Novel starch ether derivatives, a method for the preparation thereof and their use in paper.

摘要

Starch ether derivatives are prepared by reacting a starch base with N-(2-haloethyl)iminobis (methylene)diphosphonic acid or with a N-(alkyl)-N -(2-haloethyl)aminomethylphosphonic acid. The derivatives contain aminophosphonic acid groups (or their salts) as zwitterion substituents which consist of either one or two anionic methylene phosphonic acid groups bound to a cationic nitrogen. Their cationic or anionic characteristics may be increased by introducing suitable cationic or anionic groups either by simultaneous reaction with the aminophosphonic acid reagent or by consecutive reaction either prior to or subsequent to the aminophosphonic acid reaction. They are especially useful as pigment retention aids in papermaking processes.