Lithographic Printing Plate Precursor and Lithographic Printing Method

Abstract

An image-recording material containing (A) a compound having a specific partial structure and at least one group selected from an acid group having a pKa of 11 or less, the derivative of the acid group and a group capable of generating the acid group, a lithographic printing plate precursor having an image-recording layer containing the compound (A), and a lithographic printing method using the lithographic printing plate precursor, are provided.

1 . A lithographic printing plate precursor comprising a support and an image-recording layer, wherein the image-recording layer comprises (1) an infrared absorber and (2) a photochromic compound.  
     
     
         2 . The lithographic printing plate precursor as claimed in  claim 1 , wherein the image-recording layer is capable of image recording by an infrared laser exposure, and the lithographic printing plate precursor is capable of performing a printing by being loaded on a printing machine without a development processing after image recording, or by image recording after, being loaded on a printing machine.  
     
     
         3 . The lithographic printing plate precursor as claimed in  claim 1 , wherein the photochromic compound (2) is selected from the group consisting of a spiropyran compound, a naphthopyran compound, a spiroxazine compound, a fulgide compound, a chromene compound and a diarylethene compound.  
     
     
         4 . The lithographic printing plate precursor as claimed in  claim 1 , wherein the image-recording layer further comprises (3) a radical polymerizable compound and a radical polymerization initiator.  
     
     
         5 . The lithographic printing plate precursor as claimed in claim  17  wherein the image-recording layer contains a microgel.  
     
     
         6 . The lithographic printing plate precursor as claimed in  claim 5 , wherein the microgel is a microcapsule.  
     
     
         7 . A method of plate making a lithographic printing plate precursor, comprising: 
 loading the lithographic printing plate precursor as claimed in  claim 1  on a printing machine and then imagewise exposing the lithographic printing plate precursor with an infrared laser, or imagewise exposing the lithographic printing plate precursor as claimed in  claim 1  with an infrared laser and then loading the lithographic printing plate precursor on a printing machine; and    feeding a printing ink and a fountain solution to the lithographic printing plate precursor to remove the unexposed portion with the infrared laser of the image-recording layer.    
     
     
         8 . A lithographic printing method comprising: 
 loading the lithographic printing plate precursor as claimed in  claim 1  on a printing machine and then imagewise exposing the lithographic printing plate precursor with an infrared laser, or imagewise exposing the lithographic printing plate precursor as claimed in  claim 1  with an infrared laser and then loading the lithographic printing plate precursor on a printing machine;    feeding a printing ink and a fountain solution to the lithographic printing plate precursor to remove the unexposed portion with the infrared laser of the image-recording layer; and    performing a printing.