Polythiol compositions, optical compositions, and optical products

Abstract

The polythiol composition according to the exemplary embodiment includes a main polythiol compound and a by-compound having a molecular weight higher than that of the main polythiol compound. The peak area (%) corresponding to the by-compound in a high performance liquid chromatography (HPLC) analysis spectrum obtained at a wavelength of 230 nm has a retention time in the range of 34 to 40 minutes of 2.5% or less. By finely controlling the by-compound, an optical product having excellent transmittance and optical properties can be manufactured.

Description

Technical Field

[0001] This invention relates to polythiol compositions, optical compositions, and optical products. More specifically, this invention relates to polythiol compositions comprising polythiol compounds and other compounds, optical compositions comprising polythiol compounds, and optical products formed from said optical compositions. Background Technology

[0002] 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.

[0003] For example, polythiourethane compounds prepared by reacting polythiols and isocyanates can be used as substrates for optical lenses.

[0004] 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 isothiouronium salt, and then hydrolyzing it with ammonia.

[0005] Depending on the polymerization rate or reactivity of the synthesized polythiol compound with the isocyanate compound, the optical properties of optical products such as lenses may be altered. For example, the reaction rate may change due to compounds other than the desired target polythiol compound, which could reduce the reliability of the lens's required optical properties. Summary of the Invention

[0006] One objective of the exemplary embodiments is to provide polythiol compositions with improved reactivity and optical properties, and methods for preparing the same.

[0007] One objective of the exemplary embodiments is to provide an optical composition comprising a polythiol composition having improved reactivity and optical properties.

[0008] One objective of the exemplary embodiments is to provide an optical product manufactured using the above-described optical composition.

[0009] To achieve the above objectives, according to one aspect of the present invention, a polythiol composition is provided, comprising: a main polythiol compound; and a secondary compound having a molecular weight higher than that of the main polythiol compound, wherein the peak area (%) corresponding to the secondary compound in a high-performance liquid chromatography (HPLC) analysis spectrum obtained at a wavelength of 230 nm is greater than 0% and less than 2.5% in the range of 34 to 40 minutes.

[0010] In some implementations, the peak area in the HPLC analysis chromatogram with a retention time in the range of 34 to 40 minutes can be 1.5 to 2.5%.

[0011] In some implementations, multiple peaks can be detected in the HPLC analysis spectrum with retention times ranging from 34 to 40 minutes, and the sum of the areas of the multiple peaks can be greater than 0% and less than 2.5%.

[0012] In some embodiments, the main polythiol compound may include a tetrafunctional polythiol compound corresponding to a retention time in the range of 24 to 28 minutes in the HPLC analysis spectrum.

[0013] In some embodiments, the tetrafunctional polythiol compound may include C 10 H 22 S7 represents the compound.

[0014] In some embodiments, the tetrafunctional polythiol compound may include at least one of the compounds represented by formulas 1-1 to 1-3.

[0015] [Equation 1-1]

[0016]

[0017] [Equation 1-2]

[0018]

[0019] [Equation 1-3]

[0020]

[0021] In some implementations, the peak area (%) in the HPLC analysis spectrum with retention times in the range of 24 to 28 minutes can be 80 to 90%.

[0022] In some implementations, the peak area (%) in the HPLC analysis chromatogram with retention times in the range of 24 to 28 minutes can be 81 to 85%.

[0023] In some embodiments, the peak area ratio of the polythiol composition defined by Formula 1 can be from 1.5% to 3.1%:

[0024] [Formula 1]

[0025] Peak area ratio (%) = (A / B) × 100

[0026] (In Equation 1, A is the peak area (%) included in the retention time range of 34 to 40 minutes in the HPLC analysis spectrum, and B is the peak area (%) included in the retention time range of 24 to 28 minutes in the HPLC analysis spectrum).

[0027] According to another aspect of the present invention, an optical composition is provided, comprising: a polythiol composition and an isocyanate compound, said polythiol composition comprising a main polythiol compound and a by-compound with a molecular weight higher than that of the main polythiol compound, wherein the peak area (%) corresponding to the by-compound in a high-performance liquid chromatography (HPLC) analysis spectrum obtained at a wavelength of 230 nm is greater than 0% and less than 2.5% in the range of 34 to 40 minutes.

[0028] Furthermore, according to another aspect of the present invention, an optical product is provided, comprising: a copolymer of a polythiol composition and an isocyanate compound, wherein the polythiol composition comprises a main polythiol compound and a secondary compound having a molecular weight higher than that of the main polythiol compound, wherein the peak area (%) corresponding to the secondary compound in a high-performance liquid chromatography (HPLC) analysis spectrum obtained at a wavelength of 230 nm is greater than 0% and less than 2.5% in the range of 34 to 40 minutes.

[0029] The polythiol composition according to an exemplary embodiment may include a primary polythiol compound, such as a tetrafunctional polythiol compound, and secondary compounds with a molecular weight higher than that of the primary polythiol compound. The reactivity of the polythiol composition can be appropriately adjusted by finely tuning the range of secondary compound content measured by HPLC.

[0030] Therefore, by adjusting the reaction rate between the polythiol composition and the isocyanate compound, streaks and cloudiness can be suppressed, and high-transmission optical lenses with the desired refractive index can be obtained with high reliability. Attached Figure Description

[0031] Figures 1 to 3 Images of high-performance liquid chromatography (HPLC) analysis spectra of polythiol compositions prepared according to the examples and comparative examples. Detailed Implementation

[0032] 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.

[0033] 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.

[0034] According to one aspect of the present invention, a polythiol composition comprising a polythiol compound is provided.

[0035] According to an exemplary embodiment, the polythiol composition may include a primary polythiol compound and secondary compounds.

[0036] A primary polythiol compound refers to a polythiol compound that is a target material included in a polythiol composition and promotes polymerization with isocyanate compounds. For example, a primary polythiol compound may be a compound included in the polythiol composition at the highest concentration. According to an exemplary embodiment, a primary polythiol compound may be a compound corresponding to the main peak or maximum peak measured by high-performance liquid chromatography (HPLC) analysis.

[0037] The main polythiol compounds may include trifunctional polythiol compounds and / or tetrafunctional polythiol compounds.

[0038] As a non-limiting example, tetrafunctional polythiols may include, for example, compounds derived from C 10 H 22 Compounds represented by S7. Non-limiting examples of tetrafunctional polythiols may include compounds represented by formulas 1-1 to 1-3 below.

[0039] [Equation 1-1]

[0040]

[0041] [Equation 1-2]

[0042]

[0043] [Equation 1-3]

[0044]

[0045] Trifunctional polythiols can include compounds composed of C7H 16 S5 represents the compound. In one embodiment, the trifunctional polythiol compound may include the compound represented by formula 2 below.

[0046] [Equation 2]

[0047]

[0048] Preferably, the main polythiol compound may include a tetrafunctional polythiol compound. In this case, it may be advantageous in terms of the uniformity of optical properties such as refractive index and mechanical stability such as the durability of optical products such as lenses.

[0049] By-compounds can be compounds with a molecular weight higher than that of the main polythiol compound. For example, by-compounds may include reaction initiators used to synthesize polythiol compounds (e.g., 2-mercaptoethanol and epihaloalcohols), intermediates such as polyol compounds, or aggregates or oligomers such as polythiol compounds.

[0050] According to an exemplary embodiment, the by-compound may be a compound corresponding to a polythiol composition whose retention time in the high-performance liquid chromatography (HPLC) analysis spectrum obtained at a wavelength of 230 nm is in the range of 34 to 40 minutes.

[0051] According to an exemplary embodiment, the peak area (%) in the HPLC chromatogram corresponding to the by-compound with a retention time in the range of 34 to 40 minutes can be less than 2.5%. For example, in the HPLC chromatogram, the peak area (%) in the retention time range of 34 to 40 minutes can be greater than 0% and less than 2.5%.

[0052] In one embodiment, the peak area (%) corresponding to the side compound can be in the range of 0.5 to 2.5%, preferably 1 to 2.5%, more preferably 1.5 to 2.5%, or 1.5 to 2.2%.

[0053] In some embodiments, the retention time in the HPLC chromatogram of the polythiol composition may include multiple peaks in the range of 34 to 40 minutes. In this case, the by-compounds may include a variety of compounds, and the sum of the areas of the multiple peaks within the retention time range may be within the aforementioned numerical range.

[0054] When the peak area (%) of the by-compound increases excessively, the reaction rate or reactivity of the polythiol composition with the isocyanate compound may decrease excessively, and the purity of the polythiol composition may decrease. Therefore, this may lead to clouding in optical products such as lenses manufactured using the polythiol composition.

[0055] When byproducts are included in appropriate amounts within the above-mentioned numerical range, excessive flowability and an increase in the reaction rate of the composition can be suppressed. Therefore, streaking in optical products manufactured using polythiol compositions can be prevented.

[0056] As described above, in the HPLC chromatogram of the polythiol composition, the main polythiol compound may correspond to the maximal peak. In some embodiments, the main polythiol compound may be included in the HPLC chromatogram with a retention time in the range of about 24 to 28 minutes.

[0057] In some embodiments, the peak area (%) in the retention time range of 24 to 28 minutes in the HPLC analysis spectrum can be 80 to 90%. In one embodiment, the peak area (%) in the retention time range of 24 to 28 minutes in the HPLC analysis spectrum can be 81 to 90%, preferably 81 to 85%, or 82 to 85%.

[0058] Within the aforementioned range, the purity and desired optical properties of the optical composition or product can be obtained, and streaks caused by excessive increase in reaction rate can be suppressed.

[0059] In some embodiments, the retention time in the HPLC chromatogram of the polythiol composition may include multiple peaks in the range of 24 to 28 minutes. In this case, the sum of the areas of the multiple peaks within the retention time range may be within the aforementioned numerical range.

[0060] In an exemplary embodiment, the peak area ratio of the polythiol composition defined by Formula 1 below may be 1.5 to 3.1%.

[0061] [Formula 1]

[0062] Peak area ratio (%) = (A / B) × 100

[0063] In Equation 1, A represents the peak area (%) in the HPLC chromatogram with a retention time of 34 to 40 minutes, and B represents the peak area (%) in the HPLC chromatogram with a retention time of 24 to 28 minutes.

[0064] In one embodiment, the peak area ratio can be 1.8 to 3.1%, preferably 2.0 to 3.1%, or 2.0 to 3.0%.

[0065] Within the aforementioned peak area ratio range, sufficient heat resistance and an appropriate reaction rate range can be effectively achieved without causing a deterioration in the desired refractive index, transparency, and purity obtained from optical products.

[0066] The molecular weight of the byproduct compound is higher than that of the main polythiol compound, and therefore its retention time is longer. The byproduct compound can be included in the polythiol composition, for example, as a macromolecule to act as a reaction rate control agent in the polythiol composition.

[0067] In addition, the addition of high molecular weight by-compounds can increase the glass transition temperature (Tg) of optical products by increasing intermolecular attraction and interaction, and can also enhance heat resistance.

[0068] According to another aspect of the present invention, a method for preparing the above-described polythiol composition is provided. As described above, the polythiol composition may include a main polythiol compound and secondary compounds.

[0069] The preparation method of the polythiol composition according to the exemplary embodiments may include the following steps, processes or operations.

[0070] 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, S30, and S40 below. It should be understood that, for ease of description, the terms "S10, S20, S30, and S40" are used to distinguish processes and are not intended to limit their order. For example, some or all of the processes in S10, S20, S30, and S40 below may be performed sequentially, and / or in a changed order depending on the processing conditions.

[0071] S10) reacts 2-mercaptoethanol and epihaloethanol at a first temperature to form a preparative polyol compound.

[0072] S20) A metal sulfide is introduced into the preparative polyol compound, and the temperature is raised to a second temperature above the first temperature to prepare a polyol intermediate.

[0073] S30) reacts a polyol intermediate with thiourea under acidic conditions to prepare isothiourea onium salt.

[0074] S40) converts isothiourea onium salts into polythiool compounds.

[0075] For example, in step S10, 2-mercaptoethanol and epihaloethanol can be used as reaction initiators to allow the reaction to proceed according to Scheme 1 below.

[0076] [Option 1]

[0077]

[0078] As shown in Scheme 1, epichlorohydrin can be used as an epihalohydrin.

[0079] In some embodiments, a basic catalyst can be used in the reaction steps of epihaloalcohols and 2-mercaptoethanol. For example, in the synthesis of tetrafunctional polythiols, examples of basic catalysts may include tertiary amines such as triethylamine, quaternary ammonium salts, triphenylphosphine, and trivalent chromium compounds. In the synthesis of trifunctional polythiols, alkali metal catalysts such as sodium hydroxide or potassium hydroxide may be used.

[0080] According to Scheme 1, a preliminary polyol compound having, for example, the form of a diol compound containing sulfide bonds can be formed.

[0081] For example, the content of 2-mercaptoethanol can be from 0.5 mol to 3 mol based on 1 mol of epihaloethanol, preferably from 0.7 mol to 2 mol, and more preferably from 0.9 mol to 1.1 mol. A basic catalyst can be used in amounts of 0.001 mol to 0.1 mol, 0.005 mol to 0.03 mol, and more preferably from 0.007 mol to 0.015 mol based on 1 mol of epihaloethanol.

[0082] To suppress the excessive increase in heat of reaction caused by the ring-opening reaction of epihaloalcohols, step S10 can be carried out, for example, in a state where the reactor is sufficiently cooled by circulating a refrigerant.

[0083] In some implementations, step S10 can be performed at a first temperature, which can be in the range of about 0°C to 20°C, preferably below 15°C, or between 5°C and 15°C.

[0084] For example, in step S20, a metal sulfide is introduced into the preparative polyol compound, and the temperature is raised to a second temperature above the first temperature to prepare a polyol intermediate according to scheme 2 below.

[0085] [Option 2]

[0086]

[0087] As shown in Scheme 2, diol compounds containing sulfide bonds can be further reacted with each other through metal sulfides to obtain polyol intermediates including tetrafunctional polyol compounds.

[0088] Metal sulfides may include alkali metal sulfides, as shown in Scheme 2, where Na₂S can be used. For example, a polyol intermediate can be formed by introducing an aqueous solution of the metal sulfide and stirring the mixture of the aqueous solution of the metal sulfide and the prepared polyol compound.

[0089] According to an exemplary embodiment, after the metal sulfide is introduced, the temperature can be raised to a second temperature while the mixture is being stirred. The second temperature can be about 40 to 95°C. Preferably, the second temperature can be greater than 50°C. In one embodiment, the second temperature can be about 55°C to 90°C, and more preferably 60°C to 90°C.

[0090] For example, metal sulfides can be added dropwise at an intermediate temperature, such as 20°C to 25°C, which is an increase from the first temperature. After the addition is complete, the mixture can be stirred by raising the temperature from the intermediate temperature to a second temperature.

[0091] The heat of reaction can be ensured by raising the second temperature. Therefore, the amount of unreacted residue generated in step S10 can be appropriately adjusted. Thus, the amount of unreacted residue can be controlled or reduced more effectively.

[0092] For example, the unreacted residues in step S10 may generate a large number of high-molecular-weight byproducts, such as oligomers, through self-aggregation or self-reaction. However, in the preparation of polyol intermediates by introducing metal sulfides, by ensuring sufficient heat of reaction, further reactions of the unreacted residues can be promoted, thus allowing for appropriate control of the amount of byproducts.

[0093] For example, by adjusting the second temperature within the above range, the amount of by-compound can be maintained such that the peak area (%) in the HPLC analysis spectrum with a retention time in the range of 34 to 40 minutes is less than 2.5%, preferably in the range of 1.5 to 2.5%, and the above peak area ratio can be effectively ensured.

[0094] For example, in step S30, the polyol intermediate can react with thiourea. As a result, according to an exemplary embodiment, an isothiourea onium salt can be obtained.

[0095] Reflux under acidic conditions can be used in the preparation of isothiourea onium salts. To create acidic conditions, acidic compounds such as hydrochloric acid, hydrobromic acid, iodic acid, sulfuric acid, and phosphoric acid can be used.

[0096] The reflux temperature can be from 90°C to 120°C, and preferably from 100°C to 120°C, and the reflux can be carried out for about 1 hour to 10 hours. As described above, according to the exemplary embodiment, when the additionally added epihaloalcohol is reacted at an elevated second temperature in step S20, the unreacted residue can be reduced or maintained in an appropriate amount.

[0097] Therefore, even under high-temperature reflux conditions, excessive production of byproducts is suppressed, and the reaction rate of the polythiol composition can be appropriately maintained.

[0098] For example, in step S40, the isothiourea onium salt can be converted into a polythiol compound. According to an exemplary embodiment, the isothiourea onium salt can be hydrolyzed under alkaline conditions to prepare a polythiol compound.

[0099] Steps S30 and S40 above may include thiolation as exemplified by scheme 3 below.

[0100] [Option 3]

[0101]

[0102] For example, an alkaline aqueous solution can be added to the reaction solution containing isothiourea onium salt to hydrolyze it. The alkaline aqueous solution may include alkali metal hydroxides and / or alkaline earth metal hydroxides, such as NaOH, KOH, LiOH, Ca(OH)2, etc.

[0103] In one embodiment, the reaction solution containing the isothiourea onium salt is cooled to a temperature of 20°C to 60°C, preferably 25°C to 55°C, and more preferably 25°C to 50°C. Subsequently, an alkaline aqueous solution may be added.

[0104] In one embodiment, an organic solvent may be added prior to the addition of an alkaline aqueous solution. The organic solvent may be of low or substantially non-reactive nature and have a boiling point above the thiolation reaction temperature to ensure stable thiolation.

[0105] Examples of organic solvents may include toluene, xylene, chlorobenzene, and dichlorobenzene. Preferably, toluene can be used, taking into account reaction stability and toxicity from the organic solvent.

[0106] The polythiol compounds and the polythiol compositions 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 the optical materials prepared from the polythiol compositions can be improved. Subsequently, drying, filtration, etc., can be performed.

[0107] 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.

[0108] 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.

[0109] After pickling and washing, residual organic solvents and moisture can be removed by heating under reduced pressure, followed by filtration to obtain high-purity polythiol compounds.

[0110] In some embodiments, the residual moisture content in the polythiol compound or polythiol composition may be less than 1,000 ppm, preferably in the range of 100 ppm to 500 ppm, and more preferably in the range of 150 ppm to 400 ppm.

[0111] In some embodiments, the gel permeation chromatography (GPC) purity of the polythiol composition is 78% or higher. For example, the GPC purity of the polythiol composition can be 78% to 85%. Preferably, the GPC purity is 80% to 85%, and more preferably 80% to 84%.

[0112] In some embodiments, the liquid refractive index of the polythiol composition at 25°C can be 1.645 to 1.648, preferably 1.645 to 1.647, and more preferably 1.6450 to 1.6465.

[0113] In some embodiments, the thiol value (SHV) of the polythiol composition can be from about 96.0 g / eq to 98.5 g / eq. Preferably, the SHV is from 96.0 g / eq to 97.0 g / eq.

[0114] 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.

[0115] According to the above-described embodiments, the formation of byproducts can be controlled by introducing epihaloalcohols in stages. However, the present invention is not limited to the above-described preparation method; byproducts can be introduced individually into the polythiol composition in amounts corresponding to peak areas within the above-described range. Furthermore, in addition to epihaloalcohols, the amount of byproducts can be adjusted by other process conditions such as reaction temperature and reaction time.

[0116] Furthermore, according to another aspect of the present invention, an optical composition comprising the above-described polythiol composition (e.g., a polymeric composition for optical materials) is provided.

[0117] Polymerizable compositions for optical materials may include polythiol compositions and isocyanate compounds. Polythiol compositions may include primary polythiol compounds and secondary compounds.

[0118] Isocyanate compounds may include compounds that can be used as monomers in the synthesis of polythiourethanes. In a preferred embodiment, the 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.

[0119] The optical composition may further include additives such as mold release agents, reaction catalysts, heat stabilizers, ultraviolet absorbers, and bluing agents.

[0120] 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. These may be used alone or in combination of two or more thereof.

[0121] As reaction catalysts, catalysts used in the polymerization reaction of polyurethane 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 of them.

[0122] 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 acid salts, phosphorus, lead, and organotin compounds. These can be used alone or in combination of two or more.

[0123] 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.

[0124] Examples of bluing agents can include dyes, fluorescent whitening agents, fluorescent pigments, and inorganic pigments, and can be appropriately selected according to the physical properties or resin color required for the optical product to be manufactured. 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.

[0125] Polysulfuric acid ester resins can be produced by the polymerization reaction of polysulfide compounds included in the polysulfide composition with isocyanate compounds, and the polymerization rate can be adjusted or controlled by the by-compounds included in the polysulfide composition.

[0126] Therefore, yellowing or cloudiness can be prevented, the formation of streaks can be suppressed, and optical products that maintain uniformity and improved optical properties over a long period of time can be provided.

[0127] In some embodiments, based on the total weight of the optical composition, the optical composition may include about 40 to 60 wt.% (“wt.%”) of a main polythiol compound, about 40 to 60 wt.% of an isocyanate compound, and about 0.01 to 1 wt.% of additives.

[0128] In some embodiments, the reaction rate of the optical composition included in Formula 1 below is maintained in the range of 0.15 to 0.30, preferably in the range of 0.15 to 0.25, and more preferably in the range of 0.15 to 0.23, by means of the by-compound.

[0129] Furthermore, according to another aspect of the present invention, an optical product manufactured using the above-described optical composition can be provided.

[0130] For example, after degassing the polymeric composition under reduced pressure, the resulting composition can be injected into a mold for shaping optical materials. Injection into the mold can be carried out at a temperature range of, for example, 20°C to 40°C, and preferably 20°C to 35°C.

[0131] After injection into the mold, the temperature can be gradually increased to allow the polymerization reaction of the polyurethane resin to proceed. The polymerization temperature can be from 20°C to 150°C, and preferably from 25°C to 125°C. For example, the maximum polymerization temperature can be from 100°C to 150°C, preferably from 110°C to 140°C, and more preferably from 115°C to 130°C.

[0132] The heating rate can be from 1°C / min to 10°C / min, preferably from 3°C / min to 8°C / min, and more preferably from 4°C / min to 7°C / min. The polymerization time can be from 10 to 20 hours, preferably from 15 to 20 hours.

[0133] For example, by appropriately controlling the reaction rate within the above temperature range, a lens with uniform optical and mechanical properties can be obtained.

[0134] After polymerization, the polymerized polyurethane resin can be separated from the mold to obtain an optical product. In one embodiment, after separation from the mold, a curing process can be further performed. The curing process can be carried out for about 1 to 10 hours, preferably 2 to 8 hours, and more preferably 3 to 6 hours, within the range of 100°C to 150°C, preferably 110°C to 140°C, more preferably 115°C to 130°C.

[0135] Depending on the shape of the mold, optical products can be manufactured in the form of eyeglass lenses, camera lenses, light-emitting diodes, etc.

[0136] The refractive index of an optical product can be adjusted according to the type and / or content ratio of the polythiol compound and isocyanate compound used in the polymeric composition for optical materials. For example, the refractive index of an optical product can be adjusted in the range of 1.56 to 1.78, 1.58 to 1.76, 1.60 to 1.78, or 1.60 to 1.76, preferably in the range of 1.65 to 1.75 or 1.69 to 1.75.

[0137] In some embodiments, the glass transition temperature (Tg) of the optical product can be 95 to 105°C, preferably 100 to 105°C, and more preferably 100 to 104°C.

[0138] Optical products can be improved by further surface treatments such as antifouling, coloring, hard coating, surface polishing, and hardening.

[0139] In the following description, embodiments provided in this invention will be further described 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.

[0140] Example 1

[0141] 1) Synthesis of tetrafunctional polythiols

[0142] 60.0 wt. parts of water, 0.3 wt. parts of triethylamine and 73.0 wt. parts of 2-mercaptoethanol (2-ME) were introduced into the reactor, which was then cooled to 0°C. 88.2 wt. parts of epichlorohydrin (ECH) were slowly added dropwise at a temperature below 15°C to carry out the first reaction.

[0143] Next, 148.7 wt. parts of a 25% sodium sulfide (Na2S·9H2O) aqueous solution were slowly added dropwise at 25°C, and the mixture was heated to the second temperature described in Table 1 below, followed by stirring for 3 hours. Afterward, 486.8 wt. parts of 36% hydrochloric acid and 177.8 wt. parts of thiourea were added, and the mixture was refluxed at 110°C and stirred for 3 hours to carry out the thiourea-onium chlorination reaction.

[0144] After cooling the resulting reaction solution to 50°C, 305.6 wt. parts of toluene and 332.6 wt. parts of 50% NaOH were added, and then hydrolysis was carried out at 40°C to 60°C for 3 hours.

[0145] Then, after performing layer separation for 1 hour, the aqueous layer was discarded, and 120 wt. parts of 36% hydrochloric acid was added to the resulting toluene solution, followed by one-time pickling at 33°C to 40°C for 30 minutes. After pickling, 250 wt. parts of degassed water (dissolved oxygen concentration of 2 ppm) was added, and washing was performed at 35 to 45°C for 30 minutes. The washing was carried out four times. After removing toluene and residual moisture under heating and reduced pressure, filtration was performed under reduced pressure through a PTFE-type membrane filter to obtain 140 wt. parts of a polythiol composition containing the tetrafunctional polythiol compound represented by the above formula 1-1 as the main component.

[0146] 2) Preparation of polymeric compositions for optical materials and lenses

[0147] 49.0 wt. parts of the above-prepared polythiol composition, 51.0 wt. parts of xylene diisocyanate, 0.01 wt. part of dibutyltin chloride, and 0.1 wt. part of the phosphate ester mold release agent produced by UN Stepan were uniformly mixed, and then defoaming treatment was carried out at 600 Pa for 1 hour to prepare a polymeric composition for optical materials.

[0148] Then, the composition filtered through a 3-μm Teflon filter was injected into a molded casting provided with a glass mold and tape. The temperature of the molded casting was slowly raised 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 was completed, the molded casting was separated, and then the product was further cured at 120°C for 4 hours to manufacture a lens sample.

[0149] Examples 2 to 6 and Comparative Examples

[0150] Except that after adding an aqueous sodium sulfide solution, the second temperature was changed as described in Table 1 below, a polythiol composition and a lens sample were prepared in the same manner as in Example 1.

[0151] In Comparative Example 1, a polythiol composition and a lens sample were prepared in the same manner as in Example 1, except that an aqueous sodium sulfide solution was added and then stirred at 25°C.

[0152] Experimental Example

[0153] (1) Content determination by HPLC analysis spectrum

[0154] In the polythiol compositions according to each of the examples and comparative examples, the peak area (%) of the by-compound measured with a retention time in the range of 34 to 40 minutes was measured by HPLC analysis performed under the following conditions.

[0155] <HPLC analysis conditions>

[0156] i) Instrument: Agilent 1260 Infinity II

[0157] ii) Column: ZORBAX Eclipse Plus C18, 5μm 4.6×250mm

[0158] iii) Mobile phase gradient: Acetonitrile (0.1% formic acid): Water (0.01M ammonium formate) = 35-100:65-0

[0159] iv) Solvent: Acetonitrile (0.1% formic acid)

[0160] v) Wavelength: 230nm

[0161] vi) Flow rate: 1.0 ml / min, injection volume: 20 μl, sample pretreatment: sample: solvent = 0.1 g: 10 g

[0162] Figures 1 to 3 Images showing high-performance liquid chromatography (HPLC) analysis spectra of polythiol compositions prepared according to the examples and comparative examples.

[0163] Specifically, Figure 1 and Figure 2 The HPLC analytical spectra of Examples 3 and 4 are shown respectively, while Figure 3 The HPLC chromatogram of Comparative Example 1 is shown. Figures 1 to 3 In the diagram, the main peak corresponding to the main polythiol compound is indicated by an arrow, and the peaks corresponding to the side compounds with retention times in the range of 34 to 40 minutes are indicated by dashed circles.

[0164] (2) Evaluation of thiol value (SHV)

[0165] Approximately 0.1 g of the polythiol composition prepared in each example and comparative example was introduced into a beaker, 25 mL of chloroform was added, and the mixture was stirred for 10 minutes. Then, 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.

[0166] [Equation 1] SHV (g / eq.) = Sample weight (g) / {0.1 × Iodine consumption (L)}

[0167] (3) Liquid refractive index

[0168] 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)).

[0169] (4) GPC purity

[0170] 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).

[0171] i) Column: Acquity APC XT Column 45A (4.6*150mm)×2

[0172] ii) Mobile phase: THF

[0173] iii) Flow rate: 0.5 mL / min

[0174] iv) Total driving time: 10 minutes

[0175] v) Injection volume: 10 μl

[0176] vi) Detector: RID 40℃

[0177] (5) Evaluation of stripes

[0178] 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.

[0179] ○: No stripes observed

[0180] △: Fine partial stripes were observed.

[0181] X: Stripes are clearly visible to the naked eye.

[0182] (6) Evaluation of lens opacity

[0183] For the lens samples of the embodiments and comparative examples prepared as described above, each sample was illuminated by a projector in a dark room, and the presence of haze or opaque material in the lens was visually confirmed.

[0184] The evaluation criteria are as follows.

[0185] ○: No fog

[0186] △: Partial fog was observed.

[0187] X: The overall haze was clearly observed.

[0188] (7) Measurement of polymerization rate (slope of reactivity) )

[0189] Using an EMS-1000 (KEM) non-contact viscometer, the standard viscosity (standard cps) was first confirmed using a viscosity standard solution (Brookfield, 1000 cps, 25°C). Subsequently, the viscosity of the polymerizable compositions according to the examples and comparative examples was measured at 10°C for 24 hours. The measured values ​​were mathematically formulated (“mathematicalized”) with time on the X-axis and viscosity on the Y-axis, while the Y-axis was converted to a logarithmic scale as shown in Equation 1 below, from which the reaction rate was derived.

[0190] [Mathematical Expression 1]

[0191] Y = a × exp(b × X)

[0192] In mathematical formula 1, the value of 'a' represents the initial viscosity (cps), while the value of 'b' represents the reaction rate. The measured values ​​are rounded to two decimal places.

[0193] (8) Measurement of glass transition temperature (Tg)

[0194] The glass transition temperature (Tg) of the lens samples of the examples and comparative examples was measured using a thermomechanical analyzer (TMAQ400, TA Instruments) using the transmission method (load: 50g, tip diameter: Φ0.5mm, and heating rate: 10℃ / min).

[0195] The evaluation results are shown together in Tables 1 and 2 below.

[0196] [Table 1]

[0197]

[0198] [Table 2]

[0199]

[0200] Referring to Tables 1 and 2, in the cases where the retention time in the HPLC analysis spectrum at 230 nm was in the range of 34 to 40 minutes and the peak area was less than 2.5%, virtually no streaks or turbidity were observed, while maintaining an appropriate reaction rate.

[0201] In comparative cases where the HPLC peak area exceeded 2.5%, turbidity was observed, and the polymerization rate was excessively reduced.

Claims

1. A polythiol composition comprising: Main polythiol compounds; and By-compounds with a molecular weight higher than that of the main polythiol compound. Wherein, the peak area (%) corresponding to the said by-compound in the high-performance liquid chromatography (HPLC) analysis spectrum obtained at a wavelength of 230 nm, with a retention time in the range of 34 to 40 minutes, is greater than 0% and less than 2.5%. The primary polythiol compounds include trifunctional or tetrafunctional polythiol compounds. The trifunctional polythiol compound includes compounds composed of C7H 16 S5 represents the compound, The tetrafunctional polythiol compound includes compounds composed of C 10 H 22 S7 represents the compound, and The main polythiol compound corresponds to a retention time in the range of 24 to 28 minutes in the HPLC analysis spectrum.

2. The polythiol composition according to claim 1, wherein the peak area in the HPLC analysis spectrum with a retention time in the range of 34 to 40 minutes is 1.5 to 2.5%.

3. The polythiol composition according to claim 1, wherein multiple peaks were detected in the HPLC chromatogram with retention times in the range of 34 to 40 minutes, and The sum of the areas of the multiple peaks is greater than 0% and less than 2.5%.

4. The polythiol composition according to claim 1, wherein the tetrafunctional polythiol compound comprises at least one of compounds represented by formulas 1-1 to 1-3: [Equation 1-1] [Equation 1-2] [Equation 1-3] 5. The polythiol composition according to claim 1, wherein the peak area (%) in the HPLC analysis spectrum with a retention time in the range of 24 to 28 minutes is 80 to 90%.

6. The polythiol composition according to claim 1, wherein the peak area (%) in the HPLC analysis spectrum with a retention time in the range of 24 to 28 minutes is 81 to 85%.

7. The polythiol composition according to claim 1, wherein the peak area ratio defined by formula 1 is from 1.5 to 3.1%: [Formula 1] Peak area ratio (%) = (A / B) × 100 In Formula 1, A is the peak area (%) included in the HPLC analytical spectrum with a retention time of 34 to 40 minutes, and B is the peak area (%) included in the HPLC analytical spectrum with a retention time of 24 to 28 minutes.

8. An optical composition comprising: A polythiol composition comprising a main polythiol compound and a by-compound with a molecular weight higher than that of the main polythiol compound, wherein the peak area (%) corresponding to the by-compound in a high-performance liquid chromatography (HPLC) chromatogram obtained at a wavelength of 230 nm is greater than 0% and less than 2.5% in the range of 34 to 40 minutes; and Isocyanate compounds, The primary polythiol compounds include trifunctional or tetrafunctional polythiol compounds. The trifunctional polythiol compound includes compounds composed of C7H 16 S5 represents the compound, The tetrafunctional polythiol compound includes compounds composed of C 10 H 22 S7 represents the compound, and The main polythiol compound corresponds to a retention time in the range of 24 to 28 minutes in the HPLC analysis spectrum.

9. The optical composition according to claim 8, wherein the peak area in the HPLC analysis spectrum with a retention time in the range of 34 to 40 minutes is 1.5 to 2.5%.

10. The optical composition according to claim 8, wherein the peak area ratio of the polythiol composition as defined by formula 1 is 1.5 to 3.1%: [Formula 1] Peak area ratio (%) = (A / B) × 100 In Formula 1, A is the peak area (%) included in the HPLC analytical spectrum with a retention time of 34 to 40 minutes, and B is the peak area (%) included in the HPLC analytical spectrum with a retention time of 24 to 28 minutes.

11. An optical product comprising: A copolymer of polythiol composition and isocyanate compound, The polythiol composition comprises a primary polythiol compound and secondary compounds with a molecular weight higher than that of the primary polythiol compound, wherein the peak area (%) corresponding to the secondary compound in the high-performance liquid chromatography (HPLC) chromatogram obtained at a wavelength of 230 nm is greater than 0% and less than 2.5% in the range of 34 to 40 minutes. The primary polythiol compounds include trifunctional or tetrafunctional polythiol compounds. The trifunctional polythiol compound includes compounds composed of C7H 16 S5 represents the compound, The tetrafunctional polythiol compound includes compounds composed of C 10 H 22 S7 represents the compound, and The main polythiol compound corresponds to a retention time in the range of 24 to 28 minutes in the HPLC analysis spectrum.

12. The optical product according to claim 11, wherein the glass transition temperature of the optical product is in the range of 95 to 105°C.

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