CURABLE COMPOSITION AND OPTICAL MATERIAL COMPRISING CURED PRODUCT THEREOF

Abstract

A curable composition comprising an episulfide compound represented by Chemical Formula 1 and an aromatic ring compound containing two or more hydroxyl groups represented by Chemical Formula 2 or 3, and an optical material including a cured product of the curable composition.

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Claims

1. A curable composition for forming a high refractive index optical material, the curable composition comprising: an episulfide compound represented by the following Chemical Formula 1; and an aromatic ring compound containing two or more hydroxyl groups represented by the following Chemical Formula 2 or 3, wherein a weight ratio of the episulfide compound and the aromatic ring compound containing two or more hydroxyl groups is 7:3 to 9:1, ##STR00011## in Chemical Formula 1, R.sub.1 and R.sub.2 are each independently hydrogen or an alkyl having 1 to 10 carbon atoms, R.sub.3 and R.sub.4 are each independently a single bond or an alkylene having 1 to 10 carbon atoms, a is an integer of 0 to 4, and b is an integer of 0 to 6, ##STR00012## in Chemical Formula 2, R.sub.5 and R.sub.6 are each independently deuterium, halogen, cyano, nitrile, nitro, amino, an alkyl having 1 to 40 carbon atoms, an alkoxy having 1 to 40 carbon atoms, a cycloalkyl having 3 to 40 carbon atoms, an alkenyl having 1 to 40 carbon atoms, an aryl having 6 to 60 carbon atoms, or a heteroaryl having 1 to 40 carbon atoms containing at least one of O, N, Si and S, c and d are each independently an integer of 1 to 7, e and f are each independently an integer of 0 to 6, c+e is 7 or less, d+f is 7 or less, ##STR00013## in Chemical Formula 3, Ar.sub.1 and A.sub.2 are each independently an aryl having 6 to 60 carbon atoms in which one or more hydroxyl groups are substituted, R.sub.7 and R.sub.8 are each independently deuterium, halogen, cyano, nitrile, nitro, amino, an alkyl having 1 to 40 carbon atoms, an alkoxy having 1 to 40 carbon atoms, a cycloalkyl having 3 to 40 carbon atoms, an alkenyl having 1 to 40 carbon atoms, an aryl having 6 to 60 carbon atoms, or a heteroaryl having 1 to 40 carbon atoms containing at least one of O, N, Si and S, and m and n are each independently an integer of 0 to 4.

2. The curable composition according to claim 1, wherein the weight ratio of the episulfide compound and the aromatic ring compound containing two or more hydroxyl groups is 8:2 to 9:1.

3. The curable composition according to claim 1, wherein the episulfide compound comprises at least one selected from the group consisting of bis(β-epithiopropyl)sulfide, bis(β-epithiopropyl)disulfide, bis(β-epithiopropylthio)methane, 1,2-bis(β-epithiopropylthio)ethane, 1,3-bis(β-epithiopropylthio)propane, and 1,4-bis(β-epithiopropylthio)butane.

4. The curable composition according to claim 1, wherein the aromatic ring compound containing two or more hydroxyl groups comprises at least one selected from the following compounds: ##STR00014## ##STR00015##

5. The curable composition according to claim 1, wherein the curable composition further comprises a catalyst.

6. An optical material comprising a cured product of a curable composition, the curable composition comprises: an episulfide compound represented by the following Chemical Formula 1; and an aromatic ring compound containing two or more hydroxyl groups represented by the following Chemical Formula 2 or 3, wherein the episulfide compound and the aromatic ring compound containing two or more hydroxyl groups is contained in a weight ratio of 7:3 to 9:1, ##STR00016## in Chemical Formula 1, R.sub.1 and R.sub.2 are each independently hydrogen or an alkyl having 1 to 10 carbon atoms, R.sub.3 and R.sub.4 are each independently a single bond or an alkylene having 1 to 10 carbon atoms, a is an integer of 0 to 4, and b is an integer of 0 to 6, ##STR00017## in Chemical Formula 2, R.sub.5 and R.sub.6 are each independently deuterium, halogen, cyano, nitrile, nitro, amino, an alkyl having 1 to 40 carbon atoms, an alkoxy having 1 to 40 carbon atoms, a cycloalkyl having 3 to 40 carbon atoms, an alkenyl having 1 to 40 carbon atoms, an aryl having 6 to 60 carbon atoms, or a heteroaryl having 1 to 40 carbon atoms containing at least one of O, N, Si and S, c and d are each independently an integer of 1 to 7, e and f are each independently an integer of 0 to 6, c+e is 7 or less, d+f is 7 or less, ##STR00018## in Chemical Formula 3, Ar.sub.1 and A.sub.2 are each independently an aryl having 6 to 60 carbon atoms in which one or more hydroxyl groups are substituted, R.sub.7 and R.sub.8 are each independently deuterium, halogen, cyano, nitrile, nitro, amino, an alkyl having 1 to 40 carbon atoms, an alkoxy having 1 to 40 carbon atoms, a cycloalkyl having 3 to 40 carbon atoms, an alkenyl having 1 to 40 carbon atoms, an aryl having 6 to 60 carbon atoms, or a heteroaryl having 1 to 40 carbon atoms containing at least one of O, N, Si and S, and m and n are each independently an integer of 0 to 4.

7. The optical material according to claim 6, wherein the optical material has a refractive index of 1.65 or more.

8. The optical material according to claim 6, wherein the optical material has a glass transition temperature (Tg) of 80° C. or more.

9. The optical material according to claim 6, wherein the optical material has a transmittance of 80% or more.

10. The optical material according to claim 6, wherein the optical material has a haze of 1% or less.

11. The optical material according to claim 6, wherein the optical material has a yellowness index (YI) of 0.1-10.

12. The optical material according to claim 6, wherein the optical material is for a lens of a wearable device.

Description

DETAILED DESCRIPTION

[0097] Hereinafter, the actions and effects of the invention will be described in more detail through specific examples of the invention. However, these examples are for illustrative purposes only, and the scope of rights of the invention is not determined thereby.

Example 1

[0098] 90 g of the following 70A as an episulfide compound, and 10 g of the following Al as an aromatic ring compound containing two or more hydroxyl groups were vigorously mixed at 20° C. for 1 hour, and then the mixture was filtered using a glass filter having a pore size of 1 μm and then filtered once again using a PVDF filter having a pore size of 0.45 μm. Then, 1 g of N,N-dicyclohexylmethylamine was added as a catalyst and mixed for 5 minutes to prepare a curable composition.

[0099] A 1 mm thick slide glass was placed on both sides of a LCD glass having a size of 10 cm in width and length, and about 5 g of the above-mentioned mixed solution was applied to the center of the LCD glass, and then covered with another LCD glass to prepare a mold. This was put in an oven, and the curing reaction was performed at about 60° C. for about 10 hours and at about 90° C. for about 4 hours. After taken out of the oven, the LCD glass was removed to obtain a flat plastic specimen (optical material). The thickness of the plastic specimen was about 1 mm, and this thickness was measured using a Mitutoyo thickness gauge (Model: ID-C112XBS).

Examples 2 to 7 and Comparative Examples 1 to 3

[0100] A curable composition and a plastic specimen (optical material) as a cured product thereof were prepared in the same manner as in Example 1, except that the episulfide compound and the aromatic ring compound containing two or more hydroxyl groups were used in the amount of the compounds shown in Table 1 below. Meanwhile, in the case of Comparative Examples 1 to 3, the following 70A and/or 70B were used as the thiol compounds in the amounts shown in Table 2 below.

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TABLE-US-00001 TABLE 1 (unit: g) 70A 74A 70B 74B Al A2 A3 A4 A5 Example 1 90 — — — 10 — — — — Example 2 90 — — — — 10 — — — Example 3 90 — — — — — 10 — — Example 4 90 — — — — — — 10 — Example 5 90 — — — — — — — 10 Example 6 90 — — 8 — — — 2 Example 7 45 45 — — 8 — — — 2 Comparative 90 — 10 — — — — — — Example 1 Comparative — 90 — 10 — — — — — Example 2 Comparative 45 45 10 — — — — — — Example 3 Comparative 93 7 Example 4 Comparative 95 5 Example 5 Comparative 67 33 Example 6 Comparative 65 35 Example 7

Evaluation of Physical Properties

1. Evaluation of Optical Properties (Transmittance, Haze and Yellowness Index)

[0101] The transmittance, haze, and yellowness index of the sample were measured in the thickness direction of the cured product cured to a 1 mm standard thickness using COH-400 spectrometer manufactured by Nippon Denshoku Industries Co., Ltd., and the results are shown in Table 2 below.

2. Measurement of Sulfur Atom Content

[0102] The content of sulfur atoms in the specimen was measured using an elemental analysis method, and the results are shown in Table 2 below.

3. Measurement of Refractive Index

[0103] For the specimen, the refractive index value at a wavelength of 532 nm was measured using spectroscopic ellipsometry manufactured by Ellipso Technology, and the results are shown in Table 2 below.

4. Measurement of Glass Transition Temperature (Tg)

[0104] The specimen was heated-cooled-heated in a temperature range of 25 to 160° C. at 10° C./min, using a differential scanning calorimeter (DSC) DSC-2500 (TA Instrument), and in the second heating, the glass transition temperature (Tg) of the specimen was measured, and the results are shown in Table 2 below.

TABLE-US-00002 TABLE 2 Sulfur Glass atom transition Transmittance Haze Yellowness content Refractive temperature (%) (%) index (YI) (wt. %) index (° C.) Example 1 87.7 0.3 3.5 48.54 1.736 86 Example 2 89.0 0.3 1.7 48.54 1.701 87 Example 3 88.1 0.4 6.2 48.54 1.717 84 Example 4 87.8 0.3 3.4 48.54 1.700 84 Example 5 87.6 0.3 3.7 48.54 1.681 89 Example 6 87.5 0.3 3.7 48.54 1.724 88 Example 7 87.7 0.3 3.4 51.70 1.740 87 Comparative 88.0 0.3 3.4 54.77 1.705 74 Example 1 Comparative 87.3 0.3 3.3 60.98 1.738 75 Example 2 Comparative 87.7 0.3 3.4 57.93 1.734 75 Example 3 Comparative 87.9 0.3 5.4 50.15 1.698 70 Example 4 Comparative 87.8 0.3 4.3 58.14 1.715 68 Example 5 Comparative N/A N/A N/A N/A N/A N/A Example 6 Comparative N/A N/A N/A N/A N/A N/A Example 7

[0105] Referring to Table 2, it can be seen that the specimen including the cured product according to Examples of the present disclosure exhibits very high transmittance, and has a relatively high refractive index and a high glass transition temperature even while having low haze and yellowness index value.

[0106] On the other hand, it was confirmed that in the case of Comparative Example 1, the refractive index value was slightly lower even while containing a slightly larger amount of sulfur atoms compared to Examples of the present disclosure, and in the case of Comparative Example 2, the transmittance was slightly low. Further, in the case of Comparative Examples 1 to 3, the glass transition temperature was significantly lower than that of Examples, and there was a problem that curing proceeds immediately after preparation of the composition and the viscosity was excessively high, making it difficult to prepare it into a plastic resin specimen or process it into a lens.

[0107] In addition, it was confirmed that in the case of the curable compositions of Comparative Examples 4 and 5, the refractive index value was slightly low while containing a slightly larger amount of sulfur atoms, and the glass transition temperature was significantly lower than that of Examples. Furthermore, in the case of the curable compositions of Comparative Examples 6 and 7, it was not possible to manufacture a plastic specimen (optical material), due to problems of poor dissolution or precipitation of the aromatic cyclic compound containing two or more hydroxyl groups, because the content of the aromatic cyclic compound containing two or more hydroxyl groups, which is a solid curing agent, was high.