Printing plates using silicone elastomers - image deposited on surface forced into elastomer layer forming ink receptive areas avoids need for wetting system

摘要

Process for a printing layer by first coating a support with an ink repelling layer of either an organopolysiloxane elastomer or heterophase polymeric compsns. contg. a silicon phase; an image is deposited on the surface of the layer then forced by pressure into the layer thereby forming a layer with ink receptive image zones. The polymers are either copolymers of an organopolysiloxane and a polymeric prod or an organopolysiloxane and a polymeric prod in the amorphous state having a Tg of = the ambient temp. The layer is pref. 0.1 to 50 mu thick and to push the image into the layer a pressure of =14 kg/cm2 is used. Pref. silicone gums are used which are hardenable at normal temps. or by heating or a mixt of both. Partic used for direct lithographic printing where a heavy ink coating is required. Avoids the complications of photosensitive layer processes and no wetting system is required.