The present invention is to provide a method of producing polyarylene sulfide that can produce polyarylene sulfide having a low halogen content simply and easily and at low cost. The method of producing polyarylene sulfide according to an embodiment of the present invention includes: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, a dihalo aromatic compound, and an alkali metal hydroxide; a first-stage polymerization step of producing a prepolymer until a pH of a reaction system reaches a range of lower than 10 but 7 or higher by initiating a polymerization reaction by heating the mixture; and a second-stage polymerization step of continuing the polymerization reaction.

Provided is a PAS production method and a PAS production apparatus wherein, in a gas-liquid system including a gas phase containing water, a dihalo aromatic compound, and hydrogen sulfide and a liquid phase containing a polar organic solvent and PAS, the dihalo aromatic compound and the hydrogen sulfide that can be volatilized at the time of dehydration from the gas phase can be recovered. The PAS production method according to the present invention includes: a condensation step of obtaining a first intermediate gas phase containing a dihalo aromatic compound and hydrogen sulfide and a first intermediate liquid phase containing water, a dihalo aromatic compound, and a sulfur source by condensation from the gas phase in the gas-liquid; a first recovery step of bringing the first intermediate gas phase into contact with a polar organic solvent to obtain a first recovered gas phase containing hydrogen sulfide and a first recovered liquid phase containing a polar organic solvent, a dihalo aromatic compound, and a sulfur source; and a second recovery step of bringing the first recovered gas phase into contact with an alkali metal hydroxide aqueous solution to obtain a second recovered liquid phase containing water, a sulfur source, and an alkali metal hydroxide.

A method for preparing a cationic sulfoxide intermediate having the following formula ##STR00001##
wherein Ar.sub.1 and Ar.sub.2 are substituted or unsubstituted aryl groups that are the same or different, includes reacting hydrogen peroxide with (i) a compound having the following formula (2) or sulfonic acid RSO.sub.3H, wherein R is CH.sub.3, CF.sub.3, phenyl, toluene, or OH, and (ii) a cationic thioether intermediate having the following formula (4) to obtain the cationic sulfoxide intermediate: ##STR00002##
wherein R is a substituted or unsubstituted C.sub.1-C.sub.6 alkyl group; and ##STR00003##
wherein Ar.sub.1 and Ar.sub.2 are as defined above and Y is an anion.

A method for preparing a cationic sulfoxide intermediate having the following formula ##STR00001##
wherein Ar.sub.1 and Ar.sub.2 are substituted or unsubstituted aryl groups that are the same or different, includes reacting hydrogen peroxide with (i) a compound having the following formula (2) or sulfonic acid RSO.sub.3H, wherein R is CH.sub.3, CF.sub.3, phenyl, toluene, or OH, and (ii) a cationic thioether intermediate having the following formula (4) to obtain the cationic sulfoxide intermediate: ##STR00002##
wherein R is a substituted or unsubstituted C.sub.1-C.sub.6 alkyl group; and ##STR00003##
wherein Ar.sub.1 and Ar.sub.2 are as defined above and Y is an anion.

A method for forming a polyarylene sulfide is described. The method can include a multi-step cooling and precipitation process in which the cooling rate of the solution that carries the polymer is decreased during a portion of the overall cooling. This slower cooling period can encompass at least a portion of the period during which the polymer precipitates from the solution. The precipitation process can form polyarylene sulfide particles with good particle integrity and a narrow particle size distribution, which can reduce fines and improve downstream processing and final product characteristics.

A method for forming a polyarylene sulfide is described. The method can include a multi-step cooling and precipitation process in which the cooling rate of the solution that carries the polymer is decreased during a portion of the overall cooling. This slower cooling period can encompass at least a portion of the period during which the polymer precipitates from the solution. The precipitation process can form polyarylene sulfide particles with good particle integrity and a narrow particle size distribution, which can reduce fines and improve downstream processing and final product characteristics.

The present invention is to provide a method of producing polyarylene sulfide that can produce polyarylene sulfide having a low halogen content simply and easily and at low cost. The method of producing polyarylene sulfide according to an embodiment of the present invention includes: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, a dihalo aromatic compound, and an alkali metal hydroxide; a first-stage polymerization step of producing a prepolymer until a pH of a reaction system reaches a range of lower than 10 but 7 or higher by initiating a polymerization reaction by heating the mixture; and a second-stage polymerization step of continuing the polymerization reaction.

A polymer is provided. The polymer has a repeating unit having a structure represented by Formula (I) or Formula (II) ##STR00001##
wherein Ar.sup.1 and Ar.sup.2 can be substituted or unsubstituted aryl diradical; Y.sup. can be R.sup.2SO.sub.3.sup. or ClO.sub.4.sup.; R.sup.1 can be C.sub.1-6 alkyl; Ar.sup.1 and Ar.sup.2 are different; and, R.sup.2 can be C.sub.1-6 alkyl, substituted or unsubstituted aromatic ring, or C.sub.1-6 haloalkyl.

A polymer is provided. The polymer has a repeating unit having a structure represented by Formula (I) or Formula (II) ##STR00001##
wherein Ar.sup.1 and Ar.sup.2 can be substituted or unsubstituted aryl diradical; Y.sup. can be R.sup.2SO.sub.3.sup. or ClO.sub.4.sup.; R.sup.1 can be C.sub.1-6 alkyl; Ar.sup.1 and Ar.sup.2 are different; and, R.sup.2 can be C.sub.1-6 alkyl, substituted or unsubstituted aromatic ring, or C.sub.1-6 haloalkyl.

A method for preparing a compound and a method for preparing a polymer employing the same are provided. The method for preparing a compound includes reacting a compound having a structure represented by Formula (I) with a compound having a structure represented by Formula (III) in the presence of a compound having a structure represented by Formula (II) to obtain a compound having a structure represented by Formula (IV)

##STR00001##

wherein Ar.sup.1 is substituted or unsubstituted aryl group; X is O, S, or NH; R.sup.1 is independently hydrogen or C.sub.1-6 alkyl group; R.sup.2 is hydroxyl group, C.sub.1-6 alkyl group, phenyl group, or tolyl group; and R.sup.3 is independently C.sub.1-6 alkyl group, C.sub.5-8 cycloalkyl group, or C.sub.2-6 alkoxyalkyl group.