DISULPHONIC FLUORESCENT BLEACHING AGENTS Russian patent published in 2015 - IPC D21H21/30 C07D251/68 

FIELD: chemistry.

SUBSTANCE: invention relates to concentrated aqueous compositions of fluorescent bleaching agents for optical bleaching of paper. The aqueous composition comprises (a) between 5 and 80 wt % disulphonic fluorescent bleaching agent derivative of bis(triazinilamino)-stilbene, containing a carboxylic group -CO₂M in aniline rings, where M represents hydrogen, Li, Na, K, Ca, Mg, ammonium or ammonium which is mono-, di-, tri- or tetra-substituted by C₁-C₄- alkyl or C₂-C₄-hydroxyalkyl, and (b) between 95 to 20 wt % water. A paper bleaching method and produced paper are also described.

EFFECT: offered composition provides high whitening performance and enables stable concentrated aqueous preparations or solutions to be formed, without the addition of solubilising auxiliaries.

25 cl, 2 dwg, 1 tbl, 2 ex