Isocyanate compositions and polymerizable compositions comprising the same

Abstract

The present invention provides an isocyanate composition and a polymerizable composition comprising the isocyanate composition, wherein the isocyanate composition has improved storage stability, inhibits occurrence of discoloration and turbidity even over several months or more, and is capable of improving transparency when applied to optical products.

Description

Cross-references to related applications

[0001] This application claims priority to Korean Patent Application No. 10-2024-0038067, filed on March 19, 2024, and Korean Patent Application No. 10-2025-0035252, filed on March 19, 2025, the disclosures of which are incorporated herein by reference in their entirety. Technical Field

[0002] This application relates to isocyanate compositions and polymerizable compositions comprising the isocyanate compositions, which exhibit improved storage stability even over periods of several months or longer, suppress discoloration and turbidity, maintain excellent resistance to discoloration when applied to optical products, and improve transparency. Background Technology

[0003] Isocyanate-based compounds are not only highly valuable in the chemical and resin industries, but also serve as fine chemical products, including optical materials. Xylene diisocyanate (XDI), as a representative example of isocyanate-based compounds, is increasingly in demand as a high-value-added chemical material and as a raw material for poly(thio)carbamates used in high-end optical lenses and flexible displays.

[0004] However, due to the high reactivity of isocyanate-based compounds, they are prone to discoloration or turbidity during storage due to reaction with atmospheric oxygen or moisture. Furthermore, when isocyanate-based compounds are stored for months or longer, they can self-polymerize to form oligomers such as dimers (e.g., urea diketone) and trimers, leading to issues such as differences in polymerizability and problems like discoloration and turbidity in product applications.

[0005] Isocyanate-based compounds are widely used as raw materials for polyurethane in coatings, pressure-sensitive adhesives / adhesives, paints, foams, and optical materials. When manufacturing polyurethane lenses using isocyanate-based compounds that have already undergone discoloration or turbidity, the rapid increase in the molecular weight of the polymer solution leads to reduced stirring efficiency, increased filtration time, and filter clogging, resulting in decreased workability. Furthermore, lenses manufactured through inhomogeneous polymerization can cause problems such as streaks, reduced transparency, and discoloration.

[0006] To address these issues, although XDI uses nitrogen-substituted packaging during the product packaging process to ensure storage stability, the product is often not completely consumed at once, resulting in potential exposure to the atmosphere, which can often cause XDI to discolor or become cloudy.

[0007] Therefore, isocyanate compositions are being continuously researched and developed that have improved storage stability and do not pose a risk of discoloration or cloudiness even during long-term storage, and can maintain excellent resistance to discoloration and improve transparency when manufacturing optical products such as lenses. Summary of the Invention

[0008] [Technical Issues] The purpose of this application is to provide isocyanate compositions that, due to their improved storage stability, do not pose a risk of discoloration or cloudiness even during long-term storage of several months or longer, and when used as raw materials for optical articles, such as poly(thio)urethane lenses, improve the transparency of the lenses.

[0009] Furthermore, this application aims to provide a polymerizable composition comprising the above-described isocyanate composition, and an optical article comprising a polymer obtained therefrom.

[0010] [Technical Solution] According to one embodiment of this application, an isocyanate composition is provided comprising xylene diisocyanate and a compound represented by the following chemical formula 1, wherein the content of said compound is greater than 60 ppm to 200 ppm or less: [Chemical Formula 1]

[0011] In chemical formula 1, R1 is hydrogen, methyl, or ethyl.

[0012] In one embodiment, the content of the compound represented by Formula 1 in the isocyanate composition may be greater than 62 ppm to 180 ppm or less.

[0013] In one embodiment, based on the total weight of the isocyanate composition, the isocyanate composition may have a chlorine (Cl) content of 200 ppm or less, which is measured using a combustion ion chromatograph according to the American Society for Testing and Materials (ASTM) D 7359 method.

[0014] In one embodiment, the isocyanate composition may have an APHA color index of 0.1 or greater to 25 or less, which is measured using a spectrophotometer (UltrascanPro, HunterLab, light source: C / 2) according to the American Society for Testing and Materials (ASTM) E313 method.

[0015] In one embodiment, the isocyanate composition may further comprise at least one selected from the group consisting of chloromethylbenzyl isocyanate, isocyanomethylbenzaldehyde, and isocyanomethylbenzonitrile.

[0016] In one embodiment, the content of urea diketone in the isocyanate composition measured after 12 months of storage, based on 100 parts by weight of the isocyanate composition, can be 5 parts by weight or less.

[0017] According to another embodiment of this application, a method for producing an isocyanate composition is provided, comprising: reacting xylenediamine or a xylenediamine salt with phosgene to obtain a reaction mixture; and purifying the reaction mixture under reduced pressure at a temperature above 120°C and below 230°C.

[0018] According to another embodiment of this application, a polymerizable composition is provided, comprising the above-described isocyanate composition, and at least one selected from the group consisting of compounds based on polyfunctional thiols, compounds based on polyfunctional alcohols, and compounds based on polyfunctional cyclic sulfides.

[0019] The polymerizable composition may also contain at least one selected from the group consisting of polymerization initiators, internal release agents and ultraviolet absorbers.

[0020] Furthermore, according to another embodiment of this application, a composition for polyisocyanate polymerization is provided, comprising the above-described isocyanate composition; and at least one polyfunctional monomer compound selected from the group consisting of compounds based on polyfunctional thiols, compounds based on polyfunctional alcohols, and compounds based on polyfunctional cyclic sulfides.

[0021] Furthermore, according to another embodiment of this application, a polyisocyanate composition is provided, comprising a polyisocyanate obtained by polymerizing the above-described isocyanate composition with a polyfunctional alcohol-based compound.

[0022] Furthermore, according to another embodiment of this application, a polyisocyanate composition is provided, comprising a polyisocyanate obtained by polymerizing the above-described isocyanate composition with a compound based on a polyfunctional thiol or a compound of a polyfunctional cyclic sulfide.

[0023] According to another embodiment of this application, an optical article is provided comprising a polymer obtained by polymerizing the above-described polymerizable composition.

[0024] [Beneficial Effects] The isocyanate composition according to this application exhibits improved storage stability, thereby inhibiting discoloration or turbidity even during long-term storage periods of several months or longer, and improving transparency when applied to optical products. Furthermore, polymers prepared by polymerizing the isocyanate composition with compounds based on polyfunctional thiols, polyfunctional alcohols, or polyfunctional cyclic sulfides also exhibit excellent transparency, making them suitable for manufacturing articles such as optical pressure-sensitive adhesives, optical adhesives, optical coatings, and optical lenses. Detailed Implementation

[0025] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. Unless the context clearly indicates otherwise, the singular form also encompasses the plural form. In this application, the terms "comprising," "including," or "having" are used to describe the specified features, steps, components, or combinations thereof, and do not exclude the addition of one or more other features, values, steps, components, or combinations thereof.

[0026] Since the present invention can be modified in various ways and has various forms, specific embodiments are shown by way of example and will be described in detail. However, this is not intended to limit the invention to the specific forms disclosed, and it should be understood that the invention includes all modifications, equivalents, and substitutions within the concept and scope of the invention.

[0027] This application will be described in detail below.

[0028] Isocyanate Composition The isocyanate composition of this application comprises xylene diisocyanate and a compound represented by the following chemical formula 1, wherein the content of the compound represented by chemical formula 1 is greater than 60 ppm to 200 ppm or less: [Chemical Formula 1]

[0029] In chemical formula 1, R1 is hydrogen, methyl, or ethyl.

[0030] Xylylene diisocyanate (XDI) is the main component of the isocyanate composition according to embodiments of this application. Specifically, xylylene diisocyanate may be at least one selected from the group consisting of 1,2-xylylene diisocyanate (o-xylylene diisocyanate, o-XDI), 1,3-xylylene diisocyanate (m-xylylene diisocyanate, m-XDI), and 1,4-xylylene diisocyanate (p-xylylene diisocyanate, p-XDI). Preferably, xylylene diisocyanate may be m-XDI.

[0031] As the main component of the isocyanate composition, the content of xylene diisocyanate in the isocyanate composition, based on GC area % analysis, can be 97.7 area % or higher, 98.0 area % or higher, 98.3 area % or higher, 99.0 area % or higher, 99.2 area % or higher, and 99.9 area % or lower.

[0032] Meanwhile, the xylene diisocyanate (XDI) contained in the isocyanate composition may be a commercially available product or may be prepared using one of the various synthetic methods known in the art; there is no particular limitation on the specific synthetic method, and it may be synthesized, for example, from xylene diamine.

[0033] As an example, XDI can be synthesized from xylenediamine via the phosgene process. For instance, isocyanates can be prepared by directly reacting xylenediamine with phosgene in a solvent, or by forming its carbonate or hydrochloride salt and then reacting the amine salt with phosgene (COCl2) to synthesize XDI.

[0034] As another example, XDI can be synthesized from xylenediamine via a non-phosgene method. For instance, dicarbamates can be prepared by reacting xylenediamine, urea, and / or N-unsubstituted carbamates with alcohols. XDI can also be prepared from dicarbamates, for example, by pyrolysis or degassing in the presence of a catalyst.

[0035] In particular, the isocyanate composition of this application contains a compound represented by Formula 1 in a content greater than 60 ppm to 200 ppm or less, thereby exhibiting less turbidity and discoloration even after long-term storage of several months or more (e.g., 12 months or more). Furthermore, poly(thio)urethane lenses and the like manufactured using such isocyanate compositions exhibit excellent transparency and can be appropriately used as high-quality optical products.

[0036] To ensure this effect, the content of the compound represented by Formula 1 may meet the following ranges: greater than 60 ppm, or 61 ppm or greater, or 61.5 ppm or greater, or 62 ppm or greater, or 62.5 ppm or greater, or 63 ppm or greater, or 63.5 ppm or greater, or 64 ppm or greater, or 64.5 ppm or greater, or 65 ppm or greater, or 65.5 ppm or greater, or 66 ppm or greater, or 66.5 ppm or greater, or 67 ppm or greater, or 67.5 ppm or greater, or 68 ppm or greater, and 200 ppm or less, or 180 ppm or less, or 170 ppm or less, or 160 ppm or less, or 150 ppm or less, or 140 ppm or less, or 130 ppm or less, or 120 ppm or less, or 110 ppm or less, or 100 ppm or less. ppm or less.

[0037] When the content of the compound represented by Formula 1 in the isocyanate composition is 60 ppm or less, the long-term storage stability of the isocyanate composition deteriorates, and when the content exceeds 200 ppm, the colorfastness of the poly(thio)urethane lens decreases.

[0038] Meanwhile, the isocyanate composition of this application contains xylene diisocyanate and a compound represented by chemical formula 1 as basic components, wherein xylene diisocyanate is the main component and the compound represented by chemical formula 1 is the auxiliary component.

[0039] Preferably, the compound represented by chemical formula 1 may be, for example, a compound represented by the following chemical formula 1-1: [Chemical Formula 1-1] .

[0040] The compound represented by Formula 1 may be a commercially available product or may be prepared using one of the various synthetic methods known in the art; no particular synthetic method is particularly limited and may be applied. Specific preparation methods are shown in Preparation Example 1, which will be described later.

[0041] Meanwhile, the compound represented by Formula 1 can be added as a standalone additive to xylene diisocyanate, or it can be added during the manufacturing process via a side reaction; as long as the aforementioned optimization scope is met, the specific production method is not limited. Typically, xylene diisocyanate is prepared by reacting xylene diamine or xylene diamine hydrochloride or carbonate with phosgene, followed by a purification process. In some cases, the compound represented by Formula 1 is generated due to side reactions during such reactions and / or purification processes. Therefore, when preparing xylene diisocyanate, the content of the compound represented by Formula 1 can be adjusted to the aforementioned range by controlling the reaction conditions and / or purification conditions.

[0042] For example, the compound represented by Formula 1 is a chlorinated compound produced as a byproduct in the preparation of xylene diisocyanate, as described below. The compound represented by Formula 1 (dichloromethyl benzyl isocyanate, DCMBI) can be at least one selected from the group consisting of the following structural isomers: 2-(dichloromethyl)benzyl isocyanate (o-(dichloromethyl)benzyl isocyanate, o-DCMBI), 3-(dichloromethyl)benzyl isocyanate (m-(dichloromethyl)benzyl isocyanate, m-DCMBI), and 4-(dichloromethyl)benzyl isocyanate (p-(dichloromethyl)benzyl isocyanate, p-DCMBI).

[0043] Therefore, the structural isomer of dichloromethylbenzyl isocyanate, which is produced as a byproduct during the preparation of xylene diisocyanate, corresponds to the structural isomer of the prepared xylene diisocyanate. Therefore, the xylene diisocyanate composition contains dichloromethylbenzyl isocyanate corresponding to the aforementioned structural isomer of xylene diisocyanate. That is, when the xylene diisocyanate composition contains 1,2-xylene diisocyanate (o-xylene diisocyanate, o-XDI), it contains 2-(dichloromethyl)benzyl isocyanate (o-(dichloromethyl)benzyl isocyanate, o-DCMBI); when it contains 1,3-xylene diisocyanate (m-xylene diisocyanate, m-XDI), it contains 3-(dichloromethyl)benzyl isocyanate (m-(dichloromethyl)benzyl isocyanate, m-DCMBI); and if it contains 1,4-xylene diisocyanate (p-xylene diisocyanate, p-XDI), it contains 4-(dichloromethyl)benzyl isocyanate (p-(dichloromethyl)benzyl isocyanate, p-DCMBI).

[0044] Preferably, the compound represented by Formula 1 (dichloromethyl benzyl isocyanate) can be 3-(dichloromethyl)benzyl isocyanate (m-(dichloromethyl)benzyl isocyanate, m-DCMBI).

[0045] Therefore, in order to prepare the isocyanate composition according to the embodiments of this application, it is first necessary to analyze the content of the compound of formula 1 in xylene diisocyanate, which is the main raw material of the isocyanate composition. Subsequently, if necessary, the compound of formula 1 can be further added, or the content of the compound of formula 1 in xylene diisocyanate can be adjusted by purification methods such as distillation or column chromatography to obtain the isocyanate composition of this application described above. The method for analyzing the content of the compound of formula 1 in the isocyanate composition is not particularly limited; for example, it can be measured by gas chromatography-mass spectrometry (GC-MS).

[0046] For example, the isocyanate composition according to embodiments of this application can be prepared by reacting xylenediamine or a xylenediamine salt (e.g., hydrochloride or carbonate) with phosgene to obtain a reaction mixture; and purifying the reaction mixture under reduced pressure at a temperature above 120°C and below 230°C. For example, the purification step can be carried out under reduced pressure of 1 bar or less, or 0.98 bar or less, or 0.95 bar or less, or 0.9 bar or less, and in practical terms, it can be carried out under reduced pressure of 0.01 mbar or greater. Furthermore, the purification step can be carried out at temperatures of 125°C or higher, or 130°C or higher, or 140°C or higher, and 225°C or lower, or 220°C or lower, or 210°C or lower, or 200°C or lower.

[0047] Here, the step of reacting xylenediamine or a xylenediamine salt with phosgene, i.e., the phosgenation reaction, can be carried out according to conventionally known methods. For example, xylenediamine or a salt thereof can be dispersed in at least one solvent selected from the group consisting of: aromatic solvents, such as benzene, toluene, xylene, and ethylbenzene; chlorinated aromatic solvents, such as monochlorobenzene, 1,2-dichlorobenzene, and 1,4-dichlorobenzene; and chlorinated hydrocarbon solvents, such as dichloromethane, chloroform, and carbon tetrachloride; phosgene can then be injected, followed by the phosgenation reaction at a temperature of 100°C or higher, or 120°C or higher, and 150°C or lower, or 140°C or lower.

[0048] For example, a method for preparing an isocyanate composition includes: reacting xylenediamine or a xylenediamine salt with phosgene to obtain a reaction mixture; and removing the gaseous phase from the reaction mixture. Furthermore, the method may also include: a desolvation step to remove the solvent and a purification step to remove impurities from the reaction product from which the gaseous phase has been removed. Specifically, the method includes: a degassing step to remove the gaseous phase from the reaction mixture; and a desolvation step to remove the solvent from the reaction product from which the gaseous phase has been removed and a purification step to remove impurities, thereby preparing an isocyanate composition containing a compound represented by Formula 1. However, the method for preparing the isocyanate composition is not limited to that described above, and isocyanate compositions in which the content of the compound represented by Formula 1 is greater than 60 ppm to 200 ppm or less can be prepared by controlling the conditions during the phosgenation reaction, purification conditions, and / or purification techniques.

[0049] Furthermore, based on the total weight of the isocyanate composition, the isocyanate composition according to the embodiments of this application may have a chlorine (Cl) content of 200 ppm or less, or greater than 0 to 200 ppm or less, which is measured using a combustion ion chromatograph according to the American Society for Testing and Materials (ASTM) D 7359 method.

[0050] Specifically, the chlorine (Cl) content can be less than 200 ppm, or 190 ppm or lower, or 180 ppm or lower, or 170 ppm or lower, or 160 ppm or lower, or 150 ppm or lower, or 145 ppm or lower, or 140 ppm or lower, or 135 ppm or lower, or 132 ppm or lower. However, in practice, the chlorine (Cl) content can be 0.1 ppm or higher, or 0.5 ppm or higher, or 0.8 ppm or higher, or 1 ppm or higher, or 1.5 ppm or higher, or 3 ppm or higher, or 5 ppm or higher, or 10 ppm or higher, or 15 ppm or higher, or 18 ppm or higher, or 20 ppm or higher, or 25 ppm or higher, or 30 ppm or higher, or 35 ppm or higher, or 40 ppm or higher, or 42 ppm or higher, or 45 ppm or higher, or 48 ppm or higher, or 50 ppm or higher, or 52 ppm or higher, or 55 ppm or higher, or 58 ppm or higher, or 60 ppm or higher, or 61 ppm or higher. The chlorine (Cl) content is preferably 150 ppm or less, or 145 ppm or less, or 140 ppm or less, or 135 ppm or less, and in practice it may be 50 ppm or more, or 52 ppm or more, or 55 ppm or more, or 60 ppm or more.

[0051] Additionally, the isocyanate composition according to embodiments of this application may have an APHA color index of 0.1 or greater to 25 or less, which is measured using a spectrophotometer (Ultrascan Pro, HunterLab, light source: C / 2) according to the American Society for Testing and Materials (ASTM) E313 method. Here, the isocyanate composition may have an APHA value of 0.1 or greater and 10 or less immediately after preparation, and the APHA color index of the isocyanate composition may increase during storage. Specifically, the APHA color index of the isocyanate composition immediately after preparation may be 10 or less, or 9.5 or less, or 9 or less, or 8.5 or less, or 8 or less, and may be 0.1 or greater, or 0.2 or greater, or 0.5 or less. Larger, or 1 or larger, or 1.5 or larger, or 2 or larger, or 2.5 or larger, or 3 or larger, or 3.5 or larger, or 4 or larger, or 4.5 or larger, or 5 or larger. Furthermore, after 12 months of storage, the APHA color index of the isocyanate composition can be 25 or less, or 22 or less, or 20 or less, or 18 or less, and can be 0.5 or larger, or 1 or larger, or 3 or larger, or 5 or larger, or 8 or larger, or 10 or larger, or 12 or larger, or 14 or larger.

[0052] Furthermore, the isocyanate composition according to the embodiments of this application may further include at least one additional component selected from the group consisting of chloromethylbenzyl isocyanate, isocyanomethylbenzaldehyde (IMBAl), and isocyanomethylbenzamide (IMBAm).

[0053] Specifically, chloromethylbenzyl isocyanate can be represented by the following chemical formula 2, isocyanomethylbenzaldehyde can be represented by the following chemical formula 3, and isocyanomethylbenzamide (IMBAm) can be represented by the following chemical formula 4: [Chemical Formula 2]

[0054] [Chemical Formula 3]

[0055] [Chemical Formula 4]

[0056] In chemical formulas 2 to 4, R1 can be hydrogen, methyl, or ethyl, each independently.

[0057] For example, chloromethylbenzyl isocyanate can be represented by the following chemical formula 2-1, isocyanomethylbenzaldehyde can be represented by the following chemical formula 3-1, and isocyanomethylbenzamide can be represented by the following chemical formula 4-1: [Chemical Formula 2-1]

[0058] [Chemical Formula 3-1]

[0059] [Chemical Formula 4-1] .

[0060] In the isocyanate composition according to embodiments of this application, the amount of at least one additional component selected from the group consisting of chloromethylbenzyl isocyanate, isocyanomethylbenzaldehyde and isocyanomethylbenzamide may be 0.5 parts by weight or less, or 0 or more and 0.5 parts by weight or less, per 100 parts by weight of the isocyanate composition.

[0061] Specifically, in the isocyanate composition, the content of at least one additional component selected from the group consisting of chloromethylbenzyl isocyanate, isocyanomethylbenzaldehyde, and isocyanomethylbenzamide may each independently be less than 0.4 parts by weight, or 0.38 parts by weight or less, or 0.35 parts by weight or less, or 0.32 parts by weight or less, or 0.3 parts by weight or less, or 0.28 parts by weight or less, or 0.25 parts by weight or less, or 0.22 parts by weight or less, or 0.2 parts by weight or less. The weight may be 0.18 parts by weight or less, or 0.15 parts by weight or less, or 0.12 parts by weight or less, or 0.1 parts by weight or less, or 0.09 parts by weight or less, or 0.05 parts by weight or less, or 0.03 parts by weight or less, or 0.01 parts by weight or less, and 0.001 parts by weight or more, or 0.002 parts by weight or more, or 0.003 parts by weight or more, or 0.005 parts by weight or more, or 0.007 parts by weight or more.

[0062] Furthermore, the isocyanate composition according to embodiments of this application can optimize the content of the compound represented by Chemical Formula 1 (DCMBI), thereby reducing the rate of increase in the content of at least one additional component selected from the group consisting of isocyanomethylbenzaldehyde (IMBAl) and isocyanomethylbenzamide (IMBAm) after long-term storage of 12 months. For example, in the isocyanate composition stored for 12 months, per 100 parts by weight of the isocyanate composition, at least one additional component selected from the group consisting of isocyanomethylbenzaldehyde and isocyanomethylbenzamide may be independently contained in an amount of 0.01 parts by weight or higher and 0.5 parts by weight or lower. Specifically, as described above, after 12 months, the XDI composition may independently contain at least one additional component among IMBAl and IMBAm in amounts of less than 0.4 parts by weight, or 0.38 parts by weight or less, or 0.35 parts by weight or less, or 0.32 parts by weight or less, or 0.3 parts by weight or less, or 0.28 parts by weight or less, or 0.25 parts by weight or less, or 0.22 parts by weight or less, or 0.2 parts by weight or less, or 0.18 parts by weight or less, or 0.15 parts by weight or less, or 0.12 parts by weight or less, or 0.1 parts by weight or less, or 0.09 parts by weight or less, and 0.02 parts by weight or more, or 0.03 parts by weight or more, or 0.04 parts by weight or more, or 0.05 parts by weight or more, or 0.06 parts by weight or more.

[0063] Here, the content of at least one selected from the group consisting of chloromethylbenzyl isocyanate, isocyanomethylbenzaldehyde, and isocyanomethylbenzamide can be measured by component analysis using gas chromatography (GC), but is not limited thereto, and can be measured by other methods known in the art. For example, the method for measuring the content of such additional component is described in Test Example 3 below.

[0064] Specifically, the content of at least one selected from the group consisting of chloromethylbenzyl isocyanate, isocyanomethylbenzaldehyde, and isocyanomethylbenzamide can be measured by gas chromatography (GC) analysis under the following analytical conditions.

[0065] 1. GC Measurement Conditions Equipment: GC (Agilent HP-7890A FID) Column: DB-17 (30m x 0.25mm, 0.5μm) Flow split ratio: 100:1 Inlet temperature: 250℃ Detector temperature: 280℃ Oven temperature: 80℃ → 5℃ / min increase, 160℃ (hold for 8 minutes) → 20℃ / min increase, 280℃ (hold for 18 minutes) Carrier gas: N2 Carrier gas flow rate: 1.0 mL / min (constant flow control) Sample concentration: 1.0 wt% dichloromethane solution Injection volume: 1.0 μL When performing gas chromatography (GC) analysis under the above conditions, the content ratio of each compound relative to the total weight of the isocyanate composition can be expressed as the content (wt%) of each component.

[0066] For example, according to the gas chromatography (GC) analysis described above, xylene diisocyanate (XDI) represents compounds with retention times between 27.9 min and 29.0 min, isocyanomethylbenzaldehyde (IMBAl) represents compounds with retention times between 24.7 min and 26.4 min, and isocyanomethylbenzamide (IMBAm) represents compounds with retention times between 30.7 min and 32.8 min.

[0067] Specifically, by comprising one or more of the aforementioned isocyanomethylbenzaldehyde and isocyanomethylbenzamide, along with a compound represented by Formula 1 (dichloromethylbenzyl isocyanate, DCMBI), they exert an inhibitory effect on the formation of diuretic ketone and additional impurities, thereby reducing the range of increase in APHA and the lens YI of the composition, wherein diuretic ketone is a self-polymerizing compound formed during long-term storage for months or longer. For reference, the content of dichloromethylbenzyl isocyanate did not change significantly during storage.

[0068] The urea diketone content (urea diketone content in the XDI composition after 12 months) of the isocyanate composition according to the embodiments of this application, measured after 12 months of long-term storage, may be 5 parts by weight or less based on 100 parts by weight of the isocyanate composition.

[0069] Here, urea diketone is in the form of two xylene diisocyanates (XDI) whose respective two NCO groups are bonded to each other in a cyclic form, hence the name urea diketone, and two XDI molecules can bond together to form a ring. Furthermore, three XDI molecules can form a form with two urea diketone rings. In this case, the compound represented by Formula 1 (dichloromethylbenzyl isocyanate, DCMBI) can be generated through the NCO bonding of various substances in the isocyanate composition, such as the NCO bonding of XDI.

[0070] Specifically, in this application, urea diketone can be represented by the following chemical formula 5: [Chemical Formula 5]

[0071] In chemical formula 5, R1 can be hydrogen, methyl, or ethyl, each independently. R' can be independently a chloromethyl (-CH2Cl), dichloromethyl (-CHCl2), aldehyde (-CHO), or amide (-CONH2), and Each n is independently 0 or 1.

[0072] For example, diureidone can be represented by any of the following chemical formulas 5-1 to 5-3: [Chemical Formula 5-1]

[0073] [Chemical Formula 5-2]

[0074] [Chemical Formula 5-3]

[0075] In chemical formulas 5-1 to 5-3, R' is defined as described above in chemical formula 5.

[0076] Specifically, based on 100 parts by weight of the isocyanate composition, the content of urea diketone, i.e., the content of urea diketone in the XDI composition after 12 months of long-term storage of the isocyanate composition (the content of urea diketone in the XDI composition after 12 months), can be 5 parts by weight or less, or 0 to 5 parts by weight or less. After 12 months of storage, the content of urea diketone is preferably less than 5 parts by weight, or 4.9 parts by weight or less, or 4.8 parts by weight or less, or 4.5 parts by weight or less, or 4.2 parts by weight or less, or 4 parts by weight or less, or 3.8 parts by weight or less, or 3.5 parts by weight or less, or 3.2 parts by weight or less, or 3 parts by weight or less, or 2.85 parts by weight or less, or 2.7 parts by weight or less. However, in terms of the actual self-polymerization process that occurs during long-term storage, the content of diureidone after 12 months of storage may be higher than 0 parts by weight, or 0.01 parts by weight or higher, or 0.02 parts by weight or higher, or 0.03 parts by weight or higher, or 0.04 parts by weight or higher, or 0.05 parts by weight or higher, or 0.06 parts by weight or higher, or 0.08 parts by weight or higher, or 0.1 parts by weight or higher.

[0077] Here, the content of urea diketone can be measured by infrared spectroscopy (IR) analysis, but is not limited thereto, and can be measured by other methods known in the art. For example, the method for measuring the content of urea diketone is described in Test Example 3 below.

[0078] Specifically, after storing the isocyanate composition of this application in a conventional tin can for 12 months at room temperature (approximately 15°C to 25°C), the content of urea diketone in the resulting isocyanate (XDI) composition after 12 months of storage can be measured by infrared spectroscopy (IR) analysis. For example, after obtaining the infrared absorption spectrum of the isocyanate composition after 12 months of storage using an FT-IR spectrometer (Varian 4100) in ATR mode, the carbonyl group of urea diketone (1770-1790 cm⁻¹) is measured. -1 The area ratio of the absorption peaks was used to calculate the urea diketone content (wt%) based on the absorption coefficient obtained from the calibration curve.

[0079] When infrared spectroscopy (IR) analysis is performed under the above conditions, the weight ratio of the diuretic compound to the total weight of the isocyanate composition can be expressed as content (wt%).

[0080] Furthermore, the isocyanate composition according to the embodiments of this application can meet the above-mentioned chlorine (Cl) content range measured in the initial stage after preparation, even after a long storage period of 12 months.

[0081] polymerizable compositions According to another embodiment of this application, a polymerizable composition for polyisocyanate polymerization is provided, comprising the above-described isocyanate composition and at least one polyfunctional monomer compound selected from the group consisting of compounds based on polyfunctional alcohols, compounds based on polyfunctional thiols, and compounds based on polyfunctional cyclic sulfides.

[0082] The polymerizable composition uses an isocyanate composition containing xylene diisocyanate and a compound represented by chemical formula 1, wherein the content is greater than 60 ppm to 200 ppm or less, thereby facilitating control of reactivity during polymerization.

[0083] The polymerizable composition has high transparency and excellent impact strength, making it suitable for use as a high-quality optical material.

[0084] The description of the isocyanate composition contained in the polymerizable composition is the same as that described above.

[0085] Preferably, the polymerizable composition may comprise the isocyanate composition and the polyfunctional monomer compound in a mixed state; or they may comprise them in a state separate from each other. That is, in the polymerizable composition, the isocyanate composition and the polyfunctional monomer compound may be in a mixed state in contact with each other, or they may be in a separate state in which they are not in contact with each other.

[0086] Compounds based on polyfunctional alcohols are compounds containing two or more hydroxyl groups (-OH) per molecule. Specifically, they are compounds having two or more, or three or more, and eight or fewer, or four or fewer hydroxyl groups in the molecule. Specific examples include: diols, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 2-methyl-2,3-butanediol, 1,6-hexanediol, 1,2-hexanediol, polypropylene glycol, polytetramethylene ether glycol, ethylene oxide-propylene oxide block copolymer, polyalkylene carbonate glycol, polycaprolactone glycol; triols, such as glycerol, trimethylolethane, trimethylolpropane (TMP); tetraols, such as diglycerol, bis(trimethylolpropane), pentaerythritol, dipentaerythritol; pentaols, such as L-arabinol, ribitol, xylitol; hexaols, such as D-glucosyl alcohol, D-mannitol, galactitol; heptols, such as trehalose; octaols, such as sucrose, maltose; or polyols; and any one or a mixture of two or more of them may be used.

[0087] Compounds based on polyfunctional thiols are compounds containing two or more thiol groups (-SH) per molecule. Specifically, they are compounds having two or more, or three or more, and eight or fewer, or five or fewer thiol groups in the molecule.

[0088] Compounds based on polyfunctional thiols can be, for example, 2,3-bis(2-mercaptoethylthio)propane-1-thiol, 1,9-dimercapto-3,7-dithionane, 1,13-dimercapto-3,7,11-trithiatridecane, diol di(3-mercaptopropionate), 1,4-dithia-2,5-dimethyldimethylthiol, 2-mercaptomethyl-1,5-dimercapto-3-thiapentane, and trimethylolpropane 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), 3,6,9,12-tetrathiatetradecane-1,14-dithiol, 3,6,10,13-tetrathiapentadecane-1,8,15-trithiol.

[0089] Specifically, the amount of polythiol added can be such that the molar ratio of thiol groups in the polythiol to isocyanate groups in 1 mole of isocyanate compound is 0.8 or greater, or 0.9 or greater, and 1.1 or less, or 1.0. If the molar ratio of thiol groups to isocyanate groups is outside the above range and less than 0.8, the viscosity of the obtained polymer will decrease due to the excess isocyanate groups, which may lead to reduced processability. Furthermore, if the molar ratio of thiol groups to isocyanate groups exceeds 1.1, there is a concern that the presence of excess thiol groups may reduce the discoloration prevention effect.

[0090] Compounds based on polyfunctional cyclic sulfides can be compounds containing two or more cyclic sulfides (i.e., thioepoxy groups) in their molecules, and can have an aliphatic, alicyclic, or aromatic skeleton. According to examples, compounds based on polyfunctional cyclic sulfides can include bis(β-cyclothiopropylthio)methane, 1,2-bis(β-cyclothiopropylthio)ethane, 1,3-bis(β-cyclothiopropylthio)propane, 1,2-bis(β-cyclothiopropylthio)propane, 1-(β-cyclothiopropylthio)-2-(β-cyclothiopropylthiomethyl)propane, 1,4-bis(β-cyclothiopropylthio)butane, 1,3-bis(β-cyclothiopropylthio)butane, 1-(β-cyclothiopropylthio)-3-(β-cyclothiopropylthiomethyl)butane, 1,5-bis(β-cyclothiopropylthio)pentane, and 1-(β-cyclothiopropylthio)-4-(β-cyclothiopropylthiomethyl)pentane. 1,6-bis(β-cyclothiopropylthio)hexane, 1-(β-cyclothiopropylthio)-5-(β-cyclothiopropylthiomethyl)hexane, 1-(β-cyclothiopropylthio)-2-[(2-β-cyclothiopropylthioethyl)thio]ethane, 1-(β-cyclothiopropylthio)-2-[[2-(2-β-cyclothiopropylthioethyl)thioethyl]thio]ethane, tetra(β-cyclothiopropylthiomethyl)methane, 1,1,1-tris(β-cyclothiopropylthiomethyl)propane, 1,5-bis(β-cyclothiopropylthio)-2-(β-cyclothiopropylthiomethyl)-3-thiapentane, 1,5-bis(β-cyclothiopropylthio)-2,4-bis(β-cyclothiopropylthio) 1,8-Bis(β-cyclothiopropylthio)-3-thiapentane, 1,5,6-Tris(β-cyclothiopropylthio)-4-(β-cyclothiopropylthiomethyl)-3-thiapentane, 1,8-Bis(β-cyclothiopropylthio)-4-(β-cyclothiopropylthiomethyl)-3,6-dithiaoctane, 1,8-Bis(β-cyclothiopropylthio)-4,5-Bis(β-cyclothiopropylthiomethyl)-3,6-dithiaoctane, 1,8-Bis(β-cyclothiopropylthio)-4,4-Bis(β-cyclothiopropylthiomethyl)-3,6-dithiaoctane, 1,8-Bis(β-cyclothiopropylthio)-4,4-Bis(β-cyclothiopropylthiomethyl)-3,6-dithiaoctane, 1,8-Bis(β-cyclothiopropylthio)-3-thiaoctane, 1,8-Bis(β-cyclothiopropylthio)-4,2-bis(β-cyclothiopropylthiomethyl)-3,6-dithiaoctane, 1,8-Bis(β-cyclothiopropylthio)-3- ... 1,8-Bis(β-cyclothiopropylthiomethyl)-2,5-bis(β-cyclothiopropylthiomethyl)-3,6-dithiaoctane, 1,9-bis(β-cyclothiopropylthiomethyl)-5-(β-cyclothiopropylthiomethyl)-5-[(2-β-cyclothiopropylthioethyl)thiomethyl]-3,7-dithianonane, 1,10-bis(β-cyclothiopropylthiomethyl)-5,6-bis[(2-β-cyclothiopropylthioethyl)thio]-3,6,9-trithiadecane, 1,11-bis(β-cyclothiopropylthiomethyl)-4,8-bis(β-cyclothiopropylthiomethyl)-3,6,9-Trithiaundecane, 1,11-bis(β-cyclothiopropylthio)-5,7-bis(β-cyclothiopropylthiomethyl)-3,6,9-trithiaundecane, 1,11-bis(β-cyclothiopropylthio)-5,7-[(2-β-cyclothiopropylthioethyl)thiomethyl]-3,6,9-trithiaundecane, 1,11-bis(β-cyclothiopropylthio)-4,7-bis (β-Cyclothiopropylthiomethyl)-3,6,9-trithiaundecane, 1,3-bis(β-cyclothiopropylthio)cyclohexane, 1,4-bis(β-cyclothiopropylthio)cyclohexane, 1,3-bis(β-cyclothiopropylthiomethyl)cyclohexane, 1,4-bis(β-cyclothiopropylthiomethyl)cyclohexane, bis[4-(β-cyclothiopropylthio)cyclohexyl]methane, 2,2-bis[4 [-(β-cyclothiopropylthio)cyclohexyl]propane, bis[4-(β-cyclothiopropylthio)cyclohexyl]sulfide, 2,5-bis(β-cyclothiopropylthiomethyl)-1,4-dithiane, 2,5-bis(β-cyclothiopropylthioethylthiomethyl)-1,4-dithiane, 1,3-bis(β-cyclothiopropylthio)benzene, 1,4-bis(β-cyclothiopropylthio)benzene, 1,3-bis... (β-Cyclothiopropylthiomethyl)benzene, 1,4-bis(β-Cyclothiopropylthiomethyl)benzene, bis[4-(β-Cyclothiopropylthio)phenyl]methane, 2,2-bis[4-(β-Cyclothiopropylthio)phenyl]propane, bis[4-(β-Cyclothiopropylthio)phenyl]sulfide, bis[4-(β-Cyclothiopropylthio)phenyl]sulfone, and 4,4'-bis(β-Cyclothiopropylthio)biphenyl.

[0091] The polymeric composition may contain additives, such as internal release agents, ultraviolet absorbers, urethane reaction catalysts, polymerization initiators, heat stabilizers, color correctors, chain extenders, crosslinking agents, light stabilizers, fillers, and photosensitizers, as needed, without reducing the desired effects of the invention. The content of these additives may be appropriately determined within the range that does not inhibit the discoloration and discoloration inhibition properties of the composition.

[0092] The polymer composition described above can control the occurrence of turbidity by delaying or inhibiting the reaction rate and oligomerization of isocyanates through the combination of two antioxidants contained in the isocyanate composition.

[0093] The polyols contained in the polymerizable composition are compounds having two or more hydroxyl groups, and there are no restrictions on the compounds commonly used in polyurethane production. For example, polyols include: diols, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 2-methyl-2,3-butanediol, 1,6-hexanediol, and 1,2-hexanediol; triols, such as glycerol, trimethylolethane, and trimethylolpropane (TMP); tetraols, such as diglycerol, ditrimethylolpropane, pentaerythritol, and dipentaerythritol; pentaols, such as L-arabinol, ribitol, and xylitol; hexaols, such as D-glucosyl alcohol, D-mannitol, and galactitol; heptols, such as trehalose; octaols, such as sucrose and maltose; or low molecular weight polyols, such as polyepoxides with a number average molecular weight of 60 to 400.

[0094] Diethylene glycol, glycerol, trimethylolethane, trimethylolpropane, or mixtures thereof may be used, and more specifically, triols such as glycerol, trimethylolpropane, or trimethylolethane may be used alone, or mixtures of triols and other polyols may be used.

[0095] Polythiols are compounds having two or more thiol groups, and there are no limitations on the compounds commonly used in polyurethane production. For example, aliphatic polythiols, such as 2,3-bis(2-thioethylthio)propane-1-thiol, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, can be used alone or in combination of two or more, but the invention is not limited thereto.

[0096] As needed, the polymerizable composition may further include a polymerization initiator, an internal release agent, and a UV absorber.

[0097] As polymerization initiators, amines, phosphorus compounds, organotin compounds, organocopper compounds, organogallium compounds, organozirconium compounds, organoiron compounds, organozinc compounds, organoaluminum compounds, etc., can be used. Based on 100 parts by weight of the polymerizable composition, the amount of polymerization initiator can be from 0.001 to 0.1 parts by weight.

[0098] As an internal release agent, fluorinated nonionic surfactants having perfluoroalkyl, hydroxyalkyl, or phosphate groups can be used, either alone or in combination of two or more; silicone nonionic surfactants having dimethylpolysiloxane, hydroxyalkyl, or phosphate groups; alkyl quaternary ammonium salts, namely trimethylhexadecylammonium salt, trimethylstearyl, dimethylethylhexadecylammonium salt, triethyldodecylammonium salt, trioctylmethylammonium salt, diethylcyclohexadecylammonium salt; or phosphate-based compounds (such as acidic phosphate esters). Preferably, phosphate-based compounds can be used. The amount of internal release agent used is 0.01 to 1 part by weight per 100 parts by weight of polymerizable composition.

[0099] Examples of UV absorbers include benzotriazole compounds (specifically, Tinuvin 571, Tinuvin 213, Tinuvin 234, Tinuvin P (all manufactured by BASF)), formamidin-based compounds (specifically, Zikasorb R, Zikasorb BS, ZIKA-FA02, ZIKA-FUA, ZIKA-FUV, ZIKA-UVS3, ZIKA-UVS4 (all manufactured by ZIKO)), and Biosorb 583 (manufactured by Sakai Chemical Industry Co., Ltd.). The amount of UV absorber used is 0.01 to 1 part by weight per 100 parts by weight of the polymerizable composition.

[0100] The polymerizable composition described above contains the compound represented by Chemical Formula 1 as described above in the isocyanate composition, and by optimizing its content to greater than 60 ppm to 200 ppm or less, the reaction rate and oligomerization of isocyanate are delayed or inhibited, thereby controlling the occurrence of turbidity and discoloration even during long-term storage for months or longer, such as 12 months or longer. At the same time, when used as a raw material for optical products such as poly(thio)urethane lenses, the transparency of the lens can be improved.

[0101] Polyisocyanate composition According to another embodiment of this application, a polyisocyanate composition is provided, comprising a polyisocyanate obtained by polymerizing the above-described isocyanate composition with a polyfunctional alcohol-based compound. The polyisocyanate prepared in this manner by reacting with a polyol exhibits excellent transparency and excellent pressure-sensitive / adhesive properties. Therefore, it can be used in coatings, pressure-sensitive adhesives, adhesives, etc., but is not limited thereto, and can be used to manufacture optical pressure-sensitive adhesives, optical adhesives, optical coatings, or optical paints.

[0102] Here, the description of compounds based on polyfunctional alcohols can be applied in the same way as described above.

[0103] According to another embodiment of this application, a polyisocyanate composition is provided, comprising a polyisocyanate obtained by polymerizing the above-described isocyanate composition with a compound based on a polyfunctional thiol or a compound based on a polyfunctional cyclic sulfide. The polyisocyanate composition can be used in optical materials, such as optical lenses, but is not limited thereto.

[0104] Here, the descriptions of compounds based on polyfunctional thiols and compounds based on polyfunctional cyclic sulfides can be applied in the same way as described above.

[0105] In the polyisocyanate composition, the polymerization reaction between the isocyanate composition and the monomer compound (compound based on polyfunctional alcohol, compound based on polyfunctional thiol, compound based on polyfunctional cyclic sulfide) can be carried out under normal pressure in an inert atmosphere (such as nitrogen or argon).

[0106] The polymerization reaction can be carried out in a temperature range of -15°C or higher, or 0°C or higher, and 200°C or lower, or 170°C or higher. For example, when using compounds based on polyfunctional alcohols as monomers, it is preferable to carry out the reaction at 60-80°C; when using compounds based on polyfunctional thiols or compounds based on polyfunctional cyclic sulfides as monomers, it is preferable to carry out the reaction at 100-160°C.

[0107] When polymerization is carried out within the above temperature range, the reaction rate can be easily controlled without worrying about discoloration, and the reaction efficiency can also be improved, which is preferred.

[0108] The polymerization reaction can be carried out without a catalyst or in the presence of a catalyst that promotes the urethane esterification reaction (e.g., a tin-based or amine-based catalyst). When carried out in the presence of a catalyst, the catalyst can be added concurrently with the step of adding the monomer compound to the isocyanate-based mixture.

[0109] When polyfunctional alcohol-based compounds are used in the polymerization reaction, the concentration of isocyanate groups in the polymerization product can be measured using a potentiometric titration apparatus via the di-n-butylamine method, or the reaction progress can be predicted by measuring the refractive index; and in this application, the reaction can be carried out until the concentration of isocyanate groups in the polymerization product reaches the calculated value of the remaining isocyanate groups after the reaction with the monomer compound. As a result of the polymerization reaction as described above, polyisocyanate is generated.

[0110] Without diminishing the desired effects of the invention, the polyisocyanate composition may further include additives as needed, such as internal release agents, ultraviolet absorbers, polymerization initiators, heat stabilizers, antioxidants, color correctors, chain extenders, crosslinking agents, light stabilizers, fillers, and photosensitizers, and their contents may be appropriately determined within a range that does not inhibit the discoloration and discoloration inhibition properties of the composition.

[0111] Optical products According to another embodiment of this application, an article is provided comprising a polymer obtained by polymerizing the above-described isocyanate composition with at least one polyfunctional monomer compound selected from the group consisting of polyfunctional thiols, polyfunctional alcohols, and polyfunctional cyclic sulfides.

[0112] It may also be an article comprising a polymer obtained by polymerizing the isocyanate composition and the polyfunctional monomer compound in the above polymerizable composition.

[0113] The polyisocyanate composition exhibits excellent transparency and superior pressure-sensitive / adhesive properties, thus making it applicable to a wide range of fields. Specifically, it can be used as an optical material, as well as a coating, pressure-sensitive adhesive, or adhesive, and more preferably, the article can be used as an optical pressure-sensitive adhesive, optical adhesive, optical coating, or optical lens.

[0114] The article can be manufactured by a molding process following the polymerization reaction in the above composition, or by a molding process using the polymerized composition. In the latter case, the polymerization reaction occurs simultaneously during the molding process.

[0115] Preferably, when used as an optical lens, it can be a polymer obtained by polymerizing an isocyanate composition with a compound based on a polyfunctional thiol or a compound based on a polyfunctional cyclic sulfide. In this case, the polymeric composition containing the isocyanate composition and the polyfunctional thiol-based compound or the polyfunctional cyclic sulfide-based compound is injected into a lens molding die, and then the temperature of the die is raised to carry out a polymerization reaction between the isocyanate-based compound and the polyfunctional monomer compound. Here, the die is heated to the temperature range where the polyurethane polymerization reaction occurs, and after the polymerization reaction is completed, the resulting polymer (specifically polyurethane thiosulfate) is separated from the die to obtain the optical lens.

[0116] For example, an optical lens according to another embodiment of this application may have an Abbe number (Ve) of 25 or greater, or 28 or greater, or 30 or greater, or 31 or greater, or 31.4 or greater, and in practice, it may have an Abbe number of 50 or less, or 45 or less, or 43 or less, or 40 or less, or 38 or less, or 35 or less, or 32 or less. The method for measuring the Abbe number (Ve) is described in Test Example 2 below, and specific details are omitted.

[0117] Additionally, the optical lens may have a weathering index ΔYI of 0.55 or lower, or greater than 0 and 0.55 or lower, which is the deviation of the YI value compared before and after 110 hours of exposure to xenon arc light source (irradiance 0.51 W / m2 @ 340 nm, humidity 50%, temperature 60 °C) acceleration conditions. The weathering index ΔYI of the lens is preferably 0.54 or less, or 0.53 or less, and in some cases, 0.01 or greater, or 0.05 or greater, or 0.1 or greater, or 0.2 or greater, or 0.3 or greater, or 0.4 or greater, or 0.45 or greater, or 0.47 or greater.

[0118] The yellowness (YI) of a lens can be measured using a spectrophotometer (Ultrascan Pro by HunterLab) according to the method of American Society for Testing and Materials (ASTM) D1209.

[0119] Furthermore, when observing the optical lens with the naked eye using a xenon lamp light source, no lens streaks will appear.

[0120] Therefore, optical lenses can maintain excellent transparency while minimizing streaks and discoloration caused by uneven polymerization.

[0121] Meanwhile, the optical lens according to another embodiment of this application exhibits a significantly reduced yellowness (YI) to below 5 even when manufactured using an isocyanate composition that has been stored for 12 months as described above. Furthermore, it does not exhibit discoloration or cloudiness even during long-term storage, and maintains excellent resistance to discoloration while improving transparency. Preferably, the yellowness (YI) of the lens can be 4.8 or less, or 4.6 or less, or 4.4 or less, or 4.3 or less. Even when manufactured using an isocyanate composition that has been stored for 12 months, it can be 0.01 or greater, or 0.1 or greater, or 0.5 or greater, or 1 or greater, or 1.5 or greater, or 3 or greater, or 3.5 or greater, or 3.8 or greater, or 4 or greater.

[0122] Here, the methods for measuring the yellowness (YI), weather resistance index ΔYI, and stripes of the aforementioned optical lens are as described in Test Example 2 below, and specific details are omitted.

[0123] Optical elements comprising polymers obtained by polymerizing the polymerizable composition comprising the isocyanate composition of this application exhibit high transparency and improved impact resistance. Therefore, these optical elements can be usefully used as eyeglass lenses, camera lenses, adhesives, resins, etc., where transparency is required.

[0124] The present application will be described in more detail below with reference to the following embodiments. However, the following embodiments are for illustrative purposes only, and the scope of the present application is not limited thereto.

[0125] [Example] Preparation Example 1: Preparation of 3-dichloromethylbenzyl isocyanate (DCMBI) 76 g (191.6 mmol) of tungsten chloride was added to a mixed solution of 10 g (76.3 mmol) of 3-cyanobenzaldehyde and 500 mL of dichloromethane (CH2Cl2), and the mixture was reacted under reflux in dichloromethane for 4 hours, followed by cooling to room temperature. Then, 200 mL of sodium bicarbonate aqueous solution and 1100 mL of 1N sodium hydroxide aqueous solution were slowly added sequentially to the reaction solution while maintaining the temperature at 10 °C or lower. After separating the organic solvent layer (dichloromethane layer) and the aqueous layer, the mixture was extracted twice more with 500 mL of dichloromethane. The dichloromethane layer thus separated was mixed with the dichloromethane layer obtained during the extraction, and the dichloromethane layer was washed with 800 mL of brine and dried over magnesium sulfate. After drying, magnesium sulfate was filtered off from the dichloromethane layer, and dichloromethane was distilled off to obtain a concentrated solution. 13.2 g of 3-(dichloromethyl)benzonitrile was then obtained from the concentrated solution by silica gel column chromatography.

[0126] Next, at room temperature, 135 mL of a tetrahydrofuran solution (2 M, in THF) of a borane-dimethyl sulfide complex was added dropwise to a mixed solution of 10 g (53.8 mmol) of 3-(dichloromethyl)benzonitrile and 150 mL of tetrahydrofuran, and the mixture was stirred for 24 hours to allow the reaction to proceed. After the reaction, the reaction solution was immersed in ice water to lower the temperature, and 35 mL of 2 M hydrochloric acid aqueous solution was slowly added. Then, 300 mL of ethyl acetate was added to the reaction solution and the mixture was stirred for 10 minutes. The ethyl acetate layer was then separated and removed, and the solution was immersed in ice water again, and 85 mL of 1 M sodium hydroxide was slowly added to the reaction solution. Subsequently, the reaction solution was extracted four times with 250 mL of dichloromethane, and the resulting dichloromethane layer was dried with magnesium sulfate.

[0127] After such drying, magnesium sulfate was filtered out from the dichloromethane layer, and dichloromethane was distilled off to obtain 5.5 g of 3-(dichloromethyl)benzylamine.

[0128] Next, a mixed solution of 5.5 g (28.9 mmol) of the 3-(dichloromethyl)benzylamine obtained above and 90 mL of o-dichlorobenzene was added dropwise to a mixed solution of 15.1 g (50.9 mmol) of triphosgene and 90 mL of o-dichlorobenzene, and the reaction was then carried out at 120°C for 3 hours. After the reaction, the mixture was cooled to room temperature, and o-dichlorobenzene was distilled off to obtain a concentrated liquid. Then, 3.3 g of 3-(dichloromethyl)benzyl isocyanate (DCMBI) was finally obtained from the concentrated liquid by silica gel column chromatography.

[0129] Examples 1 to 3: Preparation of isocyanate compositions As described in Test Example 1 below, the 3-(dichloromethyl)benzyl isocyanate (DCMBI) content of m-xylylene diisocyanate (manufactured by TCI) was measured by GC analysis, and then 3-(dichloromethyl)benzyl isocyanate (DCMBI) was added to each to reach the DCMBI content values in Table 1 below, thereby separately preparing the isocyanate compositions of Examples 1 to 3.

[0130] Comparative Examples 1 to 3: Preparation of isocyanate compositions As described in Test Example 1 below, the 3-(dichloromethyl)benzyl isocyanate (DCMBI) content of m-xylylene diisocyanate (manufactured by TCI) was measured by GC analysis, and then 3-(dichloromethyl)benzyl isocyanate (DCMBI) was added to each to reach the DCMBI content values in Table 1 below, thereby separately preparing the isocyanate compositions of Comparative Examples 1 to 3.

[0131] [Test Example 1] For the isocyanate compositions of the Examples and Comparative Examples, the content of 3-(dichloromethyl)benzyl isocyanate (DCMBI) was measured by the following method, and the measured values are shown in Table 1 below.

[0132] <DCMBI Content Measurement Method> Using DCMBI with a purity of 99 mol% synthesized according to Preparation Example 1 as a reference material, analysis was performed by gas chromatography under the following conditions, and a calibration curve was prepared by adding the reference material to the XDI sample. (Standard addition method) Next, the XDI compositions of the above Examples and Comparative Examples were analyzed by gas chromatography under the following conditions to obtain the number of moles of DCMBI. This was converted to mass, and the content ratio of DCMBI in the XDI compositions of the respective Examples and Comparative Examples described later was calculated.

[0133] 1. GC measurement conditions Equipment: GC-MS (Agilent 8890 5977C) Column: DB-17MS (30m x 0.25mm, 0.25μm) Flow split ratio: 3:1 Inlet temperature: 200℃ Detector temperature: 280℃ Oven temperature: 50℃ (hold for 3 minutes) → 10℃ / min, 280℃ (hold for 6 minutes) Carrier gas: He Carrier gas flow rate: 1.0 mL / min (constant flow control) Sample concentration: 1.0% by mass dichloromethane solution Injection volume: 1.0 μL Detection method: SIM mode (monitored ions: m / z 180, 215) Table 1

[0134] Preparation Example 2: Preparation of XDI Adduct Under a nitrogen atmosphere, 300 g of each of the m-XDI compositions from the examples and comparative examples were added to round-bottom flasks and stirred. The temperature of the flasks was raised to 70°C and maintained at that temperature, and then 26.7 g of trimethylolpropane (TMP) was added dropwise. After the addition was complete, the reaction temperature was maintained at 70°C until the isocyanate group concentration reached the calculated value of 33%.

[0135] After the reaction was completed, the reaction product was purified using a thin-film evaporator (TFE) to separate unreacted XDI, thereby obtaining the XDI-TMP adduct.

[0136] The resulting XDI-TMP adduct was used after being diluted with ethyl acetate (75 wt% solids).

[0137] The color of the resulting XDI adduct was measured by sensory evaluation, and the results are shown in Table 2 below.

[0138] Preparation Example 3: Preparation of Optical Lenses 62.4 g of the isocyanate composition prepared in the Examples and Comparative Examples, 0.16 g of ZELEC™ UN (manufactured by Stepan) as an internal mold release agent, and 0.80 g of Tinuvin® 329 (manufactured by BASF) as an ultraviolet absorber were stirred and mixed in a flask at room temperature (23°C) for about 20 minutes to prepare a mixture. 0.024 g of DBTC (dibutyltin dichloride) was added to the prepared mixture and stirred for 10 minutes, then 57.6 g of 2,3-bis(2-sulfanylethylsulfanyl)propane-1-thiol was added, followed by degassing under a pressure of 5 mbar while stirring for 1 hour to prepare a composition for polyisocyanate polymerization.

[0139] The prepared composition for polyisocyanate polymerization was filtered using a 1 μm PTFE filter, and then injected into molds each composed of a glass mold and an adhesive tape. Thereafter, the molds were placed in an oven, and the polymerization reaction was allowed to proceed for 20 hours while the temperature was slowly increased from 10°C to 120°C. After the polymerization was completed, the molds were taken out of the oven and demolded to obtain respective plastic optical lenses. The obtained optical lenses were annealed at 120°C for 6 hours to produce optical lenses each having a thickness of 9 mm.

[0140] [Test Example 2] For the isocyanate compositions of the Examples and Comparative Examples, the XDI adducts produced using them, and the optical lenses, performance evaluations were carried out in the initial stage within 5 days after each preparation as follows, and the measurement results are shown in Table 2 below.

[0141] <Measurement of Cl Content of XDI Composition> The chlorine (Cl) content was measured by elemental analysis of the isocyanate compositions prepared in the Examples and Comparative Examples using a combustion ion chromatograph according to the American Society for Testing and Materials (ASTM) D 7359 method, and the results are shown in Table 2 below.

[0142] <Measurement of APHA of XDI Composition> The APHA color of the isocyanate compositions prepared in the Examples and Comparative Examples was measured using a spectrophotometer (Ultrascan Pro, HunterLab) (light source: C / 2) according to the American Society for Testing and Materials (ASTM) E313 method, and the results are shown in Table 2 below.

[0143] <Abbe Number of Lens> After each planar lens manufactured using the isocyanate compositions of the Examples and Comparative Examples was brought into close contact with the measurement unit of an ATAGO Abbe refractometer (DR-M4), the respective refractive indices were measured using C', F' and E' filters, and the Abbe number (Ve) was measured according to Equation 1 below.

[0144] [Equation 1]

[0145] In equation 1, Ve is an Abbe number. n e It is the refractive index at the Fraunhofer e-line (wavelength 546.1 nm). nF' is the refractive index at the Fraunhofer e-line wavelength of 480.0 nm. nC' is the refractive index at the Fraunhofer e-line (wavelength 643.9 nm).

[0146] In this context, it can be assumed that the higher the Abbe number, the higher the sharpness of the lens.

[0147] <Evaluation of the weather resistance of lenses> Lenses manufactured using the isocyanate compositions of the examples and comparative examples were exposed to accelerating conditions of a xenon arc light source (irradiance 0.51 W / m²). 2 @340nm, 50% humidity, 60℃) for 110 hours, then compare the YI values ​​before and after exposure.

[0148] After measuring yellowness (YI) using a spectrophotometer (UltrascanPro, HunterLab) according to the American Society for Testing and Materials (ASTM) D1209 method, the difference in yellowness of the lens before and after exposure to the light source, ΔYI, is calculated according to Equation 2 below to evaluate weather resistance.

[0149] [Equation 2] Weather resistance (ΔYI) = Lens YI after exposure to light source - YI before exposure to light source.

[0150] It can be said that the smaller the yellowness difference, i.e. the weather resistance ΔYI, the less yellowing occurs in the isocyanate (XDI) composition.

[0151] <Evaluation of Lens Stripes> Lenses manufactured using the isocyanate compositions of the Examples and Comparative Examples were observed with the naked eye using a xenon lamp light source device, and the striations of the lenses were evaluated according to the following three stages.

[0152] -No stripes: ◎ - Slight stripes observed: ○ - Many stripes: Δ.

[0153] [Test Example 3] The isocyanate compositions of the examples and comparative examples, the XDI adducts made using them, and the optical lenses were evaluated for performance after 12 months of storage as follows, and the measurement results are shown in Table 2 below.

[0154] Specifically, the isocyanate compositions of the examples and comparative examples were stored in a general tin can at a temperature of 15°C for 12 months. Then, using the isocyanate (XDI) compositions stored for 12 months, APHA measurement, YI measurement after lens preparation, and GC analysis of XDI after 12 months of storage were performed in the same manner as in Test Example 2.

[0155] In particular, when XDI stored for 12 months was irradiated with fluorescent lamps and zirconium lamps respectively, the presence of turbidity was visually inspected, and lens preparation was not performed if turbidity was confirmed.

[0156] <Urea diketone content in the XDI composition after 12 months of storage> Based on the preparation of urea diketone (XDI) as follows, the content of urea diketone in the XDI composition was measured by infrared spectroscopy (IR) analysis after 12 months of storage.

[0157] (1) Preparation of urea diketone XDI At room temperature, 100 g of xylene diisocyanate (XDI) was added under dry nitrogen atmosphere, and 1 g of triisodecyl phosphite and 2 g of 4-dimethylaminopyridine were added as catalysts. After 20 hours, the reaction mixture was terminated with dibutyl phosphate, and the process was carried out by thin-film distillation. Thin-film distillation yielded urea diketone XDI having the following chemical formula 5-1.

[0158] [Chemical Formula 5-1]

[0159] 13 C-NMR (100 MHz, CDCl3) δ 156.6, 137.7, 135.9, 129.4, 127.4, 126.5, 126.1, 123.3, 46.2, 44.2.

[0160] (2) Measurement of urea diketone content in the XDI composition after 12 months of storage XDI of the examples and comparative examples after 12 months of storage was measured using an FT-IR spectrometer (Varian 4100) in ATR mode.

[0161] The prepared diureidone XDI exhibits an absorption peak at the carbonyl group of diureidone (1770-1790 cm⁻¹). -1Using the prepared diuretic ketone (XDI) as a standard, calibration curves were prepared. A peak with a peak at 1770 cm⁻¹ appeared in all infrared absorption spectra of XDI stored for 12 months. -1 -1790cm -1 The absorption peak was observed. The weight of urea diketone was calculated based on the absorption coefficient obtained from the calibration curve. The content (%) of urea diketone in the XDI composition was derived based on the following Equation 3.

[0162] [Equation 3] Urea diketone (%) = weight of urea diketone / total weight of XDI composition × 100.

[0163] <Ratio of IMBAl to IMBAm content in XDI composition after 12 months> The isocyanate compositions prepared in the Examples and Comparative Examples generate isocyanomethylbenzaldehyde (IMBAl) of the following chemical formula 3-1 and isocyanomethylbenzamide (IMBAm) of the following chemical formula 4-1 during storage, and their contents are determined by gas chromatography (GC).

[0164] [Chemical Formula 3-1]

[0165] [Chemical Formula 4-1] .

[0166] Specifically, results obtained under the following analytical conditions are expressed as the content ratio of each compound relative to the total weight of the isocyanate composition, where XDI represents compounds with retention times between 27.9 and 29.0 minutes, IMBAl represents compounds with retention times between 24.7 and 26.4 minutes, and IMBAm represents compounds with retention times between 30.7 and 32.8 minutes. Prior to long-term storage, the initial content of each component measured in the isocyanate composition was IMBAl 0.007 wt% and IMBAm 0 wt%.

[0167] 1. GC Measurement Conditions Equipment: GC (Agilent HP-7890A FID) Column: DB-17 (30 m x 0.25 mm, 0.5 μm) Flow split ratio: 100:1 Inlet temperature: 250℃ Detector temperature: 280℃ Oven temperature: 80℃ → 5℃ / min increase, 160℃ (hold for 8 minutes) → 20℃ / min increase, 280℃ (hold for 18 minutes) Carrier gas: N2 Carrier gas flow rate: 1.0 mL / min (constant flow control) Sample concentration: 1.0 wt% dichloromethane solution Injection volume: 1.0 μL The isocyanate compositions of the examples and comparative examples, the XDI adducts prepared using them, and the optical lenses were evaluated for performance in the initial stage within 5 days after their respective preparation and after long-term storage for 12 months, and the measurement results are shown in Table 2.

[0168] Table 2

[0169] As shown in Table 2 above, the isocyanate compositions of Examples 1, 2, and 3 contain the compound DCMBI represented by Formula 1, and its content is optimized to 68 ppm, 100 ppm, and 150 ppm, respectively; compared with Comparative Examples 1 to 3, they exhibit improved Abbe numbers during lens manufacturing. Higher Abbe numbers result in lower dispersion, thus providing a clearer image. Simultaneously, due to improved storage stability even over extended periods of months or longer, they exhibit significantly lower APHA values, thereby suppressing discoloration and clouding, and also suppressing the increase in the proportion of impurities in XDI and diureidone that may increase during storage due to XDI self-polymerization, thus minimizing product degradation over 12 months and demonstrating a significant reduction in the yellowness of optical lenses.

[0170] On the other hand, when the DCMBI content was significantly lower at 5 ppm, as in Comparative Example 1, the stability decreased due to heat exposure during the manufacturing of the XDI adduct, resulting in turbidity, and haze appeared in the lens after 12 months. Similarly, in Comparative Example 2, the DCMBI content was 40 ppm, which was insufficient to maintain storage stability. Therefore, the XDI itself could not be maintained after 12 months or longer of storage, with an APHA of 30 and a high yellowness (YI) of 5.1. Furthermore, the contents of impurities such as IMBAl, IMBAm, and diuretic ketone were also high, with diuretic ketone content significantly increasing to 5.3 wt%. Additionally, when the DCMBI content excessively increased to 330 ppm, as in Comparative Example 3, the Cl content of XDI itself reached 201 ppm, and the XDI adduct exhibited a yellow tint. It was also confirmed that even after 12 months or longer of storage, the lens's YI remained as high as 5.8.

[0171] Therefore, it can be seen that by optimizing the content of the compound represented by Chemical Formula 1 (DCMBI) in the isocyanate composition according to this application, the reactivity of xylene diisocyanate (XDI) itself can be controlled, thereby maintaining the excellent stability of XDI itself. Furthermore, the storage stability of the isocyanate composition is improved, thus suppressing discoloration and turbidity, and exhibiting excellent effects in maintaining excellent resistance to discoloration and improving transparency when applied to optical products.

Claims

1. An isocyanate composition comprising xylene diisocyanate and a compound represented by the following chemical formula 1, wherein, The content of compounds represented by chemical formula 1 is greater than 60 ppm to 200 ppm or less: [Chemical Formula 1] In chemical formula 1, R1 is hydrogen, methyl, or ethyl.

2. The isocyanate composition according to claim 1, wherein, The concentration of the compound represented by chemical formula 1 is 62 ppm or higher up to 180 ppm or lower.

3. The isocyanate composition according to claim 1, wherein, Based on the total weight of the isocyanate composition, the isocyanate composition has a chlorine (Cl) content of 200 ppm or less, which is measured using combustion ion chromatography according to the American Society for Testing and Materials (ASTM) D 7359 method.

4. The isocyanate composition according to claim 1, wherein, The isocyanate composition has an APHA color index of 0.1 or greater to 25 or less, which is measured using a spectrophotometer (Ultrascan Pro, HunterLab, light source: C / 2) according to the American Society for Testing and Materials (ASTM) E313 method.

5. The isocyanate composition according to claim 1, further comprising at least one selected from the group consisting of chloromethylbenzyl isocyanate, isocyanomethylbenzaldehyde, and isocyanomethylbenzonitrile.

6. The isocyanate composition according to claim 1, wherein, The diuretic content, measured after 12 months of storage, is 5 parts by weight or less per 100 parts by weight of the isocyanate composition.

7. A polymerizable composition comprising: The isocyanate composition according to claim 1; and It is selected from at least one of the groups consisting of compounds based on polyfunctional thiols, compounds based on polyfunctional alcohols, and compounds based on polyfunctional cyclic sulfides.

8. The polymerizable composition according to claim 7, further comprising at least one selected from the group consisting of a polymerization initiator, an internal release agent, and an ultraviolet absorber.

9. An optical article comprising a polymer obtained by polymerizing the polymerizable composition of claim 7.

10. The optical article according to claim 9, wherein, The product is an optical pressure-sensitive adhesive, an optical adhesive, an optical coating, or an optical lens.

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