| abstract |
This invention discloses high-temperature adhesives having a good light-transmittance and excellent high-temperature flowability which comprises polyimide having recurring units represented by the following formula (I) <IMAGE> (I) (where R is a tetra-valent radical selected from the group consisting of aliphatic radical having not less than two carbons, cyclo-aliphatic radical, monoaromatic radical, condensed polyaromatic radical, and non condensed polyaromatic radical wherein aromatic radicals are mutually connected with a bond or a crosslinking function). The polyimide is obtained by preparing polyamic acid through the reaction of 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3,-hexafluoropropane as a diamine component with tetracarboxylic dianhydride such as pyromellitic dianhydride, 3,3',4,4'- biphenyltetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl) ether dianhydride and 3,3'4,4'-benzophenonetetracarboxylic dianhydride, and further conducting the ring-closing reaction of resultant polyamic acid by dehydration. |