JP5794468B2 - Method for producing polyarylene sulfide resin - Google Patents

Description

  The present invention relates to a method for producing a polyarylene sulfide resin including a purification step of a polyarylene sulfide resin (hereinafter sometimes abbreviated as PAS).

Among polyarylene sulfide resins, typical polyphenylene sulfide resins (hereinafter sometimes abbreviated as PPS) are represented by alkali metal sulfides typified by sodium sulfide or sodium hydrosulfide in polar organic solvents. It can be obtained by a method of reacting an alkali metal hydrosulfide, an alkali metal hydroxide typified by sodium hydroxide, and a polyhaloaromatic compound typified by p-dichlorobenzene.
The polyarylene sulfide resin is subjected to various purification treatments to remove impurities in the resin after solid-liquid separation of the crude reaction mixture after the polymerization reaction and the solvent is distilled off, but it is simply washed with water and filtered. However, there is a problem that the content of metal ions such as sodium ions present at the molecular ends of the polyarylene sulfide resin is high, and the crystallization time is long during the molding process, resulting in low productivity.

  Therefore, after the solid reaction separation of the crude reaction mixture after the polymerization reaction of the polyarylene sulfide resin, carbon dioxide gas or carbonated water is introduced into the system, and the carbon dioxide gas or carbonated water and the polyarylene sulfide resin are brought into contact with each other. Known (see Patent Documents 1 and 2). However, this method is to convert the basic type terminal (SNa type terminal) of the polyarylene sulfide resin into the acidic type terminal (SH) using carbonate ions generated by dissolving carbon dioxide in water, and the processing time. However, this method is inferior in productivity because it takes a long time.

  Also known is a method in which a crude reaction mixture after polymerization reaction of polyarylene sulfide resin is subjected to solid-liquid separation, and then at least one acid selected from water and inorganic acids and organic acids is added, followed by acid cleaning at high temperature ( (See Patent Document 3). However, such a method of adding an acid at the time of refining causes an increase in cost due to an increase in the number of raw materials and production facilities, and causes a decrease in productivity.

JP 2002-187949 A JP 2005-264030 A JP 2009-280637 A

  Therefore, the problem to be solved by the present invention is to obtain a polyarylene sulfide resin having a low metal ion content, which can be obtained by refining in a short time without performing acid addition. It is providing the manufacturing method of sulfide resin.

  As a result of various studies, the inventors of the present application have used polyarylene sulfide utilizing a trace amount of raw material (alkali metal hydrosulfide and its oxide) remaining in the crude reaction mixture after the polymerization reaction of polyarylene sulfide resin. The inventors have found that a polyarylene sulfide resin having a low metal ion content can be obtained by a simple means of performing terminal modification of a resin molecular chain, and have completed the present invention.

  That is, the present invention relates to polyarylene by reacting a polyhaloaromatic compound with (i) an alkali metal sulfide or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide in an organic polar solvent. After obtaining a crude reaction mixture containing a sulfide resin and an alkali metal hydrosulfide, the solvent is solid-liquid separated from the crude reaction mixture to obtain a polyarylene sulfide resin, an alkali metal hydrosulfide, a sulfur atom and its allotrope, and an alkali thiosulfate Obtaining a reaction mixture containing at least one selected from metals, and then bringing the reaction mixture into contact with water under oxygen pressure conditions in the range of oxygen pressure 0.02-0.2 [MPa] To a process for producing a polyarylene sulfide resin.

  According to the present invention, a polyarylene sulfide resin having a low metal ion content can be obtained by refining in a short time without adding an acid, and a method for producing a polyarylene sulfide resin comprising a purification step of polyarylene sulfide. Can provide.

  The present invention provides a reaction mixture of a polyhaloaromatic compound and an alkali metal sulfide in an organic polar solvent to obtain a crude reaction mixture containing a polyarylene sulfide resin and an alkali metal hydrosulfide, or a polyhaloaromatic compound and An alkali metal hydrosulfide and an alkali metal hydroxide are reacted to obtain a crude reaction mixture containing a polyarylene sulfide resin and an alkali metal hydrosulfide.

  The polyhaloaromatic 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 includes p-dichlorobenzene, o-dioxy. Chlorobenzene, m-dichlorobenzene, trichlorobenzene, tetrachlorobenzene, dibromobenzene, diiodobenzene, tribromobenzene, dibromonaphthalene, triiodobenzene, dichlorodiphenylbenzene, dibromodiphenylbenzene, dichlorobenzophenone, And dihaloaromatic compounds such as dibromobenzophenone, dichlorodiphenyl ether, dibromodiphenyl ether, dichlorodiphenyl sulfide, dibromodiphenyl sulfide, dichlorobiphenyl, dibromobiphenyl, and mixtures thereof. The compound may be block copolymerized. Of these, dihalogenated benzenes are preferred, and those containing p-dichlorobenzene of 80 mol% or more are particularly preferred.

  Further, for the purpose of increasing the viscosity of the polyarylene sulfide resin by using a branched structure, a polyhaloaromatic compound having 3 or more halogen substituents in one molecule may be used as a branching agent as desired. Examples of such polyhaloaromatic compounds include 1,2,4-trichlorobenzene, 1,3,5-trichlorobenzene, 1,4,6-trichloronaphthalene, and the like.

  Furthermore, polyhaloaromatic compounds having a functional group having active hydrogen such as amino group, thiol group, hydroxyl group can be mentioned. Specifically, 2,6-dichloroaniline, 2,5-dichloroaniline 2,4-dichloroaniline, 2,3-dichloroaniline and other dihaloanilines; 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′-dichlorodiphenyl ether and 2,4′-diamino-2 ′, 4-dichlorodiphenyl ether Examples thereof include compounds in which the amino group is replaced by a thiol group or a hydroxyl group in a mixture thereof.

  In addition, active hydrogen-containing polyhalo compounds in which the hydrogen atom bonded to the carbon atom forming the aromatic ring in these active hydrogen-containing polyhaloaromatic compounds is substituted with another inert group, for example, a hydrocarbon group such as an alkyl group. Aromatic compounds can also be used.

  Among these various active hydrogen-containing polyhaloaromatic compounds, an active hydrogen-containing dihaloaromatic compound is preferable, and dichloroaniline is particularly preferable.

  Examples of the polyhaloaromatic 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; dihalonitrodiphenyl sulfones such as 3,3′-dinitro-4,4′-dichlorodiphenyl sulfone; 2,5-dichloro-3-nitropyridine, 2-chloro-3,5 -Mono or dihalonitropyridines such as dinitropyridine; or various dihalonitronaphthalenes.

  Examples of the alkali metal sulfide used in the present invention include lithium sulfide, sodium sulfide, rubidium sulfide, cesium sulfide, and mixtures thereof. Such alkali metal sulfides can be used as hydrates, aqueous mixtures or anhydrides. The alkali metal sulfide can also be derived from the reaction between an alkali metal hydrosulfide and an alkali metal hydroxide.

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

  Examples of the organic polar solvent used in the present invention include formamide, acetamide, N-methylformamide, N, N-dimethylacetamide, tetramethylurea, N-methyl-2-pyrrolidone, 2-pyrrolidone, and N-methyl-ε-caprolactam. , Ε-caprolactam, hexamethylphosphoramide, N-dimethylpropyleneurea, amides such as 1,3-dimethyl-2-imidazolidinone, urea and lactams; sulfolanes such as sulfolane and dimethylsulfolane; benzonitrile and the like Nitriles; ketones such as methyl phenyl ketone and mixtures thereof, among which N-methyl-2-pyrrolidone, 2-pyrrolidone, N-methyl-ε-caprolactam, ε-caprolactam, hexamethyl Phosphoramide, N-dimethylpro Ren urea, 1,3-dimethyl-2-amide having an aliphatic cyclic structure imidazolidinone acid.

  In the presence of these organic polar solvents, the polymerization reaction of the polyarylene sulfide resin is carried out by combining the above-mentioned alkali metal sulfide or alkali metal hydrosulfide and alkali metal hydroxide called a sulfidizing agent with a polyhaloaromatic compound. React. The polymerization conditions are generally in the range of 200 to 330 ° C., and the pressure should be in such a range that the polymerization solvent and the polymerization monomer polyhaloaromatic compound are substantially retained in the liquid layer. It is selected from the range of 1-20 MPa, preferably from the range of 0.1-2 MPa.

  As one specific embodiment of the method for producing the polyarylene sulfide resin used in the present invention, for example, in the presence of a polyhaloaromatic compound, an alkali metal sulfide, or a hydrous alkali metal hydrosulfide and an alkali metal hydroxide are used. , A step of producing a slurry containing solid alkali metal sulfide by reacting amide, urea or lactam having an aliphatic cyclic structure while dehydrating, and further producing a polar organic solvent such as NMP after the slurry is produced. In addition, a step of dehydrating by distilling off water, and then in a slurry obtained through the dehydration step, a polyhaloaromatic compound, an alkali metal hydrosulfide, an amide having an aliphatic cyclic structure, urea or The alkali metal salt of the lactam hydrolyzate is present in an amount of 0.02 mol of water present in the reaction system with respect to 1 mol of a polar organic solvent such as NMP. Method for producing a polyarylene sulfide resin having a step of performing the polymerization by reacting the following as essential production steps and the like.

  In the present invention, a form in which the crude reaction product is reacted in the presence of a sulfidizing agent and an organic polar solvent while continuously or intermittently adding a polyhaloaromatic compound and an organic polar solvent is also included.

  After the polymerization of the polyarylene sulfide resin is completed, the crude reaction mixture containing the polymer, by-products, unreacted substances such as alkali metal salts and alkali metal hydrosulfides, and solvents is subjected to solid-liquid separation to obtain polyarylene sulfide. A reaction mixture containing the resin and alkali metal hydrosulfide is recovered. There are roughly two types of recovery methods: a flash method and a quench method described later. The flash method is a method of recovering the solvent by evaporating the solvent and simultaneously recovering the solid matter, while the quench method is a method of recovering the particulate polyarylene sulfide resin by cooling the polymerization reaction product. is there. The flash method is preferable in that a solid can be recovered relatively easily, and the quench method is preferable in that the particle size of the polyarylene sulfide resin can be easily controlled.

The reaction mixture used in the present invention may be obtained by subjecting the crude reaction mixture to solid-liquid separation and then washing with water, for example, polyarylene sulfide resin and alkali metal recovered by solid-liquid separation. The hydrosulfide may be obtained by slurrying with water and then washing with water as necessary. The water washing can be repeated once or a plurality of times under the condition of 20 to 100 ° C. in a nitrogen or air atmosphere. When water washing is repeated a plurality of times, the atmosphere and temperature conditions may be the same or different. Incidentally, when the water washing in an air atmosphere, a portion of the alkali metal hydrosulfide (MSH) is oxidized, a sulfur atom (S), (such as S ₈₎ allotrope thereof, thiosulfate alkali metal (M ₂ S ₂ O ₃ ) and other oxides may be produced. Since the alkali metal hydrosulfide or its oxide serves as a precursor of the active material in the purification step described later, the solid-liquid separation and water washing step removes the alkali metal salt as much as possible while reducing the effective component amount of alkali metal. Adjusting so that hydrosulfide or its oxide (S, S ₈ , M ₂ S ₂ O _3, etc.) remains is performed. The residual amount of the alkali metal hydrosulfide or its oxide is not particularly limited as long as the predetermined purification effect can be obtained, but if the residual amount is small, it is difficult to obtain the predetermined purification effect, When the residual amount is large, the polyarylene sulfide resin is decomposed, so the amount is in the range of 0.1 to 300 [μmol], preferably in the range of 1 to 200 [μmol], more preferably 10 to 10 g per 1 g of the polyarylene sulfide resin. It adjusts so that it may become the range of 100 [micromol].

  The reaction mixture containing the polyarylene sulfide resin and the alkali metal hydrosulfide or its oxide obtained by performing the above-described solid-liquid separation and water washing as necessary is subsequently subjected to an oxygen pressure of 0.02 to 0.1. The polyarylene sulfide resin is purified by contacting with water under oxygen pressure conditions in the range of [MPa].

As oxygen to be pressurized, only oxygen (O ₂ ) may be used, or a mixed gas with an inert gas such as nitrogen gas, argon gas, or neon gas may be used from the viewpoint of safety. Therefore, it is most preferable to use air. The temperature at which the polyarylene sulfide resin and water are brought into contact with each other under oxygen pressurization conditions is not particularly limited as long as it is equal to or higher than room temperature (23 ° C.) that exerts an effect of reducing the content of metal ions in the polyarylene sulfide resin. Specifically, since the effect of reducing the content of metal ions in the polyarylene sulfide resin is remarkable, it is 100 ° C. or higher, preferably 130 ° C. or higher, more preferably 170 ° C. or higher, more preferably 210 ° C. or higher. . The upper limit of the temperature at this time is not particularly limited, but is preferably less than the melting point of the polyarylene sulfide resin.
The amount of water used when the polyarylene sulfide resin and water are brought into contact with each other under oxygen pressure conditions is not particularly limited as long as water molecules are present as a liquid. If the pressure of the water in the closed system reaches the saturated vapor pressure at that temperature under the oxygen pressure condition, the water exists as a liquid, but in the present invention, it is dissolved in the polyarylene sulfide resin particles and water. In the range of 50 to 2000 parts by mass, and more preferably in the range of 100 to 1000 parts by mass with respect to 100 parts by mass of the polyarylene sulfide resin. Is more preferable, and the range of 200 to 800 parts by mass is even more preferable.

  In the purification conditions of the polyarylene sulfide resin of the present invention, the amount of oxygen to be added varies depending on the type of polyarylene sulfide resin to be purified or the synthesis conditions, and also dissolved in the polyarylene sulfide resin and water. Since it differs depending on the temperature and time of contact with oxygen, etc., it cannot be defined in general, but it is preferable that oxygen is saturated in the aqueous solution to be contacted. Therefore, it is preferable to increase the pressure with oxygen so that the pressure is higher than the vapor pressure of water at the temperature of contact, and the pressure to be increased in this case is in the range of 0.02 MPa to 0.2 MPa. . Furthermore, since a polyarylene sulfide resin having a high crystallization rate can be obtained while exhibiting an excellent predetermined purification effect, the lower limit value of the oxygen pressure is preferably larger than 0.021 MPa, and more preferably 0.04 MPa or more. Is more preferable, and 0.06 MPa or more is most preferable. On the other hand, the upper limit is not particularly limited, but is preferably 0.1 MPa or less from an economical viewpoint. When air is used as the oxygen source, the oxygen partial pressure may be adjusted within the above range. However, in consideration of the oxygen content in the air, it is usually preferably greater than 0.1 MPa, and more preferably 0.2 MPa. The above is more preferable, and 0.3 MPa is most preferable, while the upper limit is preferably 1 MPa or less, and more preferably 0.5 MPa or less.

  In the present invention, the contact between the polyarylene sulfide resin and water under the oxygen pressure condition may be performed continuously or may be performed batchwise.

  The present invention relates to a contact between a polyarylene sulfide resin and water under oxygen-pressurized conditions, a sealed type or a sealable mixture having a stirring blade inside a container and a filter for filtration disposed at the bottom. It can be performed in a functional container. As a schematic configuration diagram of oxygen introduction for carrying out the purification step in the present invention, FIG. 1, FIG. 2, FIG. 3 and the like can be illustrated, but are not limited thereto. Any device may be used as long as it is a sealed type capable of dissolving oxygen in the liquid layer or has a mixing function capable of being sealed, and can achieve the object of the present invention.

The present invention controls the solubility of oxygen in water by blowing oxygen into a closed system such as a closed container or an apparatus and controlling the pressure and temperature in the system. At that time, the sulfur source (SH ⁻ , S, S ₂ O ₃ ^2−, etc.) dissolved in the water is oxidized and sulfuric acid is brought into contact with the alkali metal hydrosulfide or its oxide by bringing water in which oxygen is dissolved. It is considered that ions (SO ₄ ²⁻ ) are generated, and this is brought into contact with the polyarylene sulfide resin for an appropriate time or more (for example, 5 minutes or more), thereby making the molecular end a basic type end (SNa type end). ) To an acidic type terminal (SH type terminal), and the crystallization speed of the polyarylene sulfide resin is improved.

  As described above, the present invention uses the trace amount of raw material (alkali metal hydrosulfide and its oxide) remaining in the slurry containing the polyarylene sulfide resin after the polymerization reaction to modify the terminal end of the polyarylene sulfide resin molecular chain. It is possible to omit the addition of organic acid or inorganic acid in the washing process by a simple means of performing, and polyarylene sulfide resin having a faster crystallization speed than conventional products without increasing costs and loading steel materials. Can be obtained. In addition, a purification process can be performed in a shorter time than when carbonated water or carbon dioxide is used, and a polyarylene sulfide resin having a faster crystallization rate than conventional products can be obtained while improving productivity.

  After the polyarylene sulfide resin is brought into contact with water under oxygen pressure conditions to convert the basic type terminal (SNa type terminal) to the acidic type terminal (SH type terminal), the polyarylene sulfide resin is once Solid-liquid separation. Thereafter, the polyarylene sulfide resin powder may be obtained by drying as it is, or after further washing treatment, solid-liquid separation and drying may be performed to obtain the polyarylene sulfide resin powder.

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

  The cleaning process may be performed with an organic solvent, for example. Examples of the solvent used include organic polar solvents used in the reaction, or ketones such as acetone and methyl ethyl ketone, and solvents such as alcohols such as methanol and ethanol. Washing with an organic solvent is preferably performed with a polar organic solvent used in the polymerization reaction because the removal of the oligomer can be carried out efficiently. In addition, although there is no restriction | limiting in particular in the quantity of the organic solvent used for washing | cleaning, Preferably it is the range of 20-1000 mass parts with respect to 100 mass parts of polyarylene sulfide resin, More preferably, the range of 50-700 mass parts, More preferably, it is the range of 100-500 mass parts.

  The polyarylene sulfide resin powder obtained through the purification step and the drying step in the present invention can be used as it is for various molding materials as it is, but it can be increased by heat treatment in air or oxygen-enriched air or under reduced pressure. Viscosity is possible, and after performing such a thickening operation as necessary, it may be used for various molding materials. This heat treatment temperature varies depending on the treatment time and also varies depending on the atmosphere to be treated, so it cannot be specified unconditionally. However, it is usually preferable to carry out the treatment at 180 ° C. or higher. If the heat treatment temperature is less than 180 ° C., the speed of thickening is very slow and the productivity is poor, which is not preferable. The heat treatment may be performed in a molten state using an extruder or the like above the melting point of the polymer. However, it is preferable to carry out at melting | fusing point plus 100 degrees C or less from the possibility of deterioration of a polymer or workability | operativity.

  The polyarylene sulfide resin powder obtained through the purification process and the drying process in the present invention is melted in various ways such as injection molding, extrusion molding, compression molding, and blow molding as in the conventional method for producing polyarylene sulfide resin. By the processing method, a molded product having excellent heat resistance, molding processability, dimensional stability and the like can be obtained. However, in order to further improve performance such as strength, heat resistance, and dimensional stability, it can be used 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 release agent, a colorant, a heat stabilizer, an ultraviolet stabilizer, a foaming agent, a rust inhibitor, a flame retardant, a lubricant, a cup as long as they do not deviate from the object of the present invention as additives during molding processing A ring agent can be contained. Furthermore, the following synthetic resins and elastomers can also be mixed and used. These synthetic resins include polyester, polyamide, polyimide, polyetherimide, polycarbonate, polyphenylene ether, polysulfone, polyethersulfone, polyetheretherketone, polyetherketone, polyarylene, polyethylene, polypropylene, polytetrafluoroethylene, Examples thereof include poly (difluoroethylene), 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.

  Since the polyarylene sulfide resin and the composition thereof according to the present invention are excellent in heat resistance, dimensional stability and the like, as in the case of the polyarylene sulfide resin obtained by the conventional method, Automotive parts such as electronic parts, lamp reflectors and various electrical parts, interior molding materials such as various buildings and aircrafts and automobiles, or injection molding and compression molded parts such as precision parts such as OA equipment parts, camera parts and watch parts, Alternatively, it can be widely used as extrusion molding, pultrusion molding, etc. for fibers, films, sheets, pipes and the like.

[Synthesis Example 1] Polymerization process of polyphenylene sulfide resin 33.222 kg of p-dichlorobenzene (hereinafter abbreviated as p-DCB) in a 150 liter autoclave with stirring blades connected to a pressure gauge, thermometer, condenser, decanter, and rectifying tower (226 mol), NMP 2.280 kg (23 mol), 47.33% by weight NaSH aqueous solution 27.300 kg (230 mol), and 49.21% by mass NaOH aqueous solution 18.533 kg (228 mol), while stirring, nitrogen The temperature was raised to 173 ° C. over 5 hours under an atmosphere to distill 27.300 kg of water, and the kettle was sealed. DCB distilled by azeotropy during dehydration was separated with a decanter and returned to the kettle as needed. After completion of the dehydration, the inside of the kettle was in a state where the particulate anhydrous sodium sulfide composition was dispersed in p-DCB.

  After completion of the above steps, 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 rectifying column was opened, and the temperature was raised to an internal temperature of 200 ° C. over 1 hour. At this time, the cooling and the valve opening were controlled so that the rectification tower outlet temperature was 110 ° C. or lower. The distilled steam of DCB and water was condensed by a condenser and separated by a decanter, and DCB was returned to the kettle. The amount of distilled water was 179 g.

Next, the temperature was raised from 200 ° C. to 230 ° C. over 3 hours and stirred for 1 hour, then heated to 250 ° C. and stirred for 1 hour. The final pressure was 0.48 MPa.
[Example 1] Purification process of polyphenylene sulfide resin The slurry obtained in Synthesis Example 1 was cooled, and NMP contained in 260 g of the slurry obtained after cooling was distilled off under reduced pressure at 150 ° C for 2 hours using a vacuum dryer. . To this mixture, 360 g of ion exchanged water at 70 ° C. was added and stirred for 10 minutes, followed by filtration. To the cake after filtration, 480 g of ion exchanged water at 70 ° C. was added to perform cake washing. The obtained hydrous cake and 180 g of ion-exchanged water were charged into a 0.5 liter autoclave and stirred at 70 ° C. for 30 minutes. After cooling to room temperature, the mixture was filtered, and cake washing was performed by adding 480 g of ion-exchanged water at 70 ° C. to the cake after filtration. The total amount of NaSH and its oxide (Na ₂ S ₂ O ₃ etc.) remaining in the slurry was 73 μmol per 1 g of PPS resin. The resulting wet cake and deionized water 180g was charged into a 0.5 liter autoclave, air pressurization of 0.4 MPa (oxygen pressure 0.0 84 MPa) under stirring was carried out for 30 minutes at 220 ° C.. The slurry of pH 6.5 obtained by cooling to room temperature was filtered, and 480 g of ion-exchanged water at 70 ° C. was added to the cake after filtration to perform cake washing. Then it dried 4 hours at 120 ° C., to give a melt viscosity 45 Pa · s, Na amount 150 _ppm, the Tc 2 239 ° C. of the PPS resin.

In Example 2 polyphenylene sulfide purification step in Example 1 of resin, air pressurization of 0.4MPa (oxygen pressure 0.0 84 MPa), 0.2 MPa of air pressure (oxygen pressure 0.0 42 MPa) The same operation was performed except for the following. As a result, a polyphenylene sulfide resin having a melt viscosity of 43 Pa · s, an Na amount of 250 ppm, and a Tc _{2 of} 222 ° C. was obtained from the slurry of pH 7.5.

[Example 3] Step of purifying polyphenylene sulfide resin To the slurry obtained in Synthesis Example 1, 360 g of ion exchange water at 70 ° C was added and stirred for 10 minutes, followed by filtration. The cake after filtration was subjected to 70 ° C ion exchange water. 480 g was added and the cake was washed. The obtained hydrous cake and 180 g of ion-exchanged water were charged into a 0.5 liter autoclave and stirred at 70 ° C. for 30 minutes. After cooling to room temperature, the mixture was filtered, and cake washing was performed by adding 480 g of ion-exchanged water at 70 ° C. to the cake after filtration. The total amount of NaSH and its oxides (Na ₂ S ₂ O ₃ etc.) remaining in the slurry was 25 μmol per 1 g of PPS resin. The resulting wet cake and deionized water 180g was charged into a 0.5 liter autoclave, air pressurization of 0.4 MPa (oxygen pressure 0.0 84 MPa) under stirring for 30 minutes was carried out at 0.99 ° C.. The slurry of pH 5.0 obtained by cooling to room temperature was filtered, and 480 g of ion-exchanged water at 70 ° C. was added to the cake after filtration to perform cake washing. Then, it was dried at 120 ° C. for 4 hours to obtain a PPS resin having a melt viscosity of 45 Pa · s, an Na amount of 200 ppm, and Tc _{2 of} 220 ° C.

[Example 4] Step of purifying polyarylene sulfide resin In Example 1, the same operation was carried out except that the water washing before air pressure washing was carried out at 40 ° C. As a result, the total amount of NaSH and its oxide (Na ₂ S ₂ O ₃ ) remaining in the slurry immediately before air pressure washing was 125 μmol with respect to 1 g of PPS resin, and the melt viscosity was 46 Pa · s from the slurry at pH 5.5. A polyphenylene sulfide resin having an Na content of 170 ppm and Tc _{2 of} 230 ° C. was obtained.

In Example 5 polyarylene sulfide purification step in Example 2 of the resin, the air pressure of 0.4 MPa (oxygen pressure 0.0 84 MPa), except that was carried out under 70 ° C., the same procedure It was. As a result, a polyphenylene sulfide resin having a melt viscosity of 45 Pa · s, an Na amount of 350 ppm, and a Tc _{2 of} 209 ° C. was obtained from the slurry of pH 8.0.

[Example 6] Step of purifying polyarylene sulfide resin In Example 2, the same operation was performed except that the 70 ° C water washing before the air pressure washing was carried out three times. As a result, the total amount of NaSH and its oxides (Na ₂ S ₂ O _3, etc.) remaining in the slurry immediately before air pressure washing was 5 μmol per 1 g of PPS resin, and the melt viscosity of 46 Pa · s, a polyphenylene sulfide resin having an Na amount of 250 ppm and Tc _{2 of} 211 ° C. was obtained.

In Comparative Example 1 polyarylene sulfide purification step in Example 1 of resin, the air pressure of 0.4 MPa (oxygen pressure 0.0 84 MPa), was carried out in the nitrogen pressurization of 0.3 MPa (oxygen pressure 0 MPa) The same operation was performed except that. As a result, a polyphenylene sulfide resin having a melt viscosity of 46 Pa · s, an Na amount of 520 ppm, and Tc _{2 of} 199 ° C. was obtained from the slurry of pH 9.0.

Comparative Example 2 polyarylene sulfide air pressurization (oxygen pressure 0.0 84 MPa) purification step 0.4MPa resin below, the purification treatment was stirred for 30 minutes at 220 ° C., carbon dioxide gas pressure of 0.3MPa The same operation as in Example 1 was performed except that the operation was performed at 160 ° C. for 4 hours under a pressure (oxygen pressure of 0 MPa). As a result, a polyphenylene sulfide resin having a melt viscosity of 46 Pa · s, an Na amount of 400 ppm, and Tc _{2 of} 203 ° C. was obtained.

Reference Example 1 air pressurization purification steps 0.4MPa polyarylene sulfide resin (oxygen pressure 0.0 84 MPa) under a purification treatment was stirred for 30 minutes at 220 ° C., a 0.5 wt% acetic acid In addition, the same operation as in Example 1 was performed except that the operation was performed at 180 ° C. for 1 hour. As a result, a polyphenylene sulfide resin having a melt viscosity of 46 Pa · s, an Na amount of 180 ppm, and Tc _{2 of} 231 ° C. was obtained.

[Measurement of melt viscosity]
Using a flow tester CFT-500C manufactured by Shimadzu Corporation and a die having a hole length of 10.00 mm and a hole diameter of 1.00 mm, the melt viscosity was measured at a test temperature of 300 ° C., a preheating time of 6 minutes, and a test load of 20 kgf / cm ² . .
[Na content]
The sodium content (Na content) of the obtained polyarylene sulfide resin was measured with an atomic absorption photometer using a residue obtained by baking the resin as an aqueous solution.
[Crystallization measurement]
A Perkin Elmer DSC apparatus Pyris Diamond was used to measure the peak temperature (Tc ₂ ) of the exothermic peak that appeared when the temperature was lowered at 20 ° C./min after melting at 350 ° C. for 3 minutes.

Claims (7)

In an organic polar solvent, a polyhaloaromatic compound and (i) an alkali metal sulfide or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide are reacted to form a polyarylene sulfide resin and an alkali metal. After obtaining a crude reaction mixture containing hydrosulfide, the solvent is solid-liquid separated from the crude reaction mixture, and at least selected from polyarylene sulfide resin, alkali metal hydrosulfide, sulfur atom and allotrope thereof, and alkali metal thiosulfate Obtaining a reaction mixture containing one kind, and then having a purification step in which the reaction mixture is contacted with water under oxygen pressure conditions in the range of oxygen pressure of 0.02 to 0.2 [MPa] , and
The ratio of at least one selected from alkali metal hydrosulfides, sulfur atoms and allotropes thereof, and alkali metal thiosulfate contained in the reaction mixture is in the range of 0.1 to 300 [μmol] with respect to 1 g of polyarylene sulfide resin. A process for producing a polyarylene sulfide resin. The method for producing a polyarylene sulfide resin according to claim 1, wherein the reaction mixture in a temperature range of 100 ° C or higher and lower than the melting point of the polyarylene sulfide resin is brought into contact with water under the oxygen pressure condition. 3. The method for producing a polyarylene sulfide resin according to claim 1, wherein, in the purification step, the amount of water is in the range of 50 to 2000 parts by mass with respect to 100 parts by mass of the polyarylene sulfide resin. The ratio of at least one selected from alkali metal hydrosulfides, sulfur atoms and allotropes thereof, and alkali metal thiosulfate contained in the reaction mixture is in the range of 10 to 100 [μmol] with respect to 1 g of polyarylene sulfide resin. The manufacturing method of the polyarylene sulfide resin as described in any one of 1-3. The method for producing a polyarylene sulfide resin according to any one of claims 1 to 4, wherein the reaction mixture is obtained by subjecting the crude reaction mixture to solid-liquid separation and then washing with water. The method for producing a polyarylene sulfide resin according to any one of claims 1 to 5, wherein the solid-liquid separation is performed by separating and removing the solvent by flushing. In an organic polar solvent, (i) a polyhaloaromatic compound and an alkali metal sulfide, or (ii) a polyarylene sulfide obtained by reacting a polyhaloaromatic compound with an alkali metal hydrosulfide and an alkali metal hydroxide. After obtaining a crude reaction mixture containing a resin and an alkali metal hydrosulfide, the solvent is solid-liquid separated from the crude reaction mixture to obtain a polyarylene sulfide resin, an alkali metal hydrosulfide, a sulfur atom and its allotrope, and an alkali thiosulfate Obtaining a reaction mixture comprising at least one selected from metals, and then contacting the reaction mixture with water under oxygen pressure conditions in the range of oxygen pressure 0.02-0.1 [MPa] ; and
The ratio of at least one selected from alkali metal hydrosulfides, sulfur atoms and allotropes thereof, and alkali metal thiosulfate contained in the reaction mixture is in the range of 0.1 to 300 [μmol] with respect to 1 g of polyarylene sulfide resin. A method for purifying a polyarylene sulfide resin.