PROTECTIVE LAYER FOR PHOTOPOLYMER

Abstract

The invention relates to a protective layer comprising a photopolymer layer B and and an at least partly cured protective layer C, to a process for producing the layer construction according to the invention, to a kit of parts, to the use of an at least partly cured protective layer C for protection of a photopolymer layer B and to optical displays and security documents comprising the layer construction according to the invention.

Claims

1.-17. (canceled)

18. A layer construction comprising an areal photopolymer layer B and an at least partly cured protective layer C obtained by reaction of an aqueous composition comprising (I) at least one polyvinyl alcohol, (II) at least one crosslinker for polyvinyl alcohols, (III) optionally at least one adhesion promoter, wherein the adhesion promoter is preferably at least one hydrolyzate of an aminoalkyl trialkoxysilane and (IV) optionally at least one surfactant, wherein the photopolymer layer B is at least partly joined to the layer C.

19. A kit of parts containing at least one areal photopolymer layer and an aqueous composition for generating an at least partly cured protective layer C, wherein the aqueous composition comprises (I) at least one polyvinyl alcohol, (II) at least one crosslinker for polyvinyl alcohols, (III) optionally at least one adhesion promoter, wherein the adhesion promoter is preferably at least one hydrolyzate of an aminoalkyl trialkoxysilane and (IV) optionally at least one surfactant and wherein the photopolymer layer is optionally disposed atop a substrate layer A.

20. The kit of parts according to claim 19, further containing an adhesives layer D and a substrate layer E.

21. The layer construction according to claim 18, wherein the photopolymer layer B is an unirradiated photopolymer layer comprising (I) matrix polymers, (II) writing monomers, (III) photoinitiators, (IV) optionally at least one non-photopolymerizable component and (V) optionally catalysts, free-radical stabilizers, solvents, additives and other assistant and/or added substances, or the photopolymer layer B is a semi-irradiated photopolymer layer containing a hologram, preferably a volume hologram, wherein the volume hologram is preferably selected from the group consisting of in-line holograms, off-axis holograms, full-aperture transfer holograms, white light transmission holograms, Denisyuk holograms, off-axis reflection holograms, edge-lit holograms and holographic stereograms.

22. The layer construction according to claim 18, wherein the layer construction further contains a substrate layer A, wherein the photopolymer layer B is on one side at least partly joined to the substrate layer A and is on the opposite side at least partly joined to the protective layer C.

23. The layer construction according to claim 18, wherein the layer construction further contains an adhesives layer D, wherein the protective layer C is on one side at least partly joined to the adhesives layer D and is on the opposite side at least partly joined to the photopolymer layer B.

24. The layer construction according to claim 23, wherein the layer construction further contains a substrate layer E, wherein the adhesives layer D is on one side at least partly joined to the substrate layer E and is on the opposite side at least partly joined to the protective layer C.

25. A process for producing the layer construction according to claim 18, wherein initially an at least partly cured protective layer C is applied atop a photopolymer layer B, wherein the photopolymer layer B is optionally disposed atop a substrate layer A, to afford a layer composite B-C or A-B-C, wherein the protective layer is obtainable by reaction of an aqueous composition comprising (I) at least one polyvinyl alcohol, (II) at least one crosslinker for polyvinyl alcohols, (III) optionally at least one adhesion promoter, wherein the adhesion promoter is preferably at least one hydrolyzate of an aminoalkyl trialkoxysilane and (IV) optionally at least one surfactant.

26. The process according to claim 25, wherein in a further subsequent step an adhesives layer D is applied atop the at least partly cured protective layer C to afford a layer composite BC-D or A-B-C-D and thereafter in a further subsequent step a substrate layer E is applied atop the adhesives layer D to afford a layer composite B-C-D-E or A-B-C-D-E.

27. The process according to claim 25, wherein a hologram is photoinscribed and fixed into the layer composite B-C, A-B-C, B-C-D, A-B-C-D, B-C-D-E or A-B-C-D-E.

28. The layer construction according to claim 18, process according to claim 25 or kit of parts according to claim 19, wherein the at least one polyvinyl alcohol according to DIN 53015:2001-02 as a 4% by weight solution in water at 20° C. has a viscosity of ≥25 mPa*s, and wherein the polyvinyl alcohol preferably according to DIN EN ISO 3681:2007-10-01 has a degree of hydrolysis of ≥85 mol %.

29. The layer construction according to claim 18, process according to claim 25 or kit of parts according to claim 19, wherein the crosslinker for polyvinyl alcohols is selected from the group consisting of aqueous glyoxal solution, glutaraldehyde, oxalic acid, N,N′-dimethylurea, magnesium hydroxide, calcium hydroxide, boric acid, borate salts, aluminates, aluminum sulfate, silicic acid, silicic esters and/or combinations of at least two of these.

30. A method comprising utilizing the kit of parts according to claim 19 for producing a layer construction, wherein initially an at least partly cured protective layer C is applied atop a photopolymer layer B, wherein the photopolymer layer B is optionally disposed atop a substrate layer A, to afford a layer composite B-C or A-B-C, wherein the protective layer is obtainable by reaction of an aqueous composition comprising (I) at least one polyvinyl alcohol, (II) at least one crosslinker for polyvinyl alcohols, (III) optionally at least one adhesion promoter, wherein the adhesion promoter is preferably at least one hydrolyzate of an aminoalkyl trialkoxysilane and optionally at least one surfactant.

31. A method comprising utilizing of an at least partly cured protective layer C for protection of a photopolymer layer B, wherein the protective layer C is obtainable by reaction of an aqueous composition comprising (I) at least one polyvinyl alcohol, (II) at least one crosslinker for polyvinyl alcohols, (III) optionally at least one adhesion promoter, wherein the adhesion promoter is preferably at least one hydrolyzate of an aminoalkyl trialkoxysilane and (IV) optionally at least one surfactant.

32. A method comprising utilizing the layer construction according to claim 18 as a holographic recording medium.

33. An optical display comprising a layer construction containing a hologram according to claim 18, wherein the optical display is selected from the group consisting of autostereoscopic and/or holographic displays, projection screens, displays with switchable restricted emission characteristics for privacy filters and bidirectional multiuser screens, virtual displays, head-up displays, head-mounted displays, illumination symbols, warning lamps, signal lamps, floodlights/headlights and display panels.

34. A security document comprising a layer construction containing a hologram according to claim 18.

Description

EXAMPLES

[0280] The invention will now be more particularly elucidated by means of examples.

Methods of Measurement:

[0281] Solids content: The reported solids contents were determined according to DIN EN ISO 3251.

Chemicals:

[0282] In each case, the CAS number, if known, is reported in square brackets.

Raw Materials for Photopolymer Layer B

[0283]

TABLE-US-00001 Fomrez ® UL 28 Urethanization catalyst, commercial product of Momentive Performance Chemicals, Wilton, CT, USA. Borchi ® Kat 22 Urethanization catalyst, [85203-81-2] commercial product of OMG Borchers GmbH, Langenfeld, Germany. BYK-310 silicone-containing surface additive, product of BYK-Chemie GmbH, Wesel, Germany. Desmodur ® Product of Covestro AG, Leverkusen, DE, hexane N 3900 diisocyanate-based polyisocyanate, proportion of iminooxadiazinedione of at least 30%, NCO content: 23.5%. CGI-909 tetrabutylammonium tris(3-chloro-4-methylphenyl)(hexyl)borate [1147315-11-4], product of BASF SE

[0284] Dye 1 (3,7-bis(diethylamino)phenoxazin-5-ium bis(2-ethylhexyl)sulfosuccinate) was produced as described in WO 2012062655.

[0285] Polyol 1 corresponds to Polyol 1 in WO2015091427 and was produced as described therein.

[0286] Urethane acrylate 1 (phosphorothioyltris(oxybenzene-4,1-diylcarbamoyloxyethane-2,1-diyl) trisacrylate, [1072454-85-3]) was prepared as described in WO2015091427.

[0287] Urethane acrylate 2, (2-({[3-(methylsulfanyl)phenyl]carbamoyl}oxy)ethyl prop-2-enoate, [1207339-61-4]) was produced as described in WO2015091427.

[0288] Additive 1, bis(2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl)-(2,2,4-trimethylhexano-1,6-diyl)biscarbamate [1799437-41-4] was produced as described in WO2015091427.

Raw Materials for Layer C

Polyvinyl Alcohols

[0289]

TABLE-US-00002 POVAL 60-98 - polyvinyl alcohol from Kuraray Europe GmbH, Germany. Product resin 1 having a degree of hydrolysis of 98 mol % (according to DIN EN ISO 3681: 2007 Oct. 1) and having a viscosity of 60 mPas (measured as a 4% aqueous solution at 20° C. according to DIN 53015: 2001-02); POVAL 25-88KL - polyvinyl alcohol from Kuraray Europe GmbH, Germany. Product resin 2 having a degree of hydrolysis of 88 mol % (according to DIN EN ISO 3681: 2007 Oct. 1) and having a viscosity of 25 mPas (measured as a 4% aqueous solution at 20° C. according to DIN 53015: 2001-02).

Crosslinker for Polyvinyl Alcohol

[0290]

TABLE-US-00003 Glyoxal [107-22-2] 40%(w/w) in water. Product of Sigma-Aldrich solution Chemie GmbH., Taufkirchen, Germany Boric [10043-35-3] ReagentPlus ® product (≥99.5%) from acid Sigma-Aldrich Chemie GmbH, Taufkirchen, Germany.
Adhesion promoter (optional)

TABLE-US-00004 Silquest aminoalkoxysilane hydrolyzate in water. Product of Momentive VS 142 Performance Materials, Albany, NY, USA
Surfactants (optional)

TABLE-US-00005 1-Octanol [111-87-5] ReagentPlus ® product (99%) from Sigma-Aldrich Chemie GmbH., Taufkirchen, Germany.

Solvents for Layers B and C

[0291]

TABLE-US-00006 Butyl Butyl acetate from Brenntag GmbH, Mülheim an acetate (BA) der Ruhr, Germany. Ethyl Ethyl acetate from Brenntag GmbH, Mülheim an acetate (EA) der Ruhr, Germany. 2-Butanone 2-Butanone from Brenntag GmbH, Mülheim an der Ruhr, Germany. Water deionized water.

Optically Clear Adhesives (OCA) of Layer D

[0292]

TABLE-US-00007 OCA 8211 - D01 OCA 8211 acrylic-type OCA product from 3M, St. Paul, MN, USA. Layer thickness of the adhesives layer 25 μm. 50 μm polyester liner. OCA-69604 - D02 OCA-69604, a UV-curable optically clear adhesive from Tesa SE, Norderstedt, Germany. Layer thickness of the adhesives layer 100 μm. 50 μm and 125 μm polyester liner.

Glass Substrates of Layer E

[0293]

TABLE-US-00008 Schott Glas Glass sheet having dimensions of 50 mm × 70 mm (3 mm thickness). Product of Schott AG, Mainz, Germany

Production of Holographic Media (Photopolymer Film)

[0294] 7.90 g of the above-described polyol component 1 were melted and mixed with 7.65 g of the respective urethane acrylate 2, 2.57 g of the above-described urethane acrylate 1, 5.10 g of the above-described fluorinated urethane (additive 1), 0.91 g of CGI 909, 0.232 g of dye 1, 0.230 g of BYK 310, 0.128 g of Fomrez UL 28 and 3.789 g of ethyl acetate to obtain a clear solution. This was followed by addition of 1.50 g Desmodur® N 3900 and renewed mixing.

[0295] This solution was then applied to a PET film of 36 μm in thickness in a roll-to-roll coating plant where by means of a knife coater the product was applied in a wet layer thickness of 19 μm. With a drying temperature of 85° C. and a drying time of 5 minutes, the coated film was dried and then protected with a polyethylene film of 40 μm in thickness. This film (photopolymer film of layer construction A-B) was then light-tightly packaged.

[0296] Production of the protective layer/barrier layer C on the photopolymer film A-B The formulations reported in table 1 were produced when the polyvinyl alcohol resins, dissolved at 95° C. in the water and cooled to room temperature were mixed with a crosslinker, surfactant and adhesion promoter (optional).

TABLE-US-00009 TABLE 1 Coating material * for production of protective layers C Weight ratio of poly- vinyl alcohol to cross- Solids content linker and optionally of aqueous Viscosity of Inventive Polyvinyl Adhesion to adhesion promoter coating solution solution at 23° C. examples alcohol Crosslinker promoter in lacquer [% by weight] [mPa*s] C-01 60-98 glyoxal solution 75/25 8 550 C-02 25-88KL boric acid 80/20 8 802 C-03 25-88KL boric acid Silquest 80/18/2 7 10900 VS142 All coating materials include 5 ppm of 1-octanol

TABLE-US-00010 TABLE 2-1 Holographic film composites for adhesive bonding onto glass Solvent resistance (1 h) of Thickness of protective layer C Construction of Coating layer C (or B′) toward Sample film composite material C [μm] NEP/MEK/butanol/EA Remarks Inventive examples P-01 A-B-C C-01 8 2/0/0/0 photosensitive P-02 A-B-C C-02 8 0/0/0/0 photosensitive P-03 A-B-C C-03 7 3/0/0/0 photosensitive P-04 A-B′-C C-01 8 2/0/0/0 not photosensitive P-05 A-B′-C C-02 8 0/0/0/0 not photosensitive P-06 A-B′-C C-03 7 3/0/0/0 not photosensitive Noninventive examples PN-01 A-B none none not tested photosensitive PN-02 A-B′ none none 5/5/1/5 not photosensitive (after 10 min)

[0297] The coating materials C-01 to C-03 were applied atop the B-side of the photopolymer film A-B by means of a knife coater in a roll-to-roll coating plant. At a drying temperature of 85° C. and a drying time of 10 minutes the coated film was dried and subsequently protected with a polyethylene film of 40 μm in thickness. The dry layer thickness was generally 7-8 μm. This film (photopolymer film of layer construction A-B-C) was then light-tightly packaged. The thus formed inventive samples P01 to P03 having the structure A-B-C and likewise the noninventive sample PN-01 which has the structure A-B and serves as a comparison are summarized in table 2-1. B is an unirradiated photopolymer layer.

Assessment of Solvent Resistance of Protective Layer C

[0298] The solvent resistance of the coatings was typically tested with technical quality N-ethyl-2-pyrrolidone (NEP), methyl ethyl ketone (MEK), 1-butanol and ethyl acetate (EA). The solvents were applied to the coating with a soaked cotton bud and protected from vaporization by covering. Unless otherwise stated, a contact time of 60 minutes at about 23° C. was observed. After the end of the contact time, the cotton bud is removed and the test surface is wiped clean with a soft cloth. This is followed by visual inspection immediately and after light scratching with a fingernail.

[0299] A distinction is made between the following levels: [0300] 0=unchanged; no change visible; not damageable by scratching. [0301] 1=slight swelling visible, but not damageable by scratching. [0302] 2=change clearly visible, barely damageable by scratching. [0303] 3=noticeable change, surface destroyed after firm fingernail pressure. [0304] 4=severe change, scratched through to substrate after firm fingernail pressure. [0305] 5=destroyed; lacquer already destroyed on wiping off the chemical; the test substance is not removable (eaten into surface).

[0306] Within this assessment, the test is typically passed with performance values of 0 and 1. Performance values of >1 represent a “fail”.

[0307] As is shown by the corresponding column of table 2-1 all inventive coatings made of coating material C02 register a very high level of solvent resistance. The coatings made of coating material CO and C03 show a similarly strong performance against methyl ethyl ketone, ethyl acetate and butanol. They show somewhat weaker performance against the strongly aprotic solvent NEP. Nevertheless the values even for NEP are substantially better than for the comparative samples without the protective layer C.

[0308] Production of a film composite having the layer construction A-B-C-D-E

[0309] The production of the film composite having the layer construction A-B-C-D-E comprises an initial lamination of side of the film A-B-C onto the de-linered adhesives layer D of the OCA, thus joining both layers. This is effected by pressing together the two films between the rubber rollers of a laminator. The temperature of the rollers was set to 30° C. The multilayered film produced was cooled to room temperature. The second liner film of the OCA was then peeled off from the film composite. The glass substrate was then laminated onto the side D of the film composite A-B-C-D. The thus formed inventive samples P07 to P09 and P13 to P15 having the layer construction A-B-C-D-E and likewise the noninventive and comparative samples PN-03 and PN-05 having the layer construction A-B-D-E are summarized in table 2-2. B is an unirradiated photopolymer layer.

TABLE-US-00011 TABLE 2-2 Composition of photosensitive holographic film composites and no-longer-photosensitive film composites comprising a photoinscribed and fixed hologram adhesively bonded to glass. Structure of Coating Optically Sample film composite material C clear adhesive Remarks Inventive examples P-07 A-B-C-D-E C01 D01 (3M) photosensitive P-08 A-B-C-D-E C02 D01 (3M) photosensitive P-09 A-B-C-D-E C03 D01 (3M) photosensitive P-10 A-B′-C-D-E C01 D01 (3M) not photosensitive P-11 A-B′-C-D-E C02 D01 (3M) not photosensitive P-12 A-B′-C-D-E C03 D01 (3M) not photosensitive P-13 A-B-C-D-E C01 D02 (Tesa) photosensitive P-14 A-B-C-D-E C02 D02 (Tesa) photosensitive P-15 A-B-C-D-E C03 D02 (Tesa) photosensitive P-16 A-B′-C-D-E C01 D02 (Tesa) not photosensitive P-17 A-B′-C-D-E C02 D02 (Tesa) not photosensitive P-18 A-B′-C-D-E C03 D02 (Tesa) not photosensitive Noninventive examples PN-03 A-B-D-E none D01 (3M) photosensitive PN-04 A-B′-D-E none D01 (3M) not photosensitive PN-05 A-B-D-E none D02 (Tesa) photosensitive PN-06 A-B′-D-E none D02 (Tesa) not photosensitive

Production of Test Holograms in Inventive Film Composites A-B-C and A-B-C-D-E and in Non-inventive Film Composites A-Bund A-B-D-E

[0310] The test holograms were prepared as follows: the photopolymer films with the layer construction A-B and A-B-C were in darkness cut to the desired size and using a rubber roller laminated onto a glass sheet having dimensions of 50 mm×70 mm (3 mm thick). The film composites A-B-C-D-E already include this glass sheets as layer E and were used for the test as they were. The test-holograms were produced using a test apparatus which produces Denisyuk reflection holograms using (532 nm) laser radiation. The test apparatus consists of a laser source, an optical beam guide system and a holder for the glass coupons. The holder for the glass coupons is mounted at an angle of 13° relative to the beam axis. The laser source generated the radiation which, widened to about 5 cm by means of a specific optical beam path, was guided to the glass coupon in optical contact with the mirror. The holographed object was a mirror about 2 cm×2 cm in size, and so the wavefront of the mirror was reconstructed on reconstructing the hologram. All examples were irradiated with a green 532 nm laser (Newport Corp., Irvine, Calif., USA, cat. no. EXLSR-532-50-CDRH). A shutter was used to irradiate the recording film in a defined manner for 2 seconds. This forms a film composite comprising a hologram in the layer B.

[0311] Subsequently, the samples were placed onto the conveyor belt of a UV source and irradiated twice at a belt speed of 2.5 m/min. The UV source employed was a Fusion UV “D Bulb” No. 558434 KR 85 iron-doped Hg lamp having a total power density 80 W/cm.sup.2. The parameters corresponded to a dose of 2×2.5 J/cm.sup.2 (measured with an ILT 490 Light Bug). Formed after this fixing step are the inventive film composites A-B′-C (table 2-1, samples P04 to P06) and A-B′-C-D-E (table 2-2, samples P10 to P12 and samples P-16 to P-18) and the noninventive and comparative film composites A-B′ (table 2-1, sample PN2) and A-B′-D-E (table 2-2, samples PN04 and PN06).

Adhesive Affixing of the Hologram-Including Film Composites A-B′-C/A-B′ Atop Glass (Alternative Production of Film Composite A-B′-C-D-E)

[0312] The above paragraphs described how the film A-B-C was in darkness pressed with the adhesives film D onto glass (E) and then the hologram was photoinscribed and fixed into the thus formed AB-C-D-E film composite.

[0313] An equivalent route consists of inscribing a hologram into the film composite A-B-C and then pressing the thus formed film composite A-B′-C onto glass (E) using the adhesive film D. In the case of the OCA D02 the above described optical fixing was then undertaken.

[0314] This formed the inventive film composites A-B′-C-D-E (table 2-3, samples P19 to P24) and the noninventive and comparative film composites A-B′-D-E (table 2-3, samples PN07 and PN08).

TABLE-US-00012 TABLE 2-3 Film composites formed by adhesive bonding of glass and a film composite A-B′-C comprising a previously produced hologram Additional UV curing Structure of Coating Optically for optically Sample film composite material C clear adhesive clear adhesive Inventive examples P-19 A-B′-C-D-E C01 D01 (3M) no P-20 A-B′-C-D-E C02 D01 (3M) no P-21 A-B′-C-D-E C03 D01 (3M) no P-22 A-B′-C-D-E C01 D02 (Tesa) yes P-23 A-B′-C-D-E C02 D02 (Tesa) yes P-24 A-B′-C-D-E C03 D02 (Tesa) yes Noninventive examples PN-07 A-B′-D-E none D01 (3M) no PN-08 A-B′-D-E none D02 (Tesa) yes

Characterization of Test Holograms

[0315] The holograms in layer B′ of the film composites A-B′-C, A-B′-C-D-E and A-B′ were then analysed for quality by spectroscopy.

[0316] On account of the high diffraction efficiency of the volume hologram, the diffractive reflection of such holograms may be analysed in transmission with visible light with a spectrometer (USB 2000 instrument, Ocean Optics, Dunedin, Fla., USA, was employed) and appears in the transmission spectrum as a peak with reduced transmission T.sub.Red. Evaluating the transmission curve makes it possible to determine the quality of the hologram according to ISO standard 17901-1:2015(E) taking account of the following measured values; all results are summarized in tables 3-1 to 3-3 and in tables 4-1 to 4-3 in the section “spectral quality of holograms”: [0317] T.sub.Red×100−T.sub.peak(2) Maximum depth of the transmission peak, this corresponds to the highest diffraction efficiency. Thus, 100−T.sub.peak serves as a measure for the reflection power (or visible “strength” or “quality”) of the hologram. [0318] FWHM The width of the transmission peak is determined as “full width at half maximum” (FWHM) in nanometres (nm). [0319] λ.sub.peak Spectral position of the transmission minimum of the hologram in nanometres (nm). [0320] Δλ.sub.peak spectral shift of the transmission minimum of the hologram in nanometers (nm) relative to the first measurement of the sample shown in respective line of the table

[0321] The quality of the inventive protective layers was assessed by initially inscribing test holograms into the photopolymer and subsequently storing the layer constructions to be evaluated in each case under different conditions. The results obtained are summarized in tables 3-1, 3-2, 3-3, 4-1, 4-2 and 4-3.

[0322] Tables 3-1, 3-2 and 3-3 show the results for the holograms that were inscribed into the A-B-C-D-E film composite and then subjected to UV-VIS fixing. D02 also undergoes final curing here. The freshly produced hologram was subjected to spectroscopic measurement. Samples were then stored for different lengths of time under a wide variety of external conditions and the hologram was then subjected to spectroscopic measurement once more.

[0323] Tables 4-1, 4-2 and 4-3 summarize the results where holograms were inscribed into the A-B-C film composite and then subjected to UV-VIS fixing. The holograms of the formed film composite AB′-C were subjected to spectroscopic measurement. An optically clear adhesive (OCA) was subsequently laminated onto the C-layer and the backing film of the OCA was removed. The adhesive side of the film composite was laminated onto glass and adhesively bonded. In the case of the Tesa product (D02) the film composite is additionally UV cured. The film composite A-B′-C-D-E and the noninventive comparator A-B′-D-E were then subjected to spectroscopic measurement, stored under the specified conditions and subjected to spectroscopic measurement once again.

Film Composites A-B-C and A-B-C-D-E as Holographic Recording Media

[0324] The application of the protective layer C atop the film A-B by roll to roll coating results in a film composite A-B-C whose suitability for recording holograms may be assessed on the basis of the results in tables 3-1 to 3-3 and 4-1 to 4-3.

[0325] The characteristics of the holograms recorded in the standard films A-B are shown in tables 4-1 to 4-3 (column “in A-B′”) for the noninventive samples PN-07-01 to PN-07-03 and PN-08-0l to PN08-03.

[0326] The inventive samples P-19 to P-24 (in the same three tables—column “in A-B′-C”) display the holograms with identical performance in respect of intensity (100−T.sub.peak), peak width (FWHM) and the position (λ.sub.peak) of the peak maximum.

[0327] This means that the protective layer C does not influence the recording capabilities of the holographic film A-B. As recording material for holograms the A-B-C films are equivalent to the A-B films.

[0328] Adhesive bonding of such A-B-C films onto glass with an OCA then affords the photosensitive film composites A-B-C-D-E whose performance for recording of the holograms may likewise be assessed on the basis of the results in table 3-1 to 3-3 and 4-1 to 4-3.

[0329] The inventive samples P-10 to P-18 (in tables 3-1 to 3-3—column “in A-B′-C-D-E after 5 min at RT”) display the holograms with identical performance in respect of intensity (100−T.sub.peak), peak width (FWHM) and the position (λ.sub.peak) of the peak maximum as do the above-described inventive samples P-19 to P-24 formed from the A-B-C films (in tables 4-1 to 4-3—column “in A-B′-C”).

[0330] This means that the protective layer C provides effective protection of the recording medium B from for example an OCA layer D. The inventive film composites A-B-C-D-E in which the photosensitive inventive films A-B-C are adhesively bonded onto glass with the OCA are equal as holographic recording media to these not-yet-adhesively affixed films and the A-B films.

[0331] Without the protective layer C only very faint holograms with a severely shifted position of the spectral maximum are inscribable into the layer B (noninventive samples PN-04-01 to PN-04-03 and PN-06-01 to PN-06-03 (tables 3-1 to 3-3—column “in A-B′-D-E after 5 min at RT”)). In addition, these samples are not storage stable. Without the protective layer C film composites having such a construction are not usable as recording media.

Storage Stability of the Film Composites A-B′-C-D-E

[0332] The storage stability of the film composites A-B′-C-D-E may be rated by means of the quality of the holograms inscribed in the layer B′ such as for example in the inventive examples P-10 to P-18. The results of storage under different conditions is summarized in tables 3-1 to 3-3. Storage at room temperature for a duration of one day or one week (table 3-1) results in only very minimal changes, if any, to holograms. By contrast, the noninventive samples PN-04 and PN-06 without protective layer C even under these mild conditions show severe changes to the spectral properties of the holograms which become fainter (100−T.sub.peak) and which undergo a severe shift in their absorption maximum (Δλ.sub.peak).

[0333] Table 3-2 shows the results of storage at 80° C. (for one hour and for three days). The holograms of the inventive samples P-10 bis P-18 remain very stable.

[0334] Table 3-3 shows the results of storage at 80° C. and 95% relative atmospheric humidity for 3 days. The holograms of the inventive samples P-10 to P-18 are well preserved in terms of their intensity and their absorption maximum undergoes only a slight spectral shift even under these conditions. This spectral shift differentiates different compositions of the protective layer C. Variant COI is particularly suitable for such storage conditions. The sample P-10-03 (protective layer C01 in combination with the OCA D01 (3M)) for example shows no measurable spectral influence on the hologram.

Storage Stability of the Film Composites A-B′-C Later Adhesively Affixed onto Glass

[0335] The storage stability of the thus produced film composites A-B′-C-D-E may be rated by means of the quality of the holograms inscribed in the layer B′ such as for example of the inventive examples P-19 to P-24. The results of storage under different conditions is summarized in tables 4-1 to 4-3. Storage at room temperature for a duration of one day or one week (table 4-1) results in only very minimal changes, if any, to holograms. By contrast, the noninventive samples PN-07 and PN08 without protective layer C even under these mild conditions show severe changes to the spectral properties of the holograms which become fainter (100−T.sub.peak) and which undergo a severe shift in their absorption maximum (Δλ.sub.peak).

[0336] Table 4-2 shows the results of storage at 80° C. (for one hour and for three days). The holograms of the inventive samples P-19 bis P-24 remain very stable.

[0337] Table 4-3 shows the results of storage at 80° C. and 95% relative atmospheric humidity for 3 days. The holograms of the inventive samples P-19 to P-24 are well preserved in terms of their intensity and their absorption maximum undergoes only a slight spectral shift even under these conditions. This spectral shift differentiates different compositions of the protective layer C. Variant CO is particularly suitable for such storage conditions. The sample P-19-03 (protective layer COI in combination with the OCA D01 (3M)) for example shows no measurable spectral influence on the hologram.

TABLE-US-00013 TABLE 3-1 Assessment of quality of protective layer C: Test holograms were inscribed into the A-B-C-D-E film composite and then fixed with 5-10 J/cm.sup.2 of UV-VIS to form the film composite A-B′-C-D-E. The inscribed holograms was subjected to spectroscopic measurement, stored under the specified conditions and subjected to measurement once again. Spectral quality of holograms Coating in A-B′-C-D-E (after 5 min at RT) in A-B′-C-D-E (after 1 day at RT) in A-B′-C-D-E (after 1 week at RT) material OCA 100-T.sub.peak FWHM λ.sub.peak 100-T.sub.peak FWHM λ.sub.peak Δλ.sub.peak 100-T.sub.peak FWHM λ.sub.peak Δλ.sub.peak Sample C (layer D) [%] [nm] [nm] [%] [nm] [nm] [nm] [%] [nm] [nm] [nm] Inventive examples P-10-01 C01 D01 (3M) 73.5 14.8 530.4 82.0 15.0 529.7 −0.7 81.1 14.8 529.0 −1.4 P-11-01 C02 D01 (3M) 76.3 14.5 531.4 65.4 18.7 530.4 −1.0 65.8 18.4 529.7 −1.7 P-12-01 C03 D01 (3M) 78.1 16.0 530.4 77.7 16.6 530.0 −0.4 75.1 15.7 529.3 −1.1 P-16-01 C01 D02 (Tesa)* 78.1 15.5 529.7 76.9 15.4 529.4 −0.3 76.2 15.2 529.4 −0.3 P-17-01 C02 D02 (Tesa)* 74.2 15.9 529.7 76.0 16.9 529.7 0 77.1 17.1 529.7 0 P-18-01 C03 D02 (Tesa)* 74.8 16.3 529.4 74.9 16.2 529.7 0.3 69.7 16.0 529.4 0 Noninventive examples in A-B′-C-D-E (after 5 min at RT) in A-B′-C-D-E (after 1 day at RT) in A-B′-C-D-E (after 1 week at RT) PN-04-01 none D01 (3M) 63.9 15.3 508.0 36.0 12.5 460.7 −47.3 32.8 14.2 472.4 −35.6 PN-06-01 none D02 (Tesa)* 26.5 16.5 527.6 19.2 17.6 501.4 −26.2 17.8 18.1 491.9 −35.7 *D02 also undergoes curing during irradiation

TABLE-US-00014 TABLE 3-2 Assessment of quality of protective layer C: Test holograms were inscribed into the A-B-C-D-E film composite and then fixed with 5-10 J/cm.sup.2 of UV-VIS to form the film composite A-B′-C-D-E. The inscribed holograms was subjected to spectroscopic measurement, stored under the specified conditions and subjected to measurement once again. Spectral quality of holograms Coating in A-B′-C-D-E (after 5 min at RT) in A-B′-C-D-E (after 1 h; 80° C.) in A-B′-C-D-E (after 3 days; 80° C.) material OCA 100-T.sub.peak FWHM λ.sub.peak 100-T.sub.peak FWHM λ.sub.peak Δλ.sub.peak 100-T.sub.peak FWHM λ.sub.peak Δλ.sub.peak Sample C (layer D) [%] [nm] [nm] [%] [nm] [nm] [nm] [%] [nm] [nm] [nm] Inventive examples P-10-02 C01 D01 (3M) 73.6 14.9 530.4 77.4 15.2 532.8 2.4 77.9 15.3 533.2 2.8 P-11-02 C02 D01 (3M) 76.3 14.6 531.5 78.7 16.4 531.4 −0.1 78.0 16.4 532.5 1.0 P-12-02 C03 D01 (3M) 78.1 16.1 530.4 76.5 16.3 532.1 1.7 78.8 16.6 532.8 2.4 P-16-02 C01 D02 (Tesa)* 71.3 14.8 529.4 75.7 16.3 533.2 3.8 70.6 16.2 532.5 3.1 P-17-02 C02 D02 (Tesa)* 74.9 15.9 529.7 76.8 17.3 533.2 3.5 74.6 16.9 532.9 3.2 P-18-02 C03 D02 (Tesa)* 71.4 16.5 529.7 69.4 16.4 532.9 3.2 67.5 16.6 531.8 2.1 Noninventive examples in A-B′-C-D-E (after 5 min at RT) in A-B′-C-D-E (after 1 h; 80° C.) in A-B′-C-D-E (after 3 days; 80° C.) PN-04-02 none D01 (3M) 63.9 15.4 508.1 42.7 11.8 440.0 −68.1 39.6 11.7 446.8 −61.3 PN-06-02 none D02 (Tesa)* 30.3 14.5 525.5 22.4 20.5 488.4 −37.1 18.2 14.6 485.9 −39.6 *D02 also undergoes curing during irradiation

TABLE-US-00015 TABLE 3-3 Assessment of quality of protective layer C: Test holograms were inscribed into the A-B-C-D-E film composite and then fixed with 5-10 J/cm.sup.2 of UV-VIS to form the film composite A-B′-C-D-E. The inscribed holograms was subjected to spectroscopic measurement, stored under the specified conditions and subjected to measurement once again. Spectral quality of holograms Coating in A-B′-C-D-E (after 5 min at RT) in A-B′-C-D-E (after 3 days; 80° C.; 95% AH) material OCA 100-T.sub.peak FWHM λ.sub.peak 100-T.sub.peak FWHM λ.sub.peak Δλ.sub.peak Sample C (layer D) [%] [nm] [nm] [%] [nm] [nm] [nm] Inventive examples P-10-03 C01 D01 (3M) 78.4 14.5 528.7 79.2 16.0 531.1 2.4 P-11-03 C02 D01 (3M) 52.5 17.9 530.1 60.5 17.5 518.6 −11.5 P-12-03 C03 D01 (3M) 74.6 15.8 529.4 70.4 15.1 515.8 −13.6 P-16-03 C01 D02 (Tesa)* 75.0 16.2 529.4 78.1 16.4 526.9 −2.5 P-17-03 C02 D02 (Tesa)* 70.6 15.8 529.7 75.2 15.7 519.6 −10.1 P-18-03 C03 D02 (Tesa)* 75.1 15.6 529.7 66.5 14.6 518.2 −11.5 Noninventive examples in A-B′-C-D-E (after 5 min at RT) in A-B′-C-D-E (after 3 days; 80° C.; 95% AH) PN-04-03 none D01 (3M) 31.6 12.8 470.4 13.0 # 400.1 −70.3 PN-06-03 none D02 (Tesa)* 19.5 15.1 524.2 7.1 19.8 497.9 −26.3 *D02 also undergoes curing during irradiation

TABLE-US-00016 TABLE 4-1 Assessment of quality of protective layer C: Test holograms were inscribed into the A-B-C film composite and then fixed with 5-10 J/cm.sup.2 of UV-VIS to form the film composite A-B′-C. The recited optically clear adhesive (OCA) was laminated onto this film composite and the backing film of the OCA was removed. The adhesive side of the film composite A-B′-C-D was laminated onto glass. The holograms were subjected to spectroscopic measurements before and after the storage under the specified conditions. Spectral quality of holograms in A-B′-C-D-E (after 1 h at RT) in A-B′-C-D-E (after 1 week at RT) Δλ.sub.peak Δλ.sub.peak Coating in A-B′-C vs vs material OCA 100-T.sub.peak FWHM λ.sub.peak 100-T.sub.peak FWHM λ.sub.peak A-B′-C 100-T.sub.peak FWHM λ.sub.peak A-B′-C Sample C (layer D) [%] [nm] [nm] [%] [nm] [nm] [nm] [%] [nm] [nm] [nm] Inventive examples P-19-01 C01 D01 (3M) 73.8 14.7 529.4 70.7 14.9 528.7 −0.7 69.8 14.9 530.1 0.7 P-20-01 C02 D01 (3M) 75.6 15.9 529.7 81.0 16.5 529.4 −0.3 74.2 15.5 530.4 0.7 P-21-01 C03 D01 (3M) 78.7 15.8 530.8 77.5 15.5 530.4 −0.4 79.0 15.8 531.1 0.3 P-22-01 C01 D02 (Tesa) 66.1 16.6 530.4 62.2 16.1 530.8 0.4 53.5 15.1 530.4 0 P-23-01 C02 D02 (Tesa) 65.9 17.4 529.4 67.6 17.8 529.7 0.3 67.2 16.4 529.7 0.3 P-24-01 C03 D02 (Tesa) 72.3 16.8 529.7 74.7 17.2 530.1 0.4 73.8 17.4 530.1 0.4 Noninventive examples in A-B′-C in A-B′-C-D-E (after 1 h at RT) in A-B′-C-D-E (after 1 week at RT) PN-07-01 none D01 (3M) 72.9 15.9 529.7 65.5 16.3 522.4 −5.3 42.0 10.45 442.9 −86.8 PN-08-01 none D02 (Tesa) 56.7 14.7 529.4 47.1 4.6 517.5 −11.9 30.1 12.4 442.9 −86-5 * D02 also undergoes curing during irradiation

TABLE-US-00017 TABLE 4-2 Assessment of quality of protective layer C: Test holograms were inscribed into the A-B-C film composite and then fixed with 5-10 J/cm.sup.2 of UV-VIS to form the film composite A-B′-C. The recited optically clear adhesive (OCA) was laminated onto this film composite and the backing film of the OCA was removed. The adhesive side of the film composite A-B′-C-D was laminated onto glass. The holograms were subjected to spectroscopic measurements before and after the storage under the specified conditions. Spectral quality of holograms in A-B′-C-D-E (after 1 h at 80° C.) in A-B′-C-D-E (after 3 days at 80° C.) Δλ.sub.peak Δλ.sub.peak Coating in A-B′-C vs vs material OCA 100-T.sub.peak FWHM λ.sub.peak 100-T.sub.peak FWHM λ.sub.peak A-B′-C 100-T.sub.peak FWHM λ.sub.peak A-B′-C Sample C (layer D) [%] [nm] [nm] [%] [nm] [nm] [nm] [%] [nm] [nm] [nm] Inventive examples P-19-02 C01 D01 (3M) 72.7 15.0 529.0 74.4 15.2 535.6 6.6 71.2 15.0 533.8 4.8 P-20-02 C02 D01 (3M) 83.1 15.5 530.0 78.9 15.7 531.4 1.4 78.9 14.9 531.1 1.1 P-21-02 C03 D01 (3M) 80.5 16.3 530.0 78.8 16.1 534.2 4.2 74.3 15.3 533.8 3.8 P-22-02 C01 D02 (Tesa) 65.4 15.4 529.7 67.1 16.3 534.6 4.9 68.4 16.2 533.9 4.2 P-23-02 C02 D02 (Tesa) 67.8 16.9 530.8 37.1 19.3 532.9 2.1 46.3 18.1 531.1 0.3 P-24-02 C03 D02 (Tesa) 74.6 16.0 529.4 76.2 17.1 531.8 2.4 76.1 16.8 530.8 1.4 Noninventive examples in A-B′-C in A-B′-C-D-E (after 1 h at 80° C.) in A-B′-C-D-E (after 3 days at 80° C.) PN-07-02 none D01 (3M) 74.1 17.2 528.3 37.4 11.1 440.4 −87.9 37.5 12.2 449.7 −78.6 PN-08-02 none D02 (Tesa) 74.0 15.6 528.7 33.5 12.2 438.6 −90.1 30.5 12.1 444.4 −84.3 * D02 also undergoes curing during irradiation

TABLE-US-00018 TABLE 4-3 Assessment of quality of protective layer C: Test holograms were inscribed into the A-B-C film composite and then fixed with 5-10 J/cm.sup.2 of UV-VIS to form the film composite A-B′-C. The recited optically clear adhesive (OCA) was laminated onto this film composite and the backing film of the OCA was removed. The adhesive side of the film composite A-B′-C-D was laminated onto glass. The holograms were subjected to spectroscopic measurements before and after the storage under the specified conditions. Spectral quality of holograms in A-B′-C-D-E (after 3 days at 80° C.; 95% AH) Δλ.sub.peak Coating in A-B′-C vs material OCA 100-T.sub.peak FWHM λ.sub.peak 100-T.sub.peak FWHM λ.sub.peak A-B′-C Sample C (layer D) [%] [nm] [nm] [%] [nm] [nm] [nm] Inventive examples P-19-03 C01 D01 (3M) 73.1 14.4 529.0 62.4 13.6 533.2 4.2 P-20-03 C02 D01 (3M) 80.9 15.6 529.3 76.8 15.7 522.0 −7.3 P-21-03 C03 D01 (3M) 75.0 14.8 530.7 74.4 14.7 522.0 −8.7 P-22-03 C01 D02 (Tesa)* 71.9 15.4 531.1 77.3 15.9 527.6 −3.5 P-24-03 C03 D02 (Tesa)* 75.1 16.7 528.7 74.6 16.1 519.6 −9.1 Noninventive examples in A-B′ in A-B′-D-E (after 3 days at 80° C.; 95% AH) PN-07-03 none D01 (3M) 67.4 17.5 525.9 10.2 # 430.0 −95.9 PN-08-03 none D02 (Tesa)* 65.4 15.1 529.4 31.5 11.1 452.2 −77.2 *D02 also undergoes curing during irradiation