Method and production system for reducing content of chlorinated derivatives in isocyanate composition

Abstract

The present invention relates to: a method for reducing the content of chlorinated derivatives generated in the process of preparing xylylene diisocyanate; and a production system therefor. In particular, the present invention relates to a method and system in which, in order to reduce the content of chlorinated derivatives contained in a xylylene diisocyanate composition, the chlorinated derivatives are converted into non-chlorinated derivatives, by a metal surface and an anhydrous protic acid, in an apparatus comprising at least one among a metal reactor for preparing XDI, a G / L reactor to which a metal filler is separately added, and a metal distillation column for distilling a composition of XDI.

Description

Method and manufacturing system for reducing the content of chlorinated derivatives in an isocyanate composition

[0001] The present invention relates to a method and a manufacturing system for reducing the content of chlorinated derivatives in an isocyanate composition. In particular, the invention relates to a method for reducing the content of chlorinated derivatives contained in a composition of xylylene diisocyanate (hereinafter referred to as 'XDI'), and a manufacturing system for implementing such a method. Such a manufacturing system comprises one or more of a metal reactor for producing XDI, a glass-lined reactor in which a metal packing is separately added to allow a chemical reaction, particularly a dechlorination reaction, to occur, and a metal distillation column filled with structured packing or random packing for distilling the composition of XDI. In such a reducing method and system, the chlorinated derivatives are converted into non-chlorinated derivatives by means of a metal surface and an anhydrous protic acid.

[0002] Xylylene diisocyanate is a highly useful compound in the chemical, resin, and paint industries as a raw material for polyurethane, polyurea, and polyisocyanate materials. XDI is a specific diisocyanate with a methylene group on a benzene ring, combining the characteristics of both aromatic and aliphatic isocyanates. Because it possesses the property of preventing yellowing, which is a disadvantage of aromatic diisocyanates, it is used as a urethane raw material for non-yellowing paints, coatings, leather, adhesives, and more.

[0003] XDI, which is classified as an aliphatic isocyanate despite containing an aromatic ring, generates various chlorinated derivatives as byproducts due to numerous side reactions occurring during the reaction of xylylene diamine with phosgene to produce isocyanates. These chlorinated derivatives act as impurities that adversely affect the physical properties of optical lenses in polyurethane applications. In particular, it was determined that impurities exceeding a certain content cause cloudiness or yellowing, which does not have a positive effect on the product. Therefore, these chlorinated derivatives are substances that must not be generated, or if generated, must be removed through purification or other means.

[0004] Korean Patent Publication No. 1994-0001948 states that the chlorinated derivative formed during the production of a normal aliphatic isocyanate is typically formed in an amount of 3 to 10 weight percent, and sometimes reaches up to 20 weight percent.

[0005] Korean Patent Publication No. 2018-0104330 disclosed that a resin for optical materials obtained from an XDI composition in which the concentration of the chlorinated derivative compound of formula (5) is between 0.2 ppm and less than 600 ppm has excellent resistance to yellowing and high production efficiency. Additionally, Korean Patent Publication No. 2018-0127517 disclosed that the resistance to discoloration is excellent when the compound of formula 7 among the chlorinated derivatives is present at 60 ppm or less.

[0006] Accordingly, the applicant has proposed, as a prior art invention in Korean Patent Publication No. 2020-0113074, a method for converting a chlorinated derivative into a non-chlorinated derivative by a dechlorination reaction and an isocyanate composition containing such a non-chlorinated derivative. However, since the prior art invention also requires the separate use of a precious metal catalyst or explosive hydrogen gas for the dechlorination reaction, it is determined that there are limitations to its direct use within a SUS-type metal reactor or a distillation column filled with structured packing or random packing.

[0007] Accordingly, there is an urgent need for the continuous development of methods and manufacturing systems to effectively produce XDI compositions with reduced chlorinated derivative content by utilizing chemical reactions occurring on metal surfaces within the manufacturing apparatus, particularly dechlorination reactions.

[0008] (Prior art)

[0009] (Patent Document 1) Korean Patent Publication No. 1994-0001948 (Registered Mar. 12, 1994)

[0010] (Patent Document 2) Korean Patent Publication No. 2018-0104330 (Published Sep. 20, 2018)

[0011] (Patent Document 3) Korean Patent Publication No. 2018-0127517 (Published Nov. 28, 2018)

[0012] (Patent Document 4) Korean Patent Publication No. 2020-0113074 (Published Oct. 06, 2020)

[0013] The first objective of the present invention is to provide a novel manufacturing system comprising one or more of a SUS-type metal reactor, a G / L reactor in which a metal packing is separately added, and a metal distillation column filled with structured packing or random packing for distillation, so as to enable a chemical reaction, particularly a dechlorination reaction, to occur within the composition of XDI, thereby enabling the reduction of the content of chlorinated derivatives within the composition of XDI by directly utilizing the metal and protic acid within the system.

[0014] A second objective of the present invention is to provide a method for reducing the content of a chlorinated derivative, comprising the step of converting a chlorinated derivative into a non-chlorinated derivative by a chemical reaction, particularly a dechlorination reaction, with a metal surface in an XDI manufacturing apparatus and an anhydrous protonate acid.

[0015] The inventors carefully observed the reaction and distillation steps during the manufacturing process of XDI and confirmed that the chlorinated derivatives contained in XDI are partially converted into non-chlorinated derivatives, thereby completing the present invention. The present invention is intended to provide a system that converts the chlorinated derivatives in the XDI composition into non-chlorinated derivatives within the system by means of a metal surface and an anhydrous protonate acid, in order to reduce the content of the chlorinated derivatives contained in the xylylene diisocyanate composition. Accordingly, the present invention can be distinguished from the applicant's prior art invention regarding a dechlorination reaction using a precious metal catalyst or explosive hydrogen gas under a hydrogen (H2) atmosphere. Furthermore, the present invention can be directly applied in a metal reactor or a distillation column filled with structured packing or random packing, thereby bringing economic benefits in terms of industrialization, such as a reduction in process costs.

[0016] To achieve the above objective, as a first subject matter of the present invention, the present invention is,

[0017] A manufacturing system for producing a xylylene diisocyanate (XDI) composition, comprising: a reactor for producing said XDI from xylylene diamine or a hydrochloride thereof;

[0018] A first distillation column for distilling a composition of XDI containing a chlorinated derivative of formula (2) prepared from the above reactor; comprising,

[0019] The above-mentioned first distillation column provides a manufacturing system in which the above-mentioned chlorinated derivative is converted into a non-chlorinated derivative of the following formula (3) by a chemical reaction between the metal surface in the distillation column and an anhydrous proton acid:

[0020] Chemical formula (2); Chemical formula (3).

[0021] (Here, R1 is Cl or NCO, R2 is H or Cl, and R3 is H or NCO.)

[0022] In another embodiment, the reactor for producing the XDI in the manufacturing system of the present invention may be a metal reactor and may be made of SUS (stainless steel) so that the inner surface of the metal can act as a catalyst.

[0023] In another aspect, in the manufacturing system of the present invention, when the reactor for producing the XDI is a G / L reactor, it is necessary to separately add a metal filler within the reactor so that the chemical reaction can occur.

[0024] In addition, in the present invention, the first distillation column may be a device for removing the solvent in the composition of the XDI produced from the reactor, and may include a distillation column filled with structured packing or random packing of metal, or a thin-film distillation device made of metal.

[0025] In another embodiment, the manufacturing system of the present invention may further include a second distillation column for removing low-boiling point substances in the composition of the XDI.

[0026] In another embodiment, the manufacturing system of the present invention may further include a third distillation column for removing high-boiling point substances in the composition of the XDI.

[0027] In the present invention, the proton acid may be selected from either a monoprotic acid or a polyprotic acid. Here, the proton acid may preferably be hydrogen chloride (HCl).

[0028] In the present invention, the metal filler may be a metal piece made of one or more metals selected from the group consisting of single metals of Fe, Zn, Cu, Cr, Mn, Ni, Ag, Mo, and Co, and alloys thereof, among transition metals in groups 3 to 12 of the periodic table.

[0029] In a further embodiment, the hydrogen chloride may be obtained from hydrogen chloride gas, which is a reaction byproduct generated during the process of reacting an organic primary amine with a carbonylating agent to produce the XDI:

[0030] .

[0031] Here, the carbonylation agent may be selected from phosgene, diphosgene, triphosgene, aliphatic or aromatic chloroformate, or a combination thereof.

[0032] In another embodiment, the hydrogen chloride is the following carbamoyl chloride (R4-(NH-CO-Cl) n It can be obtained through the decomposition process of , n=1 or 2):

[0033]

[0034] (Here, R4 is -NCO or -NHCOCl).

[0035] In the present invention, the content ratio of the chlorinated derivative is in the range of greater than 0 to 50,000 ppm (5 weight%), and the content ratio of the non-chlorinated derivative is in the range of 0.1 to 100,000 ppm (10 weight%). In addition, in the manufacturing system of the present invention, the content ratio of the XDI is preferably 80 mass% or more, 85 mass% or more, 85 mass% or more, 95 mass% or more, 97 mass% or more, and 99 mass% or more.

[0036] Meanwhile, as a second subject matter of the present invention, the present invention provides a method for reducing the content of a chlorinated derivative in an XDI composition comprising a chlorinated derivative represented by the following chemical formula (2) in a manufacturing apparatus for xylylene diisocyanate (XDI).

[0037] A method for reducing the content of a chlorinated derivative is provided, comprising the step of converting the chlorinated derivative into a non-chlorinated derivative of the following chemical formula (3) by a chemical reaction between a metal surface in the above-mentioned manufacturing apparatus and an anhydrous protonate acid:

[0038] Chemical formula (2); Chemical formula (3).

[0039] (Here, R1 is Cl or NCO, R2 is H or Cl, and R3 is H or NCO.)

[0040] In another embodiment, in a method for reducing the content of a chlorinated derivative, the apparatus for producing the XDI comprises a reactor for producing the XDI from xylylene diamine or a hydrochloride thereof;

[0041] It may include a first distillation column for distilling a composition of XDI containing a chlorinated derivative of formula (2) produced from the above reactor. Here, the metal reactor for producing the XDI may be made of SUS so that it can act as a catalyst on the inner surface of the metal. In addition, if the reactor for producing the XDI is a G / L reactor, a metal filler may be separately added to allow the chemical reaction to occur within the reactor.

[0042] In another embodiment, the first distillation column may be a device for removing solvent from the composition of the XDI produced from the reactor, and may be a distillation column filled with structured packing or random packing of metal, or may include a thin-film distillation device made of metal.

[0043] In another embodiment, the protic acid may be selected from either a monoprotic acid or a polyprotic acid, and the protic acid is preferably hydrogen chloride (HCl).

[0044] In another embodiment, in addition to the hydrogen chloride (HCl), the other monoprotic acid may be one or more selected from the following:

[0045] Hydrobromide (HBr), hydroiodide (HI), perchloric acid (HClO4), chloric acid (HClO3), nitric acid (HNO3), iodic acid (HIO3), oxalic acid (H2C2O4), sulfurous acid (H2SO3), hypochlorous acid (HClO2), chloroacetic acid (CH2ClCOOH), hydrofluoric acid (HF), nitrous acid (HNO2), formic acid (HCOOH), benzoic acid (C6H5COOH), hydrazous acid (HN3), acetic acid (CH3COOH), propionic acid (CH3CH2COOH), hypochlorous acid (HClO), hydrocyanic acid (HCN), and trifluoroacetic acid (CF3COOH).

[0046] In addition, the polyprotic acid may be one or more selected from the group consisting of phosphoric acid (H3PO4), phosphorous acid (H3PO3), and hypophosphorous acid (H3PO2).

[0047] In another embodiment, the metal constituting the XDI manufacturing apparatus may be one or more selected from the group consisting of single metals of Fe, Zn, Cu, Cr, Mn, Ni, Ag, Mo, and Co, and alloys thereof.

[0048] In another aspect of the present invention, the hydrogen chloride may be obtained from hydrogen chloride gas, which is a reaction byproduct generated during the process of reacting an organic primary amine with a carbonylating agent to produce the XDI:

[0049] .

[0050] In another embodiment, the carbonylating agent may be selected from phosgene, diphosgene, triphosgene, chloroformate, or a combination thereof. In particular, the hydrogen chloride of the present invention is the following carbamoyl chloride (R4-(NH-CO-Cl) n , can be additionally obtained through the decomposition process of n=1 or 2):

[0051] .

[0052] In another aspect of the present invention, the content ratio of the non-chlorinated derivative is in the range of greater than 0 to 50,000 ppm (5 weight%), and the content ratio of the non-chlorinated derivative is in the range of 0.1 to 100,000 ppm (10 weight%). In addition, in the method of the present invention, the content ratio of the XDI is preferably 80 mass% or more, 85 mass% or more, 85 mass% or more, 95 mass% or more, 97 mass% or more, and 99 mass% or more.

[0053] In another aspect of the present invention, the method of the present invention may further include a second distillation column for removing low-boiling point substances in the composition of the XDI, or a third distillation column for removing high-boiling point substances in the composition of the XDI, or both.

[0054] In the method and manufacturing system of the present invention, chlorinated derivatives can be directly converted into non-chlorinated derivatives, thereby achieving a reduction in process costs and making it economical. Furthermore, by obtaining an XDI composition with a reduced content of chlorinated derivatives, high-quality optical resins or optical products can be obtained with high economic efficiency.

[0055] FIG. 1 is a schematic diagram showing one embodiment of the present invention.

[0056] definition

[0057] All technical and scientific terms used in the description of the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention pertains, unless otherwise defined. All patent publications, application publications, and other publications cited as prior art are incorporated by reference in their entirety.

[0058] As used in this specification, the term 'combination' includes blends, mixtures, reaction products, etc.

[0059] In addition, specific numerical values ​​such as mixing ratios (content ratios), physical properties, and parameters described in the present invention may be replaced with the corresponding upper limits (numerical values ​​defined as “less than or equal to” or “less than”) or lower limits (numerical values ​​defined as “greater than or equal to” or “greater than”) of the mixing ratios (content ratios), physical properties, and parameters described. Meanwhile, the content units of the constituent components of the composition, such as “%” and ppm, are based on mass unless otherwise specifically stated.

[0060] As used in the description of the present invention, 'isocyanate' refers to a substance used as a polyurethane-based material or a polyurea-based material, and these materials are synthesized with different structures depending on the number and position of functional groups. Here, 'isocyanate' is used to include monoisocyanates, diisocyanates, or polyisocyanates. The singular form of a compound used in the description and claims of the present invention includes multiple references unless the context clearly indicates otherwise. For example, a reference to 'isocyanate' includes a mixture of two or more types of monoisocyanates, diisocyanates, and polyisocyanates.

[0061] Each of the materials disclosed in the description of the present invention is commercially available unless specifically noted, and the method of producing them is known to those skilled in the art. Furthermore, unless otherwise stated in the description of the present invention, all test standards are the most recent standards valid at the time of this application.

[0062] In the present invention, XDI of formula (1) includes structural isomers 1,2-XDI (ortho-form), 1,3-XDI (meta-form), and 1,4-XDI (para-form), which may be used alone or in combination of two or more types, preferably 1,3-XDI or 1,4-XDI, more preferably 1,3-XDI:

[0063] (Equation 1).

[0064] Isocyanates can generally be produced by the direct method, the hydrochloride method, or the carbonate method, and the term 'chlorinated derivative' refers to impurities containing chlorine generated by side reactions during the production process. In the present invention, chlorinated derivatives include chloromethylbenzyl isocyanate (Formula 4), xylylene dichloride (Formula 5), ​​dichloromethylbenzyl isocyanate (Formula 6), etc., represented by the following chemical formulas:

[0065] (Equation 4); (Equation 5); (Equation 6)

[0066] The term 'non-chlorinated derivative' is used to refer to a substance obtained by converting the above 'chlorinated derivative' to remove chlorine by substituting it with other atoms or atomic groups. In the present invention, non-chlorinated derivatives include the following methylbenzyl isocyanate (Chemical Formula 7) and xylene (Chemical Formula 8).

[0067] (Equation 7); (Equation 8)

[0068] (Here, R3 is H or NCO.)

[0069] Meanwhile, in the present invention, since a certain amount of a chlorinated derivative known as chloromethylbenzyl isocyanate (Chemical Formula 4) is produced in the hydrochloride method as in the direct method, it is necessary to reduce the content of the chlorinated derivative.

[0070] Since the isocyanate composition obtained by the manufacturing method of the present invention is used as a reactant to obtain a polymer compound such as polyurethane, it is preferable that the aliphatic amine used in the present invention be a difunctional or multi-chain or cyclic aliphatic amine.

[0071] In this invention, the term "dechlorination reaction" refers to any chemical reaction capable of converting a chlorinated derivative generated during the XDI manufacturing process into a non-chlorinated derivative; as long as such a conversion process can be brought about, there is no need to limit it to a specific reaction.

[0072] The difunctional or cyclic aliphatic amines preferably used in the present invention are not particularly limited, but reference should be made to those mentioned in the aforementioned prior art, Patent No. 10-0953019. Representative examples include hexamethylenediamine, 2,2-dimethylpentanediamine, 2,2,4-trimethylhexanediamine, butenediamine, xylylenediamine, and other chain-like aliphatic amines, and cyclic aliphatic amines such as bis(aminomethyl)cyclohexane, dicyclohexylmethanediamine, cyclohexanediamine, and bis(aminomethyl)norbornene.

[0073] The isocyanate obtained by reacting the aforementioned chain-like or cyclic aliphatic diamine with phosgene will be determined by the diamine being reacted, and reference should be made to the aforementioned prior art, Patent No. 10-0953019. Representative examples include chain-like aliphatic isocyanates such as hexamethylene diisocyanate, 2,2-dimethylpentane diisocyanate, 2,2,4-trimethylhexane diisocyanate, butene diisocyanate, and xylylene diisocyanate, and cyclic aliphatic isocyanates such as bis(isocyanatomethyl)cyclohexane, dicyclohexylmethane diisocyanate, cyclohexane diisocyanate, and bis(isocyanatomethyl)norbornene. Among the above example compounds obtained by the manufacturing method of the present invention, compounds particularly preferred for various optical device applications include xylylene diisocyanate, bis(isocyanatomethyl)norbornene, hexamethylene diisocyanate, and bis(isocyanatomethyl)cyclohexane.

[0074] The term 'carbonylation agents' refers to reagents that induce a carbonylation reaction, which is a reaction that introduces carbon monoxide into organic compounds. Carbonylation produces organic carbonyls, that is, compounds containing >C=O functional groups such as aldehydes, ketones, carboxylic acids, and esters. In particular, organic compounds containing carbonyl groups have unsaturated bonds, making them highly reactive and potentially highly selective, so they are widely used in synthetic chemistry. Representative carbonylation agents used in the present invention include phosgene, diphosgene, triphosgene, and chloroformate-based compounds, and these can be used individually or in combination of two types.

[0075] The phosgene gas that can be used in the production of xylylene diisocyanate of the invention is the common name for carbonyl chloride or carbonyl dichloride (COCl2), is a colorless gas at room temperature with a freezing point of -127.84°C and a boiling point of 7.84°C, and is generally produced by using a catalytic reaction of high-purity carbon monoxide with anhydrous chlorine gas. The phosgene substitute and / or precursor used according to the present invention may include any phosgene equivalents such as diphosgene, triphosgene, etc., and any combinations thereof. The phosgene used in the present invention may be provided by the thermal decomposition of a carbamic acid derivative using chloroformate, diphenyl carbamate, or N,N'-carbonyldiimidazole, etc.

[0076] First, the present invention aims to convert chlorinated derivatives generated during the isocyanate manufacturing process into non-chlorinated derivatives by utilizing a metal surface or metal filler within the device and an anhydrous protonate acid in an XDI manufacturing system, as shown in the reaction scheme below. By doing so, the purity of the isocyanate composition can be increased by easily reducing the content of chlorinated derivatives without undergoing complex, high-stage purification processes or without separate processes and equipment.

[0077]

[0078] (R1 is Cl or NCO, R2 is H or Cl, and R3 is H or NCO.)

[0079] The reactor or distillation tower filled with structured packing (Mellapak) or random packing used in the present invention is constructed of SUS so that it can act as a catalyst on the inner metal surface of the reactor or tower (or column). This SUS reacts with chlorinated derivatives together with anhydrous protonated acids to convert the chlorinated derivatives into non-chlorinated derivatives. For reference, although the term "SUS reactor" is conventionally used in the industry, SUS (stainless steel) is an abbreviation for the Japanese standard, while the domestic standard is STS (steel type stainless).

[0080] Representative stainless steel reactors may be selected from SUS 303, 304TP, 316, or 316L, but the present invention is not limited to these. Their specifications are shown in Table 1 below. Here, the content of iron (Fe) as a main component refers to the remaining content excluding the weight % of the chemical components indicated herein.

[0081]

[0082] The commonly used SUS 303 reactor is an ultra-low carbon steel that prevents intergranular corrosion and is used in applications requiring resistance to intergranular corrosion in welded conditions. Additionally, SUS 316 and 316L reactors have good corrosion and acid resistance and significantly increased high-temperature strength due to the addition of -Mo; in particular, since SUS 316L is an ultra-low carbon steel, it is used in applications requiring resistance to intergranular corrosion in welded conditions.

[0083] Meanwhile, metal packing materials can be classified into those usable in the reactor of the XDI manufacturing apparatus and those usable in the distillation apparatus. For metal packing materials usable in the reactor, it is sufficient if they are in a particulate form of a uniform size to facilitate the reaction, so they are not specifically limited. For packing materials usable in the distillation apparatus, structured packing or random packing can be used as representative options, but they are not limited to these. The specific surface area of ​​the metal constituting the structured and random packing materials is not specifically limited, as long as it can react with anhydrous protons and chlorinated derivatives to convert them into non-chlorinated derivatives. Structured packing is not limited to a specific product, but Mellapak™ is the most widely used worldwide. In particular, MellapakPlus™ is known as the latest generation of structured packing materials. This enhances the geometric structure of the existing Mellapak, allowing for a significantly lower pressure drop and a 50% increase in maximum capacity compared to the original Mellapak. Random packing, such as rasching rings, pall rings, and saddles, may be selectively used considering height, pressure, material, fouling, etc., similar to the theoretical plate, and is not specifically limited.

[0084] Furthermore, the distillation column of the present invention may be installed with only one structured packing bed, but may also include one or more structured packing beds. The presence of one bed of structured packing results in a shorter average residence time of liquid, particularly vapor, in the structured packing compared to the presence of two or more structured packing beds. This would be preferable to have two or more beds, as the residence time for vapor and liquid is increased due to the resistance between the two beds.

[0085] Meanwhile, the metal thin-film distillation apparatus that can be used in the present invention is a system for effectively separating and concentrating substances. It is sufficient to have a device composed of metal that applies physical force to a liquid mixture to form a thin film, thereby increasing the evaporation rate and effectively separating the substances, and is not specifically limited to such devices. In the present invention, an XDI solution containing a chlorinated derivative will flow down while forming a thin film on the inner wall of the distillation apparatus, and through a reduction process with the protonated acid containing hydrogen chloride in the solution and the inner metal surface of the distillation column, the chlorinated derivative will be efficiently converted into a non-chlorinated derivative.

[0086] The thin-film distillation apparatus that can be used in the present invention may be performed using a general metal distillation column equipped with an evaporator, a condenser, and a pressure reduction means. The rotational speed of the rotor of the thin-film distillation apparatus may be in the range of 50 rpm or more to 500 rpm or less, preferably in the range of 200 rpm or more to 350 rpm or less. The temperature during thin-film distillation may also be in the range of 170 ℃ to 130 ℃, and the pressure may be in the range of 0.001 kPa or more to 1 kPa or less. Under these thin-film distillation conditions, the conversion of the chlorinated derivative to the non-chlorinated derivative can be performed simultaneously with the reduction of the residence time of the purification step and the increase in purification efficiency, and a high-purity diisocyanate compound with a reduced content of the chlorinated derivative can be obtained. In one embodiment, the step of converting the chlorinated derivative to the non-chlorinated derivative may be performed in multiple stages while varying the temperature and / or pressure conditions. For example, a step of converting a chlorinated derivative into a non-chlorinated derivative can be performed before or after sequentially proceeding with solvent removal, removal of low-boiling point impurities, general purification steps, and / or oligomer removal steps.

[0087] There are various types of G / L reactors that can be used in the present invention, such as the AE type, which is the most common type with the upper part of the reactor connected in the form of a girth flange; the BE type, which has no girth flange on the upper part of the reactor and has the stirring shaft and blade assembled inside the reactor; the CR type, which has no girth flange between the body and the upper part of the reactor but is connected by a flange to allow the integrated stirring shaft and blade to be inserted into the motor mount area; and the buchi-chemreactor, which is designed to allow visual inspection of the inside of the reactor while utilizing the advantages of each reaction type. The present invention is not limited to these types of reactors and will be determined according to the type of isocyanate to be manufactured or the batch or continuous process type.

[0088] The proton acid that can be used in the present invention corresponds to the acid in the Brønsted-Lowry acid-base theory, which defines a proton donor as an acid, and is an extension of the acid in the commonly used Arrhenius acid-base theory.

[0089] In the present invention, the monoprotic acid may be selected from the group consisting of hydrobromide (HBr), hydroiodide (HI), perchloric acid (HClO4), hydrogen chloride (HCl), chloric acid (HClO3), nitric acid (HNO3), iodic acid (HIO3), oxalic acid (H2C2O4), sulfurous acid (H2SO3), hypochlorous acid (HClO2), chloroacetic acid (CH2ClCOOH), hydrofluoric acid (HF), nitrous acid (HNO2), formic acid (HCOOH), benzoic acid (C6H5COOH), hydrazonic acid (HN3), acetic acid (CH3COOH), propionic acid (CH3CH2COOH), hypochlorous acid (HClO), hydrocyanic acid (HCN), trifluoroacetic acid (CF3COOH), etc.

[0090] In addition, diprotic acids may be selected from the group consisting of sulfuric acid (H2SO4), oxalic acid (H2C2O4), carbonic acid (H2CO3), hydrogen sulfide (H2S), chromic acid (H2CrO4), terephthalic acid (HOOC-C6H4-COOH), butenedionic acid (HOOC-CH=CH-COOH), hydrogen telluric acid (H2Te), selenhydric acid (H2Se), etc. Furthermore, triprotic acids may be selected from the group consisting of phosphoric acid (H3PO4), arsenic acid (H3AsO4), phosphoric acid (H3PO3), hypophosphorous acid (H3PO2), etc. These diprotic and triprotic acids may be collectively referred to as polyprotic acids.

[0091] In particular, in the present invention, fluoroantimonic acid (HSbF6), magic acid (HSO3F + SbF5), fluorosulfonic acid (HSO3F), and carborene acid [H(CHB6), which are classified as super acids but are partially included in the above monoprotic or diprotic acids, are included in the monoprotic or diprotic acids. 11 Cl 11 )], trifluoromethane sulfonic acid (CF3SO3H), perchloric acid (HClO4), chlorosulfonic acid (HSO3Cl), sulfuric acid (H2SO4), hydrofluoric acid (HF), etc. may also be used.

[0092] Meanwhile, the chlorinated derivative included in the XDI composition of the present invention includes, as described above, chloromethylbenzyl isocyanate, xylylene dichloride, dichloromethylbenzyl isocyanate, etc., and may exist alone or in two or more types.

[0093] Meanwhile, the compound of methylbenzyl isocyanate as the above-mentioned non-chlorinated derivative includes structural isomers 1,2-methylbenzyl isocyanate, 1,3-methylbenzyl isocyanate, and 1,4-methylbenzyl isocyanate, similar to the structural isomers of XDI, and may exist alone or in two or more types, preferably 1,3-methylbenzyl isocyanate and 1,4-methylbenzyl isocyanate, more preferably 1,3-methylbenzyl isocyanate. In addition, in the case of xylene, it includes structural isomers 1,2-xylene, 1,3-xylene, and 1,4-xylene, and may exist alone or in two or more types, preferably 1,3-xylene and 1,4-xylene, more preferably 1,3-xylene.

[0094] In the method and manufacturing system for reducing the content of chlorinated derivatives according to the present invention, it is not necessary to specify the content of chlorinated derivatives within the XDI composition. For example, if the content of chlorinated derivatives is above a certain level, the method and system of the present invention for reducing them can be carried out. However, since the XDI composition obtained from the present invention must be within an acceptable range for the physical properties of the lens obtained therefrom, it is necessary to limit the minimum content of chlorinated derivatives and non-chlorinated derivatives.

[0095] In the first object of the present invention, the system for manufacturing an XDI composition, or in the second object, the method for reducing the content of chlorinated derivatives, it is not necessary to specify the content of chlorinated derivatives and non-chlorinated derivatives contained in the XDI composition. This is because, if the content of chlorinated derivatives is high, it may be converted into non-chlorinated derivatives by performing the system for manufacturing an XDI composition or the method for reducing the content of chlorinated derivatives multiple times, depending on the object of the present invention. Furthermore, the content of non-chlorinated derivatives contained in the XDI composition may not be specified, as it is determined by the content of chlorinated derivatives contained in the XDI composition and the number of times the system for manufacturing and the method of the present invention are performed. In particular, if the content of non-chlorinated derivatives in the XDI composition is high, it may be removed to a certain level through distillation. However, from a commercial perspective of economically and efficiently carrying out the manufacturing system of the XDI composition as the first object of the present invention, or the method of reducing the content of the chlorinated derivative as the second object, if the content of the chlorinated derivative in the composition of XDI produced from the reactor is high, it may be necessary to adjust the purity of xylylene diamine or its hydrochloride.

[0096] Accordingly, in the present invention, based on the total weight of the XDI composition, it is necessary to ensure that the content of the chlorinated derivative is 50,000 ppm or less, 40,000 ppm or less, 30,000 ppm or less, 20,000 ppm or less, and preferably 10,000 ppm or less. In addition, the chlorinated derivative may remain in the XDI composition in trace amounts even after being converted into a non-chlorinated derivative such as methylbenzyl isocyanate. If the chlorinated derivative exceeds 100,000 ppm, the yellowness of the lens will increase. Therefore, when using the XDI composition as an optical lens, the content of the chlorinated derivative is within the range of greater than 0 to 2,500 ppm or less, greater than 0 to 2,000 ppm or less, and greater than 0 to 1,700 ppm or less with respect to the total mass of the XDI composition, and preferably within the range of greater than 0 to 1,500 ppm or less.

[0097] Meanwhile, when the XDI composition obtained in the present invention is used as an optical lens, it is necessary to limit the non-chlorinated derivative, including methylbenzyl isocyanate, to a specific range. For example, if the content of the non-chlorinated derivative exceeds 100,000 ppm, the physical properties as a lens, such as heat resistance, are reduced; therefore, the content of the non-chlorinated derivative is within the range of 0.1 ppm to 100,000 ppm, 0.1 ppm to 80,000 ppm, 0.1 ppm to 70,000 ppm, and 0.1 ppm to 60,000 ppm with respect to the total mass of the XDI composition, and preferably, it is preferred to be 0.1 ppm or more to 50,000 ppm or less. In this regard, further reference should be made to the applicant's prior art mentioned in Patent Document 4 in the background art.

[0098] The manufacturing system of the isocyanate composition of the present invention shown in FIG. 1 may further include a reaction step (conducted in a reactor (30)) in which an amine or a salt thereof is reacted with phosgene under a solvent to obtain a reaction product containing an isocyanate compound; a desolvation step (conducted in a first distillation column (40)) in which the solvent is recovered from the reaction product; a low-boiling point substance removal step (conducted in a second distillation column (50)) in which a low-boiling point substance (including monoisocyanates such as (chloromethyl)benzyl isocyanate) is removed from the reaction product from which the solvent has been removed; and a high-boiling point substance removal step (conducted in a third distillation column (60)) in which a high-boiling point substance (including oligomers containing dimers or trimers or more of isocyanates) is removed from the reaction product from which the low-boiling point substance has been removed. In this way, the present invention may also further include a step of separating the non-chlorinated derivative produced in the distillation column from the XDI composition by simple distillation so that the content ratio of the non-chlorinated derivative becomes a desired composition ratio.

[0099] Meanwhile, the process of converting a chlorinated derivative into a non-chlorinated derivative according to the present invention can be divided into a reaction step and a distillation step, and can be carried out alone or in parallel. The temperature of the non-chlorinated conversion process of the chlorinated derivative is not particularly limited, but is 10 to 200 o It can be carried out at C, preferably 100 to 180 o C, more preferably 110 to 160 o C. If the temperature is too low, the reaction rate is low, resulting in a low removal rate of chlorinated derivatives; if the temperature is too high, there is a disadvantage in that the viscosity of the solution increases significantly due to oligomer formation, etc.

[0100] Meanwhile, the isocyanate composition of the present invention can be provided as a monomer raw material for polymerizing with a polyol / polythiol monomer to produce an optical polymer composition. Although not directly addressed in the present invention, the optical polymerizable composition may include the isocyanate composition monomer and the polyol / polythiol monomer in a mixed state or in a separated state. That is, within the polymerizable composition, the isocyanate composition monomer and the polyol / polythiol monomer may be in a state where they are in contact with each other and blended, or in a state where they are separated so as not to come into contact with each other.

[0101] Examples of polyol components used in optical polymerizable compositions include low molecular weight polyols and high molecular weight polyols. The polyols may be used in combination of one or more types. Examples of polythiol components include aliphatic polythiols, aromatic polythiols, heterocyclic polythiols, aliphatic polythiols containing a sulfur atom other than a mercapto group, aromatic polythiols containing a sulfur atom other than a mercapto group, and heterocyclic polythiols containing a sulfur atom other than a mercapto group.

[0102] In addition, the optically polymerizable composition may further include, as needed, additives such as internal release agents, ultraviolet absorbers, near-infrared absorbers, polymerization initiators, heat stabilizers, color correctors, chain extenders, crosslinking agents, light stabilizers, antioxidants, and fillers.

[0103] In this regard, reference should be made to the applicant's prior art mentioned as Patent Document 4 in the background art.

[0104] [Analysis Method]

[0105] 1) Content of 1,3-dichloromethylbenzyl isocyanate (DCI, chemical formula 6)

[0106] A compound of Formula 6 with a purity of 99 mol%, prepared by the synthesis method specified in Korean Patent Registration No. 10-2340535, was used as a standard substance and analyzed by gas chromatography under specified conditions, and a calibration curve was prepared from the area value of the obtained gas chromatogram to quantify the compound.

[0107] 2) Content of 1,3-xylylene diisocyanate (XDI, Chemical Formula 1)

[0108] The compound of Chemical Formula 1 was quantified by analyzing it by gas chromatography under the conditions specified in Korean Patent Registration No. 10-2340535 and preparing a calibration curve of the obtained gas chromatogram.

[0109] 3) Content of 3-chloromethylbenzyl isocyanate (CBI, chemical formula 4)

[0110] The compound of Chemical Formula 4 was quantified by analyzing it by gas chromatography under the conditions specified in Korean Patent Registration No. 10-2340535 and preparing a calibration curve of the obtained gas chromatogram.

[0111] 4) Content of 3-methylbenzyl isocyanate (MBI, chemical formula 7)

[0112] Using 98% pure methylbenzyl isocyanate (reagent, Sigma-Aldrich) as a standard substance, the content of methylbenzyl isocyanate in the compositions of each example and comparative example was calculated by proceeding in the same manner as the XDI measurement method above.

[0113]

[0114] [Example]

[0115] [Specific example of a manufacturing system as the first object of the present invention]

[0116] Next, we will examine in detail a manufacturing system for producing the XDI composition, comprising: a reactor for producing the XDI from xylylene diamine; and a first distillation column for distilling the composition of XDI containing a chlorinated derivative of formula (2) produced from the reactor.

[0117] (Synthesized Example 1)

[0118] 2160 kg of o-dichlorobenzene and 436 kg of bis(trichloromethyl)carbonate in a 3 m³ equipped with a reflux condenser 3 It was dissolved in a glass-lined (G / L) reactor. Subsequently, a solution of 120 kg of m-xylylenediamine dissolved in 120 kg of o-dichlorobenzene was slowly added to the reactor at a temperature below 60 °C. After raising the temperature to 160 °C, the reaction was carried out for 4 hours while controlling the release of hydrogen chloride gas. During the temperature increase, a solution of bis(trichloromethyl)carbonate dissolved in o-dichlorobenzene was additionally and slowly added while stirring smoothly. After the reaction was completed, nitrogen was purged from the reactor to remove unreacted phosgene and hydrogen chloride gas. The XDI obtained at this time contained 2330 ppm of CBI and 65 ppm of DCI, which are chlorinated derivatives, and had an acidity of 2850 ppm.

[0119]

[0120] Next, we will examine the process of manufacturing 1,3-xylylene diisocyanate (XDI) through the manufacturing system of Fig. 1.

[0121] (1) Isocyanation reaction in a SUS 316 metal reactor

[0122] 8,100 kg of o-dichlorobenzene and 1,634 kg of bis(trichloromethyl)carbonate are introduced into a bis(trichloromethyl)carbonate dilution container (10) and dissolved, and then the dissolved reaction product is 12 m of SUS 316 material 3The reactant was transferred to the isocyanating reactor (30) through the reactant transfer line (12). Then, a solution in which 450 kg of m-xylylenediamine was dissolved in 450 kg of o-dichlorobenzene in the m-xylylenediamine dilution container (20) was slowly added to the isocyanating reactor (30) at 60°C or lower through the reactant transfer line (22).

[0123] After raising the temperature of the reactor to 160°C, the reaction was carried out for 6 hours while controlling the released hydrogen chloride gas. During the temperature increase, a solution of bis(trichloromethyl)carbonate dissolved in o-dichlorobenzene was additionally slowly introduced into the isocyanating reactor (30) through the reactant transfer line (12) and stirred smoothly. After the reaction was finished, the nitrogen inside the reactor was purged to remove unreacted phosgene and hydrogen chloride gas through the gas discharge line (31).

[0124] At this time, the content of the chlorinated derivative CBI was 2160 ppm, the content of DCI was 41 ppm, and the acidity was 1820 ppm, confirming that 850 ppm of the non-chlorinated derivative MBI was produced. Although the content of the reactants was different, unlike Synthesis Example 1, the CBI content was about 170 ppm lower, and about 850 ppm of the non-chlorinated derivative MBI was produced.

[0125] (2) Solvent removal process using a first distillation tower made of SUS 316 metal

[0126] The first distillation column (40) for removing the solvent is made of SUS 316 metal and is filled with a structural packing made of SUS 316 metal. The temperature of the first distillation column is 50 to 120 oThe reaction product, from which unreacted phosgene and hydrogen chloride gas have been removed, is supplied stepwise through the reaction product transfer line (32) to the first distillation tower (40) for removing the solvent, and the solvent containing o-dichlorobenzene is removed through the solvent discharge line (41). The reaction product from which the solvent has been removed is transferred through the reaction product transfer line (42) to the second distillation tower (50) for removing low-boiling point substances.

[0127] The XDI composition obtained after solvent removal contained 1530 ppm of the chlorinated derivative CBI, 21 ppm of DCI, and 560 ppm of the non-chlorinated derivative MBI. Compared to the isocyanation process, the content of the chlorinated derivative decreased, and the content of the non-chlorinated derivative increased.

[0128] (3) Removal of low-boiling point substances using a second distillation tower made of SUS 316 metal

[0129] The second distillation column (50) for removing low-boiling point substances is made of SUS 316 metal material and is filled with a structural packing made of SUS 316 metal material. The temperature of the second distillation column is 130~160 o It was operated under high vacuum in the C range. Low-boiling point substances, including non-chlorinated derivative MBI and chlorinated derivative CBI, were removed through the low-boiling point substance discharge line (52).

[0130] If CBI and DCI, which are chlorinated derivatives generated in the isocyanation process of Synthesis Example 1, are to be separated and purified directly in this process, it would require a significant amount of processing time, and the separation efficiency would inevitably be low because the difference in boiling points between CBI and XDI is not large. However, in the XDI manufacturing system of the present invention, CBI, which is a chlorinated derivative, is converted into a non-chlorinated derivative with a relatively much lower boiling point during the isocyanation process and subsequent processes. This makes it considerably easier to remove low-boiling point substances in the second distillation column, thereby shortening the processing time and showing a high yield due to the high separation efficiency.

[0131] (4) High-boiling point substance removal process using a SUS 316 metal third distillation tower

[0132] The third distillation column (60) for removing high-boiling point substances is made of SUS 316 metal and is filled with a structural packing made of SUS 316 metal. The temperature of the distillation column is 130 to 160 o It was operated under high vacuum in the C range. The high-boiling point material was removed through the high-boiling point material discharge line (62), and the final XDI composition could be obtained from the isocyanate product discharge line (61).

[0133] The XDI composition had a purity of over 99.8% and contained 102 ppm of the chlorinated derivative CBI, 12 ppm of DCI, and 5 ppm of the non-chlorinated derivative MBI.

[0134] The content of chlorinated derivatives and non-chlorinated derivatives of the reaction products obtained by process in the manufacturing system schematically illustrated in Figure 1 is shown in Table 2.

[0135]

[0136] Here, (1) CBI: chloromethyl benzyl isocyanate; (2) DCI: chloromethyl benzyl isocyanate; (3) MBI: methyl benzyl isocyanate

[0137] While MBI, a non-chlorinated derivative, was not produced during the isocyanation reaction in the G / L reactor of Synthesis Example 1, MBI, a non-chlorinated derivative, was produced during the isocyanation process of the XDI manufacturing system equipped with a metal reactor and distillation column, confirming that the chlorinated derivative of XDI was converted into a non-chlorinated derivative. In addition, MBI increased as CBI decreased significantly during the distillation process.

[0138] By directly converting chlorinated derivatives into non-chlorinated derivatives within a reactor or distillation column filled with metal surfaces or metal fillers, the process time for separation and purification is reduced, thereby lowering process costs and achieving high yields. Consequently, relatively high-quality products can be obtained, making it competitive in terms of quality and price.

[0139] In the prior art, for the hydrogenation of chlorinated derivatives, a process must be carried out using an expensive (precious) metal catalyst such as Pd under a hydrogen (H2) gas atmosphere that poses a risk of explosion. Consequently, in the method of the prior art, a separate hydrogen (H2) storage and supply device and a separate process and equipment for carrying out hydrogenation are additionally required, which increases costs such as increased investment costs for the device and can significantly lower economic feasibility.

[0140] However, when isocyanates are manufactured using the XDI manufacturing system of the present invention, it is possible to conveniently convert them into non-chlorinated derivatives in-situ even when isocyanates are synthesized by a direct method, without the need for the complex process of manufacturing XDA hydrochloride to reduce the formation of chlorinated derivatives during the reaction step. Therefore, through the manufacturing system of the present invention, not only is the economic effect high, but a high-quality XDI composition is obtained, making it possible to produce high-quality optical resins or optical products with high economic efficiency.

[0141]

[0142] [Specific embodiment of the method as the second object of the present invention]

[0143] Next, we will specifically examine a method for reducing the content of the chlorinated derivative in an XDI composition containing the chlorinated derivative represented by the following chemical formula (1) within an XDI manufacturing apparatus.

[0144] 2-1. Synthesis of XDI and Preparation of XDI Compositions Containing Chlorinated Derivatives

[0145] (Synthesized Example 2-1)

[0146] 4.7 kg of bis(trichloromethyl)carbonate was dissolved in 23.4 kg of o-dichlorobenzene in a 30 L glass reaction vessel equipped with a reflux condenser. Subsequently, a solution of 1.3 kg of m-xylylenediamine dissolved in 1.3 kg of o-dichlorobenzene was slowly added to the reaction vessel at a temperature below 60 ℃. After raising the temperature to 160 ℃, the reaction was carried out for 4 hours while controlling the release of hydrogen chloride gas. During the temperature increase, the solution of bis(trichloromethyl)carbonate dissolved in o-dichlorobenzene was additionally and slowly added while stirring smoothly. After the reaction was completed, nitrogen was purged from the reactor to remove unreacted phosgene and hydrogen chloride gas, and the resulting solution was subjected to desolvation and de-low-boiling point processes to obtain XDI with a chlorinated derivative content of 3120 ppm.

[0147] (Synthesized Example 2-2)

[0148] In Synthesis Example 2-1, 200g of SUS 316 pieces were added before adding m-xylylenediamine, and the process was carried out under the same conditions. After the reaction was completed, the solution obtained was analyzed, and it was confirmed that 1790 ppm of compound (3), methylbenzyl isocyanate, was produced. Through Synthesis Example 2-2, it was confirmed that a non-chlorinated derivative is produced when a metal filler is present during the phosgene reaction.

[0149] 2-2. Production of XDI in a large-scale production facility equipped with a distillation unit filled with metal structured packing

[0150] During actual large-scale production of XDI, the conversion of the chlorinated derivative of XDI obtained from crude XDI obtained through a phosgene reaction in a G / L reactor to a non-chlorinated derivative using a distillation apparatus filled with a SUS structured packing was observed.

[0151] [Example 1]

[0152] 2.0 t of a crude XDI composition (acidity 2570 ppm) prepared by the same method as in Synthesis Example 2-1 was 12 m 3 After being introduced into the reactor, the internal reaction temperature was raised to 150 °C under high vacuum. Reflux was carried out at the above temperature. The content of the chlorinated derivative before reflux and the content of the chlorinated derivative after reflux were compared. The results are shown in Table 3.

[0153]

[0154] Through Example 1, it was confirmed that the chlorinated derivative was converted into a non-chlorinated derivative during reflux in a distillation apparatus filled with a metal structured packing.

[0155] 2-3. Investigation of the conversion behavior of chlorinated derivatives to non-chlorinated derivatives by adding SUS 316 to the XDI composition obtained in Synthesis Example 2-1

[0156] To investigate the behavior of converting chlorinated derivatives into non-chlorinated derivatives in the presence of a metal material, XDI prepared in Synthesis Example 2-1 was used, and the behavior of converting chlorinated derivatives into non-chlorinated derivatives was investigated in Examples 2 to 10 by varying the reaction temperature, amount of SUS 316 input, reaction time, acidity content, etc. (see Table 4). The acidity (HCl) of the XDI obtained in Synthesis Example 2-1 was basically adjusted to 3,200 ppm, and XDI with acidity of 200 ppm and 6,500 ppm was prepared separately to examine the effect of acidity.

[0157] [Example 2]

[0158] 50 g of XDI obtained in Synthesis Example 1 and 5 g of SUS 316 pieces (1 cm x 1 cm) were added to a 100 ml glass flask equipped with a reflux condenser. While stirring, the inside of the reactor was sufficiently purged with nitrogen. After the nitrogen purging was completed, the reaction temperature inside the reactor was raised to 130 ℃. The temperature was maintained for 5 hours, and changes in the content of chlorinated derivatives and non-chlorinated derivatives were observed before and after the reaction. The content of chlorinated derivatives and non-chlorinated derivatives is shown in Table 5.

[0159] [Examples 3, 4]

[0160] The experiment was carried out under the same conditions as Example 2, but the change according to the reaction temperature was observed.

[0161] [Examples 5, 6]

[0162] The experiment was carried out under the same conditions as Example 3, but the change according to the amount of SUS 316 pieces added was observed.

[0163] [Examples 7, 8]

[0164] The experiment was carried out under the same conditions as Example 3, but changes according to reaction time were observed.

[0165] [Examples 9, 10]

[0166] The experiment was carried out under the same conditions as Example 3, but changes according to acidity content were observed.

[0167] [Comparative Example 1]

[0168] Observed under the same conditions as Example 3 without inserting SUS 316 pieces.

[0169]

[0170]

[0171] In Examples 2 to 10 above, although there were differences in the CBI removal rate, it was confirmed that regardless of the conditions, the addition of SUS 316 reduced the content of the chlorinated derivative CBI while increasing the content of the non-chlorinated derivative MBI. On the other hand, in Comparative Example 1, when SUS 316 fragments were absent, the non-chlorinated derivative MBI was not observed. Among the conditions of the examples reviewed, the CBI removal rate was best under the conditions of Example 3. This confirmed that reaction temperature, a certain amount of SUS added, and acidity are required to increase the CBI removal rate. The conditions of the above examples represent a minimum experiment to verify the conversion of chlorinated derivatives into non-chlorinated derivatives, and the current conditions are not optimal conditions.

[0172] 2-4. Investigation of the conversion behavior of chlorinated derivatives to non-chlorinated derivatives according to the type of metal in the XDI composition obtained in Synthesis Example 2-1

[0173] To investigate the behavior of the conversion of chlorinated derivatives into non-chlorinated derivatives according to the type of metal, XDI prepared in Synthesis Example 2-1 was used, and the behavior of the conversion of chlorinated derivatives into non-chlorinated derivatives was observed in Examples 11 to 19 by varying the type of metal as described below. The acidity (HCl) of the XDI obtained in Synthesis Example 2-1 was basically adjusted to 3,200 ppm.

[0174] [Examples 11–19]

[0175] The experiment was carried out under the same conditions as Example 3, but the changes in the content of chlorinated derivatives and non-chlorinated derivatives according to the type of metal were observed. The content of chlorinated derivatives and non-chlorinated derivatives is shown in Table 6.

[0176]

[0177] In Examples 11 to 19 above, the chlorinated derivative CBI was generally converted to the non-chlorinated derivative MBI in the results. However, the range of conversion varied significantly depending on the type of metal. In the case of Fe, the CBI removal rate was 72%, and among the metals, the chlorinated derivative CBI was converted the most to the non-chlorinated derivative MBI.

[0178] 2-5. Preparation and Evaluation of Optical Lenses from XDI Compositions

[0179] XDI obtained from Example 3 was distilled using a high-vacuum distillation apparatus to obtain XDI containing 310 ppm of a chlorinated derivative and 110 ppm of a non-chlorinated derivative. 52 g of the thus prepared XDI composition, 0.015 g of dibutyltin dichloride, 0.12 g of Zerec UN (internal release agent, Stepan), and 0.08 g of UV absorber were mixed by stirring at room temperature for 1 hour, and then 48 g of 2,3-bis(2-mercaptoethylthio)propane-1-thiol was added to prepare a polymerizable composition. The polymerizable composition was stirred under reduced pressure for 1 hour to remove bubbles and filtered through a 1 µm Teflon filter. Subsequently, the mixture was poured into a mold made of a glass mold and tape, and polymerized in an oven by gradually increasing the temperature to 120°C for 20 hours. The mold was removed from the oven and released to obtain a resin (plastic). The obtained resin was annealed at 120°C for 2 more hours. As a result of investigating the physical properties of the optical lens manufactured in this way, the refractive index was 1.6656, the yellowness was 1.20, and the heat resistance was 87.3°C. It showed good results regarding cloudiness and maglie, making it suitable for use as an optical lens material.

[0180]

[0181] Meanwhile, the embodiments of the present invention described above should not be interpreted as limiting the technical scope of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and a person skilled in the art may modify, improve, or change the technical scope of the present invention in various forms. Accordingly, it will be understood that such modifications, improvements, or changes will fall within the scope of protection of the present invention insofar as they are obvious to a person skilled in the art.

[0182] (Explanation of symbols)

[0183] 10: Bis(trichloromethyl)carbonate dilution container

[0184] 12: Reactor transfer line

[0185] 20: m-xylylendiamine dilution container

[0186] 22: Reactor transfer line

[0187] 30: Isocyanating reactor

[0188] 31: Gas exhaust line

[0189] 32: Reaction product transfer line

[0190] 40: First distillation column

[0191] 41: Solvent discharge line

[0192] 42: Reaction product transfer line

[0193] 50: Second distillation tower

[0194] 51: Low-boiling point substance discharge line

[0195] 52: Reaction product transfer line

[0196] 60: Third distillation tower

[0197] 61: Isocyanate product discharge line

[0198] 62: High-boiling point substance discharge line

Claims

1. A manufacturing system for producing a xylylene diisocyanate (XDI) composition, A reactor for producing the XDI from xylylene diamine or its hydrochloride; A first distillation column for distilling a composition of XDI containing a chlorinated derivative of formula (2) prepared from the above reactor; comprising, A manufacturing system in which the first distillation column performs a process in which the chlorinated derivative is converted into a non-chlorinated derivative of the following chemical formula (3) by a dechlorination reaction by a metal surface within the distillation column and an anhydrous protic acid: Chemical formula (2); Chemical formula (3) (Here, R1 is Cl or NCO, R2 is H or Cl, and R3 is H or NCO.) 2. A manufacturing system according to claim 1, wherein the reactor for producing the XDI is a metal reactor and is made of SUS (stainless steel) so as to act as a catalyst on the inner surface of the metal.

3. A manufacturing system according to claim 1, wherein, in the case where the reactor for producing the XDI is a glass-lined reactor, a metal filler is separately added within the reactor to allow the dechlorination reaction to occur.

4. A manufacturing system according to claim 1, wherein the first distillation column is a device for removing solvent in the composition of the XDI produced from the reactor, and comprises a distillation column filled with structured packing or random packing of metal, or a thin-film distillation apparatus made of metal.

5. A manufacturing system according to claim 1, further comprising a second distillation column for removing low-boiling point substances in the composition of the XDI.

6. A manufacturing system according to claim 1, further comprising a third distillation column for removing high-boiling point substances in the composition of the XDI.

7. A manufacturing system according to any one of claims 1 to 6, wherein the proton acid is selected from either a monoprotic acid or a polyprotic acid.

8. A manufacturing system according to any one of claims 1 to 6, wherein the proton acid is hydrogen chloride (HCl).

9. A manufacturing system according to paragraph 3, wherein the metal filler is a metal piece made of one or more metals selected from the group consisting of single metals Fe, Zn, Cu, Cr, Mn, Ni, Ag, Mo, and Co, and alloys thereof, among transition metals in groups 3 to 12 of the periodic table.

10. A manufacturing system according to claim 8, wherein the hydrogen chloride is obtained from hydrogen chloride gas, which is a reaction byproduct generated during the process of reacting an organic primary amine with a carbonylating agent to produce the XDI: .

11. A manufacturing system according to claim 10, wherein the carbonylation agent is selected from phosgene, diphosgene, triphosgene, aliphatic or aromatic chloroformate, or a combination thereof.

12. In paragraph 8, the hydrogen chloride is the following carbamoyl chloride (R4-(NH-CO-Cl) n A manufacturing system obtained through a decomposition process of , n=1 or 2: (Here, R4 is -NCO or -NHCOCl).

13. A manufacturing system according to any one of claims 1 to 6, wherein the content ratio of the chlorinated derivative is greater than 0 and in the range of 50,000 ppm.

14. A manufacturing system according to any one of claims 1 to 6, wherein the content ratio of the non-chlorinated derivative is in the range of 0.1 to 100,000 ppm.

15. A manufacturing system according to any one of claims 1 to 6, wherein the content of the XDI is 80 mass% or more.

16. A method for reducing the content of a chlorinated derivative in an XDI composition comprising a chlorinated derivative represented by the following chemical formula (2) in a manufacturing apparatus for xylylene diisocyanate (XDI), wherein The method comprises the step of converting the chlorinated derivative into a non-chlorinated derivative of the following chemical formula (3) by a dechlorination reaction by a metal surface in the above-mentioned manufacturing device and an anhydrous protonate acid; A method for reducing the content of a chlorinated derivative in which the above protonated acid is hydrogen chloride (HCl): Chemical formula (2); Chemical formula (3) (Here, R1 is Cl or NCO, R2 is H or Cl, and R3 is H or NCO.) 17. In Clause 16, the manufacturing device of the XDI above A reactor for producing the XDI from xylylene diamine or its hydrochloride; A method comprising a first distillation column for distilling a composition of XDI containing a chlorinated derivative of formula (2) prepared from the above reactor.

18. The method according to claim 17, wherein the reactor for producing the XDI is a metal reactor and is made of SUS (stainless steel) so as to act as a catalyst on the inner surface of the metal.

19. A method according to claim 17, wherein, in the case where the reactor for producing the XDI is a G / L reactor, a metal filler is separately added within the reactor to allow the dechlorination reaction to occur.

20. The method according to claim 17, wherein the first distillation column is a device for removing the solvent in the composition of the XDI produced from the reactor, and comprises a distillation column filled with structured packing or random packing of metal, or a thin-film distillation device made of metal.

21. A method according to claim 16, wherein the protic acid further comprises, in addition to hydrogen chloride (HCl), another monoprotic acid or a polyprotic acid.

22. In paragraph 21, the other monoproton acid is one or more selected from the following: Hydrobromide (HBr), hydroiodide (HI), perchloric acid (HClO4), chloric acid (HClO3), nitric acid (HNO3), iodic acid (HIO3), oxalic acid (H2C2O4), sulfurous acid (H2SO3), hypochlorous acid (HClO2), chloroacetic acid (CH2ClCOOH), hydrofluoric acid (HF), nitrous acid (HNO2), formic acid (HCOOH), benzoic acid (C6H5COOH), hydrazous acid (HN3), acetic acid (CH3COOH), propionic acid (CH3CH2COOH), hypochlorous acid (HClO), hydrocyanic acid (HCN), and trifluoroacetic acid (CF3COOH).

23. A method according to claim 21, wherein the polyprotic acid is one or more selected from the group consisting of phosphoric acid (H3PO4), phosphorous acid (H3PO3), and hypophosphorous acid (H3PO2).

24. The method of claim 16, wherein the metal is one or more selected from the group consisting of single metals of Fe, Zn, Cu, Cr, Mn, Ni, Ag, Mo and Co, and alloys thereof.

25. In paragraph 16, the hydrogen chloride is obtained from hydrogen chloride gas, which is a reaction byproduct generated during the process of reacting an organic primary amine with a carbonylating agent to produce the XDI: .

26. The method according to claim 25, wherein the carbonylating agent is selected from phosgene, diphosgene, triphosgene, chloroformade, or a combination thereof.

27. In paragraph 16, the hydrogen chloride is the following carbamoyl chloride (R4-(NH-CO-Cl) n A method obtained through a decomposition process of , n=1 or 2): (Here, R4 is -NCO or -NHCOCl).

28. A method according to any one of claims 16 to 27, wherein the content of the non-chlorinated derivative is 0.1 to 100,000 ppm.

29. A method according to any one of claims 16 to 27, wherein the content ratio of the chlorinated derivative is greater than 0 and in the range of 50,000 ppm.

30. A method according to any one of claims 16 to 27, wherein the content of the XDI is 80 mass% or more.

31. A method according to any one of paragraphs 16 through 27, further comprising the following second distillation column, or third distillation column, or all of these: (i) a second distillation column for removing low-boiling point substances in the composition of the XDI above; or (ii) A third distillation column for removing high-boiling point substances in the composition of the XDI above.

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