WO2014007577A1

WO2014007577A1 - Method for producing diffuser sheet having irregular shapes, and diffuser sheet produced by the method

Info

Publication number: WO2014007577A1
Application number: PCT/KR2013/005997
Authority: WO
Inventors: 최윤기; 한창렬; 김정목; 서동규; 조재형
Original assignee: ㈜코이즈
Priority date: 2012-07-06
Filing date: 2013-07-05
Publication date: 2014-01-09
Also published as: KR101262723B1

Abstract

The present invention relates to a method for producing a diffuser sheet having irregular shapes, comprising: a first step of performing a sanding treatment on the surface of a metal roll or flat plate and degreasing the surface; a second step of performing matting treatment on the degreased surface of the metal roll or flat plate; and a third step of producing highly transparent, high haze diffuser sheet having irregular shapes corresponding to the matte surface of the metal roll or flat plate using an ultraviolet-curable resin solution.

Description

Method for producing irregularly shaped diffusion sheet and diffusion sheet produced accordingly

The present invention relates to a method for producing a high transparency high haze diffusion sheet, and more particularly, to a method for producing a high transparency high haze diffusion sheet exhibiting the same optical properties excellent in productivity and processability, and a diffusion sheet prepared accordingly. .

The diffusion sheet having an irregular shape manufactured according to the present invention may implement high transparency and high haze, thereby realizing high luminance when mounting a backlight unit (BLU).

The liquid crystal display device is one of flat panel display devices that display images using liquid crystals. The liquid crystal display device is thinner and lighter than other display devices, and has a low driving voltage and low power consumption.

Since the liquid crystal display device is a non-light emitting device in which a display panel displaying an image does not emit light by itself, a separate backlight assembly for supplying light to the display panel is required.

The backlight assembly includes a light source for generating light, a light guide plate that receives light from the light source, and emits the light upwardly, and a diffusion sheet for diffusing the light emitted through the light guide plate to the entire surface of the panel.

The diffusion sheet disperses light emitted from the light guide plate toward the front, thereby improving brightness uniformity of the backlight assembly.

In general, the diffusion sheet is manufactured by fixing a light diffusion layer containing a light diffusion material such as silica, calcium carbonate, titanium oxide, glass beads, etc. to the substrate of the transparent material (Korea Patent No. 1996-0015775). However, the light diffusion layer exhibits technical limitations in manufacturing a diffusion sheet having the same optical properties because beads are agglomerated or viscosity changes with time during mass production. In order to solve this problem, active attempts have been made on the manufacturing method of the diffusion sheet.

For example, Korean Patent Laid-Open Publication No. 2009-0014623 discloses a method for forming bubbles having a size of 1 to 20 μm through thermal decomposition of a blowing agent in a light diffusion layer for the purpose of improving diffusion performance. However, this method is limited in implementing high haze.

In addition, Korean Patent Laid-Open Publication No. 2007-0003974 discloses suppressing moire and interference fringes by forming a polygonal concave-convex surface with a depth of several micrometers by using a transfer method on a light diffusion sheet surface. However, this method cannot produce a large amount of diffusion sheets having the same optical properties, and cannot realize high haze and high brightness.

In addition, Korean Patent Publication No. 2010-0131923 discloses a method of manufacturing a diffusion sheet having a convex structure formed by using a shape transfer process, and Korean Patent No. 0882992 discloses a diffusion formed by containing a light diffusing agent in a resin. The sheet is disclosed. However, the diffusion sheet produced by this method shows a low haze value.

In addition, Korean Patent No. 1000440 discloses a diffusion sheet including a diffusion layer including a plurality of first protrusions and a plurality of first grooves on one surface of a base film. The diffusion layer includes a plurality of diffusion particles, and the convex portion and the groove portion are formed by a plurality of diffusion particles included in the diffusion layer. However, such a plurality of detachment phenomena exhibits a problem of lowering the diffusion rate of the diffusion sheet and lowering the reliability of the light efficiency of the backlight unit after mounting.

In addition, Korean Patent Application No. 2012-0035728 uses a method of transferring a shape by molding a diffusion sheet using beads to form nano-sized protrusions or depressions on the transfer shape surface to realize high haze. The diffusion sheet using the soft mold transfer method has a disadvantage that the manufacturing process is complicated and expensive.

In order to solve such a conventional problem, the present invention provides a method for producing a high-transparent high haze diffusion sheet and a diffusion sheet manufactured according to the above, characterized in that to produce a diffusion sheet of irregular shape using a sanding and easy processing process. It aims to do it.

In order to achieve the above object, the present invention

A first step of degreasing after sanding the metal roll or plate surface;

A second step of easy treating the degreasing metal roll or flat surface; And

It provides a method for producing an irregular diffusion sheet comprising a; a third step of producing a highly transparent high haze diffusion sheet of irregular shape corresponding to the surface of the easy-treated metal roll or flat plate using an ultraviolet curable resin solution.

According to the present invention, by processing the surface of the metal roll or the flat plate and using the surface as a hard mold, it is possible to produce a diffusion sheet capable of high haze having an irregular shape.

In addition, the diffusion sheet manufacturing method of the present invention has the advantage that the manufacturing process is simple by not using the beads and the diffusion agent. In addition, the present invention can be mass-produced at a low cost with high transparency and high haze diffusion sheet, which is very excellent in shielding the moiré phenomenon or the white point phenomenon when mounting the BLU due to the irregular shape. The diffusion sheet manufactured according to the present invention may implement high transparency and high haze, thereby realizing high luminance when BLU is mounted.

1 is a process chart showing the manufacturing method of the irregularly shaped diffusion sheet of the present invention.

Figure 2a is a photograph of the surface of the diffusion sheet prepared in Example 1 of the present invention under a microscope (surface shape 2000 times, 3D shape 2,000 times), Figures 2b and 2c is a surface of the produced diffusion sheet (500 times magnification) ) And a SEM photograph of the cut surface (500 magnification).

3A and 3B are photographs taken with a microscope (surface shape 400 times, 3D shape 1,000 times) of a film on the surface of an aluminum roll according to Example 2 of the present invention.

4A and 4B are photographs of the aluminum roll surface subjected to the sanding processing step of the first step of Example 3 of the present invention, and FIGS. 4C and 4D are micrographs of the degreasing aluminum roll surface of the first step. The surface shape is 400 magnification, 3D shape 1,000 magnification), and FIGS. 4E and 4F are SEM images of the surface (2,500 magnification) and the cut surface (1,000 magnification) of the film transferred to the degreasing aluminum roll surface of the first step.

4G and 4H are micrographs (surface shape 400 times, 3D shape 1,000 times) of the diffusion sheet prepared according to Example 3 of the present invention, and FIGS. 4I and 4J illustrate the surface (2,500) of the prepared diffusion sheet. Magnification) and the cut surface (1,000 times).

5A and 5B are photographs taken with a microscope of the surface of the diffusion sheet prepared in Example 4 of the present invention (surface shape 400 times, 3D shape 1,000 times).

6 is a SEM photograph of the surface of the bead type diffusion sheet prepared according to Comparative Example 1 of the present invention.

Figure 7 shows the BLU configuration for measuring the brightness of the diffusion sheet produced in the present invention, it is a comparative measurement of the displayed downdiffusion.

Hereinafter, with reference to the accompanying drawings will be described the present invention in more detail.

The present invention comprises a first step of degreasing after sanding the surface of the metal roll or plate;

A second step of easy treating the degreasing metal roll or flat surface; And

And a third step of manufacturing a highly transparent high haze diffusion sheet having an irregular shape corresponding to the surface of the easy-treated metal roll or flat plate using an ultraviolet curable resin solution.

The first step of the present invention is an important step for implementing a high transparency, high haze and non-uniform shape of the diffusion sheet, by sanding the surface of the metal roll or flat plate using a sanding ball to form an irregular shape on the surface Include.

The metal material may be aluminum (Al), magnesium (Mg), silicon (Si), manganese (Mn), copper (Cu), iron (Fe), nickel (Ni), tin (Sn), chromium (Cr), One kind or alloys thereof selected from the group consisting of lead (Pb), zinc (Zn) and titanium (Ti) may be used. In consideration of functional properties such as economy, workability, surface hardness, corrosion resistance, abrasion resistance, and electrical insulation, a metal material made of magnesium, titanium, aluminum, or an aluminum alloy is preferable.

Aluminum is classified variously depending on the metal added. They are broadly classified into whole body materials such as plates, pipes, wires, rods, and forged products, and casting materials such as mold castings and die casts.

The whole body material is 1000 series with high purity, 2000 series with copper, 3000 series with manganese, 4000 series with silicon, 5000 series with magnesium, 6000 series with magnesium and silicon, zinc and magnesium It can be classified into 7000 series containing these.

The cast material is a non-heat treatment alloy (pure aluminum, Al-Si-based AC 3A, Al-Mg-based AC 7A.B, Al-Cu-Si-based AC 2A.B, Al-Cu-based AC 1A) and heat treatment alloy (Al- Cu-Mg-Si-based AC 8A.B.C, Al-Mg-Si-based AC 4A.C).

In the present invention, an alloy containing any metal may be used. However, depending on the type of metal contained may slightly vary in the color of the surface during etching and easy treatment.

The sanding ball used in the sanding process is preferably from 1 to 500 ㎛ in diameter with a gold steel yarn, SUS ball or glass bead, more preferably from 20 to 400 ㎛ in consideration of economical and workability. Compared with other materials in terms of surface roughness, SUS balls have a very large surface finish difference due to the strong impact. In the case of sanding, the discharge pressure is preferably 0.1 to 1 MPa.

In the present invention, the surface roughness measurement value after the surface treatment was evaluated by comparing the center line average roughness Ra and the 10-point average roughness Rz measurement. By comparing the roughness before and after the stepwise processing, the surface processing state can be confirmed.

The metal roll or plate surface after sanding is a transfer film (KOLON Corporation) H32F, PET 125㎛ fabric, coating thickness within 100㎛) can be measured using. On the surface of the metal roll or flat plate after sanding, irregular shapes having a machining height difference of 2 to 50 µm formed by circular sanding balls are formed. Ra 1-10 탆, Rz 5-50 탆, haze of 85% or more, transmittance of 75% It is preferable that it is above.

In addition, the first step of the present invention is a degreasing treatment for cleaning by a method such as solvent degreasing, alkali degreasing, acidic degreasing, electrolytic degreasing, emulsion degreasing, mechanical degreasing as a method of removing the oil-retaining dirt attached to the metal surface after the sanding process Steps. In the present invention, any degreasing method may be used, and is not particularly limited. In a preferred embodiment, the foreign matter and organic matter can be removed by washing for 5 seconds to 5 minutes in a weakly acidic solution having a pH of 3-7.

Degreased metal rolls or plate surfaces can also be measured using a transfer film. On the surface of the degreasing metal roll or flat plate, irregular shapes with a difference in processing height of 2 to 50 μm are formed, surface roughness is Ra 1 to 10 μm, Rz 5 to 50 μm, and the haze is 90% or more higher than after sanding. The transmittance is preferably 75% or more.

The second step is the most important step in the present invention, by applying a curved surface to the rough surface of the degreasing metal roll or flat plate by the sanding process to increase the optical dispersion and brightness optically Step.

Easy treatment is a process of etching or surface embossing a sanded metal roll or plate surface to corrode a metal surface using an acid or alkaline solution to form a curvature surface. In a preferred embodiment of the present invention, an alkaline solution having a pH of 10 to 14, for example, sodium carbonate, sodium silicate, caustic soda, caustic potassium, etc. is treated within 5 seconds to 5 minutes or an acidic solution of pH 0-3, for example acidic. Treat within 5 seconds to 5 minutes with ammonium fluoride, ammonium fluoride, chromic acid, hydrofluoric acid, boric acid, nitric acid, phosphoric acid, sulfuric acid, dichromic acid, potassium pyrophosphate, ammonium bifluoride, aluminum chloride, iron chloride, etc.

The metal roll or plate surface after easy processing can also be measured using a transfer film. An irregular shape with a difference in processing height of 2 to 50 μm is formed on the surface of the easy-treated metal roll or flat plate, and the surface roughness is Ra 1 to 10 μm, Rz 5 to 50 μm, and the haze is 90%. As mentioned above, it is preferable that the transmittance | permeability is 75% or more.

The third step is a step of manufacturing a diffusion sheet by forming a transfer film corresponding to the surface of the easy-treated metal roll or flat plate using an ultraviolet curable resin solution. In this case, the resin for transfer film used is preferably an ultraviolet curable resin having a refractive index of 1.44 to 1.55. When the resin refractive index is out of the above range, there is a problem that the production cost increases due to the increase in the price of the resin. From the light diffusion perspective, the lower the resin refractive index, the lower the haze. In addition, in consideration of releasability, the resin preferably has an elasticity having a glass transition temperature (Tg) of 100 ° C. or less.

Examples of the ultraviolet curable resin usable in the present invention may be an alkyl (meth) acrylate as the resin that realizes a low glass transition temperature, preferably caprolactone acrylate, octyldecyl acrylate or isoocta. Methyl acrylate, lauryl (meth) acrylate, isodecyl (meth) acrylate, ethylene oxide addition (2-8 mol) phenol acrylate, tetrahydrofuran acrylate, ethoxyethoxyethyl acrylate, stearyl ( Meth) acrylate, 1,6-hexanediol di (meth) acrylate, ethylene oxide addition (2-10 mol) 1,6-hexanediol diacrylate, butanediol di (meth) acrylate, neopentylglycol di ( Meth) acrylate, propylene oxide addition (2-4 mole) neopentyl glycol diacrylate, tripropylene glycol di (meth) acrylate, dipropylene glycol di (meth) One or more types selected from the group consisting of acrylates and triethylene glycol di (meth) acrylates can be used.

Alternatively, an ethylene oxide addition bisphenol A type acrylate may be used as the ultraviolet curable resin for securing heat resistance and high temperature reliability. Preferably, bisphenol A (3 to 30 moles of ethylene oxide addition) di (meth) acrylate is used. And bisphenol A epoxy acrylate can be selected one or more.

Or polyethylene glycol di (meth) acrylate, ethylene oxide addition polyethylene glycol di (meth) acrylate, difunctional urethane acrylate, trifunctional urethane acrylate, silicone urethane (meth) acrylate and silicone to impart elasticity. One or more types selected from the group consisting of polyester acrylates can be used.

Or in order to improve the adhesive force with a base material, polyfunctional acrylate can be used, Preferably, a trimethylolpropane (meth) acrylate and ethylene oxide addition (3-15 mol) trimethylolpropane (meth) acrylate , Glycerin triacrylate, pentaerythritol tri (meth) acrylate, propylene oxide addition (3 mol) trimethylolpropane tri (meth) acrylate, tris 2-hydroxyethyl isocyanate triacrylate, ethylene oxide addition penta Erythritol tetraacrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) At least one selected from the group consisting of acrylate hexafunctional urethane acrylate can be used. .

Preferably, the ultraviolet curable resin solution contains at least one component selected from the group consisting of acrylate and urethane acrylate.

The ultraviolet curable resin solution may additionally include a photoinitiator, the photoinitiator may be used within 10% of the resin solids. Furthermore, it may contain 0.01 to 5% by weight of an antistatic agent based on the ultraviolet curable resin solid content.

In one embodiment of the present invention, between the easy-treated metal roll or plate surface and the prepared base film, a prepared resin for molding (ultraviolet curable resin solution) is injected and pressed with a pressing roll to irradiate ultraviolet rays to irradiate an irregularly shaped diffusion sheet. Can be prepared.

The base film is a transparent base film, a group consisting of polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), polypropylene (PP), polyethylene (PE) and polystyrene (PS) Although it is preferable to include at least 1 type selected from the above, in addition to being transparent, it does not inhibit the passage of light, and if it has characteristics, such as elasticity and durability corresponding to a desired use, it can be used in any one.

It is preferable that it is 20-500 micrometers, and, as for the thickness of the said base film, it is more preferable that it is 38-380 micrometers.

The method of manufacturing a diffusion sheet of the present invention may further include the step of etching the degreasing metal roll or plate surface before easy processing.

Etching is for etching easily the oxide film naturally formed on the surface of a metal roll or a flat plate. For etching, either an alkaline solution or an acidic solution may be used. In one embodiment of the present invention is treated within 1 second to 1 minute in a caustic soda solution of pH 10-14.

The method of manufacturing the diffusion sheet of the present invention may further include the step of sealing the surface of the easy-treated or etched and easy-treated metal roll or plate after anodizing (oxidation film formation).

Anodizing is a process of forming an oxide film having a very hard, corrosion resistance and extremely small porosity and wear resistance on a metal roll or flat plate surface. Specifically, anodizing is a process of producing a film of metal oxide (MxOy type, M is metal, x, y is positive) by electrochemical method by hanging metal parts on the anode.

Anodizing can be classified into the fishery method, sulfuric acid method and chromic acid method according to the chemicals used. In addition, the anodizing process can be divided into a hard anodizing process and a soft anodizing process, it is selectively used according to the purpose of use. The present invention is not particularly limited, and the hard anodizing method, which is advantageous in terms of hardness, is used, and an oxide layer of the metal oxide is formed on the metal surface using an electrochemical electrolytic method, such as hardness, corrosion resistance, abrasion resistance, electrical insulation, and the like. To give functionality.

In a preferred embodiment of the present invention, sulfuric acid was used to economically and industrially perform the oxide film formation process. That is, in the 20-25% sulfuric acid electrolytic solution, it was prepared so that the processing height difference is 2 ~ 50㎛ by treating with a hard coating condition of 0 ~ 5 ℃, current density 2 ~ 5A / dm ² , standard voltage 20 ~ 50V.

After the anodizing treatment, the water flow marks on the surface are removed by the acid through the first and second washings to maintain a clean surface free of contamination.

On the other hand, since the anodizing film formed as a result of the anodizing treatment is very active at the beginning of formation, if left as it is, it is contaminated by adsorbing gas in the air and the like. Sealing treatment methods include a hydration sealing treatment method, a metal salt sealing treatment method, an organic material sealing treatment method, a sealing treatment method by coating, etc. In one embodiment of the present invention, the metal salt sealing treatment method using nickel salt was performed.

In the mechanism of sealing, a metal salt aqueous solution enters the micropores of the anodized film, is hydrolyzed, and hydroxide is precipitated to seal the film.

Preferably, the sealing treatment may be performed by immersing in a sealing liquid containing 1 to 10% by weight of a nickel complex and 1 to 10% by weight of boric acid at 50 to 98 ° C for 20 to 30 minutes.

The surface after anodizing and sealing can also be measured using a transfer film. Anodized and sealed metal rolls or flat surfaces are irregularly formed with a very soft shape with a working height difference of 2 to 50 µm, surface roughnesses of Ra 1 to 10 µm, Rz 5 to 50 µm, and haze of 90% or more. It is preferable that the transmittance is 75% or more.

The manufacturing method of the diffusion sheet of the present invention may further include a step of neutralizing alkali and acid solutions remaining after the easy treatment using an acid solution after the easy treatment and before the anodizing process. Several washings after neutralization are performed to remove residual acid and alkali components.

The diffusion sheet produced according to the present invention preferably has a surface roughness of Ra 1 to 10 µm, Rz 5 to 50 µm, haze of 90% or more, and transmittance of 75% or more.

In addition, the diffusion sheet produced according to the present invention preferably has a surface resistance of 10 ¹⁵ or less.

In another aspect of the present invention, the diffusion sheet comprising an irregular shape prepared according to the present invention can be used as a transfer mold in the soft mold method of the irregular shape.

Hereinafter, the present invention will be described in more detail using examples and comparative examples. However, the following examples and comparative examples are intended to illustrate the present invention, the present invention is not limited by the following can be variously modified and changed.

First step: sanding and degreasing

Processed aluminum roll (Material: Aluminum Alloy Whole Material 6061, Surface Roughness Ra = 1㎛ or less, Diameter 300mm, Width 1,700mm) Discharge pressure 0.2MPa, Processing speed 15mm / min using SUS ball of 200 ~ 400㎛ size on the surface Sanding was performed. Then, the foreign material was removed by washing for 5 minutes in a weakly acidic acetic acid-nitrate solution having a pH of 6 (degreasing step).

Second step: easy processing

The aluminum roll sanded and degreased in the first step was treated in a 10% acidic ammonium fluoride (NH ₄ HF ₂ ) solution (pH = 1 or less) for 30 seconds. Then, in order to remove the acid solution present on the metal surface, the remaining acid component was removed by washing with water.

Third step: manufacturing a diffusion sheet

UV curable resin with a resin refractive index of 1.46, 65% of ethylene oxide added 1,6-hexanediol diacrylate (Miwon Corporation, product name: M202), 13% by weight of pentaerythritol tetraacrylate (Miwon Corporation, product name: M420) , Propylene 3 mole added trimethylolpropane triacrylate (Miwon Corporation, product name: M360) 15% by weight, Igacure 1173 (Shiba Corporation) 5% by weight, ionic surfactant (Khemton, product name: CHTA-402) 1 The weight% was stirred to prepare a mold resin (ultraviolet curable resin solution).

PET (product name: H32F Kolon Co., Ltd.) of 125 μm thick prepared substrate and the mold resin prepared in the second step were injected and irradiated with ultraviolet light with a light amount of about 20 to 500 mJ while pressing with a pressing roll to form an irregular shape. The diffusion sheet of was prepared. The film shape of the prepared diffusion sheet was observed, and the results are shown in FIGS. 2A, 2B, and 2C.

In addition, the optical properties were evaluated and the results are shown in Table 1. Surface roughness is Ra at 7.46 mu m, Rz at 25.77 mu m, haze at 94.2%, and transmittance at 80.8%.

The luminance of mounting the manufactured diffusion sheet on the BLU is the product name XL 513 (becomes 200 µm thick, 93.7% haze, 59.6% transmittance based on 550 nm), which is the bead type of Comparative Example 2 described later. Contrast luminance increased by 3.8%.

The same method as in Example 1 (20) except that the particle size of the ball was 40 to 100 µm, and the etching step before easy treatment (10% aqueous solution of caustic soda and washing with water after etching for 30 seconds at a liquid temperature of 70 ° C) was added. Diffusion sheet was prepared to have a shape of ~ 80㎛ 2 ~ 10㎛ height. The optical properties were evaluated and the results are shown in Table 1. The surface roughness is Ra 2.09 µm and Rz 9.19 µm, the haze is 92.1%, and the transmittance is 83.1%.

The film shape of the prepared diffusion sheet was observed, and the results are shown in FIGS. 3A and 3B. The luminance of mounting the manufactured diffusion sheet on the BLU is the product name XL 513 (becomes 200 µm thick, 93.7% haze, 59.6% transmittance based on 550 nm), which is the bead type of Comparative Example 2 described later. Contrast brightness increased 3.1%.

First step: sanding and degreasing

Sanding was performed at a discharge pressure of 0.2 MPa and a processing speed of 15 mm / min using a gold steel sand or glass bead ball having a size of 40 to 100 μm on the processed aluminum roll surface.

The surface of the aluminum roll after the sanding process was measured using a transfer film (product name: H32F Kolon, PET 125 µm fabric, coating thickness within 20 µm), and was broken by circular sanding balls as shown in FIGS. 4A and 4B. An irregular shape having a shape size of 20 to 80 µm and a processing height difference of 2 to 10 µm was formed, and the surface roughnesses were Ra 1.75 µm and Rz 7.8 µm.

Then, the foreign material was removed by washing for 5 minutes in a weakly acidic acetic acid-nitrate solution having a pH of 5 (degreasing step). As a result of measuring the surface of the aluminum roll after the degreasing process using a transfer film, as shown in FIGS. 4C, 4D, 4E, and 4F, the shape of the microparticle mass having a processing height of 2 to 10 μm with a size of 20 to 80 μm is shown. This very irregular shape was formed, the surface roughnesses of Ra were 1.77 탆 and Rz 8.19 탆, the haze was 93.1%, and the transmittance was 78.9%.

Second Step: Etching and Easy Processing

The aluminum roll sanded and degreased in the first step was immersed in an aqueous solution of caustic soda (pH = 14) for about 10 seconds, and then washed with water (etching treatment). It was then treated for 30 seconds in a 10% acidic ammonium fluoride (NH ₄ HF ₂ ) solution (pH = 1 or less) (easy treatment). Then, in order to remove the acidic solution present on the metal surface, it was washed with water to remove the residual acidic component.

Third step: anodizing and sealing

Anodizing treatment is a well-known method (Industrial Chemistry Prospect, Vol. 2 (3), 1999, p. 3-10, J. Corros Sci. Soc. Of Korea, Vol. 26 (6), 1997, p.408 ~). 501). That is, the method used was sulfuric acid method, the sulfuric acid concentration of the electrolyte solution was 22%, and treated with the specimen in the bath temperature 2 ℃, current density 3A / dm ² , standard voltage 30V region using an SCR rectifier. While checking the surface of the specimen, the surface shape height was adjusted to be located in the region of about 8 μm. After the anodizing treatment, the first and second flushes were used to create a clean surface free of traces of water flow by the acid.

The anodized aluminum roll was immersed in an aqueous solution containing 5% by weight of complex nickel and 5% by weight of boric acid at 98 ° C. for 30 minutes to complete the sealing. In addition, water washing was added once to produce an aluminum roll having a clean surface.

Fourth Step: Diffusion Sheet Manufacturing

PET (product name: H32F Kolon Co., Ltd.) of 125 μm thick prepared substrate and the resin prepared in the mold prepared in the third step were injected and pressed with a compression roll to irradiate ultraviolet rays with a light amount of about 20 to 500 mJ to form an irregular shape. The diffusion sheet of was prepared. The film shape of the prepared diffusion sheet was observed, and the results are shown in FIGS. 4G, 4H, 4I, and 4J.

In addition, the optical properties were evaluated and the results are shown in Table 1. As for surface roughness, Ra is 1.86 micrometers, Rz is 8.39 micrometers, haze is 92.0%, and the transmittance | permeability is 83.9%.

The luminance of mounting the manufactured diffusion sheet on the BLU is the product name XL 513 (becomes 200 µm thick, 93.7% haze, 59.6% transmittance based on 550 nm), which is the bead type of Comparative Example 2 described later. Contrast luminance increased by 4.9%.

A diffusion sheet was prepared in the same manner as in Example 3 (2 to 10 µm in height and 8 to 9 µm in anodizing oxide film) in the same manner as in Example 3 except that the sanding particle size was 210 to 400 µm. The surface roughness of the prepared diffusion sheet was 1.84 µm Ra, 8.27 µm Rz, 92.2% haze, and 83.5% transmittance. The film shape of the prepared diffusion sheet was observed and the results are shown in FIGS. 5A and 5B.

After mounting the manufactured diffusion sheet in the backlight unit (BLU) and the luminance was measured, the product name XL 513 of the bead type of Comparative Example 2 described later Contrast luminance increased by more than 4.8%.

Example 5

A diffusion sheet was prepared in the same manner as in Example 3, except that the bead coating (bead size 5 µm, polydisperse beads, Gantz Co., Ltd.) was applied to the opposite side of the substrate and easy-treated without an etching step. . The optical properties were evaluated and the results are shown in Table 1.

The surface roughness of the prepared diffusion sheet is Ra 1.79㎛, Rz 8.42㎛, Haze is 92.3% and transmittance is 82.1%. After mounting the manufactured diffusion sheet in the backlight unit (BLU) and the luminance was measured, the product name XL 513 of the bead type of Comparative Example 2 described later Contrast luminance increased by more than 4.5%.

Comparative Example 1

A diffusion sheet was manufactured using the method disclosed in Korean Patent No. 193-0008494 and Korean Patent No. 0863773. As the base material used, 125 μm-thick PET (product name: H32F Cologne Co., Ltd.) and bead particles were mixed with polydisperse beads (Gantz Co., Ltd.) having average particle diameters of 5, 10, and 15 μm. Diffusion sheets were made using the chemical A811 product. The film shape of the prepared diffusion sheet was observed and the results are shown in FIG. 6. The optical properties were evaluated and the results are shown in Table 1.

Comparative Example 2

The brand name XL 513 of the bead type currently on sale was evaluated. The optical properties were evaluated and the results are shown in Table 1.

Comparative Example 3

In Example 1, a transfer film was prepared by applying a resin for a mold according to the third step of Example 1 on the surface of the aluminum roll sanded and degreased by the first step. The optical properties were evaluated and the results are shown in Table 1.

Table 1

division	Pattern form	Haze (%)	Transmittance (550nm)	Luminance	Surface resistance (Ω)	Remarks (Comparative luminance)
Example 1	Movied type	94.2	80.8	4102	To 10 ¹²	103.8% compared to Comparative Example 2
Example 2	Movie type	92.1	83.1	4074	To 10 ¹²	103.1% compared to Comparative Example 2
Example 3	Movie type	92.0	83.9	4146	To 10 ¹²	104.9% compared to Comparative Example 2
Example 4	Movie type	92.2	83.5	4142	To 10 ¹²	104.8% compared to Comparative Example 2
Example 5	Movie type	92.3	82.1	4128	To 10 ¹²	104.5% compared to Comparative Example 2
Comparative Example 1	Bead type	93.2	59.5	3959	To 10 ¹⁵	100.2% compared to Comparative Example 2
Comparative Example 2	Bead type	93.7	59.6	3952	To 10 ¹³	100%
Comparative Example 3	Movie type	93.1	78.9	3809	To 10 ¹²	97.5% compared to Comparative Example 2

* Haze Meter: Nakamura HM 150, Measuring Direction: back-> front

* Surface Resistance Meter: SIMCO ST-3

* Luminance meter: BM 7 (Topcon)

* Luminance measurement BLU configuration (based on 15.6 inch)

As can be seen from the above results, the diffusion sheet of Examples 1 to 5 had a higher transmittance than the diffusion sheets of Comparative Examples 1 to 3, and the bead type diffusion sheet of Comparative Example 2 when the backlight unit (BLU) was mounted. It showed more than 3% increase in brightness. Therefore, it was confirmed that the diffusion sheet manufactured according to the present invention exhibits high transparency and high haze, thereby exhibiting a brightness increase effect compared to the bead type diffusion sheet when BLU is mounted.

Claims

A first step of degreasing after sanding the metal roll or plate surface;

A second step of easy treating the degreasing metal roll or flat surface; And

And a third step of manufacturing a highly transparent high haze diffusion sheet having an irregular shape corresponding to the surface of the easy-treated metal roll or the flat plate using an ultraviolet curable resin solution.
The method of claim 1, wherein the metal is aluminum (Al), magnesium (Mg), silicon (Si), manganese (Mn), copper (Cu), iron (Fe), nickel (Ni), tin (Sn), chromium ( Cr), lead (Pb), zinc (Zn) and titanium (Ti) is a method for producing a diffusion sheet having an irregular shape, characterized in that one or one selected from the group consisting of.
The method of claim 1, wherein the sanding ball used in the sanding process is a diamond steel, SUS ball or glass bead having a diameter of 1 ~ 500㎛, the discharge pressure during the production of the irregularly shaped diffusion sheet characterized in that 0.1 ~ 1MPa Way.
The method of claim 1, wherein the degreasing treatment is to remove foreign matters and organics by washing for 5 seconds to 5 minutes in a weak acid solution having a pH of 3-7.
The method of claim 1, wherein the easy treatment is treated for 5 seconds to 5 minutes with sodium carbonate, sodium silicate, caustic soda or caustic potassium having a pH of 10-14, or acidic ammonium fluoride, ammonium fluoride, chromic acid, hydrofluoric acid at pH 0-3. , Boric acid, nitric acid, phosphoric acid, sulfuric acid, dichromic acid, potassium pyrophosphate, ammonium bifluoride, aluminum chloride or iron chloride for 5 seconds to 5 minutes, characterized in that the manufacturing method of the irregular diffusion sheet.
The refractive index of the resin of claim 1 1.44 to 1.55, the glass transition temperature (Tg) is 100 ℃ or less method for producing a diffusion sheet of irregular shape, characterized in that.
The method of claim 1, wherein the ultraviolet curable resin solution comprises at least one component selected from the group consisting of acrylate and urethane acrylate.
The method according to claim 1, wherein the third step is to prepare a diffusion sheet having an irregular shape by irradiating ultraviolet rays while injecting a resin solution for ultraviolet curing between the easy-treated metal roll or plate surface and the base film and pressing with a compression roll. Method for producing a diffusion sheet of irregular shape characterized in that.
The method of claim 8, wherein the base film is polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), polypropylene (PP), polyethylene (PE) and polystyrene (PS) Method for producing a diffusion sheet of irregular shape comprising at least one selected.
The method according to claim 1, wherein the diffusion sheet is formed irregular shape of the processing height difference 2 ~ 50㎛, surface roughness Ra 1 ~ 10㎛, Rz 5 ~ 50㎛, haze 90% or more, transmittance is 75% or more, A method for producing an irregularly shaped diffusion sheet, characterized in that the surface resistance is 10 15 or less.
The method of claim 1, wherein the degreasing metal roll or plate surface is etched and easy treated.
12. The method of claim 1 or 11, further comprising the step of sealing the surface of the easy-treated or etched and easy-treated metal roll or plate after anodizing (oxidation film formation). Manufacturing method.
The method of claim 12, wherein the anodizing treatment is a metal film or surface of the easy-treated or etched in a 20-25% sulfuric acid electrolytic solution, the temperature of the bath 0 ~ 5 ℃ hard current conditions, current density 2 ~ 5A / dm 2 Process for manufacturing a diffusion sheet having an irregular shape, characterized in that the processing height difference is processed to be 2 ~ 50㎛ by processing with a standard voltage 20 ~ 50V.
A method of manufacturing an irregular soft diffusion sheet, characterized in that for producing a diffusion sheet having an irregular shape using a hard diffusion sheet of an irregular shape prepared according to the method of claim 1 or 11 as a transfer mold.
An irregularly shaped diffusion sheet prepared according to the method of claim 1 or 11.
A method of manufacturing an irregular soft diffusion sheet, characterized in that for producing a diffusion sheet having an irregular shape using a hard diffusion sheet of an irregular shape prepared according to the method of claim 12 as a transfer mold.
Diffusion sheet of irregular shape prepared according to the method of claim 12.