Patent ID: 7498122

Claim:
A solvent-less process for producing a transient document which is capable of self-erasing, wherein said solvent-less process comprises a) heating a photochromic compound and a binder to form a coating composition, and b) coating said coating composition onto an image-receiving side of a transient document substrate, wherein said photochromic compound is a spiropyran having the following formula wherein R 1 , R 2 , R 3 , R 4 and R 5 can be the same or different, and are selected from the group consisting of hydrogen, an alkyl having from about 1 to about 50 carbons, a cycloalkyl having from about 4 to about 10 carbons, an aryl having from about 6 to about 30 carbon atoms, and an arylalkyl having from about 7 to about 50 carbon atoms, and wherein said binder comprises crystalline polyethylene homopolymers having a melting point of from about 90 to about 125° C.