WO2020032171A1

WO2020032171A1 - Method for purifying and method for producing polyarylene sulfide

Info

Publication number: WO2020032171A1
Application number: PCT/JP2019/031355
Authority: WO
Inventors: 渡辺　創; 渡邉　英樹; 井上　敏
Original assignee: Dic株式会社
Priority date: 2018-08-10
Filing date: 2019-08-08
Publication date: 2020-02-13
Also published as: JPWO2020032171A1

Abstract

Provided are a method for purifying polyarylene sulfide (PAS) with which it is possible to efficiently reduce alkali metal halides and carboxyalkylamino-group-containing compounds in the PAS by treating the alkali metal halides and carboxyalkylamino-group-containing compounds in the PAS under a lower pressure without using a strong acid, and a method for producing PAS having a low level of alkali metal halides and carboxyalkylamino-group-containing compounds in the PAS. More specifically: a method for purifying PAS, the method having a step for removing a solvent from a crude reaction product that contains PAS and is obtained by reacting a polyhaloaromatic compound and a sulfidizing agent in an organic polar solvent and obtaining a crude-PAS-containing slurry, a step for bringing the crude-PAS-containing slurry into contact with water and an oxygen-atom-containing solvent to form the crude PAS into porous particles having a specific surface area of 30 m²/g or higher, and a step for bringing the resulting porous particles into contact with carbonated water; and a method for producing PAS, the method having the aforementioned steps.

Description

Purification method and production method of polyarylene sulfide

The present invention relates to a method for purifying and producing polyarylene sulfide (hereinafter sometimes abbreviated as PAS). More specifically, as compared with conventional refining methods using various strong acids (hydrochloric acid, sulfuric acid, etc.), it is possible to reduce the corrosiveness to manufacturing equipment and molds during molding, and to improve the quality of polyarylene sulfide. The present invention relates to a purification method and a production method that can be performed. Another object of the present invention is to provide polyarylene sulfide which is suitable as a material for a wide range of uses such as various molding materials, films, fibers, electric / electronic parts, automobile parts, and paints.

Among polyarylene sulfides, a typical polyphenylene sulfide (hereinafter sometimes abbreviated as PPS) is usually N-methyl-2-pyrrolidone, N, N-dimethyl, as described in Patent Document 1 and the like. In relatively polar organic solvents such as acetamide and N-methyl-ε-caprolactam, alkali metal sulfide represented by sodium sulfide or alkali metal sulfide represented by sodium hydrosulfide and sodium hydroxide represented by sodium sulfide Obtained by reacting an alkali metal hydroxide with a polyhaloaromatic compound represented by p-dichlorobenzene (see Patent Document 1).

The polymerization reaction is usually carried out under high temperature and pressure and under alkaline conditions, and as the polymerization reaction proceeds, salt is generated. The so-called crude reaction product after the polymerization reaction includes at least polyarylene sulfide and alkali metal halide. And, in addition, unreacted raw materials, cyclic or linear oligomers, and the following structural formula (1)

(Wherein, Ar is an aryl group having a halogen atom, R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms or a cyclohexyl group, R ² represents an alkylene group having 3 to 5 carbon atoms, X represents a hydrogen atom or an alkali metal atom, and a compound represented by -NR ¹ R ² COOX group is sometimes referred to as carboxyalkylamino group (hereinafter sometimes referred to as carboxyalkylamino group-containing compound). And other by-products.

Further, when the polyarylene sulfide is produced, as a raw material for producing the polyarylene sulfide, for example, when the amide solvent is N-methyl-2-pyrrolidone and the polyhalo aromatic compound is p-dichlorobenzene, the carboxyalkylamino group The compound represented by the following general formula (2)

(Wherein X represents a hydrogen atom or an alkali metal atom) (this compound is abbreviated as “CP-MABA”, and particularly when X is a hydrogen atom, “CP-MABA ( Hydrogen-type) "and the case of an alkali metal atom as" CP-MABA (alkali-metal salt type) ", particularly when X is a sodium atom, may be abbreviated as" CP-MABA (Na-salt type) ").

The crude reaction product after the polymerization reaction is taken out to a suitable container, and the solvent contained therein is removed by a suitable means (e.g., vacuum distillation, centrifugation, screw decanter, vacuum filtration, pressure filtration, etc.). Depending on the method, it can be separated and recovered and reused (here, this operation is referred to as “desolvation”), or, if necessary, further purified and reused.

On the other hand, after removing the solvent and separating and removing the organic polar solvent, the slurry containing the polyarylene sulfide contained in the crude reaction product (hereinafter, crude polyarylene sulfide) is generally subjected to water washing and filtration repeatedly, Polyarylene sulfide can be obtained by drying after removing impurities such as salt and alkaline substances.

The polyarylene sulfide thus obtained is used for fibers, films, paints, compounds for injection molding materials and fiber reinforced composite materials, etc. due to its excellent chemical resistance, electrical properties, and mechanical properties. However, impurities contained in polyarylene sulfide generate gas during melt processing, corrode injection molds and processing equipment, have poor adhesion to paint supports, and have the effect of reinforcing fibers in composite materials. Due to poor adhesion and the like, it has been desired to reduce the amount of impurities in polyarylene sulfide.

For this reason, as a method for purifying polyarylene sulfide, washing methods using various organic solvents have been conventionally proposed.However, the use of the organic solvent has an adverse effect on the environment and adverse effects on the human body, the manufacturing cost required for solvent recovery, and residual products. There is an unfavorable problem such as an adverse effect on quality due to the solvent used.

Further, a method has been proposed in which the amount of impurities is reduced by bringing the reaction mixture into contact with an acid (see Patent Document 2). However, many methods use a strong acid, which is a serious problem in terms of corrosiveness to equipment and facilities. In addition, the resulting polyarylene sulfide causes deterioration in color tone and product characteristics.

Therefore, a method has been proposed in which carbon dioxide or carbonated water is introduced into the system to bring carbon dioxide or carbonated water into contact with the crude polyarylene sulfide (see Patent Documents 3 and 4). However, since carbonic acid (carbon dioxide) is a gas at normal temperature and has low solubility in water, it functions weakly as an acid and therefore contains alkali metal halides and carboxyalkylamino groups in polyarylene sulfide. The effect of removing the compound was weak, and the treatment had to be performed under pressure in a pressure vessel.

Japanese Patent Publication No. 52-12240 JP-A-6-192421 JP 2005-264030 A JP 2010-187949 A

Therefore, the problem to be solved by the present invention is to use an alkali metal halide or a carboxyalkylamino group-containing compound in polyarylene sulfide at a lower pressure without using a strong acid, and to prepare an alkali metal in polyarylene sulfide. Provided is a method for purifying polyarylene sulfide, which can efficiently reduce halides and carboxyalkylamino group-containing compounds, and a method for producing polyarylene sulfides in which alkali metal halides and carboxyalkylamino group-containing compounds in polyarylene sulfide are low. May be.

As a result of various studies, the inventors of the present application have found that when introducing carbon dioxide gas or carbonated water into the system and bringing carbon dioxide gas or carbonated water into contact with the crude polyarylene sulfide, the crude polyarylene sulfide becomes porous. By forming particles, it has been found that even at a lower temperature or at a low pressure, it is possible to efficiently reduce alkali metal halides and carboxyalkylamino group-containing compounds in polyarylene sulfide. Thus, the present invention has been completed.

That is, the present invention provides a slurry containing a crude polyarylene sulfide by desolvating a crude reaction product containing a polyarylene sulfide obtained by reacting a polyhalo aromatic compound with a sulfide agent in an organic polar solvent. A step of obtaining a crude product, a slurry containing the crude polyarylene sulfide is brought into contact with water and a solvent containing an oxygen atom having 1 to 3 carbon atoms to make the crude polyarylene sulfide have a specific surface area of 30 m ² / g or more. And a step of bringing the obtained porous particles into contact with carbonated water. A method for purifying polyarylene sulfide, comprising the steps of:

The present invention also relates to a method for producing polyarylene sulfide, comprising a step of purifying polyarylene sulfide by the above-described purification method.

According to the present invention, an alkali metal halide or a carboxyalkylamino group-containing compound in a polyarylene sulfide is treated at a lower temperature or under a low pressure without using a strong acid, and the alkali in the polyarylene sulfide is treated. A method for purifying a polyarylene sulfide capable of efficiently reducing a metal halide or a carboxyalkylamino group-containing compound, and a method for producing a polyarylene sulfide having a low content of an alkali metal halide or a carboxyalkylamino group-containing compound in the polyarylene sulfide. Can be provided.

The present invention provides a slurry containing a crude polyarylene sulfide by desolvating a crude reaction product containing a polyarylene sulfide obtained by reacting a polyhalo aromatic compound with a sulfidizing agent in an organic polar solvent. The step of obtaining

Polyarylene sulfide is usually prepared by reacting at least one polyhaloaromatic compound with at least one sulfidizing agent in an organic polar solvent such as N-methyl-2-pyrrolidone under appropriate polymerization conditions. And synthesized.

The polyhalo aromatic compound used in the present invention is, for example, a halogenated aromatic compound having two or more halogen atoms directly bonded to an aromatic ring, and specifically, p-dichlorobenzene, o- Dichlorobenzene, m-dichlorobenzene, trichlorobenzene, tetrachlorobenzene, dibromobenzene, diiodobenzene, tribromobenzene, dibromonaphthalene, triiodobenzene, dichlorodiphenylbenzene, dibromodiphenylbenzene, dichlorobenzophenone Dihaloaromatic compounds such as dibromobenzophenone, dichlorodiphenylether, dibromodiphenylether, dichlorodiphenylsulfide, dibromodiphenylsulfide, dichlorobiphenyl, dibromobiphenyl, and mixtures thereof. The compounds may be block copolymerized. Of these, dihalogenated benzenes are preferred, and particularly preferred are those containing 80 mol% or more of p-dichlorobenzene.

で Further, in order to increase the viscosity of the polyarylene sulfide by forming a branched structure, a polyhalo aromatic compound having three or more halogen substituents in one molecule may be used as a branching agent, if desired. Such polyhalo aromatic compounds include, for example, 1,2,4-trichlorobenzene, 1,3,5-trichlorobenzene, 1,4,6-trichloronaphthalene and the like.

Further, polyhalo aromatic compounds having a functional group having an active hydrogen such as an amino group, a thiol group, or a hydroxyl group can be exemplified. Specifically, 2,6-dichloroaniline, 2,5-dichloroaniline Dihaloanilines such as 2,3,4-dichloroaniline and 2,3-dichloroaniline; 2,3,4-trichloroaniline, 2,3,5-trichloroaniline, 2,4,6-trichloroaniline, 3, Trihaloanilines such as 4,5-trichloroaniline; dihaloaminodiphenyl ethers such as 2,2'-diamino-4,4'-dichlorodiphenylether and 2,4'-diamino-2 ', 4-dichlorodiphenylether And compounds in which an amino group is replaced with a thiol group or a hydroxyl group in these mixtures.

Further, in these active hydrogen-containing polyhalo aromatic compounds, a hydrogen atom bonded to a carbon atom forming an aromatic ring is replaced with another inert group, for example, an active hydrogen-containing polyhalo group such as an alkyl group. Aromatic compounds can also be used.

中でも Among these various active hydrogen-containing polyhalo aromatic compounds, preferred are active hydrogen-containing dihalo aromatic compounds, and particularly preferred is dichloroaniline.

Examples of the polyhalo aromatic compound having a nitro group include mono- or dihalonitrobenzenes such as 2,4-dinitrochlorobenzene and 2,5-dichloronitrobenzene; 2-nitro-4,4'-dichlorodiphenyl ether; Dihalonitrodiphenyl ethers; dihalonitrodiphenylsulfones such as 3,3'-dinitro-4,4'-dichlorodiphenylsulfone; 2,5-dichloro-3-nitropyridine, 2-chloro-3,5 Mono- or dihalonitropyridines such as dinitropyridine; or various dihalonitronaphthalenes.

アルカリ The alkali metal sulfide used in the present invention includes lithium sulfide, sodium sulfide, rubidium sulfide, cesium sulfide and a mixture thereof. Such an alkali metal sulfide can be used as a hydrate, an aqueous mixture or an anhydride. Further, the alkali metal sulfide can also be derived by a reaction between the alkali metal hydrosulfide and the alkali metal hydroxide.

Usually, a small amount of alkali metal hydroxide may be added in order to react with a small amount of alkali metal hydrosulfide or alkali metal thiosulfate in the alkali metal sulfide.

Examples of the organic polar solvent used in the present invention include N-methyl-2-pyrrolidone, formamide, acetamide, N-methylformamide, N, N-dimethylacetamide, 2-pyrrolidone, N-methyl-ε-caprolactam, ε-caprolactam , Hexamethylphosphoramide, tetramethylurea, N-dimethylpropyleneurea, amideurea of 1,3-dimethyl-2-imidazolidinonic acid, and lactams; sulfolane such as sulfolane and dimethylsulfolane; benzonitrile and the like Nitriles; ketones such as methylphenylketone and mixtures thereof.

In the presence of these organic polar solvents, the polymerization conditions of the sulfidizing agent and the polyhaloaromatic compound are generally at a temperature of 200 to 330 ° C., and the pressure is substantially lower than the polymerization solvent and the polyhaloaromatic compound as the polymerization monomer. The range should be such that the liquid layer is kept in a liquid phase, and is generally selected from the range of 0.1 to 20 MPa, preferably 0.1 to 2 MPa. The reaction time varies depending on the temperature and pressure, but is generally in the range of 10 minutes to 72 hours, preferably 1 hour to 48 hours.

In the present invention, a form obtained by reacting a crude reaction product by continuously or intermittently adding a polyhaloaromatic compound and an organic polar solvent in the presence of a sulfidizing agent and an organic polar solvent is also included. I do.

In the present invention, the crude reaction product containing the polyarylene sulfide obtained by the polymerization reaction is subjected to suitable means (e.g., vacuum distillation, centrifugation, screw decanter, vacuum filtration, pressure filtration, etc.). After the organic polar solvent is separated and removed, a slurry containing crude polyarylene sulfide can be obtained.

In the present invention, subsequently, the slurry containing the crude polyarylene sulfide is brought into contact with water and a solvent containing an oxygen atom having 1 to 3 carbon atoms, whereby the crude polyarylene sulfide has a specific surface area of 30 [m ² / g]. There is a step of forming porous particles in the above range.

において In the present invention, an appropriate amount of water is added to the slurry containing at least the crude polyarylene sulfide obtained in the previous step, and the slurry is washed. The temperature at the time of adding water is not particularly limited, but is preferably from 10 ° C. or higher, more preferably from 20 ° C. or higher, preferably 120 ° C. or lower, more preferably 100 ° C. or lower, and still more preferably 80 ° C. or lower. . After washing, it is preferable that the solid-liquid separation is performed by filtration or the like to obtain a slurry. The amount of water used in one washing is not particularly limited, but is preferably 20 parts by mass or more, more preferably 50 parts by mass or more, and still more preferably 100 parts by mass, based on 100 parts by mass of polyarylene sulfide. To 10,000 parts by mass, preferably 5,000 parts by mass or less, more preferably 2,000 parts by mass or less.

Furthermore, using an organic solvent, the slurry is brought into contact with a slurry containing crude polyarylene sulfide and washed. The temperature at which the organic solvent is added is not particularly limited, but is preferably in the range of 10 ° C or higher, more preferably 20 ° C or higher, preferably 90 ° C or lower, more preferably 70 ° C or lower. The amount of the organic solvent used in one washing is not particularly limited, but is preferably 20 parts by mass or more, more preferably 50 parts by mass or more, and still more preferably 100 parts by mass based on 100 parts by mass of polyarylene sulfide. The amount is at least 5,000 parts by mass, preferably at most 5,000 parts by mass, more preferably at most 1,800 parts by mass, still more preferably at most 600 parts by mass.

The slurry containing the crude polyarylene sulfide may be brought into contact with water and a solvent containing an oxygen atom having 1 to 3 carbon atoms in any order, and the slurry containing the crude polyarylene sulfide is contacted with water and washed. (Hereinafter referred to as “Step (Sw)”), and then contacting the slurry containing the crude polyarylene sulfide with a solvent containing 1 to 3 carbon atoms to wash it (hereinafter referred to as “Step (Sw)”). (Ss) ”), or the step (Sw) may be performed after the step (Ss). Each step can be performed together or alternately, any one or more times. After performing the step (Ss) or the step (Sw), before performing the next step, remove water or an oxygen-containing solvent having 1 to 3 carbon atoms used for washing by solid-liquid separation. Is preferred.

Here, as the oxygen atom-containing solvent having 1 to 3 carbon atoms to be brought into contact with the slurry containing the crude polyarylene sulfide, for example, at least one selected from the group consisting of alcohol solvents and ketone solvents can be mentioned. Examples of alcohol solvents (also referred to as alcohol solvents) include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, t-butyl alcohol, ethylene glycol, propylene glycol, trimethylolpropane, and benzyl. Alcohols having 10 or less carbon atoms such as alcohols; 2-methoxyethyl alcohol, 2-ethoxyethyl alcohol, 1-methoxy-2-propyl alcohol, 1-ethoxy-2-propyl alcohol, 3-methoxy-1-butyl alcohol Alcohols having 10 or less carbon atoms containing an ether bond, such as, 2-isopropoxyethyl alcohol; alcohols having 10 or less carbon atoms containing a ketone group, such as 3-hydroxy-2-butanone; Dorokishiiso number of carbon atoms containing acid ester groups such as methyl or the like is 10 ppm alcohol are exemplified. Examples of the ketone solvent (also referred to as a ketone solvent) include acetone, methyl ethyl ketone, cyclohexanone, γ-butyl lactone, and N-methylpyrrolidinone. In the present invention, it is preferable to use a monohydric alcohol having 10 or less carbon atoms because the remaining carboxyalkylamino group-containing compound can be efficiently removed. preferable.

The present invention relates to porous particles having a specific surface area of 30 [m ² / g] or more by contacting crude polyarylene sulfide with water and the organic solvent one or more times, and contacting the same. Preferably, the porous particles have a range of 43 m ² / g or more and 200 m ² / g or less, more preferably 60 m ² / g or more and 120 m ² / g or less. Range of porous particles.

好ましい By making the coarse polyarylene sulfide into porous particles having such a specific surface area range, the carboxyalkylamino group-containing compound in the crude polyarylene sulfide can be easily reduced, which is preferable. At that time, the carboxyalkylamino group-containing compound contained in the crude polyarylene sulfide is preferably in the range of 1000 ppm or less per g of the polyarylene sulfide, more preferably 400 ppm or less, and 1 ppm or more. It is preferable to set the content in the range described above, because the effect of reducing impurities, particularly alkali metal halides, by washing with carbonated water described later becomes more excellent.

The present invention has a step of subsequently contacting the obtained porous particles with carbonated water.

In the present invention, the conditions for bringing the porous particles obtained in the previous step into contact with carbonated water are preferably 10 ° C. or higher, more preferably 20 ° C. or higher, preferably 100 ° C. or lower, more preferably 80 ° C. or lower. And the pressure (gauge pressure) is lower than 0.1 MPa, preferably lower than 0.05 MPa, more preferably under atmospheric pressure. If the conditions of temperature and pressure are within these ranges, in addition to the effects of excellent quality, in particular, the improvement of the mechanical properties by improving the reactivity with the epoxysilane-based silane coupling agent, the shortening of the isothermal crystallization time, etc. It is preferable because a polyarylene sulfide having a reduced impurity concentration such as an alkali metal halide or a compound containing a carboxyalkylamino group in the polyarylene sulfide can be obtained. For example, the ratio of the alkali metal halide in the polyarylene sulfide is preferably not more than 1000 ppm, more preferably not more than 700 ppm, and still more preferably not more than 500 ppm, per gram of the polyarylene sulfide. Can be reduced to The lower limit is not particularly limited, but is 20 ppm or more. Further, for example, the ratio of the compound (1) represented by the structural formula (1) is preferably 1000 [ppm] or less, more preferably 500 [ppm] or less, and still more preferably 300 / g / g of the polyarylene sulfide. It can be reduced to the range of [ppm] or less. The lower limit is not particularly limited, but is preferably 50 ppm or more.

One of the advantages of the present invention is that when the purification method using carbonated water of the present invention is used, there is almost no corrosion to metals under ordinary purification temperature conditions (100 ° C. or less), and the present apparatus can cope. In addition, since relatively inexpensive materials having corrosion resistance of about SUS304 can withstand corrosion, only the equipment cost advantage from the material side of the apparatus as compared with other acids can be mentioned. In addition, since it is not necessary to use a pressure-resistant container, it is preferable because it is excellent not only in equipment cost but also in maintainability and safety.

One of the advantages of the present invention is that when other acids remain in the polyarylene sulfide (especially chloride ions and sulfate ions are likely to remain in the polymer), mold corrosion during molding and molding of the molded product may occur. Although it is a major cause of deterioration in physical properties, in the case of the purification method using carbonated water of the present invention, it is easy to remove even in a water washing step which is a later step, and it is also decomposed and scattered from polyarylene sulfide even in a drying step, so other It is difficult to cause corrosion of molds such as acids and deterioration of physical properties of molded products.

Further, one of the advantages of the present invention is that when a strong acid other than carbonated water is used, a large amount of water and the number of times of washing are required after washing with the strong acid in order to remove the acid remaining in the polyarylene sulfide. In contrast, in the case of the purification method using carbonated water according to the present invention, the amount of water used after washing with carbonated water can be reduced, and the number of times of washing can be reduced. Therefore, this method is very advantageous in terms of process capability, and can be said to be a method suitable for environmental measures.

The present invention provides a polyarylene by contacting an aqueous solution in which the solubility of carbonic acid is controlled by controlling the pressure and temperature of the system by blowing carbon dioxide gas into an airtight container or apparatus, for a suitable period of time (eg, 5 minutes or longer). A purification method characterized in that the molecular end of sulfide is converted from a basic end (SNa type end) to an acidic end (SH type end), wherein the SNa group present at the molecular chain end of polyarylene sulfide is SH. To increase the affinity with other resins.

濃度 The concentration of carbon dioxide (derived carbonate ions) in carbonated water depends on the solubility of carbon dioxide in water, and more specifically follows Henry's law at the temperature and pressure. As a method for producing carbonated water, carbon dioxide gas may be bubbled into water in an open container or a closed container or piping, or may be press-fitted, or continuously using a hollow fiber membrane module or the like. Carbon dioxide may be dissolved in water.

固形 When the carbonated water of the present invention is brought into contact with the porous particles for purification, the solid content concentration in the system is preferably a ratio of 1 to 50% by weight. When the solid content is within this range, the contact between the polyarylene sulfide particles and the carbonated water is favorably performed, and the purification efficiency is suitable and more preferable. The amount of carbonated water is not particularly limited, but is preferably 50 to 10,000 parts by mass, more preferably 100 to 5,000 parts by mass, and still more preferably 200 to 2,000 parts by mass, per 100 parts by mass of polyarylene sulfide. When the amount of carbonated water is within this range, the contact between the polyarylene sulfide particles and the carbonated water is performed favorably, and the purification efficiency is suitable and more preferable.

According to the present invention, the contact between carbonated water and porous particles of polyarylene sulfide can be performed in an open-type container having a stirring blade inside the container and a filter disposed at the bottom at the bottom. It is not necessary to carry out in a hermetically sealed or hermetically sealed container having a mixing function, but naturally it can also be carried out in such a container.

Incidentally, the embodiment of the present invention is, as described above, in an organic polar solvent, after desolvating a crude reaction product containing a polyarylene sulfide obtained by reacting a polyhalo aromatic compound with a sulfidizing agent, A polyarylene sulfide having a specific surface area of 30 [m ² / g] or more by contacting with an organic solvent to form porous particles, and contacting the obtained porous particles with carbonated water. It relates to a purification method.

一つ Another embodiment of the present invention relates to a method for producing polyarylene sulfide, comprising a step of purifying polyarylene sulfide by the purification method.

(4) The polyarylene sulfide obtained through the purification method of the present invention may be dried as it is, or may be appropriately washed with water or an organic solvent, then solid-liquid separated and dried.

Drying is performed by heating to a temperature at which a solvent such as water is substantially evaporated. Drying may be performed under vacuum, or may be performed in air or under an inert atmosphere such as nitrogen.

The polyarylene sulfide obtained by the production method of the present invention can be used as it is for conventional molding materials and the like, but can be thickened by heat treatment in air or oxygen-enriched air or under reduced pressure. After performing such a thickening operation as needed, it may be used for various molding materials. Since the heat treatment temperature varies depending on the treatment time and the atmosphere in which the treatment is performed, it cannot be unconditionally specified. If the heat treatment temperature is lower than 180 ° C., the rate of thickening is extremely slow, and the productivity is poor, which is not preferable. The heat treatment may be performed in a molten state at a temperature higher than the melting point of the polymer using an extruder or the like. However, from the viewpoint of the possibility of deterioration of the polymer or workability, it is preferable to carry out the reaction at a temperature higher than the melting point plus 100 ° C.

The polyarylene sulfide obtained by the present invention is, as in the past, blended with a filler or other resin, melt-kneaded, directly or once formed into pellets, and then subjected to injection molding, extrusion molding, compression molding, blow molding. By various melt processing methods as described above, a molded article having excellent heat resistance, moldability, dimensional stability, and the like can be obtained. However, in order to further improve the performance such as strength, heat resistance and dimensional stability, it is also possible to use in combination with various fillers as long as the object of the present invention is not impaired. Examples of the filler include a fibrous filler and an inorganic filler. In addition, a small amount of a mold release agent, a colorant, a heat stabilizer, an ultraviolet stabilizer, a foaming agent, a rust inhibitor, a flame retardant, a lubricant, a cup as an additive during the molding process without departing from the object of the present invention. A ring agent can be included. Further, similarly, the following synthetic resins and elastomers can be mixed and used. As these synthetic resins, polyester, polyamide, polyimide, polyetherimide, polycarbonate, polyphenylene ether, polysulfone, polyethersulfone, polyetheretherketone, polyetherketone, polyarylene, polyethylene, polypropylene, polytetrafluoroethylene, Examples thereof include polydifluoroethylene, polystyrene, ABS resin, epoxy resin, silicone resin, phenol resin, urethane resin, and liquid crystal polymer. Examples of the elastomer include polyolefin rubber, fluorine rubber, and silicone rubber.

A molded article obtained by melt-molding the polyarylene sulfide of the present invention or a resin composition containing the same has excellent heat resistance, dimensional stability and the like as PPS obtained by a conventional method. Electric and electronic parts such as molded parts, automotive parts such as lamp reflectors and various electrical parts, interior materials for various buildings, aircraft and automobiles, and precision parts such as OA equipment parts, camera parts, watch parts, etc. It can be widely used as injection molded / compressed molded products, or extruded / pull molded products such as fibers, films, sheets and pipes.

(4) The present invention will be specifically described below with reference to examples. These examples are illustrative and not limiting.

(Measurement Method 1) Determination of CP-MABA Concentration in Polyarylene Sulfide Resin (1) Extraction of CP-MABA in Polyarylene Sulfide: A 0.05% aqueous solution of NaOH was added 20 times to the polyarylene sulfide, The temperature was raised to 200 ° C., the mixture was heated for 30 minutes, and solid-liquid separation was performed to extract CP-MABA in the polyarylene sulfide resin into the filtrate.

(2) [Method for measuring CP-MABA]
The concentration of CP-MABA in the obtained filtrate was determined by performing HPLC measurement on the filtrate sample prepared in (1) and determining the peak area and the calibration curve of the same retention time as the standard sample prepared by the following method. The concentration was determined and calculated.

(Sample preparation)
CP-MABA in the filtrate was prepared by adding the mobile phase as it was and measured.

(Standard sample: synthesis of CP-MABA)
83.4 g (1.0 mol) of a 48% aqueous NaOH solution and 297.4 g (3.0 mol) of N-methyl-2-pyrrolidone were charged into a pressure-resistant vessel equipped with a stirrer, and stirred at 230 ° C. for 3 hours. After completion of the stirring, the valve was opened at 230 ° C. and the pressure was released, and the pressure was reduced to 0.1 MPa at 230 ° C., which is about the vapor pressure of N-methyl-2-pyrrolidone, and water was distilled off. Then, it was closed again and the temperature was lowered to about 200 ° C.

147.0 g (1.0 mol) of p-dichlorobenzene was dissolved by heating under a temperature condition of 60 ° C. or higher, added to the reaction mixture, heated to 250 ° C., and stirred for 4 hours. After the stirring was completed, the mixture was cooled to room temperature. The conversion of p-dichlorobenzene was 31 mol%. After cooling, the content was taken out, water was added and the mixture was stirred, and the unreacted p-dichlorobenzene, which became insoluble, was removed by filtration.

Next, hydrochloric acid was added to the aqueous solution as a filtrate to adjust the pH of the aqueous solution to 4. At this time, brown oily CP-MABA (hydrogen type) was formed in the aqueous solution. Chloroform was added thereto to extract a brown oily substance. At this time, the aqueous phase was discarded because it contained N-methyl-2-pyrrolidone and its ring-opened product, 4-methylaminobutyric acid (hereinafter abbreviated as "MABA"). The chloroform phase was washed twice with water.

(4) In a state where water was added to the chloroform phase to form a slurry, a 48% aqueous solution of NaOH was added to adjust the pH of the slurry to 13. At this time, CP-MABA was transferred to the aqueous phase as a sodium salt, and the chloroform phase was discarded because by-products p-chloro-N-methylaniline and N-methylaniline were dissolved in the chloroform phase. The aqueous phase was washed twice with chloroform.

(4) Dilute hydrochloric acid was added to the aqueous solution to adjust the pH of the aqueous solution to 1 or less. At this time, since CP-MABA becomes a hydrochloride and remains in the aqueous solution, chloroform was added to the aqueous solution to extract p-chlorophenol as a by-product. The chloroform phase in which p-chlorophenol was dissolved was discarded.

(4) A 48% aqueous NaOH solution was added to the remaining aqueous solution to adjust the pH of the aqueous solution to 4. As a result, the hydrochloride of CP-MABA was neutralized, and brown oily CP-MABA (hydrogen type) was precipitated from the aqueous solution. CP-MABA (hydrogen type) was extracted with chloroform, and chloroform was removed under reduced pressure to obtain CP-MABA (hydrogen type).

(HPLC measurement)
From the well stirred solution, 1 ml was sampled, and 9 ml of the HPLC mobile phase was added thereto, and the filtrate was used as a measurement sample. The measurement sample was subjected to HPLC measurement, and the concentration in the liquid was determined from the peak area and the calibration curve at the same retention time as the standard sample prepared by the following method. The HPLC measurement conditions are as follows.
Apparatus name: "High Performance Liquid Chromatogram Prominence" manufactured by Shimadzu Corporation
Column: "Phenomenex Luna 5u C18 (2) 100A" manufactured by Shimadzu GLC
Detector: DAD (Diode Array Detector)
Data processing: "LCsolution" manufactured by Shimadzu Corporation
Measurement conditions: Column temperature 40 ° C
Mobile phase: methanol / acetic acid aqueous solution 1 vol% = 6/4 (vol ratio)
Flow rate: 1.0 ml / min

(Measurement Method 2) Method of Analyzing Specific Surface Area (BET Specific Surface Area) Tristar II3020 manufactured by Shimadzu Corporation was used for measuring the specific surface area. After the sample was put into the cell, it was degassed, replaced with helium, cooled, and replaced with nitrogen to measure the specific surface area.

(Measurement Method 3) Sodium Concentration in Polyarylene Sulfide Polyarylene sulfide powder is weighed in a platinum crucible, and concentrated sulfuric acid (atomic absorption grade) is immersed in the powder, and smoke is emitted with a stove HP-103K made by TOSHIBA. The mixture was heated until it could be confirmed that almost all had disappeared and ash had occurred. Thereafter, the mixture was heated in a muffle furnace at 700 ° C. for 5 hours to completely incinerate. The ash was dissolved therein with 1% hydrochloric acid and pure water, and the solution was analyzed for the amount of sodium with an atomic absorption spectrophotometer to determine the amount of sodium in the polyarylene sulfide. The water used in this operation had a conductivity of 18.2 MΩ · cm.

[Synthesis Example 1] Polymerization step of polyphenylene sulfide 33.222 kg (226 mol) of p-dichlorobenzene (hereinafter abbreviated as DCB) was placed in a 150 L autoclave equipped with a stirrer equipped with a pressure gauge, a thermometer, a condenser, a decanter, and a rectification tower, 2.280 kg (23 mol) of NMP, 27.300 kg (230 mol) of 47.23 mass% sodium hydrogen sulfide, and 18.533 kg (228 mol) of 49.21 mass% caustic soda were charged and stirred to 173 ° C. under a nitrogen atmosphere for 5 hours. After heating and distilling 27.3 kg of water, the kettle was sealed. The DCB distilled off azeotropically during the dehydration was separated by a decanter and returned to the kettle at any time. After the completion of the dehydration, the anhydrous sodium sulfide composition was dispersed in the DCB. Furthermore, the internal temperature was cooled to 160 ° C, NMP 47.492 kg (479 mol) was charged, and the temperature was raised to 185 ° C. When the pressure reached 0.00 MPa, the valve connected to the rectification column was opened, and the internal temperature was raised to 200 ° C. over 1 hour. At this time, cooling and valve opening were controlled so that the outlet temperature of the rectification column was 110 ° C. or lower. The mixed vapor of the distilled DCB and water was condensed by a condenser, separated by a decanter, and the DCB was returned to the kettle. The amount of distilled water was 179 g. Next, the internal temperature was raised from 200 ° C. to 230 ° C. over 3 hours, and after stirring for 1 hour, the temperature was raised to 250 ° C. and stirred for 1 hour. After the reaction was completed, the internal temperature of the autoclave was raised from 250 ° C. to 235 ° C. After cooling to ℃, the bottom valve of the autoclave was opened, and the system was flushed to 150 liter vacuum stirring dryer equipped with stirring blades (desolvator jacket temperature: 120 ° C) with reduced pressure to remove N-methyl-2-pyrrolidone. After cooling to room temperature and sampling, a PPS mixture having an NV of 55% was obtained.

(Example 1)
400 g of the PPS mixture obtained in Synthesis Example 1 and 634 g of isopropyl alcohol were placed in a flask and mixed by stirring at 40 ° C. for 30 minutes. The slurry was filtered under reduced pressure with a Kiriyama funnel, compacted from above, and 422 g of isopropyl alcohol was further added from above. The mixture was poured into portions and filtered. Further, the cake prepared by the filtration was transferred to a beaker, crushed into a powder with a spoonful, 634 g of water at 70 ° C. was poured therein, and the mixture was stirred and mixed for 30 minutes. The slurry was filtered under reduced pressure with a Kiriyama funnel, compacted from above, and 845 g of water at 70 ° C. was poured from the top into several portions and filtered. 8 g of the cake was crushed, sampled, dried in a hot air drier at 120 ° C. for 4 hours, and the resin content was analyzed. As a result, the specific surface area was 79 [m ² / g], and the content of CP-MABA in the resin Was 207 [ppm]. The cake was transferred to a beaker, and 636 g of carbonated water was poured into the beaker and mixed with stirring for 1 hour. The slurry was filtered under reduced pressure with a Kiriyama funnel, compacted from above, and 848 g of carbonated water was poured from above in several portions and filtered. The cake produced by the filtration was transferred to a vat, crushed into powder with a spoon, and dried at 120 ° C. for 4 hours. As a result of analyzing the amount of sodium in the obtained resin, it was 300 [ppm].

(Example 2)
317 g of methanol was used instead of 634 g of isopropyl alcohol, and 634 g of methanol was used instead of 422 g of isopropyl alcohol, and the rest was carried out under the same conditions as in Example 1. As a result of analyzing the sampled resin, the specific surface area was 83 [m ² / g], and the content of CP-MABA in the resin was 52 [ppm]. Further, the amount of carbonated water was changed to 845 g instead of 636 g, and the other conditions were the same as in Example 1. As a result of analyzing the amount of sodium in the obtained resin, it was 290 [ppm].

(Example 3)
The amount of isopropyl alcohol was changed from 634 g to 1056 g, the amount of isopropyl alcohol was changed from 422 g to 845 g, and the rest was carried out under the same conditions as in Example 1. As a result of analyzing the sampled resin, the specific surface area was 75 [m ² / g], and the content of CP-MABA in the resin was 125 [ppm]. Further, the amount of carbonated water was changed to 1584 g instead of 636 g, and the other conditions were the same as in Example 1. As a result of analyzing the amount of sodium in the obtained resin, it was 200 [ppm].

(Example 4)
The procedure was performed under the same conditions as in Example 1 except for using 221 g of ethanol instead of 634 g of isopropyl alcohol and 422 g of ethanol instead of 422 g of isopropyl alcohol. As a result of analyzing the sampled resin, the specific surface area was 60 [m ² / g], and the content of CP-MABA in the resin was 450 [ppm]. Thereafter, the steps were performed under the same conditions as in Example 1. As a result of analyzing the amount of sodium in the obtained resin, it was 230 [ppm].

(Example 5)
845 g of acetone was used instead of 634 g of isopropyl alcohol, and 845 g of acetone was used instead of 422 g of isopropyl alcohol, and the rest was performed under the same conditions as in Example 1. As a result of analyzing the sampled resin, the specific surface area was 43 [m ² / g], and the content of CP-MABA in the resin was 399 [ppm]. The amount of carbonated water was changed to 845 g instead of 636 g, and the amount of carbonated water was changed to 1267 g instead of 848 g. As a result of analyzing the amount of sodium in the obtained resin, it was 340 [ppm].

(Example 6)
1056 g of ethanol was used instead of 634 g of isopropyl alcohol, and 845 g of ethanol was used instead of 422 g of isopropyl alcohol, and the rest was performed under the same conditions as in Example 1. As a result of analyzing the sampled resin, the specific surface area was 102 [m ² / g], and the content of CP-MABA in the resin was 57 [ppm]. The amount of carbonated water was 422 g instead of 636 g, and the amount of carbonated water was 422 g instead of 848 g. As a result of analyzing the amount of sodium in the obtained resin, it was 380 [ppm].

(Example 7)
The procedure was carried out under the same conditions as in Example 1, except that 634 g of isopropyl alcohol was replaced by 211 g of methanol, and 422 g of isopropyl alcohol was replaced by 422 g of methanol. As a result of analyzing the sampled resin, the specific surface area was 75 [m ² / g], and the content of CP-MABA in the resin was 187 [ppm]. The amount of carbonated water was 422 g instead of 636 g, and the amount of carbonated water was 1267 g instead of 848 g. As a result of analyzing the amount of sodium in the obtained resin, it was 350 [ppm].

(Comparative Example 1)
845 g of toluene was used instead of 634 g of isopropyl alcohol, and 422 g of toluene was used instead of 422 g of isopropyl alcohol, and the rest was carried out under the same conditions as in Example 1. As a result of analyzing the sampled resin, the specific surface area was 45 [m ² / g], and the content of CP-MABA in the resin was 1,398 [ppm]. The amount of carbonated water was changed to 845 g instead of 636 g, and the amount of carbonated water was changed to 845 g instead of 848 g. As a result of analyzing the amount of sodium in the obtained resin, it was 870 [ppm].

(Comparative Example 2)
Methyl isobutyl ketone was used instead of isopropyl alcohol, and mesoisobutyl ketone was used instead of isopropyl alcohol. The remainder was performed under the same conditions as in Example 1. As a result of analyzing the sampled resin, the specific surface area was 13 [m ² / g], and the content of CP-MABA in the resin was 350 [ppm]. The amount of carbonated water was changed to 845 g instead of 636 g, and the amount of carbonated water was changed to 1267 g instead of 848 g. As a result of analyzing the amount of sodium in the obtained resin, it was 900 [ppm].

(Comparative Example 3)
400 g of the PPS mixture obtained in Synthesis Example 1 was transferred to a beaker, crushed into a powder with a spoon, and 848 g of 70 ° C. water was poured into the beaker, followed by stirring and mixing for 30 minutes. The slurry was filtered under reduced pressure with a Kiriyama funnel, compacted from above, and then 845 g of 70 ° C. water was poured from above into several portions and filtered. The cake was crushed, 8 g was sampled, dried with a hot air dryer at 120 ° C. for 4 hours, and the resin was analyzed. As a result, the specific surface area was 78 [m ² / g], and the content of CP-MABA in the resin was It was 3246 [ppm]. The cake was transferred to a beaker, 845 g of carbonated water was poured therein, and the mixture was stirred and mixed for 1 hour. The slurry was filtered under reduced pressure with a Kiriyama funnel, compacted from above, and further filtered and poured from above with 1267 g of carbonated water in several portions. The cake produced by the filtration was transferred to a vat, crushed into powder with a spoon, and dried at 120 ° C. for 4 hours. As a result of analyzing the amount of sodium in the obtained resin, it was 930 [ppm].

(Comparative Example 4)
400 g of the PPS mixture obtained in Synthesis Example 1 was heated to 150 ° C. by a heating vacuum dryer and reduced in pressure to remove NMP. The remaining solid was transferred to a beaker, crushed into a powder form with a spoonful, and 848 g of water at 70 ° C. was poured into the powder and mixed with stirring for 30 minutes. The slurry was filtered under reduced pressure with a Kiriyama funnel, compacted from above, and 845 g of water at 70 ° C. was poured from the top into several portions and filtered. Further, the collected cake was sealed by adding 634 g of water to an autoclave made of SUS, heated to 120 ° C., and held for 30 minutes. Thereafter, the temperature was lowered to room temperature, the slurry was filtered under reduced pressure with a Kiriyama funnel, compacted from above, and 845 g of 70 ° C. water was poured from above into several portions and filtered. The cake was crushed, 8 g was sampled, dried by a hot air drier at 120 ° C. for 4 hours, and the resin was analyzed. As a result, the specific surface area was 8 [m ² / g], and the content of CP-MABA in the resin was It was 849 [ppm]. The cake was transferred to a beaker, 845 g of carbonated water was poured therein, and the mixture was stirred and mixed for 1 hour. The slurry was filtered under reduced pressure with a Kiriyama funnel, compacted from above, and further filtered and poured from above with 1267 g of carbonated water in several portions. The cake produced by the filtration was transferred to a vat, crushed into powder with a spoon, and dried at 120 ° C. for 4 hours. As a result of analyzing the amount of sodium in the obtained resin, it was 1200 [ppm].

Claims

In an organic polar solvent, a step of obtaining a slurry containing crude polyarylene sulfide by desolvating a crude reaction product containing polyarylene sulfide obtained by reacting a polyhalo aromatic compound with a sulfide agent, The slurry containing the crude polyarylene sulfide is brought into contact with water and a solvent containing an oxygen atom having 1 to 3 carbon atoms to make the crude polyarylene sulfide have a specific surface area of 30 [m 2 / g] or more. And a step of bringing the obtained porous particles into contact with carbonated water. A method for purifying polyarylene sulfide.
The purification method according to claim 1, wherein the porous particles of polyarylene sulfide are brought into contact with carbonated water under a pressure of less than 0.1 MPa.
The method according to claim 1 or 2, wherein the porous particles of polyarylene sulfide are brought into contact with carbonated water at a temperature of 60 ° C or lower.
4. The method according to claim 1, wherein a ratio of the compound (1) represented by the following structural formula (1) contained in the porous particles is in a range of 1000 ppm or less per 1 g of the polyarylene sulfide. The purification method according to claim 1.
The purification method according to any one of claims 1 to 4, wherein the organic solvent is an alcohol solvent or a ketone solvent.
A method for producing polyarylene sulfide, comprising a step of purifying polyarylene sulfide by the purification method according to any one of claims 1 to 5.