Positive working lithographic printing plate precursor and process for preparing lithographic printing plate

Abstract

The present invention relates to a positive working lithographic printing plate precursor, comprising: (1) a substrate; and (2) an imaging layer, formed on the substrate, comprising a water-insoluble and an alkaline aqueous solution-soluble or dispersible resin and a photo-thermal converting material, wherein the imaging layer comprises either polyurethane or polyurethane urea or both of the polyurethane and the polyurethane urea, the polyurethane and the polyurethane urea comprising a unit having a substituent having an acidic hydrogen atom and a unit having a polysiloxane moiety in a side or main chain. The present invention can provide a lithographic printing plate precursor which has high printing durability, good scratch resistance, and good developing properties, as well as enhanced ink receptivity.

Dependencies are inferred from the claim text.