| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyimide precursor for optical parts from which a polyimide having low optical loss can be obtd. without decreasing the solvent resistance and heat resistance as the features of a polyimide, by incorporating sulfur atoms into the molecule. SOLUTION: The polyimide precursor compsn. contains a polyimide precursor having sulfur atoms in the molecule. The polyimide precursor is commonly obtd. by the reaction of tetracarboxylic acid dianhydride with diamine in a polar solvent such as N-methyl-2-pyrrolidone, N,N-dimethylacetoamide, g- butyrolactone, and dimethylsulfoxide. In this method, the polyimide precursor used is produced by at least partly using tetracarboxylic acid dianhydride or diamine containing sulfur atoms as the reaction component. As for the tetracarboxylic acid dianhydride containing sulfur atoms in the molecule, 4,4- sulfonyldiphthalic acid anhydride can be used. |
