Process for cross-linking and curing

A new process for cross-linking and curing coating resins is provided. The process comprises coating a substrate with a mixture of a cross-linking agent (or diluent) and a vinylic polymerizable oligomer, and irradiating the coating with high energy radiation at an elevated temperature. The cross-linking agent is selected from acrylic or methacrylic esters or other vinyl monomers. The oligomer is selected from polyester or polyamide type oligomers having some vinyl unsaturations in the molecule. When irradiated at an elevated temperature, the composition cures to give an unstretched coating having a smooth surface. In one example (parts), Me methacrylate (25), n-Bu acrylate (20), styrene (30), methacrylic acid (20) and dimethylaminoethyl methacrylate (5) were copolymerized and then reacted with glycidyl methacrylate (35) to give an oligomer having vinyl unsaturations. The oligomer (65) was diluted with 2-Et-hexyl methacrylate (35). An Al plate was coated with the composition, heated in an infrared furnace until the superficial temperature attained 800C, and then irradiated with electron beams (dose rate 1 Mrad/sec, absorbed dose 5 Mrad). Thus, the coating layer cured to give a very smooth surface. It had a high impact strength and good workability. (Kaichi, S.)