KR20180024762A - Aromatic polythiol compound used in the manufacture of an optical material - Google Patents

Abstract

An embodiment of the present invention relates to an aromatic polythiol compound for optical materials. The aromatic polythiol compound according to an embodiment includes a phenyl group and a large number of sulfur atoms in a polythiol structure, so that polythiourethane obtained therefrom has excellent heat resistance; has excellent optical properties such as high refractive indexes, low specific gravity, and the like; and has low hardening shrinkage rate, thereby being excellent in mechanical properties. Therefore the aromatic polythiol compound can be usefully used in the production of various plastic optical lenses such as spectacle lenses, camera lenses, and the like.

Description

[0001] AROMATIC POLYTHIOL COMPOUND USED IN THE OPTICAL MATERIAL [0002]

The examples relate to aromatic polythiol compounds used as raw materials for polythiourethane-based optical materials. The examples also relate to a polymerizable composition comprising the aromatic polythiol compound, a polythiourethane compound obtained therefrom and an optical material.

Optical materials using plastics are lightweight, easily broken, and excellent in dyability compared with optical materials made of inorganic materials such as glass. Therefore, plastic materials of various resins are widely used as optical materials for spectacle lenses and camera lenses. Recently, as demand for higher performance and convenience has increased, research on optical materials having properties such as high transparency, high refractive index, low specific gravity, high heat resistance, and high impact resistance continues.

BACKGROUND ART Polythiourethane-based compounds are widely used as optical materials due to their excellent optical properties and mechanical properties. The polythiourethane compound can be prepared by reacting a polythiol compound with an isocyanate compound, and the physical properties of the polythiol compound greatly affect the physical properties of the polythiourethane compound to be produced.

For example, Korean Patent No. 10-1594407 and Korean Patent No. 10-0180926 disclose polythiol compounds containing a large number of sulfur (S), but this polythiol compound does not contain a phenyl group, There is a disadvantage that it is necessary to use an isocyanate containing a phenyl group for synthesis of a polythiourethane-based optical material having a high refractive index and a low specific gravity and a hardening shrinkage ratio. Further, Korean Patent No. 10-1074450 discloses a polythiol compound containing a phenyl group, but it has a disadvantage in that a sufficient refractive index can not be secured in synthesizing a polythiourethane based optical material because the content of sulfur is small.

Accordingly, the present inventors have conducted studies to solve the above-mentioned drawbacks and found that by synthesizing tetrafunctional aromatic polythiol compounds having a high sulfur content, it is possible to obtain polythiourethane based optical materials having excellent properties such as refractive index, specific gravity, The present invention has been completed.

Korean Patent No. 10-1594407 Korean Patent No. 10-0180926 Korean Patent No. 10-1074450

Accordingly, it is intended to provide a tetrafunctional aromatic polythiol compound having a high sulfur content and a polythiourethane-based compound obtained using the same.

An embodiment provides an aromatic polythiol compound represented by the following Formula 1:

[Chemical Formula 1]

.

.

Further, the examples provide a polymerizable composition comprising the aromatic polythiol compound and the isocyanate compound.

The examples also provide polythiourethane compounds obtained from the above polymerizable compositions.

Further, the embodiment provides an optical material molded from the polythiourethane-based compound.

(1) reacting a compound of formula (2) with 2-mercaptoethanol to prepare a compound of formula (3);

(2) reacting the compound of formula (III) with a metal sulfide to produce a compound of formula (IV); And

(3) reacting and hydrolyzing a compound of formula (4) with thiourea to provide a compound of formula

[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

In this formula,

X is a halogen atom.

The aromatic polythiol compound according to the embodiment contains a phenyl group and a large number of sulfur in the polythiol structure, so that the polythiourethane obtained from the polythiourethane is excellent in heat resistance, excellent in optical properties such as high refractive index and low specific gravity, It can be usefully used for manufacturing various plastic optical lenses such as spectacle lenses and camera lenses.

An embodiment provides an aromatic polythiol compound represented by the following Formula 1:

[Chemical Formula 1]

.

.

The aromatic polythiol compound of Formula 1 may be prepared by preparing an aromatic polyol compound from an aromatic compound having a phenyl group and then reacting and hydrolyzing the aromatic polyol compound with thiourea.

(1) reacting a compound of formula (2) with 2-mercaptoethanol to produce a compound of formula (3); (2) reacting the compound of formula (III) with a metal sulfide to produce a compound of formula (IV); And (3) reacting and hydrolyzing the compound of formula (4) with thiourea (see Scheme 1).

[Reaction Scheme 1]

In the above formula, X is a halogen atom, for example, Cl, Br, I or the like.

Specifically, in step (1), the diol compound of formula (3) can be prepared by reacting the halogenated styrene oxide of formula (2) with 2-mercaptoethanol in the presence of a base as a reaction catalyst. The reaction can be carried out at a temperature of 2 to 30 캜, 5 to 20 캜 or 5 to 15 캜 for 2 to 10 hours, 2 to 8 hours or 2 to 5 hours. Further, the content of 2-mercaptoethanol may be 0.5 mol to 3 mol, specifically 0.7 mol to 2 mol, more specifically 0.9 mol to 1.1 mol, based on 1 mol of the halogenated styrene oxide. The base may be used in a catalytic amount. Specifically, the content of the base may be 0.001 mol to 0.1 mol based on 1 mol of the halogenated styrene oxide when the base is monovalent, and may be half of the monovalent amount when the base is bivalent. At this time, the base as the reaction catalyst may be triethylamine, tributylamine, etc., and may be used in the form of an aqueous solution or an alcohol solution. When the base is used in the form of an aqueous solution or an alcohol solution, the concentration of the base solution can be appropriately selected.

In step (2), a tetraol compound represented by the following formula (4) can be prepared by reacting the diol compound of formula (3) with a metal sulfide in a solvent. The reaction may be carried out at a temperature of 10 to 50 DEG C, specifically 20 to 40 DEG C for 1 to 10 hours, 1 to 8 hours or 1 to 5 hours. The metal sulfide may be, for example, sodium sulfide (Na ₂ S). The metal sulfide can be used in the form of an aqueous solution or solid, and is preferably used in the form of a hydrate, but is not limited thereto. When the metal sulfide is used in the form of an aqueous solution, it is preferable to adjust the concentration to 10 to 80%, specifically 30 to 60%. The metal sulfide may be used in an amount of 0.4 to 0.6 mol, specifically 0.45 to 0.57 mol, more specifically 0.48 to 0.55 mol, based on 1 mol of the diol compound of the formula (3).

In step (3), the obtained tetraol compound of formula (4) is reacted with thiourea to obtain an isothiouronium salt, which is then hydrolyzed to obtain the compound of formula (1). First, the compound of formula (IV) and thiourea are mixed and refluxed under acidic conditions to obtain an isothiouronium salt. The thiourea may be used in an amount of 3 mol or more, specifically 3 mol to 6 mol, more specifically 4.6 mol to 5 mol, based on 1 mol of the tetraol compound. In order to form the above acid condition, a hydrochloric acid solution, a hydrogen chloride gas, or the like can be used, and they can be used in an amount of 3 mol or more, specifically 3 mol to 12 mol, per 1 mol of the tetraol compound of the above formula (4). By using hydrogen chloride, a sufficient reaction rate can be obtained and coloring of the product can be prevented. Reflux can be carried out at 90 to 120 캜, preferably at 100 to 110 캜 for 1 to 10 hours.

Then, the obtained isothiouronium salt can be hydrolyzed in an organic solvent and under basic conditions to obtain an aromatic polythiol compound of the formula (1).

Concretely, while maintaining the reaction solution containing the isothiuronium salt at a temperature of 20 to 60 ° C, specifically 25 to 55 ° C, more specifically 25 to 50 ° C, the reaction solution was stirred for 80 minutes or less, 70 minutes The basic aqueous solution may be added for 20 to 60 minutes or 20 to 30 minutes. The addition time of the basic aqueous solution is preferably as short as possible, but is set within the above-mentioned time in consideration of the cooling facility, facilities, and the like. The basic aqueous solution is not limited as long as it is a basic substance capable of dissolving in water and capable of generating a hydroxyl group (-OH) such as ammonia, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide and aluminum hydroxide. The concentration of the basic aqueous solution may be 10 to 70%, specifically 15 to 50%. At this time, an organic solvent may be added before the basic aqueous solution is added. The organic solvent can inhibit the formation of by-products. The organic solvent may be added in an amount of 0.1 to 3.0 times, particularly 0.2 to 2.0 times, the isothiouronium salt reaction solution. Examples of the organic solvent include toluene, xylene, chlorobenzene, and dichlorobenzene, and specifically may be toluene. The basic substance may be used in an amount of 1 mole or more, specifically 1 mole to 3 moles, more specifically 1.1 mole to 2 moles, based on 1 mole of the hydrogen chloride. At this time, the basic substance can be added at a rate of 1.25 mol% / min or more, specifically 1.25 mol% / min to 3.75 mol% / min, more specifically 1.38 mol% / min to 2.5 mol% / min . The hydrolysis reaction temperature may be 10 to 130 캜, specifically 30 to 80 캜. The hydrolysis time may be 0.1 to 24 hours, and may be 0.5 to 12 hours, more specifically 1 to 8 hours.

The aromatic polythiol compound thus obtained may be subjected to further purification.

For example, it is possible to perform a plurality of times of alkaline cleaning and a plurality of times of water cleaning. Impurities and the like remaining in the polythiol can be removed through the cleaning process, thereby improving the color of the polythiol and improving the color of the optical material obtained therefrom.

Thereafter, if necessary, the desired aromatic polythiol compound can be obtained by drying, filtration and the like.

The Examples provide a polymerizable composition comprising the aromatic polythiol compound and the isocyanate compound.

The polymerizable composition may contain the aromatic polythiol compound in an amount of 100% by weight. In addition, if necessary, the polymerizable compound may further include a polythiol compound different from the aromatic polythiol compound in addition to the aromatic polythiol compound as described above, and may include, for example, an aliphatic polythiol compound. The aliphatic polythiol compound may be at least one selected from the group consisting of methanedithiol, 1,2-ethanedithiol, 1,2,3-propanetriethol, pentaerythritol tetrakis (2-mercaptoacetate), pentaerythritol tetrakis (Mercaptomethylthiomethyl) methane, tetrakis (2-mercaptoethylthiomethyl) methane, tetrakis (mercaptomethylthiomethyl) ) Methane, tetrakis (3-mercaptopropylthiomethyl) methane, bis (2,3-dimercaptopropyl) sulfide, 2,5-dimercaptomethyl- Dimercapt-1,4-dithiane, 2,5-dimercaptomethyl-2,5-dimethyl-1,4-dithiane, 1,1,3,3-tetrakis (mercaptomethylthio) propane , 1,1,2,2-tetrakis (mercaptomethylthio) ethane, 4,6-bis (mercaptomethylthio) -1,3-dithiane, and the like.

When the polymerizable composition further comprises a polythiol compound different from the aromatic polythiol compound, the aromatic polythiol compound may be contained in an amount of 5 to 70 parts by weight based on 100 parts by weight of the total thiol compound.

The isocyanate-based compound may be a conventional one used for the synthesis of polythiourethane.

Specific examples include isophorone diisocyanate, dicyclohexylmethane-4,4-diisocyanate, hexamethylene diisocyanate, 2,2-dimethylpentane diisocyanate, 2,2,4-trimethylhexane diisocyanate, butene diisocyanate, Butadiene-1,4-diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 1,6,11-undecatriisocyanate, 1,3,6-hexamethylene triisocyanate, 1,8-di (Isocyanatoethyl) ether, 1,2-bis (isocyanatomethyl) cyclohexane, 1,3-bis (isocyanatomethyl) But are not limited to, bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, dicyclohexyldimethylmethane Sociane Bis (isocyanatoethyl) sulfide, bis (isocyanatohexyl) sulfide, bis (isocyanatoethyl) sulfide, bis (Isocyanatoethylthio) methane, bis (isocyanatoethylthio) methane, bis (isocyanatoethylthio) methane, bis (isocyanatoethylthio) Bis (isocyanatoethylthio) ethane, bis (isocyanatomethylthio) ethane, 1,5-diisocyanato-2-isocyanatomethyl-3-thiapentane, 2,5- Diisocyanatotetrahydrothiophene, 2,5-bis (isocyanatomethyl) tetrahydrothiophene, 3, 5-bis (isocyanatomethyl) thiophene, , 2,5-bis (isocyanatomethyl) -1,4-dithiene, 2,5-bis (isocyanatomethyl) tetrahydrothiophene, 2,5-diisocyanato- Diisocyanato-1,3-dithiolane, 4,5-bis (isocyanatomethyl) -1,3-dithiolane, 4,5-bis (isocyanatomethyl) 2-methyl-1,3-dithiolane, and the like; (Isocyanatoethyl) benzene, bis (isocyanatoethyl) benzene, bis (isocyanatoethyl) benzene, bis (isocyanatoethyl) Examples of the aromatic diisocyanate compound include aromatic diisocyanates such as phenyl ether, phenylenediisocyanate, ethylphenylenediisocyanate, isopropylphenylenediisocyanate, dimethylphenylenediisocyanate, diethylphenylenediisocyanate, diisopropylphenylenediisocyanate, trimethylbenzene triisocyanate, Toluene diisocyanate, 4,4-diphenylmethane diisocyanate, 3,3-dimethyldiphenylmethane-4,4-diisocyanate, bibenzyl-4,4-diisocyanate, bis (isocyanato Phenyl) ethylene, 3,3-dimethoxybiphenyl-4,4-diisocyanate, hexahydrobenzene diisocyanate, hexahydrate Xylene diisocyanate, p-xylene diisocyanate, xylene diisocyanate, X-xylene diisocyanate, 1,3-bis (isocyanatomethyl) ) Cyclohexane, diphenylsulfide-2,4-diisocyanate, diphenylsulfide-4,4-diisocyanate, 3,3-dimethoxy-4,4-diisocyanatodibenzylthioether, bis -Isocyanatomethylbenzene) sulfide, 4,4-methoxybenzenethioethylene glycol-3,3-diisocyanate, diphenyldisulfide-4,4-diisocyanate, 2,2-dimethyl diphenyl disulfide Diisocyanate, 3,3-dimethyldiphenyldisulfide-5,5-diisocyanate, 3,3-dimethyldiphenyldisulfide-6,6-diisocyanate, 4,4- Diisocyanate, 5,5-diisocyanate, 3,3-dimethoxydiphenyl disulfide-4,4-diisocyanate, 4,4-dimethoxydiphenyl di From the aromatic group consisting of isocyanate-based compound, or the like feed-3,3-diisocyanate it can be used at least one member.

Specifically, the isocyanate compound may be 1,3-bis (isocyanatomethyl) cyclohexane, hexamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, toluene diisocyanate or the like.

The polymerizable composition may further contain an additive such as an internal mold release agent, a heat stabilizer, a reaction catalyst, an ultraviolet absorber, and a blueing agent, depending on the purpose.

Examples of the ultraviolet absorber include benzophenone, benzotriazole, salicylate, cyanoacrylate, oxanilide, and the like.

Examples of the internal release agent include a fluorine-based nonionic surfactant having a perfluoroalkyl group, a hydroxyalkyl group or a phosphate ester group; A silicone-based nonionic surfactant having a dimethylpolysiloxane group, a hydroxyalkyl group or a phosphate ester group; Alkyl quaternary ammonium salts such as trimethylcetylammonium salt, trimethylstearyl, dimethylethylcetylammonium salt, triethyldodecylammonium salt, trioctylmethylammonium salt, diethylcyclohexadecylammonium salt and the like; And acidic phosphate esters may be used singly or in combination of two or more.

As the reaction catalyst, a known reaction catalyst used in the production of a polythiourethane resin may be appropriately added. Dialkyltin halide systems such as dibutyltin dichloride and dimethyltin dichloride; Dialkyltin dicarboxylates such as dimethyltin diacetate, dibutyltin dioctanoate and dibutyltin dilaurate; Dialkyltin dialkoxides such as dibutyltin dibutoxide and dioctyltin dibutoxide; Dialkyltin dithioalkoxide systems such as dibutyltin di (thiobutoxide); Dialkyltin oxides such as di (2-ethylhexyl) tin oxide, dioctyltin oxide, and bis (butoxy dibutyltin) oxide; And a dialkyltin sulfide system such as dibutyltin sulfide feed. Specifically, it may be selected from the group consisting of dialkyltin halide systems such as dibutyltin dichloride, dimethyltin dichloride and the like.

Examples of the thermal stabilizer include a metal fatty acid salt, phosphorus, lead, and an organosilicate.

The bluing agent has an absorption band in the wavelength range from orange to yellow in the visible light region and has a function of adjusting the color of the optical material made of the resin. Specifically, the bluing agent may include a material that exhibits blue to violet, but is not particularly limited. Examples of the bluing agent include dyes, fluorescent whitening agents, fluorescent pigments, and inorganic pigments, but they can be appropriately selected in accordance with physical properties and resin color required for the produced optical component. These bluing agents may be used alone or in combination of two or more. From the viewpoints of the solubility in the polymerizable composition and the transparency of the resulting optical material, dyes are preferred as the bluing agent. In view of the absorption wavelength, the dye may specifically be a dye having a maximum absorption wavelength of 520 to 600 nm, and more specifically, a dye having a maximum absorption wavelength of 540 to 580 nm. Further, from the viewpoint of the structure of the compound, an anthraquinone-based dye is preferable as the dye. The method of adding the bluing agent is not particularly limited and may be added to the monomer system in advance. Specifically, the method of adding the bluing agent may be a method of dissolving the monomer in a monomer, or a method of preparing a master solution containing a high concentration of a bluing agent and diluting the monomer solution or other additives using the master solution and adding You can use branching methods.

The present invention provides a polythiourethane-based compound obtained from the polymerizable composition as described above. The polythiourethane compound is prepared by polymerizing (and curing) the aromatic polythiol compound and the isocyanate compound. The reaction mole ratio of the SH group / NCO group in the polymerization reaction may be 0.5 to 3.0, specifically 0.6 to 2.0, more specifically 0.8 to 1.3. Further, in order to control the reaction rate, the above-mentioned reaction catalyst which is conventionally used for the production of polythiourethane may be added.

The present invention also provides an optical material molded from a polythiourethane compound as described above. The optical material may be prepared by polymerizing and molding the polymerizable composition.

First, the polymerizable composition is degassed under reduced pressure, and then injected into a mold for optical material molding. Such degassing and mold injection can be performed, for example, at a temperature range of 20 to 40 캜. After injection into the mold, the polymerization is usually carried out by gradually heating from a low temperature to a high temperature.

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

Then, the polythiourethane-based optical material is separated from the mold.

The optical material may be in various shapes by changing the mold of the mold used in the production. Specifically, it may be in the form of a spectacle lens, a camera lens, a light emitting diode (LED), or the like.

The optical material may have a refractive index of 1.60 to 1.75, 1.60 to 1.70, 1.63 to 1.75 or 1.63 to 1.70. The optical material may have a specific gravity of 1.10 to 1.30, 1.15 to 1.30, or 1.20 to 1.30. The optical material may have a thermal deformation temperature (Tg) of 100 to 120 ° C, 110 to 120 ° C or 113 to 120 ° C.

The optical material may specifically be an optical lens, specifically a plastic optical lens. The optical lens can be used for surface polishing, antistatic treatment, hard coat treatment, anti-reflection coat treatment, dyeing treatment, dimming treatment (for example, Light control) processing, and the like.

As described above, the aromatic polythiol compound according to the embodiment contains a phenyl group and a large number of sulfur in the polythiol structure, so that the polythiourethane obtained from the polythiourethane has a high refractive index and a low specific gravity and is excellent in optical properties and low in hardening shrinkage, It is useful for manufacturing various plastic optical lenses such as a spectacle lens and a camera lens.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are intended to illustrate the present invention, but the scope of the present invention is not limited thereto.

[ Example ]

Aromatic Polythiol  Preparation of compounds

Example  One

154.6 g (1 mole) of 4-chlorostyrene oxide, 78.13 g (1 mole) of 2-mercaptoethanol and 0.1 g of triethylamine were fed into a three-necked, five-liter reactor equipped with a mechanical stirrer and a cooling tube, Was reacted for 4 hours while maintaining the temperature at 8 캜 to obtain a reaction solution containing the compound of formula (3-1). At this time, thin layer chromatography (TLC) was performed on the reaction solution, and when the 2-mercaptoethanol was not detected, the reaction was terminated.

To the reaction solution, a mixed solution of 124.9 g (0.52 mol) of sodium sulfide nonahydrate and 124.9 g of water was slowly added dropwise at 30 ° C for 3 hours. Thereafter, the mixture was aged at 40 DEG C for 1 hour to obtain a reaction solution containing the compound of formula (4). At this time, TLC was performed on the reaction solution to terminate the reaction when the compound of Formula 3-1 was not detected.

To the reaction solution was added 576 g (6 mol) of a 38% concentrated hydrochloric acid solution, followed by addition of 335 g (4.4 mol) of thiourea and then thiouronium chloride reaction at 110 ° C for 3 hours while refluxing to obtain the compound of Chemical Formula 5 Was obtained.

After the reaction solution was cooled to 40 캜, 650 g of toluene was added to the reaction solution, and the mixture was cooled to 25 캜. Subsequently, 637 g (4.5 mol) of 25% ammonia water was added dropwise to the reaction solution at 50 캜 for 30 minutes, and further subjected to a hydrolysis process at 60 캜 for 1 hour to obtain a reaction solution.

The toluene portion of the reaction solution was separated, and then 127 g of a 38% concentrated hydrochloric acid solution was added to the toluene, and after 30 minutes, the water portion was removed using a separating funnel (acid washing step). The pickling step was repeated twice. Next, 255 g of distilled water was added to the reaction solution which had been acid-pickled and mixed, and after 30 minutes, the distilled water was washed five times by repeating the removal of the water portion using a separating funnel. Thereafter, toluene and a small amount of water were completely removed through a heating and depressurizing process, and then filtered with a Teflon filter of 1 m to obtain a tetrafunctional aromatic polythiol compound (compound of formula (I)). At this time, the result of elemental analysis of the obtained aromatic polythiol compound with FT-IR and C ₁₃ -NMR was as follows.

Theoretical value Results C 50.5% 51.0% H 6.6% 6.8% S 42.9% 42.2

FT-IR: IR? _Max (KBr) cm ^-1 = 2600 (SH)

Polymerizable  Preparation of composition

Example  2

72.8 parts by weight of the aromatic polythiol compound prepared in Example 1 were uniformly mixed with 27.2 parts by weight of 1,3-bis (isocyanatomethyl) cyclohexane (Takenate (R) 600). 0.01 part by weight of dibutyltin dichloride as a polymerization catalyst, 0.1 part by weight of Zelec (R) UN as an inner mold release agent and 0.05 part by weight of CYASORB (R) UV-5411 as an ultraviolet absorber were added thereto and mixed uniformly to prepare a polymerizable composition.

Example  3 and 4, and Comparative Example  1 and 2

A polymerizable composition was prepared in the same manner as in Example 2 except that the components and the content (parts by weight) were changed as shown in Table 3 below.

Experimental Example  : Property check

The properties of the polymerizable compositions prepared in Examples 2 to 4 and Comparative Examples 1 and 2 were measured as described below. The measurement results are shown in Table 3 below.

(1) Refractive index

The polymerizable compositions prepared in Examples 2 to 4 and Comparative Examples 1 and 2 were degassed at 600 Pa for 1 hour and then filtered through a 3 占 퐉 Teflon filter. The filtered polymerizable composition was injected into a glass mold template assembled by tape. The mold was heated from 25 캜 to 120 캜 at a rate of 5 캜 / min and polymerization was carried out at 120 캜 for 18 hours. The cured resin in the glass mold mold was further cured at 130 캜 for 4 hours, and then the molded body was released from the glass mold mold. The molded article was a circular lens (optical material) having a center thickness of 1.2 mm (deviation: -5.00) and a diameter of 72 mm. The lens was impregnated with ST11TN-8H hard coating solution (FINE COAT) and thermally cured to coat the lens.

The refractive index of the lens was measured at 20 ° C using an Abbe refractometer DR-M4 (Atago Co.).

(2) Specific gravity

For the optical lens of the item (1), the weight and the volume ratio of the lens were measured by an underwater substitution method, and the specific gravity was calculated therefrom.

(3) Heat resistance (thermal deformation)

The glass transition temperature (Tg, thermal deformation) of the optical lens of item (1) in the optical lens of item (1) in TMA Q400 (TA corporation) under the peening method (load of 50 g, Temperature) was measured.

(4) Light fastness (yellow before and after light exposure) Exponential  Difference ; △ YI )

(1), using the polymerizable composition prepared in Examples 2 to 4 and Comparative Examples 1 and 2, except that a circular lens (optical material) having a thickness of 9 mm and a diameter of 75 mm was used as a molded article, . At this time, no coating was performed. The chromaticity coordinates x and y of the optical material were measured using a chromanometer CM-5 manufactured by Minolta Co., and the measured values were applied to the following equation (1) to calculate a yellow index (YI). Then, the optical material was exposed to a QUV / Spray model (5w) of Q-Pannerel product Co. for 200 hours, and the yellow index was measured in the same manner as described above. The difference from the initial YI value (the difference between YI values before and after light exposure) was calculated and expressed as the light resistance (? YI).

[Equation 1]

YI = (234x + 106y + 106) / y

Takenate® 600: 1,3-bis (isocyanatomethyl) cyclohexane, Mitsui Chemicals

Takenate® 500: Xylene diisocyanate, Mitsui Chemicals

IPDI: isophorone diisocyanate

Aliphatic polythiol A: 5,9-dimercaptomethyl-1,13-dimercapto-3,7,11-trithiatridecane

Aliphatic polythiol B: 2,3-bis (2-mercaptoethylthio) propane-1-thiol

DBTDC: dibutyl tin dichloride

Zelec®UN: phosphate ester release agent, Stepan

CYASORB®UV-5411: 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole,

As shown in Table 3, it can be seen that the optical lenses of Examples 2 to 4 have a low specific gravity, a high refractive index and a high heat distortion temperature, a small chromaticity difference, and excellent light resistance, as compared with Comparative Examples 1 and 2 . Thus, it is expected that the optical lens manufactured in the embodiment can be used as an optical material because it is light, can withstand a high temperature and can form a clear image.

Claims (12)

An aromatic polythiol compound represented by the following formula (1):
[Chemical Formula 1]

.
A polymerizable composition comprising the aromatic polythiol compound of claim 1 and an isocyanate compound.
3. The method of claim 2,
Wherein the polymerizable composition further comprises a polythiol compound different from the aromatic polythiol compound.
3. The method of claim 2,
Wherein the polymerizable composition comprises the aromatic polythiol compound in an amount of 5 to 70 parts by weight based on 100 parts by weight of the total polythiol compound.
3. The method of claim 2,
Wherein the isocyanate compound is at least one selected from the group consisting of 1,3-bis (isocyanatomethyl) cyclohexane, hexamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate and toluene diisocyanate.
A polythiourethane-based compound obtained from the polymerizable composition of claim 2.
An optical material molded from the polythiourethane compound of claim 6.
8. The method of claim 7,
Wherein the optical material is a plastic optical lens.
8. The method of claim 7,
Wherein the optical material has a refractive index of 1.60 to 1.75.
8. The method of claim 7,
Wherein the optical material has a specific gravity of 1.10 to 1.30.
8. The method of claim 7,
Wherein the optical material has a heat distortion temperature (Tg) of 100 to 120 占 폚.
(1) reacting a compound of formula (2) with 2-mercaptoethanol to prepare a compound of formula (3);
(2) reacting the compound of formula (III) with a metal sulfide to produce a compound of formula (IV); And
(3) A process for producing a compound represented by the following formula (1), which comprises reacting and hydrolyzing a compound represented by the formula (4) with thiourea:
[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

In this formula,
X is a halogen atom.