KR20180056528A - high brightness film for liquid crystal display device and method for preparing the same - Google Patents

Abstract

The present invention relates to a high-luminance film for a liquid crystal display device and a method for producing the same. A base film contains 10 to 40 wt% of a YAG-based phosphor and 0.01 to 5 wt% of a pigment. It can be used instead of a dual brightness enhancement film (DBEF) film.

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 (hereinafter, referred to as 'LCD') and a method of manufacturing the same, and more particularly to a YAG- And a method for producing the same.

Recently, the display market is evolving from a large-size and high-resolution competition to a color competition, and attention is focused on manufacturing a display capable of realizing excellent color.

OLED (Organic Light-Emitting Diode), which is widely regarded as the next generation display, can achieve the color recall rate up to 100% of NTSC. However, currently used LCD shows 70% color reproduction rate It is a situation.

Accordingly, although a method using a quantum dot is applied to improve the color gamut of an LCD, there is a problem that a sealing process through a barrier film must be accompanied by inherent characteristics of quantum dots susceptible to moisture and oxygen.

On the other hand, in the LCD, a luminance enhancement film is applied in order to increase the contrast. The brightness enhancement film can be attached to a back light unit (BLU) using a light shielding tape. The reflection type polarizing film is a film in which a high refractive index layer and a low refractive index layer are alternately repeatedly laminated, and commercially available is a dual brightness enhancement film (hereinafter referred to as " DBEF ') and the like are used.

However, since royalty is required to use DBEF, Korean affiliates are concentrating their research and development on localization of luminance enhancement film that can replace DBEF.

Therefore, if a film capable of improving LCD brightness without using DBEF is developed, it is expected to contribute to activation of the domestic display market.

Korean Patent Publication No. 10-2010-0018999

In order to solve the problems of the prior art as described above, the present invention relates to a high-luminance film for a liquid crystal display device which can replace a conventional DBEF by improving the luminance and color reproduction rate by adding a YAG- And a manufacturing method thereof.

In order to achieve the object of the present invention, the present invention provides a high-luminance film for a liquid crystal display device, wherein the base film contains a YAG-base phosphor and a pigment.

In addition, it is preferable to add at least one resin selected from the group consisting of polyethylene terephthalate (PET), triacetylcellulose (TAC), polycarbonate (PC), polyimide, Mixing 10 to 40 wt% of the phosphor and 0.01 to 5 wt% of the pigment to prepare a mixture; And

And a step of preparing a base film according to a casting process of the mixture in a conventional film production method. The present invention also provides a method for producing a high brightness film for a liquid crystal display device.

According to the present invention, a YAG-base phosphor and a pigment can be added to a base film to produce a high-brightness film having improved brightness and color reproducibility, and the brightness can be improved when applied to an LCD without using DBEF as a conventional brightness enhancement film Excellent brightness can be realized.

DBEF is a film in which a high refractive index layer and a low refractive index layer are alternately repeatedly laminated. However, the present invention is advantageous in that it is easy to produce a single layer structure in which a YAG fluorescent material is added in a base film.

1 is a sectional view of a high luminance film for a liquid crystal display of the present invention.
2 is a schematic view of a liquid crystal display device structure including a high-luminance film of the present invention.
FIG. 3 (a) is a view showing a spectrum of a backlight unit including a conventional white LED, and FIG. 3 (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, the high-luminance film according to the present invention contains 10 to 40 wt% of YAG-based fluorescent material 114 and 0.01 to 5 wt% of pigment 122 in the base film 100.

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-based fluorescent material 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 + (TAG: Ce)} , Y 3 Mg 2 AlSiO 12: Ce 3+ or _{Ca 3 (Sc, Mg) 2} Si 3 O 12: can be used at least one selected from the group consisting of 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.

In the base film 100, the pigment may be contained in an amount of 0.01 to 5 wt% in order to improve the color reproducibility. If the pigment is contained in an amount of less than 0.01 wt%, the color reproduction rate is not increased. Problems can arise.

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. 3 (a), and the high brightness film including the pigment 122 that absorbs the 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. 3 (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 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 10 to 40 wt% of at least one YAG-based fluorescent material 114 selected from the group consisting of Al 2 O ³ : Eu 2 ^{O 3} , and ₁₂ : Ce ³⁺ and 0.01 to 5 wt% of a pigment are mixed.

The pigment is selected from pigments selected from the group consisting of 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 Or more can be used.

The mixture is prepared by a casting process in a conventional film manufacturing method to prepare a base film 100 including the YAG fluorescent material 114 and the pigment 122.

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.

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

Manufacturing example  One

900 kg of a PET chip of Mw = 40,000 g / mol prepared by a polymerization process was melted and 100 kg of a 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 10 wt% of a Y ₃ Al ₅ O ₁₂ : Ce ³⁺ (YAG: Ce) phosphor is prepared through a biaxially stretching process.

Manufacturing example  2

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.

Manufacturing example  3

700 kg of a PET chip of Mw = 40,000 g / mol produced by a polymerization process was melted and 300 kg of Y ₃ Al ₅ O ₁₂ : Ce ^{3 +} (YAG: Ce) phosphor was precisely dispersed in a melted PET chip And then discharged into a T-die to form a sheet. A PET film containing 30 wt% of a Y ₃ Al ₅ O ₁₂ : Ce ³⁺ (YAG: Ce) phosphor is prepared through a biaxially stretching process.

Manufacturing example  4

600 kg of a PET chip of Mw = 40,000 g / mol produced by a polymerization process was melted and 400 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 40 wt% of a Y ₃ Al ₅ O ₁₂ : Ce ³⁺ (YAG: Ce) phosphor is prepared through a biaxially stretching process.

Example

Example  One

20 wt% of Y ₃ Al ₅ O ₁₂ : Ce ^{3 +} (YAG: Ce) phosphor and 0.01 wt% of pigment (Monoazo Yellow G) were added to the molten PET chip in Production Example 2 to prepare a PET film.

Example  2

A PET film was prepared by adding 20 wt% of a Y ₃ Al ₅ O ₁₂ : Ce ^{3 +} (YAG: Ce) phosphor and 0.1 wt% of a pigment (Monoazo Yellow G) to a molten PET chip in Production Example 2.

Example  3

20 wt% of Y ₃ Al ₅ O ₁₂ : Ce ^{3 +} (YAG: Ce) phosphor and 1 wt% of pigment (Monoazo Yellow G) were added to the melted PET chip in Production Example 2 to prepare a PET film.

Example  4

A PET film was prepared by adding 20 wt% of Y ₃ Al ₅ O ₁₂ : Ce ^{3 +} (YAG: Ce) phosphor and 3 wt% of pigment (Monoazo Yellow G) to the molten PET chip in Production Example 2.

Example  5

20 wt% of Y ₃ Al ₅ O ₁₂ : Ce ^{3 +} (YAG: Ce) phosphor and 5 wt% of pigment (Monoazo Yellow G) were added to the molten PET chip in Production Example 2 to prepare a PET film.

Example  6 to 10

The dye was prepared in the same manner as in Examples 1 to 5 except that the dye was changed to Disazo Yellow GG.

Example  11 ~ 15

The dye was prepared in the same manner as in Examples 1 to 5 except that the dye was changed to Carmine 6B.

Example  16-20

The dye was prepared in the same manner as in Examples 1 to 5 except that the dye was changed to Toluidine Red.

Example  21 ~ 25

The dye was prepared in the same manner as in Examples 1 to 5 except that Fast Red FGR was used.

Comparative Example

Comparative Example  One

20% by weight of Y ₃ Al ₅ O ₁₂ : Ce ^{3 +} (YAG: Ce) phosphor and 0.001% by weight of pigment (Monoazo Yellow G) are added to the molten PET chip in Production Example 2 to prepare a PET film.

Comparative Example  2

20% by weight of Y ₃ Al ₅ O ₁₂ : Ce ^{3 +} (YAG: Ce) phosphor and 7% by weight of pigment (Monoazo Yellow G) are added to the melted PET chip in Production Example 2 to prepare a PET film.

Comparative Example  3 to 4

The pigment was prepared in the same manner as in Comparative Examples 1 and 2 except that Disazo Yellow G was used.

Comparative Example  5 to 6

The pigment was prepared in the same manner as in Comparative Examples 1 and 2 except that the pigment was changed to Carmine 6B.

Comparative Example  7 to 8

The pigment was prepared in the same manner as in Comparative Examples 1 to 2 except that the pigment was changed to Toluidine Red.

Comparative Example  9-10

The pigment was prepared in the same manner as in Comparative Examples 1 to 2 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 5 below.

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Brightness (%) 107 105 103 102 100 107 97 Color recall (%) 86 90 92 95 100 82.4 100

Example 6 Example 7 Example 8 Example 9 Example 10 Comparative Example 3 Comparative Example 4 Brightness (%) 107 105 103 102 100 107 97 Color recall (%) 83 89 92 97 100 82.4 100

Example 11 Example 12 Example 13 Example 14 Example 15 Comparative Example 5 Comparative Example 6 Brightness (%) 107 105 103 102 100 107 97 Color recall (%) 85 90 92 98 100 82.4 100

Example 16 Example 17 Example 18 Example 19 Example 20 Comparative Example 7 Comparative Example 8 Brightness (%) 107 105 103 101 100 107 97 Color recall (%) 89 90 95 98 100 82.4 100

Example 21 Example 22 Example 23 Example 24 Example 25 Comparative Example 9 Comparative Example 10 Brightness (%) 107 107 103 101 100 107 97 Color recall (%) 88 91 97 95 100 82.4 100

100: base film 114: YAG-base phosphor
122: pigment

Claims (8)

A high-luminance film for a liquid crystal display device, wherein a YAG-base phosphor and a pigment are contained in 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-based fluorescent material is contained in an amount of 10 to 40 wt%. The method according to claim 1,
The high-luminance film for a liquid crystal display device according to claim 1, wherein the pigment is contained in an amount of 0.01 to 5 wt%. 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 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. Based fluorescent material 10 (hereinafter referred to as " YAG fluorescent material 10 ") is added to at least one resin selected from polyethylene terephthalate (PET), triacetylcellulose (TAC), polycarbonate (PC), polyimide, To 40 wt% and 0.01 to 5 wt% of pigment to prepare a mixture; And
And a step of preparing a base film according to a casting process of the mixture in a conventional film production method.

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