Preparation method of bio-based sulfur-containing compound and application of bio-based sulfur-containing compound in optical resin lens

Abstract

The invention relates to the field of organic materials and optical materials, and provides a preparation method of a bio-based sulfur-containing compound and application of the bio-based sulfur-containing compound in an optical resin lens, specifically, the mass content of 2, 3-epoxypropane methyl ether in bio-based epoxy chloropropane is controlled to be smaller than 0.1%, then the 2, 3-epoxypropane methyl ether reacts with a sulfydryl-containing monomer, and the bio-based sulfur-containing compound is obtained. The bio-based sulfur-containing compound is mixed with an isocyanate compound and a thiol compound to obtain the optical material composition, the optical material composition is polymerized to obtain the optical resin lens, and the result shows that the haze of the optical resin lens obtained by the method is remarkably reduced.

Description

Technical Field

[0001] The present invention relates to the fields of organic materials and optical materials, and in particular to a method for preparing a bio-based sulfur-containing compound and application of the same in optical resin lenses. Background Art

[0002] Compared to optical glass lenses, resin lenses offer advantages such as lightness, superior toughness, tintability, strong anti-fog properties, and dent resistance. For optical applications, resin lenses must possess the following key properties: low haze, high light transmittance, excellent heat resistance, high refractive index, and high Abbe number. Haze, in particular, is a crucial performance indicator for high-end optical resin lenses. The lower the haze, the greater the lens's transparency, resulting in clearer and more realistic viewing.

[0003] Optical resin lenses are made from sulfur-containing compounds that solidify at a specific temperature. These sulfur-containing compounds are synthesized using epichlorohydrin as a base material. Traditionally, epichlorohydrin (ECH) is primarily produced through the high-temperature chlorination of propylene (chlorohydrin process), but this method is plagued by fossil resource dependence, complex processes, and numerous by-products. Furthermore, the "Guiding Catalogue for Industrial Structure Adjustment (2024 Edition)" explicitly classifies epichlorohydrin production equipment using the chlorohydrin process as restricted, and epichlorohydrin calcium saponification processes (except for those that use no more than 15 tons of fresh water per ton of product and produce no more than 100 kilograms of waste residue as of December 31, 2025) as eliminated.

[0004] In recent years, the glycerol-based epichlorohydrin production process has garnered significant attention for its environmental and sustainability considerations. Furthermore, the raw material for glycerol-based epichlorohydrin is derived from plant-based glycerin, making it a bio-based raw material. Optical resin products made with glycerol-based epichlorohydrin are also bio-based, meeting the goals of achieving carbon peak and carbon neutrality. Therefore, replacing chlorohydrin-based epichlorohydrin with glycerol-based epichlorohydrin is urgent.

[0005] However, the haze of optical materials synthesized using epichlorohydrin using the glycerol method is relatively high, making it difficult to fully meet the haze requirements of optical materials. Therefore, how to use bio-based epichlorohydrin to synthesize high-quality sulfur-containing compounds and low-haze optical resin lenses has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0006] In order to solve the problem of high haze of optical resin lenses in the prior art, the present invention provides a method for preparing a bio-based sulfur-containing compound and its application in optical resin lenses. Specifically, the mass content of 2,3-epoxypropylene methyl ether in bio-based epichlorohydrin is controlled to less than 0.1%, and then the bio-based sulfur-containing compound is reacted with a thiol-containing monomer to obtain a bio-based sulfur-containing compound. The bio-based sulfur-containing compound is mixed with an isocyanate compound and / or a thiol compound to obtain an optical material composition, and the optical resin lens is obtained after polymerization. The results show that the optical resin lens obtained by this method has significantly reduced haze.

[0007] After research, the inventors determined that the trace impurity (2,3-propylene oxide methyl ether) in epichlorohydrin prepared by the glycerol process is the decisive factor affecting haze. Based on this premise, the specific technical solution provided by the present invention is as follows: A method for preparing a bio-based sulfur-containing compound, comprising reacting epichlorohydrin with R m -SH reaction; The epichlorohydrin is epichlorohydrin prepared by the glycerol method, and the mass content of 2,3-propylene oxide methyl ether in the epichlorohydrin is less than 0.1%; The R m In -SH, R is one of hydrogen, alkyl, aryl, hydroxyethyl, hydroxypropyl, and alkaline earth metal, and m is 1 or 2.

[0008] The content of 2,3-propylene oxide methyl ether in epichlorohydrin can be determined by testing, and when the content does not meet the above requirements, it can be regulated by distillation.

[0009] The 2,3-epoxypropylene methyl ether impurity in the above-mentioned epichlorohydrin will cause certain effects when synthesizing bio-based sulfur-containing compounds and applying optical resin lenses, especially the haze index of optical resin lenses. Through in-depth research, the inventors found that 2,3-epoxypropylene methyl ether and R m -SH participates in the reaction to form a monofunctional bio-based sulfur-containing compound, which cannot cross-link during the later polymerization process and is analyzed in the middle of the lens, resulting in uneven curing, increased scattering of the lens, uneven light transmission, increased haze, and poor light transmittance. Therefore, this application reduces the haze of the optical resin lens prepared from the bio-based sulfur-containing compound by controlling the mass content of 2,3-epoxypropylene methyl ether in epichlorohydrin to less than 0.1%.

[0010] The bio-based sulfur-containing compounds can be prepared by the above method, and the bio-based sulfur-containing compounds include 4-mercaptomethyl-1,8-dimercapto-3,6-dithia-octane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithia-undecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithia-undecane, 5,7-dimercaptomethyl-1,11-dimercapto- One or more of 1,6,9-trithiaundecane, bis(β-epithiopropyl) sulfide, bis(β-epithiopropyl) disulfide, bis(β-epithiopropyl) trisulfide, bis(β-epithiopropylthio)methane, 1,2-bis(β-epithiopropylthio)ethane, 1,3-bis(β-epithiopropylthio)propane, 1,4-bis(β-epithiopropylthio)butane, and bis(β-epithiopropylthioethyl) sulfide.

[0011] The present invention further provides an optical material composition, comprising the bio-based sulfur-containing compound, and further comprising an isocyanate compound, a thiol compound, an initiator, a release agent, and an ultraviolet absorber.

[0012] Preferably, the thiol compound is selected from methanethiol, 1,2-ethanedithiol, 1,1-propylenethiol, 1,2-propylenethiol, 1,3-propylenethiol, 2,2'-thiobis(ethanethiol), 1,6-dimercaptohexane, 2,3-bis(2-mercaptoethylthio)-3-propyl-1-thiol, pentaerythritol tetrakis(3-mercaptopropionic acid) ester, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiooctane, 2,2-di(mercaptoethylthio)- One or more of bis(2-mercaptoethylthio)propylthio)ethanethiol, bis(2,3-dimercaptopropanol)sulfide, bis(2,3-dimercaptopropanol)disulfide and 1,2-bis(2-mercaptoethylthio)-3-mercaptopropane.

[0013] Preferably, the isocyanate compound is selected from diethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, trimethyl hexamethylene diisocyanate, cyclohexane diisocyanate, 1,3-bis(isocyanate methyl)cyclohexane, 1,4-bis(isocyanate methyl)cyclohexane, isophorone diisocyanate, 2,6-bis(isocyanate methyl)decahydronaphthalene, tolyl diisocyanate, o-tolidine diisocyanate, diphenylmethane diisocyanate, diphenyl ether diisocyanate, 2,2'-bis(4-isocyanate phenyl)propane, triphenylmethane triisocyanate, bis(diisocyanate One or more of bis(isocyanatemethyl)norbornene, bis(isocyanatemethyl)adamantane, thiodiethyl diisocyanate, thiodipropyl diisocyanate and thiodihexyl diisocyanate.

[0014] More preferably, the isocyanate compound is selected from one or more of isophorone diisocyanate, m-xylyl diisocyanate and 1,3-bis(isocyanatemethyl)cyclohexane.

[0015] Preferably, the initiator is selected from tetramethylammonium bromide, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium bromide, tetrahexylammonium bromide, tetraethylammonium hydroxide, N,N-dihexylmethylamine, 1,2-dimethylimidazole, benzylmethylimidazole, 2-ethyl-4-methylimidazole, triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tribenzylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,2-bis(dimethylphosphino) Examples of the initiators include, but are not limited to, ethane, tetrabutylphosphine bromide, dimethyltin dichloride, dibutyltin dichloride, dibutyltin dilaurate, tin tetrachloride, dibutyltin oxide, zinc chloride, zinc acetylacetonate, aluminum chloride, aluminum fluoride, triphenylaluminum, titanium tetrachloride, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, diphenyliodonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphate, and triphenylsulfonium hexafluoroarsenate. These initiators may be used alone or in combination of two or more. The amount of the initiator used is in the range of 0.001 to 1% relative to the total mass of the optical material composition.

[0016] The release agent is a phosphate compound, and the amount used is within the range of 0.001-1% relative to the total mass of the optical material composition.

[0017] The present invention also provides an optical resin lens, which is obtained by polymerizing the optical material composition.

[0018] Preferably, the method for polymerizing the optical material composition is: mixing the optical material composition, degassing and filtering it, then injecting it into a mold, and heating and curing it.

[0019] The present invention controls the mass content of 2,3-epoxypropylene methyl ether in bio-based epichlorohydrin to less than 0.1% through a distillation method, reacts the 2,3-epoxypropylene methyl ether with a thiol-containing monomer to obtain a bio-based sulfur-containing compound, mixes the bio-based sulfur-containing compound with an isocyanate compound and / or a thiol compound to obtain an optical material composition, and obtains an optical resin lens after polymerization. The results show that the optical resin lens obtained by this method has significantly reduced haze. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be further described below in conjunction with specific embodiments. These embodiments are only used to illustrate the technical solution of the present invention in more detail and should not be construed as limiting the scope of protection of the present invention.

[0021] In the present invention, an optical resin lens is obtained by curing the optical resin composition, and the optical resin lens is used as a substrate for haze testing. The haze of the optical resin lens material is measured using a HunterLab UltraScan PRO spectrophotometer from HunterLab.

[0022] The bio-based epichlorohydrin in the following examples is all epichlorohydrin prepared by the glycerol process, and the mass content of 2,3-epoxypropylene methyl ether in the epichlorohydrin is less than 0.1%. The 2,3-epoxypropylene methyl ether content in the epichlorohydrin is determined by gas chromatography. When the content does not meet the above requirements, it can be adjusted by distillation. The different contents of 2,3-epoxypropylene methyl ether in the epichlorohydrin in the following examples are achieved by artificially adding 2,3-epoxypropylene methyl ether.

[0023] Unless otherwise specified, the percentages in the following examples are all by weight.

[0024] Example 1 Synthesis of bis(β-epithiopropyl)sulfide (1) Add 195 g (2 mol) of bio-based epichlorohydrin and 390 g of ethanol to a 2 L reaction flask equipped with a stirrer, heat exchanger, nitrogen pipeline, and thermometer. At 0-10°C, introduce 34 g (2 mol) of hydrogen sulfide gas into the flask over 1 hour. At the same temperature, add 195 g (2 mol) of bio-based epichlorohydrin dropwise over 2 hours and keep the temperature for 1 hour. The mass content of 2,3-propylene oxide methyl ether in the above-mentioned bio-based epichlorohydrin was detected to be 0.002%.

[0025] (2) Add 550 g of 32% NaOH solution to the reaction flask and keep it at 40°C for 2 h to obtain an epoxy compound reaction solution. The epoxy compound reaction solution is filtered and desolventized to remove ethanol and water to obtain 286.16 g of bis(β-epoxypropyl) sulfide.

[0026] (3) To a 2 L reaction flask equipped with a stirrer, a heat exchanger, a nitrogen gas line, and a thermometer, 286.16 g (1.96 mol) of bis(β-epoxypropyl)sulfide from step (2), 572.32 g of toluene, 286.16 g of methanol, and 372.4 g (4.9 mol) of thiourea were added. The mixture was reacted at 30°C for 8 h to obtain an episulfide reaction solution. The episulfide reaction solution was subjected to conventional filtration, desolventization under reduced pressure, acid washing, and water washing. The solution was then heated and depressurized to remove toluene and trace amounts of water. 313.9 g of bis(β-epoxypropyl)sulfide was then obtained by filtration.

[0027] Take 5 g of isophorone diisocyanate, 6.5 g of bis(2-mercaptoethyl) sulfide, 0.1 g of initiator tetrabutyl phosphonium bromide, 0.05 g of release agent di-n-butyl phosphate, and 0.05 g of UV326 ultraviolet absorber, and mix them evenly.

[0028] Add 88.5 g of the previously prepared bis(β-epithiopropyl)sulfide and mix thoroughly. Degas the mixture at 800 Pa for 1 hour. After degassing, filter through a 0.5 μm PTFE filter, inject into a mold, and begin curing.

[0029] The first curing temperature program was as follows: an initial temperature of 25°C, maintained for 2.0 hours, then raised to 60°C over 10 hours, then to 90°C over 2.0 hours, and finally cooled to 60°C over 2.5 hours. The second curing temperature was 110°C for 2 hours, resulting in an optical lens material with a haze value of 0.03%.

[0030] Example 2 The bio-based epichlorohydrin used contained 0.013% 2,3-epoxypropylene methyl ether as an impurity. Bis(β-epithiopropyl) sulfide was synthesized using the same synthesis method as in Example 1. An optical material obtained using this bis(β-epithiopropyl) sulfide and the optical material preparation method had a haze of 0.09%.

[0031] Example 3 The bio-based epichlorohydrin used contained 0.046% 2,3-epoxypropylene methyl ether as an impurity. Bis(β-epithiopropyl) sulfide was synthesized using the same synthesis method as in Example 1. An optical material obtained using this bis(β-epithiopropyl) sulfide and the optical material preparation method had a haze of 0.15%.

[0032] Example 4 The bio-based epichlorohydrin used contained 0.083% 2,3-epoxypropylene methyl ether as an impurity. Bis(β-epithiopropyl) sulfide was synthesized using the same synthesis method as in Example 1. An optical material obtained using this bis(β-epithiopropyl) sulfide and the optical material preparation method had a haze of 0.38%.

[0033] Example 5 The bio-based epichlorohydrin used contained 0.095% 2,3-epoxypropylene methyl ether as an impurity. Bis(β-epithiopropyl) sulfide was synthesized using the same synthesis method as in Example 1. An optical material obtained using this bis(β-epithiopropyl) sulfide and the optical material preparation method had a haze of 0.44%.

[0034] Example 6 Synthesis of bis(β-epithiopropyl)disulfide (1) Add 195 g (2 mol) of bio-based epichlorohydrin and 390 g of ethanol to a 2 L reaction flask equipped with a stirrer, heat exchanger, nitrogen pipeline, and thermometer. At 0-10°C, introduce 34 g (2 mol) of hydrogen sulfide gas into the flask over 1 hour. At the same temperature, add 113 g (2 mol) of 25% hydrogen peroxide dropwise over 2 hours and keep warm for 1 hour. The mass content of 2,3-propylene oxide methyl ether in the bio-based epichlorohydrin used is 0.002%.

[0035] (2) Add 287.5 g of 32% NaOH solution to the reaction flask and keep it at 40°C for 3 hours to obtain an epoxy compound reaction solution. The epoxy compound reaction solution is filtered and desolventized to remove ethanol and water to obtain 169.1 g of bis(β-epoxypropyl) disulfide; (3) To a 2 L reaction flask equipped with a stirrer, a heat exchanger, a nitrogen gas line, and a thermometer, 169.1 g (0.95 mol) of bis(β-epoxypropyl) sulfide from step (2), 507.3 g of toluene, 169.1 g of methanol, and 182.4 g (2.4 mol) of thiourea were added. The mixture was reacted at 30°C for 10 h to obtain an episulfide reaction solution. The episulfide reaction solution was filtered, desolvated under reduced pressure, acid-washed, and washed with water. The solution was then heated and depressurized to remove toluene and trace amounts of water. 179.6 g of bis(β-epoxypropyl) disulfide was then obtained by filtration.

[0036] Preparation of optical materials: Mix and dissolve 90g of bis(β-epithiopropyl) disulfide, 10g of 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 0.08g of N,N-dihexylmethylamine, and 0.005g of lauryl alcohol polyoxyethylene ether phosphate at room temperature. Degas the mixture at 800 Pa for 1 hour. After degassing, filter through a 0.5μm PTFE filter, inject into a mold, and begin curing.

[0037] The first curing temperature program was as follows: an initial temperature of 15°C, maintained for 2.0 hours, then raised to 60°C over 10 hours, then to 110°C over 5 hours, and finally cooled to 60°C over 2.5 hours. The second curing temperature was 110°C for 2 hours, resulting in an optical lens material with a haze of 0.07%.

[0038] Example 7 The bio-based epichlorohydrin used contained 0.013% 2,3-epoxypropylene methyl ether as an impurity. Bis(β-epithiopropyl) disulfide was synthesized using the same synthesis method as in Example 6. An optical material obtained using this bis(β-epithiopropyl) disulfide and the optical material preparation method had a haze of 0.13%.

[0039] Example 8 The bio-based epichlorohydrin used contained 0.046% 2,3-epoxypropylene methyl ether as an impurity. Bis(β-epithiopropyl) disulfide was synthesized using the same synthesis method as in Example 6. An optical material obtained using this bis(β-epithiopropyl) disulfide and the optical material preparation method had a haze of 0.27%.

[0040] Example 9 The bio-based epichlorohydrin used contained 0.083% 2,3-epoxypropylene methyl ether as an impurity. Bis(β-epithiopropyl) disulfide was synthesized using the same synthesis method as in Example 6. An optical material obtained using this bis(β-epithiopropyl) disulfide and the optical material preparation method had a haze of 0.39%.

[0041] Example 10 The bio-based epichlorohydrin used contained 0.095% 2,3-epoxypropylene methyl ether as an impurity. Bis(β-epithiopropyl) disulfide was synthesized using the same synthesis method as in Example 6. An optical material obtained using this bis(β-epithiopropyl) disulfide and the optical material preparation method had a haze of 0.46%.

[0042] Example 11 Synthesis of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (1) Add 156.6 g (2.0 mol) of 2-mercaptoethanol to a four-necked flask equipped with a thermometer, a stirrer, and a constant pressure dropping funnel, and add 146.7 g (1.1 mol) of a 30% aqueous sodium hydroxide solution dropwise through the constant pressure dropping funnel. Similarly, add 92.6 g (1.0 mol) of bio-based epichlorohydrin dropwise through the constant pressure dropping funnel. After the addition is complete, react for 30 minutes.

[0043] (2) Then, 405.6 g (4.0 mol) of 36% hydrochloric acid and 268.1 g (3.5 mol) of thiourea were added and reacted at 110°C for 240 min to form thiourea salt.

[0044] (3) Cool to 60°C, add 425.0 g (4.5 mol) of 18% ammonia water, and hydrolyze for 3 h. Separate the layers to obtain the crude product in the lower layer. The crude product is acid-washed and washed with water by conventional methods, and the water is removed by vacuum evaporation. After precise filtration, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiooctane is obtained.

[0045] The mass content of 2,3-propylene oxide methyl ether in the bio-based epichlorohydrin used is 0.002%.

[0046] Add 52.0 parts by mass of xylylene diisocyanate, 0.01 parts by mass of initiator (dibutyltin dichloride), and 0.08 parts by mass of release agent (polyphosphate) to a batching kettle and stir to dissolve at 15°C. Add 48.0 parts by mass of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane and stir thoroughly. Degas the mixture using a vacuum pump at 350 Pa for 0.5 hours to prepare a mixed solution, which is then poured into a glass mold.

[0047] The material was placed in an oven for programmed temperature curing. The temperature program for the first curing was as follows: the initial temperature was 25°C, kept warm for 3.0 hours, then heated to 60°C for 8 hours, heated to 120°C for 4 hours, kept warm at 120°C for 2 hours, and finally cooled to 70°C for 2.5 hours. The second curing temperature was 120°C for 2 hours to obtain an optical lens material with a haze of 0.04%.

[0048] Example 12 The bio-based epichlorohydrin used contained 0.013% 2,3-epoxypropylene methyl ether as an impurity. 4-Mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane was synthesized using the same synthesis method as Example 11. An optical material obtained using this bio-based sulfur-containing compound and the optical material preparation method had a haze of 0.16%.

[0049] Example 13 The bio-based epichlorohydrin used contained 0.046% 2,3-epoxypropylene methyl ether as an impurity. 4-Mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane was synthesized using the same synthesis method as Example 11. An optical material prepared using this bio-based sulfur-containing compound using the optical material preparation method had a haze of 0.21%.

[0050] Example 14 The bio-based epichlorohydrin used contained 0.083% 2,3-epoxypropylene methyl ether as an impurity. 4-Mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane was synthesized using the same synthesis method as Example 11. An optical material prepared using this bio-based sulfur-containing compound and using the optical material preparation method had a haze of 0.35%.

[0051] Example 15 The bio-based epichlorohydrin used contained 0.095% 2,3-epoxypropylene methyl ether as an impurity. 4-Mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane was synthesized using the same synthesis method as in Example 11. An optical material obtained using this bio-based sulfur-containing compound and the optical material preparation method had a haze of 0.41%.

[0052] Example 16 Synthesis of bio-based sulfur-containing compounds with 4,8 or 4,7 or 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane as main component (1) A reactor was charged with 51.2 parts by weight (0.6564 mol) of 2-mercaptoethanol, 26.5 parts by weight of degassed water (dissolved oxygen concentration 2 ppm), and 0.16 parts by weight (0.0020 mol) of a 49% aqueous sodium hydroxide solution. 61.99 parts by weight (0.6702 mol) of bio-based epichlorohydrin was added dropwise at 9-11°C over 6.5 hours, followed by stirring for 60 minutes to synthesize 1-chloro-3-(2-hydroxyethylthio)-2-propanol.

[0053] (2) 150.0 parts by weight (0.3327 mol) of a 17.3% sodium sulfide aqueous solution was added dropwise at 7-37°C over 5.5 hours and stirred for 120 minutes to generate a tetraol compound.

[0054] (3) 279.0 parts by weight (2.7136 mol) of hydrochloric acid with a concentration of 35.5% was added, followed by 125.8 parts by weight (1.6536 mol) of thiourea with a purity of 99.90%, and the mixture was stirred at reflux at 110°C for 3 hours to carry out a thiourea salt reaction. After cooling to 45°C, 214.0 parts by weight of toluene was added, and the mixture was cooled to 26°C. 206.2 parts by weight (3.0323 mol) of a 25% aqueous ammonia solution was added at 26°C over 30 minutes, and the mixture was stirred at 55°C for 1 hour to carry out a hydrolysis reaction, thereby obtaining a toluene solution of a polythiol containing 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane as the main component.

[0055] (4) 59.4 parts by weight of 36% hydrochloric acid was added to the toluene solution and acid-washed at 34°C for 30 minutes, twice. 118.7 parts by weight of degassed water (dissolved oxygen concentration 2 ppm) was added and washed at 35-45°C for 30 minutes, five times. Toluene and trace amounts of water were removed under reduced pressure by heating, and then the solution was filtered under reduced pressure using a 1.2 μm PTFE membrane filter to obtain a bio-based sulfur-containing compound with 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane as the main component.

[0056] The mass content of 2,3-propylene oxide methyl ether in the bio-based epichlorohydrin used is 0.002%.

[0057] Add 50.7 parts by mass of xylylene diisocyanate, 0.01 parts by mass of an initiator (dibutyltin dichloride), and 0.08 parts by mass of a release agent (polyphosphate) to a batching kettle and stir to dissolve at 15°C. Then, add 49.3 parts by mass of a bio-based sulfur-containing compound composed primarily of 4,8-, 4,7-, or 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, prepared by the aforementioned method, and stir thoroughly. Degas the mixture using a vacuum pump at a pressure of 350 Pa for 0.5 hours to prepare a mixed solution, which is then cast into a glass mold. The material was placed in an oven for programmed temperature curing. The temperature program for the first curing was as follows: the initial temperature was 25°C, kept warm for 3.0 hours, then heated to 60°C for 8 hours, heated to 120°C for 4 hours, kept warm at 120°C for 2 hours, and finally cooled to 70°C for 2.5 hours. The second curing temperature was 120°C for 2 hours to obtain an optical lens material with a haze of 0.06%.

[0058] Example 17 The bio-based epichlorohydrin used contained 0.013% 2,3-epoxypropylene methyl ether as an impurity. Using the same synthesis method as in Example 16, a bio-based sulfur-containing compound containing 4,8-, 4,7-, or 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane as the main component was synthesized. An optical material obtained using this bio-based sulfur-containing compound using the optical material preparation method had a haze of 0.14%.

[0059] Example 18 The bio-based epichlorohydrin used contained 0.046% 2,3-epoxypropylene methyl ether as an impurity. Using the same synthesis method as in Example 16, a bio-based sulfur-containing compound containing 4,8-, 4,7-, or 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane as the main component was synthesized. An optical material obtained using this bio-based sulfur-containing compound using the optical material preparation method had a haze of 0.22%.

[0060] Example 19 The bio-based epichlorohydrin used contained 0.083% 2,3-epoxypropylene methyl ether as an impurity. Using the same synthesis method as in Example 16, a bio-based sulfur-containing compound containing 4,8-, 4,7-, or 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane as the main component was synthesized. An optical material obtained using this bio-based sulfur-containing compound using the optical material preparation method had a haze of 0.34%.

[0061] Example 20 The bio-based epichlorohydrin used contained 0.095% 2,3-epoxypropylene methyl ether as an impurity. Using the same synthesis method as in Example 16, a bio-based sulfur-containing compound containing 4,8-, 4,7-, or 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane as the main component was synthesized. An optical material obtained using this bio-based sulfur-containing compound using the optical material preparation method had a haze of 0.46%.

[0062] Comparative Example 1 The bio-based epichlorohydrin used contained 0.115% 2,3-epoxypropylene methyl ether as an impurity. Bis(β-epithiopropyl) sulfide was synthesized using the same synthesis method as in Example 1. An optical material obtained using this bis(2,3-epithiopropyl) sulfide and the optical material preparation method had a haze of 1.56%.

[0063] Comparative Example 2 The bio-based epichlorohydrin used contained 0.287% 2,3-epoxypropylene methyl ether as an impurity. Bis(β-epithiopropyl) sulfide was synthesized using the same synthesis method as in Example 1. An optical material obtained using this bis(2,3-epithiopropyl) sulfide and the optical material preparation method had a haze of 2.73%.

[0064] Comparative Example 3 The bio-based epichlorohydrin used contained 0.115% 2,3-epoxypropylene methyl ether as an impurity. Bis(β-epithiopropyl) disulfide was synthesized using the same synthesis method as in Example 6. An optical material obtained using this bis(2,3-epithiopropyl) disulfide using the optical material preparation method had a haze of 1.63%.

[0065] Comparative Example 4 The bio-based epichlorohydrin used contained 0.287% 2,3-epoxypropylene methyl ether as an impurity. Bis(β-epithiopropyl) disulfide was synthesized using the same synthesis method as in Example 6. An optical material obtained using this bis(2,3-epithiopropyl) disulfide using the optical material preparation method had a haze of 2.81%.

[0066] Comparative Example 5 The bio-based epichlorohydrin used contained 0.115% 2,3-epoxypropylene methyl ether as an impurity. 4-Mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane was synthesized using the same synthesis method as Example 11. An optical material prepared using this bio-based sulfur-containing compound and using the optical material preparation method had a haze of 1.55%.

[0067] Comparative Example 6 The bio-based epichlorohydrin used contained 0.287% 2,3-epoxypropylene methyl ether as an impurity. 4-Mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane was synthesized using the same synthesis method as Example 11. An optical material prepared using this bio-based sulfur-containing compound using the optical material preparation method had a haze of 2.78%.

[0068] Comparative Example 7 The bio-based epichlorohydrin used contained 0.115% 2,3-epoxypropylene methyl ether as an impurity. Using the same synthesis method as in Example 16, a bio-based sulfur-containing compound containing 4,8-, 4,7-, or 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane as the main component was synthesized. An optical material obtained using this bio-based sulfur-containing compound using the optical material preparation method had a haze of 1.61%.

[0069] Comparative Example 8 The bio-based epichlorohydrin used contained 0.287% 2,3-epoxypropylene methyl ether as an impurity. Using the same synthesis method as in Example 16, a bio-based sulfur-containing compound containing 4,8-, 4,7-, or 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane as the main component was synthesized. An optical material obtained using this bio-based sulfur-containing compound using the optical material preparation method had a haze of 2.80%.

[0070] The haze test results of the optical materials prepared in the above examples and comparative examples are shown in Table 1: Table 1 Haze test results of optical materials prepared in Examples and Comparative Examples From the haze test results of the optical resin lenses obtained from the examples and comparative examples in Table 1, it can be seen that as the content of the impurity 2,3-propylene oxide methyl ether increases, the haze of the optical resin lens increases accordingly, and the haze of the optical resin lens of the comparative example is higher than that of the example.

[0071] The results of the above examples and comparative examples demonstrate that if the impurity 2,3-epoxypropylene methyl ether in bio-based epichlorohydrin exceeds a certain level, the haze of the resulting optical resin lens increases. In particular, when the 2,3-epoxypropylene methyl ether content in the bio-based epichlorohydrin exceeds 0.1%, the haze of the optical resin lens increases significantly. However, when the 2,3-epoxypropylene methyl ether content in the bio-based epichlorohydrin is less than 0.1%, optical resin lenses with low haze can be obtained.

[0072] The data from the above examples and comparative examples further demonstrate that the methods for preparing bio-based sulfur-containing compounds and optical resin lenses containing the compounds can provide optical resin lenses with stable low haze (e.g., a haze of less than 0.5%). The overall technical solution provided by the present invention has promising application prospects in the preparation of various optical components, such as eyeglass lenses.

[0073] From the above examples, it can be seen that the present invention provides a method for preparing a bio-based sulfur-containing compound, comprising R m -SH reacts with bio-based epichlorohydrin; the mass content of 2,3-epoxypropylene methyl ether in the bio-based epichlorohydrin is less than 0.1%; the R m -SH, R can be represented by one of hydrogen, alkyl, aryl, hydroxyethyl, hydroxypropyl, and alkaline earth metal, and m is 1 or 2; the bio-based epichlorohydrin is prepared by the glycerol method. The present invention adopts bio-based epichlorohydrin with a 2,3-epoxypropylene methyl ether content of less than 0.1% and R mThe bio-based sulfur-containing compound produced by the reaction of NH4Cl2 and NH4Cl2 is used to prepare optical resin lenses, which can make the optical resin lenses have low haze. Experimental results show that the haze of the optical resin lenses is less than 0.5%.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any equivalent replacement, modification, etc. made by technicians in this field without any creative work within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a bio-based sulfur-containing compound, comprising reacting epichlorohydrin with R m -SH reaction, characterized by: The epichlorohydrin is prepared by the glycerol method, and the mass content of 2,3-propylene oxide methyl ether in the epichlorohydrin is less than 0.1%; the R m In -SH, R is one of hydrogen, alkyl, aryl, hydroxyethyl, hydroxypropyl, and alkaline earth metal, and m is 1 or 2.

2. The method for preparing a bio-based sulfur-containing compound according to claim 1, characterized in that: The prepared bio-based sulfur-containing compound includes one of 4-mercaptomethyl-1,8-dimercapto-3,6-dithia-octane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithia-undecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithia-undecane, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithia-undecane, bis(β-epithiopropyl) sulfide, bis(β-epithiopropyl) disulfide, bis(β-epithiopropyl) trisulfide, bis(β-epithiopropylthio)methane, 1,2-bis(β-epithiopropylthio)ethane, 1,3-bis(β-epithiopropylthio)propane, 1,4-bis(β-epithiopropylthio)butane, and bis(β-epithiopropylthioethyl) sulfide.

3. An optical material composition, characterized in that The bio-based sulfur-containing compound prepared by the method for preparing the bio-based sulfur-containing compound according to claim 1 may also include an isocyanate compound, a thiol compound, an initiator, a release agent and an ultraviolet absorber.

4. The optical material composition according to claim 3, characterized in that: The thiol compound is selected from methanedithiol, 1,2-ethanedithiol, 1,1-propylenedithiol, 1,2-propylenedithiol, 1,3-propylenedithiol, 2,2'-thiobis(ethanethiol), 1,6-dimercaptohexane, 2,3-bis(2-mercaptoethylthio)-3-propyl-1-thiol, pentaerythritol tetrakis(3-mercaptopropionic acid) ester, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiooctane, 2,2-bis(mercaptomethyl) One or more of bis(2-mercaptoethylthio)propylthio)ethanethiol, bis(2,3-dimercaptopropanol)sulfide, bis(2,3-dimercaptopropanol)disulfide and 1,2-bis(2-mercaptoethylthio)-3-mercaptopropane.

5. The optical material composition according to claim 3, characterized in that: The isocyanate compound is selected from diethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, trimethyl hexamethylene diisocyanate, cyclohexane diisocyanate, 1,3-bis(isocyanate methyl)cyclohexane, 1,4-bis(isocyanate methyl)cyclohexane, isophorone diisocyanate, 2,6-bis(isocyanate methyl)decahydronaphthalene, tolyl diisocyanate, o-tolidine diisocyanate, diphenylmethane diisocyanate, diphenyl ether diisocyanate, 2,2'-bis(4-isocyanate phenyl)propane, triphenylmethane triisocyanate, bis(diisocyanate methyl) One or more of bis(isocyanatemethyl)norbornene, bis(isocyanatemethyl)adamantane, thiodiethyl diisocyanate, thiodipropyl diisocyanate and thiodihexyl diisocyanate.

6. The optical material composition according to claim 5, characterized in that: The isocyanate compound is selected from one or more of isophorone diisocyanate, m-xylyl diisocyanate and 1,3-bis(isocyanatemethyl)cyclohexane.

7. The optical material composition according to claim 3, characterized in that: The initiator is selected from tetramethylammonium bromide, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium bromide, tetrahexylammonium bromide, tetraethylammonium hydroxide, N,N-dihexylmethylamine, 1,2-dimethylimidazole, benzylmethylimidazole, 2-ethyl-4-methylimidazole, triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tribenzylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,2-bis(dimethylphosphino)ethane, tetrabutylphosphine bromide, dimethyl One or two of tin dichloride, dibutyltin dichloride, dibutyltin dilaurate, tin tetrachloride, dibutyltin oxide, zinc chloride, zinc acetylacetonate, aluminum chloride, aluminum fluoride, triphenylaluminum, titanium tetrachloride, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, diphenyliodonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphate, and triphenylsulfonium hexafluoroarsenate; the initiator is used in an amount of 0.001 to 1% relative to the total mass of the optical material composition.

8. The optical material composition according to claim 3, characterized in that: The release agent is a phosphate compound, and the amount used is 0.001-1% relative to the total mass of the optical material composition.

9. An optical resin lens, characterized in that: The optical material composition according to claim 3 is obtained by polymerizing the optical material composition.

10. The optical resin lens according to claim 9, characterized in that: The method for polymerizing the optical material composition is as follows: mixing the optical material composition, degassing and filtering it, injecting it into a mold, and heating and curing it.

Images