Unsaturated phenyl ether monomer, holographic recording medium, preparation method and related device

Abstract

The invention discloses an unsaturated phenyl ether monomer, a holographic recording medium, a preparation method and a related device, the structural general formula of the monomer is as shown in G1 and G2, R1 represents any one of R2, A1 and A2 independently represent any one of hydrogen and phenyl, A3 represents hydrogen or methyl, A4 represents C1-C4 alkyl or phenyl, n is a positive integer and n = 1-5. The unsaturated phenyl ether monomer provided by the invention has high refractive index and is in a liquid state, and the holographic recording medium with high sensitivity, high diffraction efficiency and high refractive index modulation degree can be obtained by applying the unsaturated phenyl ether monomer to preparation of the photopolymer type holographic recording medium.

Description

Technical Field

[0001] This application relates to the field of holographic materials technology, and in particular to an unsaturated phenyl ether monomer, a holographic recording medium, a preparation method, and related apparatus. Background Technology

[0002] Photopolymers used to fabricate holographic recording media typically include components such as photosensitive dyes, initiators, chain transfer agents, writing monomers, film-forming resins, and plasticizers. Photopolymers utilize light to polymerize the writing monomers, which then combine with the film-forming resin to form a refractive index-modulated phase-type holographic grating, thus achieving holographic recording. Specifically, when the writing monomers located in the coherent bright region are consumed and their concentration decreases, unreacted writing monomers located in the coherent dark region rapidly migrate to the coherent bright region, squeezing the film-forming resin from the bright region into the dark region. Ultimately, this results in the refractive index of the coherent bright region approaching that of the writing monomers, and the refractive index of the coherent dark region approaching that of the film-forming resin, thereby forming a refractive index-modulated phase-type volume holographic grating.

[0003] Therefore, improving the performance of photopolymers usually requires the base resin to have a lower refractive index and the writing monomer to have a higher refractive index to increase the refractive index difference between the two. However, the refractive index of the writing monomers currently available for photopolymers is usually below 1.6, resulting in a small refractive index difference between the writing monomer and the film-forming resin (usually 0.1 to 0.2). Meanwhile, monomers with high refractive index (n>1.65) are usually solids, which limits the diffusion and migration of monomers during the exposure process. Summary of the Invention

[0004] This application provides an unsaturated phenyl ether monomer with a high refractive index and a liquid state, which aims to solve the problem of limited diffusion and migration of solid monomers during exposure.

[0005] In a first aspect, this application provides an unsaturated phenyl ether monomer, the general structural formula of which is shown in any of the following:

[0006]

[0007] Where R1 represents R2 represents Any one of them;

[0008] A1 and A2 each independently represent hydrogen, phenyl, or... Any one of them;

[0009] A3 represents hydrogen or methyl, and A4 represents C1-C4 alkyl or phenyl.

[0010] n is a positive integer and n = 1 to 5.

[0011] As can be seen from the above technical solutions, the unsaturated phenyl ether monomers provided in the first aspect of this application possess a diphenyl disulfide structure with a high refractive index. Furthermore, the monomers contain highly polarizable groups such as phenoxy, alkyne, alkenyl, and acrylate groups, resulting in a high refractive index for the entire monomer molecule. The alkyne, alkenyl, and acrylate groups are low molar volume groups, exhibiting small free volume and a compact structure. Therefore, the entire monomer molecule has a small structure, a refractive index greater than 1.65 and less than 1.75, and exists in a liquid state.

[0012] Secondly, this application provides a method for preparing the above-mentioned unsaturated phenyl ether monomers, comprising the following steps:

[0013] Compound M1, compound M2 and a base reagent are dissolved in a first solvent, and SO2F2 gas is introduced to carry out the reaction, and a first mixture is obtained after the reaction. The first mixture is then separated to obtain compound P1.

[0014] Wherein, the first solvent is selected from any one of organic solvents or mixture systems, wherein the mixture system is formed by combining borax and the organic solvent, and the compound M1 is selected from compounds with the following general structural formula:

[0015]

[0016] A1 and A2 represent hydrogen and phenyl, respectively, independently. A4 represents C1-C4 alkyl or phenyl;

[0017] The compound M2 is selected from compounds with the following general structural formula:

[0018] The general structural formula of compound P1 is shown below: R1 represents

[0019] As can be seen from the above technical solutions, the preparation method of unsaturated phenyl ether monomers provided in the second aspect of this application is simple. It can construct the diphenyl disulfide structure without the aid of transition metal catalysts or oxidants and further obtain the desired unsaturated phenyl ether monomers through simple substitution reactions. This synthetic route conforms to the principles of green chemistry, is concise, and simple, and yields unsaturated phenyl ether monomers with a high yield of over 95%.

[0020] Thirdly, this application provides a photopolymer-type holographic recording medium, the raw material of which comprises the following components a)-h).

[0021] Component a) A compound having multiple isocyanate reactive functional groups;

[0022] Component b) Polyisocyanate group compounds;

[0023] Component c) Unsaturated phenyl ether monomers;

[0024] Component d) can polymerize monomers;

[0025] Component e) Photosensitive initiation system;

[0026] Component f) Chain transfer agent;

[0027] Component g) optionally a catalyst;

[0028] Component h) can be optionally added;

[0029] The unsaturated phenyl ether monomer is at least one of the aforementioned unsaturated phenyl ether monomers G1 or G2.

[0030] As can be seen from the above technical solution, this application achieves a sensitivity greater than 100 cm⁻¹ by introducing high-refractive-index unsaturated phenyl ether monomers into a photopolymer-type holographic recording medium. 2 / mJ, a photopolymer holographic recording medium with a recording grating diffraction efficiency greater than 95%, a refractive index modulation greater than 0.1 and a shrinkage rate less than 1% provides a material basis for the formation of a volume holographic grating with refractive index modulation using a photopolymer holographic recording medium.

[0031] Fourthly, this application provides a method for preparing the aforementioned photopolymer-type holographic recording medium, comprising:

[0032] Weigh the compound having multiple isocyanate reactive functional groups, the polyisocyanate group compound, the unsaturated phenyl ether monomer, the polymerizable monomer, the photoinitiator system, the chain transfer agent, the catalyst and the additive into a container, and stir thoroughly until dissolved to form a mixed solution;

[0033] The mixture solution is filtered using a filter membrane to obtain a first solution;

[0034] The first solution is coated onto a substrate and dried to obtain the photopolymer holographic recording medium.

[0035] As can be seen from the above technical solutions, the preparation method of the photopolymer-based holographic recording medium provided in this application is simple to operate and low in cost. It can ensure the uniform dispersion of each component, improve the light transmittance and refractive index modulation of the holographic recording medium, thereby enhancing the resolution and diffraction efficiency of the hologram. In addition, the filtration step can effectively remove impurities, reduce light scattering, and improve the storage stability and imaging quality of the holographic medium.

[0036] Fifthly, this application provides a volume holographic recording grating, wherein the photopolymer holographic recording medium used in the volume holographic recording grating includes the photopolymer holographic recording medium as described above.

[0037] Sixthly, this application provides a holographic optical element, the raw material of which includes the aforementioned photopolymer-type holographic recording medium.

[0038] In a seventh aspect, this application provides an optical device including the holographic optical element as described above.

[0039] As can be seen from the above technical solutions, this application also provides a related device made using the above-mentioned photopolymer holographic recording medium, based on the excellent properties of the photopolymer holographic recording medium, such as sensitivity greater than 100 cm / mJ, recording grating diffraction efficiency greater than 95%, refractive index modulation greater than 0.1 and shrinkage rate less than 1%.

[0040] Furthermore, based on a sensitivity greater than 100 cm / mJ, only extremely low exposure energy is required to form a stable grating, which can shorten exposure time, reduce laser power requirements, increase recording speed, and reduce energy consumption efficiency, making it suitable for dynamic recording and low-power devices. With a diffraction efficiency greater than 95%, it means that almost all incident light energy is diffracted to the target direction by the grating, thus reducing light energy loss and resulting in a clearer image. With a refractive index modulation greater than 0.1, the grating's diffraction capability is enhanced, contributing to a wider field of view. With a shrinkage rate less than 1%, accurate grating periodicity is ensured, avoiding optical distortion and reducing image quality. Therefore, target devices (such as volume holographic recording gratings, optical elements, and optical devices) fabricated using photopolymer holographic recording media possess optical properties such as high recording speed and clear imaging. Attached Figure Description

[0041] Figure 1 The exposure characteristic curves of photopolymer holographic recording media 7-1, 7-3, and 7-5 in Embodiment 7 of this application are shown.

[0042] Figure 2 The exposure characteristic curves of ordinary photopolymer holographic recording media of Comparative Examples 1 and 3 of this application are shown. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0045] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0046] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0047] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0048] It should be understood that photopolymer-based holographic recording media materials used for holographic recording utilize light to polymerize writing monomers, which then form a refractive index-modulated phase-type holographic grating with the film-forming resin to achieve holographic recording. In the coherent bright region, monomer polymerization is consumed, resulting in a decrease in concentration, while in the coherent dark region, monomers hardly react. The difference in monomer concentration between the bright and dark regions causes monomers in the dark region to begin migrating towards the bright region. Simultaneously, the film-forming resin in the bright region is squeezed into the dark region. Ultimately, the refractive index of the bright region approaches the refractive index of the polymer, and the refractive index of the dark region approaches the refractive index of the film-forming resin, thus forming a refractive index-modulated phase-type volume holographic grating.

[0049] It should be noted that photopolymer-based holographic recording media with superior performance typically require the film-forming resin to have a lower refractive index and the writing monomer to have a higher refractive index in order to increase the refractive index difference between the two. However, the refractive index of the writing monomer currently available for photopolymers is typically below 1.6, resulting in a relatively small refractive index difference between the writing monomer and the film-forming resin (typically 0.1–0.2).

[0050] In addition, high refractive index monomers (n>1.65) are usually solids, which are prone to crystallization during polymerization. Their poor fluidity makes it difficult for them to diffuse and migrate, which limits the diffusion and migration of monomers during exposure, resulting in poor performance of photopolymers.

[0051] It is understandable that molecules in solids are typically arranged in a close-packed state, their movement not only restricted by the fixed positions of surrounding molecules, making free movement difficult, but also because the scarcity and fixed nature of free volume in solids necessitates overcoming higher activation energies for migration. In contrast, the dynamic "free volume" surrounding liquid molecules effectively promotes diffusion.

[0052] Based on this, this application provides an unsaturated phenyl ether monomer as a component of a writing monomer, the general structural formula of which is shown in G1 or G2:

[0053]

[0054] Where R1 represents R2 represents Any one of them, A1 and A2 independently represent hydrogen, phenyl or Any one of them, A3 represents hydrogen or methyl, A4 represents C1-C4 alkyl or phenyl, and n is a positive integer and n = 1 to 5.

[0055] In this embodiment, the unsaturated phenyl ether monomer has a high-refractive-index diphenyl disulfide structure. The high electronic polarizability and molecular packing effect of the sulfur atom, as well as the conjugation effect of the benzene ring, all significantly affect the refractive index of the monomer. Furthermore, the monomer contains highly polarizable groups such as phenoxy, alkyne, alkenyl, and acrylate groups, which synergistically promote the increase in refractive index. Among these, the alkyne, alkenyl, and acrylate groups are low molar volume groups, characterized by small free volume and compact structure. Therefore, the entire monomer molecule has a small size, a refractive index greater than 1.65 and less than 1.75, and is in a liquid state. It should be understood that the liquid monomer has better fluidity, diffuses more easily, and does not precipitate crystals during exposure, thus not affecting diffusion and migration.

[0056] In addition, the rigid structure of the benzene ring can reduce volume shrinkage during the polymerization process, thereby maintaining the grating period accuracy and avoiding optical distortion that could lead to poor imaging.

[0057] It is understandable that, for the same physical thickness, materials with high refractive index can provide stronger phase modulation, reducing the absorption and scattering of light in the medium during holographic recording, thereby achieving the effects of reducing device size and improving diffraction efficiency. At the same time, a higher refractive index helps to enhance the optical anisotropy of the material, optimizing the resolution and storage capacity of the hologram.

[0058] In some examples, unsaturated phenyl ether monomers include, but are not limited to, compounds having the following general structural formula:

[0059]

[0060]

[0061]

[0062]

[0063] This application also provides a method for preparing the above-mentioned unsaturated phenyl ether monomers, comprising the following steps:

[0064] Step S101: Dissolve compound M1, compound M2 and alkaline reagent in a first solvent, and pass SO2F2 gas through to react and obtain a first mixture after the reaction. Separate the first mixture to obtain compound P1.

[0065] The first solvent is selected from any one of organic solvents or mixture systems, wherein the mixture system is formed by combining borax and the organic solvent, and compound M1 is selected from compounds with the following general structural formula: A1 and A2 represent hydrogen and phenyl, respectively, independently. A4 represents C1-C4 alkyl or phenyl. Compound M2 is selected from compounds with the following general structural formula: The general structural formula of compound P1 is shown below: Where R1 represents

[0066] It is understood that in step S101, compounds M1 and M2 react under the action of sulfuryl chloride gas and an alkaline reagent to generate diphenyl disulfide. In this step, compounds M1 and M2 first form a highly nucleophilic benzyl thiolate (PhS) (compound M1 or compound M2) under the action of an alkaline reagent, and further attack the sulfur atom of sulfuryl fluoride (SO2F2) to generate a thiosulfate intermediate (Ph-SOF). The thiosulfate (Ph-SOF) is unstable under alkaline conditions and can be attacked by another molecule of benzyl thiolate (compound M2 or compound M1) to generate diphenyl disulfide (Ph-SS-Ph).

[0067] It can also be understood that the first mixture includes at least compound M1, compound M2, compound P1, a base reagent, a benzene thiolate, and a thiosulfate intermediate.

[0068] In some specific examples, step S101 is carried out at 0-25°C for 0.5-3 hours, with fewer byproducts and a higher yield of compound P1.

[0069] It should be understood that in step S101, the base reagent has the function of activating benzenethiols (i.e., compounds M1 and M2) and promoting the reaction process. The base reagent includes, but is not limited to, one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, triethylamine, 1,5-diazabicyclo[4.3.0]non-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene, and tetramethylsilyl trifluoromethanesulfonate.

[0070] In some specific examples, in step S101, the molar ratio of compound M1, compound M2 and base reagent is 1:(1-1.2):(2-3).

[0071] Typical, but not limiting, molar ratios of compound M1, compound M2, and base reagent may be, for example, 1:1:2, 1:1:3, 1:1.1:2, 1:1.2:2, 1:1.1:3, or 1:1.2:3.

[0072] Furthermore, the organic solvent includes, but is not limited to, one or more of petroleum ether, dichloromethane, trichloromethane, ethyl acetate, tetrahydrofuran, acetonitrile, benzene, toluene, N,N-dimethylformamide, dimethyl sulfoxide, dimethoxyethane, and 1,4-dioxane. The first solvent includes an organic solvent, or the first solvent is a mixture of borax and an organic solvent. In some specific examples, when the first solvent is a mixture of borax and an organic solvent, the mass ratio of borax to organic solvent is 1:1.

[0073] It should be noted that the solvents mentioned above are merely illustrative examples, and the solvents that can be used in this application are not limited to these.

[0074] For example, 1 equivalent of compound M1, 1 equivalent of compound M2, and 2 equivalents of triethylamine were dissolved in dichloromethane. The air in the reaction system was replaced with nitrogen, and SO2F2 gas was introduced. After stirring for approximately 30 minutes, an acetonitrile solution of thiol and triethylamine (molar ratio of thiol to triethylamine 1:1 to 1:1.5) was added to the reaction system to quench excess SO2F2. The organic phase was extracted three times, dried with anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. Compound P1 was obtained by column chromatography.

[0075] The preparation structure has the general formula G1, and R2 in G1 is... The unsaturated phenyl ether monomers, in addition to the aforementioned step S101, also include the following steps:

[0076] Step S102: Dissolve compound P1 in an organic solvent and perform the first treatment operation to obtain a second mixture. Add a deprotonating agent to the second mixture to obtain a third mixture after the reaction. Add compound M3 to the third mixture to obtain a fourth mixture after the reaction. Separate the fourth mixture to obtain an unsaturated phenyl ether monomer G1. Compound M3 is selected from compounds with the following structural formulas:

[0077] It is understandable that the deprotonating agent deprotonates the hydroxyl group in compound P1, forming a more reactive phenoxy anion intermediate I. Phenoxy anion intermediate I further attacks the carbon in the brominated hydrocarbon (i.e., compound M3), and the bromide ion leaves as a leaving group to obtain the unsaturated phenyl ether monomer G1.

[0078] The first processing operation includes a cooling operation and a stirring operation. The cooling operation and the stirring operation can be performed simultaneously or separately. For example, the cooling operation can be performed while stirring, or the stirring operation can be performed for a period of time before the cooling operation is performed. This application does not limit the operation.

[0079] It is understood that deprotonating agents include, but are not limited to, organometallic bases, metal amino compounds, metal alkoxides and metal hydrides, inorganic bases and organic bases.

[0080] Organometallic bases include, but are not limited to, alkyllithium reagents, aryllithium reagents, and aminolithium reagents. Typically, when using organometallic bases and metal amino compounds, the reaction must be carried out under anhydrous and oxygen-free conditions, and they are usually added dropwise to the reaction system at -78°C. Further, alkyllithium reagents include at least n-butyllithium and tert-butyllithium, aryllithium reagents include at least phenyllithium, and aminolithium reagents include at least diisopropylaminolithium and hexamethyldisilaminolithium. Metal amino compounds include, but are not limited to, sodium amino, potassium amino, and bis(trimethylsilyl)aminosodium. Metal alkoxides include, but are not limited to, sodium methoxide, sodium ethoxide, potassium tert-butoxide, and sodium tert-butoxide; metal hydrides include, but are not limited to, sodium hydride and potassium hydride; inorganic bases include, but are not limited to, potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, and potassium phosphate; and organic bases include, but are not limited to, triethylamine, 1,5-diazabicyclo[4.3.0]non-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene, and tetramethylsilyltrifluoromethanesulfonate.

[0081] It should be further understood that when using deprotonating agents to deprotonate, it is necessary to determine whether the reaction needs to be carried out in an inert environment based on factors such as the different types of deprotonating agents and the properties of the reaction substrate. For example, inert gas protection can be used, including but not limited to nitrogen and argon. In other words, those skilled in the art can provide inert protection for the reaction according to actual needs, and this application does not limit it.

[0082] It should be noted that deprotonation reactions typically need to be carried out at low temperatures (-80℃ to 0℃). The choice of reaction temperature depends on the selection of the deprotonating agent, the stability and activity of the reaction substrate, and the melting point of the reaction solvent. After the deprotonation reaction is completed, the temperature can be raised according to actual needs (e.g., the activity of the reaction substrate, the reaction rate, etc.). Specifically, when organometallic bases and metal amino compounds (e.g., n-butyllithium) are used as deprotonating agents, the deprotonation reaction usually needs to be carried out at -30 to -80℃ in an inert environment to obtain better reaction results, suppress the generation of side reactions, and improve the regioselectivity of the reaction. When metal alkoxides and metal hydrides (e.g., sodium hydride, sodium methoxide, etc.) are used as deprotonating agents, the deprotonation reaction is usually carried out at 0℃ (i.e., in an ice bath), and the reaction time is usually 0.5h to 10h. It can be understood that the reaction time is related to the amount of deprotonating agent and the activity of the reaction substrate, etc., which are not limited in this application.

[0083] It should also be noted that the deprotonating agent should be added to the reaction system in batches and slowly to avoid violent reaction that could cause damage to the sprayed material and personnel.

[0084] It can also be understood that the second mixture includes at least compound P1, the third mixture includes at least compound M3, compound P1, a deprotonating agent, and phenoxy anion intermediate I formed after compound P1 is activated, and the fourth mixture includes at least unsaturated phenyl ether monomer G1, compound M3, phenoxy anion intermediate I, and a deprotonating agent.

[0085] For example, under ice bath conditions, 1 equivalent of compound P1 was dissolved in tetrahydrofuran, and 2–3 equivalents of sodium hydride were slowly added. After stirring for 0.5–10 h, 2–3 equivalents of compound M3 were added dropwise to the reaction system. After the addition was complete, stirring was continued for another 0.5–10 h. After the reaction was complete, dilute hydrochloric acid was slowly added dropwise to quench the reaction. The organic phase was extracted, washed three times with water, dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. The unsaturated phenyl ether monomer G1 was obtained by column chromatography.

[0086] In some specific examples, the molar ratio of compound P1, the deprotonating agent, and compound M3 is 1:(1-3):(1-3).

[0087] Typical, but not limiting, molar ratios of compound P1, deprotonating agent, and compound M3 can be, for example, 1:1:1, 1:1:2, 1:2:3, 1:2:2, 1:3:3, 1:3:2, etc.

[0088] The preparation structure has the general formula G1, and R2 in G1 is... The unsaturated phenyl ether monomers, in addition to the aforementioned step S101, also include the following steps:

[0089] Step S103: Dissolve compound P1 and an acid-binding agent in an organic solvent, and add compound M4 to react, obtaining a fifth mixture after the reaction. Separate the fifth mixture to obtain an unsaturated phenyl ether monomer G1. Compound M4 is acryloyl chloride or methacryloyl chloride.

[0090] It is understandable that when A3 represents hydrogen, compound M4 is acryloyl chloride, and when A3 represents methyl, compound M4 is methacryloyl chloride.

[0091] It can also be understood that in step S103, compound P1 is activated by an acid-binding agent to generate a more reactive alkoxy group, thereby enhancing nucleophilicity and further promoting the substitution reaction between compound P1 and compound M3 to form an ester, thus yielding the unsaturated phenyl ether monomer G1. In specific examples, the reaction is usually carried out at 0°C (i.e., in an ice bath), and compound M3 is added dropwise to the mixed solution of compound P1 and triethylamine at 0°C to avoid local overheating or excessive concentration that could trigger side reactions. A reaction time of 0.5 h to 3 h typically yields optimal reaction results.

[0092] It should be noted that the fifth mixture includes at least compound P1, an acid-binding agent, compound M4, and an unsaturated phenyl ether monomer G1.

[0093] For example, compound P1 and triethylamine were dissolved in dichloromethane under ice bath conditions. After stirring for 10 min, acryloyl chloride or methacryloyl chloride was added dropwise to the mixed solution of compound P1 and triethylamine at 0 °C. After the reaction was complete, dilute hydrochloric acid was added dropwise to remove excess acryloyl chloride or methacryloyl chloride. The mixture was then washed successively with saturated NaCl solution, saturated NaHCO3 solution, and deionized water. The organic phase was dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. The unsaturated phenyl ether monomer G1 was obtained by column chromatography.

[0094] In some specific examples, the reaction is more effective when step S103 uses any one of dichloromethane, trichloromethane, and ethyl acetate as the reaction solvent.

[0095] The acid-binding agents include, but are not limited to, one or more of the following: triethylamine, pyridine, N,N-diisopropylethylamine, 4-dimethylaminopyridine, tetrabutylammonium bromide, potassium carbonate, ammonium carbonate, and sodium carbonate.

[0096] It should be further understood that, because compound M4 (i.e., acryloyl chloride or methacryloyl chloride) is a highly reactive acylating agent, it is prone to side reactions, leading to a reduction in the actual amount participating in the target reaction. Therefore, it is usually necessary to use an excess to compensate for the consumption by side reactions and ensure sufficient acryloyl chloride reacts with the substrate. Furthermore, since the acid-binding agent needs to provide basic conditions to promote the deprotonation of compound P1 and neutralize the hydrochloric acid generated in the reaction to prevent the decomposition of the substrate or product, the acid-binding agent also usually needs to be used in excess. Specifically,

[0097] In some examples, the molar ratio of compound P1, acid-binding agent, and compound M4 is 1:(2-4):(1-3).

[0098] Typical, but not limiting, molar ratios of compound P1, acid-binding agent, and compound M3 can be, for example, 1:4:2, 1:4:3, 1:3:3, 1:3:2, and 1:3.5:2.5.

[0099] The preparation of unsaturated phenyl ether monomers with the general structural formula G2 includes, in addition to the aforementioned step S101, the following steps:

[0100] Step S104: Dissolve compound P1 in an organic solvent and perform the first treatment operation to obtain a second mixture. Add a deprotonating agent to the second mixture to obtain a third mixture after the reaction. Add compound M5 to the third mixture to obtain a sixth mixture after the reaction. Separate the sixth mixture to obtain compound P2.

[0101] The general structural formula of compound M5 is as follows: n is a positive integer and n = 1 to 5. The general structural formula of compound P2 is:

[0102] It should be noted that the reaction mechanism of step S104 is similar to that of step S102, and the relevant description can be found in step S102, so it will not be repeated here. It can also be understood that the sixth mixture includes at least compound P1, compound M5, a deprotonating agent, phenoxy anion intermediate I, and compound P2.

[0103] In some examples, the molar ratio of compound P1, the deprotonating agent, and compound M5 is 1:(1-3):(1-1.5).

[0104] Typical, but not limiting, molar ratios of compound P1, the deprotonating agent, and compound M5 may be, for example, 1:2:1.2, 1:3:1.5, 1:1:1, and 1:1.5:1.3.

[0105] The general formula for the preparation structure is G2, where R2 in G2 represents... The unsaturated phenyl ether monomers, in addition to the aforementioned steps S101 and 104, also include the following steps:

[0106] Step S105: Dissolve compound P2 in an organic solvent and perform the first treatment operation to obtain a seventh mixture. Add a deprotonating agent to the seventh mixture to obtain a reaction-reacted eighth mixture. Add compound M3 to the eighth mixture to obtain a reaction-reacted ninth mixture. Separate the ninth mixture to obtain an unsaturated phenyl ether monomer G2.

[0107] It should be noted that the reaction principle and conditions of step S105 are the same as those of step S102. The difference is that the reaction substrate is different, namely compound P2 or compound P1. The relevant content of step S105 can be referred to step S102, and will not be repeated here.

[0108] It can also be understood that the seventh mixture includes at least compound P2, the eighth mixture includes at least compound P2, a deprotonating agent and phenoxy anion intermediate II formed after compound P2 is activated, and the ninth mixture includes at least compound M3, compound P2, a deprotonating agent, phenoxy anion intermediate II and unsaturated phenyl ether monomer G2.

[0109] In some specific examples, the molar ratio of compound P2, the deprotonating agent, and compound M3 is 1:(1-3):(1-3).

[0110] Typical, but not limiting, molar ratios of compound P2, the deprotonating agent, and compound M3 can be, for example, 1:1:1, 1:1:2, 1:2:3, 1:2:2, 1:3:3, 1:3:2, etc.

[0111] The general formula for the preparation structure is G2, where R2 in G2 represents... The unsaturated phenyl ether monomers, in addition to the aforementioned steps S101 and 104, also include the following steps:

[0112] Step S106: Dissolve compound P2 and the acid-binding agent in an organic solvent, and add compound M4 to react and obtain the tenth mixture after the reaction. Separate the tenth mixture to obtain the unsaturated phenyl ether monomer G2.

[0113] It is understood that the tenth mixture includes at least compound P2, acid-binding agent, compound M4, and unsaturated phenyl ether monomer G2.

[0114] It should be noted that the reaction principle and conditions of step S106 are the same as those of step S103. The difference is that the reaction substrate is different, namely compound P2 or compound P1. The relevant content of step S106 can be referred to step S103, and will not be repeated here.

[0115] In some specific examples, the molar ratio of compound P2, acid-binding agent and compound M4 is 1:(2-4):(1-3).

[0116] Typical, but not limiting, molar ratios of compound P2, acid-binding agent, and compound M4 may be, for example, 1:4:2, 1:4:3, 1:3:3, 1:3:2, and 1:3.5:2.5.

[0117] In this embodiment, the diphenyl disulfide structure can be constructed without the aid of transition metal catalysts or oxidants, and the desired unsaturated phenyl ether monomers can be obtained through a simple substitution reaction. This synthetic route conforms to the principles of green chemistry, is concise, simple, and yields unsaturated phenyl ether monomers in high quantities, exceeding 95%.

[0118] This application also provides a photopolymer-type holographic recording medium, including a writing monomer, which includes unsaturated phenyl ether monomers and polymerizable monomers.

[0119] It should be understood that the refractive index of unsaturated phenyl ether monomers is positively correlated with the refractive index of writing monomers; that is, when the refractive index of unsaturated phenyl ether monomers is high, the refractive index of the resulting writing monomer is also high.

[0120] Furthermore, in some embodiments, the raw material of the photopolymer-type holographic recording medium comprises the following components a)-h):

[0121] Component a) A compound having multiple isocyanate reactive functional groups.

[0122] Component b) Polyisocyanate group compounds,

[0123] Component c) at least one of the aforementioned unsaturated phenyl ether monomers G1 or G2,

[0124] Component d) can polymerize monomers.

[0125] Component e) Photosensitive initiation system,

[0126] Component f) Chain transfer agent,

[0127] Component g) optionally a catalyst,

[0128] Component h) can be optionally added.

[0129] Among them, compounds with multiple isocyanate reactive functional groups and polyisocyanate group compounds form film-forming resins.

[0130] In this embodiment, unsaturated phenyl ether monomers with high refractive index are used as one of the components of the writing monomer, thereby enabling a greater refractive index difference between the writing monomer and the film-forming resin, thus forming a photopolymer-type holographic recording material with excellent properties such as high sensitivity and high diffraction efficiency. Specifically, the photopolymer-type holographic recording medium thus prepared has a photosensitivity greater than 100 cm / mJ, a recording grating diffraction efficiency greater than 95%, a refractive index modulation greater than 0.1, a shrinkage rate less than 1%, and an exposure amount less than 20 mJ / cm. 2 Its excellent properties.

[0131] More specifically, in some examples, the composition and content of photopolymer-type holographic recording media are as follows:

[0132] Component a) 10 wt% to 50 wt% of compounds having multiple isocyanate reactive functional groups.

[0133] Component b) Polyisocyanate group compound 10wt%–50wt%,

[0134] Component c) Unsaturated phenyl ether monomers, 1 wt% to 30 wt%.

[0135] Component d) can polymerize monomers ranging from 10 wt% to 40 wt%.

[0136] Component e) Photoinitiator system 0.1wt%~3wt%,

[0137] Component f) Chain transfer agent 0.1 wt% to 3 wt%,

[0138] Component g) Catalyst 0.1wt%~5wt%,

[0139] Component h) Additives: 0.1 wt% to 10 wt%.

[0140] In this embodiment, by rationally controlling the composition ratio of the photopolymer holographic recording medium, the various components can work together fully, and the holographic performance of the final photopolymer holographic recording medium will not deteriorate due to an excess or deficiency of a certain component. This ensures that the final photopolymer holographic recording medium has better overall holographic performance, thereby achieving high resolution, high diffraction efficiency and long-term stability.

[0141] In some embodiments, the unsaturated phenyl ether monomers account for 0.1 wt% to 30 wt% of the total content of the photopolymer holographic recording medium.

[0142] Typical, but not limiting, the content of unsaturated phenyl ether monomers in the entire photopolymer holographic recording medium can be 0.1 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, or any combination of two values.

[0143] In this embodiment, the content of unsaturated phenyl ether monomers ranges from 0.1 wt% to 30 wt%, ensuring that sufficient active monomers are provided to participate in photopolymerization so that the resulting writing monomers have a sufficient concentration to achieve the concentration difference between the bright and dark areas after the reaction under light.

[0144] In some embodiments, the isocyanate reactive functional group is a hydroxyl group. Compounds having multiple isocyanate reactive functional groups include compounds with a refractive index less than or equal to a first refractive index threshold and having two or more hydroxyl functional groups, wherein the first refractive index threshold is any value between 1.5 and 1.55. Optionally, polyisocyanate-based compounds include compounds with a refractive index less than or equal to a second refractive index threshold and having two or more isocyanate groups, wherein the second refractive index threshold is any value between 1.5 and 1.55.

[0145] Typically, but not restrictively, the first refractive index threshold can be 1.5, 1.51, 1.52, 1.53, 1.54, 1.55, or any value between any two values, and the second refractive index threshold can be 1.5, 1.51, 1.52, 1.53, 1.54, 1.55, or any value between any two values.

[0146] In this embodiment, a compound with multiple isocyanate reactive functional groups having a refractive index less than or equal to 1.5 to 1.55 forms a low-refractive-index film-forming resin with a polyisocyanate group compound having a refractive index less than or equal to 1.5 to 1.55. The low-refractive-index film-forming resin and the high-refractive-index writing monomer (i.e., including the aforementioned unsaturated phenyl ether monomers) form a significant refractive index difference (Δn≥0.1), which can enhance the diffraction efficiency of the holographic grating, while avoiding the increase in background noise caused by the high refractive index of the substrate itself.

[0147] In some embodiments, the isocyanate reactive functional group is a hydroxyl group, and the molar ratio of hydroxyl group to isocyanate functional group is 1:1. That is, in the film-forming resin that forms a photopolymer type holographic recording medium, the molar ratio of hydroxyl group in the compound having multiple isocyanate reactive functional groups to isocyanate functional group in the polyisocyanate group compound is 1:1.

[0148] Furthermore, in some examples, the compound having multiple isocyanate reactive functional groups may be one or more of tetraethylene glycol, trimethylolethane, glycerol, triethanolamine, polyester polyols with a molecular weight of 200 to 2000, polycarbonate polyols, and polyether polyols, but is not limited thereto.

[0149] Polyisocyanate compounds include, but are not limited to, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, (2,4,6-trioxotriazine-1,3,5(2H,4H,6H)-triyl)tri(hexamethylene)isocyanate, butane-1,4-diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate.

[0150] In some examples, the polymerizable monomer is selected from at least one of alkenylnaphthalene compounds, alkenylanthracene compounds, alkenylbenzene compounds, acrylic compounds, methacrylic acid compounds, acrylate compounds, methacrylate compounds, N-vinylpyrrole, N-vinylcarbazole, N-vinylimidazol, N-vinylindole, N-vinylpyrrolidone, and trans-N-3-yntynebutenylcarbazole.

[0151] In specific examples, alkenylbenzene compounds include, but are not limited to, styrene, 2-chlorostyrene, 2-bromostyrene, 3-chlorostyrene, 3-bromostyrene, 4-chlorostyrene, 4-bromostyrene, p-(chloromethyl)styrene, and p-(bromomethyl)styrene.

[0152] For example, methacrylic acid compounds can be methacrylic acid and its derivatives. For instance, methacrylate compounds can be selected from 2-phenoxyethyl methacrylate, benzyl methacrylate, p-bromophenyl methacrylate, p-chlorophenyl methacrylate, 2,4,6-trichlorophenyl methacrylate, pentabromophenyl methacrylate, pentachlorophenyl methacrylate, phenoxyethyl methacrylate, phenoxyethoxyethyl methacrylate, 1,4-di(2-thionaphthyl)2-butyl methacrylate, pentabromobenzyl methacrylate, 2-naphthyl methacrylate, bisphenol A dimethacrylate, tetrabromobisphenol A dimethacrylate, etc.

[0153] In specific examples, acrylate compounds include, but are not limited to, pentabromophenyl acrylate, pentachlorophenyl acrylate, phenoxyethyl acrylate, pentabromobenzyl acrylate, 2-naphthyl acrylate, 1,4-di(2-thionaphthyl)2-butyl acrylate, phenoxyethoxyethyl acrylate, bisphenol A diacrylate, tetrabromobisphenol A diacrylate, 2-phenoxyethyl acrylate, benzyl acrylate, p-chlorophenyl acrylate, 2,4,6-trichlorophenyl acrylate, p-bromophenyl acrylate, 2,4,6-tribromophenyl acrylate, propane-2,2-diylbis[(2,6-dibromo-4,1-phenylene)oxy(2-{[3,3,3-tris(4-chlorophenyl)propionyl]oxy}propane-3,1-diyl)oxyethane-2,1-diyl]diacrylate.

[0154] In specific examples, vinylanthracene compounds may be selected from 2-vinylanthracene, 9-vinylanthracene, etc.

[0155] In specific examples, vinylnaphthalene compounds can be selected from 1-vinylnaphthalene, 2-vinylnaphthalene, etc.

[0156] In some implementations, the photoinitiation system is composed of a photosensitizer and a photoinitiator, which work synergistically to construct a broadband visible light initiation system. The photosensitizer selectively absorbs laser energy at specific wavelengths (e.g., 532 nm or 633 nm) and activates the photoinitiator through an energy transfer mechanism, thereby significantly expanding the system's photosensitive wavelength range. Therefore, different broadband responses can be achieved by controlling the type of photosensitizer. Under irradiation with light within a specific wavelength range, the photosensitizer in the photoinitiation system is activated accordingly, absorbs light energy, and transfers the light energy to the photoinitiator. This allows the photoinitiator to be activated under light radiation of more frequencies. The activated photoinitiator efficiently generates active free radicals, rapidly initiating monomer polymerization reactions, thus enabling the construction of a holographic grating structure. This improves the photosensitivity of the photopolymer-based holographic recording medium and enhances compatibility with lasers of different wavelengths, providing a more flexible light source selection scheme for holographic storage.

[0157] It is understandable that when a photoinitiator with a suitable wavelength is selected in the raw materials of a photopolymer holographic recording medium, a photosensitizer may not be added. For example, when the photoinitiator is diacetic titanium (Irgacure 784), a photosensitizer may not be added. This highly reactive orange solid photoinitiator can initiate the polymerization reaction of unsaturated resins under visible or ultraviolet light.

[0158] In some examples, the mass ratio of photosensitizer to photoinitiator is (0.001 to 1):(0.1 to 3). Typically, but not limitingly, the mass ratio of photosensitizer to photoinitiator can be 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, or 1:3, etc.

[0159] By adjusting the ratio of photosensitizer and photoinitiator within the above range, the energy transfer efficiency of the photosensitizer and the free radical yield of the photoinitiator can be balanced, avoiding energy waste caused by excessive photosensitizer or side reactions caused by excessive initiator. This allows for efficient initiation of the polymerization reaction while controlling the reaction rate within a reasonable range, thus controlling the grating formation speed within a certain range and ensuring the light transmittance of the photopolymer holographic recording medium, thereby achieving excellent diffraction efficiency.

[0160] Among them, photosensitizers are dyes that have high electron transfer efficiency under light irradiation, including but not limited to cyanine dyes, fluorescein dyes, coumarin ketone dyes, nitrogen-containing aromatic heterocyclic compounds, aromatic amine compounds, and benzylidene cycloalkanes ketone compounds.

[0161] For example, the photosensitizer may be one or more of the following: neomethylene blue, thionine, basic yellow, pinacyanin chloride, rhodamine 6G, gallium cyanide, ethyl violet, Victoria blue R, azurite blue, methylene blue, Astrazon Orange G, Darrow red, pyrrole red Y, basic red 29, quinaldinium red, crystal violet, brilliant green, pyrimethium I, azurite A, crystal violet cyanocyanate, malachite green cyanocyanate, etc.

[0162] Photoinitiators are initiators that can be activated by photochemical radiation and initiate polymerization reactions of corresponding polymerizable groups, including but not limited to aromatic ketones, benzoin and its derivatives, benzoyl ketals, acylphosphine oxides, ammonium arylboronate, chromium salts, aryl diazonium salts, onium salts, and organometallic compounds.

[0163] Specifically, the photoinitiator can be one or more of the following: benzophenone, alkylbenzophenone, 4,4'-bis(dimethylamino)benzophenone, anthrone and halogenated benzophenone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, diacylphosphine oxide, phenyl dihydroxyacetate, camphorquinone, α-aminoalkylphenyl ketone, α,α-dialkoxyacetophenone, α-hydroxyalkylphenyl ketone, tetrabutylammonium triphenylhexylborate, tetrabutylammonium tri-(3-fluorophenyl)hexylborate, tetrabutylammonium tri-(3-chloro-4-methylphenyl)hexylborate, ferrocene compounds, iodonium salts, thiodonium salts, and hexaaryldiimidazole.

[0164] As a chain transfer agent, the chain transfer agent can control the polymer chain length within a certain reasonable range and effectively prevent excessive polymerization, ensuring that the final holographic recording medium has the required optical properties and diffraction efficiency.

[0165] In some embodiments, the chain transfer agent may be a thiol compound, such as one or more of dodecyl mercaptoethanol, mercaptoethanol, hexamethylene mercaptoethanol, phenylethyl mercaptoethanol, 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol, 4-methyl-4H-1,2,4-triazole-3-thiol, but not limited thereto.

[0166] It is understandable that the molecular weight of unsaturated phenyl ether monomers and polymerizable monomers after polymerization can be controlled by the photoinitiator system, the amount of chain transfer agent used, and the reaction conditions. The amount used can be adjusted appropriately according to their types.

[0167] As a catalyst, the catalyst can effectively increase the reaction rate of the relevant components and the consumption rate of the relevant components after exposure, thereby quickly forming the concentration difference of monomers in the bright and dark areas and realizing the phase-type volume holographic grating with refractive index modulation.

[0168] In some embodiments, the catalyst can be a tertiary amine catalyst or an organometallic catalyst, such as triethylenediamine, bis(dimethylaminoethyl) ether, dimethylethanolamine, 2-(2-dimethylaminoethoxy)ethanol, trimethylhydroxyethylpropanediamine, N,N-bis(dimethylaminopropyl)isopropanolamine, dibutyltin dilaurate, stannous octoate, potassium carboxylate catalysts, and bismuth carboxylate catalysts, but not limited thereto.

[0169] For example, additives can be selected from at least one of defoamers, leveling agents, plasticizers, and dehydrating agents. For instance, as defoamers, defoamers include silicone defoamers and silicone-free polymeric defoamers. Defoamers are mainly used to eliminate or suppress bubbles generated during material preparation and photocuring to ensure high resolution, high diffraction efficiency, and structural uniformity of the hologram.

[0170] Specifically, the defoamer can be selected from BYK-011, BYK-012, BYK-014, BYK-023, BYK-051N, BYK-085, BYK-1610, BYK-1707, BYK-1740, and BYK-1760 manufactured by BYK Corporation, DC65 and AFE-7820 manufactured by Dow Corning, or any mixture of these defoamers in any proportion, but is not limited thereto. Among them, the BYK series defoamers have excellent defoaming performance, good compatibility with other components, and good dispersibility. BYK-011, BYK-012, BYK-014, and BYK-051N are silicone-free polymeric defoamers. DC65 is a water-based ink that dries quickly, provides good printing results, and is not easily peeled off. AFE-7820 has highly efficient defoaming performance. The defoamer content in the photopolymer holographic recording medium is less than or equal to 3 wt%. Typically, but not limitingly, the defoamer content in the photopolymer holographic recording medium can be 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, etc.

[0171] In a specific example, the leveling agent is an organosilicon surface additive, and the leveling agent accounts for less than or equal to 3 wt% of the photopolymer holographic recording medium. Typically, but not limitingly, the leveling agent content in the photopolymer holographic recording medium can be 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, etc.

[0172] The leveling agent may be selected from BYK series leveling agents with excellent leveling properties manufactured by BYK Corporation, such as BYK-302, BYK-306, BYK-307, BYK-327, BYK-329, BYK-333, BYK-356, BYK-358, BYK-378, BYK-3455, BYK-3566, or any proportion of these surface additives, but is not limited thereto.

[0173] As a plasticizer, the plasticizer increases the plasticity of the polymer by intercalating between polymer molecular chains, weakening intermolecular stress, increasing molecular chain mobility, and reducing crystallinity. In specific examples, the plasticizer may be selected from one or more of toluene, xylene, dimethylformamide, dimethylacetamide, glycerol, and phthalates, but is not limited to these. The plasticizer content in the photopolymer holographic recording medium is less than or equal to 3 wt%. Typically, but not limitingly, the plasticizer content in the photopolymer holographic recording medium may be 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, etc.

[0174] It is understandable that residual moisture in photopolymer-based holographic recording media may cause hydrolysis and failure of the photoinitiator system (such as the photoinitiator), reducing photosensitivity. Simultaneously, moisture can react with isocyanate groups (-NCO) involved in film-forming resin, generating urea bonds and releasing CO2, leading to bubbles or microstructural defects. Therefore, adding a dehydrating agent to maintain system dryness ensures the efficiency of the photopolymerization reaction, thereby improving the uniformity of the holographic grating and the storage life of the medium.

[0175] As dehydrating agents, dehydrating agents include, but are not limited to, p-toluenesulfonyl isocyanate, triethyl orthoformate, CUWR-WB20 dehydrating agent from Guangzhou Yourun Synthetic Materials Co., Ltd., ALT-201 dehydrating agent from Anxiang Elite Chemical Co., Ltd., and PCCI dehydrating agent from Shanghai Luer Chemical Trading Co., Ltd.

[0176] In some embodiments, the content of the dehydrating agent in the photopolymer holographic recording medium is less than or equal to 3 wt%. Typically, but not limitingly, the content of the dehydrating agent in the photopolymer holographic recording medium can be 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, etc.

[0177] This application also provides a method for preparing a photopolymer-based holographic recording medium, the method comprising:

[0178] Weigh components a), b), c), d), e), f), g), and h) into a container and stir thoroughly until dissolved to form a mixture solution.

[0179] The mixture solution is filtered using a filter membrane to obtain a first solution, which is then coated onto a substrate and dried to obtain the photopolymer holographic recording medium.

[0180] For example, drying is carried out in a dark room with a humidity of 10% to 85% and a temperature of 20°C to 50°C.

[0181] Furthermore, this application provides a volume holographic recording grating, wherein the photopolymer holographic recording medium used in the volume holographic grating includes the photopolymer holographic recording medium described in any of the above embodiments.

[0182] It is understandable that volume holographic recording gratings are fabricated by exposing photopolymer holographic recording media using the principle of light interference. Therefore, the holographic optical properties of the photopolymer holographic recording media determine the quality of the volume holographic recording grating.

[0183] For example, the photopolymer holographic recording medium proposed in this application has a sensitivity greater than 100 cm / mJ, a recording grating diffraction efficiency greater than 95%, a refractive index modulation degree greater than 0.1, a shrinkage rate less than 1%, and an exposure amount less than 20 mJ / cm. 2 It possesses excellent properties. Therefore, the volume holographic recording grating made from it also has the advantages of the photopolymer holographic recording medium of this application. Specifically, a sensitivity greater than 100 cm / mJ indicates that only extremely low exposure energy is required to form a stable grating, which can shorten the exposure time, reduce laser power requirements, increase recording speed, and reduce energy consumption efficiency, making it suitable for dynamic recording and low-power devices. A diffraction efficiency greater than 95% indicates that almost all incident light energy is diffracted to the target direction by the grating, thereby reducing light energy loss and making the image clearer. A refractive index modulation greater than 0.1 enhances the diffraction capability of the grating, helping to form a wider field of view, while a low shrinkage rate ensures accurate grating period precision, avoiding optical distortion and reducing image quality. Furthermore, based on an exposure energy of less than 20 mJ / cm... 2 This indicates that only a small amount of light energy is needed to complete curing and photopolymerization, avoiding overheating and deformation of materials caused by high-energy exposure.

[0184] This application also provides a holographic optical element, the raw material of which includes the aforementioned photopolymer-type holographic recording medium. This holographic optical element includes, but is not limited to, optical waveguides and holographic lenses.

[0185] As can be seen from the above, the holographic optical element proposed in this application, since it includes the aforementioned photopolymer holographic recording medium, also has the advantages of the photopolymer holographic recording medium of this application, and thus has optical performance such as fast recording speed and clear imaging.

[0186] This application also provides an optical device, including the holographic optical element as described above. This optical device includes, but is not limited to, head-up displays (HUDs), augmented reality (AR) devices, virtual reality (VR) devices, and photopolymer holographic storage optical discs. The photopolymer holographic storage optical discs can be erasable and rewritable, and can record in real time, making them suitable for storing large amounts of data and providing high data transfer speeds.

[0187] As can be seen from the above, the optical device proposed in this application, since it includes the aforementioned holographic optical element, also has the advantages of the holographic optical element in this application. The optical device has excellent optical performance, clear image, and can store a large amount of data.

[0188] The following describes the unsaturated phenyl ether monomers, the preparation method of the unsaturated phenyl ether monomers, and the photopolymer holographic recording medium containing the unsaturated phenyl ether monomers in this application, with reference to specific embodiments.

[0189] Example 1

[0190] Synthesis of unsaturated phenyl ether monomer G1-1

[0191]

[0192] Compounds M1-1 (10 mmol), M2-1 (10 mmol), and triethylamine (20 mmol) were dissolved in dichloromethane (20 mL). The air in the reaction system was replaced with nitrogen, and SO2F2 gas was introduced. After stirring for approximately 30 min, an acetonitrile solution of thiol and triethylamine (molar ratio of thiol to triethylamine 1:1 to 1:1.5) was added to quench excess SO2F2 in the reaction system. The organic phase was extracted three times, dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. Compound P1-1 was obtained by column chromatography.

[0193]

[0194] Compound P1 (10 mmol) and triethylamine (30 mmol) were dissolved in dichloromethane (10 mL) under ice bath conditions. After stirring for 10 min, acryloyl chloride (30 mmol) was added dropwise to the mixed solution of compound P1 and triethylamine at 0 °C. After the reaction was complete, dilute hydrochloric acid was added to remove excess acryloyl chloride. The mixture was washed successively with saturated NaCl solution, saturated NaHCO3 solution, and deionized water. The organic phase was dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. Column chromatography was used to separate the unsaturated phenyl ether monomer G1-1 of this application, with a yield of 95.3%.

[0195] The characterization data are as follows:

[0196] 1 H NMR (600MHz, CDCl3) δ7.59–7.50(m,4H),7.41–7.33(m,3H),7.19–7.12(m,2H),6.16–6.04(dd,1H),5.82(d,1H),5.80(d,1H).

[0197] 13 C NMR (151MHz, CDCl3) δ165.54,150.06,137.09,132.78,131.09,130.09,128.53,127.66,127.49,127.42,120.98.

[0198] Example 2

[0199] Synthesis of unsaturated phenyl ether monomer G2-1

[0200]

[0201] Compounds M1-2 (10 mmol), M2-1 (10 mmol), and potassium hydroxide (20 mmol) were dissolved in a mixture of toluene and borax (toluene to borax mass ratio 1:1). The air in the reaction system was replaced with nitrogen, and SO2F2 gas was introduced. After stirring for approximately 30 min, an acetonitrile solution of thiol and triethylamine (thiol to triethylamine molar ratio 1:1 to 1:1.5) was added to quench excess SO2F2 in the reaction system. The organic phase was extracted three times, dried with anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. Compound P1-2 was obtained by column chromatography.

[0202]

[0203] Compound P1-2 (10 mmol) was dissolved in tetrahydrofuran under ice bath conditions, and sodium hydride (30 mmol) was slowly added. After stirring for 0.5–10 h, 2-bromoethanol (30 mmol) was added dropwise to the reaction system. After the addition was complete, stirring was continued for another 0.5–10 h. After the reaction was complete, dilute hydrochloric acid was slowly added dropwise to quench the reaction. The organic phase was extracted, washed three times with water, dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. Compound P2-1 was obtained by column chromatography.

[0204]

[0205] Compound P2-1 (10 mmol) was dissolved in dichloromethane under ice bath conditions, and 1,5-diazabicyclo[4.3.0]non-5-ene (30 mmol) was slowly added. After stirring for 0.5–10 h, 3-bromopropene (30 mmol) was added dropwise to the reaction system. After the addition was complete, stirring was continued for another 0.5–10 h. After the reaction was complete, dilute hydrochloric acid was slowly added dropwise to quench the reaction. The organic phase was extracted, washed three times with water, dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. The unsaturated phenyl ether monomer G2-1 was obtained by column chromatography in 96% yield.

[0206] The characterization data are as follows:

[0207] 1H NMR (600MHz, CDCl3) δ7.56–7.49(m,4H),7.31–7.22(m,2H),6.97–6.90(m,2H),5.84(tt,J=13.4,6.2Hz,1H),5.24(ddt,J=13.4,2.2,1 .0Hz,1H),5.16(ddt,J=13.4,2.2,1.0Hz,1H),4.14(t,J=7.0Hz,2H),3.94(dt,J=6.2,1.1Hz,2H),3.76(t,J=7.1Hz,2H),2.47(s,3H).

[0208] 13 C NMR (151MHz, CDCl3) δ135.34,134.30,131.24,130.34,128.73,127.73,117.04,115.98,72.01,69.18,67.11,15.46.

[0209] Example 3

[0210] Synthesis of unsaturated phenyl ether monomer G1-2

[0211]

[0212] Compounds M1-3 (10 mmol), M2-2 (10 mmol), and 1,8-diazabicyclo[5.4.0]undec-7-ene (20 mmol) were dissolved in acetonitrile (20 mL). The air in the reaction system was replaced with nitrogen, and SO2F2 gas was introduced. After stirring for approximately 30 min, an acetonitrile solution of thiol and triethylamine (molar ratio of thiol to triethylamine 1:1 to 1:1.5) was added to quench excess SO2F2 in the reaction system. The organic phase was extracted three times, dried with anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. Compound P1-3 was obtained by column chromatography.

[0213]

[0214] Under a nitrogen atmosphere, compound P1-3 (10 mmol) was dissolved in toluene (10 mL), and the reaction system was placed in a -78°C cryogenic cooler. A solution of n-butyllithium (30 mmol) was slowly added, and the reaction was stirred for 0.5 h. Then, 3-bromopropyne (30 mmol) was added dropwise to the reaction system, and stirring was continued for 0.5–10 h after the addition was complete. After the reaction was complete, dilute hydrochloric acid was slowly added dropwise to quench the reaction. The organic phase was extracted, washed three times with water, dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. The unsaturated phenyl ether monomer G1-2 was obtained by column chromatography in 96.4% yield.

[0215] The characterization data are as follows:

[0216] 1 H NMR (600MHz, CDCl3) δ7.77(t,J=1.5Hz,1H),7.64–7.56(m,2H),7.51(ddt,J=10.6,7.5,1.5Hz,2H),7.46–7. 30(m,6H),7.21(t,J=1.4Hz,1H),6.84(dt,J=7.5,1.6Hz,1H),4.77(d,J=3.1Hz,2H),3.56(t,J=3.0Hz,1H).

[0217] 13 C NMR (151MHz, CDCl3) δ157.59,139.22,139.16,138.99,138.76,136.79,129.19, 128.95,128.61,127.82,126.00,124.08,113.97,113.35,79.02,75.96,56.31.

[0218] Example 4

[0219] Synthesis of unsaturated phenyl ether monomer G2-2

[0220]

[0221] Compounds M1-4 (10 mmol), M2-2 (10 mmol), and sodium carbonate (20 mmol) were dissolved in a mixture of N,N-dimethylformamide and borax (N,N-dimethylformamide to borax mass ratio 1:1). The air in the reaction system was replaced with nitrogen, and SO2F2 gas was introduced. After stirring for approximately 30 min, an acetonitrile solution of thiol and triethylamine (thiol to triethylamine molar ratio 1:1 to 1:1.5) was added to quench excess SO2F2 in the reaction system. The organic phase was extracted three times, dried with anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. Compound P1-4 was obtained by column chromatography.

[0222]

[0223] Compound P1-4 (10 mmol) was dissolved in tetrahydrofuran under ice bath conditions, and sodium hydride (30 mmol) was slowly added. After stirring for 0.5–10 h, 5-bromopentanol (30 mmol) was added dropwise to the reaction system. After the addition was complete, stirring was continued for another 0.5–10 h. After the reaction was complete, dilute hydrochloric acid was slowly added dropwise to quench the reaction. The organic phase was extracted, washed three times with water, dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. Compound P2-2 was obtained by column chromatography.

[0224]

[0225] Compound P2-2 (10 mmol) and pyridine (40 mmol) were dissolved in ethyl acetate under ice bath conditions and stirred for 10 min. Methacryl chloride was then added to initiate the reaction. After the reaction was complete, dilute hydrochloric acid was added to remove excess methacryloyl chloride. The mixture was then washed successively with saturated NaCl solution, saturated NaHCO3 solution, and deionized water. The organic phase was dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. The unsaturated phenyl ether monomer G2-2 of this application was obtained by column chromatography with a yield of 97.8%.

[0226] The characterization data are as follows:

[0227] 1 H NMR (600MHz, CDCl3) δ7.70–7.64(m,2H),7.64–7.58(m,2H),7.56–7.51(m,2H),7.49–7.34(m,5H),7.20(t,J=1.5Hz,1H),6.91(dt,J=7.1,1 .7Hz,1H),5.96(dq,J=1.8,0.9Hz,1H),5.59(dq,J=1.8,0.9Hz,1H),4.06(dt,J=24.6,7.0Hz,4H),1.95(t,J=1.0Hz,3H),1.82–1.35(m,6H).

[0228] 13 C NMR (151MHz, CDCl3) δ167.46,141.04,138.56,137.90,136.38,129.33,128.92,128.2 1,127.53,125.04,124.66,114.45,113.43,68.74,65.97,29.37,28.04,23.21,18.27.

[0229] Example 5

[0230] Synthesis of unsaturated phenyl ether monomer G1-3

[0231]

[0232] Compounds M1-5 (10 mmol), M2-3 (10 mmol), and tetramethylsilyl trifluoromethanesulfonate (20 mmol) were dissolved in dimethyl sulfoxide (20 mL). The air in the reaction system was purged with nitrogen, and SO2F2 gas was introduced. After stirring for approximately 30 min, an acetonitrile solution of thiol and triethylamine (molar ratio of thiol to triethylamine 1:1 to 1:1.5) was added to quench excess SO2F2 in the reaction system. The organic phase was extracted three times, dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. Compound P1-5 was obtained by column chromatography.

[0233]

[0234] Compound P1-5 (10 mmol) was dissolved in dichloromethane under ice bath conditions, and potassium tert-butoxide (30 mmol) was slowly added. After stirring for 0.5–10 h, 3-bromopropene (30 mmol) was added dropwise to the reaction system. After the addition was complete, stirring was continued for another 0.5–10 h. After the reaction was complete, dilute hydrochloric acid was slowly added dropwise to quench the reaction. The organic phase was extracted, washed three times with water, dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. The unsaturated phenyl ether monomer G1-3 was obtained by column chromatography in 97% yield.

[0235] The characterization data are as follows:

[0236] 1 H NMR (600MHz, CDCl3) δ7.58–7.47(m,3H),7.42–7.28(m,7H),7.28–7.15(m,2H),7.00(dd,J=7.5,1. 5Hz, 1H), 6.03 (tt, J=13.4, 6.1Hz, 1H), 5.33 (dt, J=13.4, 1.0Hz, 2H), 4.65 (dt, J=6.2, 1.0Hz, 2H).

[0237] 13 C NMR (151MHz, CDCl3) δ157.35,135.55,134.96,132.81,130.46,129.03,128.99,128.81,126.50,123.13,117.97,114.12,70.39.

[0238] Example 6

[0239] Synthesis of unsaturated phenyl ether monomer G2-3

[0240]

[0241] Compounds M1-6 (10 mmol), M2-3 (10 mmol), and sodium bicarbonate (20 mmol) were dissolved in dimethyl sulfoxide (20 mL). The air in the reaction system was replaced with nitrogen, and SO2F2 gas was introduced. After stirring for approximately 30 min, an acetonitrile solution of thiol and triethylamine (molar ratio of thiol to triethylamine 1:1 to 1:1.5) was added to quench excess SO2F2 in the reaction system. The organic phase was extracted three times, dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. Compound P1-6 was obtained by column chromatography.

[0242]

[0243] Compound P1-6 (10 mmol) was dissolved in tetrahydrofuran under ice bath conditions, and sodium hydride (30 mmol) was slowly added. After stirring for 0.5–10 h, 3-bromo-1-propanol (30 mmol) was added dropwise to the reaction system. After the addition was complete, stirring was continued for another 0.5–10 h. After the reaction was complete, dilute hydrochloric acid was slowly added dropwise to quench the reaction. The organic phase was extracted, washed three times with water, dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. Compound P2-3 was obtained by column chromatography.

[0244]

[0245] Under a nitrogen atmosphere, compound P2-3 (10 mmol) was dissolved in toluene (10 mL), and the reaction system was placed in a -78°C cryocooler. Sodium bis(trimethylsilyl)amino (30 mmol) was slowly added, and the reaction was stirred for 0.5 h. Then, 3-bromopropyne (30 mmol) was added dropwise to the reaction system, and stirring was continued for 0.5–10 h after the addition was complete. After the reaction was complete, dilute hydrochloric acid was slowly added dropwise to quench the reaction. The organic phase was extracted, washed three times with water, dried over anhydrous sodium sulfate, and excess solvent was removed by rotary evaporation. The unsaturated phenyl ether monomer G2-3 was obtained by column chromatography in 97% yield.

[0246] The characterization data are as follows:

[0247] 1H NMR (600MHz, CDCl3) δ7.57(dd,J=7.4,1.6Hz,1H),7.46–7.41(m,2H),7.37(td,J=7.4,1.6Hz,1H),7.31–7.17(m,3H),7.02(dd,J=7.4,1. 5Hz, 1H), 4.17 (d, J = 3.1Hz, 2H), 4.13 (t, J = 7.1Hz, 2H), 3.57 (t, J = 7.1Hz, 2H), 2.51 (s, 3H), 2.45 (t, J = 3.0Hz, 1H), 2.06 (p, J = 7.1Hz, 2H).

[0248] 13 C NMR (151MHz, CDCl3) δ138.59,137.87,128.80,128.50,126.75,126.39,126.2 9,126.23,123.12,114.47,79.38,75.30,68.91,67.56,59.42,29.92,13.93.

[0249] Example 7

[0250] Photopolymer-type holographic recording media 7-1 to 7-6 were prepared using the unsaturated phenyl ether monomers described in Examples 1-6. The preparation method involved mixing all components thoroughly, filtering the mixture using a filter membrane, coating the resulting filtrate onto a substrate, and drying it in a darkroom at a humidity of 10%–85% and a temperature of 20°C–50°C to obtain the photopolymer-type holographic recording media. The specific components of the photopolymer-type holographic recording media 7-1 to 7-6 are shown in Tables 1 to 7.

[0251] Table 1

[0252]

[0253]

[0254] Table 2

[0255]

[0256] Table 3

[0257]

[0258] Table 4

[0259]

[0260]

[0261] Table 5

[0262]

[0263] Table 6

[0264]

[0265]

[0266] Comparative Example 1

[0267] The composition is roughly the same as that of the photopolymer holographic recording medium 7-1 in Example 7. The difference is that the unsaturated phenyl ether monomer G1-1 is not added in the comparative example. Instead, the amount of benzyl methacrylate added is increased to 46 wt%, thereby obtaining a common photopolymer holographic recording medium.

[0268] Comparative Example 2

[0269] The composition is roughly the same as that of the photopolymer holographic recording medium 7-3 in Example 7. The difference is that the unsaturated phenyl ether monomer G1-2 is not added in the comparative example. Instead, the amount of pentabromophenyl acrylate is increased to 42wt%, thereby obtaining a common photopolymer holographic recording medium.

[0270] Comparative Example 3

[0271] The composition is roughly the same as that of the photopolymer holographic recording medium 7-4 in Example 7. The difference is that the unsaturated phenyl ether monomer G2-2 is not added in the comparative example. Instead, the amount of 9-vinyl anthracene is increased to 40 wt%, thereby obtaining a common photopolymer holographic recording medium.

[0272] Comparative Example 4

[0273] The composition is roughly the same as that of the photopolymer holographic recording medium 7-6 in Example 7. The difference is that the unsaturated phenyl ether monomer G2-3 is not added in the comparative example. Instead, the amount of 2-chlorostyrene added is increased to 38 wt%, thereby obtaining a common photopolymer holographic recording medium.

[0274] Test case

[0275] (1) The refractive index and shrinkage rate of the unsaturated phenyl ether monomers synthesized in Examples 1 to 6 were tested, and the results are shown in Table 7.

[0276] The shrinkage rate test is conducted using the following method:

[0277] a) Place the dry specific gravity bottle (including the stopper) on the balance and record the weight W0. Pour the monomer to be tested up to the mark, remove air bubbles, wipe the outer wall dry, and weigh it to obtain W1. ρmonomer = (W1 - W0) / V, where V is the volume of the specific gravity bottle.

[0278] b) Place the dry specific gravity bottle (including the stopper) on a balance and record the weight W0. Place the polymer obtained from the monomer polymerization into the specific gravity bottle and weigh it to obtain W2. Add water to the mark, remove air bubbles, wipe the outer wall dry, and weigh it to obtain W3. ρpolymer = (W2-W0) / (V-(W3-W2) / ρwater), where V is the volume of the specific gravity bottle and ρwater is the density of water.

[0279]

[0280] (2) The performance of the photopolymer holographic recording media 7-1 to 7-6 containing unsaturated phenyl ether monomers in Example 7 and the ordinary photopolymer holographic recording media of Comparative Examples 1-4 were tested, and the results are shown in Table 8.

[0281] During testing, the various holographic recording media in Example 7 can be exposed to lasers of different wavelengths depending on the photosensitive system, with an exposure intensity of 3 mW / cm². 2 .

[0282] The detection light source uses a 785nm wavelength solid-state laser that does not react with the recording medium. The detection light is incident on the exposure area from the Bragg angle. The transmitted light and diffracted light are monitored in real time by a photodetector. The single grating diffraction efficiency (η) and the photosensitivity (S) of the photopolymer holographic recording medium are calculated by formulas (1) to (3).

[0283]

[0284] In the formula, η is the diffraction efficiency, η max For the highest diffraction efficiency, I d For diffracted light, I t S represents transmitted light, S represents photosensitivity, E represents exposure energy, and ΔE represents the exposure energy required to achieve the highest diffraction efficiency.

[0285] Table 7 Refractive indices of the monomers synthesized in Examples 1-6

[0286] Example monomer Refractive index Shrinkage rate after polymerization (%) Example 1 G1-1 1.65 0.96 Example 2 G2-1 1.66 0.87 Example 3 G1-2 1.71 0.61 Example 4 G2-2 1.66 0.94 Example 5 G1-3 1.73 0.53 Example 6 G2-3 1.70 0.47

[0287] Table 8. Holographic performance parameters of the holographic recording media of Example 7 and the comparative example.

[0288]

[0289]

[0290] like Figure 1 As shown, holographic recording media 7-1, 7-3, and 7-5 are used at relatively small exposure times (4-8 mJ / cm). 2At this level, a superior diffraction efficiency of over 90% is achieved, while from... Figure 2 It can be seen that Comparative Example 1 and Comparative Example 3 require higher exposure levels (greater than 80 mJ / cm²). 2 Only under these conditions can a diffraction efficiency of approximately 40% be achieved, and combined with... Figure 1 and Figure 2 As shown, comparing holographic recording medium 7-1 with Comparative Example 1 and holographic recording medium 7-4 with Comparative Example 3, it can be seen that the holographic recording medium containing the unsaturated phenyl ether monomer of this application has a higher diffraction efficiency and requires a lower exposure.

[0291] Furthermore, as shown in Table 7, the refractive index of the unsaturated phenyl ether monomers prepared in this application is greater than 1.65 and less than 1.75. This means the high refractive index of the unsaturated phenyl ether monomers can further enhance the refractive index difference between the writing monomer and the film-forming resin. Moreover, the shrinkage rate of the unsaturated phenyl ether monomers prepared in this application after polymerization is less than 1%, ensuring accurate grating period precision and avoiding optical distortion that could reduce image quality. More specifically, as shown in Table 8, the refractive index modulation of the holographic recording medium prepared from the unsaturated phenyl ether monomers of this application is greater than 0.1, meaning it can produce a stronger grating structure and increase grating storage density. Secondly, the diffraction efficiency of the holographic recording medium is greater than 95%. High diffraction efficiency means high light energy utilization and low light energy loss. In other words, almost all incident light energy is diffracted to the target direction by the grating, significantly improving the brightness and clarity of the holographic display. Furthermore, the holographic recording medium also has a sensitivity greater than 100 cm / mJ and an exposure amount less than 20 mJ / cm. 2 The advantages are that the higher the sensitivity, the larger the area of ​​the interference pattern that can be recorded per unit energy (millijoules), the shorter the hologram writing time, and the faster the data transmission speed. The lower the exposure, the more light energy is needed to complete the curing and photopolymerization, avoiding the overheating and deformation of the material caused by high-energy exposure.

[0292] It is understood that the above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An unsaturated phenyl ether monomer, characterized in that, The general structural formula of the unsaturated phenyl ether monomers is shown in any of the following: Where R1 represents R2 represents Any one of them; A1 and A2 each independently represent hydrogen, phenyl, or... Any one of them; A3 represents hydrogen or methyl, and A4 represents C1-C4 alkyl or phenyl. n is a positive integer and n = 1 to 5.

2. The unsaturated phenyl ether monomer according to claim 1, characterized in that, The general structural formula of the unsaturated phenyl ether monomers is shown below:

3. A method for preparing an unsaturated phenyl ether monomer as described in claim 1, characterized in that, Includes the following steps: Compound M1, compound M2 and a base reagent are dissolved in a first solvent, and SO2F2 gas is introduced to carry out the reaction, and a first mixture is obtained after the reaction. The first mixture is then separated to obtain compound P1. Wherein, the first solvent includes any one of an organic solvent or a mixture system, wherein the mixture system is formed by combining borax and the organic solvent, and the compound M1 is selected from compounds with the following general structural formula: A1 and A2 represent hydrogen and phenyl, respectively, independently. A4 represents C1-C4 alkyl or phenyl; The compound M2 is selected from compounds with the following general structural formula: The general structural formula of compound P1 is shown below: Where R1 represents 4. The preparation method according to claim 3, characterized in that, The general formula for the prepared structure is G1, where R2 in G1 represents... The unsaturated phenyl ether monomers also include the following steps: The compound P1 is dissolved in an organic solvent and subjected to a first treatment operation to obtain a second mixture. A deprotonating agent is added to the second mixture to obtain a third mixture after the reaction. Compound M3 is added to the third mixture to obtain a fourth mixture after the reaction. The fourth mixture is then separated to obtain the unsaturated phenyl ether monomer G1. The first treatment operation includes a cooling operation and a stirring operation. The compound M3 is selected from compounds with the following structural formulas: Alternatively, the general formula for the prepared structure is G1, where R2 in G1 represents... The unsaturated phenyl ether monomers also include the following steps: The compound P1 and the acid-binding agent are dissolved in an organic solvent, and compound M4 is added to react and obtain a fifth mixture after the reaction. The fifth mixture is separated to obtain the unsaturated phenyl ether monomer G1; wherein, compound M4 is acryloyl chloride or methacryloyl chloride.

5. The preparation method according to claim 3, characterized in that, The preparation of unsaturated phenyl ether monomers with the general structural formula G2 also includes the following steps: The compound P1 is dissolved in an organic solvent and subjected to a first treatment operation to obtain a second mixture. A deprotonating agent is added to the second mixture to obtain a third mixture after the reaction. Compound M5 is added to the third mixture to obtain a sixth mixture after the reaction. The sixth mixture is separated to obtain compound P2. The general structural formula of compound M5 is as follows: n is a positive integer and n = 1 to 5; The general structural formula of the compound P2 is:

6. The preparation method according to claim 5, characterized in that, The general formula for the preparation structure is G2, where R2 in G2 represents... The unsaturated phenyl ether monomers also include the following steps: The compound P2 is dissolved in an organic solvent and subjected to a first treatment operation to obtain a seventh mixture. A deprotonating agent is added to the seventh mixture to obtain a reaction-after eighth mixture. Compound M3 is added to the eighth mixture to obtain a reaction-after ninth mixture. The ninth mixture is separated to obtain the unsaturated phenyl ether monomer G2. Alternatively, the general formula for the preparation structure is G2, where R2 in G2 represents... The unsaturated phenyl ether monomers also include the following steps: The compound P2 and the acid-binding agent were dissolved in an organic solvent, and compound M4 was added to react and obtain a tenth mixture after the reaction. The tenth mixture was then separated to obtain the unsaturated phenyl ether monomer G2.

7. The preparation method according to claim 3, characterized in that, The organic solvent includes at least one of petroleum ether, dichloromethane, trichloromethane, ethyl acetate, tetrahydrofuran, acetonitrile, benzene, toluene, N,N-dimethylformamide, dimethyl sulfoxide, dimethoxyethane, and 1,4-dioxane; And / or, the alkaline reagent comprises at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, triethylamine, 1,5-diazabicyclo[4.3.0]non-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene and tetramethylsilyl trifluoromethanesulfonate; And / or, the molar ratio of the compound M1, the compound M2 and the base reagent is 1:(1-1.2):(2-3).

8. The preparation method according to any one of claims 4-6, characterized in that, The organic solvent includes at least one of petroleum ether, dichloromethane, trichloromethane, ethyl acetate, tetrahydrofuran, acetonitrile, benzene, toluene, N,N-dimethylformamide, dimethyl sulfoxide, dimethoxyethane, and 1,4-dioxane; And / or, the deprotonating agent comprises at least one of the following: n-butyllithium, tert-butyllithium, phenyllithium, sodium hydride, potassium hydride, sodium amino, potassium amino, sodium bis(trimethylsilyl)amino, diisopropylaminolithium, potassium hydroxide, sodium hydroxide, sodium methoxide, sodium tert-butoxide, potassium tert-butoxide, triethylamine, 1,5-diazabicyclo[4.3.0]non-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene, tetramethylsilyl trifluoromethanesulfonate, potassium phosphate, potassium carbonate, sodium carbonate, and sodium bicarbonate; And / or, the acid-binding agent comprises at least one of triethylamine, pyridine, N,N-diisopropylethylamine, 4-dimethylaminopyridine, tetrabutylammonium bromide, sodium carbonate, potassium carbonate, ammonium carbonate, sodium acetate, sodium hydroxide, potassium hydroxide, calcium oxide, and potassium tert-butoxide.

9. A photopolymer-based holographic recording medium, characterized in that, Its raw materials contain the following components a)-h); Component a) A compound having multiple isocyanate reactive functional groups; Component b) Polyisocyanate group compounds; Component c) Unsaturated phenyl ether monomers; Component d) can polymerize monomers; Component e) Photosensitive initiation system; Component f) Chain transfer agent; Component g) optionally a catalyst; Component h) can be optionally added; Wherein, the unsaturated phenyl ether monomer is at least one of the unsaturated phenyl ether monomers G1 or G2 as described in claim 1.

10. The photopolymer-type holographic recording medium according to claim 9, characterized in that, The composition and content of the photopolymer-type holographic recording medium are as follows: Component a) 10 wt% to 50 wt% of compounds having multiple isocyanate reactive functional groups; Component b) 10 wt% to 50 wt% of polyisocyanate compounds; Component c) Unsaturated phenyl ether monomers, 1 wt% to 30 wt%; Component d) can polymerize 10wt% to 40wt% of monomers; Component e) Photoinitiator system 0.1wt%~3wt%; Component f) Chain transfer agent 0.1 wt% to 3 wt%; Component (g) Catalyst 0.1wt%~5wt%; Component h) Additives: 0.1 wt% to 10 wt%.

11. The photopolymer-type holographic recording medium according to claim 9, characterized in that, The unsaturated phenyl ether monomers account for 0.1 wt% to 30 wt% of the total content of the photopolymer holographic recording medium; And / or, the isocyanate reactive functional group is a hydroxyl group, and the molar ratio of the hydroxyl group in component a) of the compound having a plurality of isocyanate reactive functional groups to the isocyanate functional group in component b) of the polyisocyanate group compound is 1:

1.

12. The photopolymer-type holographic recording medium according to claim 9, characterized in that, The isocyanate reactive functional group is a hydroxyl group; the compound having multiple isocyanate reactive functional groups includes compounds with a refractive index less than or equal to a first refractive index threshold and having two or more hydroxyl functional groups, wherein the first refractive index threshold is any value between 1.5 and 1.

55. And / or, the polyisocyanate-based compound includes compounds with a refractive index less than or equal to a second refractive index threshold and having two or more isocyanate groups; the second refractive index threshold is any value between 1.5 and 1.55; And / or, the polymerizable monomer is selected from at least one of alkenylnaphthalene compounds, alkenylanthracene compounds, alkenylbenzene compounds, acrylic compounds, methacrylic acid compounds, acrylate compounds, methacrylate compounds, N-vinylpyrrole, N-vinylcarbazole, N-vinylimidazol, N-vinylindole, N-vinylpyrrolidone, and trans-N-3-yntynebutenylcarbazole; And / or, the photoinitiating system includes a photosensitizer and a photoinitiator; And / or, the chain transfer agent is a thiol compound; And / or, the catalyst is a tertiary amine catalyst and an organometallic catalyst; And / or, the additives include at least one of defoamers, leveling agents, plasticizers, and dehydrating agents.

13. The photopolymer-type holographic recording medium according to claim 12, characterized in that, The compound having multiple isocyanate reactive functional groups includes at least one of tetraethylene glycol, trimethylolethane, glycerol, triethanolamine, polyester polyol with a molecular weight of 200 to 2000, polycarbonate polyol, and polyether polyol. And / or, the polyisocyanate group compound includes at least one of hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, (2,4,6-trioxotriazine-1,3,5(2H,4H,6H)-triyl)tri(hexamethylene)isocyanate, butane-1,4-diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate; And / or, the chain transfer agent comprises at least one of dodecyl mercaptan, mercaptoethanol, hexamethylene mercaptan, phenylethyl mercaptan, 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol, and 4-methyl-4H-1,2,4-triazole-3-thiol; And / or, the catalyst comprises at least one of the following: triethylenediamine, bis(dimethylaminoethyl) ether, dimethylethanolamine, 2-(2-dimethylaminoethoxy)ethanol, trimethylhydroxyethylpropanediamine, N,N-bis(dimethylaminopropyl)isopropanolamine, dibutyltin dilaurate, stannous octoate, potassium carboxylate catalysts, and bismuth carboxylate catalysts.

14. The photopolymer-type holographic recording medium according to claim 12, characterized in that, The photosensitizer includes at least one of cyanine dyes, fluorescein dyes, coumarin ketone dyes, nitrogen-containing aromatic heterocyclic compounds, aromatic amine compounds, and benzylidene cycloalkane ketone compounds; The photoinitiator includes aromatic ketone compounds, benzoin and its derivatives, benzoyl ketal, acylphosphine oxide, ammonium arylboronate, chromium salt, aryl diazonium salt, onium salt, organometallic compound, or at least one of these compounds; The mass ratio of the photosensitizer to the photoinitiator is (0.001-1):(0.1-3).

15. The photopolymer-type holographic recording medium according to claim 12, characterized in that, The defoamer is an organosilicon defoamer and / or a polymeric defoamer without organosilicon, and the content of the defoamer in the photopolymeric holographic recording medium is less than or equal to 3 wt%. And / or, the leveling agent is an organosilicon surface additive, and the leveling agent accounts for less than or equal to 3 wt% of the photopolymer holographic recording medium; And / or, the plasticizer is selected from at least one of toluene, xylene, dimethylformamide, dimethylacetamide, glycerol, and phthalates, and the plasticizer accounts for less than or equal to 3 wt% of the photopolymer holographic recording medium; And / or, the dehydrating agent includes at least one of p-toluenesulfonyl isocyanate and triethyl orthoformate, and the dehydrating agent accounts for less than or equal to 3 wt% of the photopolymer holographic recording medium.

16. A method for preparing a photopolymer-type holographic recording medium as described in any one of claims 9-15, characterized in that, Weigh the compound having multiple isocyanate reactive functional groups, the polyisocyanate group compound, the unsaturated phenyl ether monomer, the polymerizable monomer, the photoinitiator system, the chain transfer agent, the catalyst and the additive into a container, and stir thoroughly until dissolved to form a mixed solution; The mixture solution is filtered using a filter membrane to obtain a first solution; The first solution is coated onto a substrate and dried to obtain the photopolymer holographic recording medium.

17. The preparation method according to claim 16, characterized in that, The drying process is carried out in a dark room with a humidity of 10% to 85% and a temperature of 20°C to 50°C.

18. A volume holographic recording grating, characterized in that, The photopolymer holographic recording medium used in the volume holographic recording grating includes the photopolymer holographic recording medium as described in any one of claims 9-15.

19. A holographic optical element, characterized in that, Its raw materials include the photopolymer type holographic recording medium as described in any one of claims 9-15.

20. An optical device, characterized in that, Includes the holographic optical element as described in claim 19.

Images