US Patent 7230036 Foam insulation made with expandable microspheres and methods

A polyurethane and/or polyisocyanurate foam is made using expandable microspheres which encapsulate a primary blowing agent. By expanding during the foam making process, the microspheres function as a blowing agent. The foam preferably has at least 10% by weight expandable micro spheres which encapsulate a non-halogenated hydrocarbon chemical or a non-halogenated hydrocarbon chemical blend and less than 2% by weight of any non-encapsulated blowing agents.