The present invention is a novel thermally-responsive record material
comprising a substrate having provided thereon in substantially contiguous
relationship an electron donating dye precursor, an acidic developer
material, a compound of the formula
##STR1##
wherein R.sub.1, R.sub.2 and R.sub.3 are independently selected from
hydrogen, alkyl, alkoxy, aryl, aralkyl, aralkoxy, halogen, alkoxyalkoxy,
and aralkoxyalkoxy;
with the proviso that when R.sub.1, R.sub.2 and R.sub.3 are hydrogen, that
R.sub.4 is not benzyloxyethoxy or alkyl-substituted benzyloxyethoxy;
wherein R.sub.4 is independently selected from alkoxyalkyl, alkoxyalkoxy,
and aralkoxyalkoxy, and a suitable binder therefor.
In the context of the present invention the alkyl moieties in the alkyl,
aralkyl, aralkoxy, alkoxyalkyl, alkoxyalkoxy and aralkoxyalkoxy preferably
are eight carbons or less, and more preferably from one through four
carbons. Substituents on aryl moieties in aryl, aralkyl, aralkoxy, and
aralkoxyalkoxy groups can include hydrogen, alkyl, alkoxy and halogen. The
alkyl group in these substituents also is eight carbons or less, and more
preferably from one through four carbons.
The thermally responsive record material of the invention has the
unexpected and remarkable properties of enhanced image intensity or
density, and/or improved thermal response.