Dye diffusion thermal transfer printing

Abstract

A thermal transfer sheet comprising a substrate having a coating comprising a dye of Formula (1): ##STR1## wherein: Y is --H, alkyl, alkoxy, --NHCOalkyl, NHCOaryl, --NHSO.sub.2 alkyl or --NHSO.sub.2 aryl; Ring A is unsubstituted apart from the --N.dbd.N--, --Y and --N< groups or may be substituted by from 1 to 3 substituent groups; R.sup.1 and R.sup.2 each independently is alkyl; R.sup.3 is --H, alkyl, aryl, --SO.sub.2 alkyl, --Salkyl, --Saryl, halogen, pyridyl or R.sup.6 O(CH.sub.2).sub.n -- in which R.sup.6 is alkyl, acyl, aryl and n is from 1 to 10; R.sup.4 is --CN, --NO.sub.2, --SCN or --COOalkyl; and R.sup.5 is a group of Formula (2): ##STR2## in which: Z is --H, alkyl, alkoxy, --NHCOalkyl, --NHCOaryl, --NHSO.sub.2 alkyl or --NHSO.sub.2 aryl; Ring B is unsubstituted apart from the --N.dbd.N--, --Z and --N< groups or may be substituted by from 1 to 3 substituent groups; R.sup.7 and R.sup.8 each independently is --H or alkyl; R.sup.9 independently is any of the groups defined for R.sup.4 ; R.sup.10 independently is any of the groups defined for R.sup.3 ; L is bridging group; or R.sup.5 is alkyl, provided that when R.sup.5 is alkyl R.sup.3 is pyridyl or R.sup.6 O(CH).sub.n --.

Dependencies are inferred from the claim text.