Thermally stable photopolymer in the visible spectrum and photopolymer composition containing same - Patents.com

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 auxiliary and / or additional materials, wherein the at least one photoinitiator system c) consists of at least one colorant and at least one coinitiator, at least one of the colorants having a structure according to Formula (I). [Formula 1] TIFF2025507602000048.tif40150

Description

[Technical field]

[0001] The present invention relates to a photopolymer composition using a selected co-initiator, in particular a triarylalkylborate salt as a co-initiator with a selected oxidation potential, and also to a holographic medium and a hologram produced therefrom.The present invention further relates to a method for producing a specific co-initiator and also to the co-initiator obtainable by this method, as well as to a method for producing a holographic medium using a specific photopolymer composition comprising a specific co-initiator, and to a holographic medium obtainable using a photopolymer composition according to the present invention.The present invention further relates to a layer structure comprising a holographic medium according to the present invention and a specific triarylalkylborate salt, which is also suitable as a co-initiator.Furthermore, a method for calculating the oxidation potential of a specific co-initiator against a saturated calomel electrode in acetonitrile is presented.

[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, one or more acrylate-based writing monomers, 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 therefore 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 the first mentioned type of photopolymer film may consist of type II photoinitiators. In these type II photoinitiators, triarylalkylborate salts may be combined as co-initiators 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 UV, visible or near infrared light. The preparation of such PIS is widely described in the prior art, and selected tetraalkylammonium triarylalkylborates and dyes as co-initiators are commercially available. Moreover, such PIS have already been used in photopolymers and holographic media, and their advantages have been described. For example, EP 2638544 describes a dye of formula (I), for example, which, together with tris-(3-chloro-4-methylphenyl)hexylborate anion, can be utilized as a PIS for photocurable materials: [ka] In addition, EP 3058423 describes a wide selection of triarylalkylborate salts suitable for photopolymers in combination with the dye of formula (I). The selection ranges from anions with electron-rich aromatics, such as tris(4-tert-butylphenyl)hexylborate anion, to anions with highly electron-depleted aromatics, such as tris(4-trifluoromethylphenyl)hexylborate anion. However, in all these PIS, such as those described in EP 3058423, for example dye-coinitiator combinations and photopolymer compositions containing dyes and triarylalkylborate salts, no attention is paid to the thermal stability of the formulation in the unexposed state. In fact, many of the photopolymer compositions disclosed in EP 3058423 do not have sufficient thermal stability in the unexposed state. This means that at certain thermal loads, such as storage at 140°C for 30 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]

[0008] [Patent Document 1] International Publication No. 2008 / 125229 [Patent Document 2] European Patent No. 2638544 [Patent Document 3] European Patent No. 3058423 Summary of the Invention [Problem to be solved by the invention]

[0009] 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. 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 bleachability or 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]

[0010] 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) consists of at least one dye and at least one coinitiator, At least one of the dyes has a structure according to formula (I). [ka] (In the formula, R 201 is optional and, if present, is hydrogen, C1-C 16 Alkyl, C3-C6 alkenyl, C5-C7 cycloalkyl or C7-C 16 Aralkyl or C6~C 10 represents aryl, R 203 is C1~C 16 Alkyl, C3-C6 alkenyl, C5-C7 cycloalkyl or C7-C 16 Aralkyl or C6~C 10 represents aryl, R 202 is hydrogen, C1-C 16 Alkyl, C3-C6 alkenyl, C5-C7 cycloalkyl or C7-C 16 Aralkyl, C6~C 10 represents aryl or hetaryl, R 204 represents hydrogen, C1-C4 alkyl, C1-C4 alkoxy, halogen, cyano, nitro or C1-C4 alkoxycarbonyl; A is X 1 and X 2 And X 1 and X 2 represents, together with the C atom bonded thereto, a 5- or 6-membered aromatic or quasiaromatic or partially hydrogenated heterocycle which may contain 1 to 4 heteroatoms and / or may be benzo- or naphtho-fused and / or may be substituted by non-ionic groups, X 2 represents N, O or S, preferably N, X 1 is O, S, CR 205 R 206 or -CH=CH-, preferably CR 205 R 206 represents R 205 and R 206 are each independently C1-C4 alkyl, C3-C6 alkenyl, C4-C7 cycloalkyl, C7-C 10 represents aralkyl or C6 aryl, 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 1.16 V to 1.37 V versus a saturated calomel electrode (SCE) in acetonitrile, determined according to the following formula (1) by quantum mechanical calculation of the Gibbs energies at 298 K of the ground and oxidized states of the coinitiators, in particular 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:

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[0011] 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. The matrix polymer a) suitable for the photopolymer composition can in particular be crosslinked, particularly preferably three-dimensionally crosslinked.

[0012] 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).

[0013] 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.

[0014] 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.

[0015] 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, isomeric bis(isocyanatomethyl)cyclohexane, 2,4- and / or 2,6-diisocyanato-1-methylcyclohexane (hexahydrotolylene 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.

[0016] 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.

[0017] 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.

[0018] Very particular preference is given to polyisocyanates having an isocyanurate, uretdione and / or iminooxadiazinedione structure, and biurets based on HDI or mixtures thereof.

[0019] 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 b1).

[0020] 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.

[0021] 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.

[0022] Examples of suitable alcohols include, for example, C2-C 12 These include all polyhydric alcohols such as diols, the isomeric cyclohexanediols, glycerol or any mixtures of these with each other.

[0023] Suitable polycarbonate polyols are available in a manner known per se by reacting organic carbonates or phosgene with diols or diol mixtures.

[0024] Suitable organic carbonates are dimethyl carbonate, diethyl carbonate and diphenyl carbonate.

[0025] 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.

[0026] Suitable polyether polyols are the polyaddition products, optionally in a block structure, of cyclic ethers onto OH- or NH-functional starter molecules.

[0027] Suitable cyclic ethers are, for example, styrene oxide, ethylene oxide, propylene oxide, tetrahydrofuran, butylene oxide, epichlorohydrin, and any mixtures thereof.

[0028] 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.

[0029] 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 with 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 include all the respective linear and branched C3 and C4 isomers.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] All of the abovementioned isocyanate-reactive compounds aII1) can be mixed with one another if desired.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] Suitable polyfunctional isocyanate-reactive compounds of component aII) are, for example, the compounds aII1) mentioned above.

[0042] 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.

[0043] 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.

[0044] Suitable acrylate writing monomers are in particular compounds of the general formula (III) [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 straight-chain, branched, cyclic or heterocyclic organic moiety which is unsubstituted or otherwise optionally substituted by heteroatoms. More preferably, R 8 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] It is also possible for the writing monomer 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] Within the context of the present invention, type II photoinitiators are preferably used.

[0056] Such photoinitiator systems are described in principle in EP 0 223 587 and preferably consist of a mixture of one or more dyes.

[0057] Suitable dyes for component cI) which form type II photoinitiators together with the compounds of formula (II) are the cationic dyes described therein in combination with the anions described in WO2012062655.

[0058] Cationic dyes are preferably understood to mean those of the following classes: acridine dyes, xanthene dyes, thioxanthene dyes, phenazine dyes, phenoxazine dyes, phenothiazine dyes, tri(hetaryl)arylmethane dyes, in particular diamino- and triamino(hetaryl)arylmethane dyes, mono-, di-, tri- and pentamethine cyanine dyes, hemicyanine dyes, external cationic merocyanine dyes, external cationic neutrocyanine dyes, zeromethine dyes, in particular naphtholactam dyes, streptocyanine dyes. Dyes of this type are 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, and T. Gessner, U. Mayer in Ullmann's Encyclopedia of Industrial Chemistry, Triarylmethane and Diarylmethane Dyes, Wiley-VCH Verlag, 2000.

[0059] Particularly preferred are phenazine dyes, phenoxazine dyes, phenothiazine dyes, tri(hetaryl)arylmethane dyes, especially diamino- and triamino(hetaryl)arylmethane dyes, mono-, di-, tri- and pentamethine cyanine dyes, hemicyanine dyes, zeromethine dyes, especially naphtholactam dyes, streptocyanine dyes.

[0060] Examples of cationic dyes include Astrazon Orange G, Basic Blue 3, Basic Orange 22, Basic Red 13, Basic Violet 7, Methylene Blue, New Methylene Blue, Azure A, 2,4-diphenyl-6-(4-methoxyphenyl)pyrylium, Safranin O, Astraphloxine, Brilliant Green, Crystal Violet, Ethyl Violet, and Thionin.

[0061] The preferred anion (An - ) is especially suitable for C8~C 25 -Alkanesulfonates, preferably C 13 ~C 25 -Alkanesulfonates, C3-C 18 -Perfluoroalkanesulfonates, C4-C 18 -Perfluoroalkanesulfonates (with at least 3 hydrogen atoms in the alkyl chain), C9-C 25 -Alkanoates, C9~C 25 -Alkenoates, C8~C 25 -Alkyl sulfates, preferably C 13 ~C 25 -Alkyl sulfate, C8~C 25 -Alkenyl sulfate, preferably C 13 ~C 25 -Alkenyl sulfates, C3-C 18 -Perfluoroalkyl sulfates, C4~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-C4-C 25 -Alkyl-, C5-C7-cycloalkyl-, C3-C8-alkenyl- or C7-C 11 -Aralkyl-sulfosuccinates, bis-C2-C substituted with at least 8 fluorine atoms 10 -Alkyl-sulfosuccinates, C8-C 25 -Alkyl-sulfoacetate, halogen, C4~C 25-alkyl, perfluoro-C1-C8-alkyl and / or C1-C 12 -benzenesulfonate substituted by at least one group of the alkoxycarbonyl group, nitro, cyano, hydroxy, C1-C 25 -Alkyl, C1-C 12 -Alkoxy, amino, C1-C 12 -Naphthalene or biphenylsulfonate, optionally substituted by alkoxycarbonyl or chlorine, nitro, cyano, hydroxy, C1-C 25 -Alkyl, C1-C 12 -Alkoxy, C1-C 12 -Benzene, naphthalene or biphenyl disulfonate optionally substituted by alkoxycarbonyl or chlorine, dinitro, C6-C 25 -Alkyl, C4-C 12 -alkoxycarbonyl, benzoates substituted by benzoyl, chlorobenzoyl or toluoyl, anions of naphthalenedicarboxylic acids, diphenyl ether disulfonates, sulfonated or sulfated aliphatic C1-C8-alcohols or glycerol, which may be at least monounsaturated C8-C 25 -Fatty acid esters, bis-(sulfo-C2~C6-alkyl)-C3~C 12 -Alkanedicarboxylic acid esters, bis-(sulfo-C2-C6-alkyl)-itaconic acid esters, (sulfo-C2-C6-alkyl)-C6-C 18 -alkane carboxylic acid esters, (sulfo-C2-C6-alkyl)-acrylic acid- or methacrylic acid esters, triscatechol phosphates which may be substituted by up to 12 halogen groups, tetraphenylborates in which the phenyl- or phenoxy groups may be substituted by halogen, C1-C4-alkyl and / or C1-C4-alkoxy, cyanotriphenylborates, tetraphenoxyborates, C4-C 12 -Anions of the group of alkyl-triphenylborate, one or two C1-C 12 - C4-C optionally substituted at B and / or C atoms by alkyl or phenyl groups 12-Alkyl-trinaphthyl borate, tetra-C1-C 20 -Alkoxyborates, 7,8- or 7,9-dicarbanidoundecaborates (1-) or (2-), dodecahydrodicarbadodecaborates (2-) or B-C1 to 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.

[0062] Within the context of the present invention, the anions described in WO2012062655 are preferably used.

[0063] 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.

[0064] Suitable co-initiators of component cII) for type II photoinitiator systems are the borate salts, in particular the triarylalkylborate salts, described in WO 2015 / 055576. Other co-initiators can be pentacoordinate silicates or tertiary aromatic amines.

[0065] 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.

[0066] Preferably, the urethane has the general formula (XVI) [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.

[0067] In a preferred embodiment of the photopolymer composition, at least one dye according to the structure of formula (I) has the following group: R 201 is optional and, when present, represents hydrogen, methyl, ethyl, propyl, butyl, benzyl or phenethyl; R 203 represents methyl, ethyl, propyl, butyl, benzyl or phenethyl; R 202 represents hydrogen, methyl or phenyl; R 204 represents hydrogen, methyl, ethyl, cyclohexyl, phenyl, tolyl, anisyl or chlorophenyl; A is X 1 and X 2as well as pyridin-2-ylene or pyridin-4-ylene, quinolin-2-ylene or quinolin-4-ylene, 1,3-thiazol-2-ylene, 1,3-thiazolin-2-ylene, benzothiazol-2-ylene, 1,3,4-thiadiazol-2-ylene, 1,3-oxazolin-2-ylene, benzoxazol-2-ylene, imidazol-2-ylene, imidazolin-2-ylene, benzimidazol-2-ylene, pyrroline- 2-ylene, 1,3,4-triazol-2-ylene, 3H-indol-2-ylene or quinoxalin-2-ylene, in which in the case of imidazol-2-ylene, imidazolin-2-ylene and benzimidazol-2-ylene both N atoms are replaced by R41b and in the case of 1,3,4-thiadiazol-2-ylene the substituents are selected from the group consisting of dimethylamino, diethylamino, dipropylamino, dibutylamino, N-methyl-N-cyanoethylamino, bis(cyanoethyl)amino, N-methyl-N-phenylamino, pyrrolidino, piperidino and morpholino, or A is X 1 and X 2 and together with the C atom bonded therebetween represent 2H-pyran-2-ylene, 4H-pyran-4-ylene, 2H-thiopyran-2-ylene, 4H-thiopyran-4-ylene, which are substituted by two radicals of the group phenyl, tolyl or anisyl.

[0068] In a preferred embodiment of the photopolymer composition, at least one dye has the structure of formula (XVII): [ka] (In the formula, R 201 and R 203 each independently of the others is methyl, ethyl or benzyl, preferably methyl, R 202 represents hydrogen, methyl or phenyl, preferably phenyl). has.

[0069] In a preferred embodiment of the photopolymer composition, at least one dye according to formula (I) or formula (XVII) present is an anion (An - ) has an organic substituted sulfonate.

[0070] In a preferred embodiment of the photopolymer composition, at least one coinitiator is a triarylalkylborate salt.

[0071] In a preferred embodiment of the photopolymer composition, the coinitiator is preferably a triarylalkylborate according to formula (II) having a calculated oxidation potential in acetonitrile between 1.16 V vs. SCE and 1.37 V vs. SCE [ka] (In the formula, A represents a methylene group or an optionally substituted methine group; R 100 may form a maximum 10-membered ring having the formula: R 100 is a C1-C alkyl group optionally substituted with hydrogen or hydroxyl and / or alkoxy and / or acyloxy and / or halogen; 20 Alkyl, C3-C 12 Alkyl groups, C3-C 20 Alkenyl, C3-C 20 Alkynyl, C5-C7 cycloalkyl or C7-C 13 represents an aralkyl group, R 101 , R 102 and R 103 are C1 to C 10 Alkyl, C3-C5 alkenyl, C3-C5 alkynyl, C5-C7 cycloalkyl or C7-C 13up to five groups independently selected from aralkyl groups, halogen, cyano, trifluoromethyl, trichloromethyl, difluoromethyl, dichloromethyl, trifluoromethylthioyl, trichloromethylthioyl, C1-C4 alkoxy, trifluoromethoxy, trichloromethoxy, C1-C4 alkylthioyl, thioyl, difluoromethoxy, difluoromethylthioyl, carboxyl, carbonyl, 2-, 3-, or 4-pyridyl, or any substituted aryl group or hydrogen; 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:

[0072] In this embodiment of the photopolymer composition, A is preferably a methylene group.

[0073] In a preferred embodiment of the photopolymer composition, for the triarylalkyl borate of structure (II), R 100 C1~C 20 Alkyl, C3-C 12 Alkyl, C5-C7 cycloalkyl or C7-C 13 represents an aralkyl group, R 101 , R 102 and R 103 each represents one or two groups independently selected from C1-C4 alkyl, halogen, cyano, trifluoromethyl, C1-C4 alkoxy or optionally substituted aryl groups or hydrogen. 101 Group, R 102 Groups and R 103 At least one group selected from the group is not hydrogen. Preferably, at least two R 101 Group, two R 102 Group and two R 103 At least one of the groups is located in the meta or para position relative to the B atom, particularly preferably in the para position. 101 Group, two R 102 Group and two R103 In the case of the group, the two groups are respectively meta and para to the atom B. In this embodiment of the photopolymer composition, A preferably represents a methylene group.

[0074] Further, for the triarylalkyl borate of structure (II), R 100 preferably represents a C3-C5 alkyl group, A is preferably a methylene group, and R 101 Group, R 102 Groups and R 103 At least one of the radicals represents in each case 1 to 2 meta- and / or para-positioned radicals selected independently from C1-C4 alkyl radicals and halogen substituents, preferably at least R 102 and / or R 103 represent, 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.

[0075] In another preferred embodiment of the photopolymer composition, for the triarylalkyl borate of structure (II), R 100 C3~C 12 represents an alkyl group, R 101 , R 102 , and R 103 are each independently one or two meta- or para-positioned groups selected from the group consisting of C1-C4 alkyl groups and halogen substituents, and preferably at least R 102 and / or R 103 represents a halogen substituent. 101 Group, two R 102 Group and two R 103 In the case of the R group, the two groups are preferably in the meta and para positions in each case relative to the B atom. 102 and / or R 103 is a halogen substituent. Preferably, in this embodiment, A is a methylene group.

[0076] Further, preferably, for the triarylalkyl borate of structure (II), R 100 represents a C3-C5 alkyl group, A is preferably a methylene group, and R 101 , R 102 , and R 103 each represents one or two meta- and / or para-position groups independently selected from a C1-C4 alkyl group and a halogen substituent, and preferably at least R 102 and / or R 103 represents a halogen substituent.

[0077] The following triarylalkylborate salts are quite particularly preferred, in which each K + is any organic cation based on nitrogen, phosphorus, oxygen, sulfur or iodine: [ka]

[0078] 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.

[0079] In a preferred embodiment of the photopolymer composition, at least one coinitiator has an oxidation potential in acetonitrile in the range between 1.20 V vs. SCE and 1.36 V vs. SCE, preferably between 1.25 V vs. SCE and 1.35 V vs. SCE, particularly preferably between 1.28 V vs. SCE and 1.34 V vs. SCE.

[0080] Preferably, K +is an organic cation of valence n based on nitrogen, such as ammonium, pyridinium, pyridazinium, pyrimidinium, pyrazinium, imidazolium, pyrrolidinium ions, 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.

[0081] 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.

[0082] 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.

[0083] More preferably, K + are C4 to C6 which may be substituted identically or differently. 14 Alkyl, C6-C 10 Aryl, C7-C 12 Organic cations of valence n based on sulfur, such as sulfonium salts which may have arylalkyl or C5-C6 cycloalkyl groups and / or may have oligomeric or polymeric repeating linking units to build up, with 1≦n≦3, or onium compounds of sulfur, such as thiopyrylium cations or polymeric cations having the substitution patterns described.

[0084] More preferably, K +are the same or different optionally substituted C1 to C 22 Alkyl, C6-C 14 Aryl, C7-C 15 Organic cations of valence n based on iodine such as onium compounds of iodine which may have arylalkyl or C5-C7 cycloalkyl groups 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.

[0085] The photoinitiator system c) 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.

[0086] 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, P.K.T. 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 the wavelength range of 400 to 1200 nm. Finally, it is particularly preferred if the photopolymer composition contains a photoinitiator suitable for each laser light color.

[0087] Another subject of the invention is a photopolymer, in particular comprising a photopolymer composition comprising a matrix polymer, a write monomer and a photoinitiator system which further comprises a compound of formula (XVI).

[0088] The statements made above regarding the photopolymer compositions according to the invention with regard to the further preferred embodiments apply analogously to said photopolymers.

[0089] 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:

[0090] 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 photocured 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:

[0091] 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.

[0092] 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.

[0093] 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.

[0094] It is possible to expose holographic information onto such a holographic medium.

[0095] Another subject of the invention relates to a holographic medium containing a photopolymer composition according to the invention, which can be processed into a hologram by a suitable exposure process for optical applications in the NIR range as well as the entire visible and near UV range (350-1500 nm).

[0096] Holograms 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 and transmission holograms are preferred.

[0097] 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).

[0098] 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, wave guides, optical deflectors, projection lenses and / or masks. Combinations of these optical functions can also be combined independently of one another in a hologram. In many cases, these optical elements exhibit frequency selectivity depending on how the hologram is exposed and what dimensions it has.

[0099] Another subject of the invention relates to an optical display comprising a holographic medium according to the invention.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] Holograms are obtainable from the holographic medium according to the invention by appropriate exposure. [Brief description of the drawings]

[0104] [Figure 1] FIG. 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=457 nm (DPSS 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=-22°, β0=42° are the angles of incidence of the coherent beam measured outside the (media) Sample, and RD=reference direction of the turntable.)

[0105] [Diagram 2] FIG. 14 shows the measured transmitted power PT (here for Example 27b) 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

[0106] The following examples are used to illustrate the invention without limiting it thereto.

[0107] Measurement method:

[0108] OH Numbers: The specified OH numbers were determined according to DIN 53240-2. NCO value: The specified NCO values ​​(isocyanate content) were determined in accordance with DIN EN ISO 11909.

[0109] Measurement of holographic properties DE and Δn of holographic media by two-beam interference in reflection configuration:

[0110] A spatial filter (SF) was used, together with a collimator lens (CL), to transform the beam of a blue DPSS laser with an emission wavelength λ in vacuum of 457 nm into a parallel uniform beam. The final cross section of the signal and reference beams is 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 0.5 mW and the power of the signal beam was set to 0.65 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 (α0) is -22.0° and the angle of incidence of the signal beam (β0) is 42.0°. The angles are measured proceeding from the sample perpendicular to the beam direction. Thus, according to Figure 1, α0 has a negative sign and β0 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 225 nm (the refractive index of the medium was assumed to be about 1.504).

[0111] Figure 1 shows the holographic experimental setup where the diffraction efficiency (DE) of the media was measured. Figure 1 represents the geometry of the Holographic Media Tester (HMT) at λ = 457 nm (DPSS 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 = -22°, β0 = 42° are the angles of incidence of the coherent beam measured outside the (media) sample, and RD = reference direction of the turntable).

[0112] The holograms were written into the media in the following manner: · 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°. min From Ω max The angle range was swept from 0 to 1. Ω is measured from the sample perpendicular to the reference direction of the turntable. The reference direction of the turntable is obtained when, during the writing of the hologram, the angles of incidence of the reference and signal beams have the same absolute value, i.e. α0=-32° and β0=32°. Then, Ω recoding = 0°. Therefore, if α0 = -22.0° and β0 = 42.0°, then Ω recoding is 10°. In general, for the interference field during writing ("recording") a hologram:

number

number

number

[0114] 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.

[0115] 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.

[0116] The refractive index contrast Δn and thickness d of the photopolymer layer were then determined for the measured Bragg curves and 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 α0' or the corresponding angle Ω of the turntable at which the maximum diffraction efficiency is achieved is reconstructionα0 or the corresponding Ω recoding This changes the Bragg condition. This change is taken into account in the evaluation process, which is described below:

[0117] All geometric quantities that refer to the written hologram and not to the interference pattern can be expressed as quantities involving prime numbers.

[0118] On the Bragg curve η(Ω) of a reflection hologram by Kogelnik:

number

number

number

number

number

[0119] Therefore, the maximum diffraction efficiency (DE=η max ) becomes:

number

number

[0120] 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.

[0121] 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'.

[0122] 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.

[0123] 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 calculated by the power (P r = 1.31mW reference beam and P s = 1.69 mW signal beam), exposure time t, and diameter of the iris diaphragm (0.4 cm) give:

number

[0124] Calculation of the reduction potential of triarylalkylborates:

[0125] Absolute reduction potential referred to the saturated calomel electrode

number

number

number

number

number

number

[0126] Equation (20) can also be expressed as follows (Equation (1)) after inserting the constants mentioned above:

number

[0127] 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 coinitiator, specifically a 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).

[0128] material:

[0129] 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.

[0130] Polyol 1 was prepared as described in WO2015091427 with an OH number of 56.8.

[0131] Desmodur® N 3900 Product of Covestro AG, Leverkusen, Germany, hexane diisocyanate based polyisocyanate, iminooxadiazinedione content of at least 30%, NCO content: 23.5%.

[0132] Urethane acrylate 1 (phosphorothioyltris(oxybenzene-4,1-diylcarbamoyloxyethane-2,1-diyl)trisacrylate, [1072454-85-3]) was prepared as described in WO2015091427.

[0133] Urethane acrylate 2, (2-({[3-(methylsulfanyl)phenyl]carbamoyl}oxy)ethyl prop-2-enoate, [1207339-61-4]) was prepared as described in WO2015091427.

[0134] Dye 1 (1,3,3-trimethyl-2-[2-(1-methyl-2-phenyl-1H-indol-3-yl)ethenyl]-3H-indolium bis(2-ethylhexyl)sulfosuccinate)) was prepared as described in WO2012062655.

[0135] 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.

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

[0137] BYK®-310 silicone-containing surface additive, product of BYK-Chemie GmbH, Wesel, Germany.

[0138] Tinuvin® 400 UV absorber, a product of BASF SE, Ludwigshafen, Germany.

[0139] Cation 2 (N1,N 22 -Dihexadecyl-N1,N1,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.

[0140] Synthesis protocol:

[0141] Preparation of N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium chloride (cation 1):

[0142] 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). [ka]

[0143] R 101 =R 102 =R 103 Preparation protocol of tetrabutylammonium triarylalkylborate:

[0144] 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.) were introduced into a solvent mixture consisting of anhydrous toluene and anhydrous THF (5.8:1, 1.9 M). This mixture was stirred at room temperature for 30 min. Then, the corresponding bromoaromatic compound (3 eq.) was added dropwise to the mixture without first dilution until the subsequent exotherm signaled the start of the reaction, although a maximum of 10% of the undiluted bromoaromatic compound was used for this purpose. The remaining bromoaromatic compound was 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 did not exceed 45 ° C. After the end of the addition, the reaction solution was heated under reflux until the magnesium was completely dissolved or for 1 h. The reaction solution was cooled to room temperature and discharged into a mixture of ice water and tetrabutylammonium bromide (1 eq.). The mixture was stirred for 1 h and then the organic phase was separated. The organic phase was washed with water until the halide test (HNO3 (aq. 10%) + AgNO3) was negative. The solvent was removed in vacuum on a rotary evaporator and the crude product was recrystallized from methanol.

[0145] R 101 =R 102 ≠R 103 Preparation protocol of tetrabutylammonium triarylalkylborate:

[0146] 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.) were introduced into a solvent mixture consisting of anhydrous toluene and anhydrous THF (4:1, 1.9 M). This mixture was stirred at room temperature for 30 min. Then, the first bromoaromatic compound (1 eq.) was added dropwise to the mixture, initially undiluted, until the subsequent exotherm signaled the start of the reaction, although a maximum of 10% of the undiluted bromoaromatic compound was used for this purpose. The remaining bromoaromatic compounds were 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 did not exceed 45 ° C. After the addition was complete, the reaction solution was stirred at room temperature for 1 h. The corresponding second bromoaromatic compound was then added dropwise to the mixture, initially undiluted, until the subsequent exotherm signaled the start of the reaction, although up to 10% of the undiluted bromoaromatic compound was 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) was again added dropwise to the reaction solution at such a rate that the reaction temperature did not exceed 45 ° C. After the end of the addition, the reaction solution was heated under reflux until the magnesium was completely dissolved or for 1 h. The reaction solution was cooled to room temperature and drained into a mixture of ice water and tetrabutylammonium bromide (1 equivalent). The mixture was stirred for 1 h and the organic phase was separated. The organic phase was washed with water until the halide test (HNO3 (10% in water) + AgNO3) was negative. The solvent was removed in vacuum on a rotary evaporator and the crude product was recrystallized from methanol.

[0147] Protocol for the preparation of triarylalkylborates with cations of valence n=1:

[0148] The corresponding tetrabutylammonium triarylalkylborate (1 equiv.) was 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 was stirred at room temperature for 1 h. After phase separation, the organic phase was repeatedly washed with water until the halide test (HNO3 (aqueous 10%) + AgNO3) was negative. The solvent was removed in vacuum on a rotary evaporator and the product was dried under reduced pressure.

[0149] Protocol for the preparation of triarylalkylborates with cations of valence n=2:

[0150] The corresponding tetrabutylammonium triarylalkylborate (1 equiv.) was 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 was stirred at room temperature for 1 h. After phase separation, the organic phase was repeatedly washed with water until the halide test (HNO3 (aqueous 10%) + AgNO3) was negative. The solvent was removed in vacuum on a rotary evaporator and the product was dried under reduced pressure.

[0151] Photopolymer film / holographic media fabrication protocol:

[0152] 12.4 g of the polyol component 1 was 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), 0.86 g of each borate, 0.14 g of pigment 1, 0.12 g of BYK 310, 0.01 g of iron(III) trifluoroacetylacetonate, 2.4 g of additive Tinuvin® 400 and 19.2 g of ethyl acetate to obtain a clear solution. Then, 2.3 g of Desmodur® N 3900 was added and mixing was repeated. The solution was 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 12-14 μm was achieved. The coating film was dried at a drying temperature of 120° C. and a drying time of 4 minutes and then protected with a 40 μm thick polyethylene film. The film was then packaged in a light-protected manner.

[0153] Preparation of N-benzyl-N,N-dimethylhexadecylammonium tri(3-fluorophenyl)hexylborate:

[0154] R 101 =R 102 =R 103 3-Fluorobromobenzene was reacted with diisopropylhexylborate according to the general preparation protocol of tetrabutylammonium triarylhexylborate with valence n=1. The resulting tetrabutylammonium triarylalkylborate was then reacted with N-benzyl-N,N-dimethylhexadecylammonium chloride hydrate according to the general preparation protocol of triarylalkylborate with cation valence n=1. δ(ppm)(CDCl3)=-10.1 ppm 11 A colorless oil (0.72 g, 2% of theory over two steps) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.28V vs. SCE.

[0155] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium tri(3-fluorophenyl)hexylborate (Example 16 in Table 2):

[0156] Following the general fabrication protocol for photopolymer films, the photopolymer was prepared using N-benzyl-N,N-dimethylhexadecylammonium tri(3-fluorophenyl)hexylborate as a coinitiator.

[0157] Preparation of N-benzyl-N,N-dimethylhexadecylammonium-3-chlorophenyldi(3-fluorophenyl)hexylborate:

[0158] R 101 =R 102 ≠R 103 According to the general preparation protocol of tetrabutylammonium triarylhexylborate, 3-chlorobromobenzene (1 equivalent) and 3-fluorobromobenzene (2 equivalents) were reacted with diisopropylhexylborate. The resulting tetrabutylammonium triarylalkylborate 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)(CDCl3)=-10.1 ppm 11 A colorless oil (3.8 g, 24% of theory over two steps) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.29V vs. SCE.

[0159] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium-3-chlorophenyldi(3-fluorophenyl)hexylborate (Example 22 in Table 2):

[0160] Following the general fabrication protocol for photopolymer films, photopolymers were prepared using N-benzyl-N,N-dimethylhexadecylammonium-3-chlorophenyldi(3-fluorophenyl)hexylborate as a coinitiator.

[0161] Preparation of tetrabutylammonium tri(3-chlorophenyl)hexylborate:

[0162] R 101 =R 102 =R 103 Following the general preparation protocol for tetrabutylammonium triarylhexylborate, 3-chlorobromobenzene was reacted with diisopropylhexylborate. δ(ppm)(CDCl3)=-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 =1.32V vs. SCE.

[0163] Preparation of photopolymer using tetrabutylammonium tri(3-chlorophenyl)hexylborate (Example 27a in Table 2):

[0164] Following the general fabrication protocol for photopolymer films, the photopolymer was prepared using tetrabutylammonium tri(3-chlorophenyl)hexylborate as a coinitiator.

[0165] Preparation of N-benzyl-N,N-dimethylhexadecylammonium tri(3-chlorophenyl)hexylborate:

[0166] R 101 =R 102 =R 1033-Chlorobromobenzene was reacted with diisopropylhexylborate according to the general protocol for the preparation of tetrabutylammonium triarylhexylborate, 3-chlorobromobenzene was reacted with diisopropyl ... 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.

[0167] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium tri(3-chlorophenyl)hexylborate (Example 27b in Table 2):

[0168] Following the general fabrication protocol for photopolymer films, photopolymers were prepared using N-benzyl-N,N-dimethylhexadecylammonium tri(3-chlorophenyl)hexylborate as a coinitiator.

[0169] Preparation of N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium chloride (cation 1):

[0170] 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).

[0171] Preparation of N-(3-phenylpropyl)-N,N-dimethylhexadecylammonium tri(3-chlorophenyl)hexylborate:

[0172] R 101 =R 102 =R 103 3-Chlorobromobenzene was reacted with diisopropylhexylborate according to the general protocol for the preparation of tetrabutylammonium triarylhexylborate with valence n = 1. Cation 1 was then used according to the general protocol for the preparation of triarylalkylborate with valence n = 1. δ(ppm)(CDCl3) = -10.1 ppm 11 A colorless oil (2.6 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.

[0173] Preparation of photopolymer using N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium tri(3-chlorophenyl)hexylborate (Example 27c in Table 2):

[0174] Following the general fabrication protocol for photopolymer films, the photopolymer was prepared using N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium tri(3-chlorophenyl)hexylborate as a coinitiator.

[0175] Preparation of tributyltetradecylphosphonium tri(3-chlorophenyl)hexylborate:

[0176] R 101 =R 102 =R 1033-Chlorobromobenzene was reacted with diisopropylhexylborate according to the general protocol for the preparation of tetrabutylammonium triarylhexylborate with valence n = 1. Then, tributyltetradecylphosphonium bromide was used according to the general protocol for the preparation of triarylalkylborate with cation valence n = 1. δ(ppm)(CDCl3) = -10.1 ppm 11 A colorless oil (0.86 g, 33% 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.

[0177] Preparation of photopolymer using tributyltetradecylphosphonium tri(3-chlorophenyl)hexylborate (Example 27d in Table 2):

[0178] Following the general fabrication protocol for photopolymer films, the photopolymer was prepared using tributyltetradecylphosphonium tri(3-chlorophenyl)hexylborate as a coinitiator.

[0179] N1,N 22 -Dihexadecyl-N1,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-tri(3-chlorophenyl)hexylborate:

[0180] R 101 =R 102 =R 103 3-Chlorobromobenzene was reacted with diisopropylhexylborate as the bromoaromatic compound according to the general preparation protocol of tetrabutylammonium triarylhexylborate, cation 2, followed by the general preparation protocol of triarylalkylborate with cation of valence n = 2. δ(ppm)(CDCl3) = -10.1 ppm 11A colorless oil (3.98 g, 48% 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.

[0181] N1,N 22 -Dihexadecyl-N1,N1,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-tri(3-chlorophenyl)hexylborate (Example 27e in Table 2):

[0182] Following the general fabrication protocol for photopolymer films, use N1,N2 as co-initiators 22 -Dihexadecyl-N1,N1,N 22 ,N 22 A photopolymer was prepared using 10,10,13-heptamethyl-7,16-dioxo-3,6,17,20-tetraoxa-8,15-diazadocosane-1,22-diaminium bis-tri(3-chlorophenyl)hexylborate.

[0183] Preparation of N-benzyl-N,N-dimethylhexadecylammonium tri(3-chlorophenyl)butylborate:

[0184] R 101 =R 102 =R 103 3-Chlorobromobenzene was reacted with diisopropylbutylborate according to the general preparation protocol of tetrabutylammonium triarylbutylborate with valence n=1. The resulting tetrabutylammonium triarylbutylborate was then reacted with N-benzyl-N,N-dimethylhexadecylammonium chloride hydrate according to the general preparation protocol of triarylalkylborate with cation valence n=1. δ(ppm)(CDCl3)=-10.1 ppm 11A colorless oil (4.63 g, 49% 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.

[0185] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium tri(3-chlorophenyl)butylborate (Example 28 in Table 2):

[0186] Following the general fabrication protocol for photopolymer films, photopolymers were prepared using N-benzyl-N,N-dimethylhexadecylammonium tri(3-chlorophenyl)butylborate as a coinitiator.

[0187] Preparation of N-benzyl-N,N-dimethylhexadecylammonium di(3-chlorophenyl)-3-fluorophenylhexylborate:

[0188] R 101 =R 102 ≠R 103 3-Chlorobromobenzene (2 equivalents) and 3-fluorobromobenzene (1 equivalent) were reacted with diisopropylhexylborate according to the general preparation protocol for tetrabutylammonium triarylhexylborate, δ(ppm)(CDCl3)=-10.1 ppm. Then, N-benzyl-N,N-dimethylhexadecylammonium chloride hydrate was used according to the general preparation protocol for triarylalkylborate with cation of valence n=1. 11 A colorless oil (3.0 g, 29% of theory over two steps) was obtained with a signal in the B NMR spectrum. The calculated reduction potential was E ox =1.34V vs. SCE.

[0189] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium di(3-chlorophenyl)-3-fluorophenylhexylborate (Example 32 in Table 2):

[0190] Following the general fabrication protocol for photopolymer films, photopolymers were prepared using N-benzyl-N,N-dimethylhexadecylammonium di(3-chlorophenyl)-3-fluorophenylhexylborate as a coinitiator.

[0191] Non-inventive Example (NEB):

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

[0193] The preparation protocol published in WO 2018 / 099698 was used. Calculated reduction potentials were calculated as E ox =1.15V vs. SCE.

[0194] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium tri(3-chloro-4-methylphenyl)hexylborate (Example NEB-1 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)hexylborate as a coinitiator.

[0196] Preparation of N-benzyl-N,N-dimethylhexadecylammonium tri(4-trifluoromethoxyphenyl)dodecylborate:

[0197] The preparation protocol published in WO 2018 / 087064 was followed. Calculated reduction potentials were calculated as E ox =1.38V vs. SCE.

[0198] Preparation of photopolymer using N-benzyl-N,N-dimethylhexadecylammonium tri(4-trifluoromethoxyphenyl)dodecylborate (Example NEB-2 in Table 2):

[0199] Following the general fabrication protocol for photopolymer films, photopolymers were prepared using N-benzyl-N,N-dimethylhexadecylammonium tri(4-trifluoromethoxyphenyl)dodecylborate as a coinitiator.

[0200] Preparation of N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium tri(4-trifluoromethylphenyl)hexylborate:

[0201] R 101 =R 102 =R 103 3-Bromobenzenetrifluoride was reacted with diisopropylbutylborate according to the general preparation protocol of tetrabutylammonium triarylhexylborate with valence n=1. The general preparation protocol of triarylalkylborate with cation 1 was then followed. δ(ppm)(CDCl3)=-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.

[0202] Preparation of photopolymer using N,N-dimethyl-N-(3-phenylpropyl)hexadecylammonium tri(4-trifluoromethylphenyl)hexylborate (Example NEB-3 in Table 2):

[0203] 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.

[0204] [Example]

[0205] 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).

[0206] 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. [Table 1] TIFF2025507602000032.tif239161TIFF2025507602000033.tif250161TIFF2025507602000034.tif41165

[0207] Based on formula (II), the group designation R in Table 1 100 is AR in formula (II) 100 R on the aromatic ring in Table 1 corresponds to the group 101 Group, R 102 Groups and R 103 Each group is R 101 Group, R 102 Groups and R 103 Corresponding to the group.

[0208] Table 1a: Oxidation potentials of various triarylalkylborate anions calculated according to formula (II) (the specific groups refer to formula (II) in claim 6, the oxidation potentials are specified in [V] relative to a saturated calomel electrode in the solvent acetonitrile). [Table 1a] TIFF2025507602000036.tif234151TIFF2025507602000037.tif251151TIFF2025507602000038.tif122160

[0209] Evaluation of the thermal stability of photopolymer films using coinitiators according to the present invention:

[0210] The requirements for the photopolymer film produced here are both low loss of photoactivity performance after the temperature conditioning step and complete bleachability of the photopolymer film after the holographic exposure has been performed. This is examined as follows:

[0211] 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 140 °C for 30 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 in the photopolymer layer of both samples with a 457 nm laser using a two-beam interference laser setup as shown in Figure 1 and described above. The quality of this hologram was evaluated by the refractive index modulation Δn of the samples, derived from the read diffraction efficiency and its angular selectivity. Afterwards, both samples were bleached over their entire surface under UV light irradiation for 30 min. The transmission spectra (T 2,RT and T 2,Temp ) were recorded from both bleached samples as well. The thermal stability of a photopolymer with high bleachability was evaluated based on three criteria, and all three of these criteria must be met simultaneously. The three achievement criteria are explained in detail below:

[0212] 1. Thermal stability evaluated according to the transmission loss T (T): the transmission T at the absorption maximum (here 510 nm) of the dye used after the temperature adjustment step of the Temp sample 1,Temp,510 of the transmittance T of the RT sample at the same wavelength 1,RT,510The ratio of T to T must be greater than 50%. The transmittance value here must be corrected for background absorption caused by turbidity etc. (here the transmittance at 730 nm is used as the reference value) (T 2,Temp,730 ):

number

[0213] 2. Δn: Thermal stability evaluated according to TS(Δn): The refractive index difference Δn of the Temp sample must be greater than 0.007:

number

[0214] 3. Bleaching evaluated according to the residual absorption B(T): the transmittance after bleaching with UV light of the Temp sample (T 2,Temp,510 ) of the original transmittance of the RT sample (T 1,RT,510 ) should be less than or equal to 15%. The transmittance value should again be corrected for background absorption caused by turbidity etc. (T 2,Temp,730 ):

number

[0215] The following transmission and Δn values ​​were determined for some examples according to the invention and not according to the invention:

[0216] 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,510 : Transmittance of RT sample at 510 nm; T 1,Temp,510 : Transmittance of the Temp sample at 510 nm; T 2,Temp,730 : background transmittance determined at 730 nm; TS(T): evaluation of thermal stability by transmission loss; TS(Δn): evaluation of thermal stability by Δn; B(T): evaluation of bleachability by residual transmittance.

[0217] [Table 2] *Varied SCE in acetonitrile; calculated; based on triarylalkylborate used.

[0218] The results obtained show that the required properties of thermal stability and bleachability of the photopolymer are achieved with the triarylalkylborate salts according to the invention. It can therefore be assumed that the photopolymer is sufficiently thermally stable and bleachable only if the calculated oxidation potential of the borate salt used is greater than 1.15 V and less than 1.38 V vs. SCE in acetonitrile. Thus, the use of all the borates listed in Table 1 as coinitiators in the photopolymer results in thermally stable and bleachable photopolymers. The thermal stability and bleachability of the photopolymer do not depend on the cation of the borate salt used, as the comparison of Examples 27a to 27e highlights. A change in the alkyl group of the triarylalkylborate salt is also possible without losing the thermal stability and bleachability of the photopolymer, as the comparison of Examples 27b and 28 highlights.

[0219] The examples not according to the invention, NEB1, NEB2 and NEB3, fail in at least one required property and are therefore not suitable to provide 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 said dyes has a structure according to formula (I) 【number】 (In the formula, R ２０１ is optional and, when present, is hydrogen, C １ ~C １６ Alkyl, C ３ ~C ６ Alkenyl, C ５ ~C ７ Cycloalkyl or C ７ ~C １６ Aralkyl or C ６ ~C １０ represents aryl, R ２０３ is C １ ~C １６ Alkyl, C ３ ~C ６ Alkenyl, C ５ ~C ７ Cycloalkyl or C ７ ~C １６ Aralkyl or C ６ ~C １０ represents aryl, R ２０２ is hydrogen, C １ ~C １６ Alkyl, C ３ ~C ６ Alkenyl, C ５ ~C ７ Cycloalkyl or C ７ ~C １６ Aralkyl, C ６ ~C １０ represents aryl or hetaryl, R ２０４ is hydrogen, C １ ~C ４ Alkyl, C １ ~C ４ Alkoxy, halogen, cyano, nitro or C １ ~C ４ represents an alkoxycarbonyl; A is X １ and X ２ and X １ and X ２ represents, together with the C atom(s) bonded thereto, a 5- or 6-membered aromatic or semi-aromatic or partially hydrogenated heterocycle which may contain 1 to 4 heteroatoms and / or may be benzo- or naphtho-fused and / or may be substituted by non-ionic groups, X ２ represents N, O or S, preferably N, X １ O, S, CR ２０５ R ２０６ or -CH=CH-, preferably CR ２０５ R ２０６ represents R ２０５ and R ２０６ are independent of each other, C １ ~C ４ Alkyl, C ３ ~C ６ Alkenyl, C ４ ~C ７ Cycloalkyl, C ７ ~C １０ Aralkyl or C ６ represents aryl, 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 in the range of 1.16 V to 1.37 V versus a saturated calomel electrode (SCE) in acetonitrile, determined by quantum mechanical calculation of the Gibbs energies at 298 K of the ground and oxidized states of the coinitiator, in particular triarylalkylborate, after structural 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, according to the following formula (1): [Equation 1] and the at least one coinitiator is a triarylalkylborate salt; Photopolymer composition. [Equation 2]

2. The at least one dye according to the structure of formula (I) has the following group: R ２０１ is optional and, when present, represents hydrogen, methyl, ethyl, propyl, butyl, benzyl or phenethyl; R ２０３ represents methyl, ethyl, propyl, butyl, benzyl or phenethyl; R ２０２ represents hydrogen, methyl or phenyl, R ２０４ represents hydrogen, methyl, ethyl, cyclohexyl, phenyl, tolyl, anisyl or chlorophenyl, A is X １ and X ２ and pyridin-2-ylene or pyridin-4-ylene, quinolin-2-ylene or quinolin-4-ylene, 1,3-thiazol-2-ylene, 1,3-thiazolin-2-ylene, benzothiazol-2-ylene, 1,3,4-thiadiazol-2-ylene, 1,3-oxazolin-2-ylene, benzoxazol-2-ylene, imidazol-2-ylene, imidazolin-2-ylene, benzimidazol-2-ylene, pyrroline-2-ylene, quinolin-2-ylene, 1,3-thiazol-2-ylene, benzothiazol-2-ylene, 1,3,4-thiadiazol-2-ylene, 1,3-oxazolin-2-ylene, benzoxazol-2-ylene, imidazol-2-ylene, benzimidazol-2-ylene, pyrroline-2-ylene, quinolin-2-ylene, 1,3-thiazol-2-ylene, benzothiazol-2-ylene, pyrroline-2-ylene, quinolin-4-ylene, 1,3-thiazol-2-ylene, benzothiazol-2-ylene, pyrroline-2-ylene, quinolin-4-ylene, 1,3-thiazol-2-ylene, benzothiazol-2-ylene, pyrroline-2-ylene, quinolin-2 ... -ylene, 1,3,4-triazol-2-ylene, 3-H-indol-2-ylene or quinoxalin-2-ylene, in which in the case of imidazol-2-ylene, imidazolin-2-ylene and benzimidazol-2-ylene both N atoms are substituted by R41b, and in the case of 1,3,4-thiadiazol-2-ylene the substituents are selected from the group consisting of dimethylamino, diethylamino, dipropylamino, dibutylamino, N-methyl-N-cyanoethylamino, bis(cyanoethyl)amino, N-methyl-N-phenylamino, pyrrolidino, piperidino and morpholino, or A is X １ and X ２ and together with the C atom bonded therebetween, represent 2H-pyran-2-ylene, 4H-pyran-4-ylene, 2H-thiopyran-2-ylene, 4H-thiopyran-4-ylene substituted by two radicals from the group phenyl, tolyl or anisyl, The photopolymer composition of claim 1 .

3. The at least one dye has the structure of formula (XVII): 【Chemistry 2】 (In the formula, R ２０１ and R ２０３ are each independently methyl, ethyl or benzyl; R ２０２ represents hydrogen, methyl or phenyl) 10. The photopolymer composition of claim 1, having

4. The at least one dye according to formula (I) present is an anion (An － ) an organic substituted sulfonate; The photopolymer composition of claim 1 .

5. The at least one coinitiator is a triarylalkylborate according to formula (II) 【Transformation 3】 (In the formula, A represents a methylene group or any 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 １２ Alkyl group, 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 each independently of each other, C １ ~C １０ 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 ４ Alkoxy, trifluoromethoxy, trichloromethoxy, C １ ~C ４ 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; 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. The at least one coinitiator of formula (II) has the following group: R １００ is C １ ~C ２０ Alkyl, C ３ ~C １２ Alkyl group, C ５ ~C ７ Cycloalkyl or C ７ ~C １３ represents an aralkyl group, R １０１ , R １０２ and R １０３ are each independently of each other, C １ ~C ４ Alkyl, halogen, cyano, trifluoromethyl, C １ ~C ４ represents one or two groups selected from the group consisting of alkoxy or optionally substituted aryl groups and hydrogen; The photopolymer composition of claim 5.

7. R １００ is C ３ ~C １２ represents an alkyl group, R １０１ , R １０２ and R １０３ are each independently of each other, C １ ~C ４ represents one to two meta or para groups selected from the group consisting of alkyl groups and halogen substituents; The photopolymer composition of claim 5.

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

9. 2. The photopolymer composition of claim 1, wherein the at least one coinitiator has an oxidation potential in acetonitrile ranging from 1.20 V vs. SCE to 1.36 V vs. SCE, preferably from 1.25 V to 1.35 V in acetonitrile, and more preferably from 1.28 V to 1.34 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 photopolymer 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'. A cured 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 the photopolymer composition of any one of claims 1 to 9.

13. by exposure to light, 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 thereof, it being equally possible to combine these hologram types or to integrate several holograms of the same type independent of each other in the same volume of the holographic medium (multiplexing), The holographic medium of claim 12.

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

15. 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 a method selected from the group consisting of eye tracking, sensing, LIDAR, augmented reality, head mounted display and virtual reality applications, in particular in the near infrared range, and combinations of at least two thereof, Use of the holographic medium according to claim 12.

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