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:
Jun. 09, 1987
Filed:
Feb. 22, 1985
Bennett C Ward, Pineville, NC (US);
Celanese Corporation, New York, NY (US);
Abstract
A two stage process for the production of polybenzimidazoles is provided wherein an aromatic tetraamine, e.g., 3,3',4,4'-tetraaminobiphenyl, is reacted with a dicarboxylic component consisting of at least one compound having the formula: ##STR1## in which R' is a divalent organic radical and may be the same or different in the various molecules making up the dicarboxylic component and the Y's may be the hydrogen, aryl or alkyl, with no more than 95% the Y's being hydrogen or phenyl. The reactants are heated with agitation in a first stage to a temperature above the melting point of the tetraamine until the viscosity of the mixture rises as indicated by an agitator torque of at least 1.5 times that before the rise in viscosity. The agitation is then discontinued and the reaction mixture is allowed to foam while heating is continued. The foam is then allowed to cool to a friable mass and is crushed to a ground prepolymer which is heated with agitation in a second stage until the desired polymer is obtained. The invention also includes certain benzimidazole polymers as new composition of matter.