Reactive dyes containing piperazine

Abstract

Reactive dyes containing piperazine have formula (I) wherein: each of D1 and D2, independently, is a chromophoric group; each of R1, R2, R3 and R4, independently, is H or an optionally substituted alkyl group; each of X1 and X2, independently, is a labile atom or group; each of x and y, independently is 0 or 1 and at least one of x and y is 1; each of a and b independently, is 1 to 5; the or each R5, independently, is alkyl; and z is 0 to 4. For colouration of a substrate the dyes can be applied at a pH above 7 by, for example, exhaust dyeing, padding or printing.

Dependencies are inferred from the claim text.