Patent ID: 6701842
Filing Date: 2004-03-09
Classification: B41N

Abstract:
A process for the treatment of an erasable litho-graphic printing plate, comprising the steps of:(a) treating one of a used and an unused printing plate with an erasing composition to clean said printing plate, wherein said erasing composition comprises a substance which, in aqueous solution, produces one of a pH of 1-4 and a pH of 10-14, and present in an amount which is sufficient for the stated pH range, a dispersible abrasive in an amount of 1-15 g, a low-foam surfactant in an amount of 1-50 g, a solvent in an amount of 10-50 g, and water to 100 g; (b) laser imaging said printing plate with a polymeric substance to provide an image thereon; (c) applying to said printing plate any one of i) a heat-curable and water-soluble substance, immediately after step b), ii) a water-soluble substance immediately after step b), and iii) a heat-curable and water-soluble substance immediately after step b), followed by warning of said printing plate; (d) fixing said image an said priming plate; and (e) washing said water-soluble substance, or said heat-curable and water-soluble substance from said printing plate with a solution consisting essentially of water before printing with said printing plate.