KR20180056526A - high brightness film for liquid crystal display device and method for preparing the same - Google Patents

Abstract

The present invention relates to a high brightness film for a liquid crystal display device and a manufacturing method thereof. A base film includes 10-40 wt% of a YAG-based phosphor. A coating liquid including a dye is coated on one surface of the base film. Therefore, the high brightness film can increase a color gamut ratio and brightness when applied to an LCD.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a high brightness film for a liquid crystal display,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high luminance film for a liquid crystal display (LCD) and a method of manufacturing the same, and more particularly, And a high color rendering film for a liquid crystal display device having improved color reproducibility, and a method for producing the same.

The display market is evolving from large-area, high-resolution competition to color competition. For this reason, competition for the production of a display having excellent color is recently emerging.

OLED (Organic Light-Emitting Diode), which is the next generation display, can achieve color recall rate of 100% (NTSC standard), but LCD (Liquid Crystal Display) is 70% . Recently, a quantum dot (Quantum Dot) method has been applied to improve the color reproducibility in an LCD, but it has a disadvantage in that sealing through a barrier film is necessary because of inherent characteristics of quantum dots weak in moisture and oxygen.

Korean Patent Publication No. 10-2010-0018999

In order to solve the problems of the related art as described above, the present invention provides a double brightness enhancement film (DBEF) having improved brightness and color reproducibility by adding a YAG-base phosphor to a base film and coating the base film with a pigment, A dual brightness enhancement film) and a method of manufacturing the same.

According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, comprising: forming a coating layer containing a YAG-based fluorescent material in a base film in an amount of 10 to 40 wt% A high luminance film for a display device is provided.

In addition, polyethylene terephthalate (PET; Polyethylene terephthalate), triacetyl cellulose (TAC; Triacetylcelluose), polycarbonate (PC; Polycarbonate), polyimide Y ₃ in at least one resin selected from (Polyimide) or acrylic (Acryl) ^{_{A1 5 O 12: Ce 3 +}} (YAG: Ce), Tb 3 A1 5 O 12: Ce 3 + (TAG: Ce), Y 3 Mg 2 AlSiO 12: Ce 3 + or _{Ca 3 (Sc, Mg) 2} Si ₃ O ₁₂ : Ce ³⁺ in an amount of 10 to 40 wt% to prepare a mixture;

Preparing the mixture by a casting process in a conventional film manufacturing method to produce a base film containing a YAG-based phosphor;

Coating a coating liquid containing a pigment in an amount of 0.01 to 5 wt% on at least one surface of a base film containing a YAG fluorescent material, and irradiating ultraviolet light.

The high brightness film for a liquid crystal display of the present invention has better physical properties such as pencil hardness, adhesive force, curl, and bending resistance compared to a QD film, and can realize excellent color quality compared to a conventional LCD TV when applied to an LCD.

Further, since it has excellent durability as compared with conventional quantum dot film and does not require a barrier film, it is possible to produce a high luminance film having a relatively thin thickness and a high color reproducibility.

1 is a sectional view of a high luminance film for a liquid crystal display of the present invention.
2 is a sectional view of another high luminance film for a liquid crystal display of the present invention.
3 is a schematic diagram of a liquid crystal display device structure including the high-luminance film of the present invention.
Fig. 4 (a) is a view showing a spectrum of a backlight unit including a conventional white LED, and Fig. 4 (b) is a view showing a spectrum of a backlight unit using a high luminance film according to the present invention.

The present invention will now be described in detail with reference to the following examples, which should not be construed as limiting the invention.

1 is a sectional view of a high luminance film for a liquid crystal display of the present invention.

1, a high-luminance film according to the present invention comprises 10 to 40 wt% of a YAG fluorescent material 114 in a base film 100, and at least one surface of the base film 100 is coated with a pigment 122 May be formed.

2, the coating layer 120 may be formed on the upper surface or the lower surface of the base film 100 in accordance with the present invention.

The base film 100 is not particularly limited as long as it transmits active energy such as visible light and ultraviolet light. Examples of the base film 100 include a polyethylene terephthalate (PET) film, a triacetylcellulose (TAC) A polycarbonate (PC) film, a polyimide film, or an acryl film may be used. However, the scope of the present invention is not limited to these examples.

Examples of the YAG-base phosphor 114 included in the base film 100 of the present invention include Y ₃ Al ₅ O ₁₂ : Ce ^{3 +} (YAG: Ce), Tb ₃ Al ₅ O ₁₂ : Ce ^{3 +} : Ce ₃ ), Y ₃ Mg ₂ AlSiO ₁₂ : Ce ^{3 +,} or Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce ³⁺ .

In the high brightness film of the present invention, the YAG-base phosphor 114 may be contained in the base film 100 in an amount of 10 to 40 wt%. If it is less than 10 wt%, the effect of improving the brightness is insufficient. The problem that the important color recall rate is lowered in the LCD may occur.

The coating layer 120 including the pigment 122 may be coated on one surface of the base film 100 including the YAG fluorescent material 114 to enhance the color reproduction ratio. And can be coated on the base film 100 to a thickness of 0.1 to 15 탆.

If the thickness of the coating layer 120 is less than 0.1 탆, the color reproducibility is insufficient, and if the thickness of the coating layer 120 exceeds 15 탆, the brightness may be lowered.

In the coating layer 120, the pigment 122 containing 0.01 to 5 wt% is uniformly dispersed in the polymer matrix 112.

If the polymer matrix 112 contains less than 0.01 wt% of the pigment 122, there is no effect of increasing the color recall ratio. If the content of the pigment 122 exceeds 5 wt%, a problem of lowering the luminance may occur.

It is preferable that the pigment 122 absorbs light of 380 to 430 nm, 480 to 510 nm, or 560 to 600 nm.

This is because the color of the white LED is as shown in Fig. 4 (a), and the high brightness film including the pigment 122 that absorbs light of 380 to 430 nm, 480 to 510 nm, or 560 to 600 nm The color reproduction rate can be increased as shown in Fig. 4 (b).

Examples of such pigments 122 include pigments such as a soluble azo pigment (Carmine 6B), an insoluble azo pigment (Toluidine Red), a NaPhthol AS system (Fast Red FGR), a Monoazo Yellow system (Monoazo Yellow G), a Disazo Yellow system Yellow GG) pigments may be used.

The polymer matrix 112 includes at least one of a polyfunctional oligomer, a monofunctional monomer, a monomer having two or three functional groups, a photoinitiator, a leveling agent, and a defoaming agent.

As the photoinitiator that can be used in the present invention, for example, 1 to 5 wt% of two kinds of IG184, IG907, TPO and CP4 may be mixed at a weight ratio of 1: 1.

The high-luminance film according to the present invention has been described above. Hereinafter, a method for producing a high-luminance film according to the present invention will be described.

Y ₃ Al ₅ (a) is added to at least one resin selected from polyethylene terephthalate (PET), triacetylcellulose (TAC), polycarbonate (PC), polyimide or acrylic, ^{_{O 12: Ce 3 + (YAG}} : Ce), Tb 3 A1 5 O 12: Ce 3 + (TAG: Ce), Y 3 Mg 2 AlSiO 12: Ce 3 + or _{Ca 3 (Sc, Mg) 2} Si 3 O ₁₂ : Ce ³⁺ is mixed with 10 to 40 wt% of the YAG-base phosphor 114 to prepare a mixture.

The mixture is prepared according to a casting process in a conventional film manufacturing method to prepare a base film 100 containing the YAG-base phosphor 114.

In the conventional casting process according to the present invention, a thermoplastic chip produced through a polymerization process is melted and a certain width is discharged onto a T-die to form a sheet, followed by biaxial stretching to produce a stretched film.

When a coating liquid containing 0.01 to 5 wt% of the pigment 122 is coated on at least one surface of the base film 100 including the YAG-base phosphor 114, ultraviolet light is irradiated to complete the high brightness film.

The coating liquid is prepared by adding a YAG fluorescent material to a polymer matrix 112 comprising at least one of a monofunctional urethane acrylate oligomer, a monofunctional monomer, a photoinitiator, a leveling agent, and a defoaming agent, (5: 5 weight ratio) selected from IG184, IG907, TPO and CP4 is added in an amount of 1 to 5 wt%.

Hereinafter, the present invention will be described in more detail with reference to the following embodiments. It is to be understood that the same is by way of illustration and example only and is not to be taken by way of limitation.

Manufacturing example

Production Example 1 (Production of Base Film)

800 kg of a PET chip of Mw = 40,000 g / mol prepared by the polymerization process was melted and 200 kg of Y ₃ Al ₅ O ₁₂ : Ce ^{3 +} (YAG: Ce) phosphor was precisely dispersed in a molten PET chip And then discharged into a T-die to form a sheet. A PET film containing 20 wt% of a Y ₃ Al ₅ O ₁₂ : Ce ³⁺ (YAG: Ce) phosphor is prepared through a biaxially stretching process.

Production Example 2 (Preparation of coating layer)

0.01 to 5 wt% of a pigment (Monoazo Yellow G, Disazo Yellow GG, Carmine 6B, Toluidine Red or Fast Red FGR) is mixed in the polymer matrix and stirred for 60 minutes. In this case, a monofunctional urethane acrylate oligomer and a monofunctional monomer were used as the polymer matrix. Then, a photoinitiator is added to the pigment and matrix mixture. As the photoinitiator, IG184, IG907, TPO, and CP4 may be added in an amount of 1 to 5 wt%. In this case, 5 wt% of IG 184 and TPO are added at a ratio of 5: 5. Finally, the prepared coating solution is coated on one side, the other side or both sides of the PET film with a Mayer Bar and irradiated with a non-electrode lamp for about 5 seconds. The amount of light irradiated is 500 mj or less, and the thickness of the coating layer coated on the PET film is 0.1 to 15 μm.

Example

Example 1

A high-brightness film was prepared according to Preparation Example 1 and Preparation Example 2, in which 0.01 wt% of Monoazo Yellow G was added, and the thickness of the coating layer was 0.1 mu m.

Example 2

A high-brightness film was prepared according to Preparation Example 1 and Preparation Example 2, in which 0.1 wt% of Monoazo Yellow G was added and the thickness of the coating layer was 0.1 mu m.

Example 3

A high-brightness film was prepared according to Preparation Example 1 and Preparation Example 2, wherein 1 wt% of Monoazo Yellow G pigment was added, and the thickness of the coating layer was 0.1 mu m.

Example 4

A high-brightness film was prepared according to Preparation Example 1 and Preparation Example 2, wherein the pigment was added with 3 wt% of Monoazo Yellow G, and the thickness of the coating layer was 0.1 탆.

Example 5

A high brightness film was prepared according to Preparation Example 1 and Preparation Example 2, wherein 5 wt% of Monoazo Yellow G was added to the pigment, and the thickness of the coating layer was 0.1 탆.

Example 6

A high brightness film was prepared according to Preparation Example 1 and Preparation Example 2, wherein 0.1 wt% of Monoazo Yellow G was added and the thickness of the coating layer was 1 μm.

Example 7

A high brightness film was prepared according to Preparation Example 1 and Preparation Example 2, wherein 0.1 wt% of Monoazo Yellow G was added and the thickness of the coating layer was 5 탆.

Example 8

A high-brightness film was prepared according to Preparation Example 1 and Preparation Example 2, in which 0.1 wt% of Monoazo Yellow G was added, and the thickness of the coating layer was 10 탆.

Example 9

A high-brightness film was prepared according to Preparation Example 1 and Preparation Example 2, in which 0.1 wt% of Monoazo Yellow G was added, and the thickness of the coating layer was 15 탆.

Examples 10 to 18

The pigment was prepared in the same manner as in Examples 1 to 9 except that Disazo Yellow G was used.

Examples 19-27

The procedure of Examples 1 to 9 was repeated except that the pigment was changed to Carmine 6B.

Examples 28 to 36

The procedure of Examples 1 to 9 was repeated except that the pigment was changed to Toluidine Red.

Examples 37 to 45

The procedure of Examples 1 to 9 was repeated except that the pigment was changed to Fast Red FGR.

Comparative Example

Comparative Example 1

A high-brightness film was prepared according to Preparation Example 1 and Preparation Example 2, in which 0.001 wt% of Monoazo Yellow G was added and the thickness of the coating layer was 0.1 탆.

Comparative Example 2

A high brightness film was prepared according to Preparation Example 1 and Preparation Example 2, wherein 7 wt% of Monoazo Yellow G pigment was added, and the thickness of the coating layer was 0.1 mu m.

Comparative Example 3

A high-brightness film was prepared according to Preparation Example 1 and Preparation Example 2, wherein 0.1 wt% of Monoazo Yellow G was added to the pigment, and the thickness of the coating layer was 0.01 mu m.

Comparative Example 4

A high-brightness film was prepared according to Preparation Example 1 and Preparation Example 2, wherein 0.1 wt% of Monoazo Yellow G was added to the pigment, and the thickness of the coating layer was 20 탆.

Comparative Examples 5 to 8

The pigment was prepared in the same manner as in Comparative Examples 1 to 4 except that Disazo Yellow G was used.

Comparative Examples 9 to 12

The pigment was prepared in the same manner as in Comparative Examples 1 to 4 except that the pigment was changed to Carmine 6B.

Comparative Examples 13 to 16

The pigment was prepared in the same manner as in Comparative Examples 1 to 4 except that the pigment was changed to Toluidine Red.

Comparative Examples 17 to 20

The pigments were prepared in the same manner as in Comparative Examples 1 to 4 except that the pigment was changed to Fast Red FGR.

Experimental Example

The PET films prepared in Examples and Comparative Examples were cut into A4 size and then produced as shown in Fig. 2, and the luminance of the fluorescent substance-containing base film was measured through a luminance measuring apparatus (Topcon BM-7 FAST color difference luminance meter) , And the luminance values were converted into% QD Ref. (450 nit) in terms of%, and the results are shown in Tables 1 to 10 below.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Brightness (%) 107 105 103 102 100 105 103 102 100 Color recall (%) 86 90 92 95 100 91 92 95 100 Remarks

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Brightness (%) 107 97 107 97 Color recall (%) 82.4 100 82.4 100 Remarks no effect Decrease in luminance no effect Decrease in luminance

Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 Brightness (%) 107 105 103 102 100 105 103 102 100 Color recall (%) 83 89 92 97 100 90 92 95 100 Remarks

Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Brightness (%) 107 97 107 97 Color recall (%) 82.4 100 82.4 100 Remarks no effect Decrease in luminance no effect Decrease in luminance

Example 19 Example 20 Example 21 Example 22 Example 23 Example 24 Example 25 Example 26 Example 27 Brightness (%) 107 105 103 102 100 105 103 102 100 Color recall (%) 85 90 92 98 100 91 92 95 100 Remarks

Comparative Example 9 Comparative Example 10 Comparative Example 11 Comparative Example 12 Brightness (%) 107 97 107 97 Color recall (%) 82.4 100 82.4 100 Remarks no effect Decrease in luminance no effect Decrease in luminance

Example 28 Example 29 Example 30 Example 31 Example 32 Example 33 Example 34 Example 35 Example 36 Brightness (%) 107 105 103 101 100 105 103 102 100 Color recall (%) 89 90 95 98 100 91 92 95 100 Remarks

Example 28 Example 29 Example 30 Example 31 Example 32 Example 33 Example 34 Example 35 Example 36 Brightness (%) 107 105 103 101 100 105 103 102 100 Color recall (%) 89 90 95 98 100 91 92 95 100 Remarks

Example 37 Example 38 Example 39 Example 40 Example 41 Example 42 Example 43 Example 44 Example 45 Brightness (%) 107 107 103 101 100 105 103 102 100 Color recall (%) 88 91 97 95 100 91 92 95 100 Remarks

Comparative Example 17 Comparative Example 18 Comparative Example 19 Comparative Example 20 Brightness (%) 107 97 107 97 Color recall (%) 82.4 100 82.4 100 Remarks no effect Decrease in luminance no effect Decrease in luminance

100: substrate film 112: polymer matrix
114: YAG-base phosphor 120: coating layer
122: pigment

Claims (8)

9. A high luminance film for a liquid crystal display device, comprising a base film containing 10 to 40 wt% of a YAG-base phosphor, wherein a coating layer containing a pigment is formed on at least one surface of the base film. The method according to claim 1,
The base film may be at least one selected from the group consisting of a polyethylene terephthalate (PET) film, a triacetylcellulose (TAC) film, a polycarbonate (PC) film, a polyimide film, Wherein the high-brightness film is a single-layer film. The method according to claim 1,
YAG-base phosphor is _{Y 3 A1 5 O 12: Ce} 3 + (YAG: Ce), Tb 3 A1 5 O 12: Ce 3 + (TAG: Ce), Y 3 Mg 2 AlSiO 12: Ce 3+ or Ca ₃ ( _{Sc, Mg) 2 Si 3 O} 12: high brightness film for a liquid crystal display device, characterized in that at least any one selected from the group consisting of Ce ^{+ 3.} The method according to claim 1,
Wherein the coating layer containing the pigment is coated to a thickness of 0.1 to 15 占 퐉. The method according to claim 1,
Wherein the pigment is a pigment absorbing light of 380 to 430 nm, 480 to 510 nm, or 560 to 600 nm. The method according to claim 1,
The pigment may be at least one selected from the group consisting of pigments such as soluble azo pigments (Carmine 6B), insoluble azo pigments (Toluidine Red), NaPhthol AS pigments (Fast Red FGR), Monoazo Yellow pigments (Monoazo Yellow G) and Disazo Yellow pigments Wherein the high-brightness film comprises a material. The method according to claim 1,
Wherein the coating layer contains 0.01 to 5 wt% of pigment. Y ₃ Al ₅ (a) is added to at least one resin selected from polyethylene terephthalate (PET), triacetylcellulose (TAC), polycarbonate (PC), polyimide or acrylic, ^{_{O 12: Ce 3 + (YAG}} : Ce), Tb 3 A1 5 O 12: Ce 3 + (TAG: Ce), Y 3 Mg 2 AlSiO 12: Ce 3 + or _{Ca 3 (Sc, Mg) 2} Si 3 O ₁₂ : Ce ³⁺ in an amount of 10 to 40 wt% to prepare a mixture;
Preparing the mixture by a casting process in a conventional film manufacturing method to produce a base film containing a YAG-based phosphor;
Coating a coating solution containing 0.01 to 5 wt% of a pigment on at least one surface of a base film containing a YAG-base phosphor, and irradiating ultraviolet rays.

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