Document 9JEpqg2gDo0JEgopQJX1oo8Bp

Tsuguo Yamamoto, et al., High Polymes, Japan, Vol.39, No.2 112(1990) First, a basic polyimide was synthesized by ring-closing reaction of polyamic acid obtained from a reaction of aromatic diamine containing fluorine atom and tetra carboxylic acid anhydride(Figure1). This polyimide is advantageous for sensitivity, resolution, and thick-film exposure since it is transparent at longer wavelengths than the typical exposure light source wavelength of 350nm. In the ring-closing reaction, meta-xylene was used as an azeotropic agent. And the basic polyimide is soluble to polar solvent and alkaline solution because of an acidity of hydroxyl group at ortho-position of phthalimide ring.