Patent ID: 7038007
Filing Date: 2006-05-02
Classification: C08G

Abstract:
1. A process for a single-stage melt polymerization for the production of a polybenzimidazole which comprises the steps of: providing a reaction vessel having a means for agitation and a means for vacuum; charging said reaction vessel with reactants selected from: (A) a tetraaminiobiphenyl (TAB), and (B) a diphenyl isophthalate DPIP; reacting said reactants under constant agitation and under a vacuum with an inert gas sweep; maintaining a reactant temperature which does not exceed 290° C. under constant agitation allowing pressure in the vessel to increase with an inert gas sweep until a phase change is achieved, when the temperature reaches 250° C. pressure is increased to a slight positive pressure; and increasing said reactant temperature and pressuxe within said reaction vessel while maintaining constant agitation and inert gas sweep, while maintaining a slight positive pressure.