Lithographic imaging and printing with printing members having fusible polymeric particles

Abstract

Embodiments of the present invention involve printing members that utilize a particle-fusion imaging mechanism but avoid susceptibility to handling damage. In particular, printing plates in accordance with the invention may utilize two phases, and these may originate, during manufacture, as two particle systems. Both systems are initially dispersed in a single coating applied as a layer, or in multiple coatings applied as adjacent layers, on a substrate. The second particle system exhibits a glass-transition or thermal coalescing temperature well above room temperature and also above the temperature at which the coating is dried. The coalescing temperature of the first particle system is below the drying temperature. As a result, when the coating is dried, the first particle system coalesces and forms a binder that entrains the second particle system, which has not coalesced. The binder formed by the first particle system is preferably insoluble in aqueous liquids, but is swellable or softened by such liquids, whereas the binder formed by the second particle system is preferably insoluble in and not swellable by aqueous liquids. Aqueous insolubility allows the dried (and ready-to-image) coating to resist handling damage, while swellability facilitates development.