Dye diffusion thermal transfer printing

Abstract

A thermal transfer sheet comprising a substrate having a coating comprising a dye of Formula (1): ##STR1## wherein: A is the residue of a diazotisable aromatic or heterocyclic amine; R.sup.1 is an optionally substituted branched chain alkyl group; R.sup.2 is an optionally substituted straight or branched chain alkyl group; and Ring B is unsubstituted or may be substituted from 1 to 4 substituent groups, except for 4-(6-thiocyanatobenzothiazol-2-ylazo)-3-methyl-N-ethyl-N-sec butylaniline, 3-(2-[4-N-secbutyl-N-ethylamino)-2-methylphenylazo]-4-chlorothiazol-5-yl)- 2-cyanoacrylic acid ethyl ester, 3-(2-[4-(N-secbutyl-N-n-butylamino)-2-methylphenylazo]-4-chlorothiazol-5-y l)-2-cyanoacrylic acid ethyl ester, 3-(2-[4-(N-isopropyl-N-methylamino) phenylazo]-4-chloro- 3-cyanothien-5-yl)-2-cyanoacrylic acid n-butyl ester, 4-(3-[2-methoxyethyl]-4-cyanoisothiazol-5-ylazo)-3-acetylamino-N-secbutyl- N-n-butyl aniline, 4-(3-methyl-4-cyanoisothiazol-5-ylazo)-3-acetylamino-N-sechexyl-N-ethylani line, 4-(3-sechexyl-4-cyanoisothiazol-5-ylazo)-3-acetylamino-N-sechexyl-N-n-prop ylaniline, 4-(3-methyl-4-cyanoisothiazol-5-ylazo)-N-isopropyl-N-methylaniline, 4-(4,5-dicyano-1-cyanomethylimidazol-2-ylazo)-N,N-diisopropylaniline, 4-(5-nitrothiazol-2-ylazo)-3-acetylamino-6-methoxy-N-isopropyl-N-ethylanil ine and 4-(3-ethylthio-1,2,4,-thiadiazol-5-ylazo)-3-methyl-N,N-diisopropylaniline. The thermal transfer sheet is used in dye diffusion thermal transfer printing.

Dependencies are inferred from the claim text.