Patent ID: 7976670

Claim:
A method of bonding passive or weakly active substrates that are free of or essentially free of applied or inherent transition metals and without the use of primers or pre-applied activators, said method comprising the steps of i) applying an anaerobic adhesive composition comprising at least one free radically polymerizable acrylic ester component and a sufficient amount of an activation system for effecting free radical polymerization thereof under anaerobic conditions, said activation system comprising a peroxide free radical initiator and a transition metal metallocene, wherein at least one of the initiator or the metallocene is microencapsulated in a substantially initiator and metallocene impermeable polymer and wherein the microencapsulated initiator or metallocene comprises an encapsulated droplet of a liquid carrier having dispersed or dissolved therein the initiator or metallocene, to at least one of the two surfaces to be bonded, ii) mating the two surfaces to be bonded in such a way that the mating process causes the release of the microencapsulated component, and iii) allowing the mated surface to stand to effect cure; wherein at least one of the surfaces to be bonded is selected from the group consisting of aluminum, zinc, anodic coatings, stainless steel, ceramics and plastics and wherein the cure is effected within 24 hours.