Bonding method employing thermally stable hot melt moisture-cure polyurethane adhesive composition

Claim 1

A method of joining at least two substrates, which comprises: (a) forming an assembly comprising at least two substrates having therebetween a sufficient bonding amount of an adhesive having both hot melt and thermosetting urethane properties; and (b) curing the adhesive; wherein the adhesive comprises: (i) an effective film-forming amount of thermoplastic ethylene-vinyl monomer copolymer base wherein the vinyl monomer comprises an acrylate monomer or a vinyl ester of a carboxylic acid compound; (ii) an effective bonding amount of a liquid polyurethane prepolymer composition having a viscosity of less than 25,000 cP at 25° C. comprising the reaction product of a polyfunctional hydroxy compound having a number of average molecular weight of at least 1,000 and a polyfunctional isocyanate compound having an isocyanate functionality of about two or more, at a ratio of hydroxyl to isocyanate of 0.1 to 0.7:1, sufficient to form a rigid moisture cure bond; (iii) a phenol-free polymeric tackifier composition comprising the polymerization product of aromatic monomers, aliphatic monomers, or mixtures thereof, said aromatic monomers being selected from the group consisting of an indene monomer, a styrene monomer, or a dicyclopentadiene monomer, said aliphatic monomer comprising a C 5 diene; and (iv) about 0 to 5 wt-% of an antioxidant.

Claim 2

A method of joining at least two substrates, which comprises: (a) forming an assembly comprising at least two substrates having therebetween a sufficient bonding amount of an adhesive having both hot melt and thermosetting urethane properties; and (b) curing the adhesive; wherein the adhesive comprises: (i) an effective film-forming amount of thermoplastic ethylene-vinyl monomer copolymer base wherein the vinyl monomer comprises an acrylate monomer or a vinyl ester of a carboxylic acid compound; (ii) an effective bonding amount of a liquid polyurethane prepolymer composition having a viscosity of less than 25,000 cP at 25° C. comprising the reaction product of a polyfunctional hydroxy compound having a number of average molecular weight of at least 1,000 and a polyfunctional isocyanate compound having an isocyanate functionality of about two or more, at a ratio of hydroxyl to isocyanate of 0.1 to 0.7:1, sufficient to form a rigid moisture cure bond; (iii) a phenol-free polymeric tackifier composition comprising the polymerization product of aromatic monomers, aliphatic monomers, or mixtures thereof, said aromatic monomers being selected from the group consisting of an indene monomer, a styrene monomer, or a dicyclopentadiene monomer, said aliphatic monomer comprising a C 5 diene; and (iv) about 0 to 5 wt-% of an antioxidant.