Polyurethane composition comprises a writing monomer component comprising at least 10 wt.% of one or more unsaturated urethanes (I), (II), or (III) as writing monomers and polymeric compounds or corresponding matrix precursors as a matrix for the writing monomers. Polyurethane composition comprises a writing monomer component (a) comprising at least 10 wt.% of one or more unsaturated urethanes of formula (I), (II), or (III) as writing monomers and polymeric compounds or corresponding matrix precursors as a matrix for the writing monomers R : radiation curable group; and X : single bond between R and C=O or a linear, branched, or cyclic hydrocarbon radical (optionally contains heteroatoms and/or is optionally substituted by functional groups). Independent claims are included for: (1) preparing media comprising providing a mixture of the components of the polyurethane composition, applying the polyurethane composition to the substrate or in the mold and curing the polyurethane composition, where the isocyanate component is mixed only finally immediately before the application; (2) a medium produced by the process; (3) recording holograms comprising exposing the medium by means of a laser beam; and (4) the unsaturated urethanes compound (II). [Image] [Image] [Image].
Photopolymer compounds for optical elements and visual representations