Calcium phosphate di:hydrate stabilisation against hydrolysis - by treating with acylamino-alkylidene-di-phosphonic acid

摘要

In a new procedure for stabilising calcium hydrogen phosphate dihydrate against hydrolysis, CaHPO4.2H2O is treated with a diphosphonic acid of formula (I) or its water-soluble salt: (where R1, R2 and R are H or lower alkyl; and R3, R4, R5 and R6 are H or alkali). CaHPO4.2H2O is used as a polishing agent in dentifrice preparations such as tooth-pastes and toothpowders. (I) give better stabilisation against hydrolysis than the corresponding non-acylated amino-substd. diphosphonic acid derivs.