JPH08198966A - Production of polyarylene sulfide - Google Patents

Abstract

PURPOSE: To economically produce a polyarylene sulfide(PAS) having high heat resistance and mechanical strengths and excellent in adhesion to an epoxy resin, etc. CONSTITUTION: In this process for the production of a polyarylene sulfide by reaction of an alkali metal sulfide with a dihaloaromatic compound in an organic amide-based solvent 0.5 to 5.0mol%, based on the alkali metal sulfide, of a functional group-containing halosubstituted aromatic compound is added to the reaction system before or during the reaction to carry out the reaction to obtain a slurry of the polyarylene sulfide, which is then filtered and the resultant solvent-containing filtered cake is heated at 150 to 250 deg.C in a non- oxidative gas atmosphere so as to eliminate the solvent and subsequently, the cake is washed with water.

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 polyarylene sulfide (hereinafter sometimes abbreviated as PAS), and more specifically to a method for producing PAS excellent in adhesiveness with epoxy resin or thermoplastic resin. .

[0002]

2. Description of the Related Art PAS is widely used for electric / electronic parts or mechanical parts because it has excellent heat resistance and molding processability and further has good chemical resistance, flame retardancy and dimensional stability. . However, PAS has relatively poor adhesiveness with other resins, especially with epoxy resin. Therefore, for example, when the PASs are bonded to each other with an epoxy adhesive, the PASs are bonded to another material, or the electric / electronic components are sealed with an epoxy resin, poor adhesion between the PAS and the epoxy resin is a problem. It was.

In view of such problems, various attempts have been made to improve the adhesion between PAS and epoxy resin. For example, JP-A-2-272063 discloses a polyphenylene sulfide (hereinafter sometimes abbreviated as PPS) resin composition containing carnauba wax, JP-A-4-275368.
Japanese Patent Laid-Open No. 5-1711041 discloses a PPS resin composition prepared by mixing a fibrous and / or non-fibrous filler with a polyalkylene ether compound, and Japanese Patent Laid-Open No. 5-171041 discloses a super absorbent polymer such as a crosslinked polyacrylate. A PPS resin composition containing, an aromatic sulfone compound in JP-A-6-57136,
And P containing a fibrous and / or non-fibrous filler
PS resin composition, JP-A-6-107946 discloses a PPS resin composition containing an aliphatic polyester, and a fibrous and / or non-fibrous filler, and JP-A-6-107946.
No. 166816 discloses a P containing a poly (ethylenecyclohexanedimethylene terephthalate) copolymer.
Each PS resin composition is disclosed. However, in any of the above, the addition of a substance having a lower heat resistance than PPS has resulted in a decrease in the heat resistance of the resin composition and, in some resin compositions, a marked decrease in the mechanical strength.

Further, JP-A-4-198267 discloses a PAS resin composition containing a PAS containing a carboxyl group, and JP-A-5-25388 discloses a PAS resin composition containing a PAS containing an amino group. ing. However, the adhesive strength of the obtained PAS was not sufficient.

[0005]

The present invention is based on the conventional PA.
In addition to the high heat resistance and mechanical strength of S, it is possible to make PAS that has excellent adhesiveness to epoxy resin, etc. Moreover, the recovery rate of the solvent is high, and the water washing process can be simplified. It is intended to provide a method of producing a highly advantageous and cost-effective one.

[0006]

The present invention relates to a method for producing a polyarylene sulfide by reacting an alkali metal sulfide with a dihaloaromatic compound in an organic amide solvent, wherein the alkali metal sulfide is 0%. By adding 0.5 to 5.0 mol% of a functional group-containing halo-substituted aromatic compound in the reaction system before or during the reaction of the alkali metal sulfide and the dihalo-aromatic compound, and reacting After filtering the obtained slurry of polyarylene sulfide, the obtained solvent-containing filter cake is heated to 150-150 ° C. under a non-oxidizing gas atmosphere.
A method for producing a polyarylene sulfide, which comprises heating at a temperature of 250 ° C. to remove a solvent and then washing with water.

The functional group-containing halo-substituted aromatic compound added in this method has a lower limit of 0.5 mol% and an upper limit of 5.0 mol%, preferably 3.5 mol, based on the alkali metal sulfide. %. If it is less than the above lower limit, the adhesiveness is hardly improved. When the amount exceeds the above upper limit, the thermal stability of the produced PAS is remarkably deteriorated, so that a gel-like substance is generated during molding and the moldability is extremely deteriorated. The functional group-containing halo-substituted aromatic compound can be added to the reaction system at any time before or during the reaction between the alkali metal sulfide and the dihalo-aromatic compound. It is preferably added to the reaction system before the reaction, and the temperature in the reaction system is preferably 12
It is 0 to 200 ° C. Further, in this method, a relatively large amount of the functional group-containing halo-substituted aromatic compound remains unreacted in the reaction system. Therefore, it is preferable to separate and collect this after the reaction.

The functional group-containing halo-substituted aromatic compound used in the present invention has at least one aromatic ring,
It has a functional group on at least one carbon atom among the carbon atoms forming the aromatic ring and / or at least one carbon atom forming the side chain of the aromatic ring, and simultaneously forms an aromatic ring. It is possible to use an aromatic compound in which a halogen atom is bonded to at least two carbon atoms among the carbon atoms to be used. Here, examples of the aromatic ring include a benzene ring, a naphthalene ring, and an anthracene ring. Of these, a benzene ring is preferable.

When the functional group-containing halo-substituted aromatic compound has two or more aromatic rings, those aromatic rings are:
It may be directly bonded by a single bond or may be bonded via a divalent group. Examples of the divalent group include divalent hydrocarbon residues such as oxygen atom, sulfur atom, sulfinyl group, sulfonyl group, carbonyl group, oxyalkylene group, carbonylalkylene group, and polymethylene group. .

Examples of the functional group include active hydrogen-containing groups, ie, --NH ₂ , --SH, --OH, --NHR, --COOH,
-CONH _2, mention may be made of a -CONHR. R in the above functional groups represents an alkyl group, a cycloalkyl group, an aryl group, an alkaryl group, or an aryl-substituted alkyl group. Of these functional groups, —NH ₂ and —COOH are preferable. As the halogen atom, fluorine, chlorine, bromine and iodine atoms are preferable, and chlorine atom is particularly preferable.

As the halo-substituted aromatic compound containing a functional group, JP-A-62-95320 or JP-A-62-185 is known.
The one described in Japanese Patent No. 717 can be used. Examples of the functional group-containing halo-substituted aromatic compound having -NH ₂ as a functional group include 2,5-dichloroaniline and 2,6
-Dichloroaniline, 2,4-dichloroaniline, 2,
3-dichloroaniline, 3,5-dichloroaniline,
2,4-dibromoaniline, 2,2'-diamino-4,
4'-dichlorodiphenyl ether, 2,4'-diamino-2 ', 4-dichlorodiphenyl ether, 2,2'
-Diamino-4,4'-dichlorodiphenyl thioether, 2,4'-diamino-2 ', 4-dichlorodiphenyl thioether, 2,2'-diamino-4,4'-dichlorodiphenyl sulfoxide, 2,4'-diamino -2
′, 4-Dichlorodiphenyl sulfoxide, 2,2′-
Diamino-4,4'-dichlorodiphenylmethane, 2,
4'-diamino-2 ', 4-dichlorodiphenylmethane, 2,5-dichloro-4'-aminodiphenyl ether, 2,5-dibromo-4'-aminodiphenyl ether, 2,5-dichloro-4'-aminodiphenylthioether, 2,5-dibromo-4'-aminodiphenyl thioether, 2,5-dichloro-4'-aminodiphenyl sulfoxide, 2,5-dibromo-4'-aminodiphenyl sulfoxide, 2,5-dichloro-4'-aminodiphenylmethane Aromatic compounds such as 2,5-dibromo-4'-aminodiphenylmethane and 2,3,4
-Trichloroaniline, 2,3,5-trichloroaniline, 2,3,6-trichloroaniline, 2,4,5-trichloroaniline, 2,4,6-trichloroaniline,
3,4,5-trichloroaniline, 2,3,4-tribromoaniline, 2,3,5-tribromoaniline, 2,
3,6-tribromoaniline, 2,4,5-tribromoaniline, 2,4,6-tribromoaniline, 3,4
5-tribromoaniline, 2,5-dichloro-4-bromoaniline, 2,2'-diamino-3,4,4'-trichlorodiphenyl ether, 2,4'-diamino-2
′, 5 ′, 4-trichlorodiphenyl ether, 2,
4,5-Trichloro-4'-aminodiphenyl ether, 2,3,4-trichloro-4'-aminodiphenyl ether, 2,4,5-tribromo-4'-aminodiphenyl ether, 2,4,6-tribromo-4 ' -Aminodiphenyl ether, 2,5-dichloro-6-bromo-4'-aminodiphenyl ether, 2,4,5-trichloro-2'-aminodiphenyl ether, 2,2'-
Diamino-3,4,4'-trichlorodiphenylthioether, 2,4,5-trichloro-4'-aminothioether, 2,2'-diamino-4,5,4'-trichlorodiphenyl sulfoxide, 2,4,5 -Trichloro-
4'-aminodiphenyl sulfoxide, 2,2'-diamino-3,4,4'-trichlorodiphenylmethane,
Trihaloaromatic compounds such as 2,4,5-trichloro-4'-aminodiphenylmethane, 2,4,4'-trichloro-2'-aminodiphenylpropane and 3,4,4'-trichloro-3'-aminobiphenyl And 2, 3, 4,
Examples thereof include polyhaloaromatic compounds such as 5-tetrachloroaniline, 2,3,5,6-tetrachloroaniline, tetrachloroaminodiphenyl ether and tetrachloroaminodiphenylthioether. -CO as a functional group
As the halo-substituted aromatic compound having a functional group having OH,
For example, 2,6-dichlorobenzoic acid, 2,5-dichlorobenzoic acid, 2,4-dichlorobenzoic acid, 2,3-dichlorobenzoic acid, 2,6-dibromobenzoic acid, 2,5-dibromobenzoic acid, 2 Aromatic compounds such as 2,4-dibromobenzoic acid and 2,3-dibromobenzoic acid, and 2,3,4-
Trichlorobenzoic acid, 2,3,5-trichlorobenzoic acid, 2,3,6-trichlorobenzoic acid, 2,4,5-trichlorobenzoic acid, 2,4,6-trichlorobenzoic acid,
3,4,5-Trichlorobenzoic acid, 2,3,4-Tribromobenzoic acid, 2,3,5-Tribromobenzoic acid, 2,
3,6-tribromobenzoic acid, 2,4,5-tribromobenzoic acid, 2,4,6-tribromobenzoic acid, 3,4
Trihaloaromatic compounds such as 5-tribromobenzoic acid may be mentioned. Examples of the functional group-containing halo-substituted aromatic compound having -SH as a functional group include 2,6-dichlorothiophenol, 2,5-dichlorothiophenol, 2,4
-Dichlorothiophenol, 2,3-dichlorothiophenol, 2,2'-dimercapto-4,4'-dichlorodiphenyl ether, 2,4'-dimercapto-2 ',
4-dichlorodiphenyl ether, 2,2'-dimercapto-4,4'-dichlorodiphenyl thioether,
2,4'-dimercapto-2 ', 4-dichlorodiphenylthioether, 2,2'-dimercapto-4,4'-
Dichlorodiphenyl sulfoxide, 2,4'-dimercapto-2 ', 4-dichlorodiphenyl sulfoxide,
2,2'-dimercapto-4,4'-dichlorodiphenylmethane, 2,4'-dimercapto-2 ', 4-dichlorodiphenylmethane, 2,5-dichloro-4'-mercaptodiphenyl ether, 2,5-dibromo-4' -Mercaptodiphenyl ether, 2,5-dichloro-4 '
-Mercaptodiphenyl thioether, 2,5-dibromo-4'-mercaptodiphenyl thioether, 2,5
-Dichloro-4'-mercaptodiphenyl sulfoxide, 2,5-dibromo-4'-mercaptodiphenyl sulfoxide, 2,5-dichloro-4'-mercaptodiphenylmethane, 2,5-dibromo-4'-mercaptodiphenylmethane, 2,5 Dihalo aromatic compounds such as -dibromo-4'-mercaptodiphenyl ether and 2,
3,4-trichlorothiophenol, 2,3,5-trichlorothiophenol, 2,3,6-trichlorothiophenol, 2,4,5-trichlorothiophenol,
2,4,6-Trichlorothiophenol, 3,4,5-
Trichlorothiophenol, 2,3,4-tribromothiophenol, 2,3,5-tribromothiophenol, 2,3,6-tribromothiophenol, 2,4
5-tribromothiophenol, 2,4,6-tribromothiophenol, 3,4,5-tribromothiophenol, 2,2'-dimercapto-3,4,4'-trichlorodiphenyl ether, 2,4 5-trichloro-4
′ -Mercaptodiphenyl ether, 2,2′-dimercapto-4,5,4′-trichlorodiphenylthioether, 2,4,5-trichloro-4′-mercaptodiphenylthioether, 2,2′-dimercapto-3
5,4'-trichlorodiphenyl sulfoxide, 2,
4,5-Trichloro-4'-mercaptodiphenyl sulfoxide, 3,3'-dimercapto-4,4 ', 5-trichlorodiphenylmethane, 2,4,5-trichloro-
4'-mercaptodiphenylmethane, 3,3'-dimercapto-4,4 ', 5-trichlorobiphenyl, 3,
Examples include trihaloaromatic compounds such as 4,5-trichloro-4'-mercaptobiphenyl. -O as a functional group
Examples of the functional group-containing halo-substituted aromatic compound having H include 2,6-dichlorophenol, 2,5-dichlorophenol, 2,4-dichlorophenol, 2,3-dichlorophenol, 3,4-dichlorophenol, 3,5
-Dichlorophenol, 2,4-dibromophenol,
2,6-dibromophenol, 2,2'-dihydroxy-4,4'-dichlorodiphenyl ether, 2,4'-
Dihydroxy-2 ', 4-dichlorodiphenyl ether, 2,2'-dihydroxy-4,4'-dichlorodiphenyl thioether, 2,4'-dihydroxy-2',
4-dichlorodiphenyl thioether, 2,2'-dihydroxy-4,4'-dichlorodiphenyl sulfoxide, 2,4'-dihydroxy-2 ', 4-dichlorodiphenyl sulfoxide, 2,2'-dihydroxy-4,4
′ -Dichlorodiphenylmethane, 2,4′-dihydroxy-2 ′, 4-dichlorodiphenylmethane, 2,5-dichloro-4′-hydroxydiphenyl ether, 2,5
-Dibromo-4'-hydroxydiphenyl ether,
2,5-dichloro-4'-hydroxydiphenyl thioether, 2,5-dibromo-4'-hydroxydiphenyl thioether, 2,5-dichloro-4'-hydroxydiphenyl sulfoxide, 2,5-dibromo-4'-hydroxydiphenyl Sulfoxide, 2,5-dichloro-
Dihalo aromatic compounds such as 4'-hydroxydiphenylmethane, 2,5-dibromo-4'-hydroxydiphenylmethane, 2,5-dibromo-4'-hydroxydiphenyl ether and 2,3,4-trichlorophenol,
2,3,5-trichlorophenol, 2,3,6-trichlorophenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 3,4,5-
Trichlorophenol, 2,3,4-tribromophenol, 2,3,5-tribromophenol, 2,3,6
-Tribromophenol, 2,4,5-tribromophenol, 2,4,6-tribromophenol, 3,4
5-tribromophenol, 2,2'-dihydroxy-
3,4,4'-trichlorodiphenyl ether, 2,
4,5-Trichloro-4'-hydroxydiphenyl ether, 2,2'-dihydroxy-3,4,4'-trichlorodiphenylthioether, 2,4,5-trichloro-4'-hydroxydiphenylthioether, 2,2 '
-Dihydroxy-4,4 ', 5-trichlorodiphenyl sulfoxide, 2,4,5-trichloro-4'-hydroxydiphenyl sulfoxide, 2,2'-dihydroxy-4,4', 5-trichlorodiphenylmethane, 2,
Trihalo aromatic compounds such as 4,6-trichloro-4'-hydroxydiphenylmethane, 3-hydroxy-3,4,4'-trichlorobiphenyl, and 3,4,5-trichloro-4'-hydroxybiphenyl can be mentioned. Examples of the functional group-containing halo-substituted aromatic compound having -NHR as a functional group include 2,6-dichloro (phenyl) aminobenzene, 2,5-dichloro (phenyl) aminobenzene, and 2,4-dichloro (phenyl) amino. benzene,
Dihaloaromatic compounds such as 2,3-dichloro (phenyl) aminobenzene and 2,3,4-trichloro (phenylamino) benzene, 2,3,5-trichloro (phenylamino) benzene, 2,3,6-trichloro (Phenylamino) benzene, 2,4,5-trichloro (phenylamino) benzene, 2,4,6-trichloro (phenylamino) benzene, 3,4,5-trichloro (phenylamino) benzene, 2,3,4 -Tribromo (phenylamino) benzene, 2,3,5-tribromo (phenylamino) benzene, 2,3,6-tribromo (phenylamino) benzene, 2,4,5-tribromo (phenylamino) benzene, 2,4 , 6-Tribromo (phenylamino) benzene, 3,4,5-Tribromo (phenylamino) benzene Include trihalo aromatic compounds. Among the above, a functional group-containing halo-substituted aromatic compound having —NH ₂ as a functional group is preferably used, and dichloroaniline is particularly preferable.

The organic amide solvents used in the present invention are known for PAS polymerization, such as N-methylpyrrolidone (NMP), N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl Caprolactam, etc., and mixtures thereof can be used, NMP
Is preferred. They all have a lower vapor pressure than water.

Alkali metal sulphides are also known, for example lithium sulphide, sodium sulphide, potassium sulphide, rubidium sulphide, cesium sulphide and mixtures thereof. These hydrates and aqueous solutions may be used. Further, hydrosulfides and hydrates corresponding to these can be used after being neutralized with the corresponding hydroxides.
Inexpensive sodium sulfide is preferred.

The dihalo aromatic compound is, for example, Japanese Patent Publication No.
It can be selected from those described in JP-A-5-3368, but is preferably p-dichlorobenzene. Further, a copolymer can be obtained by using a small amount (20 mol% or less) of one or more kinds of para, meta or orthodihalo compounds of diphenyl ether, diphenyl sulfone or biphenyl. For example, m-dichlorobenzene, o-dichlorobenzene,
p, p'-dichlorodiphenyl ether, m, p'-dichlorodiphenyl ether, m, m'-dichlorodiphenyl ether, p, p'-dichlorodiphenyl sulfone, m, p'-dichlorodiphenyl sulfone, m, m '
-Dichlorodiphenyl sulfone, p, p'-dichlorobiphenyl, m, p'-dichlorobiphenyl, m, m'-
It is dichlorobiphenyl.

The reaction itself between the alkali metal sulfide and the dihaloaromatic compound in the organic amide solvent can be carried out in a known manner. During the reaction, it is preferable to cool a gas phase portion of the reaction can to condense a part of the gas phase in the reaction can and to reflux this to a liquid phase. This makes it possible to avoid depolymerization of the produced PAS and to produce a higher molecular weight PAS.

As a method of condensing a part of the gas phase in the reaction can by cooling the gas phase part of the reaction can and returning it to the liquid phase, the method described in JP-A-5-222196 is disclosed. Can be used.

The refluxed liquid has a high water content compared to the liquid phase bulk because of the difference in vapor pressure between water and the amide solvent.
This reflux liquid having a high water content forms a layer having a high water content on the reaction solution. As a result, the residual alkali metal sulfide (for example, Na ₂ S), alkali metal halide (for example, NaCl), oligomer and the like are contained in a large amount in the layer. In the conventional method, at a high temperature of 230 ° C. or higher, when the generated PAS and the raw materials such as Na ₂ S and by-products are uniformly mixed, not only high-molecular-weight PAS cannot be obtained but Depolymerization of PAS also occurred, and thiophenol by-product was observed. However, in the present invention, by positively cooling the gas phase portion of the reaction vessel and returning a large amount of water-rich reflux liquid to the upper portion of the liquid phase, the above-mentioned inconvenient phenomenon can be avoided and the reaction is inhibited. Of high molecular weight PA
It seems that S can be obtained. However, the present invention is not limited only to the effects due to the above-mentioned phenomenon, and high-molecular weight PAS can be obtained by various influences caused by cooling the gas phase portion.

In the present invention, it is not necessary to add water during the reaction unlike the conventional method. However, the addition of water is not excluded at all. However, some of the advantages of the present invention are lost if the operation of adding water is performed. Therefore, preferably, the total water content in the polymerization reaction system is constant throughout the reaction.

The gas phase portion of the reaction can can be cooled by external cooling or internal cooling, and can be performed by a cooling means known per se. For example, a method of flowing a cooling medium into an internal coil installed in the upper part of the reaction can, a method of flowing a cooling medium into an external coil or jacket wound around the upper part of the outside of the reaction can, and a reflux condenser installed in the upper part of the reaction can are used. The method may be such as sprinkling water or blowing gas (air, nitrogen, etc.) on the upper part of the outside of the reaction can. Any method is effective as long as it has the effect of increasing the reflux amount in the can. May be used. If the outside air temperature is relatively low (for example, room temperature), it is also possible to perform appropriate cooling by removing the heat insulating material conventionally provided on the upper part of the reaction can. In the case of external cooling, water condensed on the reactor wall surface
The amide-based solvent mixture enters the liquid phase along the wall of the reaction vessel. Thus, the water-rich mixture pools on top of the liquid phase,
Keep the water content there relatively high. For internal cooling,
The mixture condensed on the cooling surface likewise travels along the surface of the cooling device or the wall of the reaction vessel into the liquid phase.

On the other hand, the temperature of the liquid phase bulk is maintained at a predetermined constant temperature or controlled according to a predetermined temperature profile. 230 to 275 for constant temperature
It is preferable to carry out the reaction at a temperature of ° C for 0.1 to 20 hours. More preferably, the temperature is 240 to 265 ° C. and the time is 1 to 6 hours. To obtain higher molecular weight PAS, it is preferable to use a reaction temperature profile of two or more steps. This 2
When carrying out the stepwise operation, the first step is preferably carried out at a temperature of 195 to 240 ° C. If the temperature is low, the reaction rate is too slow, which is not practical. If the temperature is higher than 240 ° C., the reaction rate is too fast, PAS having a sufficiently high molecular weight cannot be obtained, and the side reaction rate remarkably increases. The end of the first stage is
Dihalo aromatic compound residual rate in the polymerization reaction system is 1 mol% to 40
It is preferable to carry out at a time of mol% and a molecular weight in the range of 3,000 to 20,000. More preferably, the residual ratio of the dihalo-aromatic compound in the polymerization reaction system is 2 mol% to 15 mol% and the molecular weight is 5,000 to 15,000. Residual rate is 40 mol%
When it is more than 1, the side reaction such as depolymerization is likely to occur in the second step reaction, while when it is less than 1 mol%, the high molecular weight P is finally obtained.
It is difficult to get AS. Thereafter, the temperature is raised, and the reaction in the final stage is preferably carried out at a reaction temperature of 240 to 270 ° C. for 1 to 10 hours. PAS with sufficiently high molecular weight at low temperature
At a temperature higher than 270 ° C., side reactions such as depolymerization are likely to occur, making it difficult to stably obtain a high molecular weight product.

As a practical operation, first, dehydration or water addition is carried out in an inert gas atmosphere, if necessary, so that the amount of water in the alkali metal sulfide in the amide solvent becomes a predetermined amount. The water content is preferably alkali metal sulfide 1
The amount is 0.5 to 2.5 mol, especially 0.8 to 1.2 mol per mol. If it exceeds 2.5 mols, the reaction rate will be low, and the amount of by-products such as phenol will increase in the filtrate after the reaction and the degree of polymerization will not increase. If it is less than 0.5 mol, the reaction rate is too fast to obtain a sufficiently high molecular weight product, and unfavorable reactions such as side reactions occur.

In the case of the one-step reaction at a constant temperature, the cooling of the gas phase portion during the reaction is preferably performed from the start of the reaction, but it must be performed at least during the temperature increase of 250 ° C. or less. In the multi-stage reaction, it is preferable to perform cooling from the first-stage reaction, but it is preferable to perform cooling at the latest after the completion of the first-stage reaction. Regarding the degree of cooling effect, the pressure inside the reaction vessel is usually the most suitable index. The absolute value of the pressure varies depending on the characteristics of the reaction vessel, the stirring state, the water content in the system, the molar ratio of the dihalo aromatic compound to the alkali metal sulfide, and the like. However, as compared with the case of not cooling under the same reaction conditions, if the reactor pressure is decreased, the amount of reflux liquid is increased, which means that the temperature at the reaction solution gas-liquid interface is decreased. It is considered that the degree of relative decrease indicates the degree of separation between the layer having a high water content and the layer having no water content. Therefore, it is preferable to cool the reactor so that the internal pressure of the reactor becomes lower than that in the case where no cooling is performed. The degree of cooling can be appropriately set by those skilled in the art according to the equipment used, operating conditions, and the like.

PAS having a desired viscosity can be produced by variously selecting the above reaction conditions.

In order to increase the molecular weight of PAS,
For example, 1,3,5-trichlorobenzene, 1,2,4-
A polyhalo compound such as trichlorobenzene can also be used in a concentration of preferably 5 mol% or less based on the total amount of para and metadihalo aromatic compounds.

Further, as a small amount of other additives, a terminal terminating agent and a monohalo compound as a modifying agent can be used in combination.

In the present invention, P obtained in the above process
After filtering the AS slurry, the solvent-containing filter cake obtained is heated at a temperature of 150 to 250 ° C. in a non-oxidizing gas atmosphere to remove the solvent, and then washed with water.

For example, the PAS obtained as described above
The slurry is filtered to give a PAS cake with solvent. The PAS cake is then helium, argon, hydrogen,
An oxygen concentration in a non-oxidizing gas stream such as nitrogen is preferably 5.
In a nitrogen gas stream of less than 0% by volume, at a temperature of 150 to 250 ° C, preferably 180 to 230 ° C, preferably 0.5.
It is heated for -20 hours, particularly preferably for 1-10 hours.
The heating is preferably carried out under normal pressure to 3 atm, particularly preferably under normal pressure. If the heating temperature is less than the above lower limit, it takes a long time to remove the solvent, resulting in a decrease in productivity. If the upper limit is exceeded, the PAS is markedly colored, which is not preferable. By removing the solvent by heating as described above, P
Since the adhesive strength of AS can be increased, the steps such as water washing can be simplified and the recovery rate of the solvent can be remarkably improved as compared with the conventional method of removing the solvent by water washing. It is highly cost effective.

Washing with water is preferably carried out by dispersing the above-mentioned heated filter cake in water. For example, the heated PAS cake obtained as described above is put into water, preferably 1 to 5 times by weight, and stirred and mixed at room temperature to 90 ° C. for preferably 5 minutes to 10 hours. After that, it is filtered. By repeating the stirring and mixing and filtering operations preferably 2 to 10 times, the solvent adhering to the PAS and the by-product salt are removed, and the washing with water is completed. By performing water washing as described above, it becomes possible to perform efficient washing with a small amount of water as compared with the washing method in which water is poured into the filter cake.

The PAS produced by the method of the present invention is
Since rapid crystallization does not proceed, it is possible to suppress the occurrence of cracks due to molding shrinkage and the like, and it has high adhesiveness with epoxy resins and thermoplastic resins. Therefore, it is useful in the field of sealing electric / electronic parts.

When the PAS of the present invention is molded and processed, conventional additives such as powdered fillers such as carbon black, calcium carbonate, silica and titanium oxide, or carbon fibers, glass fibers, asbestos fibers, polyaramid fibers are used. Fibrous fillers such as can be mixed.

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

[0032]

EXAMPLES In the examples, the melt viscosity V ₆ was 300 using a flow tester CFT-500C manufactured by Shimadzu Corporation.
It is a viscosity (poise) measured after holding for 6 minutes at L / D = 10 at a temperature of 20 kgf / cm ² and a load of 20 kgf / cm ² .

The crystallization temperature T _c was measured by DSC. The device is a differential scanning calorimeter SS manufactured by Seiko Denshi.
It measured using C / 5200 as follows. 10 mg of the sample was heated from room temperature to 320 ° C. at a heating rate of 20 ° C./min in a nitrogen stream, and then held at 320 ° C. for 5 minutes to melt. It was then cooled at a rate of 10 ° C / min. The exothermic peak temperature at this time was defined as the crystallization temperature _Tc .

Paradichlorobenzene (hereinafter p-DC
The reaction rates of B) and 2,5-dichloroaniline (hereinafter sometimes abbreviated as DCA) were calculated from the measurement results by gas chromatography. Here, each reaction rate was calculated by the following formula.

[0035]

## EQU1 ## Reaction rate (%) of p-DCB = (1-remaining p-D
CB weight / p-DCB weight) × 100

[0036]

## EQU00002 ## DCA reaction rate (%) = (1-remaining DCA weight / prepared DCA weight) × 100 The adhesive strength was measured as follows. 40 parts by weight of PPS with glass fiber (CS 3J-961S, trademark,
30 parts by weight of Nitto Boseki Co., Ltd. and calcium carbonate (SL-1000, trademark, manufactured by Takehara Chemical Industry Co., Ltd.) 3
After mixing 0 parts by weight, 3 using a twin-screw counter-rotating extruder
The mixture was kneaded at 20 ° C to prepare pellets. Cylinder temperature 320 ℃, mold temperature 130 ℃ from the obtained pellets
A test piece according to JIS K6850 was created by the injection molding machine set to. According to JIS K6850, the obtained test piece was used as an epoxy resin adhesive [manufactured by Nagase Ciba Co., Ltd., main agent (XNR3101, trademark) / curing agent (XNH
3101, trademark) = 100 parts by weight / 33.3 parts by weight] at 90 ° C. for 30 minutes, and then a tensile test is performed at a pulling speed of 5 mm / minute and a chuck distance of 130 mm to obtain the adhesive strength. It was measured. However, for Example 4, without blending glass fiber and calcium carbonate,
A test piece was prepared using only PPS, and the adhesive strength was measured.

[0037]

Example 1 Flake-shaped sodium sulfide (60.4 wt% Na ₂ S) 19.38 was placed in a 150 liter autoclave.
1 kg and N-methyl-2-pyrrolidone (hereinafter NM
45.0 kg was charged. While stirring under a nitrogen stream, the temperature was raised to 209 ° C. and water was reduced to 4.640
kg was distilled (the residual water content was 1.12 mol per mol of sodium sulfide). Then, the autoclave was closed and cooled to 180 ° C, p-DCB22.732kg,
DCA 0.170 kg (0.7 mol% with respect to sodium sulfide) and NMP 18.0 kg were charged. Liquid temperature 150 ℃
Then, the temperature was started by pressurizing to 1 kg / cm ² G with nitrogen gas. When the liquid temperature reaches 260 ° C, stop raising the temperature,
The reaction proceeded with stirring for 2 hours.

The obtained slurry was filtered to remove the solvent, and then the solvent-containing filter cake was heated at 220 ° C. for about 6 hours in a nitrogen stream having an oxygen concentration of less than 3.0% by volume to remove the solvent. Next, the obtained PPS powder is washed with water by a conventional method,
After repeating filtration seven times, it was dried in a hot air circulation dryer at 120 ° C. for about 8 hours to obtain a white powdery polymer.

The reaction rate of p-DCB is 98.6%,
The reaction rate of DCA was 33.1%.

[0040]

Example 2 The procedure of Example 1 was repeated, except that DCA was changed to 0.243 kg (1.0 mol% based on sodium sulfide).

The reaction rate of p-DCB is 98.5%,
The reaction rate of DCA was 34.0%.

[0042]

Example 3 The procedure of Example 1 was repeated, except that DCA was 0.778 kg (3.2 mol% based on sodium sulfide).

The reaction rate of p-DCB is 98.5%,
The reaction rate of DCA was 28.6%.

[0044]

Example 4 With p-DCB being 22.161 kg and DCA being 0.243 kg (1.0 mol% with respect to sodium sulfide), the reaction was carried out at a liquid temperature of 220 ° C. for 5 hours while cooling the upper part of the autoclave with water spray. , And then the temperature is increased to 260
It carried out on the same conditions as Example 1 except having performed at 5 degreeC for 5 hours.

The reaction rate of p-DCB is 98.7%,
The reaction rate of DCA was 38.0%.

[0046]

Comparative Example 1 p-DCB was set to 22.638 kg and DC
It carried out on the same conditions as Example 1 except not adding A.

The reaction rate of p-DCB was 98.4%.

[0048]

COMPARATIVE EXAMPLE 2 The procedure of Example 1 was repeated except that DCA was changed to 1.264 kg (5.2 mol% based on sodium sulfide).

The reaction rate of p-DCB is 98.5%,
The reaction rate of DCA was 38.1%. The obtained polymer was not able to be molded because of its thickening.

[0050]

[Comparative Example 3] The same procedure as in Example 1 was carried out except that the solvent-containing filter cake was not heat-treated for solvent removal, and the washing and filtering operations were repeated 9 times.

The above results are shown in Table 1.

[0052]

[Table 1] In Examples 1 to 3, the amount of DCA added was changed within the range of the present invention. The adhesive strength was high in all cases. Moreover, the adhesive strength increased as the amount of DCA added increased.
In Example 4, the reaction was carried out in two stages and the upper part of the autoclave was cooled. The adhesive strength was high. In addition, the melt viscosity V _{6 of} Example 4 was high, and high molecular weight PPS was used.
It turns out that

On the other hand, in Comparative Example 1, DCA was not added under the same conditions as in Example 1. The adhesive strength of PPS was significantly lower than that of Example 1. Comparative Example 2
Indicates that the amount of DCA added exceeds the range of the present invention under the same conditions as in Example 1. It was found that the obtained PPS had a marked increase in viscosity and could not be molded and was not practical. Comparative Example 3
Was carried out under the same conditions as in Example 1 except that the solvent-containing filter cake was not heat-treated. Compared with Example 1, the adhesive strength of PPS was extremely low.

[0054]

INDUSTRIAL APPLICABILITY The present invention provides a method for producing a PAS excellent in adhesiveness with an epoxy resin or the like in addition to the high heat resistance and mechanical strength of the conventional PAS. Further, since the solvent in the filter cake is removed by heating, the recovery rate of the solvent is extremely high and the water washing step can be simplified. Therefore, the productivity is high and the cost is advantageous.

Claims (6)

[Claims] 1. A method for producing a polyarylene sulfide by reacting an alkali metal sulfide and a dihaloaromatic compound in an organic amide solvent, wherein 0.5 to 5.0 mol% relative to the alkali metal sulfide. By adding the functional group-containing halo-substituted aromatic compound in the reaction system before or during the reaction of the alkali metal sulfide and the dihalo-aromatic compound,
After filtering the slurry of polyarylene sulfide obtained by reacting, the solvent-containing filter cake obtained is heated at a temperature of 150 to 250 ° C. under a non-oxidizing gas atmosphere to remove the solvent, and then washed with water. A method for producing a polyarylene sulfide, which comprises: 2. The method according to claim 1, wherein the functional group-containing halo-substituted aromatic compound is added in an amount of 0.5 to 3.5 mol% based on the alkali metal sulfide. 3. The method according to claim 1 or 2, wherein during the reaction, a part of the gas phase in the reaction can is condensed by cooling the gas phase part of the reaction can, and the gas is refluxed to the liquid phase. 4. The method according to claim 1, wherein the functional group-containing halo-substituted aromatic compound is dichloroaniline. 5. The heating of the filter cake is performed at 180 to 230 ° C.
The method according to any one of claims 1 to 4, wherein 6. The non-oxidizing gas has an oxygen concentration of 5.0% by volume.
The method according to any one of claims 1 to 5, which is less than nitrogen gas.