Disclosed is the use of mixtures comprising at least 2 structurally different bis(biphenyl)triazine derivatives of formula (1) wherein X is hydrogen C1-C50alkyl which may be uninterrupted or interrupted by one or more oxygen atoms and/or substituted by one or more R8 groups C3-C12-cycloalkyl which is substituted by R8 -CH((CH2)p-R8)-CO-O-(CH2)m-R9 -CH((CH2)p-R8)-CO-(NR10)-(CH2)m-R9 -CO-O-(CH2)p-Ra -CH2-CH(-O(CO)-R8)-R9 -CO-(NR10)-(Ch2)p-Ra C6-C20aryl allyl C4-C50alkenyl which is uninterrupted or is interrupted by one or more oxygen atoms C3-C12cycloalkyl which is uninterrupted or interrupted by one or more oxygen atoms C3-C20alkynyl C6-C12cycloalkynyl R1 is hydrogen unsubstituted or substituted unsubstituted or substituted C3-C12cycloalkyl unsubstituted or substituted C6-C20aryl unsubstituted or substituted C2-C20alkenyl OR7 OH SR8 SOR7 SO2R7 SO2H SO3M or a radical of the formula (c) R2, R3, R4, R5 and R6 independently of one another are hydrogen hydroxyl -CN substituted or unsubstituted C1-C20alkyl unsubstituted or substituted C3-C12-cycloalkyl unsubstituted or substituted C1-C18alkoxy unsubstituted or substituted C4-C20cycloalkoxy C7-C20phenylalkyl halogen halo-C1-C5alkyl sulfonyl carboxyl acylamino acyloxy C1-C12alkoxycarbonyl aminocarbonyl R7 is substituted or unsubstituted C1-C18alkyl unsubstituted or substituted C3-C12-cycloalkyl unsubstituted or substituted C6-C20aryl unsubstituted or substituted C2-C20alkenyl or C7-C20phenylalkyl M is alkali metal R8 and R9 independently of one another are Rx if attached to a carbon atom and are Ry if attached to an oxygen atom p is 0 to 20 m is 0 to 20 Rx is hydrogen hydroxyl C1-C30alkyl C3-C12cycloalkyl C1-C30alkoxy C3-C12cycloalkoxy C3-C12-cycloalkyl or C3-C12cycloalkoxy which is interrupted by one or more oxygen atoms C6-C12aryl hetero-C3-C12aryl -ORz NHRz Rz CONR10R11 SO3H SO3M OSO3H2 allyl, C2-C30alkenyl C4-C12-cycloalkenyl which is uninterrupted or interrupted by one or more oxygen atoms C3-C20-alkynyl or C6-C12cycloa
