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. 11, 1999
Filed:
Jun. 18, 1997
Makoto Murata, Saitama, JP;
Toru Nakamura, Tokyo, JP;
Hoechst Japan Limited, Tokyo, JP;
Abstract
Improved process for producing a polybenzimidazole compound in solution by dissolving a fully dried polybenzimidazole of the following general formula (1) or (2) in N,N-dimethylacetamide of a sufficiently reduced water content at an elevated temperature of 260.degree. C. or higher in an inert gas atmosphere and a solution of the polybenzimidazole compound produced by the process. The solution remains useful for an extended time without using metal salts or any other stabilizers: ##STR1## where R.sup.1, R.sup.2 and R.sup.5 are tetra-, di- and trivalent aromatic groups, respectively; R.sup.3, R.sup.4 and R.sup.6 are each independently a hydrogen atom, an alkyl group or an aryl group; n is an integer of 2 or more.