Negative-type soluble photosensitive polyimides derived from benzhydroltetracarboxylic dianhydride: synthesis and characterization

The present paper deals with the synthesis and the characterization of negative-type soluble photosensitive polyimides based on benzhydroltetracarboxylic dianhydride. These polymers were prepared either by a thermal or chemical imidization, and the photoreactive methacryloyl group was introduced through the reaction between the hydroxyl group and the isocyanate group of methacryloyl isocyanate to yield a carbamate linkage. Bis(4-aminophenyl)methane, bis(3,5-dimethyl-4-aminophenyl)methane and bis(3-methyl-5-isopropyl-4-aminophenyl)methane were used as aromatic diamines, and 1,1,1,3,3,3-hexafluoropropane-2,2-di(4'-phthalic anhydride) as aromatic dianhydride. 4-N,N-Dimethylamino-3',5'-diaminobenzophenone was also used in order to produce an autophotosensitive polymer. The resulting methacryloyl carbamate-modified polyimides were found to be soluble in polar solvents and they were characterized by infrared and H-1 and C-13 nuclear magnetic resonance spectroscopies. Inherent viscosities, glass transition temperatures, thermal behaviour and dielectric constants were also determined. (C) 1997 Elsevier Science Ltd.