Planographic printing plate precursor

Abstract

A planographic printing plate precursor includes a support having disposed thereon a recording layer containing a water-insoluble and alkali-soluble resin, a development inhibitor and an infrared absorber and exhibiting enhanced solubility in an aqueous alkali solution through light exposure. The recording layer may have either a mono-layer construction or a multi-layer construction containing a lower layer and an upper layer. In the case of the multi-layer construction, a layer containing the water-insoluble and alkali-soluble resin is used as the lower layer, and a layer containing the water-insoluble and alkali-soluble resin and the development inhibitor and exhibiting enhanced solubility in an aqueous alkali solution through light exposure is used as the upper layer, and at least one of the lower layer and the upper layer contains the infrared absorber.

1 . A planographic printing plate precursor comprising a support having disposed thereon a recording layer including: 
 a lower layer containing a water-insoluble and alkali-soluble resin having an amide bond in a polymer main chain; and    an upper layer containing a water-insoluble and alkali-soluble resin and a development inhibitor and exhibiting enhanced solubility in an aqueous alkali solution through light exposure,    wherein at least one of the lower layer and the upper layer of the recording layer contains an infrared absorber, and    wherein the resin in the lower layer is a poly(urethane-amide) resin.    
     
     
         2 . The planographic printing plate precursor according to  claim 1 , wherein the resin having an amide bond in a polymer main chain has a weight average molecular weight of from 5,000 to 200,000.  
     
     
         3 . The planographic printing plate precursor according to  claim 1 , wherein the resin having an amide bond in a polymer main chain is used in combination with a resin selected from the group consisting of a polyamide resin, an epoxy resin, a polyacetal resin, an acrylic resin, a methacrylic resin, a polystyrene resin, a novolak type phenol resin and a polyurethane resin.