Positive heat-sensitive lithographic printing plate

摘要

A positive heat-sensitive lithographic printing plate comprising an anodically oxidized aluminum support having laminated thereon an undercoating layer containing a polymer having a constituent having an acid radical and a constituent having an onium group, an interlayer containing a water-insoluble and alkali-soluble resin, and a heat-sensitive layer containing a water-insoluble and alkali-soluble resin and an infrared-absorbing dye in this order from the support, and the solubility of the heat-sensitive layer in an alkali aqueous solution increases by heating.