Isocyanate composition and method for producing the same

Abstract

The present invention relates to an isocyanate composition which is suppressed from discoloring and becoming cloudy, and which can improve transparency when applied to a product, and a method for producing the same.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0169322 dated November 30, 2021, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference. The present invention relates to an isocyanate composition that is inhibited from discoloring and clouding and can improve transparency when applied to products, and a method for producing the same. [Background technology]

[0002] Isocyanates are the raw material for polyurethanes and are used in a variety of applications, including coatings, adhesives, paints, foams, and optical materials. Polyurethanes used in fields that require excellent appearance, especially in the optical field where transparency is essential, must exhibit minimal discoloration. To achieve this, it is important that not only must the polyurethane reaction not cause discoloration, but the raw material isocyanates, especially polyisocyanates with bifunctionality or higher, must also not discolor.

[0003] However, because isocyanates are highly reactive, they are prone to oxidation due to oxygen in the air during storage, or to self-polymerization, resulting in deterioration or discoloration, and optical products using them, such as urethane lenses, can also suffer from discoloration or cloudiness. Furthermore, when polyisocyanates are produced by polymerization of diisocyanates, specifically polyurethanes produced by the urethane reaction of diisocyanates with polyhydric alcohols, the polymers are prone to discoloration due to the catalysts or solvents used in the polymerization reaction.

[0004] In response to this, various methods have been researched and proposed as ways to prevent discoloration in isocyanates, polyisocyanates, and products made using them, such as sealing them with nitrogen gas to block out air when manufacturing and storing them, or adding additives such as ultraviolet absorbers before storing them.

[0005] Japanese Patent Application Laid-Open No. 2-228317 discloses a method for producing a polyisocyanate for a light-colored polyurethane lacquer, in which the isocyanate is modified and then treated with a peroxide. Japanese Patent Application Laid-Open No. 8-291129 discloses a method for producing an isocyanate with reduced discoloration by contacting a discolored isocyanate with an ozone-containing gas. Further, Japanese Patent Application Publication No. 2012-506465 discloses a method for producing an isocyanate with reduced discoloration by irradiating a discolored isocyanate with light having a wavelength of 200 to 600 nm.

[0006] However, the above methods could not achieve a sufficiently reduced discoloration effect. As another method, a method of mixing and storing a compound that does not participate in the polymerization reaction with isocyanate has been proposed, but there is a problem that the added compound causes discoloration during subsequent product production.

[0007] Therefore, research on polyisocyanate compositions that are not prone to discoloration or denaturation during the synthesis process, storage process, and further product processing process of isocyanate is necessary.

Summary of the Invention

[0010] A is the Hazen color number (APHA) measured by ASTM D1003; B is the oligomer content relative to the total weight of the isocyanate mixture. According to another embodiment of the present invention, a method for producing an isocyanate-based mixture comprises reacting an amine compound with phosgene in a solvent to obtain an isocyanate-based mixture; and adding phenol and paratoluenesulfonyl isocyanate to the mixture; the mixture contains one or more compounds selected from the group consisting of a monomer, a dimer, a trimer, and an oligomer having 4 to 200 repeating units of an isocyanate compound; A method for producing an isocyanate composition is provided, which satisfies the following mathematical formula 1:

[0011] 0 A is the Hazen color number (APHA) measured by ASTM D1003; B is the oligomer content relative to the total weight of the isocyanate mixture. According to one embodiment of the present invention, there is provided a polyisocyanate composition comprising a polyisocyanate formed by a polymerization reaction between the above-described isocyanate composition and a polyhydric alcohol.

[0012] Furthermore, according to one embodiment of the present invention, there is provided an optical article comprising the polyisocyanate composition described above. [Effects of the Invention]

[0013] The isocyanate composition according to the present invention can suppress discoloration and cloudiness during the synthesis process, storage process, and further product processing process of the isocyanate composition, by controlling new parameters taking into account the content of oligomer in the composition and the Hazen color number of the composition, thereby improving the transparency of the product.

[0014] ​As a result, a polyisocyanate composition obtained by polymerizing the isocyanate composition of the present invention exhibits excellent transparency when applied to optical articles, and in particular, can exhibit excellent quality when applied to optical lenses. DETAILED DESCRIPTION OF THE INVENTION

[0015] The terms used in this specification are merely used to describe exemplary embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless the context clearly indicates otherwise. It should be understood that the terms "comprise," "comprise," or "have" used in this specification are intended to specify the presence of embodied features, numbers, steps, components, or combinations thereof, and do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0016] Although the present invention can be embodied in various forms through various modifications, specific embodiments are described in detail below by way of example, but it should be understood that this is not intended to limit the present invention to the specific disclosed embodiments, and that the present invention encompasses all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0017] Due to their high reactivity, isocyanate compounds are prone to oxidation due to oxygen in the air during storage, or to self-polymerization, resulting in deterioration or discoloration, which can cause problems such as reduced transparency in optical articles to which they are applied.

[0018] In order to solve these problems, the present inventors have conducted research into the composition of isocyanate compositions and have confirmed that even when lenses are manufactured using isocyanate compositions that have yellowed, some products do not suffer from defects. The inventors discovered that the transparency of a product is affected not only by the yellowing of the composition but also by the cloudiness of the composition, and that by controlling the content of the oligomer of the isocyanate compound contained in the composition and the Hazen color number of the composition within specific ranges, the yellowing and cloudiness can be controlled within appropriate ranges, thereby improving the transparency of the final product, leading to the completion of the present invention.

[0019] Specifically, we have confirmed that the isocyanate composition can be applied to optical articles, particularly optical lenses, to achieve excellent quality by controlling new parameters, which are the content of the isocyanate compound oligomer contained in the composition and the Hazen color number of the composition. In particular, the new parameters can be achieved by appropriately adding phenol and paratoluenesulfonyl isocyanate to an isocyanate-based mixture.

[0020] <Isocyanate composition> According to one embodiment of the invention, the isocyanate composition comprises: an isocyanate-based mixture containing one or more compounds selected from the group consisting of monomers, dimers, trimers, and oligomers having 4 to 200 repeating units of an isocyanate compound; phenol; and paratoluenesulfonyl isocyanate.

[0021] Here, the isocyanate mixture may contain, in addition to the monomer of the isocyanate compound itself, a dimer in which two isocyanate compounds are bonded, a trimer in which three isocyanate compounds are bonded, and an oligomer having a repeating unit of 4 to 200. The oligomer means a compound in which 4 to 200 isocyanate compounds are bonded.

[0022] The dimers, trimers, and oligomers of the isocyanate compound may be produced by side reactions during the synthesis of an isocyanate compound from an amine compound, or may be by-products formed by the self-polymerization of an isocyanate compound due to its high reactivity after synthesis. These by-products can affect not only the transparency and color of the isocyanate composition itself, but also cause discoloration and opacity in polyisocyanate compositions containing the isocyanate composition. Therefore, the content of these by-products must be reduced for isocyanate compositions used in optical applications. However, strict control of the content of by-products in commercial processes can be difficult in terms of process efficiency and cost. Therefore, the present invention controls the content of oligomers in the isocyanate composition to an appropriate level, thereby improving the transparency and color properties of the product while maintaining process efficiency.

[0023] In particular, the isocyanate composition contains phenol and paratoluenesulfonyl isocyanate, which allows the oligomer content in the isocyanate mixture and the Hazen color number of the composition to be controlled within appropriate ranges, thereby adjusting the parameter represented by the new mathematical formula 1 to a desired range. Here, the paratoluenesulfonyl isocyanate is a component different from the isocyanate compound.

[0024] The phenol is contained in an amount of 50 to 1,500 ppm, preferably 100 to 1,000 ppm, based on the total weight of the isocyanate mixture. By containing the phenol in this range, the oligomer content in the mixture and the Hazen color number of the composition can be controlled within appropriate ranges, thereby improving the transparency and color properties of the product while maintaining process efficiency.

[0025] The paratoluenesulfonyl isocyanate is contained in an amount of 10 to 3,000 ppm, preferably 50 to 2,000 ppm, based on the total weight of the isocyanate mixture. By containing the paratoluenesulfonyl isocyanate in this range, the oligomer content in the mixture and the Hazen color number of the composition can be controlled within appropriate ranges, thereby improving the transparency and color properties of the product while maintaining process efficiency.

[0026] Examples of the isocyanate compound include 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, methylene diphenyl diisocyanate, methylene dicyclohexyl isocyanate, toluene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, and o-xylylene diisocyanate.

[0027] Furthermore, an isocyanate composition according to one embodiment of the present invention satisfies the parameters of the following mathematical formula 1. Mathematical formula 1 is an index for controlling the yellowing and clouding of the composition, and by satisfying the mathematical formula 1, discoloration and clouding can be suppressed during the synthesis process, storage process, and further product processing process, thereby improving the transparency of the product. More specifically, mathematical formula 1 is as follows:

[0028] 0 A is the Hazen color number (APHA) measured by ASTM D1003; B is the oligomer content relative to the total weight of the isocyanate mixture. Specifically, the content of the oligomer is less than 1.6 wt % relative to the total weight of the isocyanate-based mixture. By containing the oligomer at less than 1.6 wt %, the occurrence of yellowing of the composition can be reduced, and at the same time, by satisfying the above formula 1, the occurrence of yellowing and cloudiness during the manufacturing of the product can be effectively controlled. ​

[0029] On the other hand, if the composition does not satisfy the range of Formula 1 and shows a value of 1 or more, when applied to an optical lens, the transparency is significantly reduced, green light is exhibited, and the quality of the product is significantly reduced. Preferably, within the range satisfying Formula 1, the Hazen color number (APHA) of variable A in Formula 1 is more than 0 and less than 50, and the value of the oligomer content of variable B in Formula 1 is more than 0 and less than 1.6. By satisfying these ranges, transparency and other physical properties can be significantly improved when applied to optical lenses.

[0030] The Hazen color number (APHA) of the variable A in Equation 1 is measured at room temperature (25±1° C.) according to ASTM D1003, and the specific measurement method will be described in more detail in the experimental examples. The value of the oligomer content of the variable B in Equation 1 means only the value excluding the unit in weight % of the oligomer. The oligomer content is measured by gel permeation chromatography (GPC), and the specific measurement method will be described in more detail in the experimental examples.

[0031] <Method for producing isocyanate composition> A method for producing an isocyanate composition according to one embodiment of the present invention includes the steps of reacting an amine compound with phosgene in a solvent to obtain an isocyanate-based mixture; and adding phenol and paratoluenesulfonyl isocyanate to the mixture, thereby satisfying the following mathematical formula 1:

[0032] 0 A is the Hazen color number (APHA) measured by ASTM D1003; B is the oligomer content relative to the total weight of the isocyanate mixture.

[0033] ​In particular, by further adding phenol and paratoluenesulfonyl isocyanate to the reaction mixture during the preparation of the isocyanate composition, the oligomer content in the mixture and the Hazen color number of the composition can be controlled within appropriate ranges, thereby adjusting the parameter represented by the new Equation 1 to a desired range. The above-described contents regarding Equation 1 are all equally applicable.

[0034] Hereinafter, the method for producing the isocyanate composition will be described step by step. First, the method includes a step of reacting an amine compound with phosgene in a solvent to obtain a reaction mixture containing an isocyanate compound.

[0035] Examples of the solvent used in the phosgenation reaction include aromatic hydrocarbon solvents such as benzene, toluene, xylene, and ethylbenzene; chlorinated aromatic hydrocarbon solvents such as monochlorobenzene, 1,2-dichlorobenzene, and 1,4-dichlorobenzene; and chlorinated hydrocarbon solvents such as dichloromethane, chloroform, and carbon tetrachloride. Two or more of these solvents may be mixed and used.

[0036] The amine compound used in the phosgenation reaction may be, for example, an amine compound obtained by hydrogenating a nitro compound or a chloride thereof. Specifically, the amine compound may be one or more selected from the group consisting of 1,4-tetramethylenediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,3-cyclohexylenediamine, 1,4-cyclohexylenediamine, isophoronediamine, diamine, methylenediphenyldiamine, methylenedicyclohexyldiamine, toluenediamine, m-xylylenediamine, p-xylylenediamine, o-xylylenediamine, and salts thereof, and preferably m-xylylenediamine, p-xylylenediamine, o-xylylenediamine, or salts thereof.

[0037] The amine compound is contained in an amount of 1 to 20 parts by weight relative to 100 parts by weight of the solvent. If the content of the amine compound exceeds 20 parts by weight, a large amount of the amine compound may precipitate. Preferably, the content is 1 to 15 parts by weight or 3 to 10 parts by weight.

[0038] Specifically, the phosgenation reaction can be carried out by a direct phosgenation method (Method 1) in which an amine compound is directly reacted with phosgene; a method in which an amine compound is reacted with anhydrous hydrochloric acid to form an amine-hydrochloride compound, and then the formed salt is reacted with phosgene (Method 2); or a method in which an amine compound is reacted with carbonic acid to form an aliphatic amine-carbonate compound, and then the formed salt is reacted with phosgene (Method 3).

[0039] The direct phosgenation method of Method 1 is carried out by reacting an amine compound with phosgene in the organic solvent. At this time, phosgene may be added all at once at the initial stage of the reaction, or a portion of the phosgene may be added at the initial stage of the reaction and the remainder may be added in portions during the reaction.

[0040] Meanwhile, the method 1 comprises a first step of dissolving a portion of phosgene in the solvent and then adding the amine compound, and a second step of adding the remaining phosgene and reacting it after the addition of the amine compound is complete. The first step is preferably carried out at a temperature of -15°C to -10°C to prevent the outflow of highly toxic phosgene and to prevent sudden heat generation when the amine compound is added, and the phosgenation reaction in the second step is controlled at 120°C to 140°C to ensure a suitable reaction rate without risking decomposition of the amine compound.

[0041] In Method 2, an amine compound is reacted with hydrochloric acid in an organic solvent to form an amine-hydrochloride compound, and then phosgene is added to carry out the reaction. The formation of the amine-hydrochloride compound is carried out at a temperature of 30°C or less, preferably about 23±5°C, and the reaction after the addition of phosgene is controlled to 120°C to 140°C. When carried out under these temperature conditions, the solubility of the amine-hydrochloride compound is increased and thermal decomposition of the isocyanate is prevented, thereby producing a high-purity isocyanate compound in a high yield.

[0042] In Method 3, an amine compound is reacted with carbonic acid in a solvent to form an amine-carbonate compound, and then phosgene is added to carry out the reaction. The formation of the amine-carbonate compound is carried out at a temperature of 30°C or less, preferably about 23±5°C, and the reaction temperature after the phosgene addition is controlled to 80°C to 180°C. The reaction temperature may be preferably in the range of 100°C or more, or 120°C or more, and 150°C or less, or 140°C or less. When carried out under these temperature conditions, the solubility of the amine-carbonate compound is increased and thermal decomposition of the isocyanate is prevented, thereby producing a high-purity isocyanate compound in a high yield.

[0043] The method 2 for producing an isocyanate compound is preferred because it can control the formation of by-products such as dimers, trimers, and oligomers of the isocyanate compound produced by the phosgenation reaction within an appropriate range, and can also control the color of the composition within an appropriate range, thereby allowing the composition to satisfy Equation 1.

[0044] After the reaction with phosgene is completed by each method, a step of removing unreacted phosgene and hydrogen chloride gas by nitrogen bubbling or the like and a step of removing the solvent by distillation or the like may be selectively further carried out, or these steps may be carried out by conventional methods.

[0045] Next, phenol and paratoluenesulfonyl isocyanate are added to the reaction mixture. The addition of these additives facilitates control of the oligomer content range among the components contained in the phosgenation reaction mixture, while also adjusting the color of the composition. This makes it possible to prepare an isocyanate composition that satisfies the parameters of Equation 1.

[0046] The phenol is added in an amount of 50 to 1,500 ppm, preferably 100 to 1,000 ppm, based on the total weight of the isocyanate mixture. By adding the phenol in this range, the oligomer content in the mixture and the Hazen color number of the composition can be controlled within appropriate ranges, thereby improving the transparency and color properties of the product while maintaining process efficiency.

[0047] The paratoluenesulfonyl isocyanate is a compound different from the isocyanate compound synthesized in the step of obtaining the isocyanate-based mixture. The paratoluenesulfonyl isocyanate is added in an amount of 10 to 3,000 ppm, preferably 50 to 2,000 ppm, based on the total weight of the isocyanate-based mixture. By adding the paratoluenesulfonyl isocyanate in this range, the oligomer content in the mixture and the Hazen color number of the composition can be controlled within appropriate ranges, thereby improving the transparency and color properties of the product while maintaining process efficiency.

[0048] The phenol and paratoluenesulfonyl isocyanate addition step can proceed under a nitrogen blanket.

[0049] <Polyisocyanate composition> According to another embodiment of the invention, there is provided a polyisocyanate composition comprising a polyisocyanate formed by the polymerization reaction of the isocyanate composition with a polyhydric thiol.

[0050] The polyvalent thiol is a compound containing two or more thiol groups (-SH) in one molecule, and specifically may be a compound having two or more, or three or more, but eight or fewer, or five or fewer thiol groups in one molecule.

[0051] Examples of the polyvalent thiol compound include 1,9-dimercapto-3,7-dithianonane, 1,13-dimercapto-3,7,11-trithiatridecane, glycol di(3-mercaptopropionate), and glycol di(3-mercaptopropionate). di(3-mercaptopropionate), 1,4-dithiane-2,5-diyldimethanethiol, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 2-mercaptomethyl-1,5-dimercapto-3-thiapentane, trimethylolpropane tri(3-mercaptopropionate) tri(3-mercaptopropionate), 4,8-di(mercaptomethyl)-1,11-dimercapto-3,6,9-trithiaundecane, 5,9-di(mercaptoethyl)-1,12-dimercapto-3,7,10-trithiadodecane, pentaerythritol tetra(3-mercaptopropionate), pentaerythritol tetra(mercaptoacetate) tetra(mercaptoacetate), 3,6,9,12-Tetrathiatetradecane-1,14-dithiol, 3,6,10,13-Tetrathiapentadecane-1,8,15-trithiol15-trithiol).

[0052] The polymerization reaction is carried out by a thiourethanization reaction between the isocyanate compound in the isocyanate composition and the thiol group in the polyvalent thiol.

[0053] Specifically, the polythiol is added in an amount such that the molar ratio of thiol groups in the polythiol to 1 mole of isocyanate groups in the isocyanate compound is 0.8 or more, or 0.9 or more, and 1.1 or less, or 1.0. If the molar ratio of thiol groups to isocyanate groups is less than 0.8, exceeding this range, the excess isocyanate groups may reduce the viscosity of the polymer produced, thereby reducing processability. Furthermore, if the molar ratio of thiol groups to isocyanate groups exceeds 1.1, the excess thiol groups may reduce the discoloration prevention effect.

[0054] The polymerization reaction is carried out under atmospheric pressure and in an inert gas atmosphere such as nitrogen or argon. The polymerization reaction is preferably carried out at a temperature ranging from -15°C or higher, or 0°C or higher, to 20°C or lower, or 15°C or lower, since this allows for easy control of the reaction rate without the risk of discoloration and also increases the reaction efficiency.

[0055] The polymerization reaction may be carried out without a catalyst or in the presence of a catalyst that typically promotes urethane formation, such as a tin-based or amine-based catalyst. When the polymerization reaction is carried out in the presence of a catalyst, the catalyst is added together with the polyvalent thiol in the step of adding the polyvalent thiol to the isocyanate-based mixture.

[0056] The progress of the polymerization reaction can be predicted by measuring the concentration of isocyanate groups in the polymerization reaction product by the n-dibutylamine method using a potentiometric titrator or by measuring the refractive index. In the present invention, the polymerization reaction can be carried out until the concentration of isocyanate groups in the polymerization reaction product reaches the calculated value of the isocyanate groups remaining after the reaction with the polyvalent thiol.

[0057] As a result of such a polymerization reaction, a polyisocyanate, specifically a polythiourethane, is produced.

[0058] The polyisocyanate composition may further contain additives such as an internal mold release agent, an ultraviolet absorber, a polymerization initiator, a heat stabilizer, a color corrector, a chain extender, a crosslinking agent, a light stabilizer, a filler, and a photosensitizer, as needed, and the content thereof can be appropriately determined within a range that does not inhibit the discoloration and discoloration-inhibiting properties of the composition.

[0059] The polyisocyanate composition has excellent physical properties and can be used in a wide range of fields, and may be used as an optical material that requires excellent appearance properties, particularly transparency, such as eyeglass lenses, camera lenses, plastic lenses, and prisms.

[0060] According to yet another embodiment of the invention, there is provided an article comprising or made using the polymer composition.

[0061] In this case, the article may be an optical article such as a spectacle lens, a camera lens, a plastic lens, or a prism.

[0062] The functions and effects of the present invention will be described in more detail below through specific examples of the present invention, but these examples are presented only as examples of the present invention and do not define the scope of the invention.

[0063] [Examples and Comparative Examples] Example 1-1 A flask was charged with 471 g of 1,2-dichlorobenzene, 32.5 g of m-XDA with a purity of 99.4%, and 0.24 g of 4-hydroxy TEMPO. Anhydrous hydrochloric acid was added at a rate of 20 g / hr and stirred at room temperature (23 ± 5 °C). The temperature rose to 50 °C after adding anhydrous hydrochloric acid. After 4 hours of addition, the formed salt was cooled to room temperature, and 43 g of phosgene was added to the reactor. The reactor was then heated to 130 °C. A dry ice-acetone condenser was used to prevent phosgene from leaking out from the reactor until the end of the reaction. After the reactor temperature reached 130 °C, the temperature was maintained at 125–135 °C for 2 hours until the reaction solution became clear. After the solution became clear, the reactor was cooled to 80 °C and cooled by blowing in nitrogen. The reaction solution from which phosgene had been removed was subjected to vacuum distillation to remove the solvent, and the product was purified under reduced pressure at a high temperature of 160°C to obtain an isocyanate-based mixture containing m-XDI. Under nitrogen-filled conditions, 100 ppm of phenol and 50 ppm of paratoluenesulfonyl isocyanate were added to the mixture to produce an isocyanate composition, which was then stored at 5°C for 180 days.

[0064] Example 1-2 An isocyanate composition was produced and stored in the same manner as in Example 1-1, except that the phenol content was changed to 500 ppm.

[0065] Examples 1-3 An isocyanate composition was produced and stored in the same manner as in Example 1-1, except that the phenol content was changed to 1,000 ppm.

[0066] Examples 1-4 An isocyanate composition was produced and stored in the same manner as in Example 1-1, except that the content of paratoluenesulfonyl isocyanate was changed to 1,000 ppm.

[0067] Examples 1-5 An isocyanate composition was produced and stored in the same manner as in Example 1-1, except that the content of paratoluenesulfonyl isocyanate was changed to 2,000 ppm.

[0068] Examples 1-6 An isocyanate composition was produced and stored in the same manner as in Example 1-2, except that the content of paratoluenesulfonyl isocyanate was changed to 1,000 ppm.

[0069] Examples 1-7 An isocyanate composition was produced and stored in the same manner as in Example 1-2, except that the content of paratoluenesulfonyl isocyanate was changed to 2,000 ppm.

[0070] Examples 1-8 An isocyanate composition was produced and stored in the same manner as in Example 1-3, except that the content of paratoluenesulfonyl isocyanate was changed to 1,000 ppm.

[0071] Examples 1-9 An isocyanate composition was produced and stored in the same manner as in Example 1-3, except that the content of paratoluenesulfonyl isocyanate was changed to 2,000 ppm.

[0072] Comparative Example 1-1 An isocyanate composition was produced and stored in the same manner as in Example 1-1, except that phenol and paratoluenesulfonyl isocyanate were not added.

[0073] Comparative Example 1-2 An isocyanate composition was produced and stored in the same manner as in Example 1-1, except that paratoluenesulfonyl isocyanate was not added.

[0074] [Experimental Example 1: Analysis of Isocyanate Composition] (1) Measurement of Hazen color number (APHA) The Hazen color number (APHA) measured by ASTM D1003 was measured for the isocyanate compositions produced in the above Examples and Comparative Examples, and the results are shown in Table 1. Specifically, the Hazen color number was measured using the xenon lamp light source of the Hunterlab Ultrascane device by a method of performing color difference analysis on the composition under normal temperature conditions.

[0075] (2) Gel Permeation Chromatography (GPC) Analysis Gel Permeation Chromatography (GPC) analysis was performed on the isocyanate compositions produced in the above Examples and Comparative Examples, and the oligomer contents derived therefrom are shown in Table 1.

[0076] <GPC Analysis Conditions> Equipment Used: Waters2988 Columns: Shodex KF-801, KF-802, KF-803 3 x 300 mm Sample Concentration: 1 wt / vol% (prepared by dissolving 0.1 mg of the sample in 9.9 ml of tetrahydrofuran) Carrier: THF Detection Method: UV Flow Rate: 1.0 ml / min Column Temperature: 40 °C Polystyrene with a molecular weight of 1000 - 20,000 g / mol was used when preparing the calibration curve.

[0077] (3) Derivation of the Value of Formula 1 For the isocyanate compositions produced in the above Examples and Comparative Examples, the value of the following Formula 1 was calculated, and the results are shown in Table 1. 0 < A / 50 + B / 3 < 1 ··· Formula 1 A is the Hazen color number (APHA) measured by ASTM D1003, B is the numerical value of the oligomer content with respect to the total weight of the isocyanate-based mixture.

[0078]

Table 1

[0079] [Example 2 and Comparative Example 2] Example 2-1: Manufacturing of optical lenses 20.8 g of the isocyanate composition prepared in Example 1-1, 0.04 g of Zelec UN (Stepan), and 0.04 g of Biosorb 583 (Sakai Chemical Industry Co., Ltd.) were stirred in a flask at room temperature for about 20 minutes. Next, 0.002 g of dibutyltin chloride was added and stirred for 10 minutes. 19.2 g of 2,3-bis(2-sulfanyl ethyl sulfanyl)propane-1-thiol was added to the mixture, which was then degassed at 5 mbar and stirred for 1 hour to prepare a mixed solution.

[0080] This mixture was filtered through a 1 μm PTFE filter and then poured into a mold consisting of a glass mold and tape. The mold was placed in an oven, and the temperature was gradually increased from 10°C to 120°C, where a polymerization reaction was carried out for 20 hours. After polymerization was completed, the mold was removed from the oven and demolded to obtain a plastic lens. The obtained plastic lens was annealed at 120°C for 6 hours to produce a final optical lens sample.

[0081] Examples 2-2 to 2-9 and Comparative Examples 2-1 to 2-2 Optical lenses were produced in the same manner as in Example 2-1, except that the isocyanate composition of Examples 1-2 to 1-9 and Comparative Examples 1-1 and 1-2 were used instead of the isocyanate composition of Example 1-1.

[0082] [Experimental Example 2: Optical Lens Evaluation] (1) Color evaluation The optical lenses manufactured in the examples and comparative examples were evaluated for color with the naked eye, and the results are shown in Table 2.

[0083] (2) Transparency evaluation The optical lenses manufactured in the examples and comparative examples were evaluated by the naked eye under various light source conditions for the degree of cloudiness according to the following evaluation criteria. The results are shown in Table 2.

[0084] <Evaluation criteria> C (Clear): Transparent under fluorescent and zirconium lamps SH (Slightly lamp Haze): Transparent under fluorescent lamps, but partially cloudy under zirconium lamps LH (Lamp Haze): Transparent under fluorescent lamps, but appears cloudy under zirconium lamps VH (Visual Haze): Cloudiness is observed under fluorescent and zirconium lamps.

[0085] [Table 2]

[0086] As can be seen from Table 2, the optical lenses manufactured using the compositions satisfying the parameters of Equation 1 defined by the present invention were found to be superior in both chromaticity and transparency compared to the comparative examples.

Claims

1. an isocyanate-based mixture containing one or more compounds selected from the group consisting of monomers, dimers, trimers, and oligomers having 4 to 200 repeating units of an isocyanate compound; phenol; and paratoluenesulfonyl isocyanate; The following formula 1 is satisfied: The paratoluenesulfonyl isocyanate is different from the isocyanate compound, The phenol is contained in an amount of 50 to 1,500 ppm based on the total weight of the isocyanate-based mixture, The isocyanate composition, wherein the paratoluenesulfonyl isocyanate is contained in an amount of 10 to 3,000 ppm based on the total weight of the isocyanate mixture: 0<A / 50+B / 3<1 ... Formula 1 A is the Hazen color number (APHA) measured by ASTM D1003; B is the oligomer content relative to the total weight of the isocyanate-based mixture as determined by gel permeation chromatography (GPC) analysis.

2. A is 0 or more and less than 50, The B is greater than 0 and less than 1.

6. The isocyanate composition of claim 1.

3. The oligomer is contained in an amount of less than 1.6% by weight based on the total weight of the isocyanate-based mixture. The isocyanate composition of claim 1.

4. The isocyanate compound is at least one selected from the group consisting of 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, methylene diphenyl diisocyanate, methylene dicyclohexyl isocyanate, toluene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, and o-xylylene diisocyanate. The isocyanate composition of claim 1.

5. reacting an amine compound with phosgene in a solvent to obtain an isocyanate-based mixture; and adding phenol and paratoluenesulfonyl isocyanate to the mixture; the mixture contains one or more compounds selected from the group consisting of monomers, dimers, trimers, and oligomers of isocyanate compounds having 4 to 200 repeating units; The paratoluenesulfonyl isocyanate is different from the isocyanate compound, The phenol is contained in an amount of 50 to 1,500 ppm based on the total weight of the isocyanate-based mixture, The paratoluenesulfonyl isocyanate is contained in an amount of 10 to 3,000 ppm based on the total weight of the isocyanate mixture, A method for producing an isocyanate composition that satisfies the following mathematical formula 1: 0<A / 50+B / 3<1 ... Formula 1 A is the Hazen color number (APHA) measured by ASTM D1003; B is the oligomer content relative to the total weight of the isocyanate-based mixture as determined by gel permeation chromatography (GPC) analysis.

6. A is 0 or more and less than 50, The B is greater than 0 and less than 1.

6. A method for producing the isocyanate composition according to claim 5.

7. The oligomer is contained in an amount of less than 1.6% by weight based on the total weight of the isocyanate-based mixture. A method for producing the isocyanate composition according to claim 5.

8. A polyisocyanate composition comprising a polyisocyanate formed by the polymerization reaction of the isocyanate composition of claim 1 with a polyhydric thiol.

9. An optical article comprising the polyisocyanate composition of claim 8.

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