KR20180089363A - Polythiol composition used in the manufacture of an optical material and preparation method thereof - Google Patents

Abstract

An embodiment of the present invention relates to a polythiol composition for an optical material and a manufacturing method thereof. According to an embodiment of the present invention, a manufacturing method of a polythiol composition suppresses a side reaction when manufacturing a polythiol compound and can obtain a tetrafunctional polythiol composition having low content of trifunctional polythiol which is byproduct and high purity. Therefore, a polythiol urethane obtained from the high purity tetrafunctional polythiol composition is excellent in optical properties such as a reflective index and heat resistance, thereby being usefully used in manufacturing various plastic optical materials such as a glass lens and a camera lens. The polythiol composition comprises tetrafunctional polythiol and trifunctional polythiol represented by chemical formula 1. A peak area of the trifunctional polythiol represented by chemical formula 1 in gel permeation chromatography measurement is 1 to 6 with respect to the total peak area 100 of the polythiol compound.

Description

TECHNICAL FIELD [0001] The present invention relates to a polythiol composition for optical materials and a method for producing the same,

The examples relate to a polythiol composition used as a raw material of a polythiourethane-based optical material and a method for producing the same. The examples also relate to a polymerizable composition comprising the polythiol composition and an optical material obtained therefrom.

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. At this time, the purity of the polythiol compound greatly affects the physical properties of the polythiourethane-based compound produced therefrom.

As shown in Reaction Scheme 1 below, a diol compound is prepared by reacting 2-mercaptoethanol with epihalohydrin and reacted with a metal sulfide to prepare a tetraol compound, which is reacted with thiourea and hydrolyzed Thereby producing three kinds of tetrafunctional polythiol compounds.

[Reaction Scheme 1]

In the above formula, X is a halogen atom.

However, when this production process is carried out, the halogen group of the diol compound prepared by the reaction of 2-mercaptoethanol with epihalohydrin can be easily substituted with the mercapto group of 2-mercaptoethanol, As shown in Reaction Scheme 2, there is a problem that a side reaction in which an undesirable triol intermediate is formed occurs, and the purity of the tetrafunctional polythiol compound, which is the target compound, is lowered because the trifunctional polythiol compound is produced as a by-product.

 [Reaction Scheme 2]

In the above formula, X is a halogen atom.

Korean Patent No. 10-1533207 discloses that a reaction of 2-mercaptoethanol with epihalohydrin is carried out using an aqueous solution of NaOH as a reaction catalyst, and Korean Patent Publication No. 1995-0023666 discloses a reaction between 2-mercaptoethanol and epi- Discloses the production of a tetrafunctional polythiol compound based on the above process using triethylamine as a reaction catalyst in the reaction with a halohydrin.

However, according to the preparation process disclosed in Korean Patent No. 10-1533207, the reaction between the diol compound intermediate as described above and 2-mercaptoethanol easily occurs, and undesired side reactions still occur. Further, according to the production process disclosed in Korean Patent Publication No. 1995-0023666, since the reaction of 2-mercaptoethanol with epihalohydrin must be carried out at a high temperature of 35 to 60 占 폚, But still partly occurred.

Korean Patent No. 10-1533207 Korean Patent Publication No. 1995-0023666

Accordingly, it is an object of the present invention to provide a tetrafunctional polythiol composition having a small purity of trifunctional polythiol as a by-product and a method for producing the same.

In the polythiol composition comprising a tetrafunctional polythiol and a trifunctional polythiol represented by the following formula (1), the peak area of the trifunctional polythiol represented by the formula (1) A polythiol composition is provided having a total peak area of 1 to 6 for 100:

[Chemical Formula 1]

Furthermore, the examples provide a polymerizable composition comprising the polythiol composition and the isocyanate-based compound.

Further, the embodiment provides a molded article obtained by curing the above-mentioned polymerizable composition.

Furthermore, the embodiment provides an optical material comprising the molded body.

Further, the examples are (1) a process for producing a compound represented by the following formula (2) at a temperature of -5 to 15 ° C in the presence of a catalyst selected from the group consisting of a tertiary amine, a quaternary ammonium salt, a triphenylphosphine and a trivalent chromium- Reacting a compound of formula (I) with 2-mercaptoethanol to produce a compound of formula (III);

(2) reacting the compound of Formula 3 with a metal sulfide to produce a compound of Formula 4; And

(3) reacting and hydrolyzing the compound of formula (4) with thiourea.

(2)

(3)

[Chemical Formula 4]

In this formula,

X is a halogen atom.

According to the process for producing a polythiol composition according to the embodiment, a tetrafunctional polythiol composition having a low content of trifunctional polythiol and a high purity can be obtained by suppressing side reactions during production of the polythiol compound. Therefore, the polythiourethane obtained from the tetrafunctional polythiol composition having high purity is excellent in optical properties such as refractive index and heat resistance, and thus can be usefully used for manufacturing various plastic optical materials such as spectacle lenses and camera lenses.

FIG. 1 is a graph obtained by performing gel permeation chromatography on the polythiol composition of Example 2, wherein the arrow indicates the content (peak) of the trifunctional polythiol compound. FIG.
2 is a graph obtained by performing gel permeation chromatography on the polythiol composition of Comparative Example 3, wherein the arrow indicates the content (peak) of the trifunctional polythiol compound.

The polythiol composition according to an embodiment includes a tetrafunctional polythiol and a trifunctional polythiol represented by the following formula (1), wherein a peak area of the trifunctional polythiol represented by the formula (1) in the gel permeation chromatography measurement is a polythiol compound Lt; RTI ID = 0.0 > 1 < / RTI > to 6 or 1 to 5.5 for a total peak area of 100:

 [Chemical Formula 1]

The tetrafunctional polythiol may be at least one compound selected from the compounds represented by the following general formulas (5) to (7)

[Chemical Formula 5]

[Chemical Formula 6]

(7)

Further, the compounds represented by the above formulas (5) to (7) can be obtained by reacting a compound represented by the following formula (4) with thiourea and hydrolyzing the compound:

[Chemical Formula 4]

The polythiol composition comprising the compounds of formulas (5) to (7) may be prepared by (1) reacting a polythiol compound having a number of carbon atoms of from -5 to 5 in the presence of at least one catalyst selected from the group consisting of tertiary amines, quaternary ammonium salts, triphenylphosphine, Reacting a compound represented by the following formula (2) with 2-mercaptoethanol at a temperature of 15 ° C to prepare a compound represented by the following formula (3); (2) reacting the compound of Formula 3 with a metal sulfide to produce a compound of Formula 4; And (3) reacting and hydrolyzing the compound of Formula 4 with thiourea (see Scheme 1).

[Reaction Scheme 1]

In the above formula, X may be a halogen atom such as F, Cl, Br, I, and the like.

Specifically, in step (1), the diol compound of formula (3) can be prepared by reacting 2-mercaptoethanol with the compound of formula (2) in the presence of a base as a reaction catalyst. At this time, the reaction may not use water. The reaction may be carried out at a temperature of from -5 to 15 캜, from 0 to 12 캜 or from 5 to 10 캜 for from 2 to 10 hours, from 2 to 8 hours or from 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, relative to 1 mol of the compound of formula (2). 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 compound of formula (2). At this time, the base as the reaction catalyst may be selected from the group consisting of tertiary amines, quaternary ammonium salts, triphenylphosphine and trivalent chromium compounds, and examples thereof include triethylamine, triphenylphosphine, triethyl Ammonium chloride, chromium (III) octoate, and the like.

At this time, a metallic catalyst such as sodium hydroxide, potassium hydroxide or the like is used as a catalyst, or when the reaction temperature is higher than 15 ° C, a side reaction as shown in the reaction formula 2 occurs to produce a trifunctional polythiol compound of the formula (1). If the reaction temperature is less than -5 ° C, the reaction does not proceed smoothly.

In step (2), the tetraol compound of 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 may be used in the form of an aqueous solution or solid. 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 the formula (4) is reacted with thiourea to obtain an isothiouronium salt, which is then hydrolyzed to prepare the compounds of the formulas (5) to (7). 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, per 1 mol of the compound of the formula (4). 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 moles or more, specifically 3 to 12 moles per 1 mole of the compound of the 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 ° C, specifically at 100 to 110 ° C for 1 to 10 hours.

Thereafter, the obtained isothiouronium salt can be hydrolyzed in an organic solvent and in a basic condition to obtain a tetrafunctional polythiol compound represented by the general formulas (5) to (7).

Concretely, while maintaining the reaction solution containing the isothiouronium 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, facility facilities, and the like.

The basic aqueous solution is soluble in water to generate a hydroxyl group (-OH), and examples thereof include metal hydroxides such as sodium hydroxide and potassium hydroxide; And an aqueous solution of a basic substance such as amines such as ammonia and triethylamine. 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. The basic aqueous solution may be added at room temperature or at a reflux temperature range. When the basic aqueous solution is added, the reaction temperature may be from 0 to 80 ° C or from 0 to 50 ° C, and if the amount is within the above range, the obtained polythiol compound is not colored well.

An organic solvent may be added before adding the basic aqueous solution. 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 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 above steps (1) to (3) can be carried out in air or under a nitrogen atmosphere, and are preferable in terms of color when carried out under a nitrogen atmosphere.

The polythiol composition obtained above can be further purified.

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 polythiol composition can be obtained by drying, filtration and the like.

An embodiment provides a polymerizable composition comprising the polythiol composition and the isocyanate-based 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 examples provide polythiourethane-based compounds obtained from the polymerizable composition as described above. The polythiourethane compound is prepared by polymerizing (and curing) the polythiol composition 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. Within this range, the refractive index, heat resistance And the balance and the like can be improved. 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 embodiment provides a molded article obtained by curing the polymerizable composition and an optical material comprising the molded article. 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 1.65 to 1.75 or 1.65 to 1.70. The optical material may have a thermal deformation temperature (Tg) of 100 to 110 ° C or 100 to 105 ° C.

The optical material may 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, according to the process for producing a polythiol composition according to the embodiment, a tetrafunctional polythiol composition having a low content of trifunctional polythiol and a high purity can be obtained by suppressing side reactions during production of the polythiol compound. Therefore, the polythiourethane obtained from the tetrafunctional polythiol composition having high purity is excellent in optical properties such as refractive index and heat resistance, and thus can be usefully used for manufacturing various plastic optical materials such as spectacle lenses and camera lenses.

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 ]

Polythiol  Preparation of composition

Example  One

51.7 parts by weight (0.66 mol) of 2-mercaptoethanol and 0.2 parts by weight of triethylamine were fed into the reactor, 61.8 parts by weight (0.67 mol) of epichlorohydrin was added dropwise over 4 hours while maintaining the temperature at 8 DEG C, Lt; / RTI > for 1 hour to conduct the first reaction. Subsequently, 53.0 parts (0.34 mol) of a 50% aqueous solution of sodium sulfide was added dropwise at 22 DEG C over 5.5 hours, and stirring was carried out for 120 minutes. Then, 278.4 parts by weight (2.74 mol) of 36% hydrochloric acid was added. Then, 124.5 parts by weight (1.6 mol) of thiourea was added and the mixture was reacted with thiouronium chloride for 3 hours while refluxing at 110 DEG C to obtain a reaction solution .

The reaction solution was cooled to 45 캜, 214.0 parts by weight of toluene was added, and the mixture was cooled to 26 캜. 317.5 parts by weight (2.83 mol) of a 50% by weight aqueous solution of potassium hydroxide was added at 38 캜 for 30 minutes, The reaction solution was further subjected to a hydrolysis process for a period of time.

After the toluene portion of the reaction solution was separated, 59.4 parts by weight of 36% hydrochloric acid was added to the toluene and mixed. After 30 minutes, the water portion was removed using a separating funnel at 36 ° C (acid washing step). The pickling step was repeated twice. Subsequently, 118.7 parts by weight of distilled water was added to the reaction solution which had been acid-pickled and mixed, and 30 minutes later, the distilled water was washed five times at 36 캜 to remove water using a separating funnel.

Thereafter, toluene and a small amount of water were completely removed through a heating and depressurizing process, and the solution was filtered with a Teflon filter having a thickness of 1 탆 to obtain 4,8-dimercaptomethyl-1,11-dimercapto-3,6 , 9-trithiandecane (Formula 5), 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane (Formula 6) 1,1-dimercapto-3,6,9-trithiaundecane (Formula 7) as a main component.

Example  2

Except that 0.2 part by weight of triphenylphosphine was used instead of 0.2 part by weight of triethylamine, to obtain a polythiol composition containing as a main component the compounds of the formulas (5) to (7).

Example  3

Except that 0.2 part by weight of triethylammonium chloride was used instead of 0.2 part by weight of triethylamine, to obtain a polythiol composition containing as a main component the compounds of the formulas (5) to (7).

Example  4

Except that 0.2 part by weight of triethylamine was replaced by 0.2 part by weight of HYCAT 3000S (chromium (III) octoate, Dimension Technology Chemical Systems Inc., USA) instead of 0.2 part by weight of triethylamine. To obtain a polythiol composition as a main component.

Comparative Example  One

Except that 20 parts by weight of 10% sodium hydroxide was used in place of 0.2 part by weight of triethylamine, a polythiol composition was obtained.

Comparative Example  2

Except that 20 parts by weight of 10% potassium hydroxide was used in place of 0.2 part by weight of triethylamine, to obtain a polythiol composition.

Comparative Example  3

A polythiol composition was obtained in the same manner as in Example 1, except that the reaction was carried out at 38 ° C instead of 8 ° C in the reaction of 2-mercaptoethanol with epichlorohydrin.

<Elemental analysis> Theoretical value Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 C 32.7 32.8 32.7 32.8 32.6 32.4 32.3 32.1 H 6.2 6.1 6.3 6.0 6.2 6.2 6.2 6.4 S 61.1 61.1 61.0 61.2 61.2 61.4 61.5 61.5

FT-IR: 2540 cm ^-1 (-SH stretching peak).

Polymerizable  Preparation of composition

Example  5

49.3 parts by weight of the polythiol composition prepared in Example 1 was uniformly mixed with 50.7 parts by weight of xylene diisocyanate (Takenate (R) 500). Then, 0.01 part by weight of dibutyltin dichloride as a polymerization catalyst and 0.1 part by weight of Zelec (R) UN as an internal phase were added and uniformly mixed to prepare a polymerizable composition.

Example  6 to 8 and Comparative Example  4 to 6

The polymerizable compositions of Examples 6 to 8 and Comparative Examples 4 to 6 were prepared in the same manner as in Example 5, except that the polythiol compositions of Examples 2 to 4 and Comparative Examples 1 to 3 were respectively used. Respectively.

Experimental Example  : Property check

The properties of the polythiol composition prepared in Examples 1 to 4 and Comparative Examples 1 to 3 and the polymerizable compositions prepared in Examples 5 to 8 and Comparative Examples 4 to 6 were measured as described below And the measurement results are shown in Table 3 below.

(1) trifunctional Polythiol content

The polythiol compositions prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were subjected to gel permeation chromatography and then formed at R / T 5.7 to 5.8 minutes using a RID detector (Waters) at 40 ° C. The results of Example 2 and Comparative Example 3 are shown in Figs. 1 and 2, respectively. The conditions of the gel permeation chromatography are as follows.

device APC system (Waters) Column Acquity APC XT Column 45A (4.6 * 150mm) x2 (Waters) Mobile phase Tetrahydrofuran (THF) flux 0.5 mL / min Total driving time 10 minutes Dose 10 μl

(2) SH value

After adding about 0.1 g each of the polythiol compositions prepared in Examples 1 to 4 and Comparative Examples 1 to 3, 40 mL of chloroform was added to the beaker, followed by stirring for 10 minutes. 20 mL of isopropyl alcohol was further added, Lt; / RTI &gt; The solution was titrated with 0.1 N iodine standard solution, and the SH value was calculated by applying the following equation (1) (theoretical value = 91.3):

[Equation 1]

SH value (g / eq.) = Sample weight (g) / {0.1x amount of iodine consumed (L)}.

(3) Liquid refractive index

The refractive indexes of the polythiol compositions prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were measured at 25 占 폚 using Refractometer RA-600 (Kyowa Electronics Co., Ltd.) using a liquid refractometer.

(4) Solid-state refractive index

The polymerizable compositions prepared in Examples 5 to 8 and Comparative Examples 4 to 6 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.).

(5) Heat resistance (thermal deformation)

The glass transition temperature (Tg, thermal deformation) of the optical lens of item (4) in TMA Q400 (manufactured by TA company) under the peening method (load of 50 g, pin line of 0.5 mmφ, Temperature) was measured.

As shown in Table 3, the content of the trifunctional polythiol compounds in the polythiol compositions of Examples 1 to 4 was all 6 or less with respect to the total peak area 100 of the entire polythiol compound, The content of the trifunctional polythiol in the polythiol composition of the present invention is significantly larger than that of the polythiol. In addition, both the refractive indexes before and after curing were higher than those of the comparative example, and the heat distortion temperature after curing was also higher than that of the comparative example. Therefore, it is expected that the optical lens manufactured in the embodiment is excellent in refractive index and heat resistance and can be usefully used as an optical material.

Claims (11)

A polythiol composition comprising a tetrafunctional polythiol and a trifunctional polythiol represented by the following formula (1)
Wherein the peak area of the trifunctional polythiol represented by the formula (1) in the gel permeation chromatography measurement is 1 to 6 with respect to the total peak area of the polythiol compound (100)
[Chemical Formula 1]

. The method according to claim 1,
Wherein the tetrafunctional polythiol is at least one compound selected from the compounds represented by Chemical Formulas 5 to 7:
[Chemical Formula 5]

[Chemical Formula 6]

(7)

. 3. The method of claim 2,
Wherein the compound represented by any one of Chemical Formulas 5 to 7 is obtained by reacting a compound represented by Chemical Formula 4 with thiourea followed by hydrolysis,
[Chemical Formula 4]

. (1) reacting a compound represented by the following formula (2) with a compound represented by the formula (2) in the presence of a catalyst selected from the group consisting of a tertiary amine, a quaternary ammonium salt, a triphenylphosphine and a trivalent chromium- Reacting the compound of formula (III) with mercaptoethanol to produce a compound of formula (3);
(2) reacting the compound of Formula 3 with a metal sulfide to produce a compound of Formula 4; And
(3) reacting and hydrolyzing the compound of formula (4) with thiourea.
(2)

(3)

[Chemical Formula 4]

In this formula,
X is a halogen atom. 5. The method of claim 4,
In the step (3), the compound represented by the following general formulas (5) to (7) is produced:
[Chemical Formula 5]

[Chemical Formula 6]

(7)

. 5. The method of claim 4,
Lt; RTI ID = 0.0 &gt; polythiol &lt; / RTI &gt; A polymerizable composition comprising a polythiol composition according to any one of claims 1 to 3 and an isocyanate-based compound. A molded article obtained by curing the polymerizable composition of claim 7. An optical material comprising the molded article of claim 8. 10. The method of claim 9,
Wherein the optical material has a refractive index of 1.65 to 1.75. 10. The method of claim 9,
Wherein the optical material has a thermal deformation temperature (Tg) of 100 to 110 占 폚.

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