An object of the present invention is to provide a thiol derivative dye.
A had been disclosed, the following equation (1):

[In the formula,
Represents an alkyl group having 1 -C 4, - or phenyl; L ₁ represents a hydrogen atom; an alkyl group having a carbon number of 1 to 12
X represents an alkylene group having 1 to 12 carbon atoms, an alkenylene group having 12 to 2 carbon atoms, cycloalkylene group having 10 to 5 carbon atoms, an arylene group having 10 C 5 carbon atoms or -O- group, - represents an alkylene group having 1 to 10 carbon atoms, - NH- group, -S- group, -CO- _group, o-SO 2 - arylene of C 5 carbon atoms that may be interrupted by a group 10
Y represents the residue of an organic dye,
Z is the following formula (1b):

Represent or -C≡N group; a group represented by in
In the formula (1b),
A is O group; represents or _-N-L 2 groups,; S group
B is L ₃ groups; -OL ₃ groups; -NL ₃ L ₄ groups; represents or -SL ₃ group, and L _2, L ₃ and L ₄ are, independently of one another, a hydrogen atom; 1 -C 12 It represents an alkyl group of from 12 1 carbon atoms - aryl or carbon atom number of 6 to 12; alkyl group; carbon atoms 6 to 12 of the aryl group. Is a thiol dye represented by.
The compounds, organic materials, for example keratin fibers, preferably useful for dyeing human hair.
.BACKGROUND