Polythiol compositions, optical compositions, and optical products

Abstract

The polythiol composition according to an exemplary embodiment includes a tetrafunctional polythiol compound and a parapolythiol compound, the parapolythiol compound comprising C 13 H 28 S9 represents compounds and compounds derived from C 15 H 32 S 10 The compounds are indicated. The proportion of parapolythiol compounds, as measured by high-performance liquid chromatography (HPLC), ranges from 1% to 5%. By adjusting the content of parapolythiol compounds, optical products with excellent transmittance and optical properties can be manufactured.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2020-0111005 filed with the Korean Intellectual Property Office (KIPO) on September 1, 2020 and Korean Patent Application No. 10-2020-0165577 filed on December 1, 2020, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to polythiol compositions, optical compositions, and optical products. More specifically, this invention relates to polythiol compositions comprising a variety of polythiol compounds, and optical compositions and optical products comprising the same. Background Technology

[0004] Polythiol compounds are widely used as raw materials, for example, in the manufacture of polyurethane resins. For instance, polythiol compounds are used to manufacture optical lenses using polyurethane resins, and the quality of the polythiol compounds used as raw materials, such as their purity, directly affects the quality of the optical lenses.

[0005] For example, polythiourethane compounds prepared by reacting polythiols and isocyanates can be used as substrates for optical lenses.

[0006] For example, Korean Patent Publication No. 10-1338568 discloses a method for synthesizing polythiol compounds, which involves reacting a polyol compound with thiourea to prepare isothiourea salts, followed by hydrolysis with ammonia.

[0007] During the synthesis process, reaction additives such as catalysts can be introduced, and the purity and yield of the synthesized polythiol compound can be altered based on the physical properties of these additives. Furthermore, the optical properties of the lens, such as transparency and refractive index, will undergo slight changes depending on the number of functional groups, chain length, molecular weight, and purity of the synthesized polythiol.

[0008] Therefore, it is also possible to change the optical properties of optical products made from polythiol compounds, such as optical lenses, including their refractive index and color. Summary of the Invention

[0009] The purpose of the exemplary embodiments is to provide a polythiol composition with improved transparency and optical properties, and a method for preparing the same.

[0010] Another objective according to the exemplary embodiments is to provide an optical composition comprising a polythiol composition having improved transparency and optical properties, and a method thereof for preparation thereof.

[0011] In addition, another objective of the exemplary embodiments is to provide optical products manufactured using polythiol compositions or optical compositions.

[0012] Furthermore, another objective of the exemplary embodiments is to provide metal sulfides for the synthesis of polythiol compounds.

[0013] The polythiol composition according to an exemplary embodiment includes: a tetrafunctional polythiol compound; and comprising C 13 H 28 S9 represents compounds and compounds derived from C 15 H 32 S 10 The compound represented is a sub-polythiol compound, wherein the proportion of the sub-polythiol compound represented by Formula 1 is in the range of 1% to 5%:

[0014] [Formula 1]

[0015] The proportion of polythiols = 100% × [(C 13 H 28 S9 peak region (%) + (C 15 H 32 S 10 Peak region (%) / (peak region (%) of tetrafunctional polythiol compounds)

[0016] (In Equation 1, peak area (%) is the peak area (%) of the compound measured by high performance liquid chromatography (HPLC) analysis obtained at a wavelength of 230 nm.)

[0017] In some embodiments, the tetrafunctional polythiol compound may include at least one of the tetrafunctional polythiol compounds represented by formulas 1-1 to 1-3:

[0018] [Equation 1-1]

[0019]

[0020] [Equation 1-2]

[0021]

[0022] [Equation 1-3]

[0023]

[0024] In some implementation schemes, by C 13 H 28 The compound represented by S9 can have the structure of formula 2-1:

[0025] [Equation 2-1]

[0026]

[0027] In some implementation schemes, by C 15 H 32 S 10 The compound represented can have the structure of formula 2-2:

[0028] [Equation 2-2]

[0029]

[0030] A method for preparing a polythiol composition according to an exemplary embodiment includes: generating a polyol intermediate by introducing a metal sulfide into a preparative polyol compound; and converting the polyol intermediate into a polythiol compound by thiolation. After dissolving the metal sulfide in distilled water at an amount of 17.3 parts by weight based on 100 parts by weight of distilled water, the absorbance of the metal sulfide is measured at a wavelength of 350 nm in a quartz cell with an optical path length of 50 mm, and the absorbance is between 0.7 and 2.0.

[0031] In some embodiments, the polythiol compounds may include tetrafunctional polythiol compounds and parapolythiol compounds having a larger molecular weight or a greater number of functions than tetrafunctional polythiol compounds.

[0032] In some embodiments, the parapolythiol compound may include C 13 H 28 S9 represents compounds and compounds derived from C 15 H 32 S 10 The compound represented by Formula 1 above may be in the range of 1% to 5%.

[0033] In some embodiments, if the absorbance of the metal sulfide is less than 0.7, the method may include washing the metal sulfide with alcohol, water, or an aqueous alcohol solution and then drying it to adjust the absorbance of the metal sulfide to the range of 0.7 to 2.0.

[0034] In some implementations, the metal sulfide may include Na2S.

[0035] In some implementations, the absorbance of the metal sulfide can be in the range of 0.75 to 2.0.

[0036] An optical composition according to an exemplary embodiment includes: a polythiol composition; and an isocyanate compound, said polythiol composition comprising a tetrafunctional polythiol compound and comprising C 13 H 28 S9 represents compounds and compounds derived from C 15 H 32 S10 The compound represented is a polythiol compound, wherein the proportion of the polythiol compound represented by Formula 1 above is 1% to 5%.

[0037] A method for preparing an optical composition according to an exemplary embodiment includes: preparing a polythiol compound; and mixing the polythiol compound with an isocyanate compound. The step of preparing the polythiol compound includes: generating a polyol intermediate by introducing a metal sulfide into a preparative polyol compound; and converting the polyol intermediate into a polythiol compound by thiolation. After dissolving the metal sulfide in distilled water at a concentration of 17.3 parts by weight based on 100 parts by weight of distilled water, the absorbance of the metal sulfide is measured at a wavelength of 350 nm in a quartz cell with an optical path length of 50 mm.

[0038] An optical product according to an exemplary embodiment includes a copolymer of a polythiol composition and an isocyanate-based compound, wherein the polythiol composition includes a tetrafunctional polythiol compound, and comprises C 13 H 28 S9 represents compounds and compounds derived from C 15 H 32 S 10 The compound represented is a polysulfide compound, wherein the proportion of the polysulfide compound represented by Formula 1 above is in the range of 1% to 5%.

[0039] In some embodiments, the optical product may further include at least one additive selected from the group consisting of release agents, reaction catalysts, heat stabilizers, ultraviolet absorbers, and bluing agents.

[0040] The metal sulfide used to synthesize the polythiol compound according to the exemplary embodiment has an absorbance of 0.7 to 2.0 when measured in a quartz cell with a wavelength of 350 nm in an optical path length of 50 mm after being dissolved in distilled water in an amount of 17.3 parts by weight based on 100 parts by weight of distilled water.

[0041] According to the above embodiments, the polythiol composition according to the exemplary embodiments may include a tetrafunctional polythiol compound and a parapolythiol compound having a predetermined structure and being included in a predetermined content range as measured by HPLC.

[0042] Parapolythiol compounds can have relatively large chain lengths or large functional numbers, i.e., a large number of functional groups. By adjusting the content of parapolythiol compounds, the yield and purity of lenses can be improved, while reducing optical defects in polyol compositions, such as clouding, yellowing, and streaking.

[0043] In some embodiments, metal sulfides with absorbance within a predetermined range for light at a wavelength of 350 nm can be used during the synthesis of polythiol compounds. By controlling the absorbance of the metal sulfide, the content of the polythiol compound can be finely adjusted. Furthermore, excessive use of metal sulfides during the formation of polyol intermediates is prevented, thereby inhibiting excessive formation of polymer materials and sulfide bonds.

[0044] Therefore, it is possible to obtain polythiol compounds or polythiol compositions that can produce optical products with excellent optical properties and high purity, while suppressing discoloration, turbidity, etc. Detailed Implementation

[0045] The embodiments of this application will be described in detail below. In this respect, the invention can be modified in various ways and has various embodiments, such that particular embodiments are illustrated in the accompanying drawings and described in detail in this disclosure. However, the invention is not limited to the particular embodiments, and those skilled in the art will understand that the invention is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

[0046] Unless otherwise defined, all terms used herein, including technical and scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, shall be interpreted as having a meaning consistent with their meaning in the context of the relevant field, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0047] <Polythiol Compositions and Their Preparation Methods>

[0048] According to one aspect of this application, a polythiol composition comprising polythiol compounds is provided.

[0049] According to an exemplary embodiment, the polythiol composition may include a tetrafunctional polythiol compound and a parapolythiol compound.

[0050] A tetrafunctional polythiol compound may be included as the target polythiol compound or the main polythiol compound in the polythiol composition. For example, the tetrafunctional polythiol compound has a relatively smaller molecular weight or shorter molecular length than the parapolythiol compounds described below, and can provide a sufficient reaction rate / efficiency during polymerization with isocyanate compounds used to manufacture lenses.

[0051] Non-limiting examples of tetrafunctional polythiols may include compounds represented by formulas 1-1 to 1-3. For example, a major polythiols may include at least one of compounds represented by formulas 1-1 to 1-3.

[0052] [Equation 1-1]

[0053]

[0054] [Equation 1-2]

[0055]

[0056] [Equation 1-3]

[0057]

[0058] In a preferred embodiment, the compound represented by Formula 1-1 can be used as a tetrafunctional polythiol compound.

[0059] Compared to tetrafunctional polythiols, parapolythiols can have longer chain lengths, larger molecular weights, or a greater number of functional groups (e.g., the number of thiol functional groups).

[0060] Because parapolythiols have a larger molecular weight or chain length than tetrafunctional polythiols, they can act as reaction rate modifiers. For example, in the lens manufacturing process described below, parapolythiols can reduce or suppress the formation of streaks due to excessively rapid reaction rates with isocyanate compounds.

[0061] In some embodiments, the parapolythiol compound may be a pentafunctional polythiol compound. In one embodiment, the parapolythiol compound may include at least two different pentafunctional polythiol compounds.

[0062] In some embodiments, the parapolythiol compound may include C 13 H 28 S9 represents the compounds. For example, parapolythiol compounds may include compounds represented by formula 2-1.

[0063] [Equation 2-1]

[0064]

[0065] In some embodiments, the parapolythiol compound may include C 15 H 32 S 10 The compound represented. For example, parapolythiol compounds may include compounds represented by formula 2-2.

[0066] [Equation 2-2]

[0067]

[0068] According to an exemplary embodiment, the proportion of the polythiol compound defined by Formula 1 can be in the range of 1 to 5%.

[0069] [Formula 1]

[0070] The proportion of polythiols = 100% × [(C 13 H 28 S9 peak region (%) + (C 15 H 32 S 10 Peak region (%) / (peak region (%) of tetrafunctional polythiol compounds)

[0071] The peak area (%) used in Formula 1 is the peak area (%) of the compound measured by high performance liquid chromatography (HPLC) analysis obtained at a wavelength of 230 nm.

[0072] Within the range of polythiol compound proportions represented by Formula 1 above, the chemical stability of polythiol compositions or optical products can be improved, thus effectively suppressing lens opacity and color shift.

[0073] For example, within the aforementioned range of the proportion of polythiols, by appropriately controlling the amount of high molecular weight components in the polythiols composition while maintaining an appropriate reaction rate with isocyanate compounds, the generation of streaks and the reduction in purity in optical products can be suppressed.

[0074] Furthermore, during the synthesis of polythiol compounds, as described below, the formation of polysulfides can be appropriately suppressed, thereby suppressing color shifts in the lens, such as yellowing.

[0075] In a preferred embodiment, the proportion of the polythiol compound defined by Formula 1 can be in the range of 2% to 5%, 3% to 5%, or 3.5% to 4.8%.

[0076] In some embodiments, the thiol value (SHV) of the polythiol composition is about 95 g / eq to 97 g / eq. Preferably, the SHV is 96 g / eq to 97 g / eq, more preferably 96 g / eq to 96.5 g / eq.

[0077] When titrating a polythiol composition sample with a 0.1N iodine standard solution, the SHV can be measured as a value obtained by dividing the sample weight by the iodine equivalent consumed.

[0078] In some embodiments, the liquid refractive index of the polythiol composition may be from about 1.645 to 1.647. Preferably, the liquid refractive index may be from about 1.6455 to 1.6468, and more preferably from 1.6458 to 1.6468.

[0079] The refractive index of a liquid can be measured at 25°C using a liquid refractometer.

[0080] In some embodiments, the gel permeation chromatography (GPC) purity of the polythiol composition can be 80% or higher. For example, the GPC purity of the polythiol composition can be 80% to 85%. Preferably, the GPC purity is 82% or higher, more preferably 83% or higher, and even more preferably 84% or higher.

[0081] According to one aspect of this application, a method for preparing a polythiol composition comprising polythiol compounds is provided. As described above, the polythiol composition may include a tetrafunctional polythiol compound and the aforementioned parapolythiol compound.

[0082] The preparation method of the polythiol composition according to the exemplary embodiments may include at least one of the steps, processes, or operations described in S10, S20, and S30 below. It should be understood that, for ease of description, the terms "S10" and "S20" below are used to distinguish processes and are not intended to limit their order. For example, some or all of the processes in S10, S20, and S30 below may be performed sequentially, and / or in a changed order depending on the processing conditions.

[0083] S10) Introducing metal sulfides into the preparative polyol compound to prepare a polyol intermediate.

[0084] S20) reacts a polyol intermediate with thiourea under acidic conditions to generate isothiourea salt.

[0085] S30) converts isothiourea salts into polythiool compounds.

[0086] For example, in step S10, the polyol intermediate can be produced by reacting the prepared polyol compound with a metal sulfide.

[0087] In one implementation, as exemplified by Scheme 1 below, the prepared polyol compound can be obtained by reaction with 2-mercaptoethanol and epihaloethanol.

[0088] [Option 1]

[0089]

[0090] Basic catalysts can be used to promote the reaction of 2-mercaptoethanol and epihaloethanol. Examples of basic catalysts can include tertiary amines such as triethylamine, quaternary ammonium salts, triphenylphosphine, and trivalent chromium compounds. As shown in Scheme 1, epichlorohydrin can be used as an epihaloethanol.

[0091] The obtained preparative polyol compound can be, for example, a diol compound containing a sulfide bond.

[0092] The reaction temperature for generating the preparative polyol compound can be, for example, -5°C to 15°C, preferably 0°C to 12°C, and more preferably 5°C to 10°C.

[0093] For example, the content of 2-mercaptoethanol, based on 1 mol of epihaloethanol, can be from 0.5 mol to 3 mol, preferably from 0.7 mol to 2 mol, and more preferably from 0.9 mol to 1.1 mol. The amount of basic catalyst, based on 1 mol of epihaloethanol, can be from 0.001 mol to 0.1 mol.

[0094] In one implementation, metal catalysts such as sodium hydroxide and potassium hydroxide can be excluded as reaction catalysts for the formation of preparative polyol compounds in order to suppress byproducts such as trifunctional thiols.

[0095] As shown in Scheme 2 below, a polyol intermediate can be formed by introducing a metal sulfide into a diol compound with sulfide bonds obtained as described above.

[0096] [Option 2]

[0097]

[0098] As shown in Scheme 2, diol compounds can be further reacted with each other through metal sulfides to obtain polyol intermediates including tetrafunctional polyol compounds.

[0099] Metal sulfides may include alkali metal sulfides, and in one embodiment, as shown in Scheme 2, Na2S may be used.

[0100] According to an exemplary embodiment, the proportion of the above-mentioned polythiols can be controlled by adjusting the absorbance of the metal sulfide or Na2S.

[0101] In some embodiments, the metal sulfide used herein may be a metal sulfide having an absorbance of 0.7 to 2.0, the absorbance being the absorbance measured at 25°C for light at a wavelength of 350 nm after dissolving it in distilled water in a 50 mm quartz cell in an amount of 17.3 parts by weight based on 100 parts by weight of distilled water.

[0102] In a preferred embodiment, the absorbance of the metal sulfide can be from 0.75 to 2.0, and preferably from 0.75 to 1.95 or from 0.75 to 1.5.

[0103] Within the aforementioned absorbance range, the metal sulfide can be used in a state containing an appropriate amount of moisture. Therefore, a predetermined dosage corresponding to a sufficient reaction equivalent of metal sulfide can be provided.

[0104] Metal sulfides can act as bases to promote the reaction of the diol compounds illustrated in Scheme 2 above. Therefore, polyol intermediates can be readily obtained at desired reaction rates and yields.

[0105] For example, metal sulfides can be mediated to transform into polyol intermediates by combining with leaving groups generated during the reaction of Scheme 2 through ionic, metallic, or covalent bonds.

[0106] According to an exemplary embodiment, metal sulfides within the absorbance range can be used to facilitate the efficient production of polyol intermediates.

[0107] For example, if insufficient reaction equivalents of Na₂S are supplied, high molecular weight byproducts such as oligomers may be generated, and the purity of the synthesized polythiol compounds may decrease. Therefore, the amount of the aforementioned polythiol compounds may be excessively increased, and the proportion (or ratio) of the polythiol compounds represented by Formula 1 may exceed 5%.

[0108] Furthermore, when metal sulfides with excessively high absorbance are used, the formation of polysulfide compounds can occur excessively, leading to discoloration and yellowing of optical products.

[0109] Therefore, a polythiol composition can be provided that can suppress the formation of high molecular weight byproducts by using a metal compound with absorbance in the above range, and can provide an optical product with high transparency.

[0110] In a preferred embodiment, the absorbance of the metal compound can be from 0.75 to 2.0, preferably from 0.75 to 1.95, or from 0.75 to 1.5.

[0111] When using commercially available metal sulfides, products within the aforementioned absorbance range may be selected and used. Alternatively, they may be further processed to have the aforementioned absorbance range.

[0112] In one embodiment, when a reaction equivalent corresponding to the number of moles sufficient to convert the aforementioned diol compound into a tetrafunctional polyol compound is not provided, or when a metal sulfide product with excessively low absorbance is purchased, the filter can be thoroughly cleaned with a cleaning solution and then dried. Then, after redissolving 17.3 parts by weight of the product in 100 parts by weight of distilled water, the absorbance of the solution to light at a wavelength of 350 nm is measured in a 50 mm quartz cell to confirm an absorbance in the range of 0.7 to 2.0. The metal sulfide can then be used.

[0113] For example, alcohol, water, or an aqueous solution of alcohol at temperatures below 10°C can be used as a cleaning solution. Ethanol, for example, can be used as the alcohol.

[0114] In one embodiment, when a metal sulfide product with excessively high absorbance is purchased, it is uniformly mixed with a metal sulfide product with absorbance less than 2.0. The mixture can then be used after confirming that the absorbance is within the range of 0.7 to 2.0 obtained according to the absorbance measurement method described above.

[0115] For example, in step S20, the polyol intermediate can react with thiourea. As a result, according to an exemplary embodiment, an isothiourea salt can be obtained.

[0116] Acidic reflux conditions can be used during the production of isothiourea salts. To create acidic conditions, acidic compounds such as hydrochloric acid, hydrobromic acid, iodic acid, sulfuric acid, and phosphoric acid can be used.

[0117] The reflux temperature can be from 80°C to 150°C, from 90°C to 130°C, and preferably from 100°C to 120°C, while the reflux time can be from 1 hour to 10 hours, from 2 hours to 8 hours, from 2 hours to 5 hours, and preferably from 3 hours to 5 hours.

[0118] For example, in step S30, the isothiourea salt can be converted into a polythiol compound. According to an exemplary embodiment, the isothiourea salt can be hydrolyzed under alkaline conditions to produce a polythiol compound.

[0119] Steps S20 and S30 above may include thiolation as exemplified by Scheme 3 below.

[0120] [Option 3]

[0121]

[0122] For example, hydrolysis can be achieved by adding an alkaline aqueous solution to the reaction solution containing isothiourea salt. The alkaline aqueous solution may include alkali metal hydroxides, alkaline earth metal hydroxides, and / or alkali metal hydrides, such as NaOH, KOH, LiOH, Ca(OH)₂, etc.

[0123] In one embodiment, the reaction solution containing isothiourea salt is cooled to a temperature of 20°C to 100°C, preferably 20°C to 80°C, and more preferably 30°C to 70°C, or 40°C to 70°C. Subsequently, an alkaline aqueous solution may be added.

[0124] In one embodiment, an organic solvent may be added prior to the addition of an alkaline aqueous solution. An organic solvent with low or essentially non-reactive properties and a boiling point above the thiolation reaction temperature may be used to ensure stable thiolation.

[0125] Examples of organic solvents may include toluene, xylene, chlorobenzene, and dichlorobenzene. Preferably, toluene may be used, taking into account reaction stability and toxicity from organic solvents.

[0126] The polythiol compounds obtained as described above can be further purified. For example, by repeatedly performing acid washing and water washing processes, impurities included in the polythiol compounds can be removed, and the transparency of optical materials prepared from the polythiol compositions can be improved. Afterwards, further drying, filtration, etc., can be performed.

[0127] In one embodiment, after hydrolysis, the aqueous layer can be separated or removed by layer separation. Acid washing can be performed for 20 minutes to 1 hour or 20 minutes to 40 minutes at a temperature of about 20°C to 50°C, preferably about 30°C to 40°C, by introducing an acid solution into the obtained organic phase solution.

[0128] After pickling, a water washing process can be performed by adding deaerated water with a dissolved oxygen concentration adjusted to below 5 ppm, preferably below 3 ppm, and more preferably below 2 ppm. The water washing process can be carried out at a temperature of about 20°C to 50°C, preferably about 35°C to 45°C, for 20 minutes to 1 hour, or 20 minutes to 40 minutes. The water washing process can be repeated more than twice, for example, 3 to 6 times.

[0129] After pickling and washing, residual organic solvents and moisture are removed by heating under reduced pressure, and then the mixture is filtered to obtain high-purity polythiol compounds.

[0130] <Optical Compositions and Optical Products>

[0131] According to one aspect of this application, an optical composition comprising the above-described polythiol compounds or polythiol compositions is provided. The optical composition can be a polymeric composition for manufacturing optical materials used in optical products such as lenses.

[0132] Optical compositions may include polythiol compounds or polythiol compositions, as well as isocyanate compounds.

[0133] Isocyanate compounds may include compounds that can be used as monomers in the synthesis of polythiourethanes. In preferred embodiments, isocyanate compounds may include 1,3-bis(isocyanate-methyl)cyclohexane, hexamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, and toluene diisocyanate, etc. These may be used alone or in combination of two or more thereof.

[0134] The optical composition may further include additives such as mold release agents, reaction catalysts, heat stabilizers, ultraviolet absorbers, and bluing agents.

[0135] Examples of release agents may include fluorinated nonionic surfactants having perfluoroalkyl, hydroxyalkyl, or phosphate groups; organosilicon nonionic surfactants having dimethylpolysiloxane, hydroxyalkyl, or phosphate groups; alkyl quaternary ammonium salts, such as trimethylhexadecylammonium salt, trimethylstearylammonium salt, dimethylethylhexadecylammonium salt, triethyldodecylammonium salt, trioctylmethylammonium salt, and diethylcyclohexyldodecylammonium salt; and acidic phosphate esters, etc. These may be used alone or in combination of two or more thereof.

[0136] As reaction catalysts, catalysts used in the polymerization reaction of polysulfururethane resins can be used. For example, dialkyltin halide catalysts such as dibutyltin dichloride and dimethyltin dichloride; dialkyltin dicarboxylate catalysts such as dimethyltin diacetate, dibutyltin dioctanoate, and dibutyltin dilaurate; alkoxydialkyltin catalysts such as dibutoxydibutyltinane and dibutoxydioctyltinane; dithioalkoxydialkyltin salt catalysts such as di(thiobutoxy)dibutyltin; dialkyltin oxide catalysts such as di(2-ethylhexyl)tin oxide, dioctyltin oxide, and bis(butoxydibutyltin) oxide; and dialkyltin sulfide catalysts, etc. These can be used alone or in combination of two or more.

[0137] Examples of UV absorbers include compounds based on benzophenone, benzotriazole, salicylates, cyanoacrylates, and N,N'-oxalyldiphenylamine. Examples of heat stabilizers include compounds based on metal fatty acids, phosphorus, lead, and organotin compounds. These can be used alone or in combination of two or more of them.

[0138] Bluing agents may be included as color control agents in optical materials prepared from polyurethane resins. For example, a bluing agent may have an absorption band in the visible light region ranging from orange to yellow wavelengths.

[0139] Examples of bluing agents can include dyes, fluorescent whitening agents, fluorescent pigments, and inorganic pigments, and can be appropriately selected based on the physical properties or resin color required for manufacturing optical products. When using dyes as bluing agents, for example, dyes with a maximum absorption wavelength of 520 nm to 600 nm, preferably 540 nm to 580 nm, can be used. Preferably, anthraquinone dyes can be used.

[0140] Polysulfuric ester resins can be produced by the polymerization reaction of polythiol compounds contained in a polythiol composition with isocyanate compounds.

[0141] In some embodiments, based on the total weight of the polymeric composition for optical materials, a polythiol compound may be included in an amount of about 40 wt.% to 60 wt.%, an isocyanate compound may be included in an amount of about 40 wt.% to 60 wt.%, and an additive may be included in an amount of about 0.01 wt.% to 1 wt.%.

[0142] According to one aspect of this application, an optical product manufactured using the above-described optical composition can be provided.

[0143] For example, after degassing the optical material with a polymeric composition under reduced pressure, the resulting composition can be injected into a mold used to shape the optical material. Mold injection can be performed, for example, in a temperature range of 20°C to 40°C, and preferably 20°C to 35°C.

[0144] After injection molding, the temperature can be gradually increased to allow the polymerization reaction of the polyurethane resin to proceed. The polymerization temperature can be in the range of 20°C to 150°C, and preferably in the range of 25°C to 125°C.

[0145] After polymerization, the polymerized polyurethane resin can be separated from the mold to obtain optical products. Depending on the shape of the mold, the optical products can be manufactured in the form of eyeglass lenses, camera lenses, light-emitting diodes, etc.

[0146] The refractive index of an optical product can be adjusted according to the type and / or content ratio of polythiol compounds and isocyanate compounds used in the optical composition, for example, it can be adjusted in the range of 1.65 to 1.75.

[0147] Optical products can be improved by adding surface treatments such as anti-fouling, coloring, hard coating, surface polishing, and hardening.

[0148] According to the above embodiments, metal sulfides with absorbance within the aforementioned range can be used to synthesize polythiol compounds. Therefore, for example, the purity and yield of tetrafunctional polythiol compounds can be improved. Furthermore, optical products with suppressed optical defects such as cloudiness and yellowing can be obtained from polythiol compounds.

[0149] The embodiments provided in this application will be further described below with reference to specific experimental examples. However, the following experimental examples are merely illustrative of the invention and are not intended to limit the appended claims, and those skilled in the art will clearly understand that various changes and modifications are possible within the scope and spirit of the invention. Such changes and modifications are suitably included in the appended claims.

[0150] Example 1

[0151] 1) Synthesis of tetrafunctional polythiol compounds

[0152] After introducing 60.0 parts by weight of water, 0.3 parts by weight of triethylamine, and 73.0 parts by weight of 2-mercaptoethanol into the reactor, the reactor temperature was lowered to 0°C, and 88.2 parts by weight of epichlorohydrin were slowly added dropwise at a temperature below 15°C, followed by further stirring at 30°C for 3 hours. Then, 145.8 parts by weight of a sodium sulfide solution prepared from Na₂S was slowly added dropwise at 20°C to 25°C, followed by stirring for another 3 hours. This sodium sulfide solution was dissolved in distilled water at a concentration of 17.3 parts by weight based on 100 parts by weight of distilled water. The absorbance of this solution at 25°C for light at a wavelength of 350 nm was measured to be 0.75.

[0153] Then, 473.2 parts by weight of 36% hydrochloric acid and 177.8 parts by weight of thiourea were introduced, and the mixture was stirred for 3 hours under reflux at 110°C to carry out the thiourea salting reaction.

[0154] After cooling the resulting reaction solution to 50°C, 305.6 parts by weight of toluene and 332.6 parts by weight of 50% NaOH were added, and then hydrolysis was carried out at 40°C to 60°C for 3 hours.

[0155] Then, after 1 hour of layer separation, the aqueous layer was discarded, and 120 parts by weight of 36% hydrochloric acid were added to the resulting toluene solution, followed by a single acid wash at 33°C to 40°C for 30 minutes. After acid washing, 250 parts by weight of degassed water (dissolved oxygen concentration of 2 ppm) was added, and the solution was washed four times at 35°C to 45°C for 30 minutes each. After removing toluene and residual water under heating and reduced pressure, the solution was filtered through a PTFE membrane filter under reduced pressure to obtain 140 parts by weight of the tetrafunctional polythiol compound represented by Formula 1-1 above.

[0156] 3) Preparation of optical compositions and manufacture of lenses

[0157] 49.3 parts by weight of the polythiol compound prepared above, 50.7 parts by weight of xylene diisocyanate, 0.01 parts by weight of dibutyltin chloride, and 0.1 parts by weight of... After uniformly mixing the phosphate release agent produced by UN Stepan, it was defoamed at 600 Pa for 1 hour to prepare a polymeric composition for optical materials.

[0158] The composition, filtered through a 3μm Teflon filter, was then injected into a mold containing a glass mold and adhesive tape. The mold temperature was slowly increased from 25°C to 120°C at a rate of 5°C / min, and polymerization was carried out at 120°C for 18 hours. After polymerization, the mold was separated, and the product was further cured at 120°C for 4 hours to produce lens samples.

[0159] Examples 2-8 and Comparative Examples

[0160] Except that the absorbance of Na2S used in the synthesis of the polythiol compound was changed as shown in Table 1 below, the tetrafunctional polythiol compound and the lens sample were prepared in the same manner as in Example 1.

[0161] In Examples 5 and 6, the purchased Na2S was washed with ethanol at 0 °C and dried, and then used after measuring and confirming its absorbance.

[0162] Experimental Example

[0163] (1) Measurement of the absorbance of Na2S

[0164] 17.3 parts by weight of the obtained or purchased Na2S was dissolved in 100 parts by weight of degassed water containing less than 10 ppm of dissolved oxygen, then placed in a quartz cell with an optical path length of 50 mm, and then the absorbance of light at a wavelength of 350 nm was measured using a spectrophotometer (Lambda-365, PerkinElmer).

[0165] (2) Content determination by HPLC analysis

[0166] In the polythiol compositions according to the respective examples and comparative examples, the peak area % of the polythiol compound contained in the composition was measured by HPLC analysis performed under the following conditions, and the proportion of the by-product polythiol compound was calculated according to Formula 1.

[0167] <HPLC analysis conditions>

[0168] i) Instrument: Agilent 1260 InfinityⅡ

[0169] ii) Column: ZORBAX Eclipse Plus C18, 5 μm 4.6×250 mm

[0170] iii) Mobile phase gradient: Acetonitrile (0.1% formic acid): Water (0.01 M ammonium formate) = 35 - 100:65 - 0

[0171] iv) Solvent: Acetonitrile (0.1% formic acid)

[0172] v) Wavelength: 230 nm

[0173] vi) Flow rate: 1.0 ml / min

[0174] vii) Injection volume: 20 μl

[0175] viii) Sample pretreatment: Sample: Solvent = 0.1 g:10 g

[0176] Identify specific compounds corresponding to the peaks in the HPLC chromatogram by liquid chromatography-mass spectrometry (LC-MS). The specific conditions for LC-MS analysis are as follows.

[0177] <LC-MS analysis conditions>

[0178] LC conditions

[0179] i) Instrument: LC 30A System (Shimadzu)

[0180] ii) Column: YMC-Pack ODS-A 150 mm × 6 mm (S-5μm, 12nm)

[0181] iii) Mobile phase gradient: Solvent A: water, Solvent B: acetonitrile

[0182] A:B (60:40) for 30 minutes, then (0:100) for 10 minutes

[0183] iv) Flow rate: 1 ml / min

[0184] v) Column temperature: 40 °C

[0185] vi) Detector: PDA (190 to 800 nm)

[0186] vii) Injection volume: 10 μL

[0187] Quality detector conditions

[0188] i) Instrument: Q Exactive (Thermo Fisher Scientific)

[0189] ii) Ionization method: ESI

[0190] iii) Scan range: m / z 130 to 1,950

[0191] iv) Polarity: positive & negative

[0192] Specifically, in the HPLC analysis chromatogram, measure the tetrafunctional polythiol compound corresponding to Formula 1-1, whose retention time (RT) is within the range of 25.0 to 27.0 minutes, the retention time of the by-product polythiol compound corresponding to Formula 2-1 is 29.5 to 30.5 minutes, and measure the by-product polythiol compound corresponding to Formula 2-2 within the retention time range of 31.0 to 32.5 minutes.

[0193] (3) Evaluation of thiol value (SHV)

[0194] Approximately 0.1 g of the polythiol composition prepared in each example and comparative example was introduced into a beaker, and 25 mL of chloroform was added. The mixture was then stirred for 10 minutes. Next, 10 mL of methanol (MeOH) was added and the mixture was stirred again for 10 minutes. The resulting solution was then titrated with 0.1 N iodine standard solution, and the SHV (theoretical value: 91.7) was measured according to Formula 1 below.

[0195] [Equation 1] SHV (g / eq.) = Sample weight (g) / {0.1 × Iodine consumption (L)}

[0196] (3) Liquid refractive index

[0197] For the polythiol compositions synthesized in the examples and comparative examples, the refractive index at 25°C was measured using a liquid refractometer (RA-600 (Kyoto Electronics)).

[0198] (4) GPC purity

[0199] The purity of the polythiol compositions synthesized in the examples and comparative examples was measured by gel chromatography analysis performed under the following conditions using an APC system (Waters).

[0200] i) Column: Acquity APC XT Column 45A (4.6*150mm)×2

[0201] ii) Mobile phase: THF

[0202] iii) Flow rate: 0.5 mL / min

[0203] iv) Total driving time: 10 minutes

[0204] v) Injection volume: 10 μl

[0205] vi) Detector: RID 40℃

[0206] (5) Evaluation of stripes

[0207] As described above, lens samples with a diameter of 75 mm and a polarization of -4.00 D were prepared using the polymerizable compositions according to the various embodiments and comparative examples. Light from a mercury lamp light source was transmitted through the prepared lens samples, and the transmitted light was projected onto a white board to determine the presence or absence of stripes based on the presence or absence of contrast. The evaluation criteria are as follows.

[0208] ○: No stripes observed

[0209] X: Stripes are clearly visible to the naked eye.

[0210] (6) Evaluation of lens opacity

[0211] For the lens samples of the embodiments and comparative examples prepared as described above, each sample was illuminated in a dark room with a right beam from a projector, and the presence of haze or opaque material in the lens was visually confirmed.

[0212] The evaluation criteria are as follows.

[0213] ○: No fog

[0214] △: Partial haze observed

[0215] X: The overall haze was clearly observed.

[0216] (7) Measurement of color index (yellow index (YI))

[0217] For the lens samples of the examples and comparative examples, YI was measured using a colorimeter (Shinko, Colormate). Specifically, lenses with a thickness of 9 mm and... The lens sample was analyzed, and the chromaticity coordinates x and y were measured. YI was calculated based on the measured values ​​of x and y using Equation 2 below.

[0218] [Equation 2]

[0219] YI=(234×x+106×y+106) / y

[0220] The evaluation results are shown together in Table 1 below.

[0221] [Table 1]

[0222]

[0223] Referring to Table 1, in the examples where Na2S with a predetermined absorbance range was used and the proportion of the polythiol compound of Formula 1 was adjusted to 1% to 5%, high-purity polythiol compounds and lens products were obtained while preventing turbidity and discoloration.

Claims

1. A polythiol composition comprising: a tetrafunctional polythiol compound; and a compound represented by C 13 H 28 S9 represents a compound and a by-product polythiol compound having a penta-functional structure represented by C 15 H 32 S 10 a by-product polythiol compound having a penta-functional structure represented by the following formula 1, wherein the proportion of the by-product polythiol compound represented by the following formula 1 is in the range of 1% to 5%: [Formula 1] wherein the tetrafunctional polythiol compound comprises at least one of tetrafunctional polythiol compounds represented by the following Formulas 1-1 to 1-3: Proportion of secondary polysulfid compound = 100% x [(C 13 H 28 S9 peak area (%)) + (C 15 H 32 S 10 peak area (%))] / (peak area of tetrafunctional polysulfid compound (%)) In Formula 1, the peak area (%) is a peak area (%) of each of C 13 H 28 S9and C 15 H 32 S 10 represented by the following formula, and [Formula 1-1] [Formula 1-2] [Formula 1-3] [Formula 2-1] [Formula 2-2] 2. A method for producing a polythiol composition, the method comprising: generating a polyol intermediate by introducing a metal sulfide into a preliminary polyol compound; wherein C 13 H 28 The compound represented by S9 has the structure of the following formula 2-1: and wherein C 15 H 32 S 10 The compounds represented by C have the structure of the following Formula 2-2: converting the polyol intermediate into a polythiol-based compound by thiolation, wherein the absorbance of the metal sulfide is 0.75 to 1.45 when measured in a quartz cell having an optical path length of 50 mm for light having a wavelength of 350 nm after the metal sulfide is dissolved in distilled water in an amount of 17.3 parts by weight based on 100 parts by weight of the distilled water, wherein the polythiol-based compound comprises a tetrafunctional polythiol compound and a by-product polythiol compound having a larger molecular weight or a larger functional number than the tetrafunctional polythiol compound, [Formula 1] wherein the tetrafunctional polythiol compound comprises at least one of tetrafunctional polythiol compounds represented by the following Formulas 1-1 to 1-3: [Formula 1-1] [Formula 1-2] [Formula 1-3] [Formula 2-1] [Formula 2-2] 3. The method according to claim 2, further comprising, if the absorbance of the metal sulfide is less than 0.75, washing the metal sulfide with an alcohol, water, or an alcohol aqueous solution, and then drying the metal sulfide to adjust the absorbance of the metal sulfide in the range of 0.75 to 1.

45. wherein the side polythiol compound having a pentafunctional structure includes a compound represented by C 13 H 28 S9represents a compound represented by C 15 H 32 S 10 wherein the ratio of the side polythiol compound represented by the following formula 1 is in the range of 1% to 5%:

4. The method according to claim 2, wherein the metal sulfide comprises Na2S. Proportion of secondary polysulfid compound = 100% x [(C 13 H 28 S9 peak area (%)) + (C 15 H 32 S 10 peak area (%))] / (peak area of tetrafunctional polysulfid compound (%)) In Formula 1, the peak area (%) is a value measured by a high performance liquid chromatography (HPLC) analysis chart obtained at a wavelength of 230 nm, and the peak area (%) of each of C 13 H 28 S9and C 15 H 32 S 10 the tetrafunctional polythiol compound represented by Formula 1, 5. The method according to claim 2, wherein the absorbance of the metal sulfide is in the range of 0.75 to 1.

12.

6. An optical composition comprising: a polythiol composition: and wherein C 13 H 28 The compound represented by S9 has the structure of the following formula 2-1: an isocyanate-based compound: wherein C 15 H 32 S 10 The compounds represented by C have the structure of the following Formula 2-2: [Formula 1] wherein the tetrafunctional polythiol compound comprises at least one of tetrafunctional polythiol compounds represented by the following Formulas 1-1 to 1-3: [Formula 1-1] [Formula 1-2] [Formula 1-3] [Formula 2-1] [Formula 2-2] 7. A method for producing an optical composition, the method comprising: producing a polythiol-based compound; and which includes a tetrafunctional polythiol compound and a by-product polythiol compound having a pentafunctional structure, the by-product polythiol compound including a C 13 H 28 S9 represents a compound and a compound represented by C 15 H 32 S 10 wherein the proportion of the by-product polythiol compound represented by the following formula 1 is in the range of 1% to 5%; mixing the polythiol-based compound with an isocyanate-based compound, wherein the step of producing the polythiol-based compound comprises: generating a polyol intermediate by introducing a metal sulfide into a preliminary polyol compound; Proportion of secondary polysulfid compound = 100% x [(C 13 H 28 S9 peak area (%)) + (C 15 H 32 S 10 peak area (%))] / (peak area of tetrafunctional polysulfid compound (%)) In Formula 1, the peak area (%) is a peak area (%) of each of C 13 H 28 S9and C 15 H 32 S 10 represented by the following formula, and and converting the polyol intermediate into a polythiol-based compound by thiolation, wherein the absorbance of the metal sulfide is 0.75 to 1.45 when measured in a quartz cell having an optical path length of 50 mm for light having a wavelength of 350 nm after the metal sulfide is dissolved in distilled water in an amount of 17.3 parts by weight based on 100 parts by weight of the distilled water, [Formula 1] wherein the tetrafunctional polythiol compound comprises at least one of tetrafunctional polythiol compounds represented by the following Formulas 1-1 to 1-3: wherein C 13 H 28 The compound represented by S9 has the structure of the following formula 2-1: [Formula 1-1] [Formula 1-2] [Formula 1-3] wherein C 15 H 32 S 10 The compounds represented by C have the structure of the following Formula 2-2: [Formula 2-1] [Formula 2-2] ​ ​ ​ ​ ​ ​ ​ ​ ​ wherein the by-product polysulfide compound having a pentafunctional structure contains C 13 H 28 S9represents a compound and a by-product polysulfide compound represented by C 15 H 32 S 10 wherein the ratio of the by-product polysulfide compound represented by the following formula 1 is in the range of 1% to 5%: ​ Proportion of secondary polysulfid compound = 100% x [(C 13 H 28 S9 peak area (%)) + (C 15 H 32 S 10 peak area (%))] / (peak area of tetrafunctional polysulfid compound (%)) In Formula 1, the peak area (%) is a peak area (%) of each of C 13 H 28 S9and C 15 H 32 S 10 represented by Formula 1, and ​ ​ ​ ​ wherein C 13 H 28 The compound represented by S9 has the structure of the following formula 2-1: ​ wherein C 15 H 32 S 10 The compounds represented by C have the structure of the following Formula 2-2: [Formula 2-2] 8. An optical product comprising a copolymer of a polythiol composition and an isocyanate-based compound, wherein the polythiol composition includes a tetrafunctional polythiol compound and a by-product polythiol compound having a pentafunctional structure, the by-product polythiol compound including a C 13 H 28 S9represents a compound and a compound represented by C 15 H 32 S 10 , and wherein the proportion of the by-product polythiol compound represented by the following formula 1 is in the range of 1% to 5%: [Formula 1] Proportion of secondary polysulfid compound = 100% x [(C 13 H 28 S9 peak area (%)) + (C 15 H 32 S 10 peak area (%))] / (peak area of tetrafunctional polysulfid compound (%)) In Formula 1, the peak area (%) is a peak area (%) of each of C 13 H 28 S9and C 15 H 32 S 10 represented by Formula 1, and wherein the tetrafunctional polythiol compound comprises at least one of tetrafunctional polythiol compounds represented by the following Formulas 1-1 to 1-3: [Formula 1-1] [Formula 1-2] [Formula 1-3] wherein C 13 H 28 The compound represented by S9 has the structure of the following formula 2-1: [Formula 2-1] wherein C 15 H 32 S 10 The compounds represented by C have the structure of the following Formula 2-2: [Formula 2-2] 9. The optical product according to claim 8, further comprising at least one additive selected from the group consisting of a mold release agent, a reaction catalyst, a heat stabilizer, an ultraviolet absorber, and a blueing agent.

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