Patent ID: 7582408

Claim:
A color forming composition or composite, comprising a) a polymer matrix; b) a thermally modifiable fluoran leuco dye comprising a latent developer attached thereto; and c) a radiation absorber, wherein the thermally modifiable fluoran leuco dye is developable upon the color forming composition being contacted with electromagnetic radiation which causes the radiation absorber to become energized, wherein the energized radiation absorber causes the latent developer to undergo rearrangement to produce an intermediate dye form having a phenolic substituent, wherein the intermediate dye undergoes an acid catalyzed ring opening to produce a colored dye form, wherein the polymer matrix, the thermally modifiable fluoran leuco dye, and the radiation absorber are present in one phase, and wherein the thermally modifiable fluoran leuco dye has the following structure: wherein R1, R2, R3, R4, and R5 are independently lower alkyl substituents or hydrogen.