DYES FOR LEATHER

摘要

Dyes of formula (I), in which R1 is an alkyl or cycloalkyl group preferably having 1 to 6 and more preferably having 2 to 6 carbon atoms which is preferably in the 4(para) position relative to the diazo group; R2 is a lower alkyl group preferably having 1 to 4 carbon atoms or preferably a hydrogen atom; R?3 and R4¿ are independently hydrogen, SO¿3?H, OH, halogen preferably Cl, CH3, NO2 or COOH groups. R?5¿ is hydrogen OH, NH¿2? or NHCOCH3; R?6¿ is OH, NH¿2?, NR?8R9¿ (in which each group R?8 and R9¿ is independently hydrogen or an alkyl or cycloalkyl group, preferably a lower alkyl group having 1 to 6 carbon atoms or one of the groups R8 or R9 can be an amino alkyl group preferably having 1 to 6 carbon atoms for example an amino propyl group) or NHPh in which Ph represents a phenyl or substituted phenyl group; and R7 is hydrogen SO¿3?H, a halogen preferably Cl or CH3.