Patent ID: 9195215
Filing Date: 2015-11-24
Classification: G03H,G11B

Abstract:
1. A holographic medium comprising a protective layer and a photopolymer film which is bonded to the protective layer and contains polyurethane matrix polymers, acrylate writing monomers and photoinitiators, wherein the protective layer is impermeable to the constituents of the photopolymer film, is optically clear and is transparent to electromagnetic radiation having a wavelength in the range of from 350 to 800 nm, wherein the protective layer comprises high molecular weight, uncrosslinked polymers or three-dimensional network structures of high network density, wherein the high molecular weight, uncrosslinked polymers have a mean molar mass of >7500 g/mol, and wherein the three-dimensional network structures of high network density are obtained by reacting components that have number-average equivalent molar masses of <1500 g/mol.