KR101961030B1 - Bright enhancing film and preparing method of the same - Google Patents

Abstract

The present invention relates to a brightness enhancement film and a method of manufacturing the same, and is characterized by including a base film layer, a brightness enhancement film including a YAG base phosphor dispersed in the base film layer and a LuAG base phosphor dispersed in the base film layer, The present invention can provide a brightness enhancement film having improved brightness, color reproducibility and physical properties, including a method of manufacturing a brightness enhancement film produced by uniformly dispersing a YAG-base phosphor and a LuAG-based phosphor in a casting process.

Description

Brightening Enhancing Film and Preparation Method Thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brightness enhancement film and a method of manufacturing the brightness enhancement film, and more particularly, to a brightness enhancement film and a method of manufacturing the same that can improve brightness, color reproducibility and physical properties.

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 (DBEF) ) 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 that can improve the luminance of LCD without using DBEF is developed, it is expected to contribute to the activation of the domestic display market.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a brightness enhancement film capable of improving luminance, color reproduction rate, and physical characteristics to replace DBEF.

As means for solving the above-mentioned technical problem,

The present invention relates to an optical film comprising a base film layer; A YAG-base phosphor dispersed in the base film layer; And a LuAG-based phosphor dispersed in the base film layer.

In this case, the YAG-based fluorescent material may be Y ₃ Al ₅ O ₁₂ : Ce ³⁺ (YAG: Ce), Tb ₃ Al ₅ 0 ₁₂ : Ce ³⁺ (TAG: Ce), Y ₃ Mg ₂ AlSi ₂ O ₁₂ : Ce ³⁺ , and Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce ³⁺ .

In this case, the LuAG-based fluorescent material includes at least one selected from Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ , Tb ₃ Al ₅ O ₁₂ : Ce ³⁺ , Lu ₂ CaMg ₂ Si ₃ O ₁₂ : Ce ³⁺ can do.

In this case, the YAG-base phosphor may be added in an amount of 10 to 40 wt% based on 100 wt% of the base film layer composition.

In this case, the LuAG-based phosphor may be added in an amount of 1 to 20 wt% based on 100 wt% of the base film layer composition.

In this case, the brightness enhancement film may include a back coating layer including PMMA and an antistatic agent on one side.

In this case, the back coating layer may contain 0.1 to 5 wt% of the PMMA.

In this case, the back coat layer may contain 0.01 to 3 wt% of the antistatic agent.

The present invention also provides a process for producing a brightness enhancement film, characterized in that the YAG-base phosphor and the LuAG-base phosphor are uniformly dispersed in a molten resin and then produced through a casting process.

According to the present invention, by uniformly dispersing the YAG-base phosphor and the LuAG-base phosphor in the base film layer at a predetermined ratio, it is possible to improve the brightness and color reproduction ratio when applied to an LCD to realize excellent color, , Bending resistance, and the like.

In addition, since the YAG-base phosphor and the LuAG-base phosphor are included in the base film itself, a separate coating process is unnecessary, thereby improving the productivity.

1 is a laminated structure of a brightness enhancement film according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

1 is a laminated structure of a brightness enhancement film according to the present invention.

1, the brightness enhancement film 100 according to the present invention includes a base film layer 110, a YAG-base phosphor 120, and a LuAG-base phosphor 130. As shown in FIG.

The base film layer 110 is made of a conventional resin used as a film material such as PET, TAC, PC, polyimide, and acryl.

The YAG-base phosphor 120 and the LuAG-base phosphor 130 are uniformly dispersed in the base film layer 110 at a predetermined ratio for the purpose of enhancing brightness, color reproducibility and physical properties.

In this case, the YAG-based fluorescent material is preferably Y ₃ Al ₅ O ₁₂ : Ce ³⁺ (YAG: Ce), Tb ₃ Al ₅ 0 ₁₂ : Ce ³⁺ (TAG: Ce), Y ₃ Mg ₂ AlSi ₂ O ₁₂ : Ce ^{3 +} , Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce ³⁺ , and is added in a proportion of 10 to 40 wt% based on 100 wt% of the composition for improving brightness . When the content of the YAG-base phosphor 120 is less than 10 wt%, the desired brightness enhancement effect can not be exhibited. If the content is more than 40 wt%, the coating is difficult and the color reproduction rate is lowered.

Further, the LuAG-based phosphor 130 may include at least one selected from Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ , Tb ₃ Al ₅ O ₁₂ : Ce ³⁺ , Lu ₂ CaMg ₂ Si ₃ O ₁₂ : Ce ³⁺ And is added in a proportion of 1 to 20 wt% based on 100 wt% of the composition for improving the brightness of the film (100). If the content of the LuAG-based phosphor 130 is less than 1 wt%, the desired brightness enhancement effect can not be exhibited. If the content of the LuAG-based phosphor 130 is more than 20 wt%, coating is difficult and the color reproduction rate is lowered.

Meanwhile, the brightness enhancement film 100 may further include a back coating layer (not shown). The back coating layer is formed by the particles included in the back coating layer to provide irregularities on the back surface of the brightness enhancement film 100 to prevent blocking with other optical sheets to improve workability and to prevent static electricity Function.

In the present invention, the back coating may be a bar coating method or a slot-die coating method. The coating solution used for the back coating layer may include a urethane acrylate oligomer, a monofunctional monomer, a photoinitiator, a leveling agent, .

In this case, the PMMA particles are preferably contained in an amount of 0.1 to 5 wt% with respect to the entire back coating layer. When the content of PMMA particles is less than 0.1 wt%, sufficient irregularities can not be formed on the back surface of the brightness enhancement film. If the content of PMMA particles is more than 5 wt%, transmitted light loss due to high haze occurs. Therefore, the haze of the back coating layer is adjusted to 1 To 20%.

An antistatic agent may be added to the back coat layer as an additive if necessary. The surface resistance can be controlled by adding an antistatic agent, and the antistatic agent is preferably contained in an amount of 0.01 to 3 wt% with respect to the whole of the back coat layer. When the content of the antistatic agent is less than 0.01wt%, and a lack of surface resistance for antistatic, 3wt% excess if it results in the addition of excess amount more than necessary to the antistatic agent 0.01 ~ 3wt% surface resistance of 10 ¹⁰ to 10 by the addition ¹² Ohm / < / RTI >< / RTI > This is because, when the surface resistance is 10 ¹⁰ to 10 ¹² Ohm / square, it is possible to prevent the film from being damaged in the dynamic state, and there is an effect that the charging phenomenon immediately after charging immediately attenuates.

The thickness of the back coating layer is preferably 1 to 10 mu m. If the thickness of the back coating layer is less than 1 mu m, sufficient irregularities are not formed on the back surface of the brightness enhancement film 100 to prevent blocking, and if it is more than 10 mu m, there is a problem of transmission light loss due to high haze.

The brightness enhancement film according to the present invention has been described above. Hereinafter, a method for manufacturing a brightness enhancement film according to the present invention will be described.

First, the YAG-base phosphor 120 and the LuAG-base phosphor 130 are uniformly dispersed in a molten resin such as PET, TAC, PC, Polyimide, Acryl or the like at a ratio of 10 to 40 wt% and 1 to 20 wt% ) Process for producing the brightness enhancement film 100. [

In this case, in the casting step, a thermoplastic chip produced through a polymerization process is melted and discharged into a die having a predetermined width to produce a sheet, followed by biaxial stretching to produce a stretched film An extruder process in which a dried thermoplastic resin chip is supplied and heated and melted and then extruded in a T-die, a T-die process in which molten resin is discharged through a slit gap to form a molten chip, Casting roll process to produce Melt Resin discharged from die by solidification and solidification to produce casting sheet form, MDO process to longitudinally stretch using casting sheet after heat is applied to roll, A TDO process for transversely stretching and thermally fixing the film, a T / U & Winder process for cutting both ends of the film and winding the product fabric, a winding process, and a packaging process.

The method for manufacturing the brightness enhancement film according to the present invention has been described above. Hereinafter, embodiments of the present invention will be described. The present invention can be understood more clearly by the following examples, which are merely illustrative of the present invention and are not intended to limit the scope of the present invention.

First Production Example

900 Kg of PET Chip of Mw = 40,000 g / mol prepared by the polymerization process was melted, 100 Kg of YAG fluorescent material (10 wt% relative to Resin) was precisely dispersed in the melted PET chip, And then the PET film 100M was produced through the biaxial stretching process. The specific film-forming process is as follows.

900 Kg of PET Chip produced through the polymerization process was fed and melted. 100 Kg of YAG phosphor was precisely dispersed through a high-temperature mixer and then extruded to a T-die to quantitatively extrude a molten PET chip in which a phosphor was precisely dispersed. , Melt PET Resin was discharged through a slit gap (300 μm), and Melt Resin was rapidly quenched and hardened in a casting roll to produce a casting sheet. Thereafter, heat was applied to the casting sheet at 120 ° C, and longitudinal stretching was performed using a roll primary speed (10M / min speed). The both sides of the sheet were stretched by 110% stretched with a clip and driven at a speed of 10M / Of PET film was wound up at 100M.

Example 2

890 Kg of a PET chip of Mw = 40,000 g / mol produced by a polymerization process was melted and 100 Kg of YAG fluorescent material (10 wt% of Resin) and 10 Kg of LuAG fluorescent material (1 wt% of Resin) were finely dispersed in the melted PET chip The PET film 100M was produced through a biaxially stretching process. The specific film-forming process is as follows.

890 Kg of PET Chip produced by the polymerization process was fed and melted. 100 Kg of YAG phosphor and 10 Kg of LuAG phosphor were precisely dispersed through a high-temperature mixer and then extruded in a T-die to obtain a molten PET chip in which the phosphor was precisely dispersed Melt PET Resin was discharged through a slit gap (300 μm) to form a sheet, and Melt Resin was rapidly quenched and hardened in a casting roll to produce a casting sheet. Thereafter, heat was applied to the casting sheet at 120 ° C, and longitudinal stretching was performed using a roll primary speed (10M / min speed). The both sides of the sheet were stretched by 110% stretched with a clip and driven at a speed of 10M / Of PET film was wound up at 100M.

Third Manufacturing Example

Except that the PET chip of 850 kg was used and the content of the YAG fluorescent material was adjusted to 100 Kg (10 wt% with respect to Resin) and the content of the LuAG fluorescent material to 50 Kg (5 wt% with respect to Resin) PET film was prepared.

Fourth Production Example

800 Kg PET Chip was used and the content of the YAG phosphor was adjusted to 100 Kg (10 wt% relative to Resin) and the content of the LuAG phosphor was adjusted to 100 Kg (10 wt% relative to Resin). PET film was prepared.

Fifth Manufacturing Example

A PET film was prepared in the same manner as in the first production example except that 800 Kg PET Chip was used and the content of YAG phosphor was adjusted to 200 Kg (20 wt% based on Resin).

Example 6

A PET film was produced in the same manner as in the second production example except that 790 Kg of PET chip was used and the content of YAG phosphor was adjusted to 200 Kg (20 wt% relative to Resin) and 10 Kg of LuAG phosphor (1 wt% relative to Resin) Respectively.

Seventh Manufacturing Example

750 Kg PET Chip was used and the content of the YAG fluorescent substance was adjusted to 200 Kg (20 wt% relative to Resin) and the content of the LuAG fluorescent substance was adjusted to 50 Kg (5 wt% relative to Resin) To prepare a PET film.

Example 8

600 Kg PET Chip was used and the content of the YAG fluorescent substance was adjusted to 200 Kg (20 wt% relative to Resin) and the content of the LuAG fluorescent substance was adjusted to 200 Kg (20 wt% relative to Resin) To prepare a PET film.

Ninth Production Example

A PET film was prepared in the same manner as in the first production example except that a 600 Kg PET Chip was used and the content of the YAG fluorescent material was adjusted to 400 Kg (40 wt% relative to Resin).

Example 10

A PET film was produced in the same manner as in the second production example except that 590 Kg of PET chip was used and the content of YAG phosphor was adjusted to 400 Kg (40 wt% relative to Resin) and 10 Kg of LuAG phosphor (1 wt% relative to Resin) .

Example 11

550 Kg PET Chip was used and the content of the YAG fluorescent material was adjusted to 400 Kg (40 wt% with respect to Resin) and the content of the LuAG fluorescent material was adjusted to 50 Kg (5 wt% with respect to Resin) To prepare a PET film.

Example 12

500 Kg PET Chip was used and the content of the YAG fluorescent substance was adjusted to 400 Kg (40 wt% with respect to Resin) and the content of the LuAG fluorescent substance was adjusted to 100 Kg (10 wt% with respect to Resin) To prepare a PET film.

Example 13

A PET film was produced in the same manner as in the first production example except that 950 kg of PET chip was used and the content of the YAG fluorescent material was adjusted to 50 Kg (5 wt% based on Resin).

Example 14

A PET film was prepared in the same manner as in the second production example except that 940 Kg PET Chip was used and the content of YAG phosphor was adjusted to 50 Kg (5 wt% based on Resin).

Example 15

Except that a 900 Kg PET Chip was used and the content of the YAG fluorescent material was adjusted to 50 Kg (5 wt% relative to Resin) and the content of the LuAG fluorescent material was adjusted to 50 Kg (5 wt% relative to Resin) To prepare a PET film.

Example 16

Except that the PET chip of 850 Kg was used and the content of the YAG fluorescent material was adjusted to 50 Kg (5 wt% based on Resin) and the content of the LuAG fluorescent material was adjusted to 100 Kg (10 wt% based on Resin) To prepare a PET film.

Example 17

A PET film was prepared in the same manner as in the first production example except that 500 Kg PET Chip was used and the content of the YAG fluorescent material was adjusted to 500 Kg (50 wt% relative to Resin).

Example 18

A PET film was prepared in the same manner as in the second production example except that 490 Kg PET Chip was used and the content of YAG phosphor was adjusted to 500 Kg (50 wt% relative to Resin).

Article 19 Manufacturing Example

450 Kg PET Chip was used and the content of the YAG phosphor was adjusted to 500 Kg (50 wt% relative to Resin) and the content of the LuAG phosphor was adjusted to 50 Kg (5 wt% relative to Resin). PET film was prepared.

Example 20

400 Kg PET Chip was used and the content of the YAG phosphor was adjusted to 500 Kg (50 wt% relative to Resin) and the content of the LuAG phosphor was adjusted to 100 Kg (10 wt% relative to Resin). PET A film was prepared.

Example 21

Except that a PET chip of 895 kg was used and the content of the YAG fluorescent substance was adjusted to 100 kg (10 wt% relative to Resin) and the content of the LuAG fluorescent substance was adjusted to 5 kg (0.5 wt% relative to Resin) PET film was prepared.

Article 22 Manufacturing Example

750 Kg PET Chip was used and the content of the YAG fluorescent material was adjusted to 100 Kg (10 wt% relative to Resin) and the content of the LuAG fluorescent material was adjusted to 150 Kg (15 wt% relative to Resin). PET A film was prepared.

The following Table 1 summarizes the components and compositions of the first to twenty-second production examples.

Manufacturing example One 2 3 4 5 6 7 8 9 10 11 12 PET Chip 900 890 850 800 800 790 750 600 600 590 550 500 YAG phosphor 100 100 100 100 200 200 200 200 400 400 400 400 LuAG phosphor 10 50 100 10 50 200 10 50 100 Total
(kg) 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 Manufacturing example 13 14 15 16 17 18 19 20 21 22 PET Chip 950 940 900 850 500 490 450 400 895 750 YAG phosphor 50 50 50 50 500 500 500 500 100 100 LuAG phosphor 10 50 100 10 50 100 5 150 Total
(kg) 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000

Example

The brightness enhancement films prepared according to the first to twelfth production examples were cut into A4 size, and LCDs were manufactured using the same. Then, the brightness and color gamut were measured. The results are shown in Table 2 below. . In this case, the LCD is composed of a light source (Blue LED), a POP (Prism on Prism) film, and a liquid crystal panel, and a luminance enhancement film is disposed between the light source and the POP film. Also, the luminance was measured using a BM-7 FAST color luminance meter manufactured by Topcon Co., Ltd. of Japan.

Manufacturing example One 2 3 4 5 6 7 8 9 10 11 12 YAG: LuAG
[wt%] 10: 0 10: 1 10: 5 10:10 20: 0 20: 1 20: 5 20:20 40: 0 40: 1 40: 5 40:10 Luminance
[nit] 430 450 500 550 480 520 560 600 540 550 580 620 Color Reproducibility
[%] 81.3 81.8 82.4 82.6 82.6 82.3 82.4 82.6 81.3 81.2 81.4 81.6 - Ref. DBEF (LED TV): 430 nit (luminance), 81.6% (color reproducibility)
- Ref. DBEF (QD TV): 450nit (luminance), 100% (color reproducibility)

Comparative Example

The brightness and color reproduction ratio of the brightness enhancement films prepared in Examples 13 to 22 were measured in the same manner as in Examples, and the results are shown in Table 3 below.

Manufacturing example 13 14 15 16 17 18 19 20 21 22 YAG: LuAG
[wt%] 5: 0 5: 1 5: 5 5:10 50: 0 50: 1 50: 5 50:10 10: 0.5 10:15 Luminance
[nit] 230 280 290 330 500 510 530 540 400 560 Color Reproducibility
[%] 79.8 79.3 79.3 78.3 75.0 72.3 71.3 71.3 81.0 75.0 - Ref. DBEF (LED TV): 430 nit (luminance), 81.6% (color reproducibility)
- Ref. DBEF (QD TV): 450nit (luminance), 100% (color reproducibility)

100: brightness enhancement film 110: substrate film
120: YAG-base phosphor layer 130: LuAG-base phosphor

Claims (9)

A base film layer;
A YAG-base phosphor dispersed in the base film layer; And
A LuAG-based phosphor dispersed in the base film layer;
, ≪ / RTI &
Wherein the YAG-base phosphor is at least one selected from the group consisting of Tb ₃ Al ₅ 0 ₁₂ : Ce ³⁺ (TAG: Ce), Y ₃ Mg ₂ AlSi ₂ O ₁₂ : Ce ³⁺ , Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce ³⁺ And the LuAG-based fluorescent material is at least one selected from the group consisting of Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ , Tb ₃ Al ₅ O ₁₂ : Ce ³⁺ , Lu ₂ CaMg ₂ Si ₃ O ₁₂ : Ce ³⁺ in an amount of 1 to 20 wt% based on 100 wt% of the base film layer composition. delete delete delete delete The method according to claim 1,
Wherein the brightness enhancement film comprises a back coating layer including PMMA and an antistatic agent on one surface thereof. The method according to claim 6,
Wherein the back coating layer contains 0.1 to 5 wt% of the PMMA. The method according to claim 6,
Wherein the back coating layer contains 0.01 to 3 wt% of the antistatic agent. Tb ₃ Al ₅ O ₁₂ : Ce ³⁺ (TAG: Ce), Y ₃ Mg ₂ AlSi ₂ O ₁₂ : Ce ³⁺ , and Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce ³⁺ 10 to 40 wt% of at least one YAG-based phosphor to be used, and Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ , Tb ₃ Al ₅ O ₁₂ : Ce ³⁺ , and Lu ₂ CaMg ₂ Si ₃ O ₁₂ : Ce ³⁺ Characterized in that 1 to 20 wt% of at least one LuAG-based phosphor is uniformly dispersed and then produced through a casting step.

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