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:
Sep. 06, 1988
Filed:
Jul. 21, 1987
Takao Iwasaki, Iwaki, JP;
Tsuneo Okamoto, Iwaki, JP;
Kureha Kagaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A process for treating a polyarylene sulfide polymer slurry which has been provided by reactions of an alkali sulfide and a dichloroaromatic compound in N-methylpyrrolidone, the process comprising the following steps of (i) through (iv): (i) a step of separating a polymer slurry which contains polyarylene sulfide particles, alkali chloride as a by-product in the form of crystals and a solution and an arylene sulfide oligomer and has a liquid component which is principally N-methylpyrrolidone into polyarylene sulfide particles and a slurry containing the crystalline alkali chloride, the oligomer, and unreacted organic material by screening the slurry without diluting with water; (ii) a step of subjecting the slurry containing the crystalline alkali chloride to solid-liquid separation to obtain the crystalline alkali chloride; (iii) a step of washing the polyarylene sulfide particles with an organic solvent and water; and (iv) a step of recovering the organic solvent from a filtrate obtained by solid-liquid separation.