The invention detailed herein comprises a family of radiation-curable
coating formulations specifically for metal substrates. These coating
formulations are based on multifunctional acrylate resins formed by the
reaction of acrylate monomers and oligomers with -keto esters (e.g.,
acetoacetates), -diketones (e.g., 2, 4-pentanedione), -keto amides
(e.g., acetoacetanilide, acetoacetamide), and/or other -dicarbonyl
compounds that can participate in the Michael addition reaction. An
essential novelty of these coating resins is that they will cure under
standard UV-cure conditions without the addition of traditional
photoinitiators. Other materials, both reactive (conventional acrylates)
and non-reactive (e.g., solvents) may also be incorporated into the resin
oligomers to enhance the coatings properties on metal substrates. These
materials include a variety of acrylic monomers and oligomers, primary,
secondary and tertiary amines, acid-functional monomers and oligomers,
silicones, waxes and elastomers, among others. Coatings based on these
novel multifunctional acrylate resins exhibit excellent adhesion and
shrinkage control, flexibility, solvent resistance, scratch and mar
resistance, impact resistance, color, and durability across a wide range
of plastic materials. These coatings may be cured via chemical means,
thermally, or by exposure to UV or electron beam radiation.