Four component adhesive blends and composite structures

Abstract

Compositions of matter having properties that make them strong adhesives to various substrates and especially for adhering polypropylene and polyethylene to various polar substrates. These compositions comprise blends of a graft copolymer of a polyethylene backbone grafted with at least one grafting monomer comprising one or more of polymerizable ethylenically unsaturated carboxylic acids of the anhydrides of such acids blended with a blending resin that is a mixture of one or more high density polyethylenes, one or more linear low density polyethylenes and one or more polypropylenes. The disclosure also includes composite structures comprising one or more substrates and a blend of the above as the adhesive in contact with the substrate or substrates and the method of preparing these composite structures. This invention relates to adhesive blends comprising modified polyolefin resins with improved adhesion to substrates and especially polar substrates such as metals, glass, paper, wood and polar polymers such as polyamides, polyureas, polycarbonates, polyurethanes, copolymers of olefins with vinyl esters and with vinyl alcohols, cellulose and its derivatives, etc. These adhesive blend resins can be used in any conventional process for combining dissimilar materials. Examples of these methods are lamination, coextrusion, powder and/or extrusion coating, blow molding, etc., or any combination of these processes. The adhesive blends of this invention also have excellent moisture-barrier properties.