Method for transferring heat-transferable dyes

DETAILED DESCRIPTION OF THE INVENTION In accord with the present invention a method for the transfer of heat transferable dyes employs dye receiving elements comprising a particular class of aromatic polyesters that are comprised of condensation residues of diols and carbonic acid or dicarboxylic acids wherein either the diols or dicarboxylic acids contain a saturated gem-bivalent linking radical having a saturated polycyclic structure that includes a bycyclic member containing at least one atomic bridge.
Typical of some three-dimensional polycyclic structures that provide a gem-bivalent radical is the norbornane ring.
The conventional method of drawing this ring is as follows: ##STR1## An approximate representation which shows the three-dimensional nature of the ring is as follows: ##STR2## Within the gem-bivalent connecting radical, the single carbon atom to which, for example, the two phenol nuclei of an aromatic diol or dicarboxylic acid are connected may be a carbon within the polycyclic structure, or it may be a ##STR3## group attached to the polycyclic structure.
For example, in 4,4'-(2-norbornylidene)diphenol, the phenolic groups are attached directly to a carbon atom within the polycyclic structure: ##STR4## In 4,4'-(2-norbornylmethylene)diphenol, a methylidyne group attached to the polycyclic structure carries the phenolic groups: ##STR5## There may be additional saturated rings in the polycyclic structure in addition to the bicyclic member which contains the atomic bridge.
These may be joined by fused or spiro-union linkage in the polycyclic structure.
Atomic bridges may also occur in the additional member rings of the polycyclic structure.
There may be alkyl, halogen, or aromatic substituents in the linking radical.
The atomic bridge within the polycyclic structure may have more than one carbon atom, e.
g.
, (bicyclo?2.
2.
2!-octane) ##STR6## There may be more than one bridge in the polycyclic structure: e.
g.
(tricyclo?2.
2.
1.
0.
sup.
2,6 !heptane) ##STR7## The atomic bridge may consist of an oxygen or nitrogen atom instead of carbon: e