Photopolymer type holographic recording medium as well as preparation method and application thereof

Abstract

The invention discloses a photopolymer type holographic recording medium and a preparation method and application thereof.The photopolymer type holographic recording medium comprises a writing monomer, film-forming resin, a photosensitive initiation combination agent and a catalyst, the writing monomer comprises nanoparticles and a polymerizable monomer, and the film-forming resin is prepared from the nanoparticles and the polymerizable monomer; the refractive index of the polymerizable monomer is smaller than that of the nanoparticles, and the difference between the refractive index of the nanoparticles and the refractive index of the polymerizable monomer is larger than 0.5. The film-forming resin includes a polyol compound and an isocyanate-based compound. The catalyst is used for catalyzing a polyol compound and an isocyanate compound to react to form a film. The photosensitive initiation combination agent is used for sensing light and inducing polymerization of the polymerizable monomer. According to the photopolymer type holographic recording medium disclosed by the invention, after exposure, the polymerizable monomers located in the bright area and the nanoparticles extruded to the dark area have relatively large refractive index difference, so that the refractive index modulation degree of the recording grating can be improved; the film-forming resin provides effective support for the nanoparticles, and the nanoparticles are not agglomerated.

Description

Technical Field

[0001] The present invention relates to the technical field of holographic materials, and particularly to a photopolymer-based holographic recording medium, a preparation method thereof, and an application thereof. Background Art

[0002] AR (Augmented Reality) glasses based on a holographic waveguide system have the advantages of being thin, light, portable, having high transparency, and having virtual images that are real and natural. The core optical element of the holographic waveguide system is a pair of reflective volume holographic gratings. Currently, volume holographic gratings are usually prepared using photopolymers.

[0003] Each component used to make the photopolymer-based holographic recording medium, such as a photosensitive dye, an initiator, a chain transfer agent, a writing monomer, a film-forming resin, a plasticizer, etc., jointly determines whether the performance of the photopolymer-based holographic recording medium is excellent or not.

[0004] In existing photopolymers, the refractive index difference between the writing monomer and the film-forming resin is small, usually only 0.1 - 0.2, and the refractive index modulation degree Δn of the finally formed recording grating is low, and Δn is usually less than 0.07; for photopolymers added with nanoparticles, they exist in a liquid form, and the nanoparticles are prone to agglomeration, need to be prepared and used immediately, and it is difficult to mass-produce in the form of a film material. The refractive index modulation degree of the finally formed recording grating is also low, and it is difficult to meet the application requirements in the field of AR glasses. Summary of the Invention

[0005] In view of this, the present invention provides a photopolymer-based holographic recording medium, a preparation method thereof, and an application thereof, aiming to enable the photopolymer-based holographic recording medium to have high photosensitivity, and the refractive index modulation degree of the formed recording grating is increased and it can be mass-produced.

[0006] The photopolymer-based holographic recording medium proposed in the first aspect of the present invention includes a writing monomer, and the writing monomer includes: nanoparticles and a polymerizable monomer, the refractive index of the polymerizable monomer is less than the refractive index of the nanoparticles, and the difference between the refractive index of the nanoparticles and the refractive index of the polymerizable monomer is greater than 0.5; a film-forming resin, the film-forming resin includes a polyol compound and an isocyanate group compound; a catalyst, the catalyst is used to catalyze the reaction of the polyol compound and the isocyanate group compound to form a film; a photosensitive initiation combination agent, the photosensitive initiation combination agent is used for photosensitization and inducing the polymerization of the polymerizable monomer.

[0007] As can be seen from the above technical solution, the nanoparticles and polymerizable monomers of the present invention together serve as components of the writing monomer. Under the action of exposure, the photosensitive initiator combination is sensitized and induces the polymerizable monomers in the coherent bright region to rapidly polymerize and the concentration decreases. At this time, the polymerizable monomers that have not participated in the reaction in the coherent dark region migrate to the bright region to participate in the polymerization reaction. The nanoparticles do not participate in the reaction but are squeezed into the coherent dark region, making the refractive index of the coherent bright region close to that of the polymerizable monomer, while the refractive index of the coherent dark region is close to that of the nanoparticles. Since the refractive index of the polymerizable monomer is less than that of the nanoparticles and the refractive index difference between the two is greater than 0.5, the polymerizable monomers in the bright region and the nanoparticles in the dark region increase the refractive index difference between the coherent bright region and the coherent dark region, thereby making the refractive index modulation degree of the recording grating higher. Under the action of the catalyst, the polyol compound and the isocyanate group compound in the film-forming resin react to form a film, effectively supporting the nanoparticles and preventing the nanoparticles from agglomerating and stably existing, which is beneficial to mass production and use.

[0008] In some examples of the present invention, the refractive index of the nanoparticles is greater than 2.0 and the refractive index of the polymerizable monomer is less than 1.5; and / or, the nanoparticles are selected from at least one of zirconium dioxide, chromium oxide, copper oxide, zinc sulfide, titanium dioxide, titanium pentoxide, titanium trioxide, titanium monoxide, tantalum pentoxide, hafnium oxide, niobium oxide, zinc oxide, zinc selenide, iron oxide nanoparticles; and / or, the polymerizable monomer includes at least one of methacrylate compounds, acrylate compounds, allyl ether compounds; and / or, the polyol compound includes at least two hydroxyl groups; and / or, the isocyanate group compound contains at least two isocyanate groups; and / or, the photosensitive initiator combination includes a photosensitizer and a photoinitiator, and the absorption wavelengths of the photosensitizer and the photoinitiator are different; and / or, the catalyst is at least one of tertiary amine catalysts or organometallic catalysts.

[0009] In some embodiments of the present invention, the refractive index of the polymerizable monomer is less than 1.5; wherein, the acrylate compounds include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, isobutyl acrylate, 2-ethylhexyl acrylate, tert-butyl acrylate, dodecyl acrylate, tetradecyl acrylate, hexadecyl acrylate, octadecyl acrylate, polyethylene glycol diacrylate, diethylene glycol dimethacrylate, tetraethylene glycol diacrylate, butanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, methoxypolyethylene glycol acrylate, hydroxypropyl methacrylate, trimethylolpropane triacrylate, hydroxyethyl acrylate, 2-(dimethylamino)ethyl acrylate, 2-(2-methoxyethoxy)ethyl 2-methyl-2-propenoate, disulfide acrylate, 1,10-decanediyl diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, polyethylene glycol dimethacrylate, neopentyl glycol adipate diacrylate, hydroxypivalic acid neopentyl glycol diacrylate, dicyclopentyl diacrylate, caprolactone-modified dicyclopentenyl diacrylate, methoxyethyl acrylate, ethoxyethyl acrylate, propoxyethyl acrylate, butoxyethyl acrylate, pentyloxyethyl acrylate, hexyloxyethyl acrylate, heptyloxyethyl acrylate, octyloxyethyl acrylate, nonyloxyethyl acrylate, decyloxyethyl acrylate, undecyloxyethyl acrylate, dodecyloxyethyl acrylate, tridecyloxyethyl acrylate, tetradecyloxyethyl acrylate, pentadecyloxyethyl acrylate, hexadecyloxyethyl acrylate, heptadecyloxyethyl acrylate, octadecyloxyethyl acrylate, nonadecyloxyethyl acrylate, icosyloxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxypentyl acrylate, hydroxyhexyl acrylate, hydroxyheptyl acrylate, hydroxyoctyl acrylate, hydroxynonyl acrylate, hydroxydecyl acrylate, hydroxyundecyl acrylate, hydroxydodecyl acrylate, hydroxytridecyl acrylate, hydroxy tetradecyl acrylate, hydroxypentadecyl acrylate, hydroxyhexadecyl acrylate, hydroxyheptadecyl acrylate, hydroxyoctadecyl acrylate, hydroxynonadecyl acrylate, hydroxyicosyl acrylate, one or more of them; and / or, the methacrylate compounds include, but are not limited to, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, tetradecyl methacrylate, pentadecyl methacrylate, hexadecyl methacrylate, heptadecyl methacrylate, octadecyl methacrylate, nonadecyl methacrylate, icosyl methacrylate, isopentyl methacrylate, isohexyl methacrylate, isooctyl methacrylate, isononyl methacrylate, isodecyl methacrylate, isoundecyl methacrylate,One or more of isododecyl methacrylate, isotridecyl methacrylate, isotetradecyl methacrylate, tert-butyl methacrylate, tert-amyl methacrylate, 2-ethylhexyl methacrylate, 3-methylbutyl methacrylate, 4-methylpentyl methacrylate, cyclopentyl methacrylate, cyclohexyl methacrylate, cycloheptyl methacrylate, cyclooctyl methacrylate, cyclononyl methacrylate, cyclodecyl methacrylate, cyclododecyl methacrylate, benzyl methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-propoxyethyl methacrylate, 2-butoxyethyl methacrylate, 2-pentyloxyethyl methacrylate, 2-hexyloxyethyl methacrylate, 2-heptyloxyethyl methacrylate, 2-octyloxyethyl methacrylate, 2-nonyloxyethyl methacrylate, 2-decyloxyethyl methacrylate, 2-undecyloxyethyl methacrylate, 2-dodecyloxyethyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 6-hydroxyhexyl methacrylate, 2,3-dihydroxypropyl methacrylate, 2-aminoethyl methacrylate, 2-(dimethylamino)ethyl methacrylate, N,N-dimethylaminoethyl methacrylate, 2-cyanoethyl methacrylate, 2-acetoxyethyl methacrylate; and / or, the allyl ether compounds include but are not limited to allyl ether (diallyl ether), 1-ethenyl-2-oxopropane, 3,3'-oxybis-1-propene (di-α-allyl ether), 1-propenyl-2-methoxyethane, 1-propenyl-3-methoxypropane, 1-propenyl-2-ethoxyethane, 1-propenyl-2-propoxyethane, 1-propenyl-2-butoxyethane, 1-propenyl-2-pentyloxyethane, 1-propenyl-2-hexyloxyethane, 1-propenyl-2-heptyloxyethane, 1-propenyl-2-octyloxyethane, 1-propenyl-2-nonyloxyethane, 1-propenyl-2-decyloxyethane, 1-propenyl-2-(2-methylpropyl)oxyethane, 1-propenyl-2-(1-methylethyl)oxyethane, 1-propenyl-2-cyclopentyloxyethane, 1-propenyl-2-cyclohexyloxyethane, 1-propenyl-2-cycloheptyloxyethane, 1-propenyl-2-cyclooctyloxyethane, 2-propenyl-1-methoxyethane, 2-propenyl-1-ethoxyethane, 2-propenyl-1-propoxyethane, 2-propenyl-1-butoxyethane, 2-propenyl-1-pentyloxyethane, 2-propenyl-1-hexyloxyethane, 2-propenyl-1-heptyloxyethane, 2-propenyl-1-octyloxyethane, 2-propenyl-1-nonyloxyethane, 2-propenyl-1-decyloxyethane, 2-propenyl-1-(2-methylpropyl)oxyethane, 2-propenyl-1-cyclopentyloxyethane,One or more of 2-propenyl 1-cyclohexyloxyethane, 2-propenyl 1-(2-ethoxyethyl)oxyethane, 3-propenyl 1,2-dimethoxypropane, 3-propenyl 1,2-diethoxypropane, 3-propenyl 1-ethyl-2-methoxypropane, 3-propenyl 1-methyl-2-ethoxypropane, 2-methoxy 1,3-dipropenylpropane, 2-ethoxy 1,3-dipropenylpropane, 2-propoxy 1,3-dipropenylpropane, 2-butoxy 1,3-dipropenylpropane, 2-pentyloxy 1,3-dipropenylpropane, 2-hexyloxy 1,3-dipropenylpropane, 2-heptyloxy 1,3-dipropenylpropane, 2-octyloxy 1,3-dipropenylpropane, 2-(2-methylpropoxy) 1,3-dipropenylpropane, 2-cyclopentyloxy 1,3-dipropenylpropane, 2-cyclohexyloxy 1,3-dipropenylpropane, 1,1-dipropenyl 2-methoxyethane, 1,1-dipropenyl 2-ethoxyethane, 1,1-dipropenyl 2-propoxyethane, 1,1-dipropenyl 2-butoxyethane, 1,1-dipropenyl 2-pentyloxyethane, 1,1-dipropenyl 2-hexyloxyethane, 1,1-dipropenyl 2-heptyloxyethane, 1,1-dipropenyl 2-octyloxyethane, 1,1-dipropenyl 2-(2-methylpropoxy)ethane, 1,1-dipropenyl 2-cyclopentyloxyethane, 1,1-dipropenyl 2-cyclohexyloxyethane, 1,2-dipropenyl 3-methoxypropane, 1,2-dipropenyl 3-ethoxypropane, 1,2-dipropenyl 3-propoxypropane.

[0010] In some embodiments of the present invention, the polyol compound is selected from phenyl ethylene glycol, 1,2-diphenyl ethylene glycol, 1,3-diphenyl propanediol, 1,4-diphenyl butanediol, 1,5-diphenyl pentanediol, 1,6-diphenyl hexanediol, ethylene glycol terephthalate diol, ethylene glycol isophthalate diol, ethylene glycol phthalate diol, 1,3-propanediol terephthalate diol, 1,4-butanediol terephthalate diol, 1,4-butanediol isophthalate diol, 1,4-butanediol phthalate diol, 1,6-hexanediol terephthalate diol, 1,6-hexanediol isophthalate diol, 1,6-hexanediol phthalate diol, 2,2-diphenyl-1,3-propanediol, 2,2-diphenyl-1,4-butanediol, 4,4'-dihydroxy diphenyl methane, 4,4'-dihydroxy diphenyl ether, 4,4'-dihydroxy diphenyl sulfide, 4,4'-dihydroxy diphenyl ethane, 4,4'-dihydroxy diphenyl propane, 4,4'-dihydroxy diphenyl butane, 4,4'-bis(β-hydroxy ethoxy) biphenyl, 4,4'-bis(α-methyl-β-hydroxy ethoxy) biphenyl, 3,3'-dimethyl-4,4'-dihydroxy biphenyl, 3,3',5,5'-tetramethyl-4,4'-dihydroxy biphenyl, 2,2'-dimethyl-4,4'-dihydroxy biphenyl, 2,2'-diethyl-4,4'-dihydroxy biphenyl, 2,2'-diphenyl-4,4'-dihydroxy biphenyl, 1,1'-diphenyl-4,4'-diol, 1,1'-bis(4-hydroxyphenyl) ethane, 1,1'-bis(4-hydroxyphenyl) propane, 1,1'-bis(4-hydroxyphenyl) butane, 1,1'-bis(4-hydroxyphenyl) pentane, 1,1'-bis(4-hydroxyphenyl)-3-methyl butane, 1,1'-bis(4-hydroxyphenyl) cyclohexane, 1,4-bis(4-hydroxyphenyl) benzene, 1,3-bis(4-hydroxyphenyl) benzene, 1,2-bis(4-hydroxyphenyl) ethane, 2,2-bis(4-hydroxyphenyl) propane, 2,2-bis(3-methyl-4-hydroxyphenyl) propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl) propane, triphenyl methanol, tris(4-methylphenyl) methanol, tris(3-methylphenyl) methanol, tris(2-methylphenyl) methanol, tris(4-ethylphenyl) methanol, tris(4-propylphenyl) methanol, tris(4-butylphenyl) methanol, tris(4-phenylphenyl) methanol, 1,1,1-tris(4-hydroxyphenyl) ethane, 1,1,1-tris(3-hydroxyphenyl) ethane, 1,1,1-tris(2-hydroxyphenyl) ethane, 2,2,2-tris(4-hydroxyphenyl) propane, 2,2,2-tris(3-hydroxyphenyl) propane, 2,2,2-tris(2-hydroxyphenyl) propane, 1,1,2-tris(4-hydroxyphenyl) ethane, 1,1,2-tris(3-hydroxyphenyl) ethane, 1,2,2-tris(4-hydroxyphenyl) propane, 1,2,2-tris(3-hydroxyphenyl) propane, 1,2,At least one of 3-tris(4-hydroxyphenyl)propane and 1,2,3-tris(3-hydroxyphenyl)propane; and / or, the isocyanate group compound is selected from at least one of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-phenylene diisocyanate, benzodimethyl diisocyanate, tetramethyl-m-xylylene diisocyanate, dimethylbiphenyl diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, polyaryl polyisocyanate, 1,3-bis(3-isocyanato-4-methylphenyl)-1,3-diazacyclo-2,4-butanedione, 1,3,5-tris(3-isocyanatotolyl)-1,3,5-triazine-2,4,6-trione, triphenylmethane-4,4',4”-triisocyanate, 4,4',4”-thiotri-phenylphosphate triisocyanate, dimethyltriphenylmethane tetraisocyanate.,

[0011] In some embodiments of the present invention, the photopolymerizable holographic recording medium further comprises a chain transfer agent and an additive or a solvent.

[0012] In further some embodiments of the present invention, the photopolymerizable holographic recording medium comprises raw materials of each component in the following parts by weight: the first component: 30 parts to 70 parts in total of a polyol compound and an isocyanate group compound; the second component: 10 parts to 40 parts of nanoparticles; the third component: 10 parts to 40 parts of a polymerizable monomer; the fourth component: 0.1 part to 3 parts of a photosensitive initiator combination; the fifth component: 0.1 part to 3 parts of a chain transfer agent; the sixth component: 0.01 part to 3 parts of a catalyst; the seventh component: 0.1 part to 18 parts of an additive or a solvent.

[0013] In some embodiments of the present invention, the chain transfer agent is a thiol compound; and / or, the catalyst is a tertiary amine catalyst and an organometallic catalyst; and / or, when the photopolymerizable holographic recording medium comprises an additive, the additive comprises one or more of an antifoaming agent, a leveling agent, a plasticizer, an ultraviolet absorber, a light stabilizer and an antioxidant.

[0014] The preparation method of the photopolymerizable holographic recording medium in the foregoing multiple examples proposed in the second aspect of the present invention comprises the following steps: weighing each component of the photopolymerizable holographic recording medium in a container, fully stirring until all components are dissolved; filtering with a filter membrane to obtain a mixture; coating the mixture on a substrate, and curing in a darkroom at a temperature of 10°C to 50°C, and obtaining the photopolymerizable holographic recording medium after the polyol compound and the isocyanate group compound form a film.

[0015] The preparation method of the photopolymer-based holographic recording medium proposed in the second aspect of the present invention has fewer preparation steps, is simple to operate, has easily implemented conditions, is convenient for observing the film formation progress, and the obtained photopolymer-based holographic recording medium has high photosensitivity, a higher refractive index modulation of the recorded grating, can form a film structure, and can be mass-produced and used.

[0016] A holographic optical element proposed in the third aspect of the present invention, wherein the raw material of the holographic optical element includes the photopolymer-based holographic recording medium of each of the foregoing examples.

[0017] The holographic optical element proposed in the third aspect of the present invention has excellent holographic performance, high sensitivity, a small required exposure amount, a higher refractive index modulation of the recorded grating, and is convenient for production.

[0018] An optical device proposed in the fourth aspect of the present invention includes the foregoing holographic optical element.

[0019] The optical device proposed in the fourth aspect of the present invention, such as a head-up display device, an augmented reality device, a virtual reality device, a photopolymer-based holographic storage optical disc, etc., has excellent holographic performance and is convenient for production.

[0020] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the disclosure of the embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 Selection angle curve of the recorded grating of the holographic recording medium 1-1;

[0023] Figure 2 Selection angle curve of the recorded grating of the holographic recording medium 1-2;

[0024] Figure 3 Selection angle curve of the recorded grating of the holographic recording medium 1-3;

[0025] Figure 4 Selection angle curve of the recorded grating of the holographic recording medium 1-4;

[0026] Figure 5 Selection angle curve of the recorded grating of the holographic recording medium 2-1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0029] Next, the photopolymer-type holographic recording medium of the present invention will be described.

[0030] The photopolymer-type holographic recording medium according to the present invention includes a writing monomer, and the writing monomer includes: nanoparticles and a polymerizable monomer, the refractive index of the polymerizable monomer is less than the refractive index of the nanoparticles and the difference between the refractive index of the nanoparticles and the refractive index of the polymerizable monomer is greater than 0.5; a film-forming resin, the film-forming resin includes a polyol compound and an isocyanate group compound; a catalyst, the catalyst is used to catalyze the reaction of the polyol compound and the isocyanate group compound to form a film; a photosensitive initiator combination agent, the photosensitive initiator combination agent is used for photosensitization and inducing the polymerization of the polymerizable monomer.

[0031] As can be seen from the above, from the above technical solutions, the polymerizable monomer added in the present invention can be quickly polymerized after exposure and is a substance with a relatively low refractive index itself. The nanoparticles added in the present invention have a relatively high refractive index themselves. The polymerizable monomer and nanoparticles with a large refractive index difference contribute to quickly constructing a grating, and the nanoparticles can also inhibit the shrinkage of the polymerizable monomer during polymerization and improve the dimensional stability.

[0032] Under the action of the catalyst, the polyol compound and the isocyanate group compound in the film-forming resin react to form a film, which effectively supports the nanoparticles, so that the nanoparticles do not agglomerate and exist stably, and there is no need to prepare and use immediately, which is beneficial to the batch production and use of the photopolymer-type holographic recording medium.

[0033] The nanoparticles of the present invention and polymerizable monomers together serve as components of the writing monomer. Under the action of exposure, the photosensitive initiator combination is sensitized and induces the polymerizable monomers in the coherent bright region to polymerize rapidly and the concentration decreases. At this time, the unreacted polymerizable monomers in the coherent dark region migrate to the bright region to participate in the polymerization reaction. The nanoparticles do not participate in the reaction but are squeezed into the coherent dark region, making the refractive index of the coherent bright region close to that of the polymerizable monomer, while the refractive index of the coherent dark region is close to that of the nanoparticles. Since the refractive index of the polymerizable monomer is less than that of the nanoparticles and the refractive index difference between the two is greater than 2.0, therefore, the polymerizable monomers in the bright region and the nanoparticles in the dark region increase the refractive index difference between the coherent bright region and the coherent dark region, thereby making the refractive index modulation Δn of the recording grating higher, and Δn>0.1..

[0034] It can be understood that compared with the refractive index modulation of the recording grating in the prior art being less than 0.07, the refractive index modulation of the recording grating formed in the photopolymer-based holographic recording medium of the present invention is greater than 0.1, and even up to 0.3. The refractive index modulation of the recording grating of the present invention is significantly improved. Compared with the prior art, the photopolymer nanoparticles in the liquid form are prone to agglomeration and cannot be mass-produced. The final form of the photopolymer-based holographic recording medium of the present invention is a film structure, which is convenient for mass production, and the nanoparticle size is stable and the nanoparticles do not agglomerate in the film.

[0035] In some examples of the present invention, the refractive index of the nanoparticles is greater than 2.0; the refractive index of the polymerizable monomer is less than 1.5, so that the refractive index difference between the nanoparticles and the polymerizable monomer is greater than 0.5.

[0036] In other examples, the refractive index of the polymerizable monomer is less than 1.45, so as to further increase the refractive index difference between the nanoparticles and the polymerizable monomer, and further increase the refractive index difference between the coherent bright region and the coherent dark region, and the refractive index modulation Δn of the recording grating >0.1.

[0037] In some specific examples, the nanoparticles are selected from at least one of zirconium dioxide, chromium oxide, copper oxide, zinc sulfide, titanium dioxide, titanium trioxide, titanium dioxide, titanium monoxide, tantalum pentoxide, hafnium oxide, niobium oxide, zinc oxide, zinc selenide, and iron oxide nanoparticles. When there are multiple types, the nanoparticles can be a mixture of any proportion of the above-mentioned nanoparticles. These nanoparticles can all inhibit the shrinkage of polymerizable monomers during the polymerization process. These nanoparticles can be evenly distributed in the film-forming resin without agglomeration. The evenly distributed nanoparticles themselves have a high specific surface area and good mechanical properties, which can effectively enhance the stability and durability of the photopolymer type holographic recording medium. The nanoparticles can also absorb photons and excite electrons, improving the sensitization efficiency of the photosensitive initiator combination, so that the photopolymer type holographic recording medium can form a clear grating structure under lower light conditions.

[0038] The particle size of the above-mentioned nanoparticles is in the range of 3 nm to 200 nm. For example, the particle size can be 3 nm, 10 nm, 20 nm, 50 nm, 100 nm, 120 nm, 150 nm, 170 nm, or 200 nm, etc. In specific examples, the particle size of the nanoparticles is controlled between 3 nm and 100 nm, so that the nanoparticles can better exert the aforementioned effects.

[0039] In some specific examples, the polymerizable monomers include at least one of methacrylate compounds, acrylate compounds, and allyl ether compounds.

[0040] More specifically, the polymerizable monomers are selected from acrylate compounds, methacrylate compounds, and allyl ether compounds with a refractive index lower than 1.5; further, acrylate compounds, methacrylate compounds, and allyl ether compounds with a refractive index lower than 1.45 are selected. It can be seen that in the present invention, by adding three polymerizable monomers with small volume, easy migration, and high reaction activity to the photopolymer type holographic recording medium, the photosensitivity of the photopolymer is significantly improved.

[0041] Exemplarily, the acrylate compounds include but are not limited to methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, isobutyl acrylate, 2-ethylhexyl acrylate, tert-butyl acrylate, dodecyl acrylate, tetradecyl acrylate, hexadecyl acrylate, octadecyl acrylate, polyethylene glycol diacrylate, diethylene glycol dimethacrylate, tetraethylene glycol diacrylate, butanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, methoxypolyethylene glycol acrylate, hydroxypropyl methacrylate, trimethylolpropane triacrylate, hydroxyethyl acrylate, 2-(dimethylamino)ethyl acrylate, 2-(2-methoxyethoxy)ethyl 2-methyl-2-propenoate, disulfide acrylate, 1,10-decanediyl diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, polyethylene glycol dimethacrylate, neopentyl glycol adipate diacrylate, hydroxypivalic acid neopentyl glycol diacrylate, dicyclopentyl diacrylate, caprolactone-modified dicyclopentenyl diacrylate, methoxyethyl acrylate, ethoxyethyl acrylate, propoxyethyl acrylate, butoxyethyl acrylate, pentyloxyethyl acrylate, hexyloxyethyl acrylate, heptyloxyethyl acrylate, octyloxyethyl acrylate, nonyloxyethyl acrylate, decyloxyethyl acrylate, undecyloxyethyl acrylate, dodecyloxyethyl acrylate, tridecyloxyethyl acrylate, tetradecyloxyethyl acrylate, pentadecyloxyethyl acrylate, hexadecyloxyethyl acrylate, heptadecyloxyethyl acrylate, octadecyloxyethyl acrylate, nonadecyloxyethyl acrylate, eicosyloxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxypentyl acrylate, hydroxyhexyl acrylate, hydroxyheptyl acrylate, hydroxyoctyl acrylate, hydroxynonyl acrylate, hydroxydecyl acrylate, hydroxyundecyl acrylate, hydroxydodecyl acrylate, hydroxytridecyl acrylate, hydroxy tetradecyl acrylate, hydroxypentadecyl acrylate, hydroxyhexadecyl acrylate, hydroxyheptadecyl acrylate, hydroxyoctadecyl acrylate, hydroxynonadecyl acrylate, hydroxyicosyl acrylate, or one or more of them.

[0042] Exemplarily, the methacrylate compounds include, but are not limited to, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, tetradecyl methacrylate, pentadecyl methacrylate, hexadecyl methacrylate, heptadecyl methacrylate, octadecyl methacrylate, nonadecyl methacrylate, eicosyl methacrylate, isopentyl methacrylate, isohexyl methacrylate, isooctyl methacrylate, isononyl methacrylate, isodecyl methacrylate, isoundecyl methacrylate, isododecyl methacrylate, isotridecyl methacrylate, isotetradecyl methacrylate, tert-butyl methacrylate, tert-pentyl methacrylate, 2-ethylhexyl methacrylate, 3-methylbutyl methacrylate, 4-methylpentyl methacrylate, cyclopentyl methacrylate, cyclohexyl methacrylate, cycloheptyl methacrylate, cyclooctyl methacrylate, cyclononyl methacrylate, cyclodecyl methacrylate, cyclododecyl methacrylate, benzyl methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-propoxyethyl methacrylate, 2-butoxyethyl methacrylate, 2-pentyloxyethyl methacrylate, 2-hexyloxyethyl methacrylate, 2-heptyloxyethyl methacrylate, 2-octyloxyethyl methacrylate, 2-nonyloxyethyl methacrylate, 2-decyloxyethyl methacrylate, 2-undecyloxyethyl methacrylate, 2-dodecyloxyethyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 6-hydroxyhexyl methacrylate, 2,3-dihydroxypropyl methacrylate, 2-aminoethyl methacrylate, 2-(dimethylamino)ethyl methacrylate, N,N-dimethylaminoethyl methacrylate, 2-cyanoethyl methacrylate, 2-acetoxyethyl methacrylate, or one or more of them.

[0043] Exemplarily, allyl ether compounds include, but are not limited to, allyl ether (diallyl ether), 1-vinyl-2-oxopropane, 3,3'-oxybis-1-propene (di-α-allyl ether), 1-propenyl-2-methoxyethane, 1-propenyl-3-methoxypropane, 1-propenyl-2-ethoxyethane, 1-propenyl-2-propoxyethane, 1-propenyl-2-butoxyethane, 1-propenyl-2-pentyloxyethane, 1-propenyl-2-hexyloxyethane, 1-propenyl-2-heptyloxyethane, 1-propenyl-2-octyloxyethane, 1-propenyl-2-nonyloxyethane, 1-propenyl-2-decyloxyethane, 1-propenyl-2-(2-methylpropyl)oxyethane, 1-propenyl-2-(1-methylethyl)oxyethane, 1-propenyl-2-cyclopentyloxyethane, 1-propenyl-2-cyclohexyloxyethane, 1-propenyl-2-cycloheptyloxyethane, 1-propenyl-2-cyclooctyloxyethane, 2-propenyl-1-methoxyethane, 2-propenyl-1-ethoxyethane, 2-propenyl-1-propoxyethane, 2-propenyl-1-butoxyethane, 2-propenyl-1-pentyloxyethane, 2-propenyl-1-hexyloxyethane, 2-propenyl-1-heptyloxyethane, 2-propenyl-1-octyloxyethane, 2-propenyl-1-nonyloxyethane, 2-propenyl-1-decyloxyethane, 2-propenyl-1-(2-methylpropyl)oxyethane, 2-propenyl-1-cyclopentyloxyethane, 2-propenyl-1-cyclohexyloxyethane, 2-propenyl-1-(2-ethoxyethyl)oxyethane, 3-propenyl-1,2-dimethoxypropane, 3-propenyl-1,2-diethoxypropane, 3-propenyl-1-ethyl-2-methoxypropane, 3-propenyl-1-methyl-2-ethoxypropane, 2-methoxy-1,3-dipropenylpropane, 2-ethoxy-1,3-dipropenylpropane, 2-propoxy-1,3-dipropenylpropane, 2-butoxy-1,3-dipropenylpropane, 2-pentyloxy-1,3-dipropenylpropane, 2-hexyloxy-1,3-dipropenylpropane, 2-heptyloxy-1,3-dipropenylpropane, 2-octyloxy-1,3-dipropenylpropane, 2-(2-methylpropoxy)-1,3-dipropenylpropane, 2-cyclopentyloxy-1,3-dipropenylpropane, 2-cyclohexyloxy-1,3-dipropenylpropane, 1,1-dipropenyl-2-methoxyethane, 1,1-dipropenyl-2-ethoxyethane, 1,1-dipropenyl-2-propoxyethane, 1,1-dipropenyl-2-butoxyethane, 1,1-dipropenyl-2-pentyloxyethane, 1,1-dipropenyl-2-hexyloxyethane, 1,1-dipropenyl-2-heptyloxyethane, 1,1-dipropenyl-2-octyloxyethane, 1,1-dipropenyl-2-(2-methylpropoxy)ethane, 1,One or more of 1-diallyl-2-cyclopentyloxyethane, 1,1-diallyl-2-cyclohexyloxyethane, 1,2-diallyl-3-methoxypropane, 1,2-diallyl-3-ethoxypropane, and 1,2-diallyl-3-propoxypropane.,

[0044] The optional substances of these polymerizable monomers are only exemplary and should not be construed as a limitation of the present invention. When there are multiple polymerizable monomers in the present invention, they can be combined in any proportion.,

[0045] In some examples of the present invention, the reactive functional group of the polyol compound is an alcohol hydroxyl group, which is easily oxidized and has a relatively high reactivity; for example, in some examples, the polyol compound is a compound with two or more hydroxyl functional groups.,

[0046] More specifically, the polyol compound is selected from phenyl ethylene glycol, 1,2-diphenyl ethylene glycol, 1,3-diphenyl propanediol, 1,4-diphenyl butanediol, 1,5-diphenyl pentanediol, 1,6-diphenyl hexanediol, ethylene glycol terephthalate diol, ethylene glycol isophthalate diol, ethylene glycol phthalate diol, 1,3-propanediol terephthalate diol, 1,4-butanediol terephthalate diol, 1,4-butanediol isophthalate diol, 1,4-butanediol phthalate diol, 1,6-hexanediol terephthalate diol, 1,6-hexanediol isophthalate diol, 1,6-hexanediol phthalate diol, 2,2-diphenyl-1,3-propanediol, 2,2-diphenyl-1,4-butanediol, 4,4'-dihydroxy diphenyl methane, 4,4'-dihydroxy diphenyl ether, 4,4'-dihydroxy diphenyl sulfide, 4,4'-dihydroxy diphenyl ethane, 4,4'-dihydroxy diphenyl propane, 4,4'-dihydroxy diphenyl butane, 4,4'-bis(β-hydroxyethoxy) biphenyl, 4,4'-bis(α-methyl-β-hydroxyethoxy) biphenyl, 3,3'-dimethyl-4,4'-dihydroxy biphenyl, 3,3',5,5'-tetramethyl-4,4'-dihydroxy biphenyl, 2,2'-dimethyl-4,4'-dihydroxy biphenyl, 2,2'-diethyl-4,4'-dihydroxy biphenyl, 2,2'-diphenyl-4,4'-dihydroxy biphenyl, 1,1'-diphenyl-4,4'-diol, 1,1'-bis(4-hydroxyphenyl) ethane, 1,1'-bis(4-hydroxyphenyl) propane, 1,1'-bis(4-hydroxyphenyl) butane, 1,1'-bis(4-hydroxyphenyl) pentane, 1,1'-bis(4-hydroxyphenyl)-3-methyl butane, 1,1'-bis(4-hydroxyphenyl) cyclohexane, 1,4-bis(4-hydroxyphenyl) benzene, 1,3-bis(4-hydroxyphenyl) benzene, 1,2-bis(4-hydroxyphenyl) ethane, 2,2-bis(4-hydroxyphenyl) propane, 2,2-bis(3-methyl-4-hydroxyphenyl) propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl) propane, triphenyl methanol, tris(4-methylphenyl) methanol, tris(3-methylphenyl) methanol, tris(2-methylphenyl) methanol, tris(4-ethylphenyl) methanol, tris(4-propylphenyl) methanol, tris(4-butylphenyl) methanol, tris(4-phenylphenyl) methanol, 1,1,1-tris(4-hydroxyphenyl) ethane, 1,1,1-tris(3-hydroxyphenyl) ethane, 1,1,1-tris(2-hydroxyphenyl) ethane, 2,2,2-tris(4-hydroxyphenyl) propane, 2,2,2-tris(3-hydroxyphenyl) propane, 2,2,2-tris(2-hydroxyphenyl) propane, 1,1,2-tris(4-hydroxyphenyl) ethane, 1,1,2-tris(3-hydroxyphenyl) ethane, 1,2,2-tris(4-hydroxyphenyl) propane, 1,2,2-tris(3-hydroxyphenyl) propane, 1,2,3-tris(4-hydroxyphenyl) propane, 1,2,At least one of 3-tris(3-hydroxyphenyl)propane. When there are multiple polyol compounds, the polyol compounds are a mixture in any proportion. Some of these polyols contain 2 hydroxyl groups in a single molecule, some contain 3 hydroxyl groups, and some contain 4 hydroxyl groups, with high reactivity.

[0047] In some examples of the present invention, the isocyanate group compound is a substance with two or more isocyanate groups. The isocyanate group has high reactivity and can react with the hydroxyl groups in the polyol compound to form covalent bonds and polymerize. The more the number of isocyanate groups, the higher the activity. A single molecule can react with multiple hydroxyl groups, with a fast reaction rate and saving the addition of the isocyanate group compound.

[0048] In a specific example, the isocyanate group compound is selected from one or more of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-phenylene diisocyanate, benzodimethylenebis(isocyanate), tetramethyl-m-xylylene diisocyanate, dimethylbiphenyl diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, polyaryl polyisocyanate, 1,3-bis(3-isocyanato-4-methylphenyl)-1,3-diazacyclo-2,4-dione, 1,3,5-tris(3-isocyanatotolyl)-1,3,5-triazine-2,4,6-trione, triphenylmethane-4,4',4”-triisocyanate, 4,4',4”-thiotri-phenylphosphate triisocyanate, dimethyltriphenylmethane tetraisocyanate. When there are multiple isocyanate group compounds, they can be mixed in any proportion. Some of these isocyanate group compounds contain two isocyanate groups, some contain three isocyanate groups, and some contain four isocyanate groups, with high reactivity.

[0049] In some examples of the present invention, the photosensitive initiator combination includes a photosensitizer and a photoinitiator, and the absorption wavelengths of the photosensitizer and the photoinitiator are different. The photosensitizer therein can be paired with the photoinitiator to achieve a visible light initiation system and adapt to lasers of different wavelengths. Under the irradiation of light in a specific wavelength range, the photosensitizer in the photoinitiation system is activated by the corresponding light and absorbs light energy, which is then transferred to the photoinitiator, so that the photoinitiator can be activated under light radiation of more frequencies to generate free radicals with initiation functions. The photoinitiated free radicals can initiate monomer polymerization to realize the construction of a holographic grating, improve the photosensitivity of the photopolymer-based holographic recording medium, and broaden the range of optional light sources.

[0050] Then, it can be understood that in other examples, when the present invention uses a photoinitiator adapted to the wavelength, the photosensitizer may not be added. For example, when the absorption wavelength of the photoinitiator or the absorption wavelength of the cationic photoinitiator is greater than 400 nm, it can absorb light with a longer wavelength and is easily activated. At this time, the photosensitizer may not be added.

[0051] In some examples, the photosensitizer is selected from at least one of cyanine dyes, fluorescein dyes, coumarinone dyes, nitrogen-containing heteroaromatic compounds, aromatic amine compounds, and benzylidene cycloalkanone compounds.

[0052] More specifically, the photosensitizer is selected from one or more of new methylene blue, thionine, basic yellow, pinacyanol chloride, rhodamine 6G, eosin Y, gallocyanine, ethyl violet, victoria blue R, celestine blue, methylene blue, basic orange, darrow red, pyrrole red Y, basic red 29, quinidine red, crystal violet, ethyl violet, bright green, azure A, crystal violet white nitrile, malachite green white nitrile, etc. When there are multiple kinds, it can be a mixture in any proportion. In the present invention, different wide-band responses can be achieved by regulating the type of photosensitizer. The photosensitizer is a dye with a high electron transfer efficiency under light irradiation.

[0053] In the present invention, the photoinitiator is an initiator that can be activated by actinic radiation and initiate the polymerization reaction of the corresponding polymerizable monomer.

[0054] In specific examples, the photoinitiator is selected from at least one of aromatic ketone compounds, benzoin and its derivatives, benzil ketals, acylphosphine oxides, arylborate ammonium salts, chromium salts, aryl diazonium salts, onium salts, and organometallic compounds; when there are multiple kinds, it can be a mixture of photoinitiators in any proportion. It can also be other photoinitiators with similar functions, which are not limited in the present invention.

[0055] More specifically, the photoinitiator is selected from benzophenone (absorption wavelength 210nm, 255nm), alkyl benzophenone (absorption wavelength 290nm ~ 360nm), 4,4'-bis (dimethylamino) benzophenone, anthrone (299nm ~ 366nm) and halogenated benzophenone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide (absorption wavelength 350nm ~ 400nm), bisacylphosphine oxide, phenyl glyoxylate, camphorquinone (absorption wavelength 4 00nm~500nm), a-aminoalkylphenone (absorption wavelength is 380nm~430nm), α,α-dialkoxyacetophenone, a-hydroxyalkylphenone (absorption wavelength is 320nm~380nm), triphenylhexyl borate tetrabutylammonium, tri-(3-fluorophenyl)hexyl borate tetrabutylammonium, tri-(3-chloro-4-methylphenyl)hexyl borate tetrabutylammonium, ferrocenyl compounds, iodonium salts, sulfonium salts, hexaarylbisimidazoles, etc. One or more of the above. When these photoinitiators are irradiated with light in the corresponding wavelength range, they can be quickly activated and generate active free radicals, thereby initiating polymerization reactions between the components of the photopolymer type holographic recording medium to achieve a difference in monomer concentration between the bright area and the dark area. Alternatively, when the photosensitizer coordinated therewith absorbs light in the corresponding wavelength range, it transfers heat to the photoinitiator, thereby achieving activation of the photoinitiator.

[0056] In some examples, the mass ratio of photosensitizer to photoinitiator is (0.001-1):(0.1-3). By controlling the mass ratio of photosensitizer to photoinitiator within the above range, the concentration of photosensitizer can be effectively controlled, so that during the holographic exposure process, the number of absorbed photons is controlled within a suitable range, the speed of polymerization reaction is controlled within a reasonable range, and the speed of grating formation is controlled within a certain range, so as to ensure the light transmittance of the photopolymer holographic recording medium and obtain excellent diffraction efficiency. In a more specific example, the mass of photosensitizer is 1 / 10 to 1 / 3 of the mass of photoinitiator, such as 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, 1 / 5, 1 / 4 or 1 / 3, etc.

[0057] In some examples of the present invention, the catalyst is at least one of a tertiary amine catalyst or an organic metal catalyst.

[0058] In a specific example, the catalyst is selected from at least one of triethylenediamine, bis(dimethylaminoethyl) ether, dimethylethanolamine, 2-(2-dimethylamino-ethoxy)ethanol, trimethylhydroxyethylpropylenediamine, N,N-bis(dimethylaminopropyl)isopropanolamine, dibutyltin dilaurate, stannous octoate, potassium carboxylate catalysts and bismuth carboxylate catalysts.

[0059] In some embodiments of the present invention, the photopolymerizable holographic recording medium further includes a chain transfer agent and additives or solvents. The chain transfer agent can control the length of the polymer chain; different types of additives can be added according to the needs of the reaction system; the solvent can improve the compatibility of each component and enhance the dispersion degree of each component in the whole system, facilitating the preparation of a photopolymerizable holographic recording medium with stable performance. Each component acts synergistically to form a photopolymerizable holographic recording medium with good holographic performance.

[0060] In some examples of the present invention, the chain transfer agent is a thiol compound.

[0061] In specific examples, the chain transfer agent includes one or more of dodecyl mercaptan, mercaptoethanol, hexyl mercaptan, phenylethyl mercaptan, 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol, 4-methyl-4H-1,2,4-triazole-3-thiol, etc.

[0062] In some examples of the present invention, when the photopolymerizable holographic recording medium includes additives, the additives include one or more of defoamers, leveling agents, plasticizers, ultraviolet absorbers, light stabilizers, and antioxidants.

[0063] In specific examples, the defoamer is a silicone defoamer and / or a non-silicone polymer defoamer. The function of the defoamer is as described above and will not be elaborated here.

[0064] For example, BYK-011, BYK-012, BYK-014, BYK-023, BYK-051N, BYK-085, BYK-1610, BYK-1707, BYK-1740, BYK-1760 produced by BYK Company, DC65, AFE-7820 produced by Dow Corning Corporation, or any proportion mixture of these defoamers. The BYK series of defoamers have excellent defoaming performance, good compatibility and dispersibility with other components; among them, BYK-011, BYK-012, BYK-014, and BYK-051N are non-silicone polymer defoamers. DC65 is a water-based ink with fast drying, good printing effect, and not easy to fall off. AFE-7820 has high defoaming performance.

[0065] In specific examples, the leveling agent is a silicone surface aid, such as at least one of BYK-302, BYK-306, BYK-307, BYK-327, BYK-329, BYK-333, BYK-356, BYK-358, BYK-378, BYK-3455, BYK-3566 produced by BYK Company. When there are multiple ones, it can be any proportion mixture of these surface aids. The BYK series of leveling agents have excellent leveling performance.

[0066] In a specific example, the plasticizer is selected from at least one of toluene, xylene, dimethylformamide, dimethylacetamide, glycerol, and phthalate. The function of the plasticizer is as described above and will not be elaborated here.

[0067] In a specific example, the ultraviolet absorber includes but is not limited to at least one of 2-hydroxy-4-n-octyloxybenzophenone, 2-(5-chloro-2H-benzotriazol-2-yl)-6-(1,1-dimethylethyl)-4-methylphenol, N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxalamide, 2-(2H-benzotriazol-2-yl) p-cresol, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, 2-(2H-benzotriazol-2-yl)-4,6-dipentaerythritylphenol, 2-(2H-benzotriazol-2)-4,6-bis(1-methyl-1-phenylethyl)phenol. When there are multiple ultraviolet absorbers, they can be a mixture in any proportion. The function of the ultraviolet absorber is as described above and will not be elaborated here.

[0068] In a specific example, the light stabilizer includes but is not limited to light stabilizer 944, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, light stabilizer 622, or a mixture of these additives in any proportion. The function of the light stabilizer is as described above and will not be elaborated here.

[0069] In a specific example, the antioxidant includes but is not limited to any one or more of Irganox 1010, Irganox 168, Irganox 1076, Irganox 1098, Irganox MD1024, Irganox 1035, BASF liquid antioxidant 1135, Irganox B225, Irganox PS800 (DLTP), Irganox B900, Irganox 3114, Irganox 245, Irganox B215, Irganox PS-802FL, Irganox Borchors Ascinin@P. When there are multiple antioxidants, they can be a mixture of these antioxidants in any proportion on the premise of meeting the synergistic effect after compounding. The function of the antioxidant is as described above and will not be elaborated here.

[0070] Among them, Irganox 1010 is a BASF antioxidant, which has strong anti-extractability, low volatility, good compatibility with other components, and no color stain will color the product.

[0071] Irganox 168 is a BASF antioxidant. It is not prone to discoloration, has strong hydrolysis resistance, is not easily volatile, and does not easily generate bubbles during use. Irganox 168 is an organic phosphite auxiliary antioxidant that can be compounded with Irganox 1010 and Irganox 1010 to produce a synergistic effect and effectively prevent thermal degradation of each component during polymerization.

[0072] Irganox 1076 is a BASF antioxidant. It is a highly efficient hindered phenol antioxidant and has good compatibility with most polymers, which can effectively prevent product discoloration caused by light and heat. The BASF antioxidant 1076 can play a synergistic effect and improve the antioxidant effect when used in combination with auxiliary antioxidants such as AT-168 and DLTDP.

[0073] Irganox 1098 is a BASF antioxidant. It is a hindered phenol antioxidant with low volatility and no color stain.

[0074] Irganox MD1024 is a BASF antioxidant. It is a stabilizer and highly efficient metal deactivator applied to organic copolymers. It does not produce color stain and can be used alone or in combination with phenolic antioxidants.

[0075] Irganox 1035 is a sulfur-containing hindered phenol antioxidant and heat stabilizer.

[0076] BASF liquid antioxidant 1135 is a liquid hindered phenol antioxidant and is suitable for polyols, polyurethanes and other polymers. BASF liquid antioxidant Irganox 1135 is an excellent antioxidant suitable for various polymers. When used in polyurethane flexible foam sheets, it can prevent the formation of peroxides in polyols during storage.

[0077] Irganox B225 is an antioxidant with good performance and has outstanding processing stability and long-term protection for polyolefins.

[0078] Irganox PS800 is a processing stabilizer of dialkyl esters of thiodipropionic acid and is usually used in combination with phenolic antioxidants in organic compounds. Usually, Irganox PS800 is mixed with phenolic antioxidants to enhance aging stability and light stability. In a specific example, the addition amount is 0.2% - 1% of the weight of the photopolymer type holographic recording medium.

[0079] Irganox B 900 is a compound mixture, including 80% content of Irgafos 168 and 20% content of Irganox 1076. It is mainly used in polyethylene and ethylene copolymers, such as ethylene vinyl acetate copolymer. This compound synergistic agent can also be used in other polymers, such as engineering plastics, polycarbonate, polyester, styrene homopolymers and copolymers, polyurethane, etc. In a specific example, the addition amount is 0.1% - 0.3% of the weight of the photopolymer type holographic recording medium.

[0080] Irganox 3114 is an antioxidant of BASF, which can prevent polymers from aging due to heat and oxidation, and also has light resistance. BASF antioxidant 3114 is applicable to polyolefins such as polyethylene, polypropylene and polybutene, as well as styrene-based homopolymers and copolymers, and can also be used in other organic matrices such as linear polyester, PVC, polyamide and polyurethane. It is soluble in acetone, benzene, chloroform, N, N-dimethylformamide, ethanol, methanol.

[0081] Irganox 245 is a highly efficient hindered phenol antioxidant, which can effectively prevent the thermal oxidative degradation of polymers. It can be used in compound with auxiliary antioxidants (such as thioethers, phosphites, phosphonates, furanones), light stabilizers and other functional stabilizers. The compound use of Irganox 245 and Irgafos 168 has better effect.

[0082] Irganox B215 is a compound synergistic mixture, composed of a hindered phenol and a phosphite complex. It has both the low volatility and hydrolysis resistance of the organic phosphite antioxidant 168, and the processing stability and long-term thermal stability of the antioxidant 1010. It can be used in common with other additives such as ultraviolet absorbers and light stabilizers to enhance its effect. It is applicable to olefin copolymers and polyolefins.

[0083] Irganox PS-802FL is a dialkyl ester of thiodipropionic acid and is an auxiliary antioxidant. It can be used as a synergist in common with phenolic antioxidants to improve the use effect of phenolic antioxidants. Thiodipropionate is very effective in polyolefins, such as polypropylene, polyethylene, high impact polystyrene and other organic substances.

[0084] Irganox Borchors Ascinin@P is an antioxidant of BASF, which has excellent thermal oxygen stability.

[0085] In some embodiments of the present invention, when the photopolymer type holographic recording medium includes a solvent, the weight percentage of the solvent in the photopolymer type holographic recording medium is less than or equal to 3 parts.

[0086] In a specific embodiment, the solvent is selected from at least one of petroleum ether, dichloromethane, ethyl acetate, n-hexane, tetrahydrofuran, acetone, benzene, methyl ethyl ketone, methyl formate, methyl propionate, isobutyl formate, chlorobutane, ethyl propionate, dichloroethane, chloroisopentane, methyl carbonate, trichloroethane, carbon tetrachloride, dichloroethylene, carbon disulfide, propanol, 3-pentanone, dichloropropane, methyl ethyl ketone, bromoethane, cyclohexane. These solvents have good compatibility with other components, enabling each component to be fully dissolved, and the solvent is convenient for subsequent drying and removal.

[0087] In some embodiments of the present invention, the weight of the writing monomer in the photopolymerizable holographic recording medium is 10 parts to 60 parts. When the weight of the writing monomer in the photopolymerizable holographic recording medium is within the above range, the writing monomer can have a sufficient concentration, so that there is enough writing monomer to participate in the reaction, ensuring a relatively fast polymerization rate; at the same time, a large concentration difference between the bright area and the dark area can be formed after the reaction under light irradiation. Under the driving action of a larger concentration gradient, the speed of the polymerizable monomer of the writing monomer migrating from the coherent dark area to the coherent bright area will be accelerated. In addition, when the weight of the writing monomer in the photopolymerizable holographic recording medium is within the above range, the film-forming resin can also load the writing monomer and finally polymerize to form a solid film under the action of exposure, thus effectively ensuring the quality of the formed volume holographic grating.

[0088] In further some embodiments of the present invention, the photopolymerizable holographic recording medium comprises raw materials of each component in the following weight parts: the first component: a total of 30 parts to 70 parts of a polyol compound and an isocyanate group compound; the second component: 10 parts to 40 parts of nanoparticles; the third component: 10 parts to 40 parts of a polymerizable monomer; the fourth component: 0.1 part to 3 parts of a photosensitive initiator combination; the fifth component: 0.1 part to 3 parts of a chain transfer agent; the sixth component: 0.01 part to 3 parts of a catalyst; the seventh component: 0.1 part to 18 parts of an additive or a solvent. The polyol compound and the isocyanate group compound in the film-forming resin in these examples can react to form a film. The film-forming resin belongs to the second-order reaction type, is convenient for processing, has good dimensional stability, and can provide support for other components.

[0089] Among them, the polyol compound in the first component can be 20 parts to 50 parts, for example, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 44 parts, 47 parts, 50 parts, etc.; the isocyanate group compound in the first component can be 10 parts to 40 parts, for example, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, etc. By controlling the addition amounts of the substances in the first component within the above ranges, a stable film-forming resin can be formed in the first component, thereby providing a supporting effect for other components. The specific number of parts of the first component and the second component can be determined according to the types of the polyol compound and the isocyanate group compound actually selected, and it is necessary to ensure that the molar ratio of the hydroxyl functional group to the isocyanate functional group is 1:1.

[0090] The second component nanoparticles can be 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, etc.

[0091] The third component polymerizable monomer can be 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 40 parts, etc. By controlling the addition amounts of the second component and the third component within the above ranges and selecting appropriate addition amounts, the polymerization rate of the third component can be fast after being affected by the photosensitive initiator combination agent. Under the action of the nanoparticles, the structure of the polymerized polymerizable monomer is stable and not easy to retract. When the concentration of the polymerizable monomer in the coherent dark region is greater than that in the coherent bright region, the nanoparticles in the coherent bright region are squeezed into the coherent dark region, so that a certain refractive index difference is formed between the nanoparticles in the coherent dark region and the polymerizable monomer in the coherent bright region, and a volume holographic grating can be quickly formed, and the formed volume holographic grating has stable performance, and the refractive index modulation degree of the recorded grating is relatively high, greater than 0.1.

[0092] The fourth component photosensitive initiator combination agent can be 0.1 part, 0.2 part, 0.3 part, 0.5 part, 1 part, 1.5 parts, 2.0 parts, 2.5 parts, 3.0 parts, etc. By reasonably controlling the addition amount of the fourth component, an appropriate number of photons can be absorbed during exposure, and the polymerization reaction can be controlled at a certain speed, so that the grating can also be quickly formed and a high diffraction efficiency can be obtained; in addition, the required light transmittance of the final holographic recording medium can be ensured.

[0093] The fifth component chain transfer agent can be 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.6 part, 0.8 part, 1.0 part, 1.5 parts, 2.0 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3 parts, etc. By reasonably controlling the addition amount of the fifth component, the polymer chain length can be controlled within a certain reasonable range, and the polymerization degree can be effectively prevented from being too high, ensuring that the final holographic recording medium has the required optical properties and diffraction efficiency.

[0094] The sixth component catalyst can be 0.01 part, 0.02 parts, 0.05 parts, 0.07 parts, 0.08 parts, 0.1 part, 0.2 parts, 0.3 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1.0 part, 1.5 parts, 2.0 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3 parts, etc. By reasonably controlling the addition amount of the sixth component, the reaction rate of related components can be effectively increased, and the consumption rate of related components after exposure can be increased, so as to quickly form the concentration difference of monomers in the bright and dark areas, and realize the refractive index modulated phase-type volume holographic grating.

[0095] The seventh component additive or solvent can be 0.1 part, 0.2 parts, 0.3 parts, 0.5 part, 1 part, 1.5 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 12 parts, 15 parts, 18 parts, etc.

[0096] When the seventh component is an additive, taking the leveling agent as an example, by controlling the addition amount of the leveling agent within the above range, the uniformity of the mixed solution can be effectively improved, the fluidity can be improved, and the cost can be reasonably controlled. In some examples, the weight part of the leveling agent in the photopolymer type holographic recording medium is less than or equal to 3 parts.

[0097] Taking the plasticizer as an example of the additive, by controlling the addition amount of the plasticizer within the above range, the plasticizer inserts between the polymer molecular chains, weakens the intermolecular stress, increases the mobility of the molecular chains, reduces the crystallinity, and thus increases the plasticity of the polymer. In some examples, the weight part of the plasticizer in the photopolymer type holographic recording medium is less than or equal to 3 parts.

[0098] Taking the defoaming agent as an example of the additive, by controlling the addition amount of the defoaming agent within the above range, the defoaming agent can reduce the liquid surface tension and remove bubbles, and improve the fluidity of the mixture of each component. In some examples, the weight part of the defoaming agent in the photopolymer type holographic recording medium is less than or equal to 3 parts.

[0099] Taking the ultraviolet absorber as an example of the additive, by controlling the addition amount of the ultraviolet absorber within the above range, the ultraviolet absorber can absorb ultraviolet rays, protect the photopolymer type holographic recording medium from aging or photolysis under ultraviolet irradiation, and thus improve the performance stability of the photopolymer type holographic recording medium. In some examples, the weight part of the ultraviolet absorber in the photopolymer type holographic recording medium is less than or equal to 3 parts.

[0100] Taking the additive as a light stabilizer as an example, by controlling the addition amount of the light stabilizer within the above range, the light stabilizer can absorb ultraviolet rays and convert them into heat energy, and can also release active substances and inhibit free radical reactions during the process of absorbing ultraviolet energy, effectively preventing the photo-polymerizable holographic recording medium from discoloring under ultraviolet irradiation, so that the photo-polymerizable holographic recording medium maintains its original color and luster, improving the weather resistance of the photo-polymerizable holographic recording medium and extending its service life. In some examples, the weight part of the light stabilizer in the photo-polymerizable holographic recording medium is less than or equal to 3 parts.

[0101] Taking the additive as an antioxidant as an example, by controlling the addition amount of the antioxidant within the above range, the antioxidant can produce a synergistic effect with the ultraviolet absorber, improving the weather resistance and thermo-oxidative stability of the photo-polymerizable holographic recording medium, and effectively delaying the aging and degradation of the photo-polymerizable holographic recording medium. In some examples, the weight part of the antioxidant in the photo-polymerizable holographic recording medium is less than or equal to 3 parts.

[0102] When the seventh component is a solvent, by controlling the amount of the solvent within the above range, sufficient wetting of other components by the solvent can be achieved, and the components are mutually soluble to form a relatively uniform mixed system, which is convenient for coating and fabricating the photo-polymerizable holographic recording medium.

[0103] As can be seen from the above, by reasonably controlling the addition amounts of the various components of the photo-polymerizable holographic recording medium in each embodiment, the full synergistic effect of the various components can be achieved, and the holographic performance of the finally formed photo-polymerizable holographic recording medium will not deteriorate due to too much or too little of a certain component, ensuring that the comprehensive holographic performance of the finally formed photo-polymerizable holographic recording medium is better.

[0104] In some optional examples, the photo-polymerizable holographic recording medium includes the following components in the following weight parts: the first component - 50 parts of a polyol compound, 10 parts of an isocyanate group compound, the second component - 12 parts of nanoparticles, the third component - 18 parts of a polymerizable monomer, the fourth component - 1 part of a photosensitive initiator combination agent, the fifth component - 1 part of a chain transfer agent, the sixth component - 2 parts of a catalyst, and the seventh component - 6 parts of an additive.

[0105] In some optional examples, the photo-polymerizable holographic recording medium includes the following components in the following weight parts: the first component - 22 parts of a polyol compound, 37 parts of an isocyanate group compound, the second component - 10 parts of nanoparticles, the third component - 13 parts of a polymerizable monomer, the fourth component - 3 parts of a photosensitive initiator combination agent, the fifth component - 2 parts of a chain transfer agent, the sixth component - 2 parts of a catalyst, and the seventh component - 8 parts of an additive.

[0106] In some alternative examples, the photopolymer type holographic recording medium comprises the following components in parts by weight: First component - polyol compound 20 parts, isocyanate group compound 40 parts, Second component - nanoparticles 21.1 parts, Third component - polymerizable monomer 10 parts, Fourth component - photosensitive initiator combination agent 2 parts, Fifth component - chain transfer agent 1.1 parts, Sixth component - catalyst 3 parts, Seventh component - solvent 2.8 parts.

[0107] In some alternative examples, the photopolymer type holographic recording medium comprises the following components in parts by weight: First component - polyol compound 25 parts, isocyanate group compound 20 parts, Second component - nanoparticles 30 parts, Third component - polymerizable monomer 20 parts, Fourth component - photosensitive initiator combination agent 0.1 part, Fifth component - chain transfer agent 0.1 part, Sixth component - catalyst 0.1 part, Seventh component - additive 4.7 parts.

[0108] In some alternative examples, the photopolymer type holographic recording medium comprises the following components in parts by weight: First component - polyol compound 30 parts, isocyanate group compound 10 parts, Second component - nanoparticles 40 parts, Third component - polymerizable monomer 11 parts, Fourth component - photosensitive initiator combination agent 0.2 part, Fifth component - chain transfer agent 3 parts, Sixth component - catalyst 0.8 part, Seventh component - additive 5 parts.

[0109] In some alternative examples, the photopolymer type holographic recording medium comprises the following components in parts by weight: First component - polyol compound 20 parts, isocyanate group compound 10 parts, Second component - nanoparticles 11 parts, Third component - polymerizable monomer 40 parts, Fourth component - photosensitive initiator combination agent 0.2 part, Fifth component - chain transfer agent 0.3 part, Sixth component - catalyst 0.5 part, Seventh component - additive 18 parts.

[0110] In some alternative examples, the photopolymer type holographic recording medium comprises the following components in parts by weight: First component - polyol compound 35 parts, isocyanate group compound 10 parts, Second component - nanoparticles 19 parts, Third component - polymerizable monomer 32.4 parts, Fourth component - photosensitive initiator combination agent 0.2 part, Fifth component - chain transfer agent 0.39 part, Sixth component - catalyst 0.01 part, Seventh component - solvent 3 parts.

[0111] In some alternative examples, the photopolymerizable holographic recording medium comprises the following components in parts by weight: First component - 25 parts of a polyol compound, 25 parts of an isocyanate group compound, Second component - 30 parts of nanoparticles, Third component - 15 parts of a polymerizable monomer, Fourth component - 0.2 part of a photosensitive initiator combination agent, Fifth component - 0.39 part of a chain transfer agent, Sixth component - 0.01 part of a catalyst, Seventh component - 3 parts of a solvent.

[0112] In some alternative examples, the photopolymerizable holographic recording medium comprises the following components in parts by weight: First component - 40 parts of a polyol compound, 15 parts of an isocyanate group compound, Second component - 25 parts of nanoparticles, Third component - 14 parts of a polymerizable monomer, Fourth component - 1.1 parts of a photosensitive initiator combination agent, Fifth component - 2.4 parts of a chain transfer agent, Sixth component - 2.4 parts of a catalyst, Seventh component - 0.1 part of a solvent.

[0113] It should be noted that in the above alternative examples, the molar ratio of the alcohol hydroxyl group in the polyol compound to the isocyanate group in the isocyanate group compound is 1:1, so that the two monomers react completely and less residue remains.

[0114] The preparation method of the photopolymerizable holographic recording medium in each of the foregoing examples of the present invention is described below.

[0115] Step S100: Weigh the raw materials of the components (polyol compound and isocyanate group compound, nanoparticles, polymerizable monomer, photosensitive initiator combination agent, chain transfer agent, catalyst, additive or solvent) of the photopolymerizable holographic recording medium into a container, and stir well until all components are dissolved.

[0116] Step S200: Filter the mixture using a filter membrane to obtain a mixture.

[0117] Step S300: Coat the mixture onto a substrate and cure it in a dark room at a temperature of 10°C to 50°C. After the polyol compound and the isocyanate group compound form a film, a photopolymerizable holographic recording medium is obtained.

[0118] As can be seen from the above, the preparation method of the photopolymerizable holographic recording medium proposed by the present invention has few preparation steps, is simple to operate, has conditions that are easy to implement, is convenient for observing the progress of film formation, and the obtained photopolymerizable holographic recording medium has high photosensitivity and a higher refractive index modulation of the recorded grating, Δn>0.1, and can form a film structure and be mass-produced and used.

[0119] The application of the foregoing photopolymerizable holographic recording medium of the present invention is described below.

[0120] The holographic optical element proposed by the present invention is made of a photopolymer-based holographic recording medium as described in each of the foregoing examples. The holographic optical element includes, but is not limited to, a volume holographic grating.

[0121] As can be seen from the above, since the holographic optical element proposed by the present invention contains the photopolymer-based holographic recording medium of the present invention, it also has the advantages of the photopolymer-based holographic recording medium of the present invention, with excellent holographic performance, high sensitivity, small required exposure amount, higher refractive index modulation of the recorded grating, and convenient production.

[0122] The optical device proposed by the present invention includes the aforementioned holographic optical element. The optical device includes, but is not limited to, a head-up display (HUD), an augmented reality device (AR device), a virtual reality device (VR device), a photopolymer-based holographic storage optical disc, etc. The photopolymer-based holographic storage optical disc can achieve erasable rewrite and real-time recording, is suitable for storing a large amount of data, and has a very fast data transmission speed.

[0123] As can be seen from the above, since the optical device proposed by the present invention contains the holographic optical element of the present invention, it also has the advantages of the holographic optical element of the present invention, with excellent holographic performance and convenient production of the optical device.

[0124] The following describes the photopolymer-based holographic recording medium of the present invention with reference to specific embodiments.

[0125] Example 1

[0126] In this example, the photopolymer-based holographic recording medium 1-1 includes raw materials of each component in the following weight parts:

[0127] First component: A total of 40 parts of a polyol compound and an isocyanate group compound. The polyol compound is phenylethylene glycol, and the isocyanate group compound is 2,4-toluene diisocyanate.

[0128] Second component: 40 parts of nanoparticles; the nanoparticles are zirconium dioxide.

[0129] Third component: 11 parts of a polymerizable monomer; the polymerizable monomer is methyl methacrylate.

[0130] Fourth component: 0.2 part of a photosensitive initiator combination; the photosensitive initiator combination includes a photosensitizer and a photoinitiator. Among them, 0.02 part of eosin Y is taken as the photosensitizer, and 0.18 part of benzophenone is taken as the photoinitiator.

[0131] Fifth component: 3 parts of a chain transfer agent; the chain transfer agent is mercaptoethanol.

[0132] Sixth component: 0.8 parts of catalyst; the catalyst is triethylenediamine.

[0133] Seventh component: 5 parts of additive. The additive includes an antioxidant and a leveling agent. Among them, the antioxidant is 2 parts of Irganox 1010 and 0.5 parts of Irganox 168, and the leveling agent is 2.5 parts of BYK-307.

[0134] Example 2

[0135] In this example, the photopolymerizable holographic recording medium 1-2 comprises raw materials of the following components in parts by weight:

[0136] First component: A total of 60 parts of a polyol compound and an isocyanate group compound. The polyol compound is 1,2-diphenylethylene glycol, and the isocyanate group compound is 4,4'-diphenylmethane diisocyanate.

[0137] Second component: 21.1 parts of nanoparticles; the nanoparticles are copper oxide.

[0138] Third component: 10 parts of a polymerizable monomer; the polymerizable monomer is pentaerythritol triacrylate.

[0139] Fourth component: 2 parts of a photosensitive initiator combination; the photosensitive initiator combination includes a photosensitizer and a photoinitiator. Among them, 0.3 part of rhodamine B is taken as the photosensitizer, and 1.7 parts of 2,4,6-trimethylbenzoyl diphenylphosphine oxide is taken as the photoinitiator.

[0140] Fifth component: 1.1 parts of a chain transfer agent; the chain transfer agent is hexanethiol.

[0141] Sixth component: 3 parts of catalyst; the catalyst is dimethylethanolamine.

[0142] Seventh component: 2.8 parts of solvent. The solvent is toluene.

[0143] Example 3

[0144] In this example, the photopolymerizable holographic recording medium 1-3 comprises raw materials of the following components in parts by weight:

[0145] First component: A total of 55 parts of a polyol compound and an isocyanate group compound. The polyol compound is 1,1'-bis(4-hydroxyphenyl)propane, and the isocyanate group compound is 1,3-bis(3-isocyanato-4-methylphenyl)-1,3-diazacyclo-2,4-butanedione.

[0146] Second component: 25 parts of nanoparticles; the nanoparticles are 15 parts of titanium monoxide and 10 parts of titanium sesquioxide.

[0147] The third component: 14 parts of polymerizable monomer; the polymerizable monomer is cyclohexyl methacrylate.

[0148] The fourth component: 1.1 parts of photosensitive initiator combination; the photosensitive initiator combination includes a photosensitizer and a photoinitiator. Among them, 0.3 part of rose bengal is taken as the photosensitizer, and 0.8 part of tetrabutylammonium tris-(3-chloro-4-methylphenyl) hexylborate is taken as the photoinitiator.

[0149] The fifth component: 2.4 parts of chain transfer agent; the chain transfer agent is 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol.

[0150] The sixth component: 2.4 parts of catalyst; the catalyst is dibutyltin dilaurate.

[0151] The seventh component: 0.1 part of solvent. The solvent is trichloroethane.

[0152] Example 4

[0153] In this example, the photopolymerizable holographic recording medium 1-4 comprises raw materials of each component in the following weight parts:

[0154] The first component: a total of 45 parts of polyol compound and isocyanate group compound. The polyol compound is 1,4-butanediol phthalate diol, and the isocyanate group compound is 2,4'-diphenylmethane diisocyanate.

[0155] The second component: 30 parts of nanoparticles; the nanoparticles are 15 parts of zinc oxide and 15 parts of niobium oxide.

[0156] The third component: 20 parts of polymerizable monomer; the polymerizable monomers are 10 parts of 1-propenyl-2-cycloheptyloxyethane and 10 parts of 2-hexyloxy-1,3-dipropenylpropane.

[0157] The fourth component: 0.1 part of photosensitive initiator combination; the photosensitive initiator combination includes a photosensitizer and a photoinitiator. Among them, 0.01 part of erythrosine is taken as the photosensitizer, and 0.09 part of 2,2-dimethoxy-phenylacetophenone is taken as the photoinitiator.

[0158] The fifth component: 0.1 part of chain transfer agent; the chain transfer agent is hexanethiol.

[0159] The sixth component: 0.1 part of catalyst; the catalyst is 1.3 parts of dibutyltin dilaurate.

[0160] The seventh component: 4.7 parts of additives. The additives include an antioxidant, a leveling agent and a plasticizer. Among them, 1.7 parts of Irganox B 900 is taken as the antioxidant, 2 parts of BYK-358 is taken as the leveling agent, and 1 part of glycerol is taken as the plasticizer.

[0161] Example 5

[0162] In this embodiment, the photopolymerizable holographic recording medium 1-5 comprises raw materials of each component in the following parts by weight:

[0163] The first component: A total of 59 parts of a polyol compound and an isocyanate group compound. The polyol compound is 1,6-hexanediol phthalate diol, and the isocyanate group compound is dimethyltriphenylmethane tetraisocyanate and dimethylbiphenyl diisocyanate with a molar ratio of 1:1.

[0164] The second component: 10 parts of nanoparticles; the nanoparticles are 5 parts of calcium oxide and 5 parts of iron oxide.

[0165] The third component: 13 parts of a polymerizable monomer; the polymerizable monomer is 1,2-diallyl-3-ethoxypropane.

[0166] The fourth component: 3 parts of a photosensitive initiator combination; the photosensitive initiator combination includes a photosensitizer and a photoinitiator. The photosensitizer is 0.5 part of eosin Y, and the photoinitiator is 2.5 parts of 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone.

[0167] The fifth component: 2 parts of a chain transfer agent; the chain transfer agent is mercaptoethanol.

[0168] The sixth component: 2 parts of a catalyst; the catalyst is N,N-bis(dimethylaminopropyl) isopropanolamine.

[0169] The seventh component: 8 parts of an additive. The additive contains an ultraviolet absorber, a light stabilizer, and an antioxidant. Among them, 2 parts of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxalamide is taken as the ultraviolet absorber, 3 parts of light stabilizer 944 is taken, and 3 parts of antioxidant Irganox B 900 is taken.

[0170] Example 6

[0171] In this embodiment, the photopolymerizable holographic recording medium 1-6 comprises raw materials of each component in the following parts by weight:

[0172] The first component: A total of 30 parts of a polyol compound and an isocyanate group compound. The polyol compound is 1,6-hexanediol isophthalate diol, and the isocyanate group compound is 1,3,5-tris(3-isocyanatomethylphenyl)-1,3,5-triazine-2,4,6-trione.

[0173] The second component: 11 parts of nanoparticles; the nanoparticles are chromium oxide.

[0174] The third component: 40 parts of a polymerizable monomer; the polymerizable monomer is 20 parts of neopentyl glycol diacrylate and 20 parts of 4-methylpentyl methacrylate.

[0175] Fourth component: 0.2 part of photoinitiator combination; the photoinitiator combination includes a photosensitizer and a photoinitiator, wherein the photosensitizer is 0.03 part of Rhodamine B and the photoinitiator is 0.17 part of 1-hydroxycyclohexyl phenyl ketone.

[0176] Fifth component: 0.3 part of chain transfer agent; the chain transfer agent is dodecyl mercaptan.

[0177] Sixth component: 0.5 part of catalyst; the catalyst is dibutyltin dilaurate.

[0178] Seventh component: 18 parts of additives. The additives include an antifoaming agent, a leveling agent, a plasticizer, an ultraviolet absorber, a light stabilizer and an antioxidant, wherein the antifoaming agent is 3 parts of BYK-1760, the leveling agent is 3 parts of BYK-329, the plasticizer is 3 parts of phthalate, the ultraviolet absorber is 3 parts of 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, the light stabilizer is 3 parts of bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, and the antioxidant is 3 parts of Irganox 3114.

[0179] Example 7

[0180] In this example, the photopolymerizable holographic recording medium 1-7 comprises raw materials of each component in the following weight parts:

[0181] First component: a total of 60 parts of a polyol compound and an isocyanate group compound, the polyol compound is tetraethylene glycol; the isocyanate group compound is 1,6-hexanediol phthalate diol, and the isocyanate group compound is polyaryl polyisocyanate.

[0182] Second component: 12 parts of nanoparticles, the nanoparticles are zinc selenide.

[0183] Third component: 18 parts of polymerizable monomer; the polymerizable monomer is 1-propenyl-2-methoxyethane.

[0184] Fourth component: 1 part of photoinitiator combination; the photoinitiator combination includes a photosensitizer and a photoinitiator, wherein the photosensitizer is 0.1 part of erythrosine and the photoinitiator is 0.9 part of 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone.

[0185] Fifth component: 1 part of chain transfer agent; the chain transfer agent is hexanethiol.

[0186] Sixth component: 2 parts of catalyst; the catalyst is bis(dimethylaminoethyl) ether.

[0187] Seventh component: 6 parts of additives. The additives include a leveling agent, an ultraviolet absorber, and an antioxidant. 3 parts of leveling agent BYK-329, 2 parts of ultraviolet absorber 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, and 1 part of antioxidant Irganox B900 are taken.

[0188] Example 8

[0189] In this example, the photopolymerizable holographic recording medium 1-8 comprises raw materials of each component in the following parts by weight:

[0190] First component: A total of 57 parts of a polyol compound and an isocyanate group compound. The polyol compound is 1,4-butanediol terephthalate diol; the isocyanate group compound is 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate.

[0191] Second component: 21 parts of nanoparticles. The nanoparticles are chromium oxide.

[0192] Third component: 12 parts of a polymerizable monomer; the polymerizable monomer is 1,1-diallyl-2-pentyloxyethane.

[0193] Fourth component: 3 parts of a photosensitive initiation combination agent; the photosensitive initiation combination agent includes a photosensitizer and a photoinitiator. Among them, 0.3 part of rose bengal is taken as the photosensitizer, and 2.7 parts of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide is taken as the photoinitiator.

[0194] Fifth component: 1.1 parts of a chain transfer agent; the chain transfer agent is hexanethiol.

[0195] Sixth component: 3 parts of a catalyst; the catalyst is bis(dimethylaminoethyl) ether.

[0196] Seventh component: 2.9 parts of additives. The additives are 1 part of ultraviolet absorber 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol and 1.8 parts of light stabilizer bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate.

[0197] Example 9

[0198] In this example, the photopolymerizable holographic recording medium 1-9 comprises raw materials of each component in the following parts by weight:

[0199] First component: A total of 55 parts of a polyol compound and an isocyanate group compound. The polyol compound is 1,4-butanediol terephthalate diol; the isocyanate group compound is tetramethyl-m-xylylene diisocyanate.

[0200] Second component: 12 parts of nanoparticles. The nanoparticles are niobium oxide.

[0201] The third component: 23 parts of polymerizable monomer; the polymerizable monomer is 5 parts of isostearyl methacrylate, 8 parts of 3 - allyl - 1,2 - dimethyloxypropane, and 10 parts of isobutyl acrylate.

[0202] The fourth component: 2.2 parts of photosensitive initiator combination; the photosensitive initiator combination includes a photosensitizer and a photoinitiator. Among them, 0.5 part of quinacridone red is used as the photosensitizer, and 1.7 parts of ethyl p - dimethylaminobenzoate is used as the photoinitiator.

[0203] The fifth component: 0.3 part of chain transfer agent; the chain transfer agent is phenyl ethyl mercaptan.

[0204] The sixth component: 0.5 part of catalyst; the catalyst is dibutyltin dilaurate.

[0205] The seventh component: 15 parts of additives. The additives include a leveling agent, a plasticizer, an ultraviolet absorber, a light stabilizer, and an antioxidant. 3 parts of BYK - 333 is used as the leveling agent, 3 parts of dimethylacetamide is used as the plasticizer, 3 parts of 2 - (2H - benzotriazol - 2 - yl) - 4,6 - bis(tert - pentyl)phenol is used as the ultraviolet absorber, 3 parts of Tinuvin 622 is used as the light stabilizer, and 1 part of Irganox 1010, 0.5 part of Irganox 168, and 1.5 parts of Irganox 1076 are used as antioxidants.

[0206] Comparative Example 1

[0207] In this example, it is substantially the same as each component in Example 3, except that the second - component nanoparticles in Example 3 are removed, and the addition amount of the third - component polymerizable monomer is increased to 39 parts, obtaining a common photopolymer - type holographic recording medium 2 - 1.

[0208] Test Example

[0209] Test the holographic performance of the gratings after recording gratings on the holographic recording media of Examples 1 - 9 and Comparative Example 1. The test method includes the following steps: During the test, according to the different photosensitive systems of Examples 1 - 9, lasers with different wavelengths can be selected for exposure. In the following test method, the photosensitive systems of the photopolymer - type holographic recording media in Examples 1, 3, 5, and 7 are used to select the corresponding - wavelength lasers for description.

[0210] Grating preparation: Use a solid - state laser with a wavelength of 532 nm as the light source. After passing through an expander, a beam splitter, and a half - wave plate, two beams with the same light intensity and a diameter of 8 mm are obtained. The two beams intersect inside the prepared holographic recording medium for exposure, and the light intensity is 3 mW / cm 2。The detection light source uses a 785 nm wavelength solid-state laser that does not react with the recording medium. The detection light is incident on the exposure area at the Bragg angle. The transmitted light and diffracted light are monitored in real time by a photodetector, and the single-grating diffraction efficiency (η) of the photopolymer holographic recording medium is calculated through formula (1). Using the laser with the grating recording wavelength as the probe light, irradiate the grating surface, rotate the grating left and right, record the diffraction efficiency of the grating at different angles, and obtain the refractive index modulation through fitting with the Kogelnik coupled-wave theory.

[0211]

[0212] In the formula, η is the diffraction efficiency, I d is the diffracted light, I t is the transmitted light.

[0213] The holographic performance tests of the photopolymer holographic recording media 1-1 to 1-9 in Examples 1-9 and the ordinary photopolymer holographic recording medium 2-1 in Comparative Example 1 are shown in Table 1 below.

[0214] Table 1 Holographic performance test table of each photopolymer holographic recording medium in Examples 1-9 and Comparative Example 1

[0215]

[0216] In summary, select the photopolymer holographic recording media 1-1, 1-2, 1-3, 1-4, 2-1 in Example 1, Example 2, Example 3, Example 4, and Comparative Example 1 to draw the selection angle curve of the corresponding recording grating and fit to obtain the refractive index modulation of the grating, and obtain Figures 1-5 and Table 1. Since the performance of the holographic recording medium 2-1 is poor and the grating cannot be recorded for the 3-micron sample, the 20-micron sample is selected. From Figures 1 to 5 and Table 1, it can be seen that compared with Comparative Example 1, the diffraction efficiency and refractive index modulation of the recording grating of the photopolymer holographic recording medium selected in the present invention are significantly improved.

[0217] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A photopolymer holographic recording medium, characterized in that: include: A writing monomer, wherein the writing monomer comprises nanoparticles and a polymerizable monomer, wherein the refractive index of the polymerizable monomer is less than the refractive index of the nanoparticles and the difference between the refractive index of the nanoparticles and the refractive index of the polymerizable monomer is greater than 0.5; A film-forming resin, wherein the film-forming resin comprises a polyol compound and an isocyanate compound; A catalyst, which is used to catalyze the reaction between the polyol compound and the isocyanate compound to form a film; A photosensitive initiator composition is used for sensitizing to light and inducing polymerization of the polymerizable monomer.

2. The photopolymer holographic recording medium according to claim 1, wherein: The refractive index of the nanoparticles is greater than 2.0, and the refractive index of the polymerizable monomer is less than 1.5; and / or, The nanoparticles are selected from at least one of zirconium dioxide, chromium oxide, copper oxide, zinc sulfide, titanium dioxide, titanium pentoxide, titanium trioxide, titanium monoxide, tantalum pentoxide, hafnium oxide, niobium oxide, zinc oxide, zinc selenide, and iron oxide nanoparticles; and / or, The polymerizable monomer includes at least one of a methacrylate compound, an acrylate compound, and an allyl ether compound; and / or, The polyol compound comprises at least two hydroxyl groups; and / or, The isocyanate compound comprises at least two isocyanate groups; and / or, The photosensitive initiator combination comprises a photosensitizer and a photoinitiator, and the absorption wavelength of the photosensitizer is different from the absorption wavelength of the photoinitiator; and / or, The catalyst is at least one of a tertiary amine catalyst and an organic metal catalyst.

3. The photopolymer holographic recording medium according to claim 1 or 2, wherein: The refractive index of the polymerizable monomer is lower than 1.5; wherein the acrylate compound includes methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, isobutyl acrylate, 2-ethylhexyl acrylate, tert-butyl acrylate, dodecyl acrylate, tetradecyl acrylate, hexadecyl acrylate, octadecyl acrylate, polyethylene glycol diacrylate, diethylene glycol dimethacrylate, tetraethylene glycol diacrylate, butanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, methoxy polyethylene glycol acrylate , hydroxypropyl methacrylate, trimethylolpropane triacrylate, hydroxyethyl acrylate, 2-(dimethylamino)ethyl acrylate, 2-methyl-2-acrylate-2-(2-methoxyethoxy)ethyl ester, disulfide acrylate, 2-acrylate-1,10-decanediyl ester, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, polyethylene glycol dimethacrylate, neopentyl glycol adipic acid diacrylate, hydroxypivalic acid neopentyl glycol diacrylate, dicyclopentyl diacrylate, hexanediol One or more of lactone-modified dicyclopentenyl diacrylate, methoxyethyl acrylate, ethoxyethyl acrylate, propoxyethyl acrylate, butoxyethyl acrylate, pentyloxyethyl acrylate, hexyloxyethyl acrylate, heptyloxyethyl acrylate, octyloxyethyl acrylate, nonyloxyethyl acrylate, decyloxyethyl acrylate, undecyloxyethyl acrylate, dodecyloxyethyl acrylate, tridecyloxyethyl acrylate, tetradecyloxyethyl acrylate, pentadecyloxyethyl acrylate, hexadecyloxyethyl acrylate, heptadecyloxyethyl acrylate, octadecyloxyethyl acrylate, nonadecyloxyethyl acrylate, eicosyloxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxypentyl acrylate, hydroxyhexyl acrylate, hydroxyheptyl acrylate, hydroxyoctyl acrylate, hydroxynonyl acrylate, hydroxydecyl acrylate, hydroxyundecyl acrylate, hydroxydodecyl acrylate, hydroxytridecyl acrylate, hydroxytetradecyl acrylate, hydroxypentadecyl acrylate, hydroxyhexadecyl acrylate, hydroxyheptadecyl acrylate, hydroxyoctadecyl acrylate, hydroxynonadecyl acrylate, and hydroxyeicosyl acrylate; and / or, The methacrylate compounds include but are not limited to methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, amyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, tetradecyl methacrylate, pentadecyl methacrylate, hexadecyl methacrylate, heptadecanyl methacrylate, octadecyl methacrylate, nonadecanyl methacrylate, eicosyl methacrylate, isopentyl methacrylate, isohexyl methacrylate, isoheptyl methacrylate, isooctyl methacrylate, isononyl methacrylate, isodecyl methacrylate, isoundecyl methacrylate, isododecyl methacrylate, isotridecyl methacrylate, isotetradecyl methacrylate, tert-butyl methacrylate, tert-amyl methacrylate, 2-ethylhexyl methacrylate, 3-methylbutyl methacrylate, 4-methylpentyl methacrylate, cyclopentyl methacrylate, cyclohexyl methacrylate, Cycloheptyl methacrylate, cyclooctyl methacrylate, cyclononyl methacrylate, cyclodecyl methacrylate, cyclododecyl methacrylate, benzyl methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-propoxyethyl methacrylate, 2-butoxyethyl methacrylate, 2-pentyloxyethyl methacrylate, 2-hexyloxyethyl methacrylate, 2-heptyloxyethyl methacrylate, 2-octyloxyethyl methacrylate, 2-nonyloxyethyl methacrylate, 2-decyloxyethyl methacrylate, methyl One or more of 2-undecyloxyethyl acrylate, 2-dodecyloxyethyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 6-hydroxyhexyl methacrylate, 2,3-dihydroxypropyl methacrylate, 2-aminoethyl methacrylate, 2-(dimethylamino)ethyl methacrylate, N,N-dimethylaminoethyl methacrylate, 2-cyanoethyl methacrylate, and 2-acetoxyethyl methacrylate; and / or, The allyl ether compounds include but are not limited to allyl ether (diallyl ether), 1-vinyl-2-oxypropane, 3,3'-oxybis-1-propylene (di-α-allyl ether), 1-propenyl-2-methyloxyethane, 1-propenyl-3-methyloxypropane, 1-propenyl-2-ethyloxyethane, 1-propenyl-2-propyloxyethane, 1-propenyl-2-butyloxyethane, 1-propenyl-2-pentyloxyethane, 1-propenyl-2-hexyloxyethane, 1-propenyl-2-heptyloxyethane, 1-propenyl-2-octyloxyethane, 1-propenyl-2-nonyloxyethane, 1-propenyl-2-decyloxyethane, 1-propenyl-2-(2-methylpropyl)oxyethane oxyethane, 1-propenyl-2-(1-methylethyl)oxyethane, 1-propenyl-2-cyclopentyloxyethane, 1-propenyl-2-cyclohexyloxyethane, 1-propenyl-2-cycloheptyloxyethane, 1-propenyl-2-cyclooctyloxyethane, 2-propenyl-1-methyloxyethane, 2-propenyl-1-ethyloxyethane, 2-propenyl-1-propyloxyethane, 2-propenyl-1-butyloxyethane, 2-propenyl-1-pentyloxyethane, 2-propenyl-1-hexyloxyethane, 2-propenyl-1-heptyloxyethane, 2-propenyl-1-octyloxyethane, 2-propenyl-1-nonyloxyethane, 2-propenyl-1-decyloxyethane, 2-propenyl-1-(2- 2-(2-(2-ethoxyethyl)oxy)ethane, 2-propenyl-1-cyclopentyloxyethane, 2-propenyl-1-cyclohexyloxyethane, 2-propenyl-1-(2-ethoxyethyl)oxyethane, 3-propenyl-1,2-dimethyloxypropane, 3-propenyl-1,2-diethyloxypropane, 3-propenyl-1-ethyl-2-methyloxypropane, 3-propenyl-1-methyl-2-ethyloxypropane, 2-methoxy-1,3-diapropenylpropane, 2-ethoxy-1,3-diapropenylpropane, 2-propoxy-1,3-diapropenylpropane, 2-butoxy-1,3-diapropenylpropane, 2-pentyloxy-1,3-diapropenylpropane, 2-hexyloxy-1,3-diapropenylpropane, 2-heptyloxy- 1,3-Dipropenylpropane, 2-octyloxy-1,3-dipropenylpropane, 2-(2-methylpropoxy)-1,3-dipropenylpropane, 2-cyclopentyloxy-1,3-dipropenylpropane, 2-cyclohexyloxy-1,3-dipropenylpropane, 1,1-dipropenyl-2-methoxyethane, 1,1-dipropenyl-2-ethoxyethane, 1,1-dipropenyl-2-propoxyethane, 1,1-dipropenyl-2-butoxyethane, 1,1-dipropenyl-2-pentyloxyethane, 1,1-dipropenyl-2-hexyloxyethane, 1,1-dipropenyl-2-heptyloxyethane, 1,1-dipropenyl-2-octyloxyethane, 1,1-dipropenyl-2-(2-methylpropoxy)ethane, 1,One or more of 1-dipropylene-2-cyclopentyloxyethane, 1,1-dipropylene-2-cyclohexyloxyethane, 1,2-dipropylene-3-methoxypropane, 1,2-dipropylene-3-ethoxypropane, and 1,2-dipropylene-3-propoxypropane.

4. The photopolymer holographic recording medium according to claim 1 or 2, wherein: The polyol compound is selected from phenyl glycol, 1,2-diphenyl glycol, 1,3-diphenyl propanediol, 1,4-diphenyl butanediol, 1,5-diphenyl pentanediol, 1,6-diphenyl hexanediol, ethylene terephthalate glycol, ethylene isophthalate glycol, ethylene phthalate glycol, 1,3-propanediol terephthalate, 1,4-butanediol terephthalate, 1,4-butanediol isophthalate glycol, 1,4-butanediol terephthalate glycol, 1,6-hexanediol terephthalate, 1,6-hexanediol isophthalate glycol, 1,6-hexanediol terephthalate glycol, 2,2-diphenyl-1,3-propanediol, 2,2-diphenyl-1,4-butanediol alcohol, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenylethane, 4,4'-dihydroxydiphenylpropane, 4,4'-dihydroxydiphenylbutane, 4,4'-bis(β-hydroxyethoxy)biphenyl, 4,4'-bis(α-methyl-β-hydroxyethoxy)biphenyl, 3,3'-dimethyl-4,4'-dihydroxybiphenyl, 3,3',5,5'-tetramethyl-4,4'-dihydroxybiphenyl, 2,2'-dimethyl-4,4'-dihydroxybiphenyl, 2,2'-diethyl-4,4'-dihydroxybiphenyl, 2,2'-diphenyl-4,4'-dihydroxybiphenyl, 1,1'-diphenyl-4,4'-diol, 1,1'-di( 1,1'-bis(4-hydroxyphenyl)propane, 1,1'-bis(4-hydroxyphenyl)butane, 1,1'-bis(4-hydroxyphenyl)pentane, 1,1'-bis(4-hydroxyphenyl)-3-methylbutane, 1,1'-bis(4-hydroxyphenyl)cyclohexane, 1,4-bis(4-hydroxyphenyl)benzene, 1,3-bis(4-hydroxyphenyl)benzene, 1,2-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, triphenylmethanol, tris(4-methylphenyl)methanol, tris(3-methylphenyl)methanol, tris(2-methylphenyl)methanol, tris(4-ethylphenyl)methanol, tris(4-propylphenyl)methanol, tris(4-butylphenyl)methanol, tris(4-phenylphenyl)methanol, 1,1,1-tris(4-hydroxyphenyl)ethane, 1,1,1-tris(3-hydroxyphenyl)ethane, 1,1,1-tris(2-hydroxyphenyl)ethane, 2,2,2-tris(4-hydroxyphenyl)propane, 2,2,2-tris(3-hydroxyphenyl)propane, 2,2,2-tris(2-hydroxyphenyl)propane, 1,1,2-tris(4-hydroxyphenyl)ethane, 1,1,2-tris(3-hydroxyphenyl)ethane, 1,2,2-tris(4-hydroxyphenyl)propane, 1,2,2-tris(3-hydroxyphenyl)propane, 1,2,3-tris(4-hydroxyphenyl)propane, 1,2,2-tris(4-hydroxyphenyl)propane, 1,2,2-tris(3-hydroxyphenyl)propane, 1,2,3-tris(4-hydroxyphenyl)propane, 1,2,2At least one of 3-tris(3-hydroxyphenyl)propane; and / or, The isocyanate compound is selected from 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-phenylene diisocyanate, xylylene diisocyanate, tetramethyl metaxylylene diisocyanate, dimethyl biphenyl diisocyanate, 3,3'-dimethyl-4,4'- At least one of diphenylmethane diisocyanate, polyaryl polyisocyanate, 1,3-bis(3-isocyanate-4-methylphenyl)-1,3-diazacyclo-2,4-butanedione, 1,3,5-tris(3-isocyanatetolyl)-1,3,5-triazine-2,4,6-trione, triphenylmethane-4,4',4"-triisocyanate, 4,4',4"-thiophosphoric acid triphenyl triisocyanate, and dimethyltriphenylmethane tetraisocyanate.

5. The photopolymer holographic recording medium according to claim 1, wherein: The photopolymer holographic recording medium further includes a chain transfer agent and an additive or a solvent.

6. The photopolymer holographic recording medium according to claim 5, wherein: The raw materials of each component are included in the following parts by weight: The first component: 30 to 70 parts of polyol compound and isocyanate compound; The second component: 10 to 40 parts of nanoparticles; The third component: 10 to 40 parts of polymerizable monomer; The fourth component: 0.1 to 3 parts of photosensitive initiator combination agent; The fifth component: 0.1 to 3 parts of chain transfer agent; The sixth component: 0.01 to 3 parts of catalyst; The seventh component: 0.1 to 18 parts of additives or solvents.

7. The photopolymer holographic recording medium according to claim 6, wherein: The chain transfer agent is a thiol compound; and / or, The catalyst is a tertiary amine catalyst and an organic metal catalyst; and / or, When the photopolymer type holographic recording medium includes additives, the additives include one or more of a defoaming agent, a leveling agent, a plasticizer, an ultraviolet absorber, a light stabilizer, and an antioxidant.

8. A method for preparing a photopolymer holographic recording medium as claimed in claim 6 or 7, characterized in that: The following steps are involved: Weigh the components of the photopolymer holographic recording medium into a container and stir them thoroughly until all the components are dissolved; filter the mixture using a filter membrane; apply the mixture to a substrate and cure it in a dark room at a temperature of 10° C. to 50° C. to obtain a photopolymer holographic recording medium after the polyol compound and the isocyanate compound form a film.

9. A holographic optical element, characterized in that: The raw material of the holographic optical element comprises the photopolymer holographic recording medium according to any one of claims 1 to 7.

10. An optical device, characterized in that: Comprising the holographic optical element as claimed in claim 9.

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