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:
Oct. 26, 1993
Filed:
Nov. 26, 1991
Kureha Kagaku Kogyo K.K., Tokyo, JP;
Abstract
Disclosed herein is a process for the production of a granular poly(arylene thioether) copolymer by polymerizing an alkali metal sulfide with dihalo-aromatic compounds including at least one dihalo-aromatic carboxylic acid in a polar solvent containing water. Upon the polymerization, at least a part of the dihalo-aromatic carboxylic acid is converted into an alkaline earth metal salt in advance, the hydroxide and/or oxide of an alkaline earth metal is added together with the dihalo-aromatic carboxylic acid to the polymerization reaction system, or the hydroxide and/or oxide of an alkaline earth metal is added together with an alkaline earth metal salt of the dihalo-aromatic carboxylic acid and the dihalo-aromatic carboxylic acid to the polymerization reaction system.