Four-functional fluorenyl acrylate resin monomer as well as preparation method and application thereof

Abstract

The invention relates to a tetrafunctional fluorenyl acrylate resin monomer and a preparation method and application thereof, the resin monomer has the following structural formula: # imgabs0 #, OR is-O (CH2) 2OOC-CH = CH2 or-O (CH2) 2OOC-C (CH3) = CH2, and the substitution position on the fluorene ring structure is 2, 7 or 3, 6; the preparation method comprises the following steps: # imgabs 1 # mixing a compound as shown in a formula I with a water-carrying agent, an acid catalyst, an acrylic acid compound and a polymerization inhibitor, and carrying out heating reaction to obtain a tetrafunctional fluorenyl acrylate resin monomer; the obtained four-functional fluorenyl acrylate resin monomer can be used for preparing high-refractive-index brightness enhancement film glue. Compared with the prior art, (methyl) acrylic groups are dispersed, and efficient curing is facilitated. The raw materials are easy to obtain, the synthesis process and the post-treatment process are simple, the product conversion rate is high, industrial preparation is easy, and the application scene is wide.

Description

Technical Field

[0001] The present invention belongs to the field of high refractive index functional new materials, and relates to a tetra-functionalized fluorene-based acrylate resin monomer, a preparation method thereof, and an application thereof. Background Art

[0002] Acrylic resin materials have the characteristics of impact resistance, processability, easy dyeing, and light weight compared with inorganic glass, and can be widely used in fields such as optical lenses, optical fiber communication materials, LED packaging, and functional coatings for advanced optical devices. With the progress of social production, the iterative optimization of product terminals continuously puts forward new requirements for monomer design and preparation processes. Poly(meth)acrylate resins with fluorene as the structural backbone have extremely strong mechanical strength, excellent insulation properties, heat and chemical resistance, and at the same time, they also have excellent light transmittance and film-forming ability when combined with diluents. Based on the above properties, fluorene-based acrylic resins have been widely used in optical films, advanced electronic devices, etc.

[0003] In addition, the multi-benzene ring structure of fluorene directly determines its characteristic of high refractive index. If the refractive index is higher, the thinner the material can be to achieve the same display effect. Therefore, compounds with high refractive indices have inherent advantages in the field of optical instruments, which also makes the research on fluorene-based acrylic monomers of great value. In the prior art, TWI633327B, CN 108863780A, and CN 114901628A disclose a series of fluorene-based acrylic monomers, while JP6677535B2 and US11561470 disclose two types of tetra-functional fluorene-based acrylic monomers.

[0004] In the prior art, TWI633327B, CN 108863780A, and CN 114901628A disclose a series of fluorene-based acrylic monomers, but their research mainly focuses on mono- and di-functional compounds. Multi-functional compounds (tri-functional and above) have more efficient curing activity, more excellent strength, and better diluent compatibility compared with the former. JP6677535B2 and US11561470 disclose two types of tetra-functional fluorene-based acrylic monomers, but their substitution positions are located at the 2,4 or 2,3 positions of the phenyl group respectively. Since such tetra-functional monomers have no substituents on the fluorene ring because the substitution positions are all on the benzene ring, during curing, the non-uniformity of the acrylic structure will cause problems such as incomplete curing and self-polymerization. Summary of the Invention

[0005] The purpose of the present invention is to provide a tetra-functionalized fluorene-based acrylate resin monomer that can be rapidly photocured, a preparation method thereof, and an application thereof.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The first aspect of the present invention provides a tetra-functionalized fluorenyl acrylate resin monomer with the structural formula shown below:

[0008]

[0009] In the formula, OR is -O(CH2)2OOC-CH=CH2 or -O(CH2)2OOC-C(CH3)=CH2, and the substitution positions on the fluorene ring structure are the 2,7-positions or the 3,6-positions.

[0010] The second aspect of the present invention provides a preparation method of a tetra-functionalized fluorenyl acrylate resin monomer, including:

[0011]

[0012] Mixing the compound shown in formula I with a water-carrying agent, an acidic catalyst, an acrylic compound, and an inhibitor, and heating for reaction to obtain the tetra-functionalized fluorenyl acrylate resin monomer;

[0013] When the acrylic compound is acrylic acid, OR is -O(CH2)2OOC-CH=CH2; when the acrylic compound is methacrylic acid, OR is -O(CH2)2OOC-C(CH3)=CH2.

[0014] In some specific embodiments, the water-carrying agent refers to a hydrocarbon solvent that can co-boil and distill with water but is not miscible, and is selected from one or more of n-pentane, n-heptane, n-hexane, cyclohexane, benzene, toluene, xylene, or mesitylene; preferably, the water-carrying agent is cyclohexane.

[0015] In some specific embodiments, the acidic catalyst refers to a strongly acidic inorganic / organic compound, and is selected from one or more of concentrated nitric acid, trifluoroacetic acid, concentrated sulfuric acid, hydrogen halide, p-toluenesulfonic acid, methanesulfonic acid, or trifluoromethanesulfonic acid; preferably, the acidic catalyst is p-toluenesulfonic acid.

[0016] In some specific embodiments, the inhibitor refers to a compound that can prevent the self-polymerization of the product during the heating of the reaction, and is selected from one or more of benzenediols, p-methoxyphenol, phenothiazine, or p-tert-butylphenol; preferably, the inhibitor is p-methoxyphenol.

[0017] In some specific embodiments, the molar ratio of the water-carrying agent, the acidic catalyst, the acrylic compound, the inhibitor to the compound shown in formula I is (9-10):(0.05-1):(4-10):(0.0001-0.1):1; preferably, the molar ratio of the water-carrying agent, the acidic catalyst, the acrylic compound, the inhibitor to the compound shown in formula I is 10:0.5:8:0.01:1.

[0018] In some specific embodiments, in the heating reaction, the reaction temperature is the reflux temperature of the water-carrying agent, specifically 36-180 °C, and the reaction time is preferably 4-8 h.

[0019] In some specific embodiments, the method for preparing the compound shown in Formula I includes: stirring and reacting the compound shown in Formula II with a basic inorganic salt catalyst and ethylene carbonate in N,N-dimethylformamide, then mixing with an aqueous methanol solution, filtering, and mixing the obtained solid phase with hot alcohol, followed by suction filtration.

[0020] In some specific embodiments, the basic inorganic salt catalyst refers to a strong base weak acid salt or a strong base compound with basicity, selected from one or two of sodium carbonate, potassium carbonate, cesium carbonate, sodium fluoride, potassium fluoride, cesium fluoride, sodium hydroxide or potassium hydroxide; preferably, the basic inorganic salt catalyst is potassium carbonate.

[0021] In some specific embodiments, the molar ratio of the basic inorganic salt catalyst, ethylene carbonate, and the compound shown in Formula II is (2-8):(4-10):1; preferably, the molar ratio of the basic inorganic salt catalyst, ethylene carbonate, and the compound shown in Formula II is 4:8:1.

[0022] In some specific embodiments, in the stirring reaction, the reaction temperature is 120-140 °C, and the reaction time is preferably 6-10 h.

[0023] In some specific embodiments, in the aqueous methanol solution, the methanol content is 8-12 vol%.

[0024] In some specific embodiments, the temperature of the hot alcohol is 40-50 °C, and the mixing time is preferably 10-20 min.

[0025] In some specific embodiments, the method for preparing the compound shown in Formula II includes: mixing the compound shown in Formula III with phenol, a co-catalyst, and an acid catalyst and carrying out a heat preservation reaction, followed by crystallization.

[0026] In some specific embodiments, since phenol serves as both a reaction substrate and a solvent, the molar ratio of the compound shown in Formula III to phenol is 1:(3-6); preferably, the molar ratio of the compound shown in Formula III to phenol is 1:4.

[0027] In some specific embodiments, the co-catalyst refers to a straight-chain alkyl carboxylic acid and an alkyl alcohol compound containing a mercapto group, and preferably 3-mercaptopropionic acid.

[0028] In some specific embodiments, the acid catalyst refers to a strongly acidic inorganic / organic compound, selected from concentrated nitric acid, trifluoroacetic acid, concentrated sulfuric acid, hydrogen halide, p-toluenesulfonic acid, methanesulfonic acid, or one or more of them; preferably, the acid catalyst is concentrated sulfuric acid.

[0029] In some specific embodiments, the molar ratio of the cocatalyst, the acid catalyst to the compound shown in Formula III is (0.01 - 1):(0.1 - 1):1; preferably, the molar ratio of the cocatalyst, the acid catalyst to the compound shown in Formula III is 0.02:0.1:1.

[0030] In some specific embodiments, in the heat preservation reaction, the reaction temperature is 45 - 50 °C, and the reaction time is preferably 4 - 6 h.

[0031] In some specific embodiments, after the heat preservation reaction is completed, the temperature is lowered to room temperature, the system crystallizes and transforms into a solid state. Subsequently, ethanol is added for dissolution and water (the addition amount is preferably 2 times the volume of ethanol) is added, and crystallization is allowed to occur while standing. After pouring off the liquid, an appropriate amount of sodium hydroxide solution is added to the reaction system for pulping to remove the excessive phenol. After filtration by suction and drying, the compound shown in Formula II is obtained.

[0032] In some specific embodiments, the preparation method of the compound shown in Formula III includes: dissolving the compound shown in Formula IV in a halogenated hydrocarbon, and performing a demethylation reaction with boron tribromide under an ice bath condition to obtain.

[0033] In some specific embodiments, the substitution positions on the fluorene ring structure of the compound shown in Formula I, the compound shown in Formula II, the compound shown in Formula III, and the compound shown in Formula IV are consistent with those of the tetrafunctionalized fluorenyl acrylate resin monomer.

[0034] In some specific embodiments, the halogenated hydrocarbon includes fluorinated hydrocarbons, brominated hydrocarbons, or chlorinated hydrocarbon compounds, selected from 1-fluoropentane, perfluorohexane, bromoethane, bromopropane, bromobutane, dibromoethane, dibromobutane, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, or chlorobutane, or one or more of them; preferably, the halogenated hydrocarbon is dichloromethane or chloroform.

[0035] In some specific embodiments, in order to ensure complete reaction, boron tribromide should be kept in excess. Under the preferred conditions, 1 methoxy group corresponds to 1.5 - 3 times the amount of boron tribromide, that is, the molar ratio of the compound shown in Formula IV to boron tribromide is 1:(3 - 6).

[0036] In some specific embodiments, the reaction time of the methylation reaction is 12 - 15 h.

[0037] The third aspect of the present invention provides an application of a tetrafunctionalized fluorene-based acrylate resin monomer, characterized in that the tetrafunctionalized fluorene-based acrylate resin monomer is used to prepare a high refractive index and brightening film glue.

[0038] Compared with the prior art, the present invention has the following characteristics:

[0039] The present invention provides a novel design of a tetrafunctionalized fluorene-based acrylate resin monomer and its preparation method. The (meth)acrylic acid groups in this structure are dispersed, which is beneficial to efficient curing. Its raw materials are easily available, the synthesis process and post-treatment process are simple, the product conversion rate is relatively high, it is easy to be prepared industrially, and it has a wide range of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of a sample after curing of a brightening film glue based on 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]-2,7-di(acryloyloxyethoxy)fluorene in Application Example 1 (left: front view, right: side view);

[0041] Figure 2 It is a schematic diagram of a sample after curing of a brightening film glue based on 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]-3,6-di(acryloyloxyethoxy)fluorene in Application Example 2 (left: front view, right: side view);

[0042] Figure 3 It is a tensile strength test diagram of a sample after curing of a brightening film glue based on 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]-2,7-di(acryloyloxyethoxy)fluorene in Application Example 1;

[0043] Figure 4 It is a tensile strength test diagram of a sample after curing of a brightening film glue based on 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]-3,6-di(acryloyloxyethoxy)fluorene in Application Example 2;

[0044] Figure 5 It is a tensile strength test diagram of a sample after curing of a brightening film glue based on 9,9-bis[2,4-bis(2-acryloyloxyethoxy)-phenyl]-fluorene in Comparative Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0046] The following are more detailed implementation cases, which further illustrate the technical solution of the present invention and the technical effects that can be obtained through the following implementation cases.

[0047] In the following examples, unless otherwise specified, raw material reagents or treatment techniques are conventional commercially available products or conventional treatment techniques in the art. The treatment temperature is room temperature, the treatment pressure is atmospheric pressure, and the treatment atmosphere is air. All raw materials used are purchased from Shanghai Macklin Biochemical Co., Ltd., and the actual brand is not limited, and their purity is AR grade.

[0048] Example 1:

[0049] A preparation method of 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]-2,7-bis(acryloyloxyethoxy)fluorene, comprising the following steps:

[0050]

[0051] S1: Dissolve 24 g (0.108 mol) of 2,7-dimethoxyfluorenone in 100 mL of dichloromethane, then dropwise add 100 g (38 mL, 0.4 mol) of boron tribromide under an ice bath. After reacting at room temperature for 14 hours, drop the reaction solution into ice water. After the powdery product precipitates, filter by suction and retain the filter residue to obtain 20.7 g of 2,7-dihydroxyfluorenone (yield 98%).

[0052] S2: Dissolve 20.7 g (0.098 mol) of the product 2,7-dihydroxyfluorenone from the previous step in 36.7 g (0.39 mol) of phenol in a molten state, then add 0.2 g (0.002 mol) of 3-mercaptopropionic acid while stirring at 45 °C. Then slowly dropwise add 1 g (0.01 mol) of concentrated sulfuric acid, and after dropping it within 30 min, keep the reaction at 45 °C for 4 hours. After the reaction is completed, cool down to room temperature, and the system is transformed into a solid state. Then add 50 mL of ethanol to dissolve it and add 100 mL of water, and let it stand for crystallization. After pouring off the liquid, add 100 mL of 5 wt% sodium hydroxide solution to the reaction system to slurry and remove the excess phenol. After the system is filtered by suction and dried, 34.3 g of pure white solid product 9,9-bis(4-hydroxyphenyl)-fluorene-2,7-diol is obtained (yield 92%).

[0053] S3: Dissolve 34.3 g (0.084 mol) of 9,9-bis(4-hydroxyphenyl)-fluorene-2,7-diol in 30 mL of N,N-dimethylformamide, then add 49.6 g (0.359 mol) of potassium carbonate and 63 g (0.715 mol) of ethylene carbonate. React at 120 °C for 8 hours, and the reaction system turns into a white mucus. Subsequently, add 100 mL of 10 vol% methanol aqueous solution to the system and stir vigorously until the product turns into a white powdery product. After filtering off the liquid phase by suction, add 50 mL of hot methanol at 40 °C to the solid, stir at a constant temperature for 10 minutes, and then filter while it is hot to obtain 40.6 g (yield 81%) of the white solid product 9,9-bis[4-(2-hydroxyethoxy)phenyl]-2,7-dihydroxyethoxyfluorene.

[0054] S4: In the final step, mix 40.6 g (0.077 mol) of 9,9-bis[4-(2-hydroxyethoxy)phenyl]-2,7-dihydroxyethoxyfluorene with 61.1 g (0.726 mol) of cyclohexane, 6.3 g (0.037 mol) of p-toluenesulfonic acid, 41.9 g (0.581 mol) of acrylic acid, and 90 mg (0.725 mmol) of p-methoxyphenol, and heat to 85 °C for 6 hours. After observing that no more water is separated out in the reaction, restore the reaction system to room temperature, remove the liquid phase by rotary evaporation, and then redissolve it by adding 50 mL of dichloromethane. Subsequently, wash the product layer successively with 100 mL of saturated sodium bicarbonate aqueous solution and 100 mL of water in a separating funnel, combine the organic phases, dry, and remove the solvent by rotary evaporation to obtain 41.2 g (yield 73%) of 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]-2,7-diacryloyloxyethoxyfluorene.

[0055] 1 H NMR (500 MHz, 298 K, CDCl3) δ 7.76 (d, J = 7.5 Hz, 2H), 7.47 - 7.31 (m, 2H), 7.31 - 7.23 (m, 2H), 7.23 - 7.16 (m, 4H), 7.16 - 7.06 (m, 4H), 6.42 (dt, J = 17.3, 1.3 Hz, 4H), 6.14 (ddd, J = 17.3, 10.5, 1.2 Hz, 4H), 5.83 (dd, J = 10.4, 1.3 Hz, 4H), 4.64 - 4.27 (m, 8H), 4.24 - 3.82 (m, 8H).

[0056] Example 2:

[0057] A preparation method of 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]-3,6-diacryloyloxyethoxyfluorene, comprising the following steps:

[0058]

[0059] S1: Dissolve 24 g (0.108 mol) of 3,6-dimethoxyfluorenone in 100 mL of dichloromethane. Subsequently, dropwise add 100 g (38 mL, 0.4 mol) of boron tribromide under an ice bath. After reacting at room temperature for 14 hours, drop the reaction solution into ice water. After the powdery product precipitates, filter it by suction to retain the residue to obtain 19.9 g of 3,6-dihydroxyfluorenone (yield 94%).

[0060] S2: Dissolve 19.9 g (0.094 mol) of the product 3,6-dihydroxyfluorenone from the previous step in 35.3 g (0.375 mol) of phenol in a molten state. Subsequently, add 0.2 g (0.002 mol) of 3-mercaptopropionic acid while stirring at 45°C. Then slowly dropwise add 1 g (0.01 mol) of concentrated sulfuric acid and complete the dropwise addition within 30 minutes, and then keep the temperature at 45°C for reaction for 4 hours. After the reaction is completed, cool down to room temperature. The system is transformed into a solid state. Subsequently, add 50 mL of ethanol to dissolve it and add 100 mL of water, and let it stand for crystallization. After pouring off the liquid, add 100 mL of 5 wt% sodium hydroxide solution to the reaction system to pulp and remove the excess phenol. After suction filtration and drying of the system, 34.3 g of pure white solid product 9,9-bis(4-hydroxyphenyl)-fluorene-3,6-diol is obtained (yield 94%).

[0061] S3: Dissolve 33.7 g (0.083 mol) of 9,9-bis(4-hydroxyphenyl)-fluorene-3,6-diol in 30 mL of N,N-dimethylformamide, then add 48.7 g (0.352 mol) of potassium carbonate and 62 g (0.704 mol) of ethylene carbonate, and react at 120°C for 8 hours. The reaction system is transformed into a white viscous liquid. Subsequently, add 100 mL of 10 vol% methanol aqueous solution to the system and stir vigorously until the product is transformed into a white powdery product. After suction filtration to discard the liquid phase, add 50 mL of hot methanol at 40°C to the solid, keep the temperature and stir for 10 minutes, and then filter it by suction while it is hot to obtain 41.9 g of white solid product 9,9-bis[4-(2-hydroxyethoxy)phenyl]-3,6-dihydroxyethoxyfluorene (yield 85%).

[0062] S4: In the final step, 41.9 g (0.079 mol) of 9,9-bis[4-(2-hydroxyethoxy)phenyl]-3,6-dihydroxyethoxyfluorene is mixed with 63.1 g (0.75 mol) of cyclohexane, 6.5 g (0.038 mol) of p-toluenesulfonic acid, 43.2 g (0.6 mol) of acrylic acid, and 93 mg (0.749 mmol) of p-methoxyphenol, and the mixture is heated to 85 °C and reacted for 5 hours. After observing that no more water is separated out in the reaction, the reaction system is restored to room temperature, and the liquid phase is removed by rotary evaporation and then redissolved by adding 50 mL of dichloromethane. Subsequently, the product layer is washed successively with 100 mL of saturated sodium bicarbonate aqueous solution and 100 mL of water in a separatory funnel, the organic phases are combined, dried, and the solvent is removed by rotary evaporation to obtain 47.2 g (yield 81%) of 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]-3,6-diacryloyloxyethoxyfluorene.

[0063] 1 H NMR (500 MHz, 298 K, CDCl3) δ 7.82 (d, J = 6.8 Hz, 2H), 7.58 - 7.51 (m, 2H), 7.26 - 7.22 (m, 2H), 7.20 - 7.12 (m, 4H), 7.09 - 6.99 (m, 4H), 6.34 (dt, J = 16.8, 1.1 Hz, 4H), 6.11 (ddd, J = 16.8, 9.4, 1.1 Hz, 4H), 5.91 (dd, J = 9.5, 1.1 Hz, 4H), 4.71 - 4.30 (m, 8H), 4.23 - 3.71 (m, 8H).

[0064] Example 3:

[0065] A preparation method of 9,9-bis[4-(2-methacryloyloxyethoxy)phenyl]-2,7-dimethacryloyloxyethoxyfluorene, comprising the following steps:

[0066]

[0067] S1: Dissolve 24 g (0.108 mol) of 2,7-dimethoxyfluorenone in 100 mL of dichloromethane, then dropwise add 100 g (38 mL, 0.4 mol) of boron tribromide under an ice bath. After reacting at room temperature for 14 hours, the reaction solution is dropped into ice water. After the powdery product precipitates, it is filtered by suction and the residue is retained to obtain 20.7 g (yield 98%) of 2,7-dihydroxyfluorenone.

[0068] S2: Dissolve 20.7 g (0.098 mol) of the product 2,7-dihydroxyfluorenone from the previous step in 36.7 g (0.39 mol) of phenol in a molten state. Then add 0.2 g (0.002 mol) of 3-mercaptopropionic acid while stirring at 45°C. Subsequently, slowly dropwise add 1 g (0.01 mol) of concentrated sulfuric acid, and after dropping it within 30 minutes, keep the reaction at 45°C for 4 hours. After the reaction is completed, cool down to room temperature. The system turns into a solid state. Then add 50 mL of ethanol to dissolve it and add 100 mL of water, and let it stand for crystallization. After pouring off the liquid, add 100 mL of 5 wt% sodium hydroxide solution to the reaction system to slurry and remove the excessive phenol. After the system is filtered and dried, 34.3 g of pure white solid product 9,9-bis(4-hydroxyphenyl)-fluorene-2,7-diol (yield 92%) is obtained.

[0069] S3: Dissolve 34.3 g (0.084 mol) of 9,9-bis(4-hydroxyphenyl)-fluorene-2,7-diol in 30 mL of N,N-dimethylformamide, then add 49.6 g of potassium carbonate (0.359 mol) and 63 g (0.715 mol) of ethylene carbonate, and react at 120°C for 8 hours. The reaction system turns into a white mucus. Then add 100 mL of 10 vol% methanol aqueous solution to the system and stir vigorously until the product turns into a white powdery product. After filtering and discarding the liquid phase, add 50 mL of hot methanol at 40°C to the solid, keep stirring at the same temperature for 10 minutes, and then filter while it is hot to obtain 40.6 g of white solid product 9,9-bis[4-(2-hydroxyethoxy)phenyl]-2,7-dihydroxyethoxyfluorene (yield 81%).

[0070] S4: In the final step, mix 40.6 g (0.077 mol) of 9,9-bis[4-(2-hydroxyethoxy)phenyl]-2,7-dihydroxyethoxyfluorene with 61.1 g (0.726 mol) of cyclohexane, 6.3 g (0.037 mol) of p-toluenesulfonic acid, 50.1 g (0.582 mol) of methacrylic acid, and 90 mg (0.725 mmol) of p-methoxyphenol, and heat to 85°C for 6 hours. After observing that no more water is separated out in the reaction, restore the reaction system to room temperature, remove the liquid phase by rotary evaporation, and then redissolve it in 50 mL of dichloromethane. Subsequently, wash the product layer successively with 100 mL of saturated sodium bicarbonate aqueous solution and 100 mL of water in a separatory funnel, combine the organic phases, dry, and remove the solvent by rotary evaporation to obtain 48.9 g of 9,9-bis[4-(2-methacryloyloxyethoxy)phenyl]-2,7-dimethacryloyloxyethoxyfluorene (yield 81%).

[0071] 11H NMR (500 MHz, 298 K, CDCl3) δ 7.70 (d, J = 7.3 Hz, 2H), 7.49 - 7.44 (m, 2H), 7.21 - 7.15 (m, 2H), 7.20 - 7.12 (m, 4H), 7.04 - 6.98 (m, 4H), 6.26 (s, 4H), 6.11 (s, 4H), 4.43 - 4.28 (m, 8H), 4.21 - 3.93 (m, 8H), 2.31 (s, 6H), 2.21 (s, 6H).

[0072] Example 4:

[0073] A preparation method of 9,9 - bis[4-(2 - methacryloyloxyethoxy)phenyl]-3,6 - dimethacryloyloxyethoxyfluorene, comprising the following steps:

[0074]

[0075] S1: Dissolve 24 g (0.108 mol) of 3,6 - dimethoxyfluorenone in 100 mL of dichloromethane, then dropwise add 100 g (38 mL, 0.4 mol) of boron tribromide under an ice bath. After reacting at room temperature for 14 hours, drop the reaction solution into ice water. After the powdery product precipitates, filter by suction and retain the residue to obtain 19.9 g of 3,6 - dihydroxyfluorenone (yield 94%).

[0076] S2: Dissolve 19.9 g (0.094 mol) of the product 3,6 - dihydroxyfluorenone from the previous step in 35.3 g (0.375 mol) of phenol in a molten state, then add 0.2 g (0.002 mol) of 3 - mercaptopropionic acid while stirring at 45°C. Then slowly dropwise add 1 g (0.01 mol) of concentrated sulfuric acid, and after dropping it within 30 minutes, keep the reaction at 45°C for 4 hours. After the reaction is completed, cool to room temperature, and the system is transformed into a solid state. Then add 50 mL of ethanol to dissolve it and add 100 mL of water, and let it stand for crystallization. After pouring off the liquid, add 100 mL of 5 wt% sodium hydroxide solution to the reaction system to pulp and remove the excess phenol. After filtering the system by suction and drying, obtain 34.3 g of pure white solid product 9,9 - bis(4 - hydroxyphenyl)-fluorene - 3,6 - diol (yield 94%).

[0077] S3: After dissolving 33.7 g (0.083 mol) of 9,9-bis(4-hydroxyphenyl)-fluorene-3,6-diol in 30 mL of N,N-dimethylformamide, 48.7 g (0.352 mol) of potassium carbonate and 62 g (0.704 mol) of ethylene carbonate were added. After reacting at 120 °C for 8 hours, the reaction system was transformed into a white mucus. Subsequently, 100 mL of 10 vol% methanol aqueous solution was added to the system and stirred vigorously until the product was transformed into a white powdery product. After discarding the liquid phase by suction filtration, 50 mL of hot methanol at 40 °C was added to the solid, and after stirring for 10 minutes while keeping warm, it was filtered while hot to obtain 41.9 g (yield 85%) of the white solid product 9,9-bis[4-(2-hydroxyethoxy)phenyl]-3,6-dihydroxyethoxyfluorene.

[0078] S4: In the final step, 41.9 g (0.079 mol) of 9,9-bis[4-(2-hydroxyethoxy)phenyl]-3,6-dihydroxyethoxyfluorene was mixed with 63.1 g (0.75 mol) of cyclohexane, 6.5 g (0.038 mol) of p-toluenesulfonic acid, 51.6 g of methacrylic acid (0.6 mol), and 93 mg (0.749 mmol) of p-methoxyphenol, and heated to 85 °C for reaction for 8 hours. After observing that no more water was separated out in the reaction, the reaction system was restored to room temperature. After removing the liquid phase by rotary evaporation, 50 mL of dichloromethane was added again for re-dissolution. Subsequently, the product layer was washed successively with 100 mL of saturated sodium bicarbonate aqueous solution and 100 mL of water in a separatory funnel. The organic phases were combined, dried, and the solvent was removed by rotary evaporation to obtain 47.4 g (yield 76%) of 9,9-bis[4-(2-methacryloyloxyethoxy)phenyl]-3,6-dimethacryloyloxyethoxyfluorene.

[0079] 1 H NMR (500 MHz, 298 K, CDCl3) δ 7.89 (d, J = 7.1 Hz, 2H), 7.58 - 7.52 (m, 2H), 7.17 - 7.11 (m, 2H), 7.15 - 7.09 (m, 4H), 7.05 - 6.92 (m, 4H), 6.31 (s, 4H), 6.10 (s, 4H), 4.48 - 4.29 (m, 8H), 4.20 - 3.91 (m, 8H), 2.36 (s, 6H), 2.25 (s, 6H).

[0080] Comparative example:

[0081] A preparation method of 9,9-bis[2,4-bis(2-acryloyloxyethoxy)-phenyl]-fluorene, comprising:

[0082]

[0083] 16.9 g (0.094 mol) of fluorenone, 53.6 g (0.175 mol) of 1,3-bis(2-acryloyloxyethoxy)benzene (CAS: 56745-15-4), 0.4 g (0.004 mol) of 3-mercaptopropionic acid, 5 g of zinc chloride, and 150 g of methylcyclohexane were added to a reactor equipped with a water-separating device. Subsequently, the mixture was heated to 45 °C, and 5 g (0.05 mol) of concentrated sulfuric acid was slowly added dropwise with stirring. After the addition was completed within 30 minutes, the mixture was heated to 100 °C and reacted for 12 hours until no water was separated. After cooling to room temperature, the methylcyclohexane solvent was removed, 50 mL of methanol was added to the mixture, and after complete dissolution, 100 mL of water was added, and the mixture was allowed to stand for crystallization. After the liquid was poured off, the crude product was recrystallized with cyclohexane. After the system was filtered by suction and dried, 45.9 g (yield 63%) of a pure white solid product, 9,9-bis[2,4-bis(2-acryloyloxyethoxy)phenyl]fluorene, was obtained.

[0084] The following application examples are only one of the fields where the monomers of the present invention can be applied, and do not limit the application properties of the monomers in the present invention. Any simple modification, equivalent change or modification based on the technical essence of the present invention belongs to the scope of protection of the present invention.

[0085] Application Example 1:

[0086] Brightening film glue: 3 g of 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]-2,7-diacryloyloxyethoxyfluorene prepared in Example 1, 3 g of o-phenylphenoxyethyl acrylate (OPPEA) diluent, and 20 mg of 1173 initiator were uniformly mixed by a homogenizer at 3000 rpm for 3 minutes. Then, it was pumped to vacuum and defoamed and homogenized at 4000 rpm for 3 minutes to obtain a high-refractive-index brightening film glue.

[0087] Subsequently, the liquid was poured into a mold (3 cm in length × 1 cm in width × 3 mm in thickness), and a mercury lamp with an energy of 100 mJ / (s·cm 2 ) was used for ultraviolet curing for 20 s, and it could be completely cured and shaped to obtain a sample piece.

[0088] Properties of the glue: Viscosity (25 °C) = 2200 cp (GB / T 2794-2022); Light transmittance (400 nm - 780 nm) = 97% (GB / T 2410-2008); Refractive index (25 °C) = 1.59 (GB / T 614-2021);

[0089] Testing of the sample piece: RCA abrasion resistance (55 g) 300 times (ASTM F2357-04); Scratch resistance (55 g) 400 times (ASTM D5178); Cross-cut test grade 1 (GB / T 9286-2021); △YI = 3.0 (ASTM E313). Photos of the sample piece and tensile strength test were carried out atFigure 1 and Figure 3 shown in

[0090] Application Example 2:

[0091] Brightening film glue: 3 g of 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]-3,6-diacryloyloxyethoxyfluorene prepared in Example 2, 3 g of o-phenylphenoxyethyl acrylate (OPPEA) diluent, and 20 mg of 1173 initiator were uniformly mixed by a homogenizer at 3000 rpm for 3 minutes. Then it was pumped to vacuum and defoamed and homogenized at 4000 rpm for 3 minutes to obtain a high-refractive-index brightening film glue.

[0092] Subsequently, the liquid was poured into a mold (3 cm in length × 1 cm in width × 3 mm in thickness), and using a mercury lamp with an energy of 100 mJ / (s·cm 2 ), after ultraviolet curing for 20 s, it could be completely cured and shaped.

[0093] Properties of the glue: Viscosity (25°C) = 2400 cp (GB / T 2794-2022); Light transmittance (400 nm - 780 nm) ≥ 92% (GB / T 2410-2008); Refractive index (25°C) = 1.61 (GB / T 614-2021);

[0094] Testing of the sample: RCA abrasion resistance (55 g) 280 times (ASTM F2357-04); Scratch resistance (55 g) 370 times (ASTM D5178); Cross-cut test Grade 1 (GB / T 9286-2021); △YI = 3.0 (ASTM E313). Photos of the sample and tensile strength test are shown in Figure 2 and Figure 4 shown in

[0095] Comparative Application Example:

[0096] Brightening film glue: 3 g of 9,9-bis[2,4-bis(2-acryloyloxyethoxy)phenyl]-fluorene prepared in the comparative example, 3 g of o-phenylphenoxyethyl acrylate (OPPEA) diluent, and 20 mg of 1173 initiator were uniformly mixed by a homogenizer at 3000 rpm for 3 minutes. Then it was pumped to vacuum and defoamed and homogenized at 4000 rpm for 3 minutes to obtain a high-refractive-index brightening film glue.

[0097] Subsequently, the liquid was poured into a mold (3 cm in length × 1 cm in width × 3 mm in thickness), and using a mercury lamp with an energy of 100 mJ / (s·cm 2 ), after ultraviolet curing for 60 s, it could be completely cured and shaped.

[0098] Sample test: RCA abrasion resistance (55 g) 150 times (ASTM F2357-04); scratch resistance (55 g) 200 times (ASTM D5178); crosshatch test, grade 2 (GB / T 9286-2021); △YI = 3.0 (ASTM E313). The sample tensile strength test is shown in Figure 5 as follows.

[0099] When comparing the tetra-functional monomer with all substituents on the benzene ring with the monomer of the present invention, it is found that the former requires a longer curing time, and due to the uneven curing problem caused by the crowded substituent positions, its mechanical strength is less than that of the latter.

[0100] The above description of the embodiments is provided to enable those of ordinary skill in the art to understand and use the invention. Obviously, those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention as disclosed should fall within the protection scope of the present invention.

Claims

1. A tetrafunctional fluorenyl acrylate resin monomer, characterized in that: It has the following structural formula: In the formula, OR is -O(CH2)2OOC-CH=CH2 or -O(CH2)2OOC-C(CH3)=CH2, and the substitution position on the fluorene ring structure is 2, 7 or 3, 6.

2. A method for preparing the tetrafunctional fluorenyl acrylate resin monomer as claimed in claim 1, characterized in that: include: The compound shown in formula I is mixed with a water-carrying agent, an acidic catalyst, an acrylic compound, and a polymerization inhibitor, and heated to react to obtain the tetrafunctional fluorenyl acrylate resin monomer; When the acrylic compound is acrylic acid, OR is -O(CH2)2OOC-CH=CH2; when the acrylic compound is methacrylic acid, OR is -O(CH2)2OOC-C(CH3)=CH2.

3. The method for preparing a tetrafunctional fluorenyl acrylate resin monomer according to claim 2, characterized in that: The water-carrying agent is selected from one or more of n-pentane, n-heptane, n-hexane, cyclohexane, benzene, toluene, xylene or trimethylbenzene; The acidic catalyst is selected from one or more of concentrated nitric acid, trifluoroacetic acid, concentrated sulfuric acid, hydrogen halide, p-toluenesulfonic acid, methanesulfonic acid or trifluoromethanesulfonic acid; The polymerization inhibitor is selected from one or more of hydroquinones, p-methoxyphenol, phenothiazine or p-tert-butylphenol; The molar ratio of the water-carrying agent, the acidic catalyst, the acrylic compound, the polymerization inhibitor and the compound shown in Formula I is (9-10):(0.05-1):(4-10):(0.0001-0.1):1; In the heating reaction, the reaction temperature is 36-180° C. and the reaction time is 4-8 hours.

4. The method for preparing a tetrafunctional fluorenyl acrylate resin monomer according to claim 2, characterized in that: The preparation method of the compound shown in Formula I comprises: The compound shown in formula II is reacted with a basic inorganic salt catalyst and ethylene carbonate in N,N-dimethylformamide by stirring, and then mixed with a methanol aqueous solution, filtered, and the obtained solid phase is mixed with hot alcohol and filtered to obtain the product.

5. The method for preparing a tetrafunctional fluorenyl acrylate resin monomer according to claim 4, characterized in that: The alkaline inorganic salt catalyst is selected from one or two of sodium carbonate, potassium carbonate, cesium carbonate, sodium fluoride, potassium fluoride, cesium fluoride, sodium hydroxide or potassium hydroxide: The molar ratio of the alkaline inorganic salt catalyst, ethylene carbonate, and the compound represented by formula II is (2-8):(4-10):1; During the stirring reaction, the reaction temperature is 120-140°C.

6. The method for preparing a tetrafunctional fluorenyl acrylate resin monomer according to claim 4, characterized in that: The preparation method of the compound shown in Formula II comprises: The compound shown in formula III is mixed with phenol, a co-catalyst and an acid catalyst, and the mixture is kept warm for reaction and crystallization to obtain.

7. The method for preparing a tetrafunctional fluorenyl acrylate resin monomer according to claim 6, characterized in that: The molar ratio of the compound represented by formula III to phenol is 1:(3-6); The co-catalyst is 3-mercaptopropionic acid; The acid catalyst is selected from one or more of concentrated nitric acid, trifluoroacetic acid, concentrated sulfuric acid, hydrogen halide, p-toluenesulfonic acid, methanesulfonic acid or; The molar ratio of the co-catalyst, the acid catalyst and the compound represented by Formula III is (0.01-1):(0.1-1):1; During the heat preservation reaction, the reaction temperature is 45-50°C.

8. The method for preparing a tetrafunctional fluorenyl acrylate resin monomer according to claim 6, characterized in that: The preparation method of the compound shown in Formula III comprises: The compound shown in formula IV is dissolved in a halogenated hydrocarbon, and subjected to a demethylation reaction with boron tribromide under ice bath conditions to obtain.

9. The method for preparing a tetrafunctional fluorenyl acrylate resin monomer according to claim 8, characterized in that: The halogenated hydrocarbon is selected from one or more of 1-fluoropentane, perfluorohexane, ethyl bromide, propyl bromide, butyl bromide, ethylene dibromide, dibromobutane, dichloromethane, dichloroethane, chloroform, carbon tetrachloride or butyl chloride; The molar ratio of the compound shown in formula IV to boron tribromide is 1:(3-6).

10. A use of the tetrafunctional fluorenyl acrylate resin monomer as claimed in claim 1, characterized in that: The tetrafunctional fluorenyl acrylate resin monomer is used for preparing high-refractive index brightness enhancement film glue.

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