US Patent 7524543 - Durable optics with surface modified nanoparticles

http://www.freepatentsonline.com/7524543.html

This patent from 3M is issuing based on a series of continuations going back to 2003 and includes some basic claims to optical films incorporating nanoparticles which provides more durability to brightness enhancing films.

1. An optical film comprising:

a microstructured surface comprised of a polymerized composition comprising a resin and a plurality of surface modified colloidal nanoparticles wherein the surface modified colloidal nanoparticle comprise a combination of surface treatment agents.