METHOD FOR THE MANUFACTURE OF AMINOALKYLENE PHOSPHONIC ACID

摘要

A method for the manufacture of amino alkylene phosphonic acids is disclosed. Pure P4O6 is hydrolyzed in the presence of a homogeneous Broensted acid catalyst whereby the pH of the reaction medium is maintained below 5 and the free water content of said reaction medium is, after the P4O6 hydrolysis has been completed, from 0 to 40 %. The required amine component can be added before, during, or in one preferred execution, after the P4O6 hydrolysis has been completed. Formaldehyde is then added and the reaction mixture containing the P4O6 hydrolysate, the amine and the formaldehyde is reacted in presence of a Broensted acid catalyst selected from homogeneous and heterogeneous species. The amino alkylene phosphonic acid reaction product can then be recovered in a manner known per sé.