Novel polymerizable high-refraction monomer and preparation method thereof

Abstract

The invention relates to the technical field of organic chemistry, in particular to a novel polymerizable high-refractive-index monomer and a preparation method thereof.In the design of the monomer, vinyl oxazolone with low viscosity serves as a basic structure and is combined with all high-refractive-index functional groups, so that the monomer is in a liquid state, and subsequent polymerization operation is facilitated; vinyl is used as a photopolymerizable active group, and free radical or cationic polymerization can be adopted. Oxazolone and a benzene ring in the whole molecule are rigid groups, and the polymerized material has excellent heat resistance and can be applied to special materials in the fields needing high refractive index, such as photoresist, holographic storage and electronic packaging materials.

Description

Technical Field

[0001] The invention relates to the technical field of organic chemistry, and in particular to a novel polymerizable high-refractive monomer and a preparation method thereof. Background Art

[0002] Optical resins are becoming more and more popular due to their light weight, impact resistance, easy processing and molding, dyeability and excellent optical properties. They are gradually replacing inorganic optical materials and are widely used in optical discs, optical fibers, building materials, resin lenses, precision lenses, etc. Compared with optical glass, optical resins have the disadvantages of few varieties and small range of refractive index variation. At present, the optical materials widely used in the market are mainly acrylic monomers with low refractive structure, which have high viscosity, low refractive index and unsatisfactory comprehensive performance, which limits the application range of materials. CN113461658A reports a resin including high refractive acrylic monomers and high refractive thiol monomers. Although the obtained optical resin has a high refractive index, since it still uses traditional acrylic monomers, its refractive index, high temperature resistance, solubility, etc. will be affected to a certain extent; its Abbe number is also relatively low, about 20. CN105777596A reports a polyurethane type high refractive sulfur-containing monomer. Although its refractive index is above 1.66, its transparency is low, less than 90%, and the material hardness is low and the high temperature resistance is poor. Research has found that the method of increasing the refractive index of materials is not only to introduce atoms such as sulfur and selenium into the molecular structure, but also to effectively increase the heterocyclic structure. In view of the limitations of the prior art, the present invention introduces an oxazolone group into the molecular structure, which increases the refractive index of the material and makes the monomer liquid, thereby avoiding the use of solvents during the polymerization process, being environmentally friendly and having low production costs. It can well make up for the defects of traditional acrylic ester monomers, and has good application prospects in the fields of electronic packaging glue, optical devices, etc. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art: to provide a novel polymerizable high-refractive monomer and a preparation method thereof.

[0004] In order to solve the above problems, the technical solution provided by the present invention is as follows: a new type of polymerizable high-refractive monomer, the structural formula of which is as follows:

[0005]

[0006] R1 is selected from X is selected from oxygen or sulfur.

[0007] The method for preparing the monomer comprises the following steps:

[0008] (1) Thiophenol compounds in which both ends of the R1 substituent are connected to hydrogen Reaction, formation

[0009]

[0010] (2) The compound of step 1 and Reaction to obtain compound

[0011] (3) The product of step 2 is reacted with trimethylsilyl trifluoromethanesulfonate to obtain the monomer

[0012]

[0013] The specific reaction formula is as follows:

[0014]

[0015] Preferably, in step 1, the thiophenol compound and The molar ratio is 1:2-10, and the reaction temperature is 15-40°C.

[0016] Preferably, the product of step 1 of step 2 is The molar ratio is 1:15-20, and the reaction temperature is 15-40°C.

[0017] Preferably, the molar ratio of the product of step 2 in step 3 to trimethylsilyl trifluoromethanesulfonate is 1:4-10, and the reaction temperature is -10-0°C.

[0018] Preferably, the monomer is used in electronic packaging adhesives and optical devices.

[0019] Preferably, the monomer is used in optical resin.

[0020] The specific structure of the high refractive monomer of the present invention is listed as follows:

[0021]

[0022] The beneficial effect of the present invention is that, from the perspective of the prior art, the reported high-refractive materials have the following disadvantages: they are still modified and improved on the basis of the traditional acrylate structure, and the actual refractive index has not been greatly improved. Even if the refractive index is improved, other properties are also reduced, such as high dispersion and more brittle materials; in addition, most of these monomers are solid and require solvent dissolution when used. Oxazolone is a type of material with low viscosity and high refractive index, which can effectively reduce the viscosity of the entire structure of the monomer and reduce the use of solvents during polymerization. The refractive index properties of the compounds are characterized using an Abbe refractometer. Studies have found that the refractive index of methyl acrylate is 1.435, and the refractive index of 5-methyl-3-vinyl oxazolidin-2-one is 1.484, and the refractive index of the oxazolone structure is higher. Starting from the molecular structure, the present invention uses oxazolone as the basic group and combines it with a series of high-refractive structures such as oxygen and sulfur, thereby increasing the refractive index of the material while ensuring that the monomer is in a colorless liquid state. During the polymerization process, it can be easily soluble, fully solid-containing, and pollution-free. The structure contains rigid oxazolone heterocyclic rings and non-conjugated benzene rings, and has a high sulfur content, which reduces the dispersion of the material while giving it certain physical properties. DETAILED DESCRIPTION

[0023] The present invention is described below with reference to examples, but the present invention is not limited thereto. In the art, simple replacement or improvement made by technicians in the field to the present invention belongs to the technical solution protected by the present invention.

[0024] Example 1 Preparation of Compound 1

[0025] Taking 4,4-dimercaptodiphenyl sulfide as an example, epichlorohydrin is reacted with potassium cyanate (potassium cyanide sulfate) to generate chlorine-substituted oxazol (thio) ketone, which is substituted with 4,4-dimercaptodiphenyl sulfide, and finally undergoes an ethanol elimination reaction to obtain compound 1. The reaction formula is as follows:

[0026]

[0027] Wherein, the synthesis process of compound 1-ii is as follows:

[0028] In a three-necked flask equipped with a magnetic stirrer, a thermometer, and a serpentine condenser, compound 1-i (100 g, 1.08 mol) was dissolved in 1 L of deionized water, potassium cyanate (175.21 g, 2.16 mol) and magnesium sulfate (260 g, 2.16 mol) were added, the system was heated to 100°C and stirred for 10 hours, and TLC showed that the raw material disappeared. The reactants were extracted with ethyl acetate (3×300 mL), the combined organic phases were washed once with saturated brine, dried over anhydrous sodium sulfate and concentrated to obtain pure white crystals 1-ii (133.2 g, yield: 91% HPLC purity: 98%).

[0029] The synthetic route of compound 1-iv is as follows:

[0030] In a three-necked flask equipped with a magnetic stirrer and a thermometer, compound 1-ii (133 g, 0.987 mol) was dissolved in 1.5 L of DMF solvent, and then potassium carbonate (204.41 g, 1.479 mol) and compound 1-iii (123.53 g, 0.493 mol) were added, and stirred at room temperature overnight. TLC showed that the raw material disappeared. The reaction solution was acid-base neutralized and filtered, and the filter cake was recrystallized with ethanol to obtain the target product 1-iv (205.67 g, yield: 93% HPLC purity: 93%).

[0031] The synthetic route of compound 1-vi is as follows:

[0032] In a three-necked flask equipped with a magnetic stirrer and a thermometer, compound 1-iv (205 g, 0.457 mol) was dissolved in compound 1-v (1.08 kg, 9.15 mol), and then camphorsulfonic acid (10.62 g, 0.0457 mol) was added. The mixture was stirred at room temperature for two days and two nights. TLC showed that the raw material disappeared. The reaction solution was washed once with saturated NaHCO3 and saturated NaCl aqueous solution 300 ml, dried over anhydrous sodium sulfate, purified by column chromatography, and concentrated to remove the solvent to obtain a light yellow oily compound 1-vi (265.48 g, yield: 98% HPLC purity: 98%).

[0033] The synthetic route of compound 1 is as follows:

[0034] In a three-necked flask equipped with a magnetic stirrer and a thermometer, compound 1-vi (265 g, 0.448 mol) and triethylamine (136 g, 1.344 mol) were dissolved in 1.3 L of dichloromethane and stirred for half an hour, then the system was ice-bathed and trimethylsilyl trifluoromethanesulfonate (258.6 g, 2.6 mol) was added under nitrogen protection, stirred for 20 hours, and TLC showed that the raw material disappeared. The reaction solution was diluted with deionized water (3 L), acidified with citric acid, extracted with ethyl acetate (3 × 500 mL), washed once with saturated NaCl aqueous solution 500 mL, dried over anhydrous sodium sulfate, purified by column chromatography, and concentrated to remove the solvent to obtain a light yellow oily compound 1 (206 g, yield: 92% HPLC purity: 99%, refractive index 1.662).

[0035] The chemical structure of the target compound 1 was tested, and the NMR characterization results are as follows:

[0036] 1H NMR(400MHz,Chloroform-d)δ:7.29-7.15(m,8H),6.78(dd,2H),4.68-4.58(m,2H),4.36 (dd,2H),4.20(dd,2H),3.71(t,2H),3.43(dd,2H),3.34-3.23(m,2H),3.03-2.92(m,2H).

[0037] Example 2 Preparation of Compound 2

[0038] The reaction formula of compound 2 is as follows:

[0039]

[0040] Wherein, the synthesis process of compound 2-ii is as follows:

[0041] In a three-necked flask equipped with a magnetic stirrer and a thermometer, compound 2-i (100 g, 1.01 mol) was dissolved in 2 L of chloroform, and then 2.7 M chlorine / chloroform solution 2.4 L was prepared and added dropwise to the reaction system at -10°C to -5°C. After stirring at -10°C for 2 hours, aqueous methanol (100 mL) was added, stirred at 0 to 5°C for 10 minutes, and then reacted at 0°C for 1 hour. TLC showed that the raw material disappeared. After the reaction was completed, nitrogen was introduced into the solution and maintained for 30 minutes. The chlorine gas was absorbed by sodium sulfite. The reaction solution was quenched into a 0.5 M sodium sulfite aqueous solution, extracted with ethyl acetate 3 times, and the organic phase was concentrated. The crude product was purified by silica gel column chromatography to obtain the target compound 2-ii (140 g, yield: 92% HPLC purity: 97%).

[0042] The preparation methods of compounds 2-iv, 2-vi, and 2 are the same as those of compounds 1-iv, 1-vi, and 1.

[0043] The chemical structure of the target compound 2 was tested, and the refractive index was 1.667. The NMR characterization results are as follows:

[0044] 1 H NMR(400MHz,Chloroform-d)δ:7.33-7.16(m,10H),6.10(dd,2H),4.66(dd,2H),3.73-3.44(m,6H),3.52–3.27(m,4H).

[0045] Example 3 Preparation of Compound 3

[0046] The preparation method of compound 3 is similar to that of compound 1. The difference from Example 1 is that the thiophenol compound used in this example is The structural formula of compound 3 is

[0047]

[0048] The chemical structure of the target compound 3 was tested, and the refractive index was 1.664. The NMR characterization results are as follows:

[0049] 1H NMR(400MHz,Chloroform-d)δ:7.31(dd,2H),7.08(d,2H),6.92-6.90(m,4H),6 .10(dd,2H),5.59(m,2H),4.68(dd,2H),3.31-3.06(m,4H),3.13–2.88(m,4H).

[0050] Example 4 Preparation of Compound 4

[0051] The preparation method of compound 4 is similar to that of compound 3, except that the starting material is The structural formula of compound 4 is

[0052]

[0053] The chemical structure of the target compound 4 was tested, and the refractive index was 1.671. The NMR characterization results are as follows:

[0054] 1 H NMR(400MHz,Chloroform-d)δ:7.32(dd,2H),7.10(d,2H),6.94-6.93(m,4H),6.13(dd,2H),4.66(dd,2H),3.73-3.44(m,6H),3.52–3.27(m,4H).

[0055] Example 5 Preparation of Compound 5

[0056] The preparation method of compound 5 is similar to that of compound 1. The difference from Example 1 is that the thiophenol compound used in this example is The obtained compound 5 has the structural formula

[0057]

[0058] The chemical structure of the target compound 5 was tested, and the refractive index was 1.669. The NMR characterization results are as follows:

[0059] 1H NMR(400MHz,Chloroform-d)δ:7.90(dd,2H),7.33(dd,2H),7.38-7.27(m,10H),7.08( d,4H),6.12(dd,2H),5.58(m,2H),4.67(dd,2H),3.32-3.08(m,4H),3.14–2.90(m,4H).

[0060] Example 6 Preparation of Compound 6

[0061] The preparation method of compound 6 is similar to that of compound 5. The difference from Example 3 is that the starting material used in this example is The structural formula of compound 6 is:

[0062]

[0063] The chemical structure of the target compound 6 was tested, and the refractive index was 1.674. The NMR characterization results are as follows:

[0064] 1 H NMR(400MHz,Chloroform-d)δ:7.97(dd,2H),7.55(dd,2H),7.41-7.29(m,10H), 7.12(d,4H),6.10(dd,2H),4.71(dd,2H),3.75-3.46(m,6H),3.55-3.31(m,4H).

[0065] The present invention uses oxazolone as a basic group and combines it with a series of high-refractive structures containing oxygen, sulfur and the like, thereby increasing the refractive index of the material while ensuring that the monomer is in a colorless liquid state, and can be easily soluble, fully solid-containing and pollution-free during the polymerization process; the structure contains rigid oxazolone heterocyclic rings and non-conjugated benzene rings, and has a high sulfur content, thereby reducing the dispersion of the material while providing certain physical properties.

[0066] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A novel polymerizable high refractive monomer, characterized in that: The structural formula is as follows: R1 is selected from X is selected from oxygen or sulfur.

2. The method for preparing a monomer according to claim 1, characterized in that: The method comprises the following steps: (1) Thiophenol compounds in which both ends of the R1 substituent are connected to hydrogen Reaction, formation (2) The compound of step 1 and Reaction to obtain compound (3) The product of step 2 is reacted with trimethylsilyl trifluoromethanesulfonate to obtain the monomer The specific reaction formula is as follows:

3. The method according to claim 2, characterized in that In step 1, the thiophenol compound is The molar ratio is 1:2-10, and the reaction temperature is 15-40°C.

4. The method according to claim 2, characterized in that The product of step 1 of step 2 and The molar ratio is 1:15-20, and the reaction temperature is 15-40°C.

5. The method according to claim 2, characterized in that The molar ratio of the product of step 2 in step 3 to trimethylsilyl trifluoromethanesulfonate is 1:4-10, and the reaction temperature is -10-0°C.

6. Use of the monomer as claimed in claim 1 in electronic packaging adhesives and optical devices.

7. Use of the monomer as claimed in claim 1 in optical resin.

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