Patent ID: 9540479
Date: 2017-01-10
CPC Classifications: B05D,B82Y,C08G,C08J,C08K,C09D,Y10T

Claim:
1. An erosion resistant film comprising a polyurethane nanocomposite comprising: a) a polyurethane polymer, and b) surface modified silica nanoparticles dispersed within and covalently bound to the polyurethane polymer; wherein the silica nanoparticles are covalently bound to the polyurethane polymer through a linkage derived from a first surface-modifying compound comprising a polyol to which a silane group is added by reaction with a compound comprising a silane or silane-generating group and an isocyanate group; and wherein said silica nanoparticles have a number average particle size of between 10 and 200 nanometers (nm); wherein the polyurethane nanocomposite has a silica content of greater than 12% by weight.