IMPROVEMENTS RELATING TO AMINOMETHYLENEPHOSPHONIC ACID SOLUTIONS

摘要

Solutions of aminomethylenephosphonic acids derived from diethylenetriamine and containing diethylenetriaminepenta(methylenephosphonic acid) as a principal Component are commercial products useful as metal sequestrants. Known solutions, which usually contain not more than 9% by weight of hydrochloric acid, show a tendency to deposit solid aminomethylenephosphonic acid on storage. This tendency is overcome by increasing the mineral acid content of the solution to 10% or more of hydrochloric acid by weight of the solution or an equivalent amount of at least one other non-oxidising mineral acid.