Process for producing a coating composition

An easily hardenable acrylic coating composition is produced by irradiation with low energy electron beams to economize the industrial application of the composition. A polymer with molecular weights in the 5,000 to 500,000 range is composed of 1 to 40% by weight of a vinyl monomer containing a glycidyl radical, 30 to 99% of a methacrylic monomer and 0 to 69% of other copolymerizable vinyl monomers. This polymer dissolves in a monomer containing at least 30% of an acrylic monomer and 70% of other vinyl monomers. The reaction takes place between 0.1 to 1.0 mole of vinyl monomer containing a carboxyl radical and one mole of glycidyl radical in the solution. In an embodiment, 17.5% by weight of glycidyl methacrylate and 82.5% of alkyl acrylate are polymerized in suspension in the presence of a catalyst to form a bead like polymer with molecular weights in the 5,000 to 500,000 range. After 120 parts of the bead like polymer are dissolved in 180 parts of the acrylic monomer in the presence of a polymerization inhibitor by heating, 22 parts of α, β- unsaturated monocarboxylic acid are added to the solution to react with the glycidyl radical, whereby a non-solvent type coating material containing the polymer having a vinyl radical side chain is produced. In the place of the catalyst, electron beams can be used at an energy level of 0.1 to 20 MeV. The dose rate may be in the range of 0.1 to 2.0 Mrad/sec. (Iwakiri, K.)