Patent ID: 8435412
Filing Date: 2013-05-07
Classification: C09B,C11D

Abstract:
1. A process of colour neutralizing treatment liquids, wherein the liquid treatment composition comprises a chromophore comprising monoazo dye selected from the group of: mono-azo dye having the formula: wherein R3 and R4 is selected from substituted C2 to C12 alkyl chains having optionally therein ether (—O—) or ester links, the chain being optionally substituted with —Cl, ′—Br, —CN, NO 2 , and —SO 2 CH 3 ; and, D denotes an aromatic or heteroaromatic group; mono-azo dye having the formula: wherein R3 and R4 is selected from substituted C2 to C12 alkyl chains having optionally therein ether (—O—) or ester links, the chain being optionally substituted with —Cl, ′—Br, —CN, NO 2 , and —SO 2 CH 3 ; and, D is selected from the group consisting of: azothiophenes, azobenzothiazoles and azopyridones; and mono-azo dye having the formula: where X and Y are independently selected from the group of: —H; —Cl; —B; —CN; —NO 2 ; and —SO 2 CH 3 ; A is selected from the group of: —H; —CH 3 ; —Cl; and —NHCOR; B is selected from the group of: —H; —OCH 3 ; —OC 2 H 5 ; and —Cl; R 1 and R 2 are independently, selected from the group of: —H; —CN; —OH; —OCOR; —COOR; -aryl; wherein R is C1-C8-alkyl; said process comprising the steps of: i. providing a mixing vessel with the treatment composition comprising the chromophore; ii. providing to the mixing vessel more than about 0.045% of a reducing agent selected from the group of: sulfite; thiodiurea; formaldehyde bisulfite; formaldehyde sulfoxilate; and mixtures thereof; and iii. mixing until discoloration by color neutralization of the chromophore is achieved.