| 摘要 |
PURPOSE:To obtain a fluorine-containing polyimide composition having low dielectric constant and low water absorption ratio, capable of controlling refractive index and coefficient of thermal expansion by blending at least two polyamic acids prepared from a specific acid anhydride and diamine and imidating the blend. CONSTITUTION:(A) A polyamic acid obtained by reacting A1: pyromellitic dianhydride with A2: 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl is blended with (B) a polyamic acid obtained by reacting 2,2-bis(3,4-dicarboxyphenyl)- hexafluoropropane dianhydride with A2 and imidated by heating or chemical dehydration to give a fluorine-containing polyimide comprising a fluorinated polyimide having a repeating unit shown by formula I and a fluorinated polyimide having a repeating unit shown by formula II (R1 is bifunctional organic group selected from groups shown by formula III-formula VI). |
