Patent ID: 8277905

Claim:
A process for producing a diffractive light guide element, wherein the process comprises, in the sequence indicated: (a) applying a photosensitive coating composition to a flexible backing web, (b) drying the applied coating composition of (a), (c) laminating a flexible mask onto the dried coating composition of (b), (d) exposing the dried coating composition with a mask laminated thereon of (c) through the mask, thereby obtaining a refractive index gradient in the coating composition through pattern exposure, (e) whole surface curing of the coating composition obtained in (d), thereby fixing the refractive index gradient, (a) to (e) being performed in a continuous, single-stage roll-to-roll process, and wherein the photosensitive coating composition comprises a photopolymerizable component which is a mono- or polynuclear metal complex with a ligand having a photochemically polymerizable group.