An environmentally friendly thiol optical resin material and its preparation method

Abstract

The application belongs to the technical field of optical materials, and particularly relates to an environment-friendly mercaptan optical resin material and a preparation method thereof. The preparation method comprises the following steps: (1) uniformly mixing a catalyst, a release agent and a polyisocyanate compound to prepare a mixture; (2) adding a polybasic mercaptan compound and different-particle-size titanium dioxide nanoparticles modified by a mercapto silane coupling agent into the mixture; and (3) heating and curing to obtain the environment-friendly mercaptan optical resin material. On the basis of small-particle-size titanium dioxide, a small amount of large-particle-size titanium dioxide is added. The large-particle-size titanium dioxide is not prone to agglomeration and has good dispersibility. In the blending process, the particulate large-particle-size titanium dioxide is easier to disperse, thereby preventing the agglomeration of the small-particle-size titanium dioxide. The addition of the small-particle-size titanium dioxide and the large-particle-size titanium dioxide further improves the mechanical strength of the mercaptan optical resin on the basis of maintaining the high refractive index of the mercaptan optical resin.

Description

Technical Field

[0001] This invention belongs to the field of optical materials technology, specifically relating to an environmentally friendly thiol optical resin material and its preparation method. Background Technology

[0002] Micro-nano manufacturing technology is a core foundation and support for the development of next-generation information technology, high-end equipment manufacturing, and new materials industries. Micro-nano structure manufacturing technology enables large-area, micrometer-level patterned manufacturing, and is one of the key processes for achieving high-density, low-cost mass production of micro-nano devices and products. In recent years, with the development of micro-nano structure processing technology, many novel micro-nano structures have emerged in the field of functional integrated devices. These micro-nano structures possess characteristics such as single-atom-layer thickness and multi-dimensional dimensions, playing important roles in various fields. With the development of nano-manufacturing technology, the requirements for processing precision, efficiency, and quality are becoming increasingly stringent. Currently, some novel micro-nano structures can be applied to sensors, optical communication devices, and other fields. Large-area nanoimprinting has very well-established facilities and technologies for wafer-level micro-nano optical device production, such as optical diffraction elements and optical diffusers in mobile phone lenses, which have complete production processes. Due to the performance requirements of optical devices, the preparation of high-performance optical materials has become an important link in the production chain. Currently, there are two main types of optical materials on the market: inorganic and organic materials. Inorganic optical materials possess excellent mechanical properties, high Abbe numbers, high refractive indices, and low dispersion, making them suitable for fabricating optical devices with low coefficients of thermal expansion, good heat resistance, and stable optical performance. However, inorganic materials still face some challenges in development and application, such as high cost, difficulty in processing and molding, and difficulty in mass production. Therefore, many material development companies are turning to lighter and easier-to-manufacture organic optical materials, hoping that organic optical materials will offer superior performance in terms of weather resistance, heat resistance, and high refractive index.

[0003] Currently, polyurethane is the most widely used plastic in the world. Due to its advantages such as high refractive index, good adhesive strength, excellent biocompatibility, and high hardness, polysulfurethane (thiol optical resin) has great potential for application in many fields, such as lenses, optical fibers, advanced coatings, and medical technology. Furthermore, due to the presence of hydrogen bonds in its structure, polyurethane materials possess excellent mechanical properties. Currently, one of the most widely used methods for synthesizing polysulfurethane is the base-catalyzed nucleophilic addition of thiols to isocyanates. In addition, the interfacial condensation reaction between diamines and dichlorothiocarbamate derivatives, as well as the reaction with cyclic thiocarbamates, can also be used to synthesize polysulfurethane.

[0004] However, the wide range of applications in the field of optics makes it impossible for some intrinsic materials to meet the requirements. As a result, high-performance organic-inorganic nanocomposites have been extensively studied. However, the incompatibility between inorganic particles and polymer matrix has resulted in poor material processability, mechanical properties, or optical transmittance, which has not yet been effectively resolved. Summary of the Invention

[0005] Currently, the preparation process of polyurethane resin is complex and costly. Although adding nano-titanium dioxide can improve the refractive index of the resin, nano-titanium dioxide is prone to agglomeration and has poor compatibility with the thiol optical resin matrix, resulting in poor mechanical strength and reduced refractive index of the final product.

[0006] To solve the above problems, the technical solution of the present invention is as follows:

[0007] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0008] (1) Prepare a mixture by mixing the catalyst, release agent, and polyisocyanate compound evenly in advance;

[0009] (2) Add polythiol compounds and mercaptosilane coupling agents modified titanium dioxide nanoparticles to the mixture, mix evenly, and degas to obtain a monomer mixture; the titanium dioxide nanoparticles are composed of small-particle titanium dioxide with an average particle size of less than or equal to 50 nm and large-particle titanium dioxide with an average particle size of less than or equal to 150 nm; wherein, the average particle size of the large-particle titanium dioxide is at least 50 nm larger than the average particle size of the small-particle titanium dioxide, and the mass ratio of the large-particle titanium dioxide to the small-particle titanium dioxide is 0.4%-4%;

[0010] (3) The monomer mixture is injected into the mold and heated to cure, thus obtaining the environmentally friendly thiol optical resin material.

[0011] Thiol optical resins, also known as polythiourethane resins, are widely used in various resin lenses, building material coatings, precision lenses, optical fibers, and functional coatings due to their impact resistance, dyeability, ease of processing, light weight, and excellent optical properties. However, thiol optical resins have low refractive index and mechanical properties. Therefore, introducing high-refractive-index and high-strength inorganic nanoparticles into thiol optical resins is a common method to improve their optical and mechanical properties. Titanium dioxide has a high refractive index and certain antibacterial properties, making it one of the most commonly used nanoparticles in optical resins. Generally, the higher the content of uniformly dispersed nano-titanium dioxide particles, the higher the refractive index and mechanical strength of the composite material. However, inorganic nano-titanium dioxide particles, due to their small particle size and high surface free energy, are prone to aggregation. The dispersion of nanoparticles in the resin matrix and the interfacial interaction between the nanoparticles and the resin affect the improvement of their optical and mechanical properties. Moreover, overloaded nano-titanium dioxide particles reduce the transparency of the material and the processability of the organic matrix. Therefore, a technical solution that balances the relationship between mechanical strength and optical properties is urgently needed.

[0012] This invention employs a blending method to improve the optical properties and mechanical strength of thiol resins. Compared to in-situ polymerization and sol-gel methods, the blending method is simpler, less costly, and eliminates the need for adding various toxic or harmful substances, thus meeting the requirements of environmentally friendly development.

[0013] To ensure uniform dispersion of nano-titanium dioxide particles within the matrix and prevent agglomeration that would negatively impact optical performance and mechanical strength, this invention employs a composite of titanium dioxide particles with different particle sizes (volume average particle size D50): the titanium dioxide nanoparticles consist of small-particle titanium dioxide with an average particle size of ≤50 nm and large-particle titanium dioxide with an average particle size of ≤150 nm; wherein the average particle size of the large-particle titanium dioxide is at least 50 nm larger than that of the small-particle titanium dioxide, and the mass ratio of large-particle titanium dioxide to small-particle titanium dioxide is 0.4%-4%, specifically 0.6%-2%. Furthermore, the average particle size of the large-particle titanium dioxide is 100-150 nm. Specifically, for a single particle, the small-particle titanium dioxide can have a particle size of 1-100 nm, while the large-particle titanium dioxide has a particle size of less than 200 nm. Furthermore, both small-particle-size titanium dioxide and large-particle-size titanium dioxide are monodisperse, with a distribution index (PDI) of less than 0.3, further less than 0.1, and even further less than 0.05.

[0014] Generally, the smaller the titanium dioxide particle size, the less impact it has on the transparency of optical resins; however, smaller particle sizes also result in higher surface energy, making them more prone to aggregation. Aggregated nano-titanium dioxide is detrimental to the improvement of the mechanical and optical properties of optical resins. Therefore, this invention adds a small amount of large-particle titanium dioxide to the base of small-particle titanium dioxide. Large-particle titanium dioxide is less prone to aggregation, has better dispersibility, and is easier to disperse during blending. It can act as a "barrier" for small-particle titanium dioxide, preventing its aggregation. As a solid dispersing agent, the amount of large-particle titanium dioxide should not be too high, otherwise it will be detrimental to the improvement of resin performance.

[0015] Meanwhile, to improve interfacial performance, this invention also employs a small amount of mercaptosilane coupling agent with reactive functional groups to modify the surface of titanium dioxide nanoparticles, thereby enhancing the bonding performance between the inorganic titanium dioxide nanoparticles and the matrix to prepare organic-inorganic nanocomposites with superior performance. Generally, surface modification of nanoparticles is essential for preparing high-refractive-index organic-inorganic nanocomposites; poor bonding between nanoparticles and polymers can easily lead to a loss of mechanical and optical properties. Furthermore, the residual active hydroxyl groups on the surface of nano-titanium dioxide can chemically react with isocyanate groups, promoting the connection between nano-titanium dioxide particles and the organic polymer matrix, thus enhancing the stability of the material's framework. Moreover, the strong covalent bonds formed between nano-titanium dioxide and the thiol optical resin restrict the internal rotation of surrounding polymer chain segments, making chain movement more difficult and thus enhancing the mechanical properties of the polymer material. Meanwhile, the presence of nano-titanium dioxide provides stress concentration areas for the material. The strong interfacial bonding between the nano-titanium dioxide and the thiol optical matrix facilitates stress transfer, preventing structural fracture due to excessive local stress, thus enhancing the material's toughness and improving the mechanical properties of the composite material. The optical and mechanical properties of the thiol resin are not only affected by the particle size and amount of nano-titanium dioxide, but also significantly influenced by the coupling agent modification and the bonding method with the matrix resin. The optical resin prepared using the process of this invention can better improve the performance of the composite material.

[0016] Furthermore, in step (1), the catalyst includes one or more of amine compounds or organotin compounds; the release agent is a phosphate ester compound.

[0017] Furthermore, the amine compound includes one or more of triethylamine, tributylamine, methylpyridine, and dimethylcyclohexylamine.

[0018] Furthermore, the organotin compounds include one or more of dibutyltin dichloride, dimethyltin dichloride, di-n-octyltin dilaurate, or dibutyltin dilaurate.

[0019] Furthermore, the phosphate ester compound includes one or more of dibutyl phosphate, xylene phosphate, triethyl phosphate, tributyl phosphate, or triphenyl phosphate.

[0020] Furthermore, the polyisocyanate compound in step (1) is one or more of the following: phenyl dimethyl diisocyanate, toluene diisocyanate, dicyclohexylmethane diisocyanate, cyclohexane dimethyl diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dimethylpentane diisocyanate, trimethylhexane diisocyanate, butene diisocyanate, and hexamethylene triisocyanate.

[0021] Furthermore, in step (1), the mass ratio of catalyst, release agent, and polyisocyanate compound is 0.05-1:0.1-10:1000.

[0022] Furthermore, the polythiol compound in step (2) is one or more of the following: methanedithiol, ethylenedithiol, propylenedithiol, hexanedithiol, cyclohexanedithiol, propylenetrithiol, pentaerythritol tetra(3-mercaptopropionate), trimethylolpropane tri(3-mercaptopropionate), pentaerythritol tetra(3-mercaptobutyric acid) ester, and 2,3-dithio(2-mercapto)-1-propanethiol.

[0023] Furthermore, in step (2), the mercaptosilane coupling agent is one or more of mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, mercaptopropylmethyldimethoxysilane, mercaptopropylmethyldiethoxysilane, and mercaptomethylmethyldiethoxysilane.

[0024] Furthermore, in step (2), the molar ratio of -SH in the polythiol compound and -NCO in the polyisocyanate compound is 1:1.1-1.15.

[0025] Furthermore, in step (2), the average particle size of the small-diameter titanium dioxide is 25-50 nm; the mass ratio of the sum of the masses of the small-diameter titanium dioxide and the large-diameter titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.001%-5%. The average particle size of the small-diameter nano-titanium dioxide is not particularly limited; common sizes such as 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, and 50 nm are all acceptable. If the particle size is too small, preparation is difficult, and agglomeration is likely to occur; if the particle size is too large, the quantum size effect of inorganic nanoparticles cannot be utilized, and the mechanical properties of the thiol optical resin cannot be effectively improved. Specifically, large-diameter titanium dioxide can be added first and mixed evenly before adding small-diameter titanium dioxide to better utilize the isolating effect of the large-diameter titanium dioxide. Furthermore, the mass ratio of the sum of the small-diameter and large-diameter titanium dioxide particles to the sum of the mass of the polyisocyanate compound and the polythiol compound can be 0.001%, 0.01%, 0.1%, 1%, 2%, 3%, 4%, or 5%. Specifically, the mass ratio of the sum of the small-diameter and large-diameter titanium dioxide particles to the sum of the mass of the polyisocyanate compound and the polythiol compound is 0.25%-1%. An appropriate amount of nano-titanium dioxide can enhance the mechanical properties of the resin and prevent excessive agglomeration of inorganic fillers, which would reduce toughness. Specifically, the mixing process in step (2) can employ ultrasonic technology to promote the dispersion of titanium dioxide.

[0026] Furthermore, in step (2), the average particle size of the large-diameter titanium dioxide is 100-150 nm. If the particle size is too small, it will not be able to play a role in isolation. However, an appropriate particle size can not only play the role of isolation of large-diameter titanium dioxide and prevent the problem of agglomeration caused by excessively small particle size, but also avoid the problem of easy sedimentation caused by excessively large particle size, which results in a small specific surface area and reduced interfacial interaction. Thus, it can give full play to its role in isolation and dispersion.

[0027] Furthermore, the polythiol compound in step (2) is 2,3-dithio(2-mercapto)-1-propanethiol, and its preparation process is as follows: add mercaptoethanol to the reactor, then add sodium hydroxide solution dropwise, and stir thoroughly; then add epichlorohydrin dropwise, and react for 0.5-1 h; add concentrated hydrochloric acid and thiourea to prepare a salt solution; then, after ammonia alkaline hydrolysis, water washing, and dehydration and separation, 2,3-dithio(2-mercapto)-1-propanethiol is obtained. For the specific process, please refer to the master's thesis: "Synthesis and Application Research of 2,3-dithio(2-mercaptoethyl)-1-propanethiol", Zhang Jie, Beijing University of Chemical Technology, 2021.

[0028] Further, the preparation process of the mercaptosilane coupling agent-modified titanium dioxide nanoparticles in step (2) is as follows: small-diameter or large-diameter titanium dioxide nanoparticles are uniformly dispersed in a mixed solvent of ethanol and deionized water, and mercaptosilane coupling agent is added while stirring. The mixture is then stirred for 1-3 hours, filtered, washed, and dried to obtain small-diameter or large-diameter titanium dioxide nanoparticles modified with mercaptosilane coupling agent. Further, the mass ratio of small-diameter or large-diameter titanium dioxide nanoparticles to mercaptosilane coupling agent in step (2) is 1:(0.1-0.3). Specifically, the mass ratio of small-diameter or large-diameter titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.1, or 1:0.15, 1:0.2, 1:0.25, 1:0.3, and particularly 1:(0.15-0.25). An appropriate amount of mercaptosilane coupling agent can both promote the dispersion of inorganic nanoparticles and reduce the impact of the coupling agent on the optical properties of the resin.

[0029] Furthermore, the heating process in step (3) is to heat from 30°C to 120°C over 18-22 hours.

[0030] Beneficial Effects: This invention adds a small amount of large-particle titanium dioxide to the base of small-particle titanium dioxide. Large-particle titanium dioxide is less prone to agglomeration and has better dispersibility. Furthermore, during blending, the granular large-particle titanium dioxide is easier to disperse and can act as a "barrier" for small-particle titanium dioxide, preventing its agglomeration. Simultaneously, to improve interfacial properties, this invention also uses a small amount of mercaptosilane coupling agent to modify the surface of titanium dioxide nanoparticles, thereby improving the bonding performance between the inorganic titanium dioxide nanoparticles and the matrix, resulting in a higher-performance organic-inorganic nanocomposite material. The presence of nano-titanium dioxide provides stress concentration areas for the material. The strong interfacial bonding with the thiol optical matrix facilitates stress transfer, preventing structural fracture due to excessive local stress. This strengthens the material's strength and toughness, thus enhancing the mechanical properties of the composite material. The addition of both small-particle and large-particle titanium dioxide further improves the mechanical strength while maintaining the high refractive index of the thiol optical resin. Detailed Implementation

[0031] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention are described in detail below with reference to examples. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. Unless otherwise specified, the types of raw materials and processes used in the following embodiments are the same.

[0032] The preparation process of the large-particle-size titanium dioxide nanoparticles modified with mercaptosilane coupling agent and the small-particle-size titanium dioxide nanoparticles modified with mercaptosilane coupling agent is as follows: the large-particle-size titanium dioxide nanoparticles (or small-particle-size titanium dioxide nanoparticles) are uniformly dispersed in a mixed solvent of ethanol and deionized water, and the mercaptosilane coupling agent is added while stirring. The mixture is then stirred and reacted for 2 hours. After filtration, washing, and drying, the large-particle-size titanium dioxide nanoparticles (or small-particle-size titanium dioxide nanoparticles modified with mercaptosilane coupling agent) are obtained.

[0033] Example 1

[0034] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0035] (1) The catalyst dibutyltin dichloride, the release agent dibutyl phosphate, and the polyisocyanate compound are mixed evenly in advance to prepare a mixture; the polyisocyanate compound is a mixture of isophorone diisocyanate and cyclohexanedimethyl diisocyanate in a molar ratio of 1:1.5; the mass ratio of the catalyst, the release agent, the polyisocyanate compound, and the polythiol compound is 0.1:0.8:1000;

[0036] (2) Add large-particle-size titanium dioxide nanoparticles modified with a polythiol compound and a mercaptosilane coupling agent to the mixture, mix evenly, then add small-particle-size titanium dioxide nanoparticles modified with a mercaptosilane coupling agent, mix evenly again, degas, and obtain a monomer mixture; the average particle size D50 of the large-particle-size titanium dioxide is 105 nm, and the average particle size D50 of the small-particle-size titanium dioxide is 25 nm; the mass ratio of large-particle-size titanium dioxide to small-particle-size titanium dioxide is 4%; the mercaptosilane coupling agent is mercaptopropyltrimethoxysilane; the large-particle-size titanium dioxide... The mass ratio of titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.24; the mass ratio of small-diameter titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.24; the polythiol compound is 2,3-dithio(2-mercapto)-1-propanethiol; the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.15; the mass ratio of the sum of the masses of small-diameter titanium dioxide and large-diameter titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.35%.

[0037] (3) The monomer mixture was injected into a mold and cured by heating from 30°C to 120°C for 18 hours to obtain an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.651 and the impact strength was 26.08 kJ / m. 2 .

[0038] Example 2

[0039] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0040] (1) The catalyst dibutyltin dichloride, the mold release agent dibutyl phosphate, and the polyisocyanate compound are mixed evenly in advance to prepare a mixture; the polyisocyanate compound is a mixture of isophorone diisocyanate and cyclohexanedimethyl diisocyanate in a molar ratio of 1.7:1; the mass ratio of the catalyst, the mold release agent, the polyisocyanate compound, and the polythiol compound is 0.2:1.5:1000;

[0041] (2) Add large-particle-size titanium dioxide nanoparticles modified with a polythiol compound and a mercaptosilane coupling agent to the mixture, mix evenly, then add small-particle-size titanium dioxide nanoparticles modified with a mercaptosilane coupling agent, mix evenly again, degas, and obtain a monomer mixture; the average particle size D50 of the large-particle-size titanium dioxide is 100 nm, and the average particle size D50 of the small-particle-size titanium dioxide is 50 nm; the mass ratio of large-particle-size titanium dioxide to small-particle-size titanium dioxide is 0.4%; the mercaptosilane coupling agent is mercaptopropyltriethoxysilane; the large-particle-size... The mass ratio of small-diameter titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.1; the mass ratio of small-diameter titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.1; the polythiol compound is 2,3-dithio(2-mercapto)-1-propanethiol; the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.1; the mass ratio of the sum of the masses of small-diameter and large-diameter titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.85%.

[0042] (3) The monomer mixture was injected into a mold and cured by heating from 30°C to 120°C for 22 hours to obtain an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.681 and the impact strength was 28.11 kJ / m. 2 .

[0043] Example 3

[0044] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0045] (1) The catalyst dibutyltin dichloride, the release agent dibutyl phosphate, and the polyisocyanate compound are mixed evenly in advance to prepare a mixture; the polyisocyanate compound is a mixture of isophorone diisocyanate and hexamethylene diisocyanate in a molar ratio of 1:3; the mass ratio of the catalyst, the release agent, the polyisocyanate compound, and the polythiol compound is 0.15:1.2:1000;

[0046] (2) Add small-particle-size titanium dioxide nanoparticles modified with a polythiol compound and a mercaptosilane coupling agent to the mixture, mix evenly, then add large-particle-size titanium dioxide nanoparticles modified with a mercaptosilane coupling agent, mix evenly again, degas, and obtain a monomer mixture; the average particle size D50 of the large-particle-size titanium dioxide is 110 nm, and the average particle size D50 of the small-particle-size titanium dioxide is 40 nm; the mass ratio of large-particle-size titanium dioxide to small-particle-size titanium dioxide is 1.7%; the mercaptosilane coupling agent is mercaptopropyltrimethoxysilane; the large-particle-size titanium dioxide nanoparticles are modified with a mercaptosilane coupling agent. The mass ratio of titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.18; the mass ratio of the small-diameter titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.18; the polythiol compound is 2,3-dithio(2-mercapto)-1-propanethiol; the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.13; the mass ratio of the sum of the masses of the small-diameter titanium dioxide and the large-diameter titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.74%;

[0047] (3) The monomer mixture was injected into a mold and cured by heating from 30°C to 120°C for 20 hours to obtain an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.664 and the impact strength was 27.37 kJ / m. 2 .

[0048] Example 4

[0049] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0050] (1) Prepare a mixture by mixing the catalyst dibutyltin dichloride, the release agent dibutyl phosphate, and the polyisocyanate compound in advance; the polyisocyanate compound is a mixture of phenylene diisocyanate and hexamethylene diisocyanate in a molar ratio of 1:1; the mass ratio of the catalyst, the release agent, the polyisocyanate compound, and the polythiol compound is 0.12:1.3:1000;

[0051] (2) Add large-particle-size titanium dioxide nanoparticles modified with a polythiol compound and a mercaptosilane coupling agent to the mixture, mix evenly, then add small-particle-size titanium dioxide nanoparticles modified with a mercaptosilane coupling agent, mix evenly again, degas, and obtain a monomer mixture; the average particle size D50 of the large-particle-size titanium dioxide is 110 nm, and the average particle size D50 of the small-particle-size titanium dioxide is 50 nm; the mass ratio of large-particle-size titanium dioxide to small-particle-size titanium dioxide is 0.8%; the mercaptosilane coupling agent is mercaptopropyltriethoxysilane; the large-particle-size... The mass ratio of titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.1; the mass ratio of small-diameter titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.24; the polythiol compound is 2,3-dithio(2-mercapto)-1-propanethiol; the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.1; the mass ratio of the sum of the masses of small-diameter titanium dioxide and large-diameter titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.40%.

[0052] (3) The monomer mixture was injected into a mold and cured by heating from 30°C to 120°C for 19 hours to obtain an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.657 and the impact strength was 26.43 kJ / m. 2 .

[0053] Example 5

[0054] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0055] (1) The catalyst dibutyltin dichloride, the release agent dibutyl phosphate, and the polyisocyanate compound are mixed evenly in advance to prepare a mixture; the polyisocyanate compound is a mixture of isophorone diisocyanate and hexamethylene diisocyanate in a molar ratio of 1:3; the mass ratio of the catalyst, the release agent, the polyisocyanate compound, and the polythiol compound is 0.15:1.2:1000;

[0056] (2) Add large-particle-size titanium dioxide nanoparticles modified with a polythiol compound and a mercaptosilane coupling agent to the mixture, mix evenly, then add small-particle-size titanium dioxide nanoparticles modified with a mercaptosilane coupling agent, mix evenly again, degas, and obtain a monomer mixture; the average particle size D50 of the large-particle-size titanium dioxide is 110 nm, and the average particle size D50 of the small-particle-size titanium dioxide is 40 nm; the mass ratio of large-particle-size titanium dioxide to small-particle-size titanium dioxide is 1.7%; the mercaptosilane coupling agent is mercaptopropyltrimethoxysilane; the large-particle-size titanium dioxide nanoparticles are modified with a mercaptosilane coupling agent. The mass ratio of titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.18; the mass ratio of the small-diameter titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.18; the polythiol compound is 2,3-dithio(2-mercapto)-1-propanethiol; the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.13; the mass ratio of the sum of the masses of the small-diameter titanium dioxide and the large-diameter titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 1.01%.

[0057] (3) The monomer mixture was injected into a mold and cured by heating from 30°C to 120°C for 20 hours to obtain an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.675 and the impact strength was 26.31 kJ / m. 2 .

[0058] Example 6

[0059] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0060] (1) The catalyst dibutyltin dichloride, the mold release agent dibutyl phosphate, and the polyisocyanate compound are mixed evenly in advance to prepare a mixture; the polyisocyanate compound is a mixture of toluene diisocyanate and hexamethylene diisocyanate in a molar ratio of 1:1; the mass ratio of the catalyst, the mold release agent, the polyisocyanate compound, and the polythiol compound is 0.14:1.0:1000;

[0061] (2) Add large-particle-size titanium dioxide nanoparticles modified with a polythiol compound and a mercaptosilane coupling agent to the mixture, mix evenly, then add small-particle-size titanium dioxide nanoparticles modified with a mercaptosilane coupling agent, mix evenly again, degas, and obtain a monomer mixture; the average particle size D50 of the large-particle-size titanium dioxide is 110 nm, and the average particle size D50 of the small-particle-size titanium dioxide is 45 nm; the mass ratio of large-particle-size titanium dioxide to small-particle-size titanium dioxide is 1.3%; the mercaptosilane coupling agent is mercaptopropyltriethoxysilane; the large-particle-size titanium dioxide nanoparticles and mercaptosilane coupling agent are... The mass ratio of the coupling agent is 1:0.15; the mass ratio of the small-diameter titanium dioxide nanoparticles to the mercaptosilane coupling agent is 1:0.18; the polythiol compound is a mixture of trimethylolpropane tris(3-mercaptopropionate) and 2,3-dithio(2-mercapto)-1-propanethiol in a molar ratio of 1:2; the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.12; the mass ratio of the sum of the masses of the small-diameter titanium dioxide and the large-diameter titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.46%.

[0062] (3) The monomer mixture was injected into a mold and cured by heating from 30°C to 120°C for 19 hours to obtain an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.659 and the impact strength was 26.57 kJ / m. 2 .

[0063] Example 7

[0064] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0065] (1) The catalyst dibutyltin dichloride, the release agent dibutyl phosphate, and the polyisocyanate compound are mixed evenly in advance to prepare a mixture; the polyisocyanate compound is a mixture of isophorone diisocyanate and hexamethylene diisocyanate in a molar ratio of 1:3; the mass ratio of the catalyst, the release agent, the polyisocyanate compound, and the polythiol compound is 0.15:1.2:1000;

[0066] (2) Add large-particle-size titanium dioxide nanoparticles modified with a polythiol compound and a mercaptosilane coupling agent to the mixture, mix evenly, then add small-particle-size titanium dioxide nanoparticles modified with a mercaptosilane coupling agent, mix evenly again, degas, and obtain a monomer mixture; the average particle size D50 of the large-particle-size titanium dioxide is 110 nm, and the average particle size D50 of the small-particle-size titanium dioxide is 40 nm; the mass ratio of large-particle-size titanium dioxide to small-particle-size titanium dioxide is 1.7%; the mercaptosilane coupling agent is mercaptopropyltrimethoxysilane; the large-particle-size... The mass ratio of titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.3; the mass ratio of small-diameter titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.3; the polythiol compound is 2,3-dithio(2-mercapto)-1-propanethiol; the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.13; the mass ratio of the sum of the masses of small-diameter and large-diameter titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.74%;

[0067] (3) The monomer mixture was injected into a mold and heated from 30°C to 120°C for 20 hours to cure, thus obtaining an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.658 and the impact strength was 28.71 kJ / m. 2 .

[0068] Example 8

[0069] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0070] (1) The catalyst dibutyltin dichloride, the release agent dibutyl phosphate, and the polyisocyanate compound are mixed evenly in advance to prepare a mixture; the polyisocyanate compound is a mixture of isophorone diisocyanate and cyclohexanedimethyl diisocyanate in a molar ratio of 2:1; the mass ratio of the catalyst, the release agent, the polyisocyanate compound, and the polythiol compound is 0.18:1.3:1000;

[0071] (2) Add large-particle-size titanium dioxide nanoparticles modified with a polythiol compound and a mercaptosilane coupling agent to the mixture, mix evenly, then add small-particle-size titanium dioxide nanoparticles modified with a mercaptosilane coupling agent, mix evenly again, degas, and obtain a monomer mixture; the average particle size D50 of the large-particle-size titanium dioxide is 150 nm, and the average particle size D50 of the small-particle-size titanium dioxide is 35 nm; the mass ratio of large-particle-size titanium dioxide to small-particle-size titanium dioxide is 2.0%; the mercaptosilane coupling agent is mercaptopropyltriethoxysilane; the large-particle-size titanium dioxide nanoparticles are modified with a mercaptosilane coupling agent. The mass ratio of titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.21; the mass ratio of the small-diameter titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.21; the polythiol compound is 2,3-dithio(2-mercapto)-1-propanethiol; the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.14; the mass ratio of the sum of the masses of the small-diameter titanium dioxide and the large-diameter titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.67%;

[0072] (3) The monomer mixture was injected into a mold and cured by heating from 30°C to 120°C for 21 hours to obtain an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.667 and the impact strength was 27.68 kJ / m. 2 .

[0073] Example 9

[0074] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0075] (1) The catalyst dibutyltin dichloride, the release agent dibutyl phosphate, and the polyisocyanate compound are mixed evenly in advance to prepare a mixture; the polyisocyanate compound is a mixture of cyclohexanedimethyl diisocyanate and isophorone diisocyanate in a molar ratio of 1:1; the mass ratio of the catalyst, the release agent, the polyisocyanate compound, and the polythiol compound is 0.2:1.2:1000;

[0076] (2) Add large-particle-size titanium dioxide nanoparticles modified with a polythiol compound and a mercaptosilane coupling agent to the mixture, mix evenly, then add small-particle-size titanium dioxide nanoparticles modified with a mercaptosilane coupling agent, mix evenly again, degas, and obtain a monomer mixture; the average particle size D50 of the large-particle-size titanium dioxide is 130 nm, and the average particle size D50 of the small-particle-size titanium dioxide is 40 nm; the mass ratio of large-particle-size titanium dioxide to small-particle-size titanium dioxide is 3.2%; the mercaptosilane coupling agent is mercaptopropyltriethoxysilane; the The mass ratio of large-particle-size titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.18; the mass ratio of small-particle-size titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.2; the polythiol compound is pentaerythritol tetra(3-mercaptopropionate); the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.13; the mass ratio of the sum of the masses of small-particle-size titanium dioxide and large-particle-size titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.52%.

[0077] (3) The monomer mixture was injected into a mold and cured by heating from 30°C to 120°C for 20 hours to obtain an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.661 and the impact strength was 26.91 kJ / m. 2 .

[0078] Example 10

[0079] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0080] (1) The catalyst dibutyltin dichloride, the mold release agent dibutyl phosphate, and the polyisocyanate compound are mixed evenly in advance to prepare a mixture; the polyisocyanate compound is a mixture of toluene diisocyanate and hexamethylene diisocyanate in a molar ratio of 1:3; the mass ratio of the catalyst, the mold release agent, the polyisocyanate compound, and the polythiol compound is 0.15:1.2:1000;

[0081] (2) Add large-particle-size titanium dioxide nanoparticles modified with polythiol compounds and mercaptosilane coupling agents to the mixture, mix evenly, then add small-particle-size titanium dioxide nanoparticles modified with mercaptosilane coupling agents, mix evenly again, degas, and obtain a monomer mixture; the average particle size D50 of the large-particle-size titanium dioxide is 140 nm, and the average particle size D50 of the small-particle-size titanium dioxide is 30 nm; the mass ratio of large-particle-size titanium dioxide to small-particle-size titanium dioxide is 1.7%; the mercaptosilane coupling agent is mercaptopropyltriethoxysilane; the large-particle-size titanium dioxide nanoparticles and mercaptosilane coupling agents are... The mass ratio of the silane coupling agent is 1:0.21; the mass ratio of the small-diameter titanium dioxide nanoparticles to the mercaptosilane coupling agent is 1:0.18; the polythiol compound is a mixture of trimethylolpropane tris(3-mercaptopropionate) and pentaerythritol tetrakis(3-mercaptobutyrate) esters in a molar ratio of 1:1; the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.13; the mass ratio of the sum of the masses of the small-diameter titanium dioxide and the large-diameter titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.7%;

[0082] (3) The monomer mixture was injected into a mold and cured by heating from 30°C to 120°C for 22 hours to obtain an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.671 and the impact strength was 28.24 kJ / m. 2 .

[0083] Example 11

[0084] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0085] (1) The catalyst dibutyltin dichloride, the release agent dibutyl phosphate, and the polyisocyanate compound are mixed evenly in advance to prepare a mixture; the polyisocyanate compound is a mixture of isophorone diisocyanate and hexamethylene diisocyanate in a molar ratio of 1:3; the mass ratio of the catalyst, the release agent, the polyisocyanate compound, and the polythiol compound is 0.15:1.2:1000;

[0086] (2) Add large-particle-size titanium dioxide nanoparticles modified with a polythiol compound and a mercaptosilane coupling agent to the mixture, mix evenly, then add small-particle-size titanium dioxide nanoparticles modified with a mercaptosilane coupling agent, mix evenly again, degas, and obtain a monomer mixture; the average particle size D50 of the large-particle-size titanium dioxide is 110 nm, and the average particle size D50 of the small-particle-size titanium dioxide is 40 nm; the mass ratio of large-particle-size titanium dioxide to small-particle-size titanium dioxide is 1.7%; the mercaptosilane coupling agent is mercaptopropyltrimethoxysilane; the large-particle-size titanium dioxide nanoparticles are modified with a mercaptosilane coupling agent. The mass ratio of titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.18; the mass ratio of the small-diameter titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.18; the polythiol compound is 2,3-dithio(2-mercapto)-1-propanethiol; the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.13; the mass ratio of the sum of the masses of the small-diameter titanium dioxide and the large-diameter titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.74%;

[0087] (3) The monomer mixture was injected into a mold and cured by heating from 30°C to 120°C for 20 hours to obtain an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.672 and the impact strength was 28.76 kJ / m. 2 .

[0088] Comparative Example 1

[0089] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0090] (1) The catalyst dibutyltin dichloride, the release agent dibutyl phosphate, and the polyisocyanate compound are mixed evenly in advance to prepare a mixture; the polyisocyanate compound is a mixture of isophorone diisocyanate and hexamethylene diisocyanate in a molar ratio of 1:3; the mass ratio of the catalyst, the release agent, the polyisocyanate compound, and the polythiol compound is 0.15:1.2:1000;

[0091] (2) Add large-particle-size titanium dioxide nanoparticles modified with polythiol compounds and mercaptosilane coupling agents to the mixture, mix evenly, and degas to obtain a monomer mixture; the average particle size D50 of the large-particle-size titanium dioxide is 110 nm; the mercaptosilane coupling agent is mercaptopropyltrimethoxysilane; the mass ratio of the large-particle-size titanium dioxide nanoparticles to the mercaptosilane coupling agent is 1:0.18; the polythiol compound is 2,3-dithio(2-mercapto)-1-propanethiol; the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.13; the mass ratio of the large-particle-size titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.74%;

[0092] (3) The monomer mixture was injected into a mold and cured by heating from 30°C to 120°C for 20 hours to obtain an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.638 and the impact strength was 22.32 kJ / m. 2 .

[0093] Comparative Example 2

[0094] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0095] (1) The catalyst dibutyltin dichloride, the release agent dibutyl phosphate, and the polyisocyanate compound are mixed evenly in advance to prepare a mixture; the polyisocyanate compound is a mixture of isophorone diisocyanate and hexamethylene diisocyanate in a molar ratio of 1:3; the mass ratio of the catalyst, the release agent, the polyisocyanate compound, and the polythiol compound is 0.15:1.2:1000;

[0096] (2) Add small-particle-size titanium dioxide nanoparticles modified with polythiol compounds and mercaptosilane coupling agents to the mixture, mix evenly, and degas to obtain a monomer mixture; the average particle size D50 of the small-particle-size titanium dioxide is 40 nm; the mercaptosilane coupling agent is mercaptopropyltrimethoxysilane; the mass ratio of the small-particle-size titanium dioxide nanoparticles to the mercaptosilane coupling agent is 1:0.18; the polythiol compound is 2,3-dithio(2-mercapto)-1-propanethiol; the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.13; the mass ratio of the small-particle-size titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.74%;

[0097] (3) The monomer mixture was injected into a mold and cured by heating from 30°C to 120°C for 20 hours to obtain an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.646 and the impact strength was 23.47 kJ / m. 2 .

[0098] Comparative Example 3

[0099] A method for preparing an environmentally friendly thiol optical resin material includes the following steps:

[0100] (1) The catalyst dibutyltin dichloride, the release agent dibutyl phosphate, and the polyisocyanate compound are mixed evenly in advance to prepare a mixture; the polyisocyanate compound is a mixture of isophorone diisocyanate and hexamethylene diisocyanate in a molar ratio of 1:3; the mass ratio of the catalyst, the release agent, the polyisocyanate compound, and the polythiol compound is 0.15:1.2:1000;

[0101] (2) Add large-particle-size titanium dioxide nanoparticles modified with a polythiol compound and a mercaptosilane coupling agent to the mixture, mix evenly, then add small-particle-size titanium dioxide nanoparticles modified with a mercaptosilane coupling agent, mix evenly again, degas, and obtain a monomer mixture; the average particle size D50 of the large-particle-size titanium dioxide is 110 nm, and the average particle size D50 of the small-particle-size titanium dioxide is 40 nm; the mass ratio of large-particle-size titanium dioxide to small-particle-size titanium dioxide is 8%; the mercaptosilane coupling agent is mercaptopropyltrimethoxysilane; the large-particle-size titanium dioxide... The mass ratio of titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.18; the mass ratio of small-diameter titanium dioxide nanoparticles to mercaptosilane coupling agent is 1:0.18; the polythiol compound is 2,3-dithio(2-mercapto)-1-propanethiol; the molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound is 1:1.13; the mass ratio of the sum of the masses of small-diameter titanium dioxide and large-diameter titanium dioxide to the sum of the masses of the polyisocyanate compound and the polythiol compound is 0.74%;

[0102] (3) The monomer mixture was injected into a mold and cured by heating from 30°C to 120°C for 20 hours to obtain an environmentally friendly thiol optical resin material. The refractive index and toughness of the resin were tested using an Abbe refractometer and an XJJD-50J impact testing machine, respectively. The refractive index was 1.652 and the impact strength was 23.28 kJ / m. 2 .

[0103] As can be seen from the above examples and comparative examples, a small amount of large-particle titanium dioxide was added to the thiol optical resin system based on small-particle titanium dioxide. Large-particle titanium dioxide is less prone to agglomeration and has better dispersibility. Furthermore, during blending, the granular large-particle titanium dioxide is easier to disperse and can act as a "barrier" for small-particle titanium dioxide, preventing its agglomeration. Simultaneously, a small amount of mercaptosilane coupling agent modifies the surface of the titanium dioxide nanoparticles, improving the bonding between the inorganic titanium dioxide nanoparticles and the matrix, thus preparing an organic-inorganic nanocomposite material with superior performance. The presence of nano-titanium dioxide provides stress concentration areas for the material. The strong interfacial bonding with the thiol optical matrix facilitates stress transfer, preventing structural fracture due to excessive local stress. This strengthens the material's strength and toughness, thereby enhancing the mechanical properties of the composite material. The addition of both small-particle and large-particle titanium dioxide further improves the mechanical strength of the thiol optical resin while maintaining its high refractive index. Compared to Example 11, Comparative Examples 1-2 lacked small-particle-size titanium dioxide and large-particle-size titanium dioxide, respectively, thus failing to leverage the quantum size effect of inorganic nanoparticles and effectively improve the mechanical properties of thiol optical resins. Compared to Example 11, Comparative Example 3 added an excessive amount of large-particle-size titanium dioxide. The addition of a large number of large-particle-size inorganic nanoparticles not only easily leads to uneven mixing of the system, but also reduces particle size uniformity and the insulating effect of large-particle-size titanium dioxide. Although it has little impact on optical performance, its impact toughness is significantly reduced, making it difficult to meet the application requirements.

[0104] This embodiment is merely an illustrative description of the present patent and does not limit its scope of protection. Those skilled in the art may make partial modifications to it. As long as they do not exceed the spirit and essence of the present patent, they shall be regarded as equivalent substitutions to the present patent and shall be within the scope of protection of the present patent.

Claims

1. A method for preparing an environmentally friendly thiol optical resin material, characterized by, The method comprises the following steps: (1) mixing the catalyst, the release agent and the polyisocyanate compound in advance to prepare a mixture; (2) adding the polythiol compound and the mercapto silane coupling agent modified titanium dioxide nanoparticles into the mixture, mixing uniformly, degassing to obtain a monomer mixture; the titanium dioxide nanoparticles are composed of small-particle-size titanium dioxide with an average particle size of less than or equal to 50 nm and large-particle-size titanium dioxide with an average particle size of less than or equal to 150 nm; wherein the average particle size of the large-particle-size titanium dioxide is at least 50 nm larger than that of the small-particle-size titanium dioxide, and the mass ratio of the large-particle-size titanium dioxide to the small-particle-size titanium dioxide is 0.4%-4%; (3) injecting the monomer mixture into a mold, warming and curing to obtain the environmentally friendly thiol optical resin material.

2. The method for preparing an environmentally friendly thiol optical resin material as described in claim 1, characterized in that, The catalyst in step (1) comprises one or more of amine compounds or organotin compounds.

3. The method for preparing an environmentally friendly thiol optical resin material as described in claim 1, characterized in that, The release agent in step (1) is a phosphate compound.

4. The method for preparing an environmentally friendly thiol optical resin material as described in claim 1, characterized in that, The mercapto silane coupling agent in step (2) is one or more of mercaptopropyl trimethoxysilane, mercaptopropyl triethoxysilane, mercaptopropyl methyldimethoxysilane, mercaptopropyl methyldiethoxysilane and mercaptomethyl methyldiethoxysilane.

5. The method for preparing an environmentally friendly thiol optical resin material as described in claim 1, characterized in that, The polythiol compound in step (2) is one or more of methanedithiol, ethanedithiol, propanedithiol, hexanedithiol, cyclohexanedithiol, propanetriol, pentaerythritol tetra(3-mercaptopropionate), trimethylolpropane tri(3-mercaptopropionate), pentaerythritol tetra(3-mercaptobutyrate) and 2,3-dithio(2-mercapto)-1-propane thiol.

6. The method for preparing an environmentally friendly thiol optical resin material as described in claim 1, characterized in that, The average particle size of the small-particle-size titanium dioxide in step (2) is 25-50 nm.

7. The method for preparing an environmentally friendly thiol optical resin material as described in claim 1, characterized in that, The molar ratio of -SH in the polythiol compound to -NCO in the polyisocyanate compound in step (2) is 1:1.1-1.

15.

8. The method for preparing an environmentally friendly thiol optical resin material as described in claim 1, characterized in that, The polythiol compound in step (2) is 2,3-dithio(2-mercapto)-1-propane thiol, which is prepared by adding mercaptoethanol into a reactor, then adding sodium hydroxide solution dropwise, stirring uniformly, then adding epichlorohydrin dropwise, reacting for 0.5-1 h, then adding concentrated hydrochloric acid and a thiourea salt solution, then performing alkaline hydrolysis with ammonia water, washing with water, and removing water and separating to obtain 2,3-dithio(2-mercapto)-1-propane thiol.

9. The method for preparing an environmentally friendly thiol optical resin material as described in claim 1, characterized in that, The warming process in step (3) is heating from 30℃ to 120℃ for 18-22 h.

10. An environmentally friendly mercaptan optical resin material, characterized by comprising: The environmentally friendly thiol optical resin material is prepared by the method of any one of claims 1-9.