Abstract: Disclosed are an optical film and a preparation method thereof. The optical film comprises a base layer, a plurality of polymer particles disposed in the base layer, and voids formed in the base layer and enclosing the respective polymer particles, wherein the polymer particles comprise a crosslinked polymer. The optical film has uniform voids, enhanced processing and dimensional stabilities, as well as improved optical properties such as whiteness, hiding power, reflectance and the like. Thus, the optical film can be useful for a reflector sheet for a BLU of an LCD device, and the like.

Abstract: Disclosed are an optical film and a preparation method thereof. The optical film comprises a base layer, a plurality of polymer particles disposed in the base layer, and voids formed in the base layer and enclosing the respective polymer particles, wherein the polymer particles comprise a crosslinked polymer. The optical film has uniform voids, enhanced processing and dimensional stabilities, as well as improved optical properties such as whiteness, hiding power, reflectance and the like. Thus, the optical film can be useful for a reflector sheet for a BLU of an LCD device, and the like.

Abstract: A double wavelength-reflective multi-layer film comprising a reflective layer part composed of at least one resin layer A and at least one resin layer B which are alternatively stacked, the resin layers A and B having refractive indexes different from each other and having a standard deviation in the thickness ranging from 6 to 30 nm, wherein the multi-layer film has an f-ratio of 0.01 to 0.99, is capable of reflecting two visible light wavelength regions in the form of one stack.