KR102496434B1 - Method of preparing diisocyanate composition and optical lens - Google Patents

Abstract

In the method for preparing the diisocyanate composition according to the embodiment, the yield and purity of the diisocyanate composition as well as the optical properties of the final optical lens may be improved by adjusting the pH of the diamine hydrochloride composition within a specific range. Therefore, the method for preparing the diisocyanate composition according to the embodiment can be applied to the manufacture of high-quality plastic optical lenses.

Description

Method for producing diisocyanate composition and optical lens {METHOD OF PREPARING DIISOCYANATE COMPOSITION AND OPTICAL LENS}

Embodiments relate to diisocyanate compositions and methods of making optical lenses. More specifically, embodiments relate to a method for preparing a diisocyanate composition via diamine hydrochloride, 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 produced by a phosgene method, a non-phosgene method, a thermal decomposition method, or the like.

The phosgene method is to synthesize isocyanate by reacting raw material amine with phosgene (COCl ₂ ) gas, and the non-phosgene method is to synthesize isocyanate by reacting xylylene chloride with sodium cyanate in the presence of a catalyst. After preparing carbamate by reacting with alkyl chloroformate, isocyanate is synthesized by thermal decomposition at high temperature in the presence of a catalyst.

Among these isocyanate production methods, the phosgene method is most widely used, and in particular, a direct method of directly reacting phosgene gas with amine has been generally used, but this has a problem in that it requires a number of devices for direct reaction of phosgene gas. On the other hand, in order to supplement the direct method, a hydrochloride method has been developed in which hydrogen chloride gas is reacted with amine to obtain amine hydrochloride, which is an intermediate material, and reacted with phosgene, as in Korean Patent Registration No. 1994-1948.

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

Therefore, an attempt was made to obtain hydrochloric acid salt using an aqueous hydrochloric acid solution rather than hydrogen chloride gas, but it was difficult to apply it in practice because the yield dropped significantly to 50% due to the dissolution of amine in the aqueous hydrochloric acid aqueous solution. There was a difficulty in using this low amine. In addition, phosgene gas used in the conventional phosgene method is a highly toxic and environmentally regulated material, and a separate cooling device is required to store it, which is difficult to store and manage.

Korean Registered Patent Publication No. 1994-1948

Therefore, the inventors of the present invention, in the process of preparing diisocyanate, which is mainly used as a raw material for plastic optical lenses, from diamine through hydrochloride, used an aqueous hydrochloric acid solution and an organic solvent instead of hydrogen chloride gas, and used solid triphosgene instead of phosgene gas, and the reaction conditions By controlling these, conventional environmental, yield and quality problems could be solved.

In addition, the present inventors noted that chlorine components or free amines remaining in the diamine hydrochloride composition lower the yield and purity of the diisocyanate composition prepared therefrom and cause striae, cloudiness, or yellowing in the final optical lens. In particular, the present inventors noted that the pH value of the diamine hydrochloride composition in water correlates with the extent to which such remnants are present.

As a result of research by the present inventors, it was found that the yield and purity of the diisocyanate composition as well as the optical properties of the final optical lens can be improved by adjusting the pH of the diamine hydrochloride composition used in the preparation of the diisocyanate composition to a specific range. did

Accordingly, an object of embodiments is to provide a method for preparing a diisocyanate composition having improved purity and yield using a diamine hydrochloride composition having a pH adjusted, and a method for manufacturing an optical lens having improved optical properties.

According to one embodiment, a diisocyanate composition comprising the step of obtaining a diisocyanate composition by a phosgenation reaction from a diamine hydrochloride composition, wherein the diamine hydrochloride composition has a pH of 3.0 to 4.0 when dissolved in water at a concentration of 10% by weight. A method for preparing the composition is provided.

According to another embodiment, obtaining a diisocyanate composition from a diamine hydrochloride composition by a phosgenation reaction; and mixing the diisocyanate composition with thiol or episulfide and polymerizing and curing in a mold, wherein the diamine hydrochloride composition has a pH of 3.0 to 4.0 when dissolved in water at a concentration of 10% by weight. A manufacturing method is provided.

According to the above embodiment, the yield and purity of the diisocyanate composition as well as the optical properties of the final optical lens may be improved by adjusting the pH of the diamine hydrochloride composition used in the preparation of the diisocyanate composition to a specific range. Specifically, by adjusting the pH within a specific range, the content of chlorine component or free amine remaining in the diamine hydrochloride composition can be controlled, and as a result, side reactions such as urea formation in the process of preparing the diisocyanate composition can be suppressed. can

In addition, the method for producing diisocyanate according to a preferred embodiment uses an aqueous hydrochloric acid solution instead of hydrogen chloride gas in the production of diamine hydrochloride, which is an intermediate material, so that the reaction can proceed even at atmospheric pressure, so an additional device for heating and cooling at a high temperature is required. and yield can 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 an aqueous hydrochloric acid solution and adjusting reaction conditions, thereby minimizing the dissolution of the hydrochloric acid salt in the aqueous hydrochloric acid solution to further increase the final yield. And, since it is not greatly affected by the content of moisture and impurities in the raw material diamine, the range of selection of raw materials can be widened. 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 is highly toxic, and triphosgene, which is in a solid state at room temperature and does not require a separate cooling storage device, is less toxic. Since 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.
Figure 2 shows an example of a process equipment for the reaction of the diamine hydrochloride composition and triphosgene.

In the present specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated.

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

In the present specification, "amine" means a compound having one or more amine groups at the terminal, and "diamine" means a compound having two amine groups at the terminal, and the aliphatic chain, aliphatic ring, and aromatic ring Depending on the skeleton, it can have a wide variety of structures. 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, hydrogenated xylylenediamine (H6XDA), dicyclohexylmethanediamine, cyclohexanediamine, methylcyclohexanediamine, isophoronediamine (IPDA), dicyclohexyldimethylmethanediamine, 2,2-dimethyldiamine Chlorhexylmethanediamine, 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 , norbornediamine (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) ) ethane and the like. 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 ideal The xylylenediamine (XDA) includes orthoxylylenediamine (o-XDA), metaxylylenediamine (m-XDA), and paraxylylenediamine (p-XDA).

In the present specification, "isocyanate" means a compound having an NCO group, and "diisocyanate" means a compound having two NCO groups at the ends, depending on the skeleton of an aliphatic chain, aliphatic ring, or aromatic ring. They can have very different 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, hydrogenated xylylene 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(phenylisocyanate), 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-diisocyanatomethyl tetrahydrothiophene, 2,5-diisocyanato-1,4-dithiane, 2,5-diisocyanatomethyl-1,4-dithiane, etc. there is. More specifically, the diisocyanate is a group consisting of xylylene diisocyanate (XDI), norbornene diisocyanate (NBDI), hydrogenated xylylene diisocyanate (H6XDI), isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI) It may be one or more selected from. The xylylene diisocyanate (XDI) includes orthoxylylene diisocyanate (o-XDI), metaxylylene diisocyanate (m-XDI) and p-xylylene diisocyanate (p-XDI). As a specific example, the diamine may include xylylenediamine, and the diisocyanate may include xylylenediisocyanate.

As is well known in the present specification, "composition" may mean a mixture or complex form of two or more chemical components in a solid, liquid, and/or gaseous state while generally maintaining individual unique properties.

Compounds (eg, triphosgene) used in each reaction step according to the embodiment or compounds obtained as a result of the reaction (eg, diamine hydrochloride, diisocyanate) are generally residual, side reactions, or moisture in unreacted samples in each reaction step. It exists in a mixed or combined state with heterogeneous components generated by reaction with or natural decomposition of the compound, and these heterogeneous components remain in trace amounts even after several purifications and may exist together with the main component.

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

In addition, in the present specification, in order to clearly and easily distinguish between various compositions, the term has been described in combination with the name of the main component in the composition, for example, "diamine hydrochloride composition" means a composition containing diamine hydrochloride as a main component , "diisocyanate composition" means 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, 90% by weight to 99.9% by weight.

The ppm units described herein mean ppm by weight.

[Method for producing diisocyanate composition]

A method for preparing a diisocyanate composition according to an embodiment includes obtaining a diisocyanate composition from a diamine hydrochloride composition by a phosgenation reaction, wherein the diamine hydrochloride composition has a concentration of 3.0 to 4.0 when dissolved in water at a concentration of 10% by weight. has a pH of

The diamine hydrochloride composition may be prepared by reacting diamine with an aqueous hydrochloric acid solution. Specifically, the method for preparing the diisocyanate composition according to the embodiment may further include obtaining the diamine hydrochloride composition by reacting diamine with an aqueous hydrochloric acid solution.

1 schematically shows a method for preparing a diisocyanate composition according to an embodiment. In FIG. 1 , R includes an aromatic ring, an aliphatic ring, an aliphatic chain, and the like, and as specific examples, R may be xylylene, norbornene, xylylene hydride, isophorone, or hexamethylene, but is 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 a step of 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.

Each step is described in detail below.

Preparation of diamine hydrochloride composition

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

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

[Scheme 1]

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

In the case of conventionally using hydrogen chloride gas, since hydrochloric acid is formed into fine particles during normal pressure reaction and the agitation inside the reactor is not smooth, a process of increasing the temperature inside the reactor by increasing the pressure is additionally required, and the final product There was also a problem with the yield of low.

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

The concentration of the aqueous hydrochloric acid solution may be 5% to 50% by weight. When within the above concentration range, the final yield can be increased by minimizing the dissolution of the hydrochloric acid salt in the aqueous hydrochloric acid solution, and handling properties can also be improved. 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% by weight to 45% by weight.

The introduction of the diamine and the aqueous hydrochloric acid solution may be performed while maintaining a constant temperature inside the reactor.

When the diamine and the aqueous hydrochloric acid solution are added, the internal temperature of the reactor may be 20 °C to 100 °C. When within the above temperature range, it is possible to prevent the temperature from being raised above the boiling point, which is not suitable for the reaction, or the reaction efficiency is lowered due to the temperature being too low.

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

In the conventional hydrochloride method, a lot of heat is generated in the reaction process, requiring rapid cooling through a separate cooler, whereas according to the embodiment, since the reaction material is introduced while maintaining a low temperature, a separate cooler is not required.

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

After the addition of the diamine 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 between the diamine and the aqueous hydrochloric acid solution may be performed at normal pressure, for example, while stirring for 30 minutes to 2 hours.

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

Thereafter, a step of treating the diamine hydrochloride composition may be further performed. For example, treating the diamine hydrochloride composition may include precipitating the diamine hydrochloride composition, filtering the diamine hydrochloride composition, drying the diamine hydrochloride composition, and washing the diamine hydrochloride composition, may contain 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 product, cooled, and the reaction may proceed with additional stirring.

The first organic solvent is specifically diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran, methanol, ethanol, dimethyl sulfoxide, dimethylformamide, 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. When the amount is within the above range, the yield of final hydrochloride is high and the use of excessive organic solvent can be prevented. Specifically, the first organic solvent may be introduced into the reaction in an amount of 1 to 2 times, 1 to 1.5 times, or 1.3 times to 1.5 times the weight of the diamine.

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

According to a specific example, (1a) injecting the aqueous hydrochloric acid solution into the first reactor; (1b) introducing and stirring the diamine into the first reactor; and (1c) introducing and stirring the first organic solvent into 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 adding the diamine in the step (1b); and cooling the inside of the reactor to a temperature of -5°C to 5°C after the introduction of the first organic solvent in step (1c) and before stirring.

After adding the first organic solvent, separation, filtration, washing, and drying may be further performed. For example, a solid diamine hydrochloride composition may be obtained by separating an aqueous layer after adding the first organic solvent, filtering, washing, and drying the aqueous layer. The washing may be performed one or more times using, for example, a solvent having a polarity of 5.7 or less. In addition, vacuum drying may be used for the drying, and may be performed at, for example, a temperature of 40° C. to 90° C. 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. Impurities are generated in the reaction process for preparing the diamine hydrochloride composition and are included in the first organic solvent, and the purity of the product can be increased by removing such impurities through the step of removing the first organic solvent.

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

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, 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, specifically, 80% to 95%, or 80% to 82%.

Diamine hydrochloride composition

The diamine hydrochloride composition obtained through the above process mainly includes diamine hydrochloride, and for example, the content of diamine hydrochloride based on the total weight of the composition may be 85% by weight to 99.9% by weight. At this time, the diamine hydrochloride may contain two HCl bonded to two terminal amine groups of diamine.

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

In particular, according to the above embodiment, the diamine hydrochloride composition has a pH of 3.0 to 4.0 when dissolved in water at a concentration of 10% by weight. When within the above pH range, the yield and purity of the diisocyanate composition prepared using the diamine hydrochloride composition may be improved, and the optical properties of the final optical lens may be further improved. In contrast, when the pH is less than 3.0, HCl not bound to diamine is present in the diamine hydrochloride composition, increasing the chlorine concentration during the subsequent phosgenation reaction to generate impurities. In addition, when the pH is greater than 4.0, free amine groups not bound to HCl exist in the diamine hydrochloride composition, and react with diisocyanate synthesized in a subsequent reaction to form urea.

As various examples, when the diamine hydrochloride composition is dissolved in water at a concentration of 10% by weight, the pH may be 3.0 or more, 3.1 or more, 3.2 or more, 3.3 or more, 3.4 or more, or 3.5 or more, and also 4.0 or less, 3.9 or less, or 3.8 or less, 3.7 or less, or 3.6 or less. As a specific example, when the diamine hydrochloride composition is dissolved in water at a concentration of 10% by weight, the pH may be 3.0 to 3.9, 3.1 to 4.0, 3.2 to 4.0, or 3.3 to 4.0.

Such pH can be controlled by adjusting process conditions in the process of preparing the diamine hydrochloride composition. For example, when the diamine hydrochloride composition is obtained by reacting diamine with an aqueous hydrochloric acid solution, the pH of the diamine hydrochloride composition can be adjusted by adjusting the input amount of the aqueous hydrochloric acid solution.

The input amount of the aqueous hydrochloric acid solution may be adjusted in a relative molar ratio with respect to the input amount of the diamine. For example, the aqueous hydrochloric acid solution may be added in an amount of 2.00 mol or more, 2.02 mol or more, 2.05 mol or more, 2.10 mol or more, or 2.20 mol or more of HCl per 1 mol of the diamine. In addition, the aqueous hydrochloric acid solution may be added so that the amount of HCl is 4.00 mol or less, 3.80 mol or less, 3.70 mol or less, 3.50 mol or less, 3.40 mol or less, 3.35 mol or less, or 3.25 mol or less per 1 mol of the diamine.

Specifically, the aqueous hydrochloric acid solution may be introduced into the reaction such that 2.02 mol to 4.00 mol of HCl per 1 mol of the diamine. When within the above range, some diamines do not react with the aqueous hydrochloric acid solution and remain, so that it may be more advantageous to prevent the free amine group from reacting with the diisocyanate to form urea in the subsequent reaction. It may be more advantageous to prevent the ion from generating impurities by increasing the chlorine concentration during the subsequent phosgenation reaction.

When adjusted to the above preferred pH range, free amine may be contained within a certain content range or less in the diamine hydrochloride composition.

Specifically, the content of the free amine group in the diamine hydrochloride composition may be 0.1% by weight or less, or 0.01% by weight or less, or the free amine group may not exist in the diamine hydrochloride composition.

In addition, when adjusted to the above preferred pH range, the chlorine component may be contained within a certain content range or less in the diamine hydrochloride composition.

Specifically, the content of chlorine ions in the diamine hydrochloride composition may be 0.1% by weight or less, or 0.01% by weight or less.

Preparation of diisocyanate composition

Next, a diisocyanate composition is obtained from the diamine hydrochloride composition by a phosgenation reaction. Specifically, a diisocyanate composition may be obtained by reacting the diamine hydrochloride composition with triphosgene. At this time, the reaction between the diamine hydrochloride composition and triphosgene may be performed in a second organic solvent.

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

[Scheme 2]

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

Specifically, the previously prepared diamine hydrochloride composition was added to an organic solvent, reacted with triphosgene (BTMC, bis(trichloromethyl)carbonate), and then filtered and distilled to obtain a diisocyanate composition.

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 methylcyclohexane may be one or more selected from the group consisting of there is.

The input amount (weight) of the second organic solvent may be 1 to 5 times the weight of the diamine hydrochloride composition. When the input amount is within the above range, the yield of the final diisocyanate is high and the use of excessive organic solvent can be prevented. Specifically, the second organic solvent may be introduced into 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 the diamine hydrochloride and triphosgene proceeds more smoothly, which may be advantageous for increasing yield and shortening reaction time. In addition, when the reaction temperature between 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 ℃ to 130 ℃. 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 and triphosgene may be performed for 5 hours to 100 hours. When within the above reaction time range, it is possible to minimize the generation of unreacted substances due to the generation of phosgene without excessive reaction time. Specifically, the reaction of 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 and triphosgene may be performed at a temperature of 115° C. to 160° C. for 5 hours to 100 hours.

The diamine hydrochloride composition and the triphosgene may be added to the reaction at a molar ratio of 1:0.65 to 1. Specifically, the diamine hydrochloride composition and the triphosgene may be added to the reaction at a molar ratio of 1: greater than 0.70 to less than 0.95 or 1: 0.73 to 0.90. When within the above molar ratio 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 between the diamine hydrochloride composition and triphosgene may include mixing the diamine hydrochloride composition and the second organic solvent to obtain a first solution; obtaining a second solution by mixing triphosgene and the second organic solvent; And adding and stirring the second solution to the first solution may be sequentially included. At this time, the introduction and stirring of the second solution may be performed at a temperature of 115 ℃ to 160 ℃. In addition, the injection of the second solution may be divided into two or more times for a total of 25 hours 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 additional reaction time by stirring after the addition may be 2 hours to 5 hours or 3 hours to 4 hours.

Alternatively, the reaction between the diamine hydrochloride composition and triphosgene may include (2a) injecting the second organic solvent into a second reactor; (2b) introducing and stirring the diamine hydrochloride composition into the second reactor; and (2c) introducing and stirring the triphosgene into the second reactor. At this time, in the step (2c), the triphosgene is added to 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 2 It may be divided into more than one dose. 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 additional reaction time 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 reaction may further undergo 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 the solid content may be removed by filtration.

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

The distillation may include distillation for removing the second organic solvent. For example, after the reaction, the reaction product 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 diisocyanate. For example, the distillation may include diisocyanate distillation at 100 °C to 130 °C. When within the above distillation temperature range, it effectively removes hydrolyzable chlorine compounds generated at high temperatures, such as chloromethylbenzylisocyanate (CBI) or 1,3-bis(chloromethyl)benzene, resulting in streaks, cloudiness, or yellowing in the final optical lens. It may be more advantageous to prevent deterioration of physical properties. Specifically, the distillation may be performed by setting the temperature of the bottom 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 may be calculated by measuring the yield of the diisocyanate composition after distillation compared to the theoretical amount of the diisocyanate composition calculated from the amount of the diamine hydrochloride composition introduced into the phosgenation reaction.

According to the method of the embodiment, by adjusting the reaction temperature range of the diamine hydrochloride composition and triphosgene, impurities may be very small even in the crude diisocyanate composition before purification. Specifically, the diisocyanate composition may include 98.7% by weight or more of diisocyanate before the diisocyanate distillation. In addition, the diisocyanate composition may include 99.9% by weight or more of diisocyanate after the diisocyanate is distilled.

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 thus prepared may have improved color and haze. For example, 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. Also, the haze of the diisocyanate composition may be 10% or less, 5% or less, or 3% or less.

In addition, the diisocyanate composition may have a pH of 4.5 or more, 5 or more, or 5.5 or more, and may also be 6.5 or less, 6 or less, or 5.8 or less. Specifically, the diisocyanate composition may have a pH of 5.0 to 5.8. When within the above range, it may be more advantageous to suppress striae, cloudiness, or yellowing by exhibiting an appropriate polymerization reaction rate for lens manufacturing. In addition, when within the above pH range, the chlorine component in the diisocyanate composition may be contained within a certain content range. Specifically, the content of chlorine ions in the diisocyanate composition may be 1000 ppm or less or 100 ppm or less.

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

The content of diisocyanate in the diisocyanate 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 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

Obtaining a diisocyanate composition from the diamine hydrochloride composition by a phosgenation reaction may include: (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 between the diamine hydrochloride composition and triphosgene, reaction conditions may 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 beginning 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 coordinates. 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 coordinates.

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

Alternatively, if the reaction between the metaxylylenediamine hydrochloride and triphosgene is not completed, the reaction solution may be opaque or may have a precipitate and may be pale, white or colorless. In addition, if a lot of side reactions occur, the reaction solution may be opaque or show a color other than light brown, for example, black brown to dark color.

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

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

In addition, for more accurate measurement, a part of the reaction solution may be sampled to accurately measure color and transparency. For example, the color and transparency of the reaction solution may be measured by collecting a portion of the reaction solution and measuring the color and transparency of the reaction solution.

At this time, the reaction equivalent, reaction temperature, or reaction time may be adjusted according to the color and transparency of the reaction solution. For example, the reaction end point may be determined according to the color and transparency of the reaction solution. Specifically, the reaction end point may be after the reaction solution turns a transparent light brown color.

As an example, the reactor may include a viewing window, and the color and transparency of the reaction solution may be measured through the viewing window.

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

The one or more stage condenser is connected to a first scrubber and a second scrubber, and the gas transferred from the reactor to the one or more stage condenser includes hydrogen chloride gas and phosgene gas, and the first scrubber dissolves the hydrogen chloride gas in water. By dissolving to produce an aqueous solution, the second scrubber can neutralize the phosgene gas with an aqueous solution of NaOH.

In addition, the reactor may be connected to one or more stage distiller, the reaction solution may be transferred to the one or more stage distiller, and the one or more stage distiller 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 of the diamine hydrochloride composition and triphosgene.

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

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

Thereafter, triphosgene in the second organic solvent is gradually introduced into the reactor (R-1) from the first tank (T-1). The introduction of triphosgene in the second organic solvent is performed once or twice or more, and at this time, stirring is performed while maintaining a constant internal temperature of the reactor (R-1). After the addition is completed, an additional reaction is performed while stirring for a certain period of time. As an example, the color and transparency of the reaction solution are observed with the naked eye through a 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 a viewing window (G-1) provided in the reactor (R-1). The optical device may include a digital camera, a spectrometer, optical analysis equipment, and the like.

Gases (second organic solvent, hydrogen chloride, phosgene, etc.) present in the reactor (R-1) are 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 returned 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 returned to the reactor (R-1).

As such, after the second organic solvent is removed through the multi-stage condenser, the remaining gas (hydrogen chloride, phosgene, etc.) is transferred to the first scrubber S-1. In the first scrubber (S-2), hydrogen chloride gas is dissolved in water to obtain an aqueous hydrochloric acid solution, which is 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), the phosgene (COCl ₂ ) gas can be neutralized and removed using the aqueous sodium hydroxide solution stored in the third tank (T-3).

The reaction solution obtained in the reactor (R-1) is sequentially transferred to the first distillation machine (D-1) and the second distillation machine (D-2), and diisocyanate is obtained from the reaction solution while undergoing primary distillation and secondary distillation. 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 a solvent recovery unit (V-1), and then recycled for the reaction of 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.

[Method of manufacturing 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 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 heating in a mold. The manufacturing method or characteristics of an optical lens described below should be understood as manufacturing methods or characteristics of various optical materials that can be implemented using the diisocyanate composition according to the embodiment in addition to the optical lens.

A method for manufacturing an optical lens according to an embodiment includes the steps of obtaining a diisocyanate composition from a diamine hydrochloride composition by a phosgenation reaction; and mixing the diisocyanate composition with thiol or episulfide and polymerizing and curing the diisocyanate composition in a mold, wherein the diamine hydrochloride composition has a pH of 3.0 to 4.0 when dissolved in water at a concentration of 10% by weight.

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

Specific examples of the thiol are 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-tetrathiatradecan-1,14-dithio 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, pentagram erythritol tetra Kiss (3-mercaptopropionate), trimethylolpropane tris (3-mercaptopropionate), pentaerythritoltetrakis (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-trithiaundecane-1,11-dithiol, etc. are included.

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, dipentaepithritol hexamercaptopropionate, 2,5-bismercaptomethyl -1,4-dithiane or the like.

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

In addition, specific examples of the episulfide are 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-epitiopropylthio)-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-trithiaundecane, 1,11-bis(β -Epithiopropylthio)-5,7-[(2-β-epithiopropylthioethyl)thiomethyl]-3,6,9-trithiaundecane, 1,11-bis(β-epitiopropylthio ) -4,7-bis (β-epitiopropylthiomethyl) -3,6,9-trithiaundecane, 1,3-bis (β-epitiopropylthio) cyclohexane, 1,4-bis ( β-epitiopropylthio)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) -epitiopropylthio)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 above exemplified compounds, but is not limited thereto. In addition, the episulfide may be a compound in which at least one hydrogen of its 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 separated state. That is, in the polymerizable composition, they may be in a state of being blended in contact with each other, or in a state of being separated 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, an ultraviolet stabilizer, an antioxidant, an anti-coloring agent, a dye, a filler, a mold release agent, and the like may be further added according to the purpose during the preparation of the composition for optical material and optical lens.

After mixing these thiols or episulfides with a diisocyanate composition and other additives and defoaming them, they are injected into a mold and slowly polymerized while gradually raising the temperature from a low temperature to a high temperature, and curing the resin by heating to prepare 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, the manufactured optical lens may be subjected to physical or physical treatment such as antireflection, high hardness, abrasion resistance improvement, chemical resistance, antifogging, surface polishing, antistatic treatment, hard coat treatment, antireflection coating treatment, dyeing treatment, etc., as necessary. Chemical treatment may additionally be performed.

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, and specifically may have a refractive index of 1.55 to 1.77. Alternatively, the optical lens may have a refractive index of 1.6 or more, and specifically may have a refractive index of 1.6 to 1.7. In addition, the optical lens may have an Abbe 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 total light transmittance. In addition, the optical lens may have a yellowness index (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 transmittance of 85% or more and yellowness of 22 or less.

More specific embodiments are illustrated below, but are not limited thereto.

Example 1: Preparation of diisocyanate composition

step (1)

1009.4 g (9.46 mol) of an aqueous hydrochloric acid solution having a concentration of 35% by weight 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 ℃, 600.0 g (4.4 mol) of m-XDA was added for 1 hour. At this time, the amount of the aqueous hydrochloric acid solution was equivalent to 2.15 mol of HCl per 1 mol of m-XDA. After completion of the addition, the internal temperature of the reactor was cooled to 10 ° C and stirred for 1 hour, and then 1320.0 g of tetrahydrofuran (THF) was additionally added and the internal temperature of the reactor was cooled to -5 ° C and further stirred 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 the filtered tetrahydrofuran was recovered for reuse. To remove residual solvent and moisture, residual solvent and moisture in the separated diamine hydrochloride composition were removed at 90° C. and vacuum dried at 0.1 torr.

step (2)

800 g of the diamine hydrochloride composition obtained in the previous step and 3,550 g of orthodichlorobenzene (ODCB) were introduced into Reactor A and heated at about 125° C. while stirring. 950 g of triphosgene (BTMC) and 800 g of ODCB were put into reactor B, stirred and dissolved at about 60 ° C, and added dropwise to reactor A over 24 hours while maintaining a temperature of 125 ° C so as not to precipitate. 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. to degas while bubbling. Thereafter, after cooling to 10° C., residual solids were filtered using celite, and an organic solvent (ODCB) removal and distillation process were performed 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.

Examples 2 to 5 and Comparative Examples 1 to 3

The procedure of step (1) of Example 1 was repeated, but the input amount of the aqueous hydrochloric acid solution was changed as shown in Table 1 to obtain a diamine hydrochloride composition, and then from the diamine hydrochloride composition according to the procedure of step (2) of Example 1 A diisocyanate composition was obtained.

The pH at the time of dissolving each of the diamine hydrochloride compositions obtained in step (1) of the Examples and Comparative Examples in water at a concentration of 10% by weight is shown in Table 1 below.

division Amount of aqueous hydrochloric acid solution
(Number of moles of HCl per mole of m-XDA) Diamine hydrochloride composition
pH Example 1 2.80 3.44 Example 2 2.02 3.87 Example 3 2.50 3.45 Example 4 3.00 3.31 Example 5 4.00 3.15 Comparative Example 1 2.00 4.05 Comparative Example 2 1.95 4.26 Comparative Example 3 4.20 2.95

As shown in the above table, the pH of the diamine hydrochloride composition could be changed by adjusting the amount of the aqueous hydrochloric acid solution.

manufacture of optical lenses

49.3 parts by weight of 4,8-bis(mercaptomethyl-3,6,9-trithiaundecane-1,11-dithiol, 50.7 parts by weight of the m-XDI composition prepared in Examples or Comparative Examples, dibutyl 0.01 part by weight of tin chloride and 0.1 part by weight of a phosphate release agent (ZELEC ^TM UN, Stepan) were uniformly mixed and degassed at 600 Pa for 1 hour, then filtered through a 3㎛ Teflon filter and placed in a mold made of glass mold and 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 polymerized at 130° C. for 2 hours. After releasing the molded product from the mold, it was additionally cured at 120° C. for 2 hours to obtain an optical lens. got

Assessment Methods

Evaluation methods for the above 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 amount of the diisocyanate composition calculated from the amount of the diamine hydrochloride composition introduced into the reaction with triphosgene.

(2) Diisocyanate content

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

(3) striae

A lens having a diameter of 75 mm, -2.00, -8.00 D was prepared, and a mercury lamp light source was transmitted through the prepared lens, and the transmitted light was projected onto a white plate to determine the presence or absence of striae by the presence or absence of contrast.

(4) Cloudiness (haze)

The optical lens was irradiated with a projector in the dark, and it was visually confirmed whether the optical lens was cloudy or had an opaque material.

(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 light was transmitted in a height direction to measure yellowness and transmittance. Yellowness was calculated by the following formula based on the values of x and y, which are the measurement results. Y.I = (234x + 106y) / y

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

(6) pH measurement method

pH measurement was performed at 25°C. In the case of the solid sample, the pH was measured after dissolving in distilled water at a concentration of 10% by weight in water, and in the case of the liquid phase, it was measured without any separate treatment in the stock solution state. The pH was calibrated to pH 4.0, 7.0, and 10.0 in advance using a buffer solution using a meter (LAQUA F-72G, HORIBA) and a non-aqueous electrode (6377-10D). After filling a 100 mL glass bottle with more than 50 mL of the sample, immersing the electrode and stabilizing for 1 hour, the sample was measured three times to obtain an average value.

division Diisocyanate composition optical lens distillation
transference number Diisocyanate content (% by weight) striae cloudy transmittance Y.I. before distillation after distillation Example 1 91% 99.2% 99.9% radish radish 90% 19 Example 2 89% 98.9% 99.9% radish radish 91% 21 Example 3 90% 99.1% 99.9% radish radish 89% 19 Example 4 90% 99.0% 99.9% radish radish 91% 20 Example 5 90% 98.8% 99.9% radish radish 91% 21 Comparative Example 1 87% 98.6% 99.8% you radish 89% 22 Comparative Example 2 85% 98.6% 99.7% you radish 89% 23 Comparative Example 3 89% 98.88% 99.8% radish About cloudiness 89% 24

As shown in Tables 1 and 2, the diisocyanate composition prepared using the diamine hydrochloride composition having a preferred pH range as in Examples 1 to 5 was excellent in yield and purity, and the transmittance of the final optical lens was high, striae, cloudiness. and yellowing did not occur. On the other hand, diisocyanate compositions prepared using diamine hydrochloride compositions outside the preferred pH range, as in Comparative Examples 1 to 3, had a relatively low yield and purity, and striae, cloudiness, or yellowing occurred on the final optical lens.

T-1: 1st tank, T-2: 2nd tank, T-3: 3rd tank,
R-1: reactor, D-1: first distiller, D-2: second distiller,
C-1: 1st condenser, C-2: 2nd condenser, C-3: 3rd condenser,
S-1: first scrubber, S-2: second scrubber,
G-1: viewing window, V-1: solvent recovery machine.

Claims (15)

Obtaining a diamine hydrochloride composition by reacting diamine with an aqueous hydrochloric acid solution and then adding a first organic solvent; and
Obtaining a diisocyanate composition from a diamine hydrochloride composition by a phosgenation reaction,
The step of obtaining the diamine hydrochloride composition,
(1a) injecting an aqueous hydrochloric acid solution into the first reactor; (1b) adding and stirring diamine into the first reactor; and (1c) introducing and stirring a first organic solvent into the first reactor, in order,
Further comprising the step of washing with a solvent having a polarity of 5.7 or less after the introduction of the first organic solvent,
The diamine hydrochloride composition has a pH of 3.0 to 4.0 when dissolved in water at a concentration of 10% by weight, a method for producing a diisocyanate composition.
delete According to claim 1,
The aqueous hydrochloric acid solution is added to the reaction so that 2.02 mol to 4.00 mol of HCl per 1 mol of the diamine is prepared.
According to claim 1,
The aqueous hydrochloric acid solution has a concentration of 20% to 45% by weight, a method for producing a diisocyanate composition.
According to claim 1,
Further comprising the step of treating the diamine hydrochloride composition after the reaction of the diamine and the aqueous hydrochloric acid solution,
The processing of the diamine hydrochloride composition includes at least one of precipitating the diamine hydrochloride composition, filtering the diamine hydrochloride composition, drying the diamine hydrochloride composition, and washing the diamine hydrochloride composition. To, a method for producing a diisocyanate composition.
According to claim 1,
A method for producing a diisocyanate composition in which the content of free amine groups in the diamine hydrochloride composition is 0.1% by weight or less.
According to claim 1,
Method for producing a diisocyanate composition in which the content of chlorine ions in the diamine hydrochloride composition is 0.1% by weight or less.
According to claim 1,
The phosgenation reaction is to react the diamine hydrochloride composition with triphosgene, a method for producing a diisocyanate composition.
According to claim 1,
The diisocyanate composition is obtained by distillation after the phosgenation reaction,
A method for producing a diisocyanate composition, wherein the distillation comprises distillation of diisocyanate at a temperature of 100 ° C to 130 ° C and a pressure of 2 torr or less.
According to claim 9,
The diisocyanate composition, prior to the diisocyanate distillation, a method for producing a diisocyanate composition comprising at least 98.7% by weight of diisocyanate.
According to claim 9,
A method for producing a diisocyanate composition wherein the yield of the diisocyanate distillation is 88% or more.
According to claim 9,
The method for producing a diisocyanate composition, wherein the diisocyanate composition comprises 99.9% by weight or more of diisocyanate after distillation of the diisocyanate.
According to claim 9,
The diamine is xylylenediamine,
A method for producing a diisocyanate composition, wherein the diisocyanate composition comprises xylylene diisocyanate.
Obtaining a diamine hydrochloride composition by reacting diamine with an aqueous hydrochloric acid solution and then adding a first organic solvent;
Obtaining a diisocyanate composition from a diamine hydrochloride composition by a phosgenation reaction; and
mixing the diisocyanate composition with thiol or episulfide and polymerizing and curing in a mold;
The step of obtaining the diamine hydrochloride composition,
(1a) injecting an aqueous hydrochloric acid solution into the first reactor; (1b) adding and stirring diamine into the first reactor; and (1c) introducing and stirring a first organic solvent into the first reactor, in order,
Further comprising the step of washing with a solvent having a polarity of 5.7 or less after the introduction of the first organic solvent,
The method of manufacturing an optical lens, wherein the diamine hydrochloride composition has a pH of 3.0 to 4.0 when dissolved in water at a concentration of 10% by weight.
15. The method of claim 14,
The method of manufacturing an optical lens, wherein the optical lens has a transmittance of 85% or more and a yellowness index (YI) of 22 or less.

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