Primed polyolefin surfaces for epoxy adhesives

A method for adhering a polyolefin first substrate to a second substrate with an epoxy adhesive comprising the steps of

• a) coating on said polyolefin first substrate a liquid monomer selected from the group consisting of sulfonic and carboxylic acids and alkyl esters thereof containing fewer than eight carbon atoms in the ester group, amides and mono- and di-substituted amides, alcohols, amines, epoxides, and 5-, 6-, and 7-membered heterocyclic rings having at least one oxygen and/or nitrogen atoms in the ring, in a layer less than 5 micrometers in thickness, with the proviso that said monomer contain an ethylenically unsaturated polymerizable moiety;
• b) irradiating the coated substrate with ionizing radiation to graft polymerize said monomer to said substrate;
• c) coating an epoxy adhesive on at least one of (i) said graft-polymerized monomer surface of said first substrate and (ii) a surface of said second substrate;
• d) contacting said surfaces (i) and (ii), and
• e) curing said epoxy adhesive.