KR20210071812A - Diisocyanate composition for optical lens and preparation method thereof - Google Patents

Abstract

According to the embodiment, by adjusting the pH of a diisocyanate composition used for manufacturing an optical lens to a specific range, it is possible to suppress a striae or turbidity in a final optical lens and improve optical properties. In addition, according to the manufacturing method of the embodiment, the pH of the diisocyanate composition can be adjusted to a desired range by adjusting the amount of an aqueous hydrochloric acid solution input to the reaction, and the yield and purity can also be improved.

Description

Diisocyanate composition for optical lens and manufacturing method thereof

The embodiment relates to a diisocyanate composition for an optical lens and a method for preparing the same. More specifically, the embodiment relates to a diisocyanate composition used for manufacturing an optical lens, a method for preparing the diisocyanate composition, and a method for manufacturing an optical lens using the same.

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

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

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

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

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

Korean Patent Publication No. 1994-1948

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

In addition, the present inventors found that the chlorine component or some salts remaining in the diisocyanate composition obtained through such a phosgenation reaction affects the reaction rate in the polymerization process for the manufacture of an optical lens to generate streaks or lens molding. Attention was paid to the fact that adhesive elution was caused in the taping part on the side of the mold for the purpose of generating cloudiness on the side of the lens. In particular, the present inventors have noted that the pH of the diisocyanate composition is closely related to the types and amounts of various residues that may affect the manufacture of optical lenses.

As a result of research by the present inventors, by adjusting the pH of the diisocyanate composition to a specific range, it was found that the optical properties of the final optical lens can be improved. In addition, the present inventors have found that the pH of the diisocyanate composition can be adjusted to a desired range by adjusting the amount of the aqueous hydrochloric acid solution added to the reaction during the preparation of the diisocyanate composition, and the yield and purity can also be improved.

Accordingly, an object of the embodiment is to provide a diisocyanate composition in a pH range capable of improving the properties of an optical lens, and a method for preparing the diisocyanate composition with high purity and yield, and an optical lens of excellent quality therefrom to provide a way to

According to one embodiment, having a pH of 5.0 to 5.8, a diisocyanate composition for an optical lens is provided.

According to another embodiment, the diamine is reacted with an aqueous hydrochloric acid solution to obtain a diamine hydrochloride composition; and obtaining a diisocyanate composition from the diamine hydrochloride composition by a phosgenation reaction, wherein the aqueous hydrochloric acid solution is added to the reaction so as to be 2.02 moles to 4.00 moles of HCl per mole of the diamine, a method for producing a diisocyanate composition for an optical lens this is provided

According to another embodiment, there is provided a method for producing an optical lens, comprising mixing a diisocyanate composition with thiol or episulfide and polymerizing and curing in a mold, wherein the diisocyanate composition has a pH of 5.0 to 5.8 do.

According to the embodiment, by adjusting the pH of the diisocyanate composition used in the manufacture of the optical lens to a specific range, it is possible to suppress stria or cloudiness of the final optical lens and improve optical properties. In particular, the embodiment not only newly suggests that the pH, which was not previously considered in the diisocyanate composition, has a close relationship with the properties of the optical lens, but also suggests an efficient management means by pH control compared to the existing complex quality control procedure. can do. In addition, according to the manufacturing method of the embodiment, the pH of the diisocyanate composition can be adjusted to a desired range by adjusting the amount of the aqueous hydrochloric acid solution input to the reaction, and the yield and purity can also be improved.

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

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

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

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

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

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

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

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

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

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

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

As used herein, ppm units mean ppm by weight.

[Diisocyanate composition for optical lens]

The diisocyanate composition for an optical lens according to an embodiment has a pH in the range of 5.0 to 5.8.

According to the embodiment, by adjusting the pH of the diisocyanate composition used for manufacturing the optical lens to a specific range, it is possible to suppress streaks or cloudiness in the final optical lens and improve optical properties. If the pH of the diisocyanate composition is less than 5.0, the rate of the polymerization reaction for the manufacture of the optical lens is lowered, causing the adhesive to elute from the taping part on the side of the mold for lens molding, thereby causing clouding of the lens side. In addition, when the pH of the diisocyanate composition is more than 5.8, the speed of the polymerization reaction for the manufacture of the optical lens is accelerated, and as the flowability of the polymer appears, streaks may occur in the optical lens.

As such, the embodiment not only newly suggests that the pH, which was not previously considered in the diisocyanate composition, has a close relationship with the properties of the optical lens, but also an efficient management means by pH control compared to the existing complex quality control procedure can be presented.

As more various examples, the pH of the diisocyanate composition may be 5.0 or more, 5.1 or more, 5.2 or more, 5.3 or more, or 5.5 or more, and may be 5.8 or less, 5.7 or less, or 5.6 or less. Specifically, the pH of the diisocyanate composition may be 5.1 to 5.8, 5.2 to 5.8, 5.3 to 5.8, 5.0 to 5.7, or 5.0 to 5.6. As a specific example, the pH of the diisocyanate composition may be 5.5 to 5.7.

In addition, the pH-controlled diisocyanate composition may have excellent 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. In addition, the haze of the diisocyanate composition may be 10% or less, 5% or less, or 3% or less.

The diisocyanate composition may include xylylene diisocyanate or other diisocyanates used in the manufacture of optical lenses as exemplified above. As a specific example, the diisocyanate composition is ortho-xylylene diisocyanate (o-XDI), meta-xylylene diisocyanate (m-XDI), para-xylylene diisocyanate (p-XDI), norbornene diisocyanate (NBDI), hydrogenated It may include at least one selected from the group consisting of xylylene diisocyanate (H6XDI), isophorone diisocyanate (IPDI), and hexamethylene diisocyanate (HDI).

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

In addition, the chlorine ion content in the diisocyanate composition may be 1000 ppm or less, 500 ppm or less, or 100 ppm or less.

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

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

[Method for producing diisocyanate composition for optical lens]

A method for preparing a diisocyanate composition for an optical lens according to an embodiment comprises the steps of reacting diamine with an aqueous hydrochloric acid solution to obtain a diamine hydrochloride composition; and obtaining a diisocyanate composition from the diamine hydrochloride composition by a phosgenation reaction, wherein the aqueous hydrochloric acid solution is added to the reaction in an amount of 2.02 moles to 4.00 moles of HCl per mole of the diamine.

According to the embodiment, the aqueous hydrochloric acid solution is added to the reaction so that 2.02 moles to 4.00 moles of the HCl per 1 mole of the diamine. If the amount is less than the amount, some diamines do not react with the aqueous hydrochloric acid solution and remain, so that free amine groups react with diisocyanate in a subsequent reaction to form urea. In addition, when the input amount is exceeded, the chlorine ions remaining due to the excess aqueous hydrochloric acid solution increase the chlorine concentration during the subsequent phosgenation reaction to generate impurities.

As various examples, the aqueous hydrochloric acid solution may be added to be 2.02 moles or more, 2.05 moles or more, 2.10 moles or more, or 2.20 moles or more of HCl per 1 mole of the diamine. In addition, the aqueous hydrochloric acid solution may be added in an amount of 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 of HCl per 1 mol of the diamine. As a specific example, the aqueous hydrochloric acid solution may be added in an amount of 2.02 moles to 3.80 moles, 2.50 moles to 3.70 moles, or 3.00 moles to 3.60 moles of HCl per 1 mole of the diamine.

In particular, according to the preparation method of the embodiment, the pH of the diisocyanate composition can be adjusted to 5.0 to 5.8 by adjusting the amount of the aqueous hydrochloric acid solution added to the reaction, and the yield and purity of the diisocyanate composition can also be improved.

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 a specific example, 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 reacting the diamine hydrochloride composition with triphosgene by adding triphosgene. In (b) of FIG. 1, (iv) may include at least one step selected from a degassing step, a filtration step, and a distillation step.

Hereinafter, each step will be described in detail.

Preparation of diamine hydrochloride composition

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

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 a specific example, R may be xylylene, norbornene, xylylene hydride, isophorone, or hexamethylene, but is not limited thereto.

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

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

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

The input amount of the aqueous hydrochloric acid solution may be adjusted in a molar ratio relative to the input amount of the diamine, and specific examples of the input amount are as described above.

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

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

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

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

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

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

Through the reaction of the diamine with the aqueous hydrochloric acid solution, a reaction result in an aqueous solution state in which the diamine hydrochloride composition is dissolved in water 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 a first organic solvent to the reaction product. That is, the first organic solvent may induce precipitation of the solid diamine hydrochloride composition through crystallization. More specifically, the first organic solvent may be added to the reaction result, and after cooling, the reaction may proceed while further stirring.

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

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

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

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

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

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

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

According to the method, the diamine is reacted with an aqueous hydrochloric acid solution, and the solid diamine hydrochloride composition can be obtained with high purity through 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, and specifically 85% to 95%, or 88% to 92%. .

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

Diamine hydrochloride composition

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

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

In particular, according to the above embodiment, the amount of the aqueous hydrochloric acid solution used for the preparation of the diamine hydrochloride composition is adjusted, so that the amount of chlorine component or unreacted diamine remaining in the diamine hydrochloride composition can be controlled, The pH of the diamine hydrochloride composition can also be controlled.

For example, the diamine hydrochloride composition may have a pH of 3.0 to 4.0 when dissolved in water at a concentration of 10% by weight. In addition, when within the above pH range, the yield and purity of the diisocyanate composition prepared by using the diamine hydrochloride composition may be improved, and the optical properties of the final optical lens may be further improved.

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, 3.8 or more. 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.

When adjusted to the above preferred pH range, free amine may be contained in the diamine hydrochloride composition in a predetermined content range or less. Specifically, the content of free amine groups in the diamine hydrochloride composition may be 0.1 wt% or less, or 0.01 wt% or less. When it is within the above range, it may be more advantageous to prevent the free amine groups remaining in the diamine hydrochloride composition from reacting with the diisocyanate synthesized in the subsequent reaction to form urea.

In addition, when the pH is adjusted to the preferred range, the chlorine component may be contained in the diamine hydrochloride composition in a predetermined content range or less. Specifically, the chlorine ion content in the diamine hydrochloride composition may be 0.1 wt% or less, or 0.01 wt% or less. When within the above range, HCl remaining in the diamine hydrochloride composition may be more advantageous in preventing generation of impurities by increasing the chlorine concentration during the subsequent phosgenation reaction.

Preparation of diisocyanate composition

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

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

[Scheme 2]

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

According to the method of the above embodiment, by controlling the reaction temperature range of the diamine hydrochloride composition and triphosgene, there may be very few impurities in the crude diisocyanate composition before purification. Specifically, the diisocyanate composition, before the diisocyanate distillation, may include 98.7% by weight of diisocyanate or more. In addition, the diisocyanate composition, after the diisocyanate distillation, may include the diisocyanate in an amount of 99.9% by weight or more.

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

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

Measurement of color and transparency of reaction solution

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[Manufacturing method of optical lens]

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

The method of manufacturing an optical lens according to an embodiment includes mixing a diisocyanate composition with thiol or episulfide, and polymerizing and curing in a mold, wherein the diisocyanate composition has a pH of 5.0 to 5.8. According to the embodiment, by adjusting the pH of the diisocyanate composition used in the manufacture of the optical lens to a specific range, it is possible to suppress stria or cloudiness of the final optical lens and improve optical properties.

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

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

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

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

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

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

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

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

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

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

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

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

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

[Example]

More specific examples are exemplified 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 wt% 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 60° C., 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 input, the temperature inside the reactor was cooled to 10° C. and stirred for 1 hour, then 1320.0 g of tetrahydrofuran (THF) was further added, and the temperature inside the reactor was cooled to -5° C., followed by further stirring for 1 hour. After completion of the reaction, the diamine hydrochloride composition containing m-XDA·2HCl was separated by vacuum filtration using a filter, and filtered tetrahydrofuran was recovered for reuse. In order to remove the residual solvent and moisture, the residual solvent and moisture in the separated diamine hydrochloride composition were removed at 90° C. and vacuum dried at 0.1 torr.

Step (2)

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

Examples 2 to 5 and Comparative Examples 1 to 4

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

The pH of the diamine hydrochloride composition and the diisocyanate composition obtained in steps (1) and (2) of the Examples and Comparative Examples, respectively, are shown in Table 1 below. The pH of the diamine hydrochloride composition was measured after dissolving a solid sample in water at a concentration of 10% by weight. The pH of the diisocyanate composition was measured using a measuring instrument (LAQUA F-72G, HORIBA) and a non-aqueous electrode (6377-10D), and pH 4.0, 7.0, and 10.0 were calibrated in advance with a buffer solution. Fill a 100 mL glass bottle with more than 50 mL of the sample, immerse the electrode to stabilize it for 1 hour, and then measure three times to obtain an average value.

division Hydrochloric acid aqueous solution input amount
(number of moles of HCl per mole of m-XDA) Diamine hydrochloride composition
pH diisocyanate
composition pH Example 1 2.80 3.44 5.51 Example 2 2.02 3.87 5.75 Example 3 2.50 3.45 5.62 Example 4 3.00 3.31 5.25 Example 5 4.00 3.15 5.02 Comparative Example 1 2.00 4.05 5.83 Comparative Example 2 1.95 4.26 5.91 Comparative Example 3 4.20 2.95 4.81 Comparative Example 4 4.50 2.55 4.35

As shown in the table above, it was possible to change the pH of the diamine hydrochloride composition by adjusting the input amount of the aqueous hydrochloric acid solution.

manufacture of optical lenses

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

Assessment Methods

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

(1) distillation yield

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

(2) diisocyanate content

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

(3) McLee

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

(4) Cloudy (haze)

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

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

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

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

division Diisocyanate composition optical lens distillation
yield Diisocyanate content (wt%) McLee cloudiness transmittance Y.I. before distillation after distillation Example 1 91% 99.1% 99.9% radish radish 90% 19 Example 2 89% 99.1% 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% 98.2% 99.8% U radish 88% 22 Comparative Example 2 83% 98.1% 99.7% U radish 87% 22 Comparative Example 3 89% 98.2% 99.8% radish cloudiness 85% 24 Comparative Example 4 88% 97.9% 99.6% radish cloudiness 80% 24

As shown in Tables 1 and 2, the optical lenses prepared using the diisocyanate composition having a preferred pH range as in Examples 1 to 5 had high transmittance and no streaks, white turbidity and yellowing occurred. On the other hand, streaks or white turbidity or yellowing occurred in the optical lenses prepared using the diisocyanate composition out of the preferred pH range as in Comparative Examples 1 to 4.

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

Claims (15)

Having a pH of 5.0 to 5.8, a diisocyanate composition for an optical lens.
The method of claim 1,
The diisocyanate composition comprises xylylene diisocyanate, a diisocyanate composition for an optical lens.
3. The method of claim 2,
The diisocyanate composition for an optical lens, wherein the content of xylylene diisocyanate in the diisocyanate composition is 99.9% by weight or more.
The method of claim 1,
The diisocyanate composition for an optical lens, wherein the chlorine ion content in the diisocyanate composition is 100 ppm or less.
The method of claim 1,
The pH of the diisocyanate composition is 5.5 to 5.7, a diisocyanate composition for an optical lens.
reacting diamine with an aqueous hydrochloric acid solution to obtain a diamine hydrochloride composition; and
Comprising the step of obtaining a diisocyanate composition by a phosgenation reaction from the diamine hydrochloride composition,
The hydrochloric acid aqueous solution is added to the reaction to be 2.02 moles to 4.00 moles of HCl per 1 mole of the diamine, a method for producing a diisocyanate composition for an optical lens.
7. The method of claim 6,
The phosgenation reaction is performed at a temperature condition of 115°C to 130°C, a method for producing a diisocyanate composition for an optical lens.
8. The method of claim 7,
The phosgenation reaction is performed using triphosgene, a method for producing a diisocyanate composition for an optical lens.
7. The method of claim 6,
The hydrochloric acid aqueous solution has a concentration of 20 wt% to 45 wt%, a method for producing a diisocyanate composition for an optical lens.
7. The method of claim 6,
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 for an optical lens.
7. The method of claim 6,
The content of free amine groups in the diamine hydrochloride composition is 0.1% by weight or less, a method for producing a diisocyanate composition for an optical lens.
7. The method of claim 6,
A method for producing a diisocyanate composition for an optical lens, wherein the chlorine ion content in the diamine hydrochloride composition is 0.1 wt% or less.
7. The method of claim 6,
The diisocyanate composition has a pH of 5.0 to 5.8, a method for producing a diisocyanate composition for an optical lens.
mixing the diisocyanate composition with a thiol or episulfide and polymerizing and curing in a mold;
The diisocyanate composition has a pH of 5.0 to 5.8, a method of manufacturing an optical lens.
15. The method of claim 14,
The method for manufacturing an optical lens, wherein the optical lens has a transmittance of 85% or more and a yellowness (YI) of 22 or less.

Images