Polyphenylene sulfide resin composition and molded article

Abstract

The present invention relates to a polyphenylene sulfide resin composition which is a resin composition formed by compounding, relative to 100 parts by weight of (A) a polyphenylene sulfide resin, 16 to 50 parts by weight of (B) a thermoplastic resin having a tracking resistance of 125 V or more and a glass transition temperature of 0°C or more based on the IEC 60112 standard, 10 to 25 parts by weight of (C) an olefin-based copolymer containing an epoxy group, 10 to 25 parts by weight of (D) an olefin-based copolymer having no polar functional group, and 40 to 140 parts by weight of (E) a fibrous filler material, the thermoplastic resin of (B), the olefin-based copolymer containing an epoxy group of (C), and the olefin-based copolymer having no polar functional group of (D) being dispersed so as to have a number average dispersed particle diameter of 500 nm or less. A polyphenylene sulfide resin composition and a molded product thereof are provided, which do not substantially impair the excellent mechanical strength inherently possessed by polyphenylene sulfide resin and in which tracking resistance and toughness are improved in good balance.

Description

Technical Field

[0001] This invention relates to polyphenylene sulfide resin compositions that do not significantly impair the excellent mechanical strength of polyphenylene sulfide resin and exhibit excellent resistance to tracking and toughness. In addition to their effective application in electrical / electronic components or automotive electrical components, they can also be applied in a wide range of fields. Background Technology

[0002] Polyphenylene sulfide resin (hereinafter, sometimes simply referred to as PPS resin) is an engineering plastic with excellent heat resistance, flame retardancy, chemical resistance, electrical insulation, damp heat resistance, mechanical strength, and dimensional stability. It can be molded into various molded products, fibers, films, etc. through various molding methods such as injection molding and extrusion molding, and therefore has been widely used in electrical / electronic components, mechanical components, and automotive components.

[0003] However, PPS resin has a disadvantage compared to other engineering plastics such as polyamide resin and polyester resin in terms of leakage tracking breakdown caused when a high voltage is applied to the surface of the insulator.

[0004] Therefore, although PPS resin has good heat resistance, flame retardancy, chemical resistance, electrical insulation, damp heat resistance, mechanical strength, and dimensional stability as shown above, its use is limited in real-world environments exposed to high voltages. There is still a need to improve the tracking resistance of PPS resin compositions.

[0005] Tracking breakdown, also known as leakage current breakdown, is the phenomenon where short-circuit current flows as a carbonized conductive path forms when a voltage is applied to the surface of a contaminated insulator. Especially during the formation of carbonized conductive paths under high voltage, localized surface decomposition becomes the inducing factor, rapidly leading to the formation of conductive paths, making it difficult to stably control the material properties.

[0006] To date, several attempts have been studied to improve the tracking resistance of PPS resin, including reducing the amount of PPS resin, adding inorganic fillers such as magnesium hydroxide, other polymers, and additives.

[0007] For example, Patent Document 1 discloses improving tracking resistance by adding magnesium hydroxide and polyamide resin to PPS resin. Patent Document 2 discloses a composition formed by adding magnesium hydroxide, polyamide resin, and one or more compounds selected from polyolefin polymers, silicone, and fluorinated resins to PPS resin. Furthermore, Patent Document 3 discloses a composition formed by adding magnesium hydroxide, polyamide resin, and a vinyl aromatic compound block copolymer to PPS resin.

[0008] In addition, Patent Documents 4 and 5 disclose that by adding polyamide resin and epoxy-containing compounds to PPS resin, the toughness and processability of the resin composition are improved.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: Japanese Patent Application Publication No. 5-271542

[0012] Patent Document 2: Japanese Patent Application Publication No. 8-291253

[0013] Patent Document 3: Japanese Patent Application Publication No. 2019-147943

[0014] Patent Document 4: Japanese Patent Application Publication No. 4-222864

[0015] Patent Document 5: Japanese Patent Application Publication No. 2006-104222 Summary of the Invention

[0016] The problem that the invention aims to solve

[0017] However, while Patent Documents 1 and 2 disclose the tracking resistance and mechanical strength of PPS resin compositions, they do not provide a specific description of toughness. Regarding Patent Document 3, although toughness is mentioned, its effect is not satisfactory. Furthermore, Patent Documents 4 and 5 also fail to provide PPS resin compositions with sufficient toughness.

[0018] Therefore, the objective of this invention is to obtain a PPS resin composition with excellent resistance to tracking and toughness without significantly impairing the excellent mechanical properties and other properties inherent in PPS resin.

[0019] Problem-solving methods

[0020] To address the aforementioned issues, the polyphenylene sulfide resin composition of the present invention has the following structure. That is,

[0021] A polyphenylene sulfide resin composition is a resin composition formed relative to (A) 100 parts by weight of polyphenylene sulfide resin, comprising (B) 16-50 parts by weight of a thermoplastic resin with a tracking resistance of 125V or higher and a glass transition temperature of 0°C or higher according to IEC 60112 standard, (C) 10-25 parts by weight of an epoxy-containing olefin copolymer, (D) 10-25 parts by weight of an olefin copolymer without polar functional groups, and (E) 40-140 parts by weight of a fibrous filler material, wherein the thermoplastic resin (B), the epoxy-containing olefin copolymer (C), and the olefin copolymer without polar functional groups (D) are dispersed with a number-uniformly dispersed particle size of 500 nm or less.

[0022] The molded article of the present invention has the following structure. That is,

[0023] It is a molded article made from the above-mentioned polyphenylene sulfide resin composition.

[0024] The polyphenylene sulfide resin composition of the present invention preferably has a ratio (C) / (D) of 0.6 to 2 for the amount of the epoxy-containing olefin copolymer (C) to the amount of the olefin copolymer without polar functional groups (D).

[0025] In the polyphenylene sulfide resin composition of the present invention, the thermoplastic resin of (B) is preferably a polyamide resin.

[0026] The polyphenylene sulfide resin composition of the present invention preferably has a ratio (B) / ((C)+(D)) of 1.1 to 2 relative to 100 parts by weight of the polyphenylene sulfide resin (A) and the total amount of the epoxy-containing olefin copolymer (C) and the olefin copolymer without polar functional groups (D).

[0027] The molded article of the present invention is preferably a composite with metal.

[0028] Invention Effects

[0029] The present invention provides polyphenylene sulfide resin compositions and their molded articles that do not significantly impair the excellent mechanical strength inherent in polyphenylene sulfide resin, and improve the resistance to tracking and toughness in a good balance. Detailed Implementation

[0030] The embodiments of the present invention will now be described in detail.

[0031] The (A)PPS resin used in this invention is a polymer having repeating units as shown in the following structural formula (I).

[0032]

[0033] From the perspective of heat resistance, a polymer containing 70 mol% or more, more preferably 90 mol% or more, of repeating units as shown in the above structural formula is preferred. Additionally, PPS resin, with less than 30 mol% of its repeating units, can be composed of repeating units having the following structure, etc.

[0034]

[0035] The method for manufacturing the (A)PPS resin used in this invention will be described below. First, the polyhalogenated aromatic compounds, vulcanizing agents, polymerization solvents, molecular weight regulators, polymerization aids, and polymerization stabilizers used will be explained.

[0036] [Polyhalogenated aromatic compounds]

[0037] Polyhalogenated aromatic compounds are compounds having two or more halogen atoms per 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. Alternatively, two or more different polyhalogenated aromatic compounds can be combined to form copolymers, but p-dihalogenated aromatic compounds are preferably the main component.

[0038] The amount of polyhalogenated aromatic compounds used, from the viewpoint of obtaining a PPS resin with a viscosity suitable for processing, can be exemplified as being 0.9 to 2.0 mol, preferably 0.95 to 1.5 mol, and more preferably 1.005 to 1.2 mol relative to 1 mol of vulcanizing agent.

[0039] [Vulcanizing agent]

[0040] Examples of sulfiding agents include alkali metal sulfides, alkali metal hydrogen sulfides, and hydrogen sulfide.

[0041] Specific examples of alkali metal sulfides include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and mixtures of two or more thereof, with sodium sulfide being preferred. These alkali metal sulfides can be used in the form of hydrates or aqueous mixtures, or in anhydrous form.

[0042] Specific examples of alkali metal hydrosulfides include, for example, 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 or aqueous mixtures, or in anhydrous form.

[0043] Alternatively, a vulcanizing agent prepared in situ in the reaction system from alkali metal hydrogen sulfide and alkali metal hydroxide can be used. Furthermore, a vulcanizing agent can be prepared from alkali metal hydrogen sulfide and alkali metal hydroxide and then transferred to a polymerization reactor for use.

[0044] Alternatively, a sulfiding agent prepared in situ in the reaction system from alkali metal hydroxides such as lithium hydroxide and sodium hydroxide, and hydrogen sulfide can be used. Furthermore, a sulfiding agent can be prepared from alkali metal hydroxides such as lithium hydroxide and sodium hydroxide, and hydrogen sulfide, and then transferred to the polymerization reactor for use.

[0045] In cases where some vulcanizing agent is lost before the polymerization reaction begins due to dehydration operations, the amount of vulcanizing agent added refers to the residual amount obtained by subtracting the loss from the actual amount added.

[0046] It should be noted that alkali metal hydroxides and / or alkaline earth metal hydroxides can also be used in combination with a sulfiding agent. Specific examples of alkali metal hydroxides include, for example, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, and mixtures of two or more thereof. Specific examples of alkaline earth metal hydroxides include, for example, calcium hydroxide, strontium hydroxide, barium hydroxide, etc., with sodium hydroxide being preferred.

[0047] When using alkali metal hydrogen sulfide as a sulfiding agent, it is particularly preferred to use alkali metal hydroxide simultaneously. For the amount used, examples can be found in the range of 0.95 to 1.20 moles, preferably 1.00 to 1.15 moles, and more preferably 1.005 to 1.100 moles relative to 1 mole of alkali metal hydrogen sulfide.

[0048] [Polymerization solvent]

[0049] As a polymerization solvent, a polar organic solvent is preferred. Specific examples include N-alkylpyrrolidones such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, caprolactams such as N-methyl-ε-caprolactam, 1,3-dimethyl-2-imidazolinone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphotriamide, dimethyl sulfone, tetramethylene sulfoxide, and mixtures thereof, all of which exhibit high reaction stability and are therefore preferred. Among these, N-methyl-2-pyrrolidone (hereinafter sometimes simply referred to as NMP) is particularly preferred.

[0050] The amount of organic polar solvent used is selected to be 2.0 mol to 10 mol relative to 1 mol of the vulcanizing agent, preferably 2.25 to 6.0 mol, and more preferably 2.5 to 5.5 mol.

[0051] [Molecular weight regulator]

[0052] In order to form the ends of the generated PPS resin, or to adjust the polymerization reaction, molecular weight, etc., monohalogenated compounds (which do not necessarily have to be aromatic compounds) can be used in combination with the above-mentioned polyhalogenated aromatic compounds.

[0053] [Polymerization aids]

[0054] To obtain PPS resin with a higher degree of polymerization in a shorter time, the use of polymerization aids is a preferred option. Here, polymerization aids refer to substances that increase the viscosity of the resulting PPS resin. Specific examples of such polymerization aids include, for instance, organic carboxylates, water, alkali metal chlorides, organic sulfonates, alkali metal sulfates, alkaline earth metal oxides, alkali metal phosphates, and alkaline earth metal phosphates. They can be used alone or in combination. Among these, organic carboxylates and / or water are preferred.

[0055] The aforementioned alkali metal carboxylates refer to compounds represented by the general formula R(COOM)n (where 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, and n is an integer from 1 to 3). Alkali metal carboxylates can also be used in the form of hydrates, anhydrous forms, or aqueous solutions. Specific examples of alkali metal carboxylates include lithium acetate, sodium acetate, potassium acetate, sodium propionate, lithium valerate, sodium benzoate, sodium phenylacetate, potassium p-toluene, and mixtures thereof.

[0056] Alkali metal carboxylates can be formed by adding an organic acid and 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, considering that lithium salts have high solubility in the reaction system and a significant auxiliary effect, but are expensive, and that potassium, rubidium, and cesium salts have insufficient solubility in the reaction system, sodium acetate, which is inexpensive and has moderate solubility in the polymerization system, is the most preferred choice.

[0057] 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. For obtaining a higher degree of polymerization, the range of 0.1 to 0.6 mol is preferred, and more preferably the range of 0.2 to 0.5 mol is preferred.

[0058] Furthermore, using water as a polymerization aid is one of the effective methods for obtaining a resin composition with a high balance between flowability and high toughness. The amount added is typically in the range of 0.5 to 15 moles relative to 1 mole of the added alkali metal sulfide; for obtaining a higher degree of polymerization, the range of 0.6 to 10 moles is preferred, and more preferably, the range of 1 to 5 moles.

[0059] There are no specific rules regarding the timing of adding these polymerization aids. They can be added at any time during the preceding steps, at the start of polymerization, or during the polymerization process (described later). Alternatively, they can be added in multiple stages. When using alkali metal carboxylates as polymerization aids, it is more preferable to add them simultaneously at the start of the preceding steps or at the start of polymerization for ease of addition. Furthermore, when using water as a polymerization aid, adding it during the polymerization reaction after the addition of a polyhalogenated aromatic compound is effective.

[0060] [Polymerization stabilizer]

[0061] To stabilize the polymerization reaction system and prevent side reactions, polymerization stabilizers can also be used. Polymerization stabilizers contribute to the stabilization of the polymerization reaction system and suppress undesirable side reactions. A standard example of a side reaction is the formation of thiophenol; by adding a polymerization stabilizer, the formation of thiophenol can be suppressed. 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, when using alkali metal hydrogen sulfides as vulcanizing agents, it is particularly preferred to use alkali metal hydroxides simultaneously, but an excess of alkali metal hydroxide relative to the vulcanizing agent can also serve as a polymerization stabilizer.

[0062] 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 to 0.2 mol relative to 1 mol of alkali metal sulfide, more preferably 0.03 to 0.1 mol, and even more preferably 0.04 to 0.09 mol. When the ratio is within the above-mentioned preferred range, the stabilization effect is sufficient, and on the other hand, it is economically advantageous with excellent polymer yield.

[0063] There is no particular time requirement for the addition of the polymerization stabilizer. It can be added at any time during the preceding process, at the start of polymerization, or during the polymerization process, as described later. Alternatively, it can be added in multiple stages. However, it is preferable to add it simultaneously at the start of the preceding process or at the start of polymerization, as this is easier.

[0064] Next, the preceding processes, polymerization reaction processes, recycling processes, and post-processing processes will be explained in detail.

[0065] [Previous Process]

[0066] The vulcanizing agent is typically used in hydrate form. Preferably, before adding the polyhalogenated aromatic compound, the mixture containing the organic polar solvent and the vulcanizing agent is heated to remove excess water from the system. It should be noted that if excessive water is removed through this operation, it is preferable to add water to compensate for the shortfall.

[0067] Additionally, as mentioned above, alkali metal sulfides prepared in situ in the reaction system or in a reactor separate from the polymerization reactor can also be used as vulcanizing agents. This method is not particularly limited, but the following method is preferred: Under an inert gas atmosphere, at a temperature range of room temperature to 150°C, preferably room temperature to 100°C, the alkali metal sulfide and alkali metal hydroxide are added to an organic polar solvent; under normal or reduced pressure, the temperature is raised to at least 150°C, preferably 180–260°C, to remove water by distillation. Polymerization aids can also be added at this stage. Furthermore, to promote the distillation removal of water, toluene or the like can be added to facilitate the reaction.

[0068] In the polymerization reaction, the water content in the polymerization system is preferably 0.5 to 10.0 mol relative to 1 mol of 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.

[0069] [Polymerization reaction process]

[0070] PPS resin powder is preferably manufactured by reacting a vulcanizing agent with a polyhalogenated aromatic compound in an organic polar solvent at a temperature range of above 200°C and below 290°C.

[0071] At the start of the polymerization reaction, it is preferable to add the vulcanizing agent and polyhalogenated aromatic compound to the organic polar solvent under an inert gas atmosphere and at a temperature range of room temperature to 215°C, preferably 100°C to 215°C. Polymerization accelerators may also be added at this stage. These raw materials can be added in different orders or simultaneously.

[0072] The mixture is typically heated to a temperature range of 200°C to 290°C. There are no particular restrictions on the heating rate, but a rate of 0.01 to 5°C / minute is usually chosen, and more preferably, a rate of 0.1 to 3°C / minute is preferred.

[0073] Typically, the temperature is eventually raised to 250–290°C, and the reaction is carried out at this temperature for 0.25–50 hours, preferably 0.5–20 hours.

[0074] In the stage before reaching the final temperature, for example, after reacting at 200°C to 245°C for a certain time, raising the temperature to 270°C to 290°C is effective in obtaining a higher degree of polymerization. At this time, the reaction time at 200°C to 245°C is usually selected in the range of 0.25 hours to 20 hours, preferably in the range of 0.25 hours to 10 hours.

[0075] It should be noted that, in order to obtain polymers with higher degrees of polymerization, polymerization in multiple stages is effective. When polymerizing in multiple stages, it is effective to set the point at which the conversion rate of polyhalogenated aromatic compounds in the system reaches 40 mol% or more, preferably 60 mol%, at 245°C.

[0076] [Recycling Process]

[0077] After polymerization is complete, solids are recovered from the polymerization reactants, which contain polymers, solvents, etc.

[0078] The preferred method for recycling PPS resin is under rapid cooling conditions. Flash evaporation is a preferred method for this recycling process. Flash evaporation involves subjecting the polymer reactants to high temperature and pressure (typically above 250°C and 8 kg / cm³). 2 The above-mentioned state is flash evaporated into an atmosphere of normal or reduced pressure, and the polymer is recovered in the form of powder granules while recovering the solvent. The so-called flash evaporation here refers to the ejection of the polymerization reactants from a nozzle. For the atmosphere for flash evaporation, examples include nitrogen or water vapor at normal pressure, and the temperature is usually selected in the range of 150°C to 250°C.

[0079] Flash evaporation can recover both solvent and solids simultaneously, and the recovery time is relatively short, making it an economically advantageous recovery method. However, this method is prone to the incorporation of ionic compounds, such as sodium, and low-polymerization organic substances (oligomers) into the polymer during the solidification process.

[0080] However, the method for recovering PPS resin used in this invention is not limited to flash evaporation. Any method that meets the requirements of this invention can also be used to recover particulate polymers through slow cooling (quenching). However, considering both economy and performance, the manufacturing method of this invention more preferably uses PPS resin recovered via flash evaporation.

[0081] [Post-processing steps]

[0082] In this invention, the PPS resin used is preferably a PPS resin that has undergone thermal oxidation treatment of the PPS resin obtained through the above-described polymerization reaction step and recycling step. It is also preferable to include a hot water treatment and an acid treatment step before the thermal oxidation treatment step. Alternatively, a cleaning step using an organic solvent may be included before the acid treatment and hot water treatment steps.

[0083] The acid used in the acid treatment of this invention is not particularly limited as long as it does not decompose PPS resin. Examples include acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid, and propionic acid. Acetic acid and hydrochloric acid are preferred, but acids such as nitric acid, which decompose and degrade PPS resin, should be avoided.

[0084] 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 below 7, the metal content of the PPS resin will not increase, and if the pH is above 1, it can prevent the increase of volatile components in the PPS resin.

[0085] The acid treatment method preferably involves impregnating the PPS resin in an acid or an aqueous solution of acid, and may also involve appropriate stirring and heating as needed. The heating temperature is preferably 80–250°C, more preferably 120–200°C, and even more preferably 150–200°C. Setting the temperature above 80°C ensures sufficient acid treatment effect without increasing the metal content, while setting it below 250°C effectively prevents excessive pressure. Furthermore, when treating the PPS resin by impregnating it with an aqueous acid solution, it is preferable that the pH becomes below 8 after acid treatment, more preferably above 2 and below 8. If the pH is below 8, it effectively prevents an increase in the metal content of the resulting PPS resin.

[0086] The preferred acid treatment time is the time it takes for the reaction between the PPS resin and the acid to reach full equilibrium. When the treatment is carried out at 80°C, it is preferably 2 to 24 hours, and when the treatment is carried out at 200°C, it is preferably 0.01 to 5 hours.

[0087] 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. If the ratio of acid or aqueous solution to 500g of PPS resin is 0.5L or more, the PPS resin is fully immersed in the aqueous solution, thus allowing for thorough cleaning and effectively preventing an increase in the metal content of the PPS resin. Furthermore, if the ratio of acid or aqueous solution to 500g of PPS resin is 500L or less, the solution volume relative to the PPS resin is appropriate, resulting in excellent production efficiency.

[0088] These acid treatments are performed by adding a specified amount of PPS resin to a specified amount of water and acid, and then 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 simple; examples include natural filtration, pressure filtration, vacuum filtration, and centrifugal filtration. To remove acid and impurities remaining on the surface of the PPS resin separated from the treated solution, it is preferable to wash several times with water or warm water. Examples of washing methods include filtering while sprinkling water onto the PPS resin in the filtration device, or adding the separated PPS resin to pre-prepared water and then filtering again to separate the aqueous solution from the PPS resin. The water used for washing is preferably distilled water or deionized water.

[0089] In this invention, hot water treatment is preferably performed before the acid treatment process, and the method is described below. The water used in the hot water treatment is preferably distilled water or deionized water. The hot water treatment temperature is preferably 80–250°C, more preferably 120–200°C, and even more preferably 150–200°C. Setting the temperature to 80°C or higher ensures sufficient hot water treatment and reduces the amount of volatile gases produced; setting it to 250°C or higher effectively prevents excessive pressure.

[0090] The hot water treatment time is preferably a sufficient time for extraction treatment with PPS resin and hot water. When the treatment is carried out at 80°C, it is preferably 2 to 24 hours, and when the treatment is carried out at 200°C, it is preferably 0.01 to 5 hours.

[0091] In hot water treatment, the ratio of PPS resin to water is preferably such that the PPS resin is fully immersed in the water. The water content is preferably 0.5 to 500 L per 500 g of PPS resin, more preferably 1 to 100 L, and even more preferably 2.5 to 20 L. If the water content is 0.5 L or more per 500 g of PPS resin, the PPS resin is fully immersed in the water, allowing for thorough rinsing and reducing the generation of volatile gases. Conversely, if the water content is 500 L or less per 500 g of PPS resin, an appropriate water content is achieved, resulting in excellent production efficiency.

[0092] There are no particular restrictions on the operation of these hot water treatment processes. Methods include adding a specified amount of PPS resin to a specified amount of water and heating and stirring it in a pressure vessel, or continuously performing hot water treatment. There are no particular restrictions on the method for separating the aqueous solution and PPS resin from the treated solution after hot water treatment. Filtration using sieves or filters is convenient, and examples include natural filtration, pressure filtration, vacuum filtration, and centrifugal filtration. To remove impurities remaining on the surface of the PPS resin separated from the treated solution, it is preferable to wash it several times with water or warm water. There are no particular restrictions on the washing method; examples include filtering while pouring water into the PPS resin on the filter 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.

[0093] Furthermore, to avoid the decomposition of PPS terminal groups during these acid and hot water treatments, it is preferable to conduct these treatments under an inert atmosphere. Examples of inert atmospheres include nitrogen, helium, and argon; from an economic perspective, a nitrogen atmosphere is preferred.

[0094] In this invention, a cleaning step using an organic solvent may be included before the acid treatment step and the hot water treatment step, as described below. In this invention, the organic solvents used for washing PPS resin are not particularly limited as long as they do not decompose PPS resin. Examples include nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, 1,3-dimethylimidazolium ketone, hexamethylphosphoramide, and piperazine; sulfoxide / sulfone solvents such as dimethyl sulfoxide, dimethyl sulfone, and sulfolane; ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, and acetophenone; ether solvents such as dimethyl ether, dipropyl ether, dioxane, and tetrahydrofuran; halogen solvents such as chloroform, dichloromethane, trichloroethylene, dichloroethylene, perchloroethylene, monochloroethane, dichloroethane, tetrachloroethane, perchloroethane, and chlorobenzene; alcohol / phenol solvents such as methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, and propylene 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 or more of these organic solvents may be used.

[0095] Cleaning methods using organic solvents include immersing PPS resin in the solvent, and may also involve stirring or heating as needed. There are no particular limitations on the cleaning temperature when cleaning PPS resin with organic solvents; any temperature from room temperature to approximately 300°C can be selected. There is a tendency for higher cleaning temperatures to result in higher cleaning efficiency, but generally, a cleaning temperature of room temperature to 150°C is sufficient to achieve adequate results. Cleaning can also be carried out in a pressure vessel under pressure at a temperature above the boiling point of the organic solvent. Furthermore, there are no particular limitations on the cleaning time. While it depends on the cleaning conditions, in the case of intermittent cleaning, a cleaning time of 5 minutes or more is usually sufficient to achieve adequate results. Alternatively, continuous cleaning can also be performed.

[0096] These acid treatments, hot water treatments, or cleanings using organic solvents can also be combined appropriately.

[0097] The melt flow rate of the PPS resin used in this invention (measured according to ASTM D-1238-70 at a temperature of 315.5°C and a load of 5000g) is preferably in the range of 100 to 4000 g / 10 minutes. If the melt flow rate is 100 g / 10 minutes or higher, the melt flowability of the PPS resin composition will not significantly deteriorate, especially even with high filler application, allowing for stable molding. Furthermore, by keeping the melt flow rate below 4000 g / 10 minutes, the strength of the molded articles formed from the PPS resin composition can be maintained.

[0098] In the resin composition of the present invention, 16 to 50 parts by weight of (B) a thermoplastic resin with a tracking resistance of 125V or higher and a glass transition temperature of 0°C or higher based on IEC60112 standard is added relative to 100 parts by weight of PPS resin. Specific examples include polyamide resins such as nylon 6, nylon 66, nylon 46, nylon 610, nylon 612, nylon 11, nylon 12, and aromatic nylons; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polycyclohexyldimethyl terephthalate, and polynaphthalene glycol terephthalate; polycarbonate; polytetrafluoroethylene; polyamide-imide; polyimide; polyether-imide; polyethersulfone; modified polyphenylene ether resin; polysulfone resin; polyallyl sulfone resin; polyketone resin; polyarylate resin; liquid crystal polymers; polyetherketone resin; polythioetherketone resin; polyetheretherketone resin; polyamide-imide resin; and tetrafluoroethylene resin.

[0099] Among them, polyamide resins such as nylon 6, nylon 610, nylon 612, nylon 11, and nylon 12 are preferred, as are polybutylene terephthalate, and polyamide resins having repeating units as shown in the following structural formula are even more preferred.

[0100]

[0101] Here, in the structural formula, 'a' is a natural number of 5 or more, representing the number of repeating methylene units, and 'b' is a natural number of 7 or more, representing the number of repeating methylene units. Polyamide resins with such long-chain aliphatic structures are less prone to forming carbonized conductive paths during tracking tests, which is beneficial for improving electrical properties. Here, the natural number 'a' must be 5 or more, more preferably 6 or more. Similarly, the natural number 'b' must be 7 or more, more preferably 8 or more. Examples of preferred polyamide resins include polyamide 610 with 'a' of 6 and 'b' of 8, and polyamide 612 with 'a' of 6 and 'b' of 10. Regarding the upper limits of 'a' and 'b', considering maintaining good flowability, 'a' is preferably 10 or less, and 'b' is preferably 14 or less. 'n' represents the number of repeating structural units in the polyamide resin, typically 100 or more and 100,000 or less.

[0102] The thermoplastic resin (B) used in this invention preferably has a water absorption rate of 0.5% by weight or less, more preferably 0.3% by weight or less, after immersion in water at 23°C for 24 hours. This is because, in order to maintain excellent resistance to tracking, mechanical strength, dimensional stability, and hygrothermal stability of the PPS resin composition during water absorption, it is particularly preferable to control the water absorption rate of the added thermoplastic resin (B).

[0103] It should be noted that the water absorption rate mentioned here refers to the value expressed as a percentage, calculated by dividing the weight difference of the thermoplastic resin before and after the treatment by the weight of the thermoplastic resin before the treatment, after the thermoplastic resin of (B) above has been impregnated in water at 23°C for 24 hours according to ASTM-D570, by the weight of the thermoplastic resin of (B) above before the treatment.

[0104] The amount of the thermoplastic resin (B) used in this invention is in the range of 16 to 50 parts by weight relative to 100 parts by weight of PPS resin. Preferably, the amount of the thermoplastic resin (B) is 20 to 40 parts by weight. If the amount of the thermoplastic resin (B) exceeds 50 parts by weight, the excellent heat resistance, flame retardancy, dimensional stability, hydrolysis resistance, and low water absorption properties of PPS resin deteriorate. When the amount of the thermoplastic resin (B) is less than 16 parts by weight, the effect of exhibiting resistance to tracking cannot be obtained.

[0105] As the epoxy-containing olefin copolymer used in this invention (C), known epoxy-containing olefin copolymers can be exemplified. Specific examples include (co)polymers obtained by polymerizing α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-octene, 4-methyl-1-pentene, isobutene, etc., alone or in two or more forms; copolymers of α-olefins with α,β-unsaturated acids and their alkyl esters such as acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, etc., such as ethylene / propylene copolymers (“ / ” indicates copolymerization, the same applies hereinafter), ethylene / 1-butene copolymers, ethylene / 1-hexene copolymers, etc. This product is obtained by introducing epoxy-containing monomer components (components containing functional groups) into ethylene / 1-octene copolymers, ethylene / methyl acrylate copolymers, ethylene / ethyl acrylate copolymers, ethylene / butyl acrylate copolymers, ethylene / methyl methacrylate copolymers, ethylene / ethyl methacrylate copolymers, ethylene / butyl methacrylate copolymers, etc. Examples of such epoxy-containing monomers include glycidyl acrylate, glycidyl methacrylate, glycidyl ethyl acrylate, glycidyl itaconic acid, glycidyl citrate, etc. There are no particular limitations on the method of introducing these functional group-containing components; methods such as copolymerizing olefin (co)polymers or grafting them onto olefin (co)polymers using free radical initiators are acceptable. The amount of the functional group-containing component introduced is preferably set to 0.001 to 40 mol%, more preferably to 0.01 to 35 mol%, relative to all monomers constituting the epoxy-containing olefin (co)polymer. Specific examples of olefin copolymers obtained by introducing particularly useful epoxy-containing monomer components include ethylene / propylene-glycidyl methacrylate copolymers (“g” indicates grafting, the same applies hereinafter), ethylene / 1-butene-glycidyl methacrylate copolymers, ethylene / glycidyl acrylate copolymers, ethylene / glycidyl methacrylate copolymers, ethylene / methyl acrylate / glycidyl methacrylate copolymers, and ethylene / methyl methacrylate / glycidyl methacrylate copolymers. Alternatively, in addition to glycidyl esters of α-olefins such as ethylene and propylene and α,β-unsaturated acids, epoxy-containing olefin copolymers with other monomers as essential components are preferred.

[0106] Preferred examples of (C) olefin copolymers containing epoxy groups include ethylene / glycidyl methacrylate copolymers, ethylene / methyl acrylate / glycidyl methacrylate copolymers, and ethylene / methyl methacrylate / glycidyl methacrylate copolymers. Particularly preferred substances include ethylene / glycidyl methacrylate copolymers.

[0107] In this invention, the amount of the epoxy-containing olefin copolymer (C) is selected from 10 to 25 parts by weight relative to 100 parts by weight of PPS resin, and more preferably 10 to 20 parts by weight. If the amount exceeds 25 parts by weight, the mechanical strength and low gas content of the PPS resin will be impaired; if it is less than 10 parts by weight, the toughness will be weakened.

[0108] Next, for the (D) olefin copolymers without polar functional groups used in this invention, known unmodified olefin copolymers can be cited as examples. Specific examples include (co)polymers obtained by polymerizing α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-octene, 4-methyl-1-pentene, and isobutene, either alone or in two or more forms, such as ethylene / propylene copolymers, ethylene / 1-butene copolymers, ethylene / 1-hexene copolymers, and ethylene / 1-octene copolymers. Additionally, hydrogenated products of styrene-ethylene-butadiene copolymers are also useful.

[0109] It should be noted that ethylene / 1-butene copolymers are a particularly preferred example of olefin copolymers that do not have polar functional groups.

[0110] For the amount of the olefin copolymer without polar functional groups in (D) of this invention, the range is selected as 10 to 25 parts by weight relative to 100 parts by weight of PPS resin, and more preferably 10 to 20 parts by weight. If the amount exceeds 25 parts by weight, the mechanical strength and low gas content of PPS resin will be impaired, and if it is less than 10 parts by weight, the toughness performance will be weakened.

[0111] The PPS resin composition of the present invention does not significantly impair the excellent mechanical strength inherent in PPS resin, and improves tracking resistance and toughness in a good balance. To exhibit these properties, the PPS resin is required to form an island phase (continuous phase or matrix), and the thermoplastic resin of (B), the epoxy-containing olefin copolymer of (C), and the olefin copolymer without polar functional groups of (D) are required to form an island phase (dispersed phase). Furthermore, the number-average particle size of the thermoplastic resin of (B), the epoxy-containing olefin copolymer of (C), and the olefin copolymer without polar functional groups of (D) needs to be 500 nm or less. From a productivity perspective, a number-average particle size of 1 nm or more is preferred as a lower limit. On the other hand, if the number-average particle size exceeds 500 nm, in other words, large aggregates exist, it will become the starting point for fracture during tensile and flexural tests, leading to a decrease in mechanical strength and toughness.

[0112] As a method for controlling the number-average dispersed particle size of the island phase in the PPS resin composition to be 500 nm or less, the ratio (C) / (D) of the amount of the epoxy-containing olefin copolymer (C) to the amount of the non-polar functional group-containing olefin copolymer (D) relative to at least 100 parts by weight of PPS resin is preferably in the range of 0.6 to 2. By selecting the above range, the number-average dispersed particle size of the island phase in the PPS resin composition is controlled to be 500 nm or less, which can achieve a high level of balance between tracking resistance and toughness.

[0113] It should be noted that the number-average particle size mentioned here refers to the particle size obtained by molding a type A1 test piece as specified in ISO 20753 at a molding temperature of +20 to 40°C from the melting peak temperature of PPS resin, cutting a thin sheet of less than 0.1 μm from its center at -20°C along the cross-sectional area of ​​the dumbbell sheet, and observing any 100 island phases under 1000x magnification using an H-7100 transmission electron microscope manufactured by Hitachi. First, the maximum and minimum diameters of each island phase are measured to obtain the biaxial average particle size, and then the average value of these 100 biaxial average particle sizes is calculated.

[0114] Furthermore, in this invention, the ratio (B) / ((C)+(D)) of the total amount of the thermoplastic resin in (B) to the amount of the epoxy-containing olefin copolymer in (C) and the amount of the olefin copolymer without polar functional groups in (D) is preferably 1.1 to 2, more preferably 1.1 to 1.7. If the value of the ratio (B) / ((C)+(D)) is 2 or less, the excellent mechanical strength and low gas content of PPS resin can be maintained; if it is 1.1 or more, excellent resistance to tracking and toughness can be obtained.

[0115] In this invention, (E) fibrous filler materials must be used. Specific examples include stainless steel fibers, aluminum fibers, brass fibers, asbestos, PAN-based carbon fibers, asphalt-based carbon fibers, carbon nanotubes, carbon nanofibers, calcium carbonate whiskers, wollastonite whiskers, potassium titanate whiskers, barium titanate whiskers, aluminum borate whiskers, silicon nitride whiskers, aramid fibers, alumina fibers, silicon carbide fibers, asbestos fibers, gypsum fibers, ceramic fibers, zirconium oxide fibers, silica fibers, glass fibers, titanium oxide fibers, and silicon carbide fibers, etc., and two or more of these can be used in combination. Furthermore, from the perspective of obtaining superior mechanical strength, it is preferable to pretreat these fibrous filler materials with coupling agents such as isocyanate compounds, organosilane compounds, organotitanate compounds, organoborane compounds, and epoxy compounds.

[0116] In terms of improving the rigidity of the material, it is preferable to select at least one of glass fiber and carbon fiber.

[0117] In this invention, the amount of the fibrous filler (E) relative to 100 parts by weight of PPS resin is selected in the range of 40 to 140 parts by weight, more preferably in the range of 50 to 130 parts by weight. When the amount is less than 40 parts by weight, the mechanical strength is insufficient, and when the amount exceeds 140 parts by weight, the adverse effect on toughness becomes greater.

[0118] The PPS resin composition of the present invention can be further used by adding inorganic fillers other than (E) fibrous fillers without impairing the effects of the present invention. There are no particular limitations on the inorganic fillers that can be added; specific examples include talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, bentonite, asbestos, aluminum silicate, hydrotalcite, silicates, silicon dioxide, magnesium oxide, aluminum oxide, silica (fragmented / spherical), quartz, glass beads, glass flakes, fragmented / irregularly shaped glass, glass microspheres, molybdenum disulfide, alumina (fragmented), translucent alumina (fibrous / plate-like / flaky / granular / irregularly shaped / fragmented), titanium dioxide (fragmented), and zinc oxide (fibrous / plate-like). Oxides such as (flaky / granular / irregularly shaped / fragmented materials), calcium carbonate, magnesium carbonate, zinc carbonate and other carbonates, calcium sulfate, barium sulfate and other sulfates, calcium hydroxide, magnesium hydroxide, aluminum hydroxide and other hydroxides, silicon carbide, carbon black and silicon dioxide, graphite, aluminum nitride, transparent aluminum nitride (fibrous / plate-like / flaky / granular / irregularly shaped / fragmented materials), calcium polyphosphate, graphite, metal powder, metal flakes, metal strips, metal oxides, etc. Specific examples of metal types for metal powder, metal flakes, and metal strips include silver, nickel, copper, zinc, aluminum, stainless steel, iron, brass, chromium, tin, etc. Additionally, carbon powder, graphite, carbon flakes, flake carbon, fullerenes, graphene, etc., can be hollow, and more than two of these filling materials can be used together. Alternatively, these inorganic fillers can be pretreated with coupling agents such as isocyanate compounds, organosilane compounds, organotitanate compounds, organoborane compounds, and epoxy compounds before use. Calcium carbonate, carbon powder, and graphite are preferred among these. The amount of other inorganic fillers besides the fiber filler mentioned above is preferably 0 parts by weight or more, more preferably 0.1 parts by weight or more, relative to 100 parts by weight of PPS resin, and preferably 50 parts by weight or less, more preferably 40 parts by weight or less, relative to 100 parts by weight of PPS resin.

[0119] Furthermore, in the PPS resin composition used in this invention, a silane compound having at least one functional group selected from epoxy, amino, isocyanate, hydroxyl, mercapto, and urea groups may be added to improve mechanical strength and toughness, without impairing the effects of this invention. Specific examples of such compounds include epoxy-containing alkoxysilane compounds such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; mercapto-containing alkoxysilane compounds such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane; urea-containing alkoxysilane compounds such as γ-ureopropyltriethoxysilane, γ-ureopropyltrimethoxysilane, and γ-(2-ureoethyl)aminopropyltrimethoxysilane; and γ-isocyanate-propyltriethoxysilane, γ-isocyanate-propyltrimethoxysilane, and γ-isocyanate-propyltriethoxysilane. Alkoxysilane compounds containing isocyanate groups, such as γ-propylmethyldimethoxysilane, γ-isocyanate-propylmethyldiethoxysilane, γ-isocyanate-propylethyldimethoxysilane, γ-isocyanate-propylethyldiethoxysilane, and γ-isocyanate-propyltrichlorosilane; amino-containing alkoxysilane compounds, such as γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane; and hydroxyl-containing alkoxysilane compounds, such as γ-hydroxypropyltrimethoxysilane and γ-hydroxypropyltriethoxysilane. Among these, alkoxysilanes containing epoxy, amino, isocyanate, or hydroxyl groups are particularly suitable for achieving excellent weld strength. The preferred addition amount of this silane compound is in the range of 0.05 to 3 parts by weight relative to 100 parts by weight of PPS resin.

[0120] It should be noted that, in the PPS resin composition of the present invention, other components may be added within the scope that does not impair the effect of the present invention, such as antioxidants, heat stabilizers (hindered phenols, hydroquinones, phosphorus compounds, phosphites, amines, sulfur compounds and their substitutes, etc.), weathering agents (resorcinols, salicylates, benzotriazoles, benzophenones, hindered amines, etc.), release agents and lubricants (lignite acid and its metal salts, its esters, its half-esters, stearyl alcohol, stearamide, stearate esters, diurea, etc.), pigments (cadmium sulfide, phthalocyanine, carbon black for coloring, etc.), dyes (aniline black, etc.), antistatic agents (alkyl sulfate anionic antistatic agents, quaternary ammonium cationic antistatic agents, polyoxyethylene... The additives include nonionic antistatic agents such as ethylene sorbitan monostearate and betaine-based amphoteric antistatic agents, flame retardants (such as red phosphorus, phosphate esters, melamine cyanurate, ammonium polyphosphate, etc.), heat stabilizers, lubricants such as calcium stearate, aluminum stearate, and lithium stearate, strength enhancers such as bisphenol A type bisphenol epoxy resin, phenolic varnish phenolic epoxy resin, and cresol phenolic varnish type epoxy resin, UV stabilizers, colorants, flame retardants, and foaming agents. Regarding the amount of these other components relative to 100 parts by weight of PPS resin, the lower limit is preferably 0 parts by weight or more, more preferably 0.01 parts by weight or more, and the upper limit is preferably 5 parts by weight or less, more preferably 3 parts by weight or less. Among these additives, antioxidants and heat stabilizers (hindered phenols, hydroquinones, phosphorus compounds, phosphites, amines, sulfur compounds, and their substitutes, etc.) are preferred.

[0121] More preferably, phosphorus-based antioxidants and hindered phenolic antioxidants are used.

[0122] As specific examples, the phosphorus-based and phosphite antioxidants mentioned above may include tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol-diphosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, triphenyl phosphite, tris(2,4-di-tert-butylphenyl)phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, and 4,4-butylidene-bis(3-methyl-6-tert-butylphenyl-di-tetrazane). 1,6-di-tert-butyl-4-methylphenyl) phosphite, cyclopentanetetramethylbis(octadecyl phosphite), cyclopentanetetramethylbis(2,6-di-tert-butyl-4-methylphenyl) phosphite, tri(nonylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 10-(3,5-di-tert-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 10-decoxy-9,10-dihydro-9-oxa-10-phosphenanthrene, etc., or mixtures thereof.

[0123] Examples of hindered phenolic antioxidants include triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate, 4,4'-butylenebis(3-methyl-6-tert-butylphenol), 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylaniline)-1,3,5-triazine, pentaerythritol-tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylidenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,2- Thiobis(4-methyl-6-tert-butylphenol), N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrogenated cinnamamide), 3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-dibutyl-4-hydroxybenzyl)benzene, calcium bis(3,5-di-tert-butyl-4-hydroxybenzyl sulfonate), tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate stearate, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2 '-Methylene-bis-(4-ethyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), octyl diphenylamine, 2,4-bis[(octylthio)methyl]o-cresol, isooctyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 4,4'-butylidene bis(3-methyl-6-tert-butylphenol), 3,9-bis[1,1-dimethyl-2-[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]2,4,8,10-tetraoxaspiro[5.5]undecane, phenylpropionic acid, 3-(1,1-dimethylethyl)-4-hydroxy-5-methyl-2,4,8,10-tetraoxapyrrolo[5.5]undecane-3,9-diylbis(2, 2-Dimethyl-2,1-ethanediyl) ester, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, bis[3,3'-bis(4'-hydroxy-3'-tert-butylphenyl)butyrate]diol ester, 1,3,5-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-sec-triazine-2,4,6-(1H,3H,5H)trione, d-α-tocopherol, 3,9-bis(2-(3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy)-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, etc., or mixtures thereof.

[0124] Examples of amine antioxidants include dimethyl succinate-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine condensate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidinyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidinyl)imino}], bis(1,2,2,6,6-pentamethyl-4-piperidinyl) 2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-n-butylmalonic acid bis(1,2,2,6,6-pentamethyl-4-piperidinyl), tetra(2,2,6,6-tetramethyl... 1,2,3,4-butanetetracarboxylic acid ester (-4-piperidinyl), bis-2,2,6,6-tetramethyl-4-piperidinyl sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, methyl(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 1-[2-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]ethyl]-4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, etc., or mixtures thereof.

[0125] As sulfur-based antioxidants, examples include 4,4'-thiobis(6-tert-butyl-3-methylphenol), (C12-18)3,3'-thiodipropionate dialkyl ester, pentaerythritol tetra(3-lauryl thiopropionate), or mixtures thereof.

[0126] There are no particular limitations on the preparation method of PPS resin compositions. Representative examples include feeding the raw materials into a commonly known melt mixer 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. The mixing order of the raw materials is also not particularly limited. Methods such as mixing all raw materials and then melt-mixing them using the above method, mixing a portion of the raw materials and then melt-mixing them using the above method, then mixing the remaining raw materials and melt-mixing them, or mixing a portion of the raw materials and then using a side feeder to mix the remaining raw materials during melt-mixing in a single-screw or twin-screw extruder, are all acceptable. Furthermore, regarding small amounts of additives, other components can be mixed and granulated using the above methods and then added before molding.

[0127] The resulting PPS resin composition can be used for various molding processes such as injection molding, extrusion molding, blow molding, and transfer molding, and is particularly suitable for injection molding applications.

[0128] For the PPS resin composition obtained in this invention, it is preferable to use a type A1 test piece as specified in ISO 20753 and have a tensile elongation of 2.5% or more according to ISO 527-1, ISO 527-1,-2 (2012). By having a tensile elongation of 2.5% or more, the article exhibits excellent impact resistance, resistance to thermal cycling, and interlocking properties (fitting properties), thus helping to prevent cracking that may occur during article assembly and use. To exhibit a tensile elongation of 2.5% or more, a certain amount or more of copolymers such as olefins can be incorporated. In this case, to prevent an increase in gas generation, over-mixing is preferable to avoid.

[0129] Furthermore, even when the ISO20753 A1 type test piece is treated at 225°C for 20 hours according to IEC60216-4-1, the tensile elongation according to ISO527-1-2 (2012) is preferably 2.5% or more. By ensuring that it has a tensile elongation of 2.5% or more even when exposed to high temperatures, the product exhibits excellent impact resistance even during long-term use in high-temperature environments, which helps prevent breakage that may occur during use.

[0130] For the PPS resin composition obtained in this invention, the maximum voltage at which tracking resistance does not occur in the tracking resistance test according to IEC 60112 (2003) is preferably 175V or higher. Being able to withstand higher voltages allows for a shorter surface distance, which helps in the miniaturization of the final product. While a large amount of inorganic filler can be incorporated to exhibit tracking resistance of 175V or higher, this approach suffers from compromised mechanical strength and toughness. The present invention is a resin composition formed by combining 100 parts by weight of PPS resin with 16 to 50 parts by weight of the thermoplastic resin of (B) above, 10 to 25 parts by weight of the olefin copolymer containing epoxy groups of (C) above, 10 to 25 parts by weight of the olefin copolymer without polar functional groups of (D) above, and 40 to 140 parts by weight of the fibrous filler material of (E). By employing a structure in which the thermoplastic resin of (B) above, the olefin copolymer containing epoxy groups of (C) above, and the olefin copolymer without polar functional groups of (D) above are dispersed to a number-uniformly dispersed particle size of 500 nm or less, a high level of resistance to tracking and toughness can be achieved.

[0131] Example

[0132] The following examples illustrate the present invention in more detail, but the present invention is not limited to these examples.

[0133] [Evaluation methods for manufactured PPS resin]

[0134] (1) Melt Flow Rate (MFR)

[0135] The measurement temperature was set to 315.5℃ and the load to 5000g, and the measurement was performed using a method based on ASTM-D1238-70.

[0136] [Reference Example] Preparation of PPS

[0137] In a 70°C high-pressure reactor equipped with a stirrer and a bottom stopper valve, 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.91 kg (69.80 mol) of 96% sodium hydroxide, 11.45 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), 1.89 kg (23.10 mol) of sodium acetate, and 10.5 kg of deionized water were added. The mixture was slowly heated to 245°C over approximately 3 hours while nitrogen was introduced at atmospheric pressure. After distilling off 14.78 kg of water and 0.28 kg of NMP, the reaction vessel was cooled to 200°C. The residual water content in the system, including water consumed by the hydrolysis of NMP, was 1.06 mol per mole of alkali metal sulfide added. Additionally, the amount of hydrogen sulfide escaping was 0.02 mol per mole of alkali metal sulfide added.

[0138] The mixture was then cooled to 200°C, and 10.45 kg (71.07 mol) of p-dichlorobenzene and 9.37 kg (94.50 mol) of NMP were added. The reaction vessel was sealed under nitrogen atmosphere, and the temperature was increased from 200°C to 270°C at a rate of 0.6°C / min while stirring at 240 rpm. After reacting at 270°C for 100 minutes, the bottom valve of the autoclave was opened, and the contents were flushed into a vessel equipped with a stirrer over 15 minutes while pressurizing with nitrogen. The mixture was then stirred briefly at 250°C to remove most of the NMP.

[0139] The obtained solid material and 76 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer and washed at 70°C for 30 minutes, followed by vacuum filtration using a glass filter. Then, 76 liters of ion-exchanged water heated to 70°C were poured into the glass filter and vacuum filtered again to obtain a filter cake.

[0140] The obtained filter cake and 90 liters of ion-exchanged water were added to an autoclave equipped with a stirrer, and acetic acid was added until the pH reached 7. After purging the autoclave with nitrogen, the temperature was raised to 192°C and maintained for 30 minutes. The autoclave was then cooled, and the contents were removed.

[0141] The contents were filtered through a glass filter, and then 76 liters of ion-exchanged water at 70°C were added and filtered again to obtain a filter cake. The obtained filter cake was dried at 120°C under a nitrogen stream to obtain dried PPS.

[0142] The MFR of the obtained PPS was 600g / 10min.

[0143] The PPS obtained by the above method was subjected to thermal oxidation treatment at 220°C and 2% oxygen concentration for 12 hours to obtain PPS with an MFR of 400g / 10min.

[0144] (A) PPS resin

[0145] A-1: PPS obtained by the method described in the reference example

[0146] (B) Thermoplastic resin with a tracking resistance of 125V or higher and a glass transition temperature of 0°C or higher, based on IEC60112 standard.

[0147] B-1: Polyamide 610CM2021 (manufactured by Higashi Re Co., Ltd.)

[0148] The aforementioned CM2021 has a tracking resistance of over 600V and a glass transition temperature of 50℃ based on the IEC60112 standard.

[0149] (C) Olefin copolymers containing epoxy groups

[0150] C-1: Ethylene-glycidyl methacrylate-methyl acrylate copolymer, Bond First BF-E (manufactured by Sumitomo Chemical Co., Ltd.)

[0151] (C') An olefin copolymer with polar functional groups that is not part of component (C).

[0152] C'-2: Hydrogenated form of amino-modified styrene-ethylene-butadiene copolymer, Tablet MP10 (manufactured by Asahi Kasei Corporation).

[0153] (D) Olefin copolymers that do not possess polar functional groups

[0154] D-1: Hydrogenated form of styrene-ethylene-butadiene copolymer, Tablet H1062 (manufactured by Asahi Kasei Corporation).

[0155] D-2: Ethylene-1-butene copolymer formaldehyde 4085 (Made by Mitsui Chemicals Co., Ltd.)

[0156] (E) Fibrous filler material

[0157] E-1: Short-cut raw yarn T-760H (manufactured by Nippon Electric Glass Co., Ltd.)

[0158] (F) Non-fibrous filler material

[0159] F-1: Heavy Calcium Carbonate Escron #800 (Made by Sankyo Flour Co., Ltd.)

[0160] F-2: Surface-treated magnesium hydroxide Kisma 5P (manufactured by Kamishima Chemical Industry Co., Ltd.)

[0161] [Measurement and Evaluation Methods]

[0162] The measurement and evaluation methods in this embodiment and the comparative example are described below.

[0163] (Determination of tensile strength and tensile elongation)

[0164] The test was conducted according to ISO 527-1-2 (2012). Specifically, the test was conducted as follows: Resin composition granules were fed into an injection molding machine SE50DUZ-C160 (manufactured by Sumitomo Heavy Industries, Ltd.) with a barrel temperature set at 310°C and a mold temperature set at 145°C. Filling was performed with a filling time of 0.8 seconds, and injection molding was carried out under a holding pressure of 75% of the filling pressure to obtain a type A1 test piece as specified in ISO 20753. After conditioning the test piece for 16 hours at 23°C and 50% relative humidity, the test was conducted under an atmosphere of 23°C and 50% relative humidity, with a fixture distance of 114 mm and a test speed of 5 mm / sec.

[0165] (Determination of tensile elongation after dry heat treatment)

[0166] Using the same method as described in the determination of tensile strength and elongation, a type A1 test piece as specified in ISO 20753 was obtained. This test piece was treated at 225°C for 20 hours according to IEC 60216-4-1, and then conditioned for 16 hours at 23°C and 50% relative humidity. The elongation was then determined according to ISO 527-1-2 (2012) at 23°C, 50% relative humidity, with a fixture distance of 114 mm and a test speed of 5 mm / sec.

[0167] (Determination of resistance to tracking)

[0168] The resin composition granules were fed into the aforementioned injection molding machine SE50DUZ-C160, with the barrel temperature set at 320°C and the mold temperature set at 130°C. Molding was performed at an injection speed of 100 mm / sec, an injection time of 10 sec, and a cooling time of 15 sec to obtain a square plate (80 mm × 80 mm × 3.0 mm). Using this square plate test piece, the maximum voltage at which no leakage current tracking breakdown occurred was determined according to IEC 60112 (2003). A 0.1% ammonium chloride aqueous solution was used as the electrolyte.

[0169] (Determination of number-average particle size)

[0170] Molding temperature is +20 to 40°C at the melting peak temperature of PPS resin. A1 type test piece as specified in ISO 20753 is formed. Thin slices of less than 0.1 μm are cut from the center of the dumbbell sheet at -20°C along the cross-sectional area. For any 100 island phases observed at 1000x magnification using an H-7100 transmission electron microscope manufactured by Hitachi, the maximum and minimum diameters of each island phase are first measured to calculate the biaxial average particle size. Then, the average value of these 100 biaxial average particle sizes is calculated as the number-average dispersion particle size.

[0171] [Examples 1-4, Comparative Examples 1-8]

[0172] Using a TEX-44αIII twin-screw extruder (manufactured by Nippon Steel Corporation) with a barrel temperature set at 320°C, a screw speed set at 180 rpm, and an intermediate feed port with a diameter of 44 mm, 100 parts by weight of PPS resin (A), a single thermoplastic resin with a tracking resistance of 125V or higher and a glass transition temperature of 0°C or higher according to IEC 60112, (C) an olefin copolymer containing epoxy groups, (D) an olefin copolymer without polar functional groups, and (F) a non-fibrous filler were added from the feed port to form a molten state. Then, (E) a fibrous filler was supplied from the intermediate feed port at the same weight ratio as shown in Table 1. The mixture was melt-blended at a discharge rate of 60 kg / h to obtain polyphenylene sulfide resin particles. The results of evaluating the obtained polyphenylene sulfide resin composition are shown in Table 1.

[0173]

[0174] As can be seen from Table 1, Examples 1 to 4, by adding polyamide resin, epoxy-containing olefin copolymer, olefin copolymer without polar functional groups, and fibrous filler, have a tensile elongation of more than 2.5% and a tracking resistance of 175V.

[0175] As can be seen from Examples 1 and 2 shown in Table 1, even with an increase in the total amount of polyamide resin and copolymer, excellent tensile elongation characteristics are still observed.

[0176] As can be seen from Examples 1 and 3 shown in Table 1, even when the olefin copolymer without polar functional groups is changed from the hydride of styrene / ethylene / butadiene copolymer to ethylene / 1-butene copolymer, it still exhibits excellent tensile elongation characteristics.

[0177] As can be seen from Examples 1 and 4 shown in Table 1, even with an increase in the amount of fibrous filler material, excellent tensile elongation characteristics are still observed.

[0178] In Comparative Example 1 shown in Table 1, since it did not combine olefin copolymers containing epoxy groups and olefin copolymers without polar functional groups, and did not satisfy the requirement that the number-average particle size of components (B), (C) and (D) is less than 500 nm, it can be seen that the tensile strength and tensile elongation are poor.

[0179] In Comparative Example 2 shown in Table 1, since no olefin copolymer containing epoxy groups was used and the number-average particle size of components (B), (C) and (D) was less than 500 nm, it can be seen that the tensile elongation was poor.

[0180] In Comparative Examples 3 and 4 shown in Table 1, since the amount of the epoxy-containing olefin copolymer (C) does not meet the requirement of 10 to 25 parts by weight, and the number-average particle size of components (B), (C) and (D) does not meet the requirement of less than 500 nm, it can be seen that the tensile elongation and resistance to tracking are both poor.

[0181] In Comparative Example 5 shown in Table 1, the elongation at break is poor because the amount of the olefin copolymer (D) without polar functional groups does not meet the requirement of 10 to 25 parts by weight, and the number-average particle size of components (B), (C) and (D) does not meet the requirement of less than 500 nm.

[0182] In Comparative Example 6 shown in Table 1, the elongation at break is poor because the amount of the olefin copolymer (D) without polar functional groups does not meet the requirement of 10 to 25 parts by weight, and the number-average particle size of components (B), (C) and (D) does not meet the requirement of less than 500 nm.

[0183] In Comparative Example 7 shown in Table 1, since the amount of (E) fibrous filler material exceeds 140 parts, the tensile elongation is poor.

[0184] In Comparative Example 8 shown in Table 1, the elongation at break was poor because the amount of the non-polar olefin copolymer (D) did not meet the requirement of 10 to 25 parts by weight, and the number-average particle size of components (B), (C) and (D) did not meet the requirement of 500 nm or less.

[0185] Industrial availability

[0186] Molded articles formed from the PPS resin composition of the present invention have excellent mechanical strength, resistance to tracking, and toughness, and can therefore be used in the molding of composites with metals.

[0187] Furthermore, as for the applications of molded articles formed from the PPS resin composition of the present invention, they can be applied to electrical / electronic components such as sensors, LED lights, civilian and automotive connectors, sockets, resistors, relay housings, switches, coil frames, capacitors, variable capacitor housings, oscillators, various terminal blocks, transformers, plugs, printed circuit boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, semiconductors, liquid crystals, motor brush holders, parabolic antennas, and computer-related components; and to household and office electrical appliance components such as television components, irons, hair dryers, rice cooker components, microwave oven components, audio components, audio / laser discs (registered trademark) / CDs, lighting components, refrigerator components, air conditioning components, typewriter components, and word processor components.Additionally, examples include mechanical components such as office computer components, telephone components, fax machine components, copier components, cleaning fixtures, motor components, lighters, and typewriters; optical equipment and precision mechanical components such as microscopes, binoculars, cameras, and clocks; valves, alternator terminals, alternator connectors, IC regulators, potentiometer bases for headlight dimmers, exhaust valves, and other valves; fuel-related / exhaust / intake system pipes, intake nozzle vent pipes, intake manifolds, fuel pumps, engine coolant connectors, carburetor bodies, carburetor spacers, turbine pipes, EGR valves, and exhaust gas... Door actuators, intake ports, electric turbochargers, exhaust gas sensors, coolant sensors, oil temperature sensors, throttle position sensors, crankshaft position sensors, air flow meters, brake pad wear sensors, thermal management modules, thermostats, control valves, sealing rings, oil pumps, oil jackets, fuel pump housings, radiator motor brush holders, cooling piping, cooling valve housings, water pump impellers, inlet and outlet pipes, turbine blades, insulators, rotary transformers, Causa spacers, in-wheel motor winding tubing, wiper motor components, distributors, starter switches, starter relays, transmission wiring harnesses, window washer nozzles, air conditioning panel switch boards, coils for fuel-related solenoid valves, fuses. Connectors, horn terminals, lithium-ion battery (LIB) packs, LIB housings, LIB modules, battery cut-off units, gaskets, wireless power supply unit housings, covers, electrical mounting component insulation boards, inverter housings, reactors, terminal blocks, current sensors, DC-DC converters, inverter trays, busbar modules, stepper motor rotors, lamp holders, lamp reflectors, lamp covers, sensor camera lens barrels, head-up displays, radomes, millimeter-wave radar waveguides, brake pistons, engine mounting holes, transmission drive axle gears, magnetoresistive element (MRE) sensors, variable valve timing (VCT) flat solenoids, compressors, electric power steering covers, differential gears, valves Vehicle timing control (VTC) cover, shift position sensor, bearing retainer, vacuum pump blade, connecting ring, air pump, transmission cover, rear torsion beam, solenoid coil, engine oil filter, ignition coil, ignition device housing, alternator brush bracket, alternator circuit board, alternator slip ring, stator housing, electric alternator vehicle speed sensor, engine control computer (ECU) housing, mechatronic module, intelligent power unit (IPU) support, wiring harness protector, shift by wire, pressure sensor, wiring harness protector, transformer coil, gas-liquid separator, stack manifold, neck seat, FC piping, cable liner, and other automotive / vehicle related components for various applications.

Claims

1. A polyphenylene sulfide resin composition comprising, relative to (A) 100 parts by weight of polyphenylene sulfide resin, 16-50 parts by weight of (B) a thermoplastic resin with a tracking resistance of 125V or higher and a glass transition temperature of 0°C or higher according to IEC 60112 standard, 10-25 parts by weight of an epoxy-containing olefin copolymer, 10-25 parts by weight of an olefin copolymer without polar functional groups, and (E) 40-140 parts by weight of a fibrous filler, wherein the (B) thermoplastic resin, the (C) epoxy-containing olefin copolymer, and the (D) olefin copolymer without polar functional groups are dispersed with a number-uniformly dispersed particle size of 500 nm or less.

2. The polyphenylene sulfide resin composition according to claim 1, wherein the ratio of the amount of the epoxy-containing olefin copolymer (C) to the amount of the olefin copolymer without polar functional groups (D) is in the range of 0.6 to 2.

3. The polyphenylene sulfide resin composition according to claim 1 or 2, wherein the thermoplastic resin of (B) is a polyamide resin.

4. The polyphenylene sulfide resin composition according to claim 1 or 2, wherein the ratio (B) / ((C)+(D)) of the amount of the thermoplastic resin in relation to 100 parts by weight of the polyphenylene sulfide resin in (A) to the total amount of the epoxy-containing olefin copolymer in (C) and the olefin copolymer without polar functional groups in (D) is 1.1 to 2.

5. A molded article made from the polyphenylene sulfide resin composition according to any one of claims 1 to 4.

6. The molded article according to claim 5, wherein the molded article is a composite with metal.

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