KR102217752B1 - Method of preparing diisocyanate composition and optical lens - Google Patents

Abstract

In an embodiment, in a process of preparing diisocyanate from diamine through diamine hydrochloride, a hydrochloric acid solution may be used instead of hydrogen chloride gas and solid triphosgene may be used instead of phosgene gas. In addition, an embodiment provides a method capable of preparing a high-quality diisocyanate composition and an optical lens by controlling a reaction temperature of a diamine hydrochloride composition and triphosgene to a specific range.

Description

Method of manufacturing a diisocyanate composition and an optical lens TECHNICAL FIELD [METHOD OF PREPARING DIISOCYANATE COMPOSITION AND OPTICAL LENS]

Embodiments relate to a diisocyanate composition and a method of manufacturing an optical lens. More specifically, embodiments relate to a method of preparing a diisocyanate composition using a diamine hydrochloride composition, and a method of manufacturing an optical lens using the diisocyanate composition.

Isocyanates used as raw materials for plastic optical lenses are produced by a phosgene method, a nonphosgene method, a pyrolysis method, or the like.

The phosgene method is to synthesize isocyanate by reacting a raw material amine with phosgene (COCl ₂ ) gas, and the non-phosgene method is to synthesize xylylene chloride into isocyanate by reacting with sodium cyanate in the presence of a catalyst, and the pyrolysis 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 production 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 this has a problem that requires a number of devices for direct reaction of phosgene gas. Meanwhile, in order to supplement the direct method, a hydrochloride method has been developed in which an amine is reacted with hydrogen chloride gas as in Korean Patent Publication No. 1994-0001948 to obtain an intermediate amine hydrochloride and reacts it with phosgene.

In the conventional phosgene method for synthesizing isocyanate, the method of obtaining hydrochloride as an intermediate by reacting an amine with hydrogen chloride gas is a method of obtaining hydrochloride as an intermediate substance at normal pressure, so the agitation inside the reactor is not smooth, so the pressure inside the reactor In order to increase the temperature, an additional process of increasing the temperature is required, and the yield of the final product is also low.

In addition, the phosgene gas used in the conventional phosgene method is a material subject to environmental regulations due to its severe toxicity, and storage and management are difficult, such as requiring a separate cooling device to store it.

(Patent Document 1) Korean Patent Publication No. 1994-0001948

Therefore, the present inventors, in the process of manufacturing diisocyanate, which is mainly used as a raw material for plastic optical lenses, from diamine through hydrochloride, by using an aqueous hydrochloric acid solution instead of hydrogen chloride gas and using solid triphosgene instead of phosgene gas, and adjusting the reaction conditions. , Was able to solve conventional environmental, yield and quality problems.

In addition, the present inventors noted that the diisocyanate composition obtained through the reaction of the diamine hydrochloride composition and triphosgene contains a hydrolyzable chlorine component, etc., causing clouding and yellowing during lens casting. In particular, the present inventors believe that hydrolyzable chlorine compounds such as chloromethylbenzyl isocyanate (CBI) and 1,3-bis(chloromethyl)benzene are produced at high temperatures, so if the temperature of the reaction between the diamine hydrochloride composition and triphosgene is not controlled, it is removed. I found it difficult to become.

Accordingly, an object of the embodiment is to provide a method for manufacturing a diisocyanate composition and an optical lens of higher quality by controlling the reaction temperature of the diamine hydrochloride composition and triphosgene in a specific range.

According to one embodiment, (1) reacting a diamine with an aqueous hydrochloric acid solution to obtain a diamine hydrochloride composition; And (2) comprising the step of obtaining a diisocyanate composition by reacting the diamine hydrochloride composition with triphosgene at a temperature of 115°C to 130°C, a method for preparing a diisocyanate composition is provided.

According to another embodiment, (1) reacting a diamine with an aqueous hydrochloric acid solution to obtain a diamine hydrochloride composition; (2) reacting the diamine hydrochloride composition with triphosgene at a temperature of 115°C to 130°C to obtain a diisocyanate composition; And (3) mixing the diisocyanate composition with thiol or episulfide and polymerizing and curing in a mold, there is provided a method of manufacturing an optical lens.

The method for preparing diisocyanate according to the above embodiment uses less toxic triphosgene, which is difficult to store and manage, does not use phosgene gas, which is highly toxic, and does not require a separate cooling storage device as a solid state at room temperature. Therefore, it has excellent handling and fairness. In addition, the method for preparing diisocyanate according to the above embodiment requires an additional device for high temperature heating and cooling because the reaction can proceed even at normal pressure by using an aqueous hydrochloric acid solution without using hydrogen chloride gas to prepare the intermediate diamine hydrochloride. No, the yield can also be improved.

In addition, in the method for preparing a diisocyanate composition according to the above embodiment, the final yield can be further increased by preparing a diamine hydrochloride composition using an aqueous hydrochloric acid solution, and the selection of raw materials is not largely restricted by the moisture and impurity content in the raw diamine. Can widen

In particular, according to the above embodiment, by controlling the temperature of the reaction between the diamine hydrochloride composition and triphosgene to a specific range, hydrolyzable chlorine compounds such as chloromethylbenzyl isocyanate (CBI) or 1,3-bis(chloromethyl)benzene are reduced. , In the final optical lens, it is possible to prevent deterioration of physical properties such as streak, white turbidity and yellowing.

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

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

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

In addition, all numerical ranges representing physical property values, contents, dimensions, etc. of the constituents described in the present specification are to be understood as being modified by the term "about" in all cases unless otherwise specified.

In the present specification, "amine" refers to a compound having one or more amine groups at the end, and "diamine" refers to a compound having two amine groups at the end, 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, 4,4'-methylenediamine (MDA), bis (aminoethyl) ether, bis (aminoethyl) benzene, bis (amino Propyl) 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-dimethyldicyclohexylmethanediamine, 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(amino Methyl) tricyclodecane, norbornenediamine (NBDA), bis (aminomethyl) sulfide, bis (aminoethyl) sulfide, bis (aminopropyl) sulfide, bis (aminohexyl) sulfide, bis (aminomethyl) Sulfone, bis(aminomethyl) disulfide, bis(aminoethyl) disulfide, bis(aminopropyl) disulfide, bis(aminomethylthio)methane, bis(aminoethylthio)methane, bis(aminoethylthio)ethane, Bis(aminomethylthio)ethane, etc. are mentioned. More specifically, the diamine is one selected from the group consisting of xylylenediamine (XDA), norbornenediamine (NBDA), hydrogenated xylylenediamine (H6XDA), isophoronediamine (IPDA), and hexamethylenediamine (HDA). It can be more than that. The xylylenediamine (XDA) includes orthoxylylenediamine (o-XDA), metaxylylenediamine (m-XDA), and paraxylylenediamine (p-XDA).

In the present specification, "isocyanate" refers to a compound having an NCO group, and "diisocyanate" refers to a compound having two NCO groups at the terminal, and according to the skeleton of an aliphatic chain, aliphatic ring, or 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, 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)(MDI), 1,2-bis(isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl)benzene, 1,4-bis(iso Cyanatomethyl)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, norbornenediisocyanate (NBDI), bis(isocyanatomethyl) )Sulfide, bis(isocyanatoethyl)sulfide, bis(isocyanatopropyl)sulfide, 2,5-diisocyanatotetrahydrothiophene, 2,5-diisocyanatomethyltetrahydro Thiophene, 3,4-diisocyanatomethyltetrahydrothiophene, 2,5-diisocyanato-1,4-ditian, 2,5-diisocyanatomethyl-1,4-ditian, etc. Can be mentioned. 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 paraxylylene diisocyanate (p-XDI).

In the present specification, "composition" may mean a form in which two or more chemical components are mixed or combined in a solid state, a liquid state, and/or a gas phase while generally maintaining individual characteristics.

Compounds used in each reaction step according to the above embodiment (eg, triphosgene) or compounds obtained as a result of the reaction (eg, diamine hydrochloride, diisocyanate) are generally used in each reaction step. It exists in a mixed or combined state with heterogeneous components caused 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, attention is paid to these heterogeneous components mixed or combined with the main compound, so that even a small amount of the heterogeneous component is mixed or combined with the main compound as a composition to specifically illustrate the components and contents thereof.

In addition, in the present specification, for clear and easy distinction between various compositions, terms have been described in combination with the name of the main component in the composition. For example, "diamine hydrochloride composition" refers to a composition containing diamine hydrochloride as a main component, and , "Diisocyanate composition" refers to a composition comprising 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, and may be, for example, 90% by weight to 99.9% by weight.

[Method for preparing diisocyanate composition]

A method of preparing a diisocyanate composition according to an embodiment includes the steps of: (1) reacting a diamine with an aqueous hydrochloric acid solution to obtain a diamine hydrochloride composition; And (2) reacting the diamine hydrochloride composition with triphosgene under a temperature condition of 115°C to 130°C to obtain a diisocyanate composition.

1 schematically shows a method of 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 a specific example, R may be xylylene, norbornene, hydride xylylene, isophorone, or hexamethylene, but is not limited thereto.

It will be described in detail for each step below.

Preparation of diamine hydrochloride composition

First, diamine is reacted with an aqueous hydrochloric acid solution to obtain a diamine hydrochloride composition.

In addition, after the reaction of 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 of 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, hydride xylylene, isophorone, or hexamethylene, but is not limited thereto.

Conventionally, in the case of using hydrogen chloride gas, hydrochloride is generated into fine particles during normal pressure reaction, and the agitation state inside the reactor is not smooth.Therefore, an additional step of increasing the pressure to increase the temperature inside the reactor is required. There was also a problem of low yield.

However, according to the above embodiment, since an aqueous hydrochloric acid solution is used, it is possible to solve the problem that occurs when using hydrogen chloride gas in the related art. Specifically, in the case of using an aqueous hydrochloric acid solution, since the product produced through the reaction is in a solid form rather than a slurry form, the yield is high, and since the reaction can be carried out 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 it is within the above concentration range, dissolution of the hydrochloride salt in the aqueous hydrochloric acid solution can be minimized, thereby increasing the final yield and improving the handling properties.

Specifically, the concentration of the aqueous hydrochloric acid solution may be 10% to 45% by weight, 20% to 45% by weight, or 30% to 40% by weight. More specifically, the aqueous hydrochloric acid solution may have a concentration of 20% to 45% by weight.

The diamine and the aqueous hydrochloric acid solution may be added to the reaction in an equivalent ratio of 1: 2 to 5. When it is within the above equivalent ratio range, it is possible to reduce unreacted substances and prevent the yield from lowering due to dissolution due to water generation. Specifically, the diamine and the hydrochloric acid aqueous solution may be added to the reaction in an equivalent ratio of 1:2 to 2.5.

The addition 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 hydrochloric acid aqueous solution are added, the temperature inside the reactor may be in the range of 20°C to 100°C. When it is within the above temperature range, it is possible to prevent the temperature from becoming higher than the boiling point and thus not suitable for the reaction or the temperature being too low to deteriorate the reaction efficiency. Specifically, the temperature inside the reactor when the diamine and the hydrochloric acid aqueous solution are added may be 20°C to 60°C, more specifically 20°C to 40°C, or 40°C to 60°C.

In the conventional hydrochloride method, a large amount of heat is generated in the reaction process and thus requires rapid cooling through a separate cooler, whereas according to the embodiment, since the reaction material is added while maintaining a low temperature, a separate cooler is not required.

The addition of the diamine and the aqueous hydrochloric acid solution may be performed in a sequence of, for example, first adding the aqueous hydrochloric acid solution to the reactor and then slowly adding the diamine. The diamine and/or the hydrochloric acid aqueous solution may be added for 30 minutes to 3 hours.

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

Through the reaction of the diamine and the aqueous hydrochloric acid solution, a reaction result of the diamine hydrochloride composition in the aqueous solution state may 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 the first organic solvent to the reaction result. 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 further stirred to proceed with the reaction.

Specifically, the first organic solvent is diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran, methanol, ethanol, dimethyl sulfoxide, dimethylformamide, acetonitrile, acetone, trichloroethylene, tetrachloroethane, It may be one or more selected from the group consisting of trichloroethanol, 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 range, the yield of the final hydrochloride salt is high, and excessive use of an organic solvent can be prevented. Specifically, the first organic solvent may be added to the reaction in an amount of 1 to 2 times, or 1 to 1.5 times the weight of the diamine.

The cooling temperature after the first organic solvent is added 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) adding the aqueous hydrochloric acid solution to the first reactor; (1b) adding and stirring the diamine 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 ℃ to 10 ℃ after the addition of the diamine in step (1b) before stirring; And cooling the inside of the reactor to a temperature of -5°C to 5°C before stirring after the introduction of the first organic solvent in step (1c).

After the first organic solvent is added, separation, filtration, washing and drying may be further performed. For example, after the addition of the first organic solvent, the aqueous layer may be separated, filtered, washed, and dried to obtain a solid diamine hydrochloride composition. 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 be performed using vacuum drying, for example, at 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. Therefore, 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 may be increased by removing such impurities through the removing step of the first organic solvent.

According to the above method, a solid diamine hydrochloride composition can be obtained with high purity through reaction of diamine with aqueous hydrochloric acid solution and additional treatment such as precipitation, filtration, drying, and washing. On the other hand, when diamine is reacted in hydrogen chloride gas and 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, and specifically 85% to 95%, or 88% to 92%. .

Meanwhile, the organic layer can be separated from the reactant 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%.

Preparation of diisocyanate composition

Next, the diamine hydrochloride composition is reacted with triphosgene to obtain a diisocyanate composition. At this time, the reaction of the diamine hydrochloride composition and 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 specific examples, R may be xylylene, norbornene, hydride xylylene, isophorone, or hexamethylene, but is not limited thereto.

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

Specific examples of the second organic solvent include benzene, toluene, ethylbenzene, chlorobenzene, monochlorobenzene, 1,2-dichlorobenzene (ODCB), dichloromethane, 1-chloro-n-butane, 1-chloro-n- 1 selected from the group consisting of pentane, 1-chloro-n-hexane, chloroform, carbon tetrachloride, n-pentane, n-hexane, n-heptane, n-octane, cyclohexane, cyclopentane, cyclooctane and methylcyclohexane It can be more than a species.

The input 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 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.

The reaction temperature of the diamine hydrochloride composition and triphosgene is controlled within the range of 115°C to 130°C.

The reaction temperature between the diamine hydrochloride composition and the triphosgene is 115° C. or higher, so that the reaction between the diamine hydrochloride and triphosgene proceeds more smoothly, it is advantageous to increase the yield and shorten the reaction time. In addition, the reaction temperature between the diamine hydrochloride composition and triphosgene is 130° C. or less, which can effectively suppress the formation of compounds containing chlorine (eg, chloromethylbenzyl isocyanate, 1,3-bis(chloromethyl)benzene, etc.). , In addition, it is possible to suppress the formation of other impurities such as tar.

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 to 100 hours. When within the above reaction time range, the reaction time is not excessive, and generation of unreacted substances due to generation of phosgene can be minimized. 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 130°C for 5 to 100 hours.

The diamine hydrochloride composition and the triphosgene may be added to the reaction in an equivalent ratio of 1: 1 to 5. When it is within the above equivalent ratio range, while the reaction efficiency is high, it is possible to prevent an increase in the reaction time due to excessive input. Specifically, the diamine hydrochloride composition and the triphosgene may be added to the reaction in an equivalent ratio of 1: 1.5 to 4, or 1: 2 to 2.5.

The reaction of the diamine hydrochloride composition and the triphosgene, the reaction of the diamine hydrochloride composition and the triphosgene is obtained by 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 addition and stirring of the second solution may be performed at a temperature of 115 ℃ to 130 ℃. In addition, the addition of the second solution may be divided into two or more times for a total of 25 to 40 hours. In this case, the input time for each time may be 5 to 25 hours, or 10 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 and 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) sequentially adding and stirring the triphosgene to the second reactor. In this case, in the step (2c), the triphosgene is added in the same solvent as the second organic solvent in a solution in which the triphosgene is dissolved in the reactor at a temperature of 115° C. to 130° C. for a total of 25 to 40 hours. It may be divided and injected more than once. In this case, the input time for each time may be 5 to 25 hours, or 10 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 result of the reaction may be cooled at 90°C to 110°C.

The resultant product obtained through the 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 solids may be filtered off.

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

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 diisocyanate. For example, the distillation may include diisocyanate distillation at 100°C to 130°C. When within the above distillation temperature range, hydrolyzable chlorine compounds generated at high temperature such as chloromethylbenzyl isocyanate (CBI) or 1,3-bis (chloromethyl)benzene are effectively removed, such as streak, cloudiness, and yellowing in the final optical lens. It may be more advantageous to prevent degradation of properties. Specifically, the distillation may be performed by setting the bottom temperature of the still at 100°C to 130°C. For example, the distillation may be performed by setting the temperature of a reboiler to 100°C to 130°C.

In addition, the pressure during 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 under conditions of 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 to 10 hours.

The yield of the diisocyanate distillation may be 80% or more, specifically 85% 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 diisocyanate composition produced from the amount of the diamine hydrochloride composition added to the reaction with triphosgene.

According to the method of the above embodiment, by adjusting the reaction temperature range of the diamine hydrochloride composition and triphosgene, the crude diisocyanate composition before purification may have very little impurities. Specifically, the diisocyanate composition may include 99.0% by weight or more of diisocyanate prior to distillation of the diisocyanate. In addition, the diisocyanate composition may include 99.9% by weight or more of diisocyanate after distillation of the diisocyanate.

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, or 90% or more.

Diisocyanate composition

The color and haze of the diisocyanate composition prepared using such a diamine hydrochloride composition and triphosgene may be improved.

The diisocyanate composition may have an APHA (American Public Health Association) 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.

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

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.

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

According to the method of the above embodiment, the yield of diisocyanate is high, the recycling rate of the organic solvent is excellent, and since no poisonous phosgene gas is used, it is environmentally friendly, and the normal pressure reaction is possible, and a separate device for pressurization or quenching is not required.

Measurement of color and transparency of reaction solution

Obtaining a diisocyanate composition from the diamine hydrochloride composition and triphosgene may include: (i) reacting the diamine hydrochloride composition in a reactor with triphosgene 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 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 the reaction is normally completed is transparent or transparent. It is close to and can have a light brownish 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 contrary, if the reaction between the metaxylylenediamine hydrochloride and triphosgene is not completed, the reaction solution may be opaque or have a precipitate, and the color may be pale, 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, while the reaction of 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 can be collected and the color and transparency can be precisely measured. For example, measurement of the color and transparency of the reaction solution may be performed by collecting some of the reaction solution and measuring the color and transparency of the collected 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 termination point may be determined according to the color and transparency of the reaction solution. Specifically, the reaction end time point may be after the time point when the reaction solution turns transparent light brown.

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

The reactor is 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 transfers the hydrogen chloride gas to water. The solution is dissolved to generate an aqueous solution, and the second scrubber may neutralize the phosgene gas with an aqueous NaOH solution.

In addition, the reactor is connected to one or more stills, the reaction solution is transferred to the one or more stills, and the one or more stills can 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 first tank T-1 is filled with a second organic solvent and triphosgene, and a constant temperature is maintained by refluxing hot water. The inside of the reactor (R-1) is replaced with nitrogen, a second organic solvent is added thereto, and agitated, the diamine hydrochloride composition is slowly 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 addition of triphosgene in the second organic solvent is performed once or twice or more, and stirring is performed while maintaining a constant internal temperature of the reactor (R-1). After the addition is complete, an additional reaction is carried out 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 device through the viewing window G-1 provided in the reactor R-1. The optical device may include a digital camera, a spectrometer, and optical analysis equipment.

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 first condensed by cooling in the first condenser C-1 and is 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 thirdly condensed by cooling in the third condenser (C-3) and is recovered to the reactor (R-1).

After removing the second organic solvent while passing through the multi-stage condenser as described above, the remaining gas (hydrogen chloride, phosgene, etc.) is transferred to the first scrubber S-1. Hydrogen chloride gas is dissolved in water in the first scrubber (S-2) to obtain an aqueous hydrochloric acid solution 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, the phosgene (COCl ₂ ) gas may be neutralized and removed using the aqueous sodium hydroxide solution stored in the third tank T-3.

The reaction solution obtained from the reactor (R-1) is sequentially transferred to the first distiller (D-1) and the second distiller (D-2), and while undergoing 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 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 further subjected to filtration and drying to provide a final product.

[Manufacturing method of optical lens]

The composition for an optical material may be prepared by combining the diisocyanate prepared in the above embodiment with other components.

That is, the composition for an optical material includes a diisocyanate and thiol or episulfide prepared according to the embodiment.

An optical material, specifically an optical lens, can be manufactured by using the composition for an optical material. For example, an optical lens can be manufactured by mixing the composition for an optical material and heat curing in a mold.

A method of manufacturing an optical lens according to an embodiment includes the steps of: (1) reacting a diamine with an aqueous hydrochloric acid solution to obtain a diamine hydrochloride composition; (2) reacting the diamine hydrochloride composition with triphosgene at a temperature of 115°C to 130°C to obtain a diisocyanate composition; And (3) mixing the diisocyanate composition with thiol or episulfide, and polymerizing and curing in a mold.

The thiol may be a polythiol containing 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 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-tetrathiatetradecane-1,14-diti 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-ditian, 2-(2,2-bis(mercaptodimethylthio)ethyl)-1,3-ditian, 2,5-bismercaptomethyl-1,4 -Dithian, 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-pentathia hectadecane-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, trimethanolpropanetrismercaptopropionate, glycerol trimercaptopropionate, dipentaepititol hexamercaptopropionate, 2,5-bismercaptomethyl It may be -1,4-ditian, etc. 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 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-epithiopropylthio)-5-(β-epi Thiopropylthiomethyl)-5-[(2-β -Epithiopropylthioethyl)thiomethyl]-3,7-ditianonane, 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-epithiopropylthio )-4,7-bis(β-epithiopropylthiomethyl)-3,6,9-trithiaundecane, 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-dithian, 2,5-bis(β-epithiopropylthioethylthiomethyl)-1,4-dithian, 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 of the hydrogens 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 separate state. That is, in the polymerizable composition, they may be in a state of being mixed in contact with each other, or in a state separated so as not to contact each other.

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

When preparing the composition for an optical material and an optical lens, a catalyst, a chain extender, a crosslinking agent, an ultraviolet stabilizer, an antioxidant, an anti-coloring agent, a dye, a filler, a release agent, etc. may be further added depending on the purpose.

These thiols or episulfides are mixed with a diisocyanate composition and other additives and defoamed, and then injected into a mold and gradually polymerized while gradually increasing the temperature from low to high temperature, and the resin is cured by heating to prepare an optical lens.

The temperature of the polymerization reaction may be, for example, 20°C to 150°C, and 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 has physical or physical properties such as anti-reflection, high hardness, abrasion resistance, chemical resistance, anti-fog, surface polishing, antistatic treatment, hard coat treatment, non-reflective coating treatment, dyeing treatment, etc. Chemical treatment can be carried out further.

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 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, and may be, 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 20 or less.

[Example]

Hereinafter, more specific embodiments are illustrated, but are not limited thereto.

Examples and Comparative Examples: Preparation of diisocyanate composition

Step (1) Preparation of diamine hydrochloride composition

1009.4 g (9.46 mol) of a 35% aqueous hydrochloric acid solution was added to the reactor, and the temperature inside the reactor was cooled to 15°C while stirring. While maintaining the temperature of the reactor at 50 ℃ m-XDA 600.0 g (4.4 mol) was added for 1 hour. After the addition was completed, the temperature inside the reactor was cooled to 10° C. and stirred for 1 hour, and then 1320.0 g of tetrahydrofuran (THF) was added, and the temperature inside the reactor was cooled to -5° C., followed by 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 the filtered tetrahydrofuran was recovered for reuse. In order to remove residual solvent and moisture, the separated diamine hydrochloride composition was further washed and dried at 90° C. and 0.5 torr for 4 hours.

Step (2) Preparation of diisocyanate composition

To reactor A, 800 g of the prepared diamine hydrochloride composition and 3,550 g of ODCB were added and heated at about 125°C while stirring. Triphosgene (BTMC) 950 g and ODCB 800 g were added to the reactor B, stirred and dissolved at about 50 to 60° C., and the temperature was maintained at 125° C. so as not to precipitate, and was added dropwise to the reactor A over 24 hours. After completion of the dropwise addition, the mixture was stirred for 3 to 4 hours, and when the reaction was completed, nitrogen gas was blown into the solvent at 125° C. to degas while bubbling. After cooling to 10° C., the remaining solids were filtered using celite, and the organic solvent (ODCB) was removed to obtain a diisocyanate crude composition containing m-XDI. At this time, the removal of the organic solvent was performed at a pressure of 0.5 torr or less and a temperature of 60° C. for 4 to 8 hours. Thereafter, the obtained crude diisocyanate composition was distilled for 10 hours at a pressure of 0.5 torr or less by setting the bottom temperature of the still at 120°C.

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 diisocyanate composition prepared in the previous Example or Comparative Example, dibutyl tin 0.01 parts by weight of chloride and 0.1 parts by weight of ZELEC™ UN Stepan's phosphate ester release agent were uniformly mixed, defoamed at 600 Pa for 1 hour, filtered through a 3 μm Teflon filter, and injected into a mold made of a glass mold and a tape. The mold was kept at 25° C. for 8 hours, then slowly heated up to 130° C. for 8 hours at a constant rate and polymerized for 2 hours at 130° C. The molded product was released from the mold and then cured at 120° C. for 2 hours to obtain an optical lens.

Assessment Methods

The diisocyanate compositions and optical lenses obtained in Examples and Comparative Examples were evaluated as follows.

(1) Diisocyanate content

The diisocyanate content in the diisocyanate composition was measured by gas chromatography (GC) (equipment: 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℃)

(2) stria

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 onto a white plate to determine the presence or absence of streaking based on the presence or absence of a contrast difference.

(3) 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 yellowness was measured by transmitting light in the height direction. Yellowness was calculated by the following equation based on the values of x and y, which are the measurement results. Y.I = (234x + 106y) / y

(4) Cloudiness (haze)

The optical lens was irradiated to the projector in a dark place, and it was visually checked whether the optical lens was cloudy or had opaque material.

The results are summarized in the following table.

division Phosgenation
reaction
Temperature
(℃) distillation
yield
(%) Diisocyanate composition
Diisocyanate in
Content (% by weight) Optical lens Before distillation After distillation Stria Cloudy Y.I. Example 1 115 85 99.5 99.9 none none 19 Example 2 120 88 99.6 99.9 none none 20 Example 3 125 89 99.6 99.9 none none 19 Example 4 130 90 99.4 99.9 none none 20 Comparative Example 1 90 The reaction does not proceed Comparative Example 2 100 The reaction does not proceed Comparative Example 3 140 86 98.1 99.5 none Weak haze 26 Comparative Example 4 160 84 98.3 99.6 none Weak haze 26 Comparative Example 5 180 80 97.5 98.5 none Weak haze 28

As shown in the above table, when the reaction temperature of the diamine hydrochloride composition and triphosgene was adjusted within 100 to 130°C as in Examples 1 to 4, the distillation yield and the diisocyanate content in the composition were excellent, and the final optical lens prepared therefrom It was confirmed that the striae, white turbidity and yellowness of the were improved.

On the other hand, when the reaction temperature was less than 100° C. as in Comparative Examples 1 and 2, the reaction did not proceed, and when the reaction temperature exceeded 130° C. as in Comparative Examples 3 to 5, the distillation yield and the diisocyanate content in the composition were low, Cloudiness or yellowing occurred in the resulting optical lens.

Claims (12)

(1) reacting diamine with an aqueous hydrochloric acid solution to obtain a diamine hydrochloride composition; And
(2) A method for producing a diisocyanate composition comprising the step of reacting the diamine hydrochloride composition with triphosgene under a temperature condition of 115°C to 130°C to obtain a diisocyanate composition.
The method of claim 1,
The temperature of the reaction in step (2) is 115 ℃ to 120 ℃, the method for producing a diisocyanate composition.
The method of claim 1,
The reaction of the diamine hydrochloride composition of step (2) and triphosgene
Mixing a diamine hydrochloride composition and an organic solvent to obtain a first solution;
Mixing triphosgene and an organic solvent to obtain a second solution; And
A method for producing a diisocyanate composition comprising sequentially adding and stirring the second solution to the first solution.
The method of claim 3,
Injecting and stirring the second solution is carried out at a temperature of 115 ℃ to 130 ℃, the method for producing a diisocyanate composition.
The method of claim 1,
A method for producing a diisocyanate composition, wherein the content of the aromatic compound having a halogen group in the diisocyanate composition is 1000 ppm or less.
The method of claim 1,
The diisocyanate composition is obtained by distillation after the reaction in step (2),
The distillation comprises diisocyanate distillation at a temperature of 100°C to 130°C and a pressure condition of 2 torr or less.
The method of claim 6,
The diisocyanate composition, prior to distillation of the diisocyanate, containing 99.0% by weight or more of diisocyanate, a method for producing a diisocyanate composition.
The method of claim 6,
The diisocyanate composition, after the diisocyanate distillation, comprises 99.9% by weight or more of diisocyanate, a method for producing a diisocyanate composition.
The method of claim 6,
The diisocyanate distillation yield is 85% or more, a method for producing a diisocyanate composition.
The method of claim 1,
The diamine is xylylenediamine,
The diisocyanate composition comprises xylylene diisocyanate, a method for producing a diisocyanate composition.
(1) reacting diamine with an aqueous hydrochloric acid solution to obtain a diamine hydrochloride composition;
(2) reacting the diamine hydrochloride composition with triphosgene at a temperature of 115°C to 130°C to obtain a diisocyanate composition; And
(3) Mixing the diisocyanate composition with thiol or episulfide, and polymerizing and curing in a mold.
The method of claim 11,
The method of manufacturing an optical lens, wherein the optical lens has a transmittance of 85% or more and a yellowness (YI) of 20 or less.

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