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:
Aug. 02, 1988
Filed:
Feb. 17, 1987
Tsuneo Okamoto, Fukushima, JP;
Takao Iwasaki, Fukushima, JP;
Yo Iizuka, Fukushima, JP;
Zenya Shiiki, Fukushima, JP;
Kureha Kagaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
In a process for producing a polyarylene thioether having high stability by dehalogenation/sulfurization reaction of an alkali metal (M) sulfide such as sodium sulfide and a dihaloaromatic compound such as paradichlorobenzene in a polar organic solvent, the haloaromatic compound is used excessively in an appropriate range rather than the alkali metal sulfide and the latter stage of the reaction or all period of the reaction is conducted under a powerful stirring condition to a certain degree to obtain the polyarylene thioether wherein the concentration of --SM or --SH groups of the polymer terminal is lowered. The polyarylene thioether thus obtained suppresses the coloration in the processing with an apparatus made of ferrous material such as extruder.