JPH0649762B2 - Method for producing polyarylene sulfide - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a polyarylene sulfide, more specifically, a polyarylene capable of stably producing a high-purity, high-molecular-weight polyarylene sulfide. The present invention relates to a method for producing sulfide.

[Prior Art and Its Problems] Polyarylene sulfide such as polyphenylene sulfide is a thermoplastic resin having thermosetting property in a part of its molecule, and has excellent chemical resistance and excellent mechanical properties in a wide temperature range. It has excellent properties as an engineering plastic such as properties and heat resistance.

Polyarylene sulfide such as polyphenylene sulfide is generally known to be obtained by polymerizing a dihalogen aromatic compound and an alkali metal sulfide in a polar solvent, and for example, the production of polyphenylene sulfide is usually It is carried out by polymerizing p-dichlorobenzene and sodium sulfide in a polar solvent (Japanese Patent Publication No. 52-12240).

However, since ordinary polyarylene sulfide has a small molecular weight, it is necessary to cure the low molecular weight polyarylene sulfide by heat treatment in order to obtain a high molecular weight final product, and the operation is complicated.

Conventionally, as a method for producing a high molecular weight polyphenylene sulfide, a method using an alkali metal halide such as lithium halide as a catalyst (US Pat. No. 4038263) is known, but this method is used for applications such as films and fibers. Higher molecular weight polyphenylene sulfides have not been obtained.

Further, a method is known in which a compound having three or more halogens in the molecule is present in the reaction system (see Japanese Patent Publication No. 54-8719 and Japanese Patent Publication No. 59-197430). It easily gels and has problems in production and quality.

Further, a method in which water is present in the reaction system (Japanese Patent Laid-Open No. 59-229).
No. 26, JP-A-61-17323), but there are problems such as severe corrosion of the reactor, coloring of the produced polymer and deterioration of quality.

[Object of the Invention] The present invention has been made based on the above circumstances.

That is, the object of the present invention is to solve the above problems, there is no problem such as corrosion of devices such as reactors, white and high purity, and stable high-molecular-weight polyarylene sulfide having a small melt flow. It is to provide a novel manufacturing method that can be manufactured.

In order to achieve the above-mentioned object, as a result of extensive studies by the present inventor, the reaction was carried out in two stages, the reaction of the first stage was carried out in the substantial absence of water, and after the completion of the first stage, It was found that the above object can be easily achieved by using a two-step reaction method in which a specific amount of water is added to the reaction system before the two-step reaction and the second-step reaction is carried out. The invention was reached.

[Means for Solving the Problems] An outline of the present invention for solving the problems and achieving the object is to bring a dihalogen aromatic compound and an alkali metal sulfide into contact with each other in a polar solvent. In the method for producing a polyarylene sulfide, as a first step, a dihalogenated aromatic compound and an alkali metal sulfide are heated in a polar solvent in the presence of a lithium compound and substantially in the absence of water at a temperature of The reaction is carried out in the range of 200 to 270 ° C. so that the residual concentration of the alkali metal sulfide is 5.5 g / -polar solvent or less in terms of sulfur, and then water is added in an amount of 0.1 to 10 mol per mol of the alkali metal sulfide. As the second stage,
A method for producing a polyarylene sulfide, which comprises reacting at a temperature of 220 to 280 ° C.

Examples of the polar solvent that can be used in the method of the present invention include amide compounds, lactam compounds, urea compounds,
There are cyclic organic phosphorus compounds and the like.

Of these, specific examples of suitable solvents include:
For example, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide,
N, N-diprobilacetamide, N, N-dimethylbenzoic acid amide, caprolactam, N-methylcaprolactam, N-ethylcaprolactam, N-isopropylcaprolactam, N-isobutylcaprolactam, N-propylcaprolactam, N-butylcaprolactam, N
-Cyclohexylcaprolactam, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-isobutyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-butyl-2-
Pyrrolidone, N-cyclohexyl-2-pyrrolidone, N
-Methyl-3-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-methyl-3-methyl-2
-Pyrrolidone, N-methyl-3,4,5, -trimethyl-2-
Pyrrolidone, N-methyl-2 piperidone, N-ethyl-
2-piperidone, N-isoprolyl-2-piperidone,
N-methyl-6-methyl-2-piperidone, N-methyl-3-ethyl-2-piperidone, N-methyl-2-oxo-hexamethyleneimine, N-ethyl-2-oxo-
Hexamethyleneimine, hexamethylphosphoric triamide, hexaethylphosphoric triamide, tetramethylurea, 1,3-dimethylethyleneurea, 1,3-dimethylpropyleneurea, 1-methyl-1-oxosulfolane, 1-
Ethyl-oxosulfolane, 1-phenyl-1-oxosulfolane, 1-methyl-1-oxophosphane, 1-
Propyl-1-oxophosphane, 1-phenyl-1-
Examples thereof include oxophosphane. These solvents are 1
They may be used alone or in combination of two or more.

Further, among the above-mentioned various polar solvents, N-alkyllactam, N-alkylpyrrolidone and hexaalkylphosphoric acid triamide are preferable, and N-methylpyrrolidone is particularly preferable.

Examples of the dihalogenated aromatic compound include o-
Dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, o-dibromobenzene, p-dibromobenzene, m-dibromobenzene, p-diiodobenzene,
Dihalogen-substituted benzene such as 1-chloro-4-bromobenzene and 1-chloro-4-iodobenzene; 2,5-dichlorotoluene, 2,5-dichloroP-xylene, 1-ethyl-2,5-dichlorobenzene, 1-ethyl-2,5-dibromobenzene, 1-ethyl-2-bromo-5-chlorobenzene, 1,2,4,5-tetramethyl-3,6-dichlorobenzene, 1-cyclohexyl-2,5-dibenzene Chlorobenzene, 1-phenyl-2,5-dichlorobenzene, 1-benzyl-2,5-dichlorobenzene, 1-phenyl-2,5-
Dihalogen-substituted benzenes such as dibromobenzene, 1-p-toluyl-2,5-dichlorobenzene, 1-p-toluyl-2,5-dibromobenzene, 1-hexyl-2,5-dichlorobenzene; 4,4 ' -Dihalogen-substituted biphenyl such as dichlorobiphenyl; Dihalogenated biphenylalkanes such as 2,2-di (parachlorophenyl) propane; Dihalogen-substituted such as 1,4-dichloronaphthalene, 1,6-dichloronaphthalene, and 2,6-dichloronaphthalene Examples include naphthalene. Among these, dihalogen-substituted benzene is preferable, and p-dichlorobenzene is particularly preferable.

Examples of the alkali metal sulfide include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, and cesium sulfide. Suitable alkali metal sulfides are lithium sulfide and sodium sulfide, and sodium sulfide is particularly preferable. In addition,
These may be used alone or in combination of two or more.

In the method of the present invention, the alkali metal sulfide may be an anhydride, a hydrate, or an aqueous mixture, but if a hydrate or an aqueous mixture is used, it will be described later. As described above, it is necessary to perform dehydration operation before the reaction. Therefore, it is preferable to use an anhydride since no dehydration operation is required.

Examples of the lithium compound used in the method of the present invention include lithium fluoride, lithium chloride, lithium bromide, lithium iodide, lithium carbonate, lithium hydrogen carbonate, lithium sulfate, lithium hydrogen sulfate, lithium phosphate, hydrogen phosphate. Lithium mineral acid salts such as lithium, lithium dihydrogen phosphate, lithium nitrate, lithium nitrite, lithium sulfite; lithium oxyacid salts such as lithium chlorate, lithium chromate, lithium molybdate; lithium formate,
Lithium acetate, lithium oxalate, lithium malonate,
Lithium propionate, lithium butyrate, lithium isobutyrate, lithium maleate, lithium fumarate, lithium butanedioate, lithium valerate, lithium hexanoate, lithium octanoate, lithium tartrate, lithium stearate, lithium oleate, lithium benzoate. Lithium carboxylic acid salts such as lithium phthalate; lithium benzenesulfonic acid salts, lithium p-toluenesulfonic acid lithium salts such as lithium methoxide, lithium ethoxide, lithium isopropoxide, lithium-n-.
Examples thereof include lithium alkoxides such as propoxide, lithium butoxide and lithium phenoxide; lithium acetic acid or organic lithium compounds such as lithium acetylacetonate, and various lithium compounds such as lithium sulfide, lithium oxide and lithium hydroxide. Among these, lithium halides such as lithium chloride, lithium carboxylates such as lithium acetate, lithium carbonate and the like are preferable, and lithium chloride is particularly preferable. These lithium compounds may be used alone or in combination of two or more.

In the method of the present invention, the lithium compound may be an anhydride, a hydrate or an aqueous mixture, but in the case of using a hydrate or an aqueous mixture, as described below. , It may be necessary to perform dehydration operation before the reaction.

In the method of the present invention, in the reaction of the first step and / or the reaction of the second step, if necessary, the active hydrogen-containing halogen aromatic compound, polyhalogenated aromatic compound, polyhalogenated aromatic compound is added to the reaction system. A branching agent or a molecular weight modifier such as a nitro compound, and / or a liquidity modifier such as an alkali hydroxide, and / or a polymerization additive such as a metal salt, and / or a reducing agent, and / or an inert organic solvent are used. The reaction can be carried out in the coexistence. Each of these components can be used in the anhydrous state or in the hydrated state, the hydrated state, the hydrated state such as an aqueous mixture, etc., but when the hydrated state is used in the reaction of the first step, Prior to the reaction, it is necessary to perform a dehydration operation sufficiently to provide the reaction in a substantially anhydrous state.

The active hydrogen-containing halogen aromatic compound has at least one aromatic ring, and a group having active hydrogen is bonded to at least one carbon atom among the carbon atoms forming the aromatic ring, At the same time, an aromatic compound in which a halogen atom is bonded to at least two carbon atoms among the carbon atoms forming the aromatic ring can be used.

Examples of the active hydrogen-containing halogen aromatic compound include active hydrogen-containing dihalogenbenzene compounds such as dihalogenoanilines, dihalogenothiophenols, dihalogen (phenyl) aminobenzenes; trihalogenoanilines, 2,4,5 -Active halogen-containing polyhalogenbenzene compounds such as trihalogenothiophenols, trihalogenophenols, and trihalogeno (phenylamino) benzenes can be mentioned.

Other examples include diamino-di-halogenodiphenyl ethers.

In the present invention, an active hydrogen-containing halogen in which a hydrogen atom bonded to a carbon atom forming an aromatic ring in the active hydrogen-containing halogen aromatic compound is substituted with another inert group such as a hydrocarbon group such as an alkyl group. Aromatic compounds can also be used.

Among various active hydrogen-containing halogen aromatic compounds exemplified above, active hydrogen-containing dihalogenbenzene compounds are preferable, dihaloaniline compounds are more preferable, and dichloroaniline is particularly preferable.

The polyhalogenated aromatic compound is an aromatic compound in which three or more halogen atoms are substituted. Specific examples include 1,2,4-trichlorobenzene, 1,3,5-trichlorobenzene, and 1,4,6-trichloronaphthalene.

Examples of the polyhalogenated aromatic nitro compound include dihalogeno nitrobenzenes and dihalogeno nitronaphthalene.

By using these active hydrogen-containing aromatic compounds and / or the polyhalogenated aromatic compounds and / or the polyhalogenated aromatic nitro compounds,
It is possible to increase the degree of branching of the produced polyarylene sulfide, further increase the molecular weight thereof, further reduce the melt flow, and improve various physical properties of the produced polymer such as decreasing the residual salt content.

Further, as the branching agent or the molecular weight adjusting agent, in addition to the above various compounds, for example, an organic compound having three or more reactive halogen atoms such as cyanuric chloride can be used.

In addition, these various compounds which are a branching agent or a molecular weight modifier may be used individually by 1 type, or may be used in combination of 2 or more type.

Examples of the metal salt used as the polymerization additive include sodium acetate, potassium acetate, zinc acetate, etc.
Carboxylic acid salts of metals belonging to the groups from Group IV to Group IV; alkali metal mineral acid salts such as sodium phosphate; alkaline earth metal mineral acid salts; alkali metal sulfonic acid salts such as sodium benzenesulfonate You can

These metal salts may be used alone or in combination of two or more as a polymerization additive.

Examples of the reducing agent include hydrazine, metal hydride, alkali formate, and the like.
Mention may be made of metal hydride compounds, especially sodium borohydride, calcium hydride and the like.

Examples of the inert solvent include hydrocarbons such as benzene, toluene, xylene, biphenyl, terphenyl, naphthalene and anthracene, and ethers such as diphenyl ether, p-diphenoxybenzene and polyethylene glycol. Among these, high boiling point inert organic solvents are preferable.

In the method of the present invention, the reaction in the first step is performed by the dihalogenated aromatic compound (component [A]), the alkali metal sulfide (component [B]), the lithium compound (component [C]) and the polarity. It is carried out by blending with a solvent (component [D]), or the above [A], [B],
[C] and [D] components, and in addition to them, the active hydrogen-containing halogen aromatic compound, the polyhalogenated aromatic compound, the polyhalogenated nitro compound, the branching agent or the molecular weight modifier such as cyanuric chloride. If necessary, one or more components selected from the above-mentioned liquidity adjusting agent, the above-mentioned polymerization additive, the above-mentioned reducing agent, and the above-mentioned inert solvent may be blended and carried out. However, in the method of the present invention, one of the important points is that the reaction in the first step must be carried out in the substantial absence of water.

When the respective components such as [A], [B], [C] and [D] do not substantially contain an anhydride or water, the order of blending the respective components in the reaction of the first step The method is not particularly limited. On the other hand, when at least one of the above components contains water, before the reaction,
A dehydration operation is performed to make the reaction system substantially anhydrous,
The order and method of blending each component and dehydration operation are adjusted so as to carry out the reaction.

The reaction in the first step is substantially caused by the reaction between the component [A] and the component [B]. Therefore,
At least one of the components used is
If it is hydrated or hydrated,
Before mixing the components [A] and [B], or
Before blending the component [B] and the component [A], a mixture containing a water-containing component or a water-containing blended liquid may be dehydrated and used in a substantially anhydrous state. desirable.

Specifically, for example, when the reaction in the first step is carried out by contacting the components [A], [B], [C], and [D] with the component; [B] component to be used, When at least one of the components [C] and [D] is in a water-containing state or in a hydrated state (for example,
When a hydrous salt such as sodium sulfide nonahydrate is used as the component [B]), the component [B] and the component [C] [D] are used.
The components are blended to prepare a reaction system preparation solution mixture, and the mixture solution is subjected to, for example, dehydration operation such as azeotropic distillation to prepare a substantially anhydrous reaction system preparation mixture solution. A method in which a mixed solution and a substantially anhydrous component [A] are mixed to form a reaction system is preferably used.

Further, in the reaction of the first step, the [A],
In addition to the components [B], [C], and [D], when the above components are used, if necessary, for example, the components [B], [C], and [D] When at least one of the components is in a water-containing state or in a hydrated state, the [B] component, the [C] component, the [D] component, etc. are blended to prepare a mixed solution for preparing a reaction system. Is prepared, and water is removed from this mixture by a dehydration operation such as azeotropic distillation to obtain a substantially anhydrous reaction mixture for preparing a reaction system, and this mixed solution and a substantially anhydrous component [A] are added. It is possible to preferably use a method of forming a reaction or the like by simultaneously or stepwise mixing.

In addition, each of the components used to configure the reaction,
When it is in a substantially anhydrous state, in the above-mentioned compounding order and method, the same compounding order and method as described above can be preferably used without performing dehydration operation.

In any case, as long as the reaction in the first step is carried out in the substantial absence of water, there is no particular limitation on the order of mixing the components and the method.

Here, the term "substantially in the presence of water" cannot be defined uniformly because the definition range differs depending on various other conditions such as the type of components used, the compounding ratio, the reaction conditions, etc., but it is contained in the reaction system. It means that the amount of water is usually 0.1 mol or less, preferably 0.05 mol or less, per 1 mol of the component [B] used.

If the amount of this water is more than 0.1 mol per mol of the component (B) used, the reactor will be corroded, the obtained polyarylene sulfide will be colored, the purity will be lowered, and a high molecular weight polymer will be obtained. It may not be possible.

The blending ratio or blending ratio of each of the components in the reaction in the first step is preferably as follows.

That is, the molar ratio of [A] component / [B] component is 0.75 to 2.
It is 0, preferably 0.90 to 1.2. Since the reaction between the dihalogenated aromatic compound [A] and the alkali metal sulfide [B] is an equimolar reaction, it is usually within the above range.

The molar ratio of [C] component / [B] component is usually 0.001 to 2.
It is 0, preferably 0.01 to 1.5. This molar ratio is
If it is less than 0.001, the molecular weight of the polyarylene sulfide to be produced may be low, or the content of salts such as salt remaining in the polymer, i.e., contaminant salts, may not be sufficiently low, while if it is greater than 2.0, A high concentration of the salt used as a catalyst may remain in the produced polymer.

However, when lithium sulfide is used as the [B] component, the lithium sulfide can be regarded as the [C] component as well as the [B] component.

The molar ratio of [D] component / [B] component is 1 to 15, preferably 2 to 10. If this molar ratio is less than 1, the reaction may be non-uniform, and if the molar ratio is greater than 15, productivity may be reduced.

The reaction of the first step in the method of the present invention is usually
It is carried out in the temperature range of 200 to 270 ° C, preferably 210 to 265. If the reaction temperature is lower than 200 ° C, the reaction rate is insufficient, while if it is higher than 270 ° C, a high molecular weight polyarylene sulfide may not be obtained. The reaction time is
The concentration of the residual component (B) is set to be 5.5 g / or less, preferably 2.7 g / or less in terms of sulfur with respect to the polar solvent [D] component. Therefore, this reaction time varies depending on various other conditions such as the type and amount of each component used, the reaction temperature and the like and cannot be uniformly regulated, but it can usually be in the range of 0.2 to 2 hours.

In the method of the present invention, after the reaction in the first step, water is added to the reaction system, and then the reaction in the second step (polycondensation reaction) is performed.

The mixing ratio of the water is usually 0.1 to 10 mol, preferably 0.1, based on 1 mol of the alkali metal sulfide [B] used.
It is 5 to 2.5 mol. When the mixing ratio of this water is less than 0.1 mol per mol of the alkali metal sulfide [B],
In some cases, a high molecular weight polyarylene sulfide may not be obtained, while when it exceeds 10 mols, problems such as reactor corrosion may occur.

The reaction temperature of the second step reaction is usually 220-280.
C., preferably 240 to 270.degree. This reaction temperature is
If it is lower than 220 ° C, the reaction rate of polycondensation reaction is not sufficient and high molecular weight polyarylene sulfide may not be obtained. The productivity of arylene sulfide may decrease. The reaction time for this reaction is usually 20
It is within an hour, especially about 0.1 to 8 hours.

The reaction pressure for the first-step reaction and the second-step reaction is not particularly limited, but is usually about the self pressure of the reaction system such as a solvent to about 10 kg / cm ² (absolute pressure). These reactions may be performed in an atmosphere of an inert gas such as nitrogen or carbon dioxide.

In the method of the present invention, when carrying out the reaction of the second step, each of the above components can be added to the reaction system, if necessary. The order and method of blending these components are not particularly limited, but usually, for example, after the addition of the water, the components are added to the reaction system, if necessary, and then the reaction of the second step is carried out. The method of performing can be used suitably.

The addition amount of each component added in the reaction of the second step is the same as the addition amount of each component added in the reaction of the first step and the addition amount of each component newly added in the reaction of the second step. The total amount can be set so as to fall within the range of the blending ratio of each component.

In addition, when the above-mentioned each component added as needed in the reaction of the second stage contains water, the total amount of water in each component added and the water added before the reaction of the second stage It is desirable that the total amount of the water and the amount of water be within the range of the mixing ratio of the water.

After the reaction of the second stage, the polyarylene sulfide is directly separated from the reaction solution by a standard method such as filtration or centrifugation, or after addition of water and / or diluted acid, for example, It can be obtained by separating from the reaction solution.

The filtration step is generally followed by a water wash to remove any inorganic components that may adhere to the polymer, such as alkali metal sulfides. Also, in addition to or after this washing step, washing or extraction with other washing liquids such as methanol, which can be carried out, is possible. The polymer can also be recovered by distilling off the solvent from the reaction vessel and subsequently washing as described above.

In this way, white, high-purity polyarylene sulfide such as high molecular weight polyphenylene sulfide can be easily prepared.
And it can be obtained stably.

Further, the recovered polyarylene sulfide can be suitably used in the electric and electronic fields by further performing various desalting treatments to reduce the salt concentration of salt etc. in the polymer, if necessary. .

When molding polyarylene sulfide such as polyphenylene sulfide obtained by the method of the present invention into various products, other polymers, pigments and fillers such as graphite, metal powder, glass powder, quartz powder or glass fiber, carbon It can be mixed with the additives customary for fibers or polyarylene sulfides, for example the customary stabilizers or release agents.

The polyarylene sulfide such as polyphenylene sulfide obtained by the method of the present invention has a white color, a high purity, a small melt flow and a high molecular weight, and in addition to this, a low salt amount such as salt in the polymer is low. Therefore, since it can be manufactured as a resin having high moisture resistance and high electric insulation, it can be used as a matrix resin for various molded products and composite materials, and can be used as various molded products, films, fibers, etc. It is an excellent engineering plastic that can be suitably used not only for mechanical parts but also for electric and electronic parts.

EFFECTS OF THE INVENTION According to the present invention, white, high-purity, low-melting-flow high-molecular-weight polyarylene sulfides such as polyphenylene sulfides can be easily formed without corrosion of a device such as a reactor. The polymer can be stably produced in good yield without causing gelation of the polymer. In addition, the degree of branching and the molecular weight of the polyarylene sulfide can be adjusted in a wide range, if necessary.

That is, according to the method of the present invention, it is possible to obtain remarkably superior effects as compared with the conventional method in terms of production, processing, quality and the like of polyarylene sulfide such as polyphenylene sulfide.

[Example] (Example 1) 21.5 g (0.54 mol) of p-dichlorobenzene and 25.0 g (0.54 mol) of anhydrous lithium sulfide were added to 2 autoclaves (material: SUS3).
1 / 6L), N-methyl-2-pyrrolidone (NMP)
After adding 306 ml (0.23 mol) and flowing nitrogen for 10 minutes at room temperature, the temperature was raised to 120 ° C with stirring. The autoclave was sealed and kept at 230 ° C. for 1.5 hours to carry out the first stage reaction. The amount of lithium sulfide in the reaction system was 2.1 g /-in terms of sulfur as a result of measurement by ion chromatography.
It was NMP. Then in the reaction system distilled water 9.7 g (0.54 mol)
After adding, the temperature was gradually raised to 265 ° C. and the polymerization reaction (second step reaction) was carried out for 2 hours. After completion of the reaction, the mixture was cooled to 175 ° C. with stirring, and then left to stand at room temperature. The reaction mixture was poured into water (1) and filtered, washed with water and washed with methanol. Melt flow value of the obtained white polyphenylene sulfide (measurement condition: 300 ° C, load 50 kg /
cm ² , nozzle length 10 mm) was 4.2 × 10 ^-2 ml / sec, the melting point measured by DSC was 290 ° C., and the yield was 95% by weight.

(Example 2) 130.4 g of sodium sulfide nonahydrate in the autoclave of No. 2
(0.54 mol), lithium chloride 23.0 g (0.54 mol) and N-methyl-2-pyrrolibin 370 ml were added and water was added by azeotropic distillation.
88 ml was removed. After that, p-dichlorobenzene 81.5 g (0.
56 mol) and 110 ml of N-methyl-2-pyrrolidone were added, and the first step reaction was carried out at 255 ° C. for 1 hour under a nitrogen atmosphere. The amount of sodium sulfide in the reaction system was 1.8 g / -N in terms of sulfur when measured by ion chromatography.
It was MP.

After adding 9.7 g (0.4 mol) of distilled water to the reaction system, gradually add 260
Temperature rises to ℃ and polymerization reaction takes 2 hours (second stage reaction)
Was done. After completion of the reaction, cooling, filtration, washing with water and washing with methanol were performed. The obtained white polyphenylene sulfide has a melt flow value of 2.8 × 10 ^-2 ml / sec and a melting point of 290 ° C.
And the yield was 94% by weight.

(Comparative Example 1) In Example 1, 9.7 g of distilled water (0.54 m
ol) was added and distilled water was not added during the second stage reaction, and the same operation was performed. The residual concentration of lithium sulfide before adding distilled water was 57.6 g / -NMP.
Met. The melt flow value of the obtained polyphenylene sulfide was 13.8 × 10 ^-2 ml / sec, the melting point was 288 ° C., and the yield was 90% by weight. Also, the inner wall of the autoclave was black and rusty.

(Comparative Example 2) The same procedure as in Example 1 was carried out except that distilled water was not added. The melt flow value of the obtained pale yellow polyphenylene sulfide was 5.8 ml x 10 ^-2 ml / sec, The melting point was 289 ° C. and the yield was 93% by weight.

(Comparative Example 3) In Example 2, 9.7 g (0.5
4 mol) was added, and the same operation was performed except that distilled water was not added during the second step reaction. The residual concentration of sodium sulfide before adding distilled water was 56.9 g / -NM.
It was P. The obtained pale yellow polyphenylene sulfide had a melt flow value of 10.2 × 10 ^-2 ml / sec, a melting point of 293 ° C. and a yield of 90% by weight.

(Comparative Example 4) The same operation as in Example 2 was performed except that distilled water was not added. The obtained pale yellow polyphenylene sulfide has a melt flow value of 3.4 × 10 ^-2 ml / sec and a melting point of 2
The temperature was 92 ° C, and the yield was 94% by weight.

Claims (5)

[Claims] 1. A method for producing a polyarylene sulfide by contacting a dihalogenated aromatic compound and an alkali metal sulfide in a polar solvent, the first step is, in a polar solvent, in the presence of a lithium compound, And, in the substantial absence of water, the dihalogenated aromatic compound and the alkali metal sulfide are reacted in a temperature range of 200 to 270 ° C., and the residual concentration of the alkali metal sulfide is 5.5 g / -polar in terms of sulfur. After the solvent is added, water is added in an amount of 0.1 to 10 mol per mol of the alkali metal sulfide, and then, as a second step,
A method for producing a polyarylene sulfide, which comprises reacting at a temperature of 220 to 280 ° C. 2. The method for producing a polyarylene sulfide according to claim 1, wherein the dihalogenated aromatic compound is p-dichlorobenzene. 3. The method for producing a polyarylene sulfide according to claim 1 or 2, wherein the alkali metal sulfide is sodium sulfide and / or lithium sulfide. 4. The lithium compound according to claim 1, which is lithium chloride and / or lithium sulfide.
Item 4. A method for producing a polyarylene sulfide according to any one of items 3 to 3. 5. The method for producing a polyarylene sulfide according to any one of claims 1 to 4, wherein the polar solvent is N-methylpyrrolidone.