JPH0235774B2 - - 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 in the state of branching. It was a polymer. 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. The method for producing polyarylene sulfide of the present invention involves combining the following (a) and/or (b) with a hydroiodic acid scavenger, or adding the thiol salt to a hexamethylphosphoric acid triamide solvent. The present invention provides a method for easily producing polyarylene sulfide having -Ar-S- repeating units by reacting in the presence of copper. (a) An iodoaromatic thiol represented by the general formula I-Ar-SH [ ]. (b) A diiodo aromatic compound represented by the general formula I-Ar-I[] and a diiodo aromatic compound represented by the general formula HS-Ar-SH
A substantially equimolar combination with a divalent thiol represented by [ ]. (However, Ar is a divalent aromatic residue and may vary depending on the unit in the polymer chain.) The reaction of the present invention uses hexamethylphosphoric acid triamide as a solvent to capture hydroiodic acid. Requires agent. Hydroiodic acid scavengers include amines such as secondary amines and tertiary amines, basic salts such as sodium bicarbonate, sodium carbonate, and potassium carbonate, metals such as lithium, sodium, and potassium, and sodium hydride. , metal hydrides such as calcium hydride, and lithium-tert-
Bases of alkali metal alcoholates such as butoxide, potassium tert-butoxide, sodium ethylate, sodium methylate, etc. are suitable, and it is usually preferable to use a slight excess of mol to the generated hydroiodic acid. Further, it is essential for this reaction to coexist with cuprous iodide. The amount of cuprous iodide used has a significant effect on the yield of polyarylene sulfide, and the best results are obtained when using an approximately equimolar amount to the thiol group; Even if cuprous iodide is present, no improvement in yield is observed. Examples of the iodoaromatic thiols of general formula [] that can be used in the present invention include P-iodothiophenol, 2,6-dimethyl-4-iodothiophenol, 2-iodo-P-toluidine-5-
Thiols, 2-amino-4-iodothiophenol, 4-chloro-2-iodo-thiophenol and the like. Examples of the diiodo aromatic compounds of the general formula [] include P-diiodobenzene, O-diiodobenzene, diiodonaphthalene, 4,4'-diiododiphenyl ether, 3,3'-diiododiphenyl ether, and 3,3'-diiododiphenyl ether. enyl sulfides and the like. Examples of divalent thiols of the general formula [] are:
m-phenylenedithiol, p-phenylenedithiol, toluene-3,4-dithiol, 2,5
-dimercapto-1,3,4-thiazole, 6-
Substituted-1,3,5-triazine-2,4-dithiols, bis(4-mercaptophenyl) ethers and the like are included, each used alone or in combination. Iodoaromatic thiols or divalent thiols can be reacted with a hydroiodic acid scavenger in advance, but in such a reaction, a salt is formed in the reaction system with a basic compound used as a hydroiodic acid scavenger. The formed product may be used in the present reaction after being isolated as a thiol salt; in this case, a basic compound is not necessary. The method of the present invention uses an iodoaromatic thiol represented by the general formula [] in (a), and/or (b)
A substantially equimolar combination of a diiodo aromatic compound represented by the general formula [] and a divalent thiol represented by the general formula [] and a hydriodic acid scavenger are iodized in a hexamethylphosphoric triamide solvent. 1 at a temperature of 50°C to 235°C in the presence of cuprous
The reaction is completed in ~24 hours. The reaction is preferably carried out at normal pressure, but may be carried out in a pressurized system if necessary. Alternatively, a salt of a divalent thiol may be formed in advance, and a diiodo aromatic compound may be added to the thiol salt to react.The reaction of such a thiol salt is also carried out in the presence of cuprous iodide in a hexamethylphosphoric acid triamide solvent. The reaction is completed under the above reaction conditions. After the reaction is completed, the reaction product is separated by a conventional method.
Polyarylene sulfide is obtained by washing and drying. 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 produced by the method of the present invention can be directly molded by conventional extrusion molding, injection molding, extrusion blow molding, etc., and can be used, for example, in mechanical parts, automobile parts, electronic parts, and office equipment. , can be used for household items, etc. Furthermore, other polymers, fillers, additives such as graphite, metal powder, inorganic powder, fibrous materials, glass fibers, stabilizers, pigments, etc. can be mixed to form a molded product. 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 Bis(4-iodophenyl)disulfide 4.70
(parts by weight, same hereinafter) and 30.00 parts of hexamethylphosphoric acid triamide were heated to 80°C under a nitrogen atmosphere,
After adding 0.76 parts of sodium borohydride and stirring for about 60 minutes, 3.80 parts of cuprous iodide was added and reacted at the same temperature for 10 hours. After the reaction is complete, cool to room temperature, pour the reaction mixture into water, collect the resulting precipitate by filtration, wash twice with 100 parts of concentrated hydrochloric acid, then with a large amount of water, and finally with acetone. and under reduced pressure
By drying at 100°C, 1.78 parts of poly(P-phenylene sulfide) was obtained. The infrared spectrum (KBr method) of this polymer is shown in FIG. Example 2 3.90 parts of toluene-3,4-dithiol was dissolved in 50 parts of hexamethylphosphoric acid triamide and heated to 80°C under a nitrogen atmosphere, and sodium hydride was added to the solution.
Adding 1.20 parts produces a yellow solution with vigorous foaming. Subsequently, 9.50 parts of cuprous iodide was added, and after stirring for a while, 8.25 parts of P-diiodobenzene was added and reacted at 80°C for 13 hours. After the reaction is completed, the reaction mixture is cooled to room temperature, poured into water, the resulting precipitate is separated by filtration, the product is extracted with tetrahydrofuran, and reprecipitated in methanol to obtain a polyarylene having the following structure. 8.8 parts of sulfide were obtained. FIG. 2 shows the infrared spectrum of the obtained polymer. Polymer structural formula

[Formula] Example 3 9.40 parts of 4-(4-iodophenylsulfonyl)thiophenol, 7.6 parts of anhydrous potassium carbonate, 30 parts of hexamethylphosphoric acid triamide, cuprous iodide
A mixture consisting of 4.75 parts was heated to 80° C. under a nitrogen atmosphere and allowed to react for 10 hours. After the reaction was completed, the reaction mixture was cooled to room temperature, poured into water, and the resulting precipitate was collected by filtration, washed twice with 100 parts of concentrated hydrochloric acid, then washed with a large amount of water, and finally washed with acetone.
By drying at 100° C. under reduced pressure, 6.14 parts of a polymer having a repeating unit of the following structure was obtained. Polymer structural formula

【formula】 [Brief explanation of drawings]

FIG. 1 and FIG. 2 show infrared spectra of the polyarylene sulfide produced in Example-1 and Example-2, respectively.

Claims (1)

[Scope of Claims] 1. A combination of the following (a) and/or (b) with a hydriodic acid scavenger, or the thiol salt in a hexamethylphosphoric triamide solvent in the presence of cuprous iodide. A method for producing polyarylene sulfide having -Ar-S- repeating units, which comprises reacting. (a) An iodoaromatic thiol represented by the general formula I-Ar-SH []. (b) A diiodo aromatic compound represented by the general formula I-Ar-I[] and a diiodo aromatic compound represented by the general formula HS-Ar-SH
A substantially equimolar combination with a divalent thiol represented by [ ]. (However, Ar in the formula is a divalent aromatic residue and may vary depending on the unit in the polymer chain.)