Stable solutions of fluorescent brighteners

Abstract

A stable weakly acid or neutral solution of quaternized fluorescent brighteners consisting essentially of a quaternized fluorescent brightener of the formula ##SPC1## Wherein Y.sub.1 represents hydrogen methyl, ethyl, methoxy, halogen or together with Y.sub.2 represents a fused benzene ring, Y.sub.2 represents hydrogen, methyl, ethyl, methoxy, halogen or together with Y.sub.1 or Y.sub.3 represents a fused benzene ring, Y.sub.3 represents hydrogen, methyl, ethyl, alkoxy with 1 to 4 carbon atoms, halogen or together with Y.sub.2 or Y.sub.4 represents a fused benzene ring, Y.sub.4 represents hydrogen, alkyl with 1 to 4 carbon atoms, methoxy, halogen or together with Y.sub.3 represents a fused benzene ring, Y.sub.5 represents hydrogen, alkyl with 1 to 4 carbon atoms or phenyl which is unsubstituted or substituted by methyl and/or methoxy, Y.sub.6 represents hydrogen, alkyl with 1 to 4 carbon atoms, alkylsulphonyl with 1 to 4 carbon atoms, methoxy or halogen, Y.sub.7 represents hydrogen, methyl, methoxy or halogen, Y.sub.8 represents alkyl with 1 to 4 carbon atoms, hydroxyalkyl with 2 to 4 carbon atoms, cyanoethyl, phenyl, cyclohexyl or benzyl which is unsubstituted or substituted by chlorine, methyl or methoxy, Y.sub.9 represents alkyl with 1 to 4 carbon atoms which is unsubstituted or substituted by hydroxy or alkoxy with 1 to 4 carbon atoms, benzyl which is unsubstituted or substituted by chlorine or methoxy or represents a radical --CH.sub.2 CN, --CH.sub.2 CONH.sub.2 or --CH.sub.2 COOR, wherein R represents an alkyl group with 1 to 4 carbon atoms, and Z represents halogen, an alkylsulphate with 1 to 4 carbon atoms or a phenylsulphonyl radical which is unsubstituted or substituted by methyl and, in the case of the weakly acid solution, a polar organic compound, water and a weak acid, and, in the case of the neutral solution, a polar, aprotic organic compound and water.