Method for storing xylylene diisocyanate and storage container comprising same

Abstract

The present invention relates to a method for storing xylylene diisocyanate and, more specifically, to a method for storing xylylene diisocyanate, whereby the storage stability and optical stability of the xylylene diisocyanate are improved.

Description

Method for storing xylylene diisocyanate and storage container containing the same

[0001] The present invention relates to a method for storing xylylene diisocyanate, and more specifically, to a method for storing xylylene diisocyanate with improved storage stability and optical stability.

[0002]

[0003] Xylylene diisocyanate (XDI) is widely used as a raw material for the manufacture of polyurethane resins. For example, xylylene diisocyanate compounds are used to manufacture optical lenses that utilize polyurethane resins, and the physical properties of the xylylene diisocyanate compounds used as raw materials can affect the optical properties of the optical lenses, such as transparency and refractive index.

[0004] For example, a polythiourethane-based resin produced by reacting a polythiol compound and a diisocyanate compound can be used as a base material for the optical lens.

[0005] These xylylene diisocyanates are widely utilized in various fields, taking into account their chemical and optical properties, such as reactivity and transparency.

[0006] However, xylylene diisocyanate possesses high reactivity as the benzene, an electron-withdrawing group within the molecule, increases the reactivity of NCOs; consequently, self-polymerization and side reactions tend to occur easily during storage. Since the occurrence of such self-polymerization and side reactions causes yellowing that increases the YI of resins produced using xylylene diisocyanate, there is a problem in that compositions containing xylylene diisocyanate are difficult to store for long periods.

[0007] In particular, if highly reactive moisture is contained in the diisocyanate, unexpected side reactions between the moisture and the xylylene diisocyanate may occur, resulting in the formation of urea or causing yellowing in resins and lenses manufactured using the xylylene diisocyanate. Regarding this, Korean Patent Publication 10-2021-0071401 presents a solution to this problem by controlling moisture that may occur during the manufacturing process of the diisocyanate composition; however, since it typically takes at least several months from the time the diisocyanate composition is manufactured until it is produced into resins and lenses, the problem of side reactions caused by moisture occurring during the storage period still remains.

[0008] In particular, xylylene diisocyanate is typically stored at a temperature of 5°C after production, whereas other compounds used in the polymerization of xylylene diisocyanate are typically stored at a temperature of 15°C. Accordingly, xylylene diisocyanate is stored at 15°C for a certain period of time to equalize its temperature with that of other compounds prior to polymerization. Due to this temperature difference, when the material is stored using a storage method designed for 5°C and then subsequently adjusted to 15°C for storage and synthesis, problems arise where storage stability is significantly reduced due to the different temperatures, or where the optical stability of the produced resin or lens is reduced.

[0009] Accordingly, there is a need to develop a storage method for xylylene diisocyanate that minimizes urea formation or yellowing even when stored for a long period.

[0010]

[0011] [Prior Art Literature]

[0012] [Patent Literature]

[0013] (Patent Document 1) Korean Published Patent 10-2021-0071401

[0014]

[0015] The present invention is proposed to solve the above-mentioned problems and aims to provide a storage method for xylylene diisocyanate with excellent storage stability, such as minimizing unexpected side reactions of xylylene diisocyanate even when stored for a long period.

[0016] In addition, the purpose is to provide a storage method for non-foam resins containing xylylene diisocyanate stored by the storage method of the present invention that has excellent optical properties, such as minimizing yellowing and minimizing the increase in haze value.

[0017]

[0018] In order to solve the above-mentioned problem, the present invention,

[0019] A method for storing xylylene diisocyanate is provided, comprising: (1) step of introducing xylylene diisocyanate into a storage container; and (2) step of filling the remaining space of the storage container with nitrogen gas having a relative humidity of 1 RH or less at 15˚C.

[0020] In addition, the xylylene diisocyanate of step (1) above may contain less than 100 ppm of moisture.

[0021] In addition, the relative humidity of the above nitrogen gas at 15°C may be 0.05RH or less.

[0022] In addition, inside the storage container, the nitrogen gas may be contained in an amount of 1 to 10 volume percent relative to the total volume inside the storage container.

[0023] Additionally, between the above steps (1) and (2), a step of removing moisture from the nitrogen gas may be further included.

[0024] In addition, after step (2) above, the method may further include a step of sealing the storage container.

[0025] In addition, the urea content calculated by the following formula 1 of the above xylylene diisocyanate may be 0.1 or more and less than 0.8.

[0026] <Formula 1>

[0027] Urea content = (1611~1626 cm -1 Absorption peak area) / (2255~2268 cm²) -1 Absorption peak area)

[0028] (At this time, the absorption peak area is measured using an FT-IR spectrometer.)

[0029] In addition, after sealing the storage container, the urea content calculated by the above formula 1 after 60 days may be within the range of 100 to 150% compared to the urea content immediately before sealing.

[0030] In addition, to solve the aforementioned problem, the present invention,

[0031] (1) a step of introducing xylylene diisocyanate into a storage container; and (2) a step of filling the remaining space of the storage container with nitrogen gas, wherein the urea content of the xylylene diisocyanate calculated by the following formula 1 is 0.1 or more and less than 0.8, thereby providing a method for storing xylylene diisocyanate.

[0032] <Formula 1>

[0033] Urea content = (1611~1626 cm -1 Absorption peak area) / (2255~2268 cm²) -1 Absorption peak area)

[0034] (At this time, the absorption peak area is measured using an FT-IR spectrometer.)

[0035] In addition, to solve the aforementioned problem, the present invention,

[0036] A storage container for xylylene diisocyanate is provided, which is a sealed storage container in which xylylene diisocyanate is stored, the remaining space is filled with nitrogen gas, and the relative humidity of the nitrogen gas is 1RH or less at 15˚C.

[0037] In addition, the relative humidity of the above nitrogen gas at 15°C may be 0.05RH or less.

[0038] In addition, inside the storage container, the nitrogen gas may be contained in an amount of 1 to 10 volume percent relative to the total volume inside the storage container.

[0039] In addition, the urea content of the above xylylene diisocyanate calculated by the above formula 1 may be 0.1 or more and less than 0.8.

[0040] In addition, a resin layer may be provided on the inner surface of the storage container.

[0041] In addition, the resin layer may be one or more selected from the group consisting of polyolefin resin, acrylonitrile styrene resin, acrylonitrile butadiene styrene resin, polyvinyl chloride resin, fluorine resin, polyester resin, phenolic resin, polyacrylic resin, epoxy resin, polyimide resin, polyamide resin, poly(thio)urethane resin, cellulose resin, silicone resin, and polycarbonate resin.

[0042] In addition, to solve the above-mentioned problem, the present invention provides a non-foam resin comprising xylylene diisocyanate stored in the storage container described above.

[0043] In addition, the above-mentioned non-foam resin may further contain an active hydrogen group-containing component.

[0044] In addition, the active hydrogen group-containing component may be one or more selected from the group consisting of polyol components, polythiol components, and polyamine components.

[0045] In addition, the above non-foam resin may be used for any one or more selected from the group consisting of coatings, adhesives, sealants, and elastomers.

[0046] In addition, to solve the above-described problem, the present invention provides a molded article comprising the above-described non-foam resin.

[0047] In addition, to solve the above-described problem, the present invention provides an optical element comprising the above-described molded body.

[0048] In addition, to solve the above-described problem, the present invention provides a lens comprising the above-described optical element.

[0049]

[0050] The storage method for xylylene diisocyanate according to the present invention has effects such as minimizing the deterioration of physical properties due to unexpected side reactions during the storage process of xylylene diisocyanate, and is superior in terms of storage stability compared to conventional storage methods for xylylene diisocyanate.

[0051] At the same time, the yellowing phenomenon of the non-foam resin produced by polymerizing xylylene diisocyanate stored by this storage method is suppressed, such as the yellowness hardly increasing even with a long storage period, and the haze value also hardly increases, resulting in superior optical stability compared to conventional xylylene diisocyanate storage methods.

[0052]

[0053] The embodiments of the present invention are described below in detail so that those skilled in the art can easily implement the invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0054]

[0055] As mentioned above, since xylylene diisocyanate is typically stored for periods ranging from a few months to several years after synthesis, the storage method from synthesis until use is critical in determining the physical properties of the resins and lenses produced from it. Furthermore, if moisture is present in the xylylene diisocyanate, unexpected side reactions between the highly reactive moisture and the xylylene diisocyanate generate byproducts, leading to a problem where the physical properties of the xylylene diisocyanate itself, as well as those of the resins and lenses produced therefrom, are compromised.

[0056] In the past, attempts were made to improve the physical properties of xylylene diisocyanate by controlling moisture during the synthesis stage, but the problem remained that even if moisture was controlled during the synthesis stage, the physical properties were still damaged due to moisture during the subsequent storage stage.

[0057] In particular, xylylene diisocyanate is typically stored at a temperature of 5°C after production, whereas other compounds used in the polymerization of xylylene diisocyanate are typically stored at a temperature of 15°C. Accordingly, xylylene diisocyanate is stored at 15°C for a certain period of time to equalize its temperature with that of other compounds prior to polymerization. Due to this temperature difference, when the material is stored using a storage method designed for 5°C and then subsequently adjusted to 15°C for storage and synthesis, problems arise where storage stability is significantly reduced due to the different temperatures, or where the optical stability of the produced resin or lens is reduced.

[0058] Accordingly, the present invention seeks to solve the above-mentioned problem by providing a method for storing xylylene diisocyanate comprising the steps of: (1) introducing xylylene diisocyanate into a storage container; and (2) filling the remaining space of the storage container with nitrogen gas having a relative humidity of 1 RH or less at 15°C.

[0059] At this time, the relative humidity at a specific temperature can be calculated using the following formula 2.

[0060] <Calculation Formula 2>

[0061] Relative humidity (RH) at A°C = (Partial vapor pressure / Saturated vapor pressure at A°C) × 100 (RH)

[0062]

[0063] Through this, a storage method with excellent storage stability can be provided, such as in which the physical properties of the stored xylylene diisocyanate are not damaged compared to conventional storage methods.

[0064] In addition, resins and lenses synthesized with xylylene diisocyanate stored using the said storage method are excellent in terms of optical stability, such as minimizing yellowing—with almost no increase in yellowness—and minimizing the increase in haze values ​​even as the storage period of the xylylene diisocyanate is prolonged.

[0065] Furthermore, it is superior to conventional storage methods in that storage stability is maintained even at 15°C, and storage stability and optical stability are not reduced during the actual use of xylylene diisocyanate.

[0066]

[0067] First, as a step (1), xylylene diisocyanate is added to a storage container.

[0068]

[0069] More specifically, the shape of the storage container is not limited as long as it is capable of storing xylylene diisocyanate, but preferably it may be a container of various shapes such as a gallon can, a drum, a pail can, or a canister can, and more preferably it may be one of a gallon can or a drum.

[0070] At this time, the storage container may include an inlet for introducing the xylylene diisocyanate and the nitrogen gas described below. It may be provided with an inlet for introducing xylylene diisocyanate and an inlet for introducing nitrogen gas, respectively, or it may be provided with a single inlet for introducing both xylylene diisocyanate and nitrogen gas. At this time, the shape of the inlet is not limited as long as it is in the shape of a liquid or gas inlet.

[0071] In addition, the above-mentioned inlet may preferably be provided with means to seal so that when the inlet is sealed, no inflow or outflow of any gas or liquid occurs between the inside and outside of the inlet.

[0072] In addition, the size of the storage container is not limited to the size of a storage container for xylylene diisocyanate, but is preferably 0.5L or more, more preferably 1L or more, and even more preferably 16L or more, and is also preferably 20000L or less, more preferably 250L or less.

[0073] In addition, the material of the storage container is not limited to any material that is typically used for xylylene diisocyanate storage containers, but preferably may be one or more selected from the group consisting of aluminum-based containers, stainless steel containers, carbon steel containers, tin steel containers, tin-free chromium-plated containers, tin-free steel containers, carbon steel sheets, cold-rolled steel sheets, and hot-rolled steel sheets.

[0074] At this time, the xylylene diisocyanate can be manufactured by a commonly known manufacturing method.

[0075] Specifically, xylylene diisocyanate can be produced by the following phosgenation method.

[0076] First, the method includes the step of reacting an amine compound with phosgene in a solvent to obtain a reaction mixture containing a xylylene diisocyanate compound.

[0077] The solvents used in the above phosgenation reaction may 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, and two or more of these may be mixed and used.

[0078] The amine compound used in the above phosgenation reaction may be one or more selected from the group consisting of m-xylylene diamine, p-xylylene diamine and o-xylylene diamine and salts thereof, and preferably may be m-xylylene diamine or its salt.

[0079] The above amine compound may be included in an amount of 1 to 20 parts by weight per 100 parts by weight of solvent. If the content of the amine compound exceeds 20 parts by weight, there is a risk that a large amount of amine compound will precipitate. Preferably, it may be included in an amount of 1 to 15 parts by weight, more preferably 3 to 10 parts by weight.

[0080] Specifically, the phosgenation reaction may be carried out by a direct phosgenation method in which an amine compound is directly reacted with phosgene (Method 1); 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).

[0081] The direct phosgenation method of Method 1 above can be carried out by reacting an amine compound with phosgene in the organic solvent. At this time, the phosgene may be added in a lump sum at the beginning of the reaction, or a portion may be added at the beginning of the reaction, and the remainder may be added in portions during the reaction.

[0082] Meanwhile, the above method 1 may be carried out 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 completed and reacting. At this time, the first step is preferably carried out at a temperature of -15°C to -10°C to prevent leakage of highly toxic phosgene and to prevent rapid exothermic reaction when the amine compound is added, and the phosgeneization reaction in the second step may be controlled to 120°C to 140°C so that the reaction can occur at an appropriate reaction rate without concern for the decomposition of the amine compound.

[0083] In the case of Method 2 above, the process can be carried out by reacting an amine compound with hydrochloric acid in an organic solvent to form an amine-hydrochloride compound, and then adding phosgene to react. The formation of the amine-hydrochloride compound can be carried out at a temperature of 30°C or lower, preferably about 23±5°C, and the reaction after the addition 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 is increased and thermal decomposition of xylylene diisocyanate is prevented, thereby enabling the production of a high-purity xylylene diisocyanate compound in high yield.

[0084] In the case of Method 3 above, the process can be carried out by reacting an amine compound with carbonic acid in a solvent to form an amine-carbonate compound, and then adding phosgene to react. 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 addition of phosgene can be controlled to a temperature of 80°C to 180°C. Preferably, the temperature range may be 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 xylylene diisocyanate is prevented, thereby enabling the production of a high-purity xylylene diisocyanate compound in a high yield.

[0085] After the reaction with phosgene is completed according to each method, a removal process such as nitrogen bubbling and a solvent removal process such as distillation for unreacted phosgene and hydrogen chloride gas may be optionally further performed, and these processes may be carried out according to conventional methods.

[0086]

[0087] In addition, the xylylene diisocyanate may be pure xylylene diisocyanate, or it may be a composition containing xylylene diisocyanate as a main component. In this case, the xylylene diisocyanate may contain some impurities that are generally known to be present in xylylene diisocyanate.

[0088] The impurities, for example, as by-products and impurities that may remain after the manufacture of XDI, may be one or more selected from the group consisting of xylylene diamine (XDA), chloromethylbenzyl isocyanate (CBI), 3-(dichloromethyl)benzyl isocyanate (DCI), dichloromethane iminomethylbenzyl isocyanate, xylylene dichloride (XDC), and cyanobenzyl isocyanate (MCN).

[0089]

[0090] More specifically, when the xylylene diisocyanate is a xylylene diisocyanate composition, it may include additives that can typically be added to the xylylene diisocyanate. In this case, the additive may be added during storage or may be added during the polymerization process in which the xylylene diisocyanate is manufactured into a resin.

[0091] For example, if necessary, additives such as internal release agents, reaction catalysts, UV absorbers, polymerization initiators, heat stabilizers, color correctors, chain extenders, crosslinking agents, light stabilizers, fillers, and antioxidants may be further included, and their content can be appropriately determined within a range that does not impair the coloring and discoloration inhibition properties of the xylylene diisocyanate composition.

[0092] As the above internal release agent, a component selected from, for example, a fluorine-based nonionic surfactant having a perfluoroalkyl group, a hydroxyalkyl group, or a phosphate ester group; a silicone-based nonionic surfactant having a dimethylpolysiloxane group, a hydroxyalkyl group, or a phosphate ester group; alkyl quaternary ammonium salts, namely trimethylcetylammonium salt, trimethylstearylammonium salt, dimethylethylcetylammonium salt, triethyldodecylammonium salt, trioctylmethylammonium salt, diethylcyclohexadodecylammonium salt; and acidic phosphate esters may be used alone or in combination of two or more types.

[0093] As the reaction catalyst mentioned above, catalysts used in resin polymerization reactions may be used. For example, dialkyl tin halide catalysts such as dibutyl tin dichloride and dimethyl tin dichloride; dialkyl tin dicarboxylate catalysts such as dimethyl tin diacetate, dibutyl tin dioctanoate, and dibutyl tin dilaurate; dialkyl tin dialkoxide catalysts such as dibutyl tin dibutoxide and dioctyl tin dibutoxide; dialkyl tin dithioalkoxide catalysts such as dibutyl tin di(thiobutoxide); dialkyl tin oxide catalysts such as di(2-ethylhexyl) tin oxide, dioctyl tin oxide, and bis(butoxydibutyl tin) oxide; and dialkyl tin sulfide catalysts may be used. These may be used individually or in combination of two or more.

[0094] The above-mentioned ultraviolet absorbers may include, for example, benzophenone-based, benzotriazole-based, triazine-based, salicylate-based, cyanoacrylate-based, oxanilide-based, etc.

[0095] As the above-mentioned near-infrared absorbers, for example, azo-based, aluminum-based, anthraquinone-based, cyanine-based, polymethine-based, diphenylmethane-based, triphenylmethane-based, quinone-based, diimonium-based, dithiol metal complex-based, squaryllium-based, phthalocyanine-based, and naphthalocyanine-based materials may be used. In particular, as one of the electromagnetic wave absorbers, a near-infrared absorber having a high near-infrared absorption capacity with a blocking rate of 30% or more in the vicinity of 800 to 1000 nm may be used. Such near-infrared absorbers are a mixture of multiple phthalocyanine-based pigments with different structures, and it is preferable that each of these pigments has a minimum value of a spectral transmittance curve of less than 80% within the ranges of (i) 800 nm to 850 nm, (ii) 875 nm to 925 nm, and (iii) 950 nm to 1000 nm. For example, PANAX FND-83, PANAX FND-88, PANAX FND-96, etc. can be used.

[0096] For example, the above polymerization initiator may be an amine-based, phosphorus-based, organotin-based, organocopper-based, organogallium-based, organozirconium-based, organoiron-based, organozinc-based, organoaluminum-based, or organobismuth-based.

[0097] As the above heat stabilizer, for example, one or more types such as metal fatty acid salts, phosphorus-based, lead-based, and organotin-based can be used.

[0098] The above color corrector may have an absorption band in the wavelength range from orange to yellow within the visible light region. Examples include dyes, fluorescent whitening agents, fluorescent pigments, inorganic pigments, etc., and may be appropriately selected to match the physical properties or resin color required for the optical product being manufactured. When a dye is used as the color corrector, for example, a dye with a maximum absorption wavelength of 520 to 600 nm, preferably 540 to 580 nm, may be used. Preferably, an anthraquinone-based dye may be used.

[0099] The above antioxidants may include phenolic, amine, sulfur, and phosphorus-based types, and these may be used individually or in combination of two or more types.

[0100]

[0101] According to a preferred embodiment of the present invention, the xylylene diisocyanate may contain 100 ppm or less of moisture.

[0102] As described above, xylylene diisocyanate can undergo unexpected side reactions with highly reactive moisture, and as a result, unintended by-products may be generated, which can lead to the deterioration of the physical properties of xylylene diisocyanate. Therefore, if xylylene diisocyanate contains more than 100 ppm of moisture, it may be disadvantageous in terms of storage stability.

[0103] In particular, if moisture is contained at a concentration of 100 ppm or more, the moisture may evaporate during storage, thereby increasing the relative humidity contained in the nitrogen gas described below. Consequently, this may be very disadvantageous in achieving the effects of increased storage stability and optical stability achieved by controlling the relative humidity of the nitrogen gas. Furthermore, the xylylene diisocyanate may react unexpectedly with moisture to generate urea, which may lead to an increase in yellowness and a rise in haze value, thereby damaging physical properties. Moreover, the resin and lens containing xylylene diisocyanate stored in this manner may experience yellowing and an increase in haze value, which may be very disadvantageous in terms of optical stability.

[0104]

[0105] At this time, the xylylene diisocyanate can be introduced into a storage container by a conventional method, for example, through an inlet provided in the storage container.

[0106]

[0107] Next, as step (2), nitrogen gas with a relative humidity of 1RH or less at 15˚C is filled into the remaining space of the storage container.

[0108] During the process of polymerizing xylylene diisocyanate into resins or lenses, it is mixed with additives such as catalysts or polymerization materials containing active hydrogen groups. At this time, xylylene diisocyanate is typically stored at a temperature of 5°C after production, whereas other compounds used in the polymerization of xylylene diisocyanate are typically stored at a temperature of 15°C. Accordingly, in the past, xylylene diisocyanate was stored at 15°C for a certain period of time prior to polymerization to equalize its temperature with that of other compounds. Due to this temperature difference, when stored according to a storage method established based on 5°C, problems arose where storage stability was significantly reduced or the optical stability of the produced resin or lens was reduced when the temperature was subsequently adjusted to 15°C for storage and synthesis.

[0109] In addition, in the conventional case, even if the moisture in the xylylene diisocyanate itself is controlled, there was a problem in that unexpected side reactions occurred due to moisture present in the remaining part of the storage container during the storage of xylylene diisocyanate, which was very disadvantageous in terms of storage stability and optical stability. Accordingly, the present invention solves this problem by filling the remaining space of the container in which xylylene diisocyanate is stored with nitrogen gas having a relative humidity of 1RH or less at 15˚C as described above.

[0110]

[0111] When the relative humidity of the nitrogen gas is 1 RH or less based on 15°C, the moisture content capable of reacting with xylylene diisocyanate is very low, so there is almost no unexpected side reaction between xylylene diisocyanate and moisture, allowing the xylylene diisocyanate to be stored with minimal degradation of physical properties such as increased yellowness and increased haze value. However, if the relative humidity of the nitrogen gas exceeds 1 RH based on 15°C, moisture contained in the nitrogen gas may dissolve into the xylylene diisocyanate. Consequently, the xylylene diisocyanate and moisture may react unexpectedly, causing urea to form, which may damage the aforementioned physical properties such as increased yellowness and increased haze value. Furthermore, the optical stability of the resin and lens containing xylylene diisocyanate stored in the container may be very unfavorable, such as causing yellowing and increasing haze value.

[0112] At this time, more preferably, the relative humidity of the nitrogen gas may be 0.8RH or less, 0.6RH or less, 0.4RH or less, 0.3RH or less, 0.2RH or less, or 0.15RH or less. As the relative humidity of the nitrogen gas decreases, the deterioration of physical properties such as increased yellowness and increased haze value of the xylylene diisocyanate is further minimized, and thus the optical stability, etc., may be excellent.

[0113] Most preferably, the relative humidity of the nitrogen gas may be 0.05 RH or less based on 15°C. In this case, if the relative humidity of the nitrogen gas exceeds 0.05 RH based on 15°C, there is a possibility that physical properties may be degraded due to moisture contained in the nitrogen gas if the storage period is extended significantly. Therefore, when the relative humidity is 0.05 RH or less, the effect can be significantly superior in terms of storage stability and optical stability of xylylene diisocyanate.

[0114] In this case, for nitrogen gas, nitrogen gas with already controlled moisture can be used, or moisture can be removed during the input process by the process described below.

[0115]

[0116] In addition, the nitrogen gas may be filled into the remaining space in the storage container after the xylylene diisocyanate has been filled, and preferably, the remaining space may be filled completely.

[0117] According to a preferred embodiment of the present invention, the nitrogen gas may be contained in the storage container in an amount of 1 to 10 volume% relative to the total volume inside the storage container, and more preferably in an amount of 2 to 5 volume%. At this time, in step (1), xylylene diisocyanate may be filled in an amount of 90 to 99 volume% relative to the total volume inside the storage container so that the volume of nitrogen gas is 1 to 10 volume%, and more preferably, in step (1), xylylene diisocyanate may be filled in an amount of 95 to 98 volume% relative to the total volume inside the storage container so that the volume of nitrogen gas is 2 to 5 volume%.

[0118] In this case, if the volume of nitrogen gas is added at less than 2% of the total volume inside the storage container, xylylene diisocyanate must be added to fill almost the entire storage container, which requires very precise operation during the addition process, thereby increasing process costs and potentially being disadvantageous in terms of economy. Furthermore, if the volume of nitrogen gas is added at more than 5% of the total volume inside the storage container, the amount of nitrogen gas is excessive. Even if the relative humidity of the nitrogen gas is controlled to a specific range, the absolute amount of water contained increases, which may cause problems such as the deterioration of the physical properties of xylylene diisocyanate when stored for a very long period.

[0119]

[0120] At this time, the nitrogen gas can be introduced into the storage container in a conventional manner, for example, through an inlet provided in the storage container.

[0121]

[0122] According to a preferred embodiment of the present invention, a step of removing moisture from the nitrogen gas may be further included between step (1) and step (2). More specifically, by removing moisture from the nitrogen gas, the relative humidity of the nitrogen gas can be controlled to have a value of 1 RH or less based on 15°C, and more preferably, the relative humidity of the nitrogen gas can be controlled to have a value of 0.05 RH or less based on 15°C.

[0123] At this time, the method for removing moisture from the nitrogen gas is not limited to any method capable of removing moisture from the nitrogen gas, but preferably, it may be a method of passing the nitrogen gas through a desiccant. As an example, after removing moisture from the nitrogen gas by passing the nitrogen gas through a desiccant, the nitrogen gas from which moisture has been removed can be filled into a storage container according to step (2). As another example, during the process of introducing the nitrogen gas, the nitrogen gas can be passed through a desiccant so that the nitrogen gas from which moisture has been removed can be filled into the storage container. As yet another example, after first filling the nitrogen gas into the reaction vessel, a container equipped with a desiccant can be connected to the storage container to remove moisture from the nitrogen gas contained in the storage container. At this time, the container equipped with a desiccant and the storage container can be connected through the nitrogen gas inlet.

[0124]

[0125] According to a preferred embodiment of the present invention, after step (2), the step of sealing the storage container may be further included.

[0126] More specifically, the sealing step may involve sealing the storage container so that no gas or liquid can move between the inside and outside of the storage container after sealing. In this case, the sealing method is not limited as long as it prevents any gas or liquid from moving between the inside and outside of the storage container after sealing. If the storage container is not sealed, moisture may enter from the outside, and the moisture content of the nitrogen gas contained inside the container will not be controlled. Consequently, this can significantly impair the physical properties of the xylylene diisocyanate stored inside the container, which may be very disadvantageous in terms of storage stability and optical stability.

[0127]

[0128] According to a preferred embodiment of the present invention, in a storage method for xylylene diisocyanate according to the present invention, the xylylene diisocyanate may have a urea content calculated by the following formula 1 that is 0.1 or more and less than 0.8, and more preferably may be 0.1 or more and less than 0.4.

[0129] <Formula 1>

[0130] Urea content = (1611~1626 cm -1 Absorption peak area) / (2255~2268 cm²) -1 Absorption peak area)

[0131] In this case, the absorption peak area may be measured by an FT-IR spectrometer.

[0132]

[0133] More specifically, urea is formed by the reaction of xylylene diisocyanate with moisture. In the case of the present invention, the relative humidity inside the storage container is controlled at 15°C, so that the urea content calculated by Formula 1 can be controlled to be 0.1 or more and less than 0.8, and more preferably, 0.1 or more and less than 0.4. Since the occurrence of urea causes the xylylene diisocyanate to form a resin, etc., thereby degrading physical properties such as transparency, the present invention is excellent in terms of optical stability.

[0134]

[0135] In addition, according to a preferred embodiment of the present invention, in a storage method for xylylene diisocyanate according to the present invention, compared to the urea content of xylylene diisocyanate immediately before sealing the storage container after step (2), the urea content of xylylene diisocyanate after 60 days of sealing may be in the range of 100 to 150%, and preferably in the range of 100 to 130%.

[0136] More specifically, since the relative humidity inside the storage container is controlled according to the present invention, almost no reaction occurs between xylylene diisocyanate and moisture, thereby minimizing the increase in urea content; consequently, even after 60 days of storage, the urea content can remain at 100 to 150% of the initial condition. Therefore, according to the storage method of the present invention, xylylene diisocyanate can be stored for a long period without deterioration of its physical properties.

[0137]

[0138] In addition, the present invention provides a method for storing xylylene diisocyanate, comprising the steps of: (1) introducing xylylene diisocyanate into a storage container; and (2) filling the remaining space of the storage container with nitrogen gas, wherein the urea content of the xylylene diisocyanate calculated by the following formula 1 is 0.1 or more and less than 0.8.

[0139] <Formula 1>

[0140] Urea content = (1611~1626 cm -1 Absorption peak area) / (2255~2268 cm²) -1 Absorption peak area)

[0141] (At this time, the absorption peak area is measured using an FT-IR spectrometer.)

[0142]

[0143] More specifically, when using the above storage method, the urea content is controlled, so even if the xylylene diisocyanate is stored for a long period, the urea content contained in the xylylene diisocyanate can be controlled to 0.1 or more and less than 0.8.

[0144] More specifically, the storage method of the xylylene diisocyanate above can be done by sealing the storage container after step (2).

[0145] At this time, the storage method according to the present invention may have a urea content of 0.1 or more and less than 0.8 even after 30 days have passed since the storage container was sealed. In addition, more preferably, the urea content may have a urea content of 0.1 or more and less than 0.8 even after 60, 120, and 150 days have passed since sealing, and most preferably, the urea content may have a urea content of 0.1 or more and less than 0.8 even after 1 year has passed since sealing.

[0146] As the urea content is controlled in this manner, the degradation of physical properties such as transparency is minimized when xylylene diisocyanate forms a resin, etc., and the xylylene diisocyanate stored according to the present invention is excellent in terms of optical stability.

[0147]

[0148] In addition, more specifically, when using the storage method according to the present invention, the increase in urea content can be minimized even with long-term storage, and accordingly, the urea content can be 100 to 150% of that immediately before sealing even after 30 days of storage. In addition, preferably, the urea content can be in the range of 100 to 150% of that immediately before sealing even after 60, 120, or 150 days of storage, and most preferably, the urea content can be in the range of 100 to 150% of that immediately before sealing even after 1 year of storage after sealing.

[0149]

[0150] More specifically, the urea content can be controlled to be 0.1 or more and less than 0.4, preferably, the urea content can be 0.1 or more and less than 0.4 even after storage for 30 days, more preferably 60, 120, or 150 days, and most preferably, the urea content can be 0.1 or more and less than 0.4 even after one year of storage. Since the occurrence of urea degrades physical properties such as transparency when xylylene diisocyanate forms a resin, etc., the present invention is excellent in terms of optical stability.

[0151]

[0152] More specifically, the storage method according to the present invention may minimize the increase in APHA value and Haze value even when stored for a long period.

[0153] More specifically, when using the storage method according to the present invention, compared to the APHA value immediately before sealing and storing, the APHA value after 30 days of storage may be in the range of 100 to 200%, the APHA value after 60 days of storage may be in the range of 100 to 250%, and the APHA value after 1 year of storage may be in the range of 100 to 300%.

[0154] In addition, more specifically, when using the storage method according to the present invention, the Haze value after storage may be in the range of 100 to 150% compared to the Haze value immediately before sealing and storing, preferably in the range of 100 to 150% after 30 days of storage, more preferably in the range of 100 to 150% after 60, 120, or 150 days of storage, and most preferably in the range of 100 to 150% after 1 year of storage.

[0155] In the case of the storage method of the present invention, the increase in APHA and Haze values ​​along with the urea content can be minimized, and therefore, even after forming into a resin, the deterioration of physical properties such as transparency is minimized, and the optical stability can be very excellent.

[0156]

[0157] In addition, the present invention provides a storage container for xylylene diisocyanate, wherein xylylene diisocyanate is stored inside a sealed storage container, nitrogen gas is filled in the remaining space, and the relative humidity of the nitrogen gas is 1 RH or less at 15°C. At this time, the description of parts that overlap with the storage method described above is omitted, but is not limited thereto.

[0158]

[0159] At this time, if the relative humidity of the nitrogen gas exceeds 1RH at 15˚C, the excessive moisture contained in the nitrogen gas causes unexpected side reactions with the xylylene diisocyanate, thereby impairing the physical properties of the xylylene diisocyanate, which is very disadvantageous in terms of storage stability and optical stability.

[0160] At this time, more preferably, the relative humidity of the nitrogen gas may be 0.8RH or less, 0.6RH or less, 0.4RH or less, 0.3RH or less, 0.2RH or less, or 0.15RH or less. As the relative humidity of the nitrogen gas decreases, the deterioration of physical properties such as increased yellowness and increased haze value of the xylylene diisocyanate is further minimized, and thus the optical stability, etc., may be excellent.

[0161] At this time, according to a preferred embodiment of the present invention, the relative humidity of the nitrogen gas may be 0.05 RH or less at 15°C. At this time, if the relative humidity exceeds 0.05 RH, the physical properties of xylylene diisocyanate may be degraded due to moisture contained in the nitrogen gas when stored for a very long period, which may be disadvantageous in terms of storage stability and optical stability. Therefore, when the relative humidity is 0.05 RH or less, the effect is very significant in terms of storage stability and optical stability of xylylene diisocyanate.

[0162] More specifically, the nitrogen gas may be included in an amount of 1 to 10 volume% relative to the total volume inside the storage container, and more preferably in an amount of 2 to 5 volume%. In this case, if the nitrogen gas is included in an amount of less than 2 volume% relative to the total volume inside the storage container, xylylene diisocyanate must be introduced to fill almost the entire storage container, which requires very precise operation during the introduction process, thereby increasing process costs and potentially being disadvantageous in terms of economics. Furthermore, if the nitrogen gas is included in an amount exceeding 5 volume% relative to the total volume inside the storage container, the amount of nitrogen gas is excessive; even if the relative humidity of the nitrogen gas is controlled to a value within a specific range, the absolute amount of moisture contained increases, which may cause problems such as damage to the physical properties of xylylene diisocyanate when stored for a very long period.

[0163]

[0164] According to a preferred embodiment of the present invention, in a storage container for xylylene diisocyanate according to the present invention, the xylylene diisocyanate may have a urea content calculated by the following formula 1 that is 0.1 or more and less than 0.8, and more preferably may be 0.1 or more and less than 0.4.

[0165] <Formula 1>

[0166] Urea content = (1611~1626 cm -1 Absorption peak area) / (2255~2268 cm²) -1 Absorption peak area)

[0167] In this case, the absorption peak area may be measured by an FT-IR spectrometer.

[0168]

[0169] More specifically, urea is formed by the reaction of xylylene diisocyanate with moisture. In the case of the present invention, the relative humidity inside the storage container is controlled at 15°C, so that the urea content calculated by Formula 1 can be controlled to be 0.1 or more and less than 0.8, and more preferably, 0.1 or more and less than 0.4. Since the occurrence of urea causes the xylylene diisocyanate to form a resin, etc., thereby degrading physical properties such as transparency, the present invention is excellent in terms of optical stability.

[0170]

[0171] According to a preferred embodiment of the present invention, a resin layer may be provided on the inner surface of the storage container. Conventionally, when xylylene diisocyanate is stored in a metal container, there was a problem in which the xylylene diisocyanate reacted unexpectedly with the metal on the inner surface of the storage container, causing the xylylene diisocyanate to become discolored. According to the present invention, when a resin layer is provided on the inner surface of the storage container, the xylylene diisocyanate inside the storage container does not come into direct contact with the metal container, so the xylylene diisocyanate may not become discolored.

[0172] More specifically, the resin layer can be formed by laminating resin onto the inner surface of the storage container. At this time, the method of forming the resin layer on the inner surface of the storage container is not particularly limited, and known methods may be employed. For example, the resin may be coated onto the inner surface of the storage container by a known resin coating method such as spray coating, dip coating, electrostatic coating, or powder coating. In addition, the resin may be laminated onto the inner surface of the storage container by a known resin lamination method such as dry lamination or hot melt lamination.

[0173] The thickness of the resin layer formed at this time may be, for example, 5 μm or more, preferably 10 μm or more, for example 1000 μm or less, preferably 500 μm or less.

[0174]

[0175] More specifically, the resin layer may be one or more selected from the group consisting of polyolefin resin, acrylonitrile styrene resin, acrylonitrile butadiene styrene resin, polyvinyl chloride resin, fluorine resin, polyester resin, phenolic resin, polyacrylic resin, epoxy resin, polyimide resin, polyamide resin, poly(thio)urethane resin, cellulose resin, silicone resin, and polycarbonate resin.

[0176] More specifically,

[0177] The polyolefin resin may be one or more selected from the group consisting of, for example, polyethylene resin, polypropylene resin, and cyclic polyolefin resin.

[0178] The polyester resin may be one or more selected from the group consisting of, for example, polyethylene terephthalate resin and polyethylene naphthalate resin.

[0179] The epoxy resin may be one or more selected from the group consisting of, for example, epoxyphenol resin and epoxyamine resin.

[0180] The polyamide resin may be, for example, one or more selected from various nylons and polyamideimide resins.

[0181] The poly(thio)urethane resin may be, for example, one or more selected from the group consisting of polyurethane resin and polythiourethane resin.

[0182]

[0183] In addition, the present invention provides a non-foam resin comprising xylylene diisocyanate stored in the storage container described above. Specifically, the non-foam resin described above may further include an active hydrogen group-containing component. This will be explained below.

[0184] The xylylene diisocyanate stored in the storage container described above can be suitably used as a raw material for non-foam resin. Specifically, the composition, as a xylylene diisocyanate component, forms a polymerizable composition together with an active hydrogen group-containing component that is a raw material for the resin, and a resin can be manufactured from the polymerizable composition.

[0185] The above active hydrogen group-containing component may include one or more selected from the group consisting of polyol components, polythiol components, and polyamine components.

[0186] The above polyol component is not limited as long as it is included in the xylylene diisocyanate composition and a resin can be manufactured therefrom, but preferably, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, butanetriol, 1,2-methylglucoside, pentaerythritol, dipentaerythritol, tripentaerythritol, sorbitol, erythritol, threitol, ribitol, arabinitol, xylitol, alitol, mannitol, dolcitol, iditol, glycol, inositol, hexanetriol, triglycerol, diglycerol, triethylene glycol, polyethylene glycol, tris(2-hydroxyethyl)isocyanurate, cyclobutanediol, cyclopentanediol, cyclohexanediol, cycloheptanediol, cyclooctanediol, Cyclohexanedimethanol, hydroxypropylcyclohexanol, tricyclo[5,2,1,0,2,6]decane-dimethanol, bicyclo[4,3,0]-nonanediol, dicyclohexanediol, tricyclo[5,3,1,1]dodecanediol, bicyclo[4,3,0]nonanedimethanol, tricyclo[5,3,1,1]dodecane-diethanol, hydroxypropyltricyclo[5,3,1,1]dodecaneol, spiro[3,4]octanediol, butylcyclohexanediol, 1,1'-bicyclohexylidenediol, cyclohexanetriol, aliphatic polyols such as muttol and lactitol, dihydroxynaphthalene, trihydroxynaphthalene, tetrahydroxynaphthalene, dihydroxybenzene, benzenetriol, Biphenyltetraol, pyrogallol, (hydroxynaphthyl)pyrogallol, trihydroxyphenanthrene, bisphenol A, bisphenol F, xylylene glycol, aromatic polyols such as tetrabrombisphenol A, di-(2-hydroxyethyl)sulfide, 1,2-bis-(2-hydroxyethylmercapto)ethane, bis(2-hydroxyethyl)disulfide, 1,4-dithian-2,5-diol, bis(2,3-dihydroxypropyl)sulfide, tetrakis(4-hydroxy-2-thiabyl)methane, bis(4-hydroxyphenyl)sulfone (trade name Bisphenol S), tetrabromobisphenol S, tetramethylbisphenol S, 4,4'-thiobis(6-tert-butyl-3-methylphenol), 1,It may be one or more selected from the group consisting of polyalkylene oxide ethers of polyols containing sulfur atoms such as 3-bis(2-hydroxyethylthioethyl)-cyclohexane, polyoxypropylene glyceryl ether, polyoxyethylene glyceryl ether, polyoxypropylene trimethylol propyl ether, polyoxypropylene pentaerythritol ether, etc.

[0187] The above polythiol component is not limited to those included in the xylylene diisocyanate composition from which a resin can be manufactured, provided that a resin is produced therefrom, but preferably, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecaine, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecaine, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecaine, methanedithiol, methanetrithiol, bis(2-mercaptoethyl)ether, tetrakis(mercaptomethyl)methane, 1,2-dimercaptopropane; 1,3-Dimercaptopropane, 1,4-Dimercaptobutane, 1,6-Dimercaptohexane, 2,2-Dimercaptopropane, 1,2-Bis(2-Mercaptoethyloxy)ethane, 1,2-Bis(2-Mercaptoethylthio)ethane, 2,3-Dimercapto-1-propanol, 1,2-Dimercaptoethane, 1,3-Dimercapto-2-propanol, 2-Mercaptomethyl-1,3-Dimercaptopropane, 2-Mercaptomethyl-1,4-Dimercaptobutane, 1,2,3-Trimercaptopropane, 2-(2-Mercaptoethylthio)-1,3-Dimercaptopropane, 2,4-dimercaptomethyl-1,5-dimercapto-3-thiapentane, bis(2-mercaptoethyl)sulfide, ethylene glycol bis(3-mercaptopropionate), diethylene glycol bis(2-mercaptoacetate), ethylene glycol bis(2-mercaptoacetate), 1,4-butenediol bis(2-mercaptoacetate), trimethylolpropane trismercaptopropionate, pentaerythritol tetrakismercaptoacetate, diethylene glycol bis(3-mercaptopropionate), pentaerythritol tetrakismercaptopropionate, 1,2-dimercaptocyclohexane, 1,1,1-tris(mercaptomethyl)propane, 1,4-butenediol bis(3-mercaptopropionate), 1,3-Dimercaptocyclohexane, Trimethylolpropanetrismercaptoacetate, 1,4-Dimercaptocyclohexane, 1,3-Bis(mercaptomethyl)cyclohexane, 1,4-Bis(mercaptomethyl)cyclohexane, Bis(4-mercaptophenyl)sulfone, 2,5-Dimercaptomethyl-1,4-Ditian, 2,5-Bis(2-mercaptoethylthiomethyl)-1,4-Ditian, 2,5-dimercaptomethyl-1-thian, 2,5-dimercaptoethyl-1-thian, 2,5-dimercaptomethylthiophene, bis(4-mercaptophenyl)sulfide, 1,2-dimercaptobenzene, 1,3-dimercaptobenzene, 1,4-dimercaptobenzene, 1,3-bis(mercaptomethyl)benzene, 1,4-bis(mercaptomethyl)benzene, 2,2'-dimercaptobiphenyl, bis(4-mercaptophenyl)methane, 2,2-bis(4-mercaptophenyl)propane, 4,4'-dimercaptobiphenyl, bis(4-mercaptophenyl)ether, bis(4-mercaptomethylphenyl)methane, 1,1,3,3-tetrakis(mercaptomethylthio)propane, It may be one or more selected from the group consisting of 2,2-bis(4-mercaptomethylphenyl)propane, bis(4-mercaptomethylphenyl)ether, bis(4-mercaptomethylphenyl)sulfide, 2.5-dimercapto-1,3,4-thiadiazole, and 3,4-thiophenediol.

[0188] The above polyamine component is not limited to any one of the following, provided that it is included in xylylene diisocyanate and a resin can be produced therefrom, but preferably, it may be one or more selected from the group consisting of 3,5-diethyl-2,4-diaminotoluene, 3,5-diethyl-2,6-diaminotoluene, 3,5-dithiomethyl-2,4-diaminotoluene, and 3,5-dithiomethyl-2,6-diaminotoluene.

[0189] The mixing ratio of the xylylene diisocyanate compound and the active hydrogen compound may be such that the molar ratio of the NCO group to the active hydrogen group is typically 0.5 to 2.0, and preferably 0.95 to 1.05. Examples of active hydrogen groups include hydroxyl groups, mercapto groups, and amino groups.

[0190] A non-foam resin can be manufactured through the polymerization reaction of the aforementioned active hydrogen group-containing component and xylylene diisocyanate.

[0191] For example, the mixture of the above monomer composition is injected into a mold type combining a glass or metal mold and a resin gasket to carry out polymerization.

[0192] The polymerization initiation temperature may preferably be 0 to 45°C, more preferably 10 to 40°C, and even more preferably 15 to 35°C. In addition, polymerization conditions may be appropriately set according to the above initial temperature. The temperature may be raised from the above initial temperature, and then heated to form curing. For example, the raised temperature may be 100 to 150°C according to conventional standards. The time for raising the temperature to the said temperature may preferably be 5 to 48 hours, more preferably 10 to 40 hours, and even more preferably 20 to 30 hours. The heating time after raising the temperature may preferably be 10 to 30 hours, and more preferably 20 to 30 hours.

[0193]

[0194] In addition, the above non-foam resin may be used as one or more selected from the group consisting of coatings, adhesives, sealants, and elastomers.

[0195] More specifically, the above-mentioned non-foam resin can be used as one or more raw materials selected from the group consisting of coatings, adhesives, sealants, and elastomers in oil refineries, oil transfer pipes, buildings, ships, marine equipment, automobiles, aircraft, spacecraft, railway vehicles, sports equipment, and computers, etc.

[0196]

[0197] The above resin is preferably molded by a known molding method to form a molded body.

[0198] In addition, the above-mentioned molded body may be, for example, an optical element.

[0199] In addition, the optical element may be, for example, a lens or a sheet film, and preferably a lens.

[0200] The above lenses may be, for example, clear lenses, polarizing lenses, camera lenses, sunglasses lenses, eyeglass lenses, pickup lenses, and contact lenses.

[0201] The aforementioned molded body, optical element, and lens all contain the xylylene diisocyanate. Therefore, the yellowing phenomenon is prevented, and they are significantly superior to conventional molded bodies, optical elements, and lenses in terms of resistance to yellowing and transparency.

[0202]

[0203] The present invention will be explained more specifically through the following examples, but the following examples are not intended to limit the scope of the invention and should be interpreted as being for the purpose of aiding understanding of the invention.

[0204]

[0205] <Preparation Example: Preparation of m-xylylene diisocyanate>

[0206] 471 g of 1,2-dichlorobenzene and 32.5 g of 99.4% pure m-XDA (m-xylenediamine) were placed in a flask and stirred at room temperature (23±5˚C) while injecting anhydrous hydrochloric acid at a rate of 20 g / hr. The anhydrous hydrochloric acid was injected for 4 hours, and the temperature was raised at a constant rate to 50˚C. After injecting the anhydrous hydrochloric acid for 4 hours, the formed salt was cooled to room temperature, and 43 ml of liquid phosgene was added to the reactor, after which the reactor temperature was heated to 130˚C. From the time of phosgene injection until the end of the reaction, a dry ice-acetone condenser was used to prevent the phosgene from leaking out. After the reactor temperature reached 130˚C, the reactor temperature was maintained at 125–135˚C for 2 hours to ensure the reaction solution became transparent. After the solution became clear, the inside of the reactor was cooled to 80°C and cooled while blowing in nitrogen to obtain a reaction solution from which phosgene had been removed.

[0207] Next, the solvent was removed from the reaction solution from which phosgene had been removed by vacuum distillation, and a clear m-XDI with a GC area of ​​99.8% was obtained by gas chromatography analysis. The detailed conditions for the gas chromatography analysis are as follows.

[0208]

[0209] Peak Area Measurement via Gas Chromatography Analysis

[0210] Gas chromatography (GC) analysis was performed on the m-XDI prepared in the above preparation example. As a result of the analysis, the area of ​​the detection peak for m-xylylene diisocyanate detected at a retention time of 23.489 minutes was measured, and it was confirmed that m-XDI with a GC area of ​​99.8% or more was produced.

[0211]

[0212] (Measurement conditions for gas chromatography analysis)

[0213] Measuring instrument; Agilent 7890B

[0214] Column; DB-17 (Inner diameter 0.25mm x Length 30m, Film 0.50㎛)

[0215] Injection concentration; 20 mass%, dichloromethane solution

[0216] Injection volume; 1 µL

[0217] Split Ratio : Split (ratio 30:1)

[0218] Inlet temperature; 280˚C

[0219] Detector temperature; 280˚C

[0220] Carrier gas; N2, 1 mL / min

[0221] Oven temperature: Hold at 80°C for 1 minute, increase from 80°C to 160°C at 5.0°C / min, hold for 8 minutes after reaching 160°C, increase from 160°C to 280°C at 20.0°C / min, hold for 18 minutes after reaching 280°C.

[0222]

[0223] <Example 1: Preparation of Xylylene Diisocyanate Storage Container 1>

[0224] The m-xylylene diisocyanate prepared above was adjusted to have a moisture content of 58 ppm. The moisture content was determined by measuring the moisture content of the solvent recovered after the preparation of the m-xylylene diisocyanate, and this was used as the moisture content of the m-xylylene diisocyanate; this was measured using a moisture meter. Subsequently, the moisture-adjusted m-xylylene diisocyanate was introduced to fill 96.67 volume% of the total volume of a 16L drum (nitrogen, described later, was introduced to achieve (100-96.67) volume% of the total volume of the drum). Then, nitrogen was introduced through a filter consisting of a 3-micron pre-filter and a 1-micron after-filter, with the interior filled with 4-6 mm activated alumina (BASF), and 1000 m 3 Nitrogen gas was injected at a rate of / hr to fill the remaining space of the storage container with a relative humidity of 0.03RH at 15˚C. Afterward, the storage container was sealed and stored at 15˚C.

[0225]

[0226] <Example 2: Preparation of Xylylene Diisocyanate Storage Container 2>

[0227] Nitrogen 5000m 3It was stored in the same manner as in Example 1, except that it was filled at a rate of / hr so ​​that the relative humidity of the filled nitrogen was 0.1RH based on 15˚C.

[0228]

[0229] <Example 3: Preparation of Xylylene Diisocyanate Storage Container 3>

[0230] It was stored in the same manner as in Example 1, except that m-xylylene diisocyanate was added to fill 85% of the total volume of the drum.

[0231]

[0232] <Example 4: Preparation of Xylylene Diisocyanate Storage Container 4>

[0233] The prepared m-xylylene diisocyanate was stored in the same manner as in Example 1, except that the moisture content was adjusted to 150 ppm.

[0234]

[0235] <Example 5: Preparation of Xylylene Diisocyanate Storage Container 5>

[0236] Nitrogen 5000m 3 It was stored in the same manner as in Example 1, except that it was filled at a rate of / hr so ​​that the relative humidity of the filled nitrogen was 0.1RH based on 15˚C, and m-xylylene diisocyanate was added to fill 93 volume% of the total volume of the drum.

[0237]

[0238] <Comparative Example 1: Preparation of Xylylene Diisocyanate Storage Container 6>

[0239] It was stored in the same manner as Example 1, except that nitrogen was filled without passing through a filter, and the relative humidity of the filled nitrogen was 1.5RH based on 15˚C.

[0240]

[0241] <Experimental Example 1: Measurement of APHA and Haze Values ​​According to Storage Period of Composition>

[0242] According to the method of ASTM E313, the APHA color and haze of each xylylene diisocyanate stored in Examples 1 to 5 and Comparative Example 1 were measured (light source: C / 2) using HunterLab’s Ultrascan Pro and are shown in Table 1 below.

[0243] In addition, after storing each of the xylylene diisocyanates stored in Examples 1 to 5 and Comparative Example 1 for 30 and 60 days, the APHA color and haze of each of the xylylene diisocyanates prepared in Examples 1 to 5 and Comparative Example 1 were measured (light source: C / 2) and are shown in Table 1 below.

[0244] The above APHA (Hazen color number) measurement was performed using a xenon lamp light source of Hunterlab's Ultrascan equipment, as a method for analyzing color difference under room temperature conditions in accordance with ASTM D1003.

[0245]

[0246] <Experimental Example 2: Measurement of Yellowness (YI) of Lens (Resin) According to Storage Period of Composition>

[0247]

[0248] Xylylene diisocyanate stored in Examples 1 to 5 and Comparative Example 1 was stored for 30 and 60 days, and then a resin was prepared in the following manner.

[0249] 20.8g each of xylylene diisocyanate, ZELEC as an internal release agent TM UN (Stepan) 0.04 g, Biosorb as a UV absorber TMA mixture was prepared by stirring and mixing 0.04 g of 583 (manufactured by Sakai Chemical Industry Co., Ltd.) at room temperature (23–25˚C) for 20 minutes, adding 0.002 g of DBTC (dibutyltin dichloride) to the prepared mixture and stirring for 10 minutes, adding 19.2 g of 2,3-bis(2-sulfanyl ethyl sulfanyl)propane-1-thiol, and stirring for 1 hour while degassing under a pressure of 5 mbar to prepare a polyisocyanate polymerization composition. At this time, the internal release agent, UV absorber, DBTC, and 2,3-bis(2-sulfanyl ethyl sulfanyl)propane-1-thiol were all stored at 15˚C.

[0250] The prepared polyisocyanate polymerization composition was filtered using a 1 μm PTFE filter and then injected into a mold consisting of a glass mold and a tape, respectively. Subsequently, the mold was placed in an oven, and the polymerization reaction was carried out for 20 hours while gradually increasing the temperature from 10°C to 120°C. After the polymerization was completed, the mold was removed from the oven and released to obtain the respective plastic resins. The obtained resins were annealed at 120°C for 6 hours to produce lenses (resins) with a thickness of 9 mm.

[0251] For each of the above-mentioned optical lenses, the yellowness of each was measured using HunterLab’s Ultrascan Pro according to the ASTM D1209 method and is shown in Table 1.

[0252]

[0253] <Experimental Example 3: Observation of Haze in Lens (Resin)>

[0254] Light was transmitted through the manufactured lens using a xenon lamp to visually observe the haze, and the presence or absence of haze was indicated as O or X.

[0255]

[0256] <Experimental Example 4: Measurement of Urea Content>

[0257] For the xylylene diisocyanate stored in Examples 1 to 5 and Comparative Example 1, the urea content was measured immediately after storage, 30 days after storage, and 60 days after storage, respectively, and the results are shown in Table 1.

[0258] Urea measurements were performed using the ATR mode of an FT-IR spectrometer (Varian 4100), with a measurement range of 4000–650 cm⁻¹. -1 The scan count is 32, and the resolution is 4 cm. -1 It was measured as follows. After the measurement, the absorption peak of the isocyanate group (-N=C=O) in the xylylene diisocyanate compound, 2255–2268 cm⁻¹, was measured. -1 1611–1626 cm⁻¹, the absorption peak of the carbonyl bond (-C=O) of urea relative to the peak area of -1 It was calculated as a ratio of the area, and the formula is the same as Formula 1 below.

[0259] <Formula 1>

[0260] Urea content = (1611~1626 cm -1 Absorption peak area) / (2255~2268 cm²) -1 Absorption peak area)

[0261]

[0262] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Moisture content (ppm) of xylylene diisocyanate 58 58 58 15 0 58 58 Relative humidity (RH) of nitrogen gas at 15˚C 0.0 3 0.1 0.0 3 0.0 3 0.1 1.5 Volume of nitrogen gas (volume%) 3.3 3 3.3 15 3.3 3 7 3.3 3 Urea content (%) (0-day storage) 0.3 2 0.3 6 0.3 6 0.2 9 0.2 9 0.3 30 Urea content (%) (30-day storage) 0.3 2 0.3 6 0.3 6 0.6 0.2 9 1 Urea content (%) (60-day storage) 0.3 2 0.3 6 0.3 6 3 0.2 9 5.7 5 Urea content (%) (365-day Storage) 0.33 0.36 0.37 40.30 6 APHA Value (0-day storage) 55 55 55 APHA Value (30-day storage) 67 89 89 APHA Value (60-day storage) 9 10 11 12 11 13 APHA Value (365-day storage) 14 13 14 24 13 22 Haze Value (0-day storage) 0.30 30 30 30 30 30 3 Haze Value (30-day storage) 0.30 30 30 7 0.31 0 Haze Value (60-day storage) 0.40 40 31 5 0.41 7 Haze Value (365-day storage) 0.40 40 34 00.31 8 Yellowness of Lens (0-day storage) 3.9 8 4.0 13.9 5 3.8 0 3.9 7 3.99 Yellowness of Lens (30 days Storage) 4.00 4.05 4.05 3.9 5 4.06 4.00 Lens Yellowness (60-day storage) 4.01 4.07 4.04 - 4.09 - Lens Yellowness (365-day storage) 4.05 4.18 4.26 - 4.20 - Lens Haze (0-day storage) XXXOXX Lens Haze (30-day storage) XXXOXO Lens Haze (60-day storage) XXXOXO Lens Haze (365-day storage) XXXOXO

[0263]

[0264] As can be seen from Table 1, Examples 1 to 5, in which nitrogen filled in the remaining space of the xylylene diisocyanate storage container has a relative humidity of 1 RH or less at 15˚C, show a smaller increase in APHA and Haze values ​​during storage compared to Comparative Example 1, and the amount of change in the yellowness of the lens and the Haze of the lens is also small, confirming that the storage stability is excellent.

[0265] At this time, in Comparative Example 1, the yellowness value measured after manufacturing a lens by storing the composition for 30 days was measured as a low value because too much haze occurred, and in Example 4 and Comparative Example 1, when measuring the yellowness value after manufacturing a lens by storing the composition for 60 days, the opacity of the lens increased, making it impossible to measure the yellowness value.

[0266] In addition, it can be confirmed that the storage stability of Example 1, in which the moisture content inside the xylylene diisocyanate is controlled to 100 ppm or less and nitrogen gas is filled to 1 to 10 volume%, is superior compared to the cases of Examples 2 to 5.

[0267] In addition, in the case of Example 3, which is filled with 15 volume% nitrogen gas, it can be confirmed that it is disadvantageous in terms of storage stability compared to the case of Example 1.

[0268] In addition, it can be seen that Examples 2 and 5, in which the filled nitrogen gas has a relative humidity exceeding 0.05RH at 15˚C, are somewhat less favorable in terms of storage stability compared to Example 1.

[0269] Additionally, in the case of Example 4, where the moisture content of xylylene diisocyanate exceeds 100 ppm, it can be confirmed that it is less favorable than Example 1 in terms of storage stability.

[0270] In addition, regarding the urea content, it can be confirmed that for Examples 1 to 5, the content remains in the range of 0.1 or higher and less than 0.8 until 30 days of storage, whereas for Comparative Example 1, the urea content increases to 0.8 or higher even after 30 days of storage. After 60 days of storage, for Examples 1 to 3 and Example 5, the urea content still maintains a value of less than 0.8 and further less than 0.4, and no increase in content is observed within the margin of error, whereas for Example 4, which has a high initial moisture content of xylylene diisocyanate, a significant increase is observed.

[0271] Finally, when each example and comparative example were stored for one year, it was confirmed that the increase in urea content, APHA value, and Haze value in Examples 1 to 3 and Example 5 was significantly lower than in Example 4 and the comparative example.

Claims

1. (1) A step of introducing xylylene diisocyanate into a storage container; and (2) A method for storing xylylene diisocyanate comprising the step of filling the remaining space of the storage container with nitrogen gas having a relative humidity of 1 RH or less at 15˚C.

2. In Paragraph 1, A storage method for xylylene diisocyanate, wherein the xylylene diisocyanate of step (1) above contains moisture of 100 ppm or less.

3. In Paragraph 1, A method for storing xylylene diisocyanate, wherein the relative humidity at 15°C of the above nitrogen gas is 0.05RH or less.

4. In Paragraph 1, A method for storing xylylene diisocyanate, wherein, inside the storage container, the nitrogen gas is contained in an amount of 1 to 10 volume% relative to the total volume inside the storage container.

5. In Paragraph 1, A method for storing xylylene diisocyanate, which further includes a step of removing moisture from the nitrogen gas between the above (1) and (2) steps.

6. In Paragraph 1, A method for storing xylylene diisocyanate, which further includes the step of sealing the storage container after the above (2) step.

7. In Paragraph 1, A storage method for xylylene diisocyanate, wherein the urea content calculated by the following formula 1 of the above xylylene diisocyanate is 0.1 or more and less than 0.

8. <Formula 1> Urea content = (1611~1626 cm -1 Absorption peak area) / (2255~2268 cm²) -1 Absorption peak area) (At this time, the absorption peak area is measured using an FT-IR spectrometer.) 8. In Paragraph 6, A method for storing xylylene diisocyanate, wherein, after sealing the storage container, the urea content of the xylylene diisocyanate calculated by Formula 1 is within the range of 100 to 150% compared to the urea content of the xylylene diisocyanate immediately before sealing, after 60 days.

9. (1) A step of introducing xylylene diisocyanate into a storage container; and (2) The step of filling the remaining space of the storage container with nitrogen gas, and A storage method for xylylene diisocyanate, wherein the urea content calculated by the following formula 1 of the above xylylene diisocyanate is 0.1 or more and less than 0.

8. <Formula 1> Urea content = (1611~1626 cm -1 Absorption peak area) / (2255~2268 cm²) -1 Absorption peak area) (At this time, the absorption peak area is measured using an FT-IR spectrometer.) 10. As a sealed storage container, Xylylene diisocyanate is stored inside, The remaining space is filled with nitrogen gas, and Storage container for xylylene diisocyanate, wherein the relative humidity of nitrogen gas is 1 RH or less at 15˚C.

11. In Paragraph 10, A storage container for xylylene diisocyanate, wherein the relative humidity of the nitrogen gas is 0.05 RH or less at 15°C.

12. In Paragraph 10, A storage container for xylylene diisocyanate, wherein, inside the storage container, the nitrogen gas is contained in an amount of 1 to 10 volume% relative to the total volume inside the storage container.

13. In Paragraph 10, A storage container for xylylene diisocyanate, wherein the urea content calculated by the following formula 1 of the above xylylene diisocyanate is 0.1 or more and less than 0.

8. <Formula 1> Urea content = (1611~1626 cm -1 Absorption peak area) / (2255~2268 cm²) -1 Absorption peak area) (At this time, the absorption peak area is measured using an FT-IR spectrometer.) 14. In Paragraph 10, A storage container for xylylene diisocyanate, wherein a resin layer is provided on the inner surface of the storage container.

15. In Paragraph 14, A storage container for xylylene diisocyanate, wherein the resin layer is one or more selected from the group consisting of polyolefin resin, acrylonitrile styrene resin, acrylonitrile butadiene styrene resin, polyvinyl chloride resin, fluorine resin, polyester resin, phenolic resin, polyacrylic resin, epoxy resin, polyimide resin, polyamide resin, poly(thio)urethane resin, cellulose resin, silicone resin, and polycarbonate resin.