JPH0332571B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel method for producing polyarylene sulfide. Methods for producing polyarylene sulfide include a method in which a dihaloarylene compound is reacted with an alkali metal sulfide compound or a mixture of sulfur and an alkali metal compound, and an alkali metal salt or alkaline earth metal salt of dithiophenols and a dihaloarylene compound. Various methods have been proposed, including a method of reacting an aromatic compound with a halogenated sulfur compound in the presence of an acidic catalyst, and a method of heating an alkali metal salt or alkaline earth metal salt of a halogenated thiophenol. has been done. However, these methods generally require polymerization reactions to be carried out at high temperatures for long periods of time, making it difficult to control the reaction, resulting in variations in the degree of polymerization of the produced polymers, and the possibility of branched polymers. It was a combination. In order to improve this drawback, Japanese Patent Publication No. 45-3368 discloses that in the above method, the polymerization reaction is carried out in an aprotic polar solvent such as amides, lactams, or sulfones, so that stable polymers can be obtained. A method for producing arylene sulfides is disclosed, but has the disadvantage that it is a high temperature reaction and the reaction must be carried out in a pressurized vessel of rust-free steel due to the pressure and corrosive atmosphere involved in the reaction. There is. Based on the recognition of the above-mentioned reaction problems in the method for producing polyarylene sulfide, the present inventor conducted various studies and examinations for the purpose of finding an excellent method for producing polyarylene sulfide. As a result, we have discovered a new production method in which the reaction proceeds at a lower temperature than conventional methods, and in which polyarylene sulfide can be obtained in high yield. That is, the method for producing polyarylene sulfide of the present invention is characterized by reacting the following (a) and/or (b) with an alkali carbonate in the coexistence of a solvent and a quaternary phosphonium salt catalyst. This is a method for producing polyarylene sulfide having a -S- repeating unit. (a) A haloaromatic thiol represented by the general formula X ¹ -Ar-SH []. (b) A substantially equimolar combination of a divalent thiol represented by the general formula HS-Ar-SH [] and a dihaloaromatic compound represented by the general formula X ² -Ar-X ² []. (However, in the formula, X ¹ and X ² are chlorine or bromine,
Ar is a divalent aromatic residue that may vary within the polymer chain. ) In the method of the present invention, the haloaromatic thiol of the general formula [] used is, for example,
P-bromothiophenol, m-bromothiophenol, 4-bromo-m-thiocresol, 2,
6-dimethyl-4-bromothiophenol, 4-
Chloro-2-bromo-thiophenol, 2-bromo-4-nitrothiophenol, homologous chlorides,
Included are iodides or fluorides and the like. Examples of divalent thiols of general formula [] include m-phenylenedithiol, P-phenylenedithiol, toluene-3,4-dithiol,
2,5-dimercapto-1,3,4-thiadiazole, 6-substituted-1,3,5-triazine-2,
4-dithiol, bis(4-mercaptophenyl) ether, bis(4-mercaptophenyl)
Sulfide, 4,4'-dimercaptobiphenyl and the like. Examples of dihaloaromatic compounds of the general formula [] include P-dibromobenzene, O dibromobenzene dibromonaphthalin, O, O'-dibromodiphenyl sulfone, P, P'-dibromodiphenyl sulfone, P, P'- Dibromodiphenyl sulfoxide, P,P'-dibromobenzophenone, m,
m'-dibromobenzophenone, P,P'-dibromodiphenyl ether, O,O'-dibromodiphenyl ether, P,P'-dibromodiphenyl thioether, 2,2'-dibromonaphthyl thioether, and the like. Mention may be made of chloride, iodide or fluoride and the like, each used alone or in combination. As the reaction solvent, common ones such as
N,N-dimethylformamide, dimethylacetamide, N,N'-dimethylimidazolidinone,
Examples include hexamethylphosphoramide, toluene, xylene, N-methyl-2-pyrrolidone, dimethyl sulfoxide, diphenyl sulfone, acetonitrile, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, ethoxyethanol, n-butanol, diacetone alcohol, etc. Particularly preferred is the use of aprotic polar solvents. The method of the invention typically requires an alkali carbonate and a catalyst. Alkali carbonates are used as hydrogen halide scavengers, and examples of such alkali carbonates include lithium carbonate, sodium carbonate, potassium carbonate, and the like. In particular, it is preferable to use potassium carbonate in an anhydrous state, and the amount of alkali carbonate used is preferably in excess of the molar equivalent of the generated hydrogen halide. As the catalyst, it is preferable to use a quaternary phosphonium salt, and examples of such quaternary phosphonium salts include tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, tetrabutylphosphonium iodide, hexadecyltributylphosphonium chloride, and hexadecyltributyl. Examples include phosphonium bromide, ethyltrioctylphosphonium bromide, ethylenebis[tris(cyanoethyl)phosphonium bromide], and hexadecyltributylphosphonium bromide is particularly preferred. Therefore, the amount of quaternary phosphonium salt used is 0.01 to 50 mol% of the amount of thiol group or halogen,
Preferably it is 0.1 to 20 mol%. The method of the present invention comprises a haloaromatic thiol represented by the general formula [] and/or a haloaromatic thiol represented by the general formula []
A substantially equimolar combination of a divalent thiol represented by the formula [] and a dihaloaromatic compound represented by the general formula [] and an alkali carbonate are reacted at a reaction temperature of 50°C to 50°C in the presence of a solvent and a quaternary phosphonium salt catalyst. This is carried out by heating to the boiling point of the solvent used for 1 to 24 hours, as necessary to obtain the desired degree of polymerization.
The reaction is preferably carried out at normal pressure, but may be carried out in a pressurized system if necessary. After the reaction is completed, polyarylene sulfide is obtained by collecting, washing and drying the reaction product according to a conventional method. According to the method of the present invention, the polymerization rate is significantly improved compared to conventional methods, and the reaction can be carried out at normal pressure and low temperature, making it possible to produce polyarylene sulfide in high yield. can. The polyarylene sulfide obtained by the method of the present invention can be directly molded by conventional extrusion molding, injection molding, extrusion blow molding, or the like. Furthermore, other polymers or fillers, additives such as graphite, inorganic powders, metal powders, fibrous materials, glass fibers, stabilizers,
It can be mixed with pigments to form molded products and used in mechanical parts, automobile parts, electronic parts, office equipment supplies, household goods, etc. EXAMPLES Next, the method of the present invention will be specifically explained using Examples, but the present invention is not limited to these Examples. Example 1 In a 500 ml three-necked flask equipped with a stirrer, a reflux condenser, and a nitrogen inlet tube, 18.9 parts of 4-bromothiophenol (parts by weight, same hereinafter), 150 parts of dimethylacetamide, and 30.4 parts of anhydrous potassium carbonate were added. Then, 6.6 parts of hexadecyltributylphosphonium bromide were added, and the mixture was reacted at 150° C. for 10 hours with stirring under a dry nitrogen atmosphere. After the reaction was completed, the reaction mixture was cooled to room temperature and treated with water, and the resulting precipitate was collected by filtration.
After washing twice with 0.7% diluted hydrochloric acid and then with plenty of water,
Finally, it was washed with acetone and dried at 100°C under reduced pressure to obtain 10.0 parts of poly(P-phenylene sulfide). The infrared spectrum (KBr method) of this polymer is shown in FIG. Comparative Example In Example-1, the reaction was carried out in the same manner as in Example-1 except that hexadecyltributylphosphonium bromide was not added, and the yield of the obtained polymer was 8.0 parts. Example 2 Toluene-3,
7.8 parts of 4-dithiol, 11.8 parts of dibromobenzene,
A mixture consisting of 150 parts of N,N-dimethylformamide and 15.20 parts of potassium carbonate was added, and then 0.68 parts of tetrabutylphosphonium bromide was added.
The reaction was carried out at 150° C. for 17 hours with stirring under a dry nitrogen atmosphere. After the reaction was completed, the reaction mixture was cooled to room temperature, treated with water, and the resulting precipitate was collected by filtration.
After washing twice with % diluted hydrochloric acid and subsequently with a large amount of water, the precipitate was dissolved in tetrahydrofuran, and after removing insoluble materials, it was purified by reprecipitation in methanol. It was dried at 80° C. under reduced pressure to obtain 8.5 parts of a polymer having the following structure. The infrared spectrum and NMR spectrum of the obtained polymer are shown in FIG. 2 and FIG. 3, respectively. Polymer structural formula

[Formula] Example 3 17.02 parts of 4-bromothiophenol, 2.18 parts of 4,4'-biphenyldithiol, 4,4 '-dichlorodiphenylsulfone 2.87 parts, N-methyl-2-pyrrolidone 150 parts,
A mixture consisting of 18.2 parts of potassium carbonate and 2.55 parts of hexadecyltributylphosphonium chloride was added, and the mixture was heated at 200°C for 10 minutes with stirring under a dry nitrogen atmosphere.
Allowed time to react. After the reaction was completed, the reaction mixture was cooled to room temperature, treated with water, and the resulting precipitate was collected by filtration.
After washing twice with 1% diluted hydrochloric acid and subsequently with plenty of water,
Finally, it is washed with acetone and dried at 100°C under reduced pressure to obtain a polymer 14.20 having repeating units of the following structure.
I got the department. Polymer structural formula

[Brief explanation of drawings]

Figures 1 and 2 show infrared spectra of the polyarylene sulfide produced in Example-1 and Example-2, respectively, and Figure 3 shows the infrared spectra of the polyarylene sulfide produced in Example-2. Id's
This is an NMR spectrum.

Claims (1)

[Scope of Claims] 1. Having a repeating unit of -Ar-S-, characterized in that the following (a) and/or (b) is reacted with an alkali carbonate in the coexistence of a solvent and a quaternary phosphonium salt catalyst. A method for producing polyarylene sulfide. (a) A haloaromatic thiol represented by the general formula X ¹ -Ar-SH[]. (b) A substantially equimolar combination of a divalent thiol represented by the general formula HS-Ar-SH [] and a dihaloaromatic compound represented by the general formula X ² -Ar-X ² []. (However, in the formula, X ¹ and X ² are chlorine or bromine,
Ar is a divalent aromatic residue that may vary depending on the unit in the polymer chain. )