Dry-developing photosensitive dry film resist

Claim 1

A process for selectively modifying a surface, comprising laminating a dry-developing dry film resist layer to said surface, imagewise exposing said layer to actinic radiation, removing said support sheet from said layer, whereby the exposed area of said layer remains on said surface and the unexposed area of said layer remains on said support sheet to be removed therewith, treating the resultant exposed area of said surface to modify it, the exposed area of said layer protecting the remainder of said surface from said treating, said dry-developing dry film resist comprising a flexible support sheet and a photopolymerizable layer having a greater adhesion to said support than to said surface, but upon exposure to actinic radiation, having a greater adhesion to said surface than to said support sheet, said layer comprising (1) a dispersion of at least one polymer having a Tg below 70° C. in the form of spherical-like domains within a continuous phase of (2) at least one further polymer, the adhesion between the domains of the dispersed polymer and the further polymer being low relative to the cohesion of the continuous phase of second polymer, to provide an appreciable reduction in the cohesive strength of said layer as compared to when the dispersed polymer is not present in said layer, (3) free-radical polymerizable monomer, (4) and photopolymerization initiator for initiating the polymerization of said monomer upon exposure of said layer to actinic radiation, said monomer being present in an amount in excess of the absorptive capacity of said layer, said layer being dry developed by lamination to said surface, imagewise exposure of said layer to actinic radiation to cause the exposed area of said layer to achieve said greater adhesion to said surface, and peeling away said support sheet, the reduced cohesive strength of said layer enabling the unexposed area of said layer to break free from said exposed area and be removed therefrom by said peeling.