Polyphenylene sulfide resin composition and molded article

Abstract

To provide a PPS resin composition that has extremely stable releasability even in continuous injection molding, that can reduce mold contamination during molding, and that has excellent toughness, and to provide a molded article. Provided is a polyphenylene sulfide resin composition obtained by blending 0.1-3 wt parts of (B) a release agent per 100 wt parts of (A) polyphenylene sulfide resin, the polyphenylene sulfide resin composition being characterized in that the total content of alkali metals and alkaline earth metals, excluding Li, in the polyphenylene sulfide resin composition is less than 200 ppm, and a molded article comprising the resin composition has an exothermic peak temperature (Tmc) associated with crystallization, observed by differential scanning calorimeter when the molded article is heated to 340℃ and melted, kept molten at 340℃ for 10 minutes, and then cooled at a rate of 20℃ / min, of 225-250℃.

Description

Polyphenylene sulfide resin composition and molded article

[0001] The present invention provides a polyphenylene sulfide resin composition that exhibits extremely excellent mold releasability during continuous injection molding, and also exhibits excellent toughness and mold fouling resistance.

[0002] Polyphenylene sulfide resin (hereinafter sometimes abbreviated as PPS resin) has a good balance of rigidity, heat resistance, hot water resistance, chemical resistance, and moldability, and is therefore widely used in electrical and electronic components, plumbing components, automotive components, and the like.

[0003] In particular, with the recent increase in energy density of automotive secondary batteries, the required heat resistance temperature has increased. Therefore, PPS resins are used as materials for heat-resistant insulating members. Furthermore, from the viewpoint of space saving in the internal structure of secondary batteries, insulating members are becoming smaller and thinner, and there is a demand for resin compositions that can be molded into molded articles having small and thin shapes.

[0004] Patent Document 1 discloses an insulating member for a battery made of a PPS resin composition having excellent toughness and moldability, which is obtained by adding a PPS resin having a cyclic PPS content within a specific range and polyethylene as a mold release agent within a specific range.

[0005] Patent Document 2 discloses a PPS resin composition having excellent heat aging resistance, which is obtained by blending an aromatic polyether ketone resin with a PPS resin, thereby increasing the exothermic peak temperature (Tmc) associated with crystallization, which is observed when the PPS resin is heated to 340°C by a differential scanning calorimeter, melted, and then cooled at a rate of 20°C / min.

[0006] Patent Document 3 discloses a gasket for a secondary battery that is made by adding a thermoplastic elastomer to a PPS resin to impart toughness, and is less susceptible to stress relaxation even when compressed under a certain strain, thereby maintaining airtightness for a long period of time.

[0007] Patent Document 4 discloses a gasket for a secondary battery made of a PPS resin composition that is imparted with releasability while suppressing a decrease in mechanical strength by adding an ester compound as a release agent to the PPS resin.

[0008] JP 2020-145178 A JP 2017-179041 A JP 2018-123307 A JP 2011-29167 A

[0009] PPS resin has a slower solidification rate than other engineering plastics. Therefore, it lacks rigidity during injection molding, resulting in poor moldability and poor releasability. Therefore, it is required to have stable and good releasability during continuous molding. Furthermore, insulating materials for secondary batteries are required to have good toughness to prevent cracking during assembly with other components and during use after assembly.

[0010] However, although the PPS resin composition described in Patent Document 1 improves the mold releasability by adding polyethylene as a mold release agent, the crystallization rate of the resin composition may decrease and the mold releasability may deteriorate due to the thermal history caused by resin retention and shear heat during continuous molding in injection molding, and the mold releasability was not satisfactory in the present invention.

[0011] Furthermore, Patent Documents 2 and 3 describe the use of a metal-containing PPS resin and the addition of a crystal nucleating agent to improve the melt crystallization temperature peak, but there is insufficient consideration given to improving the mold releasability during continuous molding and suppressing mold release resistance, and the mold releasability of the present invention is not satisfactory.

[0012] Patent Document 4 proposes a PPS resin composition for gaskets that has excellent toughness by blending a thermoplastic elastomer into the PPS resin, but it was found that the crystallization rate of the resin composition decreases due to thermal history caused by resin retention and shear heat during continuous molding in injection molding, resulting in poor mold releasability during molding. Furthermore, as the thermoplastic elastomer is blended into the PPS resin, mold fouling from the thermoplastic elastomer accumulates during continuous molding, which creates the problem of gradually worsening mold releasability during continuous molding, and the mold releasability and mold fouling properties of the present invention were not satisfactory.

[0013] Therefore, an object of the present invention is to provide a PPS resin composition and a molded article which have extremely stable mold releasability even during continuous injection molding, which can suppress mold contamination during molding (excellent mold contamination resistance), and which also have excellent toughness.

[0014] The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result have arrived at the present invention. Specifically, the present invention provides the following: (1) A polyphenylene sulfide resin composition comprising 100 parts by weight of (A) polyphenylene sulfide resin and 0.1 to 3 parts by weight of (B) a mold release agent, wherein the polyphenylene sulfide resin composition has a total content of alkali metals and alkaline earth metals excluding Li of less than 200 ppm, and wherein a molded article made of the polyphenylene sulfide resin composition is heated to 340°C and melted, held in the molten state at 340°C for 10 minutes, and then cooled at a rate of 20°C / min, and the exothermic peak temperature (Tmc) associated with crystallization is observed to be 225°C or higher and 250°C or lower, as measured with a differential scanning calorimeter. (2) The polyphenylene sulfide resin composition according to (1), wherein the (B) mold release agent is at least one selected from the group consisting of a polyol fatty acid ester compound and a carboxylic acid amide compound obtained by reacting a higher aliphatic monocarboxylic acid, a polybasic acid, and a diamine. (3) The polyphenylene sulfide resin composition according to (1) or (2), wherein a test piece obtained by injection molding the polyphenylene sulfide resin composition has a tensile break strain of 5% or more in a tensile test (ISO 527-1, 2). (4) The polyphenylene sulfide resin composition according to any one of (1) to (3), wherein a weight loss rate after heating at 320°C for 120 minutes is 0.5% by weight or less. (5) The polyphenylene sulfide resin composition according to any one of (1) to (4), wherein the blend amount of the thermoplastic elastomer (C) is 1 part by weight or less per 100 parts by weight of the polyphenylene sulfide resin (A). (6) The polyphenylene sulfide resin composition according to any one of (1) to (5), further comprising 0.005 to 0.15 parts by weight of (D) polyaryl ether ketone per 100 parts by weight of the polyphenylene sulfide resin (A). (7) The polyphenylene sulfide resin composition according to any one of (1) to (6), having a melt flow rate (measured in accordance with JIS K7210 at a temperature of 315°C and a load of 2160 g) of 20 g / 10 min or more and 90 g / 10 min or less.(8) The polyphenylene sulfide resin composition according to any one of (1) to (7), wherein the proportion of polyphenylene sulfide (A) in the polyphenylene sulfide resin composition is 95% by weight or more. (9) A molded article made of the polyphenylene sulfide resin composition according to any one of (1) to (8). (10) The molded article according to (9), wherein the surface having the widest area among the surfaces constituting the molded article has a ratio of area to thickness (area / thickness) of 200 to 50,000. (11) The surface having the widest area among the surfaces constituting the molded article has a thickness of 0.1 mm to 0.7 mm and / or an area of ​​100 mm. ２ Over 5000mm ２ (12) The molded article according to any one of (9) to (11), which is an insulating member for a battery.

[0015] According to the present invention, by adding a mold release agent in a specific range, by controlling the total content of alkali metals and alkaline earth metals excluding Li in the resin composition to less than a certain amount, and by controlling the exothermic peak temperature associated with crystallization when a molded article obtained by injection molding the resin composition remains molten and is then cooled within a specific range, it is possible to provide a PPS resin composition and molded article that have extremely stable mold releasability even during continuous injection molding and that are excellent in toughness and mold fouling resistance.

[0016] Schematic diagrams of a test piece for measuring mold release force. (a) is a top view, and (b) is a side view. Schematic diagrams of a thin-walled molded product for evaluating continuous moldability. (a) is a top view, and (b) is a side view. Schematic diagrams of a test piece for evaluating mold fouling properties. (a) is a front view, and (b) is a side view.

[0017] Hereinafter, embodiments of the present invention will be described in detail.

[0018] [(A) PPS Resin] The (A) PPS resin used in the present invention is a polymer having a repeating unit represented by the following structural formula (I).

[0019]

[0020] From the viewpoint of heat resistance, a polymer containing 70 mol % or more, and more preferably 90 mol % or more, of a polymer containing a repeating unit represented by the above structural formula is preferred. Furthermore, the PPS resin may be composed of a repeating unit having the following structure, etc., in an amount of less than 30 mol % of the repeating units.

[0021]

[0022] A preferred method for producing the PPS resin used in the present invention will be described below. First, the polyhalogenated aromatic compound, sulfidizing agent, polymerization solvent, molecular weight modifier, polymerization aid, and polymerization stabilizer used will be described.

[0023] [Polyhalogenated Aromatic Compound] A polyhalogenated aromatic compound refers to a compound having two or more halogen atoms per molecule. Specific examples include 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, and 1-methoxy-2,5-dichlorobenzene, with p-dichlorobenzene being preferred. While it is also possible to combine two or more different polyhalogenated aromatic compounds to form a copolymer, it is preferable to use a p-dihalogenated aromatic compound as the main component.

[0024] 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 mol of the sulfidizing agent, in order to obtain a PPS resin with a viscosity suitable for processing.

[0025] [Sulfidizing Agent] Examples of the sulfidizing agent include alkali metal sulfides, alkali metal hydrosulfides, and hydrogen sulfide.

[0026] Specific examples of alkali metal sulfides include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and mixtures of two or more of these, with sodium sulfide being preferred. These alkali metal sulfides can be used as hydrates, aqueous mixtures, or anhydrous forms.

[0027] Specific examples of alkali metal hydrosulfides include sodium hydrosulfide, potassium hydrosulfide, lithium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide, and mixtures of two or more of these, with sodium hydrosulfide being preferred. These alkali metal hydrosulfides can be used as hydrates, aqueous mixtures, or anhydrous forms.

[0028] Alternatively, a sulfidizing agent prepared in situ in the reaction system from an alkali metal hydrosulfide and an alkali metal hydroxide can be used. Alternatively, a sulfidizing agent can be prepared from an alkali metal hydrosulfide and an alkali metal hydroxide and then transferred to a polymerization vessel for use.

[0029] Alternatively, a sulfidizing agent prepared in situ in the reaction system from an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide and hydrogen sulfide can be used. Alternatively, a sulfidizing agent can be prepared from an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide and hydrogen sulfide, and then transferred to a polymerization vessel for use.

[0030] When a part of the sulfidizing agent is lost before the start of the polymerization reaction due to a dehydration operation or the like, the amount of the charged sulfidizing agent means the remaining amount obtained by subtracting the lost amount from the actual charged amount.

[0031] It is also possible to use an alkali metal hydroxide and / or an alkaline earth metal hydroxide together with the sulfidizing agent. Specific examples of the alkali metal hydroxide include sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, and mixtures of two or more of these. Specific examples of the alkaline earth metal hydroxide include calcium hydroxide, strontium hydroxide, barium hydroxide, etc., and among these, sodium hydroxide is preferably used.

[0032] When an alkali metal hydrosulfide is used as the sulfidizing agent, it is particularly preferable to use an alkali metal hydroxide simultaneously. The amount used is, for example, in the range of 0.95 to 1.20 mol, preferably 1.00 to 1.15 mol, and more preferably 1.005 to 1.100 mol per mol of the alkali metal hydrosulfide.

[0033] [Polymerization Solvent] It is preferable to use an organic polar solvent as the polymerization solvent. Specific examples include N-alkylpyrrolidones such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, caprolactams such as N-methyl-ε-caprolactam, aprotic organic solvents such as 1,3-dimethyl-2-imidazolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric triamide, dimethyl sulfone, and tetramethylene sulfoxide, and mixtures thereof. These are all preferably used because of their high reaction stability. Of these, N-methyl-2-pyrrolidone (hereinafter sometimes abbreviated as NMP) is particularly preferably used.

[0034] The amount of the organic polar solvent used is selected from the range of 2.0 to 10 moles, preferably 2.25 to 6.0 moles, more preferably 2.5 to 5.5 moles per mole of the sulfidizing agent.

[0035] [Molecular Weight Regulator] A monohalogen compound (which does not necessarily have to be an aromatic compound) can be used in combination with the polyhalogenated aromatic compound in order to form terminals in the resulting PPS resin or to regulate the polymerization reaction or molecular weight.

[0036] [Polymerization Aid] Using a polymerization aid is one preferred embodiment to obtain a PPS resin with a relatively high degree of polymerization in a shorter time. Here, polymerization aid refers to a substance that has the effect of increasing the viscosity of the resulting 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. These can be used alone or in combination of two or more. Among these, organic carboxylates and / or water are preferred.

[0037] The alkali metal carboxylate is a salt of a carboxylate represented by the general formula R(COOM) ｎ (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, anhydrous form, or aqueous solution. Specific examples of the alkali metal carboxylate include lithium acetate, sodium acetate, potassium acetate, sodium propionate, lithium valerate, sodium benzoate, sodium phenylacetate, potassium p-toluate, and mixtures thereof.

[0038] The alkali metal carboxylate may be formed by adding and reacting an organic acid with one or more compounds selected from the group consisting of alkali metal hydroxides, alkali metal carbonates, and alkali metal bicarbonates in approximately equal chemical equivalents. Among the alkali metal carboxylates, lithium salts are highly soluble in the reaction system and have a significant auxiliary effect, but are expensive, while potassium, rubidium, and cesium salts are thought to have insufficient solubility in the reaction system. Therefore, sodium acetate, which is inexpensive and has moderate solubility in the polymerization system, is most preferably used.

[0039] When these polymerization aids are used, the amount used is usually in the range of 0.01 mol to 0.7 mol per mol of the charged alkali metal sulfide, and in terms of obtaining a higher degree of polymerization, the range of 0.1 to 0.6 mol is preferred, and the range of 0.2 to 0.5 mol is more preferred.

[0040] The use of water as a polymerization aid is an effective means for obtaining a resin composition that has a high balance between fluidity and high toughness. In this case, the amount added is usually in the range of 0.5 to 15 moles per mole of the alkali metal sulfide charged, and in terms of obtaining a higher degree of polymerization, the range of 0.6 to 10 moles is preferred, and the range of 1 to 5 moles is more preferred.

[0041] The timing of addition of these polymerization aids is not particularly specified, and they may be added at any time during the pre-step, at the start of polymerization, or during the polymerization, as described below, or may be added in several divided portions, but when an alkali metal carboxylate is used as the polymerization aid, it is more preferable to add it at the start of the pre-step or at the start of polymerization from the viewpoint of ease of addition. When water is used as the polymerization aid, it is effective to add it during the polymerization reaction after charging the polyhalogenated aromatic compound.

[0042] [Polymerization Stabilizer] Polymerization stabilizers can be used to stabilize the polymerization reaction system and prevent side reactions. Polymerization stabilizers contribute to stabilizing the polymerization reaction system and suppress undesirable side reactions. One indicator of side reactions is the production of thiophenol, and the addition of a polymerization stabilizer can suppress the production of thiophenol. 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 above-mentioned alkali metal carboxylates also function as polymerization stabilizers and are therefore included in the polymerization stabilizers used in the present invention. Furthermore, when using an alkali metal hydrosulfide as a sulfidizing agent, it is particularly preferable to use an alkali metal hydroxide simultaneously. However, an excess amount of alkali metal hydroxide relative to the sulfidizing agent can also serve as a polymerization stabilizer.

[0043] These polymerization stabilizers can be used alone or in combination of two or more. The polymerization stabilizer is preferably used in a proportion of usually 0.02 to 0.2 mol, preferably 0.03 to 0.1 mol, more preferably 0.04 to 0.09 mol per mol of the charged alkali metal sulfide. If this proportion is too small, the stabilizing effect is insufficient, whereas if it is too large, it is economically disadvantageous and the polymer yield tends to decrease.

[0044] The timing of adding the polymerization stabilizer is not particularly specified, and it may be added at any time during the pre-step described below, at the start of polymerization, or during polymerization, or may be added in multiple batches, but it is more preferable to add it simultaneously at the start of the pre-step or at the start of polymerization.

[0045] Next, a preferred method for producing the PPS resin used in the embodiment of the present invention will be specifically described in order of pre-processing, polymerization reaction process, recovery process, and post-treatment process.

[0046] [Pre-step] The sulfidizing agent is usually used in the form of a hydrate, and it is preferable to heat the mixture containing the organic polar solvent and the sulfidizing agent before adding the polyhalogenated aromatic compound, and remove excess water from the system. If too much water is removed by this operation, it is preferable to add water to make up for the shortage.

[0047] As described above, an alkali metal sulfide prepared in situ in the reaction system from an alkali metal hydrosulfide and an alkali metal hydroxide, or in a vessel separate from the polymerization vessel, can also be used as the sulfidizing agent. While there are no particular limitations on this method, a preferred example is a method in which an alkali metal hydrosulfide and an alkali metal hydroxide are added to an organic polar solvent in an inert gas atmosphere at a temperature ranging from room temperature to 150°C, preferably from room temperature to 100°C, and the mixture is heated to at least 150°C or higher, preferably 180 to 245°C, under atmospheric pressure or reduced pressure, to distill off water. A polymerization aid may also be added at this stage. To promote the distillation of water, the reaction may be carried out by adding toluene or the like.

[0048] In the polymerization reaction, the amount of water in the polymerization system is preferably 0.5 to 10.0 mol per mol of the charged sulfidizing agent. Here, the amount of water in the polymerization system is the amount of water charged to the polymerization system minus the amount of water removed from the polymerization system. The charged water may be in any form, such as water, an aqueous solution, or water of crystallization.

[0049] [Polymerization Reaction Step] It is preferable to produce PPS resin powder and granules by reacting a sulfidizing agent with a polyhalogenated aromatic compound in an organic polar solvent at a temperature range of 200°C or higher but lower than 290°C.

[0050] To start the polymerization reaction, the sulfidizing agent and the polyhalogenated aromatic compound are added to an organic polar solvent, preferably in an inert gas atmosphere, at a temperature ranging from room temperature to 215°C, and preferably from 100 to 215°C. A polymerization aid may also be added at this stage. These raw materials may be added in any order, or simultaneously.

[0051] The mixture is usually heated to a temperature in the range of 200° C. to 290° C. There are no particular restrictions on the rate of temperature increase, but a rate of 0.01 to 5° C. / min is usually selected, and a range of 0.1 to 3° C. / min is more preferred.

[0052] In general, the temperature is finally raised to 250 to 290° C., and the reaction is carried out at that temperature for usually 0.25 to 50 hours, preferably 0.5 to 20 hours.

[0053] A method in which, before reaching the final temperature, the reaction is carried out for a certain period of time at, for example, 200° C. to 245° C., and then the temperature is raised to 270° C. to 290° C. is effective in obtaining a higher degree of polymerization. In this case, the reaction time at 200° C. to 245° C. is usually selected from the range of 0.25 to 20 hours, preferably 0.25 to 10 hours.

[0054] In order to obtain a polymer with a higher degree of polymerization, it is effective to carry out the polymerization in multiple stages. When carrying out the polymerization in multiple stages, it is effective to carry out the polymerization at a time when the conversion of the polyhalogenated aromatic compound in the system at 245°C reaches 40 mol% or more, preferably 60 mol%.

[0055] The conversion rate of polyhalogenated aromatic compounds (abbreviated as PHA herein) is a value calculated by the following formula: The amount of remaining PHA can usually be determined by gas chromatography.

[0056] (A) When the polyhalogenated aromatic compound is added in excess relative to the alkali metal sulfide in terms of molar ratio: Conversion rate = [PHA charge amount (mol) - remaining PHA amount (mol)] / [PHA charge amount (mol) - excess PHA amount (mol)] (B) In cases other than (A) above: Conversion rate = [PHA charge amount (mol) - remaining PHA amount (mol)] / [PHA charge amount (mol)].

[0057] [Recovery Step] After the polymerization is completed, solid matter is recovered from the polymerization reaction product containing the polymer, solvent, etc.

[0058] In the method for producing (A) PPS resin, after polymerization is complete, solid matter is recovered from a polymerization reaction product containing a polymer, a solvent, and the like. A preferred recovery method is a method (quench method) in which the product is slowly cooled after the polymerization reaction is complete to recover particulate polymer. The cooling rate is not particularly limited, but is typically about 0.1°C / min to 3°C / min. It is not necessary to cool slowly at the same rate throughout the entire cooling process; a method may be used in which the product is slowly cooled at a rate of 0.1 to 1°C / min until the polymer particles crystallize and precipitate, and then slowly cooled at a rate of 1°C / min or more.

[0059] [Post-Treatment Step] In the present invention, the PPS resin obtained through the polymerization reaction step and recovery step is preferably treated with an acid as a post-treatment step.

[0060] The acid used in the acid treatment in the present invention is not particularly limited as long as it does not have the effect of decomposing the PPS resin, and examples thereof include acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid, and propylic acid. Of these, acetic acid and hydrochloric acid are more preferably used, but acids such as nitric acid that decompose and deteriorate the PPS resin are not preferred.

[0061] When an aqueous acid solution is used, the water is preferably distilled water or deionized water. The aqueous acid solution preferably has a pH of 1 to 7, more preferably a pH of 2 to 4. A pH higher than 7 is undesirable because it increases the metal content of the PPS resin, and a pH lower than 1 is undesirable because it increases the amount of volatile components in the PPS resin.

[0062] The acid treatment method preferably involves immersing the PPS resin in an acid or an aqueous solution of an acid, and stirring and heating can be performed as necessary. The heating temperature is preferably 80 to 250°C, more preferably 120 to 200°C, and even more preferably 150 to 200°C. Temperatures below 80°C result in a small acid treatment effect and an increased metal content, while temperatures above 250°C result in excessively high pressure, which is undesirable from a safety perspective. Furthermore, when the PPS resin is immersed in an aqueous acid solution for treatment, the pH is preferably less than 8, more preferably 2 to 8, due to the acid treatment. A pH above 8 is undesirable because the metal content of the resulting PPS resin increases.

[0063] The acid treatment time is preferably a time sufficient for the reaction between the PPS resin and the acid to reach a sufficient equilibrium, and is preferably 2 to 24 hours when treated at 80°C, and 0.01 to 5 hours when treated at 200°C.

[0064] The ratio of the PPS resin to the acid or aqueous acid solution in the acid treatment is preferably such that the PPS resin is sufficiently immersed in the acid or aqueous acid solution, and the amount of acid or aqueous acid solution per 500 g of PPS resin is preferably 0.5 to 500 L, more preferably 1 to 100 L, and even more preferably 2.5 to 20 L. Using an amount of acid or aqueous acid solution of 0.5 L or more per 500 g of PPS resin allows the PPS resin to be washed while sufficiently immersed in the aqueous solution, and also reduces the metal content of the PPS resin, which is preferable.

[0065] These acid treatments are carried out by adding a predetermined amount of PPS resin to a predetermined amount of water and acid, heating and stirring the mixture in a pressure vessel, or by continuous acid treatment. Separating the aqueous solution and PPS resin from the treatment solution after acid treatment can be easily achieved by filtration using a sieve or filter, including natural filtration, pressure filtration, vacuum filtration, and centrifugal filtration. To remove the acid and impurities remaining on the surface of the PPS resin separated from the treatment solution, it is preferable to wash the PPS resin several times with cold or warm water. Examples of washing methods include filtering the PPS resin while pouring water over it on a filter, or adding the separated PPS resin to pre-prepared water and then filtering it again to separate the aqueous solution from the PPS resin. The water used for washing is preferably distilled water or deionized water. It is believed that acid-treated PPS resin undergoes changes in its terminal structure, but it is difficult to express the structure of the PPS resin obtained by acid treatment in a general formula, and it is also difficult to identify it based on its properties. Therefore, it can only be identified by the process (acid treatment) used to obtain the PPS resin.

[0066] In the present invention, hot water treatment can also be carried out before the acid treatment step. The hot water treatment temperature is preferably 80 to 250°C, more preferably 120 to 200°C, and even more preferably 150 to 200°C. Temperatures below 80°C are not preferred because the hot water treatment effect is small and the amount of volatilized gas generated increases. There are no particular limitations on the hot water treatment procedure, and it can be carried out by adding a predetermined amount of PPS resin to a predetermined amount of water and heating and stirring in a pressure vessel, or by continuously carrying out hot water treatment. After the hot water treatment, it is preferable to wash the PPS resin several times with water or warm water to remove impurities remaining on the surface of the PPS resin separated from the treatment solution.

[0067] Since decomposition of the PPS end groups during these acid treatments and hot water treatments is undesirable, it is desirable to carry out the acid treatments and hot water treatments in an inert atmosphere, such as nitrogen, helium, or argon, with a nitrogen atmosphere being preferred from an economical standpoint.

[0068] In the present invention, it is preferable to include a step of washing the PPS resin with an organic solvent before the step of acid treatment or hot water treatment, and the method is as follows: The organic solvent used for washing the PPS resin is not particularly limited as long as it does not have the action of decomposing the PPS resin, and examples thereof include nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, 1,3-dimethylimidazolidinone, hexamethylphosphoramide, and piperazinones; sulfoxide / sulfone solvents such as dimethyl sulfoxide, dimethyl sulfone, and sulfolane; ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, and acetophenone; dimethyl ether, dipropyl ether, dioxane, and tetrahydrofuran; Examples of suitable organic solvents include ether solvents such as furan, halogenated solvents such as chloroform, methylene chloride, trichloroethylene, ethylene dichloride, 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, N-methyl-2-pyrrolidone, acetone, dimethylformamide, and chloroform are particularly preferred. These organic solvents may be used alone or in combination.

[0069] Methods for washing with an organic solvent include immersing the PPS resin in the organic solvent, and stirring or heating can be performed as necessary. There are no particular limitations on the washing temperature when washing the PPS resin with an organic solvent, and any temperature between room temperature and approximately 300°C can be selected. While higher washing temperatures tend to increase the cleaning efficiency, a washing temperature between room temperature and 150°C is usually sufficient. Washing can also be performed under pressure in a pressure vessel at a temperature above the boiling point of the organic solvent. There are also no particular limitations on the washing time. While depending on the washing conditions, a batch-type washing period of 5 minutes or longer usually achieves sufficient results. Continuous washing is also possible. The acid treatment, hot water treatment, and washing with an organic solvent can also be performed in appropriate combinations.

[0070] In the present invention, from the viewpoint of obtaining a polyphenylene sulfide resin composition excellent in retention stability, a method is preferred 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, and then acid treatment is carried out.

[0071] In order to achieve excellent toughness, the PPS resin (A) in the present invention is preferably a substantially linear PPS resin and is not preferably subjected to a crosslinking treatment such as a thermal oxidation treatment. Furthermore, the PPS resin (A) used in the present invention may be a mixture of multiple PPS resins (A) having different melt viscosities.

[0072] There are no particular restrictions on the weight-average molecular weight (Mw) of the PPS resin (A) used in the present invention, but in order to obtain better mechanical properties, the weight-average molecular weight is preferably 30,000 to 150,000. It is more preferably 40,000 to 130,000, even more preferably 45,000 to 110,000, and even more preferably 50,000 to 100,000. The weight-average molecular weight is preferably 30,000 or more in order to obtain the mechanical properties of the PPS resin itself. On the other hand, by setting the weight-average molecular weight to 150,000 or less, the melt viscosity does not become too high and molding processing is easy.

[0073] The weight average molecular weight in the present invention is a value calculated in terms of polystyrene using a gel permeation chromatography (GPC) manufactured by Senshu Scientific Co., Ltd.

[0074] The melt flow rate of the PPS resin (A) used in the present invention (measured in accordance with JIS K7210 at a temperature of 315°C and a load of 2160 g) is preferably 50 to 500 g / 10 min, more preferably 70 to 380 g / 10 min.

[0075] [(B) Mold Release Agent] The PPS resin composition of the present invention contains a (B) mold release agent. The incorporation of the (B) mold release agent reduces the mold release resistance between the mold and the molded article during injection molding, improving mold releasability, suppressing molding defects such as molded article deformation due to ejector pin protrusion during mold release, and shortening the molding cycle, which is expected to improve moldability.

[0076] The amount of the (B) mold release agent used in the present invention is 0.1 to 3 parts by weight per 100 parts by weight of the (A) PPS resin. A range of 0.15 to 2 parts by weight is more preferable, and a range of 0.3 to 1.2 parts by weight is even more preferable. If the amount of the mold release agent exceeds 3 parts by weight, the amount of gas generated, which leads to mold contamination, increases. This increases the frequency of mold maintenance during continuous molding, reducing moldability. Furthermore, the appearance of the molded product also deteriorates. Furthermore, if the amount of the (B) mold release agent is less than 0.1 parts by weight, the release agent's effectiveness as a mold release agent is not fully exerted, and the mold release resistance between the molded product and the mold increases, which is undesirable.

[0077] The release agent (B) used in the present invention is preferably at least one selected from polyol fatty acid ester compounds and carboxylic acid amide compounds obtained by reacting a higher aliphatic monocarboxylic acid, a polybasic acid, and a diamine. By incorporating such a release agent, the release resistance during injection molding can be reduced, and improved release properties can be expected.

[0078] Examples of polyol fatty acid ester compounds include pentaerythritol tetrastearate, dipentaerythritol hexastearate, tripentaerythritol hexastearate, polypentaerythritol stearate, dipentaerythritol adipic stearate, and dipentaerythritol adipic stearate oligomer, with pentaerythritol tetrastearate being preferred.

[0079] Regarding the carboxylic acid amide-based compounds obtained by reacting a higher aliphatic monocarboxylic acid, a polybasic acid, and a diamine, specific examples of the higher aliphatic monocarboxylic acid include saturated aliphatic monocarboxylic acids and hydroxycarboxylic acids having 16 or more carbon atoms, such as palmitic acid, stearic acid, behenic acid, montanic acid, and 12-hydroxystearic acid, and stearic acid is particularly preferred.

[0080] Specific examples of the polybasic acid include succinic acid, adipic acid, sebacic acid, and pimelic acid, with sebacic acid being particularly preferred.

[0081] Specific examples of the diamine include ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, metaxylylenediamine, paraxylylenediamine, tolylenediamine, and phenylenediamine, with ethylenediamine being particularly preferred.

[0082] Furthermore, it is preferable that the carboxylic acid amide compound contains an antioxidant, as this leads to the prevention of mold fouling.

[0083] In addition to the above, examples of release agents that can be used in the present invention include, but are not limited to, bis-urea, silicone-based release agents, stearamide, montanic acid esters, their half esters, stearates, stearyl alcohol, polyethylene, ethylenediamine-stearic acid polycondensates, ethylenediamine-montanic acid polycondensates, etc. In the present invention, it is of course possible to use two or more of these release agents in combination.

[0084] [(C) Thermoplastic Elastomer] Generally, a thermoplastic elastomer (C) is blended into a PPS resin for the purpose of improving the toughness of the resin. However, in the present invention, it is preferable to avoid blending the thermoplastic elastomer (C) as much as possible in order to obtain good molding processability.

[0085] When a (C) thermoplastic elastomer is blended, the blending amount of the (C) thermoplastic elastomer in an embodiment of the present invention is preferably 1 part by weight or less per 100 parts by weight of the (A) polyphenylene sulfide resin. The blending amount of the (C) thermoplastic elastomer per 100 parts by weight of the (A) polyphenylene sulfide resin is more preferably less than 0.8 parts by weight, and even more preferably less than 0.5 parts by weight. It is particularly preferable not to blend the (C) thermoplastic elastomer. By keeping the content of the (C) thermoplastic elastomer at 1 part by weight or less, the amount of volatile components, particularly volatile components derived from the thermoplastic elastomer, generated during heat melting of the PPS resin composition is suppressed, so that adhesion of the volatile components to the mold and deterioration of mold releasability during continuous molding can be suppressed, which is preferable from the viewpoint of moldability.

[0086] Examples of such (C) thermoplastic elastomer include ethylene-butene copolymer, ethylene-propylene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-styrene polymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-ethyl acrylate-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, and the like.

[0087] In a preferred embodiment, the thermoplastic elastomer (C) used in the present invention contains a reactive functional group from the viewpoint of forming an intermolecular bond with the PPS resin (A).

[0088] The reactive functional group possessed by the thermoplastic elastomer is not particularly limited, and specific examples thereof include a vinyl group, an epoxy group, a carboxyl group, an acid anhydride group, an ester group, an aldehyde group, a carbonyldioxy group, a haloformyl group, an alkoxycarbonyl group, an amino group, a hydroxyl group, a styryl group, a methacryl group, an acrylic group, a ureido group, a mercapto group, a sulfide group, an isocyanate group, and a hydrolyzable silyl group.

[0089] The PPS resin composition of the present invention preferably contains (D) polyaryl ether ketone, which will be described later. Furthermore, the PPS resin composition of the present invention may contain other resins added thereto, other than (A) PPS resin, (B) mold release agent, (C) thermoplastic elastomer, and (D) polyaryl ether ketone, as long as the effects of the present invention are not impaired.

[0090] Specific examples thereof include polyamide, polybutylene terephthalate, polyethylene terephthalate, polyketone, liquid crystal polymer, 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), and polychlorotrifluoroethylene (PCTFE), but are not limited to these.

[0091] To improve toughness and other properties, the PPS resin composition of the present invention may contain an organic silane compound having at least one functional group selected from the group consisting of an epoxy group, an amino group, an isocyanate group, a hydroxyl group, a mercapto group, and a ureido group as an additive (E), within the scope of not impairing the effects of the present invention. Specific examples of the silane compound as the additive (E) include epoxy group-containing alkoxysilane compounds such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; mercapto group-containing alkoxysilane compounds such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane; ureido group-containing alkoxysilane compounds such as γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, and γ-(2-ureidoethyl)aminopropyltrimethoxysilane; γ-isocyanatepropyltriethoxysilane, γ-isocyanatepropyltrimethoxysilane, and γ-isocyanatepropyltriethoxysilane; Examples of suitable alkoxysilanes include isocyanate group-containing alkoxysilane compounds such as anthracene propylmethyldimethoxysilane, γ-isocyanate propylmethyldiethoxysilane, γ-isocyanate propylethyldimethoxysilane, γ-isocyanate propylethyldiethoxysilane, and γ-isocyanate propyltrichlorosilane; amino group-containing alkoxysilane compounds such as γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane; and hydroxyl group-containing alkoxysilane compounds such as γ-hydroxypropyltrimethoxysilane and γ-hydroxypropyltriethoxysilane. Among these, from the viewpoint of reactivity, epoxy group-containing alkoxysilane compounds, amino group-containing alkoxysilane compounds, and isocyanate-containing alkoxysilane compounds are preferred, with isocyanate group-containing alkoxysilane compounds being particularly preferred. Excellent reactivity translates into excellent toughness and mold fouling resistance.

[0092] The amount of the organosilane compound added is preferably 0.1 to 3 parts by weight, and particularly preferably 0.15 to 0.6 parts by weight, per 100 parts by weight of the (A) PPS resin. Adding an amount of the organosilane compound of 0.1 parts by weight or more not only achieves a sufficient effect of improving toughness, but also suppresses the occurrence of burrs and mold staining during molding. Adding an amount of the organosilane compound of 3 parts by weight or less is preferable because it suppresses the amount of gas generation while maintaining the effect of improving toughness, leading to the suppression of mold staining, suppresses an increase in melt viscosity, enables injection molding of thin-walled shapes, and provides excellent molding processability.

[0093] It is possible to incorporate an inorganic filler into the PPS resin composition of the present invention. However, since the incorporation of an inorganic filler leads to a decrease in toughness, it is preferable to minimize the amount of inorganic filler incorporated, if any, in order to obtain good toughness.

[0094] When an inorganic filler is blended, the amount is preferably less than 10 parts by weight, more preferably less than 1 part by weight, and even more preferably less than 0.1 parts by weight, relative to 100 parts by weight of the (A) PPS resin. It is particularly preferable that no inorganic filler is blended.

[0095] Specific examples of such inorganic fillers include fibrous fillers such as glass fibers, carbon fibers, carbon nanotubes, carbon nanohorns, potassium titanate whiskers, zinc oxide whiskers, calcium carbonate whiskers, wollastonite whiskers, aluminum borate whiskers, aramid fibers, alumina fibers, silicon carbide fibers, ceramic fibers, asbestos fibers, gypsum fibers, and metal fibers; fullerenes, talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, silica, bentonite, asbestos, silicates such as alumina silicate, metal compounds such as silicon oxide, magnesium oxide, alumina, zirconium oxide, titanium oxide, and iron oxide; carbonates such as calcium carbonate, magnesium carbonate, and dolomite; sulfates such as calcium sulfate and barium sulfate; hydroxides such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide; glass beads, glass flakes, glass powder, ceramic beads, boron nitride, silicon carbide, carbon black, silica, and graphite. These inorganic fillers may be hollow, and two or more types may be used in combination. These inorganic fillers may also be pretreated with a coupling agent before use.

[0096] The PPS resin composition of the present invention may contain other components, such as antioxidants and heat stabilizers (hydroquinone-based), weathering agents (resorcinol-based, salicylate-based, benzotriazole-based, benzophenone-based, hindered amine-based, etc.), pigments (cadmium sulfide, phthalocyanine, coloring carbon black, etc.), dyes (nigrosine, etc.), plasticizers (octyl p-oxybenzoate, N-butylbenzenesulfonamide, etc.), antistatic agents (alkyl sulfate-type anionic antistatic agents, quaternary ammonium salt-type cationic antistatic agents, nonionic antistatic agents such as polyoxyethylene sorbitan monostearate, betaine-type amphoteric antistatic agents, etc.), flame retardants ( For example, typical additives such as red phosphorus, phosphate esters, melamine cyanurate, hydroxides such as magnesium hydroxide and aluminum hydroxide, ammonium polyphosphate, brominated polystyrene, brominated polyphenylene ether, brominated polycarbonate, brominated epoxy resins, or combinations of these brominated flame retardants with antimony trioxide, heat stabilizers, lubricants such as calcium stearate, aluminum stearate, and lithium stearate, strength improvers such as bisphenol epoxy resins such as bisphenol A, novolac phenol epoxy resins, and cresol novolac epoxy resins, ultraviolet inhibitors, colorants, flame retardants, and foaming agents may be added.

[0097] The method for producing the PPS resin composition of the present invention is not particularly limited, but a representative example is a method in which the raw materials are fed into a commonly known melt mixer such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll, and kneaded at a temperature of 280 to 380°C. The order in which the raw materials are mixed is also not particularly limited, and any of the following methods may be used: a method in which all raw materials are blended and then melt-kneaded by the above-mentioned method; a method in which some raw materials are blended and then melt-kneaded by the above-mentioned method, and then the remaining raw materials are blended and melt-kneaded; or a method in which some raw materials are blended and then the remaining raw materials are mixed using a side feeder while melt-kneading in a single-screw or twin-screw extruder. Furthermore, it is of course possible to add minor additive components to the mixture before molding after the other components have been blended and pelletized by the above-mentioned method or the like.

[0098] In order to improve mold releasability during continuous molding, the PPS resin composition of the present invention must have a total content of alkali metals and alkaline earth metals excluding Li of less than 200 ppm. Possible combinations include blending only alkali metals excluding Li, blending only alkaline earth metals, and blending alkali metals and alkaline earth metals excluding Li, but these are not particularly limited. Such PPS resin compositions have a fast crystallization rate, and crystallization proceeds stably even when the resin stagnates during continuous molding. This increases the rigidity during ejection when releasing the molded product, and thus promises good mold releasability. The total content of alkali metals and alkaline earth metals excluding Li in the PPS resin composition is preferably less than 100 ppm, more preferably less than 50 ppm. Examples of alkali metals excluding Li include Na and K, and it is more preferable to avoid the inclusion of Na. Examples of alkaline earth metals include Ca. The amount of Li in the PPS resin composition is not limited.

[0099] The total content of alkali metals and alkaline earth metals excluding Li in a PPS resin composition is measured as follows: The PPS resin composition is incinerated in an electric furnace at 500°C, and the resulting incinerated material is diluted with a 0.1 N aqueous solution of hydrochloric acid and a 0.1% aqueous solution of lanthanum chloride to obtain a sample solution, which is then measured by atomic absorption spectrometry using an atomic absorption spectrophotometer.

[0100] The method for reducing the total content of alkali metals and alkaline earth metals excluding Li in the PPS resin composition to less than 200 ppm is not particularly limited, as long as such a PPS resin composition can be obtained. For example, by blending a PPS resin that has been subjected to an acid treatment in a post-treatment step, the total content of alkali metals and alkaline earth metals excluding Li can be reduced to less than 200 ppm.

[0101] The temperature-decreasing crystallization temperature of a molded article made of the PPS resin composition of the present invention is 225°C or higher but lower than 250°C. It is preferably 226°C or higher but lower than 238°C, and more preferably 228°C or higher but lower than 232°C. If the temperature-decreasing crystallization temperature of a molded article is lower than 225°C, the crystallization rate is slow. Therefore, if the resin stagnates during continuous molding, the molded article will lack rigidity when ejected from the mold for release, resulting in deformation during release, and the mold releasability of the present invention will not be satisfactory. Furthermore, if the temperature exceeds 250°C, the molded article will have a high degree of crystallization and a reduced toughness, failing to exhibit the good toughness of the present invention. Here, the temperature-decreasing crystallization temperature refers to the exothermic peak temperature (Tmc) associated with crystallization observed when a molded article made of a PPS resin composition is heated to 340°C using a differential scanning calorimeter, melted, held at 340°C in a molten state for 10 minutes, and then cooled at a rate of 20°C / min.

[0102] The molded product used to measure Tmc was a molded product having the opening shown in Figure 2 (molded product size: length 46 mm, width 22 mm, thickness 0.6 mm, maximum rib height 4 mm). Ten consecutive shots were molded at a cylinder temperature of 330°C, a mold temperature of 150°C, an injection pressure set to 180 MPa, the injection speed set so that the filling time at the VP switching position where 90% of the molded product is filled is 0.3 second, and during the dwelling step, the dwelling speed was 30 mm / sec, the dwelling time was 1 second, and the dwell pressure was set within a range where sink marks do not occur, with 50% of the peak filling pressure as a guideline. The molded product used was the product obtained from the 10th shot (molding machine used: Sumitomo Heavy Industries, Ltd. "SE-50DUZ"). That is, the temperature-lowering crystallization temperature in the present invention is a value measured by holding a molded article obtained after a resin composition has been molten and retained for a certain period of time in an injection molding machine at a temperature equal to or higher than the melting point for a certain period of time using a differential scanning calorimeter, and represents the temperature-lowering crystallization temperature after molten retention.

[0103] As described above, methods for obtaining a stable Tmc even during melt retention include, for example, adding a crystal nucleating agent as an additive (E), or repeatedly washing with an organic solvent during polymerization and with warm water at about 80°C or the above-mentioned hot water to remove residual oligomers and residual salts, followed by blending an acid-treated PPS resin, or blending a PPS resin that has not been subjected to a heat treatment after polymerization and recovery treatment. However, the present invention is not limited to these methods.

[0104] The nucleating agent used as the additive (E) may be a conventional additive such as an inorganic nucleating agent or an organic nucleating agent, such as talc, silica, kaolin, clay, etc. The type of nucleating agent is not particularly limited, but examples include inorganic nucleating agents and organic nucleating agents, with organic nucleating agents being particularly preferred.

[0105] Examples of the organic crystal nucleating agent include sorbitol compounds and metal salts thereof; phosphate metal salts; rosin compounds; amide compounds such as decanedicarboxylic acid dibenzoylhydrazide, hexanedicarboxylic acid dibenzoylhydrazide, 1,4-cyclohexanedicarboxylic acid dicyclohexylamide, trimesic acid amide, anilide compounds, 2,6-naphthalenedicarboxylic acid dicyclohexylamide, N,N'-dibenzoyl-1,4-diaminocyclohexane, N,N'-dicyclohexanecarbonyl-1,5-diaminonaphthalene, and octanedicarboxylic acid dibenzoylhydrazide; aliphatic Examples of suitable organic compounds and polymer compounds include metal carboxylates, metal salts of aromatic carboxylates, aromatic phosphonic acids and metal salts, metal salts of aromatic phosphates, metal salts of aromatic sulfonic acids, metal salts of β-diketones, metal salts of carboxyl groups, organic phosphorus compounds, polypropylene, polybutadiene, polystyrene, AS resin, ABS resin, poly(acrylic acid), poly(acrylic acid ester), poly(methacrylic acid), poly(methacrylic acid ester), polyamide 6, polyamide 46, polyamide 66, polyamide 6T, polyamide 9T, polyamide 10T, and polyaryl ether ketone. Among these, polymer compounds having a carbonyl group are preferred, and (D) polyaryl ether ketone is particularly preferred.

[0106] [(D) Polyaryletherketone] Examples of (D) polyaryletherketone include polyetherketone, polyetheretherketone, polyetheretheretherketone, polyetheretherketoneketone, and polyetherketoneketone. Among these, polyetheretherketone is particularly preferred due to its high effect of improving the crystallization rate.

[0107] The preferred amount of organic crystal nucleating agent added is 0.005 to 0.15 parts by weight, more preferably 0.01 to 0.1 parts by weight, and particularly preferably 0.03 to 0.08 parts by weight, per 100 parts by weight of (A) PPS resin. By adding an amount of organic crystal nucleating agent of 0.005 parts by weight or more, a sufficient crystallization rate can be obtained. By adding an amount of 0.15 parts by weight or less, fracture originating from the nucleating agent can be suppressed, and toughness can be maintained, which is preferred.

[0108] The PPS resin composition of the present invention preferably has a melt flow rate (measured in accordance with JIS K7210 at a temperature of 315°C and a load of 2160 g) of 20 to 90 g / 10 min. 30 to 80 g / 10 min is more preferred, and 50 to 70 g / 10 min is even more preferred. A melt flow rate of 20 g / 10 min or higher is preferred because it maintains the fluidity of the resin composition and ensures that the resin composition sufficiently fills a mold during injection molding of a thin-walled molded product. A melt flow rate of 90 g / 10 min or lower is preferred because it can suppress the generation of flash during injection molding and provides excellent moldability. To obtain a PPS resin composition with such a melt flow rate, the molecular weight distribution obtained by gel permeation chromatography (GPC) measurement of the resin composition can be adjusted to 60,000 or more and 180,000 or less. If the modulus is 60,000 or more, a test piece that fractures ductilely can be obtained, but if it exceeds 180,000, the viscosity of the resin composition becomes high and moldability deteriorates. Therefore, the modulus is preferably 70,000 or more and 160,000 or less, more preferably 80,000 or more and 140,000 or less, and most preferably 90,000 or more and 130,000 or less from the viewpoint of the balance between toughness and viscosity.

[0109] The PPS resin composition of the present invention preferably has a tensile break strain of 5% or more in a tensile test (ISO 527-1, 2) of a test piece obtained by injection molding the PPS resin composition. A tensile break strain of 8% or more is more preferable, and a tensile break strain of 10% or more is even more preferable. A tensile break strain of 5% or more indicates excellent toughness of the PPS resin composition, and is necessary from the perspective of ensuring safety because it can suppress cracking during actual use when, for example, a thin-walled molded product is fitted. A tensile break strain of less than 5% is undesirable because it tends to fracture brittlely without reaching the yield strength, causing practical problems. The higher the elongation, the more preferable the upper limit of the tensile break strain, and although there is no particular restriction, the upper limit is practically around 300%. To obtain a PPS resin composition with such a good tensile break strain, for example, the use of a PPS resin with a high weight-average molecular weight or the addition of an organosilane compound to the resin composition are preferred methods.

[0110] From the viewpoint of moldability, the PPS resin composition of the present invention preferably has a weight loss rate of 0.5 wt% or less after heating at 320°C for 120 minutes, more preferably 0.3 wt% or less, and even more preferably 0.25 wt% or less. A weight loss rate of 0.5 wt% or less is preferable because it suppresses mold contamination during molding, provides excellent moldability, and maintains electrolyte resistance. The weight loss rate is measured by heating the PPS resin composition at 320°C for 120 minutes and expressing the weight loss before and after heating as a percentage of the weight before heating. Here, the weight change rate can be determined as the amount of gas generated during heat melting. To obtain a PPS resin composition with a weight change rate within the above range, it is preferable to wash the PPS resin with an organic solvent, for example, in a post-treatment step in the PPS production method. Another preferred method is to minimize the content of thermoplastic elastomer in the PPS resin composition.

[0111] In the PPS resin composition of the present invention, the proportion of the PPS resin (A) in the resin composition is preferably 95% by weight or more, more preferably 97% by weight or more, and even more preferably 98% by weight or more, from the viewpoints of moldability and toughness. By setting the proportion of the PPS resin (A) in the PPS resin composition to 95% by weight or more, excellent fluidity and toughness can be obtained. The upper limit of the proportion of the PPS resin is preferably 99.5% by weight or less, taking into account the amount of the flame retardant (B), which is an essential component, added.

[0112] The PPS resin composition of the present invention has excellent crystallization properties, mold releasability, and mold fouling resistance, which make it extremely excellent in mold releasability during continuous molding, making it useful for thin-walled molded products. In thin-walled molded products such as insulating plate-like members, the surface with the largest area is generally used as the ejector pin protruding surface, but when released from the mold in injection molding, the thinner the thickness of the molded product from which the ejector pin protrudes relative to the area of ​​the protruding surface, the more likely the molded product is to deform during release.

[0113] The PPS resin composition of the present invention has excellent mold releasability in thin-walled shapes and can suppress deformation, and is therefore useful for molded articles having a shape in which the surface having the largest area among the surfaces constituting the molded article has an area-to-thickness ratio (area / thickness) of from 200 to 50,000, and a more preferred range for the area-to-thickness ratio is from 250 to 20,000. The larger this area / thickness ratio, the more likely deformation occurs during mold release.

[0114] The specific shape of the useful molded article is preferably such that the surface having the widest area among the constituent surfaces has a thickness of 0.1 mm or more and 0.7 mm or less and / or an area of ​​100 mm ２ Over 5000mm ２ The following thin-walled shapes are possible. A more preferable area range is 100 mm ２ Over 1500mm ２ The following compact shapes are available:

[0115] As described above, the PPS resin composition of the present invention not only has the excellent insulating properties, heat resistance, and chemical resistance inherent to PPS resin, but also has excellent crystallization properties, mold releasability, and mold fouling resistance, which result in extremely excellent mold releasability during continuous molding. Therefore, the PPS resin composition of the present invention is particularly useful for fine, thin-walled molded products such as insulating members for batteries. Furthermore, because of its excellent toughness, the PPS resin composition is particularly useful for insulating members for high-capacity primary or secondary batteries.

[0116] Examples of primary or secondary batteries include primary batteries such as alkaline manganese dry batteries, galvanic batteries, nickel-based primary batteries, lithium batteries, manganese dry batteries, mercury batteries, and all-solid-state batteries, and secondary batteries such as lead-acid batteries, lithium-air batteries, lithium-ion secondary batteries, lithium-ion polymer secondary batteries, lithium iron phosphate ion batteries, lithium-sulfur batteries, nickel-cadmium storage batteries, nickel-metal hydride rechargeable batteries, nickel-lithium batteries, nickel-zinc batteries, and all-solid-state batteries.

[0117] Examples of insulating members for batteries include insulating plates, gaskets, terminal holders, cases, insulating rings, insulating tubes, etc. In particular, preferred examples include gaskets and insulating plates that require a thin wall shape, toughness, and electrolyte resistance.

[0118] Examples of applications to which the PPS resin composition of the present invention can be applied include electric and electronic components such as sensors, LED lamps, consumer connectors, sockets, resistors, relay cases, switches, coil bobbins, capacitors, variable capacitor cases, oscillators, various terminal boards, transformers, plugs, printed circuit boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, semiconductors, liquid crystal displays, FDD carriages, FDD chassis, motor brush holders, parabolic antennas, and computer-related components; and household and office electrical appliance components such as VTR components, television components, irons, hair dryers, rice cooker components, microwave oven components, acoustic components, audio equipment components such as audio equipment, laser discs (registered trademark), and compact discs; lighting components, refrigerator components, air conditioner components, typewriter components, and word processor components.

[0119] Other applications of the PPS resin composition of the present invention include machine-related parts such as office computer parts, telephone parts, facsimile parts, copier parts, cleaning tools, motor parts, lighters, and typewriters; optical instruments and precision machinery parts such as microscopes, binoculars, cameras, and clocks; plumbing parts such as water faucet tops, mixer taps, pump parts, pipe joints, water volume control valves, relief valves, hot water temperature sensors, water volume sensors, and water meter housings; valves, alternator terminals, alternator connectors, IC regulators, light dimmer potentiometer bases, and various valves such as exhaust gas valves; various pipes for fuel, exhaust, and intake systems; air intake nozzles, snorkels, intake manifolds, fuel pumps, engine coolant joints, carburetor main bodies, carburetor spacers, exhaust gas sensors, and cooling systems. Examples of various applications include automobile and vehicle related parts such as cooling water sensors, oil temperature sensors, throttle position sensors, crankshaft position sensors, air flow meters, brake pad wear sensors, air conditioner thermostat bases, heating hot air flow control valves, radiator motor brush holders, water pump impellers, turbine vanes, wiper motor related parts, distributors, starter switches, starter relays, transmission wire harnesses, windshield washer nozzles, air conditioner panel switch boards, fuel-related electromagnetic valve coils, fuse connectors, horn terminals, electrical component insulating plates, step motor rotors, lamp sockets, lamp reflectors, lamp housings, brake pistons, solenoid bobbins, engine oil filters, ignition device cases, vehicle speed sensors, and cable liners.

[0120] The present invention will be explained in more detail below by showing examples, but the present invention is not limited to the descriptions of these examples.

[0121] Reference Example 1 PPS Polymerization (PPS-1) A 70-liter autoclave equipped with a stirrer and a bottom stop valve was charged with 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.94 kg (70.63 mol) of 96% sodium hydroxide, 11.45 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), 2.24 kg (27.30 mol) of sodium acetate, and 5.50 kg of ion-exchanged water. The mixture was gradually heated to 245°C over approximately 3 hours under atmospheric pressure while passing nitrogen through it. After distilling off 9.77 kg of water and 0.28 kg of NMP, the reaction vessel was cooled to 200°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.06 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.02 mol per mole of charged alkali metal sulfide.

[0122] After that, it was cooled to 200 ° C., 10.32 kg (70.20 mol) of p-dichlorobenzene and 9.37 kg (94.50 mol) of NMP were added, the reaction vessel was sealed under nitrogen gas, and the temperature was raised from 200 ° C. to 235 ° C. at a rate of 0.8 ° C. / min while stirring at 240 rpm, and the reaction was carried out at 235 ° C. for 40 minutes. Thereafter, the temperature was raised to 270 ° C. at a rate of 0.8 ° C. / min, and the reaction was carried out at 270 ° C. for 70 minutes. After that, 2.40 kg (133 mol) of water was injected while cooling from 270 ° C. to 250 ° C. over 15 minutes. Then, it was gradually cooled from 250 ° C. to 220 ° C. over 75 minutes, and then rapidly cooled to near room temperature and the contents were removed.

[0123] The contents were diluted with approximately 35 liters of NMP to form a slurry, which was stirred at 85°C for 30 minutes and then filtered through an 80-mesh wire mesh (opening 0.175 mm) to obtain a solid. The resulting solid was similarly washed and filtered with approximately 35 liters of NMP. The resulting solid was diluted with 70 liters of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh to recover the solid. This operation was repeated three times. The resulting solid and 32 g of acetic acid were diluted with 70 liters of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh. The resulting solid was further diluted with 70 liters of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh to recover the solid. The solid thus obtained was dried at 120°C under a nitrogen stream to obtain dried PPS.

[0124] The resulting PPS had a melt flow rate (MFR) of 95 g / 10 min and a weight average molecular weight Mw of 70,000.

[0125] Reference Example 2 Polymerization of PPS (PPS-2) A 70-liter autoclave equipped with a stirrer and a bottom stop valve was charged with 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.94 kg (70.63 mol) of 96% sodium hydroxide, 11.45 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), 1.89 kg (23.10 mol) of sodium acetate, and 5.50 kg of ion-exchanged water. The mixture was gradually heated to 245°C over approximately 3 hours under atmospheric pressure while passing nitrogen through it. 9.77 kg of water and 0.28 kg of NMP were distilled off, and the reaction vessel was then cooled to 200°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.06 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.02 mol per mole of charged alkali metal sulfide.

[0126] The mixture was then cooled to 200°C, and 10.42 kg (70.86 mol) of p-dichlorobenzene and 9.37 kg (94.50 mol) of NMP were added. The reaction vessel was sealed under nitrogen gas, and the temperature was raised from 200°C to 270°C at a rate of 0.6°C / min while stirring at 240 rpm, and the reaction was carried out at 270°C for 140 minutes. Thereafter, 2.40 kg (133 mol) of water was injected while the mixture was cooled from 270°C to 250°C over 15 minutes. The mixture was then gradually cooled from 250°C to 220°C over 75 minutes, after which it was rapidly cooled to near room temperature and the contents were removed.

[0127] The contents were diluted with approximately 35 liters of NMP to form a slurry, which was stirred at 85°C for 30 minutes and then filtered through an 80-mesh wire mesh (mesh opening: 0.175 mm) to obtain a solid. The resulting solid was similarly washed and filtered with approximately 35 liters of NMP. The resulting solid was diluted with 70 liters of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh to recover the solid. This procedure was repeated three times. The resulting solid and 32 g of acetic acid were diluted with 70 liters of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh. The resulting solid was further diluted with 70 liters of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh to recover the solid. The solid thus obtained was dried at 120°C under a nitrogen stream to obtain a linear PPS.

[0128] The resulting linear PPS had an MFR of 300 g / 10 min and a weight average molecular weight of 50,000.

[0129] Reference Example 3 Polymerization of PPS (PPS-3) A 70-liter autoclave equipped with a stirrer and a bottom stop valve was charged with 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.94 kg (70.63 mol) of 96% sodium hydroxide, 11.45 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), 2.24 kg (27.30 mol) of sodium acetate, and 5.50 kg of ion-exchanged water. The mixture was gradually heated to 245°C over approximately 3 hours under atmospheric pressure while passing nitrogen through it. 9.77 kg of water and 0.28 kg of NMP were distilled off, and the reaction vessel was then cooled to 200°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.06 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.02 mol per mole of charged alkali metal sulfide.

[0130] The mixture was then cooled to 200°C, and 10.32 kg (70.20 mol) of p-dichlorobenzene and 9.37 kg (94.50 mol) of NMP were added. The reaction vessel was sealed under nitrogen gas, and the temperature was raised from 200°C to 270°C at a rate of 0.6°C / min while stirring at 240 rpm, and the reaction was carried out at 270°C for 140 minutes. Thereafter, 2.40 kg (133 mol) of water was injected while the mixture was cooled from 270°C to 250°C over 15 minutes. The mixture was then gradually cooled from 250°C to 220°C over 75 minutes, after which it was rapidly cooled to near room temperature and the contents were removed.

[0131] The contents were diluted with approximately 35 liters of NMP to form a slurry, which was stirred at 85°C for 30 minutes and then filtered through an 80-mesh wire mesh (mesh opening: 0.175 mm) to obtain a solid. The resulting solid was similarly washed and filtered with approximately 35 liters of NMP. The resulting solid was diluted with 70 liters of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh to recover the solid. This procedure was repeated three times. The resulting solid and 36 g of calcium acetate were diluted with 70 liters of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh. The resulting solid was further diluted with 70 liters of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh to recover the solid. The solid thus obtained was dried at 120°C under a nitrogen stream to obtain a linear PPS.

[0132] The resulting linear PPS had an MFR of 100 g / 10 min and a weight average molecular weight Mw of 55,000.

[0133] (A) PPS resin PPS-1: PPS resin polymerized by the method described in Reference Example 1 PPS-2: PPS resin polymerized by the method described in Reference Example 2 PPS-3: PPS resin polymerized by the method described in Reference Example 3

[0134] (B) Mold Release Agent B-1: Polyol fatty acid ester compound (Roxiol VPG-861 manufactured by Emery Oleochemicals) B-2: Carboxylic acid amide compound obtained by reacting a higher aliphatic monocarboxylic acid, a polybasic acid, and a diamine (Lightamide (registered trademark) WH500 manufactured by Kyoeisha Chemical Co., Ltd.).

[0135] (C) Thermoplastic elastomer C: Thermoplastic elastomer (manufactured by Sumitomo Chemical Co., Ltd., "Bondfast (registered trademark)" 7M ethylene-glycidyl methacrylate-methyl acrylate copolymer).

[0136] (D) Polyaryletherketone D: Organic crystal nucleating agent (Polyetheretherketone PEEK450-PF manufactured by Victrex MC) (E) Additives E-1: Inorganic crystal nucleating agent (Hitron hydrated magnesium silicate manufactured by Takehara Chemical Industry Co., Ltd.) E-2: Silane compound (3-isocyanatepropyltriethoxysilane) (KBE-9007N manufactured by Shin-Etsu Chemical Co., Ltd.).

[0137] [Measurement and Evaluation Methods] The measurement and evaluation methods in the present examples and comparative examples are as follows.

[0138] [Mold Release Force] The obtained resin composition was injection molded using an SE30D injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd.) under conditions of a resin temperature of 320°C and a mold temperature of 130°C to form a box-shaped molded article having dimensions of 35 mm (length) × 35 mm (width) × 25 mm (height), a mold thickness of 1.5 mm, and an opening on one side, as shown in Figure 1. When the molded article was ejected from the mold, the load applied to the ejector pin was measured and recorded as the mold release resistance. The smaller the mold release resistance, the better the mold release property.

[0139] [Total Content of Alkali Metals and Alkaline Earth Metals Other than Li in Resin Composition] 5 g of a PPS resin composition was incinerated in an electric furnace at 500°C, and then diluted with a 0.1 N hydrochloric acid aqueous solution and a 0.1% lanthanum chloride aqueous solution to prepare a sample. The contents of alkali metals other than Li and alkaline earth metals in the resin composition were measured by atomic absorption spectrometry using an atomic absorption spectrophotometer AA-6300 manufactured by Shimadzu Corporation.

[0140] [Crystallization temperature of molded product during melt retention] The thin-walled molded product shown in FIG. 2 (molded product size: length 46 mm, width 22 mm, thickness 0.6 mm, maximum rib height 4 mm, area of ​​the surface having the widest area 1012 mm) ２ The ratio of the area to the thickness of the widest surface (area / thickness) was 2310, with a cylinder temperature of 330°C, a mold temperature of 150°C, an injection pressure set at 180 MPa, and an injection speed set at 0.3 seconds at the VP switch position where the molded product was 90% filled. The pressure-holding step involved a pressure-holding speed of 30 mm / sec, a pressure-holding time of 1 second, and a pressure-holding pressure set within a range that did not cause sink marks, aiming for 50% of the peak pressure. The cooling time was 15 seconds. Ten consecutive shots were molded, and the molded product from the 10th shot was used as the sample (molding machine used: Sumitomo Heavy Industries, Ltd., "SE-50DUZ"). The sample was heated to 340°C and melted, held at 340°C for 10 minutes, and then cooled at a rate of 20°C / min. The exothermic peak temperature (Tmc) associated with crystallization observed during cooling was used as the melt-dwell crystallization temperature of the molded product.

[0141] [Mold releasability during continuous molding] Continuous molding was carried out using the obtained PPS resin composition under the same molding conditions as those for the molded article used in measuring the crystallization temperature during cooling during molten retention of the molded article, to continuously mold the molded article shown in Fig. 2. For the molded article at the 1000th shot, the mold releasability during continuous molding was evaluated as follows: mold release was impossible when mold release was poor and deformation occurred in the molded article, x when mold release was possible but the molded article was deformed, and ○ when mold release was possible and no deformation was observed in the molded article.

[0142] [Melt flow rate (MFR)] The MFR of the PPS resin composition was measured at a temperature of 315°C and a load of 2160 g in accordance with JIS K7210 using a melt indexer manufactured by Toyo Seiki Co., Ltd. The larger this value, the better the fluidity and moldability for thin-walled shapes, etc.

[0143] [Tensile Breaking Strain] Measurement was carried out in accordance with ISO 527-1, 2 (2012). Specifically, measurement was carried out as follows. Pellets of the PPS resin composition of the present invention were dried using a hot air dryer at 130°C for 3 hours, and then fed into an injection molding machine (SE-50D) manufactured by Sumitomo Heavy Industries, Ltd., with a cylinder temperature of 310°C and a mold temperature of 145°C. Test specimens were obtained by injection molding using a mold with a Type A1 test specimen shape (4 mm thick) specified in ISO 20753 (2008) under conditions where the average speed of the molten resin passing through the cross-sectional area of ​​the central parallel portion was 400±50 mm / s. After conditioning the test specimen for 16 hours at 23°C and 50% relative humidity, the tensile breaking strain was measured in accordance with ISO 527-1, 2 (2012) under the conditions of 23°C, 50% relative humidity, a gripper distance of 114 mm, and a test speed of 50 mm / min. A tensile strain value of 5% or more can be said to be a product level that presents no practical problems, but a higher value is preferable because it makes it less likely for cracks to occur when the molded product is crimped to other members.

[0144] [Weight Loss Rate] 10 g of pellets of the PPS resin composition of the present invention were weighed into an aluminum cup that had been heated in advance at 330°C for 3 hours, and heated for 120 minutes in a hot air dryer at 320°C. The pellets were then removed from a desiccator containing a desiccant, cooled, and weighed. The weight loss rate (%) was calculated as the weight loss before and after heating as a percentage of the weight before heating. A smaller value is preferable because it allows for more suppression of gas generation during melting during injection molding.

[0145] [Mold Fouling] The obtained PPS resin composition was continuously molded using a gas evaluation mold for the molded product shown in Figure 3 (molded product size: length 55 mm, width 20 mm, thickness 2 mm; gate size: width 2 mm, thickness 1 mm (side gate); maximum gas vent length 20 mm, width 10 mm, depth 5 μm) at a cylinder temperature of 330°C, a mold temperature of 130°C, an injection speed of 100 mm / s, and an injection pressure set within the range of 50 to 80 MPa so that the filling time for each resin composition was 0.4 seconds. The mold contamination status of the mold gas vent was visually observed every 10 shots (molding machine used: "SE-30D" manufactured by Sumitomo Heavy Industries). A practically usable level can be achieved if the number of shots until mold fouling adherence is 100 or more, but a higher number of shots indicates better mold fouling resistance, which is preferable. Since the accumulation of mold fouling leads to an increase in mold release resistance, excellent mold fouling resistance also leads to improved mold release properties. The number of shots until mold contamination occurred was 100 or more, and the number of shots until mold contamination occurred was evaluated as "good," and the number of shots until mold contamination occurred was evaluated as "poor."

[0146] [Production of PPS Resin Composition] (Examples and Comparative Examples) Using a 47 mm diameter twin-screw extruder (TEX-44α manufactured by The Japan Steel Works, Ltd.) with a cylinder temperature set to 320°C and a screw rotation speed set to 400 rpm, raw materials were added through the raw material supply port in the weight ratios shown in Tables 1 and 2 to form a molten state, and the material was melt-kneaded at a discharge rate of 50 kg / hour to obtain pellets. These pellets were used to evaluate the above-mentioned properties. The results are shown in Tables 1 and 2.

[0147]

[0148]

[0149] The PPS resin compositions of Examples 1 to 9 have excellent mold releasability during continuous molding, and also exhibit good mold fouling resistance, toughness, and molding processability including flowability, due to the addition of a mold release agent, and the contents of alkali metals and alkaline earth metals excluding Li in the resin composition, and the temperature-lowering crystallization temperature (Tmc) after a molded article made of the resin composition is allowed to remain in a melt, all within specific ranges.

[0150] In Comparative Example 1, the amount of (B) mold release agent added to the PPS resin composition was insufficient, which increased the mold release resistance from the mold, resulting in deformation during molding of thin-walled molded products and poor mold releasability. On the other hand, in Comparative Example 2, the amount of (B) mold release agent added was too high, resulting in poor mold fouling resistance.

[0151] In Comparative Example 3, the total content of alkali metals and alkaline earth metals excluding Li in the PPS resin composition was high, so the crystallization rate was insufficient, and deformation occurred during molding of the thin-walled molded article, resulting in poor releasability.In Comparative Examples 4 and 5, the crystallization rate was insufficient due to the low crystallization temperature during cooling after retention of the molded article made of the resin composition, resulting in deformation during molding of the thin-walled molded article, resulting in poor releasability.

[0152] The PPS resin composition of the present invention not only has the excellent insulating properties, heat resistance, and chemical resistance inherent to PPS resin, but also has excellent crystallization properties, mold releasability, and mold fouling resistance, which result in extremely excellent mold releasability during continuous molding. Therefore, the composition is useful for insulating materials for batteries that require the simultaneous molding of a large number of fine, thin-walled molded products. Furthermore, because the composition also has excellent toughness, it is particularly useful for insulating materials for high-capacity primary or secondary batteries.

[0153] 1. Hole 2. Gate 3. Hole 4. Cavity 5. Gate

Claims

1. A polyphenylene sulfide resin composition comprising 100 parts by weight of (A) polyphenylene sulfide resin and 0.1 to 3 parts by weight of (B) a mold release agent, wherein the polyphenylene sulfide resin composition has a total content of alkali metals and alkaline earth metals, excluding Li, of less than 200 ppm, and wherein a molded article made of the polyphenylene sulfide resin composition is heated to 340°C and melted, held in the molten state at 340°C for 10 minutes, and then cooled at a rate of 20°C / min, and the exothermic peak temperature (Tmc) associated with crystallization is observed to be 225°C or higher and 250°C or lower, as measured with a differential scanning calorimeter.

2. The polyphenylene sulfide resin composition according to claim 1, wherein the (B) release agent is at least one selected from the group consisting of polyol fatty acid ester compounds and carboxylic acid amide compounds obtained by reacting a higher aliphatic monocarboxylic acid, a polybasic acid, and a diamine.

3. The polyphenylene sulfide resin composition according to claim 1 or 2, which has a tensile break strain of 5% or more in a tensile test (ISO 527-1, 2) of a test piece obtained by injection molding the polyphenylene sulfide resin composition.

4. The polyphenylene sulfide resin composition according to claim 1 or 2, which has a weight loss rate of 0.5% by weight or less after heating at 320°C for 120 minutes.

5. A polyphenylene sulfide resin composition according to claim 1 or 2, in which the amount of thermoplastic elastomer (C) blended is 1 part by weight or less per 100 parts by weight of polyphenylene sulfide resin (A).

6. The polyphenylene sulfide resin composition according to claim 1 or 2, further comprising 0.005 to 0.15 parts by weight of (D) polyaryl ether ketone per 100 parts by weight of (A) polyphenylene sulfide resin.

7. A polyphenylene sulfide resin composition according to claim 1 or 2, having a melt flow rate (measured in accordance with JIS K7210 at a temperature of 315°C and a load of 2160 g) of 20 g / 10 min or more and 90 g / 10 min or less.

8. A polyphenylene sulfide resin composition according to claim 1 or 2, wherein the proportion of the polyphenylene sulfide resin (A) in the polyphenylene sulfide resin composition is 95% by weight or more.

9. A molded article made from the polyphenylene sulfide resin composition according to claim 1 or 2.

10. The molded product according to claim 9, wherein the ratio of area to thickness (area / thickness) of the surface having the largest area among the surfaces constituting the molded product is 200 or more and 50,000 or less.

11. The surface with the widest area among the surfaces constituting the molded product has a thickness of 0.1 mm or more and 0.7 mm or less, and / or an area of ​​100 mm ２ Over 5000mm ２ 10. The molded article according to claim 9, wherein:

12. The molded article according to claim 9, wherein the molded article is a battery insulating member.

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