Process for the preparation of acid n- (hydroxymethyl) -1-aminoalkan-1,1-diphosphonic acid or N, N-bis (hydroxy-methyl-1-aminoalkan-1,1-diphosphonic

摘要

Disclosed are novel N-(hydroxy methyl)-1-amino alkane-1,1-diphosphonic acids and N,N-Bis-(hydroxy-methyl)-1-amino alkane-1,1-diphosphonic acids, preferably N-(hydroxy methyl)-1-amino ethane-1,1-diphosphonic acid, N,N-Bis-(hydroxy methyl)-1-amino ethane-1,1-diphosphonic acid, and their water-soluble salts. Also disclosed is a method for preparing these compounds by reacting the corresponding 1-amino alkane-1,1-diphosphonic acids with formaldehyde in an alkaline medium at elevated temperature. The new phosphonic acid compounds are excellent stabilizing agents for hydrogen peroxide-containing alkaline bleaching liquors, especially useful for bleaching cellulose fibers and blends thereof with synthetic fibers, such as polyester fibers.