METHOD OF PREPARING PHOTOSENSITIVE PRINTING PLATE, AQUEOUS DEVELOPING SOLUTION SUITED FOR THE PREPARATION, AQUEOUS RINSING SOLUTION AND DEVELOPER FOR THE PHOTOSENSITIVE PRINTING PLATE

摘要

A method of preparing a photosensitive printing plate comprising a step of irradiating the surface of a photosensitive printing plate with activating light through a mask pattern, and a step of developing the surface of the photosensitive printing plate with an aqueous developing solution and removing unexposed portions. As the aqueous developing solution, an aqueous solution containing a chelating agent and a surfactant is used. By using such an aqueous solution containing a chelating agent and a surfactant, the developing rate is increased in preparing the photosensitive printing plate. The tackiness of development dregs and the surface of the photosensitive printing plate, dregs are prevented from sticking onto the surface of the printing plate, and the image reproduceability is enhanced. It is desirable that the method further includes a step of rinsing the developed photosensitive printing plate with an aqueous rinsing solution. The rinsing after the development prevents no developing solution remaining on the surface of the printing plate, improves the wettability of the surface of the printing plate with ink, and the image reproduceability at the time of printing. Since few dregs remain on the surface of the printing plate, the image reproduceability is improved. In the preparation method, furthermore, it is preferable to arrange a scraping means that comes into contact with the surface of the photosensitive plate from above at the time of development with an aqueous developing solution, and to supply the aqueous developing solution through the scraping means.