Patent ID: 6168903
Filing Date: 2001-01-02
Classification: B41C,B41N

Abstract:
A method of imaging a lithographic printing member, the method comprising the steps of: a. providing a printing member having (i) a solid substrate, (ii) first and second imaging layers over the substrate, and (iii) a topmost layer, the topmost layer and the substrate having different affinities for at least one of ink and a fluid to which ink will not adhere, the first imaging layer comprising a thermally activated gas-forming composition but not including a material absorptive of imaging radiation and the second layer comprising a material absorptive of imaging radiation, the second layer becoming sufficiently hot, upon absorption of said radiation, to cause evolution of gas from the first layer; b. selectively exposing, in a pattern representing an image, the printing member, whereby the first and second imaging layers are destroyed and the topmost layer detached by the evolved gas in the exposed region; and c. removing remnants of the first layer where the printing member received radiation, thereby revealing the substrate to form a lithographic image.