Thermographic copying paper

Claim 1

A HEAT-SENSITIVE COPYING PAPER CAPABLE OF REPRODUCING COPIES OF HEAT-ABSORBING GRAPHIC MATERIALS BY THERMOGRAPHIC COPYING MEANS UPON BEING PLACED IN HEAT-CONDUCTIVE RELATION WITH SAID COPIES OF GRAPHIC MATERIALS AND SUBJECTED TO HIGH-INTENSITY IRRADIATION, COMPRISING A THIN FLEXIBLE BACKING, A HEAT-SENSITIVE COATING ON SAID BACKING, SAID COATING COMPRISING A COMPLEX INCLUDING A COLOR FORMING SOLID MATERIAL CONSISTING OF A COLORLESS DERIVATIVE OF A DYE-STUFF ADAPTED TO BE CONVERTED INTO THE CORRESPONDING COLORED DYESTUFF ON REACTION WITH A COUPLING REAGENT, A COUPLING REAGENT FOR SAID COLOR FORMING SOLID MATERIAL INCLUDING A COMPOUND SELECTED FROM THE GROUP CONSISTING OF ARYLAMIDES OF O-HYDROXY CARBOXYLIC ACIDS AND ACYLACETARYLAMIDES, AND A THIRD REAGENT INCLUDING A SOLID FUSIBLE ACID MATERIAL INACTIVE AT TEMPERATURE RANGES BELOW ABOUT 60*C., SAID COMPLEX BEING SUBSTANTIALLY UNIFORMLY DISTRIBUTED THROUGHOUT A THIN TRANSLUCENT PLASTIC BINDER, SAID THIRD REAGENT BECOMING EFFECTIVE AT A TEMPERATURE RANGE OF ABOUT 60-120*C. AND FORMING A MILIEU IN WHICH THE COUPLING REACTION OF THE COLOR FORMING SOLID MATERIAL AND THE COUPLING REAGENT FROM A DYE FACSIMILE IMAGE OF THE GRAPHIC MATERIALS WHEN HEAT DEVELOPED IN THE GRAPHIC MATERIALS IS TRANSFERRED TO THE COATING.