Patent ID: 7972386
Filing Date: 2011-07-05
Classification: C11D,D06L,D21C

Abstract:
1. A method for industrial bleaching of a substrate selected from textiles, raw cotton, or wood pulp, the method comprising subjecting the substrate to an aqueous medium, the aqueous medium comprising: from 0.1 to 100 micromolar of a preformed transition metal catalyst salt; from 0.01 to 10 g/l of an aminocarboxylate sequestrant or alkali/alkaline metal salt thereof; from 5 to 1500 mM hydrogen peroxide; wherein the aqueous medium is buffered with a buffer selected from the group consisting of a carbonate buffer wherein the aqueous medium has a pH in the range from 7.5 to 9.5 and a borate buffer wherein the aqueous medium has a pH in the range from 9 to 10.3; and wherein the preformed transition metal catalyst salt is a mononuclear or dinuclear complex of a Mn II-V transition metal catalyst, and the preformed transition metal catalyst salt comprises a ligand of formula (I): wherein: p is 3; R is independently selected from the group consisting of: hydrogen, C1-C6-alkyl, CH R