Holographic medium containing a photopolymer layer for holographic exposure and a highly resistant coating layer

Patent metadata

Field	Value
Publication number	US-2020166888-A1
Application number	US-201816611380-A
Country	US
Kind code	A1
Filing date	May 7, 2018
Priority date	May 9, 2017
Publication date	May 28, 2020
Grant date	—

Abstract

The invention relates to a holographic medium containing a layer construction comprising a curable protective layer C and a photopolymer layer B, to a method for producing such a holographic medium, to a method for producing a hologram using such a holographic medium, to a sealed holographic medium and to the use of such a holographic medium for producing a hologram.

First claim

1 .- 16 . (canceled)

17 . A holographic medium containing a layer construction comprising a photopolymer layer B containing matrix polymers, writing monomers, photoinitiators, optionally at least one non-photopolymerizable component and optionally catalysts, free-radical stabilizers, solvents, additives and other assistant and/or added substances and at least one curable protective layer C containing at least one thermoplastic resin having a glass transition temperature between −20° C. and 190° C., at least one reactive diluent, at least one photoinitiator and optionally at least one additive, wherein the protective layer C is at least partly joined to the areal photopolymer layer B, characterized in that all reactive diluents of the protective layer C are identical to at least one writing monomer of the photopolymer layer B.

18 . The holographic medium according to claim 17 , characterized in that the photopolymer layer B is disposed on a substrate layer A, wherein the photopolymer layer B is on one side at least partly joined to the substrate layer A and the photopolymer layer B is on the other side at least partly joined to the protective layer C.

19 . The holographic medium according to claim 17 , characterized in that the protective layer C is disposed on a substrate layer D, wherein the protective layer C is on one side at least partly joined to the substrate layer D and the protective layer C is on the other side at least partly joined to the photopolymer layer B.

20 . The holographic medium according to claim 17 , characterized in that the layer construction consists of at least four layers at least partly joined to one another, wherein the layers are arranged directly atop one another in the sequence substrate layer A, photopolymer layer B, protective layer C and substrate layer D.

21 . A process for producing the holographic medium according to claim 17 , wherein atop a photopolymer layer B at least one curable protective layer C is applied, wherein the photopolymer layer contains matrix polymers, writing monomers, photoinitiators, optionally at least one non-photopolymerizable component and optionally catalysts, free-radical stabilizers, solvents, additives and other assistant and/or added substances and the at least one curable protective layer C contains at least one thermoplastic resin having a glass transition temperature between −20° C. and 190° C., at least one reactive diluent, at least one photoinitiator and optionally at least one additive, characterized in that all reactive diluents of the protective layer C are identical to at least one writing monomer of the photopolymer layer B.

22 . The process according to claim 21 , characterized in that in a first step the photopolymer layer B is applied atop a substrate layer A to afford a layer composite A-B, in a second step the protective layer C is applied atop a substrate layer D to afford a layer composite C-D and in a third step the layer composite A-B is areally joined to the layer composite C-D to obtain a layer composite A-B-C-D, wherein the layer composite A-B is preferably joined to the layer composite C-D by lamination.

23 . A process for producing a hologram comprising the steps of:
a) providing a holographic medium comprising a layer composite A-B-C-D comprising
I) a substrate layer A,
II) a photopolymer layer B containing matrix polymers, writing polymers, photoinitiators, optionally at least one non-photopolymerizable component and optionally catalysts, free-radical stabilizers, solvents, additives and other assistant and/or added substances,
III) a protective layer C containing at least one thermoplastic resin having a glass transition temperature between −20° C. and 190° C., at least one reactive diluent, at least one photoinitiator and optionally at least one additive,
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, wherein all reactive diluents of the protective layer C are identical to at least one writing monomer of the photopolymer layer B,
b) photoinscribing a hologram into the photopolymer layer B to form a layer composite A-B*-C-D, wherein B* is an irradiated photopolymer layer B, c) subjecting the layer composite A-B*-C-D from step (b) to actinic radiation, preferably UV 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 optionally 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′.

24 . The holographic medium according to claim 17 , wherein the at least one reactive diluent and the at least one writing monomer is a compound selected from the group consisting of compound of formula (VIII)

wherein
n≥1 and n≤4,
R 41 is a linear, branched, cyclic or heterocyclic unsubstituted or else optionally heteroatom-substituted organic radical and
R 42 is hydrogen, a linear, branched, cyclic or heterocyclic unsubstituted or else optionally heteroatom-substituted organic radical, preferably wherein R 42 is hydrogen or methyl and/or R 4′ is a linear, branched, cyclic or heterocyclic unsubstituted or else optionally heteroatom-substituted organic radical,
compound of formula (Ia)

compound of formula (Ib)

compound of formula (Ic)

wherein in formulae (Ia) to (Ic)
R 1 is independently at each occurrence a radiation-curable group and
X is independently at each occurrence a single bond between R 1 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)
R 1 and X are as defined in formula (Ia)-(Ic),
R 11 is a linear or branched, optionally heteroatom-substituted aliphatic, aromatic or araliphatic radical,
R 12 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,
R 13 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 at least one of the carbon atoms 1, 2, 3, 4, 5, 6, 7, 8 with an R acryl radical of formula (IV),

wherein in formula (IV)
R 1 is as defined in formula (Ia)-(Ic),
R 21 is oxygen or sulfur,
R 22 is a carboxamide (—C(O)N—) or a carboxylic ester (—C(O)O—) or a sulfonamide (—SO 2 N—) group,
R 23 is a saturated or unsaturated or linear or branched optionally substituted radical comprising 2-10 carbon atoms or a polyether comprisi

Assignees

• Covestro Deutschland Ag

Inventors

• Kostromine Serguei
• Herzberg Benjamin
• Rölle Thomas
• Hönel Dennis
• Fäcke Thomas
• Auweiler Heinz-Günter

Classifications

• G11B7/24044 Primary

  for storing optical interference patterns, e.g. holograms; for storing data in three dimensions [3D], e.g. volume storage (G11B7/24038 takes precedence) · CPC title

• G03H2250/39

  Protective layer · CPC title

• G03H1/0256 Primary

  having specific functional layer · CPC title

• G03H2260/12

  Photopolymer · CPC title

• G03H1/0248

  Volume holograms · CPC title