Stannous chelates and process for their manufacture

摘要

The invention comprises stannous chelates of alkylene polyamine-polycarboxylic acid chelating agents in which the chelating agents preferably have the formula:- wherein n is 2, 3 or 4, m is 0, 1, 2, 3 or 4 and all or part of the m-carboxymethyl groups are replaced by b -hydroxyethyl groups and all or part of the carboxymethyl groups are replaced by carboxymethyl groups. The above chelates are prepared by double decomposition between a stannous salt and an aqueous solution of a chelating acid or a partial or complete alkali metal, ammonium or amine salt thereof.ALSO:Tooth pastes, tooth powders, mouth lotions and mouth washes contain as an active ingredient a stannous chelate of an alkylene polyamine polycarboxylic acid chelating agent in which the chelating agents preferably have formula (HOOC.CH2)2N[(CH2)nN(CH2COOH(]m CH2COOH wherein n is 2, 3 or 4, m is 0, 1, 2, 3 or 4 and all or part of the m-carboxymethyl groups are replaced by b -hydroxyethyl groups and all or part of the carboxymethyl groups are replaced by carboxyethyl groups.