A polythiocarbonate, a method for preparing the same and a photocurable composition

Abstract

The application provides a polysulfide carbonate, a preparation method thereof and a photocurable composition, and belongs to the technical field of optical resins.The polysulfide carbonate provided by the application has a structure shown in formula I.The polysulfide carbonate provided by the application has high molar refractivity and low molar volume by introducing an aromatic group and a sulfur atom, so that the refractivity of the polysulfide carbonate is improved.The results of examples show that the refractivity of the polysulfide carbonate provided by the application reaches 1.7 or more.

Description

Technical Field

[0001] This invention belongs to the field of optical resin technology, specifically relating to a polythiocarbonate, its preparation method, and a photocurable composition. Background Technology

[0002] Bisphenol A type polycarbonate resin is the most commonly used polycarbonate. However, due to its low refractive index, its application in different scenarios is limited, making it difficult to continuously meet the ever-increasing demands for lens imaging quality. Developing high refractive index polycarbonate resin can greatly improve imaging quality.

[0003] To improve the refractive index of polycarbonate, patent CN103257376A uses 9,9-bis-(4-(2-hydroxyethoxy)phenyl)fluorene as a comonomer, but the resulting polycarbonate has a refractive index of only 1.64, which is still insufficient to meet the requirements. Therefore, how to improve polycarbonate to increase its refractive index has become an urgent technical problem to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to provide a polythiocarbonate, its preparation method, and a photocurable composition. The polythiocarbonate provided by this invention has a high refractive index.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a polythiocarbonate having the structure shown in Formula I:

[0007] Formula I;

[0008] In Formula I, Ar1 and Ar2 are independently substituted or unsubstituted aromatic groups or substituted or unsubstituted heterocyclic groups, X is oxygen or sulfur, and m and n are independently integers from 1 to 30.

[0009] Preferably, the polythiocarbonate has a weight-average molecular weight of 1,000 to 50,000 and a dispersion of 1.0 to 2.0.

[0010] Preferably, the substituted group includes at least one selected from halogen atoms, hydroxyl groups, amino groups, cyano groups, alkyl groups, cycloalkyl groups, alkoxy groups, and phenyl groups.

[0011] Preferably, when the aromatic group contains at least two benzene rings, the benzene rings are connected by bridging groups, wherein the bridging groups are at least one of oxygen atom, sulfur atom, alkylene group having 1 to 10 carbon atoms, and alkeneoxy group having 1 to 10 carbon atoms.

[0012] Preferably, Ar1 and Ar2 are independently the following groups:

[0013] , , , , , , or .

[0014] The present invention also provides a method for preparing the polythiocarbonate described in the above technical solution, comprising:

[0015] The compound, triphosgene, solvent, and catalyst are mixed and polymerized to obtain polythiocarbonate; the compound includes aromatic compounds containing thiol groups or heterocyclic compounds containing thiol groups.

[0016] The present invention also provides a photocurable composition comprising the following components in weight percentage:

[0017] Polysulfide carbonate 10-30%;

[0018] Acrylic monomers 10-30%;

[0019] Photoinitiator 0~10%;

[0020] and organic solvents 30-80%;

[0021] The polythiocarbonate is the polythiocarbonate described in the above technical solution or the polythiocarbonate prepared by the preparation method described in the above technical solution.

[0022] Preferably, the acrylate monomer is at least one selected from 1,6-hexanediol diacrylate, triethylene glycol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, bisphenol A diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, and propoxylated glycerol triacrylate.

[0023] Preferably, the photoinitiator is at least one selected from 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphosphonate, 2-methyl-1-[4-methylthiophenyl]-2-morpholino-1-propanone, 2-isopropylthioxanthone, ethyl 4-dimethylaminobenzoate, and benzoin dimethyl ether.

[0024] Preferably, the organic solvent is at least one selected from dichloromethane, chloroform, tetrahydrofuran, benzene, toluene, valerolactone, butyrolactone, propylene glycol monoalkyl ether, propylene glycol monoalkyl ether acetate, cyclopentanone, cyclohexanone, butyl acetate, N,N-dimethylformamide, and N-methylpyrrolidone.

[0025] This invention provides a polythiocarbonate having the structure shown in Formula I. By introducing aromatic groups and sulfur atoms, this invention achieves a high molar refractive index and a low molar volume, thereby increasing the refractive index of the polythiocarbonate. Results from the embodiments show that the polythiocarbonate provided by this invention has a refractive index of 1.7 or higher. Attached Figure Description

[0026] Figure 1 The 1H NMR spectrum of the polythiocarbonate prepared in Example 1;

[0027] Figure 2 The IR infrared spectra of 1,4-benzenedithiol, 4,4'-thiodibenzenedithiol in Example 1 and the polythiocarbonates prepared in Examples 1-2 are shown.

[0028] Figure 3 The UV-Vis spectra of the polythiocarbonates prepared in Examples 1-2 are shown. Detailed Implementation

[0029] This invention provides a polythiocarbonate having the structure shown in Formula I:

[0030] Formula I;

[0031] In Formula I, Ar1 and Ar2 are independently substituted or unsubstituted aromatic groups or substituted or unsubstituted heterocyclic groups, X is oxygen or sulfur, and m and n are independently integers from 1 to 30.

[0032] In one implementation, m and n can independently be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28 or 29.

[0033] In this invention, the substituted groups preferably include at least one selected from halogen atoms, hydroxyl groups, amino groups, cyano groups, alkyl groups, cycloalkyl groups, alkoxy groups, and phenyl groups.

[0034] In this invention, the aromatic group preferably includes a monocyclic aromatic group or a polycyclic aromatic group; when the aromatic group contains at least two benzene rings, the benzene rings are preferably connected by a bridging group; the bridging group is preferably at least one of an oxygen atom, a sulfur atom, an alkylene group having 1 to 10 carbon atoms, and an alkene group having 1 to 10 carbon atoms.

[0035] In this invention, the heterocyclic group is preferably a pentacyclic heterocyclic group.

[0036] In this invention, the Ar1 and Ar2 are preferably, independently, the following groups:

[0037] , , , , , , or .

[0038] In this invention, the weight-average molecular weight of the polythiocarbonate is preferably 1000-50000; the dispersion of the polythiocarbonate is preferably 1.0-2.0. As one embodiment, the weight-average molecular weight of the polythiocarbonate can be 5000, 10000, 20000, 30000, or 40000; the dispersion of the polythiocarbonate can be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, or 1.9.

[0039] This invention improves the refractive index of polythiocarbonate by introducing aromatic groups and sulfur atoms, which have high molar refractive index and low molar volume. The refractive index at 632 nm is 1.65~1.80, and the transmittance at 450~800 nm is ≥80%, providing a wider range of material choices for optoelectronic devices.

[0040] The polythiocarbonate provided by this invention not only has the advantages of high refractive index and high transmittance, but also good processing performance. It can be cured by ultraviolet light for nanoimprinting, or it can be patterned to prepare gratings through processes such as mask exposure and development.

[0041] This invention is based on the Lorentz-Lorenz equation: The refractive index n is determined by the ratio of the molar refractive index [R] of the atoms or groups contained in the molecule to the molar volume V0. Introducing substituents with a high [R] / V0 value can effectively increase the refractive index of the polymer. Therefore, from a molecular design perspective, polythiocarbonates introduce a large number of aromatic groups and sulfur atoms, resulting in a significant increase in refractive index.

[0042] The present invention also provides a method for preparing the polythiocarbonate described in the above technical solution, comprising:

[0043] The compound, triphosgene, solvent, and catalyst are mixed and polymerized to obtain polythiocarbonate; the compound is an aromatic compound containing a thiol group or a heterocyclic compound containing a thiol group.

[0044] The present invention does not have any special limitations on the source of the raw materials, and commercially available products known to those skilled in the art can be used.

[0045] The present invention does not specifically limit the types of the thiol-containing aromatic compounds or thiol-containing heterocyclic compounds, but can select them according to the required Ar1 and Ar2.

[0046] In one embodiment, the thiol-containing aromatic compound may be 4,4'-thiodiphenylthiol and 1,4-benzenedithiol; the molar ratio of 4,4'-thiodiphenylthiol and 1,4-benzenedithiol may be 1:(1~9), or may be 3:7, 1:4 or 1:8.

[0047] In one embodiment, the thiol-containing aromatic compound may be 4,4'-thiodiphenylthiol and 1,4-benzenedimethylthiol; the molar ratio of 4,4'-thiodiphenylthiol and 1,4-benzenedimethylthiol may be (1~9):1, or it may be 7:3.

[0048] In this invention, the compound further includes hydroxyl-containing aromatic compounds. This invention does not specifically limit the types of hydroxyl-containing aromatic compounds; selection is based on the desired Ar1 and Ar2.

[0049] In one embodiment, the thiol-containing aromatic compound can be 4,4'-thiodiphenylthiol; the hydroxyl-containing aromatic compound can be 2,2-bis(p-hydroxyphenyl)propane (bisphenol A); the molar ratio of 2,2-bis(p-hydroxyphenyl)propane to 4,4'-thiol can be 1:(1~5), or even 1:4. This invention uses thiol-containing and hydroxyl-containing aromatic compounds for polymerization, which can weaken intermolecular interactions and solve the problem of poor solubility caused by introducing too many aromatic structures.

[0050] In this invention, the preferred molar ratio of the compound to triphosgene is (3~6):1. As one embodiment, the molar ratio of the compound to triphosgene can be 3.3:1.

[0051] In this invention, the solvent is preferably an organic solvent; the organic solvent is preferably at least one selected from toluene, xylene, cyclopentanone, cyclohexanone, N,N-dimethylformamide, N,N-dimethylacetamide, dichloromethane, chloroform, trichloroethane, acetone, tetrahydrofuran, and ethers. This invention does not have a specific limitation on the amount of solvent used, as long as all raw materials are completely dissolved.

[0052] In this invention, the catalyst is preferably at least one selected from sodium hydroxide, potassium hydroxide, lithium hydroxide, pyridine, 2-methylpyridine, 2,6-dimethylpyridine, trimethylamine, triethylamine, monoethanolamine, diethanolamine, tetraisopropyl titanate, tetrabutyl titanate, diisobutyltin laurate, tin octoate, and boron trifluoride; the molar ratio of the compound to the catalyst is preferably 1:(1~2).

[0053] In one embodiment, the molar ratio of the compound to the catalyst can be 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8 or 1:1.9.

[0054] The present invention does not have any special limitations on the operation of mixing the compound, triphosgene, solvent and catalyst, and any technical solution for preparing the mixture well known to those skilled in the art can be used.

[0055] In this invention, the preferred temperature for the polymerization reaction is -10℃ to 60℃; the preferred time for the polymerization reaction is 5 to 20 hours. As one embodiment, the temperature for the polymerization reaction can be -5℃, 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, or 55℃; the preferred time for the polymerization reaction can be 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, or 19 hours. By limiting the temperature and time of the polymerization reaction to the above ranges, this invention can further improve the degree of polymerization.

[0056] In this invention, when triphosgene is still present after the polymerization reaction is completed, it is preferable to quench the triphosgene. This invention does not impose any special limitations on the operation of quenching triphosgene; any operation well-known to those skilled in the art can be used.

[0057] As one implementation method, the quenching of triphosgene can be performed by quenching unreacted triphosgene with deionized water.

[0058] After the polymerization reaction is completed, the present invention preferably performs acid washing and water washing on the reaction solution obtained from the polymerization reaction, then uses methanol for precipitation, then filters to obtain filter cake, and then dries the filter cake to obtain polythiocarbonate.

[0059] The present invention does not impose any particular limitation on the pickling operation; any operation well known to those skilled in the art can be used. As one embodiment, the pickling agent used for pickling can be a 1 wt% hydrochloric acid aqueous solution.

[0060] The present invention does not impose any special limitations on the water washing operation; any operation known to those skilled in the art can be used to wash until the water is neutral.

[0061] This invention does not impose any special limitations on the operation of using methanol for sedimentation; any operation known to those skilled in the art can be used.

[0062] The present invention does not impose any special limitations on the filtration operation; the filter cake can be obtained by using operations well known to those skilled in the art.

[0063] The present invention does not have any special limitations on the drying operation; drying to constant weight can be achieved using a vacuum drying oven.

[0064] The preparation method provided by this invention is simple.

[0065] The present invention also provides a photocurable composition comprising the following components in weight percentage:

[0066] Polysulfide carbonate 10-30%;

[0067] Acrylic monomers 10-30%;

[0068] Photoinitiator 0~10%;

[0069] and organic solvents 30-80%;

[0070] The polythiocarbonate is the polythiocarbonate described in the above technical solution or the polythiocarbonate prepared by the preparation method described in the above technical solution.

[0071] The photocurable composition provided by the present invention comprises 10-30% polythiocarbonate by weight percentage. As one embodiment, the polythiocarbonate may be 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, or 29% by weight.

[0072] The photocurable composition provided by the present invention comprises 10-30% acrylate monomers by weight percentage. As one embodiment, the weight percentage of the acrylate monomers may be 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, or 29%.

[0073] In this invention, the acrylate monomer is preferably at least one of 1,6-hexanediol diacrylate, triethylene glycol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, bisphenol A diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, and propoxylated glycerol triacrylate.

[0074] The photocurable composition provided by the present invention comprises 0-10% photoinitiator by weight percentage. As one embodiment, the weight percentage of the photoinitiator may be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, or 9%.

[0075] In this invention, the photoinitiator is preferably at least one selected from 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphosphonate, 2-methyl-1-[4-methylthiophenyl]-2-morpholino-1-propanone, 2-isopropylthioxanthone, ethyl 4-dimethylaminobenzoate, and benzoin dimethyl ether.

[0076] The photocurable composition provided by the present invention comprises 30-80% organic solvent by weight percentage. As one embodiment, the organic solvent may be 35%, 40%, 45%, 50%, 55%, 60%, 63%, 65%, 70%, or 75% by weight percentage.

[0077] In this invention, the organic solvent is preferably at least one selected from dichloromethane, chloroform, tetrahydrofuran, benzene, toluene, valerolactone, butyrolactone, propylene glycol monoalkyl ether, propylene glycol monoalkyl ether acetate, cyclopentanone, cyclohexanone, butyl acetate, N,N-dimethylformamide, and N-methylpyrrolidone.

[0078] The polythiocarbonate of this invention is end-capped with mercapto groups, which can undergo a "mercapto-olefin" click reaction with acrylate monomers for photocuring, thereby obtaining high-refractive-index optical materials and providing a wider range of material choices for the application of high-end optical components.

[0079] The photocurable composition provided by this invention has both high refractive index and high transparency, is easy to process, and the optical lens obtained by processing it has a light weight.

[0080] In summary, the polythiocarbonate of the present invention improves the refractive index by introducing benzene rings and sulfur elements, and improves the solubility while improving the refractive index through copolymerization and the introduction of benzene ring substituents, thus giving the polythiocarbonate good comprehensive performance as an optical material.

[0081] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0082] For ease of testing, the polythiocarbonates prepared in the examples were all film-formed using the following method:

[0083] 0.5 g of polythiocarbonate was dissolved in 1 mL of N-methylpyrrolidone, then spin-coated onto a glass slide, and the solvent was dried at 120 °C on a heated stage to prepare a film with a thickness of approximately 20 μm. The film was then tested using the following methods:

[0084] 1. Refractive index (nD)

[0085] The refractive index of the fabricated film at 632 nm was measured at 25 °C using a prism-coupled refractometer.

[0086] 2. Weight-average molecular weight Mw

[0087] Using gel permeation chromatography (GPC), a standard curve was prepared using tetrahydrofuran as the developing solvent and standard polystyrene with a known molecular weight (molecular weight distribution = 1). Based on this standard curve, Mw was calculated from the retention times in GPC.

[0088] 3. Ultraviolet-visible light transmittance

[0089] The transmittance of ultraviolet-visible light was measured on a 20 μm thick film using an ultraviolet-visible-near-infrared spectrophotometer.

[0090] Example 1

[0091] A polythiocarbonate has the following structure:

[0092] ;

[0093] Where m is 2 and n is 17 (calculated based on molecular weight, the same below); the weight-average molecular weight is 3723 and the dispersion is 1.26;

[0094] The preparation method of the polythiocarbonate is as follows:

[0095] 0.01 mol of 4,4'-thiodiphenylthiol and 0.09 mol of 1,4-benzened dithiol were added to a 50 mL three-necked round-bottom flask and dissolved in N,N-dimethylformamide. 0.18 mol of pyridine and 0.03 mol of triphosgene were added to the reaction system. The polymerization reaction was monitored at room temperature and ended after 8 hours. Unreacted triphosgene was then quenched with deionized water. The reaction solution was then acid-washed with a 1 wt% hydrochloric acid aqueous solution, followed by water washing until neutral. The solution was then precipitated with methanol and filtered to obtain a white solid powder. Finally, it was dried in a vacuum drying oven to obtain polythiocarbonate.

[0096] The reaction equation for the preparation of polythiocarbonate in Example 1 is as follows:

[0097]

[0098] The polythiocarbonate prepared in Example 1 has a refractive index of 1.71 and a UV-Vis transmittance of 89%.

[0099] Example 2

[0100] A polythiocarbonate has the following structure:

[0101] ;

[0102] Where m is 7 and n is 27 (calculated based on molecular weight, the same below); the weight-average molecular weight is 6912 and the dispersion is 1.38;

[0103] The preparation method of the polythiocarbonate is as follows:

[0104] 0.02 mol of 4,4'-thiodiphenylthiol and 0.08 mol of 1,4-benzened dithiol were added to a 50 mL three-necked round-bottom flask and dissolved in N,N-dimethylformamide. 0.18 mol of pyridine and 0.03 mol of triphosgene were added to the reaction system. The polymerization reaction was monitored at room temperature. After the reaction was completed in 8 hours, the unreacted triphosgene was quenched with deionized water. The reaction solution was then acid-washed with a 1 wt% hydrochloric acid aqueous solution, followed by water washing until neutral. The solution was then precipitated with methanol and filtered to obtain a white solid powder. The powder was then dried in a vacuum drying oven to obtain polythiocarbonate.

[0105] The polythiocarbonate prepared in Example 2 has a refractive index of 1.72 and a UV-Vis transmittance of 92%.

[0106] Example 3

[0107] A polythiocarbonate has the following structure:

[0108] ;

[0109] Where m is 10 and n is 24 (calculated based on molecular weight, the same below); the weight-average molecular weight is 7204 and the dispersion is 1.32;

[0110] The preparation method of the polythiocarbonate is as follows:

[0111] 0.03 mol of 4,4'-thiodiphenylthiol and 0.07 mol of 1,4-benzened dithiol were added to a 50 mL three-necked round-bottom flask and dissolved in N,N-dimethylformamide. 0.18 mol of pyridine and 0.03 mol of triphosgene were added to the reaction system. The polymerization reaction was monitored at room temperature. After the reaction was completed in 8 hours, the unreacted triphosgene was quenched with deionized water. The reaction solution was then acid-washed with a 1 wt% hydrochloric acid aqueous solution, followed by water washing until neutral. The solution was then precipitated with methanol and filtered to obtain a white solid powder. The powder was then dried in a vacuum drying oven to obtain polythiocarbonate.

[0112] The polythiocarbonate prepared in Example 3 has a refractive index of 1.728 and a UV-Vis transmittance of 92%.

[0113] A comparison of Examples 1-3 shows that copolymerization of different amounts of monomers yields polymers with different refractive indices, and different comonomers yield polymers with different refractive indices. By adjusting the ratio of monomers and comonomers, polythiocarbonate polymers with adjustable refractive indices can be obtained.

[0114] Example 4

[0115] A polythiocarbonate has the following structure:

[0116] ;

[0117] Where m is 16 and n is 8 (calculated based on molecular weight, the same below); the weight-average molecular weight is 6302 and the dispersion is 1.40;

[0118] The preparation method of the polythiocarbonate is as follows:

[0119] 0.07 mol of 4,4'-thiodiphenylthiol and 0.03 mol of 1,4-phenyldimethylthiol were added to a 50 mL three-necked round-bottom flask and dissolved in N,N-dimethylformamide. 0.18 mol of pyridine and 0.03 mol of triphosgene were added to the reaction system. The polymerization reaction was monitored at room temperature. After the reaction was completed in 8 hours, the unreacted triphosgene was quenched with deionized water. The reaction solution was then acid-washed with a 1 wt% hydrochloric acid aqueous solution, followed by water washing until neutral. The solution was then precipitated with methanol and filtered to obtain a white solid powder. The powder was then dried in a vacuum drying oven to obtain polythiocarbonate.

[0120] The reaction equation for the preparation of polythiocarbonate in Example 4 is as follows:

[0121] .

[0122] The polythiocarbonate prepared in Example 4 has a refractive index of 1.703 and a UV-Vis transmittance of 93%.

[0123] Example 5

[0124] A polythiocarbonate has the following structure:

[0125] ;

[0126] Where m is 21 and n is 6 (calculated based on molecular weight, the same below); the weight-average molecular weight is 7853 and the dispersion is 1.28;

[0127] The preparation method of the polythiocarbonate is as follows:

[0128] 0.08 mol of 4,4'-thiodiphenylthiol and 0.02 mol of bisphenol A were added to a 50 mL three-necked round-bottom flask and dissolved in N,N-dimethylformamide. 0.18 mol of pyridine and 0.03 mol of triphosgene were added to the reaction system. The polymerization reaction was monitored at room temperature. After the reaction was completed in 8 hours, the unreacted triphosgene was quenched with deionized water. The reaction solution was then acid-washed with a 1 wt% hydrochloric acid aqueous solution, followed by water washing until neutral. The solution was then precipitated with methanol and filtered to obtain a white solid powder. The powder was then dried in a vacuum drying oven to obtain polythiocarbonate.

[0129] The reaction equation for the preparation of polythiocarbonate in Example 5 is as follows:

[0130] .

[0131] The polythiocarbonate prepared in Example 5 has a refractive index of 1.687 and a UV-Vis transmittance of 95%.

[0132] Example 6

[0133] The photocurable composition consists of the following components by weight percentage:

[0134] 10% polysulfide carbonate;

[0135] 25% trimethylolpropane triacrylate;

[0136] 2-Hydroxy-2-methyl-1-phenyl-1-propanone photoinitiator 2%;

[0137] and N-methylpyrrolidone 63%;

[0138] The method for preparing the photocurable composition is as follows:

[0139] The polythiocarbonate prepared in Example 3 and trimethylolpropane triacrylate were dissolved in N-methylpyrrolidone, and 2-hydroxy-2-methyl-1-phenyl-1-propanone photoinitiator was added. The mixture was then spin-coated onto a glass slide. The solvent was first pre-baked at 70°C for 5 min and then at 120°C for 10 min, and then exposed under a UV lamp with an exposure dose of 2100 mJ / cm². 2 The pattern on the photomask is transferred to the resin, followed by post-baking at 70℃ for 5 min and 120℃ for 10 min to accelerate the reaction. Finally, the pattern on the photomask can be obtained by development.

[0140] Based on the characterization results, test images of Examples 1 and 2, which showed better overall refractive index and transparency, are provided. The 1H NMR spectrum of the polythiocarbonate prepared in Example 1 is shown below. Figure 1 As shown; the IR infrared spectra of 1,4-benzenedithiol, 4,4'-thiodibenzenethiol in Example 1 and the polythiocarbonates prepared in Examples 1-2 are as follows. Figure 2 As shown; the UV-Vis spectra of the polythiocarbonates prepared in Examples 1-2 are as follows. Figure 3 As shown.

[0141] from Figure 1 As can be seen, the chemical shift of hydrogen on the benzene ring in the 1H NMR spectrum is around 7.2, and the chemical shift of hydrogen on the mercapto group is around 3.5.

[0142] from Figure 2 It can be seen that the wavelength is 2562cm. -1 The characteristic absorption peak of the thiol group is at 1710 cm⁻¹. -1 The peak at this point is a characteristic absorption peak for the carbonyl group.

[0143] from Figure 3 It can be seen that the transmittance of the coated film in the visible light region is over 85%, indicating good transparency.

[0144] As can be seen from the examples, the polythiocarbonate provided by the present invention has a high refractive index.

[0145] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A polythiocarbonate, characterized by, having a structure represented by Formula I: Formula I; In the formula I, Ar1is ; Ar2is or X is sulfur, m is an integer from 7 to 30, and n is an integer from 1 to 30.

2. The polythiocarbonate according to claim 1, characterized in that, The polythiocarbonate has a weight average molecular weight of 1000-50000 and a dispersity of 1.0-2.

0.

3. The process for the preparation of a polythiocarbonate according to any one of claims 1 to 2, characterized in that, Comprising: The compound includes a thiol-containing aromatic compound.

4. A photocurable composition characterized by comprising: Comprising the following components in mass percentage: Polythiocarbonate 10-30%; Acrylate monomer 10-30%; Photoinitiator 0-10%; And organic solvent 30-80%; The polythiocarbonate is the polythiocarbonate according to any one of claims 1-2 or prepared by the preparation method according to claim 3.

5. The photocurable composition according to claim 4, characterized in that, The acrylate monomer is at least one of 1,6-hexanediol diacrylate, triethylene glycol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, bisphenol A diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate and propoxylated glycerol triacrylate.

6. The photocurable composition according to claim 4, characterized in that, The photoinitiator is at least one of 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2,4,6-trimethylbenzoyldiphenyl phosphine oxide, 2,4,6-trimethylbenzoyl ethyl phosphonate, 2-methyl-1-[4-methylthiophenyl]-2-morpholin-1-propanone, 2-isopropylthioxanthone, 4-dimethylamino-benzoic acid ethyl ester and benzoin dimethyl ether.

7. The photocurable composition according to claim 4, characterized in that, The organic solvent is at least one of dichloromethane, chloroform, tetrahydrofuran, benzene, toluene, valerolactone, butyrolactone, propylene glycol monoalkyl ether, propylene glycol monoalkyl ether acetate, cyclopentanone, cyclohexanone, butyl acetate, N,N-dimethylformamide and N-methyl pyrrolidone.

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