FORMATION OF MIXTURES OF SCHIFF BASE WHICH HAVE LIQUID CRYSTAL PROPERTIES

摘要

1431281 Schiff bases EASTMAN KODAK CO 2 July 1973 [3 July 1972 12 Feb 1973] 31426/73 Heading C2C [Also in Division C4] The invention comprises a process for interconversion of Schiff bases by a process comprising the steps of mixing together at least two different nematic liquid crystalline Schiff base reactants of the formula wherein R and RSP1/SP each represent an alkyl, alkoxy, alkanoyloxy, alkoxycarbonyloxy or CN radical and heating the resultant mixture in the presence of a catalyst, preferably a basic or acidic ion-exchange resin, to form a mixture of different Schiff bases having all possible combinations of the selected substituents R and RSP1/SP contained in the original Schiff base reactants. Other catalysts which may be employed in the above process are salts of specified secondary and tertiary amines, quaternary salts of the said amines, salts of inorganic acids and ammonium and sodium salts of organic acids. Trace amounts of water may also be present during the interconversion reaction.