Patent ID: 7790266

Claim:
A reboundable optical structure comprising: a) a base layer; and b) an optical element layer attached to the base layer, said optical element layer having a microstructured surface resistant to scratches and abrasions by substantially recovering its original configuration and functionality over a period of minutes or hours, and wherein the optical element layer comprises from about 50% to about 90% by weight of a multi-functional terminally unsaturated urethane oligomer, wherein said urethane oligomer is the reaction product of (i) a terminally unsaturated isocyanate-containing polyurethane oligomer with (ii) an alkoxylated polyhydric alcohol; (iii) from about 1% to about 25% by weight of a modifying monomer selected from one or more di-trimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate and their alkoxylated analogs; and (iv) from about 0% to about 50% by weight of a reactive diluent.