Production method of lithographic printing plate, lithographic printing plate precursor and lithographic printing method

Abstract

A method for producing a lithographic printing plate is provided, wherein, in the non-alkaline development of a lithographic printing plate precursor having a protective layer, even if the protective layer components are mingled into the developer, the reduction in development removability of the image recording layer and the generation of development scum can be inhibited; an on-press development type lithographic printing plate precursor with excellent inking property, high scratch resistance, satisfied on-press developability and good fine line reproducibility is provided; and a lithographic printing method is provided, each of which is a method for producing a lithographic printing plate, comprising: imagewise exposing a lithographic printing plate precursor comprising a support, an image recording layer and a protective layer, and rubbing the plate surface by a rubbing member of an automatic processor in the presence of a developer at a pH of 2 to 10 to remove the protective layer and the image recording layer in the unexposed area; a lithographic printing plate precursor comprising a support, an image recording layer removable with a printing ink and/or a fountain solution, and a protective layer containing a polyvinyl alcohol having a carboxyl group and/or a sulfonic acid group within the molecule; and a lithographic printing method comprising on-press development.

1 . A method for producing a lithographic printing plate, comprising:
 imagewise exposing a lithographic printing plate precursor comprising a support, a radical polymerizable image recording layer and a protective layer, in this order, to cure the radical polymerizable image recording layer in the exposed area; and then,   rubbing the plate surface by a rubbing member in an automatic processor in the presence of a developer, comprising a surfactant, at a pH of 3 to 9 to remove the radical polymerizable image recording layer in the unexposed area and the protective layer at the same time.   
     
     
         2 . The method for producing a lithographic printing plate as claimed in  claim 1 , wherein the rubbing member is a rotating brush roller. 
     
     
         3 . The method for producing a lithographic printing plate as claimed in  claim 1 , wherein said protective layer contains an inorganic layered compound. 
     
     
         4 . The method for producing a lithographic printing plate as claimed in  claim 3 , wherein said inorganic layered compound is a mica. 
     
     
         5 . The method for producing a lithographic printing plate as claimed in  claim 1 , wherein a coated amount of said protective layer is from 0.05 to 0.5 g/m 2 , in terms of the coated amount after drying. 
     
     
         6 . The method for producing a lithographic printing plate as claimed in  claim 1 , wherein the pH of the developer is from 4 to 8. 
     
     
         7 . The method for producing a lithographic printing plate as claimed in  claim 1 , wherein said lithographic printing plate precursor further comprises an undercoat layer, comprising a compound having a polymerizable group, on the support. 
     
     
         8 . The method for producing a lithographic printing plate as claimed in  claim 7 , wherein said compound is a compound comprising a polymerizable group and a support-adsorbing group. 
     
     
         9 . The method for producing a lithographic printing plate as claimed in  claim 8 , wherein said support-adsorbing group is a sulfonic acid group, a phosphoric acid group or a phosphoric acid ester. 
     
     
         10 . The method for producing a lithographic printing plate as claimed in  claim 8 , wherein the compound further comprises a hydrophilicity-imparting group. 
     
     
         11 . The method for producing a lithographic printing plate as claimed in  claim 1 , wherein the radical polymerizable image recording layer comprises an infrared absorbent. 
     
     
         12 . The method for producing a lithographic printing plate as claimed in  claim 1 , wherein said imagewise exposure is performed by using a laser emitting light having a wavelength of any one of 760 to 1200 nm. 
     
     
         13 . The method for producing a lithographic printing plate as claimed in  claim 1 , wherein the radical polymerizable image recording layer comprises a sensitizing dye. 
     
     
         14 . The method for producing a lithographic printing plate as claimed in  claim 1 , wherein the radical polymerizable image recording layer comprises a hexaarylbiimidazole compound. 
     
     
         15 . The method for producing a lithographic printing plate as claimed in  claim 1 , wherein the radical polymerizable image recording layer comprises a chain transfer agent. 
     
     
         16 . The method for producing a lithographic printing plate as claimed in  claim 1 , wherein said imagewise exposure is performed by using a laser emitting light having a wavelength of any one of 250 to 420 nm.