Lithographic printing plate precursor for newspaper printing and method for producing the same, and plate making method of lithographic printing plate

摘要

An object of the invention is to provide a lithographic printing plate precursor of on-press development type for newspaper printing which has good on-press development property at the edge portion thereof and is prevented from the occurrence of edge stain even when a large number of printings is performed, a method for producing the same, and a plate making method using the lithographic printing plate precursor and is directed to a lithographic printing plate precursor for newspaper printing including on a support, an image-recording layer which contains an infrared absorbing dye, a radical polymerization initiator, a radical polymerizable compound, a polymer compound having a polyoxyalkylene chain in its side chain and an anionic or nonionic surfactant and is capable of being developed with at least one of printing ink and dampening water on a cylinder of a printing machine, wherein the lithographic printing plate precursor has a shear droop in which a shear droop amount (X) is from 35 to 150 µm and a shear droop width (Y) is from 50 to 300 µm at an edge of the image-recording layer side, and a region within 1 cm from an edge surface of the lithographic printing plate precursor including the shear droop has been treated with a treating solution containing an anionic or nonionic surfactant, a method for producing the same, and a plate making method using the lithographic printing plate precursor.