The present disclosure relates to a method of more efficiently separating and purifying a polyarylene sulfide exhibiting excellent strength, heat resistance, flame retardancy, and processability when processed into a molded product after polymerization.

A polymer (B) essentially contains units represented by the following formulas (1), (2) and (3), wherein the number of moles of unit (1) is 0 to 95, the number of moles of unit (2) is 0 to 50, and the number of moles of unit (3) is 2 to 80 when the total number of moles of units (1), (2) and (3) is 100:

##STR00001##

In units (1) to (3), “X” is a recurring unit having a benzene ring, in unit (2), —CH.sub.3 is substituted on the benzene ring, “m” is an integer of 1-6, unit (3) is obtained by substituting a hydrogen of —CH.sub.3 in unit (2) by a substituent “Z” derived from a carboxylic acid or anhydride thereof, “n” is an integer of 1-6 indicative of the number of substitutions, l+n=m, and unit (3) is a unit in which “n” is an integer of 1-6 or a combination thereof.

A polymer (B) essentially contains units represented by the following formulas (1), (2) and (3), wherein the number of moles of unit (1) is 0 to 95, the number of moles of unit (2) is 0 to 50, and the number of moles of unit (3) is 2 to 80 when the total number of moles of units (1), (2) and (3) is 100:

##STR00001##

In units (1) to (3), “X” is a recurring unit having a benzene ring, in unit (2), —CH.sub.3 is substituted on the benzene ring, “m” is an integer of 1-6, unit (3) is obtained by substituting a hydrogen of —CH.sub.3 in unit (2) by a substituent “Z” derived from a carboxylic acid or anhydride thereof, “n” is an integer of 1-6 indicative of the number of substitutions, l+n=m, and unit (3) is a unit in which “n” is an integer of 1-6 or a combination thereof.

A method for producing polyarylene sulfide that can have a high melt viscosity while suppressing ultra-fine powder generation. The method for producing polyarylene sulfide includes: (1) preparing a prepared mixture containing an organic polar solvent, a sulfur source, and a dihalo aromatic compound; (2) initiating a polymerization reaction by heating the prepared mixture to produce a prepolymer; (3) adding water as a phase separation agent to a reaction mixture in a reaction system to form a phase-separated state; and (4) continuing the polymerization reaction after phase separation. In the method, when a dihalo aromatic compound conversion ratio is 80 mass % or greater and 93 mass % or less and after the prepolymer reaches a weight average molecular weight of 10000 or greater in the first-stage polymerization step, an aromatic compound having 3 or more halogen atoms bonded to an aromatic ring is added to the reaction mixture.

A preparation method of a polyarylene sulfide that may produce a polyarylene sulfide having properties equal to or higher than those of the conventional method with a high molecular weight at a high yield by optimizing the content and molar ratio of an amide-based compound in a polymerization step.

A preparation method of a polyarylene sulfide that may produce a polyarylene sulfide having properties equal to or higher than those of the conventional method with a high molecular weight at a high yield by optimizing the content and molar ratio of an amide-based compound in a polymerization step.

A method for manufacturing a pre-lithiated polyphenylene sulfide with a high solid solubility of lithium includes: placing NMP, Li.sub.2S, and LiOH into a high-pressure reactor to obtain a mixture, and heating the mixture to 150-250° C. for a high-temperature dehydration for 2-5 h, and then cooling the mixture to 100° C. and adding p-DCB to the mixture for a reaction at 150-250° C. for 80-200 min; dropwise adding hydrochloric acid in an identical amount as that of the LiOH neutralize LiOH, and removing NMP and H.sub.2O by evaporation or sublimation, to obtain a dry mixed powder; and to the dry mixed powder, adding a chloride ion complexing agent to obtain a mixture, stirring the mixture to homogeneity, and placing the mixture in a sealed reactor for a reaction at 150-250° C. for 80-200 min, followed by washing and drying, to obtain the pre-lithiated polyphenylene sulfide.

The production method of the present invention includes a step of supplying an organic polar solvent, a sulfur source, and a dihalo aromatic compound as reaction raw materials to at least one of a plurality of reaction vessels mutually communicated via a gas phase; a step of removing at least a portion of the water present in the reaction vessels; and a step of performing a polymerization reaction. These steps are carried out in parallel, and the reaction mixture is sequentially moved between reaction vessels. At that time, the internal temperatures of the reaction vessels are all not less than 150° C.

The present disclosure relates to a preparation method of a polyarylene sulfide, and this method may produce a polyarylene sulfide having properties equal to or higher than those of the conventional method at a high yield by adding an acidic compound in addition to existing materials for dehydration.

The present disclosure relates to a preparation method of a polyarylene sulfide, and this method may produce a polyarylene sulfide having properties equal to or higher than those of the conventional method at a high yield by adding an acidic compound in addition to existing materials for dehydration.