Urethane acrylate having a high refractive index and reduced double bond density
View Patent ↗The invention relates to novel specially substituted urethane acrylates based on tris(p-isocyanatophenyl)thiophosphate having a high refractive index and reduced double bond density, and to a method for the production and use thereof.
1. A photopolymer formulation comprising matrix polymers, writing monomers and photoinitiators, wherein the writing monomers comprise
a urethane acrylate of the formula (I)
wherein
X represents oxygen or sulphur, and
R 1 , R 2 , R 3 , independently of one another, represent an olefinically unsaturated organic radical or an aliphatic alcohol, wherein at least one of the radicals R 1 , R 2 , R 3 represents an olefinically unsaturated organic radical and at least one of the radicals R 1 , R 2 , R 3 represents an aliphatic alcohol and
wherein the photopolymer formulation further comprises urethanes as plasticizers,
wherein the urethanes are substituted by at least one fluorine atom.
2. The photopolymer formulation according to claim 1 , wherein the matrix polymers comprise polyurethanes.
3. The photopolymer formulation according to claim 1 , wherein the photoinitiators comprise an anionic, cationic or neutral dye and a coinitiator.
4. The photopolymer formulation according to claim 1 , wherein the urethanes have the formula (III)
wherein
n is from 1 to 8 and
R 4 , R 5 , R 6 independently of one another, represent hydrogen or linear, branched, cyclic or heterocyclic organic radicals which are unsubstituted or optionally substituted by heteroatoms.
5. The photopolymer formulation according to claim 4 , wherein at least one of the radicals R 4 , R 5 , R 6 are substituted by at least one fluorine atom.
6. The photopolymer formulation according to claim 4 , wherein R 4 represents an organic radical having at least one fluorine atom.
7. The photopolymer formulation according to claim 1 , wherein the writing monomers further comprise a monofunctional writing monomer.
8. The photopolymer formulation according to claim 1 , wherein the writing monomers further comprise a monofunctional acrylate.
9. The photopolymer formulation according to claim 8 , wherein the monofunctional acrylate has the formula (IV)
wherein
R 7 , R 8 independently of one another, represent hydrogen or linear, branched, cyclic or heterocyclic organic radicals which are unsubstituted or optionally also substituted by heteroatoms.
10. The photopolymer formulation according to claim 1 , wherein the writing monomers further comprise a monofunctional urethane acrylate.
11. The photopolymer formulation according to claim 1 , wherein the aliphatic alcohol or alcohols is or are substituted by at least one fluorine atom.
12. The photopolymer formulation according to claim 1 , wherein the aliphatic alcohol or alcohols has or have linear or branched C1-C10 radicals.
13. The photopolymer formulation according to claim 1 , wherein the aliphatic alcohol or alcohols has or have linear C 2 -C 4 or branched C 3 -alkyl radicals.
14. The photopolymer formulation according to claim 1 , wherein the aliphatic alcohols comprise trifluoroethanol and/or 1,1,1,3,3,3-hexafluoropropan-2-ol.
15. The photopolymer formulation according to claim 1 , wherein the olefinically unsaturated organic radical or radicals comprise acrylate or methacrylate structures.
16. The photopolymer formulation according to claim 1 , wherein the olefinically unsaturated organic radical or radicals is or are substituted by one or more heteroatoms.
17. A method comprising forming in-line holograms, off-axis holograms, full aperture transfer holograms, white light transmission holograms, Denisyuk holograms, off-axis reflection holograms, edge-lit holograms or holographic stereograms, wherein the holograms or stereograms are produced with the photopolymer formulation according to claim 1 by exposure to recording light.