Thermally transferable fluorescent compounds

A thermal transfer assemblage comprising:

• (a) a donor element comprising a support having on one side thereof a thermally transferable heterocyclic compound dispersed in a polymeric binder, and
• (b) a receiving element comprising a support having thereon an image-receiving layer, said receiving element being in a superposed relationship with said donor element so that said one side of the donor element is in contact with said image-receiving layer,
• said donor element comprising a support having on one side thereof a thermally transferable fluorescent heterocyclic compound dispersed in a polymeric binder, said fluorescent compound corresponding to one of the following general formulae (A) and (B):
• ##STR7## wherein:
• R.sup.1 represents a hydrocarbon group or a substituted hydrocarbon group;
• R.sup.2 represents hydrogen, a hydrocarbon group, a substituted hydrocarbon group, a carboxylic acid group, an ester group, a nitro group, a carbamoyl group, a substituted carbamoyl group, an amino group or a substituted amino group;
• R.sup.3 represents hydrogen, a hydrocarbon group or a substituted hydrocarbon group, a carboxylic acid group, an ester group, a carbamoyl group or a substituted carbamoyl group;
• R.sup.4 represents hydrogen or a hydrocarbon group or a substituted hydrocarbon group;
• X represents an electronegative substituent with respect to the carbon atom to which it is attached;
• and
• Z represents the atoms necessary to close a quinoline nucleus or such a nucleus in substituted form.

A process of forming a thermal transfer image comprising image-wise heating a donor element, and transferring an image to a receiving element comprising a support and an image-receiving layer to form said thermal transfer image, wherein said donor element comprises a support having on one side thereof a thermally transferable fluorescent heterocyclic compound dispersed in a polymeric binder, said fluorescent compound corresponding to one of the following general formulae (A) and (B):

• ##STR8## wherein:
• R.sup.1 represents a hydrocarbon group or a substituted hydrocarbon group;
• R.sup.2 represents hydrogen, a hydrocarbon group, a substituted hydrocarbon group, a carboxylic acid group, an ester group, a nitro group, a carbamoyl group, a substituted carbamoyl group, an amino group or a substituted amino group;
• R.sup.3 represents hydrogen, a hydrocarbon group or a substituted hydrocarbon group, a carboxylic acid group, an ester group, a carbamoyl group or a substituted carbamoyl group;
• R.sup.4 represents hydrogen or a hydrocarbon group or a substituted hydrocarbon group;
• X represents an electronegative substituent with respect to the carbon atom to which it is attached;
• and
• Z represents the atoms necessary to close a quinoline nucleus or such a nucleus in substituted form.