Lithographic printing plate precursor

Abstract

A lithographic printing plate precursor is disclosed, comprising a hydrophilic support having thereon a heat-sensitive layer containing either a microcapsule containing a compound having a functional group capable of reacting by heat or a fine particulate polymer, wherein (1) when the heat-sensitive layer contains a fine particulate polymer, the fine particulate polymer may be a fine particulate polymer capable of combining or incapable of combining by heat used for the image formation and the fine particulate polymer has a functional group capable of reacting with a functional group present in another fine particulate polymer or with a functional group present in another component in the heat-sensitive layer; or (2) when the heat-sensitive layer contains a microcapsule containing a compound having a functional group capable of reacting by heat, the microcapsule may be a microcapsule having an outer wall capable of rupturing or incapable of rupturing by heat used for the image formation and a light-to-heat converting material is contained in the heat-sensitive layer or in a layer adjacent thereto.

1 - 15  (Cancelled).  
     
     
         16 . A method of lithographically printing images on a receiving medium, comprising in order: (a) providing on a lithographic press a lithographic printing member comprising (i) a substrate that is a sheet material or a seamless sleeve mounted on a plate cylinder or is the surface of a plate cylinder of the lithographic press; and (ii) a thermosensitive layer capable of hardening through polymerization upon exposure to an infrared radiation; wherein said thermosensitive layer is soluble or dispersible in ink (for waterless plate) or ink and/or fountain solution (for wet plate), and at least the hardened areas of said thermosensitive layer exhibit an affinity or aversion substantially opposite to the affinity or aversion of said substrate to at least one printing liquid selected from the group consisting of ink and an abhesive fluid for ink; (b) imagewise exposing the plate with the infrared radiation to cause hardening of the thermosensitive layer in the exposed areas; and (c) operating said press to contact said exposed plate with ink and/or fountain solution to remove the thermosensitive layer in the non-hardened areas, and to lithographically print images from said plate to the receiving medium.  
     
     
         17 . A method of lithographically printing images on a receiving medium, comprising in order: (a) providing a lithographic plate comprising (i) a hydrophilic aluminum substrate, and (ii) an oleophilic thermosensitive layer comprising a polymer, a polymerizable monomer, an initiator capable of initiating the polymerization of said monomer, and an infrared absorbing dye; wherein said thermosensitive layer is soluble or dispersible in ink and/or fountain solution, and capable of hardening upon exposure to an infrared radiation; (b) imagewise exposing the plate with the infrared radiation according to digital imaging information to cause hardening of the thermosensitive layer in the exposed areas; and (c) contacting said exposed plate with ink and/or fountain solution on a lithographic press to remove the thermosensitive layer in the non-hardened areas, and to lithographically print images from said plate to the receiving medium.  
     
     
         18 . The method of  claim 17  wherein said plate further includes a water soluble or dispersible overcoat on the thermosensitive layer, and said plate is rinsed with water or an aqueous solution to remove the overcoat without developing the thermosensitive layer after imagewise exposure and before on-press development with ink and fountain solution.