Photosensitive coatings containing crosslinked beads

Claim 1

A photosensitive coating composition consisting essentially of (a) 5 to 45% by weight based on the weight of components (a) to (d) of at least one nongaseous, ethylenically unsaturated compound having at least one terminal ethylenic group, said compound being capable of forming a high polymer by free-radical initiated, chain-propagating addition polymerization; (b) 0.05 to 10% by weight based on the weight of components (a) to (d) of an organic, radiation-sensitive, free-radical generating system, activatable by actinic radiation which initiates polymerization of the unsaturated compound; (c) at least one organic polymeric binder; (d) discrete, substantially nonswellable crosslinked polymeric beads having an average diameter in the range of 0.02 to 4.0 μm, wherein at least 90% of the beads by population are below 6 μm, the beads being insoluble and nonagglomerating in a solvent for the organic polymeric binder component, said crosslinked polymeric beads are taken from the class consisting of homopolymers and copolymers of tri-, and tetraacrylate, and tri-, and tetramethacrylate monomers which contain three or more free-radical polymerizable double bonds per molecule, copolymers of at least one of said acrylate and methacrylate monomers and up to 25% by weight of at least one monomer having one terminal ethylenic group, and copolymers of at least one of said acrylate and methacrylate monomers and up to 75% by weight of at least one monomer having two terminal ethylenic groups, the total weight percent of the combination of components (c) and (d) based on the total weight of components (a) to (d) being 40 to 70% by weight, component (d) being present in an amount of 15 to 90% by weight based on the weight of components (c) and (d); and (e) at least one solvent for components (a), (b) and (c), the crosslinked polymeric beads being resistant to absorbing or being plasticized by any component or mixture of components of the coating composition, being mutually compatible with the dissolved ingredients a, b, c and e of the coating composition in which said beads are dispersed.