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. 25, 2020
Filed:
Sep. 30, 2016
Kureha Corporation, Tokyo, JP;
KUREHA CORPORATION, Tokyo, JP;
Abstract
Provided is a method of producing polyarylene sulfide at low cost while productivity enhancement and resource saving are attempted by avoiding the use of a complicated step and special apparatus (facility). 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 in an amount less than an equimolar amount relative to an amount of the sulfur source; a first-stage polymerization step of initiating a polymerization reaction by heating the mixture, and producing a prepolymer having a dihalo aromatic compound conversion ratio of 50% or greater; and a second-stage polymerization step of adding an alkali metal hydroxide such that the alkali metal hydroxide is in an amount of 1.00 to 1.10 mol per 1 mol of the sulfur source, and continuing the polymerization reaction in a homogeneous liquid phase condition.