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 benzhydrolte tracarboxylic dianhydride. These polymers were prepared either by a th ermal or chemical imidization, and the photoreactive methacryloyl grou p was introduced through the reaction between the hydroxyl group and t he isocyanate group of methacryloyl isocyanate to yield a carbamate li nkage. Bis(4-aminophenyl)methane, bis(3,5-dimethyl-4-aminophenyl)metha ne and bis(3-methyl-5-isopropyl-4-aminophenyl)methane were used as aro matic diamines, and 1,1,1,3,3,3-hexafluoropropane-2,2-di(4'-phthalic a nhydride) as aromatic dianhydride. 4-N,N-Dimethylamino-3',5'-diaminobe nzophenone was also used in order to produce an autophotosensitive pol ymer. The resulting methacryloyl carbamate-modified polyimides were fo und to be soluble in polar solvents and they were characterized by inf rared and H-1 and C-13 nuclear magnetic resonance spectroscopies. Inhe rent viscosities, glass transition temperatures, thermal behaviour and dielectric constants were also determined. (C) 1997 Elsevier Science Ltd.