Patent attributes
High speed violet or ultraviolet laser sensitive lithographic printing plate comprising on a hydrophilic substrate a specific photosensitive composition is described. The photosensitive layer comprises an alkaline soluble polymeric binder, a multifunctional (meth)acrylate monomer, a free-radical initiator, and a sensitizing dye. The plate is imagewise exposed with a violet or ultraviolet laser at a dosage of less than 300 μJ/cm2, and then developed with an aqueous alkaline developer. Higher monomer to polymer weight ratio is advantageously used. A pigment is preferably incorporated into the photosensitive coating solution as a liquid dispersion. The exposed plate is preferably developed on a processor with an alkaline developer coupled with a replenisher having higher pH.
