Patent ID: 6852464

Claim:
A method for forming a multi-layer positive-working imageable element, the imageable element comprising: a substrate comprising a hydrophilic surface; an underlayer over the hydrophilic surface of the substrate; and an imageable layer over the underlayer; the method comprising the steps of: (a) coating the underlayer over the hydrophilic surface of the substrate; (b) coating the imageable layer over the underlayer; and (c) heating the imageable element at a temperature between about 130° C. and about 200° C. for a time sufficient to increase resistance of the imageable element to an alkaline developer and to decrease the white light sensitivity of the imageable element; in which: the imageable element comprises a photothermal conversion material; the imageable layer is ink receptive; the imageable layer is insoluble in the alkaline developer; the imageable layer comprises: a first polymeric material, and an o-diazonaphthoquinone containing material; and the underlayer comprises a second polymeric material.