POLYAMIC ACID AND PROCESS FOR PROCESSING POLYAMIC ACID TO POLYIMIDEBENZOXAZOLE FILM

摘要

PROBLEM TO BE SOLVED: To improve mechanical properties of a polyimidebenzoxazole polymer used for a fiber or the like. SOLUTION: This invention is concerned with a polyamic acid and a process for converting this polyamic acid to the polyimidebenzoxazole polymer. The polyamic acid is prepared by reacting an acid dianhydride with a diaminobenzoxazole under a condition sufficient to form a polyamic acid having an intrinsic viscosity of not less than 2.0 dl/g measured at 0.2g/dl in N-methyl pyrrolidinone at 25°C. The polyamic acid is processed to a polyimidebenzoxazole in the forms of a film, a fiber and a coating film by heat and chemical processes. COPYRIGHT: (C)2005,JPO&NCIPI