Additive for long-term storage of isocyanate compound, isocyanate mixture comprising same, and method for storing isocyanate compound using same

Abstract

The present invention relates to an additive for long-term storage of an isocyanate compound, an isocyanate mixture comprising same, and a method for storing an isocyanate compound using same.

Description

Additive for long-term storage of isocyanate compounds, isocyanate mixture containing the same, and method for storing isocyanate compounds using the same

[0001] The present invention relates to an additive for long-term storage of an isocyanate compound, an isocyanate mixture containing the additive, and a method for storing an isocyanate compound using the additive.

[0002]

[0003] Isocyanate compounds are raw materials for polyurethane, widely used in coatings, adhesives, paints, foams, and optical materials. Polyurethanes used in fields requiring superior appearance properties, particularly optical applications requiring transparency, require minimal discoloration. To achieve this, it is crucial that not only does the polyurethane polymer resist discoloration during the polyurethane reaction, but also that the raw isocyanate compounds themselves, particularly those with higher than difunctionality, remain discolored.

[0004] However, since isocyanate compounds are highly reactive, they are easily oxidized by oxygen in the air during the storage process, or they form self-polymers, causing deterioration or discoloration. There was also a problem of discoloration or clouding occurring in optical products such as urethane lenses that applied them.

[0005] To this end, various methods have been studied and proposed to suppress discoloration in isocyanate compounds and products manufactured using them, such as sealing with nitrogen gas to block air and storing in a refrigerator, or storing by adding additives such as ultraviolet absorbers.

[0006] However, in order to use an isocyanate compound, it must be moved from the storage location to the atmospheric environment. During this process, the isocyanate compound may discolor or become cloudy depending on changes in the moisture content or temperature of the atmosphere. If an isocyanate compound that has discolored or become cloudy is used to manufacture optical lenses, there is a problem that the clarity is reduced, resulting in a deterioration in quality.

[0007] In addition, in the method of storing isocyanate compounds by adding additives, there is difficulty in ensuring long-term storage stability of existing additives.

[0008]

[0009] The present invention has been devised to overcome the above-described problem, and provides an additive for long-term storage of an isocyanate compound having excellent storage stability even when the isocyanate compound is stored for a long period of time by using an additive including a hindered phenol type antioxidant, an isocyanate mixture including the additive, and a method for storing an isocyanate compound using the additive.

[0010] In addition, the present invention aims to provide an additive for long-term storage of an isocyanate compound, which can produce a polyurethane resin with excellent thermal stability using an isocyanate compound stored for a long time, an isocyanate mixture containing the additive, and a method for storing an isocyanate compound using the additive.

[0011] In addition, the present invention aims to provide an additive for long-term storage of an isocyanate compound, which can manufacture a transparent optical material (e.g., an optical lens) with a low possibility of causing defects by using an isocyanate compound stored for a long period of time, an isocyanate mixture containing the additive, and a method for storing an isocyanate compound using the additive.

[0012]

[0013] To solve the above-described problem, the long-term storage additive of the isocyanate compound of the present invention may include a hindered phenol type antioxidant.

[0014] As a preferred embodiment of the present invention, the long-term storage additive for the isocyanate compound of the present invention may further include at least one selected from a compound represented by the following chemical formula 2 and a compound represented by the following chemical formula 3.

[0015] [Chemical Formula 2]

[0016]

[0017] In the above chemical formula 2, R7 is -H, a straight-chain alkyl group of C1 to C12, or a branched alkyl group of C3 to C12.

[0018] [Chemical Formula 3]

[0019]

[0020] In the above chemical formula 3, R8 is -H, a straight-chain alkyl group of C1 to C12, or a branched alkyl group of C3 to C12.

[0021] As a preferred embodiment of the present invention, the long-term storage additive for the isocyanate compound of the present invention may include a compound represented by the above chemical formula 2, a hindered phenolic antioxidant, and a compound represented by the above chemical formula 3 in a weight ratio of 1:0.005 to 2.0:0.004 to 2.0.

[0022] As a preferred embodiment of the present invention, the hindered phenolic antioxidant may be a compound containing two or more hydroxyl groups.

[0023] As a preferred embodiment of the present invention, the hindered phenolic antioxidant may include a compound represented by the following chemical formula 1.

[0024] [Chemical Formula 1]

[0025]

[0026] In the above chemical formula 1, R1 and R2 are each a hydroxyl group, and R3 is -H, a straight-chain alkyl group of C1 to C12, or a branched alkyl group of C3 to C12.

[0027] As a preferred embodiment of the present invention, the hindered phenolic antioxidant may include a compound represented by the following chemical formula 1-1.

[0028] [Chemical Formula 1-1]

[0029]

[0030] In the above chemical formula 1-1, R4, R5 and R6 are each independently -H or a C1 to C3 straight-chain alkyl group.

[0031] As a preferred embodiment of the present invention, the isocyanate compound may include at least one selected from 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, methylenediphenyl diisocyanate, methylenedicyclohexyl isocyanate, toluene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, and o-xylylene diisocyanate.

[0032] Meanwhile, the isocyanate mixture of the present invention includes an isocyanate compound and an additive for long-term storage of the isocyanate compound, and the additive for long-term storage of the isocyanate compound may include a hindered phenol type antioxidant.

[0033] As a preferred embodiment of the present invention, the isocyanate mixture of the present invention may include an isocyanate compound and an additive for long-term storage of the isocyanate compound in a weight ratio of 1:0.001 to 0.3.

[0034] As a preferred embodiment of the present invention, the long-term storage additive for an isocyanate compound may include a compound represented by the following chemical formula 2, a hindered phenolic antioxidant, and a compound represented by the following chemical formula 3.

[0035] [Chemical Formula 2]

[0036]

[0037] In the above chemical formula 2, R7 is -H, a straight-chain alkyl group of C1 to C12, or a branched alkyl group of C3 to C12.

[0038] [Chemical Formula 3]

[0039]

[0040] In the above chemical formula 3, R8 is -H, a straight-chain alkyl group of C1 to C12, or a branched alkyl group of C3 to C12.

[0041] As a preferred embodiment of the present invention, the long-term storage additive for an isocyanate compound may include a compound represented by the above chemical formula 2, a hindered phenolic antioxidant, and a compound represented by the above chemical formula 3 in a weight ratio of 1:0.005 to 2.0:0.004 to 2.0.

[0042] Furthermore, the method for storing an isocyanate compound of the present invention includes a first step of preparing an isocyanate mixture by mixing an isocyanate compound and an additive for long-term storage of the isocyanate compound, and a second step of storing the isocyanate mixture under conditions of a temperature of 20°C or lower and a humidity of 1% RH or lower under a nitrogen-substituted atmosphere, wherein the additive for long-term storage of the isocyanate compound may include a hindered phenol type antioxidant.

[0043] As a preferred embodiment of the present invention, the second step may be to store the isocyanate mixture under nitrogen-substituted atmosphere, at a temperature of 0 to 20°C and a humidity of 0.0001 to 1%RH.

[0044] Meanwhile, the optical lens of the present invention may include the isocyanate mixture of the present invention.

[0045] As a preferred embodiment of the present invention, the optical lens of the present invention may have a haze of 0.3% or less.

[0046] Furthermore, the non-foam resin of the present invention may include the isocyanate mixture of the present invention.

[0047] As a preferred embodiment of the present invention, the non-foam resin of the present invention may be used for a coating, an adhesive, a sealant, or an elastomer.

[0048]

[0049] The additive for long-term storage of an isocyanate compound of the present invention, the isocyanate mixture containing the additive, and the method for storing an isocyanate compound using the additive have excellent storage stability even when the isocyanate compound is stored for a long period of time by using a hindered phenol type antioxidant.

[0050] In addition, the additive for long-term storage of an isocyanate compound of the present invention, the isocyanate mixture containing the additive, and the method for storing an isocyanate compound using the additive can produce a polyurethane resin having excellent thermal stability using an isocyanate compound stored for a long period of time.

[0051] In addition, an additive for long-term storage of an isocyanate compound, an isocyanate mixture containing the additive, and a method for storing an isocyanate compound using the additive can produce a transparent optical material with a low possibility of causing defective elements.

[0052]

[0053] Hereinafter, the present invention will be described in more detail.

[0054] Various methods have been studied and proposed to suppress discoloration in existing isocyanate compounds and products manufactured using them, such as sealing them with nitrogen gas to block air and storing them in a refrigerator, or storing them using additives such as ultraviolet absorbers. However, in order to use isocyanate compounds, they must be moved from their storage location to the open air. During this process, the isocyanate compounds may discolor or become cloudy depending on changes in the moisture content or temperature of the air. If discolored or cloudy isocyanate compounds are used to manufacture optical lenses, there is a problem that clarity is reduced, resulting in a decline in quality. In addition, when storing isocyanate compounds by adding additives, it is difficult to ensure long-term storage stability with existing additives.

[0055] Accordingly, the present invention introduces an additive for long-term storage of an isocyanate compound including a hindered phenol type antioxidant, thereby providing excellent storage stability even when the isocyanate compound is stored for a long period of time.

[0056]

[0057] The long-term storage additive for the isocyanate compound of the present invention may include a hindered phenol type antioxidant.

[0058] Specifically, the hindered phenolic antioxidant may be a compound containing two or more hydroxyl groups, and preferably a compound containing two hydroxyl groups.

[0059] More specifically, the hindered phenolic antioxidant may include a compound represented by the following chemical formula 1, and preferably may include a compound represented by the following chemical formula 1-1.

[0060] [Chemical Formula 1]

[0061]

[0062] In the above chemical formula 1, R1 and R2 are each a hydroxyl group, and R3 is -H, a straight-chain alkyl group of C1 to C12, or a branched alkyl group of C3 to C12.

[0063] [Chemical Formula 1-1]

[0064]

[0065] In the above chemical formula 1-1, R4, R5 and R6 are each independently -H or a C1 to C3 straight-chain alkyl group.

[0066]

[0067] Meanwhile, the long-term storage additive for the isocyanate compound of the present invention may further include at least one selected from a compound represented by the following chemical formula 2 and a compound represented by the following chemical formula 3, and preferably may further include a compound represented by the following chemical formula 2 and a compound represented by the following chemical formula 3.

[0068] [Chemical Formula 2]

[0069]

[0070] In the above chemical formula 2, R7 is -H, a straight-chain alkyl group of C1 to C12 or a branched alkyl group of C3 to C12, preferably a straight-chain alkyl group of C1 to C12, and more preferably a straight-chain alkyl group of C1 to C3.

[0071] [Chemical Formula 3]

[0072]

[0073] In the above chemical formula 3, R8 is -H, a straight-chain alkyl group of C1 to C12 or a branched alkyl group of C3 to C12, preferably a straight-chain alkyl group of C1 to C12, and more preferably a straight-chain alkyl group of C1 to C3.

[0074] In addition, the long-term storage additive of the isocyanate compound of the present invention may include the compound represented by the above chemical formula 2, the hindered phenolic antioxidant, and the compound represented by the above chemical formula 3 in a weight ratio of 1:0.005 to 2.0:0.004 to 2.0, preferably 1:0.01 to 2.0:0.005 to 2.0, more preferably 1:0.05 to 0.5:0.01 to 0.3, still more preferably 1:0.07 to 0.3:0.02 to 0.15, and most preferably 1:0.08 to 0.2:0.04 to 0.1. If the weight ratio of the compound represented by the above chemical formula 2 and the hindered phenolic antioxidant is less than 1:0.005, not only is the storage stability reduced, but there may be a problem that the optical lens manufactured using it becomes opaque due to an increase in haze, and if it exceeds 1:2.0, there may be a problem that the isocyanate compound and / or the optical lens manufactured using it becomes yellow.

[0075]

[0076] Furthermore, the isocyanate compound of the present invention may include at least one selected from among 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, methylenediphenyl diisocyanate, methylenedicyclohexyl isocyanate, toluene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, and o-xylylene diisocyanate, and preferably may include m-xylylene diisocyanate.

[0077]

[0078] Meanwhile, the isocyanate mixture of the present invention may include an isocyanate compound and an additive for long-term storage of the isocyanate compound. In this case, the isocyanate compound and the additive for long-term storage of the isocyanate compound are as described above.

[0079] In addition, the isocyanate mixture of the present invention may contain an isocyanate compound and an isocyanate compound long-term storage additive in a weight ratio of 1:0.001 to 0.3, preferably 1:0.01 to 0.2, more preferably 1:0.03 to 0.1. If the weight ratio is less than 1:0.001, storage stability may be reduced, causing a clouding phenomenon, and an optical lens manufactured using the same may be opaque due to an increase in haze. If it exceeds 1:0.3, the isocyanate compound and / or an optical lens manufactured using the same may cause a problem of yellowing.

[0080]

[0081] Furthermore, the method for storing an isocyanate compound of the present invention may include a first step of preparing an isocyanate mixture by mixing an isocyanate compound and an additive for long-term storage of the isocyanate compound, and a second step of storing the isocyanate mixture under conditions of a temperature of 20°C or lower, preferably 0 to 20°C, more preferably 5 to 15°C, and a humidity of 1%RH or lower, preferably 0.0001 to 1%RH, more preferably 0.001 to 0.1%RH, in a nitrogen-substituted atmosphere. At this time, the isocyanate compound and the additive for long-term storage of the isocyanate compound are as described above, respectively.

[0082] In addition, if the storage temperature exceeds 20℃ in the second step, not only will the storage stability deteriorate, but there may be a problem that the optical lens manufactured using it becomes opaque due to an increase in haze and / or that the optical lens manufactured using it may not be manufactured. In addition, if the storage humidity exceeds 1% RH in the second step, not only will the storage stability deteriorate, but there may be a problem that the optical lens manufactured using it becomes opaque due to an increase in haze.

[0083]

[0084] Meanwhile, the optical lens of the present invention may include the isocyanate mixture of the present invention, and may have a haze of 0.3% or less, preferably 0.1 to 0.28%, and more preferably 0.2 to 0.26%.

[0085]

[0086] Furthermore, the non-foam resin of the present invention may include the isocyanate mixture of the present invention.

[0087] The non-foam resin of the present invention is a resin that does not have a foam shape, and can be used as a coating agent, an adhesive, a sealant, or an elastomer, but is not limited thereto.

[0088] As a specific example, the non-foaming resin of the present invention may be a reaction product of the isocyanate mixture of the present invention and an active hydrogen group-containing component. The active hydrogen group-containing component may include a polyol component (a component mainly containing a polyol having two or more hydroxyl groups), a polythiol component (a component mainly containing a polythiol having two or more mercapto groups (thiol groups)), a polyamine component (a compound mainly containing a polyamine having two or more amino groups), etc., and a preferable example of the active hydrogen group-containing component may be a raw material required for producing a polyurethane resin.

[0089] Meanwhile, the non-foam resin of the present invention used for coating, adhesive, sealant or elastomer may be a raw material used in the manufacture of automobiles, ships, flexible packaging, food packaging, construction, paints, inks, solar cells, microcapsules, adhesives for displays, optical materials and fuel cells, but is not limited thereto.

[0090]

[0091] Furthermore, a method for producing the isocyanate compound of the present invention described above will be described as an example as follows.

[0092] Isocyanate compounds are synthesized by reacting amine compounds with phosgene in a solvent.

[0093] Solvents that can be used in the above 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 can be used in combination.

[0094] The amine compound used in the above 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 at least one selected from the group consisting of 1,4-tetramethylene diamine, 1,5-pentamethylene diamine, 1,6-hexamethylene diamine, 1,3-cyclohexylene diamine, 1,4-cyclohexylene diamine, isophorone diamine, diamine, methylenediphenyl diamine, methylenedicyclohexyl diamine, toluene diamine, m-xylylene diamine, p-xylylene diamine, and o-xylylene diamine, and salts thereof, and preferably m-xylylene diamine, p-xylylene diamine, o-xylylene diamine, or a salt thereof.

[0095] The above amine compound may be included in an amount of 1 to 20 parts by weight per 100 parts by weight of the solvent. If the content of the amine compound exceeds 20 parts by weight, there is a risk of precipitation of a large amount of the amine compound. Preferably, the content may be included in an amount of 1 to 15 parts by weight or 3 to 10 parts by weight.

[0096] 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).

[0097] The direct phosgenation method of the above method 1 can be performed by reacting an amine compound and phosgene in the above organic solvent. At this time, the phosgene can be introduced all at once at the beginning of the reaction, or can be introduced in part at the beginning of the reaction and the remainder can be introduced in installments during the reaction.

[0098] Meanwhile, the above method 1 can be performed by 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 after the addition of the amine compound is complete and causing a reaction. At this time, the first step is preferably performed at a temperature of -15°C to -10°C to prevent leakage of highly toxic phosgene and also to prevent rapid heat generation when the amine compound is added, and the phosgenation reaction in the second step can be controlled to 120°C to 140°C so that the reaction can occur at an appropriate reaction rate without concern for decomposition of the amine compound.

[0099] In the case of the above method 2, it can be carried out by a step of reacting an amine compound with hydrochloric acid in an organic solvent to form an amine-hydrochloride compound, and then introducing phosgene to cause the reaction. The formation of the amine-hydrochloride compound can be carried out at a temperature of 30°C or lower, preferably at a temperature of about 23±5°C, and the reaction after the introduction of phosgene can be controlled to 120°C to 140°C. When carried out under such temperature conditions, the solubility of the amine-hydrochloride compound can be increased, and thermal decomposition of the isocyanate can be prevented, thereby producing a high-purity isocyanate compound in high yield.

[0100] In the case of the above method 3, it can be carried out by a step of reacting an amine compound with carbonic acid in a solvent to form an amine-carbonate compound, and then introducing phosgene to cause the reaction. At this time, the formation of the amine-carbonate compound can be carried out at a temperature of 30°C or lower, preferably about 23±5°C, and the reaction after the introduction of phosgene can be controlled to 80°C to 180°C. Preferably, it can be in the range of 100°C or higher, or 120°C or higher, and 150°C or lower, or 140°C or lower. When carried out under such 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.

[0101] After the reaction with phosgene is completed according to each method, a removal process such as nitrogen bubbling for unreacted phosgene and hydrogen chloride gas and a solvent removal process such as distillation may be optionally further performed, and these processes may be performed according to a conventional method.

[0102]

[0103] Hereinafter, the present invention will be described in more detail through examples, but the following examples do not limit the scope of the present invention, and should be interpreted as helping to understand the present invention.

[0104]

[0105] Example 1: Preparation of an additive for long-term storage of isocyanate compounds

[0106] An isocyanate compound long-term storage additive was prepared by mixing a compound represented by the following chemical formula 2-1, an antioxidant, and a compound represented by the following chemical formula 3-1 in a weight ratio of 1:0.1:0.06. At this time, a hindered phenol type antioxidant was used as the antioxidant, and a compound represented by the following chemical formula 1-2 was used as the hindered phenol type antioxidant.

[0107] [Chemical Formula 1-2]

[0108]

[0109] In the above chemical formula 1-2, R4, R5 and R6 are each a methyl group.

[0110] [Chemical Formula 2-1]

[0111]

[0112] In the above chemical formula 2-1, R7 is a methyl group.

[0113] [Chemical Formula 3-1]

[0114]

[0115] In the above chemical formula 3-1, R8 is a methyl group.

[0116]

[0117] Example 2: Preparation of an additive for long-term storage of isocyanate compounds

[0118] An isocyanate compound storage solution was prepared in the same manner as in Example 1. However, unlike Example 1, a compound represented by the following chemical formula 4 was used as an antioxidant.

[0119] [Chemical Formula 4]

[0120]

[0121]

[0122] Example 3: Preparation of an additive for long-term storage of isocyanate compounds

[0123] An isocyanate compound storage solution was prepared in the same manner as in Example 1. However, unlike Example 1, a compound represented by the following chemical formula 5 was used as an antioxidant.

[0124] [Chemical Formula 5]

[0125]

[0126]

[0127] Example 4: Preparation of an additive for long-term storage of isocyanate compounds

[0128] An isocyanate compound storage solution was prepared in the same manner as in Example 1. However, unlike Example 1, a compound represented by the following chemical formula 6 was used as an antioxidant.

[0129] [Chemical Formula 6]

[0130]

[0131]

[0132] Example 5: Preparation of an additive for long-term storage of isocyanate compounds

[0133] An isocyanate compound storage solution was prepared in the same manner as in Example 1. However, unlike Example 1, a compound represented by the following chemical formula 7 was used as an antioxidant.

[0134] [Chemical Formula 7]

[0135]

[0136] In the above chemical formula 7, n is an integer satisfying 3.

[0137]

[0138] Example 6: Preparation of an additive for long-term storage of isocyanate compounds

[0139] An isocyanate compound storage solution was prepared in the same manner as in Example 1. However, unlike Example 1, a compound represented by the following chemical formula 8 was used as an antioxidant.

[0140] [Chemical Formula 8]

[0141]

[0142] In the above chemical formula 8, m is an integer satisfying 4.

[0143]

[0144] Example 7: Preparation of an additive for long-term storage of isocyanate compounds

[0145] An isocyanate compound storage solution was prepared in the same manner as in Example 1. However, unlike Example 1, a compound represented by the following chemical formula 9 was used as an antioxidant.

[0146] [Chemical Formula 9]

[0147]

[0148]

[0149] Experimental Example 1: Appearance Evaluation of Isocyanate Compounds with Additives for Long-Term Storage of Isocyanate Compounds

[0150] 1 kg of m-xylylene diisocyanate (m-XDI) solution was prepared as an isocyanate compound, and 60 g of each of the long-term storage additives of the isocyanate compounds prepared in Examples 1 to 7 were added and mixed to the prepared m-XDI solution to prepare an m-XDI mixture.

[0151] The manufactured m-XDI mixture and the m-XDI solution without additives (=Reference) were stored for one year under nitrogen-substituted atmosphere, temperature of 15℃, and humidity of 0.1%RH, and then the stored m-XDI mixture was visually observed to evaluate its appearance. The appearance was evaluated as × when it was transparent, △ when it was cloudy when it was observed with light, and ○ when it was cloudy when it was observed with the naked eye only, and these evaluations are shown in Table 1 below.

[0152]

[0153] As can be seen in Table 1 above, it was confirmed that the m-XDI mixture using the long-term storage additive of the isocyanate compound manufactured in Examples 1, 2, 6 and 7 had excellent storage stability.

[0154]

[0155] Manufacturing Example 1: Manufacturing of an optical lens

[0156] In Experimental Example 1, 20.8 g of each m-XDI mixture and the m-XDI solution without additives (=Reference) were prepared, 0.04 g of ZELEC UN (manufactured by Stepan) as an internal release agent, and 0.04 g of Biosorb 583 (manufactured by Sakai Chemical industry Co., Ltd) as an ultraviolet absorber were stirred and mixed at room temperature (=23°C) for 20 minutes to prepare a mixture, 0.002 g of DBTC (dibutyltin dichloride) was added to the prepared mixture, stirred for 10 minutes, and 19.2 g of 2,3-bis(2-sulfanyl ethyl sulfanyl)propane-1-thiol was added, and then stirred for 1 hour while degassing under a pressure condition of 5 mbar to prepare a composition for polyisocyanate polymerization.

[0157] The manufactured polyisocyanate polymerization composition was filtered using a 1 μm PTFE filter and then injected into a mold formed from a glass mold and tape, respectively. Thereafter, the mold was placed in an oven and polymerization was performed for 20 hours while gradually increasing the temperature from 10°C to 120°C. After completion of the polymerization, the mold was taken out from the oven and released to obtain each plastic optical lens. The obtained optical lenses were annealed at 120°C for 6 hours to produce optical lenses having a thickness of 9 mm, respectively.

[0158]

[0159] Experimental Example 3: Color difference measurement, haze measurement, and evaluation

[0160] According to the method of ASTM E313, the color difference values ​​(L* value, a* value, b* value), yellowness (YI; Yellowness) and haze of each optical lens manufactured in Manufacturing Example 1 were measured (light source: D65) using HunterLab's Ultrascan Pro, and the results are shown in Table 2 below. In addition, the measured optical lens was visually observed, and if an opaque element was confirmed in the whole or a part, it was evaluated as a haze defect. If the degree of haze defect was evenly spread throughout the whole, it was evaluated as ○, if there was one or more hazy circular defective elements, it was evaluated as △, and if there was no haze defective element and it was transparent, it was evaluated as ×, and the results are shown in Table 2 below.

[0161]

[0162] To manufacture transparent optical lenses, both excellent transparency and a low level of impurities are essential. A lower chromatic difference value indicates better discoloration resistance, while a greater haze change indicates a higher degree of cloudiness.

[0163] As can be seen in Table 2, the optical lens manufactured using the isocyanate compound long-term storage additive of Example 1 not only had excellent transparency, but also had low haze and no haze defects. In comparison, the optical lenses manufactured using the isocyanate compound long-term storage additives of Examples 2 and 4 to 7 had reduced transparency, and the optical lenses manufactured using the isocyanate compound long-term storage additive of Example 3 and the optical lenses manufactured without using the isocyanate compound long-term storage additive (=Reference) had high haze and were somewhat opaque.

[0164]

[0165] The above illustrates and describes specific embodiments. However, the invention is not limited to the aforementioned embodiments, and those skilled in the art will readily appreciate that various modifications and implementations can be made without departing from the spirit and scope of the invention as set forth in the claims below.

Claims

1. An additive for long-term storage of an isocyanate compound, comprising a hindered phenol type antioxidant.

2. In paragraph 1, An additive for long-term storage of an isocyanate compound, wherein the additive further comprises at least one selected from a compound represented by the following chemical formula 2 and a compound represented by the following chemical formula 3. [Chemical Formula 2] [Chemical Formula 3] In the above chemical formula 2, R7 is -H, a straight-chain alkyl group of C1 to C12 or a branched alkyl group of C3 to C12, In the above chemical formula 3, R8 is -H, a straight-chain alkyl group of C1 to C12, or a branched alkyl group of C3 to C12.

3. In paragraph 2, The above additive is an additive for long-term storage of an isocyanate compound, comprising a compound represented by the above chemical formula 2, a hindered phenolic antioxidant, and a compound represented by the above chemical formula 3 in a weight ratio of 1:0.005 to 2.0:0.004 to 2.

0.

4. In paragraph 1, The above hindered phenol antioxidant is an additive for long-term storage of an isocyanate compound, which is a compound containing two or more hydroxyl groups.

5. In paragraph 4, The above hindered phenolic antioxidant is an additive for long-term storage of an isocyanate compound, comprising a compound represented by the following chemical formula 1. [Chemical Formula 1] In the above chemical formula 1, R1 and R2 are each a hydroxyl group, and R3 is -H, a straight-chain alkyl group of C1 to C12, or a branched alkyl group of C3 to C12.

6. In paragraph 5, The above hindered phenolic antioxidant is an additive for long-term storage of an isocyanate compound, comprising a compound represented by the following chemical formula 1-1. [Chemical Formula 1-1] In the above chemical formula 1-1, R4, R5 and R6 are each independently -H or a C1 to C3 straight-chain alkyl group.

7. In paragraph 1, An additive for long-term storage of an isocyanate compound, wherein the isocyanate compound comprises at least one selected from among 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, methylenediphenyl diisocyanate, methylenedicyclohexyl isocyanate, toluene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, and o-xylylene diisocyanate.

8. Including an isocyanate compound; and an additive for long-term storage of the isocyanate compound; The above isocyanate compound long-term storage additive is an isocyanate mixture containing a hindered phenol type antioxidant.

9. In paragraph 8, The above isocyanate mixture is an isocyanate mixture comprising an isocyanate compound and an isocyanate compound long-term storage additive in a weight ratio of 1:0.001 to 0.

3.

10. In paragraph 9, The above additive is an isocyanate mixture comprising a compound represented by the following chemical formula 2, a hindered phenolic antioxidant, and a compound represented by the following chemical formula 3. [Chemical Formula 2] [Chemical Formula 3] In the above chemical formula 2, R7 is -H, a straight-chain alkyl group of C1 to C12 or a branched alkyl group of C3 to C12, In the above chemical formula 3, R8 is -H, a straight-chain alkyl group of C1 to C12, or a branched alkyl group of C3 to C12.

11. In paragraph 10, The above additive is an isocyanate mixture comprising a compound represented by the above chemical formula 2, a hindered phenolic antioxidant, and a compound represented by the above chemical formula 3 in a weight ratio of 1:0.005 to 2.0:0.004 to 2.

0.

12. A first step of preparing an isocyanate mixture by mixing an isocyanate compound and an additive for long-term storage of the isocyanate compound; and A second step of storing the above isocyanate mixture under a nitrogen-substituted atmosphere, at a temperature of 20°C or lower and a humidity of 1%RH or lower; A method for storing an isocyanate compound, wherein the above isocyanate compound long-term storage additive includes a hindered phenol type antioxidant.

13. In paragraph 12, The second step is a method for storing an isocyanate compound, wherein the isocyanate mixture is stored under a nitrogen-substituted atmosphere at a temperature of 0 to 20°C and a humidity of 0.0001 to 1%RH.

14. An optical lens comprising the isocyanate mixture of clause 8.

15. In paragraph 14, The above optical lens is an optical lens having a haze of 0.3% or less.

16. A non-foam resin comprising the isocyanate mixture of clause 8.

17. In paragraph 16, The above non-foam resin is a non-foam resin for coating, adhesive, sealant or elastomer.

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