Radiation and chemical curable coating composition

A method for coating a substrate comprising the steps of:

• (a) providing a coating composition, wherein said coating composition comprises a mixture of:
• (i) a component A comprising one or more acrylic polymers having one or more chemically crosslinkable functional groups X selected from the group consisting of hydroxyl, thiol, isocyanate, epoxy, acid, thioisocyanate, acetoacetoxy, carboxyl, amine, anhydride, ketimine, aldimine, and urethane group;
• and
• (ii) a component B comprising one or more monomers or oligomers having one or more functional groups Y that react with one or more of the functional groups X to form a crosslink and one or more radiation crosslinkable functional groups D which are radiation crosslinkable ethylenically unsaturated double bonds;
• wherein the mixture is present as a sprayable liquid prior to application of the mixture to a substrate and prior to exposure to actinic radiation, wherein the mixture remains as the sprayable liquid indefinitely until exposure to actinic radiation, and wherein a layer of said coating composition applied over the substrate cures into a dry coating when exposed to actinic radiation;
• wherein one or more of said functional groups X and Y are pair-wise selected from a hydroxyl group and an isocyanate group, a thiol group and an isocyanate group, an epoxy group and an acid group, an epoxy group and an isocyanate group, an isocyanate group and an amine group, and an isocyanate group and a urethane group;
• wherein the ratio of X to Y in said component A and said component B is greater than or equal to 5 to 1;
• b) applying the coating composition to the substrate to form a coating layer;
• and
• c) irradiating the coating layer with actinic radiation to form a dry coating on said substrate.