WO2021206269A1 - Method for producing polythiol compound, polymerizable composition for optical material including same, and optical lens - Google Patents

Abstract

A thiol-based composition for an optical material according to the present invention is characterized by including a compound of chemical formula 1 and a compound of chemical formula 2.

Description

Method for producing polythiol compound, polymerizable composition for optical material including same, and optical lens

The present invention relates to a method for producing a polythiol compound, and to a polymerization composition for an optical material using the polythiol compound. In particular, a lens manufactured using the polythiol compound is clear and transparent, has a uniform color, and is a high-purity poly The present invention relates to a method and a composition for an optical material capable of producing a thiol compound inexpensively and having excellent optical properties with high heat resistance and high refractive index and ultra-high refractive index.

Lenses using plastic optical materials are lighter than optical materials made of inorganic materials such as glass, do not break easily, and can be dyed. is being used

In modern times, as the demand for lighter, higher performance and convenience plastic materials increases, research on optical materials with characteristics such as high stability, transparency, high refractive index, and low cost is continuing, and thiol compounds have excellent optical properties. For this reason, it is widely used as an optical material.

An optical lens obtained by polymerization of a thiol compound and an isocyanate compound is widely used as an optical lens material having excellent optical properties such as transparency, Abbe's number, transmittance, heat resistance, and tensile properties. In addition, there is a problem that the heat resistance of the 1.67 refractive index lens of the plastic optical material to which the conventionally known thiol-based compound is applied is as low as 100 ° C. it is necessary.

As such a thiol-based compound, thiol-based compounds having various structures are known, and related preparation methods are also known in various ways. It is known that a thiol compound having a relatively high yield (87%) can be obtained when a compound containing a double unsaturated carbon bond is synthesized using a radical reaction and prepared by thiourea reaction. However, such a radical reaction still has problems such as low purity and low yield, and yellowing of by-products generated during the reaction.

In addition, as mentioned above, the plastic optical material to which the conventionally known thiol-based compound is applied has a problem with low heat resistance of 100° C. or less, so there is a limitation in applying it to a high-temperature process. development is needed.

(Patent Document 1) Republic of Korea Patent Publication No. 10-2014-0141723

(Patent Document 2) Republic of Korea Patent Publication No. 10-2013-0050263

(Patent Document 3) Republic of Korea Patent Publication No. 10-0078120

(Patent Document 4) Republic of Korea Patent Publication No. 10-2017-0008679

(Patent Document 5) International Patent Publication WO 2013/176506 A1

(Patent Document 6) US Patent Publication No. US005608115A

An object of the present invention is to provide a method for preparing a composition containing a thiol compound having remarkably excellent heat resistance when applied to an optical material.

Another object of the present invention is to provide a method for preparing a composition containing a thiol compound having a high Abbe number when applied to an optical material.

Another object of the present invention is to provide a method for preparing a composition containing a thiol compound that meets the refractive index of a standard standard when applied to an optical material.

Another object of the present invention is to provide a method for preparing a composition containing a thiol compound having excellent yield and purity.

In the method for producing a polythiol compound of the present invention, as shown in Scheme 1 below, 2-mercaptoethanol and epichlorohydrin are reacted to obtain a diol compound, and the compound obtained by substituting hydrogen sulfide for the obtained compound is added to epichlorohydrin. A process to obtain a polyalcohol compound by reacting the polyalcohol compound, a reaction containing an isothiuronium salt by reacting the obtained polyalcohol compound with thiourea and a hydrolysis reaction of the isothiuronium salt with ammonia water, so that the molecular weight is uniform and contains less polyol A polythiol compound of the following Scheme 1 can be prepared.

The method for preparing the polythiol compound of the present invention can be represented by Scheme 1.

[Scheme 1]

In Scheme 1, R ₁ is an unsubstituted alcohol group having 2 to 3 carbon atoms.

In Scheme 1, R ₂ is a halogen atom

The polythiol compound obtained by the above production method obtains a polythiol compound in which two positional isomers are mixed.

The present invention relates to a method for preparing a thiol-based composition for an optical material comprising the compound of Formula 1 as a starting material as epichlorohydrin.

[Formula 1]

The thiol-based composition for an optical material prepared by the method for preparing a composition for an optical material according to an embodiment of the present invention may further include a compound of Formula 2 below.

[Formula 2]

The thiol-based composition prepared by the method for preparing a thiol-based composition for an optical material according to an embodiment of the present invention may contain 4 to 7 parts by weight of the compound of Formula 2 based on 100 parts by weight of the compound of Formula 1 above.

The method for preparing a composition containing a thiol-based compound for an optical material according to an embodiment of the present invention is

A first step of reacting epichlorohydrin with mercapto alcohol;

a second step of reacting the product of the first step with a hydrogen sulfide salt to replace the chlorine at the end with a hydrogen sulfide group, and reacting with epichlorohydrin; and

and a third step of reacting the compound produced in the second step with thiourea.

In the method for preparing a composition containing a thiol-based compound for an optical material according to an embodiment of the present invention, the molar ratio of the hydrogen sulfide salt to the compound prepared in the first step may be 1:1 to 1.2.

The present invention also provides an optical material, and the optical material according to the present invention may be prepared by the method for producing a thiol-based compound for an optical material according to an embodiment of the present invention.

The optical material according to an embodiment of the present invention may be characterized in that the heat resistance temperature is 100 ℃ or more.

The optical lens prepared by using the composition containing the thiol-based compound prepared according to the present invention was clear and transparent and had excellent color. In particular, the composition containing the thiol-based compound prepared in the present invention has excellent polymerizability with each polyisocyanate, so it is suitable for high-refractive ultra-high refractive (1.60, 1.67) lenses. It was possible to manufacture optical lenses with high purity and excellent thermal stability. In addition, the optical material obtained according to the present invention has excellent impact resistance, heat resistance, moldability, dyeability, and light transmittance, and thus can be used in various fields.

1 shows the IR spectrum results of the compound of Formula 1 prepared by the preparation method according to an embodiment of the present invention.

2 shows the mass spectrum results of the compound of Formula 1 prepared by the preparation method according to an embodiment of the present invention.

^{3 shows 1} H-NMR results of the compound of Formula 1 prepared by the preparation method according to an embodiment of the present invention.

^{4 shows 13} C-NMR results of the compound of Formula 1 prepared by the preparation method according to an embodiment of the present invention.

Advantages and features of embodiments of the present invention, and methods of achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

In describing the embodiments of the present invention, if it is determined that a detailed description of a well-known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms to be described later are terms defined in consideration of functions in an embodiment of the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification. The composition containing the thiol-based compound for optical materials according to the present invention is prepared from epichlorohydrin as a starting material, and the compound of Formula 1 is include

[Formula 1]

In addition, the composition containing the thiol-based compound for an optical material according to the present invention is characterized in that epichlorohydrin is used as a starting material, and the compound of formula 1 is prepared through reaction with mercapto alcohol, hydrogen sulfide, etc., which will be described later. can do. When the compound of Formula 1 is prepared in this way, there is an advantage that the compound of Formula 1 can be prepared in a remarkably high yield of 90% or more. It has characteristics that indicate

The composition containing the thiol-based compound for an optical material according to an embodiment of the present invention further includes a compound of Formula 2 below.

[Formula 2]

The compound of Formula 2 is produced as a by-product as a structural isomer of Formula 1 in the process of preparing the compound of Formula 1, and finally, the composition containing the thiol-based compound for an optical material is a composition containing the compound of Formula 1 and the compound of Formula 2 simultaneously. There is an advantage that can exhibit higher heat resistance by including.

In the composition containing the thiol-based compound for an optical material according to an embodiment of the present invention, 4 to 7 parts by weight of the compound of Formula 2 may be included relative to 100 parts by weight of the compound of Formula 1, preferably the compound of Formula 2 5 to 6 parts by weight may be included. By satisfying this range, the thiol-based compound for an optical material according to an embodiment of the present invention can exhibit high heat resistance, and also exhibit refractive indices close to 1.60 and 1.67 meeting international standards, and exhibit a high Abbe's number. There is a characteristic.

The method for preparing a composition containing a thiol-based compound for an optical material according to an embodiment of the present invention specifically includes a first step of reacting epichlorohydrin with mercapto alcohol;

a second step of reacting the product of the first step with a hydrogen sulfide salt to replace the chlorine at the end with a hydrogen sulfide group, and reacting with epichlorohydrin; and

and a third step of reacting the compound produced in the second step with thiourea.

The method for preparing a thiol-based compound according to the present invention uses epichlorohydrin as a starting material, and by sequentially including the first to third steps, the yield of formula 1 and chemistry 2 is greater than 90%, preferably greater than or equal to 92%. There is an advantage of being able to prepare a thiol-based composition containing a compound of

In the method for preparing a thiol-based compound according to an embodiment of the present invention, the first step is to open the epoxy group of epichlorohydrin to form a terminal hydroxyl group. At this time, the molar ratio of mercapto alcohol: epichlorohydrin may be 1:1, and by satisfying the above-mentioned range, the ratio of mercapto alcohol or epichlorohydrin that is discarded without reaction is minimized and thiol-based compound is prepared in high yield There are possible advantages.

At this time, the reaction temperature may be 20 ℃ or less, preferably 5 to 10 ℃, there is a possibility that side reactions may occur when the temperature is too high, and a problem that the reaction rate is slowed when the temperature is low may occur.

The method for preparing Formula 1 according to an embodiment of the present invention includes a second step of reacting the product of the first step with a hydrogen sulfide salt to replace the chlorine at the end with a hydrogen sulfide group, and reacting with epichlorohydrin. In this case, the chlorine at the terminal is derived from epichlorohydrin. Specifically, the second step includes a step 2-1 of reacting the product of the first step with a hydrogen sulfide salt to replace the chlorine at the end with a hydrogen sulfide group, and a step 2-2 of reacting with epichlorohydrin after substitution with a hydrogen sulfide group. .

In this case, the hydrogen sulfide salt includes a -SH group and a cation and can be used without limitation if it is a compound that is soluble in water, and the cation may be lithium, sodium, potassium, calcium or magnesium, preferably lithium, sodium or potassium. may be, but the present invention is not limited thereto.

Specifically, the second step includes the step of slowly adding the compound prepared in the first step to a solution in which the hydrogen sulfide salt is dissolved, and the molar ratio of the hydrogen sulfide salt to the compound prepared in the first step is 1:1 to 1.2. can be

Step 2-1 may be performed at a temperature of 40 to 60 ° C. for 3 to 10 hours, and when the temperature is too high, there is a risk of side reactions, and when the temperature is too low, a problem of lengthening the reaction time may occur. .

In addition, step 2-2 includes adding sodium hydroxide to the product of step 2-1, and then further adding epichlorohydrin, wherein the product of step 2-1: sodium hydroxide: epichlorohydrin The molar ratio of dried may be 1: 0.5: 0.5. By satisfying the above-described addition ranges of sodium hydroxide and epichlorohydrin, there is an advantage in that the production of by-products is blocked and the thiol-based compound can be prepared in a high yield.

In the case of the addition of sodium hydroxide and epichlorohydrin, the temperature of step 2-2 may be carried out at 5 to 10 °C, and then the reaction may proceed while stirring at a temperature of 35 to 50 °C.

a third step of reacting the compound produced in the second step with thiourea; and, through the three steps, the -OH group included at the end of the product of the second step can be substituted with a -SH group, Finally, the desired compound of Formula 1 can be prepared.

In this case, the third step can be used without limitation in the case of a method of substituting a -OH group with a -SH group using a commonly known thiourea, and the present invention is not limited thereto.

Specifically, the third step includes a step of stirring the product of the second step in a container by adding hydrochloric acid and thiourea and raising the temperature. In this case, the molar ratio of the product of the second step: hydrochloric acid: thiourea may be 1: 5.5: 5.5 to 1: 6: 6, and in this range, the unsubstituted hydroxyl group is prevented from remaining and the thiol-based compound is produced in a high yield. There are advantages to manufacturing. In addition, after the addition of hydrochloric acid and thiourea is completed, the reaction may be performed by raising the temperature to 90 to 110° C. In this case, the reaction may be performed for 4 to 8 hours, but the present invention is not limited thereto.

The method for producing a thiol-based compound according to an embodiment of the present invention may further include a washing step of washing the product generated after the third step, wherein the washing may use an aqueous hydrochloric acid solution, brine, etc., but the present invention does not It is not limited.

The present invention also provides an optical material, the optical material according to the present invention is an optical material according to an embodiment of the present invention, a thiol and an isocyanate compound for an optical material prepared by the manufacturing method according to an embodiment of the present invention are polymerized it has become

As described above, when an optical material is manufactured using the thiol-based compound of the present invention, the manufactured optical material exhibits a high Abbe's number, can exhibit a refractive index conforming to international standards, and has high heat resistance. Specifically, the optical material according to an embodiment of the present invention may have a heat resistance temperature of 100 ℃ or more, preferably 110 ℃ or more, and thus, there is an advantage that can be applied to an optical material having a relatively high temperature in use.

In the optical material according to an embodiment of the present invention, the isocyanate compound may be used without limitation if it is an isocyanate compound typically used in an optical material, and the present invention is not limited thereto. As a specific and non-limiting example, the isocyanate compound is isophorone diisocyanate (IPDI), dicyclohexylmethane-4-4-diisocyanate (H ₁₂ MDI), hexamethylene diisocyanate (HDI), 1,3- Bis (methyl isocyanate) cyclohexane (H ₆ XDI) and m, o, P - may include one or two or more selected from xylene diisocyanate, but the present invention is not limited thereto.

At this time, the amount of isocyanate added is controlled through the ratio of functional groups, and the molar ratio of -SH functional group: NCO functional group included in the isocyanate compound may be 1: 1 to 2.5, preferably 1.5 to 2, and by satisfying this range, the residual after curing It minimizes unreacted monomers and has the advantage of being able to manufacture an optical material that is strong and has excellent mechanical properties. In addition, there is an advantage that the heat resistance temperature of the optical material manufactured by satisfying the above-described functional group ratio is 100 ° C. or higher, preferably 110 ° C. or higher, which can significantly broaden the application range of the plastic-based optical material.

The optical material according to an embodiment of the present invention may include a UV absorber, a release agent, a dye, etc. as necessary in addition to the thiol-based compound and isocyanate compound of the present invention, but the present invention is not limited thereto.

The ultraviolet absorber can be used without limitation if it is an ultraviolet absorber typically used in optical materials, and the present invention is not limited thereto. As a specific and non-limiting example, the ultraviolet absorber may be one or two or more selected from benzophenone-based, benzotriazo-based, salicylate-based, cyanoacrylate-based and oxanilite-based, etc., but the present invention is limited thereto. it's not going to be

The dye can also be used without limitation if it is a dye used in a conventional plastic optical material, and the present invention is not limited thereto. As a specific and non-limiting example, the dye may be one or two or more selected from perinone-based dyes, heterocyclic dyes, perylene-based dyes, heterocyclic dyes, anthraquinone-based dyes, azo-based dyes and indigoid-based dyes. , the present invention is not limited thereto.

The optical material according to an embodiment of the present invention may include a polymerization initiator for polymerization of the isocyanate and the compound of Formula 1 above. The polymerization initiator can be used without limitation if it is a polymerization initiator for thermal polymerization of isocyanate, and the present invention is not limited thereto. As a specific and non-limiting example, the polymerization initiator may be an amine-based polymerization initiator or a tin-based polymerization initiator, preferably a tin-based polymerization initiator. The tin-based polymerization initiator is specifically dibutyltin laurate, dibutyltin chloride, dibutyltin acetate, stannous oxylate, dibutyltin dilaurate, tetrafluorotin, tetrachlorotin and tetrabrorotin It may be one or two or more selected from the like, but the present invention is not limited thereto.

* Hereinafter, the present invention will be specifically described by way of Examples and Comparative Examples. The examples below are only for helping understanding of the present invention, and the scope of the present invention is not limited by the examples below.

test analysis method

(1) HPLC measurement: LC 20A (Shimazhu, Japan), C18 reversed-phase column (Ace 5,250 × 4.6 mm, ACE-121-2548) solvent: CH3CN:H2O was used.

(2) 1H, 13C NMR: Fourier 300 MHz was used.

(3) Elemental analysis: Thermo Flash 2000 of Thermo Fisher scientific was used.

(4) LC-MS: Analyzed using 1290 infinityII/Qtrap6500.

(5) IR spectrum: analyzed by Shimadzu Corporation's FTIR-8300.

(6) Refractive index (nd) alc Abbe's number (vd): Measured at 20°C using an Atago (Atago, Japan) refractometer.

(7) Heat resistance: The glass transition temperature (Tg) of the test piece was measured using a DSC N-650 thermal analyzer manufactured by SCINCO to confirm the heat resistance.

(8) Polymerization imbalance: 100 lenses are manufactured and observed with the naked eye in the arc lamp. Lenses with different refractive indices around the lenses, which have an arc image, are judged to have polymerization imbalance, and if 5 or less, 0 is displayed, If there are 5 or more polymerization imbalances, it is indicated by ×.

(9) Cloudiness: 100 lenses are produced and visually observed with the arc lamp. Lenses with variable or central cloudiness are judged to have cloudiness. If there is more than one, it is marked with ×

[Example of thiol-based compound preparation]

Preparation Example 1: Reaction 1 of Scheme

Preparation of 1-(2-hydroxyethylthio)-3-chloropropan-2ol

Put 2-mercaptoethanol (78.1 g. 1 mol) and 2 g of triethylamine (TEA) in a 1L round-bottom flask, and stir. Epichlorohydrin (92.5 g. 1 mol) is slowly added dropwise at 10°C or lower. After dropwise addition, the mixture was stirred at 40° C. for 1 hour to obtain 170 g of 1-(2-hydroxyethylthio)-3-chloropropan-2-ol compound in the form of a colorless oil. Reaction confirmation was confirmed by HPLC (liquid chromatography).

Preparation of 1,3-bis(3-mercapto-1-(2-hydroxyethylthio)-2-propanol)-2-propanol

In a 2L round bottom flask, add NaSH.xH2O (88 g. 1.2 mol) to 150 mL of water and stir to dissolve. 1-Chloro-2-(mercaptoethanol)-3-propanol (170 g. 1 mol) was slowly added dropwise at room temperature, stirred at 35-40° C. for 4 hours, cooled to room temperature, and stirred for 4 hours. After that, add 100 mL of sodium hydroxide (20 g. 0.5 mol) solution in ice water, stir for 10 minutes, and then slowly add epichlorohydrin (46.3 g. 0.5 mol) dropwise at 10°C or lower, then raise the temperature to 40°C and stir for 1 hour. 200 g of a polyalcohol compound (2,3-bis(3-hydroxy-2-(2-ethanol)thio-1-propylthio)-1-propanol) in the form of an oil in the lower layer was obtained by using a separatory funnel. Reaction confirmation was confirmed by HPLC (liquid chromatography).

Preparation of 2,3-bis(3-mercapto-2-(2-mercaptoethylthio)-1-propylthio)-1-propanethiol

Thiolurea (228.36 g. 3 mol) was added to hydrochloric acid (303.8 g 3. mol) in a 5L round-bottom flask, and while stirring, an oily polyalcohol compound (2,3-bis (3-hydroxy-2- (2) -Ethanol)thio-1-propylthio)-1-propanol (200g, 0.51 mol) was added, and the temperature was raised to 110° C., followed by reflux reaction for 6 hours After the reaction, after cooling to room temperature, 300 mL of toluene was added, and 25% aqueous ammonia (306.5 g. 4.5 mol) is slowly added dropwise, hydrolyzed at 80° C. for 3 hours, then cooled to room temperature After separating the water layer and the organic solvent layer, wash twice with a mixture of 100 mL of water and 201.2 g of hydrochloric acid in an organic solvent. and washed once more with brine, and the organic solvent toluene was distilled to obtain a compound in the form of a transparent oil (229 g, yield 95%).

In the IR spectrum obtained using FTIR-8300 (manufactured by Shimadzu Corporation), the absorption spectrum unique to the thiol compound was observed at 2537.9 cm -1 .

2 to 4 are the mass spectrum and NMR analysis data, and the specific results are as follows.

Mass Spectrum: m/z = 472.95(M+)MA

¹ H NMR: 1.7-1.8 (CH ₂ S H , m. 5H), 2.67-2.70 (CHC H ₂ S, m. 4H),

_{2.71-2.74 (C H 2 SH, m} . 4H), 2.75-2.77 (CHC H 2 SH, m. 6H),

_{2.80-2.98 (CH 2 C H 2 SH} , 6H) 3.0-3.03 (C H CH 2 S, m. 3H)

*

¹³ C NMR: 24-25 (SCH ₂ C H ₂ SH, 2C), 28.6-28.7 (CH C H ₂ SH, 3C),

35.2-35.7 (S C H ₂ CH ₂ SH, 2C) 36-37 (CH C H ₂ S, 3C);

48.8-49.7 (CH ₂ S C HCH ₂ . 3C)

Elemental Analysis:

Theoretical value: C: 33.01%, H: 5.97%, S: 61.02%

Experimental value: C: 33.09%, H: 5.96%, S: 61.74%

As a result of HPLC solvent CH ₃ CN: H 2 O analysis, the phase (area) was shown in a ratio of 94.6: 5.4, which was 2,3-bis(3-mercapto-2-(2-mercaptoethylthio)- 1-propylthio)-1-propanethiol (2,3-Bis(3-mercapto-2-(2-mercaptoethylthio)-1-propylthio)-1-propanthiol) based on 100 parts by weight of 1,3, the compound of Formula 2 -Bis(3-mercapto-2-(2-mercaptoethyl)thio-propylthio)-2-propanethiol was confirmed to be contained in 5.7 parts by weight.

In the case of the method disclosed in Korean Patent Application Laid-Open No. 10-2013-0050263, it can be confirmed that the present invention, in which the yield is 87.5% and the yield is 95%, can prepare the compound of Formula 1 in a remarkably high yield.

Preparation Example 1: Reaction 2 of Scheme

Prepared in the same manner as in Preparation Example 1, but in step 2, the reaction was performed using 1-chloro-2-(mercaptoethanol)-3-propanol instead of epichlorohydrin, and it was confirmed that the final product was the same as 1 did.

[Manufacturing of optical lenses]

Example 1

54.77 g of isocyanate was used. Among them, 21.64 g of dicyclohexylmethane-4,4'-diisocyanate (H12MDI), 17.75 g of isophorone diisocyanate (IPDI) and 15.37 g of hexamethylene diisocyanate (HDI) were mixed, followed by vacuum defoaming at 20 ° C. Put into a mixer capable of stirring, and to this, Zelec UNTM 0.08g, HOPET 1.2g, DBTC 0.08g. Put HTAQ 20PPm, and PRD10PPm, and after stirring for 30 minutes under a nitrogen stream, 41 g of (monomer) prepared in Preparation Example of the present invention and 9 g of PETMP were added to obtain a polymerizable composition, then degassed under reduced pressure at 0.1 torr or less for 1 hour and 20 minutes and injected into a glass mold fixed with an adhesive tape under nitrogen pressure.

Example 2

Meta-xylene diisocyanate (XDI) 49.78g was placed in a mixer capable of vacuum degassing and stirring at 20°C, and here Zelec UNTM 0.08g, HOPET 1.2g, DBTC 0.08g. Put HTAQ 30PPm, and PRD20PPm, and after stirring for 30 minutes under a nitrogen stream, 50 g of the thiol-based composition (monomer) prepared in Preparation Example of the present invention was added to obtain a polymerizable composition, and then degassed under reduced pressure at 0.1 torr or less for 1 hour and 20 minutes and injected into a glass mold fixed with an adhesive tape under nitrogen pressure.

Put the glass mold injected with the polymerizable composition into a circulating oven, heated to 20-35 ℃ 6 hours, 35-50 ℃ 7 hours, 50-90 ℃ 7 hours, 90-130 ℃ 4 hours, 130 ℃ After holding for 2 hours and cooling at 120-80°C for 1 hour, the solid material is removed from the mold to obtain an optical lens.

The optical lens thus obtained is processed to have a diameter of 72 mm and then annealed at a temperature of 120 to 130° C. for 2 hours to obtain a plastic optical lens.

Examples 3 and 4 were carried out in the same manner as in Example 1.

Comparative Examples 1 to 4 are 2,3-bis(2-mercaptoethylthio)-propane-1- which is a known thiol-based compound (refer to Korean Patent Publication No. 10-2017-0008679 and Korean Patent Publication No. 10-2013-0050263). Thiol (GST). 4,8-dimercaptomethyl-1.11-dimercapto-3,6,9-trithioundecane (DMDDU), 2-(2-mercaptoethylthio)-3-(3-mercapto-2- [3-mercapto-2-(2-mercaptoethylthio)-propylthio]propylthio)-propane-1-thiol (MMPT) is shown in Table 2 by comparing the results of measurement of physical properties with Table 1 with reference to .

[Table 1]

Check the physical properties of the lens

The refractive index, Abbe's number, and heat resistance temperature of the lenses prepared in Examples and Comparative Examples were checked, and the results are shown in Table 2.

[Table 2]

Referring to Table 2, it can be seen that, in the case of Examples including the compound prepared in Preparation Example, the Abbe's number is equivalent or superior to that of Comparative Example, and shows a remarkably excellent heat resistance temperature.

Preparation Example: 2,3-bis(3-mercapto-2-(2-mercaptoethylthio)-1-propylthio)-1-propanethiol and 1,3-Bis(3-mercapto-2-( Composition containing 2-mercaptoethyl)thio-propylthio)-2-propanethiol

GST: 2,3-bis(2-mercaptoethylthio)-propane-1-thiol

DMDDU: 4,8-dimercaptomethyl-1.11-dimercapto-3,6,9-trithiaundecane.

PETMP: pentaerythritol-tetrakis (3-mercaptopropionate)

H ₆ XDI: 1,3-bis (isocyanatomethyl) cyclohexane

H ₁₂ MDI: dicyclohexylmethane-4,4'-diisocyanate

IPDI: isophorone diisocyanate

HDI: hexamethylene diisocyanate

XDI: Meta-xylene diisocyanate

Zelec UN ^TM : Acidic phosphate ester compound from Stepan

HOPBT: 2-(2'-hydroxyl-5'-t-octiphenyl)-2H-benzotriazole

HTAQ: 1-hydroxy-4-(para-poludine) entroquinone

PRD: Perinone Dyes

DBTC: dibutyltin dichloride

GST:

DMDDU:

MMPT:

Claims (8)

1. A thiol-based composition for an optical material comprising a compound of Formula 1 and a compound of Formula 2 below.

   [Formula 1]

   

   [Formula 2]

   
2. The method of claim 1 .

   The thiol-based composition for an optical material is a thiol-based composition for an optical material containing 4 to 7 parts by weight of the compound of Formula 2 based on 100 parts by weight of the compound of Formula 1.
3. A method for producing a thiol-based composition for an optical material containing a compound of the following formula 1 using epichlorohydrin as a starting material.

   [Formula 1]

   
4. 4. The method of claim 3,

   The thiol-based composition for an optical material is a method for producing a thiol-based composition for an optical material further comprising a compound of formula (2).

   [Formula 2]

   
5. 5. The method of claim 4,

   A method for producing a thiol-based composition for an optical material, wherein 4 to 7 parts by weight of the compound of Formula 2 is contained relative to 100 parts by weight of the compound of Formula 1 in the thiol for an optical material.
6. 4. The method of claim 3,

   The method for preparing the thiol-based composition for an optical material is

   A first step of reacting epichlorohydrin with mercapto alcohol;

   a second step of reacting the product of the first step with a hydrogen sulfide salt to replace the chlorine at the end with a hydrogen sulfide group, and reacting with epichlorohydrin; and

   A method for producing a thiol-based composition for an optical material comprising a; a third step of reacting the compound produced in the second step with thiourea.
7. 7. The method of claim 6,

   The molar ratio of the hydrogen sulfide salt: the compound prepared in the first step is 1:1 to 1.2. Method for producing a thiol-based composition for an optical material
8. An optical material in which the thiol-based composition according to claim 1 or 2 and an isocyanate compound are polymerized.

Images