WO2015190809A1 - Novel thiol compound and polymerizable composition containing same - Google Patents

Abstract

The present invention relates to a novel thiol compound and a polymerizable composition containing the same. The present invention provides a thiol compound and a polymerizable composition containing the same. The thiol compound and the polymerizable composition containing the same, of the present invention, are suitable for the production of urethane-based plastic materials satisfying both product quality and economic feasibility, and are suitable for the production of, especially, urethane-based plastic materials required to have colorless transparency and high or middle refractive property.

Description

New thiol compounds and polymerizable compositions containing them

The present invention relates to a novel thiol compound and a polymerizable composition comprising the same.

Plastic optical materials are lighter and less easily broken than optical materials made of inorganic materials, and can be dyed. In recent years, plastic materials of various resins have been used for optical materials, and their required properties are also increasing day by day.

In Korean Patent Nos. 10-0136698, 10-0051275, 10-0051939, 10-0056025, 10-0040546, 10-0113627, and the like, a polyisocyanate compound and a polythiol compound are thermally cured to obtain a urethane optical lens. Urethane-based optical materials have excellent optical properties such as formability, transparency, Abbe's number, heat resistance, light resistance, weather resistance, transmittance, and tensile strength compared to other optical materials, and have excellent coating and workability. However, urethane-based optical materials have a higher production cost than other plastic optical materials and are mainly used for expensive high refractive lenses.

In particular, 2,3-bis (2-mercaptoethylthio) -3-propane-1-thiol (GST) and 2- (2-mercaptoethylthio) propane-1,3 which are currently used in many urethane optical materials -Thiol compounds, such as dithiol (GMT) and pentaerythritol tetrakis (3-methcaptopropionate) (PETMP), are expensive and cause the production cost of optical materials to increase. In addition, such thiol compounds are 3,8-bis (isocyanatomethyl) tricyclo [5,2,1,02,6] decane and 3,9-bis (isocyanatomethyl having excellent mixing properties as isocyanate compounds. Tricyclo [5,2,1,02,6] decane, 4,8-bis (isocyanatomethyl) tricyclo [5,2,1,02,6] decane, 4,9-bis (isosia) Natomethyl) tricyclo [5,2,1,02,6] decane, 2,5 - bis (isocyanatomethyl) bicyclo [2,2,1] heptane, 2,6-bis (isocyanatomethyl ) When using the bicyclo [2,2,1] heptane to form a polymerizable composition, high quality optical materials can be obtained without any problems. However, isophorone diisocyanate and dicyclohexyl methane-4,4- are an isocyanate compound. diisocyanate (H ₁₂ MDI), the low quality, such as 1,6-hexamethylene off during polymerization reactivity when using an isocyanate compound such as isocyanate for inexpensive multipurpose striae, birch, microbubbles This phenomenon often occurs.

In addition to improving lens quality, production cost reduction is a major concern in recent years. In view of this, new thiol compounds that can be used in transparent plastic materials having high refractive indexes, such as optical materials, are one of the problems continuously required in this field.

[Preceding technical literature]

[Patent Documents]

(Patent Document 1) Republic of Korea Patent Registration 10-0136698

(Patent Document 2) Republic of Korea Patent Publication 10-0051275

(Patent Document 3) Republic of Korea Patent Publication 10-0051939

(Patent Document 4) Republic of Korea Patent Registration 10-0056025

(Patent Document 5) Republic of Korea Patent Publication 10-0040546

An object of the present invention is to provide a new thiol compound, a polymerizable composition comprising the same, and a method of manufacturing the same, which can be used in place of a conventional thiol compound such as a urethane optical material.

In the present invention,

A thiol compound represented by the following formula (1) is provided.

[Formula 1]

In the present invention,

There is provided a method for preparing a thiol compound represented by the formula (1) comprising the step of putting malic acid and 2-mercaptoethanol in a reactor and esterifying under elevated temperature and reduced pressure.

In the present invention,

A polymerizable composition comprising a thiol compound represented by Chemical Formula 1 is provided.

In the present invention,

A plastic material obtained by polymerizing the polymerizable composition and an optical lens made of this plastic material are provided. The optical lens in particular comprises an spectacle lens.

The thiol compound of the present invention may be used in place of a conventional thiol compound such as a urethane optical material. When the thiol compound of the present invention is used, it is possible to obtain a plastic material that is clear and transparent, has a high initial heat deformation temperature, and is excellent in heat resistance, and in particular, a medium- and high-refractive urethane-based plastic material satisfying both quality and economy can be obtained. In particular, the polymerizable composition containing the thiol compound of the present invention can produce a urethane-based optical material having a high colorless transparency with high yield even when a general purpose isocyanate compound having low reactivity with an isocyanate compound can be produced. It is effective to reduce.

The thiol compound of the present invention is represented by the formula (1) below.

[Formula 1]

According to a preferred embodiment, the thiol compound of the present invention may be prepared by the method represented by Scheme 1 below.

According to a preferred embodiment,

Malic acid, 2-mercaptoethanol, toluene, and p-toluenesulfonic acid were added to the reactor, followed by esterification under elevated temperature and reduced pressure conditions to form a new thiol compound, bis (2-mercaptoethyl) -2-hydroxysuccinate. Nate (bis (2-mercaptoethyl) -2-hydroxysuccinate) was obtained.

The final product obtained further includes a polynuclear species represented by the following Chemical Formula 2 in addition to the mono product bis (2-mercaptoethyl) -2-hydroxysuccinate (bis). Can be. The polynuclear species (Formula 2), some thioesterification reaction occurs in the esterification reaction in the preparation of bis (2-mercapto ethyl) -2-hydroxysuccinate (bis (2-mercaptoethyl) -2-hydroxysuccinate) Side products produced.

Scheme 1

[Formula 2]

(A, B, C, D is H or OH, X, Y is O or S, and m is an integer from 1 to 10.)

The polymerizable composition of the present invention contains a thiol compound represented by the formula (1). This thiol compound makes it possible to obtain a plastic material that is clear and transparent, has a high initial heat deformation temperature, and has excellent heat resistance. The thiol compound has particularly good compatibility with general purpose isocyanate compounds that are less reactive, so that even if a general purpose isocyanate compound is used in the polymerizable composition, a colorless transparent urethane optical material can be obtained. The polymerizable composition of the present invention may further include other thiol compounds in addition to the thiol compound represented by Chemical Formula 1. The other thiol compound is not particularly limited, and a compound having two or more thiol groups in one molecule may be used. For example, another thiol compound is a compound represented by the formula (2); 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane; 2,3-bis (2-mercaptoethylthio) -3-propane-1-thiol; 2,2-bis (mercaptomethyl) -1,3-propanedithiol; Bis (2-mercaptoethyl) sulfide; Tetrakis (mercaptomethyl) methane; 2- (2-mercaptoethylthio) propane-1,3-dithiol; 2- (2,3-bis (2-mercaptoethylthio) propylthio) ethanethiol; Bis (2,3-dimercaptopropanyl) sulfide; Bis (2,3-dimercaptopropanyl) disulfide; 1,2-bis (2-mercaptoethylthio) -3-mercaptopropane; 1,2-bis (2- (2-mercaptoethylthio) -3-mercaptopropylthio) ethane; Bis (2- (2-mercaptoethylthio) -3-mercaptopropyl) sulfide; 2- (2-mercaptoethylthio) -3-2-mercapto-3- [3-mercapto-2- (2-mercaptoethylthio) -propylthio] propylthio-propane-1-thiol; 2,2 -bis- (3-mercapto-propionyloxymethyl) -butyl ester; 2- (2-mercaptoethylthio) -3- (2- (2- [3-mercapto-2- (2-mercaptoethylthio) -propylthio] ethylthio) ethylthio) propane-1-thiol ; (4R, 11S) -4,11-bis (mercaptomethyl) -3,6,9,12-tetrathiatetradecane-1,14-dithiol; (S) -3-((R-2,3-dimercaptopropyl) thio) propane-1,2-dithiol; (4R, 14R) -4,14-bis (mercaptomethyl) -3,6,9,12,15-pentathiaheptan-1,17-dithiol, (S) -3-((R-3- Mercapto-2-((2-mercaptoethyl) thio) propyl) thio) propyl) thio) -2-((2-mercaptoethyl) thio) propane-1-thiol; 3,3'-dithiobis (propane-1,2-dithiol); (7R, 11S) -7,11-Bis (mercaptomethyl) -3,6,9,12,15-pentatahetan-1,17-dithiol; (7R, 12S) -7, 12-bis (mercaptomethyl) -3,6,9,10,13,16-hexathiaoctadecane-1,18-dithiol; 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaoundecan; 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaoundecan; 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaoundecan; Pentaerythritol tetrakis (3-mercaptopropionate); Trimethylolpropane tris (3-mercaptopropionate); Pentaerythritol tetrakis (2-mercaptoacetate); Bispentaerythritol-ether-hexakis (3-mercaptopropionate); 1,1,3,3-tetrakis (mercaptomethylthio) propane; 1,1,2,2-tetrakis (mercaptomethylthio) ethane; 1 type selected from the group consisting of 4,6-bis (mercaptomethylthio) -1,3-dithiane and 2- (2,2-bis (mercaptodimethylthio) ethyl) -1,3-diethane Or two or more compounds. Preferably, the thiol compound is 2- (2-mercaptoethylthio) propane-1,3-dithiol; 2,3-bis (2-mercaptoethylthio) propane-1-thiol; 2- (2,3-bis (2-mercaptoethylthio) propylthio) ethanethiol; 1,2-bis (2-mercaptoethylthio) -3-mercaptopropane; 1,2-bis (2- (2-mercaptoethylthio) -3-mercaptopropylthio) -ethane; Bis (2- (2-mercaptoethylthio) -3-mercaptopropyl) sulfide; 2- (2-mercaptoethylthio) -3-2-mercapto-3- [3-mercapto-2- (2-mercaptoethylthio) -propylthio] propylthio-propane-1-thiol; 2,2'- thiodiethanethiol; 4,14-bis (mercaptomethyl) -3,6,9,12,15-pentathiahexadecane-1,17-dithiol; 2- (2-mercaptoethylthio) -3- [4- (1- {4- [3-mercapto-2- (2-mercaptoethylthio) -propoxy] -phenyl} -1-methylethyl ) -Phenoxy] -propane-1-thiol; Pentaerythritol tetrakis (3-mecapcaptopropionate); Pentaerythritol mecapcaptoacetate; Trimetholol propane trismecaptopropionate; Glycerol trimecaptopropionate; Compounds such as dipenta epitritol hexamecapcaptopropionate may be used alone or in combination of two or more thereof. In addition, a compound in which some unreacted hydroxy groups are mixed may be included.

The polymerizable composition of the present invention may further contain an isocyanate compound. As the isocyanate compound, a general-purpose isocyanate compound which is supplied at low cost may be used. For example, an isocyanate compound is 2, 5-bis (isocyanatomethyl) bicyclo [2, 2, 1] heptane (NBDI); Isophorone diisocyanate; Dicyclohexylmethane-4,4'-diisocyanate (H ₁₂ MDI); Hexamethylene diisocyanate; Methylcyclohexanediisocyanate; Tolylene diisocyanate; Phenylene diisocyanate; 1,3,5-tris (6-isocyanato-hexyl)-[1,3,5] -trigianan-2,4,6-trione (HDI trimer); One or two or more isocyanates selected from the group consisting of o, m, p-xylene diisocyanate and tetramethylxylylene diisocyanate (TMXDI) can be used alone or together.

However, the isocyanate compound usable in the polymerizable composition of the present invention is not limited to the above-mentioned general purpose isocyanate compound, and any compound can be used as long as it is a compound having at least one isocyanate and / or iso (thio) cyanate group. That is, one or two or more different iso (thio) cyanate compounds may be included instead of the general purpose isocyanate compound or together with the general purpose isocyanate compound. For example, such other iso (thio) cyanate compounds include 2,2-dimethylpentane diisocyanate; 2,2,4-trimethylhexanediisocyanate; Butane diisocyanate; 1,3-butadiene-1,4-diisocyanate; 2,4,4-trimethylhexamethylene diisocyanate; 1,6,11-undectriisocyanate; 1,3,6-hexamethylenetriisocyanate; 1,8-diisocyanate-4-isocyanatomethyloctane; Bis (isocyanatoethyl) carbonate; Aliphatic isocyanate compounds containing bis (isocyanatoethyl) ether,

1,2-bis (isocyanatomethyl) cyclohexane; 1,3-bis (isocyanatomethyl) cyclohexane; 1,4-bis (isocyanatomethyl) cyclohexane; Cyclohexanediisocyanate; Methylcyclohexanediisocyanate; Dicyclohexyldimethylmethane isocyanate; Alicyclic isocyanate compounds containing 2,2-dimethyldicyclohexylmethane isocyanate,

Bis (isocyanatobutyl) benzene; Bis (isocyanatomethyl) naphthalene; Bis (isocyanatomethyl) diphenyl ether; Phenylene diisocyanate; Ethylphenylene diisocyanate; Isopropylphenylene diisocyanate; Dimethylphenylene diisocyanate; Diethylphenylene diisocyanate; Diisopropylphenylene diisocyanate; Trimethylbenzenetriisocyanate; Benzenetriisocyanate; Biphenyl diisocyanate; Toluidine diisocyanate; 4,4-diphenylmethane diisocyanate; 3,3-dimethyldiphenylmethane-4,4-diisocyanate; Bibenzyl-4,4-diisocyanate; Bis (isocyanatophenyl) ethylene; 3,3-dimethoxybiphenyl-4,4-diisocyanate; Hexahydrobenzene diisocyanate; Aromatic isocyanate compounds containing hexahydrodiphenylmethane-4,4-diisocyanate,

Bis (isocyanatoethyl) sulfide; Bis (isocyanatopropyl) sulfide; Bis (isocyanatohexyl) sulfide; Bis (isocyanatomethyl) sulfone; Bis (isocyanatomethyl) disulfide; Bis (isocyanatopropyl) disulfide; Bis (isocyanatomethylthio) methane; Bis (isocyanatoethylthio) methane; Bis (isocyanatoethylthio) ethane; Bis (isocyanatomethylthio) ethane; Sulfur-containing aliphatic isocyanate compounds containing 1,5-diisocyanato-2-isocyanatomethyl-3-thiapentane,

Diphenylsulfide-2,4-diisocyanate; Diphenylsulfide-4,4-diisocyanate; 3,3-dimethoxy-4,4-diisocyanatodibenzylthioether; Bis (4-isocyanatomethylbenzene) sulfide; 4,4-methoxybenzenethioethylene glycol-3,3-diisocyanate; Diphenyldisulfide-4,4-diisocyanate; 2,2-dimethyldiphenyldisulfide-5,5-diisocyanate; 3,3-dimethyldiphenyldisulfide-5,5-diisocyanate; 3,3-dimethyldiphenyldisulfide-6,6-diisocyanate; 4,4-dimethyldiphenyldisulfide-5,5-diisocyanate; 3,3-dimethoxy diphenyldisulfide-4,4-diisocyanate; Sulfur-containing aromatic isocyanate compounds containing 4,4-dimethoxydiphenyldisulfide-3,3-diisocyanate, and

2,5-diisocyanatothiophene; 2,5-bis (isocyanatomethyl) thiophene; 2,5-diisocyanatotetrahydrothiophene; 2,5-bis (isocyanatomethyl) tetrahydrothiophene; 3,4-bis (isocyanatomethyl) tetrahydrothiophene; 2,5-diisocyanato-1,4-dithiane; 2,5-bis (isocyanatomethyl) -1,4-dithiane; 4,5-diisocyanato-1,3-dithiolane; 4,5-bis (isocyanatomethyl) -1,3-dithiolan; Sulfur-containing heterocyclic isocyanate compounds containing 4,5-bis (isocyanatomethyl) -2-methyl-1,3-dithiolane

One or two or more iso (thio) cyanate compounds selected from the group consisting of can be used.

The polymerizable composition of the present invention may be composed of a thiepoxy polymerizable composition by further including a thioepoxy compound. There is no particular limitation on the thioepoxy compound. The thioepoxy compound is, for example, bis (2, 3- epithiopropyl) sulfide; Bis (2,3-epiopropyl) disulfide; 2,3-epidithiopropyl (2,3-ethiothiopropyl) disulfide; 2,3- epidithiopropyl (2,3- epithiopropyl) sulfide; 1,3 and 1,4-bis (β-ethiothiopropylthio) cyclohexane; 1,3 and 1,4-bis (β-ethiothiopropylthiomethyl) cyclohexane; Bis [4- (β-epithiopropylthio) cyclohexyl] methane; 2,2-bis [4- (β-ethiothiopropylthio) cyclohexyl] propane; Episulfide compounds having an alicyclic skeleton such as bis [4- (β-epithiopropylthio) cyclohexyl] sulfide, 1,3 and 1,4-bis (β-ethiothiopropylthiomethyl) benzene; Bis [4- (β-epithiopropylthio) phenyl] methane; 2,2-bis [4- (β-ethiothiopropylthio) phenyl] propane; Bis [4- (β-epithiopropylthio) phenyl] sulfide; Bis [4- (β-epithiopropylthio) phenyl] sulpin; Episulfide compounds having an aromatic skeleton such as 4,4-bis (β-epithiopropylthio) biphenyl, 2,5-bis (β-ethiothiopropylthiomethyl) -1,4-dithiane; 2,5-bis (β-epithiopropylthioethylthiomethyl) -1,4-dithiane; 2,5-bis (β-epithiopropylthioethyl) -1,4-dithiane; Episulfide compounds having a dithiane chain skeleton such as 2,3,5-tri (β-epithiopropylthioethyl) -1,4-dithiane, 2- (2-β-epithiopropylthioethylthio) -1,3-bis (β-epithiopropylthio) propane; 1,2-bis [(2-β-ethiothiopropylthioethyl) thio] -3- (β-ethiothiopropylthio) propane; Tetrakis (β-epithiopropylthiomethyl) methane; 1,1,1-tris (β-ethiothiopropylthiomethyl) propane; And an episulfide compound having an aliphatic skeleton such as bis- (β-epithiopropyl) sulfide. In addition to the thioepoxy compound, halogen substituents such as chlorine substituents and bromine substituents, alkyl substituents, alkoxy substituents, nitro substituents and prepolymer-modified compounds with polythiol may be used.

The polymerizable composition of the present invention is a polymerizable composition containing, as a main component, a thiol compound of the present invention and a compound such as an isocyanate compound capable of polymerization reaction thereof, and an internal mold release agent, an ultraviolet absorber, a polymerization initiator, a dye, and a stabilizer, if necessary. It may further include an optional component such as a bluing agent.

The internal mold release agent may preferably include a phosphate ester compound. Phosphate ester is prepared by adding 2-3 moles of alcohol compound to phosphorus pentoside (P ₂ O ₅ ). There may be various types of phosphate ester compounds depending on the type of alcohol used. Typical examples include those in which ethylene oxide or propylene oxide is added to the aliphatic alcohol, or ethylene oxide or propylene oxide is added to the nonylphenol group. When the phosphate ester compound added with ethylene oxide or propylene oxide is included in the composition of the present invention as an internal mold release agent, an optical material having good release property and excellent quality can be obtained.

UV absorbers may be included in the polymerizable composition of the present invention for improving the light resistance of the optical material and blocking ultraviolet rays. As the ultraviolet absorber, a known ultraviolet absorber can be used without limitation. For example, ethyl-2-cyano-3,3-diphenyl acrylate; 2- (2'-hydroxy-5-methylphenyl) -2H-benzotriazole; 2- (2'-hydroxy-3 ', 5'-di-t-butylphenyl) -5-chloro-2H-benzotriazole; 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chloro-2H-benzotriazole; 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) -2H-benzotriazole; 2- (2'-hydroxy-3 ', 5'-di-t-butylphenyl) -2H-benzotriazole; 2- (2'-hydroxy-5'-t-butylphenyl) -2H-benzotriazole; 2- (2'-hydroxy-5'-t-octylphenyl) -2H-benzotriazole; 2,4-dihydroxybenzophenone; 2-hydroxy-4-methoxybenzophenone; 2-hydroxy-4-octyloxybenzophenone; 4-dodecyloxy-2-hydroxybenzophenone; 4-benzooxy-2-hydroxybenzophenone; 2,2 ', 4,4'-tetrahydroxybenzophenone; 2,2'- dihydroxy-4,4'- dimethoxy benzophenone etc. can be used individually or in mixture of 2 or more types. More preferably, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl)-has good ultraviolet absorption in the wavelength range of 400 nm or less and has good solubility in the composition of the present invention. 5-chloro-2H-benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) -2H-benzotriazole and the like can be used. Such an ultraviolet absorber can block 400 nm or more when used in an amount of 0.6 g or more with respect to 100 g of the optical resin composition.

The polymerization initiator may be an amine or tin compound. As a tin type compound, Butyl tin dilaurate; Dibutyl tin dichloride; Dibutyl tin diacetate; Stannous oxyl acid; Dibutyl dilaurate; Tetrafluorotin; Tetrachlorotin; Tetrabromotin; Tetraiodine tin; Methyl tin trichloride; Butyltin trichloride; Dimethyltin dichloride; Dibutyltin dichloride; Trimethyltin chloride; Tributyltin chloride; triphenyltin chloride; Dibutyltin sulfide; Di (2-ethylsecyl) tin oxide and the like may be used alone or in combination of two or more thereof.

The optical material of the present invention can be produced by, for example, injecting and curing a polymerizable composition containing a thiol compound, an isocyanate compound of the present invention, and optional components selected as necessary into a mold for a lens. Moreover, it is also possible to further mix and polymerize here the epoxy compound, the thioepoxy compound, the compound which has a vinyl group or an unsaturated group, a metal compound, etc. which are copolymerizable with a urethane resin composition. The urethane-based optical material, for example, the urethane-based lens produced in the present invention is produced by mold polymerization. Specifically, after dissolving various additives and catalysts in an isocyanate compound, vacuum degassing is performed while adding a thiol compound and cooling. Then, after a suitable time elapses, the glass mold is molded into a tape and cured by slowly applying heat from low temperature to high temperature for about 24 to 48 hours.

The urethane-based optical material produced by the present invention is characterized by low dispersion at high refractive index, excellent heat resistance and durability, light weight and excellent impact resistance, and good color. Therefore, it is suitable for the use of the urethane type optical lens, prism, etc. which concerns on this invention, and is especially suitable for the lens use, such as a spectacle lens and a camera lens.

 The urethane-based optical material of the present invention is also very low in tape whitening and bubbles, it can be produced in a good yield. The optical material of the present invention may be subjected to surface polishing, antistatic treatment, hard coat treatment, for the purpose of improving antireflection, high hardness, abrasion resistance, chemical resistance, antifouling, or fashion, as necessary. Physical and chemical treatments such as anti-reflective coating treatment, dyeing treatment, and dimming treatment can be performed.

Hereinafter, the present invention will be described in more detail with reference to specific examples. However, these examples are only for illustrating the present invention in more detail, the scope of the present invention is not limited by these examples.

Assessment Methods

Refractive index (nd and nE) and Abbe number: It was measured at 20 ° C. using an Abbe refractometer, an IT and DR-M4 model of Atago.

Initial heat deflection temperature (Tg): TMA was measured under high purity nitrogen using a penetration probe of TMAQ400 (TA instruments) at a load of 0.5 N, a pin tip of 0.5 mm, and an elevated temperature of 5 ° C / min.

Synthesis Example 1

BMHS1 (Bis (2-mercaptocaptoethyl) -2-hydroxysuccinate (bis (2-mercaptoethyl) -2-hydroxysuccinate))

A Dean-stark device was mounted in a 1 L reactor capable of temperature control, malic acid (134.09 g, 1.00 mol), 2-mercaptoethanol (156.26 g, 2.00 mol), toluene 130 g, p-toluene sulphonic acid (11.41 g, 0.06 mol) was added and stirred, and the mixture was reacted for 7 hours while maintaining the reduced pressure at 100 torr and the internal temperature of 50 ° C. The water produced in the reaction was reacted while removing water using Dean-stark apparatus. The reaction was terminated when 36 g of theoretical water produced and the starting material 2-mercaptoethanol disappeared on HPLC. At the end of the reaction, the reactor was cooled down and at room temperature, the catalyst was removed by slowly neutralizing with 200 g of 5 wt% NaHCO ₃ (aq) to remove the remaining p-toluenesulfonic acid, followed by deionized water to remove salt. The organic layer was washed three times with 100 g of pure water and concentrated under reduced pressure to give 203 g of a thiol compound. The yield was 80%, and the refractive index (nd, 20 ° C.) was 1.527.

Synthesis Example 2

BMHS2 (Bis (2-mercaptocaptoethyl) -2-hydroxysuccinate (bis (2-mercaptoethyl) -2-hydroxysuccinate))

The Dean-stark apparatus was mounted in a 1 L reactor capable of temperature control, and was equipped with malic acid (134.09 g and 1.00 moles), 2-mercaptoethanol (160.20 g and 2.05 moles), toluene 200 g, and p-toluene sulphonic acid (11.41 g, 0.06 mol) was added and stirred, and the mixture was reacted for 7 hours while maintaining the reduced pressure at 100 torr and the internal temperature of 50 ° C. The water produced in the reaction was reacted while being removed from the reactant using a Dean-stark apparatus. The reaction was terminated when the amount of theoretical water and the starting material 2-mercaptoethanol disappeared on HPLC. At the end of the reaction, the reactor was cooled down, and upon reaching room temperature, the catalyst was removed by slowly neutralizing with 200 g of 5 wt% NaHCO ₃ (aq) to remove the remaining p-toluenesulfonic acid, and deionized water to remove salt. The organic layer was washed three times with 100 g of pure water and concentrated under reduced pressure to give 212 g of a thiol compound. The yield was 83%, and the refractive index (nd, 20 ° C.) was 1.527.

EXAMPLE

The thiol compound, the isocyanate compound, and the additive prepared in the synthesis example were mixed in the composition as shown in Table 1, and the polymerization was carried out to prepare a urethane-based optical lens, and the refractive index and the Abbe's number were evaluated.

Example 1

53.37 g of the compound (BMHS1), 2,5 (6) -bis (isocyanatomethyl) bicyclo [2.2.1] heptane (NBDI) prepared in Synthesis Example 1, zere UN 0.12 g as a release agent, and an ultraviolet absorber 1.50 g of 2- (2'-hydroxy-5-methylphenyl) -2H-benzotriazole, 0.05 dibutyltin dichloride as a polymerization initiator, 1-hydroxy-4-paris-toluidine) as an organic dye, anthraquinone (Blue ) 20 ppm and 10 ppm of perinone dye were placed in a mixing vessel equipped with a stirrer and replaced with nitrogen to remove air in the mixing vessel. The mixed solution was defoamed at 1 torr for 1 hour. Then, it filtered by the 1 micrometer PTFE filter, and inject | poured into the glass mold fixed with tape. The mold was charged into a polymerization oven, and gradually heated to 25 ° C to 130 ° C over 21 hours to polymerize. After the end of the polymerization, the mold was taken out of the oven. Mold release from the mold was good, and the obtained resin was further annealed at 130 ° C for 4 hours. The physical properties of the obtained resin had a refractive index (nE) of 1.559, an Abbe number (υe) 44, and an initial heat deformation temperature (Tg) of 120 ° C.

Examples 2-3

Except that according to the composition described in Table 1 below, the composition and the optical lens were prepared and evaluated in the same manner as in Example 1, and the results are shown in Table 1 below.

Table 1

<Abbreviation>

BMHS : (bis (2-mercaptocaptoethyl) -2-hydroxysuccinate (bis (2-mercaptoethyl) -2-hydroxysuccinate))

PETMP: pentaerythritol tetra (3-mercaptopropionate) (pentaerythritol tetra (3-mercaptopropionate))

H ₁₂ MDI: dicyclohexyl methane-4,4'-diisocyanate

HDI: Hexamethylene diisocyanate

NBDI: 2,5 (6) -bis (isocyanatomethyl) bicyclo [2.2.1] heptane (2,5 (6) -Bis (isocyanatomethyl) bicyclo [2.2.1] heptane)

HOPBT: 2- (2'-hydroxy-5'-t-octylphenyl) -2H-benzotriazole (2- (2'-hydroxy-5'-t-octylphenyl) -2H-benzotriazole)

HTAQ: 1-hydroxy-4- (p-tolludine) -entroquinone (1-hydroxy-4- (p-toluidine) anthraquinone)

PRD: perinone dye

As can be seen from Table 1, the plastic material obtained from the polymerizable composition containing the thiol compound of the present invention was clear and transparent in color, high initial heat deformation temperature and excellent heat resistance. These results indicate that when the thiol compound of the present invention is used as a main component of the polymerizable composition for a urethane-based optical lens, an optical lens having excellent optical characteristics can be manufactured at low cost. The thiol compound of the present invention can be widely applied to a transparent plastic material having a refractive index, including a low-cost urethane-based optical lens.

The thiol compound of the present invention and the polymerizable composition including the same are suitable for the production of urethane-based plastic materials satisfying both quality and economy, and are particularly suitable for the production of urethane-based plastic materials requiring colorless transparency and high or medium refractive index. Specifically, the present invention provides a variety of optical materials such as recording media substrates, color filters, UV absorbing filters, such as spectacle lenses, polarizing lenses, camera lenses, prisms, optical fibers, LCDs, optical disks, magnetic disks, LCDs, monitor screens, It can be widely used in a field where a transparent plastic such as a surface protective cover of an electronic product is required.

Claims (12)

1. Thiol compound represented by the formula (1) below.

   [Formula 1]

   
2. Method of preparing a thiol compound represented by the following formula (1) comprising the step of putting malic acid and 2-mercaptoethanol in a reactor and esterification under elevated temperature and reduced pressure.

   [Formula 1]

   
3. Polymerizable composition comprising a thiol compound represented by the formula (1) below.

   [Formula 1]

   
4. The polymerizable composition of claim 3 further comprising an isocyanate compound.
5. The polymerizable composition of claim 3 further comprising a thioepoxy compound.
6. The method of claim 4, wherein the isocyanate compound is 2,5-bis (isocyanatomethyl) bicyclo [2,2,1] heptane, isophorone diisocyanate, dicyclohexyl methane-4,4'- diisocyanate, Hexamethylene diisocyanate, methylcyclohexane diisocyanate, tolylene diisocyanate, phenylene diisocyanate, 1,3,5-tris (6-isocyanato-hexyl)-[1,3,5] -triziane-2,4 The polymerizable composition which is 1 type, or 2 or more types of compounds chosen from the group which consists of a 6-trione, o, m, p-xylene diisocyanate, and a tetramethyl xylylene diisocyanate.
7. The polymerizable composition according to any one of claims 3 to 5, further comprising another thiol compound in addition to the thiol compound represented by Chemical Formula 1.
8. The method of claim 7, wherein the other thiol compound,

   A thiol compound represented by Formula 2 below, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 2,3-bis (2-mercaptoethylthio) -3-propane-1-thiol, 2,2-bis ( Mercaptomethyl) -1,3-propanedithiol, bis (2-mercaptoethyl) sulfide, tetrakis (mercaptomethyl) methane; 2- (2-mercaptoethylthio) propane-1,3-dithiol, 2- (2,3-bis (2-mercaptoethylthio) propylthio) ethanethiol, bis (2,3-dimercapto Propaneyl) sulfide, bis (2,3-dimercaptopropanyl) disulfide, 1,2-bis (2-mercaptoethylthio) -3-mercaptopropane, 1,2-bis (2- (2- Mercaptoethylthio) -3-mercaptopropylthio) ethane, bis (2- (2-mercaptoethylthio) -3-mercaptopropyl) sulfide, 2- (2-mercaptoethylthio) -3-2 -Mercapto-3- [3-mercapto-2- (2-mercaptoethylthio) -propylthio] propylthio-propane-1-thiol, 2,2-bis- (3-mercapto-propionyloxy Methyl) -butyl ester, 2- (2-mercaptoethylthio) -3- (2- (2- [3-mercapto-2- (2-mercaptoethylthio) -propylthio] ethylthio) ethylthio Propane-1-thiol, (4R, 11S) -4,11-bis (mercaptomethyl) -3,6,9,12-tetrathiatetradecane-1,14-dithiol, (S) -3- ((R-2,3-dimercaptopropyl) thio) propane-1,2-dithiol, (4 R, 14R) -4,14-bis (mercaptomethyl) -3,6,9,12,15-pentathiaheptan-1,17-dithiol, (S) -3-((R-3-mer Capto-2-((2-mercaptoethyl) thio) propyl) thio) propyl) thio) -2-((2-mercaptoethyl) thio) propane-1-thiol, 3,3'-dithiobis (propane -1,2-dithiol), (7R, 11S) -7,11-bis (mercaptomethyl) -3,6,9,12,15-pentatahetan-1,17-dithiol, (7R, 12S) -7,12-bis (mercaptomethyl) -3,6,9,10,13,16-hexathiaoctadecane-1,18-dithiol, 5,7-dimercaptomethyl-1,11 -Dimercapto-3,6,9-trithiaoundecan, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaoundecan, 4,8-dimer Captomethyl-1,11-dimercapto-3,6,9-trithiaoundecan, pentaerythritol tetrakis (3-mercaptopropionate), trimethylolpropane tris (3-mercaptopropionate ), Pentaerythritol tetrakis (2-mercaptoacetate), bispentaerythritol-ether-hexakis (3-mercaptopropionate), 1,1, 3,3-tetrakis (mercaptomethylthio) propane, 1,1,2,2-tetrakis (mercaptomethylthio) ethane, 4,6-bis (mercaptomethylthio) -1,3-dithiane And 2- (2,2-bis (mercaptodimethylthio) ethyl) -1,3-diethane. The polymerizable composition of claim 1 or 2 or more compounds selected from the group consisting of.

   [Formula 2]

   

   (A, B, C, D is H or OH, X, Y is O or S, and m is an integer from 1 to 10.)
9. The polymerizable composition according to any one of claims 3 to 5, further comprising a ultraviolet absorber.
10. The plastic material obtained by superposing | polymerizing the polymeric composition of any one of Claims 3-5.
11. An optical lens made of the plastic material of claim 10.
12. The optical lens of claim 11, wherein the optical lens is an eyeglass lens.