| 摘要 |
<p>There is described a method of preparing a water-less lithographic plate which comprises a support having an oleophilic surface there being coated on the oleophilic surface a mixture which comprises as one component an ink-repellent and water-repellent release material or a mixture of such materials, and as the other essential component a water-insoluble photosensitive composition which is rendered aqueous developable by light exposure, or a water-insoluble composition which is rendered aqueous developable by heat, the ratio of release material to water-insoluble composition in the mixture being from 20 to 80 release material to 80 - 20 water-insoluble composition by weight, imagewise treating the mixture on the support, developing the mixture with an aqueous alkali solution to render the treated areas of the water-insoluble composition water-soluble and to remove this composition together with the release material, to expose the oleophilic surface of the support in the treated areas of the plate and leaving the release material and the water-insoluble composition in the untreated areas of the plate so yielding a negative working water-less lithographic plate.</p> |
