| 摘要 |
PURPOSE:To enhance image density and ensure uniformity of images, by providing a thermal recording layer comprising an inorganic pigment, a thermal plastic resin, a foamable substance and a heat-fusible substance as main constituents on a water-resistant base to produce a planographic plate material. CONSTITUTION:A mixture containing an inorganic pigment, a thermoplastic resin, a foamable substance, a heat-fusible substance and, if required, a dispersing adjuvant is dispersed and mixed by a dispersing machine such as a ball mill and an attritor to prepare a coating liquid for forming a thermal recording layer. The coating liquid is applied to a water-resistant base such as a paper enhanced in wet strength by a melamine-formaldehyde resin or the like, followed by drying to produce a planographic plate material. The weight ratio of the inorganic pigment to the thermoplastic resin is preferably 1/1-5/1, and the amount of the heat-fusible substance is preferably 0.1-20wt% based on the total amount of the pigment and the resin. |
