Film structure containing a photopolymer layer for holographic exposure and a coating layer of high resistance

A process for producing a hologram comprising the steps of:

• a) providing a multilayer recording material containing a layer composite A-B-C-D comprising
• I) a substrate layer A,
• II) a photopolymer layer B comprising polyurethane matrix polymers, acrylate writing monomers and photoinitiators;
• III) a protective layer C, comprising
• IIIa) at least one thermoplastic resin selected from the group consisting of polyvinylbutyral with Mw≥100 000 g/mol or amorphous polymethyl methacrylate with Mw≥100 000 g/mol;
• IIIb) at least one reactive diluent selected from the group consisting of pentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, compound of formula (Ia)
• compound of formula (Ib)
• compound of formula (Ic)
• wherein in formulae (Ia) to (Ic)
• R1 is independently at each occurrence a radiation-curable group and
• X is independently at each occurrence a single bond between R1 and C═O or a linear, branched or cyclic optionally heteroatom-containing and/or optionally functional-group-substituted hydrocarbon radical,
• compound of formula (II)
• wherein in formula (II)
• R1 and X are as defined in formula (Ia)-(Ic),
• R11 is a linear or branched, optionally heteroatom-substituted aliphatic, aromatic or araliphatic radical,
• R12 is independently at each occurrence up to four substituents selected from methyl, ethyl, propyl, n-butyl, tert-butyl, chlorine, bromine, iodine, methylthio, phenyl and/or phenylthio,
• R13 is independently at each occurrence up to five substituents selected from methyl, ethyl, propyl, n-butyl, tert-butyl, chlorine, bromine, iodine, methylthio, phenyl and/or phenylthio,
• compound of formula (III)
• i) which is substituted at least one of the carbon atoms 1, 2, 3, 4, 5, 6, 7, 8 with an Racryl radical of formula (IV),
• wherein in formula (IV)
• R1 is as defined in formula (Ia)-(Ic),
• R21 is oxygen or sulfur,
• R22 is a carboxamide (—C(O)N—) or a carboxylic ester (—C(O)O—) or a sulfonamide (—SO2N—) group,
• R23 is a saturated or unsaturated or linear or branched optionally substituted radical comprising 2-10 carbon atoms or a polyether comprising up to five (—CH2—CH2—O—)— or (—C(CH3)H—CH2—O—)— groups or a polyamine comprising up to five nitrogen atoms, and
• ii) the compound of formula (III) is at least one further carbon atom 1, 2, 3, 4, 5, 6, 7, 8 substituted with a radical of formula (V),
• wherein in formula (V)
• the carbon atoms of the compound of formula (V) are each independently substituted with hydrogen, halogen, a cyano group, a nitro group or an optionally substituted alkyl, alkenyl, alkynyl, aralkyl, aryl or heteroaryl group or an optionally substituted alkoxy or alkylthio group or any substituted carbamoyl group, which also may be linked bridgingly to a radical of formula (III), or a trifluoromethyl group or a trifluoromethoxy group or an Racryl′ radical of formula (VI),
• wherein in formula (VI)
• R1′ has the same definition as R1 in formula (IV),
• R21′ is oxygen or sulfur,
• R22′ is a carboxamide (—C(O)N—) or a carboxylic ester (—C(O)O—) or a sulfonamide (—SO2N—) group,
• R23′ is a saturated or unsaturated or linear or branched optionally substituted radical comprising 2-10 carbon atoms or a polyether comprising up to five (—CH2—CH2—O—)— or (—C(CH3)H—CH2—O—)— groups or a polyamine comprising up to five nitrogen atoms,
• iii) the remaining carbon atoms of the compound of formula (III) are each independently substituted with hydrogen, halogen, a cyano group, a nitro group or an optionally substituted alkyl, alkenyl, alkynyl, aralkyl, aryl or heteroaryl group or an optionally substituted alkoxy or alkylthio group or a trifluoromethyl group or a trifluoromethoxy group, and
• compound of formula (VII)
• wherein in formula (VII)
• R31, R32, R33 are each independently of one another OH, halogen or an organic radical, wherein at least one of the radicals is an organic radical comprising a radiation-curable group;
• and
• IIIc) comprises at least one photoinitiator, and
• IV) a substrate layer D,
• wherein the layers in the sequence substrate layer A, photopolymer layer B, protective layer C and substrate layer D are arranged directly atop one another;
• b) photoinscribing a hologram into the photopolymer layer B to form a layer composite A-B*-C-D, wherein B* is a photopolymer layer with an inscribed hologram;
• c) subjecting the layer composite A-B*-C-D from step (b) to actinic radiation, to form a layer composite A-B′-C′-D, wherein B′ is the bleached, through-polymerized and no-longer-photosensitive photopolymer layer B comprising a fixed hologram and C′ is the cured protective layer C;
• and
• d) delaminating the substrate layer D of the layer composite A-B′-C′-D from step (c) to form a layer composite A-B′-C′.