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:
Oct. 24, 2023
Filed:
Nov. 25, 2020
Kureha Corporation, Tokyo, JP;
Takeshi Sato, Tokyo, JP;
Yoshinori Suzuki, Tokyo, JP;
Kureha Corporation, Tokyo, JP;
Abstract
A method for producing PAS having an average particle size of 50 μm or greater and 550 μm or less is provided. The method can include: (1) a preparation step of preparing a prepared mixture containing an organic polar solvent, a sulfur source, and a dihalo aromatic compound; (2) a pre-stage polymerization step of initiating a polymerization reaction by heating the prepared mixture to produce a prepolymer; (3) a phase separation step of adding water as a phase separation agent to a reaction mixture in a reaction system to form a phase separation state; and (4) a post-stage polymerization step of continuing the polymerization reaction after the phase separation step, in which an organic sulfonic acid metal salt having a specific solubility in water is contained in the prepared mixture or the reaction mixture.