Patent ID: 6878825

Claim:
A rylene derivative of formula Ia or formula Ib: where the variables have the following meanings: R is hydrogen; C 1 -C 30 -alkyl, whose carbon chain may be interrupted by one or more —O—, —S—, —NR 2 —, —CO— and/or —SO 2 — groups and which may be monosubstituted or polysubstituted by carboxyl, sulfo, hydroxyl, cyano, C 1 -C 6 -alkoxy and/or by a 5- to 7-membered heterocyclic radical which is bonded via a nitrogen atom, may contain further heteroatoms and may be aromatic; aryl or hetaryl, each of which may be monosubstituted or polysubstituted by C 1 -C 18 -alkyl, C 1 -C 6 -alkoxy, halogen, hydroxyl, cyano, carboxyl, —CONHR 3 , —NHCOR 3 and/or aryl- or hetarylazo, each of which may be substituted by C 1 -C 1 -alkyl, C 10 -C 6 -alkoxy, halogen, hydroxyl, cyano and/or carboxyl; R 1 is hydrogen or bromine; R 2 is hydrogen or C 1 -C 6 -alkyl; R 3 is hydrogen; C 1 -C 18 -alkyl; aryl or hetaryl, each of which may be substituted by C 1 -C 8 -alkyl, C 2 -C 6 -alkoxy, halogen, hydroxyl and/or cyano.