POLYBENZIMIDAZOLE, PRECURSOR POLYAMIDE THEREOF, AND METHOD FOR PRODUCING SAME

A polybenzimidazole production method for producing the polybenzimidazole including a repeating unit represented by the following formula (1): wherein Ris —SO—, —O—, —CO—, an alkylene group optionally containing a substituent, or a group represented by the following formula (a): two Xs are each individually a hydrogen atom or a monovalent organic group; and Ris a divalent organic group, the production method including a step (1-1) of polymerizing a tetramine compound and a dicarboxylic acid derivative compound to provide a polybenzimidazole precursor polyamide, and a step (1-2) of dehydrocyclizing the polybenzimidazole precursor polyamide.