Patent ID: 8936899
Filing Date: 2015-01-20
Classification: B41C,B41N,G03F

Abstract:
1. A positive-working, infrared radiation-sensitive lithographic printing plate precursor that comprises: a grained and anodized aluminum-containing substrate, a poly(vinyl phosphonic acid) interlayer disposed directly on the grained and anodized aluminum substrate, a first ink receptive layer that is disposed directly on the poly(vinyl phosphonic acid) interlayer, the first ink receptive layer comprising at least one water-insoluble, alkali solution-soluble or -dispersible resin, and an aromatic acid dye that comprises at least two aromatic groups and at least one anionic group selected from the group consisting of carboxylate, sulfonate, phenolate, and phosphonate groups, and a second ink receptive layer disposed over the first ink receptive layer, wherein the aromatic acid dye is present in an amount of at least 0.5 weight %, based on the total dry weight of the first ink receptive layer, and the positive-working, infrared radiation-sensitive lithographic printing plate precursor further comprising an infrared radiation absorber in either the first ink receptive layer or in the second ink receptive layer, or in both of the first and second ink receptive layers, so that the first ink receptive layer, and the second ink receptive layer become more removable by an alkaline developer upon exposure to infrared radiation having a wavelength of at least 700 nm.