PROCESS OF BLEACHING

摘要

The invention provides a preformed transition metal catalyst salt, which salt is a mononuclear or dinuclear complex of a Mn(III) or Mn(IV) transition metal catalyst having a non-coordinating counter ion selected to provide a preformed transition metal catalyst salt that has a water solubility of at least 30 g/l at 20 °C and wherein the ligand of the transition metal catalyst is of formula (I):
wherein:
p is 3;
R is independently selected from: hydrogen, C1-C6-alkyl, CH2CH2OH, and CH2COOH, or one of R is linked to the N of another Q via an ethylene bridge; and R1, R2, R3, and R4 are independently selected from: H, C1-C4-alkyl, and C1-C4-alkylhydroxy,
which salt is in the form of:
(i) an aqueous solution present in a buffer system that maintains the solution in a pH range of 2 to 7;
(ii) an aqueous solution comprising the salt at a concentration of 0.1 to 10%;
(iii) a solid; or
(iv) a slurry.