Process of making photosensitive resin printing plates

摘要

A support convenient for preparing a printing plate in situ using a liquid photosensitive resin of an unsaturated polyurethane resin is disclosed. This support consists of a base plate and coated thereon a layer of a composition consisting of a mercapto-containing ester obtained by polycondensing a thiocarboxylic acid or thioalcohol with a polyglycol or polycarboxylic acid or an aromatic tertiary amine and a polymer binder. The support of this invention, which has a broadened base of a sectionally trapezoidal configuration, provides a relief image that is firmly adhered to the support.