PURPOSE: To obtain an amphoteric starch usable in the paper industry with a high selectivity by reacting a cationic starch with a specified halogen-contg. compd. and a hydrogen peroxide soln. and selectively oxidizing the reducing groups of a formed compd.
CONSTITUTION: A cationic starch is reacted in an aq. soln. with hydrobromic acid or bromine and a hydrogen peroxide soln. By this reaction, the reducing terminal groups of the cationic starch or the reducing groups of a compd. obtd. by the acid hydrolysis of the cationic starch are selectively oxidized to give carboxyl groups. The cationic starch having reducing terminal groups is thus oxidize. After the oxidation, the aq. soln. is treated particularly by adding an alcohol and the objective starch having cationic and carboxyl groups is isolated as a solid precipitate.
JIYATSUKU DEFUAIE
ANDORE GADEERU
JIYATSUKU KERUBUENNARU
