Patent ID: 7291440

Claim:
An imageable element comprising: a substrate, an underlayer over the substrate, and a imageable layer over the underlayer; in which: the element comprises a photothermal conversion material; the imageable layer is substantially free of the photothermal conversion material; the imageable layer is ink receptive; before thermal imaging, the imageable layer is not removable by an alkaline developer; after thermal imaging to form imaged regions in the imageable layer, the imaged regions are removable by the alkaline developer; the underlayer is removable by the alkaline developer; and the underlayer comprises an acidic copolymer that comprises, in polymerized form, about 10 mol % to about 75 mol % of an acidic monomer or mixture of acidic monomers of the formula: CH 2 ═CH(R 1 )-Z-X—NH—CO—NH—C 6 H 3 —(R 2 )(CO 2 H); in which: R 1 is H or CH 3 ; R 2 is H or OH; Z is —C 6 H 4 — or —C(O)—Y—wherein Y is —NH—;and X is selected from —C(CH 3 ) 2 —, —CH(CH 3 )— and —(CH 2 ) n —, in which n is an integer from 1 to 12.