Two stage polybenzimidazole process and product
US4672104A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 22, 1985 |
| Grant date | Jun 9, 1987 |
| Priority date | — |
| Expiry date | Feb 22, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G73/18
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.