JP2021138936A - Polyphenylene sulfide resin composition and method for producing the same, and molding comprising the same and method for producing the same - Google Patents

Abstract

To provide a polyphenylene sulfide resin composition that prevents a decrease in rigidity at high temperatures while maintaining the original properties of a polyphenylene sulfide resin and a method for producing the same, and a molding comprising the same and having excellent dimensional stability and a method for producing the same.SOLUTION: A polyphenylene sulfide resin composition comprises (a) a polyphenylene sulfide resin and (b) a polyphenylene ether resin. When the resin composition is subjected to differential scanning calorimetry, a glass transition temperature of it is 95°C or higher and 160°C or lower.SELECTED DRAWING: None

Description

INDUSTRIAL APPLICABILITY The present invention relates to a polyphenylene sulfide resin composition and a method for producing the same, which suppresses a decrease in rigidity under high temperature conditions while maintaining the original characteristics of the polyphenylene sulfide resin, and a molded product and its production which are excellent in dimensional stability. It's about the method.

Polyphenylene sulfide (sometimes abbreviated as PPS) resin is a crystalline polymer generally having a glass transition temperature of 80 to 90 ° C and a melting point of 275 to 285 ° C. It is a resin that has excellent heat resistance derived from the above thermal properties, chemical resistance, mechanical properties, and melt moldability, and can be used for various molded products, fibers, films, etc. by various molding methods such as injection molding and extrusion molding. Since it can be molded, it is put to practical use in a wide range of fields such as electric / electronic parts, mechanical parts and automobile parts. In recent years, many applications have been studied, especially for applications used under high temperature conditions. However, while PPS resin can withstand use at high temperatures due to its high melting point, it has the essential problem that its rigidity drops sharply at a glass transition temperature of 80 to 90 ° C. or higher as compared with a temperature lower than that. Had had.

Various studies have been conducted to improve the glass transition temperature of PPS resin. For example, Patent Documents 1 to 3 disclose reports on PPS copolymers having a PPS structure and a rigid molecular structure in the same molecule. ing.

Further, the resin composition (polymer alloy) obtained by melt-kneading two or more kinds of resins can keep the manufacturing cost low and maintain the original characteristics of the main resin, while maintaining the main resin. It is one of the useful methods that can impart the characteristics of other resins to the resin. A study of adding a polyphenylene ether (sometimes abbreviated as PPE) resin, which is one of the amorphous resins having a high glass transition temperature, using this method for the purpose of improving the characteristics of the PPS resin has been reported, for example, in Patent Document 4. ing.

Japanese Unexamined Patent Publication No. 2017-132839 Japanese Unexamined Patent Publication No. 2-133428 Japanese Unexamined Patent Publication No. 5-98007 Japanese Unexamined Patent Publication No. 2-33622

However, although the glass transition temperature is certainly improved by the methods disclosed in Patent Documents 1 to 3, PPS is improved to a melting point of 300 ° C. or higher due to the molecular structure of the PPS copolymer. There is a problem that the inherent properties of the resin, for example, the melt moldability, are impaired. In addition, there is a concern that the production cost of these PPS copolymers will be high. As in Patent Document 4, in the study on the improvement of the PPS resin by the PPE resin, although the improvement of the impact characteristics of the PPS resin has been achieved, there is no description about the heat resistance, and in particular, the improvement of the glass transition temperature cannot be expected.

Therefore, the present invention relates to a PPS resin composition and a method for producing the same, which suppresses a decrease in rigidity under high temperature conditions while maintaining the original characteristics of the PPS resin, and a molded product and a method for producing the same, which are excellent in dimensional stability. The purpose is to provide.

As a result of studies to solve such a problem, the present inventors have obtained a polyphenylene sulfide resin composition obtained by blending (a) a polyphenylene sulfide resin and (b) a polyphenylene ether resin. A polyphenylene sulfide resin composition having a glass transition temperature in the range of 95 ° C. or higher and 160 ° C. or lower when the differential scanning calorimetry was performed was obtained.

That is, the present invention has been made to solve at least a part of the above-mentioned problems, and can be implemented as the following embodiments.
(1) A polyphenylene sulfide resin composition obtained by blending (a) a polyphenylene sulfide resin and (b) a polyphenylene ether resin, and the glass transition temperature when the differential scanning calorimetry of the resin composition is measured is 95 ° C. As mentioned above, the polyphenylene sulfide resin composition in the range of 160 ° C. or lower.
(2) A molded product comprising the polyphenylene sulfide resin composition according to (1).
(3) A molded product made of the polyphenylene sulfide resin composition according to (2), wherein the temperature-modulated differential scanning calorimetry of the molded product (conditions: heating rate 2 ° C./min, amplitude ± 0.8 ° C., A molded product comprising a polyphenylene sulfide resin composition having (a) a polyphenylene sulfide resin composition which exceeds the glass transition temperature of the polyphenylene sulfide resin and does not have a heat absorption peak at 280 ° C. or lower in the non-reverse flow curve when the cycle is 60 seconds.
(4) The method for producing the polyphenylene sulfide resin composition according to (1), wherein the pellet obtained by melt-kneading (a) the polyphenylene sulfide resin and (b) the polyphenylene ether resin is heat-treated. A method for producing a polyphenylene sulfide resin composition.
(5) The method for producing a polyphenylene sulfide resin composition according to (4), wherein the temperature at which the pellets are heat-treated is (a) a melting point of -100 ° C. or higher when the differential scanning calorimetry of the polyphenylene sulfide resin is measured, -5. A method for producing a polyphenylene sulfide resin composition, which comprises a temperature of ° C. or lower.
(6) A method for producing a molded product comprising the polyphenylene sulfide resin composition according to any one of (2) to (3), wherein (a) polyphenylene sulfide resin and (b) polyphenylene ether resin are used. A method for producing a molded product comprising a polyphenylene sulfide resin composition, which comprises heat-treating the pellets obtained by melt-kneading and then melt-molding the heat-treated pellets to obtain a molded product.
(7) In the method for producing a molded product composed of the polyphenylene sulfide resin composition according to (6), the temperature at which the pellets are heat-treated is (a) the melting point of -100 ° C. when the differential scanning calorimetry of the polyphenylene sulfide resin is measured. As described above, a method for producing a molded product made of a polyphenylene sulfide resin composition, which is characterized by having a temperature of −5 ° C. or lower.

According to the present invention, a polyphenylene sulfide resin composition and a method for producing the same, which maintain the original characteristics of the polyphenylene sulfide resin and suppress a decrease in rigidity under high temperature conditions, and a molded product having excellent dimensional stability. The manufacturing method is provided.

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

(1) (a) Polyphenylene sulfide resin The (a) PPS resin used in the present invention is a polymer having a repeating unit represented by the following structural formula.

From the viewpoint of heat resistance, a polymer containing 70 mol% or more, more preferably 90 mol% or more of the polymer containing the repeating unit represented by the above structural formula is preferable. Further, (a) less than 30 mol% of the repeating unit of the PPS resin may be composed of a repeating unit having the following structure or the like.

Since the PPS copolymer having a part of such a structure has a low melting point, such a resin composition is advantageous in terms of molding processability.

The melt viscosity of the (a) PPS resin used in the present invention is not particularly limited, but it is preferable that the melt viscosity is high in order to obtain better toughness. For example, a range exceeding 30 Pa · s (300 ° C., shear rate 1000 / s) is preferable, 50 Pa · s or more is more preferable, and 100 Pa · s or more is further preferable. The upper limit is preferably 600 Pa · s or less from the viewpoint of maintaining melt fluidity. The melt viscosity in the present invention is a value measured using a capillograph manufactured by Toyo Seiki under the conditions of 300 ° C. and a shear rate of 1000 / s.

Hereinafter, the method for producing the (a) PPS resin used in the present invention will be described, but the method is not limited to the following method as long as the (a) PPS resin having the above characteristics can be obtained.

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

[Polyhalogenated aromatic compounds]
The polyhalogenated aromatic compound is a compound having two or more halogen atoms in one molecule. Specific examples include p-dichlorobenzene, m-dichlorobenzene, o-dichlorobenzene, 1,3,5-trichlorobenzene, 1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene, and hexa. Polyhalogenated aromatics such as chlorobenzene, 2,5-dichlorotoluene, 2,5-dichloro-p-xylene, 1,4-dibromobenzene, 1,4-diiodobenzene, 1-methoxy-2,5-dichlorobenzene. Group compounds are mentioned, and p-dichlorobenzene is preferably used. Further, for the purpose of introducing a carboxyl group, a carboxyl group-containing dihalogenated aromatic such as 2,4-dichlorobenzoic acid, 2,5-dichlorobenzoic acid, 2,6-dichlorobenzoic acid, and 3,5-dichlorobenzoic acid. It is also one of the preferable embodiments to use the compound and a mixture thereof as a copolymerization monomer, and it is also possible to combine two or more different polyhalogenated aromatic compounds to form a copolymer. It is preferable to use a p-dihalogenated aromatic compound as a main component.

The amount of the polyhalogenated aromatic compound used is 0.9 to 2.0 mol, preferably 0.95 mol, per mol of the sulfidizing agent from the viewpoint of obtaining the (a) PPS resin having a viscosity suitable for processing. The range of 1.5 mol, more preferably 1.005 mol to 1.2 mol, can be exemplified.

[Sulfidating agent]
Examples of the sulfidizing agent include alkali metal sulfide, alkali metal hydrosulfide, and hydrogen sulfide.

Specific examples of the alkali metal sulfide include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and a mixture of two or more of these, and sodium sulfide is preferably used. These alkali metal sulfides can be used as hydrates or aqueous mixtures, or in the form of anhydrides.

Specific examples of the alkali metal hydrosulfide include sodium hydrosulfide, potassium hydrosulfide, lithium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide, and a mixture of two or more of these, among which sodium hydrosulfide is used. It is preferably used. These alkali metal hydrosulfides can be used as hydrates or aqueous mixtures, or in the form of anhydrides.

Further, an alkali metal sulfide prepared in situ in the reaction system from the alkali metal hydrosulfide and the alkali metal hydroxide can also be used. Further, an alkali metal sulfide can be prepared from an alkali metal hydrosulfide and an alkali metal hydroxide, and the alkali metal sulfide can be transferred to a polymerization tank for use.

Alternatively, an alkali metal sulfide prepared in situ in the reaction system from an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide and hydrogen sulfide can also be used. Further, an alkali metal sulfide can be prepared from alkali metal hydroxides such as lithium hydroxide and sodium hydroxide and hydrogen sulfide, and the alkali metal sulfide can be transferred to a polymerization tank for use.

The amount of the charged sulfidating agent shall mean the residual amount obtained by subtracting the lost amount from the actual charged amount when a partial loss of the sulfidizing agent occurs before the start of the polymerization reaction due to a dehydration operation or the like.

It is also possible to use an alkali metal hydroxide and / or an alkaline earth metal hydroxide in combination with the sulfidizing agent. Specific examples of the alkali metal hydroxide include, for example, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, and a mixture of two or more of these, and alkaline earth. Specific examples of the metal hydroxide include calcium hydroxide, strontium hydroxide, barium hydroxide and the like, and sodium hydroxide is preferably used.

When alkali metal hydrosulfide is used as the sulfidizing agent, it is particularly preferable to use alkali metal hydroxide at the same time, but the amount used is 0.95 mol to 1 mol per 1 mol of alkali metal hydrosulfide. Examples include the range of .20 mol, preferably 1.00 mol to 1.15 mol, more preferably 1.005 mol to 1.100 mol.

[Polymerization solvent]
It is preferable to use an organic polar solvent as the polymerization solvent. Specific examples include N-alkylpyrrolidones such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, caprolactams such as N-methyl-ε-caprolactam, and 1,3-dimethyl-2-imidazolidi. Examples thereof include aprotic organic solvents typified by non-, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphate triamide, dimethylsulfone, tetramethylenesulfoxide, and mixtures thereof, all of which are used. It is preferably used because of its high reaction stability. Among these, N-methyl-2-pyrrolidone (hereinafter, may be abbreviated as NMP) is particularly preferably used.

The amount of the organic polar solvent used is preferably in the range of 2.0 mol to 10 mol, preferably 2.25 mol to 6.0 mol, more preferably 2.5 mol to 5.5 mol, per 1 mol of the sulfide agent. Is done.

[Molecular weight regulator]
(A) A monohalogen compound (not necessarily an aromatic compound) is combined with the polyhalogenated aromatic compound in order to form the terminal of the PPS resin to be produced, or to adjust the polymerization reaction or the molecular weight. Can be used together.

[Polymerization aid]
It is also one of the preferable embodiments to use a polymerization aid in order to obtain the (a) PPS resin having a relatively high degree of polymerization in a shorter time. Here, the polymerization aid means a substance having an action of increasing the viscosity of the obtained (a) PPS resin. Specific examples of such a polymerization aid include organic carboxylates, water, alkali metal chlorides, organic sulfonates, alkali metal sulfates, alkaline earth metal oxides, alkali metal phosphates and alkaline soils. Examples include metal phosphates. These may be used alone or in combination of two or more. Of these, organic carboxylate, water, and alkali metal chloride are preferable, alkali metal carboxylate is preferable as the organic carboxylate, and lithium chloride is preferable as the alkali metal chloride.

The alkali metal carboxylate is a general formula R (COOM) _n (in the formula, R is an alkyl group, a cycloalkyl group, an aryl group, an alkylaryl group or an 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 of 1 to 3). Alkali metal carboxylates can also be used as hydrates, anhydrides or aqueous solutions. Specific examples of the alkali metal carboxylate include lithium acetate, sodium acetate, potassium acetate, sodium propionate, lithium valerate, sodium benzoate, sodium phenylacetate, potassium p-toluic acid, and mixtures thereof. Can be mentioned.

The alkali metal carboxylate is a reaction in which an organic acid and one or more compounds selected from the group consisting of alkali metal hydroxide, alkali metal carbonate and alkali metal bicarbonate are added in approximately equal chemical equivalents and reacted. May be formed by. Among the above alkali metal carboxylates, the lithium salt has high solubility in the reaction system and has a large auxiliary effect, but is expensive, and the potassium, rubidium and cesium salts have insufficient solubility in the reaction system. Therefore, sodium acetate, which is inexpensive and has an appropriate solubility in a polymerization system, is most preferably used.

When these alkali metal carboxylates are used as polymerization aids, the amount used is usually in the range of 0.01 mol to 2 mol with respect to 1 mol of the charged alkali metal sulfide, and in the sense of obtaining a higher degree of polymerization, it is possible to obtain a higher degree of polymerization. The range of 0.1 mol to 0.6 mol is preferable, and the range of 0.2 mol to 0.5 mol is more preferable.

When water is used as a polymerization aid, the amount added is usually in the range of 0.3 mol to 15 mol with respect to 1 mol of the charged alkali metal sulfide, and 0.6 mol in the sense of obtaining a higher degree of polymerization. The range of 10 mol is preferable, and the range of 1 mol to 5 mol is more preferable.

Of course, two or more of these polymerization aids can be used in combination. For example, when an alkali metal carboxylate and water are used in combination, it is possible to increase the molecular weight in a smaller amount of each.

The timing of addition of these polymerization aids is not particularly specified, and they may be added at any time of the pre-process, the start of polymerization, and the middle of polymerization, which will be described later, or may be added in a plurality of times. When an alkali metal carboxylate is used as the polymerization aid, it is more preferable to add it at the same time as the start of the previous step or the start of polymerization because it is easy to add. When water is used as a polymerization aid, it is effective to add the polyhalogenated aromatic compound in the middle of the polymerization reaction after charging it.

[Polymerization stabilizer]
Polymerization stabilizers can also be used to stabilize the polymerization reaction system and prevent side reactions. The polymerization stabilizer contributes to the stabilization of the polymerization reaction system and suppresses unwanted side reactions. One guideline for side reactions is the production of thiophenol, and the addition of a polymerization stabilizer can suppress the production of thiophenol. Specific examples of the polymerization stabilizer include compounds such as alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, and alkaline earth metal carbonates. Among them, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide are preferable. The alkali metal carboxylate described above also acts as a polymerization stabilizer. Further, when an alkali metal hydrosulfide is used as the sulfide agent, it is particularly preferable to use the alkali metal hydroxide at the same time, but here, the alkali metal water that is excessive with respect to the sulfide agent. Oxides can also be polymerization stabilizers.

These polymerization stabilizers can be used alone or in combination of two or more. The ratio of the polymerization stabilizer to 1 mol of the charged alkali metal sulfide is usually 0.02 to 0.2 mol, preferably 0.03 to 0.1 mol, and more preferably 0.04 to 0.09 mol. It is preferable to use in. If this ratio is small, the stabilizing effect is insufficient, and if it is too large, it tends to be economically disadvantageous or the polymer yield tends to decrease.

The timing of addition of the polymerization stabilizer is not particularly specified, and it may be added at any time of the pre-process, the start of polymerization, and the middle of polymerization, which will be described later, or it may be added in a plurality of times. It is more preferable because it is easy to add at the same time at the start of the process or the start of polymerization.

Next, a preferable method for producing the (a) PPS resin used in the present invention will be specifically described step by step in the order of a pre-step, a polymerization reaction step, a recovery step, and a post-treatment step, but of course, it is limited to this method. It's not something.

[pre-process]
(A) In the method for producing a PPS resin, the sulfidizing agent is usually used in the form of a hydrate, but before adding the polyhalogenated aromatic compound, the mixture containing the organic polar solvent and the sulfidizing agent is raised. It is preferred to warm and remove excess water out of the system.

Further, as described above, as the sulfidizing agent, a sulfidizing agent prepared from alkali metal hydrosulfide and alkali metal hydroxide in situ in the reaction system or in a tank separate from the polymerization tank is also used. Can be done. Although this method is not particularly limited, it is desirable to use alkali metal hydrosulfide and alkali metal hydroxide as an organic polar solvent in a temperature range of normal temperature to 150 ° C., preferably normal temperature to 100 ° C. in an inert gas atmosphere. In addition, a method of distilling off water by raising the temperature to at least 150 ° C. or higher, preferably 180 to 260 ° C. under normal pressure or reduced pressure can be mentioned. A polymerization aid may be added at this stage. Further, in order to promote the distillation of water, toluene or the like may be added to carry out the reaction.

The amount of water in the polymerization system in the polymerization reaction is preferably 0.3 to 10.0 mol per 1 mol of the charged sulfidizing agent. Here, the amount of water in the polymerization system is the amount obtained by subtracting the amount of water removed from the polymerization system from the amount of water charged in the polymerization system. Further, the water to be charged may be in any form such as water, an aqueous solution, and water of crystallization.

[Polymerization reaction step]
(A) PPS resin is produced by reacting a sulfidizing agent and a polyhalogenated aromatic compound in an organic polar solvent within a temperature range of 200 ° C. or higher and lower than 290 ° C.

When starting the polymerization reaction step, an organic polar solvent, a sulfidizing agent and a polyhalogenated aromatic compound are mixed in a temperature range of preferably room temperature to 240 ° C., preferably 100 ° C. to 230 ° C. in an inert gas atmosphere. do. A polymerization aid may be added at this stage. The order of charging these raw materials may be random or simultaneous.

The temperature of such a mixture is usually raised to a range of 200 ° C. to less than 290 ° C. The rate of temperature rise is not particularly limited, but a rate of 0.01 to 5 ° C./min is usually selected, and a range of 0.1 to 3 ° C./min is more preferable.

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

A method of reacting at 200 ° C. to 260 ° C. for a certain period of time before reaching the final temperature and then raising the temperature to less than 270 ° C. to 290 ° C. is effective in obtaining a higher degree of polymerization. At this time, the reaction time at 200 ° C. to 260 ° C. is usually selected in the range of 0.25 hours to 20 hours, preferably in the range of 0.25 hours to 10 hours.

In addition, in order to obtain a polymer having a higher degree of polymerization, it may be effective to carry out the polymerization in a plurality of steps. When the polymerization is carried out in a plurality of steps, it is effective that the conversion rate of the polyhalogenated aromatic compound in the system at 245 ° C. reaches 40 mol% or more, preferably 60 mol%.

The conversion rate of the polyhalogenated aromatic compound (abbreviated as PHA here) is a value calculated by the following formula. The residual amount of PHA can usually be determined by gas chromatography.

(A) When the polyhalogenated aromatic compound is excessively added to the alkali metal sulfide in a molar ratio, conversion rate = [PHA charge amount (mol) -PHA residual amount (mol)] / [PHA charge amount (mol)) -PHA excess (mol)].

(B) In cases other than the above (A) Conversion rate = [PHA charge amount (mol) -PHA residual amount (mol)] / [PHA charge amount (mol)].

[Recovery process]
(A) In the method for producing a PPS resin, after completion of polymerization, a solid substance is recovered from a polymerization reaction product containing a polymer, a solvent and the like. As the recovery method, any known method may be adopted. For example, a method of slowly cooling after completion of the polymerization reaction to recover the particulate polymer may be used. The slow cooling rate at this time is not particularly limited, but is usually about 0.1 ° C./min to 3 ° C./min. It is not necessary to slowly cool the polymer particles at the same rate in the entire process of the slow cooling process. It may be adopted.

It is also one of the preferable methods to carry out the above recovery under quenching conditions. Among these recovery methods, a flash method can be mentioned as a preferable method. In the flash method, the polymerization reaction product is flushed from a high temperature and high pressure (usually 250 ° C. or higher, 8 kg / cm ² or higher) into an atmosphere of normal pressure or reduced pressure, and the polymer is recovered in powder form at the same time as the solvent is recovered. The method. The term "flash" as used herein means that the polymerization reaction product is ejected from the nozzle. Specific examples of the flushing atmosphere include nitrogen or water vapor under normal pressure, and the temperature is usually selected in the range of 150 ° C. to 250 ° C.

[Post-treatment process]
(A) The PPS resin may be produced through the above polymerization reaction step and recovery step, and then subjected to acid treatment, hot water treatment, washing with an organic solvent, and alkali metal or alkaline earth metal treatment. ..

When performing acid treatment, it is as follows. The acid used for the acid treatment of (a) PPS resin is not particularly limited as long as it does not have the action of decomposing (a) PPS resin, such as acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid and propyl acid. Of these, acetic acid and hydrochloric acid are more preferably used, but those that decompose and deteriorate (a) PPS resin such as nitric acid are not preferable.

The acid treatment method includes (a) immersing the PPS resin in an acid or an aqueous solution of an acid, and if necessary, stirring or heating can be performed as appropriate. For example, when acetic acid is used, a sufficient effect can be obtained by immersing the PPS resin powder in an aqueous solution of pH 4 heated to 80 to 200 ° C. and stirring for 30 minutes. The pH after the treatment may be 4 or more, for example, pH 4 to 8. The acid-treated (a) PPS resin is preferably washed with water or warm water several times in order to remove residual acid or salt. The water used for washing is preferably distilled water or deionized water in the sense that the effect of (a) preferable chemical modification of the PPS resin by the acid treatment is not impaired.

When hot water treatment is performed, it is as follows. (A) When treating the PPS resin with hot water, the temperature of the hot water is preferably 100 ° C. or higher, more preferably 120 ° C. or higher, still more preferably 150 ° C. or higher, and particularly preferably 170 ° C. or higher. Below 100 ° C., (a) the effect of preferable chemical modification of the PPS resin is small, which is not preferable.

The water used is preferably distilled water or deionized water in order to exhibit the effect of preferable chemical modification of (a) PPS resin by hot water treatment. The operation of hot water treatment is not particularly limited, and a method of adding a predetermined amount of (a) PPS resin to a predetermined amount of water, heating and stirring in a pressure vessel, a method of continuously performing hot water treatment, etc. Be told. The ratio of (a) PPS resin to water is preferably large in water, but usually, a bath ratio of (a) 200 g or less of PPS resin is selected with respect to 1 liter of water.

Further, since the decomposition of the terminal group is not preferable in the treatment atmosphere, it is desirable to set the treatment atmosphere in an inert atmosphere in order to avoid this. Further, the (a) PPS resin that has been subjected to this hot water treatment operation is preferably washed with warm water several times in order to remove residual components.

When cleaning with an organic solvent, it is as follows. The organic solvent used for cleaning the (a) PPS resin is not particularly limited as long as it does not have the action of decomposing the (a) PPS resin. For example, N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, etc. Nitrogen-containing polar solvents such as 1,3-dimethylimidazolidinone, hexamethylphosphorasamide, and piperazinones, sulfoxide-sulfone solvents such as dimethylsulfoxide, dimethylsulfone, and sulfolane, and ketones such as acetone, methylethylketone, diethylketone, and acetophenone. Solvents, ether solvents such as dimethyl ether, dipropyl ether, dioxane, tetrahydrofuran, chloroform, methylene chloride, trichloroethylene, ethylene dichloride, perchlorethylene, monochloroethane, dichloroethane, tetrachloroethane, perchlorethane, chlorobenzene, etc. Alcohol-based solvents such as halogen-based solvents, methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, phenol, cresol, polyethylene glycol, polypropylene glycol and aromatic hydrocarbon-based solvents such as benzene, toluene and xylene. Examples include solvents. Among these organic solvents, the use of N-methyl-2-pyrrolidone, acetone, dimethylformamide, chloroform and the like is particularly preferable. Moreover, these organic solvents are used in one kind or a mixture of two or more kinds.

As a method of cleaning with an organic solvent, there is a method such as immersing the (a) PPS resin in the organic solvent, and it is also possible to appropriately stir or heat if necessary. The cleaning temperature when cleaning the (a) PPS resin with an organic solvent is not particularly limited, and any temperature of about room temperature to 300 ° C. can be selected. The higher the cleaning temperature, the higher the cleaning efficiency tends to be, but usually, a sufficient effect can be obtained at a cleaning temperature of room temperature to 150 ° C. It is also possible to wash under pressure in a pressure vessel at a temperature higher than the boiling point of the organic solvent. In addition, there is no particular limitation on the cleaning time. Although it depends on the cleaning conditions, in the case of batch-type cleaning, a sufficient effect is usually obtained by cleaning for 5 minutes or more. It is also possible to wash continuously.

Examples of the method for treating alkali metal and alkaline earth metal include a method of adding an alkali metal salt and an alkaline earth metal salt before, during, and after the above-mentioned pre-step, before the polymerization step, during the polymerization step, and after the polymerization step. Later, a method of adding an alkali metal salt or an alkaline earth metal salt into the polymerization kettle, or a method of adding an alkali metal salt or an alkaline earth metal salt at the first, middle, or last stages of the above-mentioned cleaning step can be mentioned. Among them, the easiest method includes a method of adding an alkali metal salt and an alkaline earth metal salt after removing residual oligomers and salts by washing with an organic solvent or washing with warm water or hot water. Alkali metals and alkaline earth metals are preferably introduced into PPS in the form of alkali metal ions such as acetates, hydroxides and carbonates, and alkaline earth metal ions. Further, it is preferable to remove excess alkali metal salt and alkaline earth metal salt by washing with warm water or the like. The alkali metal ion and alkaline earth metal ion concentrations at the time of introducing the alkali metal and alkaline earth metal are preferably 0.001 mmol or more, more preferably 0.01 mmol or more with respect to 1 g of PPS. The temperature is preferably 50 ° C. or higher, more preferably 75 ° C. or higher, and particularly preferably 90 ° C. or higher. Although there is no particular upper limit temperature, it is usually preferably 280 ° C. or lower from the viewpoint of operability. The bath ratio (weight of the cleaning liquid with respect to the weight of the dried PPS) is preferably 0.5 or more, more preferably 3 or more, and even more preferably 5 or more.

In the present invention, from the viewpoint of obtaining a polyphenylene sulfide resin composition having excellent retention stability, residual oligomers and residual salts were removed by repeating organic solvent washing and hot water at about 80 ° C. or the above-mentioned hot water treatment several times. After that, a method of treating with an acid treatment or an alkali metal salt or an alkaline earth metal salt is preferable, and a method of treating with an alkali metal salt or an alkaline earth metal salt is more preferable.

In addition, (a) the PPS resin can be used after the polymerization is completed by heating in an oxygen atmosphere and by performing thermal oxidative cross-linking treatment by adding a cross-linking agent such as a peroxide to increase the molecular weight.

In the case of dry heat treatment for the purpose of increasing the molecular weight by thermal oxidative crosslinking, the temperature is preferably 160 ° C. to 260 ° C., more preferably 170 ° C. to 250 ° C. Further, it is desirable that the oxygen concentration is 5% by volume or more, more preferably 8% by volume or more. The upper limit of the oxygen concentration is not particularly limited, but is limited to about 50% by volume. The treatment time is preferably 0.5 hours to 100 hours, more preferably 1 hour to 50 hours, and even more preferably 2 hours to 25 hours. The heat treatment device may be a normal hot air dryer, a rotary type or a heating device with a stirring blade, but for efficient and more uniform processing, heating with a rotary type or a stirring blade. It is more preferable to use the device.

It is also possible to perform dry heat treatment for the purpose of suppressing thermal oxidation cross-linking and removing volatile components. The temperature is preferably 130 ° C. to 250 ° C., more preferably 160 ° C. to 250 ° C. Further, the oxygen concentration in this case is preferably less than 5% by volume, more preferably less than 2% by volume. The treatment time is preferably 0.5 hours to 50 hours, more preferably 1 hour to 20 hours, and even more preferably 1 hour to 10 hours. The heat treatment device may be a normal hot air dryer, a rotary type or a heating device with a stirring blade, but for efficient and more uniform processing, heating with a rotary type or a stirring blade. It is more preferable to use the device.

The PPS resin (a) of the present invention is not particularly limited in the presence or absence of the thermal oxidative cross-linking treatment, but from the viewpoint of exhibiting excellent toughness, it is a substantially linear type that is not increased in molecular weight by the thermal oxidative cross-linking treatment. The PPS resin is preferably a semi-crosslinked PPS resin that has been lightly thermally oxidatively crosslinked, and a substantially linear PPS resin is more preferable. Further, in the present invention, a plurality of (a) PPS resins having different melt viscosities may be mixed and used.

(2) (b) Polyphenylene ether resin The (b) PPE resin used in the present invention is a polymer containing the structural unit shown below in the main chain, and may be a homopolymer, a copolymer or a graft polymer. May be good.

Here, R _{1 to} R ₄ are selected from hydrogen, halogen, an alkyl group having 1 to 7 carbon atoms, a phenyl group, a haloalkyl group, an aminoalkyl group and the like. R ₁ and R ₂ are preferably independent primary alkyl groups having 1 to 3 carbon atoms, respectively, and R _{3 and R 4} are independent primary alkyl groups having 1 to 3 carbon atoms or hydrogen atoms, respectively. Is preferable. Further, R ₁ and R ₂ are more preferably methyl groups, and R ₃ and R ₄ are more preferably hydrogen atoms. Such (b) PPE resin can be obtained by oxidative polymerization in the presence of oxygen or an oxygen-containing gas using one or more phenol compounds and an oxidation coupling catalyst.

(B) More specific structures of the PPE resin include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, and poly (2,). 6-Dipropyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2-methyl-6-propyl-1,4-phenylene) ether, poly (2-methyl-6-propyl-1,4-phenylene) ether, poly ( 2-Ethyl-6-propyl-1,4-phenylene) ether, 2,6-dimethylphenol / 2,3,6-triethylphenol copolymer, 2,6-diethylphenol / 2,3,6-trimethylphenol Examples thereof include a copolymer and a 2,6-dipropylphenol / 2,3,6-trimethylphenol copolymer.

In addition, styrene was grafted onto a copolymer obtained by graft-polymerizing styrene on poly (2,6-dimethyl-1,4-phenylene ether), and on a 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer. Examples include copolymers.

In addition, a polyphenylene ether resin modified with maleic anhydride, glycidyl methacrylate, or the like is also preferably used. In particular, for the PPS resin composition of the present invention, a polyphenylene ether resin modified with maleic anhydride is more preferably used from the viewpoint of improving toughness. However, in the case of a polyphenylene ether resin modified with excess maleic anhydride, the melt viscosity of the resin composition becomes too high and the lower limit of molding pressure rises, so that maleic anhydride is added to 100 parts by weight of the polyphenylene ether resin. It is preferable to modify the amount to 5 parts by weight or less. When fluidity is more important, a non-modified polyphenylene ether resin is suitable, and of course, it can be used in combination with a modified polyphenylene ether resin.

Among these (b) PPE resins, poly (2,6-dimethyl-1,4-phenylene) ether, 2,6-dimethylphenol and 2,3 are used from the viewpoint of improving the glass transition temperature of the PPS resin composition. , 6-trimethylphenol copolymer and the like are preferably used without modification.

The weight average molecular weight of the (b) PPE resin in the present invention is preferably in the range of 4000 to 100,000, more preferably 1000 to 80000, and even more preferably 2500 to 70000. When (b) the weight average molecular weight of the PPE resin is 4000 or more, the glass transition temperature of the (b) PPE resin becomes high, and the effect of improving the glass transition temperature of the PPS resin composition can be obtained, which is preferable. (B) When the weight average molecular weight of the PPE resin is 100,000 or less, the melt moldability is not impaired, which is preferable.

(B) The weight average molecular weight of the PPE resin is a value obtained from the polystyrene-equivalent molecular weight measured by gel permeation chromatography.

The reduced viscosity of the (b) PPE resin in the present invention is preferably 0.1 to 0.55 dL / g, more preferably 0.25 to 0.50 dL / g, and 0.30 to 0. It is more preferably 45 dL / g. When the reduced viscosity of (b) PPE resin is 0.1 dL / g or more, the glass transition temperature of (b) PPE resin becomes high, and the effect of improving the glass transition temperature of the PPS resin composition can be obtained, which is preferable. .. (B) When the reducing viscosity of the PPE resin is 0.55 dL / g or less, the melt moldability is not impaired, which is preferable.

The reduced viscosity of (b) PPE resin is a value measured with an Ubbelohde viscous tube under the condition of a temperature of 30 ° C. using a chloroform solution of 0.5 g / dL.

The glass transition temperature of the (b) PPE resin in the present invention is preferably 150 ° C. or higher from the viewpoint of sufficiently improving the glass transition temperature of the PPS resin composition. There is no particular upper limit, but it is substantially 300 ° C. or lower. It is preferable that the glass transition temperature is 300 ° C. or lower without impairing the melt moldability.

The terminal group of the (b) PPE resin in the present invention is not particularly limited, but from the viewpoint of (a) compatibility with the PPS resin, a hydroxyl group, a carboxylic acid group, an acid anhydride group, an amino group, a vinyl group, and a glycidyl. Groups, isocyanate groups and the like can be preferably exemplified. Excellent compatibility is preferable from the viewpoint of obtaining excellent toughness and the effect of improving the glass transition temperature.

Further, the PPE resin is generally modified with a styrene resin, but in the present invention, a PPE resin composition containing a styrene resin may be used as the (b) PPE resin. The type of styrene resin is not particularly limited, but for example, polystyrene, styrene-acrylonitrile copolymer, styrene-rubber polymer-acrylonitrile copolymer (ABS resin), rubber-reinforced polystyrene (HIPS), styrene block-conjugated diene. Examples thereof include hydrogenated compounds of compound block copolymers. The PPE resin composition may contain one or more styrene resins.

(3) Other Additives Further, a resin other than (a) PPS resin and (b) PPE resin may be appropriately blended in the PPS resin composition of the present invention as long as the effects of the present invention are not impaired. Specific examples thereof include polyether sulfone, polyetherimide, polyphenylene sulfone, polysulfone, polycarbonate, polyamide, polybutylene terephthalate, polyethylene terephthalate, polyketone, liquid crystal polymer, polyether ketone, polyether ether ketone, and fluororesin (polytetrafluoro). Ethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-perfluoro (alkyl vinyl ether) copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene- Examples thereof include olefin polymers and copolymers such as tetrafluoroethylene-hexafluoropropylene copolymer, polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE)), and ethylene / butene copolymer. It is not limited to these.

Further, the following compounds can be added for the purpose of modification. Plasticizers such as polyalkylene oxide oligoma compounds, thioether compounds, ester compounds, and organic phosphorus compounds, crystal nucleating agents such as organic phosphorus compounds and polyether ether ketones, waxes montanate, lithium stearate, aluminum stearate. Metal soaps such as ethylenediamine / stearic acid / sebacic acid polycondensate, mold release agents such as silicone compounds, anticoloring agents such as hypophosphate, other water, lubricants, ultraviolet inhibitors, coloring agents, foaming Ordinary additives such as agents can be blended. If any of the above compounds exceeds 20 parts by weight of the entire composition, the original characteristics of the PPS resin composition of the present invention are impaired, which is not preferable, and it is preferable to add 10 parts by weight or less, more preferably 1 part by weight or less.

Further, in the present invention, a compatibilizer can be used in combination for the purpose of enhancing the compatibility between the resins. Specifically, epoxy resins and organic silane compounds can be exemplified.

Specific examples of such epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, brominated epoxy resin, special skeleton bifunctional epoxy resin having biphenyl skeleton, naphthalene skeleton and the like, cresol novolac type and trisphenol methane type. Glycidyl ether type epoxy resin typified by polyfunctional epoxy resin such as dicyclopentadiene type, glycidylamine type epoxy resin typified by aromatic amine type and aminophenol type, typified by hydrophthalic acid type and dimer acid type Glycidyl ester type epoxy resin can be mentioned.

The amount of the epoxy resin added is preferably 0.1 to 5 parts by weight, particularly preferably 0.2 to 3 parts by weight, based on 100 parts by weight of the total PPS resin composition.

Specific examples of such organic silane compounds include epoxy groups such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysisilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. An alkoxysilane compound, a mercapto group-containing alkoxysilane compound such as γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysisilane, γ- (2-) Ureidoethyl) Ureido group-containing alkoxysilane compounds such as aminopropyltrimethoxysilane, γ-isocyanatepropyltriethoxysilane, γ-isocyanatepropyltrimethoxysilane, γ-isocyanatepropylmethyldimethoxysilane, γ-isocyanatepropylmethyldiethoxysilane, Isocyanate group-containing alkoxysilane compounds such as γ-isocyanatepropylethyldimethoxysilane, γ-isocyanatepropylethyldiethoxysilane, γ-isocyanatepropyltrichlorosilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2) -Aminoethyl) Organic silane compounds such as amino group-containing alkoxysilane compounds such as aminopropyltrimethoxysilane and γ-aminopropyltrimethoxysilane, among which, from the viewpoint of reactivity, epoxy group-containing alkoxysilane compounds, Amino group-containing alkoxysilane compounds and isocyanate-containing alkoxysilane compounds are preferable, and isocyanate group-containing alkoxysilane compounds are particularly preferable. Excellent reactivity leads to improvement in toughness of the PPS resin composition.

The amount of the organic silane compound added is preferably 0.2 to 5 parts by weight, particularly preferably 0.2 to 3 parts by weight, based on 100 parts by weight of the total PPS resin composition. Further, 0.2 to 2 parts by weight is preferable.

A radical generator can also be added to the PPS resin composition of the present invention. It is preferable to add a radical generator because the glass transition temperature of the PPS resin composition can be improved. Specifically, it is preferable to add a radical generator having a half-life temperature of 170 ° C. or higher for 1 minute. When the half-life temperature for 1 minute is 170 ° C. or higher, the effect as a radical generator at the processing temperature of the PPS resin composition can be obtained, and the effect of improving the glass transition temperature is sufficient, which is preferable. The 1-minute half-life temperature is more preferably 200 ° C. or higher, more preferably 230 ° C. or higher, and particularly preferably 250 ° C. or higher. Specific examples of the radical generator having a one-minute half-life temperature of 170 ° C. or higher include n-butyl-4,4-bis (t-butylperoxy) valerate and 1,3-bis [(t-butylperoxy). ) Isopropyl] benzene, dicumyl peroxide, di-t-hexyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, t-butyl-cumyl peroxide, di-t- Butyl peroxide, 2,3-dimethyl-2,3-diphenylbutane, 2,3-diethyl-2,3-diphenylbutane, 2,3-diethyl-2,3-diphenylhexane, 2,3-diethyl-2 , 3-Di (p-methylphenyl) butane and the like.

Above all, from the viewpoint of the effect and safety of the PPS resin composition as a radical generator at the processing temperature, 2,5-dimethyl-2,5-di-t-butylperoxyhexane and 2,3-dimethyl-2 , 3-Diphenylbutane is preferred. 2,3-Dimethyl-2,3-diphenylbutane is more preferred because it has a higher 1-minute half-life temperature.

The amount of these radical generators used is preferably 0.1 part by weight to 5.0 parts by weight, more preferably 0.3 parts by weight to 3.0 parts by weight, based on 100 parts by weight of the PPS resin composition. At 0.1 parts by weight or more, the effect of the radical generator can be obtained, and at 5.0 parts by weight or less, the effect of the radical generator and the safety in the processing step of the PPS resin composition can be compatible, which is preferable.

Although it is not an essential component, the PPS resin composition of the present invention can be used by blending an inorganic filler as long as the effects of the present invention are not impaired. Specific examples of such inorganic fillers include glass fibers, carbon fibers, carbon nanotubes, carbon nanohorns, potassium titanate whisker, zinc oxide whisker, calcium carbonate whisker, wallastenite whisker, aluminum borate whisker, aramid fiber, alumina fiber, and silicon carbide fiber. , Ceramic fiber, asbestos fiber, stone shaving fiber, metal fiber and other fibrous fillers, or fullerene, talc, wallastenite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, silica, bentonite, asbestos, alumina. Silates such as silicate, silicon oxide, magnesium oxide, alumina, zirconium oxide, titanium oxide, metal compounds such as iron oxide, carbonates such as calcium carbonate, magnesium carbonate and dolomite, sulfates such as calcium sulfate and barium sulfate, and water. Hydroxides such as calcium oxide, magnesium hydroxide and aluminum hydroxide, glass beads, glass flakes, glass powder, ceramic beads, boron nitride, silicon carbide, carbon black and non-fibrous fillers such as silica and graphite are used. Of these, glass fiber, silica, and calcium carbonate are preferable, and calcium carbonate and silica are particularly preferable from the viewpoint of the effects of food-proofing materials and lubricating materials. Further, these inorganic fillers may be hollow, and two or more kinds thereof can be used in combination. Further, these inorganic fillers may be pretreated with a coupling agent such as an isocyanate compound, an organic silane compound, an organic titanate compound, an organic borane compound and an epoxy compound before use. Of these, calcium carbonate, silica, and carbon black are preferable from the viewpoint of food-proofing materials and lubricants.

The blending amount of the inorganic filler is selected in the range of less than 30 parts by weight, preferably less than 20 parts by weight, more preferably less than 10 parts by weight, based on 100 parts by weight of the total PPS resin composition. A range of 5 parts by weight or less is more preferable. There is no particular lower limit, but 0.0001 parts by weight or more is preferable. The blending of the inorganic filler is effective for improving the strength of the material, but the blending of more than 30 parts by weight causes a decrease in toughness, which is not preferable.

(4) PPS Resin Composition and Method for Producing The PPS Resin Composition of the present invention is a polyphenylene sulfide resin composition obtained by blending (a) PPS resin and (b) PPE resin. The glass transition temperature when measuring the differential scanning calorimetry of an object was in the range of 95 ° C or higher and 160 ° C or lower, and it was possible to suppress the decrease in rigidity under high temperature conditions while maintaining the original characteristics of the PPS resin. ..

As a method for producing such a PPS resin composition, it is preferable to heat-treat the pellets of the PPS resin composition as described later.

The PPS resin composition of the present invention is excellent in productivity in that it can be used for various moldings and can heat-treat a large amount of pellets at one time, and does not require heat treatment of the molded product. It is possible to obtain a molded product in which the decrease in rigidity under high temperature conditions is suppressed while solving the problems.

The pellets are at least (a) PPS resin and (b) PPE resin melt-kneaded using an extruder or the like, and the obtained melt-kneaded product is cut by a strand cutter, an underwater cutter, a hot cutter or the like. It was obtained by In the present invention, a melt-kneaded product cut into a pellet shape by a strand cutter or the like is referred to as a resin composition, and a product obtained by melt-molding the pellets with a molding machine or the like is formed of a resin composition. Defined as an article (sometimes abbreviated as an article).

It is essential that the glass transition temperature when the differential scanning calorimetry of the PPS resin composition of the present invention is measured is in the range of 95 ° C. or higher and 160 ° C. or lower. If the glass transition temperature is less than 95 ° C., it is difficult to suppress the decrease in rigidity under high temperature conditions, which is not preferable. On the other hand, if the glass transition temperature exceeds 160 ° C., the melt moldability of the PPS resin composition is impaired, which is not preferable. By appropriately heat-treating the pellets of the resin composition as described later, the glass transition temperature of the PPS resin composition can be kept within the above range. The upper limit of the glass transition temperature is preferably 140 ° C. or lower, more preferably 120 ° C. or lower, and particularly preferably 110 ° C. or lower, from the viewpoint of melt moldability.

The glass transition temperature in the present invention is the value of the inflection point of the baseline shift detected when the temperature is raised from 50 ° C. to 340 ° C. at a rate of 20 ° C./min using a differential scanning calorimeter. When two or more glass transition temperatures are detected, the one detected on the lowest temperature side within the measurement temperature range is defined as the glass transition temperature of the PPS resin composition in the present invention.

The (a) PPS resin and (b) PPE resin, which are essential components in the PPS resin composition of the present invention, are (a) PPS resin with respect to a total of 100 parts by weight of (a) PPS resin and (b) PPE resin. It can be exemplified that it is preferable to mix the PPE resin in an amount of 95 parts by weight to 65 parts by weight and (b) PPE resin in an amount of 5 parts by weight to 35 parts by weight. It is more preferable that (a) PPS resin is 95 parts by weight to 70 parts by weight, (b) PPE resin is 5 parts to 30 parts by weight, and (a) PPS resin is 90 parts by weight to 80 parts by weight, (b). ) It is more preferable that the PPE resin is 10 parts by weight to 20 parts by weight. When (a) PPS resin is 95 parts by weight or less and (b) PPE resin is 5 parts by weight or more, the glass transition temperature of the PPS resin composition is sufficiently improved, and the decrease in rigidity under high temperature conditions is suppressed. Can be preferred. It is preferable that (a) the PPS resin is 65 parts by weight or more and (b) the PPE resin is 35 parts by weight or less without impairing the melt moldability of the PPS resin composition.

The resin phase-separated structure of the PPS resin composition in the present invention observed with an electron microscope is such that (a) the PPS resin forms a continuous phase (sea phase or matrix) and (b) the PPE resin is a dispersed phase (island phase). It is preferable to form. By forming the above-mentioned resin phase-separated structure, a PPS resin composition in which the inherent characteristics of the PPS resin are sufficiently exhibited can be obtained.

(B) The number average dispersed particle size of the dispersed phase (island phase) of the PPE resin can be exemplified in a preferable range of 1000 nm or less. It is more preferably 800 nm or less, still more preferably 500 nm or less. (B) The number average dispersed particle diameter of the dispersed phase (island phase) of the PPE resin is in the above range, which means that the compatibility between the (a) PPS resin and the (b) PPE resin is good. It is preferable from the viewpoint of obtaining excellent toughness and an effect of improving the glass transition temperature.

The PPS resin composition of the present invention can be obtained by production in a molten state. For production in the molten state, melt-kneading by an extruder, melt-kneading by a kneader, or the like can be used, but from the viewpoint of productivity, melt-kneading by an extruder capable of continuously producing is preferably used. For melt-kneading with an extruder, at least one extruder such as a single-screw extruder, a twin-screw extruder, a multi-screw extruder such as a four-screw extruder, or a twin-screw single-screw compound extruder can be used. From the viewpoint of improving reactivity and productivity, a multi-screw extruder such as a twin-screw extruder or a four-screw extruder can be preferably used, and melt-kneading by the twin-screw extruder is most preferable.

A more specific method for melt-kneading is not necessarily limited to this, but the L / D (L: screw length, D: screw diameter) is 10 or more, preferably 20 or more, and kneading. It is preferable to use a twin-screw extruder having two or more parts, preferably three or more parts. The upper limit of L / D is not particularly limited, but 60 or less is preferable from the viewpoint of economy. Further, the upper limit of the number of kneading portions is not particularly limited, but it is preferably 10 or less from the viewpoint of productivity. The ratio of the kneading portion to the total length of the screw is preferably 15% or more, more preferably 20% or more, still more preferably 30% or more. When the ratio of the kneading portion to the total length of the screw is less than 15%, the kneading force is inferior, so that (b) the number average dispersion diameter of the PPE resin becomes coarse, which leads to a decrease in toughness. On the other hand, the upper limit of the ratio of the kneading portion to the total length of the screw is preferably 70% or less from the viewpoint of preventing deterioration of the resin due to the generation of excessive shear heat generation during kneading.

As for the screw rotation speed, a method of kneading under the conditions of 150 to 1000 rotations / minute, preferably 300 to 1000 rotations / minute is preferable.

The preferred cylinder temperature (° C.) range is preferably a temperature range of + 5 to 100 ° C., which is the highest melting point or glass transition temperature among the melting points of (a) PPS resin and (b) PPE resin. Specifically, it is in the range of 280 to 400 ° C., more preferably in the range of 280 to 360 ° C., and even more preferably in the range of 280 to 330 ° C.

The mixing order of the raw materials at the time of melt-kneading is not particularly limited, but a method of melting and kneading all the raw materials by the above method after mixing, and a method of melting and kneading some of the raw materials by the above method after mixing are performed. Either this and the remaining raw materials are mixed and melt-kneaded, or some of the raw materials are mixed and then the remaining raw materials are mixed using a side feeder during melt-kneading with a twin-screw extruder. May be used.

The melt-kneaded product obtained by melt-kneading is cut into pellets by cutting with a strand cutter, an underwater cutter, a hot cutter, or the like. The shape of the pellet is not particularly limited, and for example, a cylindrical shape can be exemplified as a preferable shape. Regarding the size of the pellets, the length of the pellets is preferably 1 mm to 10 mm, more preferably 2 mm to 5 mm. When the length of the pellet is 1 mm or more, the molding process is easy, and when it is 10 mm or less, the molding process is easy, and the pellet can be uniformly heated during the heat treatment as described later. The glass transition temperature is sufficiently improved, which is preferable.

Heat-treating the pellets of the PPS resin composition of the present invention is a preferable method because the glass transition temperature of the PPS resin composition can be significantly improved. The device for such heat treatment is not particularly limited, but may be a normal hot air dryer, a rotary type, or a heating device with a stirring blade. The atmosphere of the heat treatment may be in air, in vacuum, or in an inert gas such as nitrogen.

The temperature for heat-treating the pellets in the present invention is preferably (a) a melting point of -100 ° C. or higher and -5 ° C. or lower when the differential scanning calorimetry of the PPS resin is measured. It is more preferably −100 ° C. or higher and −10 ° C. or lower, and further preferably −95 ° C. or higher and −10 ° C. or higher. When the heat treatment temperature is (a) the melting point of the PPS resin is -100 ° C or higher, the effect of improving the glass transition temperature is large, and when the melting point is -5 ° C or lower, deformation or fusion due to melting of the pellets does not occur and molding is performed. It is preferable because the workability does not decrease.

The melting point of the (a) PPS resin in the present invention is a value measured using a differential scanning calorimeter under the condition of raising the temperature from 50 ° C. to 340 ° C. at a rate of 20 ° C./min.

The time for heat-treating the pellets cannot be unconditionally specified because it varies depending on the mixing ratio of (a) PPS resin and (b) PPE resin in the PPS resin composition, but it is preferably 1 minute to 6000 minutes. Can be exemplified as. It is more preferably 5 minutes to 4800 minutes, and even more preferably 10 minutes to 2400 minutes. When the heat treatment temperature is 1 minute or more, the effect of improving the glass transition temperature is obtained, and when it is 6000 minutes or less, the melt viscosity is remarkably increased and the melt moldability is not impaired.

(5) Molded product made of PPS resin composition and its manufacturing method The molded product made of the PPS resin composition of the present invention is measured for temperature-modulated differential scanning calorimetry (conditions: temperature rise rate 2 ° C./min, amplitude). In the non-reverse flow curve when ± 0.8 ° C. and cycle 60 seconds), it is preferable that (a) the glass transition temperature of the PPS resin is exceeded and the heat absorption peak is not formed at 280 ° C. or lower. Having an endothermic peak in the temperature range means that the molded product has been heat-treated, but it is not preferable to heat-treat the molded product because dimensional changes occur. On the other hand, the molded product made of the resin composition of the present invention is excellent in dimensional stability of the molded product because the decrease in rigidity under high temperature conditions can be suppressed without requiring heat treatment of the molded product. .. In addition, embrittlement due to excessive crystallization associated with heat treatment of the molded product can be suppressed, which is useful for maintaining the toughness of the molded product.

The molded product made of the PPS resin composition of the present invention does not heat-treat the pellets of the resin composition obtained by cutting the melt-kneaded product obtained by melt-kneading with a strand cutter or the like, or the above-mentioned method. It can be obtained by heat-treating with a molding machine or the like and melt-molding with a molding machine or the like. A molded product obtained by melt-molding the heat-treated pellets is preferable because it can further suppress a decrease in rigidity under high temperature conditions. Specific molding methods include injection molding, extrusion molding, compression molding, injection molding, injection compression molding, and the like. Among them, injection molding can be exemplified as a preferable molding method. The mold temperature at the time of injection molding can be exemplified as a preferable range of 130 ° C. to 150 ° C. When the mold temperature is 130 ° C. or higher, crystallization is sufficient, and when the mold temperature is 150 ° C. or lower, it is preferable in terms of energy, cycle, and safety.

The molded product made of the PPS resin composition of the present invention preferably has a deflection temperature under load (sometimes abbreviated as DTUL) of 110 ° C. or higher. A DTUL of 110 ° C. or higher means excellent rigidity under high temperature conditions.

The DTUL uses a strip test piece with a length of 80 mm, a width of 10 mm, and a thickness of 4 mm as a sample, conforms to ASTM D648, uses an HDT-500 (manufactured by Yasuda Seiki Seisakusho), and has a load of 1.82 MPa. It is a value measured in.

(6) Applications The applications of the PPS resin composition of the present invention and molded products made from the same are electrical / electronic parts, audio equipment parts, household and office electrical product parts, machine-related parts, optical equipment, precision machine-related parts, and water. Examples include peripheral parts, automobile / vehicle-related parts, aviation / space-related parts, and various other uses. Above all, it is particularly suitable as an electric / electronic part, an automobile / vehicle-related part, and an aerospace-related part from the viewpoint of suppressing a decrease in rigidity under high temperature conditions.

Applications of molded products obtained by injection molding include generators, motors, transformers, current transformers, voltage regulators, rectifiers, inverters, relays, power contacts, switches, machine breakers, knife switches, and other poles. Electrical equipment parts such as rods and electrical parts cabinets; sensors, LED lamps, connectors, sockets, resistors, relay cases, small switches, coil bobbins, condensers, variable condenser cases, optical pickups, oscillators, various terminal boards, metaphors, plugs. , Printed boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, power modules, semiconductors, liquid crystal, FDD carriages, FDD chassis, motor brush holders, parabolic antennas, computer-related parts, and other electronic parts; VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave parts, acoustic parts, audio equipment parts such as audio / laser discs (registered trademarks) / compact discs; lighting parts, refrigerator parts, air conditioner parts, typewriters Home and office electrical parts such as parts and word processor parts; office computer related parts, telephone equipment related parts, facsimile related parts, copying machine related parts, cleaning jigs, motor parts, writers, typewriters, etc. Machine-related parts; Optical equipment / precision machine-related parts such as microscopes, binoculars, cameras, watches, etc .; Alternator terminals, alternator connectors, IC regulators, potency meter bases for light dimmers, various valves such as exhaust gas valves, Fuel-related / exhaust system / intake system pipes and ducts, turbo ducts, air intake nozzle snorkel, intake manifold, fuel pump, engine cooling water joint, carburetor main body, carburetor spacer, exhaust gas sensor, cooling water sensor, oil temperature sensor , Brake pad wear sensor, Throttle position sensor, Crank shaft position sensor, Air flow meter, Brake pad wear sensor, Thermostat base for air conditioner, Heating hot air flow control valve, Brush holder for radiator motor, Water pump impeller, Turbine vane, Wiper Motor parts, Dustributor, Starter switch, Starter relay, Transmission wire harness, Win Dwasher nozzle, air conditioner panel switch board, fuel-related electromagnetic valve coil, fuse connector, horn terminal, electrical component insulation plate, step motor rotor, lamp socket, lamp reflector, lamp housing, brake piston, solenoid bobbin, engine oil filter , Crash pads, insulators, binding bands, ignition device cases, and other automobile / vehicle-related parts; for primary or secondary batteries such as mobile phones, smartphones, notebook computers, tablet computers, video cameras, hybrid vehicles, and electric vehicles. The gasket and the like can be exemplified.

Examples of the molded product obtained by extrusion molding include round bars, square bars, sheets, films, tubes, pipes and the like. Specific applications include electrical insulation materials for water heater motors, air conditioner motors, drive motors, film capacitors, speaker diaphragms, magnetic tape for recording, printed board materials, printed board peripheral parts, seamless belts, semiconductor packages. , Semiconductor transport tray, process / release film, protective film, automobile film sensor, wire cable insulation tape, insulation washer in lithium ion battery, hot water and cooling water, chemical tube, automobile fuel tube , Hot water piping, chemical piping for chemical plants, piping for ultra-pure water and ultra-high purity solvents, automobile piping, piping pipes for freon and supercritical carbon dioxide refrigerant, workpiece holding rings for polishing equipment, etc. can. In addition, wire harnesses and control wires for hybrid automobiles, electric automobiles, railways, coating molded bodies for motor coils of power generation equipment, heat-resistant electric wire cables for home appliances, flat cables used for wiring in automobiles, communication, etc. Examples thereof include a signal transformer for transmission, high frequency, audio, measurement, etc., or a coating molded body of a winding of an in-vehicle transformer.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

In Examples and Comparative Examples, the following were used as (a) PPS resin, (b) PPE resin, and (c) radical generator.

[(A) PPS resin (a-1)]
Reference example: Preparation of PPS resin (a-1)
8267.37 g (70.00 mol) of 47.5% sodium hydrosulfide, 2957.21 g (70.97 mol) of 96% sodium hydroxide, N-methyl-2-pyrrolidone (NMP) in a 70 liter autoclave with a stirrer. ) 11434.50 g (115.50 mol), 2583.00 g (31.50 mol) of sodium acetate, and 10500 g of ion-exchanged water were charged. The reaction vessel was cooled to 160 ° C. after distilling 14780.1 g of water and 280 g of NMP by gradually heating to 245 ° C. over about 3 hours while passing nitrogen under normal pressure. The amount of residual water in the system per 1 mol of the charged alkali metal sulfide was 1.06 mol including the water consumed for the hydrolysis of NMP. The amount of hydrogen sulfide scattered was 0.02 mol per mol of the charged alkali metal sulfide.

To this reaction mixture, 10235.46 g (69.63 mol) of p-dichlorobenzene and 900.00 g (91.00 mol) of NMP 900900 g (91.00 mol) were added, the reaction vessel was sealed under nitrogen gas, and the mixture was stirred at 240 rpm at 0.6 ° C. The temperature was raised to 238 ° C. at a rate of / min. After the reaction was carried out at 238 ° C. for 95 minutes, the temperature was raised to 270 ° C. at a rate of 0.8 ° C./min. After the reaction was carried out at 270 ° C. for 100 minutes, 1260 g (70 mol) of water was press-fitted over 15 minutes and cooled to 250 ° C. at a rate of 1.3 ° C./min. Then, it was cooled to 200 ° C. at a rate of 1.0 ° C./min and then rapidly cooled to near room temperature.

The contents were taken out from the reaction vessel, diluted with 26300 g of NMP, the solvent and solids were filtered off by a sieve (80 mesh), and the obtained particles were washed with 31900 g of NMP and filtered off. This was washed with 56,000 g of ion-exchanged water several times and filtered off, and then washed with 70000 g of a 0.05 wt% acetic acid aqueous solution and filtered off. Subsequently, after washing with 70,000 g of ion-exchanged water and filtering, the obtained hydrous PPS particles were dried with hot air at 80 ° C. and further dried under reduced pressure at 120 ° C. The obtained PPS (a-1) had a melt viscosity of 200 Pa · s (300 ° C., a shear rate of 1000 / s), a melting point of 280 ° C., and a glass transition temperature of 93 ° C.

[(B) PPE resin (b-1, b-2)]
b-1: Non-denatured PPE (manufactured by SABIC, PPO640), glass transition temperature: 215 ° C.
b-2: Maleic anhydride-modified PPE (manufactured by Dainichiseika Kogyo Co., Ltd., HPPO-40), glass transition temperature: 210 ° C.

[Radical generator (c-1)]
c-1: 2,3-dimethyl-2,3-diphenylbutane (Nof Corporation, Nofmer BC)
In the following examples, the characteristics were evaluated by the following method.

[Melting viscosity]
The melt viscosity (Pa · s) was measured using a capillary graph 1B (capillary having a length of 10 mm and a diameter of 1 mm) manufactured by Toyo Seiki Co., Ltd. under the conditions of 300 ° C. and a shear rate of 1000 / s.

[Heat treatment]
The pellets and dumbbell test pieces obtained from each Example and Comparative Example were heat-treated at a predetermined temperature and time using a hot air dryer (manufactured by ESPEC, PHH202), and then heated at a temperature of 23 ° C. and a relative humidity of 50. Under the% condition, it was allowed to cool for 24 hours.

[Melting point, glass transition temperature (Tg)]
The pellets, dumbbell test pieces, and strip test pieces obtained from each Example and Comparative Example were heat-pressed at 320 ° C. for 4 minutes and then rapidly cooled in water at 23 ° C. to prepare an amorphous film. Using this as a sample, measurement was performed using a differential scanning calorimeter (Q200) manufactured by TA Instruments, Inc. under the condition that the temperature was raised from 50 ° C. to 340 ° C. at a rate of 20 ° C./min.

[Deflection temperature under load (DTUL)]
Using an injection molding machine (SE75DUZ-C250) manufactured by Sumitomo Heavy Industries, Ltd., an ISO5272-1A dumbbell test piece was molded at a resin temperature of 310 ° C. and a mold temperature of 150 ° C. The dumbbell test piece was allowed to cool for 24 hours under the conditions of a temperature of 23 ° C. and a relative humidity of 50%. After that, the dumbbell test piece was cut to a length of 80 mm, a width of 10 mm, and a thickness of 4 mm to make a strip test piece, which conforms to ASTM D648 and is loaded using HDT-500 (manufactured by Yasuda Seiki Seisakusho). The deflection temperature under load (DTUL) was measured under the condition of 1.82 MPa. The higher the deflection temperature under load, the better the rigidity under high temperature conditions.

[Non-reverse flow curve (NR) endothermic peak]
For the dumbbell test pieces obtained from each Example and Comparative Example, a differential scanning calorimeter (Q200) manufactured by TA Instruments Co., Ltd. was used, and the temperature rise rate was 2 ° C./min, the amplitude was ± 0.8 ° C., and the period was 60 seconds. Under the conditions, the temperature was raised from room temperature to 300 ° C., and the presence or absence of an endothermic peak in the non-reverse flow curve was confirmed.

[Dimension measurement]
The ISO5272-1A dumbbell test piece was molded under the same conditions as those used for the deflection temperature under load, and allowed to cool for 24 hours under the conditions of a temperature of 23 ° C. and a relative humidity of 50%. The thickness of the dumbbell test piece that had been allowed to cool was measured using a caliper. For Examples 2 and Comparative Examples 2 and 3, the thickness was measured again after being left to stand for 24 hours under the conditions of a temperature of 23 ° C. and a relative humidity of 50%. For Comparative Example 4, the dumbbell test piece was heat-treated under the conditions shown in Table 1, allowed to cool for 24 hours under the conditions of a temperature of 23 ° C. and a relative humidity of 50%, and then the thickness was measured again. In the first and second measurements, it was confirmed whether or not there was a change in dimensions (thickness).

[Examples 1 to 8 and Comparative Examples 1 to 5]
After dry-blending (a) PPS resin, (b) PPE resin, and (c) radical generator at the ratios shown in Tables 1 and 2, a TEX30α twin-screw extruder manufactured by Japan Steel Works, Ltd. equipped with a vacuum vent ( 30 mmφ, L / D = 45), screw arrangement is set at 3 kneading parts, the ratio of the kneading part to the total length of the screw is 30%, the cylinder temperature is set to 320 ° C., and the screw rotation speed is set to 300 rpm for melt kneading. bottom. The amount of the (c) radical generator in the table is based on 100 parts by weight of the total amount of the (a) PPS resin and (b) PPE resin. Then, it was pelletized by a strand cutter to obtain a resin composition. In Comparative Examples 1, 2 and 4, the obtained pellets were dried at 130 ° C. overnight, and then DSC measurement was performed. In Examples 1 to 8 and Comparative Examples 3 and 5, the pellets were heat-treated with a hot air dryer under the conditions shown in Table 1, and then DSC measurement was performed. Further, in Example 2 and Comparative Example 3, pellets heat-treated under predetermined conditions were subjected to injection molding to obtain dumbbell test pieces. In Comparative Example 2, pellets that had only been dried were subjected to injection molding to obtain dumbbell test pieces. Further, the dumbbell test piece of Comparative Example 2 was heat-treated under predetermined conditions and used as the dumbbell test piece of Comparative Example 4. Then, the dumbbell test pieces of each Example and Comparative Example were cut, and DTUL and temperature-modulated differential scanning calorimetry were performed. The results were as shown in Tables 1 and 2.

The results of the above-mentioned Examples and Comparative Examples will be compared and described.

In Examples 1 to 6, (a) PPS resin and (b) PPE resin are blended, and the respective Tg is within a specific range. By blending the radical generator in Examples 7 and 8, the Tg is further improved as compared with Examples 2 and 4 in which the radical generator is not blended. On the other hand, in Comparative Examples 1 to 5, each Tg is not within a specific range.

The DTUL of the strip test piece obtained by cutting a dumbbell test piece obtained by injection molding a pellet having a Tg of 98 ° C. in Example 2 was measured and found to be 113 ° C. On the other hand, the DTUL of the strip test piece obtained by cutting the dumbbell test piece obtained by injection molding the pellets in which the Tg of Comparative Examples 2 and 3 was 93 and 94 ° C. was 107 and 105 ° C., respectively. Further, as shown in Comparative Example 4, a dumbbell test piece obtained by injection molding a pellet having a Tg of 93 ° C. obtained in Comparative Example 2 was heat-treated and then cut, and the DTUL measurement of the strip test piece was performed at 112 ° C. there were. Only in the dumbbell test piece of Comparative Example 4, an endothermic peak and a dimensional change were observed in the temperature-modulated differential scanning calorimetry.

From the above, it can be seen that the PPS resin composition of the present invention and the molded product made from the PPS resin composition can suppress a decrease in rigidity under high temperature conditions and are excellent in dimensional stability.

Claims (7)

A polyphenylene sulfide resin composition obtained by blending (a) a polyphenylene sulfide resin and (b) a polyphenylene ether resin, wherein the glass transition temperature when the differential scanning calorimetry of the resin composition is measured is 95 ° C. or higher, 160. A polyphenylene sulfide resin composition in the range of ° C. or lower. A molded product comprising the polyphenylene sulfide resin composition according to claim 1. A molded product made of the polyphenylene sulfide resin composition according to claim 2, wherein the temperature-modulated differential scanning calorimetry of the molded product (conditions: heating rate 2 ° C./min, amplitude ± 0.8 ° C., period 60 seconds). ), In the non-reverse flow curve, (a) a molded product made of a polyphenylene sulfide resin composition which exceeds the glass transition temperature of the polyphenylene sulfide resin and does not have a heat absorption peak at 280 ° C. or lower. The method for producing the polyphenylene sulfide resin composition according to claim 1, wherein the pellets obtained by melt-kneading (a) a polyphenylene sulfide resin and (b) a polyphenylene ether resin are heat-treated. A method for producing a polyphenylene sulfide resin composition. The method for producing a polyphenylene sulfide resin composition according to claim 4, wherein the temperature at which the pellets are heat-treated is (a) a melting point of −100 ° C. or higher and −5 ° C. or lower when the differential scanning calorimetry of the polyphenylene sulfide resin is measured. A method for producing a polyphenylene sulfide resin composition. A method for producing a molded product comprising the polyphenylene sulfide resin composition according to any one of claims 2 to 3, wherein (a) the polyphenylene sulfide resin and (b) the polyphenylene ether resin are melt-kneaded. A method for producing a molded product comprising a polyphenylene sulfide resin composition, which comprises heat-treating the obtained pellets and then melt-molding the heat-treated pellets to obtain a molded product. The method for producing a molded product made of the polyphenylene sulfide resin composition according to claim 6, wherein the temperature at which the pellets are heat-treated is (a) a melting point of -100 ° C. or higher when the differential scanning calorimetry of the polyphenylene sulfide resin is measured. A method for producing a molded product, which comprises a polyphenylene sulfide resin composition having a temperature of 5 ° C. or lower.