METHOD FOR PRODUCING HOLOGRAPHIC MEDIA

• US 20120214090A1
• Filed: 11/02/2010
• Published: 08/23/2012
• Est. Priority Date: 11/03/2009
• Status: Active Grant

• Current Assignee: Covestro Deutschland AG
• Original Assignee: Bayer Intellectual Property GmbH (Bayer AG)
• Inventors: Weiser, Marc-Stephan, Rölle, Thomas, Hönel, Dennis, Bruder, Friedrich-Karl, Fäcke, Thomas
• Granted Patent: US 8,771,904 B2
• Time in Patent Office: Days
• US Class Current: 430/2
• CPC Class Codes: C08G 18/2885 containing halogen atoms
• CPC Class Codes: C08G 18/4277 Caprolactone and/or substituted caprolactone
• CPC Class Codes: C08G 18/4854 Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group
• CPC Class Codes: C08G 18/4866 having a low unsaturation value
• CPC Class Codes: C08G 18/68 Unsaturated polyesters
• CPC Class Codes: C08G 18/71 Monoisocyanates or monoisothiocyanates
• CPC Class Codes: C08G 18/715 containing sulfur in addition to isothiocyanate sulfur
• CPC Class Codes: C08G 18/776 phosphorus
• CPC Class Codes: C08G 18/8175 with esters of acrylic or alkylacrylic acid having only one group containing active hydrogen
• CPC Class Codes: C08L 75/14 Polyurethanes having carbon-to-carbon unsaturated bonds
• CPC Class Codes: G01N 5/04 by removing a component, e.g. by evaporation, and weighing the remainder
• CPC Class Codes: G03F 7/001 Phase modulating patterns, e.g. refractive index patterns
• CPC Class Codes: G03F 7/027 Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds G03F7/075 takes precedence
• CPC Class Codes: G03F 7/035 the binders being polyurethanes
• CPC Class Codes: G03H 1/02 Details of features involved during the holographic process; Replication of holograms without interference recording
• CPC Class Codes: G03H 1/04 Processes or apparatus for producing holograms G03H1/26 takes precedence
• CPC Class Codes: G03H 2001/0264 Organic recording material
• CPC Class Codes: G03H 2227/04 Production line for mass production
• CPC Class Codes: G03H 2260/12 Photopolymer
• CPC Class Codes: G03H 2260/54 Photorefractive reactivity wherein light induces photo-generation, redistribution and trapping of charges then a modification of refractive index, e.g. photorefractive polymer
• CPC Class Codes: G11B 7/24044 : for storing optical interference patterns, e.g. holograms; for storing data in three dimensions, e.g. volume storage G11B7/24038 takes precedence
• CPC Class Codes: G11B 7/245 : containing a polymeric component
• CPC Class Codes: G11B 7/26 : Apparatus or processes specially adapted for the manufacture of record carriers

Abstract

The invention relates to a method for producing holographic media, wherein a photopolymer formulation comprising matrix polymers, writing monomers, a photoinitiator system, and optionally auxiliary materials and additives as components is provided, the photopolymer formulation is applied as a coating on the surface of a carrier film and the photopolymer formulation is dried on the carrier film at a temperature XX<T>YY DEG C., wherein only those compounds having TGA 95 values >100 DEG C. and at least 30 DEG C. above the temperature T are selected as components for the photopolymer formulation. The invention further relates to a holographic medium that can be obtained by means of the method according to the invention.

Claims

1-14. -14. (canceled)

15. A process for producing holographic media comprising:

i) providing a photopolymer formulation comprising, as components;

A) matrix polymers,

B) writing monomers,

C) a photoinitiator system,

D) optionally a non-photopolymerizable component, and

E) optionally catalysts, free radical stabilizers, solvents, additives and other auxiliaries and/or additives;

ii) applying the photopolymer formulation as a layer to a substrate film; and

iii) drying the photopolymer formulation on the substrate film at a temperature (T) of between 60 to 120°

C.;

wherein the components chosen for the photopolymer formulation are only compounds having a TGA 95 value greater than 100°

C. and are at least 30°

C. above the temperature (T).

16. The process according to claim 15, wherein the TGA 95 values of the individual components are determined by weighing an amount of about 10 mg of the sample of the respective component into a small aluminium pan having a volume of 70 μ

l, introducing the small aluminium pan an oven of a thermobalance, and measuring the loss of mass of the sample in the open small aluminium pan at a constant oven heating rate of 20 K/min, the start temperature of the oven being 30°

C. and the end temperature 600°

C., the oven being flushed with a 200 ml/min nitrogen stream during the determination and the temperature at which a loss of mass of the sample of 5% by weight, based on the originally weighed in amount of the sample, has occurred being determined as the TGA 95 value of the respective component.

17. The process according to claim 15, wherein the photopolymer formulation is dried at a temperature of between 70 to 100°

C.

18. The process according to claim 15, wherein the matrix polymers comprise polyurethanes.

19. The process according to claim 18, wherein the polyurethanes are obtained by reacting an isocyanate component a) and an isocyanate-reactive component b).

20. The process according to claim 15, wherein the writing monomers comprise acrylates and/or methacrylates.

21. The process according to claim 15, wherein the writing monomers comprise a combination of a monofunctional and a polyfunctional writing monomer.

22. The process according to claim 21, wherein the monofunctional writing monomer has the formula (II)

23. The process according to claim 22, wherein the monofunctional writing monomer has a glass transition temperature of less than 0°

C. and a refractive index of greater than 1.50 at 405 nm.

24. The process according to claim 21, wherein the polyfunctional writing monomer has the formula (III)

25. The process according to claim 24, wherein the polyfunctional writing monomer has a refractive index of greater than 1.50 at 405 nm.

26. The process according to claim 15, wherein the photopolymer formulation comprises urethanes as a plasticizer.

27. The process according to claim 26, wherein the urethanes are substituted by at least one fluorine atom.

28. The process according to claim 27, wherein the urethanes have the formula (IV)

29. The process according to claim 28, wherein at least one of the radicals R10, R11, R12 are substituted by at least one fluorine atom.

30. The process according to claim 28, wherein R10 represents an organic radical having at least one fluorine atom.

31. The process according to claim 15, wherein the photoinitiator system comprises an anionic, cationic or neutral dye and a coinitiator.

32. The process according to claim 15, wherein the photopolymer formulation is applied as a film to a substrate film and the film is covered by a protective film.

33. A holographic medium obtained by the process according to claim 15.