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:
Feb. 17, 2026
Filed:
Dec. 22, 2020
Kureha Corporation, Tokyo, JP;
Takeshi Sato, Tokyo, JP;
Mizuki Saito, Tokyo, JP;
Ken-Ichi Takaki, Tokyo, JP;
Yoshinori Suzuki, Tokyo, JP;
Kureha Corporation, Tokyo, JP;
Abstract
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.