Patent ID: 6040058
Filing Date: 2000-03-21
Classification: A61L,C08G,C08J,Y10T

Abstract:
A material bearing thereon a coating of a lubricious, hydrated hydrophilic polyurethane-polyurea hydrogel, said material being produced by a process comprising the steps of:a) making a surface of a metal substrate reactive by affixing reactive chemical functional groups thereto, at least a portion of which are amine-containing groups;b) coating a reactive metal substrate surface which results from step (a) with a first coating comprising a hydrophilic polyurethane prepolymer intermediate, containing terminal isocyanate groups, such that at least a portion of said terminal isocyanate groups are reacted with and are covalently bonded to said reactive chemical functional groups on said substrate surface, forming covalent polyurea bonds therewith, resulting in the formation of a tie coat of a polyurethane-polyurea hydrogel-forming polymer, on said substrate surface, that adheres to said substrate surface, and wherein at least a portion of said terminal isocyanate groups of said polyurethane prepolymer intermediate are present in said polyurethane-polyurea hydrogel-forming polymer such that they remain free to react with other species; andc) coating a tie coat of the first-coated substrate surface which results from step (b) with a second coating comprising a moisture-containing, hydrogel-forming compound or mixture, which contains isocyanate-reactive functional groups, such that a barrier coat of a lubricious, hydrated hydrogel is formed upon the application of said second coating to said tie coat;wherein said moisture of said hydrogel-forming compound or mixture is bound with said polyurethane-polyurea hydrogel-forming polymer of said tie coat to form a hydrogel of said barrier coat, on said tie coat, such that said hydrogel is a polyurethane-polyurea polymer hydrogel; andwherein said isocyanate-reactive functional groups of said hydrogel-forming compound or mixture are reacted with and are covalently bonded to at least a portion of said terminal isocyanate groups of said polyurethane-polyurea hydrogel-forming polymer that remain free to react with other species, thereby directly attaching said polyurethane-polyurea polymer hydrogel to said tie coat and thus also indirectly attaching to said substrate surface.