Photopolymerizable elements containing light stable coloring materials

Claim 1

A PHOTOPOLYMERIZABLE ELEMENT COMPRISING A SUPPORT BEARING A THERMOPLASTIC PHOTOPOLYMERIZABLE STRATUM, SAID STRATUM BEING SOLID BELOW 40*C., THERMALLY TRANSFERABLE BY HAVING A STICK OR TRANSFER TEMPERATURE ABOVE 18*C. AND BELOW 220*C. AND COMPRISING: (A) AN ETHYLENICALLY UNSATURATED COMPOUND CONTAINING AT LEAST ONE TERMINAL CH2=C<GROUP, HAVING A BOILING POINT ABOVE 100*C. AT NORMAL ATMOSPHERIC PRESSURE AND BEING CAPABLE OF FORMING A HIGH POLYMER BY PHOTO-INITIATED ADDITION POLYMERIZATION, (B) A FREE RADICAL GENERATING ADDITION POLYMERIZATION INITIATOR ACTIVATABLE BY ACTINIC LIGHT IN THE VISIBLE REGION OF THE SPECTRUM AND INACTIVE THERMALLY BELOW 85*C., AND (C) A COLORING MATERIAL FOR SAID STRATUM WHICH IS STABLE TO LIGHT DURING AN IMAGEWISE EXPOSURE OF THE STRATUM, THERMALLY STABLE AT 18*C.-220*C., DURING A THERMAL TRANSFER OF THE UNDEREXPOSED AREAS OF THE STRATUM, ABSORBS RADIATION IN A REGION OF THE VISIBLE SPECTRUM AND IMPARTS AN OPTICAL DENSITY OF AT LEAST 0.5 IN SAID REGION, AND IMPARTS AN OPTICAL DENSITY LESS THAN 0.3 AND TRANSMITS APPRECIABLE ACTINIC RADIATION IN ANOTHER REGION WHERE SAID INITIATOR IS ACTIVATABLE TO PROMOTE POLYMERIZATION.