High-refractive-index optical monomer and preparation method therefor, and resin mixture and use thereof

Abstract

A high-refractive-index optical monomer and a preparation method therefor, and a resin mixture and the use thereof. The high-refractive-index optical monomer comprises at least one group of hybrid units and two polysulfide chains respectively located at two terminal chains of the hybrid units, wherein the hybrid units comprise three benzosulfur rings connected via sulfur, and each benzosulfur ring comprises a benzene ring and two cyclohexyldithioalkyl groups hybridized with the benzene ring.

Description

High-refractive-index optical monomers and their preparation methods, resin mixtures and their applications

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 2024114558229, filed on October 17, 2024, entitled "High Refractive Index Optical Monomer and Preparation Method Thereof, Resin Mixture and Application Thereof", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of optical materials, and in particular to high-refractive-index optical monomers and their preparation methods, resin mixtures and their applications. Background Technology

[0004] High-performance optical devices are increasingly trending towards lightweight, miniaturized, and integrated designs. Nanoimprinting technology transfers designed patterns onto high-refractive-index optical resins to meet these demands. Currently, commercially available resins in China have a refractive index of less than 1.65, which significantly limits their application, making nanoimprinting impossible or resulting in poor light transmittance after nanoimprinting. Summary of the Invention

[0005] In view of this, this application proposes a high refractive index optical monomer and its preparation method, resin mixture and its application, aiming to achieve the performance of high refractive index and high light transmittance of the optical monomer.

[0006] The high-refractive-index optical monomer proposed in the first aspect of this application includes at least one set of hybrid units and two polysulfide chains located at the two ends of the hybrid unit; the hybrid unit includes three benzo[a]thio rings connected by sulfur, each of the benzo[a]thio rings including a benzene ring and two cyclohexanedithioalkyl groups hybridized and connected to the benzene ring.

[0007] The high-refractive-index optical monomer proposed in the first aspect of this application is rich in sulfur, benzene ring structures, and benzothioring ring structures in its hybrid unit. These structures themselves have high molar refractive indices, resulting in a high overall refractive index for the molecule. The benzene ring itself possesses a certain degree of rigidity and structural stability, which improves the molecule's heat resistance. The polysulfide chain increases the chain length of the entire molecule, enhancing its flexibility. The polysulfide chain itself is rich in sulfur with a high molar refractive index; together with the hybrid unit, the polysulfide chain facilitates the separation of chromophores and disrupts intramolecular conjugation interactions, thus promoting visible light transmission. Therefore, the optical monomer of this application exhibits high visible light transmittance, high refractive index, and good heat resistance.

[0008] In some embodiments, the polysulfide chain comprises at least three linked sulfur groups; and / or, the polysulfide chain is connected to unsaturated functional groups.

[0009] In some embodiments, the optical unit has the following general structural formula (I):

[0010] Among them, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 Each is either H or substituted / unsubstituted C. 1-20 Alkylene, substituted or unsubstituted C 1-30 alkylene ether group, substituted or unsubstituted C 6-30 aryl and substituted or unsubstituted C 7-30 One of arylalkylene and fluoroalkyl; R 13 R 14 Each of them is either H or methyl; n1, n2, and n3 are positive integers from 1 to 50.

[0011] In some embodiments, n1, n2, and n3 are each 1, and R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 They are H and R respectively. 13 R 14 Each is either H or methyl;

[0012] The structural formula of the optical unit is as follows (A-1) or (A-2):

[0013] or,

[0014] In some embodiments, n1, n2, and n3 are each 1, and R1, R3, R5, R7, R9, and R 11 Each of them is a phenyl group, R2, R4, R6, R8, and R... 10 R 12 They are respectively H; R 13 R 14 Each is either H or methyl;

[0015] The structural formula of the optical unit is as follows (A-3) or (A-4):

[0016] or,

[0017] In some embodiments, n1, n2, and n3 are each 1, and R1, R3, R5, R7, R9, and R 11 Each of them is a methyl group, R2, R4, R6, R8, and R. 10 R 12 They are respectively H; R 13 R 14 Each is either H or methyl; the structural formula of the optical monomer is as follows (A-5) or (A-6):

[0018] or,

[0019] The resin mixture proposed in the second aspect of this application comprises the following components by weight percentage: solvent 10% to 79%; high refractive index optical monomers of the foregoing embodiments 10% to 79%; diluent 10% to 50%; photoinitiator 0.1% to 10%; leveling agent 0.1% to 5%; and silane coupling agent 0.1% to 5%.

[0020] The resin mixture proposed in the second aspect of this application has a high refractive index and good light transmittance.

[0021] In some embodiments, the solvent is at least one selected from propylene glycol methyl ether acetate, ethyl acetate, dichloromethane, ethanol, isopropanol, butyl acetate, tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylformamide, tetramethylethylenediamine, and carbon tetrachloride.

[0022] In some embodiments, the diluent is at least one of propylene glycol methyl ether acetate, EM2206, and 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene.

[0023] In some embodiments, the absorption wavelength of the photoinitiator is 368 nm to 420 nm; and / or, the photoinitiator is acylphosphine oxide, thioxanthone and its derivatives, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxyl chloride, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxy-2-methyl ester, diethoxyacetophenone, 4-tert-butyltrichloroacetophenone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-dimethylaminoethylbenzoate, 4,6-trimethylbenzoyldimethoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, benzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiethoxyphenylphosphine oxide, benzoyldiethoxyphosphine oxide, benzophenone and its derivatives, benzoin and its derivatives, anthracene Quinones and their derivatives, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, p-dimethylaminoethyl benzoate, diphenyl disulfide, camphorquinone, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxylic acid, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxy-2-bromoethyl ester, 2-methyl At least one of the following: 1-[4-(methylthio)phenyl-13-yl]-2-morpholinylpropane-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-1-butanone, α-aminoalkylphenyl ketone derivatives, phenyl-glyoxylic acid-methyl ester or oxy-phenyl-acetic acid 2-[2-oxy-2-phenyl-ethoxy-ethoxy]-ethyl ester and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester.

[0024] In some embodiments, the leveling agent is one of BYK331, BYK370, BYK3505, and BYK348.

[0025] In some embodiments, the silane coupling agent is one of KH570, KH550, and KH560.

[0026] In some embodiments, the refractive index of the resin mixture is greater than 1.73.

[0027] The application of the resin mixture proposed in the third aspect of this application, the resin mixture being used for nanoimprinting.

[0028] The resin mixture proposed in the third aspect of this application has good shape retention and high light transmittance when applied to nanoimprinting.

[0029] The method for preparing a high-refractive-index optical monomer according to the fourth aspect of this application includes at least the following steps: reacting a first monomer and a second monomer in the presence of ethanol and sodium ethoxide, and then extracting, removing the solvent, and purifying the mixture to obtain a compound containing a benzothiocyclic ring group as a first product; processing the first product to generate a second product; reacting the second product with the first product in the presence of ethanol and sodium ethoxide to generate a compound with hybrid units as a third product; reacting the third product with a third monomer to generate a compound with multiple sulfur-containing hybrid units at both ends as a fourth product; and reacting the fourth product with a fourth monomer to generate a high-refractive-index optical monomer.

[0030] The method for preparing high-refractive-index optical monomers proposed in the fourth aspect of this application involves multiple reaction steps to obtain optical monomers with the desired structure. The prepared optical monomers have high refractive index and heat resistance, and high visible light transmittance.

[0031] In some embodiments, the structural formula of the first monomer is: And / or,

[0032] The structural formula of the second monomer is: And / or,

[0033] The structural formula of the third monomer is: And / or,

[0034] The structural formula of the fourth monomer is:

[0035] In some embodiments, processing the first product to generate the second product includes: stirring and refluxing the first product at 100°C to 110°C for 7 to 9 hours in the presence of toluene solution, sodium hydrosulfide solution, and tetrabutylammonium bromide to generate the second product.

[0036] In some embodiments, the structure is further defined as follows: The reactants were stirred and refluxed at 55℃~65℃ for 3h~5h in the presence of toluene solution, sodium hydrosulfide solution, and tetrabutylammonium bromide to produce the product with the following structural formula: The first monomer.

[0037] In some embodiments, the reaction conditions for reacting the third product with the third monomer to generate a compound with multiple sulfur hybrid units connected to both ends of the chain include: adding the third monomer and the third product sequentially at 0°C under a nitrogen atmosphere and stirring, stirring at room temperature for 32-40 hours, and obtaining the fourth product after extraction, drying, solvent removal, and purification.

[0038] In some embodiments, the reaction conditions for reacting the fourth product with the fourth monomer to generate a high-refractive-index optical monomer include: reacting the fourth product with the fourth monomer in dichloromethane solvent and triethylamine for 15 h to 20 h.

[0039] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the disclosure of the embodiments of this application. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 shows the general structural formula I of a high-refractive-index optical monomer proposed in some embodiments of this application;

[0042] Figure 2 shows the high-refractive-index optical monomer with the compound structure A-1 proposed in this application;

[0043] Figure 3 shows the high-refractive-index optical monomer with the compound structure A-2 proposed in this application;

[0044] Figure 4 shows the high-refractive-index optical monomer with the compound structure A-3 proposed in this application;

[0045] Figure 5 shows the high-refractive-index optical monomer with the compound structure A-4 proposed in this application;

[0046] Figure 6 shows the high-refractive-index optical monomer of the compound with structural formula A-5 proposed in this application;

[0047] Figure 7 shows the high-refractive-index optical monomer with the compound structure A-6 proposed in this application;

[0048] Figure 8 illustrates the multi-step reaction involved in the preparation method of a high-refractive-index optical monomer with compound structural formula A-1 proposed in some embodiments of this application.

[0049] Figure 9 is a schematic diagram of the structure B-1 of the optical unit in Comparative Example 1 of this application.

[0050] Figure 10 is a schematic diagram of the preparation reaction of the optical monomer proposed in Comparative Example 1 of this application.

[0051] Figure 11 is a schematic diagram of the structure B-2 of the optical unit in Comparative Example 2 of this application.

[0052] Figure 12 is a schematic diagram of the structure B-3 of the optical unit in Comparative Example 3 of this application.

[0053] Figure 13 is a cross-sectional view of the micro / nano structure of the resin mixture of this application after nanoimprinting. Detailed Implementation

[0054] 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.

[0055] 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.

[0056] It should also be further understood that the term "and / or" as used in this application specification and the appended claims refers to any combination of one or more of the associated listed items, and all possible combinations thereof. Without conflict, the following embodiments and features described herein can be combined with each other.

[0057] Existing commercially available resins all have a refractive index of less than 1.65, which makes it impossible to achieve nanoimprinting, or the light transmittance is poor after nanoimprinting, affecting the performance of the product.

[0058] In view of this, embodiments of this application propose a high-refractive-index optical monomer 100, as shown in Figures 1 to 7, comprising at least one set of hybrid units and two polysulfide chains located at the two ends of the hybrid unit; the hybrid unit comprises three benzo[a]thio rings connected by sulfur, each benzo[a]thio ring comprising a benzene ring and two cyclohexanedithioalkyl groups hybridized and connected to the benzene ring.

[0059] Therefore, the high-refractive-index optical monomer proposed in this application is rich in sulfur and benzo[a]thio] ring structures in its hybrid unit. Due to its unique electronic structure and atomic radius, sulfur slows down the propagation speed of light through these materials, thereby increasing the refractive index. Sulfur itself possesses high molar refractive index and low molecular dispersion, and also provides a certain degree of chain flexibility, facilitating reactions and connections with other functional groups. The benzo[a]thio ring itself has a high refractive index, and the conjugated structure within it slows down the propagation speed of light, increasing the refractive index. Therefore, the hybrid unit in this application enables the overall molecule to have a very high refractive index.

[0060] Furthermore, the connection between the benzene ring and the cyclohexanedithioalkyl group in this application gives it a certain degree of rigidity and makes its structure relatively stable, which can improve the heat resistance of the molecule.

[0061] The polysulfide chains in this application increase the overall chain length of the molecule, enhancing its flexibility. This increased chain flexibility reduces birefringence and improves transparency. The polysulfide chains themselves are rich in sulfur elements with high molar refractive indices. Together with the hybrid units, the polysulfide chains facilitate the separation of chromophores and disrupt intramolecular conjugation interactions, increasing the overall refractive index of the molecule and promoting visible light transmission. The longer polysulfide chains also possess unique infrared transmittance properties.

[0062] As can be seen from the above, the optical unit of this application has high visible light transmittance, and also has high refractive index and good heat resistance.

[0063] Understandably, compared to the shortcomings of existing optical monomers used to prepare resins, which have low refractive index and are not easily penetrated by visible light, the high refractive index optical monomers of this application have high refractive index, high light transmittance, and a certain degree of heat resistance.

[0064] In some embodiments, the polysulfide chain comprises at least three linked sulfur atoms. This allows the polysulfide chain to have a certain length and contain more sulfur, increasing both the molecular refractive index and the molecular toughness. In some examples, the amount of sulfur in the polysulfide chain is an integer multiple of 3.

[0065] In some embodiments, the polysulfide chain is linked with unsaturated functional groups. The introduction of unsaturated functional groups gives the entire molecule easily activated sites at both ends. In the resin mixture, under the action of a photoinitiator, the unsaturated functional groups can link individual molecules together to form a network structure.

[0066] Optionally, the unsaturated functional groups can be in the form of C=C, C=O, etc., while also taking into account the cost of the reactants being kept within a reasonable range and the ease of reaction.

[0067] In some embodiments, as shown in FIG1, the optical unit has the following general structural formula (I):

[0068] Among them, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 Each is either H or substituted / unsubstituted C. 1-20 Alkylene, substituted or unsubstituted C 1-30 alkylene ether group, substituted or unsubstituted C 6-30 aryl and substituted or unsubstituted C 7-30One of arylalkylene and fluoroalkyl; R 13 R 14 Each of them is either H or methyl; n1, n2, and n3 are positive integers from 1 to 50.

[0069] For example, n1, n2, and n3 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50.

[0070] When the above groups include long-chain alkane structures, the overall steric hindrance is small, the chemical bonds can rotate freely, and stress transfer can be achieved when subjected to external force, thus giving the molecule good flexibility.

[0071] When the above groups include alkylene ether groups, the rotational flexibility of the molecular chain can be improved, thereby making the entire molecule more flexible.

[0072] When the above groups include arylene groups, the molecule has high hardness.

[0073] When the above groups include alkylene groups, they possess both a certain degree of flexibility and hardness.

[0074] When the aforementioned groups include fluoroalkyl groups, the lubricity of the molecule can be improved. Fluorine atoms have high electronegativity and small atomic radii. When they replace hydrogen atoms in alkanes, they alter the electron cloud distribution of the carbon chain. This change reduces the flexibility of the carbon chain, making the molecular structure more rigid and stable. During lubrication, the rigid molecular structure can better withstand pressure and shear forces, maintaining the integrity of the lubricating film and thus exhibiting good lubricity. At the same time, the introduction of fluorine atoms lowers the surface energy of the molecule. The low surface energy makes it easier for fluoroalkanes to spread and form a uniform lubricating film at the friction interface, reducing direct contact between friction surfaces, lowering the coefficient of friction, and thus exhibiting lubricity.

[0075] It should be noted that R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 It can be the same structure or different structures. R 13 R 14 It can be the same structure or different structures.

[0076] As can be seen from the above, the optical monomer of this application has a roughly symmetrical arrangement of structures on both sides of the hybrid unit as the center, resulting in a higher sulfur content in the entire molecule. The molecular structure is rich in sulfur, benzo[a]thio] ring structures, and other structures with high molar refractive indices, enabling the entire molecule to achieve both high refractive index and high visible light transmittance.

[0077] In some embodiments, n1, n2, and n3 are each 1, and R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 They are H and R respectively. 13 R 14 Each is either H or methyl; as shown in Figures 2 and 3, the structural formulas of the optical monomers are as follows (A-1) or (A-2):

[0078] In A-1, R 13 R 14 Each is H; in A-2, R 13 R 14 Each of them is a methyl group.

[0079] In some embodiments, n1, n2, and n3 are each 1, and R1, R3, R5, R7, R9, and R 11 Each of them is a phenyl group, R2, R4, R6, R8, and R... 10 R 12 They are respectively H; R 13 R 14 Each is either H or methyl; as shown in Figures 4 and 5, the structural formulas of the optical monomers are as follows (A-3) or (A-4):

[0080] In A-3, R 13 R 14 Each is H; in A-4, R 13 R 14 Each of them is a methyl group.

[0081] In some embodiments, n1, n2, and n3 are each 1, and R1, R3, R5, R7, R9, and R 11 Each of them is a methyl group, R2, R4, R6, R8, and R. 10 R 12 They are respectively H; R 13 R 14 Each is either H or methyl; as shown in Figures 6 and 7, the structural formulas of the optical monomers are as follows (A-5) or (A-6):

[0082] In A-5, R 13 R 14 Each is H; in A-6, R 13 R 14 Each of them is a methyl group.

[0083] In the above examples, compounds A-1, A-2, A-3, A-4, A-5 and A-6 all have three benzo[a]thio rings, and the benzene rings at both ends of the benzo[a]thio rings are respectively connected to three sulfur groups and C=O and C=C, which makes the molecules small and consume less material while achieving high refractive index and high light transmittance, and gives the entire molecule end an active site.

[0084] Of course, in other embodiments, the high-refractive-index optical monomer can also be other structures, mainly including the aforementioned hybrid units and polysulfide chains, within the scope of the above general formula.

[0085] This application discloses a resin mixture comprising the following components by weight percentage: 10% to 79% solvent; 10% to 79% high refractive index optical monomers of the aforementioned embodiments; 10% to 50% diluent; 0.1% to 10% photoinitiator; 0.1% to 5% leveling agent; and 0.1% to 5% silane coupling agent.

[0086] It is understood that this application uses a solvent with a weight percentage of 10% to 79% to ensure that the components are mixed evenly. If the concentration is lower than the above range, the components will not be mixed evenly and the compatibility will be reduced. If the concentration is higher than the above range, the effective components will be insufficient.

[0087] The use of optical monomers with a weight percentage of 10% to 79% in this application can enable the resin mixture to have high refractive index, high transmittance and thermal stability after curing. If the weight percentage is lower than the above range, the refractive index of the mixture after curing will be insufficient and the material consumption will increase; if the weight percentage is higher than the above range, it will be detrimental to film formation.

[0088] This application uses a diluent with a weight percentage of 10% to 50% to adjust the concentration and viscosity of the mixture, making it easy to use and apply. If the concentration is below the above range, the mixture will be too concentrated and difficult to apply, and the fluidity will be too low; if the concentration is above the above range, the curing efficiency will be affected.

[0089] This application uses a photoinitiator with a weight percentage of 0.1% to 10% to initiate the polymerization reaction under light irradiation. If the percentage is lower than the above range, fewer free radicals will be generated under light irradiation, which will result in a slower curing process or even failure to cure effectively. If the percentage is higher than the above range, the curing process will be faster and the reaction will be difficult to control.

[0090] The application uses a leveling agent with a weight percentage of 0.1% to 5% to help the mixture spread evenly on the substrate and reduce bubbles and surface defects; below the above range, it is not conducive to the spread of the mixture; above the above range, the cost is high and the spread is too fast.

[0091] This application uses a silane coupling agent with a weight percentage of 0.1% to 5% to enhance the adhesion between materials and improve the overall performance of the prepared resin material; if the weight percentage is below the above range, it will not be conducive to sufficient adhesion between materials, and if the weight percentage is above the above range, the cost will be high and the viscosity will be too high.

[0092] As can be seen from the above, this application uses the aforementioned optical monomers with high refractive index to prepare resin mixtures. The prepared resin mixtures have high refractive index and good light transmittance, making them easy to coat. They can be cured quickly after being exposed to light, and nanoimprinting can be performed after curing.

[0093] In an optional embodiment, the resin mixture may include the following components by weight percentage: 10% solvent, 40% high refractive index optical monomer, 30% diluent, 10% photoinitiator, 5% leveling agent, and 5% silane coupling agent.

[0094] In an optional embodiment, the resin mixture may include the following components by weight percentage: 20% solvent, 45% high refractive index optical monomer, 20% diluent, 8% photoinitiator, 2% leveling agent, and 5% silane coupling agent.

[0095] In an optional embodiment, the resin mixture may include the following components by weight percentage: 30% solvent, 50% high refractive index optical monomer, 10% diluent, 6% photoinitiator, 3.9% leveling agent, and 0.1% silane coupling agent.

[0096] In an optional embodiment, the resin mixture may include the following components by weight percentage: 40% solvent, 30% high refractive index optical monomer, 25% diluent, 4% photoinitiator, 0.1% leveling agent, and 0.9% silane coupling agent.

[0097] In an optional embodiment, the resin mixture may include the following components by weight percentage: 50% solvent, 40% high refractive index optical monomer, 9% diluent, 0.4% photoinitiator, 0.3% leveling agent, and 0.3% silane coupling agent.

[0098] In an optional embodiment, the resin mixture may include the following components by weight percentage: 60% solvent, 10% high refractive index optical monomer, 19% diluent, 0.1% photoinitiator, 10% leveling agent, and 0.9% silane coupling agent.

[0099] In an optional embodiment, the resin mixture may include the following components by weight percentage: 79% solvent, 10% high refractive index optical monomer, 10% diluent, 0.1% photoinitiator, 0.5% leveling agent, and 0.4% silane coupling agent.

[0100] In an optional embodiment, the resin mixture may include the following components by weight percentage: 10% solvent, 79% high refractive index optical monomer, 10% diluent, 0.8% photoinitiator, 0.1% leveling agent, and 0.1% silane coupling agent.

[0101] Optionally, the solvent is at least one selected from propylene glycol methyl ether acetate (PGMEA), ethyl acetate, dichloromethane, ethanol, isopropanol, butyl acetate, tetrahydrofuran, dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), tetramethylethylenediamine, and carbon tetrachloride. These solvents have the ability to dissolve a variety of substances, have good compatibility with various components, facilitate homogeneous mixing of components, and are easy to remove.

[0102] Optionally, the diluent is at least one of polyethylene glycol o-phenyl phenyl ether acrylate (OPPEA), EM2206 (a bifunctional acrylate monomer, purchased from Changxing Chemical Industry Co., Ltd., brand name ETERMER 2206), and 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene. The other components of the above diluents have good compatibility and can adjust the concentration and viscosity of the resin mixture. The above diluents readily polymerize around the high-refractive-index optical monomers of this application, especially readily polymerizing with unsaturated functional groups to form a large network structure, thereby enabling the resin mixture to cure rapidly.

[0103] In some examples, the photoinitiator absorbs light at wavelengths of 368 nm to 420 nm. The photoinitiator can be activated by ultraviolet light at these wavelengths, enabling it to initiate the polymerization reaction under illumination without affecting the overall light transmittance of the cured resin mixture.

[0104] Optionally, the photoinitiator is acylphosphine oxide, thioxanthone and its derivatives, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxyl chloride, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxy-2-methyl ester, diethoxyacetophenone, 4-tert-butyltrichloroacetophenone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-dimethylaminoethylbenzoate, 4,6-trimethylbenzoyldimethoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, benzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiethoxyphenylphosphine oxide, benzoyldiethoxyphosphine oxide, benzophenone and its derivatives, benzoin and its derivatives, anthraquinone and its derivatives, benzoin, benzoin methyl ether The following are included: benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, p-dimethylaminoethyl benzoate, diphenyl disulfide, camphorquinone, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxylic acid, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxy-2-bromoethyl ester, 2-methyl-1-[4-(methylthio)phenyl13-yl]-2-morpholinylpropane-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-1-butanone, α-aminoalkylphenyl ketone derivatives, phenyl-glyoxylic acid-methyl ester or oxy-phenyl-acetic acid 2-[2-oxy-2-phenyl-ethoxy-ethoxy]-ethyl ester and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester. When these photoinitiators are irradiated by a light source, they can be rapidly activated and generate active free radicals, which in turn initiate polymerization reactions between the substances in the UV-resistant resin, further achieving curing. The photoinitiators in these embodiments mainly absorb light in the wavelength range of 368nm to 420nm.

[0105] Optionally, the leveling agent is one of BYK331, BYK370, BYK3505, and BYK348. Specifically, BYK331, BYK370, BYK3505, and BYK348 are leveling agents manufactured by BYK GmbH, Germany. The BYK series of leveling agents have excellent leveling properties.

[0106] Optionally, the silane coupling agent is one of KH570, KH550, and KH560. Specifically, KH570, KH550, and KH560 are silane coupling agents produced by the Chinese Academy of Sciences.

[0107] KH570, also known as γ-methacryloyloxypropyltrimethoxysilane, is an organic functional group silane coupling agent. KH570 is used to improve the mechanical and electrical properties of resin materials.

[0108] KH550, also known as γ-aminopropyltriethoxysilane, can enhance the adhesion of resin materials and improve the mechanical, water-resistant, and anti-aging properties of products.

[0109] KH560, also known as γ-glycidyl etheroxypropyltrimethoxysilane, can improve the strength properties of resin materials.

[0110] Advantageously, the resin mixture has a refractive index greater than 1.73, which facilitates nanoimprinting.

[0111] This application proposes the application of resin mixtures. When the resin mixtures in the aforementioned examples are coated onto a substrate and cured, a resin material is obtained and used for nanoimprinting. Therefore, when applied to nanoimprinting, it exhibits good shape retention and high light transmittance.

[0112] This application proposes a method for preparing a high-refractive-index optical monomer, which includes at least the following steps:

[0113] S1. The first monomer and the second monomer are reacted in the presence of ethanol and sodium ethoxide. After extraction, solvent removal and purification, a compound containing a benzothiocyclic group is obtained as the first product.

[0114] Optionally, the structural formula of the first monomer is:

[0115] Optionally, the structural formula of the second monomer is:

[0116] Optionally, the first monomer described above can be prepared by the following steps: [The following is a description of a monomer with the structural formula...] The reactants were stirred and refluxed at 55℃~65℃ for 3h~5h in the presence of toluene solution, sodium hydrosulfide solution, and tetrabutylammonium bromide to produce the product with the following structural formula: The first monomer. For example, the stirring and reflux temperatures are 55°C, 60°C, and 65°C; the stirring and reflux times are 3h, 4h, and 5h.

[0117] S2. Process the first product to generate the second product.

[0118] For example, the first product is stirred and refluxed at 100°C–110°C for 7–9 hours in the presence of toluene solution, sodium hydrosulfide solution, and tetrabutylammonium bromide to generate the second product. For example, the stirring and reflux temperatures are 100°C, 105°C, and 110°C, and the reflux times are 7 hours, 8 hours, and 9 hours, respectively.

[0119] S3. The second product is reacted with the first product in the presence of ethanol and sodium ethoxide to generate a compound with hybrid units as the third product.

[0120] S4. The third product is reacted with the third monomer to generate a compound with multiple sulfur hybrid units connected to both ends of the chain, which is the fourth product.

[0121] Optionally, the structural formula of the third monomer is:

[0122] Optionally, under a nitrogen atmosphere at 0°C, the third monomer and the third product are added sequentially and stirred. The reaction is carried out at room temperature for 32-40 hours. After extraction, drying, solvent removal, and purification, the fourth product is obtained. For example, the reaction times are 32, 33, 34, 35, 36, 37, 38, 39, and 40 hours.

[0123] S5. React the fourth product with the fourth monomer to generate an optical monomer with a high refractive index.

[0124] Optionally, the structural formula of the fourth monomer is:

[0125] Optionally, the fourth product and the fourth monomer are reacted in dichloromethane solvent and triethylamine for 15 to 20 hours. Exemplarily, the reaction time is 15, 16, 17, 18, 19, or 20 hours.

[0126] The method for preparing high-refractive-index optical monomers proposed in this application involves multiple reaction steps to obtain optical monomers with the desired structure. The prepared optical monomers have high refractive index and heat resistance, and high visible light transmittance.

[0127] In some specific examples, the preparation conditions and reaction formulas for the high-refractive-index optical monomer with compound structural formula A-1 can be seen in Figure 8. Exemplarily, the specific reaction steps are as follows:

[0128] The structural formula is The reactant (compound f1 shown in Figure 8) (143 g, 312 mmol) was added to a toluene solution (800 mL), followed by an aqueous solution of NaHS (16 g of NaHS dissolved in 100 g of water), and then 0.8 g of tetrabutylammonium bromide. The mixture was stirred and refluxed at 60 °C for 4 h to obtain the product with the following structural formula: The first monomer (compound f2 shown in Figure 8), 48.47 g, 55% yield.

[0129] 1000 ml of anhydrous ethanol, 48.47 g (172 mmol) of the first monomer (compound f2 shown in Figure 8), and 65 g (350 mmol) of the second monomer (compound f3 shown in Figure 8) were added to the reaction apparatus under anhydrous and oxygen-free conditions. The mixture was stirred at room temperature for 30 min. 24 g of sodium ethoxide was dissolved in 400 ml of anhydrous ethanol and slowly added dropwise to the reaction apparatus. The mixture was refluxed at room temperature for 36 h. After the reaction was completed, saturated brine was added, the organic layer was extracted with diethyl ether, the solvent was removed under reduced pressure, and the product was purified by column chromatography to obtain the first product (compound f4 shown in the figure), 26.91 g, 48% yield.

[0130] The first product (compound f4 shown in Figure 8) (26.91 g, 82.56 mmol) was added to a toluene solution (200 mL), followed by an aqueous solution of NaHS (4 g of NaHS dissolved in 25 g of water), and then 0.2 g of tetrabutylammonium bromide. The mixture was stirred and refluxed at 110 °C for 8 h to obtain the second product (compound f shown in Figure 8), 15.95 g, 60% yield.

[0131] Under a nitrogen atmosphere at 0°C, the second product (compound f shown in Figure 8) (15.09 g, 46.86 mmol), EtONa (6.8 g, 100 mmol), and anhydrous ethanol (500 ml) were added and stirred for 1 h. Then, the first product (compound f4 shown in Figure 8) (30.96 g, 95 mmol) was added at 0°C and stirred for 1 h. The mixture was then brought back to room temperature and stirred for another 36 h. After the reaction was complete, the mixture was extracted with CH2Cl2, and the organic layer was dried over MgSO4. The solvent was removed under reduced pressure, and the mixture was purified by column chromatography to give the third product (compound g shown in Figure 8), 22.46 g, 53% yield.

[0132] Under a nitrogen atmosphere at 0°C, the third monomer (compound i shown in Figure 8) (5.1 g, 52 mmol), NaH (1.44 g, 60 mmol), and 200 mL of anhydrous THF were added and stirred for 1 h. The third product (compound g shown in Figure 8) (22.46 g, 24.83 mmol) was then added at 0°C and stirred for 1 h. The mixture was then brought back to room temperature and stirred for another 18 h. After the reaction was complete, unreacted NaH was quenched in saturated brine at 0°C, and the mixture was extracted with CH₂Cl₂. The organic layer was dried over MgSO₄. The solvent was removed under reduced pressure, and the mixture was purified by column chromatography to give 18.33 g of the fourth product (compound k shown in Figure 8) in 72% yield.

[0133] The fourth product (compound k shown in Figure 8) (18.33 g, 17.82 mmol) and the fourth monomer (compound h shown in Figure 8) (3.6 g, 40 mmol) were reacted in dichloromethane solvent with triethylamine for 17 h to give a high-refractive-index optical monomer with the compound structure A-1, 14.34 g, 71% yield.

[0134] In other words, as shown in Figures 2-7, the high-refractive-index optical monomers with structural formulas A-1, A-2, A-3, A-4, A-5, and A-6 of this application can all be prepared by similar reaction steps as shown in Figure 8.

[0135] Compared to preparing high-refractive-index optical monomers with the structural formula A-1, when preparing high-refractive-index optical monomers with the structural formula A-2, it is only necessary to replace compound h—the fourth monomer—with methacryloyl chloride.

[0136] Compared to preparing a high-refractive-index optical monomer with structural formula A-1, preparing a high-refractive-index optical monomer with structural formula A-3 only requires replacing compound f3—the second monomer—with (1,2-dibromoethyl)benzene. The structures of the first, second, third, and fourth products all change accordingly.

[0137] Compared to preparing a high-refractive-index optical monomer with structural formula A-1, preparing a high-refractive-index optical monomer with structural formula A-4 only requires replacing compound f3—the second monomer—with (1,2-dibromoethyl)benzene and compound h—the fourth monomer—with methacryloyl chloride. The structures of the first, second, third, and fourth products all change accordingly.

[0138] Compared to preparing a high-refractive-index optical monomer with structural formula A-1, preparing a high-refractive-index optical monomer with structural formula A-5 only requires replacing compound f3—the second monomer—with 1,2-dibromopropane. The structures of the first, second, third, and fourth products all change accordingly.

[0139] Compared to preparing a high-refractive-index optical monomer with structural formula A-1, preparing a high-refractive-index optical monomer with structural formula A-6 only requires replacing compound f3—the second monomer—with 1,2-dibromopropane and compound h—the fourth monomer—with methacryloyl chloride. The structures of the first, second, third, and fourth products all change accordingly.

[0140] The optical monomers and resin mixtures of this application will be further described below with reference to specific embodiments and test data.

[0141] Example 1

[0142] Preparation of a high-refractive-index optical monomer with compound structural formula A-1:

[0143] Referring to Figure 8, compound f1 (143 g, 312 mmol) was added to a toluene solution (800 mL), followed by an aqueous solution of NaHS (16 g of NaHS dissolved in 100 g of water), and then 0.8 g of tetrabutylammonium bromide. The mixture was stirred and refluxed at 60 °C for 4 h to obtain compound f2, 48.47 g, with a yield of 55%.

[0144] 1000 ml of anhydrous ethanol, compound f2 (48.47 g, 172 mmol), and compound f3 (65 g, 350 mmol) were added to the reaction apparatus under anhydrous and oxygen-free conditions. The mixture was stirred at room temperature for 30 min. 24 g of sodium ethoxide was dissolved in 400 ml of anhydrous ethanol and slowly added dropwise to the reaction apparatus. The mixture was refluxed at room temperature for 36 h. After the reaction was completed, saturated brine was added, the organic layer was extracted with diethyl ether, the solvent was removed under reduced pressure, and the mixture was purified by column chromatography to obtain compound f4, 26.91 g, 48% yield.

[0145] Compound f4 (26.91 g, 82.56 mmol) was added to a toluene solution (200 mL), followed by an aqueous solution of NaHS (4 g of NaHS dissolved in 25 g of water), and then 0.2 g of tetrabutylammonium bromide. The mixture was stirred and refluxed at 110 °C for 8 h to obtain compound f, 15.95 g, 60% yield.

[0146] Compound f (15.09 g, 46.86 mmol), EtONa (6.8 g, 100 mmol), and anhydrous ethanol (500 ml) were added at 0 °C under a nitrogen atmosphere and stirred for 1 h. Compound f4 (30.96 g, 95 mmol) was then added at 0 °C and stirred for 1 h. The mixture was then brought back to room temperature and stirred for another 36 h. After the reaction was complete, the mixture was extracted with CH2Cl2, and the organic layer was dried over MgSO4. The solvent was removed under reduced pressure, and the mixture was purified by column chromatography to give compound g (22.46 g, 53% yield).

[0147] Compound i (5.1 g, 52 mmol), NaH (1.44 g, 60 mmol), and 200 mL of anhydrous THF were added at 0 °C under a nitrogen atmosphere and stirred for 1 h. Compound g (22.46 g, 24.83 mmol) was then added at 0 °C and stirred for another 1 h. The mixture was then brought back to room temperature and stirred for another 18 h. After the reaction was complete, unreacted NaH was quenched with saturated brine at 0 °C, and the mixture was extracted with CH₂Cl₂. The organic layer was dried over MgSO₄. The solvent was removed under reduced pressure, and the mixture was purified by column chromatography to give compound k 18.33 g in 72% yield.

[0148] Compound k (18.33 g, 17.82 mmol) and compound h (3.6 g, 40 mmol) were reacted in dichloromethane solvent with triethylamine for 17 h to give a high-refractive-index optical monomer with the structural formula A-1, 14.34 g, 71% yield.

[0149] Compound f2 is the first monomer of this application; compound f3 is the second monomer of this application; compound f4 is the first product of this application; compound f is the second product of this application; compound g is the third product of this application; compound i is the third monomer of this application; compound k is the fourth product of this application; and compound h is the fourth monomer of this application.

[0150] Preparation of resin mixture HIA-1: Propylene glycol methyl ether acetate (PGMEA) (10g), A-1 (10g), 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene (2g), TPO (0.3g), BYK370 (0.03g), and KH570 (0.05g) were added to a 50mL volumetric flask. The mixture was vigorously mixed for 2 hours under light-protected conditions, and then filtered through a 0.45μm syringe filter to obtain the resin mixture.

[0151] The resin mixture was homogenized on a 4-inch resin wafer (3500 rpm, 60 s), followed by grating imprinting to form a nanoimprint adhesive. Refractive index, transmittance, and grating structure parameters were measured using SEM.

[0152] Example 2

[0153] Preparation of high-refractive-index optical monomers with compound structure A-2: The overall process is the same as A-1, but compound h (i.e., the fourth monomer) is replaced with methacryloyl chloride.

[0154] Preparation of resin mixture HIA-2: Add PGMEA (10g), A-2 (10g), 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene (2g), TPO (0.3g), BYK370 (0.03g), and KH570 (0.05g) to a 50mL volumetric flask. Mix vigorously for 2 hours in the dark, and then filter through a 0.45μm syringe filter to obtain the resin mixture.

[0155] The resin mixture was homogenized on a 4-inch resin wafer (3500 rpm, 60 s), followed by grating imprinting to form a nanoimprint adhesive. Refractive index, transmittance, and grating structure parameters were measured using SEM.

[0156] Example 3

[0157] Preparation of high-refractive-index optical monomers with compound structure A-3: The process is the same as A-1, but compound f3 (i.e., the second monomer) is replaced with (1,2-dibromoethyl)benzene.

[0158] Preparation of resin mixture HIA-3: Add PGMEA (10g), A-3 (10g), 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene (2g), TPO (0.3g), BYK370 (0.03g), and KH570 (0.05g) to a 50mL volumetric flask. Mix vigorously for 2 hours in the dark. After filtration through a 0.45μm syringe filter, the resin mixture is obtained.

[0159] The resin mixture was homogenized on a 4-inch resin wafer (3500 rpm, 60 s), followed by grating imprinting to form a nanoimprint adhesive. Refractive index, transmittance, and grating structure parameters were measured using SEM.

[0160] Example 4

[0161] Preparation of high-refractive-index optical monomers with compound structure A-4: The process is the same as A-1, but compound f3 (i.e., the second monomer) is replaced with (1,2-dibromoethyl)benzene, and compound h (i.e., the fourth monomer) is replaced with methacryloyl chloride.

[0162] Preparation of resin mixture HIA-4: Add PGMEA (10g), A-4 (10g), 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene (2g), TPO (0.3g), BYK370 (0.03g), and KH570 (0.05g) to a 50mL volumetric flask. Mix vigorously for 2 hours under light-protected conditions. Filter the mixture through a 0.45μm syringe filter to obtain the resin mixture.

[0163] The resin mixture was homogenized on a 4-inch resin wafer (3500 rpm, 60 s), followed by grating imprinting to form a nanoimprint adhesive. Refractive index, transmittance, and grating structure parameters were measured using SEM.

[0164] Example 5

[0165] Preparation of high-refractive-index optical monomers with compound structure A-5: The process is the same as A-1, but compound f3 (i.e., the second monomer) is replaced with 1,2-dibromopropane.

[0166] Preparation of resin mixture HIA-5: Add PGMEA (10g), A-5 (10g), 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene (2g), TPO (0.3g), BYK370 (0.03g), and KH570 (0.05g) to a 50mL volumetric flask. Mix vigorously for 2 hours in the dark, and then filter through a 0.45μm syringe filter to obtain the resin mixture.

[0167] The resin mixture was homogenized on a 4-inch resin wafer (3500 rpm, 60 s), followed by grating imprinting to form a nanoimprint adhesive. Refractive index, transmittance, and grating structure parameters were measured using SEM.

[0168] Example 6

[0169] Preparation of high-refractive-index optical monomers with compound structure A-6: The process is the same as A-1, but compound f3 (i.e., the second monomer) is replaced with 1,2-dibromopropane, and compound h (i.e., the fourth monomer) is replaced with methacryloyl chloride.

[0170] Preparation of resin mixture HIA-6: Add PGMEA (10g), A-6 (10g), 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene (2g), photoinitiator TPO (0.3g), BYK370 (0.03g), and KH570 (0.05g) to a 50mL volumetric flask. Mix vigorously for 2 hours under light-protected conditions. Filter the mixture through a 0.45μm syringe filter to obtain the resin mixture.

[0171] The resin mixture was homogenized on a 4-inch resin wafer (3500 rpm, 60 s), followed by grating imprinting to form a nanoimprint adhesive. Refractive index, transmittance, and grating structure parameters were measured using SEM.

[0172] Comparative Example 1

[0173] As shown in Figures 9 and 10, an optical monomer with the compound structural formula B-1 was prepared.

[0174] Compound j (89.78, 100 mmol) and compound h (18.45 g, 205 mmol) were reacted in dichloromethane solvent with triethylamine for 17 h to give compound B-1, 65.37 g, 65% yield.

[0175] Preparation of resin mixture HIB-1: Add PGMEA (10g), B-1 (10g), 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene (2g), TPO (0.3g), BYK370 (0.03g), and KH570 (0.05g) to a 50mL volumetric flask. Mix vigorously for 2 hours under light-protected conditions. Filter the mixture through a 0.45μm syringe filter to obtain the resin mixture.

[0176] The resin mixture was homogenized on a 4-inch resin wafer (3500 rpm, 60 s), followed by grating imprinting to form a nanoimprint adhesive. Refractive index, transmittance, and grating structure parameters were measured using SEM.

[0177] Comparative Example 2

[0178] As shown in Figure 11, the optical monomer with compound structure B-2 was prepared in the same manner as B-1, except that compound j was replaced with compound with structure B-2. Compounds.

[0179] Preparation of resin mixture HIB-2: Add PGMEA (10g), B-2 (10g), 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene (2g), TPO (0.3g), BYK370 (0.03g), and KH570 (0.05g) to a 50mL volumetric flask. Mix vigorously for 2 hours under light-protected conditions. Filter the mixture through a 0.45μm syringe filter to obtain the resin mixture.

[0180] The resin mixture was homogenized on a 4-inch resin wafer (3500 rpm, 60 s), followed by grating imprinting to form a nanoimprint adhesive. Refractive index, transmittance, and grating structure parameters were measured using SEM.

[0181] Comparative Example 3

[0182] As shown in Figure 12, an optical monomer with the compound structural formula B-3 was prepared. The preparation of B-3 was the same as that of B-1, except that compound j was replaced with a compound with the structural formula B-3. Compounds.

[0183] Preparation of resin mixture HIB-3: Add PGMEA (10g), B-3 (10g), 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene (2g), TPO (0.3g), BYK370 (0.03g), and KH570 (0.05g) to a 50mL volumetric flask. Mix vigorously for 2 hours in the dark. After filtration through a 0.45μm syringe filter, the resin mixture is obtained.

[0184] The resin mixture was homogenized on a 4-inch resin wafer (3500 rpm, 60 s), followed by grating imprinting to form a nanoimprint adhesive. Refractive index, transmittance, and grating structure parameters were measured using SEM.

[0185] Comparative Example 4

[0186] No optical components are added in this embodiment.

[0187] Add PGMEA (10g), 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene (10g), photoinitiator TPO (0.3g), BYK370 (0.03g), and KH570 (0.05g) to a 50mL volumetric flask. Mix vigorously for 2 hours in the dark, and then filter through a 0.45μm syringe filter to obtain a resin mixture.

[0188] The resin mixture was homogenized on a 4-inch resin wafer (3500 rpm, 60 s), followed by grating imprinting to form a nanoimprint adhesive. Refractive index, transmittance, and grating structure parameters were measured using SEM.

[0189] Solvents used in this embodiment and comparative example:

[0190] Solvent used: Propylene glycol methyl ether acetate (PGMEA), purchased from Energi.

[0191] Photoinitiator: Phosphine oxide (TPO), purchased from IGM;

[0192] The diluent used was 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, purchased from TCI.

[0193] The leveling agent used was BYK 370, purchased from BYK Germany.

[0194] The silane coupling agent used was KH570, purchased from Anaiji.

[0195] It should be noted that in the above embodiments, propylene glycol methyl ether acetate was selected as the solvent, phosphine oxide as the photoinitiator, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene as the diluent, BYK370 as the leveling agent, and KH570 as the silane coupling agent. These components were used together with optical monomers with compound structural formulas A-1, A-2, A-3, A-4, A-5, A-6, B-1, B-2, and B-3 to prepare resin mixtures for specific performance testing. However, other solvents, photoinitiators, diluents, leveling agents, and silane coupling agents listed in this application also have similar effects and should be included in the protection scope of this application.

[0196] The cured films obtained in Examples 1-6 and Comparative Examples 1-4 were subjected to performance tests, and the test results are shown in Table 1.

[0197] The performance testing methods and standards are as follows:

[0198] (1) Refractive index: Tested using an ellipsometer (ME-L Muller matrix spectral ellipsometer, Yiguang Technology);

[0199] (2) Light transmittance: High-precision haze meter (HM-150 Murakami Color MCRL);

[0200] (3) Yellowness: High-precision haze meter (HM-150 Murakami Color MCRL);

[0201] (4) Grating parameter testing: Micro-nano structures were measured using a SEM (SU5000 Hitachi);

[0202] (5) Membrane thickness: The membrane thickness was measured using a SEM (SU5000 Hitachi);

[0203] (6) Haze: High-precision haze meter (HM-150 Murakami Color MCRL);

[0204] Table 1. Comparison of test performance of cured films after grating imprinting of resin mixtures in various embodiments and comparative examples.

[0205] From the test data of Examples 1-6 and Comparative Examples 1-4 in Table 1, it can be seen that:

[0206] The refractive indices of the cured films in Examples 1-6 are all greater than 1.73, indicating high refractive indices. The refractive indices of Comparative Examples 1-4 are all lower than those of the Examples, which is due to the low sulfur content in the mixtures of Comparative Examples 1-3; Comparative Example 4 has a polycyclic benzene ring structure, hence its lowest refractive index.

[0207] Examples 1-6 and Comparative Examples 1-4 all have transmittance greater than 90%, indicating that the structures of A-1, A-2, A-3, A-4, A-5, A-6, B-1, B-2, B-3, and 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene have high transmittance.

[0208] The yellowness of the examples 1-6 and the comparative examples were all between 1 and 1.6.

[0209] In Examples 1-6, the microstructure surfaces were free of particles, and the surface molecules demolded well. In Comparative Examples 1-3, the microstructures contained particles, and the lack of long-chain sulfur alkanes on the surface negatively impacted demolding. Comparative Example 4 showed surface cracks, possibly because the rigid fluorene groups in the molecular chains made the material prone to stress accumulation during nanoimprint crosslinking and curing, which then developed into cracks during demolding.

[0210] As shown in Table 1, the height, width, and period of the microstructures in Examples 1-6 and Comparative Examples 1-3 are all within the design range. Figure 13 shows that the resin mixture containing compounds with structural formulas A-1, A-2, A-3, A-4, A-5, and A-6 in this application exhibits good shape retention properties and can accurately replicate the pattern on the template. The height of the nanoimprinted pattern is between 70 nm and 90 nm, and the width is between 140 nm and 160 nm. The structure in this application also contains the three benzothiocyclic structures with structural formulas B-1, B-2, and B-3 mentioned above. Comparative Example 4 is a sulfur-free structure. The micro-nano structure and micro-nano period of the sulfur-free resin mixture deviate significantly from the design values, indicating that a high sulfur content is beneficial for the shape retention of the micro-nano structure.

[0211] 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 optical monomer of high refractive index, wherein, It includes at least one set of hybrid units and two polysulfide chains located at the two ends of the hybrid unit; The hybrid unit comprises three benzo[a]thio rings linked by sulfur, each of the benzo[a]thio rings comprising a benzene ring and two cyclohexanedithioalkyl groups hybridized and linked to the benzene ring.

2. The high refractive optical monomer of claim 1, wherein, The polysulfide chain comprises at least three linked sulfur groups; and / or, the polysulfide chain is connected to an unsaturated functional group.

3. The high refractive optical monomer of claim 2, wherein, The optical monomer has the following general structural formula (I): wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 each independently is H or one of substituted, unsubstituted C 1-20 alkylene, substituted or unsubstituted C 1-30 alkylene ether group, substituted or unsubstituted C 6-30 arylene and substituted or unsubstituted C 7-30 aralkylene and fluoroalkyl; R 13 , R 14 each is independently H or methyl; n1, n2, n3 are each a positive integer from 1 to 50.

4. The high refractive optical monomer of claim 3, wherein, n1, n2, n3 are each 1, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 each is independently H, R 13 , R 14 each is independently H or methyl; The structural formula of the optical monomer is as follows (A-1) or (A-2): or 5. The high refractive optical monomer of claim 3, wherein, n1, n2, n3 are each 1, R1, R3, R5, R7, R 11 each is independently phenyl, R2, R4, R6, R 10 , R 12 each is independently H; R 13 , R 14 each is independently H or methyl; The structural formula of the optical monomer is as follows (A-3) or (A-4): or 6. The high refractive optical monomer of claim 3, wherein, n1, n2, n3 are each 1, R1, R3, R5, R7, R9, R 11 each is independently methyl, R2, R4, R6, R8, R 10 , R 12 each is independently H; R 13 , R 14 each is independently H or methyl; the optical monomer has a structural formula as follows (A-5) or (A-6): or, 7. A resin mixture, wherein, The resin mixture comprises the following components by weight percentage: Solvent content: 10%–79%; The high refractive index optical monomer as described in any one of claims 1-6 comprises 10% to 79%; Diluent 10%–50%; Photoinitiator 0.1%–10%; Leveling agent 0.1%–5%; Silane coupling agent: 0.1%–5%.

8. The resin mixture of claim 7, wherein, The solvent is at least one selected from propylene glycol methyl ether acetate, ethyl acetate, dichloromethane, ethanol, isopropanol, butyl acetate, tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylformamide, tetramethylethylenediamine, and carbon tetrachloride.

9. The resin mixture of claim 7, wherein, The diluent is at least one of propylene glycol methyl ether acetate, EM2206, and 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene.

10. The resin mixture of claim 7, wherein, The photoinitiator has an absorption wavelength of 368 nm to 420 nm; and / or, The photoinitiator is acylphosphine oxide, thioxanone and its derivatives, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxyl chloride, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxy-2-methyl ester, diethoxyacetophenone, 4-tert-butyltrichloroacetophenone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-dimethylaminoethylbenzoate, 4,6-trimethylbenzoyldimethoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, benzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiethoxyphenylphosphine oxide, benzoyldiethoxyphosphine oxide, benzophenone and its derivatives, benzoin and its derivatives, anthraquinone and its derivatives, benzoin, benzoin methyl ether. The following are included: benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, p-dimethylaminoethyl benzoate, diphenyl disulfide, camphorquinone, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxylic acid, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxy-2-bromoethyl ester, 2-methyl-1-[4-(methylthio)phenyl13-yl]-2-morpholinylpropane-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-1-butanone, α-aminoalkylphenyl ketone derivatives, phenyl-glyoxylic acid-methyl ester or oxy-phenyl-acetic acid 2-[2-oxy-2-phenyl-ethoxy-ethoxy]-ethyl ester and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester.

11. The resin mixture of claim 7, wherein, The leveling agent is one of BYK331, BYK370, BYK3505, and BYK348.

12. The resin mixture of claim 7, wherein, The silane coupling agent is one of KH570, KH550, and KH560.

13. The resin mixture of any one of claims 7 to 12, wherein, The refractive index of the resin mixture is greater than 1.

73.

14. Use of a resin mixture as claimed in any one of claims 7 to 13, wherein Resin mixtures are used for nanoimprinting.

15. A method of making an optical monomer having a high refractive index, wherein, It should include at least the following steps: The first monomer and the second monomer were reacted in the presence of ethanol and sodium ethoxide. After extraction, solvent removal and purification, a compound containing a benzothiocyclic ring group was obtained as the first product. The first product is processed to generate the second product; The second product is reacted with the first product in the presence of ethanol and sodium ethoxide to generate a compound with hybrid units as the third product. The third product is reacted with the third monomer to generate a compound with multiple sulfur hybrid units connected to both ends of the chain, which is the fourth product. The fourth product is reacted with the fourth monomer to generate a high-refractive-index optical monomer.

16. The method for preparing a high-refractive-index optical monomer as described in claim 15, wherein, The first monomer has a structural formula of: and / or, The structural formula of the second monomer is: And / or, The third monomer has a structural formula of: And / or, The fourth monomer has a structural formula of:

17. The method for preparing a high-refractive-index optical monomer as described in claim 15, wherein, The process of generating the second product from the first product includes: stirring and refluxing the first product at 100°C to 110°C for 7 to 9 hours in the presence of toluene solution, sodium hydrosulfide solution, and tetrabutylammonium bromide to generate the second product.

18. The method for preparing a high-refractive-index optical monomer as described in claim 16, wherein, Also included is the reaction of a reactant having the structure in the presence of a toluene solution, a sodium hydrosulfide solution, and tetrabutylammonium bromide at 55°C to 65°C for 3 hours to 5 hours to form a first monomer having the structure .

19. The method for preparing a high-refractive-index optical monomer as described in claim 16, wherein, The reaction conditions for the third product to react with the third monomer to generate a compound with multiple sulfur hybrid units connected to both ends of the chain include: adding the third monomer and the third product sequentially at 0°C under a nitrogen atmosphere and stirring, stirring at room temperature for 32-40 hours, and obtaining the fourth product after extraction, drying, solvent removal and purification.

20. The method for preparing a high-refractive-index optical monomer as described in claim 16, wherein, The reaction conditions for reacting the fourth product with the fourth monomer to generate a high-refractive-index optical monomer include: reacting the fourth product with the fourth monomer in dichloromethane solvent and triethylamine for 15-20 hours.

Images