Photomasking Film Using Phthalocyanine Electrophotographic Layer

Paper presented at a symposium on “Photography in the Printing Industry” organized by the Scientific & Technical Group of The Royal Photographic Society, 13-16 September 1983 at New College, Oxford.

Abstract

Photoconductive copper-phthalocyanine is dispersed in a negative-working-type photopolymer and coated on an ITO transparent layer or the conductive layer including SnO, and negative-type photopolymer. The film-making process consists of corona charging, image exposure, liquid toner development, uniform UV exposure and trichloroethylene development steps. A film can be charged positively to 340 V and the incident energy required to discharge the photoreceptor to one-half its maximum surface potential is 650erg/cm2. The toner image formed on the photoconductive layer can be served as a good optical mask for the UV exposure to photopolymer as binder resin. The photoconductive layer under the toner layer can be dissolved away by an organic solution, and the other area exposed to UV light is left on the transparent sheet. This negative-type electrophotographic film can be used for the optical mask to a negative-working-type presensitized printing plate.

Notes

Paper presented at a symposium on “Photography in the Printing Industry” organized by the Scientific & Technical Group of The Royal Photographic Society, 13-16 September 1983 at New College, Oxford.