Low energy surface bonding system containing a primer with long open time

Abstract

The invention is a composition comprising a) one or more prepolymers having on average three or more aliphatic isocyanate groups and further containing alkoxysilane groups; b) one or more aromatic polyisocyanates; c) one or more compounds having at least one heterocyclic ring which hydrolyzes when exposed to moisture to form at least one isocyanate reactive group; d) one or more solvents; and e) one or more amine and/or organometallic polyurethane catalysts; wherein the ratio of aromatic isocyanate groups to aliphatic isocyanate groups in the composition is from about 0.5:1.0 to about 1.5:1.0, preferably about 0.9:1.0 to about 1.5:1.0, and the equivalent ratio of isocyanate groups to isocyanate reactive groups derivable from the one or more compounds having at least one hydrolyzable heterocylic ring is from about 0.8:1.0 to about 5.3:1.0, and most preferably about 1.5:1.0 to about 1.7:1.0.

Dependencies are inferred from the claim text.