Ultrahigh-refractive-index blue light protective material and preparation method therefor

Abstract

An ultrahigh-refractive-index blue light protective material and a preparation method therefor. The blue light protective material is formed by polymerizing an isocyanate and / or isothiocyanate, a cyclohexasulfur compound represented by formula I, and core-shell S8 nanocomposite microspheres. The weight ratio between the three is (36-50):(50-68):(1-6). The core-shell S8 nanocomposite microsphere has a core made of an S8 nanocrystalline sphere, an intermediate layer made of an ultraviolet absorber, and a shell made of polyurethane. The blue light protective material has the capability of differential absorption across different waveband spectra while maintaining high refractive index and high transmittance. The blue light protective material absorbs harmful light, transmits beneficial light, and has a transmittance of less than 0.1% for 280-380 nm ultraviolet light, a transmittance of less than 25% for 385-445 nm blue light, a transmittance of greater than 70% for 475-500 nm blue light, a transmittance of greater than 90% for 520-780 nm visible light, and a refractive index of greater than 172. R1, R2, and R3 are the same or different and each independently OH or CH3.

Description

Blue light protection material with super-high refractive index and preparation method thereof TECHNICAL FIELD

[0001] The present application belongs to the technical field of light weight and light protection, and particularly relates to a blue light protection material with super-high refractive index and a preparation method thereof. BACKGROUND

[0002] The refractive index of an optical material refers to the ability to refract light. Under the premise of other parameters being the same, the higher the refractive index of the material, the thinner the edge thickness, so the high-refractive optical material can reduce the curvature, thickness and weight of the optical equipment as much as possible under the premise of guaranteeing the optical performance and function.

[0003] The refractive index of an optical resin material is inversely proportional to the molecular volume and proportional to the molar refractive index, and the molar refractive index is proportional to the medium polarizability. In order to improve the refractive index of the resin, mainly by introducing groups with high molar refraction and small molecular volume into the molecular structure of the polymer; In recent years, there are more related reports on introducing sulfur atoms to improve the refractive index of mercaptan monomers through molecular design. Because there is a d orbital outside the sulfur atom, the two pairs of outermost electrons are easily polarized, so the sulfur atom has both low molecular dispersion and high molecular refractive index.

[0004] As a part of visible light, blue light has a wavelength of 380-500 nm. Due to the high proportion of blue light spectrum in the light emitted by electronic products such as LED lamps, computers and mobile phones, long-term overuse can cause eye dryness, fatigue, tearing, accelerated myopia, macular lesions and other problems. At present, the future development trend of domestic and foreign anti-blue light technology optical material technology is to develop multi-functional integrated technology, and single function cannot meet the requirements of light weight, integration and intelligentization of optical components.

[0005] Transparent high-sulfur polyurethane has the characteristics of high refractive index, good light transmittance, high strength and good impact resistance, and is widely used in high-end optical component fields such as optical lenses, instrument prisms, light filtering protection, LED lighting, intelligent automobiles and window materials. High-refractive polyurethane anti-blue light material is a new material with excellent optical properties and blue light protection function in the field of light protection and control, and is also a rising star in the field of optical materials in the twenty-first century. It is of great significance to integrate and compatible light weight technology and blue light protection technology, so that the optical device can selectively transmit or cut off different wavelengths of light spectrum while maintaining light weight, to meet the design requirements of precise control and protection of blue light. SUMMARY

[0006] In view of the above problems of the prior art, the present application provides a hexacyclic sulfur compound (Formula I) with super-high refractive index and a blue light protection material prepared therefrom. The blue light protection material is polymerized from isocyanate and / or isothiocyanate, the hexacyclic sulfur compound and core-shell S8 nano-composite microspheres. The hexacyclic sulfur compound monomer has good light transmittance and high refractive index; the core of the core-shell S8 nano-composite microspheres is S8 nanocrystal with surface modification of light absorbers, and the shell is polyurethane. The blue light protection material prepared by the method of the present application has super-high refractive index, and the absorption spectrum range is red-shifted from the ultraviolet spectrum region to the blue light spectrum region. In the case of maintaining high refractive index and high light transmittance, the material has the performance of distinguishing and absorbing different wavebands of spectrum, absorbs harmful light and transmits beneficial light. The transmittance of 280-380 nm ultraviolet light is less than 0.1%, the transmittance of 385-445 nm short-wave blue light is less than 25%, the transmittance of 475-500 nm long-wave blue light is more than 70%, the transmittance of 520-780 nm visible light is more than 90%, and the refractive index is more than 1.72.

[0007] To achieve the above object, the present application provides the following technical solutions.

[0008] A blue light protection material with super-high refractive index is polymerized from isocyanate and / or isothiocyanate, a hexacyclic sulfur compound shown in Formula I and core-shell S8 nano-composite microspheres; the weight ratio of the three is (36-50):(50-68):(1-6).

[0009] wherein R1, R2 and R3 are the same or different, and each is OH or CH3.

[0010] The core of the core-shell S8 nano-composite microspheres is S8 nanocrystal ball, the intermediate layer is ultraviolet light absorber, and the shell is polyurethane. The outer diameter of the composite microspheres is 10-20 nm. The weight ratio of S8, ultraviolet light absorber and polyurethane is 1:(0.2-0.8):(0.2-1).

[0011] Preferably, the isocyanate compound is a compound containing two or more isocyanate groups in the molecular structure; and the isothiocyanate compound is a compound containing -N=C=S groups in the molecular structure.

[0012] Preferably, the isocyanate compound is at least one selected from toluene diisocyanate, 1,6-hexane diisocyanate, methylcyclohexyl diisocyanate, naphthalene-1,5-diisocyanate, dicyclohexyl methane diisocyanate, m-xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, tetramethylxylylene diisocyanate and isophorone diisocyanate.

[0013] The ultrahigh refractive index blue light protection material as described above, preferably, the isothiocyanate compound is selected from one of 2-bromoethyl isothiocyanate, allyl isothiocyanate, butyl isothiocyanate, sec-butyl isothiocyanate, isobutyl isothiocyanate, 3-butenyl isothiocyanate, phenethyl isothiocyanate, pentyl isothiocyanate, m-dicarba isothiocyanate and 4-pentenyl isothiocyanate.

[0014] The ultrahigh refractive index blue light protection material as described above, preferably, the core-shell S8 nanocomposite microspheres are prepared by the following method:

[0015] (1) Preparation of precursor solution: sulfur powder is added to a mixed solution of carbon disulfide and butyl acetate, the weight ratio of sulfur powder, carbon disulfide and butyl acetate is (0.5-1.2):(10-50):(280-450), the sulfur powder is dissolved by stirring at room temperature, and the insoluble substances and impurities are filtered to obtain a sulfur-containing precursor solution;

[0016] (2) Preparation of donor solution: the ultraviolet light absorber is added to the sulfur-containing precursor solution, wherein the amount of ultraviolet light absorber added is 0.2-0.8 times the weight of the sulfur powder in step (1); vacuum nitrogen is passed for 2-5 times, each time for 10-20 minutes, and then heated to 85-120°C to form a donor solution containing UV-S8 nanocrystals;

[0017] (3) Preparation of ligand-modified sulfur-containing nanomicrospheres: the alcohol compound, isocyanate compound and dibutyltin dilaurate are sequentially added to the donor solution containing UV-S8 nanocrystals prepared in the above step (2), wherein the weight ratio of the donor solution containing UV-S8 nanocrystals, the alcohol compound, the isocyanate compound monomer is (300-500):(0.5-1.2):(0.8-1.5), and the amount of dibutyltin dilaurate is 1-3 wt% of the isocyanate compound monomer; after stirring uniformly, heating to 50-60°C for 30-50 min, and standing for 2-5 hours, the precipitate is collected, filtered, washed and dried to obtain core-shell S8 nanocomposite microspheres.

[0018] The ultrahigh refractive index blue light protection material as described above, preferably, the ultraviolet light absorber is selected from at least one of UV-P, UV-326, UV-327, UV-328, UV-329, UV-360, UV-531 and UV-928.

[0019] The polyurethane is preferably prepared by condensation reaction of an alcohol compound and an isocyanate. The alcohol compound is one of isopropyl alcohol, benzyl alcohol, n-butyl alcohol, ethylene glycol, or a mixture of two or more thereof, and more preferably a mixture of n-butyl alcohol and ethylene glycol. The isocyanate is at least one selected from the group consisting of toluene diisocyanate, 1,6-hexane diisocyanate, methylcyclohexyl diisocyanate, naphthalene-1,5-diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane-4,4'-diisocyanate, m-xylylene diisocyanate, tetramethylxylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

[0020] In another aspect, the present application provides a hexacyclic sulfur compound having a structure as shown in Formula A:

[0021] In still another aspect, the present application provides a method for preparing the hexacyclic sulfur compound as described above, the method comprising the steps of:

[0022] (1) Sulfuration: sodium pentathio-carbonate is added to methanol, completely dissolved, and heated to 25-45°C, and then 1,3-dimercaptoisopropanol is added, and the reaction is stirred slowly for about 1-3 hours;

[0023] (2) Extraction: the above reaction solution is diluted with purified water, extracted with chloroform, and the water layer is separated, and then the extraction solution is combined and dried;

[0024] (3) Distillation: the dried solution is filtered, and the chloroform is removed by distillation, to obtain a viscous compound;

[0025] (4) Purification: the viscous compound after distillation is dissolved in pyridine solvent, insoluble substances are removed by filtration, and the solvent is recovered under reduced pressure, to obtain an oily hexacyclic sulfur compound.

[0026] In the preparation method as described above, the weight ratio of 1,3-dimercaptoisopropanol to sodium pentathio-carbonate in step (1) is preferably (1-2):(1-5).

[0027] In the preparation method of the hexacyclic sulfur compound as described above, the mass ratio of chloroform, purified water, and methanol is preferably (1-2):(1-2):(30-70).

[0028] In still another aspect, the present application provides a method for preparing a blue light protection material having an ultrahigh refractive index, the method comprising the steps of:

[0029] I. The following components are weighed according to the weight ratio:

[0030] A component: isocyanate and / or isothiocyanate, 36-50 parts by weight;

[0031] Group B: hexacyclic sulfur compound shown in formula I, 50-68 parts by weight;

[0032] Group C: core-shell S8 nanocomposite microspheres, 1-6 parts by weight;

[0033] wherein R1, R2, R3 are the same or different, each being OH or CH3;

[0034] The inner core of the core-shell S8 nanocomposite microspheres is S8 nanocrystal ball, the middle layer is light absorber, and the outer shell is polyurethane; the outer diameter of the composite microspheres is 10-20 nm; the weight ratio of S8, ultraviolet light absorber and polyurethane is 1:(0.2-0.8):(0.2-1);

[0035] The above A, B and C components are mixed in proportion to obtain a prepolymer;

[0036] II. The prepolymer obtained in step I is added with auxiliary agent, catalyst and solvent under stirring, and pre-polymerized at 50-80°C for 10-60 min, and then the gas bubbles are removed in vacuum, and then injected into a mold;

[0037] III. The mold containing the prepolymer is placed in a curing oven at 35-55°C for heating for 2-10 h, and then gradually increased to 80-100°C, and then placed for 2-3 h, and then cooled to room temperature to be demolded, thereby obtaining a blue light protection material with super-high refractive index.

[0038] In the preparation method as described above, preferably, when the isothiocyanate compound is mixed with the isocyanate compound, the isothiocyanate compound is first heated to 55-135°C for melting, and then the isocyanate compound is added thereto to obtain a mixture.

[0039] In the preparation method as described above, preferably, the auxiliary agent is triethyldiamine, and the weight percentage of triethyldiamine to isothiocyanate is (0.1-0.3):(1-7).

[0040] In the preparation method as described above, preferably, the catalyst is dibutyltin dilaurate or stannous octoate, and the catalyst is 1-3 wt% of the prepolymer.

[0041] In the preparation method as described above, preferably, the solvent is one of methanol, ethanol, propanol, diethyl ether, dioxane and tetrahydrofuran, and the amount of the solvent is 0-5 wt% of the prepolymer.

[0042] In the preparation method as described above, preferably, the hexacyclic sulfur compound is a compound shown in formula A:

[0043] The preparation method as described above, preferably, the core-shell type S8 nanocomposite microspheres are prepared by the following method:

[0044] (1) Preparation of precursor solution: sulfur powder is added to a mixed solution of carbon disulfide and butyl acetate, the weight ratio of sulfur powder, carbon disulfide and butyl acetate is (0.5-1.2):(10-50):(280-450), the sulfur powder is dissolved by stirring at room temperature, and the insoluble substances and impurities are filtered to obtain a sulfur-containing precursor solution;

[0045] (2) Preparation of donor solution: an ultraviolet light absorber is added to the sulfur-containing precursor solution, wherein the amount of the ultraviolet light absorber added is 0.2-0.8 times the weight of the sulfur powder in step (1); nitrogen is passed through vacuum for 2-5 times, each time for 10-20 minutes, and then heated to 85-120°C, so that the dissociation adsorption force of S8 molecules reaches a peak value, so that the ultraviolet light absorber molecules are adsorbed on the surface of the sulfur ions, and a donor solution containing UV-S8 nanocrystals is formed by coordination coating;

[0046] (3) Preparation of ligand-modified sulfur-containing nanomicrospheres: alcohol compound, isocyanate compound and dibutyltin dilaurate are sequentially added to the donor solution containing UV-S8 nanocrystals prepared in the above step (2), wherein the weight ratio of the donor solution containing UV-S8 nanocrystals, alcohol compound, isocyanate compound monomer is (300-500):(0.5-1.2):(0.8-1.5), and the amount of dibutyltin dilaurate is 1-3 wt% of the isocyanate compound monomer; after stirring uniformly, heating to 50-60°C for 30-50 min, and standing for 2-5 hours, the precipitate is collected, filtered, washed and dried to obtain core-shell type S8 nanocomposite microspheres.

[0047] The preparation method as described above, preferably, the alcohol compound in step (3) is preferably a mixture of n-butanol and ethylene glycol, and the mass ratio of n-butanol to ethylene glycol is (1-3):(1-5).

[0048] The preparation method as described above, preferably, the isocyanate compound in step (3) is at least one selected from toluene diisocyanate, 1,6-hexane diisocyanate, methylcyclohexyl diisocyanate, naphthalene-1,5-diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane-4,4'-diisocyanate, m-xylylene diisocyanate, tetramethylxylylene diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

[0049] The preparation method as described above, preferably, the ultraviolet light absorber is at least one selected from UV-P, UV-326, UV-327, UV-328, UV-329, UV-360, UV-531 and UV-928.

[0050] Preferably, the mass ratio of the three, trichloromethane, pure water and methanol, is (1-2):(1-2):(30-70).

[0051] The S8 in the present application refers to a molecular crystal composed of 8 sulfur atoms, the sulfur atoms in each molecule are connected to each other by S-S single bond to form a ring structure. The S8 nanocrystal ball is composed of monodisperse S8 molecular nanocrystals or grains.

[0052] The core-shell S8 nanocomposite microsphere is a polyurethane / light absorber / S8 three-layer nanocomposite core-shell structure, the inner core is the S8 nanocrystal ball, the middle layer is the light absorber, and the outer shell is the polyurethane; the outer diameter of the composite microsphere is 10-20 nm, the diameter of the S8 crystal ball is 4-10 nm, the thickness of the middle layer is 1.5-2.5 nm, and the thickness of the outer shell is 1.5-2.5 nm; the weight ratio of S8, light absorber and polyurethane is 1:(0.2-0.8):(0.2-1).

[0053] The blue light protection material of the present application contains hexacyclic sulfur compound (I), which effectively improves the refractive index of the material and has good polymerization performance. At the same time, the material is doped with core-shell S8 nanocomposite microspheres, the inner core S8 crystal ball is composed of monodisperse 8-ring sulfur molecular nanocrystals or grains, the light absorber particles in the middle layer are dispersed on the surface of the S8 crystal ball, and the outer shell is polyurethane, as shown in Figure 4. The S8 molecule itself has the performance of absorbing ultraviolet and blue light, and through the photosensitization treatment of the surface modified light absorber, the mutual synergistic effect between different molecules is enhanced, the spectral absorption wavelength is red-shifted from 415 nm to 445 nm, the response range is expanded, and the amount is small, and the blue light protection effect is good. The blue light protection material with ultra-high refractive index of the present application realizes the integration of high refractivity and blue light protection, ensures the light weight of the optical device, and realizes effective blue light protection. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 is the FT-IR infrared spectrum of the hexacyclic sulfur compound monomer prepared in the specific embodiment.

[0055] Figure 2 is a transmission electron microscope (TEM) diagram of the core-shell S8 nanocomposite microsphere prepared in the specific embodiment.

[0056] Figure 3 is a high-resolution transmission electron microscope (HTEM) diagram of the core-shell S8 nanocomposite microsphere prepared in the specific embodiment.

[0057] Figure 4 is a schematic diagram of the structure of the core-shell S8 nanocomposite microsphere. DETAILED DESCRIPTION

[0058] The application will be further described in the following with specific examples, but it is not meant to limit the scope of the application.

[0059] I. The hexacyclic sulfur compound monomer and the core-shell S8 nanocomposite microspheres in the following examples are prepared by the following method.

[0060] 1. Preparation of hexacyclic sulfur compound monomer:

[0061] The reaction formula is as follows:

[0062] 3200 g of sodium pentathio-carbonate is added to 85000 g of methanol, completely dissolved and heated to 30℃, 1650 g of 1,3-dimercaptoisopropanol is added, and slowly stirred for about 2 h; 2500 g of pure water and 2400 g of chloroform are added, the water layer is separated, and the extraction liquid is combined, anhydrous sodium sulfate is added for drying, filtered, and the solvent is evaporated at 60℃; the viscous compound after distillation is dissolved in pyridine solvent, insoluble substances are removed by filtration, and the solvent is recovered under reduced pressure to obtain 1840 g of hexacyclic sulfur compound (A) with a yield of 38.7%.

[0063] The FT-IR spectrum is shown in Figure 1, and the characteristic peaks (cm -1 ) are as follows: 2565-2590 for C-H stretching vibration peak, 1035-1025 for strong absorption peak of -OH hydroxyl on the ring, and 455-460 for S-S weak vibration absorption peak. -1 -1 -1

[0064] 1 H NMR (δ): δ 2.78 (m, 1H), 2.91 (m, 2H), 3.04 (m, 2H), 3.18 (m, 1H); the hydrogen signal in the hydrogen spectrum is severely overlapped, indicating that the compound has high symmetry.

[0065] 2. Preparation of core-shell UV-S8 nanocomposite microspheres:

[0066] (1) Core-shell UV-S8 nanocomposite microspheres (PS-1)

[0067] ​​​The 66g sulfur powder and 2100g carbon disulfide are added into 22500g butyl acetate solution, the sulfur powder is dissolved by stirring at room temperature, and the insoluble substances and impurities are filtered; 54g ultraviolet absorber UV-P is added, vacuum nitrogen is passed for 3 times, each time for 20 minutes, heated to 105°C, the dissociation adsorption force of S8 molecules reaches the peak, the ultraviolet light absorber molecules are adsorbed on the surface of sulfur ions, and the donor solution containing S8 nanocrystals is formed by coordination coating; 28.5g n-butanol, 45g ethylene glycol, 93.5g toluene diisocyanate and 1.8g dibutyltin dilaurate are added by stirring, heated to 55°C after uniform stirring, and kept for 30min, and after standing for 2.5S, the core-shell type UV-S8 nanocomposite microspheres (PS-1) are collected, filtered, washed and dried to obtain 192.4g.

[0068] Fig. 3 is a high-resolution transmission electron microscope (HTEM) image of the core-shell type UV-S8 nanocomposite microspheres. It can be seen from the figure that the appearance morphology is spherical, the particle size is about 12nm, the size is uniform, the S8 core presents an electron diffraction ring, and the polyurethane outer shell is colorless and transparent material, so it is displayed as a white bright circle in the transmission electron microscope photograph. Through the Scherrer formula (D=K / Bcos0) and Zeta potential analysis calculation, it is obtained that the S8 crystal core diameter is about 6.6nm, and the average thickness of the light absorber and the polyurethane coating shell is about 2.7nm.

[0069] According to the phase angle of the structure factor measured and deduced by the X-ray diffractometer, it is obtained that the crystal S-S-S bond angle is 108°, the dihedral angle formed by the adjacent 5 atoms is 98°, the 8 sulfur atoms are not in the same plane, and the overall crown-shaped ring structure is determined to be in the form of the eight-ring sulfur crystal structure.

[0070] (2) Core-shell type UV-S8 nanocomposite microspheres (PS-2)

[0071] The 66g sulfur powder and 950g carbon disulfide are added into 19500g butyl acetate solution, the sulfur powder is dissolved by stirring at room temperature, and the insoluble substances and impurities are filtered; 56g ultraviolet absorber UV-326 is added, vacuum nitrogen is passed for 3 times, each time for 20 minutes, heated to 105°C, the dissociation adsorption force of S8 molecules reaches the peak, the ultraviolet light absorber molecules are adsorbed on the surface of sulfur ions, and the donor solution containing S8 nanocrystals is formed by coordination coating; 28g n-butanol, 45g ethylene glycol, 95g diphenyl methane diisocyanate and 1.8g dibutyltin dilaurate are added by stirring, heated to 55°C after uniform stirring, and kept for 30min, and after standing for 2.5S, the core-shell type UV-S8 nanocomposite microspheres (PS-2) are collected, filtered, washed and dried to obtain 194.1g.

[0072] (3) Core-shell type UV-S8 nanocomposite microspheres (PS-3)

[0073] Sulfur powder 66 g and carbon disulfide 1050 g were added into butyl acetate solution 25000 g, and the sulfur powder was dissolved by stirring at room temperature. The insoluble substances and impurities were filtered. Ultraviolet absorber UV-327 55 g was added, and the system was vacuumed and purged with nitrogen for 3 times, 20 min each time. The system was heated to 105℃, and the dissociation adsorption of S8 molecules reached the peak, so that the ultraviolet absorber molecules were adsorbed on the surface of sulfur ions. After stirring, n-butanol 30 g, ethylene glycol 45 g, isophorone diisocyanate 90 g and dibutyltin dilaurate 1.8 g were added. After stirring, the system was heated to 55℃ and kept for 30 min. After standing for 2.5 S, the product was collected, filtered, washed and dried to obtain 192.7 g of core-shell type UV-S8 nanocomposite microspheres (PS-3).

[0074] II. Examples and Comparative Examples

[0075] Example 1: Preparation of ultrahigh refractive index blue light protection material

[0076] Metadiisocyanate 70 g was heated to 75℃, and toluene diisocyanate 125 g was added to form a mixture. Then, hexacyclic sulfur compound A 240 g and nanocomposite microspheres PS-1 9.5 g were added to the mixture to obtain a prepolymer. Then, triethyldiamine 3.5 g, dibutyltin dilaurate 8.2 g and methanol 6 g were added to the prepolymer, and the system was heated to 60℃ and pre-polymerized for 45 min. The bubbles were removed by vacuum. The system was injected into a mold. The mold containing the prepolymer was placed in a curing oven at 50℃ for 6 h, then heated to 90℃ and continued to stand for 2.5 h, and finally cooled to room temperature and demolded to obtain the ultrahigh refractive index blue light protection material.

[0077] Example 2: Preparation of ultrahigh refractive index blue light protection material

[0078] Nanocomposite microspheres (PS-2) 9.5 g and methylcyclohexyl diisocyanate 185 g were added to hexacyclic sulfur compound A 240 g, and the system was stirred and mixed uniformly to obtain a prepolymer. Then, dibutyltin dilaurate 8.2 g was added to the prepolymer, and the system was heated to 60℃ and pre-polymerized for 45 min. The bubbles were removed by vacuum. The system was injected into a mold. The mold containing the prepolymer was placed in a curing oven at 50℃ for 6 h, then heated to 90℃ and continued to stand for 2.5 h, and finally cooled to room temperature and demolded to obtain the ultrahigh refractive index blue light protection material.

[0079] Example 3: Preparation of ultrahigh refractive index blue light protection material

[0080] Heat 125 g of meta-dicarbinyl isothiocyanate to 75 °C, add 70 g of 1,6-hexane diisocyanate, stir to form a mixture, then add 240 g of hexacyclic sulfur compound A and 12.5 g of nanocomposite microspheres (PS-3) to the mixture to obtain a prepolymer; add 4.2 g of triethyldiamine, 8.2 g of dibutyltin dilaurate and 8 g of methanol to the prepolymer while stirring, heat to 60 °C for prepolymerization for 45 min, remove the bubbles under vacuum, and inject into a mold; place the mold containing the prepolymer in a curing oven at 50 °C for 6 h, then increase the temperature to 90 °C and continue to place for 2.5 h, and finally cool to room temperature and demold to obtain the ultrahigh refractive index blue light protection material.

[0081] Example 4: Preparation of an ultrahigh refractive index blue light protection material

[0082] Heat 70 g of butyl isothiocyanate to 75 °C, add 125 g of toluene diisocyanate, stir to form a mixture, then add 210 g of hexacyclic sulfur compound A and 10 g of nanocomposite microspheres (PS-1) to the mixture to obtain a prepolymer; add 3.5 g of triethyldiamine, 8.2 g of dibutyltin dilaurate and 6 g of methanol to the prepolymer while stirring, heat to 60 °C for prepolymerization for 45 min, remove the bubbles under vacuum, and inject into a mold; place the mold containing the prepolymer in a curing oven at 50 °C for 6 h, then increase the temperature to 90 °C and continue to place for 2.5 h, and finally cool to room temperature and demold to obtain the ultrahigh refractive index blue light protection material.

[0083] Example 5: Preparation of an ultrahigh refractive index blue light protection material

[0084] Heat 70 g of butyl isothiocyanate to 75 °C, add 125 g of toluene diisocyanate, stir to form a mixture, then add 210 g of hexacyclic sulfur compound A and 10 g of nanocomposite microspheres (PS-1) to the mixture to obtain a prepolymer; add 3.5 g of triethyldiamine, 8.2 g of dibutyltin dilaurate and 6 g of methanol to the prepolymer while stirring, heat to 60 °C for prepolymerization for 45 min, remove the bubbles under vacuum, and inject into a mold; place the mold containing the prepolymer in a curing oven at 50 °C for 6 h, then increase the temperature to 90 °C and continue to place for 2.5 h, and finally cool to room temperature and demold to obtain the ultrahigh refractive index blue light protection material.

[0085] Example 6: Preparation of an ultrahigh refractive index blue light protection material

[0086] A mixture of 9.5 g of nanocomposite microspheres (PS-1) and 195 g of methylcyclohexyl diisocyanate was added to 240 g of hexacyclic sulfur compound A, stirred and mixed uniformly to obtain a prepolymer; 8.2 g of dibutyl tin dilaurate was added to the prepolymer while stirring, heated to 60°C and prepolymerized for 45 min, vacuumed to remove bubbles, and injected into a mold; the mold containing the prepolymer was placed in a curing oven at 50°C for 6 h, the temperature was raised to 90°C and the mold was kept at this temperature for another 2.5 h, and finally cooled to room temperature and demolded to obtain the ultrahigh refractive index blue light protection material.

[0087] Comparative Example 1: Preparation of a blue light protection material (without nanocomposite microspheres)

[0088] A mixture of 70 g of meta-dicarba isothiocyanate was heated to 75°C, 125 g of toluene diisocyanate was added, stirred and mixed uniformly to form a mixture, 240 g of hexacyclic sulfur compound A, 4.5 g of UV absorber UV-P and 5 g of sulfur powder were added to the mixture, stirred and mixed uniformly to obtain a prepolymer; 3.5 g of triethyldiamine, 8.2 g of dibutyl tin dilaurate and 6 g of methanol were added to the prepolymer, heated to 60°C and prepolymerized for 45 min, vacuumed to remove bubbles, and injected into a mold; the mold containing the prepolymer was placed in a curing oven at 50°C for 6 h, the temperature was raised to 90°C and the mold was kept at this temperature for another 2.5 h, and finally cooled to room temperature and demolded to obtain the ultrahigh refractive index blue light protection material.

[0089] Comparative Example 2: Preparation of a blue light protection material doped with UV-S8 (without hexacyclic sulfur compound A)

[0090] A mixture of 70 g of meta-dicarba isothiocyanate was heated to 75°C, 125 g of toluene diisocyanate was added, stirred and mixed uniformly to form a mixture, 240 g of 2,3-dimercaptoethyl thiopropyl alcohol and 9.5 g of nanocomposite microspheres (PS-1) were added to the mixture to obtain a prepolymer; 3.5 g of triethyldiamine, 8.2 g of dibutyl tin dilaurate and 6 g of methanol were added to the prepolymer while stirring, heated to 60°C and prepolymerized for 45 min, vacuumed to remove bubbles, and injected into a mold; the mold containing the prepolymer was placed in a curing oven at 50°C for 6 h, the temperature was raised to 90°C and the mold was kept at this temperature for another 2.5 h, and finally cooled to room temperature and demolded to obtain the blue light protection material.

[0091] Comparative Example 3: Preparation of a blue light protection material (without hexacyclic sulfur compound A and nanocomposite microspheres)

[0092] The mixture of 70 g of meta-dicarba isothiocyanate and 125 g of toluene diisocyanate was heated to 75°C, and 240 g of 2,3-dimercaptoethylthiopropyl alcohol, 4.5 g of UV absorber UV-P and 5 g of sulfur powder were added to the mixture to obtain a prepolymer. 3.5 g of triethyldiamine, 8.2 g of dibutyltin dilaurate and 6 g of methanol were added to the prepolymer, and the mixture was heated to 60°C for prepolymerization for 45 min. The prepolymer was degassed in vacuum and injected into a mold. The mold containing the prepolymer was placed in a curing oven at 50°C for 6 h, and then heated to 90°C for 2.5 h. Finally, the mold was cooled to room temperature and demolded to obtain the blue light protection material.

[0093] Comparative Example 4: Preparation of an optical protection material containing a UV absorber (without nano-composite microspheres and S8 sulfur powder)

[0094] The mixture of 70 g of meta-dicarba isothiocyanate and 125 g of toluene diisocyanate was heated to 75°C, and 240 g of 2,3-dimercaptoethylthiopropyl alcohol, 4.5 g of UV absorber UV-P and 5 g of sulfur powder were added to the mixture to obtain a prepolymer. 3.5 g of triethyldiamine, 8.2 g of dibutyltin dilaurate and 6 g of methanol were added to the prepolymer, and the mixture was heated to 60°C for prepolymerization for 45 min. The prepolymer was degassed in vacuum and injected into a mold. The mold containing the prepolymer was placed in a curing oven at 50°C for 6 h, and then heated to 90°C for 2.5 h. Finally, the mold was cooled to room temperature and demolded to obtain the blue light protection material.

[0095] Comparative Example 5: Preparation of a blue light protection material containing S8 (without a UV absorber)

[0096] The mixture of 70 g of meta-dicarba isothiocyanate and 125 g of toluene diisocyanate was heated to 75°C, and 240 g of 2,3-dimercaptoethylthiopropyl alcohol, 4.5 g of UV absorber UV-P and 5 g of sulfur powder were added to the mixture to obtain a prepolymer. 3.5 g of triethyldiamine, 8.2 g of dibutyltin dilaurate and 6 g of methanol were added to the prepolymer, and the mixture was heated to 60°C for prepolymerization for 45 min. The prepolymer was degassed in vacuum and injected into a mold. The mold containing the prepolymer was placed in a curing oven at 50°C for 6 h, and then heated to 90°C for 2.5 h. Finally, the mold was cooled to room temperature and demolded to obtain the blue light protection material.

[0097] III. Optical performance detection experiment of the polyurethane optical material

[0098] The polyurethane optical materials prepared in Examples 1-6 and Comparative Examples 1-5 were subjected to optical performance detection. The light transmittance is one of the most important properties of optical materials, which is expressed by transmittance ratio. The UV-8000 UV-visible light photometer from Shanghai Yuanzhi Instrument Co. Ltd. was used for the detection. The WZS1 Abbe refractometer from Shanghai Optical Instrument Equipment Co. Ltd. was used for the refractive index detection. The detection results are shown in Table 1.

[0099] Table 1 Optical performance of the detected samples

[0100] From the above detection results, it can be seen that the hexacyclic sulfur compound A of the present application has good light transmittance and a refractive index of 1.80. Meanwhile, the blue light protection material containing the core-shell S8 nanocomposite microspheres has an increased red shift amount of the absorption spectrum in the ultraviolet-visible light region under the premise of maintaining high refractive index, and the harmful spectrum absorption capacity is enhanced, wherein the transmittance ratio in the ultraviolet region of 280-380 nm is <0.1%, the blue light transmittance ratio in the range of 385-445 nm is <25%, the blue light transmittance ratio in the range of 475-500 nm is >70%, the visible light transmittance ratio in the range of 520-780 nm is >90%, and the refractive index is >1.72.

Claims

1. An ultrahigh refractive index blue light protection material, characterized by, It is polymerized by isocyanate and / or isothiocyanate, hexacyclic sulfur compound shown in formula I and core-shell type S8 nanocomposite microspheres; the weight ratio of the three is (36-50):(50-68):(1-6); wherein R1, R2, R3 are the same or different, each being OH or CH3; The core-shell type S8 nanocomposite microspheres have a S8 nanocrystal ball as the inner core, an ultraviolet light absorber as the intermediate layer, and polyurethane as the outer shell; the outer diameter of the microspheres is 10-20 nm; and the weight ratio of S8, the ultraviolet light absorber, and polyurethane is 1:(0.2-0.8):(0.2-1).

2. The ultrahigh refractive index, blue light protective material of claim 1, wherein, The isocyanate compound is a compound having two or more isocyanate groups in the molecular structure; and the isothiocyanate compound is a compound having an -N=C=S group in the molecular structure.

3. The ultrahigh refractive index, blue light protective material of claim 2, wherein, The isocyanate compound is at least one selected from toluene diisocyanate, 1,6-hexane diisocyanate, methylcyclohexyl diisocyanate, naphthalene-1,5-diisocyanate, dicyclohexylmethane diisocyanate, m-phenylene diisocyanate, diphenylmethane-4,4'-diisocyanate, tetramethylxylylene diisocyanate, and isophorone diisocyanate; The isothiocyanate compound is at least one selected from 2-bromoethyl isothiocyanate, allyl isothiocyanate, butyl isothiocyanate, sec-butyl isothiocyanate, isobutyl isothiocyanate, 3-butenyl isothiocyanate, phenethyl isothiocyanate, pentyl isothiocyanate, m-dicarba isothiocyanate, and 4-pentenyl isothiocyanate.

4. The ultrahigh refractive index, blue light protective material of any one of claims 1-3, wherein, The core-shell type S8 nanocomposite microspheres are prepared by the following method: (1) preparing a precursor solution: sulfur powder is added to a mixed solution of carbon disulfide and butyl acetate, the weight ratio of sulfur powder, carbon disulfide, and butyl acetate being (0.5-1.2):(10-50):(280-450), the sulfur powder is dissolved by stirring at room temperature, and the insoluble substances and impurities are filtered to obtain a sulfur-containing precursor solution; (2) preparing a donor solution: an ultraviolet light absorber is added to the sulfur-containing precursor solution, wherein the amount of the ultraviolet light absorber added is 0.2-0.8 times the weight of the sulfur powder in step (1); nitrogen is introduced into the solution for 2-5 times, each time for 10-20 minutes, and then the solution is heated to 85-120°C to form a donor solution containing UV-S8 nanocrystals; (3) preparing ligand-modified sulfur-containing nanomicrospheres: an alcohol compound, an isocyanate compound monomer, and dibutyltin dilaurate are sequentially added to the donor solution containing UV-S8 nanocrystals prepared in step (2), wherein the weight ratio of the donor solution containing UV-S8 nanocrystals, the alcohol compound, and the isocyanate compound monomer is (300-500):(0.5-1.2):(0.8-1.5), and the amount of dibutyltin dilaurate is 1-3 wt% of the isocyanate compound monomer; after uniform stirring, the solution is heated to 50-60°C and kept for 30-50 min, and then the precipitate is collected, filtered, washed, and dried to obtain the core-shell type S8 nanocomposite microspheres.

5. The ultrahigh refractive index, blue light protective material of any one of claims 1-3, wherein, The ultraviolet light absorber is at least one selected from UV-P, UV-326, UV-327, UV-328, UV-329, UV-360, UV-531, and UV-928.

6. The ultrahigh refractive index, blue light protective material of any one of claims 1-3, wherein, The polyurethane is made by condensation reaction of alcohol compound and isocyanate; the alcohol compound is one of isopropyl alcohol, benzyl alcohol, n-butyl alcohol, ethylene glycol or mixture of two or more; the isocyanate is at least one selected from toluene diisocyanate, 1,6-hexane diisocyanate, methylcyclohexyl diisocyanate, naphthalene-1,5-diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane-4,4'-diisocyanate, m-xylylene diisocyanate, tetramethylxylylene diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

7. A hexacyclic sulfur compound characterized in that, The structure of this compound is shown in Formula A:

8. The method of claim 7, wherein the six-membered sulfur compound is prepared by the reaction of a six-membered sulfur compound of formula (2) with a six-membered sulfur compound of formula (3) in the presence of a base. The method comprises the following steps: (1) thio: take sodium pentathio-carbonate and add to methanol, completely dissolve, heat to 25-45℃, then add 1,3-dimercaptoisopropanol, slowly stir for about 1-3h; (2) extraction: dilute the above reaction liquid with pure water, extract with chloroform, combine the extract after separating the water layer, and dry; (3) distillation: filter the dried solution, remove chloroform by distillation, and obtain viscous compound; (4) purification: dissolve the viscous compound after distillation in pyridine solvent, filter to remove insoluble matter, recover the solvent under reduced pressure, and obtain oily hexacyclic sulfur compound.

9. The production method according to claim 8, wherein The weight ratio of 1,3-dimercaptoisopropanol to sodium pentathio-carbonate in step (1) is (1-2):(1-5).

10. A method for preparing a blue light protection material having an ultrahigh refractive index, characterized in that, The method comprises the following steps: I. the following components are weighed according to the weight ratio: A component: isocyanate and / or isothiocyanate, 36-50 parts by weight; B component: hexacyclic sulfur compound shown in formula I, 50-68 parts by weight; C component: core-shell type S8 nano-composite microspheres, 1-6 parts by weight; wherein, R1, R2, R3 are the same or different, each being OH or CH3; The core-shell type S8 nanocomposite microsphere has S8 nanocrystal ball as the core, light absorber as the middle layer, and polyurethane as the shell; the outer diameter of the composite microsphere is 10-20nm; the weight ratio of S8, ultraviolet light absorber and polyurethane is 1:(0.2-0.8):(0.2-1); The above A, B and C components are mixed in proportion to obtain a prepolymer; II. under stirring, additives, catalyst and solvent are added to the prepolymer obtained in step I, pre-polymerization is carried out at 50-80℃ for 10-60min, gas bubbles are removed under vacuum, and then the prepolymer is injected into a mold; III. the mold containing the prepolymer is placed in a curing oven at 35-55℃ for heating for 2-10h, then gradually increased to 80-100℃, and continued to be placed for 2-3h, and finally cooled to room temperature to demold, thereby obtaining the super-high refractive index blue light protection material.

11. The production method according to claim 10, wherein When the isothiocyanate compound is mixed with the isocyanate compound, the isothiocyanate compound is first heated to 55-135℃ for melting, and then the isocyanate compound is added to obtain a mixture.

12. The production method according to claim 10, wherein The additive is triethyldiamine, and the weight percentage of triethyldiamine to isothiocyanate is (0.1-0.3):(1-7).

13. The production method according to claim 10, wherein The catalyst is dibutyltin dilaurate or stannous isooctoate, and the catalyst is 1-3wt% of the prepolymer.

14. The production method according to claim 10, wherein The solvent is one of methanol, ethanol, propanol, diethyl ether, dioxane and tetrahydrofuran, and the amount of the solvent is 0-5wt% of the prepolymer.

15. The production method according to any one of claims 10 to 14, wherein The core-shell S8 nanocomposite microspheres are prepared by the following method: (1) preparing a precursor solution: sulfur powder is added to a mixed solution of carbon disulfide and butyl acetate, the weight ratio of sulfur powder, carbon disulfide and butyl acetate is (0.5-1.2):(10-50):(280-450), the sulfur powder is dissolved at room temperature, and the insoluble substances and impurities are filtered to obtain a sulfur-containing precursor solution; (2) preparing a donor solution: an ultraviolet light absorber is added to the sulfur-containing precursor solution, wherein the amount of the ultraviolet light absorber is 0.2-0.8 times the weight of the sulfur powder in step (1); nitrogen is passed through the solution for 2-5 times, each time for 10-20 minutes, and then heated to 85-120℃, so that the dissociation adsorption force of S8 molecules reaches a peak value, the ultraviolet light absorber molecules are adsorbed on the surface of sulfur ions, and the UV-S8 nanocrystal-containing donor solution is formed by coordination coating; (3) preparing ligand-modified sulfur-containing nanomicrospheres: alcohol compounds, isocyanate compounds and dibutyltin dilaurate are sequentially added to the UV-S8 nanocrystal-containing donor solution prepared in step (2), wherein the weight ratio of the UV-S8 nanocrystal-containing donor solution, the alcohol compounds, the isocyanate compounds and the dibutyltin dilaurate is (300-500):(0.5-1.2):(0.8-1.5), and the amount of the dibutyltin dilaurate is 1-3wt% of the isocyanate compounds; after stirring uniformly, heating to 50-60℃ for 30-50min, and standing for 2-5 hours, the precipitate is collected, filtered, washed and dried to obtain the core-shell S8 nanocomposite microspheres.

16. The production method according to claim 15, wherein The alcohol compounds in step (3) are preferably a mixture of n-butanol and ethylene glycol, and the mass ratio of n-butanol to ethylene glycol is (1-3):(1-5).

17. The production method according to claim 15, wherein The isocyanate compounds in step (3) are selected from at least one of toluene diisocyanate, 1,6-hexane diisocyanate, methylcyclohexyl diisocyanate, naphthalene-1,5-diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane-4,4'-diisocyanate, m-xylylene diisocyanate, tetramethylxylylene diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

18. The production method according to claim 15, wherein The ultraviolet light absorber is selected from at least one of UV-P, UV-326, UV-327, UV-328, UV-329, UV-360, UV-531 and UV-928.

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