| 摘要 |
<p>RD-13036 METHOD FOR MAKING AROMATIC BIS(ETHER ANHYDRIDE)S A method is provided for making aromatic bis(ether phthalic anhydride), for example, 2,2-bis¢4- (3,4-dicarboxyphenoxy)phenyl!propane dianhydride by effecting an exchange reaction between molten aromatic bis(ether-imide) and phthalic anhydride in the presence of water and an imide-anhydride exchange catalyst. An enhanced rate of aromatic bis(ether phthalic anhydride) production has been found to occur, if the molten aromatic bis(ether imide) is contacted with the phthalic anhydride in the form of an aqueous feed mixture of phthalic acid and exchange catalyst and the resulting equilibrated mixture extracted with organic solvent.</p> |
