MACHINE PLATE OFFSET PRINTING, ITS PRODUCTION AND METHOD FOR REGENERATING MACHINE PLATE

摘要

PROBLEM TO BE SOLVED: To provide a machine plate for offset printing of a low cost having high image quality which is free from problems relating to the repetitive durability to a change in hydrophilic/hydrophobic properties and the stability of the unstable structure of photothermal responsive molecules by reusing a machine plate base material. SOLUTION: The machine plate for offset printing is produced by utilizing a means for dispersing or dissolving a developer which is reversed in the hydrophilic/hydrophobic properties by the change in the dipole moment of the photothermal responsive molecules into a solvent exhibiting the same kind of the hydrophilic/hydrophobic properties as the photothermal responsive melecules in a coal and dark portion and bringing this developer into contact with the machine plate base material having a surface exhibiting the hydrophilic/hydrophobic properties reverse from those of the developer solvent, a means for exposing the developer to image writing lightλ1 to change the hydrophilic/hydrophobic properties of the developing agent and adhering the developer to the machine plate base material surface, a means for fixing the developer to the machine plate base material by heating and pressurizing and a mean for returning the hydrophilic/hydrophobic properties on the surface of the developer particles to the original hydrophilic/hydrophobic properties by heating and (or) irradiating with light of a wavelengthλ2 .