Triarylalkylborate salts as coinitiators in NIR photopolymer compositions

Abstract

The present invention relates to a photopolymer composition comprising: a) a matrix polymer; b) a write monomer; c) at least one photoinitiator system; d) optionally at least one non-photopolymerizable component; and e) optionally catalysts, radical stabilizers, solvents, additives and other auxiliaries and / or admixtures, wherein the at least one photoinitiator system c) is comprised of at least one dye and at least one coinitiator, at least one of the dyes having a structure according to formula (II), and the at least one coinitiator having a calculated oxidation potential (A) as confirmed according to formula (1) shown below by quantum mechanical calculation of the Gibbs free energies of the ground and oxidized states of triarylalkylborate at 298 K after successful geometry optimization consisting of ab initio energy calculation based on the previously confirmed molecular geometry coordinates in the solvent acetonitrile using a compliant energy minimization with the AM1 force field followed by solvent field correction by the PCM method in the range of 1.01 V to 1.31 V vs. a saturated calomel electrode (SCE) in acetonitrile (1).

Description

[Technical field]

[0001] The present invention relates to a photopolymer composition using a selected triarylalkylborate salt as a coinitiator photopolymer composition having a selected oxidation potential, and also to a holographic medium and hologram produced therefrom, as well as a method for producing a holographic medium using a specific photopolymer composition comprising a specific coinitiator, and a holographic medium that can be obtained using a photopolymer composition according to the present invention.Furthermore, the present invention relates to a layer structure comprising a holographic medium according to the present invention and a specific triarylalkylborate salt that is also suitable as a coinitiator.Furthermore, a method for calculating the oxidation potential of a specific coinitiator against a saturated calomel electrode in acetonitrile is presented.Furthermore, a method for producing a specific coinitiator and also the coinitiator that can be obtained by this method are also described. [Background technology]

[0002] Photopolymer compositions containing common forms of triarylalkylborate salts are known in the prior art. For example, WO 2008 / 125229 describes photopolymer compositions containing a polyurethane matrix polymer, an acrylate-based writing monomer, and a photoinitiator containing a coinitiator and a dye, as well as photopolymers obtainable therefrom. In the use of photopolymers, the refractive index modulation Δn produced by holographic exposure plays a decisive role. In holographic exposure, the interference field of the signal light beam and the reference light beam (in the simplest case, the interference field of two plane waves) is mapped onto a refractive index grating by local photopolymerization of a writing monomer, for example a high refractive index acrylate, at the location of high intensity of the interference field. The refractive index grating in the photopolymer (hologram) contains all the information of the signal light beam. The signal can be reconstructed by illuminating the hologram only with the reference light beam. The intensity of the signal thus reconstructed relative to the intensity of the irradiated reference light is called the diffraction efficiency, hereinafter DE.

[0003] In the simplest case of a hologram obtained from the superposition of two plane waves, the DE is the ratio of the intensity of the light diffracted during reconstruction to the sum of the intensities of the diffracted and non-diffracted light. The higher the DE, the more efficient the hologram is with respect to the amount of reference light needed to visualize a signal with a defined brightness.

[0004] In order that very high Δn and very high DE can be realized for the hologram, the matrix polymer and the writing monomer of the photopolymer composition should in principle be selected so that there is a very large difference in their refractive index. One possible way to achieve this is to use a matrix polymer with a very low refractive index and a writing monomer with a very high refractive index. A suitable matrix polymer with a low refractive index is, for example, a polyurethane, which can be obtained by reaction of a polyol component with a polyisocyanate component.

[0005] However, in addition to high DE and Δn values, it is also very important for holographic media made with photopolymer compositions that the matrix polymer in the finished medium is highly crosslinked. If the degree of crosslinking is too low, the medium will lack sufficient stability. This can significantly reduce the quality of the hologram written in the medium and may change over time, which is undesirable. In the worst case, the hologram may even be destroyed afterwards.

[0006] Furthermore, for large-scale use of holographic media from photopolymer compositions, it is particularly important that photopolymer films containing the photopolymer compositions have a large processing window and can be exposed without losing the refractive index modulation. In particular, the selection of a suitable photoinitiator here is crucial for the properties of the photopolymer.

[0007] Photoinitiators well suited for photopolymer films of the first mentioned type may consist of type II photoinitiators. In these type II photoinitiators, triarylalkylborate salts can be combined as coinitiators together with suitable sensitizers, such as cationic, anionic or neutral dyes as photoinitiating systems (PIS), so that the radical photopolymerization of suitable monomers can be triggered by visible or near infrared light. The preparation of such PIS is widely described in the prior art, and selected tetraalkylammonium triarylalkylborates and dyes in the near infrared (NIR) range are commercially available. Moreover, such PIS have already been used in photopolymers and holographic media, and their advantages have been described. For example, EP 0438123 describes NIR dyes of formula (I), for example, which, together with triphenylbutylborate anions, can be utilized as PIS for photocurable materials. [ka]

[0008] The application also focuses on the tri(p-anisyl)butylborate anion or the tri(1-naphthyl)butylborate anion as suitable coinitiators for PIS with cationic NIR dyes. Furthermore, it is known from US Pat. No. 6,022,664, in which the preparation of a heat-activatable photopolymer is described, that a recording material containing a PIS consisting of an NIR dye of formula (I) and certain triarylalkylborate salts is almost completely cured after 5 seconds at a temperature of 120° C. However, in all these PIS, such as those described in EP 0 438 123, for example dye-coinitiator combinations and photopolymer compositions containing NIR dyes and triarylalkylborate salts, no attention is paid to the thermal stability of the formulations in the unexposed state. In fact, all the formulations disclosed in EP 0 438 123 do not have sufficient thermal stability in the unexposed state. This means that at certain heat loads, such as storage at 110°C for 10 minutes, which may be necessary for the production of holographic optical products, undesirable side reactions occur in the photopolymer film, significantly reducing or even completely preventing the realization of the photoreactions that occur during exposure, thus significantly reducing the quality of the written hologram or making it impossible to create a hologram. As a result, existing photopolymer films cannot be heat treated to the required extent before exposure. However, this is detrimental to certain applications that require handling of unexposed photopolymer films at high temperatures. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] International Publication No. 2008 / 125229 [Patent Document 2] European Patent No. 0438123 [Patent Document 3] U.S. Patent No. 6,022,664 Summary of the Invention [Problem to be solved by the invention]

[0010] It was therefore an object of the present invention to provide a photopolymer composition which allows handling of unexposed photopolymer films under increased thermal loads, without either the bleachability or the sensitivity being adversely affected during the exposure process. Furthermore, it was an object to provide a photopolymer composition which increases the thermal stability of the photopolymer film in the unexposed state. Preferably, other properties, such as the bleachability or the sensitivity during the exposure process, should not be adversely affected here. This technical problem is solved by the subject matter of claim 1 and its dependent claims. [Means for solving the problem]

[0011] The first subject of the present invention is a) a matrix polymer; b) a writing monomer; c) at least one photoinitiator system; d) optionally at least one non-photopolymerizable component; and e) optionally with catalysts, radical stabilizers, solvents, additives and other auxiliaries and / or adjuvants; A photopolymer composition comprising: At least one photoinitiator system c) comprises at least one dye and at least one coinitiator, the dye having the structure according to formula (II) [ka] (In the formula, R 205 is hydrogen, halogen, C 1 ~C 4 Alkyl, C 1 ~C 4 Alkoxy or NR 210 R 211 represents R 206 is hydrogen, halogen, C 1 ~C 4 Alkyl, C 1 ~C 4Alkoxy or NR 212 R 213 represents R 201 ~R 204 and R 210 ~R 213 are each independently hydrogen, C 1 ~C 16 Alkyl, C 4 ~C 7 Cycloalkyl, C 7 ~C 16 Aralkyl, C 6 ~C 10 represents an aryl or heterocyclic group, NR 201 R 202 , N.R. 203 R 204 , N.R. 210 R 211 and N.R. 212 R 213 represent, independently of each other, a 5- or 6-membered saturated ring bonded via N, which may further contain N or O and / or be substituted by non-ionic groups, R 207 ~R 209 are each independently hydrogen, C 1 ~C 16 Alkyl, C 4 ~C 7 Cycloalkyl, C 7 ~C 16 Aralkyl, C 6 ~C 10 represents aryl, halogen or cyano; Two optional bridging groups X 1 and X 2 are independent of each other, SiR 214 R 215 , C.R. 216 R 217 or O, R 214 ~R 217 are each independently hydrogen or C 1 ~C 4 represents an alkyl group, An -represents an anion selected from a halide, a cyanide, a nitrate, an azide, a perchlorate, a hexafluorophosphate, a hexafluoroantimonate, an optionally substituted phosphate, an optionally substituted phosphonate, an optionally substituted sulfonimide, for example a bis(trifluoromethyl)sulfonimide, an optionally substituted organic borate, for example a tetrafluoroborate, a tetraarylborate, a triarylalkylborate or a cyanotriarylborate, an optionally substituted alkyl or alkenyl sulfate, an optionally substituted mono- or di-sulfonate, for example a methylsulfonate, a p-toluenesulfonate, a trifluoromethylsulfonate or a sulfosuccinate, or an optionally substituted organic mono- or di-carboxylate) having At least one coinitiator has a calculated oxidation potential in the range of 1.01 V to 1.31 V versus a saturated calomel electrode (SCE) in acetonitrile, determined according to the following equation (1) by quantum mechanical calculation of the Gibbs energies at 298 K of the ground and oxidized states of triarylalkylborate after structure optimization consisting of conformer energy minimization with the AM1 force field followed by ab initio conformer energy calculation based on previously determined molecular geometric coordinates in the solvent acetonitrile under solvent field correction with the PCM method:

number

number

[0012] The matrix polymer a) can be any matrix polymer a) that a person skilled in the art would choose for the photopolymer composition according to the invention. Suitable matrix polymers a) of the photopolymer composition can in particular be crosslinked, particularly preferably three-dimensionally crosslinked.

[0013] The matrix polymer a) is preferably a polyurethane, which is obtainable in particular by reacting at least one polyisocyanate component aI) with at least one isocyanate-reactive component aII).

[0014] The polyisocyanate component aI) preferably comprises at least one organic compound having at least two NCO groups. These organic compounds may in particular be monomeric di- and triisocyanates, polyisocyanates and / or NCO-functional prepolymers. The polyisocyanate component aI) may also comprise or consist of mixtures of monomeric di- and triisocyanates, polyisocyanates and / or NCO-functional prepolymers.

[0015] The monomeric di- and triisocyanates which can be used include all of the compounds or mixtures thereof which are known per se to the person skilled in the art. These compounds may have an aromatic, araliphatic, aliphatic or cycloaliphatic structure. In small amounts, the monomeric di- and triisocyanates may also include monoisocyanates, i.e. organic compounds having one NCO group.

[0016] Examples of suitable monomeric di- and tri-isocyanates include butane 1,4-diisocyanate, pentane 1,5-diisocyanate, hexane 1,6-diisocyanate (hexamethylene diisocyanate, HDI), 2,2,4-trimethylhexamethylene diisocyanate and / or 2,4,4-trimethylhexamethylene diisocyanate (TMDI), isophorone diisocyanate (IPDI), 1,8-diisocyanato-4-(isocyanatomethyl )octane, bis(4,4'-isocyanatocyclohexyl)methane and / or bis(2',4-isocyanatocyclohexyl)methane and / or mixtures thereof with any isomeric content, cyclohexane 1,4-diisocyanate, the isomeric bis(isocyanatomethyl)cyclohexanes, 2,4- and / or 2,6-diisocyanato-1-methylcyclohexane (hexahydrotrilene 2,4- and / or 2,6-diisocyanate, H6 -TDI), phenylene 1,4-diisocyanate, tolylene 2,4- and / or 2,6-diisocyanate (TDI), naphthylene 1,5-diisocyanate (NDI), diphenylmethane 2,4'- and / or 4,4'-diisocyanate (MDI), 1,3-bis(isocyanatomethyl)benzene (XDI) and / or similar 1,4 isomers, or any desired mixture of the foregoing compounds.

[0017] Suitable polyisocyanates are compounds having a urethane, urea, carbodiimide, acylurea, amide, isocyanurate, allophanate, biuret, oxadiazinetrione, uretdione and / or iminooxadiazinedione structure and which are derived from the aforementioned di- or triisocyanates.

[0018] More preferably, the polyisocyanates are oligomerized aliphatic and / or cycloaliphatic di- or triisocyanates, it being especially possible to use the aliphatic and / or cycloaliphatic di- or triisocyanates mentioned above.

[0019] Very particular preference is given to polyisocyanates having an isocyanurate, uretdione and / or iminooxadiazinedione structure, and biurets based on HDI or mixtures thereof.

[0020] Suitable prepolymers contain urethane and / or urea groups and may contain further structures formed through modification of the NCO groups described above. Prepolymers of this kind are obtained, for example, by reaction of the monomeric di- and triisocyanates and / or polyisocyanates aI1) with isocyanate-reactive compounds aII1).

[0021] Alcohols, amino or mercapto compounds, preferably alcohols, can be used as isocyanate-reactive compounds aII1). These can in particular be polyols. Very preferably, the isocyanate-reactive compounds aII1) used can be polyester polyols, polyether polyols, polycarbonate polyols, poly(meth)acrylate polyols and / or polyurethane polyols.

[0022] Suitable polyester polyols are linear polyester diols or branched polyester polyols, which can be obtained in known manner, for example, by reacting aliphatic, cycloaliphatic or aromatic di- or polycarboxylic acids or their anhydrides with polyhydric alcohols having an OH functionality of at least 2. Examples of suitable di- or polycarboxylic acids are polybasic carboxylic acids, such as succinic acid, adipic acid, suberic acid, sebacic acid, decanedicarboxylic acid, phthalic acid, terephthalic acid, isophthalic acid, tetrahydrophthalic acid or trimellitic acid, and acid anhydrides, such as phthalic anhydride, trimellitic anhydride or succinic anhydride, or any mixtures thereof. The polyester polyols may be based on natural raw materials, such as castor oil. It is also possible for the polyester polyols to be based on homo- or copolymers of lactones, preferably obtained by addition of lactones, such as butyrolactone, ε-caprolactone and / or methyl-ε-caprolactone, or lactone mixtures, to hydroxy-functional compounds, such as polyhydric alcohols having an OH functionality of at least 2, for example of the type listed below.

[0023] Examples of suitable alcohols include, for example, C 2 ~C 12 These include all polyhydric alcohols such as diols, the isomeric cyclohexanediols, glycerol or any mixtures of these with each other.

[0024] Suitable polycarbonate polyols are available in a manner known per se by reacting organic carbonates or phosgene with diols or diol mixtures.

[0025] Suitable organic carbonates are dimethyl carbonate, diethyl carbonate and diphenyl carbonate.

[0026] Suitable diols or mixtures include polyhydric alcohols with an OH functionality of 2 or more, which are mentioned per se in the context of the polyester segment, preferably butane-1,4-diol, hexane-1,6-diol and / or 3-methylpentanediol. The polyester polyols can also be converted into polycarbonate polyols.

[0027] Suitable polyether polyols are the polyaddition products, optionally in a block structure, of cyclic ethers onto OH- or NH-functional starter molecules.

[0028] Suitable cyclic ethers are, for example, styrene oxide, ethylene oxide, propylene oxide, tetrahydrofuran, butylene oxide, epichlorohydrin, and any mixtures thereof.

[0029] The starters used can be polyhydric alcohols with an OH functionality of 2 or more, which are mentioned per se in the context of polyester polyols, as well as primary or secondary amines and amino alcohols.

[0030] Preferred polyether polyols are those of the aforementioned type based exclusively on propylene oxide or random or block copolymers based on propylene oxide and further 1-alkylene oxides. Particularly preferred are propylene oxide homopolymers and also statistical or block copolymers having oxyethylene, oxypropylene and / or oxybutylene units, the proportion of oxypropylene units being at least 20% by weight, preferably at least 45% by weight, based on the total amount of all oxyethylene, oxypropylene and oxybutylene units. Oxypropylene and oxybutylene here refer to all respective linear and branched C 3 and C 4Includes isomers.

[0031] Furthermore, suitable constituents of the polyol component aII1) as polyfunctional isocyanate-reactive compounds are also aliphatic, araliphatic or cycloaliphatic di-, tri- or polyfunctional alcohols of low molecular weight, i.e. with a molecular weight of 500 g / mol or less, having a short chain, i.e. containing 2 to 20 carbon atoms.

[0032] These may be, for example, in addition to the abovementioned compounds, neopentyl glycol, 2-ethyl-2-butylpropanediol, trimethylpentanediol, positional isomeric diethyloctanediols, cyclohexanediol, cyclohexane-1,4-dimethanol, hexane-1,6-diol, cyclohexane-1,2- and -1,4-diol, hydrogenated bisphenol A, 2,2-bis(4-hydroxycyclohexyl)propane or 2,2-dimethyl-3-hydroxypropionic acid, 2,2-dimethyl-3-hydroxypropyl ester. Examples of suitable triols are trimethylolethane, trimethylolpropane or glycerol. Suitable higher functional alcohols are di(trimethylolpropane), pentaerythritol, dipentaerythritol or sorbitol.

[0033] It is particularly preferred that the polyol component is a difunctional polyether, polyester or polyether-polyester block copolyester or a polyether-polyester block copolymer having primary OH functionality.

[0034] It is also possible to use amines as isocyanate-reactive compounds aII1). Examples of suitable amines are ethylenediamine, propylenediamine, diaminocyclohexane, 4,4'-dicyclohexylmethanediamine, isophoronediamine (IPDA), difunctional polyamines such as Jeffamines®, especially amine-terminated polymers with a number average molecular weight of up to 10 000 g / mol. Mixtures of said amines can also be used.

[0035] It is likewise possible to use aminoalcohols as isocyanate-reactive compounds aII1). Examples of suitable aminoalcohols are the isomeric aminoethanols, isomeric aminopropanols, isomeric aminobutanols and isomeric aminohexanols or any mixtures thereof.

[0036] All of the abovementioned isocyanate-reactive compounds aII1) can be mixed with one another if desired.

[0037] It is also preferred if the isocyanate-reactive compound aII1) has a number average molecular weight of 200 to 10 000 g / mol, more preferably 500 to 8 000 g / mol and very particularly preferably 800 to 5 000 g / mol. The OH functionality of the polyol is preferably 1.5 to 6.0, particularly preferably 1.8 to 4.0.

[0038] The prepolymers of the polyisocyanate component aI) may in particular have a residual content of free monomeric di- and triisocyanates of less than 1% by weight, particularly preferably less than 0.5% by weight and very particularly preferably less than 0.3% by weight.

[0039] It may also be possible for the polyisocyanate component aI) to fully or partially contain organic compounds whose NCO groups have been fully or partially reacted with blocking agents known from coating technology. Examples of blocking agents are alcohols, lactams, oximes, malonic esters, pyrazoles and amines, such as butanone oxime, diisopropylamine, diethyl malonate, ethyl acetoacetate, 3,5-dimethylpyrazole, ε-caprolactam or mixtures thereof.

[0040] When the polyisocyanate component aI) comprises a compound having an aliphatically bound NCO group, it is particularly preferred that the aliphatically bound NCO group is understood to mean a group bound to a primary C atom. The isocyanate-reactive component aII) preferably comprises at least one organic compound having on average at least 1.5, preferably 2 to 3, isocyanate-reactive groups. In the context of the present invention, isocyanate-reactive groups are preferably considered to be hydroxyl, amino or mercapto groups.

[0041] The isocyanate-reactive component may in particular include compounds having a number average of at least 1.5, preferably 2 to 3, isocyanate-reactive groups.

[0042] Suitable polyfunctional isocyanate-reactive compounds of component aII) are, for example, the compounds aII1) mentioned above.

[0043] In another preferred embodiment, it may be provided that the substance catalyzing the polyurethane formation is from the group of tin-based organyls or is based on iron(II), iron(III), gallium(III), bismuth(III), vanadium(III), vanadium(IV), terbium(III), tin(II), zinc(II), zirconium(IV) complexes with suitable monodentate or bidentate ligands.

[0044] The writing monomer b) can be any writing monomer that a person skilled in the art would choose for the photopolymer composition according to the invention. Preferably, the writing monomer b) comprises or consists of at least one monofunctional and / or one multifunctional writing monomer. More preferably, the writing monomer b) comprises or consists of at least one monofunctional and / or one multifunctional (meth)acrylate writing monomer. Very preferably, the writing monomer comprises or consists of at least one monofunctional and / or one multifunctional urethane (meth)acrylate.

[0045] Suitable acrylate writing monomers are in particular compounds of the general formula (IV) [ka] (wherein m ≧ 1 and m ≦ 4; R 5 is a linear, branched, cyclic or heterocyclic organic moiety that is unsubstituted or otherwise optionally substituted by heteroatoms, and / or R 6 is hydrogen or a linear, branched, cyclic or heterocyclic organic moiety which is unsubstituted or otherwise optionally substituted by heteroatoms. More preferably, R 6 is hydrogen or methyl, and / or R 5 is a straight-chain, branched, cyclic or heterocyclic organic moiety which is unsubstituted or optionally substituted by heteroatoms.

[0046] In this context, acrylate and methacrylate refer to esters of acrylic acid and methacrylic acid, respectively.Examples of acrylate and methacrylate that can be preferably used include phenyl acrylate, phenyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, phenoxyethoxyethyl acrylate, phenoxyethoxyethyl methacrylate, phenylthioethyl acrylate, phenylthioethyl methacrylate, 2-naphthyl acrylate, 2-naphthyl methacrylate, 1,4-bis(2-thionaphthyl)-2-butyl acrylate, 1,4-bis(2-thionaphthyl)-2-butyl methacrylate, bisphenol A diacrylate, bisphenol A dimethacrylate, and their ethoxylated analogues or N-carbazolyl acrylate.

[0047] Urethane acrylates are understood in the present context to mean compounds having at least one acrylic ester group and at least one urethane bond. Such compounds can be obtained, for example, by reacting a hydroxy-functional acrylate or methacrylate with an isocyanate-functional compound.

[0048] Examples of isocyanate-functional compounds which can be used for this purpose are the monoisocyanates and also the monomeric diisocyanates, triisocyanates and / or polyisocyanates mentioned under aI). Examples of suitable monoisocyanates are phenylisocyanate, the isomeric methylthiophenylisocyanates. The di-, tri- or polyisocyanates mentioned above are triphenylmethane 4,4',4"-triisocyanate and tris(p-isocyanatophenyl)thiophosphate or derivatives thereof having a urethane, urea, carbodiimide, acylurea, isocyanurate, allophanate, biuret, oxadiazinetrione, uretdione or iminooxadiazinedione structure, and mixtures thereof. Aromatic diisocyanates, aromatic triisocyanates or aromatic polyisocyanates are preferred here.

[0049] Hydroxy-functional acrylates or methacrylates for preparing urethane acrylates are, for example, 2-hydroxyethyl (meth)acrylate, polyethylene oxide mono(meth)acrylate, polypropylene oxide mono(meth)acrylate, polyalkylene oxide mono(meth)acrylate, poly(ε-caprolactone) mono(meth)acrylate, e.g. Tone® M100 (Dow, Schwalbach, Germany), 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3- Compounds such as hydroxy-2,2-dimethylpropyl (meth)acrylate, hydroxypropyl (meth)acrylate, acrylic acid 2-hydroxy-3-phenoxypropyl ester, polyhydric alcohols, for example trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol, hydroxy-functional mono-, di- or tetraacrylates of ethoxylated, propoxylated or alkoxylated trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol, or technical mixtures thereof. 2-Hydroxyethyl acrylate, hydroxypropyl acrylate, 4-hydroxybutyl acrylate and poly(ε-caprolactone) mono(meth)acrylate are preferred.

[0050] It is likewise possible to use customary hydroxyl-containing epoxy (meth)acrylates with an OH content of 20 to 300 mg KOH / g or hydroxyl-containing polyurethane (meth)acrylates with an OH content of 20 to 300 mg KOH / g or acrylated polyacrylates with an OH content of 20 to 300 mg KOH / g and also mixtures of these with one another, and also mixtures with hydroxyl-containing unsaturated polyesters and also with polyester (meth)acrylates or mixtures of hydroxyl-containing unsaturated polyesters and polyester (meth)acrylates.

[0051] Preferably, the urethane acrylates are obtainable in particular from the reaction of tris(p-isocyanatophenyl)thiophosphate and / or m-methylthiophenyl isocyanate with alcohol-functional acrylates such as hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate and / or hydroxybutyl(meth)acrylate, or from the reaction products of 2-isocyanatoethyl acrylate and / or 2-isocyanatoethyl methacrylate and / or 1,1-(bisacryloyloxymethyl)ethyl isocyanate with optionally substituted naphthols.

[0052] It is also possible for the writing monomers b) to comprise or consist of further unsaturated compounds, such as α,β-unsaturated carboxylic acid derivatives, for example maleates, fumarates, maleimides, acrylamides, as well as vinyl ethers, propenyl ethers, allyl ethers and compounds containing dicyclopentadienyl units, and also olefinically unsaturated compounds, for example styrene, α-methylstyrene, vinyltoluene and / or olefins.

[0053] The at least one photoinitiator system c) can be any photoinitiator system that a person skilled in the art would choose for the photopolymer composition according to the invention. The photoinitiators of component c) are usually compounds activatable by actinic radiation that can cause the polymerization of the write monomers. Photoinitiators can be differentiated as unimolecular (type I) and bimolecular (type II) initiators. Furthermore, with regard to their chemical nature, they are differentiated into photoinitiators for radical, anionic, cationic or mixed type polymerization.

[0054] Type I photoinitiators for radical photopolymerization (Norrish Type I) form free radicals on irradiation through unimolecular bond cleavage. Examples of Type I photoinitiators include triazines, oximes, benzoin ethers, benzil ketals, bisimidazoles, aroylphosphine oxides, sulfonium salts and iodonium salts.

[0055] Type II photoinitiators for radical polymerization (Norrish type II) consist of a dye as a sensitizer and a coinitiator that undergo a bimolecular reaction when irradiated with light coordinated with the dye. First, the dye absorbs a photon and transfers energy from its excited state to the coinitiator. The latter releases the polymerization-initiating radical through electron or proton transfer or direct hydrogen abstraction.

[0056] Type II photoinitiators are preferably used.

[0057] Such photoinitiator systems are described in principle in EP 0 223 587 and preferably consist of a mixture of one or more dyes.

[0058] Suitable NIR chromophores which together with the compounds of formula (III) form type II photoinitiators are, for example, the cationic dyes described in EP 0 438 123 B1.

[0059] Furthermore, pentamethine cyanine and heptamethine cyanine dyes, hemicyanine dyes, merocyanine dyes, oxonol and neutrocyanine dyes are understood as cationic NIR dyes and are preferred.This type of dye is described, for example, in H.Berneth in Ullmann's Encyclopedia of Industrial Chemistry, Azine Dyes, Wiley-VCH Verlag, 2008, H.Berneth in Ullmann's Encyclopedia of Industrial Chemistry, Methine Dyes and Pigments, Wiley-VCH Verlag, 2008, T.Gessner, U.Mayer in Ullmann's Encyclopedia of Industrial Chemistry, Triarylmethane and Diarylmethane Dyes, Wiley-VCH Verlag, 2000.

[0060] Pentamethine cyanine and heptamethine cyanine dyes are particularly preferred.

[0061] Particularly preferred cationic NIR dyes are those represented by the following structural formula (V): [ka] The dye is "Karenz IR-T" available from Showa Denko, having the following structure:

[0062] Preferred anions (An - ) is, in particular, C 8 ~C 25 -Alkanesulfonates, preferably C 13 ~C 25 -Alkanesulfonates, C 3 ~C 18 -Perfluoroalkanesulfonates, C 4 ~C 18 -perfluoroalkanesulfonates (having at least 3 hydrogen atoms in the alkyl chain), C 9 ~C 25 -Alkanoates, C 9 ~C 25 -Alkenoates, C 8 ~C 25 -Alkyl sulfates, preferably C 13 ~C 25 -Alkyl sulfate, C 8 ~C 25 -Alkenyl sulfate, preferably C 13 ~C 25 -Alkenyl sulfate, C 3 ~C 18 -Perfluoroalkyl sulfate, C 4 ~C 18 - perfluoroalkyl sulfates (having at least 3 hydrogen atoms in the alkyl chain), polyether sulfates based on at least 4 equivalents of ethylene oxide and / or 4 equivalents of propylene oxide, bis-C 4 ~C 25 -Alkyl-, C 5 ~C 7 -cycloalkyl-, C 3 ~C 8 -Alkenyl- or C 7~C 11 -Aralkyl-sulfosuccinates, bis-C substituted with at least 8 fluorine atoms 2 ~C 10 -Alkyl-sulfosuccinates, C 8 ~C 25 -Alkyl-sulfoacetate, halogen, C 4 ~C 25 -Alkyl, Perfluoro-C 1 ~C 8 -Alkyl and / or C 1 ~C 12 -benzenesulfonate substituted by at least one group of the group alkoxycarbonyl, nitro, cyano, hydroxy, C 1 ~C 25 -Alkyl, C 1 ~C 12 -Alkoxy, Amino, C 1 ~C 12 -Naphthalene- or biphenylsulfonate, optionally substituted by alkoxycarbonyl or chlorine, nitro, cyano, hydroxy, C 1 ~C 25 -Alkyl, C 1 ~C 12 -Alkoxy, C 1 ~C 12 -Benzene-, naphthalene- or biphenyl disulfonates, optionally substituted by alkoxycarbonyl or chlorine, dinitro, C 6 ~C 25 -Alkyl, C 4 ~C 12 -Alkoxycarbonyl, benzoates substituted by benzoyl, chlorobenzoyl or toluoyl, anions of naphthalenedicarboxylic acids, diphenyl ether disulfonates, aliphatic C 1 ~C 8 -C, which may be at least monounsaturated, sulfonated or sulfated alcohols or glycerol 8 ~C 25 -Fatty acid esters, bis-(sulfo-C 2 ~C 6 -alkyl)-C 3 ~C 12-Alkanedicarboxylic acid esters, bis-(sulfo-C 2 ~C 6 -alkyl)-itaconic acid esters, (sulfo-C 2 ~C 6 -alkyl)-C 6 ~C 18 -Alkane carboxylic acid esters, (sulfo-C 2 ~C 6 -alkyl)-acrylic or methacrylic acid esters, triscatechol phosphates optionally substituted with up to 12 halogen groups, phenyl or phenoxy groups being halogen, C 1 ~C 4 -Alkyl and / or C 1 ~C 4 -tetraphenylborate, cyanotriphenylborate, tetraphenoxyborate, which may be substituted by alkoxy; 4 ~C 12 -Anions of the group of alkyl-triphenylborates, with one or two C 1 ~C 12 C, optionally substituted at B and / or C atoms by alkyl or phenyl groups 4 ~C 12 -Alkyl-trinaphthyl borate, tetra-C 1 ~C 20 -Alkoxyborates, 7,8- or 7,9-dicarbanidoundecaborate (1-) or (2-), dodecahydrodicarbadodecaborate (2-) or BC 1 ~C 12 -alkyl-C-phenyl-dodecahydrodicarbadodecaborate(1-), and in the case of polyvalent anions such as naphthalene disulfonate, An - represents one equivalent of this anion, and the alkane and alkyl groups may be branched and / or substituted by halogen, cyano, methoxy, ethoxy, methoxycarbonyl or ethoxycarbonyl.

[0063] Preferably, the anion described in WO2012062655 is An - Used as.

[0064] Anion of the dye - It is also preferable that the compound has an AClogP in the range of 1 to 30, more preferably in the range of 1 to 12, and particularly preferably in the range of 1 to 6.5. AClogP is calculated according to J. Comput. Aid. Mol. Des. 2005, 19, 453; Virtual Computational Chemistry Laboratory, http: / / www.vcclab.org.

[0065] Suitable coinitiators for type II photoinitiator systems are the anionic borates, in particular the anionic triarylalkylborates, described in WO 2015 / 055576. Other coinitiators can be pentacoordinate silicates or tertiary aromatic amines.

[0066] In a preferred embodiment of the photopolymer composition, at least one dye is R 205 But hydrogen, C 1 ~C 4 Alkyl, or NR 210 R 211 represents R 206 But hydrogen, C 1 ~C 4 Alkyl, or NR 212 R 213 represents R 201 ~R 204 and R 210 ~R 213 each independently represent hydrogen, methyl, ethyl, propyl, butyl, chloroethyl, cyanomethyl, cyanoethyl, methoxyethyl, cyclopentyl, cyclohexyl, cyclohexylmethyl, benzyl, phenyl, tolyl, anisyl or chlorophenyl; or NR 201 R 202 , N.R. 203 R 204 , N.R. 210 R 211 and N.R. 212 R 213are each independently pyrrolidino, piperidino, morpholino or N-methylpiperazino, R 207 ~R 209 represents hydrogen, Two optional bridging groups X 1 and X 2 are independent of each other, SiMe 2 or O, It has the structure of formula (II). In a preferred embodiment of the photopolymer composition, at least one dye has the structure of formula (XVX): [ka] (In the formula, R 201 ~R 204 and R 210 ~R 213 are each independently hydrogen or methyl, ethyl, propyl or butyl. has.

[0067] In a preferred embodiment of the photopolymer composition, at least one dye according to formula (I) or formula (XVX) present is an anion (An - ) has an organic substituted sulfonate.

[0068] In a preferred embodiment of the photopolymer composition, at least one coinitiator is a triarylalkylborate salt.

[0069] In a preferred embodiment of the photopolymer composition, the coinitiator is a triarylalkylborate according to formula (III) having a calculated oxidation potential in acetonitrile between 1.01 V vs. SCE and 1.31 V vs. SCE. [ka] (In the formula, A represents a methylene group or an optionally substituted methine group; R 10 may form a ring having up to 10 members, R 100is hydrogen or C optionally substituted by hydroxyl and / or alkoxy and / or acyloxy and / or halogen; 1 ~C 20 Alkyl, C 3 ~C 20 Alkenyl, C 3 ~C 20 Alkynyl, C 5 ~C 7 Cycloalkyl or C 7 ~C 13 is an aralkyl group, R 101 , R 102 and R 103 are respectively, C 1 ~C 20 Alkyl, C 3 ~C 5 Alkenyl, C 3 ~C 5 Alkynyl, C 5 ~C 7 Cycloalkyl or C 7 ~C 13 Aralkyl group, halogen, cyano, trifluoromethyl, trichloromethyl, difluoromethyl, dichloromethyl, trifluoromethylthioyl, trichloromethylthioyl, C 1 ~C 12 Alkoxy, trifluoromethoxy, trichloromethoxy, C 1 ~C 12 represents up to five groups independently selected from alkylthioyl, thioyl, difluoromethoxy, difluoromethylthioyl, carboxyl, carbonyl, 2-, 3-, or 4-pyridyl, or any substituted aryl group, or hydrogen, the groups being selected such that the group-dependent calculated oxidation potential of triarylalkylborate (III) is in the range of between 1.01 V vs. SCE and 1.31 V vs. SCE in acetonitrile; K + represents an optionally substituted organic cation of valence n based on nitrogen, phosphorus, oxygen, sulfur and / or iodine, (n represents 1, 2 or 3) Contains:

[0070] In this embodiment of the photopolymer composition, A is preferably a methylene group.

[0071] In a preferred embodiment of the photopolymer composition, for the triarylalkyl borate of structure (III), R 100 C 1 ~C 20 Alkyl, C 5 ~C 7 Cycloalkyl or C 7 ~C 13 represents an aralkyl group, R 101 , R 102 and R 103 are respectively, C 1 ~C 4 Alkyl, halogen, cyano, trifluoromethyl, C 1 ~C 4 represents one or two groups independently selected from alkoxy or an optionally substituted aryl group or hydrogen. 101 Group, R 102 Groups and R 103 At least one group selected from the group R is not hydrogen. 101 Group, two R 102 Group and two R 103 In the case of a group, the two groups are located meta and para, respectively, to the B atom of the aromatic moiety. Preferably, in this embodiment, A represents a methylene group.

[0072] Further, for the triarylalkyl borate of structure (II), R 100 is preferably C 3 ~C 5 represents an alkyl group, A is preferably a methylene group, and R 101 Group, R 102 Groups and R 103 At least one of the groups is, in each case, C 1 ~C 4 represents 1 to 2 meta- and / or para-position groups independently selected from alkyl groups and halogen substituents, and preferably at least R 102 and / or R 103represent, independently of each other, selected halogen substituents, including halogen groups such as Cl or F groups, as well as trihaloalkyl groups, particularly trihalomethyl and trihaloethyl groups, and especially trifluoromethyl and trichloromethyl groups.

[0073] In another preferred embodiment of the photopolymer composition, for the triarylalkyl borate of structure (II), R 100 C 3 ~C 12 represents an alkyl group, R 101 , R 102 , and R 103 are independent of each other, C 1 ~C 4 R represents one or two meta- or para-position groups selected from the group consisting of alkyl groups and halogen substituents, and preferably represents at least 102 and / or R 103 represents a halogen substituent. 101 Group, two R 102 Group and two R 103 In the case of a group, the two groups are preferably in the meta and para positions in each case relative to the B atom. Preferably, in this embodiment, A represents a methylene group.

[0074] Further, preferably, for the triarylalkyl borate of structure (II), R 100 is C 3 ~C 5 represents an alkyl group, A is preferably a methylene group, and R 101 , R 102 , and R 103 are C 1 ~C 4 represents 1 to 2 meta- and / or para-position groups independently selected from alkyl groups and halogen substituents, and preferably at least R 102 and / or R 103 represents a halogen substituent.

[0075] The following triarylalkylborates are quite particularly preferred, in which each K +is any organic cation based on nitrogen, phosphorus, oxygen, sulfur or iodine: [ka]

[0076] In a preferred embodiment of the photopolymer composition, the organic cation K of the triarylalkylborate salt + is a nitrogen- or phosphorus-based monovalent or divalent cation, preferably a nitrogen-based monovalent or divalent cation, particularly preferably a monovalent ammonium cation.

[0077] In a preferred embodiment of the photopolymer composition, at least one coinitiator, in particular in interaction with one of said cationic dyes, has an oxidation potential, calculated according to formula (1) in acetonitrile versus a saturated calomel electrode, in the range between 1.01 V vs. SCE and 1.20 V vs. SCE, preferably between 1.01 V vs. SCE and 1.17 V vs. SCE, particularly preferably between 1.01 V vs. SCE and 1.15 V vs. SCE in acetonitrile.

[0078] Furthermore, K + may be an organic cation of valence n based on nitrogen, such as ammonium ion, pyridinium ion, pyridazinium ion, pyrimidinium ion, pyrazinium ion, imidazolium ion, pyrrolidinium ion, which may have further functional groups in one or more side chains, such as ether, ester, amide and / or carbamate, and which may be present in oligomeric or polymeric or crosslinked form.

[0079] Preferably, K +is an organic cation of valence n based on phosphorus, such as an optionally substituted tetraalkyl-phosphonium, trialkyl-aryl-phosphonium, dialkyl-diaryl-phosphonium, alkyl-triaryl-phosphonium or tetraaryl-phosphonium cation, which may bear further functional groups in one or more side chains, such as carbonyl, amide and / or carbamate, and which may exist in oligomeric or polymeric or crosslinked form.

[0080] More preferably, K + is an organic cation of valence n based on oxygen, such as a benzopyrylium, flavylium, naphthoxanthenium cation, or an optionally substituted pyrylium cation which may also exist in fused ring form, such as a polymeric cation having the substitution pattern described.

[0081] More preferably, K + are the same or different optionally substituted C 4 ~C 14 Alkyl, C 6 ~C 10 Aryl, C 7 ~C 12 Aryl alkyl or C 5 ~C 6 It is an organic cation of valence n based on sulfur, such as a sulfonium salt, which may have cycloalkyl groups and / or may establish oligomeric or polymeric repeating linking units, where 1≦n≦3, or an onium compound of sulfur, such as a thiopyrylium cation or a polymeric cation, having the substitution pattern described.

[0082] More preferably, K + are the same or different optionally substituted C 1 ~C 22 Alkyl, C 6 ~C 14 Aryl, C 7 ~C 15 Aryl alkyl or C 5 ~C 7It is an organic cation of valence n based on iodine such as an onium compound of iodine which may have a cycloalkyl group and / or may establish oligomeric or polymeric repeating linking units to build up iodonium salts where 1≦n≦3, or further polymeric cations having the substitution patterns described.

[0083] The photoinitiator system may also contain further coinitiators cIII), such as trichloromethyl initiators, iodonium salts, sulfonium salts, aryloxide initiators, bis-imidazole initiators, ferrocene initiators, oxime initiators, thiol initiators or peroxide initiators.

[0084] It may be advantageous to use mixtures of these coinitiators with various dyes. Depending on the radiation source used, the type and concentration of the PIS must be adapted in a manner known to those skilled in the art. For further information, see, for example, PKT Oldring (Ed.), Chemistry & Technology of UV & EB Formulations For Coatings, Inks & Paints, Vol. 3, 1991, SITA Technology, London, pp. 61-328. It is particularly preferred if the PIS comprises a combination of a dye having an absorption spectrum that at least partially covers the spectral range from 400 nm to 1200 nm and at least one coinitiator matched to the dye. It is also preferred that at least one photoinitiator suitable for the color of the laser light is contained in the photopolymer composition. It is even more preferred if the photopolymer composition contains a photoinitiator suitable for each of at least two laser light colors selected from blue, green and red and NIR. Finally, it is particularly preferred if the photopolymer composition contains a photoinitiator suitable for each laser light color.

[0085] The at least one non-photopolymerizable component d) can be any component d) that a person skilled in the art would choose for the photopolymer composition according to the present invention. It is preferred if the photopolymer composition further contains a urethane as an additive of component d), the urethane being particularly substituted by at least one fluorine atom.

[0086] Preferably, the urethane has the general formula (XVIII) [ka] (wherein o≧1 and o≦8; R 7 , R 8 and R 9 is a linear, branched, cyclic or heterocyclic unsubstituted or optionally heteroatom-substituted organic group, and / or R 8 , R 9 are each independently hydrogen, preferably R 7 Group, R 8 Group, R 9 At least one of the groups is substituted with at least one fluorine atom, particularly preferably R 7 is an organic group having at least one fluorine atom. Particularly preferably, R 9 is a linear, branched, cyclic or heterocyclic organic group which is unsubstituted or optionally substituted by heteroatoms such as fluorine.

[0087] In particular, photopolymers containing a photopolymer composition comprising a matrix polymer, a write monomer, and a photoinitiator system further comprising a compound of formula (XVIII) are preferred.

[0088] The statements made above regarding the photopolymer compositions according to the invention with regard to the further preferred embodiments apply analogously to the photopolymers according to the invention. Another subject of the invention is a composition comprising at least the following layers: A. A substrate layer A, which may be part of a further layer structure; B. a photopolymer layer B formed from a photopolymer composition according to the present invention; and C. A top layer C, which may be part of a further layer structure The present invention relates to a layer structure comprising: Another subject of the invention is a composition comprising at least the following layers: A. A substrate layer A, which may be part of a further layer structure; B'. an exposed or cured photopolymer layer B' produced from a photopolymer composition according to the invention by curing with light; and C. A top layer C, which may be part of a further layer structure The present invention relates to a layer structure comprising:

[0089] Further disclosed is a method for producing a holographic medium using the disclosed photopolymer composition. The photopolymer composition can be used for the production of a holographic medium, in particular in the form of a film. In this case, as a carrier A, a layer of a material transparent to light in the visible and NIR spectral range (transmittance of more than 85% in the wavelength range of 400-1200 nm) or a layer of an assembly of such materials may be coated on one or both sides in the dark with a photopolymer composition B, and a covering layer C may be applied on one or more photopolymer layers B. Preferred materials or material assemblies of the carrier are based on polycarbonate (PC), polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene, polypropylene, cellulose acetate, cellulose hydrate, cellulose nitrate, cycloolefin polymers, polystyrene, polyepoxides, polysulfones, cellulose triacetate (CTA), polyamides, polymethyl methacrylate, polyvinyl chloride, polyvinyl butyral or polydicyclopentadiene or mixtures thereof. They are more preferably based on PC, PET and CTA. The material assemblies may be film laminates or coextrusions. Preferred material assemblies are double and triple films constructed according to one of the schemes A / B, A / B / A or A / B / C. PC / PET, PET / PC / PET and PC / TPU (TPU=thermoplastic polyurethane) are particularly preferred. The carrier material or material assemblies may be provided with a non-stick, antistatic, hydrophobic or hydrophilic finish on one or both sides. The described modifications are used on the side facing the photopolymer layer B so that the photopolymer layer B can be non-destructively removed from the carrier A. The modification of the carrier side facing away from the photopolymer layer B serves to ensure that the media according to the invention meets the specific mechanical requirements required for processing, for example in roller laminators, in particular roll-to-roll processes.

[0090] Further disclosed is a further method for producing a holographic medium using the photopolymer composition according to the invention, which also provides a holographic medium in the form of a film. In this case, as a carrier A, a layer of a material transparent to light in the visible and NIR spectral range (transmittance of more than 85% in the wavelength range of 400-1200 nm) or a layer of an assembly of such materials may be applied on one side by 2D printing in the dark with a photopolymer composition B, and a covering layer C may be applied on one or more photopolymer layers B. All common inkjet techniques may be used here. If desired, the photopolymer composition B may be printed in a targeted manner only in the areas required for functionality. Preferred materials or material assemblies of the carrier are based on glass, silicon (in the form of highly polished wafers known from semiconductor technology), polycarbonate (PC), polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene, polypropylene, cellulose acetate, cellulose hydrate, cellulose nitrate, cycloolefin polymers, polystyrene, polyepoxides, polysulfones, cellulose triacetate (CTA), polyamides, polymethyl methacrylate, polyvinyl chloride, polyvinyl butyral or polydicyclopentadiene or mixtures thereof. They are more preferably based on PC, PET and CTA. The material assemblies can be film laminates or coextrusions. Preferred material assemblies are double and triple films constructed according to one of the schemes A / B, A / B / A or A / B / C. PC / PET, PET / PC / PET and PC / TPU (TPU=thermoplastic polyurethane) are particularly preferred. The material or material assemblies of the carrier can be provided with a non-stick, antistatic, hydrophobic or hydrophilic finish on one or both sides. The described modifications are used on the side facing the photopolymer layer B so that the photopolymer layer B can be non-destructively removed from the carrier A. The modifications of the carrier side facing away from the photopolymer layer B serve to ensure that the media according to the invention meets the specific mechanical requirements needed for processing, for example in a roller laminator, in particular a roll-to-roll process.

[0091] Further disclosed are material assemblies of the above type which comprise a photoexposed, preferably photocured, photopolymer layer B', thus forming double and triple films according to schemes A / B', A / B' / A or A / B' / C.

[0092] It is possible to expose holographic information onto such a holographic medium.

[0093] Another subject of the invention relates to a holographic medium containing a photopolymer composition according to the invention. The holographic medium can be processed into a hologram by suitable exposure processes for optical applications in the red and NIR range (600-1200 nm). Visual holograms and holograms operating in the NIR range include all holograms that can be recorded by methods known to those skilled in the art. These include in-line (Gabor) holograms, off-axis holograms, full aperture transfer holograms, white light transmission holograms ("rainbow holograms"), Denisyuk holograms, off-axis reflection holograms, edge-lit holograms and holographic stereograms. Reflection holograms, Denisyuk holograms or transmission holograms are preferred. Another subject of the invention relates to a holographic medium converted into a hologram, the hologram being selected from the group consisting of reflection, transmission, in-line, off-axis, full aperture transfer, white light transmission, Denisyuk, off-axis reflection or edge-lit holograms and holographic stereograms, preferably reflection, transmission or edge-lit holograms or a combination of at least two of them, it being likewise possible to integrate a combination of these hologram types or several holograms of the same type independent of one another in the same volume of the holographic medium (multiplexing).

[0094] The possible optical functions of the holograms that can be produced with the photopolymer composition according to the invention correspond to the optical functions of optical elements such as lenses, mirrors, deflection mirrors, filters, diffusing lenses, diffractive elements, diffusers, light guides, wave guides, projection lenses and / or masks. Combinations of these optical functions can also be combined independently of each other in a hologram (multiplexing). In many cases, these optical elements show frequency selectivity depending on how the hologram was exposed and what dimensions it has.

[0095] The above mentioned features of the holograms producible with the photopolymer composition according to the invention are used, for example but not limited to, in the fields of eye tracking, sensing and also LIDAR and augmented reality, head mounted displays and virtual reality applications in the NIR range.

[0096] Another subject of the invention relates to an optical display comprising a holographic medium according to the invention.

[0097] Furthermore, by means of the holographic medium it is also possible to produce holographic images or diagrams for example for personal portraits, biometric identification of security documents or for photographic images or image structures which can generally represent digital data including advertising, security labels, brand protection, branding, labels, design elements, decorations, illustrations, collectible cards, photographs etc. and combinations with the above mentioned products. Holographic images can have the impression of a three-dimensional image, but also represent image sequences, short films or several different objects, depending on the angle etc. at the irradiated (moving) light source etc. Due to this variety of possible designs, holograms, especially volume holograms, constitute an attractive technical solution for said applications.

[0098] Another subject of the invention relates to the use of the holographic medium according to the invention in a medium for producing chip cards, identity cards, 3D images, product protection tags, labels, banknotes or holographic optical elements, in particular for optical displays or for realizing methods selected from the group consisting of eye tracking, sensing, LIDAR, augmented reality, head mounted displays and virtual reality applications, in particular in the near infrared range, and combinations of at least two thereof.

[0099] The holographic medium can be used for recording in-line, off-axis, full aperture transfer, white light transmission, Denisyuk, off-axis reflection or edge-lit holograms, and also for recording holographic stereograms, in particular for producing optical elements, images or image displays.

[0100] A hologram is obtainable from the holographic medium according to the invention by suitable exposure. [Brief description of the drawings]

[0101] [Figure 1] Figure 1 shows the holographic experimental setup where the diffraction efficiency (DE) of the media was measured, and depicts the geometry of the Holographic Media Tester (HMT) at λ=850 nm (NIR Laser). (M=mirror, S=shutter, SF=spatial filter, CL=collimator lens, λ / 2=λ / 2 plate, PBS=polarization sensitive beam splitter, D=detector, I=iris, α0=-21.8°, β0=41.8° are the angles of incidence of the coherent beam measured outside the (media) Sample, and RD=reference direction of the turntable.)

[0102] [Diagram 2]FIG. 14 shows the measured transmitted power PT (here for Example 3a) plotted as a solid line versus the angular detuning ΔΩ (right y-axis), the measured diffraction efficiency η (left y-axis) plotted as open circles versus the angular detuning ΔΩ (up to the allowed finite size of the detector), and the fit to Kogelnik theory (left y-axis) as a dashed line. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0103] Description of the Examples and Figures:

[0104] The following examples are used to illustrate the invention without limiting it thereto.

[0105] Determination of OH and NCO values:

[0106] OH Numbers: The specified OH numbers were determined according to DIN 53240-2.

[0107] NCO value: The specified NCO values ​​(isocyanate content) were determined in accordance with DIN EN ISO 11909.

[0108] Measurement of holographic properties DE and Δn of holographic media / photopolymer films by two-beam interference in reflection configuration:

[0109] A spatial filter (SF) was used to convert the beam of the NIR laser (emission wavelength 850 nm) into a parallel uniform beam together with a collimator lens (CL). The final cross sections of the signal and reference beams are fixed by an iris diaphragm (I). The diameter of the iris opening is 0.4 cm. A polarizing beam splitter (PBS) splits the laser beam into two coherent equally polarized beams. The power of the reference beam was set to 1.75 mW and the power of the signal beam was set to 2.25 mW through a λ / 2 plate. The power was determined using a semiconductor detector (D) with the sample removed. The angle of incidence of the reference beam (α 0) is -21.8°, and the incidence angle of the signal beam (β 0 ) is 41.8°. The angle is measured proceeding from the sample perpendicular to the beam direction. Thus, according to Scheme 1, α 0 has a negative sign, and β 0 has a positive sign. At the location of the sample (medium), the interference field of the two overlapping beams produced a pattern of light and dark strips perpendicular to the angle bisector of the two beams incident on the sample (reflection hologram). The strip spacing Λ, also called the grating period in the medium, is about 296 nm (we assumed a refractive index of the medium of about 1.51).

[0110] Figure 1 shows the holographic experimental setup where the diffraction efficiency (DE) of the medium was measured. Figure 1 shows the geometry of the holographic medium tester (HMT) at λ = 850 nm (NIR laser) (M = mirror, S = shutter, SF = spatial filter, CL = collimator lens, λ / 2 = λ / 2 plate, PBS = polarization sensitive beam splitter, D = detector, I = iris, α 0 =-21.8°, β 0 = 41.8° is the angle of incidence of the coherent beam measured outside the sample (of the medium), and RD = reference direction of the turntable).

[0111] The holograms were written into the media in the following manner:

[0112] · Both shutters (S) are open for an exposure time t. Afterwards, with the shutter (S) closed, the medium was left for 5 min for diffusion of the not yet polymerized writing monomer.

[0113] The written hologram was then read out in the following way: The signal beam shutter remained closed. The reference beam shutter was open. The reference beam iris was closed to a diameter of less than 1 mm. This ensured that for all rotation angles (Ω) of the medium, the beam was always completely within the previously written hologram. The turntable was then rotated under computer control in angular steps of 0.05°. minFrom Ω max The angle range was swept from α to 0. Ω is measured from the sample perpendicular to the reference direction of the turntable, which is the direction in which the angles of incidence of the reference and signal beams have the same absolute value during the writing of the hologram, i.e., α 0 =-31.8° and β 0 = 31.8°. In that case, Ω recording = 0°. Therefore, α 0 =-21.8° and β 0 = 41.8°, Ω recording is 10°. In general, for the interference field during writing ("recording") a hologram:

number

number

[0114] Therefore, in this case, θ 0 =-31.8°. At each setting of the rotation angle Ω, the power of the transmitted beam to the zeroth order was measured by the corresponding detector D, and the power of the diffracted beam to the first order was measured by detector D. The diffraction efficiency was calculated at each setting of the angle Ω as the quotient:

number

[0115] By the above method, the Bragg curve describing the diffraction efficiency η as a function of the rotation angle Ω of the written hologram was measured and stored in a computer. In addition, the intensity transmitted in the zeroth order was also recorded versus the rotation angle Ω and stored in a computer.

[0116] The maximum diffraction efficiency of a hologram (DE=η max ), i.e., its peak value is Ω reconstruction In some cases, for this purpose it was necessary to change the position of the detector of the diffracted beam in order to determine this maximum.

[0117] The refractive index contrast Δn and thickness d of the photopolymer layer were then determined for the measured Bragg curves and the angular course of the transmitted intensity using the coupled wave theory (see H. Kogelnik, The Bell System Technical Journal, volume 48, November 1969, number 9, page 2909-page 2947). It should be noted that due to the thickness shrinkage caused by photopolymerization, the strip spacing Λ' and the orientation (tilt) of the strips of the hologram may deviate from the strip spacing Λ and its orientation of the interference pattern. Therefore, the angle α at which the maximum diffraction efficiency is achieved is 0 ' or the corresponding angle Ω of the turntable reconstruction Also, α 0 or the corresponding Ω recording This changes the Bragg condition. This change is taken into account in the evaluation process, which is described below:

[0118] All geometric quantities that refer to the written hologram and not to the interference pattern can be expressed as quantities involving prime numbers.

[0119] On the Bragg curve η(Ω) of a reflection hologram by Kogelnik:

number

number

[0120] When the hologram is read out ("reconstruction"), similarly to above the following applies:

number

[0121] In the Bragg condition, "dephasing" occurs when DP = 0. Correspondingly, we have:

number

[0122] The unknown angle β' can be determined by comparing the Bragg conditions for the interference field when writing the hologram with those when reading it, assuming that only thickness contraction occurs, which results in:

number

[0123] Therefore, the maximum diffraction efficiency (DE=η max ) becomes:

number

number

[0124] As DE is known, the shape of the theoretical Bragg curve according to Kogelnik is determined only by the thickness d' of the photopolymer layer. Δn is corrected via DE for a given thickness d' so that the measurement and theory of DE always coincide. Here, d' is adjusted until the angular position of the first minimum of the theoretical Bragg curve corresponds to the angular position of the first minimum of the transmitted intensity and until the full width at half maximum (FWHM) of the theoretical Bragg curve and the transmitted intensity coincide.

[0125] Although the orientation of the reflection hologram also rotates when reconstructed by an Ω-scan, the detector of the diffracted light can only cover a finite angular range, so the Bragg curve of a wide hologram (small d') is not completely covered by an Ω-scan given a suitable detector positioning, only the central region is covered. Therefore, the shape of the transmitted intensity, which is complementary to the Bragg curve, is further used to tune the layer thickness d'.

[0126] FIG. 2 shows plots of the Bragg curve η according to coupled-wave theory (dashed line), the measured diffraction efficiency (open circles) and the transmitted power (solid black line) versus the angular detuning ΔΩ.

[0127] For formulation, this procedure may be repeated several times in different media and for different exposure times t to determine the average energy dose of the incident laser beam at which DE reaches its saturation value when writing the hologram. The average energy dose E is given by the angle α 0 and β 0 The power of the two partial beams (P r = 1.75mW reference beam and P s = 2.25 mW signal beam), exposure time t, and diameter of the iris diaphragm (0.4 cm) give:

number

[0128] The power of the component beams is expressed as the angle α 0 and β 0 The values ​​were adjusted so that the same power density was achieved in the medium.

[0129] Calculation of the oxidation potential of triarylalkylborates:

[0130] Absolute oxidation potential (

number

number

number

number

number

number

number

[0131] Calculation of the Gibbs energies at 298 K of the ground and oxidized states was performed according to the following procedure: First, a three-dimensional molecular geometry of the triarylalkylborate was generated using ChemDraw 3D and this geometry was subjected to conformer analysis. The conformers found were energetically minimized by the AM1 force field and the coordinates of the resulting molecular geometry (usually only one conformer was obtained) were used for the calculation of the electronic energies. The electronic ground state was geometry optimized in a suitable solvent (PCM approach for acetonitrile) and the absolute electronic energies of the optimized structures were determined and corrected for the effects of the solvent field (G 298 ) The molecular geometry thus optimized was then reduced by one electron, and the absolute electronic energies of the oxidized molecule, also calculated in acetonitrile (PCM method), were determined again (G 298 (oxidized).

[0132] material:

[0133] Solvents, reagents and all bromoaromatic compounds used were purchased from chemical suppliers. Where appropriate, bromoaromatic compounds were freshly distilled. Anhydrous solvents contain less than 50 ppm water.

[0134] Polyol 1 was prepared as described in WO2015091427 with an OH number of 56.8.

[0135] Desmodur® N 3900 Product of Covestro AG, Leverkusen, Germany, hexane diisocyanate based polyisocyanate, iminooxadiazinedione content of at least 30%, NCO content: 23.5%.

[0136] Iron(III) trifluoroacetylacetonate [14526-22-8] is available from ABCR GmbH & Co. KG, Karlsruhe, Germany.

[0137] Urethane acrylate 1 (phosphorothioyltris(oxybenzene-4,1-diylcarbamoyloxyethane-2,1-diyl)trisacrylate, [1072454-85-3]) was prepared as described in WO2015091427.

[0138] Urethane acrylate 2, (2-({[3-(methylsulfanyl)phenyl]carbamoyl}oxy)ethyl prop-2-enoate, [1207339-61-4]) was prepared as described in WO2015091427.

[0139] Additive 1, bis(2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl)-(2,2,4-trimethylhexane-1,6-diyl) biscarbamate [1799437-41-4], was prepared as described in WO2015091427.

[0140] Karenz™ IR-T was purchased from Showa Denko EUROPE GmbH, [96233-24-8].

[0141] Karenz™ P3B was purchased from Showa Denko EUROPE GmbH, [120307-06-4].

[0142] Cation 2 N 1 ,N 22 -Dihexadecyl-N 1 ,N 1,N 22 ,N 22 ,10,10,13-Heptamethyl-7,16-dioxo-3,6,17,20-tetraoxa-8,15-diazadocosane-1,22-diaminium dibromide was prepared as described in WO2018087064.

[0143] BYK-310 silicone-containing surface additive, product of BYK-Chemie GmbH, Wesel, Germany.

[0144] Synthesis protocol:

[0145] Protocol for the preparation of N-ethyl-N-[4-[1,5,5-tris[4-(diethylamino)phenyl]-2,4-pentadienylidene]-2,5-cyclohexadien-1-ylidene]ethanaminium bis(2-ethylhexyl) sulfosuccinate (Dye 1):

[0146] 4.08 g of sodium bis(2-ethylhexyl) sulfosuccinate (1.0 equiv.) was dissolved in 80 mL of deionized water. 7.44 g of Karenz IR-T (1.0 equiv.) in 100 mL of butyl acetate was added to this solution and the biphasic mixture was stirred at room temperature for 3 h. The aqueous phase was then separated and the organic phase was washed five times with 80 mL of deionized water. Finally, the solvent was removed under vacuum on a rotary evaporator to give the product as a dark blue resin (9.50 g, 98% of theory).

[0147] Preparation of N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium chloride (cation 1):

[0148] 1.28 mol of dimethylcetylamine was dissolved in 2.4 L of tert-butyl methyl ether (MTBE) in a 5 L flange vessel at 30° C. 1.28 mol of 3-chlorophenylpropane was added dropwise to this solution at such a rate that the reaction temperature did not exceed 40° C. After the end of the metered addition, the reaction solution was stirred at 90° C. for 5 hours, then cooled to 40° C. over 1 hour and transferred to a suitable vessel for crystallization. The crystals formed overnight were isolated, washed with 500 mL of cold MTBE and dried. A colorless solid of melting point 59° C. was obtained (450 g, 83% of theory).

[0149] R 101 =R 102 =R 103 Preparation protocol of tetrabutylammonium triarylalkylborate:

[0150] [ka] (twenty four)

[0151] In a four-neck flask equipped with a thermometer, reflux condenser, dropping funnel and magnetic stirrer, the corresponding diisopropyl alkyl borate (1.0 eq.) and magnesium turnings (3 eq.) are introduced into a solvent mixture consisting of anhydrous toluene and anhydrous THF (5.8:1, 1.9 M). The mixture is stirred at room temperature for 30 minutes. The corresponding bromoaromatic compound (3 eq.) is then added dropwise to the mixture, not initially diluted, until the subsequent exotherm signals the start of the reaction, but a maximum of 10% of the undiluted bromoaromatic compound is used for this purpose. The remaining bromoaromatic compound is added dropwise to the reaction solution in a solvent mixture consisting of anhydrous toluene and anhydrous THF (1:1, dilution to 0.4 M total molar concentration) at such a rate that the reaction temperature does not exceed 45 ° C. After the end of the addition, the reaction solution is heated under reflux until the magnesium is completely dissolved or for 1 hour. The reaction solution is cooled to room temperature and discharged into a mixture of ice water and tetrabutylammonium bromide (1 eq.). The mixture is stirred for 1 hour and then the organic phase is separated. Halide test (HNO 3 (Aqueous solution 10%)+AgNO 3The organic phase is washed with water until the chromatogram is negative. The solvent is removed in a rotary evaporator in vacuum and the crude product is recrystallized from methanol.

[0152] R 101 =R 102 ≠R 103 Preparation protocol of tetrabutylammonium triarylalkylborate:

[0153] In a four-neck flask equipped with a thermometer, reflux condenser, dropping funnel and magnetic stirrer, the corresponding diisopropyl alkyl borate (1.0 eq.) and magnesium turnings (3 eq.) are introduced into a solvent mixture consisting of anhydrous toluene and anhydrous THF (4:1, 1.9 M). This mixture is stirred at room temperature for 30 minutes. The first bromoaromatic compound (1 eq.) is then added dropwise to the mixture, initially undiluted, until the subsequent exotherm signals the start of the reaction, but a maximum of 10% of the undiluted bromoaromatic compound is used for this purpose. The remaining bromoaromatic compounds are added dropwise to the reaction solution in a solvent mixture consisting of anhydrous toluene and anhydrous THF (1.1:1, dilution to 0.7 M total molar concentration) at such a rate that the reaction temperature does not exceed 45 ° C. After the addition is complete, the reaction solution is stirred at room temperature for 1 hour. The corresponding second bromoaromatic compound is then added dropwise to the mixture, initially undiluted, until the subsequent exotherm signals the start of the reaction, with a maximum of 10% of the undiluted bromoaromatic compound being used for this purpose. The remaining bromoaromatic compound in the residual solvent mixture consisting of anhydrous toluene and anhydrous THF (1.1:1, dilution to 0.4 M total molar concentration) is again added dropwise to the reaction solution at such a rate that the reaction temperature does not exceed 45 ° C. After the end of the addition, the reaction solution is heated under reflux until the magnesium is completely dissolved or for 1 h. The reaction solution is cooled to room temperature and drained into a mixture of ice water and tetrabutylammonium bromide (1 equivalent). The mixture is stirred for 1 h and the organic phase is separated. Halide test (HNO 3 (Aqueous solution 10%)+AgNO 3 The organic phase is washed with water until the chromatogram is negative. The solvent is removed in a rotary evaporator in a vacuum and the crude product is recrystallized from methanol.

[0154] Protocol for the preparation of triarylalkylborates with cations of valence n=1:

[0155] The corresponding tetrabutylammonium triarylalkylborate (1 equiv.) is dissolved in butyl acetate (0.04 M) and mixed with an aqueous solution of the corresponding cation (halide salt, 1.05 equiv., 0.05 M) and sodium bis(2-ethylhexyl) sulfosuccinate (0.05 equiv.), and the mixture is stirred at room temperature for 1 h. After phase separation, the halide test (HNO 3 (Aqueous solution 10%)+AgNO 3 The organic phase is washed repeatedly with water until the chromatogram is negative. The solvent is removed in a rotary evaporator in vacuo and the product is dried under reduced pressure.

[0156] Protocol for the preparation of triarylalkylborates with cations of valence n=2:

[0157] The corresponding tetrabutylammonium triarylalkylborate (1 equiv.) is dissolved in butyl acetate (0.04 M) and mixed with an aqueous solution of the corresponding cation (halide salt, 0.525 equiv., 0.05 M) and sodium bis(2-ethylhexyl) sulfosuccinate (0.05 equiv.), and the mixture is stirred at room temperature for 1 h. After phase separation, the halide test (HNO 3 (Aqueous solution 10%)+AgNO 3 The organic phase is washed repeatedly with water until the chromatogram is negative. The solvent is removed in a rotary evaporator in vacuo and the product is dried under reduced pressure.

[0158] Photopolymer film / holographic media fabrication protocol:

[0159] 14.9 g of the polyol component 1 is melted and mixed in the dark with 6.6 g of urethane acrylate 1, 6.6 g of urethane acrylate 2, 9.2 g of fluorinated urethane (additive 1), 0.45 g of each borate, 0.10 g of dye 1, 0.12 g of BYK-310, 0.01 g of iron(III) trifluoroacetylacetonate, 10.5 g of ethyl acetate, 1.1 g of butyl acetate and 7.7 g of 1-methoxy-2-propyl acetate to obtain a homogeneous solution. Then, 2.8 g of Desmodur® N 3900 is added and the mixing is repeated. The solution is placed on a 60 μm thick TAC film on a roll-to-roll coating line in the dark and coated by a doctor blade so that a wet film thickness range of 14 to 17 μm is achieved. The coating film is dried at a drying temperature of 80° C. and a drying time of about 4 minutes, then protected with a polyethylene film having a thickness of 40 μm. The film is then packaged in a light-protected manner.

[0160] Preparation of N-benzyl-N,N-dimethylhexadecylammonium di(3-chloro-4-methylphenyl)(4-methylphenyl)hexylborate:

[0161] R 101 =R 102 ≠R 103 According to the general protocol for the preparation of tetrabutylammonium triarylalkylborate, 3-chloro-4-methylbromobenzene (2 equivalents) and 4-methylbromobenzene (1 equivalent) were reacted with diisopropylhexylborate. The resulting tetrabutylammonium triarylhexylborate was then reacted with N-benzyl-N,N-dimethylhexadecylammonium chloride hydrate according to the general protocol for the preparation of triarylhexylborate with a cation of valence n=1. δ (ppm) (CDCl 3 )=-10.6 ppm 11 A colorless oil (18.92 g, 42% of theory over two steps) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox=1.02V vs. SCE.

[0162] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium di(3-chloro-4-methylphenyl)(4-methylphenyl)hexylborate (Example 3a in Table 2):

[0163] Following the general fabrication protocol for photopolymer films, photopolymers were prepared using N-benzyl-N,N-dimethylhexadecylammonium di(3-chloro-4-methylphenyl)(4-methylphenyl)hexylborate as a coinitiator.

[0164] Preparation of N-(3-phenylpropyl)-N,N-dimethylhexadecylammonium di(3-chloro-4-methylphenyl)(4-methylphenyl)hexylborate:

[0165] R 101 =R 102 ≠R 103 3-Chloro-4-methylbromobenzene (2 equiv.) and 4-methylbromobenzene (1 equiv.) were reacted with diisopropylhexylborate according to the general protocol for the preparation of tetrabutylammonium triarylalkylborate, 1. The general protocol for the preparation of triarylalkylborate with cation of valence n=1 was then followed using cation 1. δ (ppm) (CDCl 3 )=-10.6 ppm 11 A colorless oil (2.5 g, 42% of theory over two steps) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.02V vs. SCE.

[0166] Preparation of photopolymer using N-(3-phenylpropyl)-N,N-dimethylhexadecylammonium di(3-chloro-4-methylphenyl)(4-methylphenyl)hexylborate (Example 3b in Table 2):

[0167] Following the general fabrication protocol for photopolymer films, photopolymers were prepared using N-(3-phenylpropyl)-N,N-dimethylhexadecylammonium di(3-chloro-4-methylphenyl)(4-methylphenyl)hexylborate as a coinitiator.

[0168] Preparation of tributyltetradecylphosphonium di(3-chloro-4-methylphenyl)(4-methylphenyl)hexylborate:

[0169] R 101 =R 102 ≠R 103 3-Chloro-4-methylbromobenzene (2 equivalents) and 4-methylbromobenzene (1 equivalent) were reacted with diisopropylhexylborate according to the general protocol for the preparation of tetrabutylammonium triarylalkylborate, δ (ppm) (CDCl 3 )=-10.6 ppm 11 A colorless oil (1.2 g, 42% of theory over two steps) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.02V vs. SCE.

[0170] Preparation of photopolymer using tributyltetradecylphosphonium di(3-chloro-4-methylphenyl)(4-methylphenyl)hexylborate (Example 3c in Table 2):

[0171] Following the general fabrication protocol for photopolymer films, photopolymers were prepared using tributyltetradecylphosphonium di(3-chloro-4-methylphenyl)(4-methylphenyl)hexylborate as a coinitiator.

[0172] N 1 ,N 22 -Dihexadecyl-N 1 ,N1 ,N 22 ,N 22 Preparation of 10,10,13-heptamethyl-7,16-dioxo-3,6,17,20-tetraoxa-8,15-diazadocosane-1,22-diaminium bis-di(3-chloro-4-methylphenyl)(4-methylphenyl)hexylborate:

[0173] R 101 =R 102 ≠R 103 3-Chloro-4-methylbromobenzene (2 equiv.) and 4-methylbromobenzene (1 equiv.) were reacted with diisopropylhexylborate according to the general protocol for the preparation of tetrabutylammonium triarylalkylborate, cation 2, followed by the general protocol for the preparation of triarylalkylborate with cation valence n = 1. δ (ppm) (CDCl 3 )=-10.6 ppm 11 A colorless oil (2.7 g, 42% of theory over two steps) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.02V vs. SCE.

[0174] N 1 ,N 22 -Dihexadecyl-N 1 ,N 1 ,N 22 ,N 22 Preparation of photopolymer using 10,10,13-heptamethyl-7,16-dioxo-3,6,17,20-tetraoxa-8,15-diazadocosane-1,22-diaminium bis-di(3-chloro-4-methylphenyl)(4-methylphenyl)hexylborate (Example 3d in Table 2):

[0175] Following the general fabrication protocol for photopolymer films, use N as a coinitiator. 1 ,N 22 -Dihexadecyl-N 1 ,N 1 ,N 22 ,N 22A photopolymer was prepared using 10,10,13-heptamethyl-7,16-dioxo-3,6,17,20-tetraoxa-8,15-diazadocosane-1,22-diaminium bis-di(3-chloro-4-methylphenyl)(4-methylphenyl)hexylborate.

[0176] Preparation of N-benzyl-N,N-dimethylhexadecylammonium di(4-chlorophenyl)(4-methylphenyl)hexylborate:

[0177] R 101 =R 102 ≠R 103 According to the general protocol for the preparation of tetrabutylammonium triarylalkylborate, 4-chlorobromobenzene (2 equivalents) and 4-methylbromobenzene (1 equivalent) were reacted with diisopropylhexylborate. The resulting tetrabutylammonium triarylhexylborate was then reacted with N-benzyl-N,N-dimethylhexadecylammonium chloride hydrate according to the general protocol for the preparation of triarylhexylborate with a cation of valence n=1. δ (ppm) (CDCl 3 )=-10.7 ppm 11 A colorless oil (2.4 g, 60% of theory over two steps) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.03V vs. SCE.

[0178] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium di(4-chlorophenyl)(4-methylphenyl)hexylborate (Example 8 in Table 2):

[0179] Following the general fabrication protocol for photopolymer films, photopolymers were prepared using N-benzyl-N,N-dimethylhexadecylammonium di(4-chlorophenyl)(4-methylphenyl)hexylborate as a coinitiator.

[0180] Preparation of N-(3-phenylpropyl)-N,N-dimethylhexadecylammonium tri(3-chloro-4-methylphenyl)cyclohexylborate:

[0181] The preparation protocol for preparing tetrabutylammonium tri(3-chloro-4-methylphenyl)cyclohexylborate published in WO 2018 / 087064 was followed. Then, using cation 1, the general preparation protocol for triarylalkylborates with a cation of valence n=1 was followed. δ (ppm) (CDCl 3 )=-8.7 ppm 11 A slightly yellowish oil (5.0 g, 99% of theory) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.03V vs. SCE.

[0182] Preparation of photopolymer using N-(3-phenylpropyl)-N,N-dimethylhexadecylammonium tri(3-chloro-4-methylphenyl)cyclohexylborate (Example 11 in Table 2):

[0183] Following the general fabrication protocol for photopolymer films, the photopolymer was prepared using N-(3-phenylpropyl)-N,N-dimethylhexadecylammonium tri(3-chloro-4-methylphenyl)cyclohexylborate as a coinitiator.

[0184] Preparation of N-benzyl-N,N-dimethylhexadecylammonium diphenyl(3-chloro-4-methylphenyl)hexylborate:

[0185] R 101 =R 102 ≠R 103Bromobenzene (2 equivalents) and 3-chloro-4-methylbromobenzene (1 equivalent) were reacted with diisopropylhexylborate according to the general preparation protocol of tetrabutylammonium triarylalkylborate, . The reaction product was obtained after silica gel column chromatography (dichloromethane / toluene 70:30). The resulting tetrabutylammonium triarylhexylborate was then reacted with N-benzyl-N,N-dimethylhexadecylammonium chloride hydrate according to the general preparation protocol of triarylhexylborate with cation of valence n=1. δ(ppm) (CDCl 3 )=-10.4ppm 11 A colorless oil (0.68 g, 76% of theory over two steps) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.04V vs. SCE.

[0186] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium diphenyl(3-chloro-4-methylphenyl)hexylborate (Example 12 in Table 2):

[0187] Following the general fabrication protocol for photopolymer films, photopolymers were prepared using N-benzyl-N,N-dimethylhexadecylammonium diphenyl(3-chloro-4-methylphenyl)hexylborate as a coinitiator.

[0188] Preparation of N-benzyl-N,N-dimethylhexadecylammonium diphenyl(4-fluorophenyl)hexylborate:

[0189] R 101 =R 102 ≠R 103Bromobenzene (2 equivalents) and 4-fluorobromobenzene (1 equivalent) were reacted with diisopropylhexylborate according to the general preparation protocol of tetrabutylammonium triarylalkylborate, where . The reaction product was obtained after silica gel column chromatography (dichloromethane / toluene 70:30). The resulting tetrabutylammonium triarylhexylborate was then reacted with N-benzyl-N,N-dimethylhexadecylammonium chloride hydrate according to the general preparation protocol of triarylalkylborate with cation of valence n=1. δ(ppm) (CDCl 3 )=-10.5ppm 11 A colorless oil (0.74 g, 34% of theory over two steps) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.06V vs. SCE.

[0190] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium diphenyl(4-fluorophenyl)hexylborate (Example 15 in Table 2):

[0191] Following the general fabrication protocol for photopolymer films, photopolymers were prepared using N-benzyl-N,N-dimethylhexadecylammonium diphenyl(4-fluorophenyl)hexylborate as a coinitiator.

[0192] Preparation of N-benzyl-N,N-dimethylhexadecylammonium tri(3-chloro-4-methylphenyl)-3-phenylpropylborate:

[0193] The preparation protocol for preparing tetrabutylammonium tri(3-chloro-4-methylphenyl)-3-phenylpropylborate published in WO 2018 / 087064 was followed. The resulting tetrabutylammonium triarylalkylborate was then reacted with N-benzyl-N,N-dimethylhexadecylammonium chloride hydrate according to the general preparation protocol for triarylalkylborate with cations of valence n=1. δ(ppm) (CDCl 3 )=-10.3ppm 11 A slightly yellowish oil (4.8 g, 99% of theory) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.11V vs. SCE.

[0194] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium tri(3-chloro-4-methylphenyl)-3-phenylpropylborate (Example 38 in Table 2):

[0195] Following the general fabrication protocol for photopolymer films, the photopolymer was prepared using N-benzyl-N,N-dimethylhexadecylammonium tri(3-chloro-4-methylphenyl)-3-phenylpropylborate as a coinitiator.

[0196] Preparation of tetrabutylammonium tri(4-fluorophenyl)dodecylborate:

[0197] The preparation protocol for preparing tetrabutylammonium tri(4-fluorophenyl)dodecylborate published in WO 2018 / 087064 was followed. δ (ppm) (CDCl 3 )=-10.4ppm 11 A colorless oil (8.9 g, 12% of theory) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.13V vs. SCE.

[0198] Preparation of photopolymer using tetrabutylammonium tri(4-fluorophenyl)dodecylborate (Example 41 in Table 2):

[0199] Following the general fabrication protocol for photopolymer films, the photopolymer was prepared using tetrabutylammonium tri(4-fluorophenyl)dodecylborate as a coinitiator.

[0200] Preparation of N-benzyl-N,N-dimethylhexadecylammonium tri(3-chloro-4-methylphenyl)hexylborate:

[0201] The preparation protocol published in WO 2018 / 099698 was followed. Calculated reduction potentials were calculated as E ox =1.15V vs. SCE.

[0202] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium tri(3-chloro-4-methylphenyl)hexylborate (Example 48 in Table 2):

[0203] Following the general fabrication protocol for photopolymer films, the photopolymer was prepared using N-benzyl-N,N-dimethylhexadecylammonium tri(3-chloro-4-methylphenyl)hexylborate as a coinitiator.

[0204] Preparation of N-benzyl-N,N-dimethylhexadecylammonium tri(3-chloro-4-methylphenyl)butylborate:

[0205] R 101 =R 102 =R 1033-Chloro-4-methylbromobenzene was reacted with diisopropylbutylborate according to the general protocol for the preparation of tetrabutylammonium triarylalkylborate, 3-chloro-4-methylbromobenzene was reacted with diisopropylbutylborate according to the general protocol for the preparation of triarylalkylborate with a cation of valence n=1. The resulting tetrabutylammonium triarylbutylborate was then reacted with N-benzyl-N,N-dimethylhexadecylammonium chloride hydrate according to the general protocol for the preparation of triarylalkylborate with a cation of valence n=1. δ(ppm)(CDCl 3 )=-10.6 ppm 11 A colorless oil (2.4 g, 24% of theory over two steps) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.15V vs. SCE.

[0206] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium tri(3-chloro-4-methylphenyl)butylborate (Example 49 in Table 2):

[0207] Following the general fabrication protocol for photopolymer films, the photopolymer was prepared using N-benzyl-N,N-dimethylhexadecylammonium tri(3-chloro-4-methylphenyl)butylborate as a coinitiator.

[0208] Preparation of tetrabutylammonium tri(4-chlorophenyl)hexylborate:

[0209] R 101 =R 102 =R 103 4-Chlorobromobenzene was reacted with diisopropylhexylborate according to the general preparation protocol of tetrabutylammonium triarylalkylborate, δ(ppm)(CDCl 3 )=-9.9 ppm 11 Colorless crystals (56 g, 50% of theory) were obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.17V vs. SCE.

[0210] Preparation of photopolymer using tetrabutylammonium tri(4-chlorophenyl)hexylborate (Example 56 in Table 2):

[0211] Following the general fabrication protocol for photopolymer films, the photopolymer was prepared using tetrabutylammonium tri(4-chlorophenyl)hexylborate as a coinitiator.

[0212] Preparation of N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium triphenylbutylborate:

[0213] Following the general protocol for the preparation of triarylalkylborates with a cation of valence n=1, tetrabutylammonium triphenylbutylborate (Karenz P3B) was reacted with N-benzyl-N,N-dimethylhexadecylammonium chloride hydrate to give N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium triphenylbutylborate. δ (ppm) (CDCl 3 )=-10.3ppm 11 A colorless amorphous solid (54 g, >99% of theory) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox = 1.00 V vs. SCE.

[0214] Preparation of photopolymer using N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium triphenylbutylborate (Example NEB1 in Table 2):

[0215] Following the general fabrication protocol for photopolymer films, photopolymers were prepared using N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium triphenylbutylborate as a coinitiator.

[0216] Preparation of N-benzyl-N,N-dimethylhexadecylammonium tri(3-chlorophenyl)hexylborate:

[0217] R 101 =R 102 =R 103 3-Chlorobromobenzene was reacted with diisopropylhexylborate according to the general protocol for the preparation of tetrabutylammonium triarylalkylborate, 3-chlorobromobenzene was reacted with diisopropylhexyl ... 3 )=-10.1 ppm 11 A colorless oil (2.5 g, 50% of theory over two steps) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.32V vs. SCE.

[0218] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium tri(3-chlorophenyl)hexylborate (Example NEB2 in Table 2):

[0219] Following the general fabrication protocol for photopolymer films, photopolymers were prepared using N-benzyl-N,N-dimethylhexadecylammonium tri(3-chlorophenyl)hexylborate as a coinitiator.

[0220] Preparation of N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium tri(4-trifluoromethylphenyl)hexylborate:

[0221] R 101 =R 102 =R 103 4-Bromobenzene trifluoride was reacted with diisopropylhexylborate according to the general protocol for the preparation of tetrabutylammonium triarylalkylborate, 1 ...3 )=-10.0 ppm 11 A colorless oil (2.5 g, 22% of theory over two steps) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.45V vs. SCE.

[0222] Preparation of photopolymer using N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium tri(4-trifluoromethylphenyl)hexylborate (Example NEB3 in Table 2):

[0223] Following the general fabrication protocol for photopolymer films, the photopolymer was prepared using N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium tri(4-trifluoromethylphenyl)hexylborate as a coinitiator.

[0224] [Example]

[0225] The oxidation potentials of various trialkylarylborates according to the invention and not according to the invention were determined using the software package GAMESS (G. M. J. Barca, C. Bertoni, L. Carrington, D. Datta, N. De Silva, J. E. Deustua, D. G. Fedorov, J. R. Gour, A. O. Gunina, E. Guidez, T. Harville, S. Irle, J. Ivanic, K. Kowalski, S. Leang, H. Li, W. L., J. J. Lutz, I. Magoulas, J. Mato, V. Mironov, H. Nakata, B. Q. Pham, P. Piecuch, D. Poole, S. R. Pruitt, A. P. Endell, L. B. Roskop, K. Ruedenberg, T. Sattasathuchana, M. W. Schmidt, J. Shen, L. Slipchenko, M. Sosonkina, V. Sundriyal, A. Tiwari, J. L. Galvez). The oxidation potentials of triarylalkylborates were calculated using the method described above for calculating the oxidation potentials of triarylalkylborates using the method described above (Vallejo, B. Westheimer, M. Wloch, P. Xu, F. Zahariev, MS Gordon; J. Chem. Phys. 152; 154102 (2020)). The results of these calculations are listed in the table below. In calculating the oxidation potentials, the cations of the corresponding trialkylarylborates are irrelevant, so the values ​​listed below are calculated based on the following general structure: [ka] (twenty four) (In the formula, K + or K 2+ represents any ammonium or phosphonium cation).

[0226] Table 1. Oxidation potentials of various triarylalkylborate anions calculated according to Equation (1), where the specific groups refer to the above general structure of Equation (24), and the oxidation potentials (V) are reported relative to a saturated calomel electrode in the solvent acetonitrile.

[0227] [Table 1] TIFF2025510495000033.tif231160TIFF2025510495000034.tif232160TIFF20255104950 00035.tif233160TIFF2025510495000036.tif230160TIFF2025510495000037.tif182164

[0228] Table 1a: Oxidation potentials of various triarylalkylborate anions calculated according to formula (III) (the specific groups refer to formula (III) in claim 6, the oxidation potentials are specified in [V] relative to a saturated calomel electrode in the solvent acetonitrile). [Table 1a] TIFF2025510495000039.tif234156TIFF2025510495000040.tif234156TIFF2025510495000041.tif23215 6TIFF2025510495000042.tif238156TIFF2025510495000043.tif236156TIFF2025510495000044.tif85160

[0229] Evaluation of the thermal stability of photopolymer films using coinitiators according to the present invention:

[0230] The requirement for the photopolymer film produced here is low performance loss in photoactivity after the temperature adjustment step, i.e. the transmittance of the photopolymer after the temperature adjustment step should not increase critically and at the same time the diffraction efficiency after hologram exposure should not decrease critically.

[0231] First, two samples were prepared in the same way for each example. The preparation involved first removing the laminate film of the photopolymer layer structure, and then laminating the resulting unprotected photopolymer face onto a glass sheet so that there was always a glass-photopolymer-substrate film layer structure. From one of these samples, later called the room temperature sample (RT), a transmission spectrum (T 1,RT ) was recorded directly without temperature adjustment. The second sample, later called the temperature-adjusted sample (Temp), was temperature-adjusted at 110 °C for 10 min in a drying oven. After the temperature adjustment step, the transmission spectrum (T 1,Temp ) were recorded from the samples as well. As a result, test holograms were written into the photopolymer layer of both samples with an 850 nm laser, using the laser settings as described above. The quality of the holograms was evaluated by the refractive index difference (Δn) between the exposed and unexposed surfaces in the samples, derived from the read diffraction efficiency. The thermal stability of the NIR-sensitive photopolymer was evaluated based on two criteria that must be absolutely met. The two achievement criteria are explained in detail below:

[0232] 1. Thermal stability evaluated according to the transmission loss T (T): the transmission T at the absorption maximum (here 830 nm) of the dye used after the temperature adjustment step of the Temp sample 1,Temp,830 of the transmittance T of the RT sample at the same wavelength 1,RT,830 The ratio of the transmittance to the transmittance at 1000 nm must be greater than 50%. The transmittance value here must be corrected for background absorption caused by turbidity, etc. (here the transmittance at 1000 nm is used as the reference value) (T 2,Temp,1000 ):

number

number

[0233] The following transmission and Δn values ​​were determined for some examples according to the invention and not according to the invention:

[0234] Table 2. Measured transmittance and Δn values ​​of examples according to the invention and not according to the invention, and the ratings calculated therefrom. 1,RT,830 : Transmittance of RT sample at 830 nm; T 1,Temp,830 : Transmittance of the Temp sample at 830 nm; T 2,Temp,1000 : background transmittance determined at 1000 nm; TS(T): evaluation of thermal stability by transmission loss; TS(Δn): evaluation of thermal stability by Δn. [Table 2] *Varied SCE in acetonitrile; calculated; based on triarylalkylborate used.

[0235] The results clearly show that the necessary thermal stability of the photopolymer is achieved with the triarylalkylborate salts according to the invention. It can therefore be assumed that the photopolymer is sufficiently thermally stable only if the calculated oxidation potential of the borate salt used is greater than 1.00 V and less than 1.32 V vs. SCE in acetonitrile. Thus, the use of all the borates listed in Table 1 as coinitiators in the photopolymer results in a thermally stable photopolymer according to the objectives of the invention. It is also noteworthy that the thermal stability of the photopolymer does not depend on the countercation of the borate salt used, as the comparison of Examples 3a-3d shows. A change in the alkyl group of the triarylalkylborate salt is also possible without losing the thermal stability of the photopolymer, as highlighted by Examples 11, 38, 48 and 49.

[0236] The non-inventive examples NEB1, NEB2 and NEB3 fail in at least one required property and are therefore not suitable for providing a photopolymer composition having the required properties.

Claims

1. a) a matrix polymer; and b) a writing monomer; and c) at least one photoinitiator system; and d) optionally at least one non-photopolymerizable component; and e) optionally with catalysts, radical stabilizers, solvents, additives and other auxiliaries and / or adjuvants; 1. A photopolymer composition comprising: said at least one photoinitiator system c) consisting of at least one dye and at least one coinitiator; At least one of the dyes has a structure according to formula (II). 【number】 (In the formula, R ２０５ is hydrogen, halogen, C １ ~C ４ Alkyl, C １ ~C ４ Alkoxy or NR ２１０ R ２１１ represents R ２０６ is hydrogen, halogen, C １ ~C ４ Alkyl, C １ ~C ４ Alkoxy or NR ２１２ R ２１３ represents R ２０１ ~R ２０４ and R ２１０ ~R ２１３ are each independently hydrogen, C １ ~C １６ Alkyl, C ４ ~C ７ Cycloalkyl, C ７ ~C １６ Aralkyl, C ６ ~C １０ represents an aryl or heterocyclic group, NR ２０１ R ２０２ , N.R. ２０３ R ２０４ , N.R. ２１０ R ２１１ and NR ２１２ R ２１３ represent, independently of one another, a 5- or 6-membered saturated ring bonded via N, which may further contain N or O and / or be substituted by non-ionic groups, R ２０７ ~R ２０９ are each independently hydrogen, C １ ~C １６ Alkyl, C ４ ~C ７ Cycloalkyl, C ７ ~C １６ Aralkyl, C ６ ~C １０ represents aryl, halogen or cyano; two optional bridging groups X １ and X ２ are each independently SiR ２１４ R ２１５ , C.R. ２１６ R ２１７ or O, R ２１４ ~R ２１７ are each independently hydrogen or C １ ~C ４ represents alkyl, An － represents an anion selected from halide, perchlorate, tetrafluoroborate, hexafluorophosphate, hexafluoroantimonate, tetraarylborate, triarylalkylborate, nitrate, cyanide, tosylate, trifluoromethylsulfonate, bis(trifluoromethyl)sulfonimide, azide, methylsulfonate, phosphate, hydrogen phosphate, dihydrogen phosphate, sulfate, hydrogen sulfate, optionally substituted carboxylate, optionally substituted organic mono- or di-sulfonate, or optionally substituted organic mono- or di-carboxylate. and The at least one coinitiator has a calculated oxidation potential, determined according to the following formula (1), by quantum mechanical calculation of Gibbs energies at 298 K of the ground and oxidized states of the triarylalkylborate after geometry optimization, consisting of conformer energy minimization using the AM1 force field, followed by ab initio conformer energy calculation based on previously determined molecular geometric coordinates in the solvent acetonitrile under solvent field correction by the PCM method, in the range of 1.01 V to 1.31 V versus a saturated calomel electrode (SCE) in acetonitrile: [Equation 1] and the at least one coinitiator is a triarylalkylborate salt; Photopolymer composition. [Equation 2]

2. The at least one dye is R ２０５ But hydrogen, C １ ~C ４ Alkyl, or NR ２１０ R ２１１ represents R ２０６ But hydrogen, C １ ~C ４ Alkyl, or NR ２１２ R ２１３ represents R ２０１ ~R ２０４ and R ２１０ ~R ２１３ each independently represent hydrogen, methyl, ethyl, propyl, butyl, chloroethyl, cyanomethyl, cyanoethyl, methoxyethyl, cyclopentyl, cyclohexyl, cyclohexylmethyl, benzyl, phenyl, tolyl, anisyl or chlorophenyl, or NR ２０１ R ２０２ , N.R. ２０３ R ２０４ , N.R. ２１０ R ２１１ and NR ２１２ R ２１３ are each independently pyrrolidino, piperidino, morpholino or N-methylpiperazino, R ２０７ ~R ２０９ represents hydrogen, two optional bridging groups X １ and X ２ are independently SiMe ２ or represents O, The photopolymer composition of claim 1 having the structure of formula (II):

3. The at least one dye has the structure of formula (XIX): 【Chemistry 2】 (In the formula, R ２０１ ~R ２０４ and R ２１０ ~R ２１３ each independently represents hydrogen or methyl, ethyl, propyl or butyl) 10. The photopolymer composition of claim 1, having

4. The at least one dye according to formula (II) present is an anion (An － 10. The photopolymer composition of claim 1, wherein said aryl group is an organically substituted sulfonate.

5. the at least one coinitiator is a triarylalkylborate salt according to formula (III) 【Transformation 3】 (In the formula, A represents a methylene group or an optionally substituted methine group; R １００ may form a ring with up to 10 members having the formula R １００ is hydrogen or C optionally substituted by hydroxyl and / or alkoxy and / or acyloxy and / or halogen; １ ~C ２０ Alkyl, C ３ ~C ２０ Alkenyl, C ３ ~C ２０ Alkynyl, C ５ ~C ７ Cycloalkyl or C ７ ~C １３ is an aralkyl group, R １０１ , R １０２ and R １０３ are respectively, C １ ~C ２０ Alkyl, C ３ ~C ５ Alkenyl, C ３ ~C ５ Alkynyl, C ５ ~C ７ Cycloalkyl or C ７ ~C １３ Aralkyl group, halogen, cyano, trifluoromethyl, trichloromethyl, difluoromethyl, dichloromethyl, trifluoromethylthioyl, trichloromethylthioyl, C １ ~C １２ Alkoxy, trifluoromethoxy, trichloromethoxy, C １ ~C １２ represent up to five groups independently selected from alkylthioyl, thioyl, difluoromethoxy, difluoromethylthioyl, carboxyl, carbonyl, 2-, 3-, or 4-pyridyl, or any substituted aryl group, or hydrogen, wherein the groups are selected such that the group-dependent calculated oxidation potential of the triarylalkylborate (III) is in the range of 1.01 V vs. SCE to 1.31 V vs. SCE in acetonitrile; K ｎ＋ represents an optionally substituted organic cation of valence n based on nitrogen, phosphorus, oxygen, sulfur and / or iodine, n represents 1, 2 or 3) The photopolymer composition of claim 1 comprising:

6. R １００ is C １ ~C ２０ Alkyl, C ５ ~C ７ Cycloalkyl or C ７ ~C １３ represents an aralkyl group, R １０１ , R １０２ and R １０３ are respectively, C １ ~C ４ Alkyl, halogen, cyano, trifluoromethyl, C １ ~C ４ 10. The photopolymer composition of claim 1, wherein R represents one or two groups independently selected from an alkoxy or an optionally substituted aryl group or hydrogen.

7. R １００ is C ３ ~C １２ represents an alkyl group, and R １０１ , R １０２ and R １０３ are C １ ~C ４ 10. The photopolymer composition of claim 1, which exhibits 1 to 2 meta or para groups independently selected from alkyl groups and halogen substituents.

8. 2. The photopolymer composition of claim 1, wherein the organic cation Kn+ of the triarylalkylborate salt is a nitrogen- or phosphorus-based monovalent or divalent cation, preferably a nitrogen-based monovalent or divalent cation, particularly preferably a monovalent ammonium cation.

9. 2. The photopolymer composition of claim 1, wherein the at least one coinitiator has an oxidation potential in acetonitrile between 1.01 V vs. SCE and 1.20 V vs. SCE, preferably between 1.02 V and 1.17 V vs. SCE in acetonitrile, and more preferably between 1.02 V and 1.15 V vs. SCE.

10. At least the following layers: A. A substrate layer A, which may be part of a further layer structure; B. A photopolymer layer B formed from the polymer composition of any one of claims 1 to 9, and C. A top layer C that may be part of a further layer structure A layer structure containing

11. At least the following layers: A. A substrate layer A, which may be part of a further layer structure; B'. An exposed photopolymer layer B' prepared from the photopolymer composition of any one of claims 1 to 9 by curing with light, and C. A top layer C that may be part of a further layer structure A layer structure containing

12. A holographic medium containing or obtainable using a photopolymer composition according to any one of claims 1 to 9.

13. 13. The holographic medium according to claim 12, characterized in that the holograms are selected from the group consisting of reflection, transmission, in-line, off-axis, full aperture transfer, white light transmission, Denisyk, off-axis reflection or edge-lit holograms and holographic stereograms, preferably reflection, transmission or edge-lit holograms or a combination of at least two thereof, and it is likewise possible to integrate a combination of these hologram types or several holograms of the same type independent of one another in the same volume of the holographic medium (multiplexing).

14. 13. An optical display comprising the holographic medium of claim 12.

15. 13. Use of the holographic medium according to claim 12 in a medium for producing chip cards, identity cards, 3D images, product protection tags, labels, banknotes or holographic optical elements, in particular for optical displays or for realising methods selected from the group consisting of eye tracking, sensing, LIDAR, augmented reality, head mounted displays and virtual reality applications, in particular in the near infrared range, and combinations of at least two thereof.

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