Mixtures of optical brighteners

Mixtures of optical brighteners consisting of from 0.05 to 0.95 part by weight of a compound of the formula I ##STR29## and of from 0.95 to 0.05 part by weight of a compound of the formula IV ##STR30## in which the symbols X, R.sup.1, R.sup.2, A and B are defined as follows:

• X is oxygen or sulfur, R.sup.1 and R.sup.2, which may be identical or different, are hydrogen, fluorine, chlorine, phenyl, C.sub.1-9 alkyl, C.sub.1-4 alkoxy, C.sub.1-4 dialkylamino, acylamino, carboxy, cyano, carbonamido, mono- or di-alkylcarbonamido, carboalkoxy, sulfo, sulfonamido, mono- or di-alkyl-sulfonamido, alkyloxysulfonyl, two vicinal radicals R.sup.1 and R.sup.2, when taken together, are a fused benzo ring, lower alkylene or 1, 3-dioxapropylene;
• A is cyano, a group of the formula --COOR.sup.3, CONR.sub.2.sup.3 with R.sup.3 being hydrogen, C.sub.1-18 alkyl, cycloalkyl, aryl, alkylaryl, halogenaryl, aralkyl, alkoxyalkyl, halogenalkyl, hydroxyalkyl, alkylaminoalkyl, carboxyalkyl, carboalkoxyalkyl, two alkyl or alkylene, when taken together with the nitrogen atom, being a morpholino, piperidino or piperazino ring;
• or A is a group of the formula ##STR31## in which R.sup.4 is straight chain or branched alkyl having from 1 to 18 carbon atoms, preferably 1 to 6 carbon atoms, which may be substituted by hydroxy, halogen, lower alkoxy, dialkylamino, lower alkylmercapto, chloroaryloxy, aryloxy, arylmercapto or aryl radicals both alkyl groups contained in the dialkylaminoalkyl groups, when taken together, may form a morpholino, piperidino or piperazino ring;
• or R.sup.4 is a group of the formula --(CH.sub.2 CH.sub.2 O).sub.n --R with n being 1, 2 or 3 and R being hydrogen;
• lower alkyl, dialkylaminoalkoxyalkyl or alkylthioalkoxyalkyl, the alkyl groups in dialkylaminoalkoxyalkyl, when taken together, may form a piperidino, pyrrolidino, hexamethylenimino, morpholino or piperazino ring;
• or R.sup.4 is a group of the formula --(CH.sub.2).sub.m --CH.dbd.CH--R with m being an integer of from 0 to 5, or R.sup.4 is a radical of the formula ##STR32## wherein R.sup.5 and R.sup.6, which may be the same or different, are hydrogen, fluorine, chlorine, phenyl, lower alkyl, lower alkoxy, C.sub.1-4 acylamino, carboxy, cyano, carbonamido, mono- or di-alkylcarbonamido, carboalkoxy, sulfo, sulfonamido, mono- or di-alkyl-sulfonamido, alkyloxysulfonyl, two vicinal radicals R.sup.5 and R.sup.6, when taken together, may form lower alkylene, a fused benzo ring or 1,3-dioxapropylene;
• B is a polycyclic aromatic radical having at least three condensed rings;
• C is amino, substituted by one or two alkyl, hydroxyalkyl, acyl or phenyl groups, and two alkyl groups, when taken together with the nitrogen atom of the amino group may form a pyrrolidino or piperidino ring or, when taken together with a further nitrogen or oxygen atom, a piperazino or morpholino ring;
• or C is alkoxy, hydroxyalkyl, acyloxy, alkylthio or carbalkylmercapto;
• D independent from C is defined as C and may further stand for a chlorine atom.