Patent ID: 8231971

Claim:
A process for preparing an anti-fog coating on a surface of a substrate comprising: a) providing nucleophilic groups at the surface of said substrate, wherein said nucleophilic groups are selected from hydroxyl groups, thiol groups, amino groups, aminosilanes and mixtures thereof; b) adding a first polymer layer by covalently bonding a polyanhydride polymer to said nucleophilic groups; and c) adding a second polymer layer by covalently bonding a polymer selected from the group consisting of polyvinyl alcohol, partially hydrolyzed polyvinyl ester and polyether to said first polymer layer wherein the polyanhydride is selected from poly(ethylene-alt-maleic anhydride), poly(maleic anhydride-alt-1-octadecene), poly(isobutylene-alt-maleic anhydride), poly(styrene-alt-maleic anhydride), poly(methyl vinyl ether-alt-maleic anhydride) and poly[(isobutylene-alt-maleic acid, ammonium salt)-co-(isobutylene-alt-maleic anhydride)].