JP3235038B2 - Method for producing polyarylene sulfide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyarylene sulfide, and more particularly, to a method for producing a high-quality polyarylene sulfide suitable for use in a wide range of fields such as an electric / electronic field and a high-rigidity material field such as a dryer. The present invention relates to a method for producing polyarylene sulfide which can be produced simply and economically with simple equipment that does not require expensive equipment.

[0002]

2. Description of the Related Art In a conventional method for producing a polyarylene sulfide (hereinafter sometimes referred to as a PAS), a high-temperature PAS polymerization reaction product is directly washed to thereby improve the cleaning efficiency. And the process was simplified. However, in this case, the organic solvent solution containing PAS in a molten state, which is separated after washing the PAS polymerization reaction product, contains a large amount of volatile components. Components need to be removed. In the conventional method,
The removal of the volatile components has been carried out by washing and drying the PAS polymer formed into particles. However, according to such a method, there is a problem that a large amount of washing water and expensive equipment such as a dryer are required.

[0003] By the way, US Patent No. 3,707,528.
The publication discloses that such a volatile component is recovered by flushing a PAS polymerization reaction slurry to easily produce a PAS having a small content of impurities.

[0004] However, in this case, the flushed PAS is recovered in a powder state, so that it is necessary to perform a washing step, a drying step, and the like, which makes the operation and equipment complicated, and makes it possible to produce high-quality polyarylene sulfide. The problem still remains that simple and economical production is not possible with simple equipment.

[0005] The present invention solves the above-mentioned problems and provides a polyarylene sulfide suitable for a wide range of fields such as the fields of electric / electronics and high-rigidity materials by using simple equipment that does not require expensive equipment such as a dryer. An object of the present invention is to provide a method for producing polyarylene sulfide which can be produced simply and economically.

[0006]

According to the first aspect of the present invention, there is provided a method of polymerizing lithium N-methylaminobutyrate, hydrogen sulfide and a dihalogen aromatic compound in an aprotic organic polar solvent. An organic solvent solution containing a polyarylene sulfide polymer in a molten state, separated from the resulting polyarylene sulfide polymerization reaction product, is isothermally flashed at a temperature of 285 to 370 ° C. in a flash drum. The production method according to claim 2, wherein the alkali metal sulfide and the dihalogen aromatic compound are separated from a polyarylene sulfide polymerization reaction product obtained by a polymerization reaction in an aprotic organic polar solvent. Flash the organic solvent solution containing the polyarylene sulfide polymer of A method for producing polyarylene sulfide, comprising isothermally flashing at a temperature of 285 to 370 ° C. in a tank.

Hereinafter, a method for producing a polyarylene sulfide according to the present invention will be described in detail. The method for producing polyarylene sulfide according to the present invention includes 1) a PAS polymerization step and 2) a flash step.

1) PAS Polymerization Step In this PAS polymerization step, a PAS polymerization reaction obtained by polymerizing lithium N-methylaminobutyrate, hydrogen sulfide and a dihalogen aromatic compound in an aprotic organic polar solvent. A PAS polymer in a molten state from the product (a) or from a PAS polymerization reaction product (b) obtained by polymerizing an alkali sulfide and the dihalogen aromatic compound in the aprotic organic polar solvent. The organic solvent solution is separated.

-PAS polymerization reaction product (a)-The lithium N-methylaminobutyrate is not particularly limited, and a compound known per se can be used.
The lithium N-methylaminobutyrate may be used alone or in combination of two or more. In the method of the present invention, the lithium N-methylaminobutyrate may be used as an anhydride, or may be used as a hydrate or an aqueous solution. When the lithium salt of N-methylaminobutyric acid is used as a raw material, it is possible to prevent the by-product of NaCl, which has conventionally occurred. As a result, PA
The flushing step described below can be performed directly on the organic solvent solution containing the PAS polymer in a molten state separated therefrom without washing the S polymerization reaction product, which is efficient.

The hydrogen sulfide is not particularly limited.

As the dihalogen aromatic compound, 2
Any aromatic compound having one halogen atom may be used, and examples thereof include compounds known per se. Specifically, dihalobenzenes such as m-dihalobenzene and p-dihalobenzene; 2,3-dihalotoluene;
2,5-dihalotoluene, 2,6-dihalotoluene,
3,4-dihalotoluene, 2,5-dihaloxylene, 1
-Ethyl-2,5-dihalobenzene, 1,2,4,5-
Alkyl-substituted dihalobenzenes such as tetramethyl-3,6-dihalobenzene and 1-n-hexyl-2,5-dihalobenzene; cycloalkyl-substituted dihalobenzenes such as 1-cyclohexyl-2,5-dihalobenzene; 1-phenyl-2. 5-dihalobenzene, 1-benzyl-2,5
Aryl-substituted dihalobenzenes such as -dihalobenzene and 1-p-toluyl-2,5-dihalobenzene; 4,4 '
Dihalobiphenyls such as dihalobiphenyl; 1,4-
Dihalonaphthalene, 1,6-dihalonaphthalene, 2,6
And dihalonaphthalenes such as dihalonaphthalene. The two halogen elements in these dihalogen aromatic compounds are respectively fluorine, chlorine, bromine or iodine, and they may be the same,
They may be different from each other. Among the dihalogen aromatic compounds, dihalobenzenes are preferable, and particularly, p-dichlorobenzene or a mixture of 80 mol% or more of p-dichlorobenzene and m-dichlorobenzene is preferable.

The aprotic organic polar solvent includes:
Examples thereof include aprotic organic solvents such as amide compounds, lactam compounds, urea compounds, and cyclic organic phosphorus compounds.

Examples of the amide compound include N, N
Formamides such as -dimethylformamide; N, N
Acetamides such as -dimethylacetamide, N, N-diethylacetamide and N, N-dipropylacetamide; and aromatic carboxylic acid amides such as N, N-dimethylbenzoic acid amide.

Examples of the lactam compound include caprolactam and N-methylcaprolactam, N-ethylcaprolactam, Nn-propylcaprolactam,
Caprolactams such as N-alkylcaprolactam such as N-isopropylcaprolactam, Nn-butylcaprolactam, N-isobutylcaprolactam, N-cyclohexylcaprolactam; N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N- n-propyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, Nn-butyl-2-pyrrolidone, N-isobutyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-methyl-3-methyl- 2-pyrrolidone, N-ethyl-3-methyl-2-pyrrolidone, N-methyl-3,
Pyrrolidones such as N-alkyl such as 4,5-trimethyl-2-pyrrolidone; N-methyl-2-piperidone;
-Ethyl-2-piperidone, N-isopropyl-2-piperidone, N-methyl-6-6-methyl-2-piperidone, N-methyl-3-ethyl-2-piperidone and the like.

Further, other aprotic organic polar solvents include urea compounds such as tetramethylurea, N, N'-dimethylethyleneurea and N, N-dimethylpropyleneurea, and 1-methyl-1-oxosulfolane. ,
1-ethyl-1-oxosulfolane, 1-phenyl-1
Oxosulfolane such as -oxosulfolane, 1-methyl-1-oxophosphorane, 1-n-propyl-1-
Oxophosphoranes such as oxophosphorane and 1-phenyl-1-oxophosphorane can be mentioned.

Among these solvents, particularly preferred are amide compounds and lactam compounds, among which N-alkyllactams and N-alkylpyrrolidones are preferred, and N-methylpyrrolidone is particularly preferred. The aprotic organic polar solvent may be used alone or in combination of two or more.

In the present invention, the lithium salt of N-methylaminobutyric acid, hydrogen sulfide and the dihalogen aromatic compound may be added to or brought into contact with the aprotic organic polar solvent in any order.

The polymerization reaction can be carried out using a polymerization reaction tank under appropriately selected polymerization conditions. The polymerization reaction tank is not particularly limited, and a known apparatus can be used.

The polymerization conditions include temperature, time, pressure and the like.

The temperature is usually from 180 to 330.
° C, preferably 210-290 ° C. The temperature is 1
When the temperature is lower than 80 ° C., the reaction rate becomes slow, so that it is not practical. On the other hand, when the temperature exceeds 330 ° C., a side reaction or deterioration or decomposition of the produced polymer may occur, which may cause coloring or gelation.

The above-mentioned time cannot be determined unconditionally because it varies depending on the type and amount of each component used, the type and amount of the acid scavenger, the reaction time, etc., but it is usually not more than 20 hours, preferably 0. 1 to 8 hours. If the above-mentioned time exceeds 20 hours, the volume of the reaction tank becomes large, which may not be practical.

The pressure is not particularly limited, but is usually from the self-pressure of a polymerization reaction system such as a solvent to 50 kg / cm ^2.
(Absolute pressure).

The proportion of lithium N-methylaminobutyrate used in the polymerization reaction is usually 0.05 to 3.0 mol per mol of hydrogen sulfide and 1 mol of dichlorobenzene.
Preferably it is 1.5 to 2.2 mol. The ratio is 0.
When the amount is less than 05 mol, the effect of using the lithium N-methylaminobutyrate may not be sufficiently exerted. On the other hand, if it exceeds 2.0 mol, no change may be observed in the effect obtained by using the lithium N-methylaminobutyrate.

The ratio of the dihalogen aromatic compound used in the polymerization reaction is usually 0.90 to 1.3 mol, preferably 0.95 to 1.2 mol, per 1 mol of hydrogen sulfide. If the ratio is less than 0.90 mol, thiophenols may be produced as by-products. On the other hand, if it exceeds 1.3 mol, the molecular weight of the obtained polyarylene sulfide may decrease.

The proportion of each of the above components can be selected according to the physical properties of the desired polyarylene sulfide, such as the molecular weight and the amount of a branching agent to be described later.

The amount of the aprotic organic polar solvent is not particularly limited as long as it is an amount sufficient for the reaction to proceed uniformly, but is usually in the range of 1 to 20 mol per mol of hydrogen sulfide. It is preferred that If the amount is less than 1 mol, the reaction may not proceed sufficiently. On the other hand, if it exceeds 20 moles, the volumetric efficiency may deteriorate, leading to a decrease in productivity.

In the method of the present invention, the polymerization reaction can be carried out in an atmosphere of an inert gas such as nitrogen, argon, carbon dioxide or the like. Further, the polymerization reaction may be a single-stage reaction performed at a steady temperature, a multi-stage reaction in which the temperature is increased stepwise, or a reaction mode in which the temperature is gradually increased continuously.

In the method of the present invention, an active hydrogen-containing halogen aromatic compound, a polyhalogen aromatic compound having three or more halogen atoms in a molecule, a halogen aromatic nitro compound, etc. A branching agent, a molecular weight regulator such as a monohalogen aromatic compound or an active hydrogen-containing compound, a reducing agent, an inert organic solvent and the like can be appropriately selected and added to the polymerization reaction system.

Examples of the active hydrogen-containing halogen aromatic compound which is a kind of the branching agent include a halogen aromatic compound having a functional group having an active hydrogen such as an amino group, a thiol group or a hydroxyl group. Dihaloanilines such as 2,6-dichloroaniline, 2,5-dichloroaniline, 2,4-dichloroaniline, and 2,3-dichloroaniline; 2,3,4-trichloroaniline, 2,3,5-trichloro Aniline, 2,4,6
Trihaloanilines such as -trichloroaniline and 3,4,5-trichloroaniline; 2,2'-diamino-4,
In dihaloaminodiphenyl ethers such as 4′-dichlorodiphenyl ether and 2,4′-diamino-2 ′, 4-dichlorodiphenyl ether, and mixtures thereof, one or more of the halogen atoms is, in addition to the chlorine atom, It may be substituted with fluorine, bromine, etc.,
Further, compounds in which an amino group is replaced with a thiol group or a hydroxyl group can be exemplified. Further, an active hydrogen-containing halogen in which a hydrogen atom bonded to a carbon atom forming an aromatic ring in these active hydrogen-containing aromatic 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 halogen aromatic compounds, active hydrogen-containing dihalogen aromatic compounds are preferable, and dichloroaniline is particularly preferable.

Examples of the polyhalogen aromatic compound that can be used as the branching agent include 1,2,4
-Trichlorobenzene, 1,3,5-trichlorobenzene, 1,4,6-trichloronaphthalene and the like.

Further, examples of the halogen aromatic nitro compound which can be used as a branching agent include, for example, 2,4
Mono- or dihalonitrobenzenes such as dinitrochlorobenzene and 2,5-dichloronitrobenzene; dihalonitrodiphenylethers such as 2-nitro-4,4'-dichlorodiphenylether;3,3'-dinitro-
Dihalonitrodiphenylsulfones such as 4,4'-dichlorodiphenylsulfone; mono- or dihalonitropyridines such as 2,5-dichloro-3-nitropyridine and 2-chloro-3,5-dinitropyridine, or various types Examples thereof include dihalonitronaphthalenes. In these compounds, the halogen aromatic nitro compound is reduced in the reaction system and acts as a branching agent, and has a higher branching efficiency than other branching agents. The halogen atoms in the polyhalogen aromatic compound and the halogen aromatic nitro compound may be the same or different, and may be fluorine, bromine or the like in addition to the chlorine atom.

By using these active hydrogen-containing halogen-aromatic compounds, polyhalogen-aromatic compounds, nitro-halogen-aromatic compounds, etc., the degree of branching of the resulting polymerization reaction product can be increased, and the molecular weight can be further increased. Thus, various properties of the polyarylene sulfide polymerization product produced by the method of the present invention can be further improved.

The proportion of the branching agent is usually 0.0005 to 0.05 mol, preferably 0.001 to 0.02 mol, per mol of the dihalogen aromatic compound used in the method of the present invention. preferable.

Examples of the monohalogen aromatic compound which is a kind of the molecular weight modifier include chlorobenzene, bromobenzene, α-bromobenzene, α-chlorotoluene,
o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, α-bromotoluene, o-bromotoluene,
Examples thereof include m-bromotoluene and p-bromotoluene.

Examples of the active hydrogen-containing compound include thiophenol, phenol, aniline and the like.

As the branching agent or the molecular weight regulator, in addition to the above-mentioned compounds, compounds having three or more reactive halogen atoms such as cyanuric chloride can be used. In the method of the present invention, these branching agents or molecular weight modifiers may be used alone or in combination of two or more.

As the reducing agent, for example, hydrazine,
Examples thereof include metal hydride, alkali formate, and sulfur. Among these, metal hydrides are preferred, and sodium borohydride and calcium hydride are particularly preferred.

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

-PAS polymerization reaction product (b)-Examples of the alkali sulfide include alkali metal sulfides and alkaline earth metal sulfides.

Examples of the alkali metal sulfide include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, and cesium sulfide. Among these, lithium sulfide and sodium sulfide are preferred,
Particularly, sodium sulfide is preferable. These may be used alone or in combination of two or more.

Examples of the alkaline earth metal sulfide include calcium sulfide, strontium sulfide, barium sulfide, and magnesium sulfide. Among these, calcium sulfide and barium sulfide are preferable, and calcium sulfide is particularly preferable. These may be used alone or in combination of two or more.

Further, the alkali metal sulfide or the alkaline earth metal sulfide may be obtained by reacting each of an alkali metal hydrosulfide or an alkaline earth metal hydrosulfide with a base.

Examples of the alkali metal hydrosulfide include lithium hydrosulfide, sodium hydrosulfide, potassium hydrosulfide, and cesium hydrosulfide. Examples of the alkaline earth metal hydrosulfide include calcium hydrosulfide, strontium hydrosulfide, barium hydrosulfide, and barium hydrosulfide.

Examples of the base include various compounds such as inorganic bases and organic bases.

As the inorganic base, alkali metal hydroxides and the like can be suitably used, and examples thereof include lithium hydroxide, sodium hydroxide, potassium hydroxide and rubidium hydroxide.

Examples of the organic base include metal salts of ω-hydroxycarboxylic acid and alkali metal salts of aminocarboxylic acid.

In the present invention, the alkali sulfide and the dihalogen aromatic compound may be added to or brought into contact with the aprotic organic polar solvent in any order.

The polymerization reaction can be carried out by a method known per se under a polymerization condition appropriately selected using a polymerization reaction tank. The polymerization reaction tank is not particularly limited, and a known apparatus can be used.

The PAS polymerization reaction product (b) obtained as described above, unlike the PAS polymerization reaction product (a), contains an alkali halide as a by-product. Therefore,
Converting the alkali halide into the PAS polymerization reaction product (b)
It is necessary to remove it from inside. The method for performing such removal is not particularly limited, and examples thereof include a method using a solid-liquid separator known per se, and a method for performing hot filtration or hot extraction.

The method for separating the organic solvent solution containing the PAS polymer in a molten state from the polyarylene sulfide polymerization reaction product obtained as described above is not particularly limited, and an appropriate method can be selected. For example,
This can be carried out by allowing the PAS polymerization reaction product to stand still, or by adding and mixing a phase separator such as water to the high-temperature PAS polymerization reaction product in the polymerization reaction tank, and removing the aqueous phase. .

2) Flash Step In this flash step, the organic solvent solution containing the PAS polymer in a molten state is flash-isothermally flashed in a flash tank under appropriately selected flash conditions to be contained in the organic solvent solution. The volatile components are removed and the PAS particulates are precipitated.

As the flash tank, a flash device known per se having an appropriately selected capacity, a polymer heater heat transfer area, and the like can be used as long as flash distillation can be performed. For example, a flash drum capable of automatically controlling various conditions such as temperature and pressure can be preferably used.

The flash conditions include pressure, temperature, time, the concentration of the organic solvent solution, the processing speed of the organic solvent solution, and the like.

The pressure is usually lower than the polymerization reaction pressure in the PAS polymerization step.
0 × 10 ⁻³ Torr to atmospheric pressure is preferable, and especially 1 to 10
0 Torr is preferred. If the pressure is higher than the polymerization reaction pressure in the PAS polymerization step, the flash may be incomplete and the volatile components may not be sufficiently removed from the organic solvent solution.

The temperature is usually higher than the melting point of PAS, preferably 285 to 370 ° C., more preferably 29 to 370 ° C.
0-350 ° C is preferred. The temperature can be adjusted by appropriately setting the polymer heater temperature. If the temperature is lower than the melting point of the PAS, the PAS may be precipitated while containing the volatile component, and in this case, a high-quality PAS containing no impurities cannot be produced.

The time is usually from 0.01 to 120.
Minutes, preferably 0.01 to 30 minutes, particularly 0.05
-20 minutes is preferred. If the time is less than 0.01 minutes, the flash may be incomplete and the volatile components may not be sufficiently removed from the organic solvent solution. On the other hand, even if it exceeds 120 minutes, the effect corresponding to it may not be obtained.

The concentration of the organic solvent solution is such that the weight ratio of aprotic organic polar solvent / (PAS + aprotic organic polar solvent) is usually 100 wtppm to 70 wt%, preferably 1000 wtppm to 50 wt%. Particularly, 2000 wtppm to 50 wt% is preferable.
If the concentration exceeds 70 wt% , the amount of volatile components that must be removed is too large, and the size of the flash tank and the heat exchanger are too large, which may not be economical.

The volatile components can be removed by the above-mentioned flash step. The volatile component is usually
It is a solution component containing the aprotic organic polar solvent in a high proportion of 95% by weight or more and slightly containing dihalogen aromatic compounds and the like as impurities. Specifically, the aprotic organic polar solvent is N-methyl-2-pyrrolidone (hereinafter, referred to as N-methyl-2-pyrrolidone).
Sometimes referred to as NMP. )), When the dihalogen aromatic compound is p-dichlorobenzene (hereinafter sometimes referred to as PDCB), it is a solution component containing 95% by weight or more of NMP and 5% by weight or less of PDCB.

Among the volatile components removed here, the aprotic organic polar solvent can be reused by performing distillation or the like after the removal, and in this case, the cost can be reduced.

In the present invention, the removal of the volatile components may be performed by a single flash step, or may be performed by two or more flash steps. In order to sufficiently remove the volatile components, two or more flash steps are preferable.

The flash step may be performed in a batch system or a continuous system. In the case of the continuous type, the organic solvent solution is continuously supplied to the flash tank set to a predetermined condition, and a PAS polymer is withdrawn by starting a withdrawal pump such as a gear pump, and volatilized by using a vacuum pump or the like. Extract the sexual component. In this case, the supply amount of the organic solvent solution and the extraction amount of the PAS polymer can be appropriately selected.

The method of obtaining PAS granules from the PAS polymer melt from which volatile components have been removed obtained in the flash step is not particularly limited, but examples thereof include methods such as strand cutting and underwater cutting. be able to. In the present invention, PAS granules from which volatile components have been removed can be obtained, so that there is no need to perform complicated steps such as washing and drying the slurry liquid after the flashing step. As a result, expensive equipment such as a dryer is not required, and cost reduction and simplification of operation can be achieved. In the present invention, PA
A PAS cleaning step may be provided between the S polymerization step and the flash step, and in this case, the obtained PAS granules have a high quality that does not further contain impurities.

As described above, in the present invention, 1)
By performing only the PAS polymerization step and 2) the flash step, a high-quality PAS polymer can be produced simply and economically with simple equipment that does not require expensive equipment such as a dryer. When the PAS polymer produced by the method of the present invention is used for various products,
For example, it can be molded by blending other polymer, pigment, graphite, metal powder, glass powder, quartz powder, filler such as glass fiber, stabilizer, release agent and the like. The PAS polymer obtained by the method of the present invention can be used as a matrix resin of various molded articles and composite materials, and can be formed into films, sheets, fibers, various molded articles, and the like. -It can be suitably used in a wide field such as an electronic field and a high-rigidity material field.

[0064]

EXAMPLES Examples and comparative examples of the present invention will be described below. The present invention is not limited to these embodiments.

(Examples 1 to 7) 1) PPS polymerization step A 10 L autoclave was used as a polymerization reaction tank, and 860.13 g of p-dichlorobenzene (hereinafter sometimes referred to as PDCB) was contained therein. 86 mol),
1380.5 g of lithium N-methylaminobutyrate (hereinafter sometimes referred to as LMAB) (11.952 mo)
1) and N-methyl-2-pyrrolidone (hereinafter referred to as NMP)
It may be called. ) Dissolved in 3000 ml, and further accommodated a solution in which 199.7 g (5.86 mol) of hydrogen sulfide was dissolved. Next, the solution was added in a closed system to 140-1.
After stirring at 50 ° C. for 1 hour, prepolymerization was performed at 200 ° C. for 5 hours. Thereafter, a polymerization reaction was further performed at 260 ° C. for 3 hours to obtain a PPS polymerization reaction product.

After the completion of the polymerization reaction, this PPS polymerization reaction product was allowed to stand to separate into a reaction solvent containing no PPS polymer and an organic solvent solution containing the PPS polymer in a molten state. A part of the organic solvent solution was withdrawn from a withdrawal line provided at the bottom of the polymerization reactor, cooled, washed with water and acetone, dried, and the molecular weight was measured. The result was η _inh = 0.25. Was.

2) Flush Step The separated organic solvent solution was passed through a 10 L autoclave through a stainless steel tube having an inner diameter of 8 mm and kept warm for 5 minutes.
L-scale flash drum (manufactured by Mitsui Engineering & Shipbuilding Co., Ltd .; S
US316L). At this time, the moving amount of the organic solvent solution was controlled to be constant by a needle valve provided in the middle of the stainless steel tube.

Then, a flash step was performed in the flash drum under the conditions shown in Table 1. Thereafter, the PAS melt from which volatile components were removed was strand-cut to obtain PPS granules. Regarding the amount of volatile components remaining in the obtained PPS granules,
Analysis was performed by purge trap gas chromatography. The results are shown in Table 1.

Thousands of ppm by the first flash process
It was confirmed that the amount of volatile components remaining to a certain extent could be reduced. Further, when a second flash step was performed, the amount of the residual volatile components was reduced to 60 pp.
m was confirmed to be able to be reduced to about m.

[0070]

[Table 1]

(Comparative Example 1) P obtained in the same manner as in Example 1
The PS polymerization reaction product was cooled while stirring, and the resulting PPS was obtained.
The granules were washed with water and dried in a vacuum dryer.
The amount of volatile components remaining in the dried PPS granules was analyzed by purge trap gas chromatography in the same manner as in Example 1. The results are shown in Table 2.

[0072]

[Table 2]

(Example 8) 1) PPS polymerization step An alkali sulfide, a dihalogen aromatic compound and an aprotic organic polar solvent in the amounts and types shown in Table 3 were used.
A mixing operation, a distillation operation and a polymerization reaction operation were performed according to the conditions shown in Table 3. Note that a 2 L SUS316L autoclave was used as a polymerization reaction tank.

While the obtained PPS polymerization reaction product was kept at a high temperature (260 ° C.), it was transferred to a pressure filter provided with a 10 μm filter to remove NaCl as a by-product.

[0075]

[Table 3]

2) Flashing step The organic solvent solution containing PAS after the removal was used in Example 1.
As well as led to a flash drum. And Example 1
A flash step was performed in the same manner as in Example 1 to obtain PPS granules. The amount of volatile components remaining in the obtained PPS granules was analyzed by purge trap gas chromatography. The results are shown in Table 1.

[0077]

According to the present invention, polyarylene sulfide suitable for a wide range of fields such as electric and electronic fields and high-rigidity materials can be easily and economically manufactured with simple equipment that does not require expensive equipment such as a dryer. Can be provided.

────────────────────────────────────────────────── (5) References JP-A-2-298515 (JP, A) US Patent 4,415,643 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 75 / 00-75/02

Claims (2)

(57) [Claims] 1. A molten poly (arylene sulfide) polymer obtained by a polymerization reaction of lithium N-methylaminobutyrate, hydrogen sulfide and a dihalogen aromatic compound in an aprotic organic polar solvent. A method for producing polyarylene sulfide, comprising isothermally flashing an organic solvent solution containing an arylene sulfide polymer in a flash tank at a temperature of 285 to 370 ° C. 2. An organic solvent containing a polyarylene sulfide polymer in a molten state, which is separated from a polyarylene sulfide polymerization product obtained by polymerizing an alkali sulfide and a dihalogen aromatic compound in an aprotic organic polar solvent. The solution was placed in a flash tank at 285-3
A method for producing polyarylene sulfide, comprising isothermally flashing at a temperature of 70 ° C.