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. 05, 2019
Filed:
Aug. 03, 2015
Kureha Corporation, Tokyo, JP;
KUREHA CORPORATION, Tokyo, JP;
Abstract
The present invention is a production method for producing polyarylene sulfide, wherein an unreacted dihalo aromatic compound is recovered and reused. The present production method includes: (a) a polymerization step; (b) a separation step; and (c) a recovery step of recovering unreacted dihalo aromatic compound from a water-containing mixture of the separated liquid by steam distillation entailing adjusting the reflux ratio of water in the steam distillation column without adding water other than the refluxed water. Alternatively, the production method includes: (a) a polymerization step; (d) a dehydration step; and (c) a recovery step of recovering unreacted dihalo aromatic compound from a water-containing mixture of a water-containing liquid mixture and/or a water-containing steam mixture containing a raw material mixture and/or a polymerization reaction solution by steam distillation entailing adjusting the reflux ratio of water in the steam distillation column without adding water other than the refluxed water in the dehydration step.