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 paper making processes.
淀粉醚衍
生物是通过将淀粉基与N-(2-卤乙基)
亚胺基双(亚甲基)
二膦酸或N-(烷基)-N-(2-卤乙基)
氨基
甲基膦酸反应制备而成。这些衍
生物含有
氨基膦酸基团(或其盐)作为离子双替位基,其中包括一个或两个阴离子亚
甲基膦酸基团与一个阳离子氮原子结合。它们的阳离子或阴离子特性可以通过同时与
氨基膦酸试剂反应或在
氨基膦酸反应之前或之后进行连续反应引入适当的阳离子或阴离子基团来增加。它们在造纸工艺中作为
颜料保留助剂尤其有用。