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:
May. 22, 2007
Filed:
Jul. 11, 2003
Mitsuhiro Matsuzaki, Fukushima-ken, JP;
Masaru Kagoshima, Fukushima-Ken, JP;
Mitsuhiro Matsuzaki, Fukushima-ken, JP;
Masaru Kagoshima, Fukushima-Ken, JP;
Kureha Corporation, Tokyo, JP;
Abstract
A process for producing polyarylene sulfide includes: steps of reacting an aromatic dihalide compound and an alkaline metal compound in a polar organic solvent for polymerization under heating and cooling a system including the reaction mixture to recover particulate polyarylene sulfide (PAS). The system after the reaction is gradually cooled at an average cooling speed of 0.2 to 1.0 deg. C./min. selectively in a temperature range of from 1 deg. C. below to 1 deg. C. above a maximum system-viscosity temperature. As a result, the process can be operated at a relatively short polymerization cycle and yet provides the product PAS particles with a high and stable bulk density as to exhibit good processability in the transportation and storage, and excellent transportability in a hopper or a screw of an extruder or a molding machine.