Patent ID: 7939240

Claim:
A lithographic printing plate precursor comprising: a porous aluminum support; a layer containing a water-soluble polymer resin having a hydrophilic group and a sulfonic acid group, the hydrophilic group being adsorbable to a surface of the porous aluminum support; and an image recording layer, wherein after the image recording layer is exposed to light, an unexposed area can be removed from the image recording layer on a printing machine by supplying an oil-based ink and an aqueous component to the image recording layer without being subjected to development, wherein the layer containing the water-soluble polymer resin has the sulfonic acid group left therein after coming in contact with the oil-based ink and the aqueous component, and wherein the water-soluble resin has a content of a unit having the sulfonic group of from 30 to 98 mol-%, wherein the image recording layer is disposed directly on the layer containing a water-soluble polymer resin, and wherein the water-soluble polymer resin comprises a crosslinkable group.