Patent ID: 8608907

Claim:
A composition suitable for paper brightening, wherein the composition comprises: three fluorescent whitening agents (FWA) represented by formula (1), formula (2) and formula (3): wherein R represents independently hydrogen, C 1 -C 3 alkyl or C 1 -C 3 hydroxyalkyl; R 1 , R 2 , R 3 and R 4 represent independently of each other, hydrogen, cyano, C 1 -C 4 alkyl, C 2 -C 4 hydroxyalkyl, C 1 -C 4 alkoxy, wherein alkyl is linear or branched; or R 2 and R 1 or R 3 and R 4 independently of each other together with N atom form a morpholine ring, a piperidine ring or pyrrolidine ring; or —(CH 2 ) 1 —SO 3 M, where 1 is 1, 2 or 3; or wherein the —SO 3 M groups can be in o-, m-, or p-position and k is an integer from 0 to 3; or —(CH 2 ) i —COOR, —(CH 2 ) i —CONHR, —(CH 2 ) i —COR, where i is an integer from 1 to 4, R is C 1 -C 3 alkyl or equals to M; and M represents hydrogen, or one equivalent of a cation selected from the group consisting of Li, Na, K, Ca, Mg, and ammonium, wherein the ammonium cation is unsubstituted or mono- di-, tri- or tetra-substituted by C 1 -C 4 alkyl or C 2 -C 4 hydroxyalkyl; and wherein the composition contains the fluorescent whitening agent of formula (1) in an amount of 50 to 90 weight-%, the fluorescent whitening agent of formula (2) in an amount of 1 to 20 weight-% and the fluorescent whitening agent of formula (3) in an amount of 1 to 30 weight-%, wherein the weight-% is based on a total amount of the fluorescent whitening agents.