KR20210071802A - Method of preparing diisocyanate composition and optical lens - Google Patents

Abstract

A method for manufacturing a diisocyanate composition according to the embodiment can improve optical properties of final optical lens as well as yield and purity of the diisocyanate composition by adjusting a b* value according to CIE color coordinates of a diamine composition to a specific range. Therefore, the method for manufacturing the diisocyanate composition according to the embodiment can be applied to the manufacture of high-quality plastic optical lenses.

Description

Diisocyanate composition and manufacturing method of an optical lens {METHOD OF PREPARING DIISOCYANATE COMPOSITION AND OPTICAL LENS}

Embodiments relate to diisocyanate compositions and methods of making optical lenses. More specifically, the embodiment relates to a method for preparing a diisocyanate composition from a diamine composition through a diamine hydrochloride composition, and a method for manufacturing an optical lens using the diisocyanate composition thus prepared.

Isocyanate used as a raw material for plastic optical lenses is manufactured by a phosgene method, a non-phosgene method, a thermal decomposition method, or the like.

The phosgene method is to react a raw material amine with phosgene (COCl ₂ ) gas to synthesize isocyanate, and the biphosgene method is to react xylylene chloride with sodium cyanate in the presence of a catalyst to synthesize isocyanate, and the thermal decomposition method is to synthesize an amine After reacting with alkyl chloroformate to prepare carbamate, it is pyrolyzed at high temperature in the presence of a catalyst to synthesize isocyanate.

Among these isocyanate manufacturing methods, the phosgene method is the most widely used, and in particular, a direct method of directly reacting phosgene gas with an amine has been generally used, but there is a problem that requires a large number of devices for the direct reaction of the phosgene gas. Meanwhile, in order to supplement the direct method, a hydrochloride method has been developed in which an intermediate material, amine hydrochloride, is obtained by reacting hydrogen chloride gas with an amine, as in Korean Patent Publication No. 1994-1948, and reacts it with phosgene.

However, in the conventional method of obtaining hydrochloride as an intermediate by reacting an amine with hydrogen chloride gas in the phosgene method for synthesizing isocyanate, the hydrochloride is generated as fine particles at normal pressure and the stirring condition inside the reactor is not smooth, so the inside of the reactor In order to increase the pressure, a process of increasing the temperature is additionally required, and there is a problem in that the yield of the final product is also low.

Therefore, there is an attempt to obtain hydrochloric acid using an aqueous hydrochloric acid solution instead of hydrogen chloride gas, but the amine is dissolved in the hydrochloric acid aqueous solution and the yield drops to 50%, making it difficult to apply in practice. There was a difficulty in using this low amine. In addition, the phosgene gas used in the conventional phosgene method is a substance subject to environmental regulations as it is highly toxic, and a separate cooling device is required to store it, so storage and management are difficult.

Korean Patent Publication No. 1994-1948

Accordingly, the present inventors reacted while using an aqueous hydrochloric acid solution and an organic solvent instead of hydrogen chloride gas and an organic solvent and using solid triphosgene instead of phosgene gas in the process of producing diisocyanate, which is mainly used as a raw material for plastic optical lenses, from a diamine composition through hydrochloride. By adjusting the conditions, it was possible to solve conventional environmental, yield and quality problems.

In addition, the present inventors have found that oxidation, such as the formation of a double bond in diamine, occurs during storage of the diamine composition, and as a result, the purity and yield of the diisocyanate composition obtained using the same, and whitening and yellowing of the final optical lens. paid attention. In particular, the present inventors noted that the b* value according to the CIE color coordinate of the diamine composition has a correlation with the degree of oxidation of the diamine composition.

As a result of the study by the present inventors, the b* value according to the CIE color coordinates of the diamine composition used for the preparation of the diisocyanate composition was adjusted to a specific range to improve the yield and purity of the diisocyanate composition as well as the optical properties of the final optical lens found that it can be done.

Accordingly, an object of the embodiment is to provide a method for preparing a diisocyanate composition having improved purity and yield using a diamine composition having a b* value adjusted according to the CIE color coordinate, and a method for manufacturing an optical lens having improved optical properties.

According to one embodiment, obtaining a diamine hydrochloride composition from the diamine composition; and obtaining a diisocyanate composition by a phosgenation reaction from the diamine hydrochloride composition, wherein the diamine composition has a b* value of 0.01 to 3.0 according to the CIE color coordinate, a method for preparing a diisocyanate composition is provided.

According to another embodiment, obtaining a diamine hydrochloride composition from the diamine composition; obtaining a diisocyanate composition by a phosgenation reaction from the diamine hydrochloride composition; and mixing the diisocyanate composition with thiol or episulfide and polymerizing and curing in a mold, wherein the diamine composition has a b* value of 0.01 to 3.0 according to the CIE color coordinate, a method of manufacturing an optical lens is provided do.

According to the above embodiment, by adjusting the b* value according to the CIE color coordinate of the diamine composition used for the preparation of the diisocyanate composition to a specific range, the yield and purity of the diisocyanate composition as well as the optical properties of the final optical lens can be improved. have. Specifically, by adjusting the b* value within a specific range, the degree of oxidation of the diamine present in the diamine composition can be controlled, and as a result, side reactions in the process of preparing the diisocyanate composition can be suppressed.

In addition, in the method for producing diisocyanate according to a preferred embodiment, by using an aqueous hydrochloric acid solution without using hydrogen chloride gas for the production of diamine hydrochloride as an intermediate material, the reaction can proceed even at normal pressure, so an additional device for high temperature heating and cooling is required and the yield can also be improved. In addition, in the method for preparing a diisocyanate composition according to a preferred embodiment, the diamine hydrochloride composition is prepared by using an organic solvent together with the aqueous hydrochloric acid solution and adjusting the reaction conditions, thereby minimizing the dissolution of the hydrochloride in the hydrochloric acid aqueous solution to further increase the final yield. and the range of raw material selection can be broadened because it is not significantly affected by the moisture and impurity content in the raw material diamine composition. In addition, the method for producing diisocyanate according to a preferred embodiment does not use phosgene gas, which is difficult to store and manage and highly toxic, and as a solid state at room temperature, it does not require a separate cooling storage device and low toxicity triphosgene. Because it is used, handling and fairness are excellent.

Therefore, the method for preparing the diisocyanate composition according to the embodiment can be applied to the manufacture of high-quality plastic optical lenses.

1 shows a method for preparing a diisocyanate composition according to an embodiment.
2 shows an example of a process device for the reaction of a diamine hydrochloride composition and triphosgene.

In the present specification, when a part "includes" a certain component, this means that other components may be further included rather than excluding other components unless otherwise stated.

In addition, it should be understood that all numerical ranges indicating physical property values, contents, dimensions, etc. of the components described in the present specification are modified by the term "about" in all cases unless otherwise specified.

As used herein, "amine" means a compound having one or more amine groups at the terminal, "diamine" means a compound having two amine groups at the terminal, and an aliphatic chain, an aliphatic ring, and an aromatic ring. It may have a very diverse structure depending on the skeleton. Specific examples of the diamine include xylylenediamine (XDA), hexamethylenediamine (HDA), 2,2-dimethylpentanediamine, 2,2,4-trimethylhexanediamine, butenediamine, 1,3-butadiene-1, 4-diamine, 2,4,4-trimethylhexamethylenediamine, bis(aminoethyl)carbonate, bis(aminoethyl)ether, lysine diaminomethyl ester, bis(aminoethyl)benzene, bis(aminopropyl)benzene, α ,α,α',α'-tetramethylxylylenediamine, bis(aminobutyl)benzene, bis(aminomethyl)naphthalene, bis(aminomethyl)diphenyl ether, bis(aminoethyl)phthalate, 2,6- Di(aminomethyl)furan, xylylenediamine hydride (H6XDA), dicyclohexylmethanediamine, cyclohexanediamine, methylcyclohexanediamine, isophoronediamine (IPDA), dicyclohexyldimethylmethanediamine, 2,2-dimethyldish Chlohexylmethanediamine, 2,5-bis(aminomethyl)bicyclo-[2,2,1]-heptane, 2,6-bis(aminomethyl)bicyclo-[2,2,1]-heptane, 3 ,8-bis(aminomethyl)tricyclodecane, 3,9-bis(aminomethyl)tricyclodecane, 4,8-bis(aminomethyl)tricyclodecane, 4,9-bis(aminomethyl)tricyclodecane , norbornenediamine (NBDA), bis(aminomethyl)sulfide, bis(aminoethyl)sulfide, bis(aminopropyl)sulfide, bis(aminohexyl)sulfide, bis(aminomethyl)sulfone, bis(amino Methyl)disulfide, bis(aminoethyl)disulfide, bis(aminopropyl)disulfide, bis(aminomethylthio)methane, bis(aminoethylthio)methane, bis(aminoethylthio)ethane, bis(aminomethylthio) ) and ethane. More specifically, the diamine is one selected from the group consisting of xylylenediamine (XDA), norbornenediamine (NBDA), hydrogenated xylylenediamine (H6XDA), isophoronediamine (IPDA), and hexamethylenediamine (HDA) may be more than The xylylenediamine (XDA) includes ortho-xylylenediamine (o-XDA), meta-xylylenediamine (m-XDA) and para-xylylenediamine (p-XDA).

In the present specification, "isocyanate" means a compound having an NCO group, "diisocyanate" means a compound having two NCO groups at the terminal, and according to the skeleton of an aliphatic chain, an aliphatic ring, and an aromatic ring It can have a wide variety of structures. Specific examples of the diisocyanate include xylylene diisocyanate (XDI), hexamethylene diisocyanate (HDI), 2,5-bis(isocyanatomethyl)-bicyclo[2.2.1]heptane, 2,6-bis (isocyanatomethyl)-bicyclo[2.2.1]heptane, xylylene hydride diisocyanate (H6XDI), dicyclohexylmethane diisocyanate, isophorone diisocyanate (IPDI), 1,2-diisocyanatobenzene , 1,3-diisocyanatobenzene, 1,4-diisocyanatobenzene, 2,4-diisocyanatotoluene, ethylphenylene diisocyanate, dimethylphenylene diisocyanate, biphenyl diisocyanate, toluidine diisocyanate, 4,4'-methylenebis(phenyl isocyanate), 1,2-bis(isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl)benzene, 1,4-bis(isocyanato) methyl)benzene, 1,2-bis(isocyanatoethyl)benzene, 1,3-bis(isocyanatoethyl)benzene, 1,4-bis(isocyanatoethyl)benzene, α,α, α′,α′-tetramethylxylylenediisocyanate, bis(isocyanatomethyl)naphthalene, bis(isocyanatomethylphenyl)ether, norbornene diisocyanate (NBDI), bis(isocyanatomethyl)sulfide , bis(isocyanatoethyl)sulfide, bis(isocyanatopropyl)sulfide, 2,5-diisocyanatotetrahydrothiophene, 2,5-diisocyanatomethyltetrahydrothiophene, 3,4-diisocyanatomethyltetrahydrothiophene, 2,5-diisocyanato-1,4-dithiane, 2,5-diisocyanatomethyl-1,4-dithiane, etc. are mentioned. have. More specifically, the diisocyanate is xylylene diisocyanate (XDI), norbornene diisocyanate (NBDI), hydrogenated xylylene diisocyanate (H6XDI), isophorone diisocyanate (IPDI) and the group consisting of hexamethylene diisocyanate (HDI) It may be one or more selected from. The xylylene diisocyanate (XDI) includes ortho-xylylene diisocyanate (o-XDI), meta-xylylene diisocyanate (m-XDI) and para-xylylene diisocyanate (p-XDI). As a specific example, the diamine may include xylylenediamine, and the diisocyanate may include xylylenediisocyanate.

As used herein, the term “composition” may refer to a form in which two or more chemical components are mixed or combined in a solid, liquid and/or gaseous phase while generally maintaining their respective unique properties.

A compound (eg, triphosgene) or a compound obtained as a result of the reaction (eg, diamine hydrochloride, diisocyanate) used in each reaction step according to the embodiment is generally a residual, side reaction or moisture of an unreacted sample in each reaction step. It exists in a mixed or combined state with heterogeneous components generated by reaction with or natural decomposition of compounds, and these heterogeneous components may be present together with the main component in a trace amount even after several purifications.

According to the above embodiment, since attention is paid to these heterogeneous components mixed or combined with the main compound, even a trace amount of the heterogeneous component is treated as a composition mixed or combined with the main compound, and the components and contents thereof are specifically exemplified.

In addition, in this specification, for clear and easy distinction between various compositions, terms are also described in combination with the name of the main component in the composition, for example, "diamine composition" means a composition containing diamine as a main component, " The term "diamine hydrochloride composition" refers to a composition containing diamine hydrochloride as a main component, and "diisocyanate composition" refers to a composition containing diisocyanate as a main component. At this time, the content of the main component in the composition may be 50% by weight or more, 80% by weight or more, or 90% by weight or more, for example, may be 90% by weight to 99.9% by weight.

As used herein, ppm units mean ppm by weight.

[Method for producing diisocyanate composition]

A method for preparing a diisocyanate composition according to an embodiment comprises the steps of: (1) obtaining a diamine hydrochloride composition from a diamine composition; and (2) obtaining a diisocyanate composition by phosgenation from the diamine hydrochloride composition, wherein the diamine composition has a b* value of 0.01 to 3.0 according to the CIE color coordinate.

The diamine hydrochloride composition may be prepared by reacting the diamine composition with an aqueous hydrochloric acid solution.

1 schematically shows a method for preparing a diisocyanate composition according to an embodiment. 1 (a) and (b), R includes an aromatic ring, an aliphatic ring, an aliphatic chain, and the like, and as a specific example, R may be xylylene, norbornene, xylylene hydride, isophorone, or hexamethylene. , but not limited thereto.

In (a) of FIG. 1, (i) may include a step of reacting diamine with an aqueous hydrochloric acid solution by adding an aqueous hydrochloric acid solution. In (a) of FIG. 1, (ii) may include at least one step selected from a precipitation step, a filtration step, a drying step, and a washing step. In (b) of FIG. 1, (iii) may include reacting the diamine hydrochloride composition with triphosgene by adding triphosgene. In (b) of FIG. 1, (iv) may include at least one step selected from a degassing step, a filtration step, and a distillation step.

Hereinafter, each step will be described in detail.

Preparation of diamine composition

The diamine composition used as a starting material in the method of the above embodiment may include xylylenediamine or other diamines used in the manufacture of optical lenses, specifically orthoxylylenediamine (o-XDA), metaxylylenediamine (m-XDA), paraxylylenediamine (p-XDA), norbornenediamine (NBDA), hydrogenated xylylenediamine (H6XDA), isophoronediamine (IPDA) and hexamethylenediamine (HDA) selected from the group consisting of It may include one or more types.

The content of the diamine in the diamine composition may be 90 wt% or more, 95 wt% or more, 99.5 wt% or more, or 99.9 wt% or more, and specifically may be 90 wt% to 99.9 wt%.

In particular, according to the embodiment, the b* value according to the CIE color coordinate of the diamine composition is adjusted within the range of 0.01 to 3.0.

As such, by adjusting the range of b* values according to the CIE color coordinates of the diamine composition, it is possible to improve the yield and purity of the diisocyanate composition as well as the optical properties of the final optical lens. Specifically, oxidation, such as the formation of a double bond in diamine, occurs during storage of the diamine composition, and as a result, the purity and yield of the diisocyanate composition obtained using the same, and cloudiness and yellowing of the final optical lens may occur. Since the degree of oxidation of the diamine composition is related to the b* value according to the CIE color coordinate of the diamine composition, the degree of oxidation of the diamine present in the diamine composition can be controlled by adjusting the b* value within a specific range. As a result, it is possible to suppress side reactions in the process of preparing the diisocyanate composition.

For example, the b* value according to the CIE color coordinate of the diamine composition may be 0.01 or more, 0.1 or more, 0.3 or more, 0.5 or more, 0.7 or more, 1.0 or more, 1.3 or more, or 1.5 or more. Also, the b* value may be 3.0 or less, 2.5 or less, 2.0 or less, 1.5 or less, or 1.0 or less. For example, the diamine composition may have a b* value of 0.01 to 1.0 according to the CIE color coordinate. Specifically, the b* value according to the CIE color coordinates of the diamine composition may be 0.1 to 3.0, 0.1 to 2.5, 0.1 to 2.0, 0.1 to 1.5, 0.1 to 1.0, 0.5 to 3.0, 1.0 to 3.0, or 1.5 to 3.0. .

The b* value according to the CIE color coordinate of the diamine composition may be adjusted in advance before the diamine composition is added to the reaction. For example, the b* value according to the CIE color coordinate of the diamine composition may be measured in advance, and if the measured b* value is greater than 3.0, the b* value of the diamine composition may be adjusted and then added to the reaction.

That is, the manufacturing method of the diisocyanate composition according to the embodiment, before the step (1), measuring the b* value according to the CIE color coordinates of the diamine composition; and adjusting the b* value to 0.01 to 3.0.

The measurement of the b* value can be performed using a colorimeter, etc. Specifically, in the case of a liquid sample, a quartz cell having a thickness of 10 mm is filled, and in the case of a solid sample, the b* value can be measured after dissolving it in an organic solvent. have.

A method of adjusting the b* value is not particularly limited, but may include, for example, distilling the diamine composition at least once.

The temperature at the time of distillation of such a diamine composition may be, for example, 100 ℃ to 130 ℃. Specifically, the distillation may be performed by setting the bottom temperature of the distiller to 100°C to 130°C. For example, the distillation may be performed by setting the temperature of the reboiler to 100°C to 130°C.

In addition, the pressure at the time of distillation of the diamine composition may be 2.0 torr or less, 1.0 torr or less, 0.5 torr or less, or 0.1 torr or less.

Specifically, the diamine composition may be distilled, for example, at a temperature of 100° C. to 130° C. and a pressure of 0.1 Torr to 1 Torr. When it is within the above preferred range, it is possible to effectively remove oxides such as diamine in which a double bond is formed during storage of the diamine composition.

In addition, the distillation time may be 1 hour or more, 2 hours or more, or 3 hours or more, and may be 10 hours or less, or 5 hours or less.

After such distillation, the step of measuring the b* value according to the CIE color coordinate of the diamine composition may be additionally performed, and as a result, when the measured b* value is greater than 3.0, the b* value of the diamine composition by distillation or the like once again can be adjusted.

As a result, the b* value according to the CIE color coordinate of the diamine composition may be adjusted to 0.01 to 3.0.

Preparation of diamine hydrochloride composition

Thereafter, a diamine hydrochloride composition is obtained from the diamine composition. The diamine hydrochloride composition may be obtained by reacting the diamine composition with an aqueous hydrochloric acid solution. In addition, after the reaction of the diamine composition with the aqueous hydrochloric acid solution, a first organic solvent may be additionally added to obtain the diamine hydrochloride composition in a solid phase.

Scheme 1 below shows an example of the reaction of this step.

[Scheme 1]

in the above formula

In the above formula, R includes an aromatic ring, an aliphatic ring, an aliphatic chain, and the like, and as a specific example, R may be xylylene, norbornene, xylylene hydride, isophorone, or hexamethylene, but is not limited thereto.

In the case of using hydrogen chloride gas in the prior art, since hydrochloride is generated as fine particles during the atmospheric reaction and the stirring state inside the reactor is not smooth, a process of raising the internal temperature of the reactor by increasing the pressure is additionally required, and the final process product There was also a problem of low yield.

However, according to the above embodiment, since the aqueous hydrochloric acid solution is used, it is possible to solve the problem that occurs when using hydrogen chloride gas in the prior art. Specifically, when an aqueous hydrochloric acid solution is used, the yield is high because the product produced through the reaction is in the form of a solid rather than in the form of a slurry, and a separate device or process for rapid cooling is not required because the reaction can be carried out even at atmospheric pressure.

The concentration of the aqueous hydrochloric acid solution may be 5 wt% to 50 wt%. When it is within the concentration range, it is possible to minimize the dissolution of hydrochloric acid in the aqueous hydrochloric acid solution, thereby increasing the final yield and improving handling. Specifically, the concentration of the aqueous hydrochloric acid solution may be 10 wt% to 45 wt%, 20 wt% to 45 wt%, or 30 wt% to 40 wt%. More specifically, the aqueous hydrochloric acid solution may have a concentration of 20 wt% to 45 wt%.

The input amount of the aqueous hydrochloric acid solution may be adjusted in a molar ratio relative to the input amount of the diamine. For example, the aqueous hydrochloric acid solution may be added so that 2 moles or more, 2.02 moles or more, 2.05 moles or more, 2.1 moles or more, or 2.2 moles or more of HCl per 1 mole of the diamine in the diamine composition. Also, the aqueous hydrochloric acid solution may be added in an amount of 3 mol or less, 2.7 mol or less, 2.5 mol or less, 2.4 mol or less, 2.35 mol or less, or 2.25 mol or less of HCl per 1 mol of the diamine. Specifically, the aqueous hydrochloric acid solution may be added to the reaction in an amount of 2.02 moles to 2.50 moles of HCl per 1 mole of the diamine. When it is within the above range, it may be more advantageous to prevent some diamines from reacting with the aqueous hydrochloric acid solution and remaining, so that free amine groups react with diisocyanate in a subsequent reaction to form urea, and at the same time, residual chlorine due to an excess of aqueous hydrochloric acid solution It may be more advantageous to prevent the ions from generating impurities by increasing the chlorine concentration in the subsequent phosgenation reaction.

The diamine composition and the aqueous hydrochloric acid solution may be added while maintaining a constant temperature inside the reactor.

The temperature inside the reactor when the diamine composition and the aqueous hydrochloric acid solution are added may be in a range of 20°C to 100°C. When it is within the above temperature range, it is possible to prevent the temperature from being higher than the boiling point and not suitable for the reaction or the reaction efficiency from being lowered because the temperature is too low.

Specifically, the temperature inside the reactor when the diamine composition and the aqueous hydrochloric acid solution are added may be 20°C to 60°C, or 20°C to 40°C.

In the conventional hydrochloride method, a large amount of heat is generated in the reaction process and rapid cooling through a separate cooler is required, whereas according to the above embodiment, a separate cooler is not required because the reactant is introduced while maintaining a low temperature.

The diamine composition and the aqueous hydrochloric acid solution may be added, for example, in the order of first introducing the hydrochloric acid aqueous solution into the reactor and then slowly introducing the diamine composition. The diamine composition and/or the aqueous hydrochloric acid solution may be added for 30 minutes to 1 hour.

After the addition of the diamine composition and the aqueous hydrochloric acid solution is completed, the internal temperature of the reactor may be cooled to 0°C to 20°C, 0°C to 10°C, or 10°C to 20°C.

The reaction of the diamine composition and the aqueous hydrochloric acid solution may be carried out at normal pressure, for example, may be performed while stirring for 30 minutes to 2 hours.

Through the reaction of the diamine composition with the aqueous hydrochloric acid solution, a reaction result in an aqueous solution state in which the diamine hydrochloride composition is dissolved in water can be obtained.

Thereafter, the step of treating the diamine hydrochloride composition may be further performed. For example, treating the diamine hydrochloride composition includes precipitating the diamine hydrochloride composition, filtering the diamine hydrochloride composition, drying the diamine hydrochloride composition, and washing the diamine hydrochloride composition, It may include at least one.

Specifically, a solid diamine hydrochloride composition may be precipitated by adding a first organic solvent to the reaction product. That is, the first organic solvent may induce precipitation of the solid diamine hydrochloride composition through crystallization. More specifically, the first organic solvent may be added to the reaction result, and after cooling, the reaction may proceed while further stirring.

The first organic solvent is specifically diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran, methanol, ethanol, dimethyl sulfoxide, dimethyl formamide, acetonitrile, acetone, trichloroethylene, tetrachloroethane, It may be at least one selected from the group consisting of trichloroethane, n-butanol, isobutanol, methyl ethyl ketone, methyl butyl ketone, isopropanol, hexane, chloroform and methyl acetate.

The input amount (weight) of the first organic solvent may be 1 to 5 times the weight of the diamine composition. When it is within the above dosage range, it is possible to prevent the use of excessive organic solvent while the yield of the final hydrochloride is high. Specifically, the first organic solvent may be added to the reaction in an amount of 1 to 2 times, 1 to 1.5 times, or 1.3 to 1.5 times the weight of the diamine composition.

The cooling temperature after the input of the first organic solvent may be -10 °C to 10 °C or -5 °C to 5 °C. In addition, the additional reaction time after the cooling may be 30 minutes to 2 hours, or 30 minutes to 1 hour.

According to a specific example, (1a) adding the aqueous hydrochloric acid solution to the first reactor; (1b) adding and stirring the diamine composition to the first reactor; and (1c) adding and stirring the first organic solvent to the first reactor may be sequentially performed.

More specifically, cooling the inside of the reactor to a temperature of 0° C. to 10° C. before stirring after the addition of the diamine composition in step (1b); and cooling the inside of the reactor to a temperature of -5°C to 5°C after the input of the first organic solvent in step (1c) and before stirring.

After the first organic solvent is added, separation, filtration, washing and drying may be further performed. For example, a solid diamine hydrochloride composition may be obtained by separating the aqueous layer after the input of the first organic solvent, filtration, washing and drying. The washing may be performed one or more times using, for example, a solvent having a polarity of 5.7 or less. In addition, the drying may use vacuum drying, for example, may be carried out at a temperature of 40 ℃ to 90 ℃ and a pressure of 2.0 torr or less.

As a result, impurities generated in the step of obtaining the diamine hydrochloride composition may be removed together with the first organic solvent. Accordingly, the method may further include removing impurities generated in the step of obtaining the diamine hydrochloride composition together with the first organic solvent. In the reaction process for preparing the diamine hydrochloride composition, impurities are generated and included in the first organic solvent, and the purity of the product can be increased by removing such impurities through the removing step of the first organic solvent.

According to the method, a solid diamine hydrochloride composition can be obtained with high purity by reacting the diamine composition with an aqueous hydrochloric acid solution and performing additional treatment such as precipitation, filtration, drying, and washing. On the other hand, when the diamine composition is reacted with hydrogen chloride gas in an organic solvent as in the prior art, a slurry of diamine hydrochloride is obtained, which is not easy to purify.

The yield of the diamine hydrochloride composition thus obtained may be 50% or more, 65% or more, 80% or more, 85% or more, or 90% or more, and specifically 85% to 95%, or 88% to 92%. .

Meanwhile, the organic layer may be separated from the reactants and reused as an organic solvent. Accordingly, the recovery rate of the first organic solvent may be 80% or more, 85% or more, or 90% or more, and specifically, 80% to 95%, or 80% to 82%.

Diamine hydrochloride composition

According to the above embodiment, since the diamine composition whose b* value is adjusted according to the CIE color coordinate is used as a starting material, the b* value of the diamine hydrochloride composition obtained therefrom can also be adjusted. For example, the diamine hydrochloride composition prepared by the method according to the embodiment may have a b* value according to the CIE color coordinate of 1.5 or less, 1.2 or less, 1.0 or less, or 0.8 or less when dissolved in water at a concentration of 8% by weight. Specifically, the b* value according to the CIE color coordinate may be 0.01 to 1.2, 0.1 to 1.2, 0.1 to 1.0, 0.1 to 0.8, or 0.2 to 1.0.

In addition, in order to control the b* value of the diamine hydrochloride composition, an aqueous hydrochloric acid solution having an Fe ion content below a certain level may be used as a raw material. For example, the Fe ion content in the aqueous hydrochloric acid solution used for preparing the diamine hydrochloride composition may be 0.5 ppm or less. Specifically, the Fe ion content in the aqueous hydrochloric acid solution may be 0.3 ppm or less, or 0.2 ppm or less. More specifically, the Fe ion content in the aqueous hydrochloric acid solution may be 0.001 ppm to 0.5 ppm, or 0.1 ppm to 0.3 ppm.

Alternatively, the b* value according to the CIE color coordinate of the diamine hydrochloride composition may be adjusted by washing with a solvent having a polarity of 5.7 or less. In this case, the solvent having a polarity of 5.7 or less may include dichloromethane, and other solvents are also possible. In addition, the temperature of the solvent having a polarity of 5.7 or less may be 5°C or less, for example, 0°C to 5°C.

That is, the method according to the embodiment may further include washing the diamine hydrochloride composition with a solvent of 5° C. or less having a polarity of 5.7 or less.

In addition, the method according to the embodiment may further include measuring the b* value according to the CIE color coordinate of the diamine hydrochloride composition. If the measured b* value is greater than 1.5, the b* value of the diamine hydrochloride composition may be adjusted by repeating washing as described above. As a result, when the diamine hydrochloride composition is dissolved in water at a concentration of 8 wt%, the b* value according to the CIE color coordinate may be adjusted to be 1.5 or less.

The diamine hydrochloride composition obtained through the above process mainly includes diamine hydrochloride, and the content of the diamine hydrochloride salt may be 85 wt% or more to 99.9 wt% based on the total weight of the composition. In this case, the diamine hydrochloride salt may contain two HCl bonded to the two terminal amine groups of the diamine.

In addition, the diamine hydrochloride composition may include Fe ions, and the content of Fe ions based on the total weight of the diamine hydrochloride composition may be 10 ppm or less.

In addition, the water content of the diamine hydrochloride composition may be 5 wt% or less, 1 wt% or less, 0.1 wt% or less, or 0.01 wt% or less.

Preparation of diisocyanate composition

Next, a diisocyanate composition is obtained by a phosgenation reaction from the diamine hydrochloride composition. Specifically, the diamine hydrochloride composition may be reacted with triphosgene to obtain a diisocyanate composition. In this case, the reaction of the diamine hydrochloride composition with triphosgene may be performed in a second organic solvent.

Scheme 2 below shows an example of the reaction of this step.

[Scheme 2]

In the above formula, R includes an aromatic ring, an aliphatic ring, an aliphatic chain, and the like, and as a specific example, R may be xylylene, norbornene, xylylene hydride, isophorone, or hexamethylene, but is not limited thereto.

Specifically, the diamine hydrochloride composition prepared above is added to an organic solvent, reacted with triphosgene (BTMC, bis(trichloromethyl)carbonate), and then a diisocyanate composition is obtained through filtration and distillation.

Specific examples of the second organic solvent include benzene, toluene, ethylbenzene, chlorobenzene, monochlorobenzene, 1,2-dichlorobenzene, dichloromethane, 1-chloro-n-butane, 1-chloro-n-pentane, 1 -Chloro-n-hexane, chloroform, carbon tetrachloride, n-pentane, n-hexane, n-heptane, n-octane, cyclohexane, cyclopentane, cyclooctane, and may be at least one selected from the group consisting of methylcyclohexane have.

The amount (weight) of the second organic solvent may be 1 to 5 times the weight of the diamine hydrochloride composition. When it is within the above dosage range, it is possible to prevent the use of an excessive organic solvent while the yield of the final diisocyanate is high. Specifically, the second organic solvent may be added to the reaction in an amount of 2 to 5 times, or 3 to 5 times the weight of the diamine hydrochloride composition.

When the reaction temperature of the diamine hydrochloride composition and triphosgene is 115° C. or higher, the reaction between diamine hydrochloride and triphosgene proceeds more smoothly, which may be advantageous in increasing yield and shortening reaction time. In addition, when the reaction temperature of the diamine hydrochloride composition and triphosgene is 160° C. or less, generation of impurities such as tar can be suppressed during final diisocyanate production. For example, the reaction temperature of the diamine hydrochloride composition and triphosgene may be 115°C to 160°C, 115°C to 130°C, or 130°C to 160°C.

In addition, when the reaction temperature of the diamine hydrochloride composition and triphosgene is 130° C. or less, it may be more advantageous to suppress chlorine-containing impurities (eg, chloromethylbenzyl isocyanate, 1,3-bis(chloromethyl)benzene, etc.). Specifically, the reaction temperature of the diamine hydrochloride composition and triphosgene may be 115°C to 130°C. More specifically, the reaction temperature of the diamine hydrochloride composition and triphosgene may be 115°C to 120°C.

The reaction of the diamine hydrochloride composition with triphosgene may be performed for 5 to 100 hours. When it is within the reaction time range, the reaction time is not excessive, and generation of unreacted substances due to phosgene generation can be minimized. Specifically, the reaction between the diamine hydrochloride composition and triphosgene may be performed for 15 hours to 40 hours, 20 hours to 35 hours, or 24 hours to 30 hours.

As a specific example, the reaction of the diamine hydrochloride composition with triphosgene may be performed at a temperature of 115°C to 160°C for 5 hours to 100 hours.

The diamine hydrochloride composition and triphosgene may be added to the reaction in a molar ratio of 1:0.65 to 1. Specifically, the diamine hydrochloride composition and the triphosgene may be added to the reaction in a molar ratio of 1: 0.70 to less than 0.95, or 1: 0.73 to 0.90. When the molar ratio is within the range, it may be more advantageous to prevent the reaction time from increasing due to excessive input while the reaction efficiency is high.

The reaction of the diamine hydrochloride composition and triphosgene, the reaction of the diamine hydrochloride composition and triphosgene includes mixing the diamine hydrochloride composition and the second organic solvent to obtain a first solution; mixing triphosgene and the second organic solvent to obtain a second solution; and sequentially adding and stirring the second solution to the first solution. At this time, the input and stirring of the second solution may be performed at a temperature of 115 ℃ to 160 ℃. In addition, the input of the second solution may be divided into two or more times for a total of 25 to 40 hours. In addition, at this time, the input time for each time may be 5 hours to 25 hours, or 10 hours to 14 hours. In addition, the time for further reaction by stirring after the addition may be 2 hours to 5 hours, or 3 hours to 4 hours.

Alternatively, the reaction of the diamine hydrochloride composition with triphosgene is performed by (2a) adding the second organic solvent to a second reactor; (2b) adding and stirring the diamine hydrochloride composition to the second reactor; and (2c) adding and stirring the triphosgene to the second reactor in sequence. At this time, the introduction of the triphosgene in the step (2c) is a solution in which the triphosgene is dissolved in the same solvent as the second organic solvent in the reactor at a temperature of 115° C. to 130° C. for a total of 25 hours to 40 hours. It may be divided into more than one time. In addition, at this time, the input time for each time may be 5 hours to 25 hours, or 10 hours to 14 hours. In addition, the time for further reaction by stirring after the addition may be 2 hours to 5 hours or 3 hours to 4 hours.

After the reaction, the reaction product may be cooled at 90°C to 110°C.

The product obtained through the above reaction may be further subjected to separation, degassing, cooling, filtration, distillation, and the like.

For example, after the reaction, degassing may be performed at 80° C. to 150° C. while bubbling the reaction product with nitrogen gas. In addition, after the degassing, it may be cooled to 10°C to 30°C and filtered to remove the solid content.

The diisocyanate composition may be obtained by distillation after the diamine hydrochloride composition and the phosgenation reaction.

The distillation may include distillation to remove the second organic solvent. For example, after the reaction, the resultant of the reaction may be distilled at 40° C. to 60° C. for 2 to 8 hours to remove the second organic solvent. The pressure during the distillation may be 2.0 torr or less, 1.0 torr or less, 0.5 torr or less, or 0.1 torr or less. In addition, the second organic solvent may be recovered and recycled through the distillation.

In addition, the distillation may include distilling the diisocyanate. For example, the distillation may include diisocyanate distillation at 100°C to 130°C. When it is within the distillation temperature range, it effectively removes hydrolyzable chlorine compounds generated at high temperatures such as chloromethylbenzyl isocyanate (CBI) or 1,3-bis(chloromethyl)benzene in the final optical lens, such as streaks, cloudiness, and yellowing. It may be more advantageous to prevent deterioration of physical properties. Specifically, the distillation may be performed by setting the bottom temperature of the distiller to 100°C to 130°C. For example, the distillation may be performed by setting the temperature of the reboiler to 100°C to 130°C.

In addition, the pressure during the distillation may be 2.0 torr or less, 1.0 torr or less, 0.5 torr or less, or 0.1 torr or less. Specifically, the distillation may include diisocyanate distillation at a temperature of 100° C. to 130° C. and a pressure of 2 torr or less.

In addition, the diisocyanate distillation time may be 1 hour or more, 2 hours or more, or 3 hours or more, and may be 10 hours or less, or 5 hours or less. Specifically, the diisocyanate distillation may be performed for 2 hours to 10 hours.

The yield of the diisocyanate distillation may be 80% or more, specifically 85% or more, 87% or more, or 90% or more. At this time, the distillation yield can be calculated by measuring the yield of the diisocyanate composition after distillation compared to the theoretical production amount of the diisocyanate composition calculated from the amount of the diamine hydrochloride composition added to the phosgenation reaction.

According to the method of the above embodiment, by controlling the reaction temperature range of the diamine hydrochloride composition and triphosgene, there may be very few impurities in the crude diisocyanate composition before purification. Specifically, the diisocyanate composition, before the diisocyanate distillation, may include 99.0% by weight or more of diisocyanate. In addition, the diisocyanate composition, after the diisocyanate distillation, may include the diisocyanate in an amount of 99.9% by weight or more.

In addition, the content of the aromatic compound having a halogen group in the diisocyanate composition may be 1000 ppm or less.

In addition, the yield of the finally obtained diisocyanate composition may be 80% or more, 85% or more, 88% or more, or 90% or more.

Diisocyanate composition

The diisocyanate composition prepared as described above may have improved color and haze.

In particular, the diisocyanate composition prepared by the method according to the embodiment may have a b* value of 0.01 to 2.0 according to the CIE color coordinate. An optical lens manufactured using a diisocyanate composition having a b* value in the above range may have improved streaks, transmittance, yellowness and refractive index. Specifically, the b* value according to the CIE color coordinate of the diisocyanate composition may be 0.1 to 2.0, 0.1 to 1.5, 0.1 to 1.2, 0.1 to 1.0, or 0.1 to 0.8.

In addition, the diisocyanate composition may have an American Public Health Association (APHA) color value of 20 or less, or 10 or less. Specifically, the diisocyanate composition may have an APHA color value of 1 to 20, or 1 to 10.

In addition, the haze of the diisocyanate composition may be 10% or less, 5% or less, or 3% or less.

The diisocyanate composition may include xylylene diisocyanate or other diisocyanates used in the manufacture of optical lenses, specifically ortho-xylylene diisocyanate (o-XDI), meta-xylylene diisocyanate (m-XDI) 1 selected from the group consisting of , para-xylylene diisocyanate (p-XDI), norbornene diisocyanate (NBDI), hydrogenated xylylene diisocyanate (H6XDI), isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI) It may include more than one species.

The content of diisocyanate in the diisocyanate composition may be 90% by weight or more, 95% by weight or more, 99.5% by weight or more, or 99.9% by weight or more, and specifically may be 90% by weight to 99.9% by weight.

In addition, the Fe ion content in the diisocyanate composition may be 10 ppm or less, 5 ppm or less, or 1 ppm or less. Specifically, the content of Fe ions in the diisocyanate composition may be 0.2 ppm or less.

In addition, the diisocyanate composition may further include benzyl isocyanate, methylbenzyl isocyanate, cyanobenzyl isocyanate, and the like, and the total content of these components may be about 1% by weight or less.

Therefore, the diisocyanate composition obtained by the manufacturing method according to the embodiment can be applied to the manufacture of high-quality plastic optical lenses.

Measurement of color and transparency of reaction solution

The step of obtaining a diisocyanate composition from the diamine hydrochloride composition by phosgenation reaction includes the steps of: (i) reacting the diamine hydrochloride composition in a reactor with triphosgene in a second organic solvent to obtain a reaction solution; (ii) measuring the color and transparency of the reaction solution; and (iii) obtaining a diisocyanate composition from the reaction solution.

In the reaction of the diamine hydrochloride composition and triphosgene, the reaction conditions can be adjusted by measuring the color and transparency of the reaction solution.

For example, in the reaction of obtaining metaxylylenediisocyanate from metaxylylenediamine hydrochloride and triphosgene, the reaction solution at the initial stage of the reaction may be opaque, colorless to white, and the reaction solution at the time when the reaction is normally completed is transparent or transparent It is close to and may have a light brown color.

For example, in the step of measuring the color and transparency of the reaction solution, the reaction solution may exhibit a transparent light brown color.

Specifically, the reaction solution may have an L* value of 45 to 60, an a* value of 3 to 15, and a b* value of 15 to 30 in the CIE-LAB color coordinate. More specifically, the reaction solution may have an L* value of 50 to 55, an a* value of 5 to 10, and a b* value of 20 to 25 in the CIE-LAB color coordinate.

In addition, the reaction solution may have a transmittance of 60% or more, 70% or more, 80% or more, or 90% or more for light having a wavelength of 550 nm. In addition, the reaction solution may have a haze of 20% or less, 10% or less, 5% or less, or 3% or less. Specifically, the reaction solution may have a transmittance of 70% or more and a haze of 10% or less for light having a wavelength of 550 nm. More specifically, the reaction solution may have a transmittance of 80% or more and a haze of 5% or less for light having a wavelength of 550 nm.

On the other hand, if the reaction between metaxylylenediamine hydrochloride and triphosgene is not completed, the reaction solution may be opaque or have a precipitate, and the color may be faint, white, or colorless. In addition, if a large number of side reactions occur, the reaction solution may be opaque or may exhibit a color other than light brown, for example, may exhibit a dark brown to dark color.

The reaction step of the diamine hydrochloride composition and triphosgene may be performed simultaneously with the step of measuring the color and transparency of the reaction solution.

That is, the color and transparency of the reaction solution can be measured in real time while the reaction of the diamine hydrochloride composition and triphosgene is in progress.

In addition, for more accurate measurement, color and transparency can be precisely measured by collecting a portion of the reaction solution. For example, the measurement of the color and transparency of the reaction solution may be performed by collecting a portion of the reaction solution and measuring the color and transparency of the collected reaction solution.

In this case, the reaction equivalent, reaction temperature, or reaction time may be adjusted according to the color and transparency of the reaction solution. For example, the end time of the reaction may be determined according to the color and transparency of the reaction solution. Specifically, the completion time of the reaction may be after the time when the reaction solution changes to a transparent light brown color.

As an example, the reactor may have a viewing window, and measurement of color and transparency of the reaction solution may be performed through the viewing window.

The reactor may be connected to one or more condensers, and after the gas generated in the reactor is transferred to the one or more condensers, the second organic solvent present in the gas may be condensed and recovered to the reactor.

The one or more condensers are connected to the first scrubber and the second scrubber, and the gas transferred from the reactor to the one or more condensers includes hydrogen chloride gas and phosgene gas, and the first scrubber converts the hydrogen chloride gas into water. Dissolving to produce an aqueous solution, the second scrubber can neutralize the phosgene gas by the NaOH aqueous solution.

In addition, the reactor may be connected to one or more stills, and the reaction solution may be transferred to the one or more stills, and the one or more stills may separate the diisocyanate composition and the second organic solvent from the reaction solution.

The separated second organic solvent may be recycled for the reaction between the diamine hydrochloride composition and triphosgene.

2 shows an example of a process device for the reaction of a diamine hydrochloride composition and triphosgene.

First, a second organic solvent and triphosgene are filled in the first tank T-1, and a constant temperature is maintained by reflux of hot water. The inside of the reactor (R-1) is replaced with nitrogen, and a second organic solvent is added thereto and stirred, the diamine hydrochloride composition is slowly added thereto and stirred while maintaining the inside of the reactor at a constant temperature.

Then, triphosgene in the second organic solvent is slowly introduced into the reactor (R-1) from the first tank (T-1). The input of triphosgene in the second organic solvent is carried out once or divided into two or more times, and at this time, stirring is performed while maintaining the internal temperature of the reactor (R-1) constant. After the addition is completed, an additional reaction is performed while stirring for a predetermined time. As an example, the color and transparency of the reaction solution are visually observed through the viewing window (G-1) provided in the reactor (R-1). As another example, the color and transparency of the reaction solution are measured with an optical instrument through the viewing window (G-1) provided in the reactor (R-1). The optical device may include a digital camera, a spectrometer, an optical analysis device, and the like.

The gas (second organic solvent, hydrogen chloride, phosgene, etc.) existing inside the reactor R-1 is transferred to the first condenser C-1. The second organic solvent is primarily condensed by cooling in the first condenser (C-1) and recovered to the reactor (R-1), and the remaining gas is transferred to the second condenser (C-2). The second organic solvent is secondarily condensed by cooling in the second condenser (C-2) and recovered to the reactor (R-1), and the remaining gas is transferred to the third condenser (C-3). The second organic solvent is tertiarily condensed by cooling in the third condenser (C-3) and is recovered to the reactor (R-1).

After the second organic solvent is removed through the multi-stage condenser as described above, the remaining gas (hydrogen chloride, phosgene, etc.) is transferred to the first scrubber S-1. Hydrochloric acid aqueous solution is obtained by dissolving hydrogen chloride gas in water in the first scrubber S-2, and stored in the second tank T-2, and the remaining gas is transferred to the second scrubber S-2. In the second scrubber (S-2), using the sodium hydroxide aqueous solution stored in the third tank (T-3), phosgene (COCl ₂ ) It can be removed by neutralizing the gas.

The reaction solution obtained in the reactor (R-1) is sequentially transferred to the first still (D-1) and the second still (D-2), and through primary and secondary distillation, diisocyanate from the reaction solution The composition and the second organic solvent are separated.

The second organic solvent separated from the reaction solution may be transferred to and stored in the solvent recovery unit V-1, and then may be recycled for the reaction between the diamine hydrochloride composition and triphosgene.

In addition, the diisocyanate composition separated from the reaction solution may be provided as a final product through further filtration and drying.

[Manufacturing method of optical lens]

A composition for an optical material may be prepared by combining the diisocyanate composition prepared in the above embodiment with other components. That is, the composition for an optical material includes the diisocyanate composition prepared according to the embodiment, and thiol or episulfide. An optical material, specifically, an optical lens may be manufactured by using the composition for an optical material. For example, an optical lens may be manufactured by mixing the composition for an optical material and curing by heat in a mold. The manufacturing method or characteristics of the optical lens described below should be understood as a manufacturing method or characteristic of various optical materials that can be implemented using the diisocyanate composition according to the embodiment in addition to the optical lens.

A method of manufacturing an optical lens according to an embodiment comprises the steps of (1) obtaining a diamine hydrochloride composition from a diamine composition; (2) obtaining a diisocyanate composition by phosgenation from the diamine hydrochloride composition; and (3) mixing the diisocyanate composition with thiol or episulfide and polymerizing and curing in a mold, wherein the diamine composition has a b* value of 0.01 to 3.0 according to the CIE color coordinate.

The thiol may be a polythiol including two or more SH groups, and may have an aliphatic, alicyclic, or aromatic skeleton. The episulfide may have two or more thioepoxy groups, and may have an aliphatic, alicyclic, or aromatic skeleton.

Specific examples of the thiol include bis(2-mercaptoethyl)sulfide, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 2,3-bis(2-mercaptoethylthio ) Propane-1-thiol, 2,2-bis(mercaptomethyl)-1,3-propanedithiol, tetrakis(mercaptomethyl)methane, 2-(2-mercaptoethylthio)propane-1,3 -dithiol, 2-(2,3-bis(2-mercaptoethylthio)propylthio)ethanethiol, bis(2,3-dimercaptopropanyl)sulfide, bis(2,3-dimercaptopropanyl) ) disulfide, 1,2-bis(2-mercaptoethylthio)-3-mercaptopropane, 1,2-bis(2-(2-mercaptoethylthio)-3-mercaptopropylthio)ethane; Bis(2-(2-mercaptoethylthio)-3-mercaptopropyl)sulfide, bis(2-(2-mercaptoethylthio)-3-mercaptopropyl)disulfide, 2-(2-mer Captoethylthio)-3-2-mercapto-3-[3-mercapto-2-(2-mercaptoethylthio)-propylthio]propylthio-propane-1-thiol, 2,2-bis-( 3-Mercapto-propionyloxymethyl)-butyl ester, 2-(2-mercaptoethylthio)-3-(2-(2-[3-mercapto-2-(2-mercaptoethylthio)- Propylthio]ethylthio)ethylthio)propane-1-thiol, (4R,11S)-4,11-bis(mercaptomethyl)-3,6,9,12-tetrathiatetradecane-1,14-dithi ol, (S)-3-((R-2,3-dimercaptopropyl)thio)propane-1,2-dithiol, (4R,14R)-4,14-bis(mercaptomethyl)-3, 6,9,12,15-pentathiaheptane-1,17-dithiol, (S)-3-((R-3-mercapto-2-((2-mercaptoethyl)thio)propyl)thio) Propyl)thio)-2-((2-mercaptoethyl)thio)propane-1-thiol, 3,3'-dithiobis(propane-1,2-dithiol), (7R,11S)-7,11 -bis(mercaptomethyl)-3,6,9,12,15-pentathiaheptadecane-1,17-dithiol, (7R,12S)-7,12-bis(mercaptomethyl)-3,6 ,9,10,13,16-hexathiaoctadecane-1,18-dithiol, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7 -Dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, penta Erythritol Tetra Kiss (3-mercaptopropionate), trimethylolpropane tris (3-mercaptopropionate), pentaethritol tetrakis (2-mercaptoacetate), bispentaerythritol-ether-hexakis ( 3-mercaptopropionate), 1,1,3,3-tetrakis(mercaptomethylthio)propane, 1,1,2,2-tetrakis(mercaptomethylthio)ethane, 4,6-bis (mercaptomethylthio)-1,3-dithiane, 2-(2,2-bis(mercaptodimethylthio)ethyl)-1,3-dithiane, 2,5-bismercaptomethyl-1,4 -dithiane, bis(mercaptomethyl)-3,6,9-trithiaundecan-1,11-dithiol, and the like.

Preferably, the thiol is 2-(2-mercaptoethylthio)propane-1,3-dithiol, 2,3-bis(2-mercaptoethylthio)propane-1-thiol, 2-(2, 3-bis(2-mercaptoethylthio)propylthio)ethanethiol, 1,2-bis(2-mercaptoethylthio)-3-mercaptopropane, 1,2-bis(2-(2-mercapto) Ethylthio)-3-mercaptopropylthio)-ethane, bis(2-(2-mercaptoethylthio)-3-mercaptopropyl)sulfide, 2-(2-mercaptoethylthio)-3-2 -Mercapto-3-[3-mercapto-2-(2-mercaptoethylthio)-propylthio]propylthio-propane-1-thiol, 2,2'-thiodiethanethiol, 4,14-bis (mercaptomethyl)-3,6,9,12,15-pentathiahexadecane-1,17-dithiol, 2-(2-mercaptoethylthio)-3-[4-(1-{4- [3-Mercapto-2-(2-mercaptoethylthio)-propoxy]-phenyl}-1-methylethyl)-phenoxy]-propane-1-thiol, pentaerythritol tetrakis (3-mercapto propionate), pentaerythritol mercaptoacetate, trimethylolpropanetrismercaptopropionate, glycerol trimercaptopropionate, dipentaepitritol hexamercaptopropionate, 2,5-bismercaptomethyl -1,4-dithiane and the like.

The thiol may be any one or two or more of the exemplary compounds, but is not limited thereto.

In addition, specific examples of the episulfide include bis(β-epithiopropylthio)methane, 1,2-bis(β-epithiopropylthio)ethane, 1,3-bis(β-epithiopropylthio)propane , 1,2-bis(β-epithiopropylthio)propane, 1-(β-epithiopropylthio)-2-(β-epithiopropylthiomethyl)propane, 1,4-bis(β-epithio Propylthio)butane, 1,3-bis(β-epithiopropylthio)butane, 1-(β-epithiopropylthio)-3-(β-epithiopropylthiomethyl)butane, 1,5-bis( β-epithiopropylthio)pentane, 1-(β-epithiopropylthio)-4-(β-epithiopropylthiomethyl)pentane, 1,6-bis(β-epithiopropylthio)hexane, 1- (β-epithiopropylthio)-5-(β-epithiopropylthiomethyl)hexane, 1-(β-epithiopropylthio)-2-[(2-β-epithiopropylthioethyl)thio]ethane , 1-(β-epithiopropylthio)-2-[[2-(2-β-epithiopropylthioethyl)thioethyl]thio]ethane, tetrakis(β-epithiopropylthiomethyl)methane, 1 ,1,1-tris(β-epithiopropylthiomethyl)propane, 1,5-bis(β-epithiopropylthio)-2-(β-epithiopropylthiomethyl)-3-thiapentane, 1, 5-bis(β-epithiopropylthio)-2,4-bis(β-epithiopropylthiomethyl)-3-thiapentane, 1-(β-epithiopropylthio)-2,2-bis(β -Epithiopropylthiomethyl)-4-thiahexane, 1,5,6-tris(β-epithiopropylthio)-4-(β-epithiopropylthiomethyl)-3-thiahexane, 1,8- Bis(β-epithiopropylthio)-4-(β-epithiopropylthiomethyl)-3,6-dithiaoctane, 1,8-bis(β-epithiopropylthio)-4,5-bis( β-epithiopropylthiomethyl)-3,6-dithiaoctane, 1,8-bis(β-epithiopropylthio)-4,4-bis(β-epithiopropylthiomethyl)-3,6- Dithiaoctane, 1,8-bis(β-epithiopropylthio)-2,4,5-tris(β-epithiopropylthiomethyl)-3,6-dithiaoctane, 1,8-bis(β -epithiopropylthio)-2,5-bis(β-epithiopropylthiomethyl)-3,6-dithiaoctane, 1,9-bis(β-epithiopropylthio)-5-(β-epi Thiopropylthiomethyl)-5-[(2-β -epithiopropylthioethyl)thiomethyl]-3,7-dithianonane, 1,10-bis(β-epithiopropylthio)-5,6-bis[(2-β-epithiopropylthioethyl) Thio]-3,6,9-trithiadecane, 1,11-bis(β-epithiopropylthio)-4,8-bis(β-epithiopropylthiomethyl)-3,6,9-trithia Undecane, 1,11-bis(β-epithiopropylthio)-5,7-bis(β-epithiopropylthiomethyl)-3,6,9-trithioundecane, 1,11-bis(β -epithiopropylthio)-5,7-[(2-β-epithiopropylthioethyl)thiomethyl]-3,6,9-trithioundecane, 1,11-bis(β-epithiopropylthio )-4,7-bis(β-epithiopropylthiomethyl)-3,6,9-trithioundecane, 1,3-bis(β-epithiopropylthio)cyclohexane, 1,4-bis( β-epithiopropylthio)cyclohexane, 1,3-bis(β-epithiopropylthiomethyl)cyclohexane, 1,4-bis(β-epithiopropylthiomethyl)cyclohexane, bis[4-(β -epithiopropylthio)cyclohexyl]methane, 2,2-bis[4-(β-epithiopropylthio)cyclohexyl]propane, bis[4-(β-epithiopropylthio)cyclohexyl]sulfide, 2,5-bis(β-epithiopropylthiomethyl)-1,4-dithiane, 2,5-bis(β-epithiopropylthioethylthiomethyl)-1,4-dithiane, 1,3- Bis(β-epithiopropylthio)benzene, 1,4-bis(β-epithiopropylthio)benzene, 1,3-bis(β-epithiopropylthiomethyl)benzene, 1,4-bis(β- epithiopropylthiomethyl)benzene, bis[4-(β-epithiopropylthio)phenyl]methane, 2,2-bis[4-(β-epithiopropylthio)phenyl]propane, bis[4-(β -epithiopropylthio)phenyl]sulfide, bis[4-(β-epithiopropylthio)phenyl]sulfone, 4,4'-bis(β-epithiopropylthio)biphenyl, and the like.

The episulfide may be any one or two or more of the exemplary compounds, but is not limited thereto. In addition, the episulfide may be a compound in which at least one hydrogen of a thioepoxy group is substituted with a methyl group.

The composition for an optical material may include the diisocyanate composition and the thiol or episulfide in a mixed state or in a separate state. That is, in the polymerizable composition, they may be in a mixed state in contact with each other, or may be in a separated state so as not to contact each other.

The composition for an optical material may include the thiol or episulfide and the diisocyanate composition in a weight ratio of 2:8 to 8:2, 3:7 to 7:3, or 4:6 to 6:4.

A catalyst, a chain extender, a crosslinking agent, a UV stabilizer, an antioxidant, a color inhibitor, a dye, a filler, a mold release agent, and the like may be further added according to the purpose of the composition for the optical material and the optical lens.

After mixing these thiols or episulfides with the diisocyanate composition and other additives and defoaming, they are poured into a mold and polymerized while slowly rising from a low temperature to a high temperature, and the resin is cured by heating to manufacture an optical lens.

The temperature of the polymerization reaction may be, for example, 20 °C to 150 °C, specifically 25 °C to 120 °C. In addition, in order to control the reaction rate, a reaction catalyst commonly used in the production of polythiourethane may be added, and specific types thereof are as exemplified above.

In addition, if necessary, the manufactured optical lens may have physical or physical properties such as anti-reflection, high hardness, abrasion resistance, chemical resistance, anti-fogging, surface polishing, antistatic treatment, hard coat treatment, anti-reflection coating treatment, dyeing treatment, etc. A chemical treatment may be further carried out.

The optical lens manufactured by the above method has excellent optical properties such as transparency, refractive index, and yellowness. For example, the optical lens may have a refractive index of 1.55 or more, specifically, a refractive index of 1.55 to 1.77. Alternatively, the optical lens may have a refractive index of 1.6 or more, specifically, a refractive index of 1.6 to 1.7. In addition, the optical lens may have an Abbe's number of 30 to 50, specifically 30 to 45, or 31 to 40. In addition, the optical lens may have a light transmittance of 80% or more, 85% or more, or 87% or more, which may be a total light transmittance. In addition, the optical lens may have a yellowness (Y.I.) of 30 or less, 25 or less, or 20 or less, for example, 1 to 25, or 10 to 20. Specifically, the optical lens may have a transmittance of 85% or more and a yellowness of 22 or less.

More specific examples are exemplified below, but are not limited thereto.

Examples and Comparative Examples

Step (1) Preparation of diamine hydrochloride composition

First, prepare a diamine composition containing m-XDA, measure the b* value according to its CIE color coordinate, and when the b* value exceeds 3.0, the b* value is distilled at 100 to 130 ° C and 0.1 to 1 torr. It was adjusted so that it might become this 0.01-3.0 range. 1009.4 g (9.46 mol) of a 35% aqueous hydrochloric acid solution was added to the reactor, and the internal temperature of the reactor was cooled to 15°C while stirring. While maintaining the temperature of the reactor at 60° C., 600.0 g (4.4 mol) of the previously prepared diamine composition was added for 1 hour. After completion of the input, the temperature inside the reactor was cooled to 10° C. and stirred for 1 hour, then 1320.0 g of tetrahydrofuran (THF) was further added, and the temperature inside the reactor was cooled to -5° C., followed by further stirring for 1 hour. After completion of the reaction, the diamine hydrochloride composition containing m-XDA·2HCl was separated by vacuum filtration using a filter, and filtered tetrahydrofuran was recovered for reuse. In order to remove the residual solvent and moisture, the residual solvent and moisture in the separated diamine hydrochloride composition were removed at 90° C. and vacuum dried at 0.1 torr.

Step (2) Preparation of diisocyanate composition

800 g of the diamine hydrochloride composition obtained in the previous step and 3,550 g of orthodichlorobenzene (ODCB) were added to reactor A and heated at about 125° C. with stirring. 950 g of triphosgene (BTMC) and 800 g of ODCB were put into reactor B, and stirred and dissolved at about 60° C., and the temperature was maintained at 125° C. to prevent precipitation, and it was added dropwise to reactor A over 24 hours. After completion of the dropping, stirring was performed for 4 hours, and when the reaction was completed, nitrogen gas was blown into the solvent at 125° C. and degassed while bubbling. After cooling to 10° C., the remaining solid was filtered using Celite, and the organic solvent (ODCB) was removed and distilled to obtain a diisocyanate composition containing m-XDI. At this time, the organic solvent was removed at a pressure of 0.5 torr or less and a temperature of 60° C. for 8 hours, and distillation was performed at a pressure of 0.1 torr or less and a temperature of 120° C. for 10 hours.

The b* values according to the CIE color coordinates of the diamine compositions used as starting materials in Examples and Comparative Examples, and the diamine hydrochloride compositions and diisocyanate compositions obtained in steps (1) and (2), respectively, are summarized in the table below. The b* value was measured using a colorimeter (Colormate, Shinko) by filling a quartz cell with a thickness of 10 mm in the case of a liquid sample and dissolving it in an organic solvent (ODCB) at 8 wt % in the case of a solid sample.

division b* value diamine composition Diamine hydrochloride composition Diisocyanate composition Example 1 0.4 0.6 0.4 Example 2 2.7 1.0 0.8 Example 3 1.5 0.8 0.6 Example 4 3.3 before distillation / 0.5 after distillation 0.7 0.5 Example 5 4.5 before distillation / 0.6 after distillation 0.7 0.6 Comparative Example 1 3.3 1.4 2.1 Comparative Example 2 4.5 1.8 2.7

As shown in the above table, by adjusting the b* value according to the CIE color coordinate of the diamine composition, the b* value of the diamine hydrochloride composition and the diisocyanate composition could be changed.

manufacture of optical lenses

4,8-bis(mercaptomethyl-3,6,9-trithiaundecan-1,11-dithiol 49.3 parts by weight, 50.7 parts by weight of the m-XDI composition prepared in the previous example or comparative example, dibutyl After uniformly mixing 0.01 parts by weight of tin chloride and 0.1 parts by weight of a phosphoric acid ester release agent (ZELEC ^TM UN, Stepan), defoaming at 600 Pa for 1 hour, filtration through a 3㎛ Teflon filter, and a glass mold and a mold made of tape After maintaining the mold at 25° C. for 8 hours, the temperature was slowly raised to 130° C. for 8 hours at a constant rate and polymerization was performed for 2 hours at 130° C. After releasing the molded product from the mold, it was further cured at 120° C. for 2 hours to obtain an optical lens got

Assessment Methods

The evaluation methods for the Examples and Comparative Examples are as follows.

(1) distillation yield

The distillation yield was calculated by measuring the yield of the diisocyanate composition after distillation compared to the theoretical production amount of the diisocyanate composition calculated from the amount of the diamine hydrochloride composition added to the reaction with triphosgene.

(2) diisocyanate content

The diisocyanate content in the diisocyanate composition was measured by gas chromatography (GC) (instrument: Agilent 6890/7890, carrier gas: He, injection temperature 250° C., oven temperature 40-320° C., column: HP-1, Wax, 30 m, detector: FID, 300°C)

(3) McLee

A lens having a diameter of 75 mm, -2.00, -8.00 D was manufactured, and a Mercury lamp light source was transmitted through the manufactured lens, and the transmitted light was projected on a white plate to determine whether stria occurred by the presence or absence of contrast.

(4) Cloudy (haze)

The optical lens was irradiated to the projector in the dark to visually check whether the optical lens was cloudy or had opaque materials.

(5) transmittance and yellowness (Y.I.)

An optical lens was manufactured in the form of a cylinder having a radius of 16 mm and a height of 45 mm, and the light was transmitted in the height direction to measure the yellowness and transmittance. Yellowness was calculated by the following equation based on the measurement results of x and y. Y.I = (234x + 106y) / y

The evaluation results of the above Examples and Comparative Examples are shown in the table below.

division Diisocyanate composition optical lens distillation
yield Diisocyanate content (wt%) McLee cloudiness transmittance Y.I. before distillation after distillation Example 1 91% 99.1 99.9 none none 90% 19 Example 2 88% 99.0 99.9 none none 91% 22 Example 3 90% 99.1 99.9 none none 89% 20 Example 4 90% 99.1 99.9 none none 91% 21 Example 5 91% 99.1 99.9 none none 91% 21 Comparative Example 1 85% 98.5 99.8 none slightly cloudy 90% 25 Comparative Example 2 83% 98.4 99.7 none slightly cloudy 88% 29

As shown in Tables 1 and 2 above, the diisocyanate composition prepared using the diamine composition having a preferred b* range as in Examples 1 to 5 was excellent in yield and purity, and the transmittance of the final optical lens was high and streaks and cloudiness and yellowing did not occur. On the other hand, as in Comparative Examples 1 and 2, the diisocyanate composition prepared using the diamine composition outside the preferred b* range had relatively low yield and purity, and white turbidity and yellowing occurred in the final optical lens.

T-1: 1st tank, T-2: 2nd tank, T-3: 3rd tank,
R-1: reactor, D-1: first still, D-2: second still,
C-1: first capacitor, C-2: second capacitor, C-3: third capacitor,
S-1: first scrubber, S-2: second scrubber,
G-1: sight window, V-1: solvent recovery device.

Claims (10)

(1) obtaining a diamine hydrochloride composition from the diamine composition; and
(2) obtaining a diisocyanate composition from the diamine hydrochloride composition by a phosgenation reaction,
The method for producing a diisocyanate composition, wherein the diamine composition has a b* value of 0.01 to 3.0 according to the CIE color coordinate.
The method of claim 1,
The manufacturing method of the diisocyanate composition, before the step (1),
measuring the b* value according to the CIE color coordinate of the diamine composition; and
The method for producing a diisocyanate composition, further comprising the step of adjusting the b* value to 0.01 to 3.0.
3. The method of claim 2,
Control of the b* value comprises distilling the diamine composition one or more times, a method for producing a diisocyanate composition.
4. The method of claim 3,
Distillation of the diamine composition is performed at a temperature of 100° C. to 130° C. and a pressure condition of 0.1 Torr to 1 Torr, a method for preparing a diisocyanate composition.
5. The method of claim 4,
The method for producing a diisocyanate composition, wherein the diamine composition has a b* value of 0.01 to 1.0 according to the CIE color coordinate.
The method of claim 1,
The diamine hydrochloride composition has a b* value of 1.2 or less according to the CIE color coordinate when dissolved in water at a concentration of 8% by weight, a method for producing a diisocyanate composition.
The method of claim 1,
The diisocyanate composition has a b* value of 0.01 to 2.0 according to the CIE color coordinate, a method for producing a diisocyanate composition.
The method of claim 1,
The diamine hydrochloride composition is prepared by reacting the diamine composition with an aqueous hydrochloric acid solution, and the diisocyanate composition is obtained by distillation after reacting the diamine hydrochloride composition with triphosgene, and the distillation is carried out at a temperature of 100 ° C. to 130 ° C. and A method for producing a diisocyanate composition, comprising diisocyanate distillation at a pressure condition of 2 torr or less.
The method of claim 1,
The diamine composition comprises xylylenediamine,
The diisocyanate composition is a method for producing a diisocyanate composition comprising xylylene diisocyanate.
(1) obtaining a diamine hydrochloride composition from the diamine composition;
(2) obtaining a diisocyanate composition by phosgenation from the diamine hydrochloride composition; and
(3) mixing the diisocyanate composition with thiol or episulfide and polymerizing and curing in a mold;
The method for producing an optical lens, wherein the diamine composition has a b* value of 0.01 to 3.0 according to the CIE color coordinate.

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