| 摘要 |
PURPOSE:To obtain an amphoteric polyimide precursor which can be formed into a film by the Langmuir-Blodgett method and can give a film having low water absorption rate and moisture absorption rate and improved heat resistance, chemical resistance, mechanical properties, etc., by using specified repeating units. CONSTITUTION:An acid chloride is obtained by acylating a half-ester obtained from pyromellitic dianhydride and stearyl alcohol with thionyl chloride. This acid chloride is dissolved in hexamethylphosphoramide and reacted with 2,2'-bis(4-aminophenoxyphenyl)hexafluoropropane dissolved in dimethylacetamide to obtain the title precursor mainly consisting of repeating units of formula I wherein R<1> is a tetravalent group having at least two carbon atoms; R<2> is formula II; R<3> to R<6> are each (cyclo)aliphatic or aromatic 1-30C monovalent group (which may be substituted with a halogen, a nitro, an amino, a cyano, a methoxy or an acetoxy) or H, and at least one of R<3> to R<6> is a 12-30C group. |
