reactivity and operability, the preferred organosilane compounds are 3-isocyanate-propyltriethoxysilane, 3-aminopropyltriethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane.

[0152] These alkoxyorganosilanes can be used individually or in mixtures of two or more.

[0153] The amount of these organosilane compounds used in this invention is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, relative to 100 parts by weight of the PPS resin constituting component (a), and 0.3 to 3 parts by weight is an example of a more preferred embodiment. Since the amount of organosilane compounds is 10 parts by weight or less, the flame retardancy of the resulting PPS resin composition can be maintained, which is therefore preferred. If the amount of organosilane compounds is 0.01 parts by weight or more, the reaction between the PPS resin and the organosilane compounds becomes sufficient, resulting in excellent toughness, which is also preferred.

[0154] Specific examples of epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, brominated epoxy resins, special backbone difunctional epoxy resins with biphenyl or naphthalene backbones, glycidyl ether type epoxy resins (represented by polyfunctional epoxy resins such as cresol phenolic varnish type, triphenol methane type, and dicyclopentadiene type), glycidyl amine type epoxy resins (represented by aromatic amine type and aminophenol type), and glycidyl ester type epoxy resins (represented by phthalic acid type and dimer acid type). The amount of such epoxy resin added relative to 100 parts by weight of the total PPS resin composition is preferably 0.1 to 5 parts by weight, and particularly preferably 0.2 to 3 parts by weight.

[0155] In the PPS resin composition of the embodiments of the present invention, although not an essential component, inorganic fillers can be mixed and used without impairing the effects of the present invention. Specific examples of such inorganic fillers include fibrous fillers such as glass fiber, carbon fiber, carbon nanotubes, carbon nanotubes, potassium titanate whiskers, zinc oxide whiskers, calcium carbonate whiskers, wollastonite whiskers, aluminum borate whiskers, aromatic polyamide fibers, alumina fibers, silicon carbide fibers, ceramic fibers, asbestos fibers, gypsum fibers, and metal fibers; or fullerenes, talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, silica, bentonite, asbestos, and aluminum silicate. Non-fibrous filler materials include silicates, silicon dioxide, magnesium oxide, aluminum oxide, zirconium oxide, titanium dioxide, iron oxide, and other metallic compounds; calcium carbonate, magnesium carbonate, dolomite, and other carbonates; calcium sulfate, barium sulfate, and other sulfates; glass beads, glass flakes, glass powder, ceramic beads, boron nitride, silicon carbide, carbon black, silica, and graphite. Glass fiber, silica, and calcium carbonate are preferred, with calcium carbonate and silica being particularly preferred from the perspective of their effectiveness as corrosion inhibitors and lubricants. Furthermore, these inorganic fillers can be hollow, and two or more types can be used in combination. These inorganic fillers can also be pretreated with coupling agents such as isocyanate compounds, organosilane compounds, organotitanate compounds, organoborane compounds, and epoxy compounds. From the viewpoint of being corrosion inhibitors and lubricants, calcium carbonate, silica, and carbon black are preferred.

[0156] The amount of such inorganic filler mixed relative to 100 parts by weight of the total PPS resin composition is preferably less than 10 parts by weight, more preferably less than 5 parts by weight, more preferably less than 3 parts by weight, and even more preferably less than 1 part by weight. There is no particular limitation on the lower limit, but it is preferably 0.0001 parts by weight or more. While the mixing of inorganic fillers is effective in improving the strength of the material, mixing amounts exceeding 10 parts by weight leads to a decrease in toughness and flexibility, which is therefore undesirable. Since the flexural modulus of elasticity increases significantly through the mixing of inorganic fillers such as glass fibers, it is difficult to obtain a polyphenylene sulfide resin composition that combines toughness, flexibility, and flame retardancy. Furthermore, in this invention, the mixing of inorganic fillers such as glass fibers tends to reduce flame retardancy.

[0157] (5) Method for manufacturing PPS resin composition

[0158] Methods for manufacturing the PPS resin composition of the present invention can include manufacturing in the molten state and manufacturing in the solution state, but from the viewpoint of simplicity, manufacturing in the molten state is preferred. Regarding manufacturing in the molten state, melt mixing using an extruder or melt mixing using a kneader can be used, but from the viewpoint of productivity, melt mixing using an extruder, which allows for continuous manufacturing, is preferred. Regarding melt mixing using an extruder, at least one single-screw extruder, a twin-screw extruder, a four-screw extruder, or a twin-screw / single-screw composite extruder can be used, but from the perspective of improved mixing properties, reactivity, and productivity, multi-screw extruders such as twin-screw extruders or four-screw extruders are preferred, and melt mixing using a twin-screw extruder is most preferred.

[0159] As a further specific method for melt mixing, it is not necessarily limited to this, but it is preferable to use a twin-screw extruder with an L / D ratio (L: screw length, D: screw diameter) of 10 or more, preferably 20 or more, and having 2 or more, preferably 3 or more kneading sections. There is no particular limit to the upper limit of L / D, but from an economic point of view, 60 or less is preferred. Furthermore, there is no particular limit to the upper limit of the number of kneading sections, but from a productivity point of view, 10 or less is preferred. The ratio of the kneading section to the total screw length is preferably 15% or more, more preferably 20% or more, and even more preferably 30% or more. When the ratio of the kneading section to the total screw length is less than 15%, the mixing force is poor, and therefore (b) the number-average dispersion particle size of the organosilicon polymer becomes coarse, and the desired physical properties are difficult to achieve. On the other hand, regarding the upper limit of the ratio of the kneading section to the total screw length, from the viewpoint of preventing resin deterioration caused by excessive shear heating during mixing, 70% or less is preferred.

[0160] Regarding the screw speed, a mixing method is preferably performed at 150–1000 rpm, more preferably 150–600 rpm, more preferably 150–500 rpm, and particularly preferably 200–500 rpm. When the screw speed is higher than 150 rpm, due to sufficient mixing force, (b) the number-average particle size of the organosilicon polymer is refined, resulting in the desired toughness. When the screw speed is higher than 1000 rpm, the resin and additives deteriorate due to excessive shear heat during mixing, leading to reduced toughness, reduced mold contamination, and decreased molding processability such as flash caused by reduced melt viscosity; therefore, this is not preferred.

[0161] The preferred barrel temperature range is 250 to 280°C relative to the melting point of the PPS resin, which is component (a), and is preferably a temperature range of +5 to 100°C, specifically a range of 280 to 400°C, more preferably a range of 280 to 360°C, and even more preferably a range of 280 to 330°C.

[0162] There are no particular restrictions on the order of mixing raw materials during melt blending. Any method can be used, such as mixing all raw materials and then melt blending them using the above method, mixing a portion of raw materials and then melt blending them using the above method, further mixing the remaining raw materials, or mixing a portion of raw materials and then using a side feeder in a twin-screw extruder to blend the remaining raw materials.

[0163] (6) PPS resin composition

[0164] The flexural modulus of elasticity (measured according to ISO 178 using test pieces obtained by injection molding at a barrel temperature of 310°C, a mold temperature of 145°C, a bending speed of 2 mm / min, and a temperature of 23°C), one of the physical properties of the polyphenylene sulfide resin composition of the present invention as an indicator of the material's flexibility, must be 3.0 GPa or less, preferably 2.8 GPa or less, more preferably 2.5 GPa or less, and particularly preferably 2.3 GPa or less. In piping components having a hollow shape, flexibility is required from the viewpoints of the pipe component's workability during manufacturing and actual use, and the suppression of damage when the joint component is pressed into the pipe component; therefore, the flexural modulus of elasticity of the resin composition is required to be 3.0 GPa or less. From the viewpoint of flexibility, a lower flexural modulus is more preferred; there is no particular lower limit, but examples of 0.1 GPa or more that substantially maintains the shape can be exemplified. There is no particular limitation on the method for obtaining a PPS resin composition with such properties. Examples include a resin composition in which the amount of (c) olefin elastomer mixed with 1 part by weight or more and 40 parts by weight or less relative to 100 parts by weight of the PPS resin constituting (a) component, and a resin composition in which the content of (b) organosilicon polymer compound is 3 parts by weight or more and 40 parts by weight or less.

[0165] In the UL94 standard, which is used as an indicator of the flame retardancy of materials, the PPS resin composition of the present invention must achieve a flame retardancy rating of V-0 in test pieces with a thickness of 1.6 mm or less, preferably V-0 in test pieces with a thickness of 1.0 mm or less, and preferably V-0 in test pieces with a thickness of 0.5 mm or less. Generally, flame retardancy tends to be better with thicker test pieces, but the PPS resin composition of the present invention also exhibits a V-0 characteristic in test pieces with a thickness of 1.6 mm or less. Such flame retardancy means excellent flame retardancy, and allows for thinner molded articles and consequently lighter molded articles. This not only contributes to reducing human and economic losses caused by fires but also contributes to energy-saving effects associated with lightweighting, thus making it suitable for use in automotive components such as electric vehicles. There is no particular limitation on the method for obtaining a PPS resin composition with such properties. For example, a resin composition is prepared in which the content of component (b) is 3 parts by weight or more and 40 parts by weight relative to 100 parts by weight of component (a), and component (b) forms a micro-dispersed structure in the PPS resin composition with a number-uniformly dispersed particle size of 3.0 μm or less.

[0166] The tensile elongation at break (dumbbell test piece (ISO 527-2-1A), tensile speed 50 mm / min, 23°C, according to ISO 527-1,2 (2012)) of the PPS resin composition of the present invention, which is one of the physical properties of the material indicating toughness, is preferably 10% or more, more preferably 12.5% ​​or more, further preferably 15% or more, particularly preferably 20% or more, and even more preferably 25% or more. From the viewpoint of suppressing damage during actual use of piping components having a hollow shape and various molded articles, it is desirable that the tensile elongation at break of the molded article of the resin composition is 10% or more. From the viewpoint of suppressing component fracture during actual use, the tensile elongation at break is preferably higher, and no particular upper limit is set, but it can be exemplified as substantially 500% or less. There is no particular limitation on the method for obtaining a PPS resin composition with such properties. For example, a resin composition is prepared in which the amount of (c) olefin elastomer mixed with 1 part by weight or more and 40 parts by weight or less relative to 100 parts by weight of the PPS resin constituting (a) component, and the content of (b) organosilicon polymer compound is 3 parts by weight or more and 40 parts by weight or less, and the (b) component forms a microdispersed structure in the PPS resin with a number-uniformly dispersed particle size of 3.0 μm or less.

[0167] The PPS resin composition of the present invention exhibits excellent flame retardancy even when the flexibility and toughness of the PPS resin are improved by containing an organosilicon polymer compound. To achieve this property, the phase structure of the PPS resin composition must consist of a continuous phase of PPS resin (component A) and a dispersed phase of organosilicon polymer compound (component B) with a number-average particle size of 3.0 μm or less. Preferably, component A forms a continuous phase, and component B forms a dispersed phase with a number-average particle size of 2.0 μm or less. More preferably, the number-average particle size of component B as the dispersed phase is 1.0 μm or less, and particularly preferably 0.5 μm or less. As a lower limit, a finer dispersion diameter is more preferred; an example is approximately 1 nm, which is the smallest dispersion diameter that is substantially incompatible with the resin composition. On the other hand, a number-average particle size exceeding 3.0 μm indicates poor dispersion of the organosilicon polymer compound in the resin composition, resulting in relatively large aggregates. In this dispersed state, it becomes the starting point of the fracture point in tensile and flexural tests, and is therefore considered undesirable. Furthermore, the presence of a relatively coarse dispersed phase of the organosilicon polymer compound can lead to a decrease in flame retardancy through combustion based on it, and is therefore undesirable. As a means to control the number-average particle size of the organosilicon polymer compound in the PPS resin composition to 3.0 μm or less, a preferred method is to achieve an L / D of 20 or more, provide at least two kneading sections, and have a screw speed of 200 to 500 rpm during melt mixing of at least component (a) and component (b) using a twin-screw extruder. Furthermore, achieving a melt viscosity of 400 Pa·s or more in the PPS resin composition is also preferred as a means to control the number-average particle size of the organosilicon polymer compound to 3.0 μm or less. To achieve a melt viscosity of 400 Pa·s or more in the PPS resin composition, it is preferable to use, for example, an olefin elastomer (c) or a PPS resin with a high melt viscosity. To control the number-uniform particle size of the organosilicon polymer compound to 3.0 μm or less, it is particularly preferable to combine the above-described melt mixing method with a melt viscosity of 400 Pa·s or more for the PPS resin composition. From the viewpoint of achieving a finer number-uniform particle size of the organosilicon polymer compound and obtaining excellent toughness and flame retardancy, the melt viscosity of the PPS resin composition is more preferably 500 Pa·s or more, further preferably 800 Pa·s or more, and particularly preferably 1200 Pa·s or more. From the viewpoint of maintaining melt flowability, the upper limit of the melt viscosity of the PPS resin composition is preferably 3000 Pa·s or less. Furthermore, within this melt viscosity range, a higher melt viscosity of the PPS resin composition tends to result in better traction of the molten resin during extrusion molding and a more improved appearance of the extruded product.

[0168] Furthermore, the so-called number-average dispersed particle size referred to here is determined by cutting a thin sheet of less than 0.1 μm from the center of an ISO527-1-1A test piece at a molding temperature of +20 to 40°C, using a Hitachi High-Tech Field Emission Scanning Electron Microscope SU8220 at room temperature, with the cutting direction perpendicular to the resin flow direction during dumbbell sheet molding. The sheet was then observed at magnification of 1000 to 5000 times. For any 100 organosilicon polymer compounds at this time, the maximum and minimum diameters of each compound were first measured, and the average value was set as the dispersed particle size. The average value was then calculated. In the morphology (phase structure) of the PPS resin composition of the present invention, when the component (b) above is agglomerated, the agglomerated portion is designated as one dispersed phase.

[0169] The melt viscosity of the PPS resin composition in this invention is measured using a capsule at 300°C with a pore length L (mm) / pore diameter D (mm) = 10, and the shear rate is 122 s. -1 The value below.

[0170] (7) Uses of PPS resin compositions

[0171] The polyphenylene sulfide resin composition of the present invention can be molded by various molding methods such as injection molding, extrusion molding, compression molding, blow molding, and injection compression molding, but it is particularly useful for extrusion molding or injection molding applications. In particular, the polyphenylene sulfide resin composition of the present invention, due to its excellent flexibility and toughness, is suitable for piping components with a hollow shape, including piping components for automotive applications requiring heat resistance and low water absorption, such as pipes and cooling pipes, as well as piping components for water-using applications in residential equipment. Furthermore, it is also suitable for piping components for urban air transportation applications requiring both high performance and lightweight design. Further, by possessing the flame retardancy characteristic of the polyphenylene sulfide resin composition of the present invention, higher safety can be achieved in these applications.

[0172] Examples of applications for molded products obtained through injection molding include electrical equipment components such as generators, motors, transformers, converters, voltage regulators, rectifiers, inverters, relays, power contacts, switches, circuit breakers, knife switches, multi-transistors, and electrical component cabinets; sensors; LED lights; connectors; sockets; resistors; relay boxes; miniature switches; winding tubes; capacitors; variable capacitor housings; optical pickup devices; oscillators; various terminal blocks; converters; plugs; printed circuit boards; tuners; speakers; microphones; headsets; miniature motors; magnetic head bases; power modules; semiconductors; liquid crystal displays; FDD (Floppy Disk Drive) trays; FDD chassis; motor brush holders; parabolic antennas; and computer-related components; as well as electronic components such as VTR (Video Tape) devices. Components for household / office electrical products, including parts for recorders (cassette recorders), televisions, irons, hair dryers, rice cookers, microwave ovens, audio equipment, audio / laser discs (registered trademark) / CDs, lighting, refrigerators, air conditioners, typewriters, and word processors; mechanical components, including office computer components, telephone components, fax machine components, copier components, washing machine clamps, electric motor components, igniters, and typewriters; optical equipment / precision machinery components, including microscopes, binoculars, cameras, and clocks; alternator terminals, alternator connectors, IC regulators, potentiometer bases for dimmers, exhaust valves and other valves, fuel-related / exhaust / intake system pipes and conduits, turbine pipes, intake nozzle vent pipes, intake manifolds, fuel pumps, engine coolant connectors, carburetor bodies, etc. Automotive / vehicle related components, including air conditioner spacers, exhaust sensors, coolant sensors, oil temperature sensors, brake pad wear sensors, throttle position sensors, crankshaft position sensors, air flow meters, brake pad wear sensors, thermostat bases for air conditioners, heater airflow control valves, brush holders for radiator motors, water pump impellers, turbine blades, wiper motor components, distributors, starter switches, starter relays, wiring harnesses for transmissions, window washer nozzles, air conditioner panel switch base plates, coils for fuel-related solenoid valves, connectors for fuses, horn terminals, electrical component insulation boards, stepper motor rotors, lamp holders, lamp reflectors, lamp housings, brake pistons, solenoid coils, engine oil filters, shock absorbers, cable ties, ignition device housings, etc.; and gaskets for primary or secondary batteries in mobile phones, smartphones, laptops, tablets, cameras, hybrid vehicles, electric vehicles, etc.

[0173] Examples of molded products obtained through extrusion molding include round bars, square bars, sheets, films, tubes, and pipes. Further specific applications include electrical insulation materials for water heater motors, air conditioner motors, and drive motors; film capacitors; speaker diaphragms; magnetic tapes for recording; printed circuit board materials; peripheral components for printed circuit boards; seamless tapes; semiconductor packaging; semiconductor delivery reels; process / release films; protective films; film sensors for automobiles; insulating tapes for cables; insulating gaskets in lithium-ion batteries; pipes for hot water, cooling water, and chemicals; fuel lines for automobiles; hot water, cooling water, and chemicals for urban air transportation; hot water piping; pharmaceutical piping for chemical plants; piping for ultrapure water and ultra-high purity solvents; automotive piping; piping for Freon and supercritical carbon dioxide cooling media; and workpiece retaining rings for grinding equipment. Examples of other examples include wire harnesses such as those used in hybrid electric vehicles, electric vehicles and fuel cell vehicles, railways, and electric motor coils for power generation equipment; heat-resistant wires and cables for household appliances; flat cables used in automotive wiring harnesses; and wire harnesses for control lines, communication, transmission, high-frequency, audio, and measurement signal converters or vehicle-mounted converters.

[0174] Examples of applications for molded products obtained by blow molding include fuel tanks, oil tanks, resonators, intercoolers, intake manifolds, turbine pipes, intake and exhaust pipes, radiator pipes, radiator upper water tanks, expansion tanks, and oil circulation pipes for automobiles.

[0175] These various molded products can also be used for secondary processing such as hot plate welding, laser welding, induction heating welding, high frequency welding, rotary welding, vibration welding, ultrasonic welding, and injection welding.

[0176] Example

[0177] The present invention is further illustrated by the following examples, but the present invention is not limited thereto.

[0178] In the examples and comparative examples, the following substances were used as (a) polyphenylene sulfide resin, (b) organosilicon polymer, (c) olefin elastomer, and (d) other additives.

[0179] [(a) Polyphenylene sulfide resin (a-1, a-2, a-3, a-4, a-5)]

[0180] [Refer to Example 1: PPS Resin (a-1)]

[0181] In a high-pressure reactor equipped with a stirrer, 8267.37 g (70.00 mol) of 47.5% sodium hydrosulfide, 2923.88 g (70.17 mol) of 96% sodium hydroxide, 11434.50 g (115.50 mol) of N-methyl-2-pyrrolidone (NMP), 1894.20 g (23.10 mol) of sodium acetate, and 10500 g of deionized water were added. The mixture was slowly heated to 230°C for approximately 3 hours under atmospheric pressure while nitrogen was introduced. After distilling off 14780.1 g of water and 280 g of NMP, the reaction vessel was cooled to 160°C. The residual water content per 1 mole of added alkali metal sulfide, including water consumed by the hydrolysis of NMP, was 1.06 mol. Furthermore, the amount of hydrogen sulfide escaping per 1 mole of added alkali metal sulfide was 0.017 mol.

[0182] Next, 10458.90 g (71.15 mol) of p-dichlorobenzene and 9078.30 g (91.70 mol) of NMP were added. The reaction vessel was sealed under nitrogen atmosphere, and the temperature was increased to 240 °C at a rate of 0.6 °C / min while stirring at 240 rpm. After reacting at 240 °C for 40 minutes, the temperature was increased to 275 °C at a rate of 0.8 °C / min. Then, 2394 g (133 mol) of ion-exchanged water was pressurized into the autoclave while cooling at a rate of 1.3 °C / min to 250 °C. The autoclave was then cooled to 200 °C at a rate of 1.0 °C / min and then quenched to near room temperature.

[0183] The contents were removed, diluted with 26300g of NMP, and the solvent and solids were separated by filtration through an 80-mesh sieve. The resulting particles were washed with 31900g of NMP and filtered again. They were then washed several times with 56000g of deionized water and filtered again, followed by washing with 70000g of 0.05% acetic acid aqueous solution and filtering again. After washing with 70000g of deionized water and filtering again, the resulting aqueous PPS particles were hot-air dried at 80℃ and then vacuum-dried at 120℃. The obtained PPS resin (a-1) had a non-Newtonian index of 1.25, a weight-average molecular weight of 54000, a melting point of 280℃, a carboxyl content of 42μmol / g, and a melt viscosity of 170Pa·s.

[0184] [Refer to Example 2: PPS Resin (a-2)]

[0185] In a high-pressure reactor equipped with a stirrer and a bottom stopper valve, 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.91 kg (69.80 mol) of 96% sodium hydroxide, 11.45 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), and 10.5 kg of deionized water were added. The mixture was slowly heated to 245°C for approximately 3 hours while nitrogen was introduced at atmospheric pressure. After distilling off 14.78 kg of water and 0.28 kg of NMP, the reaction vessel was cooled to 200°C. The residual water content per 1 mol of added alkali metal sulfide, including water consumed by the hydrolysis of NMP, was 1.06 mol. Furthermore, the amount of hydrogen sulfide escaping per 1 mol of added alkali metal sulfide was 0.02 mol.

[0186] The mixture was then cooled to 200°C, and 10.48 kg (71.27 mol) of p-dichlorobenzene and 9.37 kg (94.50 mol) of NMP were added. The reaction vessel was sealed under nitrogen atmosphere, and the temperature was increased from 200°C to 270°C at a rate of 0.6°C / min while stirring at 240 rpm. After reacting at 270°C for 100 minutes, the bottom valve of the autoclave was opened, and the contents were flash-evaporated into a vessel equipped with a stirrer over 15 minutes while pressurizing with nitrogen atmosphere. The mixture was then stirred briefly at 250°C to remove most of the NMP.

[0187] The obtained solid material and 76 liters of ion-exchanged water were added to an autoclave equipped with a stirrer and washed at 70°C for 30 minutes, followed by filtration through a glass filter. Then, 76 liters of ion-exchanged water heated to 70°C were injected into the glass filter for further filtration to obtain a filter cake.

[0188] The resulting filter cake and 90 liters of deionized water were added to an autoclave equipped with a stirrer, and acetic acid was added to achieve a pH of 7. After purging the autoclave with nitrogen, the temperature was raised to 192°C and maintained for 30 minutes. The autoclave was then cooled, and the contents were removed.

[0189] After filtering the contents through a glass filter, 76 liters of deionized water at 70°C were injected and filtered again to obtain a filter cake. The resulting filter cake was dried at 120°C under a nitrogen stream to obtain dried PPS. Heat treatment at 200°C under an oxygen stream yielded cross-linked PPS resin (a-2). The obtained PPS resin (a-2) has the following characteristics: non-Newtonian index: 1.45; weight-average molecular weight: 56,000; melting point: 280°C; carboxyl content: 25 μmol / g; melt viscosity: 155 Pa·s.

[0190] [Refer to Example 3: PPS Resin (a-3)]

[0191] In a high-pressure reactor equipped with a stirrer, 8267.37 g (70.00 mol) of 47.5% sodium hydrosulfide, 2923.88 g (70.17 mol) of 96% sodium hydroxide, 11434.50 g (115.50 mol) of N-methyl-2-pyrrolidone (NMP), 1894.20 g (23.10 mol) of sodium acetate, and 10500 g of deionized water were added. The mixture was slowly heated to 230°C for approximately 3 hours under atmospheric pressure while nitrogen was introduced. After distilling off 14780.1 g of water and 280 g of NMP, the reaction vessel was cooled to 160°C. The residual water content in the system relative to each mole of added alkali metal sulfide, including water consumed by the hydrolysis of NMP, was 1.06 mol. Furthermore, the amount of hydrogen sulfide escaping was 0.017 mol relative to each mole of added alkali metal sulfide.

[0192] Next, 10420 g (70.89 mol) of p-dichlorobenzene and 9078.30 g (91.70 mol) of NMP were added. The reaction vessel was sealed under nitrogen atmosphere, and the temperature was increased to 240 °C at a rate of 0.6 °C / min while stirring at 240 rpm. After reacting at 240 °C for 40 minutes, the temperature was increased to 275 °C at a rate of 0.8 °C / min. Then, 2394 g (133 mol) of ion-exchanged water was pressurized into the autoclave while cooling at a rate of 1.3 °C / min to 250 °C. The autoclave was then cooled to 200 °C at a rate of 1.0 °C / min and then quenched to near room temperature.

[0193] The contents were removed, diluted with 26300g of NMP, and the solvent and solids were separated by filtration through an 80-mesh sieve. The resulting particles were washed with 31900g of NMP and filtered again. They were then washed several times with 56000g of deionized water and filtered again, followed by washing with 70000g of 0.05% acetic acid aqueous solution and filtering again. After washing with 70000g of deionized water and filtering again, the resulting aqueous PPS particles were hot-air dried at 80℃ and then vacuum-dried at 120℃. The obtained PPS resin (a-3) had a non-Newtonian index of 1.35, a weight-average molecular weight of 73000, a melting point of 280℃, a carboxyl content of 35μmol / g, and a melt viscosity of 398Pa·s.

[0194] [Refer to Example 4: PPS Resin (a-4)]

[0195] In a high-pressure reactor equipped with a stirrer, 8.26 kg (70.0 mol) of 47.5% sodium hydrosulfide, 2.94 kg (70.6 mol) of 96% sodium hydroxide, 11.45 kg (115.5 mol) of N-methyl-2-pyrrolidone (NMP), 1.61 kg (19.6 mol) of sodium acetate, and 5.50 kg of deionized water were added. The mixture was slowly heated to 240°C while purging with nitrogen at atmospheric pressure. Heating was stopped and cooling began when 9.82 kg of water and 0.28 kg of NMP were distilled off. At this point, the residual water content in the system relative to each mole of alkali metal hydrosulfide added, including the water consumed by the hydrolysis of NMP, was 1.01 mol. Furthermore, 1.4 mol of hydrogen sulfide was dispersed, resulting in a total of 68.6 mol of sulfiding agent in the system after this dehydration process. Additionally, 1.4 mol of sodium hydroxide was newly formed in the system due to the dispersion of hydrogen sulfide.

[0196] Next, after adding 10.33 kg (70.2 mol) of p-dichlorobenzene (p-DCB), 0.044 kg (0.24 mol) of 1,2,4-trichlorobenzene (TCB), and 9.37 kg (94.5 mol) of NMP, the reaction vessel was sealed under nitrogen atmosphere. The temperature was increased from 200 °C to 270 °C while stirring, and maintained at 270 °C for 180 minutes to carry out the polymerization reaction. After the reaction was completed, the temperature was cooled to 200 °C at a rate of 1.0 °C / min, and then quenched to near room temperature. A slurry was prepared by dilution with NMP, stirred at 85 °C for 30 minutes, and then filtered through an 80-mesh metal mesh to obtain the solid material. The obtained solid material was similarly washed and filtered with NMP. The obtained solid material was diluted with deionized water, stirred at 70 °C for 30 minutes, and then filtered through an 80-mesh metal mesh to recover the solid material. This operation was repeated four times. Then, the solids were recovered by washing in an aqueous solution containing 0.5% by weight of calcium acetate relative to 1 g of PPS resin and filtered through an 80-mesh metal screen. After further washing with deionized water and filtration, the resulting aqueous PPS particles were hot-air dried at 80°C and then vacuum-dried at 120°C. The resulting PPS resin (a-4) had a non-Newtonian index of 2.05, a weight-average molecular weight of 90,000, a melting point of 275°C, and a melt viscosity of 2761 Pa·s.

[0197] [Refer to Example 5: PPS Resin (a-5)]

[0198] In a high-pressure reactor equipped with a stirrer, 8267.37 g (70.00 mol) of 47.5% sodium hydrosulfide, 2962.50 g (71.10 mol) of 96% sodium hydroxide, 11434.50 g (115.50 mol) of N-methyl-2-pyrrolidone (NMP), 516.60 g (6.30 mol) of sodium acetate, and 10500 g of deionized water were added. The mixture was slowly heated to 230°C for approximately 3 hours under atmospheric pressure while nitrogen was introduced. After distilling off 14780.1 g of water and 280 g of NMP, the reaction vessel was cooled to 160°C. The residual water content in the system relative to each mole of added alkali metal sulfide, including water consumed by the hydrolysis of NMP, was 1.06 mol. Furthermore, the amount of hydrogen sulfide escaping relative to each mole of added alkali metal sulfide was 0.017 mol. Next, 10363.50 g (70.50 mol) of p-dichlorobenzene and 9078.30 g (91.70 mol) of NMP were added. The reaction vessel was sealed under nitrogen atmosphere, and the temperature was increased to 270 °C at a rate of 0.6 °C / min while stirring at 240 rpm. This temperature was maintained at 270 °C for 140 min. Then, while cooling to 250 °C at a rate of 1.3 °C / min, 2520 g (140 mol) of ion-exchanged water was pressurized into the autoclave. The autoclave was then cooled to 200 °C at a rate of 1.0 °C / min, followed by quenching to near room temperature. The contents were removed, diluted with 26300 g of NMP, and the solvent and solids were separated by filtration through an 80-mesh sieve. The resulting particles were washed with 31900 g of NMP and then filtered. The PPS particles were washed several times with 56,000 g of deionized water, filtered, and then washed again with 70,000 g of 0.05% acetic acid aqueous solution, followed by filtration. After washing with 70,000 g of deionized water and filtration, the resulting aqueous PPS particles were hot-air dried at 80°C and then vacuum-dried at 120°C. The obtained PPS resin (a-5) had a non-Newtonian index of 1.10, a weight-average molecular weight of 42,000, a melting point of 280°C, a carboxyl content of 45 μmol / g, and a melt viscosity of 74 Pa·s.

[0199] [Reference Example 6: A mixture of PPS resin (a-3) (83 wt%) and PPS resin (a-4) (17 wt%)]

[0200] Non-Newtonian index: 1.50, melting point: 280℃, melt viscosity: 560Pa·s.

[0201] [Reference Example 7: A mixture of PPS resin (a-3) (50 wt%) and PPS resin (a-4) (50 wt%)]

[0202] Non-Newtonian index: 1.75, melting point: 280℃, melt viscosity: 890 Pa·s.

[0203] [(b) Organosilicon-based polymers (b-1, b-2, b-3)]

[0204] b-1: Organosilicon-acrylic core-shell rubber (Kaneka Corporation, Kaneace MR-01), average primary particle size: 0.13μm

[0205] b-2: Methacrylamide-modified silicone elastomer powder (Dau Corporation EP-2720), average primary particle size: 1.8 μm

[0206] b-3: Epoxy-terminated polydimethylsiloxane.

[0207] [(c) Olefin-based elastomers (c-1)]

[0208] c-1: Ethylene-glycidyl methacrylate copolymer (olefin resin manufactured by Sumitomo Chemical Co., Ltd., Bond First E, melting point 103°C, MFR: 3g / 10min (190°C, 21.2N load)), reactive functional group content: 12% by weight.

[0209] [(d) Other additives (d-1, d-2)]

[0210] d-1: 3-Isocyanate-propyltriethoxysilane (Shin-Etsu Silicon Co., Ltd., KBE-9007N)

[0211] d-2: Glass fiber (manufactured by Nippon Electric Glass Co., Ltd., T760H).

[0212] In the following embodiments, the material properties were evaluated using the following methods.

[0213] [Bending Test]

[0214] PPS resin composition granules were dried in a hot air dryer at 130°C for 3 hours, then fed into a Sumitomo Heavy Industries injection molding machine (SE-75DUZ) set to a barrel temperature of 310°C and a mold temperature of 145°C. Using a mold of type A1 test piece shape as specified in ISO 20753 (2008), injection molding was performed at an average velocity of 400 ± 50 mm / s through the cross-sectional area of ​​the central parallel section to obtain a test piece. The central parallel section of this test piece was cut out to obtain a type B2 test piece. After conditioning the test piece at 23°C and 50% relative humidity for 16 hours, the flexural modulus was determined according to ISO 178 (2010) at a span of 64 mm and a test speed of 2 mm / min.

[0215] [Flame retardant test]

[0216] PPS resin composition granules were dried in a hot air dryer at 130°C for 3 hours, and then fed into a Sumitomo Heavy Industries injection molding machine (SE-75DUZ) set to a barrel temperature of 320°C and a mold temperature of 150°C to obtain test pieces for flame retardancy evaluation. The flame retardancy of the test pieces was evaluated according to the evaluation criteria specified in the UL94 vertical test. Flame retardancy was graded in the order of decreasing V-0 > V-1 > V-2. Failure to meet the V-2 criterion was marked as "out". Test piece thicknesses of 1.6 mm, 1.0 mm, and 0.5 mm were used.

[0217] [Tension Test]

[0218] The A1 type test piece, obtained in the same manner as the bending test, was conditioned for 16 hours at 23°C and 50% relative humidity. Then, the tensile elongation at break (nominal strain) was determined according to ISO 527-1,2 (2012) at a clamping distance of 114 mm and a test speed of 50 mm / min.

[0219] [(b) Number-average particle size of the component]

[0220] The A1 type test piece, obtained in the same manner as the bending test, was cut at room temperature. A thin sheet less than 0.1 μm from the center of its central parallel portion was cut along a cross-sectional direction perpendicular to the resin flow direction during dumbbell sheet molding. The sheet was observed using a Hitachi High-Tech Noroge SU8220 field emission scanning electron microscope at magnifications of 1000–5000x. For any 100 components (b), the maximum and minimum diameters of each component were first measured, and the average value was set as the dispersed particle size. Then, the average dispersed particle size of each particle was calculated and set as the number-average dispersed particle size. In the case where the organosilicon polymer of component (b) was agglomerated, the agglomerated substance was measured as one dispersed phase, and the number-average dispersed particle size was determined.

[0221] [(c) Number-average particle size of olefin-based elastomers]

[0222] The A1 type test piece, obtained in the same manner as the bending test, was cut at room temperature. A thin sheet less than 0.1 μm from the center of its central parallel portion was cut along a cross-sectional direction perpendicular to the resin flow direction during dumbbell sheet molding. The sheet was then observed using a Hitachi High-Tech Noroges field emission scanning electron microscope SU8220, magnified to 1000–5000 times. For any 100 (c) olefin elastomers, their maximum and minimum diameters were first measured, and the average value was set as the dispersed particle size of that (c) olefin elastomer. Then, the average dispersed particle size of each (c) olefin elastomer was calculated and set as the number-average dispersed particle size.

[0223] [Non-Newtonian exponents]

[0224] The non-Newtonian index of PPS resin was determined using the following method. Using a capillary tube (10 mm in length and 1 mm in diameter) manufactured by Toyo Seiki Co., Ltd., the shear rate was measured at 300°C, ranging from 60 to 6080 s. -1 The non-Newtonian index was calculated by substituting the shear rate-shear stress relationship into the following equation (1).

[0225] SR = K·SS N ...(1)

[0226] (Here, N represents the non-Newtonian exponent, SR represents the shear rate (1 / second), and SS represents the shear stress (dynes / cm). 2 (where K represents a constant.)

[0227] [Melt viscosity]

[0228] The melt viscosity of the PPS resin composition was determined by the following method. A capillary tube (10 mm in length and 1 mm in diameter) manufactured by Toyo Seiki Co., Ltd. was used, and the viscosity was measured at 300°C with a shear rate of 122 s under the condition that the orifice length L (mm) / orifice diameter D (mm) = 10. -1 The value below.

[0229] [GPC Measurement]

[0230] The number-average molecular weight (Mn) and weight-average molecular weight (Mw) of PPS resin were determined using gel permeation chromatography (GPC) manufactured by Senshur Scientific Co., Ltd., under the conditions shown below, and calculated in polystyrene form.

[0231] Device: Seton Science SSC-7110

[0232] Column name: Shodex UT806M×2

[0233] Eluent: 1-Chloronaphthalene

[0234] Detector: Differential refractive index detector

[0235] Column temperature: 210℃

[0236] Preheating bath temperature: 250℃

[0237] Pump thermostatic bath temperature: 50℃

[0238] Detector temperature: 210℃

[0239] Flow rate: 1.0 mL / min

[0240] Sample injection volume: 300 μL.

[0241] [Examples 1-6, 8-10, 12-21, Comparative Examples 1-13]

[0242] PPS resin, olefin elastomers, silicone polymers, and other additives were dry-blended according to the formulations shown in Tables 1-3, and then fed into a TEX30α twin-screw extruder (L / D = 30, 3 kneading sections) manufactured by Nippon Steel Co., Ltd. for melt mixing. The mixing conditions were conducted at a temperature of 300°C and a rotation speed of 300 rpm. This mixing method is designated as Method A (Tables 1-3). Particles granulated by a wire pelletizer and dried at 130°C for 3 hours were then used for injection molding. The number-average particle size distribution, flexural modulus, flame retardancy, elongation at break, and melt viscosity of the silicone polymers and olefin elastomers are shown in Tables 1-3.

[0243] [Examples 7, 11]

[0244] The kneading section was set to 1 point for melt mixing. Otherwise, melt mixing was performed under the same conditions as in Example 1 to obtain resin composition particles, and various properties were evaluated. The melt mixing method using these conditions is designated as Method B. The results are shown in Tables 1 and 2.

[0245]

[0246] Table 2

[0247]

[0248] Table 3

[0249]

[0250] The results of the above embodiments are compared with those of the comparative examples for illustration.

[0251] In Examples 1-7, PPS resin compositions containing (a) polyphenylene sulfide resin and (b) organosilicon polymers with a specific composition, and where the number-average particle size of component (b) is less than 3.0 μm, exhibit both excellent softness and flame retardancy, as well as excellent toughness, represented by tensile elongation at break. In Examples 1-3, the smaller the number-average particle size of component (b), the better the toughness. Furthermore, comparing Examples 3 and 4 with Examples 5 and 6 shows that by using organosilicon polymers with a small average primary particle size (b), the number-average particle size of component (b) is reduced, resulting in even better toughness and flame retardancy. Compared to Example 1, Example 7, with its different mixing method, exhibits poor dispersibility of the organosilicon polymer, resulting in poorer flame retardancy and tensile elongation at break.

[0252] Comparative Examples 1 and 2, which are PPS resins alone, and Comparative Example 3, which has a low content of organosilicon polymers, have excellent flame retardancy, but they are also highly rigid and have low elongation at break, making them difficult to use in components requiring toughness.

[0253] Comparative Examples 4-6 and 11, although containing silicone-based polymers, achieved excellent flexibility and flame retardancy, but exhibited low elongation at break. This is presumably due to insufficient melt viscosity of the PPS resin composition, resulting in coarse number-average particle size of the silicone-based polymers. Comparative Example 7, which incorporated glass fibers, showed a tendency towards smaller number-average particle size compared to Comparative Example 5; however, in addition to a significant increase in flexural modulus, a decrease in flame retardancy was observed through the incorporation of glass fibers.

[0254] Examples 1 and 18 show that further blending with olefin-based elastomers can result in excellent toughness and flexibility. Examples 8-10, 15, and 16 show that the larger the non-Newtonian index of the PPS resin and the smaller the number-average particle size of the organosilicon polymer, the greater the improvement in toughness and flame retardancy. Comparing Examples 12 and 13, it is evident that by using organosilicon polymers with smaller average primary particle size (b), the number-average particle size of component (b) is reduced, resulting in superior toughness and flame retardancy. Compared to Example 9, Example 11, with its different blending methods, exhibits poor dispersibility of the organosilicon polymer, resulting in poorer flame retardancy and tensile elongation at break.

[0255] Comparative Examples 9 and 10, due to the addition of olefin-based elastomers, exhibit excellent softness and elongation at break, but tend to have reduced flame retardancy due to the presence of olefin-based elastomers.

[0256] Comparative Example 13, which has the same composition as Example 1 (sample No. 4) described in prior art document 4, shows softness and high tensile elongation at break, but low flame retardancy, and does not achieve the PPS resin composition with softness, flame retardancy and toughness that is the target of this application.

[0257] As can be seen from the above, only by possessing the constituent elements of the present invention can a PPS resin composition that combines softness, flame retardancy, and toughness be obtained.

Claims

1. A polyphenylene sulfide resin composition comprising (a) a polyphenylene sulfide resin and (b) an organosilicon polymer, hereinafter referred to as "(a) component" and "(b) component", wherein component (b) is selected from at least one of organosilicon rubber, organosilicon elastomer, organosilicon resin, and a composite comprising organopolysiloxane, and the content of component (b) is 3 parts by weight or more and 40 parts by weight or less relative to 100 parts by weight of component (a), and the polyphenylene sulfide resin composition has a phase separation structure in which component (a) forms a continuous phase and component (b) forms a dispersed phase with a number-average particle size of 3.0 μm or less, and the test piece obtained by injection molding the polyphenylene sulfide resin composition at a barrel temperature of 310°C and a mold temperature of 145°C is conformed to ISO 2010. In the flexural test of 178, it has a flexural modulus of elasticity below 3.0 GPa. In the UL94 standard test, the flame retardancy measured in test pieces with a thickness of less than 1.6 mm is V-0. The aforementioned silicone rubber, silicone elastomers, and silicone resins are all high-molecular-weight silicones with organopolysiloxanes as their basic framework. Based on the degree of their 3D network structure, substances lacking a 3D network structure are called silicone rubbers, substances with a slight 3D network structure are called silicone elastomers, and substances with a high degree of 3D network structure are called silicone resins. The composite containing organopolysiloxane is a core-shell rubber in which organosilicone elastomer particles are coated with an acrylic component, or a composite powder in which organosilicone elastomers are coated with organosilicone resin.

2. The polyphenylene sulfide resin composition according to claim 1, wherein, relative to 100 parts by weight of component (a), there is a mixture of at least 1 part by weight and less than 40 parts by weight of olefin elastomer (c).

3. The polyphenylene sulfide resin composition according to claim 1 or 2, wherein the flame retardancy of the polyphenylene sulfide resin composition measured in a test piece with a thickness of less than 1.0 mmt according to UL94 standard is V-0.

4. The polyphenylene sulfide resin composition according to claim 1 or 2, wherein the elongation at break is 10% or more in a tensile test according to ISO 527-1,2 (2012).

5. The polyphenylene sulfide resin composition according to claim 1 or 2, wherein the morphology, i.e., phase structure of the polyphenylene sulfide resin composition, has a phase separation structure in which component (a) forms a continuous phase and component (b) forms a dispersed phase dispersed with a number-average particle size of 1.0 μm or less.

6. The polyphenylene sulfide resin composition according to claim 1 or 2, wherein component (a) was measured at a shear rate of 60–6080 s using a capillary rheometer (trade name: Capilograf) at 300°C and a pore length L / pore diameter D = 10. -1 The non-Newtonian index N, calculated by the following equation (1), is 1.30 or higher under shear stress, where L and D are in mm. SR=K·SS N ···(1) in, N represents the non-Newtonian index, SR represents the shear rate (in 1 / second), and SS represents the shear stress (in dynes / cm). 2 K represents a constant.

7. The polyphenylene sulfide resin composition according to claim 1 or 2, wherein the shear rate of the polyphenylene sulfide resin composition is measured using a capillary rheometer with the trade name Capilograf at 300°C and a pore length L / pore diameter D = 10, is 122 s. -1 The melt viscosity below is above 400 Pa·s, of which, The units for L and D are mm.

8. The polyphenylene sulfide resin composition according to claim 1 or 2, wherein component (b) is an organosilicon core-shell rubber.

9. A molded article formed from the polyphenylene sulfide resin composition according to any one of claims 1 to 8.

10. The molded article formed from the polyphenylene sulfide resin composition according to claim 9, which is a molded article for piping with a hollow shape.

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