Substituted divinyl stilbenes as optical brighteners

摘要

Disclosed are compounds of formula I ##STR1## in which R.sub.1 and R. sub.4, independently, are hydrogen, a non-chromophoric second order substituent, or alkyl or alkenyl unsubstituted or substituted by a non- chromophoric group,PPR.sub.2 and R.sub.5, independently, are hydrogen or alkyl or alkenyl, unsubstituted or substituted by a non- chromophoric group,PPR.sub.3 and R. sub.6, independently, are hydrogen, alkyl, carboxyl or a non-chromophoric esterified carboxyl group,PPor R.sub.2, together with R. sub.3, and/or R.sub.5 together with R.sub.6, signify an alkylene bridge, PPR.sub. 7 and R.sub.8, independently, signify hydrogen or a non-chromophoric substituent,PP or, when R.sub.7 is in the 3-position and/or R.sub.8 in the 3' position, R.sub.7 together with R.sub.2, and/or R.sub.8 together with R.sub.5 signify an alkylene bridge,P Pwith the proviso that no more than one of R.sub. 1 and R.sub.2 and no more than one of R.sub.4 and R.sub.5 signify hydrogen,PP their production and use as optical brightening agents.