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. 20, 2018
Filed:
Mar. 27, 2015
Kureha Corporation, Tokyo, JP;
KUREHA CORPORATION, Tokyo, JP;
Abstract
Provided is a method of producing polyarylene sulfide (PAS) that suppresses side reactions and produces PAS with a high purity and a high molecular weight at a high yield. A method of producing PAS in which a sulfur source and a dihalo aromatic compound are polymerized in an organic amide solvent, the method of producing PAS comprising the following steps 1 to 3: step 1: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, water, a dihalo aromatic compound, and an alkali metal hydroxide in an amount that is less than an equimolar amount relative to the sulfur source; step 2: a first-stage polymerization step of initiating a polymerization reaction by heating the mixture, and producing a prepolymer having a dihalo aromatic compound conversion rate of 50% or greater; and step 3: a second-stage polymerization step of adding from 0.11 to 0.3 mol of an alkali metal hydroxide per 1 mol of the sulfur source, and continuing the polymerization reaction. A PAS polymerization reaction solution having a low content of byproduct. PAS having an average particle diameter of 10 to 5,000 μm, a melt viscosity (temperature 310° C., shear rate 1,216 sec) of 0.1 to 3,000 Pa·s, and a nitrogen content of 750 ppm or less.