Process for preparing an overcoated photopolymer printing plate

Claim 1

A process for preparing a flexographic printing plate which comprises (1) exposing to actinic radiation through an image a flexographic photopolymerizable element prepared by passing into the nip of a calender a mass of a hot photopolymerizable composition comprising an elastomeric binder, an ethylenically unsaturated compound having at least one terminal ethylenic group, and a photoinitiator or photoinitiator system, and, while hot, calendering the photopolymerizable composition between a support and a multilayer cover element to form a photopolymerizable layer therebetween, wherein the multilayer cover element consists essentially of a flexible cover film and a layer of an elastomeric composition and optionally between the flexible cover film and the layer of elastomeric composition a flexible polymeric film, the layer of elastomeric composition being adjacent to the photopolymerizable layer and being photosensitive or becoming photosensitive during or after calendering by contact with the photopolymerizable layer, said layer of elastomeric composition comprising an elastomeric polymeric binder and optionally a second polymeric binder and a nonmigratory dye or pigment and, in addition, when said layer of elastomeric composition is photosensitive one or more ethylenically unsaturated monomeric compounds and/or photoinitiator or initiator system, the cover film of said photopolymerizable element optionally has been removed after calendering but prior to exposure, (2) removing the image and cover film if still present, and (3) removing by liquid development the flexible polymeric film, if present, and the unexposed areas of the layer of elastomeric composition and photopolymerizable layer; and (4) optionally removing any residual liquid developer by drying.