US 4,764,178 AGranted

Thermal transfer printing: hetero-aromatic azo dye

AssigneeImperial Chemical Industries PLC

InventorsPeter Gregory, Raymond L. White

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Abstract

A thermal transfer printing sheet comprising a substrate having a coating comprising at least one azo dye of the formula: A--N.dbd.N--E I wherein: A is the residue of a diazotizable heteroaromatic amine, A--NH.sub.2, in which A is selected from imidazolyl, pyrazolyl, thiazolyl, benzothiazolyl, isothiazolyl, benzoisothiazolyl, pyridoisothiazolyl and thienyl; and E is the residue of an aromatic coupling component, E--X wherein X is a group displaceable by a diazotized aromatic amine and E is optionally substituted aminophenyl, tetrahydroquinolinyl, julolidyl or aminoquinolinyl, and a process for the transfer of dye from the transfer sheet to a receiver sheet by the selective application of heat to the transfer sheet while it is contact with the receiver sheet.

Claims5

Dependent claims

A thermal transfer printing sheet comprising a substrate having a coating comprising at least one azo dye of the formula:

A--N.dbd.N--E I
wherein:
A is the residue of a diazotisable heteroaromatic amine, A--NH.sub.2, in which A is selected from imidazolyl, pyrazolyl, isothiazolyl, pyridoisothiazolyl and thienyl, substituted by groups selected only from cyano, thiocyano, nitro, halogen, C.sub.1-4 -alkoxy, formyl, cyano-C.sub.1-4 -alkyl, C.sub.1-4 -alkylsulphonyl, trifluoromethyl, fluorosulphonyl, C.sub.1-4 -alkylcarbonyl and C.sub.1-4 -alkoxycarbonyl;
and E is a group of the formula:
##STR4## wherein R.sup.1 is selected from H, chloro, C.sub.1-4 -alkyl and C.sub.1-4 -alkylcarbonylamino;
and R.sup.2 and R.sup.3 are selected from H, C.sub.1-4 -alkyl and C.sub.1-4 -alkyl, substituted by a group selected from phenyl chloro, cyano, C.sub.1-4 -alkoxy, C.sub.1-4 -alkoxycarbonyl and C.sub.1-4 -alkycarbonyloxy.

3 more elements

Dependencies are inferred from the claim text.