LIQUID CRYSTAL DEVICE

Abstract

The present invention relates to a liquid crystal device, a method of manufacturing the liquid crystal device, and the use of the liquid crystal device. The liquid crystal device according to the present invention has excellent light shielding rate variability characteristics. Such a liquid crystal device can be applied to various optical modulation devices such as a smart window, a window protection film, a flexible display device, an active retarder for displaying a 3D image, or a viewing angle adjustment film.

Claims

1. A liquid crystal device comprising: two or more partition walls comprising a polymer network and a first liquid crystal compound dispersed in the polymer network; and a liquid crystal layer comprising a second liquid crystal compound and an anisotropic dye, both of which are present in a region formed between the two or more partition walls.

2. The liquid crystal device of claim 1, wherein a gap between the partition walls is in a range of 10 μm to 1,000 μm.

3. The liquid crystal device of claim 1, wherein a width of the partition walls is in a range of 3 μm to 100 μm.

4. The liquid crystal device of claim 1, wherein a height of the partition walls is in a range of 3 μm to 100 μm.

5. The liquid crystal device of claim 1, wherein an area ratio of the partition walls is in a range of 0.1% to 50%, based on 100% of the total area of the liquid crystal layer.

6. The liquid crystal device of claim 1, wherein the first liquid crystal compound, the second liquid crystal compound, or the anisotropic dye is present in an unaligned state.

7. The liquid crystal device of claim 1, wherein the anisotropic dye is a black dye or a color dye.

8. The liquid crystal device of claim 1, further comprising a substrate layer that is adjacent to the partition walls or a region in which the second liquid crystal compound and the anisotropic dye are present.

9. The liquid crystal device of claim 1, further comprising an electrode layer that is adjacent to the partition walls or the region in which the second liquid crystal compound and the anisotropic dye are present.

10. The liquid crystal device of claim 1, which has a variable light shielding rate ranging from 3% to 90%.

11. A method of manufacturing a liquid crystal device, comprising: forming two or more partition walls using a composition comprising a curable polymer network precursor and a first liquid crystal compound; and disposing a second liquid crystal compound and an anisotropic dye in a region formed between the two or more partition walls.

12. The method of claim 11, wherein the partition walls are formed by imprinting a layer of the composition comprising the curable polymer network precursor and the first liquid crystal compound.

13. The method of claim 11, further comprising: laminating a first substrate and a second substrate on each other, wherein the two or more partition walls formed using the composition comprising the curable polymer network precursor and the first liquid crystal compound are present on a surface of the first substrate, and a layer comprising the second liquid crystal compound and the anisotropic dye is formed on the second substrate.

14. An optical modulation device comprising the liquid crystal device defined in claim 1.

Description

DESCRIPTION OF DRAWINGS

[0057] FIGS. 1 to 3 are schematic diagrams showing an exemplary liquid crystal device.

[0058] FIG. 4 shows results of the evaluation of the light shielding rate.

BEST MODE

[0059] Hereinafter, the present invention will be described in further detail with reference to the following Example and Comparative Example, but it is to be understood that the description proposed herein is not intended to limit the scope of the invention.

EXAMPLE 1

[0060] 100 mg of a urethane acrylate-multifunctional oligomer (SU530, Mw: 5,000, commercially available from Soltech Ltd.), 300 mg of a bifunctional acrylate (HDDA commercially available from Sigma-Aldrich), 20 mg of a trifunctional acrylate (PETA commercially available from Sigma-Aldrich), 570 mg of a monofunctional acrylate (EHA commercially available from TCI), and 10 mg of a photoinitiatior (Zs-539 commercially available from Fuji Film) were mixed to prepare a polymer precursor, and 2.3 g of a liquid crystal compound (HPC21600 commercially available from HCCH) was added to the precursor. Thereafter, 40 mg of a ball-typed spacer having a diameter of 10 μm was added, and the mixture was agitated for 7 hours in an agitator to prepare a PDLC composition. A surface of an ITO layer of a PET film (100 mm×100 mm) (hereinafter referred to as a PET/ITO film) on which an ITO transparent electrode layer was deposited was bar-coated with the PDLC composition using a Mayer bar (#10), covered with a soft mold (diameter: 200 um, barrier rib width: 20 um, and barrier rib height: 15 um), and then laminated. Thereafter, the imprinted PDLCs were transferred to a surface of the PET/ITO film by irradiating the PDLCs with UV rays for 20 seconds under a high-pressure mercury lamp (30 mW). Next, another PET/ITO film was coated with a second liquid crystal composition including 2 g of a liquid crystal compound (HPC21600 commercially available from HCCH) and 20 mg of an anisotropic dye (X12 commercially available from BASF), and the two films were then laminated.

Comparative Example 1

[0061] 100 mg of a urethane acrylate-multifunctional oligomer (SU530, Mw: 5,000, commercially available from Soltech Ltd.), 300 mg of a bifunctional acrylate (HDDA commercially available from Sigma-Aldrich), 20 mg of a trifunctional acrylate (PETA commercially available from Sigma-Aldrich), 570 mg of a monofunctional acrylate (EHA commercially available from TCI), 23 mg of an anisotropic dye (X12 commercially available from BASF), and 10 mg of a photoinitiatior (Zs-539 commercially available from Fuji Film) were mixed to prepare a polymer precursor, and 2.3 g of a liquid crystal compound (HPC21600 commercially available from HCCH) and 20 mg of an anisotropic dye (X12 commercially available from BASF) were added to the precursor. Thereafter, 20 mg of a ball-typed spacer having a diameter of 25 μm was added, and the mixture was agitated for 7 hours in an agitator to prepare a liquid crystal composition. Then, a surface of an ITO layer of the PET/ITO film was bar-coated with the liquid crystal composition using a Mayer bar (#14). Another PET/ITO film was laminated onto the coated composition so that the other PET/ITO film came in contact with the composition, and then irradiated with UV rays for 20 seconds under a high-pressure mercury lamp (30 mW) to manufacture a liquid crystal device.

Experimental Example 1

Evaluation of Light Shielding Rate of Liquid Crystal Device

[0062] The total transmittance of each of the liquid crystal devices manufactured in Example 1 and Comparative Example 1 in an initial state and when a voltage is applied thereto was measured using a hazemeter (NDH-5000SP) to evaluate a shielding rate. The results are shown in FIG. 4 and listed in Table 1. The results of evaluation of the total transmittance showed that the total transmittance of the liquid crystal device of Comparative Example 1 in the initial state and upon the application of the voltage was changed from 21% to 55%, and the total transmittance of the liquid crystal device of Example 1 in the initial state and upon the application of the voltage was changed from 23% to 72%. From the results of evaluation of such a shielding rate, it can be seen that the liquid crystal device of Comparative Example 1 had degraded light shielding rate variability characteristics due to contamination of the polymer network by the anisotropic dye, and the liquid crystal device of Example 1 had excellent light shielding rate variability characteristics since the contamination of the polymer network by the anisotropic dye may be reduced.

TABLE-US-00001 TABLE 1 Comparative Example 1 Example 1 Shielding rate Initial state (0 V) 23% 21% Voltage applied (100 V) 72% 55%

Brief Description of Parts in the Drawings

[0063] 1: liquid crystal layer

[0064] 101: barrier rib

[0065] 1011: polymer network

[0066] 1012: first liquid crystal compound

[0067] 102: region formed between partition walls

[0068] 1021: second liquid crystal compound

[0069] 1022: anisotropic dye

[0070] 201A, 201B: substrate layer

[0071] 301A, 301B: electrode layer