KR101870380B1 - Aromatic polythiol compound used in the manufacture of an optical material - Google Patents

Abstract

The examples relate to aromatic polythiol compounds for optical materials. The aromatic polythiol compounds according to the examples include phenyl groups and a large number of sulfur atoms in the polythiol structure, so that the polythiourethanes obtained therefrom have a high refractive index and a low specific gravity And is excellent in mechanical properties since it has a low hardening shrinkage ratio. Therefore, it can be usefully used for manufacturing various plastic optical lenses such as spectacle lenses and camera lenses.

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.

Plastic materials of various resins are widely used as optical materials such as spectacle lenses and camera lenses because they are lightweight and do not break easily and are excellent in dyability compared with optical materials made of inorganic materials such as glass. In recent years, higher performance of optical materials is required, and specifically high transparency, high refractive index, low specific gravity, high heat resistance, and high impact resistance are required.

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 or 2:

[Chemical Formula 1]

(2)

In this formula,

R ₁ and R ₁ 'are each independently a sulfur atom, an oxygen atom, O = S = O, CX ₁ Y ₁ or C = CX ₂ Y ₂ ,

X _1, Y _1, X ₂ and Y ₂ are each independently a hydrogen atom, a halogen atom, a C _{1 -6} alkyl, C _{6 -10} aryl, C _{3 -6} cycloalkyl or C _{1 -6} alkoxy, wherein X ₁ and Y _1, and may form a C _{3 -10} ring wherein X ₂ and Y ₂ are bonded to each other, they may be substituted with at least one member selected from the group consisting of halogen atoms, C _{1 -6} alkyl and hydroxy In addition,

R ₂ are each independently an oxygen atom or a sulfur atom,

R ₃ are each independently a hydrogen atom, a halogen atom, C _{1 -10} alkyl or C _{6 -10} aryl.

Further, the embodiment provides a polymerizable composition comprising the aromatic polythiol compound and the isocyanate-based compound.

The examples also provide a polythiourethane-based compound obtained by polymerizing an aromatic polythiol compound and an isocyanate compound.

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

(1) reacting a compound of formula (3) with epichlorohydrin to prepare a compound of formula (4); (2) reacting the compound of formula (4) with 2-mercaptoethanol to prepare a compound of formula (5); And (3) reacting and hydrolyzing the compound of formula (5) with thiourea;

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 1]

In this formula,

Each R < ₂ > is independently hydroxy or thiol,

R ₁ , X ₁ , Y ₁ , X ₂ , Y ₂ , R ₂ , and R ₃ are each as defined above.

Further, the present invention provides a process for preparing a compound represented by the formula (7 '): (1') reacting a compound of the formula (6) with epichlorohydrin to prepare a compound of the formula (2 ') reacting a compound of formula (7) with 2-mercaptoethanol to produce a compound of formula (8); And (3 ') reacting and hydrolyzing a compound of formula (8) with thiourea;

[Chemical Formula 6]

(7)

[Chemical Formula 8]

(2)

In this formula,

R ₁ , R ₁ ', X ₁ , Y ₁ , X ₂ , Y ₂ , R ₂ , R ₂ ' and R ₃ are each as defined 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 has excellent optical properties such as low hardening shrinkage and excellent mechanical properties Therefore, 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 or 2:

[Chemical Formula 1]

(2)

In this formula,

R ₁ , R ₁ 'X ₁ , Y ₁ , X ₂ , Y ₂ , R ₂ , and R ₃ are each as defined above.

Specifically, each of X ₁ and Y ₁ is independently a hydrogen atom, a halogen atom, C _{1 -6} alkyl or C _{6 -10} aryl, X ₂ and Y ₂ are each independently a halogen atom, and X ₁ and Y ₁ may form a C _{3 -10} ring bonded to each other, it may be substituted with at least one member selected from the group consisting of a halogen atom and a C _{1 -6} alkyl.

More specifically, R ₁ and R ₁ 'are each independently a sulfur atom, an oxygen atom, O═S═O or CX ₁ Y ₁ , X ₁ and Y ₁ are each independently a hydrogen atom, a halogen atom or C _{1 Lt; /} RTI >

The aromatic polythiol compound of Formula 1 or 2 may be prepared by preparing an aromatic polyol compound from an aromatic compound having two or three phenyl groups, and then reacting and hydrolyzing the aromatic polyol compound with thiourea.

Specifically, the aromatic polythiol compound of Formula 1 may be prepared by (1) reacting a compound of Formula 3 with epichlorohydrin to prepare a compound of Formula 4 having a chlorohydrin structure; (2) reacting the compound of formula (4) with 2-mercaptoethanol to produce an aromatic polyol compound of formula (5) having a polyhydric alcohol structure; And (3) reacting an aromatic polyol compound represented by the formula (5) with thiourea to obtain an isothiouronium salt, followed by hydrolyzing the isothiouronium salt (see Scheme 1).

[Reaction Scheme 1]

In this formula,

Each R < ₂ > is independently hydroxy or thiol,

R ₁ , X ₁ , Y ₁ , X ₂ , Y ₂ , R ₂ , and R ₃ are each as defined above.

The aromatic polythiol compound of Formula 2 may be prepared by reacting a compound of Formula 6 with epichlorohydrin to produce a compound of Formula 7 having a chlorohydrin structure; (2 ') reacting the compound of formula (7) with 2-mercaptoethanol to produce an aromatic polyol compound of formula (8) having a polyhydric alcohol structure; And (3 ') reacting an aromatic polyol compound of formula (8) with thiourea to obtain an isothiouronium salt and hydrolyzing the isothiouronium salt (see Scheme 2).

[Reaction Scheme 2]

In the above formula

R ₁ , R ₁ ', X ₁ , Y ₁ , X ₂ , Y ₂ , R ₂ , R ₂ ' and R ₃ are each as defined above.

The above steps (1) and (1 ') are carried out in the presence of a catalyst such as triethylamine, sodium hydroxide, potassium hydroxide, chromium octoate or triphenylphosphine at 40 to 100 ° C, . The epichlorohydrin may be reacted in an amount of 0.8 to 1.2 equivalents based on 1 equivalent of the compound of the formula (3) or (6).

Steps (2) and (2 ') can be carried out by reacting the compound of formula (4) or (7) with 2-mercaptoethanol in water in the presence of a base to produce the aromatic polyol compound of formula (5) or (8). Examples of the base include tertiary amines such as sodium hydroxide, potassium hydroxide, trimethylamine and triethylamine; Secondary amines such as dimethylamine and diethylamine; Primary amines such as methylamine and ethylamine; Ammonia and the like can be used. The reaction may be carried out at 40 to 100 ° C, specifically at 50 to 60 ° C. The 2-mercaptoethanol may be reacted in an amount of 0.8 to 1.2 equivalents based on 1 equivalent of the compound of formula (4) or (7).

In the above steps (3) and (3 '), the aromatic polyol compound of formula (5) or (8) is mixed with thiourea and refluxed under acidic conditions to obtain an isothiouronium salt. The thiourea can be reacted in an amount of 1 to 3 equivalents, specifically 1 to 2 equivalents based on 1 equivalent of the hydroxyl group of the aromatic polyol compound. In order to form the acid condition, an aqueous hydrochloric acid solution, hydrogen chloride gas, or the like can be used. The temperature at the reflux may be 60 to 130 캜, and may be 90 to 120 캜. The reflux time can be from 2 to 24 hours, and in particular from 2 to 12 hours.

Thereafter, the isothiouronium salt is hydrolyzed in an organic solvent to obtain an aromatic polythiol compound of formula (1) or (2). Examples of the organic solvent include toluene, xylene, chlorobenzene, and dichlorobenzene. To suppress the by-product, toluene is preferred. The reaction temperature for the hydrolysis may be 10 to 130 캜, more specifically 30 to 80 캜. The hydrolysis time may be 0.1 to 24 hours, and may be 0.5 to 12 hours.

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

For example, acid cleaning and water cleaning can be performed a plurality of times. 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 obtained aromatic polythiol compound may have a thiol value (SHV, SH value) of 100 to 400 g / eq. The aromatic polythiol compound includes a phenyl group and a large number of sulfur atoms in its structure, and thus has excellent optical properties such as high refractive index and specific gravity through subsequent reaction with isocyanate, low hardening shrinkage ratio, A material can be formed.

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. 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.

More specifically, 1,3-bis (isocyanatomethyl) cyclohexane, hexamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, toluene diisocyanate and the like can be used.

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 solubility in the polymerizable composition and transparency of the obtained optical material, a dye is preferably used 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 it in a monomer, a method of preparing a master solution containing a high concentration of a bluing agent, and a method of diluting the monomer solution or other additives using the master solution, There are several ways to use it.

The examples provide polythiourethane-based compounds 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 0.5 to 1.5, more specifically 0.8 to 1.5. 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 examples also provide optical materials molded from the polythiourethane compounds 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 1.55 to 1.75, 1.55 to 1.70, 1.59 to 1.75, or 1.59 to 1.70. The optical material may have a specific gravity of 1.10 to 1.30, 1.10 to 1.25, 1.15 to 1.30, 1.15 to 1.25, 1.20 to 1.25, or 1.20 to 1.22. The optical material may have a heat distortion temperature (Tg) of 105 to 130 DEG C, 105 to 120 DEG C, 108 to 130 DEG C, or 108 to 120 DEG C.

The optical material may preferably be an optical lens, specifically a plastic optical lens.

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

250 g (1 mole) of 4,4-thiobisbenzenethiol, 435 g of water and 0.5 g of triethylamine were fed into a three-necked, five-liter reactor equipped with a mechanical stirrer and a cooling tube, and the temperature was maintained at 50 占 폚. Subsequently, 185 g (2 mol) of epichlorohydrin was added dropwise to the reactor over 1 hour, and the mixture was aged at 60 캜 for 5 hours to obtain a reaction solution. A thin layer chromatograph (TLC) was performed on the resulting reaction solution, and when epichlorohydrin was not detected, the reaction was terminated and the compound of formula (4-1) having a chlorohydrin structure was obtained.

A mixture of 500 g of water and 156 g (2 mol) of 2-mercaptoethanol and 100 g (2 mol) of 80% sodium hydroxide was slowly added dropwise to the resulting compound of formula (4-1) at 50 DEG C over 2 hours, Lt; 0 > C for 3 hours to obtain a reaction solution. TLC was performed on the obtained reaction solution, and if no 2-mercaptoethanol was detected, the reaction was terminated to obtain an aromatic polyol compound of formula (5-1).

576 g (6 moles) of a 38% concentrated hydrochloric acid solution was added to the obtained aromatic polyol compound of the formula (5-1), followed by addition of 335 g (4.4 moles) of thiourea, followed by refluxing at 110 ° C for 3 hours to form thiouronium Chloride reaction. Then, the reaction solution was cooled to 40 캜, and then 650 g of toluene was added to the reaction solution, followed by cooling 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. 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 mu m to obtain a tetrafunctional aromatic polythiol compound (compound of Formula 1-1).

H-NMR: ppm 1.7 (2H , -SH), 2.7 ~ 3.3 (9H, -SCH 2 -), 7.0 (4H, -SCH 2 = CH 2 -), 7.1 (-CH 2 = CH 2 -).

Example  2

A reaction was carried out in the same manner as in Example 1 except that 218 g (1 mole) of 4,4-thiophenol was used instead of 250 g (1 mole) of 4,4-thiobisbenzenethiol to obtain a tetrafunctional aromatic polythiol compound (Compound of formula 1-2).

H-NMR: ppm 1.7 (2H , -SH), 2.7 ~ 3.4 (7H, -SCH 2 -), 4.1 ~ 4.4 (2H, -CH 2 O-), 6.6 (4H, -OCH 2 = CH 2 -) _{, 7.1 (4H, -CH 2 =} CH 2 -).

Example  3

A reaction was carried out in the same manner as in Example 1 except that 200 g (1 mole) of bisphenol F was used instead of 250 g (1 mole) of 4,4-thiobisbenzenethiol to obtain a tetrafunctional aromatic polythiol compound (compound 1 -3).

H-NMR: ppm 1.7 (2H , -SH), 2.7 ~ 3.4 (7H, -SCH 2 -), 3.9 (2H, -CH 2 -), 4.1 ~ 4.4 (2H, -CH 2 O-), 6.6 ( _{4H, -OCH 2 = CH 2 -} ), 7.0 (4H, -CH 2 = CH 2 -).

Polymerizable  Preparation of composition

Example  4

61.2 parts by weight of the aromatic polythiol compound prepared in Example 1 was uniformly mixed with 38.8 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 internal mold release agent and 0.05 part by weight of CYASORB (R) UV-5411 as an ultraviolet absorber were added thereto and uniformly mixed to prepare a polymerizable composition.

Example  5 to 8 and Comparative Example  1 to 4

A polymerizable composition was prepared in the same manner as in Example 4 except that the components and the content (parts by weight) were changed as shown in Table 1 below.

Experimental Example  : Property check

The properties of the polymerizable compositions prepared in Examples 4 to 8 and Comparative Examples 1 to 4 were measured as described below. The measurement results are shown in Table 1 below.

(1) Refractive index

The polymerizable compositions prepared in Examples 4 to 8 and Comparative Examples 1 to 4 were degassed at 600 Pa for 1 hour and then filtered through a Teflon filter of 3 占 퐉. 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 )

Using the polymerizable compositions prepared in Examples 4 to 8 and Comparative Examples 1 to 4, a molded article was produced in the same manner as in item (1), except that a circular lens (optical material) having a thickness of 9 mm and a diameter of 75 mm . 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-Pannel lad product 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

Takenate® 500: Xylene diisocyanate

TDI: toluene 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: Phosphoric acid ester release agent, Stepan

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

As shown in Table 1, it can be seen that the optical lenses of Examples 4 to 8 have a low specific gravity, a high heat distortion temperature, a small chromaticity difference, and excellent light resistance, as compared with Comparative Examples 1 to 4, Are also maintained at the same level. 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 (14)

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

In this formula,
R ₁ is a sulfur atom,
R ₂ are each independently an oxygen atom or a sulfur atom,
R ₃ is a hydrogen atom.
The method according to claim 1,
And R ₂ is an oxygen atom.
The method according to claim 1,
And R ₂ is a sulfur atom.
The method according to claim 1,
Wherein the aromatic polythiol compound has a thiol value (SHV, SH value) of 100 to 400 g / eq.
A polymerizable composition comprising the aromatic polythiol compound of claim 1 and an isocyanate compound.
6. The method of claim 5,
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 polymer obtained from the polymerizable composition of claim 5.
An optical material molded from the polythiourethane-based polymer of claim 7.
9. The method of claim 8,
Wherein the optical material is a plastic optical lens.
9. The method of claim 8,
Wherein the optical material has a refractive index of 1.55 to 1.75.
9. The method of claim 8,
Wherein the optical material has a specific gravity of 1.10 to 1.30.
9. The method of claim 8,
Wherein the optical material has a heat distortion temperature (Tg) of 105 to 130 占 폚.
(1) reacting a compound of formula (3) with epichlorohydrin to prepare a compound of formula (4);
(2) reacting the compound of formula (4) with 2-mercaptoethanol to prepare a compound of formula (5); And
(3) reacting and hydrolyzing a compound of formula (5) with thiourea;
(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 1]

In this formula,
R ₁ is a sulfur atom,
R ₂ are each independently an oxygen atom or a sulfur atom,
Each R < ₂ > is independently hydroxy or thiol,
R ₃ is a hydrogen atom. delete