The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 30, 2025
Filed:
Dec. 16, 2020
Kureha Corporation, Tokyo, JP;
Takeshi Sato, Tokyo, JP;
Yoshinori Suzuki, Tokyo, JP;
Kureha Corporation, Tokyo, JP;
Abstract
A method for producing a polyarylene sulfide comprising: initiating a polymerization reaction by heating a mixture containing an organic polar solvent, a sulfur source, water, a polyhaloaromatic compound, and an alkali metal hydroxide in the presence of at least one auxiliary agent selected from the group consisting of carboxylates and the like, to form a reaction mixture containing a prepolymer having a conversion rate of a polyhaloaromatic compound of 50 mol % or greater, then a phase separation agent addition step of adding a phase separation agent into the reaction mixture, then continuing the polymerization reaction, and then cooling the reaction mixture, in the cooling step, the coolant being added to the reaction mixture at a temperature that is at least 5° C. higher than a maximum thickening temperature and lower than 250° C., and a cooling rate at the maximum thickening temperature being 2.2° C./min or higher and 3.9° C./min or lower.