Method for producing ester thiol compound and optical resin containing the same

Abstract

【assignment】 [Solution] The present invention relates to a method for producing an ester thiol compound by reacting a polyhydric alcohol with a mercaptocarboxylic acid, and also to an optical resin or optical lens obtained therefrom, which has excellent optical properties.

Description

[Technical Field]

[0001] The present invention relates to a method for producing an ester thiol compound, and to a poly(thio)urethane-based polymerizable composition and an optical resin having excellent optical properties, which contain the ester thiol compound obtained thereby. [Background technology]

[0002] Polythiourethane optical materials have a refractive index similar to that of glass optical materials, and because they are lighter, more impact resistant, and more easily dyed than glass optical materials, they are widely used as various optical materials such as eyeglass lenses and camera lenses. In recent years, there has been a demand for optical materials with high functionality, such as impact resistance and heat resistance, and high optical transparency, high refractive index, and high Abbe number performance are required.

[0003] In order to improve the impact resistance of polythiourethane-based optical materials, research into ester thiol compounds has been steadily underway, and optical material compositions containing ester thiol compounds can be used as photocurable thio-ene compositions and curing agents for epoxy curing systems.

[0004] Ester thiol compounds are produced by an esterification method in which a general polyhydric alcohol and a mercaptocarboxylic acid are reacted in the presence of an esterification catalyst while removing by-produced water by distillation (see Prior Art Documents 1 to 4).

[0005] However, in the conventional method for producing an ester thiol compound, a special purification process is required to remove the homogeneous catalyst after the reaction because a homogeneous catalyst is used, which may result in additional process costs and environmental pollution due to the generation of a large amount of wastewater. In addition, some of the homogeneous catalyst may remain in the ester thiol compound, which may cause striae, opacity, yellowing, etc. when producing an optical resin. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Republic of Korea Patent Application No. 10-2010-7028490 [Patent Document 2] Republic of Korea Patent Application No. 10-2016-0090624 [Patent Document 3] Republic of Korea Patent Application No. 10-2017-7035596 [Patent Document 4] Republic of Korea Patent Application No. 10-2019-0005901 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the present inventors have conducted research to solve the above-mentioned shortcomings, and as a result, have attempted to efficiently produce ester thiol compounds by introducing a solid acid independent of the reaction system to produce ester thiol compounds, thereby simplifying the production process by converting the more complicated purification process that would result from using a homogeneous catalyst into a simple process such as a filter. In addition, by reusing the used catalyst, the amount of wastewater and waste generated can be reduced, making it an economical and environmentally friendly process, which is a distinctive feature compared to existing processes. Therefore, the present invention can bring economic benefits in terms of industrialization by reducing process costs, obtaining high yields, and obtaining high-quality products. [Means for solving the problem]

[0008] The above-mentioned object of the present invention is achieved, as one aspect of the present invention, by a method for producing an ester thiol compound of the following formula 3 by reacting a polyhydric alcohol of the following formula 1 with a mercaptocarboxylic acid of the following formula 2 using a heterogeneous solid acid catalyst.

[0009] [ka] [ka] [ka] [In the above chemical formula, R1 and R2 are each independently H or CH3, l is an integer of 0 to 2, m is an integer of 1 to 4, and n is an integer of 0 to 3.]

[0010] The solid acid catalyst may be natural clay, synthetic silica-alumina, zeolite, ion exchange resin, heteropolyacid, or a super-strong acid mesoporous material catalyst. The solid acid catalyst is preferably a super-strong acid mesoporous material catalyst. In particular, a mesoporous material containing sulfonic acid as a super-strong acid is more preferred.

[0011] On the other hand, the super strong acid mesoporous material catalyst can be used in a weight ratio of 0.2 to 20, preferably 1 to 20.

[0012] The polyhydric alcohol of the above formula 1 and the mercaptocarboxylic acid of the above formula 2 can be used in a ratio of 20-30:80-70.

[0013] The process of the present invention is preferably carried out in a fixed-bed tubular reactor packed with the heterogeneous solid acid catalyst.

[0014] In another aspect of the present invention, the present invention can provide a polymerizable composition containing a polyisocyanate together with the ester thiol compound produced by the above-described production method, and which may further contain another polythiol or polyol.

[0015] In another aspect, the present invention can provide a poly(thiol)urethane composition obtained by polymerizing the polythiol or polyol of the polymerizable composition and polyisocyanate in a reactor so that the molar ratio of SH (or OH) groups to NCO groups is in the range of 0.5 to 1.5.

[0016] In another aspect, the present invention can provide a resin obtained by curing the poly(thiol)urethane composition, and the resulting resin can be used as an optical material, particularly an optical lens. [Effects of the Invention]

[0017] The production method of the present invention can improve the production efficiency and quality of ester thiol compounds, which are widely used in the chemical, resin, and coating industrial fields, including the optical materials field, and is therefore of great technological and industrial value.

[0018] The ester thiol compound obtained by the production method using a heterogeneous catalyst, which is a feature of the present invention, is economically superior and can produce high-quality products. Furthermore, by using such a catalyst, excellent quality optical resins and optical products can be obtained economically. DETAILED DESCRIPTION OF THE INVENTION

[0019] Specific numerical values ​​of the blending ratio (content ratio), physical property values, parameters, etc. described in the present invention can be replaced with the corresponding upper limit (numerical value defined as "not more than" or "less than") or lower limit (numerical value defined as "not less than" or "exceeding") of the blending ratio (content ratio), physical property value, parameter, etc. Meanwhile, "%" is based on mass unless otherwise specified.

[0020] Next, the method for producing the ester thiol compound of the present invention will be described in detail.

[0021] First, the present invention aims to easily produce a high-purity ester thiol compound without undergoing any additional complicated purification steps by using a heterogeneous catalyst as an ester catalyst used in the production process of an ester thiol compound.

[0022] As described above, ester thiol compounds are produced by esterification of polyhydric alcohols with mercaptocarboxylic acids in the presence of an ester catalyst while removing the by-product water. Esterification catalysts are generally available in a variety of forms, including Brönsted acids, Lewis acids, and solid acid catalysts. Homogeneous catalysts are typically used in conventional esterification reactions. Homogeneous catalysts, which act in a molecular state, are highly active and highly selective due to the molecular state of the reaction, making them highly effective. However, because the catalyst exists as a single phase like the reaction system, separation from the product and reuse after the reaction is complete is difficult, and additional facility operation related to separation is costly. The chemicals and costs required for the separation process can reduce the process's economic viability and even lead to environmental pollution. In light of these issues, the present invention aims to use heterogeneous solid catalysts that are easily separated and reusable. In particular, solid acid catalysts, which have developed alongside the petrochemical industry, are available in a wide variety of types and have a wide range of acid strength adjustment, making them highly applicable to the production process of the present invention. Furthermore, if the selectivity can be increased by utilizing the pore structure of the solid catalyst, it will be extremely useful in terms of suppressing the production of by-products and preventing environmental pollution.

[0023] Heterogeneous catalysts that can be used in the production of the ester thiol compound of the present invention are not particularly limited. Representative examples include natural clay, silica-alumina, zeolites, ion exchange resins, heteropolyacids, and superacid mesoporous materials. While amorphous catalysts are available, there are also zeolites and mesoporous materials with regular pores. Catalysts with uniform pore size and shape can also be expected to exhibit shape-selective catalytic activity due to their pore structure. Zeolite pores are similar in size to normal molecules such as benzene, and the use of zeolites allows for the differentiation of substances based on molecular size. Introducing these properties into catalytic reactions can effectively control the reaction rate or enhance selectivity for specific products by utilizing the size of reactants or the diffusion rate of products. The size of the pores can also affect the transition state, enhancing selectivity for specific products.

[0024] Zeolites are crystalline aluminosilicates, and over 170 types of zeolites with different framework structures are available, including MFI, FAU, MOR, BEA, LTA, and CHA. The physical and chemical properties of zeolites and their catalytic potential are determined by factors such as framework structure, pore opening size, pore shape and size, Si / Al molar ratio, and particle size. The framework structure, which is the basic element of zeolites, is determined by the type of secondary basic units that form the crystal and how they are connected. Furthermore, the framework determines the shape, size, and connection method of pores, as well as the size of pore openings. Having many large pores provides a large surface area that can contact the reactants, which can increase catalytic activity but reduces mechanical stability. The Si / Al molar ratio, which indicates the degree of aluminum content in the framework, is related to the generation of acid sites and is also a major factor determining the hydrothermal stability of zeolites. The particle size determines the distance that reactants and products can travel within zeolites, and small particles have a large outer surface, resulting in extremely high activity in catalytic reactions that must first occur on the outer surface. Zeolites are extremely useful catalytic materials because their catalytic properties, especially their acidity, can be broadly adjusted through various methods, including cation exchange, framework element exchange, the loading of specific substances, and the shielding of acid sites on the outer surface.

[0025] In addition to these functions, highly effective catalysts can be produced by utilizing the fact that reaction properties change depending on the shape and size of the pores. However, the pore openings of zeolites are smaller than 0.7 nm, preventing large molecules from entering the pores. This makes them unsuitable for use as catalysts in organic synthesis reactions involving large molecules. Mesoporous materials, discovered in 1992, overcome this limitation by developing mesopores in the 3-10 nm range. Not only can the size and shape of the pores be broadly controlled depending on the mold material used, but the incorporation of aluminum along with silicon into the framework also makes them highly promising as acid catalysts. However, unlike zeolites, the amorphous pore walls do not generate strong acid sites, and the pores are too large for the reactants, making it difficult to expect increased selectivity due to interactions between the pore walls and the reactants. Instead, the uniformly sized mesopores are regularly developed, resulting in a large surface area and rapid mass transfer. By attaching specific functional groups to the pore walls, excellent catalytic performance can be expected.

[0026] In particular, the catalyst can be used by introducing a superacid stronger than sulfuric acid into a mesoporous material. Examples of superacids that can be used include sulfonic acid (RSO3H), trifluoromethanesulfonic acid (CF3SO3H), perchloric acid (HClO4), fluoric acid (HF), sulfuric acid derivatives such as chlorosulfuric acid (ClSO3H) and fluorosulfuric acid (FSO3H).

[0027] A preferred superacid is a sulfonic acid, which is a mesoporous material with sulfonic acid groups (-SO3H) attached to its surface. While the active sites function as a heterogeneous catalyst, the active sites act as a homogeneous catalyst. This material can be used to create catalysts. In particular, when sulfonic acid groups are attached to the surface via organic bonds, they become effective acid catalysts for organic synthesis reactions. The number of attached sulfonic acid groups and the surrounding structure determine the number of acid sites and the acid strength, allowing for the creation of solid acid catalysts tailored to specific applications. By reacting silanes containing alkoxy groups along with -SH functional groups with the surface hydroxyl groups of mesoporous materials made of silica, -SH functional groups can be attached to the pore walls. Treatment of this with an appropriate oxidizing agent produces an acid catalyst with an attached sulfonic acid group. Furthermore, by adding alkoxysilanes or chlorosilanes with -SH functional groups or sulfide bonds to the mother liquor used to synthesize mesoporous materials, acidic functional groups can also be attached to the pore walls during the synthesis process. By immobilizing Nafion groups, which have extremely strong acid strength, it is possible to immobilize very strong acid sites on the pore walls of mesoporous materials. Unlike zeolites, solid acid catalysts produced in this way do not offer the shape selectivity that comes from the pore structure, but they have a large surface area, fast mass transfer, and are highly active in catalytic reactions of large molecules.

[0028] The polyhydric alcohol of formula (1) used in the method for producing an ester thiol of the present invention is a commercially available substance, and is not particularly limited, and examples thereof include pentaerythritol.

[0029] Examples of mercaptocarboxylic acids of formula (2) include, but are not limited to, 4-mercaptobutyric acid, 3-mercaptobutyric acid, 3-mercaptopropionic acid, 2-mercaptopropionic acid, and 2-mercaptoacetic acid. In this embodiment, or from the viewpoint of lens polymerization reaction, 3-mercaptopropionic acid and 2-mercaptoacetic acid are preferred.

[0030] The weight ratio of the polyhydric alcohol of the above formula (1) to the mercaptocarboxylic acid of the formula (2) is 10-40:90-60, and a preferred weight ratio is 20-30:80-70.

[0031] Meanwhile, reactors used in the method for producing ester thiols of the present invention include batch reactors and tubular reactors. Among tubular reactors, fixed-bed tubular reactors, which can be filled with the heterogeneous solid acid catalyst of the present invention, are preferred. In particular, such catalyst fixed-bed reactors can be used by connecting multiple catalyst fixed beds depending on the purpose, and have the advantage of high conversion rates per catalyst weight in the reaction. In addition, such reactors facilitate the production of products that are difficult to handle in batch reactors and enable continuous production, offering various advantages such as reduced process costs and ease of mass production.

[0032] The temperature of the ester thiol compound production process of the present invention is not particularly limited, but can be from 0 to 250°C, preferably from 50 to 200°C, and more preferably from 100 to 180°C.

[0033] In order to exclude oxygen during the production process of the present invention, it is preferable to carry out the process in a nitrogen atmosphere or a hydrogen atmosphere, and it is also possible to carry out the process in a solvent or in a state where the solvent has been removed.

[0034] The solvent used in the present invention is not particularly limited either. Examples of the inactivating solvent include aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as octane and decane, alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, and ethylcyclohexane, halogenated aromatic hydrocarbons such as chlorotoluene, chlorobenzene, dichlorobenzene, dibromobenzene, and trichlorobenzene, nitrogen-containing compounds such as nitrobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, and N,N'-dimethylimidazolidineone, ethers such as dibutyl ether, ethylene glycol dimethyl ether, and ethylene glycol diethyl ether, and amyl formate and n-butyl acetamide. Examples of suitable esters include acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, methyl isoamyl acetate, methoxybutyl acetate, 2-ethoxyethyl acetate, sec-hexyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, benzyl acetate, ethyl propionate, n-butyl propionate, isoamyl propionate, ethyl acetate, butyl stearate, butyl lactate, and amyl lactate, and aromatic carboxylic acid esters such as methyl salicylate, dimethyl phthalate, and methyl benzoate, which may be used alone or in combination of two or more. Preferred are aromatic hydrocarbons, and more preferred are toluene, chlorobenzene, and dichlorobenzene.

[0035] The products produced using the ester thiol compounds obtained as above can meet high optical properties, so they can be used to produce optical materials, specifically plastic optical lenses.

[0036] According to the present invention, there is provided a polymerizable composition comprising a polythiol / polyol composition containing the above-described ester thiol compound and an isocyanate composition.

[0037] The polymerizable composition may contain the isocyanate composition and the polyol / polythiol in a mixed state or in a separate state. That is, in the polymerizable composition, the isocyanate composition and the polyol / polythiol may be in a blended state in contact with each other, or may be in a separated state so as not to contact each other.

[0038] The polyol component used in the polymerizable composition of the present invention may be, for example, a low molecular weight polyol or a high molecular weight polyol. The above polyols may be used alone or in combination of two or more.

[0039] The low-molecular-weight polyol is a compound having two or more hydroxyl groups and a number-average molecular weight of 60 or more but less than 400. Examples of low-molecular-weight polyols include ethylene glycol, propylene glycol, 1,3-propenediol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, 1,5-pentenediol, 1,6-hexenediol, diethylene glycol, triethylene glycol, dipropylene glycol, and mixtures thereof, 1,4-cyclohexenediol, hydrogenated bisphenol A, bisphenol A, and other dihydric alcohols, for example, glycerin, tetrahydric alcohols, for example, tetramethylolmethane (pentaerythritol), pentahydric alcohols, for example, xylitol, and hexahydric alcohols, for example, sorbitol, mannitol, allitol, iditol, and other hexahydric alcohols.

[0040] The high-molecular-weight polyol is a compound having two or more hydroxyl groups and a number-average molecular weight of 400 or more, for example, 10,000 or less, preferably 5,000 or less. Examples of high-molecular-weight polyols include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, silicone polyols, fluorine polyols, and vinyl monomer-modified polyols.

[0041] Examples of polythiol components containing the above-mentioned ester thiol used in the polymerizable composition of the present invention include aliphatic polythiols, aromatic polythiols, heterocycle-containing polythiols, aliphatic polythiols containing sulfur atoms in addition to mercapto groups, aromatic polythiols containing sulfur atoms in addition to mercapto groups, and heterocycle-containing polythiols containing sulfur atoms in addition to mercapto groups. The thiols may be thiol oligomers or polythiols, and one or more of them may be used in combination. Specific examples of the thiols include 3,3'-thiobis[2-[(2-mercaptoethyl)thio]-1-propanethiol], bis(2-(2-mercaptoethylthio)-3-mercaptopropyl)sulfide, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 2,3-bis(2-mercaptoethylthio)propane-1-thiol (GST), and 2,2-bis(mercaptomethyl)-1,3-propanedithiol. Thiol, bis(2-mercaptoethyl) sulfide, tetrakis(mercaptomethyl)methane, 2-(2-mercaptoethylthio)propane-1,3-dithiol, 2-(2,3-bis(2-mercaptoethylthio)propylthio)ethanethiol, bis(2,3-dimercaptopropanyl) sulfide, bis(2,3-dimercaptopropanyl) disulfide, 1,2-bis[(2-mercaptoethyl)thio]-3-mer mercaptopropane, 1,2-bis(2-(2-mercaptoethylthio)-3-mercaptopropylthio)ethane, 2-(2-mercaptoethylthio)-3-2-mercapto-3-[3-mercapto-2-(2-mercaptoethylthio)-propylthio]propylthio-propane-1-thiol, 2,2-bis-(3-mercapto-propionyloxymethyl)-butyl ester, 2-(2-mercaptoethylthio)-3-(2- (2-[3-mercapto-2-(2-mercaptoethylthio)-propylthio]ethylthio)ethylthio)propane-1-thiol, (4R,11S)-4,11-bis(mercaptomethyl)-3,6,9,12-tetrathiatetradecane-1,14-dithiol, (S)-3-((R-2,3-dimercaptopropyl)thio)propane-1,2-dithiol, (4R,14R)-4,14-bis(mercaptomethyl)-3,6,9,12,15-Pentathiaheptane-1,17-dithiol, (S)-3-((R-3-mercapto-2-((2-mercaptoethyl)thio)propyl)thio)-2-((2-mercaptoethyl)thio)propane-1-thiol, 3,3'-dithiobis(propane-1,2-dithiol), (7R,11S)-7,11-bis(mercaptomethyl)-3,6,9,12,15-pentathiaheptane Butadecane-1,17-dithiol, (7R,12S)-7,12-bis(mercaptomethyl)-3,6,9,10,13,16-hexathiaoctadecane-1,18-dithiol, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,8-dimercaptomethyl -1,11-dimercapto-3,6,9-trithiaundecane, pentaerythritol tetrakis(3-mercaptopropionate), trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), bispentaerythritol ether hexakis(3-mercaptopropionate), 1,1,3,3-tetrakis(mercaptomethylthio)propane, 1,1,2,2-tetrakis(mercaptomethylthio)ethane, 4,6-bis(mercaptomethylthio)-1,3-dithiane, pentaerythritol tetrakis(2-mercaptoacetate), pentaerythritol tetrakis(3-mercaptopropionate) (PETMP), 2-(2,2-bis(mercaptodimethylthio)ethyl)-1,3-dithiane, etc.

[0042] The isocyanate composition used in the polymerizable composition of the present invention can be one or more of alkylene diisocyanate compounds, alicyclic diisocyanate compounds, heterocyclic diisocyanate compounds, sulfur-containing aliphatic diisocyanate compounds, and the like.

[0043] Alkylene diisocyanate compounds include, for example, ethylene diisocyanate; trimethylene diisocyanate; tetramethylene diisocyanate; 1,6-hexamethylene diisocyanate; octamethylene diisocyanate; nonamethylene diisocyanate; 2,2-dimethylpentane diisocyanate; 2,2,4-trimethylhexane diisocyanate; decamethylene diisocyanate; butene diisocyanate; 1,3-butadiene-1,4-diisocyanate; 2,4,4-trimethylhexamethylene diisocyanate; 1,6,11-undecane triisocyanate; 1,3,6-hexamethylene triisocyanate; 1,8-diisocyanate-4-isocyanatemethyloctane; 2,5,7-trimethyl-1,8-diisocyanate-5-isocyanatemethyloctane. bis(isocyanatoethyl)carbonate; bis(isocyanatoethyl)ether; 1,4-butylene glycol dipropyl ether-1,2-diisocyanate; 1,4-butylene glycol dipropyl ether-1,3-diisocyanate; 1,4-butylene glycol dipropyl ether-1,4-diisocyanate; 1,4-butylene glycol dipropyl ether-2,3-diisocyanate; 1,4-butylene glycol dipropyl ether-2,4-diisocyanate; methylisocyanate; lysine triisocyanate; 2-isocyanatoethyl-2,6-diisocyanatohexanoate; 2-isocyanatopropyl-2,6-diisocyanatohexanoate; mesitylene triisocyanate; 2,6-di(isocyanatomethyl)furan, etc.

[0044] Alicyclic diisocyanate compounds include, for example, isophorone diisocyanate; dicyclohexylmethane diisocyanate; 3,8-bis(isocyanatomethyl)tricyclo[5,2,1,0,6]decane; 3,9-bis(isocyanatomethyl)tricyclo[5,2,1,0,6]decane; 4,8-bis(isocyanatomethyl)tricyclo[5,2,1,0,6]decane; 4,9-bis(isocyanatomethyl)tricyclo[5,2,1,0,6]decane; 2,5-bis(isocyanatomethyl)bicyclo[2,2,1]heptane; 2,6-bis(isocyanatomethyl)bicyclo[2,2,1]heptane; Cyanatomethyl)bicyclo[2,2,1]heptane;Bis(isocyanatomethyl)cyclohexane;Dicyclohexylmethane diisocyanate;Cyclohexane diisocyanate;Methylcyclohexane diisocyanate (DIMC);Dicyclohexyldimethylmethane diisocyanate;2,2'-Dimethyldicyclohexylmethane diisocyanate;Bis(4-isocyanato-n-butylidene)pentaerythritol;Dimer acid diisocyanate;2-Isocyanatomethyl-3-(3-isocyanatopropyl)-5-isocyanate Methylbicyclo[2,2,1]heptane;2-Isocyanatomethyl-3-(3-isocyanatopropyl)-6-isocyanatomethylbicyclo[2,2,1]heptane;2-Isocyanatomethyl-2-(3-isocyanatopropyl)-5-isocyanatomethyl-bicyclo[2,2,1]heptane;2-Isocyanatomethyl-2-(3-isocyanatopropyl)-6-isocyanatomethyl-bicyclo[2,2,1]heptane;2-Isocyanatomethyl-3-(3-isocyanatopropyl)-6-(2-isocyanatomethyl)bicyclo[2,2,1]heptane 2-Isocyanatomethyl-2-(3-isocyanatopropyl)-5-(2-isocyanatoethyl)-bicyclo[2,2,1]-heptane;2-Isocyanatomethyl-2-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)-bicyclo[2,2,1]-heptane;2-Isocyanatomethyl-2-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)-bicyclo[2,2,1]-heptane;1,3,5-Tris(isocyanatomethyl)-cyclohexane;Dicyclohexylmethane-4,4-diisocyanate (H12MDI) and others.

[0045] Heterocyclic diisocyanate compounds include, for example, thiophene-2,5-diisocyanate; methylthiophene-2,5-diisocyanate; 1,4-dithiane-2,5-diisocyanate; methyl 1,4-dithiane-2,5-diisocyanate; 1,3-dithiolane-4,5-diisocyanate; methyl 1,3-dithiolane-4,5-diisocyanate; methyl 1,3-dithiolane-2-methyl-4,5-diisocyanate; ethyl 1,3-dithiolane-2,2-diisocyanate; tetrahydrothiolane These include thiophene-2,5-diisocyanate; methyl tetrahydrothiophene-2,5-diisocyanate; ethyl tetrahydrothiophene-2,5-diisocyanate; methyl tetrahydrothiophene-3,4-diisocyanate; 1,2-diisothiocyanate ethane; 1,3-diisothiocyanate propane; 1,4-diisothiocyanate butane; 1,6-diisothiocyanate hexane; p-phenylenediisopropylidenediisothiocyanate; and cyclohexane diisothiocyanate.

[0046] Examples of sulfur-containing aliphatic diisocyanate compounds include 4-isocyanate-4'-isothiocyanate diphenyl sulfide; 2-isocyanate-2'-isothiocyanate diethyl disulfide; thiodiethyl diisocyanate; thiodipropyl diisocyanate; thiodihexyl diisocyanate; dimethyl sulfone diisocyanate; dithiodimethyl diisocyanate; dithiodiethyl diisocyanate; dithiodipropyl diisocyanate; dicyclohexylsulfa-4,4'-diisocyanate; 1-isocyanatemethylthia-2,3-bis(2-isocyanateethylthia)propane, and the like.

[0047] The polymerizable composition may further contain additives such as an internal mold release agent, an ultraviolet absorber, a near-infrared absorber, a polymerization catalyst, a heat stabilizer, a color corrector, a chain extender, a crosslinking agent, a light stabilizer, an antioxidant, and a filler, as needed.

[0048] The internal mold release agent may be a component selected from the group consisting of a fluorine-based nonionic surfactant having a perfluoroalkyl group, a hydroxyalkyl group, or a phosphate ester group; a silicone-based nonionic surfactant having a dimethylpolysiloxane group, a hydroxyalkyl group, or a phosphate ester group; and an alkyl quaternary ammonium salt, i.e., trimethylcetylammonium salt, trimethylstearyl, dimethylethylcetylammonium salt, triethyldodecylammonium salt, trioctylmethylammonium salt, diethylcyclohexadodecylammonium salt, and acidic phosphate ester, used alone or in combination of two or more kinds.

[0049] As the ultraviolet absorber, benzophenone-based, benzotriazole-based, triazine-based, salicylate-based, cyanoacrylate-based, oxanilide-based, etc. can be used.

[0050] Examples of the near-infrared absorbing agent that can be used include azo-based, aminium-based, anthraquinone-based, cyanine-based, polymethine-based, diphenylmethane-based, triphenylmethane-based, quinone-based, diammonium-based, dithiol metal complex-based, squarylium-based, phthalocyanine-based, and naphthalocyanine-based agents.

[0051] Examples of polymerization catalysts that can be used include amine-based, phosphorus-based, organotin-based, organocupper-based, organogallium-based, organozirconium-based, organofiber-based, organozinc-based, organoaluminum-based, and organobismuth-based catalysts. Specifically, tin compounds such as dibutyltin dilaurate, dibutyltin dichloride, dimethyltin dichloride, tetramethyldiacetoxydistannoxane, tetraethyldiacetoxydistannoxane, tetrapropyldiacetoxydistannoxane, and tetrabutyldiacetoxydistannoxane, as well as amine compounds such as tertiary amines, can be used. These catalysts can be used alone or in combination of two or more. The catalyst is preferably added in an amount ranging from 0.001 to 1% by weight based on the total weight of the monomers in the composition. This range is preferable in terms of not only polymerization ability but also pot life during processing, transparency of the resulting resin, various optical properties, and light resistance.

[0052] As the heat stabilizer, metal fatty acid salts, phosphorus-based, lead-based, organotin-based, etc. can be used alone or in combination of two or more.

[0053] The resin composition for optical lenses of the present invention may further contain a color correction agent for correcting the initial color of the lens. Examples of color correction agents that can be used include organic dyes, organic pigments, and inorganic pigments. Adding such organic dyes or the like in an amount of 0.1 to 50,000 ppm, preferably 0.5 to 10,000 ppm, per 1 resin composition for optical lenses can prevent the lens from becoming yellowish due to the addition of ultraviolet absorbers, optical resins, monomers, and the like.

[0054] The present invention also provides a poly(thio)urethane obtained from the polymerizable composition. That is, the poly(thio)urethane may be produced by polymerizing (and curing) the isocyanate compound and thiol in the polymerizable composition. The polymerization reaction may be carried out so that the molar ratio of SH groups to NCO groups is 0.5 to 1.5, and more preferably 0.9 to 1.1.

[0055] When curing the composition of the present invention, various molding methods can be used depending on the application, and there is no particular limit to the curing method, but generally, heat curing is mainly used. In this way, the resin of the present invention can be obtained. The resin of the present invention can be obtained by cast polymerization, which is a common method of mold injection.

[0056] The process for producing eyeglass lenses by thermally curing the resin composition of the present invention is as follows. First, a polymerization initiator is added to the composition of the present invention, and nitrogen is sprayed into the compounding tube to remove air. The mixture is then stirred under reduced pressure for 1 to 5 hours. After stirring is stopped, the mixture is degassed under reduced pressure and poured into a mold. The mold is preferably a glass mold or metal mold secured with a plastic gasket or polyester or polypropylene adhesive tape. The glass mold into which the mixture has been poured is placed in a forced-circulation oven, slowly heated from room temperature to 120 to 130°C, held at 120 to 140°C for 1 to 4 hours, slowly cooled to 60 to 80°C, and the solid is then released from the mold to obtain an optical lens. The optical lens thus obtained is then annealed at 120 to 140°C for 1 to 4 hours to obtain the final plastic eyeglass lens (raw material).

[0057] Furthermore, the optical lens obtained by the above method can be subjected to hard coating and multi-coating treatments to improve its optical properties. The hard coating layer is formed by applying a coating composition containing at least one silane compound having a functional group such as an epoxy group, an alkoxy group, or a vinyl group, and at least one or more metal oxide colloids such as silicic acid oxide, titanium oxide, antimony oxide, tin oxide, tungsten oxide, or aluminum oxide as its main components to a thickness of 0.5 to 10 mm on the surface of the optical lens by impregnation or spin coating, and then curing the coating by heating or ultraviolet light to complete the coating film.

[0058] The multi-coating layer, i.e., the anti-reflection coating layer, can be formed by vacuum deposition or sputtering of metal oxides such as silicon oxide, magnesium fluoride, aluminum oxide, zirconium oxide, titanium oxide, tantalum oxide, and yttrium oxide. Most preferably, silicon oxide and zirconium oxide films are vacuum-deposited three or more times on the hard coating film on both sides of the lens, followed by vacuum deposition of the silicon oxide film. If necessary, a water film (fluororesin) can be placed at the end, or an ITO layer can be placed between the silicon oxide and zirconium oxide films.

[0059] The optical lens of the present invention can also be used after being colored with a disperse dye or a photochromic dye, if necessary.

[0060] The resin composition for optical lenses of the present invention can be used not only for plastic eyeglass lenses but also for various other optical products.

[0061] It was necessary to evaluate whether the optical lens produced according to the present invention had suitable physical properties for use as a plastic eyeglass lens. The physical properties of (1) refractive index and Abbe number (υ), (2) heat resistance (Tg), (3) yellowness index, and (4) striae and opacity were evaluated by the following test methods.

[0062] (1) Refractive index (nE20): The refractive index at 546 nm (E wavelength) was measured at 20°C using an ABBE refractometer, model DR-M4, manufactured by ATAGO. (2) Heat resistance: The glass transition temperature (Tg) of the test piece was measured using a SCINCO DSCN-650 thermal analyzer to determine the heat resistance. (3) Yellowness: The YI value of a 2 mm test piece was measured using a UV-2600 spectrometer manufactured by SHIMADZU, and the yellowness was compared. (4) Striae and cloudiness: 100 lenses were visually inspected, and the occurrence of striae and cloudiness was evaluated by notation: 10 or more: ×, 5 to 9: △, 3 to 4: ◯, and 2 or less: ⊚.

[0063] The present invention is illustrated, but not limited, by the following examples.

[0064] The abbreviations used in the examples have the following meanings:

[0065] TESPT:Bis ( ( Bird ethoxysilyl) Propyl) Tetrasulfide TEOS: Tetraethyl orthosilicate CTABr: Cetyltrimethylammonium B Romid PETMA: Pentaerythritol tetrathioglycolate TPA: Dodecatungstophosphoric acid

[0066] 1. Preparation of superacid mesoporous material catalyst [Synthesis Example 1-1] 5 g of CTABr (0.0137 mol) was dissolved in a solution containing 100 ml of deionized water and 50 ml of 28% ammonium hydroxide (0.55 mol) in a 300 ml Teflon® reactor and stirred for 15 minutes. 9 g of TEOS (0.038 mol) and 2.59 g of TESPT (0.0096 mol) were added over 30 minutes and stirred for 2 hours. The Teflon reactor was then placed in an autoclave reactor and aged at 100°C for 3 days. The resulting solid solution was then filtered and thoroughly washed with deionized water and ethanol. The resulting solid was dried in an oven at 100°C and calcined at 500°C.

[0067] 1 g of the resulting solid was dispersed in 50 ml of 35% hydrochloric acid, and then 2 g of bromine (Br2) was added at -10°C for 1 hour and stirred at room temperature for 10 hours. The resulting solid was washed with 100 ml of purified water and then with 200 ml of methanol, and then vacuum dried to obtain a sulfonic acid-incorporated superacid mesoporous material (TESPT-10-MCM).

[0068] [Synthesis Examples 1-2 to 1-3] Super strong acid mesoporous materials TESPT-20-MCM and TESPT-30-MCM were obtained according to the compositions shown in Table 1 in the same manner as in Synthesis Example 1-1.

[0069] [Table 1]

[0070] 2. Preparation of ester thiol compounds [Synthesis Example 2-1] Dean-St ar A reactor equipped with a k apparatus, a nitrogen gas purge tube, and a thermometer was charged with 100 g of pentaerythritol (SAMYANG CHEMICAL CORPORATION, 99%), 5 g of the superacid mesoporous material (TESPT-10-MCM) obtained in Synthesis Example 1-1, 300 ml of toluene, and 312 g of 3-mercaptopropionic acid (Alpha Acer, 99%). The reactor was heated to the toluene reflux temperature and the reaction was continued for 4 hours while continuously removing the generated water. The reaction was then cooled to room temperature. The amount of water removed was 99.0% of the theoretically calculated amount of water.

[0071] The reaction mixture was cooled to room temperature, filtered to remove the catalyst, and then concentrated under reduced pressure to obtain 330 g of the ester thiol compound pentaerythritol tetrakis(3-mercaptopropionate) (hereinafter abbreviated as PETMP). The obtained PETMP was confirmed to be pentaerythritol tetrakis(3-mercaptopropionate) using high-performance liquid chromatography and an infrared spectrometer, and its APHA was 6.

[0072] [Synthesis Examples 2-2 to 2-6, Synthesis Comparative Example 1] PETMP was obtained in the same manner as in Synthesis Example 2-1, except that the catalyst listed in Table 2 was used instead of the superacid mesoporous material (TESPT-10-MCM). The obtained PETMP was characterized using high-performance liquid chromatography and infrared spectroscopy in the same manner as in Synthesis Example 2-1, and the results are shown in Table 2.

[0073] [Synthesis Examples 2-7 to 2-8] PETMP was obtained by reusing the catalysts used in Synthesis Examples 2-2 and 2-6, and by producing it in the same manner as in Synthesis Example 1. The results of the obtained PETMP were similar to those obtained using fresh catalysts.

[0074] [Synthesis Example 2-9] Dean-St ar 100 g of pentaerythritol, 5 g of the super strong acid mesoporous material (TESPT-20-MCM) obtained in Synthesis Example 1-2, 500 ml of toluene, and 271 g of mercaptoacetic acid were added to a reactor equipped with a k apparatus, a nitrogen gas purge tube, and a thermometer. The internal temperature of the reactor was heated to the toluene reflux temperature, and the reaction was carried out for 4 hours while continuously removing the generated water, and then the reaction mixture was cooled to room temperature. The reaction mixture was cooled to room temperature, filtered to separate the catalyst, and then concentrated under reduced pressure to obtain the ester thiol compound pentaerythritol tetrakis( M The resulting PETMA was confirmed by high performance liquid chromatography and infrared spectroscopy in the same manner as in Synthesis Example 2-1, and its APHA was found to be 7.

[0075] [Comparative Synthesis Example 1] Dean-St ar A reactor equipped with a k apparatus, a nitrogen gas purge tube, and a thermometer was charged with 100 g of pentaerythritol (SAMYANG CHEMICAL CORPORATION, 99%), 5 g of methanesulfonic acid, 300 ml of toluene, and 312 g of thioglycolic acid (DAICEL, 99%). The reactor was heated to the toluene reflux temperature and reacted for 4 hours while continuously removing the generated water. The reaction mixture was then cooled to room temperature. 246 g of a 5% aqueous sodium carbonate solution was then added to the resulting reaction mixture, which was stirred at 25°C for 1 hour. The layers were then separated, the lower layer was removed, and the mixture was washed twice more with 246 g of distilled water. The mixture was then heated and concentrated under vacuum to completely remove the toluene and traces of water, and filtered to obtain the ester thiol compound PETM. AThe obtained ester thiol compound had a color of APHA15.

[0076] [Table 2]

[0077] Using a heterogeneous solid acid catalyst in the production of an ester thiol compound, an ester thiol compound with excellent yield and color can be synthesized. In particular, it was confirmed that the amount of wastewater generated was significantly less than in Comparative Synthesis Example 1, in which a homogeneous catalyst was used. Furthermore, as in Synthesis Examples 2-7 and 2-8, it was possible to reuse the heterogeneous solid acid catalyst in the production process of the present invention. Thus, the introduction of a heterogeneous solid acid catalyst in the production of an ester thiol compound will enable the application of a continuous production method via a catalyst layer instead of the existing batch production method.

[0078] 3. Optical lens manufacturing and evaluation [Example 1] 46.5 g of methylcyclohexane diisocyanate (DIMC) was mixed with 30.8 g of 2,3-bis(2-mercaptoethylthio)propane-1-thiol (GST), 19.7 g of pentaerythritol tetrakis(3-mercaptopropionate) (PETMP) prepared in the above Synthesis Example, 0.1 g of dibutyltin dichloride (DBDC), 0.12 g of ZELEC UN, and 1.5 g of 2-(2-hydroxy-5-t-octylphenyl)-2H-benzotriazole, stirred under a nitrogen stream for 10 minutes, degassed under vacuum at 1 Torr or less for 1 hour, purged with nitrogen, and then injected into a glass mold using nitrogen pressure. The glass mold containing the optical resin composition was slowly heated from 30°C to 125°C in a forced circulation oven and held at 125°C for 2 hours. The glass mold was then cooled to 70°C and the optical resin was demolded to obtain an eyeglass lens with a center thickness of 1.3 mm. The resulting eyeglass lenses were processed to a width of 72 mm, then immersed in an alkaline aqueous cleaning solution and ultrasonically cleaned, and then annealed at 125°C for 2 hours. After this, the lenses were dip-coated in a hardening solution and thermally cured, and then multi-coated with metal oxides and fluororesin using vacuum deposition to obtain eyeglass lenses.

[0079] [Examples 2 to 8, Comparative Example 1] In addition to using the PETMP listed in Table 3, optical resins were produced in the same manner as in Example 1, and their physical properties were evaluated. The results are shown in Table 3.

[0080] [Table 3]

[0081] The ester thiol compounds prepared using heterogeneous solid acid catalysts in the examples were usable as optical lenses. When comparing Example 2 and Comparative Example 1, the yellowness index was 1.25 and 1.82, respectively, showing a significant difference. Lenses using the ester thiol compounds prepared using heterogeneous solid acid catalysts showed significantly better results in terms of yellowness index than those prepared using homogeneous catalysts.

[0082] Furthermore, when comparing the Examples and Comparative Examples, the lenses using the ester thiol compounds produced with the heterogeneous solid acid catalyst showed better optical properties such as striae and opacity than those using the homogeneous catalyst, demonstrating that they could be used as optical materials.

Claims

1. a step of reacting pentaerythritol with 3-mercaptopropionic acid and / or mercaptoacetic acid using an acid catalyst to produce pentaerythritol tetrakis(3-mercaptopropionate) and / or pentaerythritol tetrakis(mercaptoacetate), the acid catalyst has sulfonic acid groups formed by oxidizing SH groups or sulfide groups fixed to the pore walls of a mesoporous silica material having a pore diameter of 2 to 10 nm, The method for producing an ester thiol compound, wherein the step is carried out in a fixed-bed tubular reactor packed with the acid catalyst.

2. 2. The method according to claim 1, wherein the acid catalyst is used in a weight ratio of 0.2 to 20 g based on 100 g of polyhydric alcohol.

3. 2. The method according to claim 1, wherein the pentaerythritol and the 3-mercaptopropionic acid and / or mercaptoacetic acid are used in a weight ratio of 20-30:80-70.

4. 4. The method according to claim 1, wherein the method is carried out under a nitrogen or hydrogen atmosphere.

5. (i) producing pentaerythritol tetrakis(3-mercaptopropionate) and / or pentaerythritol tetrakis(mercaptoacetate) by the method of any one of claims 1 to 3; (ii) providing a polyisocyanate; (iii) a step of preparing a polythiol or polyol other than the compound obtained in step (i).

6. 6. The method for producing a polymerizable poly(thio)urethane composition according to claim 5, wherein the molar ratio of the SH (or OH) groups of said polythiol or polyol to the NCO groups of said polyisocyanate is in the range of 0.5 to 1.

5.

7. A method for producing a resin, comprising the step of curing the polymerizable poly(thio)urethane composition obtained by the method of claim 6.

8. The method for producing a resin according to claim 7 , wherein the resin is used as an optical material.

9. A method for producing an optical lens using a resin obtained by the method according to claim 8.

Images