Triazinylaminostilbene derivative as fluorescent whitening agents

Abstract

The present invention relates to compounds having formula ( ): wherein each R represents, independently, a linear C -C -alkylene residue which is unsubstituted or substituted by hydroxy, C -C -alkyl, C -C -alkoxy, C -C -hydroxy- or alkoxy-alkoxy, —OCOM, —OCOC -C -alkyl, or an amino acid residue from which a hydrogen atom on the amino group has been removed; each R represents, independently, a linear C -C -alkylene residue which is unsubstituted or substituted by hydroxy, C -C -alkyl, C -C -alkoxy, C -C -hydroxy- or alkoxy-alkoxy, —OCOM, —OCOC -C -alkyl, —CO M, CO C -C -alkyl SO M or phenoxy which is unsubstituted or substituted by halogen, C -C -alkyl or C -C -alkoxy, —CO M or CO C -C -alkyl, NH or mono- or disubstituted amino; or phenyl which is unsubstituted or substituted by 1 to 3 SO M, SO NHC -C -alkyl, —SO NH , —CO M, —CO M, —CO C -C -alkyl, —CONH , —CONHC -C -alkyl, —NHCOC -C -alkyl or mono- or disubstituted amino groups; each R represents independently, hydrogen, C -C -alkyl, halogen, cyano, SO M, —SO NH , SO NHC -C -alkyl, —CO M, —CO C -C -alkyl, —CONH , —CONHC -C -alkyl, or —NHCOC -C -alkyl; M is hydrogen, an alkali metal atom, ammonium or a cation formed from an amine and m is an integer of 1 to 3, a process for their preparation and use of the compounds as optical brightening agents for synthetic or natural organic materials or for removing stain in photographic materials.