Hot-Light Resistant Blue Dispersion Dyes

A dye of the general formula I

• where
• R1 to R4 are independently hydrogen, (C1-C4)-alkyl, (C1-C4)-alkoxy, CF3, NO2, CN, halogen, COR5, COOR5CONR6R7, SO2R5 or SO2NR6R7
• where R5, R6 and R7 are each hydrogen or (C1-C4)-alkyl, but R6 and R7 cannot both be hydrogen;
• and
• Y is —CO(CH2)3Cl or —SO2R8,
• where R8 is (C1-C8)-alkyl, (C1-C8)-alkyl, substituted by NO2, CN, halogen or phenyl, phenyl, phenyl substituted by one or more substituents selected from (C1-C4)-alkyl, (C1-C4)-alkoxy, CF3, NO2, CN, halogen, COR5, COOR5, CONR6R7, SO2R5 and SO2NR6R7, or is naphthyl or naphthyl substituted by one or more substituents selected from
• (C1-C4)-alkyl, (C1-C4)-alkoxy, CF3, NO2, CN, halogen, COR5, COOR5, CONR6R7, SO2R5 and SO2NR6R7,
• although R8 cannot be 4-methylphenyl when R1 to R4 are all hydrogen and cannot be phenyl or 4-methylphenyl when R1 and R3 are both chlorine and R2 and R4 are both hydrogen.