Polyphenylene sulfide resin composition for battery insulating member, and battery insulating member

Abstract

A polyphenylene sulfide resin composition for a battery insulating member, which is obtained by blending (a) a polyphenylene sulfide resin and (b) a silicone elastomer having a cross-linked structure, and wherein 0.1-15.0 parts by weight of the (b) silicone elastomer having a cross-linked structure is blended per 100 parts by weight of the (a) polyphenylene sulfide resin, and 0.1-15.0 parts by weight of the (b) silicone elastomer having a cross-linked structure is blended per 100 parts by weight of the (a) polyphenylene sulfide resin. A sample obtained by injection molding the resin composition has a bending elastic modulus of 3.1 GPa or more and 3.6 GPa or less in a bending test according to ISO 178 (2010). The polyphenylene sulfide resin composition for a battery insulating member, which has excellent productivity, safety and long-term reliability, and the battery insulating member can be obtained.

Description

Technical Field

[0001] The present invention relates to a polyphenylene sulfide resin composition for a battery insulating member and a battery insulating member having excellent productivity, safety and long-term reliability. Background Art

[0002] With the awareness of global environmental protection increasing, CO2 emissions can be reduced during driving. 2 Electric vehicles that reduce emissions and secondary batteries for home use that are intended to effectively utilize surplus power at night are becoming more widespread, and there is a demand for further efficiency improvements in batteries used for vehicle and residential use.

[0003] Polyphenylene sulfide (hereinafter sometimes abbreviated as PPS) resin is a super engineering plastic with well-balanced properties such as heat resistance, chemical resistance, and flame retardancy. PPS resin has a cost advantage over other super engineering plastics, so it is a highly versatile resin material second only to the five major engineering plastics, and is used in a wide range of applications such as automobiles, housing equipment, and electrical / electronic applications, and research on its application to various battery components is being conducted.

[0004] Patent Document 1 discloses a PPS resin composition mixed with an olefin-based elastomer as a type of thermoplastic elastomer and a gasket for a secondary battery formed therefrom. The PPS resin composition can achieve improvements in moisture and heat resistance, electrolyte resistance, and compressive stress relaxation under a certain strain by mixing an olefin-based elastomer as a material that is softer than the PPS resin, and the PPS resin composition is applied to a gasket for a secondary battery.

[0005] Patent Document 2 discloses a PPS resin composition having excellent high-temperature compression creep properties and high weld strength by adding silicone oil as a silane compound to a PPS resin, assuming application to electrode insulating sealing materials for lithium batteries and the like.

[0006] Patent Document 3 discloses that inorganic powder supporting silicone oil as an organic silicon compound is added to PPS resin to improve moisture and heat resistance, electrolyte resistance, and compressive stress relaxation under a certain strain, and the PPS resin composition is applied to a gasket for a secondary battery.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2011-29167

[0010] Patent Document 2: Japanese Patent Application Publication No. 2001-2920

[0011] Patent Document 3: Japanese Patent Application Publication No. 2011-29166 Summary of the invention

[0012] Problems to be solved by the invention

[0013] Storage batteries such as lithium-ion batteries used for vehicle-mounted and residential fixed use have the problem of reduced battery performance due to the influence of heat in the use environment. Therefore, in battery development, from the perspective of life cycle management during long-term use of the battery, the long-term reliability and degradation suppression of the materials used in the battery components are being paid attention to. Specifically, by improving the resistance to seepage, physical property retention, and creep resistance during long-term high-temperature use, it is expected to improve the long-term reliability of the battery. In addition, from the perspective of the productivity of the battery components, in order to suppress the breakage of the insulating components during caulking in the battery manufacturing process, the toughness of the material becomes important. In addition, from the perspective of battery safety, it is expected to improve the flame retardancy of the battery components.

[0014] However, the inventors of the present invention have evaluated the flame retardancy of the resin composition composed of PPS resin and olefin elastomer described in patent document 1, and found that the flame retardancy of the resin composition is greatly reduced compared with the single PPS resin. It can be considered that the reason is that the single PPS resin has high flame retardancy, while the flame retardancy of the composition is reduced due to the mixing of olefin elastomers with significantly poor flame retardancy. In addition, the retention rate of toughness before and after long-term high temperature treatment was evaluated, and it was found that the retention rate is greatly reduced. This composition has the advantages of flexibility and toughness, and on the other hand, it does not show the excellent flame retardancy and long-term high temperature durability inherent to PPS resin, so for the use of battery applications, there is a problem of reduced safety and long-term reliability.

[0015] The inventors of the present invention evaluated the long-term high-temperature durability of the PPS resin composition in which silicone oil is added to the PPS resin described in Patent Document 2, and found that, compared with the PPS resin alone, a bleed component considered to be the source of the silicone oil component is generated on the surface of the molded product after treatment. When the present resin composition is applied to a battery component, there is a concern that the bleed component generated from the surface of the molded product will not only reduce the insulation but also reduce the power generation efficiency of the battery, which is not preferred.

[0016] In addition, the PPS resin composition described in Patent Document 3, in which a component for carrying silicone oil on an inorganic powder is added to a PPS resin, cannot achieve the toughness required as a battery insulating component due to the addition of the inorganic powder, resulting in a decrease in the productivity and long-term reliability of the battery component, which is not preferred.

[0017] Therefore, an object of the present invention is to obtain a polyphenylene sulfide resin composition for a battery insulating member having excellent productivity, safety, and long-term reliability.

[0018] Means for solving problems

[0019] The present inventors have conducted research to solve such problems, and as a result, have found that a polyphenylene sulfide resin composition having a flexural modulus of 3.1 GPa or more and 3.6 GPa or less is prepared by mixing (a) a polyphenylene sulfide resin and (b) a cross-linked silicone elastomer in a specific composition, and the resin composition is used for an insulating member of a battery, thereby having excellent productivity and having characteristics of safety and long-term reliability. That is, the present invention is made to solve at least part of the above problems, and can be implemented in the following forms.

[0020] (1) A polyphenylene sulfide resin composition for a battery insulating member, comprising: (a) a polyphenylene sulfide resin and (b) a cross-linked silicone elastomer, wherein 0.1 to 15.0 parts by weight of the (b) cross-linked silicone elastomer is mixed with respect to 100 parts by weight of the (a) polyphenylene sulfide resin, and the resin composition has a flexural modulus of 3.1 GPa or more and 3.6 GPa or less in a flexural test in accordance with ISO 178 (2010) of a specimen obtained by injection molding the resin composition.

[0021] (2) The polyphenylene sulfide resin composition for a battery insulating member according to (1), wherein the resin composition does not substantially contain (c) a thermoplastic elastomer.

[0022] (3) The polyphenylene sulfide resin composition for a battery insulating member according to (1) or (2), wherein the flame retardancy of a sample obtained by injection molding the resin composition is V-0 in a measurement in accordance with UL94 standard for a sample having a thickness of 1.0 mmt or less.

[0023] (4) The polyphenylene sulfide resin composition for a battery insulating member according to any one of (1) to (3), wherein a specimen obtained by injection molding the resin composition has a tensile elongation at break of 8% or more in a tensile test in accordance with ISO 527-1, 2 (2012).

[0024] (5) The polyphenylene sulfide resin composition for a battery insulating member according to any one of (1) to (4), wherein the (b) silicone elastomer having a crosslinked structure is fine particles having an average primary particle diameter of 100 nm to 10 μm.

[0025] (6) The polyphenylene sulfide resin composition for a battery insulating member according to any one of (1) to (5), wherein the (b) silicone elastomer having a cross-linked structure has a Shore A hardness of 60 HS or less.

[0026] (7) The polyphenylene sulfide resin composition for a battery insulating member according to any one of (1) to (6), wherein the structural unit derived from organopolysiloxane in the (b) crosslinked silicone elastomer accounts for 90% by weight or more.

[0027] (8) A battery insulating member made of the polyphenylene sulfide resin composition for a battery insulating member according to any one of (1) to (7).

[0028] Effects of the Invention

[0029] According to the present invention, a polyphenylene sulfide resin composition for a battery insulating member and a battery insulating member having excellent productivity, safety and long-term reliability can be obtained. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present invention will be described in detail.

[0031] (1) (a) Polyphenylene sulfide resin

[0032] The (a) polyphenylene sulfide resin used in the present invention is a polymer having a repeating unit represented by the following structural formula:

[0033]

[0034] From the viewpoint of heat resistance, the polymer preferably contains 70 mol% or more, and further 90 mol% or more of the repeating unit represented by the above structural formula. In addition, less than about 30 mol% of the repeating units of the (a) PPS resin may be composed of repeating units having the following structure.

[0035]

[0036] Since the PPS copolymer partially having such a structure has a lower melting point than 280° C. which is the general melting point of PPS, such a resin composition is advantageous in terms of molding processability.

[0037] The weight average molecular weight of the (a) PPS resin used in the present invention is not particularly limited, but from the perspective of obtaining more excellent mechanical properties, the weight average molecular weight is preferably 30,000 to 150,000, more preferably 40,000 to 130,000, more preferably 45,000 to 110,000, and more preferably 50,000 to 90,000. When the weight average molecular weight is small, the mechanical properties of the PPS resin itself are reduced, and component damage occurs during the caulking and fitting processes during the manufacture of battery components, so it is preferably 30,000 or more. In addition, from the perspective of flame retardancy, when the weight average molecular weight is small, the flame retardancy is reduced due to dripping and surface renewal (reappearance of the combustible component caused by dripping on the surface) during the flame retardancy test, so it is also preferably 30,000 or more. On the other hand, when the weight average molecular weight exceeds 150,000, the melt viscosity becomes significantly large, so it is not preferred in the molding process. In the present invention, a plurality of (a) PPS resins having different weight average molecular weights may be mixed and used.

[0038] In addition, the weight average molecular weight in the present invention is a value calculated in terms of polystyrene using a gel permeation chromatograph (GPC) manufactured by Senshou Scientific Co., Ltd.

[0039] Hereinafter, a method for producing the (a) PPS resin used in the present invention will be described. However, the method is not limited to the following method as long as the (a) PPS resin having the above-mentioned properties can be obtained.

[0040] First, the contents of the polyhalogenated aromatic compound, the sulfidizing agent, the polymerization solvent, the molecular weight modifier, the polymerization aid, and the polymerization stabilizer used in the production method are described.

[0041] [Polyhalogenated aromatic compounds]

[0042] The so-called polyhalogenated aromatic compound refers to a compound having two or more halogen atoms in one molecule. As a specific example, polyhalogenated aromatic compounds such as p-dichlorobenzene, m-dichlorobenzene, o-dichlorobenzene, 1,3,5-trichlorobenzene, 1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene, hexachlorobenzene, 2,5-dichlorotoluene, 2,5-dichloro-p-xylene, 1,4-dibromobenzene, 1,4-diiodobenzene, 1-methoxy-2,5-dichlorobenzene can be cited, and p-dichlorobenzene is preferably used. In addition, for the purpose of introducing a carboxyl group, using a dihalogenated aromatic compound containing a carboxyl group such as 2,4-dichlorobenzoic acid, 2,5-dichlorobenzoic acid, 2,6-dichlorobenzoic acid, 3,5-dichlorobenzoic acid, and a mixture thereof as a comonomer is also one of the preferred schemes. Furthermore, two or more different polyhalogenated aromatic compounds can be combined to form a copolymer, but it is preferred that a para-dihalogenated aromatic compound be used as the main component.

[0043] From the viewpoint of obtaining a (a) PPS resin having a viscosity suitable for processing, the amount of the polyhalogenated aromatic compound used is, for example, in the range of 0.9 to 2.0 mol, preferably 0.95 to 1.5 mol, and more preferably 1.005 to 1.2 mol per 1 mol of the vulcanizing agent.

[0044] [Vulcanizing agent]

[0045] Examples of the sulfiding agent include alkali metal sulfides, alkali metal hydrosulfides and hydrogen sulfide.

[0046] Specific examples of alkali metal sulfides include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and mixtures of two or more thereof, among which sodium sulfide is preferably used. These alkali metal sulfides can be used in the form of hydrates or aqueous mixtures, or in the form of anhydrous substances.

[0047] Specific examples of alkali metal hydrosulfides include sodium hydrosulfide, potassium hydrosulfide, lithium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide, and mixtures of two or more thereof, among which sodium hydrosulfide is preferably used. These alkali metal hydrosulfides may be used in the form of hydrates or aqueous mixtures, or in the form of anhydrous substances.

[0048] Alternatively, an alkali metal sulfide prepared in situ in the reaction system from an alkali metal hydrosulfide and an alkali metal hydroxide may be used. Alternatively, an alkali metal sulfide prepared from an alkali metal hydrosulfide and an alkali metal hydroxide may be used after transferring the prepared alkali metal sulfide to a polymerization tank.

[0049] Alternatively, an alkali metal sulfide prepared in situ in a reaction system from an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide and hydrogen sulfide may be used. Alternatively, an alkali metal sulfide may be prepared from an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide and hydrogen sulfide and then transferred to a polymerization tank for use.

[0050] When a part of the sulfiding agent is lost before the start of the polymerization reaction due to a dehydration operation or the like, the amount of the sulfiding agent added means the remaining amount obtained by subtracting the lost part from the actual amount added.

[0051] It should be noted that an alkali metal hydroxide and / or an alkaline earth metal hydroxide can also be used together with the sulfiding agent. As a specific example of the alkali metal hydroxide, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide and a mixture of two or more thereof can be cited as a preferred example, and as a specific example of the alkaline earth metal hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, etc. can be cited, among which sodium hydroxide is preferably used.

[0052] When an alkali metal hydrosulfide is used as the sulfidizing agent, it is particularly preferred to use an alkali metal hydroxide simultaneously. The amount used is, for example, in the range of 0.95 mol to 1.20 mol, preferably 1.00 mol to 1.15 mol, and more preferably 1.005 mol to 1.100 mol per 1 mol of the alkali metal hydrosulfide.

[0053] [Polymerization solvent]

[0054] As a polymerization solvent, an organic polar solvent is preferably used. As a specific example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone and other N-alkylpyrrolidones, N-methyl-ε-caprolactam and other caprolactams, 1,3-dimethyl-2-imidazolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric triamide, dimethyl sulfone, tetramethylene sulfoxide and the like are represented by aprotic organic solvents and mixtures thereof, and they are all preferably used because of their high stability of the reaction. Among them, N-methyl-2-pyrrolidone (hereinafter, sometimes abbreviated as NMP) is particularly preferably used.

[0055] The amount of the organic polar solvent used is selected to be in the range of 2.0 mol to 10 mol, preferably 2.25 mol to 6.0 mol, and more preferably 2.5 mol to 5.5 mol per 1 mol of the sulfiding agent.

[0056] [Molecular weight regulator]

[0057] In order to form the terminals of the produced (a) PPS resin or to adjust the polymerization reaction, molecular weight, etc., a monohalogen compound (which may not necessarily be an aromatic compound) may be used together with the above-mentioned polyhalogenated aromatic compound.

[0058] [Polymerization aid]

[0059] The use of a polymerization aid in order to obtain a (a) PPS resin with a higher degree of polymerization in a shorter time is also one of the preferred solutions. The so-called polymerization aid here refers to a substance that has the effect of increasing the viscosity of the obtained (a) PPS resin. As specific examples of such polymerization aids, organic carboxylates, water, alkali metal chlorides, organic sulfonates, alkali metal sulfates, alkaline earth metal oxides, alkali metal phosphates and alkaline earth metal phosphates can be cited. They can be single, and more than two kinds can also be used at the same time. Among them, organic carboxylates, water and alkali metal chlorides are preferred, and as organic carboxylates, alkali metal carboxylates are preferred, and as alkali metal chlorides, lithium chloride is preferred.

[0060] The alkali metal carboxylates are of the general formula R(COOM): nA compound represented by the formula (wherein R is an alkyl group, cycloalkyl group, aryl group, alkylaryl group or arylalkyl group having 1 to 20 carbon atoms; M is an alkali metal selected from lithium, sodium, potassium, rubidium and cesium; and n is an integer of 1 to 3). The alkali metal carboxylate can also be used as a hydrate, anhydride or aqueous solution. Specific examples of the alkali metal carboxylate include, for example, lithium acetate, sodium acetate, potassium acetate, sodium propionate, lithium valerate, sodium benzoate, sodium phenylacetate, potassium p-methylbenzoate and mixtures thereof.

[0061] The alkali metal carboxylate can be formed by adding an organic acid and one or more compounds selected from alkali metal hydroxides, alkali metal carbonates and alkali metal hydrogencarbonates in almost equimolar amounts and reacting them. Among the above alkali metal carboxylates, the lithium salt has high solubility in the reaction system and a large auxilliary effect but is expensive. Potassium, rubidium and cesium salts are considered to have insufficient solubility in the reaction system, so sodium acetate which is cheap and has moderate solubility in the polymerization system is most preferably used.

[0062] When using these alkali metal carboxylates as polymerization auxiliaries, the amount used is usually in the range of 0.01 mol to 2 mol, preferably in the range of 0.1 mol to 0.6 mol, and more preferably in the range of 0.2 mol to 0.5 mol, relative to 1 mol of the alkali metal sulfide added.

[0063] In addition, when using water as a polymerization auxiliary, the amount added is usually in the range of 0.3 mol to 15 mol, preferably in the range of 0.6 mol to 10 mol, and more preferably in the range of 1 mol to 5 mol, relative to 1 mol of the alkali metal sulfide added.

[0064] Of course, two or more of these polymerization auxiliaries can also be used in combination. For example, if an alkali metal carboxylate and water are used in combination, higher molecular weight can be achieved with smaller amounts of each.

[0065] The addition time of these polymerization auxiliaries is not particularly specified and can be added at any time during the aforementioned pre-process, at the start of polymerization, or during the polymerization process. In addition, it can be added in multiple portions. However, when using an alkali metal carboxylate as a polymerization auxiliary, it is more preferably added simultaneously at the start of the pre-process or at the start of polymerization from the aspect of easy addition. In addition, when using water as a polymerization auxiliary, it is effective to add it during the polymerization reaction after adding the polyhaloaromatic compound.

[0066] [Polymerization stabilizer]

[0067] In order to stabilize the polymerization reaction system and prevent side reactions, a polymerization stabilizer can also be used. The polymerization stabilizer helps to stabilize the polymerization reaction system and inhibits undesirable side reactions. As a criterion for side reactions, the generation of thiophenol can be cited, and the generation of thiophenol can be inhibited by the addition of a polymerization stabilizer. As specific examples of polymerization stabilizers, compounds such as alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides and alkaline earth metal carbonates can be cited. Among them, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide are preferred. The above-mentioned alkali metal carboxylates also act as polymerization stabilizers. In addition, in the case of using alkali metal hydrosulfide as a sulfiding agent as mentioned above, it is particularly preferred to use alkali metal hydroxides at the same time, and the alkali metal hydroxides in excess relative to the sulfiding agent can also become polymerization stabilizers.

[0068] These polymerization stabilizers can be used alone or in combination of two or more. The polymerization stabilizer is preferably used in a ratio of 0.02 to 0.2 moles, preferably 0.03 to 0.1 moles, and more preferably 0.04 to 0.09 moles relative to 1 mole of the added alkali metal sulfide. If the ratio is small, the stabilization effect is insufficient, and on the contrary, even if it is too much, it becomes economically disadvantageous or the polymer yield tends to decrease.

[0069] The polymerization stabilizer is not particularly specified when it is added. It can be added at any time during the pre-process described below, at the start of polymerization, or during polymerization. It can also be added in multiple times. However, it is more preferable to add it at the start of the pre-process or at the start of polymerization from the perspective of convenience.

[0070] Next, a preferred method for producing the (a) PPS resin used in the present invention will be specifically described in order of the pre-process, polymerization reaction process, recovery process, and post-processing process, but the present invention is not limited to this method.

[0071] [Pre-process]

[0072] In the method for producing (a) a PPS resin, the vulcanizing agent is usually used in the form of a hydrate, and it is preferred that the mixture containing the organic polar solvent and the vulcanizing agent be heated to remove excess water to the outside of the system before adding the polyhalogenated aromatic compound.

[0073] In addition, as described above, as a sulfiding agent, a sulfiding agent prepared from alkali metal hydrosulfide and alkali metal hydroxide in situ in the reaction system or in a tank different from the polymerization tank can also be used. There is no particular limitation on the method, and examples include a method in which alkali metal hydrosulfide and alkali metal hydroxide are added to an organic polar solvent at room temperature to 150°C, preferably at room temperature to 100°C, under an inert gas atmosphere, and the temperature is raised to at least 150°C, preferably 180 to 260°C, under normal pressure or reduced pressure to distill off water. A polymerization aid can be added at this stage. In addition, toluene or the like can be added to promote the distillation of water and to carry out the reaction.

[0074] The amount of water in the polymerization system during the polymerization reaction is preferably 0.3 mol to 10.0 mol per 1 mol of the added sulfidizing agent. The amount of water in the polymerization system here refers to the amount of water added to the polymerization system minus the amount of water removed from the polymerization system. In addition, the added water may be in any form of water, aqueous solution, crystal water, etc.

[0075] [Polymerization reaction step]

[0076] The (a) PPS resin is produced by reacting a vulcanizing agent with a polyhalogenated aromatic compound in an organic polar solvent at a temperature ranging from 200° C. to less than 290° C.

[0077] When starting the polymerization reaction step, it is desirable to mix the organic polar solvent, the sulfiding agent and the polyhalogenated aromatic compound in an inert gas atmosphere at room temperature to 240° C., preferably in a temperature range of 100° C. to 230° C. A polymerization aid may also be added at this stage. The order of adding these raw materials may be different or may be simultaneous.

[0078] Such a mixture is usually heated to a temperature in the range of 200° C. to less than 290° C. The heating rate is not particularly limited, but is usually selected from 0.01 to 5° C. / min, more preferably 0.1 to 3° C. / min.

[0079] Generally, the temperature is finally 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.

[0080] In the stage before reaching the final temperature, for example, after reacting at 200° C. to 260° C. for a certain period of time, a method of raising the temperature to 270° C. to less than 290° C. is effective in obtaining a higher degree of polymerization. In this case, 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.

[0081] It should be noted that in order to obtain a polymer with a higher degree 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 the polyhalogenated aromatic compound in the system at 245° C. reaches 40 mol % or more, preferably 60 mol %.

[0082] The conversion rate of the polyhalogenated aromatic compound (abbreviated as PHA herein) is a value calculated by the following formula: The amount of PHA remaining can usually be determined by gas chromatography.

[0083] (A) When the polyhalogenated aromatic compound is added in excess of the alkali metal sulfide in terms of molar ratio

[0084] Conversion rate = [PHA added amount (mol) - PHA residual amount (mol)] / [PHA added amount (mol) - PHA excess amount (mol)].

[0085] (B) Other than the above (A)

[0086] Conversion rate = [PHA added amount (mol) - PHA residual amount (mol)] / [PHA added amount (mol)].

[0087] [Recycling process]

[0088] In the method for producing (a) PPS resin, after the polymerization is completed, solid matter is recovered from the polymerization reaction product including the polymer, solvent, etc. As for the recovery method, a method of slowly cooling after the polymerization reaction is completed to recover the polymer in particulate form must be adopted. There is no particular restriction on the slow cooling rate at this time, which is usually about 0.1°C / min to 3°C / min. It is not necessary to slowly cool at the same rate throughout the slow cooling process, and a method of slowly cooling at a rate of 0.1 to 1°C / min and then at a rate of more than 1°C / min until the polymer particles are crystallized and precipitated can be adopted.

[0089] [Post-processing process]

[0090] (a) The PPS resin may be subjected to acid treatment, hot water treatment, washing with an organic solvent, or alkali metal or alkaline earth metal treatment after being produced through the above-mentioned polymerization and recovery steps.

[0091] The acid treatment is as follows. The acid used for the acid treatment of the (a) PPS resin is not particularly limited as long as it does not decompose the (a) PPS resin, and examples thereof include acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid, and propionic acid, among which acetic acid and hydrochloric acid are more preferably used, but substances such as nitric acid that decompose and deteriorate the (a) PPS resin are not preferred.

[0092] The acid treatment methods include methods such as impregnating (a) PPS resin in an acid or an aqueous solution of an acid, and stirring or heating can be appropriately carried out as needed. For example, in the case of using acetic acid, the PPS resin powder is impregnated during heating an aqueous solution with pH 4 to 80 - 200 °C, and stirred for 30 minutes to obtain sufficient effects. The pH after treatment can be 4 or more, for example, around pH 4 - 8. In order to remove residual acid, salts, etc., the (a) PPS resin subjected to acid treatment is preferably washed several times with water or warm water. With the intention of not impairing the preferred chemical modification effect of the (a) PPS resin brought about by acid treatment, the water used for washing is preferably distilled water or deionized water.

[0093] The case of performing heat treatment with hot water is as described below. When performing heat treatment with hot water on (a) PPS resin, it is preferred that the temperature of the hot water is 100 °C or more, more preferably 120 °C or more, further preferably 150 °C or more, and particularly preferably 170 °C or more. If it is less than 100 °C, the preferred chemical modification effect of the (a) PPS resin is small, so it is not preferred.

[0094] In order to exhibit the preferred chemical modification effect of the (a) PPS resin brought about by washing with hot water, the water used is preferably distilled water or deionized water. There is no particular limitation on the operation of heat treatment with hot water, and it can be carried out by the following methods: a method of putting a specified amount of (a) PPS resin into a specified amount of water and heating and stirring in a pressure vessel; a method of continuously performing heat treatment with hot water, etc. The ratio of (a) PPS resin to water is preferably more water, and usually a bath ratio is selected such that for 1 liter of water, the (a) PPS resin is 200 g or less.

[0095] In addition, since the decomposition of end groups is not preferred, in order to avoid this, it is desired that the treatment atmosphere is an inert atmosphere. Further, in order to remove residual components, the (a) PPS resin that has completed this heat treatment with hot water operation is preferably washed several times with warm water.

[0096] The case of washing with an organic solvent is as described below. The organic solvent used for washing the (a) PPS resin has no particular limitation as long as it does not have an effect of decomposing the (a) PPS resin, etc., and examples include nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, 1,3-dimethylimidazolidinone, hexamethylphosphoramide, piperazinones, etc., sulfoxide / sulfone-based solvents such as dimethyl sulfoxide, dimethyl sulfone, sulfolane, etc., ketone-based solvents such as acetone, methyl ethyl ketone, diethyl ketone, acetophenone, etc., dimethyl ether, dipropyl ether, di The present invention relates to organic solvents such as ether solvents such as alkane and tetrahydrofuran, chloroform, dichloromethane, trichloroethylene, 1,2-dichloroethane, perchloroethylene, monochloroethane, dichloroethane, tetrachloroethane, perchloroethane, halogen solvents such as chlorobenzene, methanol, ethanol, propanol, butanol, amyl alcohol, ethylene glycol, propylene glycol, phenol, cresol, polyethylene glycol, polypropylene glycol, alcohol / phenol solvents and aromatic hydrocarbon solvents such as benzene, toluene and xylene. Among these organic solvents, N-methyl-2-pyrrolidone, acetone, dimethylformamide and chloroform are particularly preferably used. In addition, these organic solvents are used in combination of one or more.

[0097] As a method of washing with an organic solvent, there is a method of immersing the (a) PPS resin in an organic solvent, and appropriate stirring or heating can also be performed as needed. There is no particular restriction on the washing temperature when washing the (a) PPS resin with an organic solvent, and any temperature between room temperature and about 300°C can be selected. There is a tendency that the higher the washing temperature, the higher the washing efficiency, but generally a sufficient effect can be obtained at a washing temperature of room temperature to 150°C. It is also possible to wash under pressure in a pressure vessel at a temperature above the boiling point of the organic solvent. In addition, there is no particular restriction on the washing time. Although it is related to the washing conditions, in the case of intermittent washing, a sufficient effect can be obtained by generally washing for more than 5 minutes. In addition, washing can also be performed continuously.

[0098] As a method for treating with alkali metals and alkaline earth metals, there can be mentioned a method of adding alkali metal salts and alkaline earth metal salts before, during, or after the above-mentioned pre-process, a method of adding alkali metal salts and alkaline earth metal salts in a polymerization kettle before, during, or after the polymerization process, or a method of adding alkali metal salts and alkaline earth metal salts at the initial, intermediate, or final stages of the above-mentioned washing process. Among them, the easiest method can be cited as washing with an organic solvent, and a method of adding alkali metal salts and alkaline earth metal salts after removing residual oligomers and residual salts by washing with warm or hot water. Alkali metals and alkaline earth metals are preferably introduced into PPS in the form of alkali metal ions and alkaline earth metal ions such as acetates, hydroxides, and carbonates. In addition, excess alkali metal salts and alkaline earth metal salts are preferably removed by washing with warm water, etc. As the concentration of alkali metal ions and alkaline earth metal ions when introducing the above-mentioned alkali metals and alkaline earth metals, it is preferably 0.001 mmol or more relative to 1gPPS, and more preferably 0.01 mmol or more. The temperature is preferably 50° C. or higher, more preferably 75° C. or higher, and particularly preferably 90° C. or higher. The upper limit temperature is not particularly limited, but is generally preferably 280° C. or lower from the viewpoint of operability. The bath ratio (the weight of the washing liquid relative to the weight of the dry PPS) is preferably 0.5 or higher, more preferably 3 or higher, and further preferably 5 or higher.

[0099] In the present invention, from the viewpoint of obtaining a polyphenylene sulfide resin composition having excellent retention stability, a method in which residual oligomers and residual salts are removed by repeating washing with an organic solvent and washing with warm water at about 80° C. or the above-mentioned hot water several times, followed by acid treatment or treatment with an alkali metal salt or alkaline earth metal salt is preferred, and a method in which an alkali metal salt or alkaline earth metal salt is treated is particularly preferred.

[0100] The (a) PPS resin can also be used by increasing the molecular weight by a thermal oxidation crosslinking treatment using heating in an oxygen atmosphere or heating with the addition of a crosslinking agent such as a peroxide after the polymerization is completed.

[0101] When dry heat treatment is performed for the purpose of high molecular weight by thermal oxidation crosslinking, the temperature is preferably in the range of 160 to 260°C, more preferably in the range of 170 to 250°C. In addition, the desired oxygen concentration is 5% by volume or more, and further 8% by volume or more. There is no particular restriction on the upper limit of the oxygen concentration, but it is limited to about 50% by volume. The treatment time is preferably 0.5 to 100 hours, more preferably 1 to 50 hours, and further preferably 2 to 25 hours. The device for heat treatment can be a conventional hot air dryer, or a rotary heating device or a heating device with stirring blades, but in the case of efficient and more uniform treatment, it is more preferred to use a rotary heating device or a heating device with stirring blades.

[0102] In addition, it is also possible to suppress thermal oxidation crosslinking and remove volatile components for the purpose of dry heat treatment. The temperature is preferably 130 to 250 ° C, more preferably in the range of 160 to 250 ° C. In addition, it is desired that the oxygen concentration in this case is less than 5% by volume, and further less than 2% by volume. The treatment time is preferably 0.5 to 50 hours, more preferably 1 to 20 hours, and further preferably 1 to 10 hours. The device for heat treatment can be a common hot air dryer, or a rotary or a heating device with a stirring blade, but in the case of good efficiency and more uniform treatment, it is more preferred to use a rotary or a heating device with a stirring blade.

[0103] From the viewpoint of improving the reactivity with (b) a silicone elastomer having a cross-linked structure and other additives, the (a) PPS resin of the present invention can introduce functional groups such as carboxyl groups and amino groups at the ends and side chains of the PPS resin. The amount of functional groups can be 25 to 400 μmol / g as a preferred embodiment, more preferably 25 to 250 μmol / g, more preferably 30 to 150 μmol / g, and more preferably 30 to 80 μmol / g. It is preferred that the amount of functional groups is 25 μmol / g or more to obtain reactivity with (b) a silicone elastomer having a cross-linked structure and other additives. On the other hand, it is preferred that the amount of functional groups in the PPS resin is 400 μmol / g or less to suppress the decrease in processability, flame retardancy and chemical resistance associated with an increase in the amount of volatile components.

[0104] As a method for introducing functional groups such as carboxyl groups and amino groups into the (a) PPS resin, there can be exemplified: a method of copolymerizing a polyhalogenated aromatic compound containing carboxyl groups and amino groups with a sulfiding agent; a method of introducing by adding a compound containing carboxyl groups and amino groups, such as maleic anhydride, sorbic acid, etc., and reacting them while melt-kneading with the (a) PPS resin, etc. The type of the functional group is preferably a carboxyl group or an amino group.

[0105] (2) (b) Silicone elastomer with cross-linked structure

[0106] In order to realize a polyphenylene sulfide resin composition for a battery insulating member having excellent productivity, safety, and long-term reliability, it is necessary to mix (b) a silicone elastomer having a crosslinked structure with the PPS resin composition of an embodiment of the present invention.

[0107] Such a so-called (b) cross-linked silicone elastomer has a main chain structure of an organopolysiloxane and a molecular structure in which the molecules of the organopolysiloxane are bonded by cross-linking. The degree of polymerization of the cross-linked silicone elastomer is preferably 100 or more, and the weight average molecular weight is preferably 10,000 or more. It should be noted that silicone oil and uncross-linked silicone gum do not have a cross-linked structure and are therefore not included in the (b) cross-linked silicone elastomer.

[0108] As the method for introducing the cross-linked structure, peroxide cross-linking, condensation reaction cross-linking, addition reaction cross-linking, and ultraviolet cross-linking methods can be cited. As peroxide cross-linking, a method of using alkyl peroxides and acyl peroxides as organic peroxides to react the alkyl or vinyl groups of the organosilicon polymer to form cross-linking can be cited. As condensation reaction cross-linking, a condensation reaction using the reaction between the silanol group of the organosilicon polymer and the cross-linking agent can be cited, and the cross-linking agent can be representatively listed as dealcohol type, deacetic acid type, deoxime type, deamidation type, dehydroxylamine type, and deacetone type. In addition, in order to promote the reaction, it is preferred to use tin compounds, titanium compounds, metal fatty salts, and amino-containing compounds as catalysts. As addition reaction cross-linking, the hydrosilylation reaction of multiple bonds of the vinyl group of the organosilicon elastomer and the Si-H group can be cited. At this time, it is preferred to use transition metal compounds, especially platinum compounds as catalysts.

[0109] (b) The silicone elastomer having a cross-linked structure may also include a form having a copolymer component in a part of the molecular structure. Specifically, the copolymer may include an organopolysiloxane component and one or more copolymer components selected from polyolefins (polyethylene, polypropylene, polybutene, etc.), polycarbonate, polyamide, polybutylene terephthalate, polyester elastomer, polystyrene, polyetherimide, polyketone, liquid crystal polymer, polyether ketone, polyether ether ketone, polyacrylate (polymethyl methacrylate, etc.), etc., but the above-mentioned (b) silicone elastomer having a cross-linked structure preferably contains 90% by weight or more of the structural unit derived from the organopolysiloxane.

[0110] As a composite containing an organopolysiloxane as a structural unit, a core-shell rubber (organosilicone acrylic core-shell rubber) in which silicone elastomer particles are covered with an acrylic component, a composite powder in which a silicone elastomer is covered with a silicone resin, etc. can also be used, but from the viewpoint of flame retardancy and long-term durability, it is preferred that the organopolysiloxane content is 90% by weight or more.

[0111] (b) The silicone elastomer having a cross-linked structure preferably has one or more hydrocarbon groups selected from alkyl groups having 1 to 8 carbon atoms (methyl, ethyl, propyl, butyl, 2-ethylbutyl, octyl, etc.), cycloalkyl groups having 3 to 8 carbon atoms (cyclohexyl, cyclopentyl, etc.), alkenyl groups having 2 to 8 carbon atoms (vinyl, propenyl, butenyl, heptenyl, hexenyl, allyl, etc.), and aryl groups (phenyl, tolyl, xylyl, naphthyl, diphenyl, etc.), among which methyl, phenyl, and vinyl are preferred.

[0112] In addition, it is preferred that the organopolysiloxane structure contains one or more functional groups selected from alkoxy groups having 1 to 8 carbon atoms (methoxy, ethoxy, propoxy, butoxy, etc.), amino groups, epoxy groups, methanol groups, methacryl groups, ether groups, mercapto groups, carboxyl groups, phenol groups, silanol groups, acryloyl groups, carboxylic anhydride groups, polyether groups, aralkyl groups, fluoroalkyl groups, long-chain alkyl groups, higher fatty acid ester groups, higher fatty acid amide groups, etc. at the molecular chain end or molecular chain side chain. Among them, alkoxy groups, amino groups, epoxy groups, methacryl groups, mercapto groups, carboxyl groups, and acryloyl groups are preferably contained, and alkoxy groups, epoxy groups, and methacryl groups are particularly preferred.

[0113] (b) The silicone elastomer having a cross-linked structure may be in any shape, including particles, blocks, powders, powder agglomerates, flakes, etc., and particles, powders, powder agglomerates, and flakes are preferred from the viewpoint of handling, processability, and dispersibility.

[0114] In the case where the shape of the silicone elastomer with a cross-linked structure is microparticles, from the viewpoints of dispersibility, flame retardancy and toughness of the PPS resin composition, the average primary particle size (number average primary particle size) is preferably 10 μm or less, more preferably 5 μm or less, and further preferably 3 μm or less. In the case where the average primary particle size exceeds 10 μm, it becomes the starting point of cracks, resulting in a decrease in mechanical properties and is therefore not preferred. On the other hand, as a lower limit, it is preferably 100 nm or more from the viewpoint of productivity. It should be noted that (b) the average primary particle size of the silicone elastomer with a cross-linked structure can be calculated by arbitrarily specifying 100 particle diameters from a scanning electron microscope photograph and finding the arithmetic average thereof. In the above photograph, in the case of not being a perfect circle, that is, in the case of an ellipse, the maximum diameter of the particle is set to its particle size. The method for obtaining a microparticle-shaped silicone elastomer with a cross-linked structure can be representatively cited as a method of dissolving it in a soluble solvent and then precipitating it, a method of recovering it after forming an emulsion using an emulsifier, and a method of mechanically crushing and miniaturizing a particle or block-shaped silicone elastomer with a cross-linked structure.

[0115] The compounding amount of the (b) cross-linked silicone elastomer used in the present invention must be 0.1 parts by weight or more and 15.0 parts by weight or less relative to 100 parts by weight of the (a) PPS resin, preferably 0.5 parts by weight or more and 12.0 parts by weight or less, and more preferably 1 part by weight or more and 10.0 parts by weight or less. If the compounding amount of the cross-linked silicone elastomer relative to 100 parts by weight of the PPS resin exceeds 15.0 parts by weight, the PPS resin composition is too soft and creeps as a battery insulating component, thereby reducing long-term reliability. On the other hand, when the (b) cross-linked silicone elastomer is less than 0.1 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, so it is not preferred from the perspective of productivity and long-term reliability as a battery insulating component.

[0116] Furthermore, two or more silicone elastomers having a cross-linked structure may be used in combination.

[0117] (b) The Shore hardness A of the cross-linked silicone elastomer is preferably 60HS or less, more preferably 50HS or less, and further preferably 45HS or less. The Shore hardness A of the cross-linked silicone elastomer is preferably 60HS or less, so that the flame retardancy and toughness desired as an insulating member can be obtained. On the other hand, the lower limit is not particularly limited, but a significantly smaller Shore hardness means that it is equivalent to silicone oil, and exudation is shown during long-term high-temperature use, so it is substantially preferably 10HS or more.

[0118] (3)(c) Thermoplastic elastomer

[0119] The PPS resin composition of the embodiment of the present invention preferably does not substantially contain (c) thermoplastic elastomer. Here, the so-called "substantially does not contain (c) thermoplastic elastomer" means that the mixing amount of (c) thermoplastic elastomer is less than 0.5 parts by weight relative to 100 parts by weight of PPS resin, and the mixing amount of (c) thermoplastic elastomer is more preferably less than 0.3 parts by weight relative to 100 parts by weight of PPS resin, and further preferably less than 0.1 parts by weight. It is most preferred not to contain (c) thermoplastic elastomer. Thermoplastic elastomer is a material that plasticizes at high temperatures and shows rubber-like elasticity at room temperature. When a thermoplastic elastomer is added to the PPS resin composition, the long-term high-temperature durability of the thermoplastic elastomer is accompanied by thermal degradation, thereby reducing the mechanical properties of the battery insulating component, dissolution of the degraded component in the electrolyte, etc., resulting in a reduction in long-term reliability. In addition, since the flame retardancy of the battery insulating member is reduced due to the low flame retardancy of the thermoplastic elastomer itself, the PPS resin composition of the embodiment of the present invention does not substantially contain (c) thermoplastic elastomer. In addition, the silicone elastomer is different from the (c) thermoplastic elastomer because it is a thermosetting elastomer.

[0120] Specific examples of thermoplastic elastomers include olefin-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and styrene-based thermoplastic elastomers. Examples of olefin-based thermoplastic 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.

[0121] (4)(d) Other additives

[0122] The PPS resin composition according to the embodiment of the present invention may contain resins other than (a) the PPS resin and (b) the silicone elastomer having a crosslinked structure, within a range not impairing the effects of the present invention. Specific examples thereof include polyamide, polybutylene terephthalate, polyethylene terephthalate, polyetherimide, polyetherimide-siloxane copolymer, polyketone, liquid crystal polymer, polyetherketone, polyetheretherketone, fluororesin (polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-perfluoro (alkyl vinyl ether) copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene-hexafluoropropylene copolymer, polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), but are not limited thereto. The amount of such resin added is preferably less than 10 parts by weight, preferably less than 5 parts by weight, and more preferably less than 3 parts by weight relative to 100 parts by weight of the PPS resin. It should be noted that as the lower limit, it is preferably not to include these resins, that is, 0 parts by weight.

[0123] In the PPS resin composition of the embodiment of the present invention, the following compounds can be added for the purpose of modification. Plasticizers such as polyoxyalkylene oligomer compounds, thioether compounds, ester compounds, and organophosphorus compounds, crystal nucleating agents such as organophosphorus compounds and polyetheretherketone, montanic acid waxes, metal soaps such as lithium stearate and aluminum stearate, mold release agents such as ethylenediamine / stearic acid / sebacic acid polycondensates, water, lubricants, ultraviolet light inhibitors, coloring agents, colorants, foaming agents, phosphorus flame retardants, halogen flame retardants, inorganic flame retardants, and other common additives can be mixed. The above compounds are not preferred because the original characteristics of the PPS resin composition of the present invention are impaired if the addition amount exceeds 10 parts by weight relative to a total of 100 parts by weight of the PPS resin composition. It is better to add 5 parts by weight or less, and more preferably 1 part by weight or less.

[0124] Furthermore, in the present invention, an organic silane compound or an epoxy resin may be added for the purpose of improving the toughness of the PPS resin composition.

[0125] As a specific example of the organosilane compound, it is preferably an organosilane compound having at least one functional group selected from an isocyanate group, an epoxy group, an amino group, a hydroxyl group, a mercapto group, a urea group, and an alkoxy group. As a specific example, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxysilane, 3-glycidoxypropyl methyl dimethoxysilane, 3-glycidoxypropyl methyl diethoxysilane, 2-(3,4-epoxycyclohexyl) ethyl trimethoxysilane, N-(2-aminoethyl)-3-aminopropyl trimethoxysilane, N-(2-aminoethyl)-3-aminopropyl methyl dimethoxysilane, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 3-aminopropyl methyl diethoxysilane, N-phenylaminomethyl trimethoxysilane, 3-Isocyanatepropyltrimethoxysilane, 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-isocyanatepropylmethyldimethoxysilane, 3-isocyanatepropylmethyldiethoxysilane, 3-isocyanatepropylethyldimethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptomethyldimethoxysilane, γ-ureidopropyltrimethoxysilane, etc.

[0126] Among the above-mentioned organosilane compounds, 3-isocyanatepropyltriethoxysilane, 3-aminopropyltriethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane are preferred from the viewpoints of reactivity and handling.

[0127] These alkoxyorganosilane compounds may be used alone or in combination of two or more.

[0128] The amount of these organosilane compounds used in the present invention is preferably 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, relative to 100 parts by weight of the PPS resin, and can be exemplified as 0.3 to 3 parts by weight as a more preferred embodiment. The amount of the organosilane compound is 10 parts by weight or less, so that the flame retardancy of the obtained PPS resin composition can be maintained, which is preferred. If the amount of the organosilane compound is 0.01 parts by weight or more, the reaction between PPS and the organosilane compound becomes sufficient, and excellent toughness can be exhibited, which is preferred.

[0129] As specific examples of the epoxy resin, there can be mentioned glycidyl ether type epoxy resins typified by bisphenol A type epoxy resin, bisphenol F type epoxy resin, brominated epoxy resin, special skeleton difunctional epoxy resins having a biphenyl skeleton, a naphthalene skeleton, etc., novolak type, triphenol methane type, dicyclopentadiene type, etc. polyfunctional epoxy resins, glycidyl amine type epoxy resins typified by aromatic amine type, aminophenol type, etc., and glycidyl ester type epoxy resins typified by hydrogen phthalic acid type, dimer acid type, etc. The addition amount of such an epoxy resin is preferably 0.1 to 5 parts by weight, particularly preferably 0.2 to 3 parts by weight, based on 100 parts by weight in total of the PPS resin composition.

[0130] In the PPS resin composition of the embodiment of the present invention, although not an essential component, an inorganic filler can also be blended and used within a range not impairing the effects of the present invention. As specific examples of such an inorganic filler, fibrous filler materials such as glass fiber, carbon fiber, carbon nanotube, carbon nanohorn, potassium titanate whisker, zinc oxide whisker, calcium carbonate whisker, wollastonite whisker, aluminum borate whisker, aromatic polyamide fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, gypsum fiber, metal fiber, etc., or non-fibrous filler materials such as fullerene, talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, bentonite, asbestos, aluminum silicate, etc. silicate, silicon oxide, magnesium oxide, alumina, zirconia, titanium oxide, iron oxide, etc. metal compound, calcium carbonate, magnesium carbonate, dolomite, etc. carbonate, calcium sulfate, barium sulfate, etc. sulfate, glass bead, glass flake, glass powder, ceramic bead, boron nitride, silicon carbide, carbon black, graphite, etc. are used. Among them, glass fiber, calcium carbonate, and carbon black are preferred, and further calcium carbonate and carbon black are particularly preferred in view of the effects of anticorrosive materials and lubricating materials. In addition, these inorganic fillers can be hollow, and further two or more kinds can be used in combination. In addition, these inorganic fillers can be pretreated with a coupling agent such as an isocyanate compound, an organosilane compound, an organic titanate compound, an organic borane compound, and an epoxy compound and used.

[0131] The blending amount of such an inorganic filler is selected in a range of less than 10 parts by weight, preferably less than 5 parts by weight, more preferably less than 3 parts by weight, and further preferably 1 part by weight or less, based on 100 parts by weight in total of the PPS resin composition. There is no particular limitation on the lower limit, but it is preferably 0.0001 part by weight or more. The blending of the inorganic filler is effective in improving the strength of the material. On the other hand, blending exceeding 10 parts by weight results in a decrease in toughness, and thus is not preferred.

[0132] (5) Method for producing the resin composition

[0133] As the method for manufacturing the PPS resin composition of the embodiment of the present invention, the manufacture in the molten state, the manufacture in the solution state, etc. can be cited, but from the viewpoint of simplicity, the manufacture in the molten state is preferably used. Regarding the manufacture in the molten state, the melt mixing using an extruder, the melt mixing using a kneader, etc. can be used, but from the viewpoint of productivity, the melt mixing using an extruder that can be manufactured continuously is preferably used. Regarding the melt mixing using an extruder, at least one of the extruders such as a single screw extruder, a twin screw extruder, a four-screw extruder, a twin screw single screw composite extruder, etc. can be used, but from the viewpoint of improving mixing, reactivity, productivity, it is preferably possible to use a twin screw extruder, a four-screw extruder, etc., and the melt mixing using a twin screw extruder is most preferably used.

[0134] As a more specific method for melt kneading, although not necessarily limited thereto, it is preferred to use a twin-screw extruder having an L / D (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 restriction on the upper limit of L / D, but it is preferably 60 or less from an economic point of view. In addition, there is no particular restriction on the upper limit of the number of kneading sections, but it is preferably 10 or less from a productivity point of view. From the perspective of the dispersibility of (b) the silicone elastomer with a cross-linked structure in the PPS resin, the ratio of the kneading section to the total length of the screw is preferably 5% or more, more preferably 10% or more, and further preferably 15% or more. On the other hand, with respect to the upper limit of the ratio of the kneading section to the total length of the screw, from the perspective of preventing deterioration of the resin caused by the occurrence of excessive shear heat during kneading, it is preferably 40% or less.

[0135] Regarding the screw speed, it is preferred to perform kneading under the conditions of 150 to 1000 rpm, preferably 300 to 1000 rpm, and more preferably 350 to 800 rpm. When the screw speed is higher than 150 rpm, the kneading force is sufficient, so the aggregation of (b) the silicone elastomer having a cross-linked structure is suppressed, 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 kneading, which also leads to a decrease in toughness, a decrease in mold contamination, the generation of burrs due to a decrease in melt viscosity, and a decrease in the long-term reliability of the battery insulating component due to decomposition products, so it is not preferred.

[0136] The preferred range of the cylinder temperature (°C) is specifically 280 to 400°C, more preferably 280 to 360°C, and even more preferably 280 to 330°C.

[0137] There is no particular restriction on the order of mixing the raw materials during melt kneading, but any of the following methods can be used: a method in which all raw materials are mixed and then melt kneaded by the above method; a method in which a part of the raw materials are mixed and then melt kneaded by the above method, and then they are further mixed with the remaining raw materials and melt kneaded; or a method in which a part of the raw materials are mixed and then the remaining raw materials are mixed using a side feeder during melt kneading using a twin-screw extruder, etc.

[0138] (6) PPS resin composition

[0139] The PPS resin composition of the present invention must have a flexural modulus (based on ISO178 (2010), a bending speed of 2 mm / min, and a condition of 23°C), which is one of the physical properties indicating the flexibility of the material, of 3.1 GPa or more and 3.6 GPa or less. Preferably, it is 3.2 GPa or more and 3.6 GPa or less. The PPS resin composition for battery insulating components requires flexibility from the viewpoint of suppressing breakage in the insulating component manufacturing process, but requires high rigidity from the viewpoint of creep deformation during long-term use. Since these opposite properties are required, the flexural modulus of the resin composition must be 3.1 GPa or more and 3.6 GPa or less. There is no particular limitation on the method for obtaining a PPS resin composition having such properties, and examples thereof include a resin composition in which the blending amount of (b) a silicone elastomer having a cross-linked structure is 0.1 to 15.0 parts by weight relative to 100 parts by weight of (a) polyphenylene sulfide resin.

[0140] The PPS resin composition of the present invention preferably has a flame retardancy of V-0 measured for a sample with a thickness of 1.0 mmt or less in a measurement using the UL94 standard as an index of the flame retardancy of the material, and more preferably has a flame retardancy of V-0 for a sample with a thickness of 0.7 mmt or less. Having such flame retardant properties means that while having excellent flame retardant properties, thinning of the wall of the molded product and the accompanying lightweighting of the molded product can be achieved, which not only contributes to suppressing human / economic losses caused by fire, but also contributes to the energy saving effect accompanying lightweighting, and therefore can be suitably used for battery insulating components for automobiles such as electric vehicles. The method for obtaining a PPS resin composition having such properties is not particularly limited, and examples thereof include: making the blending amount of (b) a cross-linked silicone elastomer to be 0.1 to 15.0 parts by weight relative to 100 parts by weight of (a) polyphenylene sulfide resin; using a microparticle-shaped cross-linked silicone elastomer having a particle size of 100 nm to 10 μm; and using a cross-linked silicone elastomer having a Shore A hardness of 60 HS or less. Although the flame retardant mechanism is still unclear, it was found that when a silicone elastomer with a cross-linked structure having a particle size and hardness within the above range is used, the flame retardant performance is improved compared to when a silicone elastomer outside the range is used. The reason is presumed to be that the flame retardant layer derived from the silicone elastomer is different when burned.

[0141] The tensile elongation at break, which is one of the physical property values ​​indicating the toughness of the material of the PPS resin composition of the present invention (dumbbell specimen (ISO527-2-1A), tensile speed 50 mm / min, 23°C, based on (ISO527-1, 2 (2012))), is preferably 8% or more, more preferably 10% or more, further preferably 12% or more, and particularly preferably 14% or more. From the viewpoint of suppressing the damage of the battery insulating component during actual use, the tensile elongation at break of the resin composition is expected to be 8% or more. The tensile elongation at break is preferably higher from the viewpoint of suppressing the breakage of the component during actual use and its long-term reliability, and no upper limit is particularly set, but it can be exemplified as substantially 500% or less. The method for obtaining a PPS resin composition having such properties is not particularly limited, and examples thereof include: adjusting the mixing amount of (b) a cross-linked silicone elastomer to 0.1 to 15.0 parts by weight relative to 100 parts by weight of (a) polyphenylene sulfide resin; using a cross-linked silicone elastomer in the form of microparticles having a particle size of 100 nm to 10 μm; and using an organic silane compound and an epoxy resin in combination.

[0142] From the viewpoint of the long-term durability of the battery insulation member, the PPS resin composition of the present invention preferably has excellent exudation resistance. The generation of exudation components on the surface of the molded product not only causes a decrease in insulation but also a decrease in the power generation efficiency of the battery, which is not preferable. The evaluation of exudation resistance can be carried out by the following method. A dumbbell specimen (ISO527-2-1A) obtained by injection molding is placed in a Geer aging oven set at 180 °C. After being treated for 250 hours and cooled at room temperature for more than 24 hours, the exudation resistance is evaluated by whether exudation components are generated on the surface. The method for obtaining the PPS resin composition having such characteristics is not particularly limited, and examples include selecting and using a silicone elastomer having a crosslinked structure instead of a non-crosslinked silicone oil.

[0143] From the viewpoint of the long-term durability of the battery insulation member, the elongation retention rate of the PPS resin composition of the present invention before and after long-term durability treatment is preferably 50% or more, more preferably 60% or more, still more preferably 70% or more, and further preferably 80% or more. The higher the elongation retention rate of the resin composition before and after long-term durability treatment, the more preferable it is. There is no particular upper limit, but the substantial upper limit value is 100%, so it is preferably 100% or less. The evaluation of the elongation retention rate before and after long-term durability treatment can be carried out by the following method. A dumbbell specimen (ISO527-2-1A) obtained by injection molding is placed in a Geer aging oven set at 180 °C. After being treated for 250 hours and cooled at room temperature for more than 24 hours, the tensile fracture elongation is measured (based on ISO527-1, 2 (2012)) under the conditions of a tensile speed of 50 mm / min and 23 °C, and the change rate when the elongation before long-term durability treatment is set to 100% is calculated as the retention rate. The method for obtaining the PPS resin composition having such characteristics is not particularly limited. For example, it is possible to make the content of (b) a silicone elastomer having a crosslinked structure relative to 100 parts by weight of (a) polyphenylene sulfide resin be 0.1 to 15.0 parts by weight and not contain a thermoplastic elastomer.

[0144] The PPS resin composition of the present invention preferably has a tensile creep displacement suppressed to a low level under a high temperature environment. In the case where a battery insulating component is formed from a material with a large tensile creep displacement under a high temperature environment, deformation occurs during long-term use, and the airtightness of the electrolyte is reduced, which is not preferred in terms of safety. As for the tensile creep displacement, it is preferably 4.0% or less, more preferably 3.7% or less, further preferably 3.5% or less, and more preferably 3.0% or less. The closer the tensile creep displacement of the resin composition is to 0%, the more preferred it is. There is no particular lower limit, but the actual lower limit is 0%, so it is preferably above 0%. The evaluation of the tensile creep displacement can be carried out by the following method. The dumbbell specimen (ASTM No. 4, thickness 1.6 mm) obtained by injection molding is evaluated for displacement after being treated under the conditions of 80°C, 20 MPa, and 100 hours using a tensile creep testing machine with a chuck distance of 64 mm. The method for obtaining a PPS resin composition having such properties is not particularly limited, and examples thereof include controlling the flexural modulus of the resin composition to be within a range of 3.1 GPa to 3.6 GPa by weight, with respect to 100 parts by weight of the (a) polyphenylene sulfide resin, by blending 0.1 to 15.0 parts by weight of the (b) silicone elastomer having a cross-linked structure.

[0145] The PPS resin composition of the present invention preferably has excellent fluidity when melted. In the case of a resin composition with poor fluidity, molding into a thin-walled battery insulating component is difficult, so it is not preferred. Fluidity can be measured using melt viscosity. The melt viscosity of the PPS resin composition of the present invention is measured using a capillary graph at a shear rate of 1216s under the conditions of 320°C and orifice length L (mm) / orifice diameter D (mm) = 10. -1 The melt viscosity is preferably 250 Pa·s or less, more preferably 200 Pa·s or less, and further preferably 160 Pa·s or less. In addition, from the viewpoint of suppressing burrs during molding, the melt viscosity is preferably 80 Pa·s or more, more preferably 90 Pa·s or more, and further preferably 100 Pa·s or more. There is no particular limitation on the method for obtaining a PPS resin composition having such properties, and examples thereof include: the PPS resin composition substantially does not contain (c) a thermoplastic elastomer; (a) a PPS resin having a weight average molecular weight of 30,000 to 150,000 is used; 0.01 to 10 parts by weight of an organic silane compound is mixed with 100 parts by weight of the PPS resin; and 0.1 to 5 parts by weight of an epoxy resin is mixed with 100 parts by weight of the PPS resin composition.

[0146] In general, when the fluidity of the resin composition is excellent, the flame retardancy of the resin composition tends to decrease in a combustion test using the UL94 standard. This is believed to be because dripping occurs during the combustion test, and the combustible components reappear on the surface due to the dripping and continue to burn. On the other hand, the PPS resin composition for battery insulating components of the present invention can exhibit the excellent fluidity required for the molding process of the battery insulating components while also exhibiting the flame retardancy of the thin-walled molded product.

[0147] (7) Battery insulation components

[0148] The battery insulating member formed of the PPS resin composition of the present invention refers to an insulating member for primary or secondary batteries, and is used to prevent internal short circuits and external short circuits in the primary or secondary batteries. Examples of the primary or secondary batteries include primary batteries such as alkaline manganese dry batteries, galvanic cells, nickel-based primary batteries, lithium batteries, manganese dry batteries, mercury batteries, and all-solid batteries, and secondary batteries such as lead storage batteries, lithium / air batteries, lithium ion secondary batteries, lithium ion polymer secondary batteries, lithium iron phosphate batteries, lithium / sulfur batteries, nickel / cadmium storage batteries, nickel / hydrogen rechargeable batteries, nickel / lithium batteries, nickel / zinc batteries, and all-solid batteries.

[0149] Examples of battery insulating components include insulating plates, gaskets, terminal retainers, housings, insulating rings, insulating tubes, wire coverings, busbar coverings, etc. The battery insulating components made of the PPS resin composition of the present invention have excellent toughness, thereby reducing the risk of breakage during the caulking process and also have excellent long-term reliability. Therefore, they are preferably applied to insulating plates, gaskets, terminal retainers, and housings, which are important safety guarantee components of batteries.

[0150] The battery insulating member of the present invention can be molded by various molding methods such as injection molding, extrusion molding, compression molding, blow molding, injection compression molding, etc. Among them, injection molding is preferred from the viewpoint of productivity.

[0151] Example

[0152] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.

[0153] In Examples and Comparative Examples, the following substances were used as (a) PPS resin, (b) silicone elastomer having a cross-linked structure, (c) thermoplastic elastomer, and (d) other additives.

[0154] [(a) PPS resin (a-1)]

[0155] [Reference Example 1 PPS resin (a-1)]

[0156] 8267.37 g (70.00 moles) of 47.5% sodium hydrosulfide, 2923.88 g (70.17 moles) of 96% sodium hydroxide, 11434.50 g (115.50 moles) of N-methyl-2-pyrrolidone (NMP), 1894.20 g (23.10 moles) of sodium acetate, and 10500 g of ion-exchanged water were added to an autoclave equipped with a stirrer. While introducing nitrogen at atmospheric pressure, it was slowly heated to 230°C over about 3 hours. After distilling out 14780.1 g of water and 280 g of NMP, the reaction vessel was cooled to 160°C. The amount of residual water in the system per 1 mole of the added alkali metal sulfide, including the water consumed in the hydrolysis of NMP, was 1.06 moles. In addition, the amount of hydrogen sulfide scattered was 0.017 moles per 1 mole of the added alkali metal sulfide.

[0157] Next, 10420 g (70.89 moles) of p-dichlorobenzene and 9078.30 g (91.70 moles) of NMP were added. The reaction vessel was sealed under nitrogen, and while stirring at 240 rpm, it was heated to 240°C at a rate of 0.6°C / minute. After reacting at 240°C for 40 minutes, it was heated to 275°C at a rate of 0.8°C / minute. Then, while cooling to 250°C at a rate of 1.3°C / minute, 2394 g (133 moles) of ion-exchanged water was injected into the autoclave. Then, after cooling to 200°C at a rate of 1.0°C / minute, it was quenched until near room temperature.

[0158] The content was taken out, diluted with 26300 g of NMP, and then the solvent and solid matter were separated by filtration through a sieve (80 mesh). The obtained particles were washed and separated by filtration with 31900 g of NMP. After washing and separating it several times with 56000 g of ion-exchanged water, it was washed and separated by filtration with 70000 g of 0.05 wt% acetic acid aqueous solution. After washing and separating it with 70000 g of ion-exchanged water, the obtained water-containing PPS particles were dried by hot air at 80°C and dried under reduced pressure at 120°C. The obtained PPS resin (a-1) had a weight-average molecular weight of 73000, a melting point of 280°C, and a carboxyl group content of 35 μmol / g.

[0159] [(b) Organosilicon elastomers (b-1, b-2, b-3) having a crosslinked structure]

[0160] b-1: Organosilicon elastomer having a crosslinked structure (Dow Corning Toray's Dow Corning "EP5500"), Shore hardness A: 30 HS, amount of polyorganosiloxane: 90% or more, average primary particle size 3 μm

[0161] b-2: Silicone elastomer with a cross-linked structure (Dausil "EP2600" manufactured by Duroto Corporation), Shore A hardness: 50 HS, polyorganosiloxane content: 90% or more, average primary particle size 2 μm

[0162] b-3: Silicone elastomer with a cross-linked structure (Dausil "EP2720" manufactured by Duroto Corporation), Shore A hardness: 70 HS, polyorganosiloxane content: 90% or more, average primary particle size 2 μm, containing methacryloyloxy

[0163] [(c) Thermoplastic elastomer (c-1)]

[0164] c-1: ethylene-glycidyl methacrylate copolymer (olefin resin manufactured by Sumitomo Chemical Co., Ltd., Bond Filter ETX-6, melting point 105°C, MFR: 3 g / 10 min (190°C, 21.2 N load)), reactive functional group content: 6 wt%

[0165] [(d) Other additives (d-1, d-2, d-3)]

[0166] d-1: Silicone powder (Dausil "Toray F-202" manufactured by Dulux Corporation, a powder in which 60% by mass of silicone oil (viscosity (25°C): 60,000 cs (62,000 mPa·s)) is supported on an inorganic powder (silicon dioxide))

[0167] d-2: Silicone oil (Hoshiro "SH200" manufactured by Toru Co., Ltd., viscosity (25°C): 60,000cs (62,000mPa·s))

[0168] d-3: 3-isocyanatepropyltriethoxysilane ("KBE9007N" manufactured by Shin-Etsu Silicone Co., Ltd.)

[0169] In the following examples, material properties were evaluated by the following methods.

[0170] [Bending test]

[0171] After drying the PPS resin composition pellets of the present invention at 130°C for 3 hours using a hot air dryer, the pellets were supplied to a Sumitomo Heavy Industries injection molding machine (SE-75DUZ) set at a barrel temperature of 320°C and a mold temperature of 145°C. The pellets were injection molded using a mold of the A1 type sample shape specified in ISO 20753 (2008) under the condition that the average speed of the molten resin passing through the cross-sectional area of ​​the central parallel portion was 400±50 mm / s to obtain a sample. The central parallel portion of the sample was cut out to obtain a B2 type sample. After the sample was conditioned for 16 hours at 23°C and a relative humidity of 50%, the bending modulus was measured based on the ISO 178 (2010) method at a span of 64 mm and a test speed of 2 mm / min.

[0172] [Tensile test]

[0173] The A1 type specimen obtained under the same molding conditions as the bending test was conditioned for 16 hours at 23°C and a relative humidity of 50%, and then the tensile elongation at break (nominal strain) was measured based on the ISO 527-1, 2 (2012) method at a chuck distance of 114 mm and a test speed of 50 mm / min.

[0174] [Flame retardant test]

[0175] After the PPS resin composition particles of the present invention were dried at 130°C for 3 hours using a hot air dryer, they were supplied to a Sumitomo Heavy Industries injection molding machine (SE-75DUZ) with a barrel temperature set at 320°C and a mold temperature set at 150°C to obtain a sample for flame retardancy evaluation. The flame retardancy of the sample was evaluated based on the evaluation criteria specified in the UL94 vertical test. The flame retardancy is graded in the order of V-0>V-1>V-2. If the V-2 benchmark is not met, it is expressed as out. The thickness of the sample used was 1.0mmt and 0.7mmt.

[0176] [Bleeding resistance]

[0177] The A1 type sample obtained under the same molding conditions as the bending test was conditioned for 16 hours at 23°C and a relative humidity of 50%, then placed in a Gill aging thermostat set at 180°C, treated for 250 hours, and then left to cool at room temperature for more than 24 hours, and the oozing resistance was evaluated from the state of the surface. Specifically, the level of color change different from the base material PPS resin composition confirmed on the surface after heat treatment by visual observation was judged as poor oozing resistance (bad), and the level of no color change was judged as good (good).

[0178] [Elongation retention before and after long-term durability treatment]

[0179] The A1 type specimen obtained under the same molding conditions as the bending test was conditioned for 16 hours at 23°C and 50% relative humidity, then placed in a Gill aging thermostat set at 180°C, treated for 250 hours, cooled at room temperature for more than 24 hours, and then evaluated by measuring the tensile elongation at break under the same conditions as the tensile test. The change rate of the elongation after the long-term durability treatment when the elongation before the long-term durability treatment was set to 100% was calculated as the elongation retention rate.

[0180] [Tensile creep displacement]

[0181] The PPS resin composition pellets of the present invention were dried at 130°C for 3 hours using a hot air dryer and then fed to a Sumitomo Heavy Industries injection molding machine (SE-75DUZ) set at a barrel temperature of 300°C and a mold temperature of 150°C to obtain a dumbbell specimen with a parallel portion width of 6 mm and a thickness of 1.6 mm. The displacement after treatment using a tensile creep tester under the conditions of a chuck distance of 64 mm, 80°C, 20 MPa, and 100 hours was evaluated.

[0182] [Melt viscosity]

[0183] The PPS resin composition pellets of the present invention were measured using Capilog 1B manufactured by Toyo Seiki Co., Ltd. at 320°C and under the conditions of orifice length L (mm) / orifice diameter D (mm) = 10. The shear rate was 1216s -1 The value below.

[0184] [Examples 1 to 8, Comparative Examples 1 to 6]

[0185] PPS resin, silicone elastomer with a cross-linked structure, thermoplastic elastomer, and other additives were dry-blended in the blending composition shown in Table 1, and then put into a TEX30α twin-screw extruder (L / D=30, 2 kneading sections) manufactured by Nippon Steel Works, Ltd., and melt-kneaded. The kneading conditions were implemented at a temperature of 300°C and a rotation speed of 300 rpm. After pelletizing by a strand pelletizer, it was dried at 130°C for 3 hours, and the resulting pellets were provided for injection molding. The evaluation results are shown in Table 1.

[0186] [Table 1]

[0187]

[0188] The results of the above-described examples and comparative examples will be described in comparison.

[0189] In Examples 1 to 8, by preparing a PPS resin composition containing (a) a PPS resin and (b) a cross-linked silicone elastomer in a specific composition, excellent toughness represented by tensile elongation at break and flame retardancy are achieved, and oozing resistance, elongation retention before and after long-term durability treatment, and tensile creep properties are exhibited. When Examples 6 to 8 having different Shore hardnesses of the cross-linked silicone elastomer are compared, Example 6 having a lower Shore hardness is superior in flame retardancy compared to Examples 7 and 8.

[0190] Compared with Examples 1 to 8, Comparative Example 1 does not contain a cross-linked silicone elastomer, so the tensile elongation at break, which is an indicator of toughness, is low, and the elongation retention before and after long-term durability treatment is also significantly poor. A PPS resin composition having both flame retardancy and toughness required for battery insulating components cannot be obtained. The flexural modulus is also high, and the flexibility required for battery insulating components is not satisfied.

[0191] Compared with Example 2, Comparative Examples 2 and 3 add an organosilicon compound that is not equivalent to component (b). In Comparative Example 2, the tensile elongation at break and flame retardancy are greatly reduced by the addition. It is presumed that the toughness is reduced due to the use of inorganic powder organosilicon powder. On the other hand, it can be seen that although Comparative Example 3 using silicone oil has excellent toughness and flame retardancy before heat treatment, the exudate components presumed to be derived from the silicone oil are generated on the surface of the molded product through heat treatment, and the elongation retention rate after heat treatment is also low, which is not suitable for battery insulating components used in long-term high-temperature environments.

[0192] Comparative Example 4 is inferior to Examples 1 to 8 in flame retardancy, long-term durability, and creep displacement because the compounding amount of the silicone elastomer having a cross-linked structure is large.

[0193] Comparative Examples 5 and 6 were at the level of thermoplastic elastomers, but were inferior in flame retardancy, long-term durability, and creep displacement as in Comparative Example 4. This is presumably because the thermoplastic elastomer had low flame retardancy and long-term durability, which deteriorated the physical properties of the resin composition.

Claims

1. A polyphenylene sulfide resin composition for a battery insulating member, which is a resin composition comprising (a) a polyphenylene sulfide resin and (b) a silicone elastomer having a cross-linked structure, in, 0.1 to 15.0 parts by weight of the (b) cross-linked silicone elastomer is mixed with 100 parts by weight of the (a) polyphenylene sulfide resin, and a specimen obtained by injection molding the resin composition has a flexural modulus of 3.1 GPa to 3.6 GPa in a flexural test based on ISO178-2010. 2 . The polyphenylene sulfide resin composition for a battery insulating member according to claim 1 , wherein the resin composition does not substantially contain (c) a thermoplastic elastomer.

3. The polyphenylene sulfide resin composition for a battery insulating member according to claim 1, wherein the flame retardancy of a sample obtained by injection molding the resin composition is V-0 in a measurement based on UL94 standards for a sample having a thickness of 1.0 mmt or less. 4 . The polyphenylene sulfide resin composition for a battery insulating member according to claim 1 , wherein a specimen obtained by injection molding the resin composition has a tensile elongation at break of 8% or more in a tensile test in accordance with ISO527-1, 2-2012. 5 . The polyphenylene sulfide resin composition for a battery insulating member according to claim 1 , wherein the (b) silicone elastomer having a cross-linked structure is fine particles having an average primary particle size of 100 nm to 10 μm. 6 . The polyphenylene sulfide resin composition for a battery insulating member according to claim 1 , wherein the (b) silicone elastomer having a cross-linked structure has a Shore A hardness of 60 HS or less. 7 . The polyphenylene sulfide resin composition for a battery insulating member according to claim 1 , wherein the structural unit derived from organopolysiloxane in the (b) cross-linked silicone elastomer accounts for 90% by weight or more.

8. A battery insulating member, which is made of the polyphenylene sulfide resin composition for a battery insulating member according to any one of claims 1 to 7.

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