Dye-donor element for use in thermal dye sublimation transfer

Thermal dye sublimation transfer method comprising the step of imagewise heating a dye donor element in face-to-face relation with a receiving element, said donor element comprising a support provided with a dye layer containing a dye dispersed in a polymeric binder, characterized in that said dye corresponds to the following formula (I) ##STR20## wherein R.sup.1, R.sup.2 and R.sup.3 independently represent hydrogen, halogen, nitro, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, a alkylthio group, a arylthio group, an acylamino group, a sulfamoyl group, a carbamoyl group, which groups may be substituted, or R.sup.2 and R.sup.3 together can form a saturated or aromatic or heterocyclic ring fused-on the cyclohexadiene ring, which ring may be substituted;

• B represents ##STR21## wherein R.sup.4 represents hydrogen, an alkyl group, a cycloalkyl group, an aryl group, which groups may be substituted, SO.sub.2 R.sup.10, COR.sup.10, POR.sup.10 R.sup.11 ;
• R.sup.5 represents hydrogen, halogen, nitro, cyano, an alkyl group, an aryl group, an alkoxy group, an alkylthio group, which groups may be substituted;
• R.sup.6 and R.sup.6' independently represent an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an amino group or a heterocyclic group, which groups may be substituted, or R.sup.6 and R.sup.6' together form a 5- or 6-membered ring, which ring may be substituted;
• R.sup.7 represents an alkyl group, an aryl group, a cycloalkyl group, which groups may be substituted;
• R.sup.8 and R.sup.9 independently represent hydrogen, an alkyl group, an aryl group, a cycloalkyl group, which groups may be substituted, or R.sup.8 and R.sup.9 together can form a heterocyclic ring, which ring may be substituted;
• R.sup.10 and R.sup.11 independently represent an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an amino group or a heterocyclic group, which groups may be substituted, or R.sup.10 and R.sup.11 together form a 5- or 6-membered ring, which ring may be substituted;
• K represents ##STR22## wherein:
• R.sup.12 and R.sup.13 (independently) represent hydrogen, an alkyl group, an aryl group, a heterocyclic group, which groups may be substituted, or R.sup.12 and R.sup.13 together represent the necessary atoms to close a heterocyclic ring, which ring may be substituted, or R.sup.12 and/or R.sup.13 together with R.sup.14 and/or R.sup.17 represent the necessary atoms to close a ring fused-on the benzene ring, which ring may be substituted;
• R.sup.14, R.sup.15, R.sup.16 and R.sup.17 (independently) represent hydrogen, hydroxy, halogen, an alkyl group, a cycloalkyl group, an aryl group, an alkyloxy group, an aryloxy group, a carbamoyl group, a sulfamoyl group, which groups may be subsituted, NH--SO.sub.2 R.sup.18, NH--COR.sup.18, O--SO.sub.2 R.sup.18, O--COR.sup.18, or R.sup.14 and R.sup.15 together and/or R.sup.16 and R.sup.17 together represent the necessary atoms to close (a) ring(s) fused-on the benzene ring or R.sup.14 and/or R.sup.17 together with R.sup.12 and/or R.sup.13 represent the necessary atoms to close a heterocyclic ring fused-on the benzene ring, which groups may be substituted;
• R.sup.18 represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an aryl group, an alkyloxy group, an aryloxy group, an alkylthio group, an arylthio group, an amino group, a heterocyclic group, which groups may be substituted.