Patent ID: 6017577
Filing Date: 2000-01-25
Classification: A61L,C08G,C08J,Y10T

Abstract:
A process for producing a material bearing thereon a coating of a lubricious, hydrated hydrophilic polyurethane-urea hydrogel, said process comprising the steps of:a) making a surface of a hydrophilic or hydrophilicized hydrophobic polymer substrate reactive by affixing reactive chemical functional groups thereto, at least a portion of which are amine groups;b) coating a reactive polymer substrate surface which results from step (a) with a first coating comprising a hydrophilic polyurethane prepolymer intermediate, containing terminal isocyanate groups, such that a first 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 urea bonds therewith, resulting in the formation of a tie coat of a polyurethane-urea hydrogel-forming polymer, on said substrate surface, that adheres to said substrate surface, and wherein a second portion of said terminal isocyanate groups of said polyurethane prepolymer intermediate are present in said polyurethane-urea hydrogel-forming polymer such that they remain free to react with other species; andc) coating the tie coat which results from step (b) with a second coating comprising a moisture-containing, hydrogel-forming compound or mixture, which contains isocyanate-reactive functional groups;whereby said isocyanate-reactive functional groups of said hydrogel-forming compound or mixture react with at least a portion of said second portion terminal isocyanate groups of said polyurethane-urea hydrogel-forming polymer;and whereby said moisture of said hydrogel-forming compound or mixture hydrates said polyurethane-urea hydrogel-forming polymer of said tie coat.