| 摘要 |
PURPOSE:To obtain the title precursor suitable for LB membranes, because of its excellent heat resistance, adhesion, chemical resistance and electric properties by reaction of benzidine-dicarboxylic acid with carboxylic dihalide followed by esterification. CONSTITUTION:The objective precursor having recurring units of formula II (R<2>, R<3> are 1-30C aliphatic groups) is obtained by allowing (A) benzidine-3,3'- dicarboxylic acid to react with (B) a carboxylic dihalide of the formula and subjecting the product to esterification. the precursor is dissolved in benzene, preferably in the concentration of 2-5X10<-4>M, and extended on the water surface to form an LB membrane of 5-1,000Angstrom thickness by the LB method or level deposition method and, preferably heated at 200-400 deg.C to effect ring closure to form an ultra-thin film.
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