Branched polybenzoxazole-based material, film for solar cell substrate, and method for producing branched polybenzoxazole-based material

摘要

A multi-branched-linear polybenzoxazole material having excellent mechanical characteristics, heat resistance and film formability (thin-film formability), a low linear thermal expansion coefficient, and excellent dimensional stability, is provided. A branched polybenzoxazole precursor is obtained by polymerizing a monomer group, which comprises 1,3,5-benzenetricarboxylic acid chloride,4,4'-diamino-3,3'-dihydroxybiphenyl, and isophthalic acid chloride, and which has a branched monomer mole percent, calculated according to the equation below, of 5 to 30 mol %, and the branched polybenzoxazole material is obtained by converting this branched polybenzoxazole precursor into an oxazole.