Patent ID: 6499745
Filing Date: 2002-12-31
Classification: C09K

Abstract:
A method of forming a fluid impermeable seal between the faying surfaces of two metallic substrates with a polyurethane sealant, the method comprising the steps of:applying a layer of the polyurethane sealant in a pre-cured liquid condition to at least one of the faying surfaces, the polyurethane sealant comprising a copolymer of an isocyanate and a polyol, the isocyanate and polyol when mixed before curing containing a dibutyl tin dilaurate catalyst in an amount predetermined to cause an intended cure rate, the polyurethane sealant including zinc borate as a corrosion resistance component in amounts by weight between about 3% and about 30% of the polyurethane sealant, and wherein the isocyanate and polyol when mixed before curing contain the zinc borate; permitting the layer of polyurethane sealant to cure to a dry solid; and mechanically fastening the metallic substrates together such that the faying surfaces thereby compress the polyurethane sealant between them to form a liquid impermeable seal.