JPH08176302A - Production of polyarylene sulfide - Google Patents

Abstract

PURPOSE: To economically obtain a polyarylene sulfide(PAS) resin excellent in adhesion to e.g. epoxy resins as well as having high heat resistance and mechanical strength. CONSTITUTION: This PAS resin is obtained by reaction between dihaloaromatic compounds and an alkali metal sulfide in an organic amide solvent. Specifically, the process is as follows: at a point when the conversion of the p-dihaloaromatic compound in the reaction system stands at <80%, 0.5-10mol%, based on the total amount of the dihaloaromatic compounds charged, of a m-dihaloaromatic compound is added to the reaction system, and also during reaction, part of the vapor phase in the reaction vessel is condensed by cooling the vapor phase portion of the reaction vessel and the resultant liquid is refluxed to the liquid phase to obtain a polyarylene sulfide slurry, which is then subjected to filtration, and the resultant solvent-contg. cake is heated at 150-250 deg.C in a nonoxidative gas atmosphere to remove the solvent in the cake, and the solvent-free cake is then washed with water.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing polyarylene sulfide (hereinafter sometimes abbreviated as PAS).

[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, these are produced, for example, by copolymerizing dichlorobenzene having a carboxyl group or an amino group, but there is a production problem that these dichlorobenzenes remain in the reaction system, and adhesion of the obtained PAS It was not strong enough.

[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 a PAS resin that also has excellent adhesiveness to epoxy resin and the like, and since the solvent recovery rate is high and the water washing process can be simplified, It is intended to provide a method of producing with high productivity and cost advantage.

[0006]

The present invention provides a method for producing a polyarylene sulfide by reacting an alkali metal sulfide with a dihaloaromatic compound in an organic amide solvent, comprising a paradihaloaromatic compound and a reaction system. When the reaction rate of the paradihaloaromatic compound is 0 to less than 80%, the amount is 0.5 to 10 relative to the total amount of the charged dihaloaromatic compound.
To add a mol% of metadihaloaromatic compound to the reaction system, and to cool the gas phase part of the reaction vessel during the reaction to condense a part of the gas phase in the reaction vessel and then to reflux it to the liquid phase. After filtering the slurry of polyarylene sulfide obtained by the above, the obtained solvent-containing filter cake 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. Is a method for producing polyarylene sulfide.

In the present invention, it was unexpected that adhesion would be significantly improved without the need to add a third substance or functional group as in the prior art.

In the para and metadihaloaromatic compounds added in the present invention, the lower limit of the amount of the metadihaloaromatic compound is 0.5 mol%, preferably 1 mol%, and the upper limit of the total amount of the charged dihaloaromatic compounds. Is 10 mol%, preferably 5.0 mol%. If it is less than the above range, the adhesiveness of the produced PAS is inferior, and if it exceeds the above range, the melting point of the produced PAS is remarkably lowered, the heat resistance which is the original property of PAS is impaired, and there is a problem in practicality. It is not preferred.

The metadihaloaromatic compound is added when the reaction rate of the paradihaloaromatic compound in the reaction system is 0 to less than 80%. The reaction rate of paradihalo aromatic compounds is 8
When it is 0% or more, the adhesiveness of the produced PAS is poor, the viscosity is lowered, and the metadihaloaromatic compound remains unreacted in the reaction system, which is not preferable. Preferably the para and metadihalo aromatic compounds are added to the reaction system simultaneously. Thus, by simultaneously adding both of them, the adhesiveness of PAS can be further improved. The total amount of para and metadihalo aromatic compounds added to the polymerization reaction system is based on 1 mol of the alkali metal sulfide.
Preferably 0.9 to 1.1 moles, particularly preferably 0.9
It is 6 to 1.05 mol. By using within this range, high molecular weight PAS can be obtained. If the amount added is less than the above range, only PAS having a remarkably low molecular weight can be obtained, and the reaction rates of the para and metadihalo aromatic compounds decrease, which is economically disadvantageous. If it exceeds the above range, depolymerization occurs, which is not preferable. When the metadihaloaromatic compound is charged during the reaction, for example, the metadihaloaromatic compound is directly or dissolved in N-methylpyrrolidone or the like used as an organic amide solvent, and a reaction vessel using a pressure injection pump is used. It can be performed by press-fitting the inside.

The para and metadihaloaromatic compounds used in the method of the present invention are known. For example, it can be selected from those described in JP-B-45-3368, JP-A-2-103232, or JP-B-4-64618.

Examples of the paradihaloaromatic compound include dihalogenated benzenes such as p-dichlorobenzene, p-dibromobenzene and 1-chloro-4-bromobenzene.
Alternatively, 2,5-dichlorotoluene, 2,5-dichloroxylene, 1-ethyl-2,5-dichlorobenzene, 1
-Ethyl-2,5-dibromobenzene, 1-ethyl-2
-Bromo-5-chlorobenzene, 1,3,4,6-tetramethyl-2,5-dichlorobenzene, 1-cyclohexyl-2,5-dichlorobenzene, 1-phenyl-2
5-dichlorobenzene, 1-benzyl-2,5-dichlorobenzene, 1-phenyl-2,5-dibromobenzene, 1-p-toluyl-2,5-dichlorobenzene, 1
Examples thereof include substituted dihalogenated benzenes such as -p-toluyl-2,5-dibromobenzene and 1-hexyl-2,5-dichlorobenzene. Of the above, dihalogenated benzene is preferable, and of these, p-dichlorobenzene is particularly preferable. Moreover, these compounds can be used individually or as a mixture.

Examples of the metadihalo aromatic compound include dihalogenated benzenes such as m-dichlorobenzene, m-dibromobenzene and 1-chloro-3-bromobenzene.
Alternatively, 2,4-dichlorotoluene, 2,4-dichloroxylene, 1-ethyl-2,4-dibromobenzene, 1
-Ethyl-2-bromo-4-chlorobenzene, 1,2,
4,6-Tetramethyl-3,5-dichlorobenzene, 1
-Cyclohexyl-2,4-dichlorobenzene, 1-phenyl-2,4-dichlorobenzene, 1-benzyl-
2,4-dichlorobenzene, 1-phenyl-2,4-dibromobenzene, 1-p-toluyl-2,4-dichlorobenzene, 1-p-toluyl-2,4-dibromobenzene, 1-hexyl- Substituted dihalogenated benzene such as 2,4-dichlorobenzene and the like can be mentioned. Of the above, dihalogenated benzene is preferable, and of these, m-dichlorobenzene is particularly preferable. These compounds can be used individually or as a mixture.

A method for condensing a part of the gas phase in the reaction vessel by cooling the gas phase portion of the reaction vessel of the present invention and returning it to the liquid phase is described in JP-A-5-222196. Can be used.

The refluxed liquid has a high water content compared to the liquid phase bulk because of the vapor pressure difference 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 so that the amount of water in the alkali metal sulfide in the amide solvent becomes a predetermined amount, if necessary. 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.

The organic amide solvent used here is PA
Known for S polymerization, for example N-methylpyrrolidone (NMP), N, N-dimethylformamide,
N, N-dimethylacetamide, N-methylcaprolactam, etc., and mixtures thereof can be used, with NMP being preferred. They all have a lower vapor pressure than water.

Alkali metal sulfides used in the present invention are also known, such as lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide 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.

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,
Heated in a stream of non-oxidizing gas such as nitrogen, preferably in a stream of nitrogen gas at a temperature of 150 to 250 ° C., preferably 180 to 230 ° C., preferably 0.5 to 20 hours, particularly preferably 1 to 10 hours. It The heating is preferably normal pressure to
It is carried out under 3 atmospheres, particularly preferably under normal pressure. By performing the solvent removal by heating as described above, it is possible to increase the adhesive strength of PAS and simplify the steps such as water washing as compared with the conventional method of removing the solvent by water washing.
Moreover, since the recovery rate of the solvent can be remarkably improved, the productivity is high and the cost is advantageous.

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 a thermoplastic resin such as an epoxy resin. 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 and 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.

[0031]

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 .

According to DSC, the crystallization temperature T _c and the melting point T
_m was measured. As an apparatus, a differential scanning calorimeter SSC / 5200 manufactured by Seiko Instruments Inc. was used, and measurement was performed 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 . The endothermic peak temperature when the temperature was raised from room temperature to 320 ° C. at a rate of 10 ° C./min was defined as the melting point T _m .

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

[0034]

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

[0035]

## EQU2 ## Reaction rate (%) of m-DCB = (1-remaining m-D
CB weight / prepared m-DCB 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, Example 5 was carried out by mixing 60 parts by weight of PPS with 40 parts by weight of the glass fiber.

[0036]

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 sealed and cooled to 180 ° C, p-DCB22.185kg,
0.453 kg of m-DCB (2.0 mol% based on total DCB) and 18.0 kg of NMP were charged. Liquid temperature 150
The temperature was started by pressurizing to 1 kg / cm ² G with nitrogen gas at 0 ° C. The reaction was allowed to proceed while stirring at a liquid temperature of 260 ° C. for 3 hours, and the upper portion of the autoclave was cooled by watering. Next, the temperature was lowered and the cooling of the upper part of the autoclave was stopped. During cooling of the upper part of the autoclave, the liquid temperature was kept constant so as not to drop. The maximum pressure during the reaction is 8.5
It was ² kg / cm ² G.

The resulting slurry was filtered to remove the solvent, and then the solvent-containing filter cake was heated in a nitrogen stream at 220 ° C. for about 6 hours to remove the solvent. Next, the obtained PPS powder was washed with water and filtered seven times by a conventional method, and then 12
It was dried in a hot air circulation dryer at 0 ° C. for about 8 hours to obtain a white powdery polymer.

The reaction rate of p-DCB is 98.1%,
The reaction rate of m-DCB was 100%.

[0039]

Example 2 p-DCB of 22.525 kg, m-DC
0.113 kg of B (0.5 mol% based on total DCB)
Other than the above, the same conditions as in Example 1 were used.

The reaction rate of p-DCB is 98.4%,
The reaction rate of m-DCB was 100%.

[0041]

Example 3 21.506 kg of p-DCB, m-DC
1.132 kg of B (5.0 mol% based on total DCB)
Other than the above, the same conditions as in Example 1 were used.

The reaction rate of p-DCB is 98.2%,
The reaction rate of m-DCB was 100%.

[0043]

Example 4 20.827 kg of p-DCB, m-DC
1.811 kg of B (8.0 mol% based on total DCB)
Other than the above, the same conditions as in Example 1 were used.

The reaction rate of p-DCB is 98.1%,
The reaction rate of m-DCB was 100%.

[0045]

Example 5 21.609 kg of p-DCB, m-DC
0.441 kg of B (2.0 mol% based on total DCB)
And the reaction was carried out under the same conditions as in Example 1 except that the reaction was carried out at a liquid temperature of 220 ° C. for 5 hours and then at a liquid temperature of 260 ° C. for 5 hours.

The reaction rate of p-DCB is 99.1%,
The reaction rate of m-DCB was 100%.

[0047]

Comparative Example 1 p-DCB was added without adding m-DCB.
It carried out on the same conditions as Example 1 except having set it as 2.638 kg.

The reaction rate of p-DCB was 98.4%.

[0049]

[Comparative Example 2] p-DCB 22.593 kg, m-DC
0.045 kg of B (0.2 mol% based on total DCB)
Other than the above, the same conditions as in Example 1 were used.

The reaction rate of p-DCB is 98.5%,
The reaction rate of m-DCB was 100%.

[0051]

[Comparative Example 3] 19.921 kg of p-DCB, m-DC
It carried out on the same conditions as Example 1 except having set B to 2.717 kg (12 mol% with respect to total DCB).

The reaction rate of p-DCB is 98.2%,
The reaction rate of m-DCB was 100%.

[0053]

[Comparative Example 4] The same procedure as in Example 5 was carried out except that the upper part of the autoclave was not cooled. The maximum pressure during the reaction was 10.31 kg / cm ² G.

The reaction rate of p-DCB is 99.1%,
The reaction rate of m-DCB was 100%.

[0055]

[Comparative Example 5] The procedure of Example 1 was repeated, except that the solvent-containing filter cake was not heat-treated in a nitrogen stream.

The reaction rate of p-DCB is 98.1%,
The reaction rate of m-DCB was 100%.

The above results are shown in Table 1.

[0058]

[Table 1] In Examples 1 to 4, the amount of m-DCB added was changed within the range of the present invention. When the amount of m-DCB added is increased, the adhesive strength tends to increase. Further, both the crystallization temperature T _c and the melting point T _m decreased. In Example 5, the reaction was carried out in two stages under the same conditions as in Example 1.
The adhesive strength was good, and the effects of the present invention could be sufficiently achieved.

On the other hand, in Comparative Examples 1 and 2, under the same conditions as in Example 1, m-DCB was not added and the addition amount was lowered to below the range of the present invention. In each case, the adhesive strength was extremely low. In Comparative Example 3, the amount of m-DCB added exceeded the range of the present invention under the same conditions as in Example 1. V ₆ , T _c and T _m
Was extremely low, and the original heat resistance of PAS was impaired, which was not practical. In Comparative Example 4, the upper part of the autoclave was not cooled under the same conditions as in Example 5. The adhesive strength of PPS was significantly lower than that of Example 5. Comparative Example 5 is one in which the solvent-containing filter cake was not heat-treated in a nitrogen stream under the same conditions as in Example 1.
The adhesive strength of PPS was significantly lower than that of Example 1.

[0060]

INDUSTRIAL APPLICABILITY The present invention provides a method for producing a PAS resin excellent in adhesiveness with an epoxy resin and the like in addition to the high heat resistance and mechanical strength of conventional PAS. Also,
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 (5)

[Claims] 1. A method for producing a polyarylene sulfide by reacting an alkali metal sulfide with a dihaloaromatic compound in an organic amide solvent, comprising reacting a paradihaloaromatic compound with a paradihaloaromatic compound in the reaction system. When the ratio is 0 to less than 80%, 0.5 to 10 mol% of the metadihaloaromatic compound is added to the reaction system based on the total amount of the charged dihaloaromatic compound, and during the reaction, the gas phase portion of the reaction vessel is A part of the gas phase in the reaction can is condensed by cooling, and the polyarylene sulfide slurry obtained by refluxing this in the liquid phase is filtered, and then the solvent-containing filter cake obtained is mixed with a non-oxidizing gas. 150-250 in the atmosphere
A method for producing a polyarylene sulfide, which comprises heating at a temperature of ℃ to remove the solvent and then washing with water. 2. The method according to claim 1, wherein the paradihaloaromatic compound and the metadihaloaromatic compound are simultaneously added into the reaction system. 3. The method according to claim 1, wherein 1.0 to 5.0 mol% of the metadihaloaromatic compound is added. 4. The heating of the filter cake is performed at 180 to 230 ° C.
The method according to any one of claims 1 to 3, which is carried out in. 5. The method according to claim 1, wherein washing with water is performed by dispersing the filter cake after heating in water.