(Methyl) acrylate monomer as well as preparation method and application thereof

Abstract

The invention relates to a (methyl) acrylate monomer as well as a preparation method and application thereof, the structural general formula of the (methyl) acrylate monomer is shown as G1, G2, G3 and G4: # imgabs0 #, and R1 is methyl or hydrogen. The whole (methyl) acrylate monomer provided by the invention is relatively small in molecular size, not easy to agglomerate, high in refractive index, liquid, low in viscosity and good in intermiscibility with other components.

Description

Technical Field

[0001] The invention relates to the technical field of holographic materials, in particular to (meth)acrylate monomers and a preparation method and application thereof. Background Art

[0002] The various components used to make holographic recording media, such as photosensitive dyes, initiators, chain transfer agents, writing monomers, film-forming resins, dehydrating agents, etc., work together to determine whether the performance of the holographic recording media is good or not.

[0003] Among them, the migration rate and polymerization rate of the writing monomer jointly determine the speed of grating formation. The migration rate of the writing monomer is faster than the polymerization rate to obtain a grating with a stable refractive index modulation. After the writing monomer located in the coherent bright area is polymerized, the unreacted writing monomer located in the coherent dark area quickly migrates to the coherent bright area, and squeezes the film-forming resin in the bright area into the coherent dark area, so that the refractive index of the bright area is close to the refractive index of the writing monomer, and the refractive index of the dark area is close to the refractive index of the film-forming resin. At the same time, the writing monomer and the film-forming resin have a refractive index difference to form a refractive index modulated volume holographic grating. The greater the refractive index difference between the writing monomer and the film-forming resin, the faster the holographic recording medium can form a refractive index modulated volume holographic grating. In the existing refractive index modulated phase-type volume holographic grating prepared by photopolymer, the writing monomer viscosity is required to be low, specifically, the kinematic viscosity is less than 100mm. 2 / s, and the writing monomer needs to have a high refractive index, specifically a refractive index n>1.6. However, writing monomers with a refractive index higher than 1.6 are usually solid or viscous liquids, and the kinematic viscosity of these writing monomers is higher than 200mm 2 / s, which limits the amount of writing monomer added to the photopolymer, resulting in an insufficiently significant difference in the refractive index between the writing monomer and the film-forming resin, affecting the improvement of the holographic performance of the holographic recording medium. Summary of the invention

[0004] In view of this, the present invention proposes a (meth)acrylate monomer and a preparation method and application thereof, aiming to achieve that the (meth)acrylate monomer has a higher refractive index and is in a liquid state, so as to improve the holographic optical performance of a photopolymer holographic recording medium containing the (meth)acrylate monomer.

[0005] In a first aspect of the present invention, a (meth)acrylate monomer is provided, and its general structural formula is shown in Formulas G1, G2, G3 and G4:

[0006] Among them, R 1 Methyl or hydrogen.

[0007] It can be seen from the above technical scheme that the (meth) acrylate monomer proposed in the first aspect of the present invention has a (meth) acrylate group, and has high refractive index and low volume shrinkage properties; the monomer contains multiple aromatic rings, sulfur heterocycles and other groups with high molar refractive index and low molar volume, so that the entire monomer molecule presents an extremely high refractive index. The entire monomer has a small structure, low viscosity, and is in a liquid state.

[0008] The second aspect of the present invention provides a method for preparing a (meth) acrylic acid ester monomer in each of the above examples, comprising the following steps: dissolving compound P1 in a solvent, adding a hydride and stirring for a certain period of time, then adding compound M1 to react, removing excess solvent, and separating to obtain compound P2;

[0009] Dissolving compound P2 and an acid-binding agent in a solvent, and adding compound M2 until the reaction is complete, removing excess reactants and the solvent, and separating to obtain the (meth)acrylate monomer;

[0010] The compound P1 is selected from compounds having the following structural formula:

[0011]

[0012] The compound M1 includes 2,3-dibromo-1-propanol and / or 2,3-dichloro-1-propanol;

[0013] The compound M2 is acryloyl chloride or methacryloyl chloride.

[0014] The preparation method of the (meth)acrylate monomer proposed in the second aspect of the present invention can synthesize the required (meth)acrylate monomer through two-step reaction. The reaction conditions in the synthesis process are easy to control. The hydrogen on the thiol group in the compound P1 can be captured by a hydride, so that the compound P1 is activated. The S in the thiol group on the compound P1 further attacks the halogen functional group in the compound M1, forming a rapid polymerization reaction of the compound P1 and the compound M1 to generate a compound P2 with a heterosulfur ring; and the hydroxyl group in the compound P2 reacts with the halogen in the compound M2 to finally generate a compound with a (meth)acrylate group, and the molecular structure of the entire compound is stable.

[0015] The third aspect of the present invention provides a photopolymer holographic recording medium containing (meth)acrylate monomers, comprising a writing monomer, wherein the writing monomer comprises the (meth)acrylate monomer and a polymerizable monomer.

[0016] The third aspect of the present invention proposes a photopolymer holographic recording medium containing (meth)acrylate monomers. By adding (meth)acrylate monomers and polymerizable monomers, the two components cooperate with each other to form a writing monomer component with a higher refractive index, so that the writing monomer and the film-forming resin can have a larger refractive index difference, providing the photopolymer holographic recording medium with the required material basis for forming a phase-type volume holographic grating with refractive index modulation.

[0017] A fourth aspect of the present invention provides a holographic optical element, wherein the material of the holographic optical element includes the photopolymer holographic recording medium in each of the above examples.

[0018] The holographic optical element proposed in the fourth aspect of the present invention has excellent holographic performance, high diffraction efficiency, high sensitivity, and small exposure amount required.

[0019] A fifth aspect of the present invention provides an optical device, comprising the holographic optical element as described above.

[0020] The optical device proposed in the fifth aspect of the present invention, such as a head-up display device, an augmented reality device, a virtual reality device, a photopolymer holographic storage optical disc, etc., has excellent holographic performance.

[0021] It should be understood that the above general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure of the embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained like these accompanying drawings without paying any creative work.

[0023] Figure 1 is a graph showing holographic exposure characteristics of the photopolymer holographic recording media 5-1, 5-3, and 5-5 in Example 5;

[0024] Figure 2 It is a comparative holographic exposure characteristic curve. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the present invention.

[0026] The photopolymer material used for holographic recording realizes holographic recording by polymerizing the writing monomers under light and then forming a phase-type holographic grating with refractive index modulation with the film-forming resin. The monomers in the coherent bright area are consumed and the concentration is reduced, while the monomers in the coherent dark area hardly react. The difference in monomer concentration between the bright and dark areas causes the monomers in the dark area to begin to migrate to the bright area, and the film-forming resin in the bright area is squeezed into the dark area. Finally, the refractive index of the bright area is close to that of the polymer, and the refractive index of the dark area is close to that of the film-forming resin, thereby forming a phase-type volume holographic grating with refractive index modulation.

[0027] Improving the performance of photopolymers generally requires that the film-forming resin has a lower refractive index and the writing monomer has a higher refractive index. However, the refractive index of existing low-viscosity monomers that can be used in photopolymers is usually lower than 1.60, and the polymerizable monomers with a refractive index higher than 1.60 are usually solid or viscous liquid, which limits their addition amount in photopolymers. Therefore, the refractive index difference between the writing monomer and the film-forming resin is relatively small, usually only 0.1 to 0.2.

[0028] The present invention provides a (meth)acrylate monomer as a component of the writing monomer, and the refractive index of the (meth)acrylate monomer of the present invention is higher than 1.61, and it is in liquid state, and the kinematic viscosity of the (meth)acrylate monomer of the present invention is lower than 100mm 2 / s. The liquid (meth) acrylate monomer with a high refractive index and the isocyanate-alcohol with a relatively low refractive index as a film-forming resin are combined to form a refractive index modulated volume holographic grating with a larger refractive index difference, thereby improving the holographic performance of the photopolymer holographic recording medium, and making the photopolymer holographic recording medium have high sensitivity and high recording grating diffraction efficiency.

[0029] In the absence of conflict, the following embodiments and features of the embodiments may be combined with each other.

[0030] The (meth)acrylate monomer of the present invention is described below.

[0031] According to the present invention, a (meth)acrylate monomer has a general structural formula as shown in Formulas G1, G2, G3 and G4:

[0032] Among them, R 1 Methyl or hydrogen.

[0033] As can be seen from the above, the (meth)acrylate monomer proposed in the present invention has at least one (meth)acrylate group, and has high refractive index and low volume shrinkage properties; the monomer contains multiple aromatic rings, sulfur heterocycles and other groups with high molar refractive index and low molar volume, as well as some sulfur atoms that have high refractive index themselves, so that the entire monomer molecule presents an extremely high refractive index as a whole. The entire monomer has a small structure, low viscosity, and is in a liquid state. It has good compatibility with other components and can improve holographic performance when used in photopolymer holographic recording media.

[0034] In some examples, the (meth)acrylate monomer is selected from monomers having the following structural formula:

[0035]

[0036] Then, the (meth)acrylate monomers of each structure in the above examples all have the advantages of high refractive index (refractive index higher than 1.61), small molecular structure for easy migration, low viscosity, and good solubility in liquid state with other components.

[0037] In some examples, the (meth)acrylate monomer has a refractive index of 1.61 to 1.67 and a kinematic viscosity of 10 to 100 mm 2 / s.

[0038] The following is a description of the preparation method of the (meth)acrylate monomer of the present invention.

[0039] The method for preparing the (meth)acrylate monomer in each of the above examples according to the present invention comprises the following steps:

[0040] Step S1, dissolving compound P1 in a solvent, adding hydride and stirring for a certain period of time, then adding compound M1 to react, removing excess solvent, and separating to obtain compound P2.

[0041] The structural formula of compound P1 in step S1 is:

[0042] Compound M1 includes 2,3-dibromo-1-propanol and / or 2,3-dichloro-1-propanol;

[0043] The structural formula of the compound P2 generated after the reaction of compound P1 and compound M1 is:

[0044]

[0045] It can be understood that in step S1, the hydrogen on the thiol group in compound P1 can be extracted by using hydride, so that compound P1 is activated, and the S in the thiol group on compound P1 further attacks the halogen functional group in compound M1, forming a rapid polymerization reaction of compound P1 and compound M1 to generate compound P2 with a heterosulfur ring. At the same time, compound P2 has both the aromatic ring on the original compound P1 and the hydroxyl group on the original compound M1.

[0046] In some examples, the hydride includes at least one of sodium hydride or potassium hydride. That is, sodium hydride or potassium hydride can be used, or both can be used. When adding the hydride, it can be added slowly multiple times while stirring, so that the reaction is more complete and compound P1 is fully activated.

[0047] In some specific examples, the stirring reaction time of compound P1 and hydride is 0.2 h to 2 h, for example, 0.2 h, 0.5 h, 0.7 h, 0.8 h, 1 h, 1.2 h, 1.5 h, 1.8 h or 2 h, so that compound P1 and hydride can react fully.

[0048] In some examples, the molar ratio of compound P1, hydride and compound M1 is 1:(2-5):(1-2). Within the above ratio range, the reaction process is reasonable, the hydrogen on the thiol group of compound P1 can be fully captured by the hydride, and the reaction of compound P1 and compound M1 is relatively complete with less residue. For example, the molar ratio of compound P1, compound M1 and the first photoinitiator is 1:3:1, 1:2:1, 1:3:2, 1:4:2, 1:5:2, etc.

[0049] In some examples, the reaction time of compound P1 and compound M1 is controlled within 0.1 h to 1 h, which can achieve complete reaction while ensuring that the time of the entire reaction process is controlled within a reasonable range. For example, the reaction time is 0.1 h, 0.2 h, 0.3 h, 0.5 h, 0.8 h, 1 h, etc.

[0050] In some examples, the solvent selected in step S1 includes one or more of ethanol, petroleum ether, dichloromethane, chloroform, ethyl acetate, tetrahydrofuran, acetonitrile, N,N-dimethylformamide or dimethyl sulfoxide. These solvents have good compatibility with compound P1, compound M1, and hydride; it is also convenient to control the concentration of the two compounds to make the reaction system more uniform; after the reaction is completed, these solvents have good volatility, so it is convenient to remove the above solvents to obtain the desired reacted substance such as compound P2, which is convenient for further operation.

[0051] Step S2, dissolving compound P2 and an acid-binding agent in a solvent, and adding compound M2 until the reaction is complete, removing excess reactants and solvent, and separating to obtain the (meth)acrylate monomer;

[0052] The compound M2 used in step S2 is Where R 1 is methyl or hydrogen, R 1 When it is methyl, it is methacryloyl chloride, R 1 When it is hydrogen, it is acryloyl chloride.

[0053] It can be understood that in step S2, the hydroxyl group in compound P2 can react with the halogen in compound M2 to finally generate a compound with a (meth)acrylate group, and the molecular structure of the entire compound is stable.

[0054] In some examples, the molar ratio of compound P2, acid binding agent and compound M2 is 1: (1-2): (1-2). By using an acid binding agent, the protons in the reaction system can be effectively neutralized, the effect of the acid on the reaction can be reduced, and the hydrogen ions in the solution can be fixed to protect other substances from the acidic environment, thereby facilitating further reaction between compound P2 and compound M2. For example, in a specific example, the molar ratio of compound P2, acid binding agent and compound M2 is 1: 1: 1, 1: 2: 1, 1: 1.5: 1, 1: 2: 2. In a more specific example, the molar ratio of compound P2, acid binding agent and compound M2 can be selected between 1: (1-1.5): (1-2).

[0055] In a specific example, the acid-binding agent includes at least one of triethylamine, pyridine, N,N-diisopropylethylamine, 4-dimethylaminopyridine, tetrabutylammonium bromide, potassium carbonate, ammonium carbonate and sodium carbonate. The raw materials are easily available and can be easily separated from the (meth)acrylate monomers finally obtained.

[0056] In some examples, the reaction temperature of compound P2, acid-binding agent and compound M2 is controlled at 0°C, for example, by using an ice bath, which helps control the reaction rate and prevents overheating from causing an increase in side reaction products or decomposition of the target substance, thereby helping to improve the yield and selectivity of the main reaction, reduce the volatilization of volatile substances and the degradation of unstable substances. It is also helpful for the subsequent separation and purification of the target product.

[0057] In some examples, removing excess compound M2 from the reactants is achieved by adding dilute hydrochloric acid.

[0058] In some examples, the mixed solution after the reaction in step S2 is treated with saturated NaCl solution, saturated NaHCO 3The solution is washed with deionized water, the organic phase is dried over anhydrous sodium sulfate, excess solvent is removed by rotary evaporation, and then the (meth)acrylate monomer of the present invention is obtained by column chromatography separation.

[0059] In some examples, the solvent includes one or more of ethanol, petroleum ether, dichloromethane, chloroform, ethyl acetate, tetrahydrofuran, acetonitrile, N,N-dimethylformamide or dimethyl sulfoxide, as long as it can facilitate the reaction of compound P2 and compound M2, and has good compatibility with compound P2, acid binding agent and compound M2. For example, in step S2, more specifically, the following solvents can be selected: dichloromethane, chloroform, ethyl acetate.

[0060] As can be seen from the above, the preparation method of the (meth) acrylate monomer proposed in the present invention can synthesize the required (meth) acrylate monomer through two-step reaction, and the reaction conditions are easy to control during the synthesis process. The hydrogen on the thiol group in the compound P1 can be captured by the hydride, so that the compound P1 is activated, and the S in the thiol group on the compound P1 further attacks the halogen functional group in the compound M1, forming a rapid polymerization reaction of the compound P1 and the compound M1, and generating a compound P2 with a heterosulfur ring; and the hydroxyl group in the compound P2 reacts with the halogen in the compound M2, and finally generates a compound with a (meth) acrylate group, and the molecular structure of the whole compound is stable.

[0061] In the following examples, compound M1 takes 2,3-dibromo-1-propanol as an example to illustrate the preparation method of (meth)acrylate monomers, and the specific two-step reaction steps, when compound M1 is 2,3-dichloro-1-propanol, are not described in detail.

[0062] Then, the preparation method of the (meth)acrylate monomer with the general structural formula G1 includes the following two steps:

[0063] The first step is to react the thiol group in compound P1-1 with the halogen functional group in compound M1 to form a -SC- saturated bond, as shown below:

[0064]

[0065] The second step is that the carbonyl group of methacryloyl chloride / acryloyl chloride reacts with the hydroxyl group in compound P2-2 to generate a compound with a methacrylate group or an acrylate group in a (meth)acrylate monomer of structural formula G1, as shown below:

[0066]

[0067] Then, the preparation method of the (meth)acrylate monomer with the general structural formula G2 includes the following two steps:

[0068] The first step is to react the thiol group in compound P1-2 with the halogen functional group in compound M1 to form a -SC- saturated bond, as shown below:

[0069]

[0070] The second step is that the carbonyl group of methacryloyl chloride / acryloyl chloride reacts with the hydroxyl group in compound P2-2 to generate a compound with a methacrylate group or an acrylate group in a (meth)acrylate monomer having a structural formula of G2, as shown below:

[0071]

[0072] Then, the preparation method of the (meth)acrylate monomer with the general structural formula G3 includes the following two steps:

[0073] The first step is to react the thiol group in compound P1-3 with the halogen functional group in compound M1 to form a -SC- saturated bond, as shown below. At this time, the molar ratio of compound P1-3 to compound M1 is 1:2:

[0074]

[0075] The second step is that the carbonyl group of methacryloyl chloride / acryloyl chloride reacts with the hydroxyl group in compound P2-3 to generate a compound with a methacrylate group or an acrylate group in a (meth)acrylate monomer of structural formula G3, as shown below:

[0076]

[0077] Then, the preparation method of the (meth)acrylate monomer with the general structural formula G4 includes the following two steps:

[0078] The first step is to react the thiol group in compound P1-4 with the halogen functional group in compound M1 to form a -SC- saturated bond, as shown below:

[0079]

[0080] The second step is that the carbonyl group of methacryloyl chloride / acryloyl chloride reacts with the hydroxyl group in compound P2-4 to generate a compound with a methacrylate group or an acrylate group in a (meth)acrylate monomer of structural formula G3, as shown below:

[0081]

[0082] The photopolymer type holographic recording medium containing a (meth)acrylate monomer of the present invention is described below.

[0083] The photopolymer holographic recording medium according to the present invention, which contains the (meth)acrylate monomers in the above examples, comprises a writing monomer, wherein the writing monomer comprises a (meth)acrylate monomer and a polymerizable monomer.

[0084] The photopolymer holographic recording medium containing (meth)acrylate monomers proposed in the present invention can form a writing monomer component with a higher refractive index by adding (meth)acrylate monomers and polymerizable monomers. The two components cooperate with each other, so that the writing monomer and the film-forming resin can have a larger refractive index difference, providing the photopolymer holographic recording medium with the required material basis for forming a phase-type volume holographic grating with refractive index modulation.

[0085] In some examples of the present invention, the weight percentage of the writing monomer in the entire photopolymer holographic recording medium is 15% to 55%. This allows the writing monomer to have a sufficient concentration to achieve a concentration difference between a bright area and a dark area after reaction under light. The photopolymer holographic recording medium also includes a film-forming resin, a photosensitive initiator composition, a chain transfer agent, a catalyst and an additive, and the film-forming resin includes a compound having multiple isocyanate reactive functional groups and a polyisocyanate compound. When the film-forming resin and the writing monomer are combined, a phase-type volume holographic grating with a refractive index difference and refractive index modulation can be formed.

[0086] In some embodiments of the invention, the photopolymer holographic recording medium containing (meth)acrylate monomers comprises the following components in parts by weight:

[0087] First component: 15 to 40 parts of a compound having multiple isocyanate-reactive functional groups, for example, 15 parts, 20 parts, 30 parts, 35 parts, 40 parts, etc.

[0088] Second component: 15 to 40 parts of polyisocyanate compound, for example, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, etc.

[0089] The third component: 1 to 30 parts of (meth)acrylate monomers, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, etc.

[0090] The fourth component: 10 to 40 parts of polymerizable monomers, for example, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, etc.

[0091] The fifth component: 0.1 to 3 parts of the photosensitive initiator combination agent, for example, 0.1, 0.2, 0.3, 0.5, 1, 1.5, 2.0, 2.5, 3, etc.

[0092] Sixth component: 0.1 to 3 parts of chain transfer agent, for example, 0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 1.0, 1.5, 2.0, 2.2, 2.5, 2.8, 3, etc.

[0093] Seventh component: 0.1 to 5 parts of catalyst, for example, 0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 1.0, 1.5, 2.0, 2.2, 2.5, 2.8, 3, 3.5, 4, 4.2, 4.6, 5, etc.

[0094] The eighth component: 0.1 to 9 parts of additives, for example, 0.1, 0.2, 0.3, 0.5, 1, 1.5, 2.0, 2.5, 3.0, 3.5, 4, 5, 6, 6.5, 7, 8, 9, etc.

[0095] As can be seen from the above, the photopolymer holographic recording medium containing (meth)acrylate monomers proposed in the present invention can achieve full synergistic effect of each component by reasonably controlling the addition amount of each component, and the holographic performance of the final photopolymer holographic recording medium will not be deteriorated due to excessive or insufficient amount of a certain component, thereby ensuring that the comprehensive holographic performance of the final photopolymer holographic recording medium is better.

[0096] For example, by controlling the compound with multiple isocyanate reactive functional groups to 15 to 40 parts and the polyisocyanate-based compound to 15 to 40 parts, the first component and the second component together form a film-forming resin with a lower refractive index, thereby providing support for the other components. In some specific examples, the compound with multiple isocyanate reactive functional groups is further controlled to 20 to 35 parts, and the polyisocyanate-based compound is further controlled to 20 to 35 parts.

[0097] By controlling the (meth)acrylate monomers to 1 to 30 parts, and the polymerizable monomers to 10 to 40 parts, the third component and the fourth component are a writing monomer system, and the intermolecular bonding refractive index will be higher after polymerization, then the interaction of the above four components can realize a photopolymer holographic recording medium having a high refractive index component and a low refractive index component with a large refractive index difference, and form a high refractive index difference between the film-forming resin and the writing monomer. Therefore, under the action of light, the monomers in the bright area (such as the third component and the fourth component) are polymerized and consumed and the concentration is reduced, and the monomers in the dark area hardly react. The difference in monomer concentration between the bright and dark areas causes the high-concentration monomers in the dark area to begin to migrate to the bright area, and the components of the film-forming resin in the bright area (such as the first component and the second component) are squeezed into the dark area, so that the refractive index of the bright area is close to the refractive index of the third component and the fourth component, and the refractive index of the dark area is close to the refractive index of the first component and the second component, forming a phase-type volume holographic grating with refractive index modulation. In some specific examples, the (meth)acrylate monomer is further controlled to be 3 parts to 20 parts; and the polymerizable monomer is further controlled to be 20 parts to 35 parts.

[0098] For example, controlling the photosensitive initiator composition to 0.1 to 3 parts can absorb a suitable number of photons during exposure, control the polymerization reaction at a certain speed, enable the grating to be formed quickly, and obtain a higher diffraction efficiency; in addition, it can also ensure that the final holographic recording medium has the required light transmittance and that the grating has a certain diffraction efficiency. In some specific examples, the photosensitive initiator composition is 0.3 to 2 parts.

[0099] For example, controlling the chain transfer agent to 0.1 to 3 parts can keep the polymer chain length within a reasonable range and effectively prevent excessive polymerization, ensuring that the final holographic recording medium has the required optical properties and diffraction efficiency. In some specific examples, the chain transfer agent is further controlled to 0.5 to 2 parts.

[0100] For example, controlling the catalyst to 0.1 to 5 parts can effectively increase the reaction rate of the relevant components and the consumption rate of the relevant components after exposure, thereby quickly forming a concentration difference between the monomers in the bright and dark areas and realizing a phase-type volume holographic grating with refractive index modulation. In some specific examples, the catalyst is further controlled to 0.5 to 3 parts.

[0101] For example, controlling the additive to 0.1 to 9 parts, taking the additive as a leveling agent, can effectively improve the uniformity of the mixed liquid, improve fluidity, and reasonably control costs. In some specific examples, the additive is further controlled to 0.6 to 6 parts.

[0102] In some optional examples, the photopolymer holographic recording medium containing (meth)acrylate monomers includes the following components in parts by weight: a first component - 15 parts of a compound having multiple isocyanate-reactive functional groups, a second component - 31 parts of a polyisocyanate compound, a third component - 30 parts of a (meth)acrylate monomer, a fourth component - 20 parts of a polymerizable monomer, a fifth component - 1 part of a photosensitive initiator combination agent, a sixth component - 1 part of a chain transfer agent, a seventh component - 0.7 parts of a catalyst, and an eighth component - 1.3 parts of an additive.

[0103] In some optional examples, the photopolymer holographic recording medium containing (meth)acrylate monomers includes the following components in parts by weight: a first component - 20 parts of a compound having multiple isocyanate-reactive functional groups, a second component - 37 parts of a polyisocyanate compound, a third component - 3 parts of a (meth)acrylate monomer, a fourth component - 24 parts of a polymerizable monomer, a fifth component - 3 parts of a photosensitive initiator combination agent, a sixth component - 3 parts of a chain transfer agent, a seventh component - 3 parts of a catalyst, and an eighth component - 7 parts of an additive.

[0104] In some optional examples, the photopolymer holographic recording medium containing (meth)acrylate monomers includes the following components in parts by weight: a first component - 40 parts of a compound having multiple isocyanate-reactive functional groups, a second component - 15 parts of a polyisocyanate compound, a third component - 2 parts of a (meth)acrylate monomer, a fourth component - 33 parts of a polymerizable monomer, a fifth component - 1 part of a photosensitive initiator combination agent, a sixth component - 1 part of a chain transfer agent, a seventh component - 2 parts of a catalyst, and an eighth component - 6 parts of an additive.

[0105] In some optional examples, the photopolymer holographic recording medium containing (meth)acrylate monomers includes the following components in parts by weight: a first component - 34 parts of a compound having multiple isocyanate-reactive functional groups, a second component - 15 parts of a polyisocyanate compound, a third component - 1 part of a (meth)acrylate monomer, a fourth component - 30 parts of a polymerizable monomer, a fifth component - 3 parts of a photosensitive initiator combination agent, a sixth component - 3 parts of a chain transfer agent, a seventh component - 5 parts of a catalyst, and an eighth component - 9 parts of an additive.

[0106] In some optional examples, the photopolymer holographic recording medium containing (meth)acrylate monomers includes the following components in parts by weight: a first component - 30 parts of a compound having multiple isocyanate-reactive functional groups, a second component - 16 parts of a polyisocyanate compound, a third component - 30 parts of a (meth)acrylate monomer, a fourth component - 12 parts of a polymerizable monomer, a fifth component - 2.9 parts of a photosensitive initiator combination agent, a sixth component - 0.1 parts of a chain transfer agent, a seventh component - 2 parts of a catalyst, and an eighth component - 7 parts of an additive.

[0107] In some optional examples, the photopolymer holographic recording medium containing (meth)acrylate monomers includes the following components in parts by weight: a first component - 33 parts of a compound having multiple isocyanate-reactive functional groups, a second component - 18 parts of a polyisocyanate compound, a third component - 35 parts of a (meth)acrylate monomer, a fourth component - 11 parts of a polymerizable monomer, a fifth component - 1 part of a photosensitive initiator combination agent, a sixth component - 1 part of a chain transfer agent, a seventh component - 0.1 parts of a catalyst, and an eighth component - 0.9 parts of an additive.

[0108] In some optional examples, the photopolymer holographic recording medium containing (meth)acrylate monomers includes the following components in parts by weight: a first component - 25 parts of a compound having multiple isocyanate-reactive functional groups, a second component - 30 parts of a polyisocyanate compound, a third component - 22 parts of a (meth)acrylate monomer, a fourth component - 13 parts of a polymerizable monomer, a fifth component - 0.2 parts of a photosensitive initiator combination agent, a sixth component - 0.8 parts of a chain transfer agent, a seventh component - 3 parts of a catalyst, and an eighth component - 6 parts of an additive.

[0109] In some optional examples, the photopolymer holographic recording medium containing (meth)acrylate monomers includes the following components in parts by weight: a first component - 35 parts of a compound having multiple isocyanate-reactive functional groups, a second component - 15 parts of a polyisocyanate compound, a third component - 21 parts of a (meth)acrylate monomer, a fourth component - 28.6 parts of a polymerizable monomer, a fifth component - 0.1 parts of a photosensitive initiator combination agent, a sixth component - 0.1 parts of a chain transfer agent, a seventh component - 0.1 parts of a catalyst, and an eighth component - 0.1 parts of an additive.

[0110] In some examples of the present invention, in the compound having multiple isocyanate reactive functional groups, the isocyanate reactive functional groups are hydroxyl groups. Hydroxyl groups are polar groups, in which alcoholic hydroxyl groups are easily oxidized and have high reactivity. For example, in a specific example, the compound having multiple isocyanate reactive functional groups is a compound having a refractive index of less than 1.5 and having two or more hydroxyl functional groups.

[0111] More specifically, the compound having multiple isocyanate reactive functional groups is selected from at least one of tetraethylene glycol, trimethylolethane, glycerol, triethanolamine, polyester polyols with a molecular weight of 200 to 2000, polycarbonate polyols, and polyether polyols. The refractive index of these substances is also relatively low, for example: the refractive index of tetraethylene glycol is 1.46 (20° C.); the refractive index of trimethylolethane is 1.5; the refractive index of glycerol is 1.474 (20° C.); the refractive index of triethanolamine is 1.482 to 1.485 (20° C.).

[0112] In some examples of the present invention, the polyisocyanate-based compound is a compound having a refractive index less than 1.5 and having two or more isocyanate groups.

[0113] In a specific example, the polyisocyanate compound is selected from at least one of hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, (2,4,6-trioxotriazine-1,3,5(2H,4H,6H)-triyl)tris(hexamethylene)isocyanate, butane-1,4-diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate. The refractive index of these compounds is also low: the refractive index of hexamethylene diisocyanate is 1.453; the refractive index of trimethylhexamethylene diisocyanate is 1.462; the refractive index of (2,4,6-trioxotriazine-1,3,5(2H,4H,6H)-triyl)tris(hexamethylene)isocyanate is 1.472; the refractive index of butane-1,4-diisocyanate is 1.453; the refractive index of isophorone diisocyanate is 1.484; and the refractive index of dicyclohexylmethane diisocyanate is 1.496 (25°C).

[0114] In some examples of the present invention, the polymerizable monomer is selected from at least one of alkenyl naphthalene compounds, alkenyl anthracene compounds, alkenyl benzene compounds, acrylic compounds, methacrylic compounds, acrylate compounds, methacrylate compounds, N-vinyl pyrrole, N-vinyl carbazole, N-vinylimidazole, N-vinyl indole, N-vinyl pyrrolidone, and trans-N-3-ynyl butenyl carbazole.

[0115] In a specific example, the alkenyl naphthalene compound is selected from at least one of 1-vinyl naphthalene and 2-vinyl naphthalene.

[0116] In a specific example, the alkenyl anthracene compound is selected from at least one of 2-vinyl anthracene and 9-vinyl anthracene.

[0117] In a specific example, the alkenylbenzene compound is selected from at least one of styrene, 2-chlorostyrene, 2-bromostyrene, 3-chlorostyrene, 3-bromostyrene, 4-chlorostyrene, 4-bromostyrene, p-(chloromethyl)styrene, and p-(bromomethyl)styrene.

[0118] In a specific example, the methacrylic compound includes at least one of methacrylic acid and derivatives thereof.

[0119] In a specific example, the acrylate compound is selected from at least one of 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-tri(4-chlorophenyl)propionyl]oxy}propane-3,1-diyl)oxyethane-2,1-diyl]diacrylate.

[0120] In a specific example, the methacrylate compound is selected from at least one of 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, and tetrabromobisphenol A dimethacrylate.

[0121] In some examples of the present invention, the photosensitive initiator combination includes a photosensitizer and a photoinitiator. The photosensitizer can be matched with a photoinitiator to realize a visible light initiation system and adapt to lasers of different wavelengths. Under the irradiation of light in a specific wavelength range, the photosensitizer in the photoinitiator system is activated by the corresponding light, absorbs light energy, and transfers the light energy to the photoinitiator, so that the photoinitiator can be activated under light radiation in a wider wavelength range to generate free radicals with initiation function. The photoinitiator free radicals can initiate monomer polymerization to realize the construction of a holographic grating, improve the photosensitivity of the photopolymer holographic recording medium, and broaden the range of optional radiation sources for light radiation.

[0122] It can be understood that, in other examples, when the present invention uses a wavelength-adapted photoinitiator, no photosensitizer may be added.

[0123] When the photosensitive initiator combination contains both a photosensitizer and a photoinitiator, further, the mass ratio of the photosensitizer to the photoinitiator is (0.001-1):(0.1-3). By controlling the mass ratio of the photosensitizer to the photoinitiator within the above range, the concentration of the photosensitizer can be effectively controlled, so that during the holographic exposure process, the number of absorbed photons is controlled within a suitable range, the speed of the polymerization reaction is controlled within a reasonable range, and the speed of grating formation is controlled within a certain range, thereby ensuring the light transmittance of the photopolymer holographic recording medium and obtaining excellent diffraction efficiency. In a more specific example, the mass of the photosensitizer is 1 / 10 to 1 / 3 of the mass of the photoinitiator, such as 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, 1 / 5, 1 / 4 or 1 / 3, etc.

[0124] In the present invention, different broadband responses can be achieved by regulating the type of photosensitizer. For example, the photosensitizer is a dye with high electron transfer efficiency under light.

[0125] In a specific example, the photosensitizer is selected from at least one of cyanine dyes, fluorescein dyes, coumarin ketone dyes, nitrogen-containing aromatic heterocyclic compounds, aromatic amine compounds, and benzylcycloalkane ketone compounds.

[0126] More specifically, the photosensitizer is selected from new methylene blue (maximum absorption wavelength 666nm), thionine (absorption wavelength 602.5nm), basic yellow (absorption wavelength 412nm), pinacol cyanol chloride, rhodamine 6G (absorption wavelength 400nm-700nm), gallocyanine, ethyl violet (absorption wavelength 596nm), Victoria blue R (maximum absorption wavelength 615nm), lapis lazuli blue (absorption wavelength 630-640nm), methylene blue (maximum absorption wavelength 662nm), basic orange, daro red (maximum absorption wavelength 502nm) , pyrrole red Y (strong absorption wavelengths are 235nm, 267nm, 336nm, 515nm), basic red 29, quinaldine red (maximum absorption wavelength 528nm), crystal violet (absorption wavelength 588nm ~ 592nm), ethyl violet (maximum absorption wavelength 596nm), brilliant green (maximum absorption wavelength 630nm), azure A (maximum absorption wavelength 633nm), crystal violet white nitrile (maximum absorption wavelength 579nm), malachite green white nitrile, eosin (absorption wavelength 510nm ~ 518nm) one or more.

[0127] In a specific example, the photoinitiator is selected from at least one of aromatic ketone compounds, benzoin and its derivatives, benzyl ketal, acylphosphine oxide, aryl ammonium borate, chromium salt, aryl diazonium salt, onium salt, and organic metal compound. It can also be other photoinitiators with similar functions, which are not limited in the present invention.

[0128] More specifically, the photoinitiator is selected from benzophenone (absorption wavelength 210nm, 255nm), alkyl benzophenone (290nm ~ 360nm), 4,4'-bis (dimethylamino) benzophenone, anthrone (299nm ~ 366nm) and halogenated benzophenone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide (absorption wavelength 350nm ~ 400nm), bisacylphosphine oxide, phenyl dihydroxyacetate, camphorquinone (absorption wavelength 400nm ~ 400nm), .... One or more of the following: a-aminoalkylphenone (absorption wavelength of 380nm to 430nm), α,α-dialkoxyacetophenone, α-hydroxyalkylphenone (absorption wavelength of 320nm to 380nm), tetrabutylammonium triphenylhexylborate, tetrabutylammonium tri-(3-fluorophenyl)hexylborate, tetrabutylammonium tri-(3-chloro-4-methylphenyl)hexylborate, ferrocenyl compounds, iodonium salts, sulfonium salts, hexaarylbisimidazoles, etc. When these photoinitiators are irradiated with light in the corresponding wavelength range, they can be quickly activated and generate active free radicals, thereby initiating polymerization reactions between the components of the photopolymer-type holographic recording medium, and achieving a difference in monomer concentration between the bright area and the dark area. Alternatively, when the photosensitizer coordinated therewith absorbs light in the corresponding wavelength range, it transfers heat to the photoinitiator, thereby achieving activation of the photoinitiator.

[0129] In some examples of the present invention, the chain transfer agent is a thiol compound.

[0130] In a specific example, the chain transfer agent includes one or more of dodecyl mercaptan, mercaptoethanol, hexanethiol, phenylethyl mercaptan, 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol, 4-methyl-4H-1,2,4-triazole-3-thiol, and the like.

[0131] In some examples of the present invention, the catalyst is a tertiary amine catalyst or an organic metal catalyst.

[0132] In a specific example, the catalyst is selected from at least one of triethylenediamine, bis(dimethylaminoethyl)ether, dimethylethanolamine, 2-(2-dimethylamino-ethoxy)ethanol, trimethylhydroxyethylpropylenediamine, N,N-bis(dimethylaminopropyl)isopropanolamine, dibutyltin dilaurate, stannous octoate, potassium carboxylate catalysts and bismuth carboxylate catalysts. The catalyst is not limited to the above-listed types, as long as it can catalyze the polymerization reaction of the aforementioned related components under light, and those skilled in the art should understand that these all fall within the scope of protection of the present invention.

[0133] In some examples of the present invention, the additive includes one or more of a defoamer, a leveling agent, and a water remover.

[0134] In a specific example, the defoamer is an organosilicon defoamer and / or a polymer defoamer without organosilicon, and the weight of the defoamer in the photopolymer holographic recording medium is less than or equal to 3%. The defoamer can reduce the surface tension of the liquid and remove bubbles, thereby improving the fluidity of the mixture of the components.

[0135] More specifically, for example, BYK-011, BYK-012, BYK-014, BYK-023, BYK-051N, BYK-085, BYK-1610, BYK-1707, BYK-1740, BYK-1760 produced by BYK, DC65, AFE-7820 produced by Dow Corning, or any mixture of these defoamers in any proportion. BYK series defoamers have excellent defoaming performance, good compatibility with other components, and good dispersibility; among them, BYK-011, BYK-012, BYK-014 and BYK-051N are polymer defoamers that do not contain silicone. DC65 is a water-based ink that dries quickly, has good printing effects, and is not easy to fall off. AFE-7820 has high efficiency in defoaming performance.

[0136] In a specific example, the leveling agent is an organic silicon surface additive, and the weight of the leveling agent in the photopolymer holographic recording medium is less than or equal to 3%. For example, BYK-302, BYK-306, BYK-307, BYK-327, BYK-329, BYK-333, BYK-356, BYK-358, BYK-378, BYK-3455, BYK-3566 produced by BYK or any mixture of these surface additives. BYK series leveling agents have excellent leveling properties.

[0137] In a specific example, the dehydrating agent is selected from toluenesulfonyl isocyanate, triethyl orthoformate, CUWR-WB20 dehydrating agent of Guangzhou Yourun Synthetic Materials Co., Ltd., ALT-201 dehydrating agent of Anxiang Elite Chemical Co., Ltd., PCCI dehydrating agent of Shanghai Ruhr Chemical Trading Co., Ltd., etc.

[0138] In some examples, the weight percentage of the dehydrating agent in the photopolymer holographic recording medium is less than or equal to 3%. The dehydrating agent can remove excess water during the reaction, so that the components can be mixed better without stratification.

[0139] Next, the application of the photopolymer type holographic recording medium containing a (meth)acrylate monomer of the present invention will be described.

[0140] The holographic optical element proposed by the present invention is made of materials including the photopolymer holographic recording media in the above-mentioned examples. The holographic optical element includes but is not limited to a volume holographic grating.

[0141] It can be seen from the above that the holographic optical element proposed in the present invention, because it includes the photopolymer holographic recording medium of the present invention, also has the advantages of the photopolymer holographic recording medium of the present invention, such as high diffraction efficiency, high sensitivity and small exposure required.

[0142] The optical device proposed by the present invention includes the holographic optical element as described above. The optical device includes but is not limited to a head-up display device (HUD), an augmented reality device (AR device, Augmented Reality), a virtual reality device (VR device, Virtual Reality), a photopolymer holographic storage disc, etc. The photopolymer holographic storage disc can be erasable and rewritable and record in real time, is suitable for storing a large amount of data, and has a very fast data transmission speed.

[0143] It can be seen from the above that the optical device proposed by the present invention, because it includes the holographic optical element mentioned above, also has the advantages of the holographic optical element of the present invention. The optical device has excellent holographic performance, clear images, and can store a large amount of data.

[0144] The (meth)acrylate monomer, the preparation method of the (meth)acrylate monomer, and the photopolymer holographic recording medium containing the (meth)acrylate monomer of the present invention are described below with reference to specific embodiments.

[0145] Example 1

[0146] The general structural formula of the (meth)acrylate monomer in this embodiment is G1:

[0147] The preparation method of the (meth)acrylate monomer of structural formula G1 comprises the following steps:

[0148] Step S1: Compound P1-1 is dissolved in ethanol solvent, stirred evenly and sodium hydride is slowly added, stirred and reacted for 1 hour, then compound M1 is added and reacted for 0.5 hour, excess solvent is removed by rotary evaporation, and the target product compound P2-1 is obtained by column chromatography separation. The reaction equation is as follows:

[0149]

[0150] Step S2: Compound P2-1 and acid-binding agent triethylamine were dissolved in solvent ethyl acetate, stirred for 10 min, and compound M2 methacryloyl chloride / acryloyl chloride was added until the reaction was complete, and dilute hydrochloric acid was added to remove excess compound M2, and saturated NaCl solution, saturated NaHCO 3The solution was washed with deionized water, the organic phase was dried over anhydrous sodium sulfate, and then the excess solvent was removed by rotary evaporation, and then the (meth)acrylate monomer G1 of the present invention was obtained by column chromatography. The reaction equation is as follows:

[0151]

[0152] Then, when the R of compound M2 1 At different times, monomers G1 (including G1-a and G1-b) with different structures are generated in the present application, as shown in Table 1 below.

[0153] The characterization data are as follows:

[0154] G1-a: 1 H NMR (400 MHz, CDCl 3 )δ7.37–7.26(m,4H),5.77(dq,J=1.9,0.9Hz,1H),5.64

[0155] (dq,J=1.8,0.8Hz,1H),4.47–4.35(m,2H),3.95(p,J=7.7Hz,1H),3.50(d,J=7.5Hz,1H),3.00(d,J=7.5Hz,1H),1.94(t,J=0.9Hz,3H).

[0156] G1-b: 1 H NMR (400 MHz, CDCl 3 )δ7.37–7.25(m,4H),6.16–6.05(m,1H),5.91(dd,J=

[0157] 17.7, 2.7Hz, 1H), 5.84 (dd, J = 17.4, 2.7Hz, 1H), 4.36 (d, J = 7.8Hz, 2H), 3.92 (p, J = 7.6Hz, 1H), 3.50 (d, J = 7.5Hz, 1H), 3.00 (d, J = 7.5Hz, 1H).

[0158] Table 1 M2 corresponding to G1 with different structures and performance parameters

[0159] Example Reactant M2 Target monomer G1 G1 refractive index <![CDATA[Kinematic viscosity (mm 2 / s)]]> 1-1 Methacryloyl chloride G1-a 1.62 11 1-2 Acryloyl chloride G1-b 1.63 13

[0160] Example 2

[0161] The general structural formula of the (meth)acrylate monomer in this embodiment is G2:

[0162] The preparation method of the (meth)acrylate monomer of structural formula G2 comprises the following steps:

[0163] Step S1: Compound P1-2 is dissolved in ethyl acetate, stirred evenly and sodium hydride is slowly added, stirred and reacted for 1 hour, then compound M1 is added and reacted for 0.5 hour, excess solvent is removed by rotary evaporation, and the target product compound P2-2 is obtained by column chromatography separation. The reaction equation is as follows:

[0164]

[0165] Step S2: Compound P2-2 and acid-binding agent pyridine were dissolved in dichloromethane solvent, stirred for 10 min, and compound M2 methacryloyl chloride / acryloyl chloride was added until the reaction was complete, and dilute hydrochloric acid was added to remove excess compound M2, and saturated NaCl solution, saturated NaHCO 3 The solution was washed with deionized water, the organic phase was dried over anhydrous sodium sulfate, and then the excess solvent was removed by rotary evaporation, and then the (meth)acrylate monomer G2 of the present invention was obtained by column chromatography. The reaction equation is as follows:

[0166]

[0167] Then, when the R of compound M2 1 At different times, monomers G2 (including G2-a and G2-b) with different structures are generated in the present application, as shown in Table 2 below.

[0168] The characterization data are as follows:

[0169] G2-a: 1 H NMR (400 MHz, CDCl 3 )δ7.24(d,J=7.7Hz,1H),7.15–7.09(m,1H),7.13–7.06

[0170] (m,1H),5.79(dq,J=1.7,0.9Hz,1H),5.65(dq,J=1.8,0.8Hz,1H),4.47–4.35(m,2H),3.95(p,J =7.7Hz,1H),3.51(d,J=7.5Hz,1H),3.01(d,J=7.5Hz,1H),2.31(s,3H),1.94(t,J=0.9Hz,3H).

[0171] G2-b: 1 H NMR (400 MHz, CDCl 3 )δ7.21(d,J=7.5Hz,1H),7.15–7.08(m,2H),6.15–6.04

[0172] (m,1H),5.88(ddd,J=26.9,17.5,2.7Hz,2H),4.36(d,J=7.8Hz,2H),3.92(p,J=7.6Hz,1H),3.29(dd,J=17.6,7.5Hz,2H),2.30(s,3H).

[0173] Table 2 M2 corresponding to G2 with different structures and performance parameters

[0174]

[0175] Example 3

[0176] The general structural formula of the (meth)acrylate monomer in this embodiment is G3:

[0177] The preparation method of the (meth)acrylate monomer of structural formula G3 comprises the following steps:

[0178] Step S1: Dissolve compound P1-3 in petroleum ether, stir evenly and slowly add sodium hydride, stir and react for 1 hour, then add compound M1 and react for 0.5 hour, remove excess solvent by rotary evaporation, and separate by column chromatography to obtain the target product compound P2-3. In this step, the molar ratio of compound P1-3 to compound M1 is 1:2. The reaction equation is as follows:

[0179]

[0180] Step S2: Compound P2-3 and acid-binding agent pyridine were dissolved in chloroform solvent, stirred for 10 min, and compound M2 methacryloyl chloride / acryloyl chloride was added until the reaction was complete, and dilute hydrochloric acid was added to remove excess compound M2, and saturated NaCl solution, saturated NaHCO 3 The solution was washed with deionized water, the organic phase was dried over anhydrous sodium sulfate, and then the excess solvent was removed by rotary evaporation, and then separated by column chromatography to obtain the (meth)acrylate monomer G3 of the present invention. In this step, the molar ratio of compound P2-3 to compound M2 is 1:2. The reaction equation is as follows:

[0181]

[0182] Then, when the R of compound M2 1 At different times, monomers G3 (including G3-a and G3-b) with different structures are generated in the present application, as shown in Table 3 below.

[0183] The characterization data are as follows:

[0184] G3-a: 1H NMR (400 MHz, CDCl 3 )δ7.25(s,1H),7.19(s,1H),5.80(q,J=1.6Hz,1H),5.76

[0185] (dq,J=1.8,0.9Hz,1H),5.61(ddt,J=14.9,2.7,1.2Hz,2H),4.34(d,J=7.7Hz,4H),3.99(p,J= 7.7Hz,2H),3.35(d,J=7.5Hz,2H),3.23(d,J=7.7Hz,2H),1.94(d,J=2.9Hz,2H),1.94(s,4H).

[0186] G3-b: 1 H NMR (400 MHz, CDCl 3 )δ7.25(s,1H),7.19(s,1H),6.14–6.04(m,2H),5.95–5.87(m,2H),5.85(dt,J=14.7,2.7Hz,2H),4.37(d d,J=10.6,7.7Hz,2H),4.32(dd,J=10.6,7.9Hz,2H),3.97(p,J=7.6Hz,2H),3.25(dd,J=12.3,7.7Hz,4H).

[0187] Table 3 M2 corresponding to G3 with different structures and performance parameters

[0188]

[0189] Example 4

[0190] The general structural formula of the (meth)acrylate monomer in this embodiment is G4:

[0191] The preparation method of the (meth)acrylate monomer of structural formula G4 comprises the following steps:

[0192] Step S1: Compound P1-4 is dissolved in petroleum ether, stirred evenly and sodium hydride is slowly added, stirred and reacted for 1 hour, then compound M1 is added and reacted for 0.5 hour, excess solvent is removed by rotary evaporation, and the target product compound P2-4 is obtained by column chromatography separation. The reaction equation is as follows:

[0193]

[0194] Step S2: Compound P2-4 and acid-binding agent potassium carbonate were dissolved in acetonitrile solvent, stirred for 10 min, and compound M2 methacryloyl chloride / acryloyl chloride was added until the reaction was complete, and dilute hydrochloric acid was added to remove excess compound M2, and saturated NaCl solution, saturated NaHCO 3 The solution was washed with deionized water, the organic phase was dried over anhydrous sodium sulfate, and then the excess solvent was removed by rotary evaporation, and then the (meth)acrylate monomer G4 of the present invention was obtained by column chromatography. The reaction equation is as follows:

[0195]

[0196] Then, when the R of compound M2 1 At different times, monomers G4 (including G4-a and G4-b) with different structures are generated in the present application, as shown in Table 4 below.

[0197] The characterization data are as follows:

[0198] G4-a: 1 H NMR (400 MHz, CDCl 3 )δ7.29(d,J=1.7Hz,1H),7.21(d,J=1.8Hz,1H),5.76

[0199] (dq,J=1.7,0.8Hz,1H),5.64(dq,J=1.7,0.9Hz,1H),4.47–4.35(m,2H),3.93(p,J=7.7Hz,1H),3.39(dd,J=15.6,7.6Hz,2H),1.94(t,J=0.9Hz,3H).

[0200] G4-b: 1 H NMR (400 MHz, CDCl 3 )δ7.27(dd,J=13.2,1.6Hz,2H),6.15–6.05(m,1H),5.91

[0201] (dd,J=17.8,2.7Hz,1H),5.84(dd,J=17.4,2.7Hz,1H),4.40–4.30(m,2H),3.91(p,J=7.7Hz,1H),3.39(d,J=7.5Hz,1H),3.30(d,J=7.5Hz,1H).

[0202] Table 4 M2 corresponding to G4 with different structures and performance parameters

[0203]

[0204] The solvent and acid binding agent in embodiment 1-4 are only used for schematic description and cannot be construed as limiting the application. The solvent can be one or more of ethanol, petroleum ether, methylene chloride, chloroform, ethyl acetate, tetrahydrofuran, acetonitrile, N,N-dimethylformamide or dimethyl sulfoxide. The acid binding agent includes at least one of triethylamine, pyridine, N,N-diisopropylethylamine, 4-dimethylaminopyridine, tetrabutylammonium bromide, potassium carbonate, ammonium carbonate and sodium carbonate. Those skilled in the art should understand that these should all be within the scope of protection of the present invention.

[0205] Example 5

[0206] Photopolymer holographic recording media 5-1 to 5-8 containing the (meth)acrylate monomers in Examples 1 to 4 were used: the specific components of the photopolymer holographic recording media 5-1 to 5-8 are shown in Table 5 below.

[0207] Table 5 Composition of each photopolymer type holographic recording medium containing the (meth)acrylate monomer of each example

[0208]

[0209]

[0210] In this embodiment, the components selected may also be other components listed above, and these embodiments should not be construed as limiting the scope of protection of the present invention.

[0211] Comparative Example

[0212] The composition of the photopolymer holographic recording medium 5-1 is substantially the same as that of Example 5, except that the (meth)acrylate monomer G1-a of the photopolymer holographic recording medium 5-1 is removed so that the proportion of the (meth)acrylate monomer becomes 0, while the polymerizable monomer 2-chlorostyrene is increased to 27 parts, thereby obtaining a common photopolymer holographic recording medium.

[0213] Test example

[0214] The performance of the photopolymer holographic recording media 5-1 to 5-8 containing (meth)acrylate monomers in Example 5 and the ordinary photopolymer holographic recording media in the comparative example were tested, and the results are shown in Table 6. During the test, the holographic recording media in Example 5 were exposed to lasers of different wavelengths according to different photosensitive systems, and the exposure intensity was 3 mW / cm 2 .

[0215] The corresponding holographic performance graphs were plotted using the photopolymer holographic recording medium 5-1 containing (meth)acrylate monomers, the photopolymer holographic recording medium 5-3 containing (meth)acrylate monomers, and the photopolymer holographic recording medium 5-5 containing (meth)acrylate monomers in Example 5 to obtain Figure 1 .

[0216] Specifically, for the three holographic recording media 5-1, 5-3, and 5-5, solid-state lasers with wavelengths of 633nm, 457nm, and 532nm are used as light sources, respectively. After the beam expander, beam splitter, and half-wave plate, two beams with the same light intensity and a diameter of 8mm are obtained. The two beams intersect in the prepared holographic recording medium for exposure, and the light intensity is 3mW / cm 2 The detection light source is a 785nm wavelength solid 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 the photodetector. The single grating diffraction efficiency (η) of the photopolymer holographic recording medium and the photosensitivity (S) of the photopolymer holographic recording medium are calculated by formulas (1) to (3).

[0217]

[0218] Where η is the diffraction efficiency, η max is the highest diffraction efficiency, I d is the diffracted light, I t is the transmitted light, S is the photosensitivity, E is the exposure energy, and ΔE is the exposure energy when the highest diffraction efficiency is achieved.

[0219] like Figure 1 As shown in the figure, it is finally measured that the diffraction efficiency of the photopolymer holographic recording medium of the present invention is greater than 95%, and the exposure amount is less than 20mJ / cm 2 , sensitivity greater than 100cm 2 / mJ.

[0220] And as Figure 2 As shown, the conventional photopolymer holographic recording medium of the comparative example was exposed at an exposure wavelength of 633 nm and an exposure light intensity of 3 mW / cm 2 The diffraction efficiency of the ordinary photopolymer holographic recording medium in the comparative example is less than 50%, and the required exposure is greater than 100 mJ / cm 2 , the sensitivity is lower.

[0221] The holographic performance tests of the photopolymer holographic recording media 5-1 to 5-8 in Example 5 and the common photopolymer holographic recording media of the comparative example are shown in Table 6 below.

[0222] Table 6 Holographic performance test table of each photopolymer holographic recording medium in Example 5 and Comparative Example

[0223]

[0224] In summary, reference Figure 1 , Figure 2 As shown in Table 6, the diffraction efficiency of the photopolymer holographic recording medium of the embodiment of the present invention is much higher than that of the comparative example, the sensitivity is much higher than that of the comparative example, and the required exposure amount is small. The kinematic viscosity of the (meth) acrylate monomers of Examples 1-2 of the present invention and the (meth) acrylate monomers of Example 4 are both less than 20 mm 2 / s, the kinematic viscosity of the (meth)acrylate monomer of Example 3 of the present invention is less than 100 mm 2 / s, low kinematic viscosity, and in liquid state; and the refractive index of the (meth)acrylate monomers in Examples 1-4 of the present invention is between 1.61 and 1.67, and the refractive index is high. It can be seen that the (meth)acrylate monomers of the present invention can be added in a relatively high amount in the photopolymer, thereby effectively improving the refractive index of the writing monomer, and further improving the refractive index difference between the writing monomer and the film-forming resin, so that the holographic performance of the photopolymer-type holographic recording medium containing the (meth)acrylate monomers of the present invention can be significantly improved.

[0225] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A (meth)acrylate monomer, characterized in that: The general structural formulas are shown in formulas G1, G2, G3 and G4: Wherein, R1 is methyl or hydrogen.

2. The (meth)acrylate monomer according to claim 1, characterized in that The (meth)acrylate monomer is selected from monomers having the following structural formula:

3. A method for preparing a (meth)acrylate monomer according to claim 1 or 2, characterized in that: The method comprises the following steps: dissolving compound P1 in a solvent, adding a hydride and stirring for a certain period of time, then adding compound M1 to react, removing excess solvent, and separating to obtain compound P2; Dissolving compound P2 and an acid-binding agent in a solvent, and adding compound M2 until the reaction is complete, removing excess reactants and the solvent, and separating to obtain the (meth)acrylate monomer; The compound P1 is selected from compounds having the following structural formula: The compound M1 includes 2,3-dibromo-1-propanol and / or 2,3-dichloro-1-propanol; The compound M2 is acryloyl chloride or methacryloyl chloride.

4. The method for preparing a (meth)acrylate monomer according to claim 3, characterized in that: The hydride comprises at least one of sodium hydride or potassium hydride; and / or, The stirring reaction time of the compound P1 and the hydride is 0.2h to 2h; The molar ratio of the compound P1, the hydride and the compound M1 is 1:(2-5):(1-2); and / or, The reaction time of the compound P1 and the compound M1 is 0.1 h to 1 h.

5. The method for preparing a (meth)acrylate monomer according to claim 3, characterized in that: The molar ratio of the compound P2, the acid-binding agent and the compound M2 is 1:(1-2):(1-2); and / or, When the compound P2, the acid-binding agent and the compound M2 react, the reaction temperature is controlled at 0°C; and / or, The solvent includes ethanol, petroleum ether, dichloromethane, chloroform, ethyl acetate, tetrahydrofuran, acetonitrile, N,N-dimethylformamide or dimethyl sulfoxide; and / or, The acid binding agent includes at least one of triethylamine, pyridine, N,N-diisopropylethylamine, 4-dimethylaminopyridine, tetrabutylammonium bromide, potassium carbonate, ammonium carbonate and sodium carbonate.

6. A photopolymer holographic recording medium containing the (meth)acrylate monomer according to claim 1 or 2, characterized in that: The invention comprises a writing monomer, wherein the writing monomer comprises the (meth)acrylic acid ester monomer and a polymerizable monomer.

7. The photopolymer holographic recording medium according to claim 6, wherein: The weight percentage of the writing monomer in the entire photopolymer holographic recording medium is: 15% to 55%; The photopolymer holographic recording medium further comprises a film-forming resin, a photosensitive initiator assembly agent, a chain transfer agent, a catalyst and additives. The film-forming resin comprises a compound having a plurality of isocyanate-reactive functional groups and a polyisocyanate-based compound.

8. The photopolymer holographic recording medium according to claim 7, wherein: The composition comprises the following components in parts by weight: First component: 15 to 40 parts of a compound having multiple isocyanate-reactive functional groups; The second component: 15 to 40 parts of polyisocyanate compound; The third component: 1 to 30 parts of (meth)acrylate monomer; The fourth component: 10 to 40 parts of polymerizable monomer; The fifth component: 0.1 to 3 parts of photosensitive initiator combination agent; The sixth component: 0.1 to 3 parts of chain transfer agent; The seventh component: 0.1 to 5 parts of catalyst; The eighth component: 0.1 to 9 parts of additives.

9. The photopolymer holographic recording medium according to claim 7 or 8, wherein: In the compound having a plurality of isocyanate-reactive functional groups, the isocyanate-reactive functional groups are hydroxyl groups; and / or, The compound having multiple isocyanate reactive functional groups is selected from at least one of tetraethylene glycol, trimethylolethane, glycerol, triethanolamine, polyester polyols with a molecular weight of 200 to 2000, polycarbonate polyols, and polyether polyols; and / or, The polyisocyanate compound is a compound having two or more isocyanate groups; and / or, The polymerizable monomer is selected from at least one of alkenyl naphthalene compounds, alkenyl anthracene compounds, alkenyl benzene compounds, acrylic compounds, methacrylic compounds, acrylate compounds, methacrylate compounds, N-vinyl pyrrole, N-vinyl carbazole, N-vinylimidazole, N-vinyl indole, N-vinyl pyrrolidone, and trans-N-3-ynyl butenyl carbazole; and / or, The photosensitive initiator combination comprises a photosensitizer and a photoinitiator; the mass ratio of the photosensitizer to the photoinitiator is (0.001-1):(0.1-3); the absorption wavelength of the photosensitizer selected in the photosensitive initiator combination is different from the absorption wavelength range of the photoinitiator; and / or, The chain transfer agent is a thiol compound; and / or, The catalyst is a tertiary amine catalyst or an organic metal catalyst; and / or, The additives include one or more of a defoamer, a leveling agent and a dewatering agent.

10. A holographic optical element, characterized in that: The raw material of the holographic optical element comprises the photopolymer holographic recording medium as claimed in any one of claims 6 to 9.

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

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