发明授权
US5047560A Process for producing highly pure 3,3',4,4'-biphenyltetracarboxylic acid or dianhydride thereof 失效
制备高纯度3,3',4,4'-联苯四羧酸或其二酐的方法

Process for producing highly pure 3,3',4,4'-biphenyltetracarboxylic acid
or dianhydride thereof
摘要:
Highly pure 3,3',4,4'-biphenyltetracarboxylic acid (BPTA) and dianhydride thereof (BPDA) are produced by heating crude BPTA to give BPDA, treating the BPDA with hot water to give highly pure BPTA, and in the case of highly pure BPDA, heat treating the pure BPTA to give highly pure BPDA.
信息查询
0/0