Abstract: A method of producing a sintered article of polybenzimidazole by using a polybenzimidazole resin is disclosed. This method comprises the steps of: filling a mold with a polybenzimidazole resin; after closing the mold so that the polybenzimidazole resin can be densely packed in the mold, heating the mold to a predetermined temperature ranging from 500° C. to 600° C. without applying pressure to the mold from the outside; after increasing the pressure on the mold from 0 kg/cm2 to 50-750 kg/cm2, sintering the polybenzimidazole resin while maintaining the temperature and the pressure for 15 to 200 minutes; cooling the mold; and removing the sintered article of the polybenzimidazole resin from the mold. By this method, sintered articles of polybenzimidazole resins having no weak parts can be obtained in high yields.

Abstract: A method of producing a sintered article of polybenzimidazole by using a polybenzimidazole resin. This method comprises, in the following order, the steps of: filling a mold with a polybenzimidazole resin; after closing the mold so that the polybenzimidazole resin can be densely packed in the mold, heating the mold to a predetermined temperature ranging from 500° C. to 600° C. without applying pressure to the mold from the outside; after increasing the pressure on the mold from 0 kg/cm2 to 50-750 kg/cm2, sintering the polybenzimidazole resin while maintaining the temperature and the pressure for 15 to 200 minutes; cooling the mold; and removing the sintered article of the polybenzimidazole resin from the mold. In this method, the polybenzimidazole resin is is brought into contact with substantially no oxygen from the beginning of the step of heating the resin to the end of the sintering step.

Abstract: Provided is a process for manufacturing sintered polybenzimidazole (PBI) articles at high yields, said articles having neither voids nor porous, low-strength parts resulting from oxidative deterioration. To produce said sintered PBI articles from a particulate PBI resin, said PBI resin is compacted in a closed mold, the mold is heated up to a predetermined temperature of from 350.degree. to 600.degree. C. without applying any external pressure thereto, then, after having heated up to said predetermined temperature, the mold is pressed to have a predetermined external pressure of from 140 to 1400 kg/cm2 at said predetermined temperature whereby the resin is sintered for from 60 to 350 minutes under that conditions, and finally the sintered PBI article is cooled and taken out of the mold.