Composition containing polymerizable entities having oxirane groups and terminal olefinic unsaturation in combination with free-radical and cationic photopolymerizations means

DETAILED DESCRIPTION What is claimed is: 1.
A photocurable resin composition comprising (A) a partially esterified epoxyester of a terminally unsaturated monocarboxylic acid and a polyepoxide, (B) a curing system consisting essentially of (1) a free radical photoinitiator and (2) a radiation sensitive aromatic onium salt of an element of Group Va or VIIa, said onium salt capable of inducing the cure of (A) by releasing a Lewis acid catalyst when exposed to radiant energy.
2.
The resin composition of claim 1 wherein said epoxyester is a polyepoxide having from 10 to 90 percent of its oxirane groups esterified with said monocarboxylic acid.
3.
The resin composition of claim 1 wherein said epoxyester is the reaction product of a diglycidyl ether and acrylic acid.
4.
The resin composition of claim 3 wherein said diglycidyl ether is a digylcidyl ether of a polyhydric phenol.
5.
The resin composition of claim 4 wherein said polyhydric phenol is bisphenol A.
6.
The resin composition of claim 1 wherein said epoxyester is the reaction product of a diglycidyl ether and a hydroxyalkyl acrylate ester of a dicarboxylic acid.
7.
The resin composition of claim 1 wherein said curing system is p-tertiarybutyl-.
alpha.
,.
alpha.
,.
alpha.
-trichloroacetophenone.




Description:
BACKGROUND OF THE INVENTION The prior known coating processes have conventionally been carried out by dissolving film-forming materials in a volatile solvent, applying the solution to a substrate and drying and curing the coating with the release of the solvent.
Commonly, heat is applied to accelerate the film formation.
The release of the solvent frequently leaves pinholes in the resulting coating.
Also, the release of such solvents into the atmosphere is environmentally unacceptable.
More recently, solvent-free prepolymers such as epoxy resins and modified epoxy resins such as acrylic esters of polyepoxides, have been developed.
Many of such formulations employ reactive diluents to adjust the viscosity of the composition to that suitable for casting or other fabrication techniques