| 摘要 |
The photolithographic receptor material for producing images by diffusion transfer is coated with a layer of hydrophilic colloidal silica on a support. This layer of colloidal silica contains silver-precipitating nuclei which result in deposition of the silver in the image areas in the production of a printing plate made from this photolithographic receptor material. In the photolithographic receptor materials described here, the layer of colloidal silica is built up from touching spherical particles which are chemically bonded to one another at the points of contact. The spherical particles comprise two types of particle of different particle size, the first type of particle being 2.5 times larger than the second type of particle. This lattice of hydrophilic silica is ideally suited to the production of lithographic plates with silver image, since not only is optimum silver deposition at the surface ensured, but to a certain extent silver can also be deposited within the silica lattice, and the resistance of the plate to abrasion and impression is thus increased. |
