Polyphenylene sulfide resin composition and molded article

Abstract

Provided is a PPS resin composition and a molded article, which have very stable mold releasability even when continuously injection molded, can inhibit mold contamination during molding, and are excellent in toughness. A polyphenylene sulfide resin composition, which contains 0.1 to 3 parts by weight of a mold release agent (B) with respect to 100 parts by weight of a polyphenylene sulfide resin (A), has a total content of alkali metals and alkaline earth metals other than Li of less than 200 ppm, and has a crystallization exothermic peak temperature (Tmc) of 225°C or higher and 250°C or lower when a molded article formed from the polyphenylene sulfide resin composition is melted by raising the temperature to 340°C using a differential scanning calorimeter, held in a molten state at 340°C for 10 minutes, and then cooled at a rate of 20°C / minute.

Description

Technical Field

[0001] This invention provides a polyphenylene sulfide resin composition that exhibits excellent demolding properties, toughness, and mold stain resistance during continuous molding in injection molding. Background Technology

[0002] Polyphenylene sulfide resin (hereinafter sometimes referred to as PPS resin) has a good balance of rigidity, heat resistance, hot water resistance, chemical resistance and molding processability, and is therefore widely used in electrical and electronic components, water pipe components and automotive parts.

[0003] Especially for automotive secondary batteries, the required heat resistance temperature has increased with the improvement of energy density in recent years. Therefore, PPS resin is used as a material for insulating components that require heat resistance. In addition, from the viewpoint of saving space in the internal structure of secondary batteries, the miniaturization and thinning of insulating components require resin compositions that can be molded into small, thin-walled articles.

[0004] Patent Document 1 discloses an insulating component for batteries, which is composed of a PPS resin composition having excellent toughness and molding processability, obtained by adding PPS resin with a cyclic PPS content of a specific range and polyethylene as a release agent in a specific range.

[0005] Patent Document 2 discloses a PPS resin composition that exhibits excellent heat aging resistance by mixing aromatic polyetherketone resin into PPS resin, heating it to 340°C using a differential scanning calorimeter to melt it, and then cooling it at a rate of 20°C / min, which shows an increase in the exothermic peak temperature (Tmc) associated with crystallization.

[0006] Patent document 3 discloses a sealing gasket for secondary batteries, which is made tough by adding thermoplastic elastomer to PPS resin and is not prone to stress relief even when compressed under certain strain, thus maintaining airtightness for a long time.

[0007] Patent document 4 discloses a sealing gasket for secondary batteries made of a PPS resin composition, which is given release properties by adding an ester compound as a release agent to the PPS resin while suppressing the reduction of mechanical strength.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2020-145178

[0011] Patent Document 2: Japanese Patent Application Publication No. 2017-179041

[0012] Patent Document 3: Japanese Patent Application Publication No. 2018-123307

[0013] Patent Document 4: Japanese Patent Application Publication No. 2011-29167 Summary of the Invention

[0014] The problem that the invention aims to solve

[0015] Compared to other engineering plastics, PPS resin cures more slowly. Therefore, it suffers from insufficient rigidity, poor release properties, and poor formability during injection molding. Consequently, stable and good release properties are required in continuous molding. Furthermore, insulating components for secondary batteries must possess good toughness to prevent cracking during assembly with other components and during post-assembly use.

[0016] However, although the PPS resin composition described in Patent Document 1 improves the release properties by adding polyethylene as a release agent, the crystallization rate of the resin composition decreases due to the thermal process caused by resin retention or shear heat during continuous molding in injection molding, and the release properties sometimes deteriorate, failing to meet the release properties required in this invention.

[0017] Furthermore, while patent documents 2 and 3 describe methods for increasing the peak melt crystallization temperature by adding a nucleating agent while using metal-containing PPS resin, there is insufficient research on improving demolding performance and suppressing demolding resistance during continuous molding, which does not meet the demolding performance requirements of this invention.

[0018] Patent Document 4 proposes a PPS resin composition for gaskets that exhibits excellent toughness by incorporating thermoplastic elastomers into PPS resin. However, during continuous molding in injection molding, the crystallization rate of the resin composition decreases due to the thermal process caused by resin retention or shear heat, resulting in poor mold release properties during molding. Furthermore, as thermoplastic elastomers are incorporated into the PPS resin, contaminants from the thermoplastic elastomer gradually accumulate on the mold during continuous molding, thus presenting a problem of gradually deteriorating mold release properties during continuous molding, failing to meet the mold release properties and mold contamination resistance requirements of this invention.

[0019] Therefore, the objective of this invention is to provide a PPS resin composition and molded article that exhibit very stable release properties even during continuous injection molding, suppress mold contamination during molding (excellent mold contamination resistance), and consequently possess excellent toughness.

[0020] Problem-solving methods

[0021] In order to solve the above-mentioned problems, the inventors conducted repeated and in-depth research, and as a result, completed this invention. That is, this invention provides the following content.

[0022] [1]. A polyphenylene sulfide resin composition is a polyphenylene sulfide resin composition in which 0.1 to 3 parts by weight of (B) release agent are mixed with 100 parts by weight of (A) polyphenylene sulfide resin, wherein the total content of alkali metals and alkaline earth metals other than Li in the polyphenylene sulfide resin composition is less than 200 ppm, and the exothermic peak temperature (Tmc) of crystallization is observed when the molded article formed from the polyphenylene sulfide resin composition is heated to 340°C using a differential scanning calorimeter to melt it, and then held in the molten state at 340°C for 10 minutes and then cooled at a rate of 20°C / min, and the temperature is above 225°C and below 250°C.

[0023] [2]. The polyphenylene sulfide resin composition as described in [1], wherein the (B) release agent is at least one selected from polyol fatty acid ester compounds and carboxylic acid amide compounds obtained by reacting higher aliphatic monocarboxylic acids, polyacids and diamines.

[0024] [3]. The polyphenylene sulfide resin composition as described in [1] or [2], wherein the specimen obtained by injection molding of the polyphenylene sulfide resin composition has a tensile breaking strain of 5% or more in a tensile test (ISO527-1, 2).

[0025] [4]. The polyphenylene sulfide resin composition according to any one of [1] to [3] has a weight reduction rate of less than 0.5% by weight after heating at 320°C for 120 minutes.

[0026] [5]. The polyphenylene sulfide resin composition according to any one of [1] to [4] is mixed in an amount of 1 part by weight or less of (C) thermoplastic elastomer relative to 100 parts by weight of (A) polyphenylene sulfide resin.

[0027] [6]. The polyphenylene sulfide resin composition according to any one of [1] to [5] is further mixed with 0.005 to 0.15 parts by weight of (D) polyarylether ketone relative to 100 parts by weight of (A) polyphenylene sulfide resin.

[0028] [7]. The polyphenylene sulfide resin composition as described in any one of [1] to [6] has a melt flow rate (measured according to JISK7210 at a temperature of 315°C and a load of 2160g) of 20g / 10min or more and 90g / 10min or less.

[0029] [8]. The polyphenylene sulfide resin composition as described in any one of [1] to [7], wherein the proportion of (A) polyphenylene sulfide resin in the polyphenylene sulfide resin composition is 95% by weight or more.

[0030] [9]. A molded article formed from the polyphenylene sulfide resin composition described in any one of [1] to [8].

[0031]

[10] . As described in [9], the ratio of the area of ​​the largest surface in the surface constituting the molded article to its thickness (area / thickness) is 200 or more and 50,000 or less.

[0032]

[11] . As described in [9] or

[10] , the thickness of the surface with the largest area among the surfaces constituting the molded article is 0.1 mm or more and 0.7 mm or less, and / or the area is 100 mm². 2 Above and 5000mm 2 the following.

[0033]

[12] . A molded article as described in any of [9] to

[11] , wherein the molded article is a battery insulating component.

[0034] According to the present invention, by adding a release agent within a specific range, the total content of alkali metals and alkaline earth metals other than Li in the resin composition is less than a certain amount, so that the exothermic peak temperature of the molded article formed by injection molding of the above resin composition during cooling after melting is within a specific range, it is possible to provide a PPS resin composition and molded article that have very stable release properties during continuous injection molding, as well as excellent toughness and mold stain resistance. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the test piece used for determining the release force. (a) shows the top view, and (b) shows the side view.

[0036] Figure 2 This is a schematic diagram of a thin-walled molded article used for evaluating continuous formability. (a) shows a top view, and (b) shows a side view.

[0037] Figure 3 This is a schematic diagram of a test piece used for evaluating the stain resistance of a mold. (a) shows the front view, and (b) shows the side view. Detailed Implementation

[0038] The embodiments of the present invention will now be described in detail.

[0039] [(A) PPS resin]

[0040] The (A)PPS resin used in this invention is a polymer having repeating units as shown in the following structural formula (I).

[0041]

[0042] From a heat resistance perspective, polymers containing 70 mol% or more, and more preferably 90 mol% or more, repeating units as shown in the above structural formula are preferred. Additionally, approximately 30 mol% of the repeating units in the PPS resin may be composed of repeating units having the following structure.

[0043]

[0044] The preferred manufacturing method of the PPS resin used in this invention will be described below. First, the contents of the polyhalogenated aromatic compounds, vulcanizing agents, polymerization solvents, molecular weight regulators, polymerization aids, and polymerization stabilizers used will be described.

[0045] [Polyhalogenated aromatic compounds]

[0046] Polyhalogenated aromatic compounds are compounds containing two or more halogen atoms in one molecule. Specific examples include: p-dichlorobenzene, m-dichlorobenzene, o-dichlorobenzene, 1,3,5-trichlorobenzene, 1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene, hexachlorobenzene, 2,5-dichlorotoluene, 2,5-dichlorop-xylene, 1,4-dibromobenzene, 1,4-diiodobenzene, and 1-methoxy-2,5-dichlorobenzene, with p-dichlorobenzene being preferred. Furthermore, copolymers can be prepared by combining two or more different polyhalogenated aromatic compounds, but p-dihalogenated aromatic compounds are preferred as the main component.

[0047] From the viewpoint of obtaining a PPS resin with a suitable viscosity for processing, the amount of polyhalogenated aromatic compound used is, for example, 0.9 to 2.0 moles per mole of vulcanizing agent, preferably 0.95 to 1.5 moles, and more preferably 1.005 to 1.2 moles.

[0048] [Vulcanizing agent]

[0049] Examples of sulfurizing agents include alkali metal sulfides, alkali metal hydrogen sulfides, and hydrogen sulfide.

[0050] 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 in the form of hydrates, aqueous mixtures, or anhydrous forms.

[0051] Specific examples of alkali metal hydrosulfides include: sodium hydrosulfide, potassium hydrosulfide, lithium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide, and mixtures of two or more thereof, with sodium hydrosulfide being preferred. These alkali metal hydrosulfides can be used in the form of hydrates, aqueous mixtures, or anhydrous forms.

[0052] Alternatively, a vulcanizing agent prepared in situ from alkali metal hydrogen sulfide and alkali metal hydroxide in the reaction system can be used. Alternatively, the vulcanizing agent can be prepared first from alkali metal hydrogen sulfide and alkali metal hydroxide, and then transferred to the polymerization reactor for use.

[0053] Alternatively, a sulfiding agent prepared in situ from alkali metal hydroxides such as lithium hydroxide and sodium hydroxide with hydrogen sulfide in the reaction system can be used. The sulfiding agent can also be prepared first from alkali metal hydroxides such as lithium hydroxide and sodium hydroxide with hydrogen sulfide, and then transferred to the polymerization reactor for use.

[0054] The amount of vulcanizing agent added refers to the remaining amount after deducting the amount of loss from the actual amount added, when some vulcanizing agent is lost before the polymerization reaction begins due to dehydration operations or other reasons.

[0055] Additionally, alkali metal hydroxides and / or alkaline earth metal hydroxides can be used in conjunction with a vulcanizing agent. Preferred examples of alkali metal hydroxides include sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, and mixtures of two or more thereof; examples of alkaline earth metal hydroxides include calcium hydroxide, strontium hydroxide, barium hydroxide, etc., with sodium hydroxide being preferred.

[0056] When using alkali metal hydrogen sulfide as a sulfiding agent, it is particularly preferred to use alkali metal hydroxide simultaneously; the amount of alkali metal hydrogen sulfide is 0.95 to 1.20 moles relative to 1 mole of alkali metal hydrogen sulfide, preferably 1.00 to 1.15 moles, and even more preferably in the range of 1.005 to 1.100 moles.

[0057] [Polymerization solvent]

[0058] Organic polar solvents are preferred as polymerization solvents. 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-imidazolinone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric triamine, dimethyl sulfone, and cyclobutane sulfoxide; and mixtures of the above solvents. These solvents all exhibit high reaction stability and are therefore preferred. Among these, N-methyl-2-pyrrolidone (sometimes abbreviated as NMP) is particularly preferred.

[0059] The amount of organic polar solvent used is selected relative to 1 mole of vulcanizing agent, in the range of 2.0 to 10 moles, preferably in the range of 2.25 to 6.0 moles, and more preferably in the range of 2.5 to 5.5 moles.

[0060] [Molecular weight regulator]

[0061] To adjust the end structure, polymerization degree, or molecular weight of the generated PPS resin, monohalogenated compounds (not necessarily aromatic compounds) can be used together with the aforementioned polyhalogenated aromatic compounds.

[0062] [Polymerization aids]

[0063] Using polymerization aids to obtain PPS resin with a higher degree of polymerization in a shorter time is also a preferred method. Here, polymerization aids refer to substances that increase 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 substances can be used alone or in combination. Among these, organic carboxylates and / or water are preferred.

[0064] The aforementioned alkali metal carboxylates have the general formula R(COOM). n (In the formula, R is an alkyl, cycloalkyl, aryl, alkylaryl, or arylalkyl group having 1 to 20 carbon atoms. M is an alkali metal selected from lithium, sodium, potassium, rubidium, and cesium. n is an integer from 1 to 3.) The compound shown is an alkali metal carboxylate. Alkali metal carboxylates can also be used in the form of hydrates, anhydrous forms, or aqueous solutions. Specific examples of alkali metal carboxylates include, for example, lithium acetate, sodium acetate, potassium acetate, sodium propionate, lithium valerate, sodium benzoate, sodium phenylacetate, potassium p-methylbenzoate, and mixtures thereof.

[0065] Alkali metal carboxylates can also be formed by adding an organic acid to one or more compounds selected from alkali metal hydroxides, alkali metal carbonates, and alkali metal bicarbonates in approximately equal stoichiometric amounts and reacting them. Among the aforementioned alkali metal carboxylates, lithium salts are considered to have high solubility and a strong auxiliary effect in the reaction system, but are expensive; potassium salts, rubidium salts, and cesium salts have poor solubility in the reaction system; therefore, sodium acetate, which is inexpensive and has suitable solubility in the polymerization system, is the most preferred choice.

[0066] The amount of these polymerization aids used is typically in the range of 0.01 to 0.7 mol relative to 1 mol of alkali metal sulfide added, and preferably in the range of 0.1 to 0.6 mol, more preferably in the range of 0.2 to 0.5 mol, in order to obtain a higher degree of polymerization.

[0067] Furthermore, using water as a polymerization aid is one of the effective means to obtain a resin composition with a high balance between flowability and high toughness. In this case, the amount added is typically in the range of 0.5 mol to 15 mol relative to 1 mol of alkali metal sulfide, and preferably in the range of 0.6 to 10 mol from the perspective of obtaining a higher degree of polymerization, more preferably in the range of 1 to 5 mol.

[0068] The timing of adding these polymerization aids is not specifically specified; they can be added at any time during the preceding steps, at the start of polymerization, or during polymerization (described later). They can also be added in multiple stages. However, from the viewpoint of ease of addition, when using alkali metal carboxylates as polymerization aids, it is preferable to add them simultaneously at the start of the preceding steps or at the start of polymerization. Furthermore, when using water as a polymerization aid, adding it during the polymerization reaction after the addition of a polyhalogenated aromatic compound is effective.

[0069] [Polymerization stabilizer]

[0070] To stabilize the polymerization reaction system and prevent side reactions, polymerization stabilizers can also be used. Polymerization stabilizers help stabilize the polymerization reaction system and suppress undesirable side reactions. For example, the formation of thiophenols can be cited as a benchmark for side reactions; the addition of polymerization stabilizers can suppress the formation of thiophenols. Specific examples of polymerization stabilizers include compounds such as alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, and alkaline earth metal carbonates. Among these, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide are preferred. The aforementioned alkali metal carboxylates also function as polymerization stabilizers and are therefore among the polymerization stabilizers used in this invention. Furthermore, as previously stated, when using alkali metal hydrogen sulfides as vulcanizing agents, it is particularly preferable to simultaneously use alkali metal hydroxides; however, alkali metal hydroxides in excess of vulcanizing agents can also serve as polymerization stabilizers.

[0071] These polymerization stabilizers can be used individually or in combination of two or more. The polymerization stabilizer is typically used at a ratio of 0.02–0.2 mol, preferably 0.03–0.1 mol, and more preferably 0.04–0.09 mol, relative to 1 mol of alkali metal sulfide. If this ratio is too low, the stabilization effect is insufficient; conversely, even excessive amounts are economically disadvantageous and tend to reduce polymer yield.

[0072] There is no specific specification for the timing of adding the polymerization stabilizer. It can be added at any time during the preceding process, at the start of polymerization, or during polymerization, as described below. Alternatively, it can be added in multiple stages, but it is more preferable to add it simultaneously at the start of the preceding process or at the start of polymerization.

[0073] Next, the preferred manufacturing method of the PPS resin used in the embodiments of the present invention will be specifically described in the order of the pre-process, the polymerization reaction process, the recycling process, and the post-process.

[0074] [Previous Process]

[0075] Vulcanizing agents are typically used in hydrate form, but it is preferable to heat the mixture containing the organic polar solvent and the vulcanizing agent before adding the polyhalogenated aromatic compound to remove excess water from the system. Additionally, if excessive water is removed by this operation, it is preferable to add the insufficient amount of water to compensate.

[0076] In addition, as mentioned above, alkali metal sulfides generated in situ in the reaction system from alkali metal hydrogen sulfides and alkali metal hydroxides, or alkali metal sulfides prepared in a tank different from the polymerization tank, can also be used as vulcanizing agents. There are no particular limitations on this method, and the following methods can be listed: preferably, under an inert gas atmosphere and at a temperature range of room temperature to 150°C, preferably room temperature to 100°C, alkali metal hydrogen sulfides and alkali metal hydroxides are added to an organic polar solvent, and the temperature is raised to at least 150°C, preferably 180 to 245°C, under normal or reduced pressure, to remove moisture by distillation. Polymerization aids can also be added at this stage. Furthermore, to promote the distillation removal of moisture, toluene or the like can be added to facilitate the reaction.

[0077] In the polymerization reaction, the water content in the polymerization system is preferably 0.5 to 10.0 mol relative to 1 mol of the added vulcanizing agent. Here, the water content in the polymerization system refers to the amount obtained by subtracting the water removed from the polymerization system from the water content added to the polymerization system. Furthermore, the added water can be in any form, such as water, aqueous solution, or water of crystallization.

[0078] [Polymerization reaction process]

[0079] PPS resin powder is preferably manufactured by reacting a vulcanizing agent and a polyhalogenated aromatic compound in an organic polar solvent at a temperature range of above 200°C and below 290°C.

[0080] At the start of the polymerization reaction, preferably under an inert gas atmosphere and at a temperature range of room temperature to 215°C, more preferably 100°C to 215°C, a vulcanizing agent and a polyhalogenated aromatic compound are added to an organic polar solvent. Polymerization aids may also be added at this stage. The order in which these raw materials are fed can vary or be simultaneous.

[0081] The mixture is typically heated to a temperature range of 200°C to 290°C. There are no particular restrictions on the heating rate, which is usually selected as 0.01 to 5°C / minute, and more preferably 0.1 to 3°C / minute.

[0082] The final temperature is generally raised to 250–290°C, and the reaction time is usually 0.25–50 hours at this temperature, preferably 0.5–20 hours.

[0083] In the stage before reaching the final temperature, for example, by reacting at 200℃ to 245℃ for a certain time and then raising the temperature to 270℃ to 290℃, it is effective to obtain a higher degree of polymerization. At this time, the reaction time at 200℃ to 245℃ is usually selected in the range of 0.25 hours to 20 hours, and preferably in the range of 0.25 hours to 10 hours.

[0084] Furthermore, to obtain polymers with higher degrees of polymerization, it is effective to perform polymerization in multiple stages. When polymerizing in multiple stages, it is effective when the conversion rate of polyhalogenated aromatic compounds in the system reaches 40 mol% or more, preferably 60 mol%, at 245°C.

[0085] In addition, the conversion rate of polyhalogenated aromatic compounds (hereinafter referred to as PHA) is calculated using the following formula. The residual amount of PHA can usually be determined by gas chromatography.

[0086] (A) Cases where polyhalogenated aromatic compounds are added in excess molar ratio relative to alkali metal sulfides.

[0087] Conversion rate = [PHA added (moles) - PHA residue (moles)] / [PHA added (moles) - PHA excess (moles)]

[0088] (B) Other than (A) above

[0089] Conversion rate = [PHA added (moles) - PHA residue (moles)] / [PHA added (moles)]. [Recycling process]

[0090] After polymerization is complete, solids are recovered from the polymerization reactants containing polymers, solvents, etc.

[0091] In the manufacturing method of (A) PPS resin, after polymerization, solids are recovered from the polymerization reactants containing polymer, solvent, etc. Regarding the recovery method, a method of recovering granular polymer by slow cooling after the polymerization reaction (quenching method) is preferred. There are no particular limitations on the slow cooling rate at this time, which is typically around 0.1°C / min to 3°C / min. Throughout the slow cooling process, it is not necessary to maintain the same slow cooling rate; a method can also be used, such as slow cooling at a rate of 0.1 to 1°C / min before polymer particle crystallization and then slow cooling at a rate of 1°C / min or higher.

[0092] [Post-processing steps]

[0093] In this invention, as a post-processing step, it is preferable to subject the PPS resin obtained through the above-described polymerization reaction step and recycling step to acid treatment.

[0094] In this invention, any acid used for acid treatment can be used as long as it does not decompose PPS resin. There are no particular limitations. Examples include acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid, and propionic acid. Acetic acid and hydrochloric acid are preferred, but acids such as nitric acid, which decompose and degrade PPS resin, are not suitable.

[0095] When using an aqueous solution of acid, distilled water or deionized water is preferred. The aqueous solution of acid is preferably pH 1 to 7, more preferably pH 2 to 4. If the pH is greater than 7, the metal content of the PPS resin increases, which is not preferred; if the pH is less than 1, the volatile components of the PPS resin increase, which is also not preferred.

[0096] Regarding the acid treatment method, it is preferable to impregnate the PPS resin in an acid or an aqueous solution of acid, and stirring and heating may also be used as needed. The heating temperature is preferably 80–250°C, more preferably 120–200°C, and even more preferably 150–200°C. Below 80°C, the acid treatment effect is minimal, and the metal content increases; above 250°C, the pressure is too high, and therefore it is not preferred from a safety perspective. Furthermore, the pH of the PPS resin during impregnation with an aqueous solution of acid is preferably reduced to less than 8, more preferably pH 2–8. When the pH exceeds 8, the metal content of the resulting PPS resin increases, and therefore it is not preferred.

[0097] The preferred acid treatment time is the time when the reaction between PPS resin and acid reaches full equilibrium. When treated at 80°C, the preferred time is 2 to 24 hours, and when treated at 200°C, the preferred time is 0.01 to 5 hours.

[0098] Regarding the ratio of PPS resin to acid or an aqueous solution of acid in acid treatment, it is preferable to perform the treatment while the PPS resin is fully immersed in the acid or aqueous solution of acid. The ratio of acid or aqueous solution to 500g of PPS resin is preferably 0.5 to 500L, more preferably 1 to 100L, and even more preferably 2.5 to 20L. By making the ratio of acid or aqueous solution of acid to 500g of PPS resin 0.5L or more, cleaning can be performed while the PPS resin is fully immersed in the aqueous solution, and the metal content of the PPS resin is also reduced, which is therefore preferable.

[0099] These acid treatments are performed by adding a specified amount of PPS resin to a specified amount of water and acid, heating and stirring in a pressure vessel, or by continuously performing the acid treatment. Regarding the method of separating the aqueous solution and PPS resin from the treated solution after acid treatment, filtration using a sieve or filter is relatively simple; examples include natural filtration, pressure filtration, vacuum filtration, and centrifugal filtration. To remove residual acid or impurities from the surface of the PPS resin separated from the treated solution, it is preferable to wash it several times with water or warm water. Examples of washing methods include filtering while simultaneously pouring water onto the PPS resin in the filtration device, or filtering again after adding the separated PPS resin to pre-prepared water. The water used for washing is preferably distilled water or deionized water. Furthermore, it is believed that the terminal structure of the PPS resin changes after acid treatment, but it is difficult to express the structure of the PPS resin obtained through acid treatment using a general formula, and it is also difficult to determine based on its characteristics. Therefore, this is the first time that the structure has been determined through the process (acid treatment) used to obtain PPS resin.

[0100] In this invention, hot water treatment can also be performed before the acid treatment process. The preferred hot water treatment temperature is 80–250°C, more preferably 120–200°C, and even more preferably 150–200°C. Temperatures below 80°C are less effective and result in increased volatile gas production, therefore this is not preferred. There are no particular limitations on the hot water treatment operation; it can be performed by adding a specified amount of PPS resin to a specified amount of water, heating and stirring in a pressure vessel, or by continuously performing the hot water treatment. After hot water treatment, it is preferable to wash the surface of the PPS resin separated from the treatment solution several times with water or warm water to remove any residual impurities.

[0101] Decomposition of PPS end groups during these acid or hot water treatments is undesirable; therefore, it is preferable to perform acid or hot water treatments under an inert atmosphere. Examples of inert atmospheres include nitrogen, helium, and argon, but from an economic point of view, a nitrogen atmosphere is preferred.

[0102] In this invention, it is preferable to include a cleaning step with an organic solvent before the acid treatment step or the hot water treatment step of the PPS resin, as follows. There are no particular restrictions on organic solvents used for cleaning PPS resin, as long as they do not decompose the PPS resin. Examples include nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, 1,3-dimethylimidazolinone, hexamethylphosphoric triamine, and piperazine; sulfoxide and sulfone solvents such as dimethyl sulfoxide, dimethyl sulfone, and sulfolane; ketone solvents such as acetone, butanone, and acetophenone; ether solvents such as dimethyl ether, dipropyl ether, dioxane, and tetrahydrofuran; halogen solvents such as chloroform, dichloromethane, trichloroethylene, dichloroethane, perchloroethylene, monochloroethane, dichloroethane, tetrachloroethane, perchloroethane, and chlorobenzene; alcohol and 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. Furthermore, one of these organic solvents may be used, or a mixture of two or more may be used.

[0103] Cleaning methods using organic solvents include impregnating PPS resin in the solvent, and stirring or heating can be added as needed. There are no particular restrictions on the cleaning temperature when cleaning PPS resin with organic solvents; any temperature from room temperature to approximately 300°C can be selected. Higher cleaning temperatures tend to result in higher cleaning efficiency, but generally, a cleaning temperature of room temperature to 150°C is sufficient. In pressure vessels, cleaning can also be performed under pressure at temperatures above the boiling point of the organic solvent. Furthermore, there are no particular restrictions on the cleaning time. The cleaning time varies depending on the cleaning conditions; in batch cleaning, cleaning for 5 minutes or more usually yields sufficient results. Continuous cleaning is also possible. These acid treatments, hot water treatments, or cleaning methods using organic solvents can also be appropriately combined.

[0104] In this invention, from the viewpoint of obtaining a polyphenylene sulfide resin composition with excellent retention stability, it is preferable to perform acid treatment after repeatedly washing with organic solvents and warm water at about 80°C or the above-mentioned hot water to remove residual oligomers or residual salts.

[0105] In order to exhibit excellent toughness, the (A)PPS resin used in this invention is not preferably cross-linked through thermal oxidation or other treatments, and is preferably a substantially linear PPS resin. Furthermore, as the (A)PPS resin used in this invention, multiple (A)PPS resins with different melt viscosities can also be mixed and used.

[0106] There is no particular limitation on the weight-average molecular weight (Mw) of the (A) PPS resin used in this invention, but from the perspective of obtaining superior mechanical properties, the weight-average molecular weight is preferably 30,000 to 150,000. More preferably, it is 40,000 to 130,000; even more preferably, it is 45,000 to 110,000; and even more preferably, it is 50,000 to 100,000. From the viewpoint of obtaining the mechanical properties of the PPS resin itself, the weight-average molecular weight is preferably 30,000 or more. On the other hand, by keeping the weight-average molecular weight below 150,000, the melt viscosity will not become too high, and molding and processing will be easier.

[0107] In addition, the weight-average molecular weight in this invention is a value calculated using Senshu scientific gel permeation chromatography (GPC) through polystyrene conversion.

[0108] The melt flow rate of the (A) PPS resin used in this invention (measured according to JIS K 7210 at a temperature of 315°C and a load of 2160g) is preferably 50 to 500 g / 10 minutes, more preferably 70 to 380 g / 10 minutes.

[0109] [(B) Release agent]

[0110] The PPS resin composition of the present invention incorporates a mold release agent (B). By incorporating mold release agent (B), the demolding resistance between the mold and the molded article during injection molding is reduced, resulting in good demolding properties. This helps to suppress molding defects represented by deformation of the molded article caused by ejector pins during demolding, shortens the molding cycle, and can be expected to improve the processability of the molded product.

[0111] The amount of release agent (B) used in this invention is 0.1 to 3 parts by weight relative to 100 parts by weight of (A) PPS resin. More preferably, it is 0.15 to 2 parts by weight, and even more preferably, it is 0.3 to 1.2 parts by weight. When the amount of release agent exceeds 3 parts by weight, the amount of gas generated, which is related to mold contamination, increases. Therefore, the maintenance frequency of the mold during continuous molding increases, and the mold processability decreases. In addition, the appearance of the molded article also decreases. Furthermore, if the amount of release agent (B) is less than 0.1 parts by weight, its effect as a release agent cannot be fully utilized, and the demolding resistance between the molded article and the mold increases, which is therefore not preferred.

[0112] As the release agent (B) used in this invention, it is preferably selected from at least one of polyol fatty acid ester compounds and carboxylic acid amide compounds obtained by reacting higher aliphatic monocarboxylic acids, polyacids, and diamines. By mixing such release agents, the demolding resistance during injection molding is reduced, and improved demolding performance can be expected.

[0113] Examples of polyol fatty acid ester compounds include pentaerythritol tetrastearate, dipentaerythritol hexastearate, tripentaerythritol hexastearate, polypentaerythritol stearate, dipentaerythritol adipate stearate, and dipentaerythritol adipate stearate oligomers, among which pentaerythritol tetrastearate is preferred.

[0114] Regarding the reaction of higher aliphatic monocarboxylic acids, polycarboxylic acids, and diamines to obtain carboxylamide compounds

[0115] Specific examples of the aforementioned higher aliphatic monocarboxylic acids include saturated aliphatic monocarboxylic acids and hydroxycarboxylic acids with 16 or more carbon atoms, such as palmitic acid, stearic acid, docosanoic acid, linalic acid, and 12-hydroxystearic acid, with stearic acid being particularly preferred.

[0116] Specific examples of the aforementioned polyacids include succinic acid, adipic acid, sebacic acid, and pimelic acid, with sebacic acid being particularly preferred.

[0117] Specific examples of the aforementioned diamines include ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, m-phenylenediamine, p-phenylenediamine, toluenediamine, and phenylenediamine, with ethylenediamine being particularly preferred.

[0118] Furthermore, carboxylic acid amide compounds containing antioxidants help suppress mold contamination and are therefore preferred.

[0119] In addition to the above, examples of release agents that can be used in this invention include, but are not limited to, diurea, silicone-based release agents, stearamide, lignite esters and their half-esters, stearate esters, stearyl alcohol, polyethylene, ethylenediamine-stearic acid condensate, ethylenediamine-lignite acid condensate, etc. Furthermore, in this invention, two or more of the above-mentioned release agents can of course be used in combination.

[0120] [(C) Thermoplastic elastomers]

[0121] Generally, thermoplastic elastomers (C) are blended in PPS resin to improve its toughness. However, in this invention, from the viewpoint of obtaining good molding processability, it is preferable to avoid blending with thermoplastic elastomers (C).

[0122] In the embodiment of the present invention, when blending (C) thermoplastic elastomer, the amount of (C) thermoplastic elastomer blended relative to 100 parts by weight of (A) polyphenylene sulfide resin is preferably 1 part by weight or less. More preferably, the amount of (C) thermoplastic elastomer blended relative to 100 parts by weight of (A) polyphenylene sulfide resin is less than 0.8 parts by weight, and even more preferably less than 0.5 parts by weight. Particularly preferred is that (C) thermoplastic elastomer is not blended. By controlling the content of (C) thermoplastic elastomer to less than 1 part by weight, the generation of volatile components, especially volatile components from the thermoplastic elastomer, during the heating and melting of the PPS resin composition can be suppressed. Therefore, the deterioration of demolding properties during continuous molding caused by volatile components adhering to the mold can be suppressed, which is preferred from the perspective of molding processability.

[0123] Examples of thermoplastic elastomers (C) 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.

[0124] From the viewpoint that the (C) thermoplastic elastomer used in this invention forms an intermolecular bond with the (A) PPS resin, the preferred form can be described as containing reactive functional groups.

[0125] There are no specific limitations on the reactive functional groups that thermoplastic elastomers may possess. Examples include vinyl, epoxy, carboxyl, acid anhydride, ester, aldehyde, carbonyl dioxy, haloformyl, alkoxy carbonyl, amino, hydroxyl, styrene, methacryloyl, acryloyl, urea, mercapto, thioether, isocyanate, and hydrolyzable silane.

[0126] The PPS resin composition of the present invention preferably contains polyaryletherketone (D) described later; in addition, other resins other than PPS resin (A), mold release agent, thermoplastic elastomer and polyaryletherketone (D) may be added to the PPS resin composition of the present invention without impairing the effects of the present invention.

[0127] Specific examples include polyamides, polybutylene terephthalate, polyethylene terephthalate, polyketones, liquid crystal polymers, and fluoropolymers (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)), etc., but are not limited to these.

[0128] Without impairing the effects of the present invention, for purposes such as improving toughness, the PPS resin composition of the present invention may be mixed with an organosilane compound having at least one functional group selected from epoxy, amino, isocyanate, hydroxyl, mercapto and urea groups as an (E) additive. Specific examples of organosilane compounds that are additives of this (E) include: alkyl silane compounds containing epoxy groups such as γ-glycidyl etheroxypropyltrimethoxysilane, γ-glycidyl etheroxypropyltriethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; alkyl silane compounds containing mercapto groups such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane; alkyl silane compounds containing urea groups such as γ-ureopropyltriethoxysilane, γ-ureopropyltrimethoxysilane, and γ-(2-ureoethyl)aminopropyltrimethoxysilane; and alkyl silane compounds containing urea groups such as γ-isocyanate-propyltriethoxysilane and γ-isocyanate-propyltrimethoxysilane. The alkoxysilane compounds containing isocyanate groups include silanes, γ-isocyanate-propylmethyldimethoxysilane, γ-isocyanate-propylmethyldiethoxysilane, γ-isocyanate-propylethyldimethoxysilane, γ-isocyanate-propylethyldiethoxysilane, and γ-isocyanate-propyltrichlorosilane; alkoxysilane compounds containing amino groups include γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane; and alkoxysilane compounds containing hydroxyl groups include γ-hydroxypropyltrimethoxysilane and γ-hydroxypropyltriethoxysilane. From a reactivity perspective, alkoxysilane compounds containing epoxy groups, amino groups, and isocyanate groups are preferred; alkoxysilane compounds containing isocyanate groups are particularly preferred. Excellent reactivity is associated with superior toughness and mold stain resistance.

[0129] The amount of the organosilane compound added relative to 100 parts by weight of (A)PPS resin is preferably 0.1 to 3 parts by weight, and particularly preferably 0.15 to 0.6 parts by weight. When the amount of the organosilane compound added is 0.1 parts by weight or more, not only can the toughness improvement effect be fully obtained, but also the generation of flash and mold contamination during molding can be suppressed. By keeping the amount of the organosilane compound added to 3 parts by weight or less, the amount of gas generation can be suppressed while maintaining the toughness improvement effect, which helps to suppress mold contamination. At the same time, the increase in melt viscosity is suppressed, and thin-walled injection molding can be achieved, resulting in excellent molding processability. Therefore, it is preferred.

[0130] Inorganic fillers can also be mixed into the PPS resin composition of the present invention, but the addition of inorganic fillers will cause a decrease in toughness. Therefore, in order to obtain good toughness, even if inorganic fillers are added, it is preferable to control them to the minimum amount.

[0131] When mixing inorganic fillers, the amount used is preferably less than 10 parts by weight relative to 100 parts by weight of (A)PPS resin, more preferably less than 1 part by weight, and even more preferably less than 0.1 parts by weight. It is particularly preferred not to mix inorganic fillers.

[0132] Specific examples of this inorganic packing material include:

[0133] Fibrous fillers such as glass fiber, carbon fiber, carbon nanotubes, carbon nanotubes, potassium titanate whiskers, zinc oxide whiskers, calcium carbonate whiskers, wollastonite whiskers, aluminum borate whiskers, aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, gypsum fiber, and metal fiber; or silicates such as fullerene, talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, silica, bentonite, asbestos, and aluminum silicate; metal oxides such as silicon oxide, magnesium oxide, aluminum oxide, 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 sheets, glass powder, ceramic beads, boron nitride, silicon carbide, carbon black, silica, and graphite. These inorganic fillers can have hollow structures, or two or more can be used in combination. Alternatively, coupling agents can be used to pretreat the inorganic fillers before use.

[0134] Without impairing the effects of the present invention, other common additives may be added to the PPS resin composition of the present invention, such as: antioxidants, heat stabilizers (hydroquinone-based), weathering agents (resorcinol-based, salicylates-based, benzotriazole-based, benzophenone-based, hindered amine-based, etc.), pigments (cadmium sulfide, phthalocyanine, carbon black for coloring, etc.), dyes (nigrossine), plasticizers (octyl p-hydroxybenzoate, N-butylbenzenesulfonamide, etc.), antistatic agents (alkyl sulfate anionic antistatic agents, quaternary ammonium cationic antistatic agents, polyoxyethylene sorbitan monostearate, etc.). Nonionic antistatic agents, betaine-based amphoteric antistatic agents, flame retardants (e.g., red phosphorus, phosphate esters, melamine cyanurate, magnesium hydroxide, aluminum hydroxide and other hydroxides, ammonium polyphosphate, brominated polystyrene, brominated polyphenylene ether, brominated polycarbonate, brominated epoxy resin, and combinations of these brominated flame retardants with antimony trioxide, etc.), heat stabilizers, calcium stearate, aluminum stearate, lithium stearate and other lubricants, bisphenol A type and other bisphenol epoxy resins, phenol linear phenolic epoxy resins, cresol linear phenolic epoxy resins and other strength modifiers, ultraviolet absorbers, colorants, foaming agents, etc.

[0135] The method for preparing the PPS resin composition of the present invention is not particularly limited. Representative examples include feeding the raw materials into a commonly known melt-mixing mill such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roller, and mixing them at a temperature of 280–380°C. There are no particular restrictions on the mixing order of the raw materials; any method can be used, such as: mixing all the raw materials and then melt-mixing them using the above method; mixing a portion of the raw materials, then melt-mixing them using the above method, and then adding the remaining raw materials for melt-mixing; or mixing a portion of the raw materials and mixing the remaining raw materials using a side feeder during melt-mixing in a single-screw or twin-screw extruder. Furthermore, for small amounts of additive components, it is also possible to first mix and granulate the other components using the above method, and then add these additive components before molding for molding processing.

[0136] From the viewpoint of improving demolding properties during continuous molding, the PPS resin composition of the present invention must satisfy the following condition: the total content of alkali metals other than Li and alkaline earth metals is less than 200 ppm. It is conceivable that only alkali metals other than Li are mixed in, only alkaline earth metals are mixed in, or both alkali metals other than Li and alkaline earth metals are mixed in, but these are not particularly limited. Such PPS resin compositions exhibit rapid crystallization, and even when resin stagnation occurs during continuous molding, they can still crystallize stably, resulting in high rigidity during ejection of the molded article and promising good demolding properties. The total content of alkali metals other than Li and alkaline earth metals in the PPS resin composition is preferably less than 100 ppm, more preferably less than 50 ppm. Examples of alkali metals other than Li include sodium and potassium, but sodium is preferably avoided. Examples of alkaline earth metals include calcium. Furthermore, there is no limitation on the amount of lithium mixed in the PPS resin composition.

[0137] The method for determining the total content of alkali metals and alkaline earth metals other than Li in the PPS resin composition is as follows: The PPS resin composition is ashed in a muffle furnace at 500°C. The resulting ashed material is diluted with 0.1 mol / L hydrochloric acid aqueous solution and 0.1% lanthanum chloride aqueous solution. The resulting aqueous solution is used as a sample, and the content is determined by atomic absorption spectrophotometry.

[0138] There are no particular limitations on the method used to ensure that the total content of alkali metals and alkaline earth metals (excluding Li) in the PPS resin composition is below 200 ppm, as long as such a PPS resin composition can be obtained. For example, by blending PPS resins that have undergone acid treatment in a post-processing step, it is possible to achieve a total content of alkali metals and alkaline earth metals (excluding Li) of below 200 ppm.

[0139] The cooling crystallization temperature of the molded article made from the PPS resin composition of the present invention is 225°C or higher and 250°C or lower; preferably 226°C or higher and 238°C or lower, more preferably 228°C or higher and 232°C or lower. If the cooling crystallization temperature of the molded article is lower than 225°C, the crystallization rate is slow, and when resin stagnation occurs during continuous molding, the rigidity of the molded article is insufficient during demolding, and deformation occurs during demolding, which fails to meet the demolding performance requirements of the present invention. In addition, if the temperature exceeds 250°C, the degree of crystallinity of the molded article is high and the toughness decreases, which fails to give full play to the good toughness of the present invention. The cooling crystallization temperature here refers to the exothermic peak temperature (Tmc) observed during crystallization when the molded article made from the PPS resin composition is heated to 340°C to melt it using a differential scanning calorimeter, held in the molten state at 340°C for 10 minutes, and then cooled at a rate of 20°C / min.

[0140] Used as a molded product for determining Tmc Figure 2 The molded article shown (with openings, dimensions: length 46mm, width 22mm, thickness 0.6mm, maximum reinforcing rib height 4mm) was obtained from the 10th injection molding under the following conditions (using a Sumitomo Heavy Industries "SE-50DUZ" molding machine). The conditions were: barrel temperature 330°C, mold temperature 150°C, injection pressure set at 180MPa, and an injection speed set with a filling time of 0.3 seconds at the VP switching position when 90% of the molded article is filled. In the holding pressure process, the holding pressure speed was set to 30mm / sec, the holding pressure time to 1sec, and the holding pressure was set based on 50% of the peak filling pressure, within a range that does not produce shrinkage marks. The cooling time was 15sec. The cooling crystallization temperature in this invention is the value measured using a differential scanning calorimeter after the molded article, obtained by melting and holding the resin composition in the injection molding machine for a certain time, is held above the melting point for a certain time. This value represents the cooling crystallization temperature after melting and holding.

[0141] Thus, as a method for obtaining Tmc that is stable even during molten retention, examples include, for instance, adding a nucleating agent as an additive (E); repeatedly washing with organic solvents during polymerization and with warm water at around 80°C or the aforementioned hot water to remove residual oligomers or residual salts, and then mixing with acid-treated PPS resin; or mixing with PPS resin that has not undergone heat treatment after polymerization and recycling treatment, etc., but the present invention is not limited to these methods.

[0142] As the nucleating agent for this (E) additive, inorganic nucleating agents such as talc, silica, kaolin, and clay, or common additives such as organic nucleating agents, can be added. There are no particular restrictions on the type of nucleating agent; inorganic nucleating agents and organic nucleating agents can be listed, with organic nucleating agents being particularly preferred.

[0143] Examples of organic nucleating agents include sorbitol compounds and their metal salts; phosphate ester metal salts; rosin compounds; and amidated compounds such as dibenzoyl hydrazide decanedicarboxylate, dibenzoyl hydrazide hexanedicarboxylate, dicyclohexyl amide 1,4-cyclohexanedicarboxylate, pyromellitic acid amide, N-phenylamide (anilide) compounds, dicyclohexyl amide 2,6-naphthalenedicarboxylate, N,N'-dibenzoyl-1,4-diaminocyclohexane, N,N'-dicyclohexanecarbonyl-1,5-diaminonaphthalene, and dibenzoyl hydrazide octanedicarboxylate. Organic compounds and polymers including compounds, aliphatic carboxylic acid metal salts, aromatic carboxylic acid metal salts, aromatic phosphonic acids and metal salts, aromatic phosphate metal salts, aromatic sulfonic acid metal salts, β-diketone metal salts, carboxyl metal salts, organophosphorus compounds, polypropylene, polybutadiene, polystyrene, AS resin, ABS resin, polyacrylic acid, polyacrylate, polymethacrylic acid, polymethacrylate, polyamide 6, polyamide 46, polyamide 66, polyamide 6T, polyamide 9T, polyamide 10T, polyaryletherketones, etc. Among these, polymers with carbonyl groups are preferred, and (D) polyaryletherketones are particularly preferred.

[0144] [(D) Polyaryletherketone]

[0145] (D) As a polyaryletherketone, for example, polyetherketone, polyetheretherketone, polyetheretheretherketone, polyetheretheretherketone, polyetheretherketoneketone, polyetherketoneketone, etc. can be listed as examples, among which polyetheretherketone has a high effect on improving the crystallization rate, and is therefore particularly preferred.

[0146] The preferred amount of this organic nucleating agent is 0.005 to 0.15 parts by weight, more preferably 0.01 to 0.1 parts by weight, and even more particularly preferably 0.03 to 0.08 parts by weight, relative to 100 parts by weight of (A) PPS resin. By adding 0.005 parts by weight or more of the organic nucleating agent, a sufficient crystallization rate can be obtained. By adding 0.15 parts by weight or less, damage originating from the nucleating agent can be suppressed, and toughness can be maintained, which is therefore preferred.

[0147] The preferred melt flow rate of the PPS resin composition of the present invention (measured according to JIS K7210 at a temperature of 315°C and a load of 2160g) is 20 to 90 g / 10 minutes. More preferably, it is 30 to 80 g / 10 minutes, and even more preferably, it is 50 to 70 g / 10 minutes. By maintaining a melt flow rate of 20 g / 10 minutes or more, the fluidity of the resin composition can be maintained, and the resin composition is fully filled into the mold during injection molding of thin-walled molded articles, which is therefore preferred. By maintaining a melt flow rate of 90 g / 10 minutes or less, the generation of flash during injection molding can be suppressed, resulting in excellent molding processability, which is also preferred. To obtain a PPS resin composition with such a melt flow rate, a molecular weight distribution of the resin composition determined by gel permeation chromatography (GPC) with a value of 60,000 or more and 180,000 or less can be listed. If the viscosity is above 60,000, specimens that fracture with plastic deformation (toughness) can be obtained. However, if it exceeds 180,000, the viscosity of the resin composition is high and the moldability deteriorates. Therefore, it is preferable to have a viscosity of 70,000 or more and 160,000 or less, more preferably 80,000 or more and 140,000 or less. From the viewpoint of balancing toughness and viscosity, it is most preferable to have a viscosity of 90,000 or more and 130,000 or less.

[0148] In a tensile test (ISO 527-1, 2) of a specimen obtained by injection molding of the PPS resin composition of the present invention, the PPS resin composition preferably has a tensile breaking strain of 5% or more. More preferably, 8% or more, and even more preferably 10% or more. A tensile breaking strain of 5% or more means that the PPS resin composition has excellent toughness and can suppress breakage during actual use when used in the case of interlocking thin-walled molded articles, etc., which is necessary from the viewpoint of ensuring safety. When the tensile breaking strain is less than 5%, there is a strong tendency for brittle failure before reaching the yield point strength, which causes practical problems and is therefore not preferred. As for the upper limit of the tensile breaking strain, a higher elongation is more preferred, so there is no particular limitation, but the practical upper limit is about 300%. In order to obtain a PPS resin composition with such good tensile breaking strain, the preferred methods are to use a PPS resin with a high weight-average molecular weight and to add an organosilane compound to the resin composition.

[0149] From the viewpoint of molding processability, the PPS resin composition of the present invention preferably has a weight reduction rate of 0.5% by weight or less after heating at 320°C for 120 minutes, more preferably 0.3% by weight or less, and even more preferably 0.25% by weight or less. A weight reduction rate of 0.5% by weight or less can suppress mold contamination during molding, resulting in excellent molding processability and maintaining electrolyte resistance, thus it is preferred. The weight reduction rate is the percentage by weight of the weight reduction before and after heating the PPS resin composition at 320°C for 120 minutes relative to the weight before heating. Here, the weight change rate can be determined as the amount of gas generated during heating and melting. To obtain a PPS resin composition with a weight change rate within the above range, for example, in the post-processing step of the PPS manufacturing method, it is preferable to clean the PPS resin using an organic solvent. Furthermore, a preferred method is to minimize the presence of thermoplastic elastomers in the PPS resin composition.

[0150] From the viewpoint of molding processability and toughness, the proportion of (A) PPS resin in the PPS resin composition of the present invention is preferably 95% by weight or more, more preferably 97% by weight or more, and even more preferably 98% by weight or more. Excellent flowability and toughness can be obtained by making the proportion of (A) PPS resin in the PPS resin composition 95% by weight or more. Considering the amount of flame retardant (B), which is an essential component, the upper limit of the proportion of PPS resin is preferably 99.5% by weight or less.

[0151] The PPS resin composition of this invention exhibits excellent crystallization properties, mold release properties, and mold contamination resistance, resulting in superior mold release properties during continuous molding, making it useful for thin-walled molded products. Thin-walled molded products, such as insulating plate-shaped parts, typically use the surface with the largest area as the ejector pin ejection surface. However, during demolding in injection molding, the thinner the thickness of the molded product ejected by the ejector pin relative to the area of ​​the ejector surface, the more easily the molded product deforms during demolding.

[0152] The PPS resin composition of the present invention exhibits excellent demolding properties in thin-walled shapes, thus suppressing deformation. Therefore, it is useful for molded articles with an area-to-thickness ratio (area / thickness) of 200 or more and 50,000 or less in the face with the largest area among the constituent surfaces. More preferably, the area-to-thickness ratio is 250 or more and 20,000 or less. The larger this area / thickness ratio, the easier it is for deformation to occur during demolding.

[0153] Furthermore, as specific shapes for the aforementioned useful molded articles, it is preferable to list the surface with the largest area among the constituent surfaces as having a thickness of 0.1 mm or more and 0.7 mm or less, and / or an area of ​​100 mm². 2 Above and 5000mm 2The following are thin-walled shapes. As a more preferred area range, 100 mm can be listed. 2 Above and 1500mm 2 Small shapes like the ones shown below.

[0154] As described above, the PPS resin composition of the present invention, in addition to the excellent insulation properties, heat resistance, and chemical resistance inherent in PPS resin, has excellent crystallization properties, mold release properties, and mold stain resistance. It has excellent mold release properties during continuous molding, and is therefore particularly useful for insulating parts for batteries as micro- and thin-walled molded products. It also has excellent toughness, and is therefore particularly useful for insulating parts for high-capacity primary or secondary batteries.

[0155] As primary or secondary batteries, examples include alkaline manganese dry cell batteries, galvanic cells, nickel-based primary batteries, lithium batteries, manganese dry cell batteries, mercury batteries, all-solid-state batteries, lead-acid batteries, lithium-air batteries, lithium-ion secondary batteries, lithium-ion polymer secondary batteries, lithium iron phosphate batteries, lithium-sulfur batteries, nickel-cadmium batteries, nickel-hydrogen rechargeable batteries, nickel-lithium batteries, nickel-zinc batteries, and all-solid-state batteries.

[0156] Examples of insulating components for batteries include insulating plates, gaskets, terminal retainers, housings, insulating rings, and insulating tubes. Among these, gaskets and insulating plates with thin-walled shapes that require toughness and electrolyte resistance are preferred examples.

[0157] As for the applications of the PPS resin composition of the present invention, it can be applied to, for example, electrical and electronic components such as sensors, LED lights, civilian connectors, sockets, resistors, relay housings, switches, coil frames, capacitors, variable capacitor housings, oscillators, various terminal boards, transformers, plugs, printed circuit boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, semiconductors, liquid crystal devices, FDD brackets, FDD bases, motor brush holders, parabolic antennas, and computer-related components; and components of household and office appliances such as VTR components, television components, electric irons, hair dryers, rice cooker components, microwave oven components, audio components, audio equipment components such as laser disc players (registered trademark: Audio Laser Disc) / CDs, lighting components, refrigerator components, air conditioner components, typewriter components, and word processor components.

[0158] Other applications for which the PPS resin composition of the present invention is applicable include: mechanical components such as office computer parts, telephone parts, fax machine parts, copier parts, cleaning tools, motor parts, lighters, and typewriters; optical instruments and precision mechanical components such as microscopes, binoculars, cameras, and clocks; waterway components such as faucet valve cores, mixing valves, pump parts, pipe joints, water flow regulating valves, pressure relief valves, water temperature sensors, water flow sensors, and water meter housings; various valves such as generator terminals, generator connectors, IC regulators, dimmer potentiometer bases, and exhaust valves; various pipelines in fuel-related / exhaust / intake systems; intake manifolds, intake nozzles, fuel pumps, and engines. Coolant connectors, carburetor bodies, carburetor diaphragms, exhaust gas sensors, coolant sensors, oil temperature sensors, throttle position sensors, crankshaft position sensors, air flow meters, brake pad wear sensors, air conditioning thermostat bases, heater airflow control valves, radiator motor brush holders, water pump impellers, turbine blades, wiper motor components, distributors, starter switches, starter relays, transmission wiring harnesses, windshield washer nozzles, air conditioning panel switch base plates, fuel-related solenoid valve coils, fuse connectors, horn terminals, electrical component insulation boards, stepper motor rotors, lamp sockets, lamp reflectors, lamp housings, brake pistons, solenoid coil frames, engine oil filters, ignition housings, vehicle speed sensors, cable sheaths, and other automotive-related components for various applications.

[0159] Example

[0160] The present invention will be described in more detail below with reference to embodiments, but the present invention is not limited to the description of these embodiments.

[0161] [Reference Example 1] Polymerization of PPS resin (PPS-1)

[0162] 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide aqueous solution, 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 deionized water were added to a 70 L high-pressure reactor equipped with a stirrer and a bottom valve. The reactor was slowly heated to 245 °C for approximately 3 hours under normal pressure while nitrogen was introduced. 9.77 kg of water and 0.28 kg of NMP were separated by distillation. The reactor was then cooled to 200 °C. The residual water content in the system corresponding to 1 mole of the added alkali metal sulfide, including the water consumed by the hydrolysis of NMP, was 1.06 mol. Additionally, the amount of hydrogen sulfide volatilized corresponding to 1 mole of the added alkali metal sulfide was 0.02 mol.

[0163] 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 atmosphere, and the temperature was increased from 200°C to 235°C at a rate of 0.8°C / min while stirring at 240 rpm. The reaction was carried out at 235°C for 40 minutes. Then, the temperature was increased 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, the mixture was cooled from 270°C to 250°C over 15 minutes, while 2.40 kg (133 mol) of water was injected. The mixture was then slowly cooled from 250°C to 220°C over 75 minutes, and then rapidly cooled to near room temperature. The contents were then removed.

[0164] The contents were diluted with approximately 35 liters of NMP to form a slurry. After stirring at 85°C for 30 minutes, the slurry was filtered through an 80-mesh metal screen (0.175 mm aperture) to obtain a solid. The resulting solid was then washed and filtered again with approximately 35 liters of NMP. The following operation was repeated three times: The resulting solid was diluted with 70 liters of deionized water, stirred at 70°C for 30 minutes, and filtered through an 80-mesh metal screen to recover the solid. The resulting solid and 32 g of acetic acid were diluted with 70 liters of deionized water, stirred at 70°C for 30 minutes, and filtered through an 80-mesh metal screen. The resulting solid was then diluted with 70 liters of deionized water, stirred at 70°C for 30 minutes, and filtered through an 80-mesh metal screen to recover the solid. The resulting solid was dried at 120°C under a nitrogen stream to obtain dried PPS.

[0165] The resulting PPS had a melt flow rate (MFR) of 95 g / 10 min and a weight-average molecular weight (Mw) of 70,000.

[0166] [Reference Example 2] Polymerization of PPS (PPS-2)

[0167] 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 deionized water were added to a 70°C autoclave equipped with a stirrer and a bottom valve. The autoclave was slowly heated to 245°C over approximately 3 hours under normal pressure while purging with nitrogen. 9.77 kg of water and 0.28 kg of NMP were distilled off. The reaction vessel was then cooled to 200°C. The residual water content in the system corresponding to each mole of the added alkali metal sulfide, including water consumed by the hydrolysis of NMP, was 1.06 mol. Additionally, the amount of hydrogen sulfide scattering corresponding to each mole of the added alkali metal sulfide was 0.02 mol.

[0168] 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 atmosphere, and the temperature was increased from 200°C to 270°C at a rate of 0.6°C / min while stirring at 240 rpm. The reaction was carried out at 270°C for 140 minutes. Then, the mixture was cooled from 270°C to 250°C over 15 minutes, while 2.40 kg (133 mol) of water was injected. Next, the mixture was slowly cooled from 250°C to 220°C over 75 minutes, and then rapidly cooled to near room temperature. The contents were then removed.

[0169] The contents were diluted with approximately 35 liters of NMP to form a slurry. After stirring at 85°C for 30 minutes, the slurry was filtered through an 80-mesh metal mesh (0.175 mm) to obtain a solid. The resulting solid was washed and filtered again with approximately 35 liters of NMP. The solid was then diluted with 70 liters of deionized water, stirred at 70°C for 30 minutes, and filtered through an 80-mesh metal mesh. This solid recovery process was repeated three times. The resulting solid and 32 g of acetic acid were diluted with 70 liters of deionized water, stirred at 70°C for 30 minutes, and filtered through an 80-mesh metal mesh. The solid was then diluted again with 70 liters of deionized water, stirred at 70°C for 30 minutes, and filtered through an 80-mesh metal mesh to recover the solid. The resulting solid was dried at 120°C under a nitrogen stream to obtain linear PPS.

[0170] The obtained linear PPS had an MFR of 300 g / 10 min and a weight-average molecular weight of 50,000.

[0171] [Reference Example 3] Polymerization of PPS (PPS-3)

[0172] 8.27 kg (70.00 mol) of 47.5% sodium sulfide hydrate, 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 deionized water were added to a 70°C autoclave equipped with a stirrer and a bottom valve. The autoclave was gradually heated to 245°C over approximately 3 hours under normal pressure and nitrogen atmosphere. After distilling off 9.77 kg of water and 0.28 kg of NMP, the reaction vessel was cooled to 200°C. The residual water content in the system per mole of added alkali metal sulfide, including water consumed by the hydrolysis of NMP, was 1.06 mol. Additionally, the amount of hydrogen sulfide escaping was 0.02 mol per mole of added alkali metal sulfide.

[0173] 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 atmosphere, and the temperature was increased from 200°C to 270°C at a rate of 0.6°C / min while stirring at 240 rpm. The reaction was carried out at 270°C for 140 minutes. Then, the mixture was cooled from 270°C to 250°C over 15 minutes, while 2.40 kg (133 mol) of water was injected. Next, the mixture was slowly cooled from 250°C to 220°C over 75 minutes, and then rapidly cooled to near room temperature. The contents were then removed.

[0174] The contents were diluted with approximately 35 liters of NMP and stirred as a slurry at 85°C for 30 minutes. The slurry was then filtered through an 80-mesh metal screen (0.175 mm aperture) to obtain a solid. The resulting solid was also washed and filtered with approximately 35 liters of NMP. The following steps were repeated three times: The resulting solid was diluted with 70 liters of deionized water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh metal screen to recover the solid. The resulting solid was diluted with 70 liters of deionized water and 36 g of calcium acetate was stirred at 70°C for 30 minutes and then filtered through an 80-mesh metal screen. The resulting solid was then diluted with 70 liters of deionized water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh metal screen to recover the solid. The resulting solid was dried at 120°C under a nitrogen stream to obtain linear PPS.

[0175] The obtained linear PPS had an MFR of 100 g / 10 min and a weight-average molecular weight (Mw) of 55,000.

[0176] (A) PPS resin

[0177] PPS-1: PPS resin polymerized by the method described in Reference Example 1

[0178] PPS-2: PPS resin polymerized by the method described in Reference Example 2

[0179] PPS-3: PPS resin polymerized by the method described in Example 3.

[0180] (B) Release agent

[0181] B-1: Polyol fatty acid ester compound (LOXIOL VPG-861 manufactured by Emery Oleochemicals)

[0182] B-2: A carboxylic acid amide compound obtained by reacting a higher aliphatic monocarboxylic acid, a polycarboxylic acid, and a diamine (manufactured by Kyoei Chemical Co., Ltd., "Light Amide (registered trademark)" WH500).

[0183] (C) Thermoplastic elastomers

[0184] C: Thermoplastic elastomer (Sumitomo Chemical Co., Ltd. "BONDFAST (registered trademark)" 7M ethylene-glycidyl methacrylate-methyl acrylate copolymer).

[0185] (D) Polyaryletherketone

[0186] D: Organic nucleating agent (PEEK450-PF manufactured by VICTREX MC)

[0187] (E) Additives

[0188] E-1: Inorganic nucleating agent (Haitron hydrated magnesium silicate manufactured by Takehara Chemical Industry Co., Ltd.)

[0189] E-2: Silane compound (3-isocyanate-propyltriethoxysilane) (Shin-Etsu Chemical Industry Co., Ltd. KBE-9007N).

[0190] [Measurement and Evaluation Methods]

[0191] The measurement and evaluation methods in this embodiment and comparative examples are as follows.

[0192] [Demolding force]

[0193] Using an injection molding machine SE30D (manufactured by Sumitomo Heavy Industries, Ltd.), the obtained resin composition was injection molded at a resin temperature of 320°C and a mold temperature of 130°C. Figure 1 The box-shaped molded body shown has dimensions of 35mm (length) × 35mm (width) × 25mm (height), a molding thickness of 1.5mm, and an opening on one side. The load applied to the ejector pin when the molded body is ejected from the mold is measured and used as the demolding resistance. The smaller the demolding resistance, the better the demolding performance.

[0194] [Total content of alkali metals and alkaline earth metals other than Li in the resin composition]

[0195] After ashing 5g of PPS resin composition in an electric furnace at 500℃, it was diluted with 0.1mol / L hydrochloric acid aqueous solution and 0.1% lanthanum chloride aqueous solution. The resulting aqueous solution was used as a sample, and the content of alkali metals and alkaline earth metals other than Li in the resin composition was determined by atomic absorption spectrometry using a Shimadzu AA-6300 atomic absorption spectrophotometer.

[0196] [Crystallization temperature during molten retention of the molded part]

[0197] Will Figure 2The thin-walled molded article shown has the following dimensions: length 46mm, width 22mm, thickness 0.6mm, maximum height of reinforcing rib 4mm, and area of ​​the largest surface 1012mm². 2 The ratio of the area to the thickness of the largest surface (area / thickness) was 2310. Ten consecutive injection molding operations were performed under the following conditions, and the molded part obtained from the tenth injection was used as a sample (using a Sumitomo Heavy Industries "SE-50DUZ" molding machine). The conditions were: barrel temperature 330°C, mold temperature 150°C, injection pressure set at 180 MPa, and the injection speed set with a filling time of 0.3 seconds at the VP switching position when 90% of the molded part was filled. In the holding pressure process, the holding pressure speed was set at 30 mm / sec, the holding pressure time at 1 sec, and the holding pressure was set within a range that did not produce shrinkage marks, based on 50% of the filling peak pressure. The cooling time was 15 sec. After the sample was heated to 340°C and melted, it was held at 340°C in the molten state for 10 minutes, and then cooled at a rate of 20°C / min. The exothermic peak temperature (Tmc) observed at this time, accompanied by crystallization, was taken as the cooling crystallization temperature of the molded part during molten residence.

[0198] [Demolding properties during continuous molding]

[0199] Using the obtained PPS resin composition, continuous molding was performed under the same molding conditions as the molding article used in the above-mentioned molding article's melt retention and cooling crystallization temperature determination, to continuously mold out... Figure 2 The molded articles shown are evaluated. For the 1000th injection shot, the demolding performance during continuous molding is evaluated. Molded articles with poor demolding and deformation are evaluated as non-demoldable, molded articles that can be demolded but deformed are evaluated as ×, and molded articles that can be demolded and no deformation is observed are evaluated as ○.

[0200] Melt Flow Rate (MFR)

[0201] The melt flow index (MFR) of the PPS resin composition was determined using a melt indexer manufactured by Toyo Seiki Co., Ltd., based on JIS K 7210, at a temperature of 315°C and a load of 2160g. A higher MFR indicates better flowability and better moldability for thin-walled shapes.

[0202] [Tensile fracture strain]

[0203] The determination was performed according to ISO 527-1, 2 (2012). The specific determination is as follows: PPS resin composition particles of the present invention were dried in a hot air dryer at 130°C for 3 hours. They were then fed into an injection molding machine (SE-50D) manufactured by Sumitomo Heavy Industries, Ltd., with the barrel temperature set to 310°C and the mold temperature to 145°C. Using a mold of type A1 specimen shape (4 mm thickness) as specified in ISO 20753 (2008), injection molding was performed at an average velocity of 400 ± 50 mm / s through the cross-sectional area of ​​the central parallel section to obtain a specimen. After conditioning the specimen at 23°C and 50% relative humidity for 16 hours, tensile strain at break was determined according to ISO 527-1, 2 (2012) under an atmosphere of 23°C and 50% relative humidity, with a fixture distance of 114 mm and a test speed of 50 mm / min. When the tensile strain value is above 5%, it can be said that the product level is practically problem-free. However, the higher the value, the less likely it is to crack when pressing the molded part with other components, so it is preferred.

[0204] [Weight Reduction Rate]

[0205] 10g of the PPS resin composition particles of the present invention were weighed into an aluminum cup that had been preheated at 330°C for 3 hours, and then heated in a hot air dryer at 320°C for 120 minutes. The particles were then removed and placed in a desiccant-filled dryer for cooling, and then weighed. The weight reduction percentage (%) was calculated as the weight decrease before and after heating relative to the weight before heating. A smaller value indicates better suppression of gas generated during injection molding, and is therefore preferred.

[0206] [Mold Stain Resistance]

[0207] The obtained PPS resin composition was used Figure 3The molded article shown (article dimensions: length 55mm, width 20mm, thickness 2mm; gate dimensions: width 2mm, thickness 1mm (side gate); maximum length of vent 20mm, width 10mm, depth 5μm) was continuously molded using a gas evaluation mold. The conditions were: barrel temperature 330°C, mold temperature 130°C, injection speed 100mm / s, and injection pressure set between 50 and 80MPa to ensure a filling time of 0.4 seconds for each resin composition. Mold contamination at the vent was visually observed every 10 injections (using a Sumitomo Heavy Industries "SE-30D" molding machine). If the number of injections until contamination adheres to the mold is 100 or more, it can be considered practically usable; the higher the number of injections, the better the mold's contamination resistance, which is preferred. Since the accumulation of contaminants on the mold increases demolding resistance, excellent mold contamination resistance also contributes to improved demolding performance. A score of 0 indicates 100 or more injections before contamination adheres to the mold, and a score of × indicates less than 50 injections.

[0208] [Preparation of PPS Resin Compositions] (Examples, Comparative Examples)

[0209] Using a 47mm diameter twin-screw extruder (TEX-44α, manufactured by Nippon Steel Corporation) with a barrel temperature set at 320°C and a screw speed set at 400 rpm, raw materials were added from the feed inlet at the weight ratios shown in Tables 1 and 2 until molten. Particles were obtained by melt mixing at a discharge rate of 50 kg / hour. The aforementioned properties were evaluated using these particles. The results are shown in Tables 1 and 2.

[0210]

[0211]

[0212] The PPS resin compositions of Examples 1-9 exhibit excellent release properties during continuous molding by adding a release agent, setting the content of alkali metals and alkaline earth metals other than Li in the resin composition, and setting the cooling crystallization temperature (Tmc) of the molded article formed by the resin composition within a specific range. They also exhibit good moldability, including good mold stain resistance, toughness and flowability.

[0213] In Comparative Example 1, the amount of release agent (B) in the PPS resin composition was insufficient, resulting in increased demolding resistance with the mold. Consequently, the thin-walled molded article deformed during molding, exhibiting poor demolding properties. On the other hand, in Comparative Example 2, the amount of release agent (B) was excessive, leading to poor mold stain resistance.

[0214] In Comparative Example 3, the PPS resin composition contained a relatively high total content of alkali metals (excluding Li) and alkaline earth metals, resulting in insufficient crystallization rate. Consequently, the thin-walled molded articles deformed during molding and exhibited poor demolding properties. In Comparative Examples 4 and 5, the molded articles formed from the resin compositions had low post-retention cooling crystallization temperatures, leading to insufficient crystallization rate, deformation of the thin-walled molded articles during molding, and poor demolding properties.

[0215] Industry availability

[0216] The PPS resin composition of the present invention, in addition to the excellent insulation properties, heat resistance and chemical resistance inherent in PPS resin, has excellent crystallization properties, mold release properties and mold stain resistance. It has excellent mold release properties during continuous molding, so it is useful for battery insulating parts and the like that require the simultaneous molding of multiple micro, thin-walled molded parts. It also has excellent toughness, so it is particularly suitable for insulating parts for high-capacity primary or secondary batteries.

[0217] Explanation of symbols in attached drawings

[0218] 1 hole

[0219] 2 gates

[0220] 3 holes

[0221] Type 4 cavity

[0222] 5 gates

Claims

1. A polyphenylene sulfide resin composition comprising (A) a polyphenylene sulfide resin mixed with 0.1 to 3 parts by weight of (B) a release agent, wherein the total content of alkali metals and alkaline earth metals other than Li in the polyphenylene sulfide resin composition is less than 200 ppm, wherein a molded article formed from the polyphenylene sulfide resin composition is heated to 340°C using a differential scanning calorimeter to melt it, and then 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 accompanying crystallization is observed to be above 225°C and below 250°C.

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

3. The polyphenylene sulfide resin composition as described in claim 1 or 2, wherein the test piece obtained by injection molding the polyphenylene sulfide resin composition exhibits a tensile breaking strain of 5% or more in the tensile test of ISO 527-1, 2.

4. The polyphenylene sulfide resin composition according to claim 1 or 2, wherein the weight reduction rate after heating at 320°C for 120 minutes is less than 0.5% by weight.

5. The polyphenylene sulfide resin composition according to claim 1 or 2, wherein the amount of (C) thermoplastic elastomer mixed is less than 1 part by weight relative to 100 parts by weight of (A) polyphenylene sulfide resin.

6. The polyphenylene sulfide resin composition according to claim 1 or 2, wherein, relative to 100 parts by weight of (A) polyphenylene sulfide resin, 0.005 to 0.15 parts by weight of (D) polyarylether ketone is further mixed.

7. The polyphenylene sulfide resin composition according to claim 1 or 2, wherein the melt flow rate is 20 g / 10 min or more and 90 g / 10 min or less, said melt flow rate being a value measured according to JIS K 7210 at a temperature of 315°C and a load of 2160 g.

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

9. A molded article formed from the polyphenylene sulfide resin composition of claim 1 or 2.

10. The molded article as claimed in claim 9, wherein the ratio of the area to the thickness of the surface with the largest area among the surfaces constituting the molded article, i.e., area / thickness, is 200 or more and 50,000 or less.

11. The molded article as claimed in claim 9, wherein the thickness of the surface with the largest area among the surfaces constituting the molded article is 0.1 mm or more and 0.7 mm or less, and / or the area is 100 mm². 2 Above and 5000mm 2 the following.

12. The molded article as claimed in claim 9, wherein the molded article is a battery insulating component.

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