Patent ID: 6800426
Filing Date: 2004-10-05
Classification: B41C,G03F,Y10S

Abstract:
A negative-working image forming process which comprises the steps of:(1) flood exposing with actinic radiation a photosensitive assembly that comprises: (a) a hydrophilic support which can be used as a lithographic base and having thereon; (b) a first layer comprising: (i) at least one polymer that is soluble or dispersible in an aqueous alkaline solution, wherein the polymer in the first layer is a copolymer having at least one functional group selected from the group consisting of carboxylic acid, N-substituted cyclic imide, and amide; (c) a second layer on top of the first layer, the second layer comprising at least one o-quinonediazide compound; whereby the flood exposure coverts the at least one O-quinonediazide compound to the corresponding indenecarboxylic acid compound; and (d) at least one photothermal conversion material in either the first layer, the second layer, or both layers, wherein the at least one photothermal conversion material is at least one infrared absorbing compound; (2) imagewise exposing the flood exposed photosensitive assembly with infrared radiation and converting the indenecarboxylic acid compound in the second layer in the imagewise exposed areas to the corresponding indene compound; and (3) developing the imagewise exposed photosensitive assembly with an alkaline developing solution and dissolving out the imagewise unexposed areas of the second layer and the areas of the first layer underlying the imagewise unexposed areas of the second layer.