To provide a lithographic printing original plate which is capable of writing with an infrared laser, has a protective layer, improves productivity in plate-making work, and suppresses generation of development scum, and a plate-making method for the same.
The lithographic printing original plate has a photosensitive layer containing an infrared absorbent, a polymerization initiator, an unsaturated polyurethane compound and a binder polymer and the protective layer containing an inorganic layered compound in this order on an aluminum support. In the plate-making method for the lithographic printing original plate, such lithographic printing original plates are set in a plate setter in such a way that the protective layer and the rear face of the aluminum support come in contact with each other, and the lithographic printing original plates are automatically transported one by one, exposed at a wavelength of 750-1,400 nm, and then developed without passing through a heating and/or washing step.
YAMAMOTO OSAO
Hironori Honda
Toshimitsu Ichikawa
Takeshi Takamatsu
Kiyozumi Yazawa