Patent No. U.S. 6,511,752 B1
Sika Corp. has obtained a patent for a method for adhering a polyurethane-based sealant or adhesive to a substrate. The method comprises applying an aqueous primer solution onto a substrate, the primer solution comprising water, an aminotitanate compound, and an epoxysilane compound having at least one epoxy group and at least two alkoxy groups; applying a polyurethane adhesive or sealant to the primer-treated substrate; and forming a reaction product of the primer and the polyurethane. Also provided are a substrate having a layer of a polyurethane adhesive or sealant, and a stabilized aqueous primer solution containing an epoxysilane compound and an aminotitanate compound.