KR100858136B1 - Light diffuser plate for LCD back light unit - Google Patents

Abstract

A light diffusion plate for a liquid crystal display device backlight unit using a styrene resin as a base resin is provided. The light diffusing plate for a liquid crystal display device backlight unit according to the present invention comprises 0.1 to 10 parts by weight of siloxane-based crosslinked particles as the first light diffusing agent and 0.01 to 100 parts by weight of styrene resin, and a methacryl-based light diffusing agent as the second light diffusing agent. A base layer comprising 1 to 10 parts by weight of acrylic resin, and 20 parts by weight and an impact modifier; An application layer laminated on one surface or both surfaces of the substrate layer, the coating layer including 0.1 to 30 parts by weight of an acrylic light diffusing agent based on 100 parts by weight of a methacrylic resin; And a coating layer laminated on the surface of the coating layer or the interface between the substrate layer and the coating layer, and containing an ultraviolet absorber.

LCD, backlight unit, light diffusing plate, styrene resin, light diffusing agent, UV absorber, base layer, coating layer, coating layer

Description

Light diffuser plate for LCD back light unit of liquid crystal display device

1 is a cross-sectional view showing a direct backlight unit.

2A to 2D are cross-sectional views illustrating a light diffusion plate for a backlight unit of a liquid crystal display according to an exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

200: base material layer 210: coating layer

220: coating layer

The present invention relates to a light diffusing plate for a backlight unit of a liquid crystal display device, and more particularly, to add a stiffening resin to a styrene resin having excellent water absorption and warping characteristics but weak impact resistance, and manufacturing a light diffusing plate in multiple layers. The present invention relates to a light diffusion plate for a backlight unit of a liquid crystal display device, which improves warpage and weather resistance and has a UV absorption coating layer formed on its surface.

The backlight unit of the liquid crystal display may be divided into an edge method and a direct method.

Dual direct type is mainly used in large area such as LCD TV.

1 is a cross-sectional view showing a direct backlight unit.

As shown in FIG. 1, the direct backlight unit includes a fluorescent lamp 100 for generating light, a reflector 110 for reflecting the generated light in a direction in which the panel is located, and a light diffusion plate 120.

The reason why the backlight unit 10 illustrated in FIG. 1 is called a direct type is that the fluorescent lamp 100 is not positioned at the side of the backlight unit 10 but is perpendicular to the surface where the actual image information is displayed. Because it is located.

There is a light diffusion plate 120 in the direct type backlight unit 10, the light diffusion plate 120 scatters the light generated from the fluorescent lamp 100 to uniformize the light in the entire panel Play a role.

The light diffusing plate 120 mainly contains calcium carbonate, barium sulfate, titanium dioxide, aluminum hydroxide, silica, glass, talc, mica, white carbon, and oxides in order to improve light transmittance and light diffusing property to methacrylic resin (Methacrylate). It is prepared by adding a light diffusing agent made of inorganic fine particles such as magnesium and zinc oxide.

The light diffusing agent has a light transmission effect that transmits light generated from direct sunlight or a fluorescent lamp with high transmittance, and a hiding power and light diffusion effect such that the light source is not visible to the naked eye.

However, when the light diffusion plate is manufactured by extrusion molding based on methacrylic resin, there is a difficulty in the manufacturing process due to the severe deformation depending on the cooling conditions during extrusion molding, and is applicable to a light source device such as a backlight unit of a liquid crystal display device. In this case, there is a problem that warpage or wrinkle of the light diffuser is easily generated by temperature change and moisture absorption caused by lighting and turning off of the light source.

In addition, the methacryl-based resin is relatively expensive in the polymer resin, and there is a problem in that the manufacturing cost is high.

Styrene-based resins are in the spotlight as a substitute for methacryl-based resins, but styrene-based resins have a problem of being fragile due to their poor impact resistance and weather resistance compared to methacryl-based resins and easily denatured by external environmental factors.

Therefore, in the manufacture of a light diffusion plate using a low-cost styrene resin, research and development are required to improve impact resistance and weather resistance.

The technical problem to be achieved by the present invention is to add a predetermined impact modifier to styrene resin instead of methacryl resin, and to form a coating layer for improving weather resistance, thereby improving impact resistance and weather resistance as well as low manufacturing cost A light diffusing plate for a backlight unit of an apparatus is provided.

Technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

The light diffusing plate for the backlight unit of the liquid crystal display device according to the embodiment of the present invention for solving the above technical problem is 0.1 to 10 parts by weight of siloxane-based crosslinked particles as the first light diffusing agent, based on 100 parts by weight of styrene resin, A base layer comprising 0.01 to 20 parts by weight of a methacryl-based light diffusing agent as the second light diffusing agent and 1 to 10 parts by weight of an acrylic resin as the impact modifier; An application layer laminated on one surface or both surfaces of the substrate layer, the coating layer including 0.1 to 30 parts by weight of an acrylic light diffusing agent based on 100 parts by weight of a methacrylic resin; And a coating layer laminated on the surface of the coating layer or the interface between the substrate layer and the coating layer, and containing an ultraviolet absorber.

Specific details of other embodiments are included in the detailed description and the accompanying drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, only the present embodiments to make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

In addition, in the drawings, the size and thickness of layers and films or regions are exaggerated for clarity of description, and when any film or layer is described as being formed "on" of another film or layer, It may be directly on top of the other film or layer, and a third other film or layer may be interposed therebetween.

2A to 2B are cross-sectional views illustrating a light diffusion plate for a backlight unit of a liquid crystal display according to an exemplary embodiment of the present invention.

As shown in FIGS. 2A to 2B, the light diffusion plates 20 and 21 for the backlight unit of the liquid crystal display according to the exemplary embodiment of the present invention may include a base layer 200, an application layer 210, and a coating layer 220. It includes.

However, if both of the base layer 200 and the coating layer 210 include both layers at least one or more layers, the same or similar effects as the present invention can be obtained. However, if necessary, the base layer 200 may be formed as shown in FIG. 2A. The coating layer 210 may be bonded to both sides, or as shown in FIG. 2B, the base layer 200 and the coating layer 210 may be combined 1: 1. In addition, the light diffusion plates 20 and 21 shown in FIG. 2A or 2B may be laminated and used as needed.

The base layer 200 serves as a support layer when the light diffusion plates 20 and 21 according to the embodiment of the present invention are actually applied to the backlight unit, and the light diffusing agent and the impact reinforcing agent are generally used as the base resin. Physically dispersed throughout, or chemically bound.

It is preferable that the thickness of the said base material layer 200 is 100-10000 micrometers.

The styrene resin may be a polymer of styrene monomer alone or a copolymer obtained by copolymerizing 50% by weight or more of styrene monomer and 50% by weight or less of unsaturated monomer.

In this case, the styrene monomer may be a pure styrene monomer, and one of the benzene ring functional groups such as chloro styrene and bromo styrene is substituted with a halogen element, or one of the benzene ring functional groups such as vinyltoluene and α-methyl styrene is an alkyl group. The styrene monomer may be substituted with 2 or more types of said styrene monomer as needed.

Unsaturated monomers include methacrylates such as ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, and the like. Rates; Methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate Acrylates such as 2-hydroxyethyl acrylate and the like; It can be selected from unsaturated acids such as methacrylic acid, acrylic acid, styrene α-styrene, acrylonitrile, methacrylonitrile, maleic anhydride, phenylmaleimide, cyclohexylmaleimide and the like.

Among the materials constituting the base layer 200, the light diffusing agent includes a first light diffusing agent of siloxane-based crosslinked particles and a second light diffusing agent of methacryl-based resin, and the light diffusing agents include the base layer 200. It is evenly physically dispersed or chemically bound throughout the entire volume of.

As the first light diffusing agent, the siloxane-based crosslinked particles include both silicone rubbers having low crosslinking density and flexibility as silicone-based resin particles which are solid at room temperature, and silicone resins having high crosslinking density and hardness.

Specific examples of the siloxane light diffusing agent include polydialkyl siloxane resins such as polydimethyl siloxane and polydiethyl siloxane, and silicone resins having a three-dimensional network structure such as siloxane having an epoxy in the terminal group.

Since the siloxane-based crosslinked particles have excellent weather resistance, yellowing does not occur in which the exposed part turns yellow even when the final resin composition is exposed to light for a long time.

In addition, the siloxane light diffusing agent has a refractive index of 1.40 ~ 1.42, which is lower than other organic cross-linking particles, has the advantage that the light diffusion and light transmittance equivalent to that of other light diffusing agents can be obtained.

As the first light diffusing agent used in the substrate layer 200 of the present invention, the siloxane-based crosslinked particles are spherical crosslinked fine particles having an average particle diameter of 1 to 20 µm, and the amount of addition is 0.1 to 10 when the styrene resin is 100 parts by weight. Add parts by weight.

The reason why the siloxane-based light diffusing agent should have the above particle size and addition amount is as follows.

If the average particle diameter is smaller than 1 μm, the concealability of the light source is lowered. If the average particle diameter is larger than 20 μm, a problem arises in that an excess light diffusing agent must be added to secure proper light diffusivity.

In addition, when the amount of the siloxane-based light diffusing agent is less than 0.1 part by weight, the light diffusivity of the final resin composition is not sufficient, so that it is difficult to see a lamp or to diffuse light, and when the amount of use is more than 10 parts by weight, the light transmittance is too high. Apart from this, there is a problem of reducing the brightness.

It is preferable to add 0.01-20 weight part with respect to 100 weight part of styrene resin as a 2nd light-diffusion agent, and it is preferable to use the thing of 0.1-20 micrometers in average particle size.

The reason for having the addition amount and the particle size as described above is as follows.

When the methacryl-based light diffusing agent is used in an amount less than 0.01 part by weight based on 100 parts by weight of the styrene resin, there is a problem in that light scattering is reduced and the light source itself is visible, that is, the light source concealability is lowered. When the agent is used in an amount of more than 20 parts by weight based on 100 parts by weight of the styrene resin, the light transmittance is reduced, resulting in a problem that the transparency is weakened.

In addition, when the average particle size of the methacryl-based light diffusing agent is less than 0.1 μm, the concealment and light scattering properties of the light source are inferior.

An impact modifier is added to the base layer 200 to enhance the impact resistance of the styrene resin used as the base resin.

At this time, the impact modifier may be methyl methacrylate butadiene styrene (MBS) resin, polyethylene chloride (CPE) resin, acrylic resin.

Among them, the acrylic resin is used as the impact modifier in the present invention, because the acrylic resin impact modifier is excellent in weatherability and can increase impact resistance without deteriorating the physical properties and transparency inherent in the acrylic resin.

The reason why the acrylic resin is excellent as an impact reinforcing material is that the acrylic resin transmits the impact applied from the outside to the acrylic rubber layer from the matrix resin, and the energy is absorbed and diverged from the rubber layer, so the impact reinforcing effect is excellent.

Specific examples of acrylic impact modifiers include methacrylic monomers, styrene derivatives, vinyl monomers themselves, and copolymers thereof.

Acrylic impact modifiers are prepared by cross-polymerizing vinyl monomers and graft agents such as acrylic monomers, styrene derivatives and vinyl induction systems.

The acrylic resin impact modifier is added in an amount of 1 to 10 parts by weight based on 100 parts by weight of the styrenic resin, which is the base resin of the base layer 200, and when it is 1 part by weight or less, it cannot exert an effect as an impact modifier. This is because the addition of the impact reinforcing effect is small or may affect the physical properties of the base layer, such as transparency even if added.

Moreover, it is preferable that the average particle diameter of the acrylic resin impact modifier used for this invention is 0.1-5 micrometers.

The coating layer 210 is laminated on both sides of the substrate layer 200 as shown in FIG. 2A or on one surface of the substrate layer 200 as shown in FIG. 2B, and the coating layer 210 is based on methacryl-based resin based on acrylic light diffusion. I am evenly distributed throughout the entire volume of the resin.

It is preferable that the thickness of the said application layer is 10-1000 micrometers.

The methacrylic resin used as the base resin of the coating layer 210 is a polymer of methyl methacrylate alone as the monomer, or 50% by weight or more of methyl methacrylate as the monomer, ethyl methacrylate, beryl methacrylate, and methacrylic. Methacrylic acid esters such as cyclohexyl acid, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate; Acrylic esters such as methyl acrylate, ethyl acrylate, beta acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethyl hexyl acrylate, and 2-hydroxy ethyl acrylate; Unsaturated acids such as methacrylic acid and acrylic acid; 50 wt% or less of one or two or more monomers selected from the group consisting of styrene, α-methyl styrene, acrylonitrile, methacrylonitrile, maleic anhydride, phenyl maleimide and cyclohexyl maleimide is copolymerized It may be.

In addition, the methyl methacrylate resin may further contain glutaric anhydride and glutarimide units.

In order to control the matte touch having a white or irregularly shaped surface on the surface of the light diffusing plate according to the present invention and to make the appearance beautiful, the coating layer 210 uses an acrylic light diffuser in a range that does not impair light transmittance.

At this time, the average diameter of the acrylic light diffusing agent particles is 1 ~ 50㎛, the refractive index has a range of about 1.46 ~ 1.55.

The amount of the acrylic light diffusing agent is added so as to be 0.1 to 30 parts by weight based on 100 parts by weight of the methyl methacrylate resin.

The coating layer 220 is coated on one side or both sides of the coating layer 210 (FIGS. 2A and 2B show coating on one side, and FIG. 2C and 2D show coating on both sides). It contains an absorbent (ultraviolet ray blocker).

UV absorbers are used to block ultraviolet rays generated from the light source. Any UV absorber that can absorb wavelengths in the range of 250-800 nm can be used. Especially, the maximum absorption wavelength is in the range of 250-320 nm. It is preferable because it improves the light resistance of and can suppress the coloring of the diffusion plate due to ultraviolet absorption.

Specifically, one containing at least one of a benzophenone-based, cyanoacrylate-based, sarichireto-based, nickel complex salt-based ultraviolet absorber may be used.

In order to form the coating layer 220 on one side or both sides of the coating layer 210, first, a UV absorber is diluted 1-100 times in alcohols (eg, methanol, ethanol, propanol, butanol, isopropyl alcohol, etc.). Spraying on both sides or one surface of the coating layer 210 using a spray (spray), and when dried, the coating layer 220 is formed on the surface of the coating layer 210.

At this time, it is necessary to appropriately control the rate of dilution of the UV absorber in alcohols, because if the alcohol is diluted too thin, the light resistance of the light diffusion plate is not sufficient. Alternatively, the UV absorber may not be evenly coated or the appearance of the light diffusion plate may be damaged.

The light diffusing plates 20 and 21 according to the embodiment of the present invention may further include an additive within a range that does not affect the intrinsic properties of the light diffusing plates, and the additives may include a hindered amine light stabilizer and a resin. Among blowing agents, other plasticizers, antistatic agents, antioxidants, heat stabilizers, lubricants, flame retardants, fillers, mold release agents, dyes, pigments, antibacterial agents, antidropping agents and nucleating agents added to prevent the appearance defects caused by yellowing caused by deterioration An additive including any one or more may be further included.

In the light diffusion plate according to the embodiment of the present invention, the coating layer 220 has been described as being formed by a spray method. In order to manufacture the base layer 200 and the coating layer 210, the above-described raw materials are mixed and used specifically. Depending on the use of the light diffusion plate, all methods of molding thermoplastic resins such as injection molding, extrusion molding, vacuum molding, hot press molding, and coextrusion molding can be used.

Hereinafter, specific examples and comparative examples will be described that the light diffusion plate for the backlight unit of the liquid crystal display device manufactured according to the embodiment of the present invention is excellent in impact resistance and weather resistance while maintaining the conventional basic physical properties. Details not described herein are omitted because they can be sufficiently inferred by those skilled in the art.

1. Examples and Comparative Examples

<Example 1>

(1) Production of base layer

Methacrylic crosslinked particles having 1.0 parts by weight of siloxane-based crosslinked particles (GE Toshiba Silicon, 2000B) having an average particle diameter of 6 µm and 100 µm of styrene resin (Toyo styrene Co., HRM-40) Ganz, GM-0806S) 0.3 parts by weight, and 1.0 parts by weight of an acrylic impact modifier (Ganz, GI-006) having an average particle diameter of 0.3㎛ was prepared.

(2) Preparation of Coating Layer

Manufactured by adding 3 parts by weight of acrylic crosslinked particles (Ganz, GSM-0854S) having an average particle size of 8 parts to 100 parts by weight of methyl methacrylate resin (Denka Co. TX-600XL) copolymerized with styrene resin. It was.

(3) Preparation of Coating Layer

A UV absorber (Ciba, Tinuvin329) was prepared by spray coating by diluting 50 times with alcohol containing butanol and isopropyl alcohol in a ratio of 1: 1.

(4) Production of a multilayer light diffuser plate in which a base layer, an application layer, and a coating layer are laminated

In order to laminate the coating layers on both sides of the substrate layer, the composition for the production of the substrate layer and the composition for the preparation of the coating layer were introduced into each extruder, melted and kneaded, and then supplied to the feed block die. To form a three-layer light diffusing plate in which the coating layer / substrate layer / coating layer has a three-layer structure of 100 μm / 1800 μm / 100 μm. The spray coating process was performed to form.

<Example 2>

The same as in Example 1 except for the addition of 2 parts by weight of an acrylic impact modifier in preparing the base layer.

Comparative Example 1

The same process as in Example 1 except that the acrylic impact modifier was not added in preparing the base layer.

Comparative Example 2

It is the same as Example 1 except not forming a separate coating layer and adding 0.5 weight part of ultraviolet absorbers as an additive of an application layer.

Comparative Example 3

1 part by weight of siloxane-based crosslinked particles (GE Toshiba Silicon, 2000B) having an average particle size of 6 µm in 100 parts by weight of methacryl-based resin (Mitsubishi Rayon Co., VH-6) instead of styrene-based resin in preparing the base layer; It is the same as Example 1 except having manufactured by adding 0.3 weight part of methacryl-type bridge | crosslinking particle | grains (Ganz, GM-0806S) whose average particle diameter is 8 micrometers.

Table 1 below shows the specifications for the examples and comparative examples described above.

A: siloxane light diffuser B: methacrylic light diffuser C: acrylic impact modifier D: acrylic light diffuser E: ultraviolet absorber

2. Property evaluation

(1) Impact strength measurement

The IZOD impact of the molded articles prepared in the above Examples and Comparative Examples was measured according to ASTM D256 (1/4 kPa, 1/8 kPa, 23 ° C).

(2) light resistance measurement

The light resistance of the molded article prepared in the above Examples and Comparative Examples was measured by using the ATLAS-UVCON, after irradiating ultraviolet rays for 48 h at a temperature of 60 ℃, the amount of YI (Yellow Index) change was measured.

(3) luminance measurement

The luminance of the molded article prepared in the above Examples and Comparative Examples was measured by the brightness value of 5 points after 30 minutes of aging at room temperature using BM-7 to record the average value.

Table 2 shows the results of measuring the properties of the examples prepared as described above and the comparative examples in the same manner as described above.

Referring to Table 2, when the acrylic impact modifier is used for the styrene base resin as in Examples 1 and 2, the impact strength of the light diffusion plate using the methacryl resin as shown in Comparative Example 3 is shown. It can be seen that.

In addition, in the application of the ultraviolet absorber, the coating layer was formed as in the examples, and the ΔYI value was superior to that of the compounding method as in Comparative Example 2, and the same level was maintained in terms of luminance. It can be seen that.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings and tables, the present invention is not limited to the above embodiments, but may be manufactured in various forms, and common knowledge in the art to which the present invention belongs. Those skilled in the art can understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

According to the light diffusing plate for the backlight unit of the liquid crystal display according to the embodiment of the present invention, one or more of the following effects exist.

First, the impact strength could be increased by adding an acrylic impact modifier to the styrene resin, which is advantageous in terms of heat and water absorption but is vulnerable to weather resistance.

Second, it is possible to manufacture a light diffusion plate having excellent light stability by forming a coating layer on the surface rather than the conventional compounding method.

Third, the ultraviolet absorber is added to the surface of the light diffusion plate in a manner that enables efficient absorption of ultraviolet rays.

Fourth, the production cost can be lowered because it is based on styrene resin, which is relatively inexpensive instead of expensive methyl methacrylate resin.

Fifth, when applied to the backlight unit of the liquid crystal display device, it prevents the difference between light and dark in several lamps, transmits or diffuses light with uniform brightness, and does not cause yellowing even when exposed to light for a long time. It is possible to produce high-quality liquid crystal display device.

Claims (19)

0.1 to 10 parts by weight of siloxane-based crosslinked particles as the first light diffusing agent, 0.01 to 20 parts by weight of methacrylic light diffusing agent as the second light diffusing agent, and 1 to 10 parts of acrylic resin as the impact modifier with respect to 100 parts by weight of the styrene resin. A base layer including parts by weight; An application layer laminated on one surface or both surfaces of the substrate layer and including 0.1 to 30 parts by weight of an acrylic light diffusing agent based on 100 parts by weight of a methacrylic resin; And A coating layer laminated on a surface of the coating layer or an interface between the base layer and the coating layer and including an ultraviolet absorber; Light diffusion plate for a backlight unit of the liquid crystal display device comprising a. The method of claim 1, The styrene resin is a polymer of styrene monomer alone, A light diffusion plate for a backlight unit of a liquid crystal display device, characterized in that a copolymer obtained by copolymerizing at least 50% by weight of a styrene monomer and at least 50% by weight of an unsaturated monomer. The method of claim 2, The styrene monomer is pure styrene; Halogenated styrenes including chloro styrene and bromo styrene; A light diffusion plate for a liquid crystal display device backlight unit, characterized in that styrene selected from the group consisting of vinyl toluene and alkyl styrenes containing? -Methyl styrene. The method of claim 2, The unsaturated monomers are methacrylates such as ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, and the like. Rates; Methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate Acrylates such as 2-hydroxyethyl acrylate and the like; Unsaturated acids such as methacrylic acid, acrylic acid, styrene α-styrene, acrylonitrile, methacrylonitrile, maleic anhydride, phenylmaleimide, cyclohexylmaleimide and the like; An optical diffuser plate for a backlight unit of a liquid crystal display device, characterized in that one selected from the group consisting of three kinds. The method of claim 1, The siloxane-based crosslinked particles as the first light diffusing agent are spherical fine particles having an average particle diameter of 1 to 20 µm. The method of claim 1, The methacryl-based light diffusing agent as the second light diffusing agent has an average particle diameter of 0.1 ~ 20㎛, the light diffusion plate for a backlight unit of the liquid crystal display device. The method of claim 1, The acrylic resin as the impact modifier has an average particle diameter of 0.1 ~ 5㎛ light diffusion plate for a backlight unit of a liquid crystal display device. The method according to claim 1 or 7, The acrylic resin as the impact modifier is a light diffusion plate for a backlight unit of a liquid crystal display device, characterized in that selected from methacryl monomers, styrene derivatives, vinyl monomers. The method of claim 1, The methacrylic resin used in the coating layer, Or a polymer of methyl methacrylate alone as a monomer, 50% by weight or more of methyl methacrylate as the monomer, ethyl methacrylate, methyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, methacrylic acid 2 Methacrylic acid esters such as hydroxy ethyl; Acrylic esters such as methyl acrylate, ethyl acrylate, beta acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethyl hexyl acrylate, and 2-hydroxy ethyl acrylate; Unsaturated acids such as methacrylic acid and acrylic acid; Styrene, α-methyl styrene, acrylonitrile, methacrylonitrile, maleic anhydride, phenyl maleimide, cyclohexylmaleimide, glutaric anhydride, gulutarimide greater than 0 and 50 weight A light diffusion plate for a backlight unit of a liquid crystal display device, characterized in that less than or equal to copolymerization. The method of claim 1, The average particle diameter of the acryl-based light diffusing agent is 1 ~ 50㎛ light diffusion plate for a backlight unit of the liquid crystal display device. The method of claim 1, The UV absorber included in the coating layer has a maximum absorption wavelength in the range of 250 ~ 800nm light diffusion plate for a backlight unit of the liquid crystal display device. The method according to claim 1 or 11, wherein The ultraviolet absorber is selected from a benzophenone-based, cyanoacrylate-based, sarichireto-based, nickel complex salt-based ultraviolet absorber, the light diffusion plate for a backlight unit of the liquid crystal display device. The method of claim 1, The coating layer is a light diffusion plate for a backlight unit of the liquid crystal display device, characterized in that formed by spray coating after diluting the ultraviolet absorber to 1 to 100 times the alcohol. The method of claim 1, The thickness of the base layer is a light diffusion plate for a backlight unit of the liquid crystal display device, characterized in that 100 ~ 10000㎛. The method of claim 1, The thickness of the coating layer is a light diffusion plate for a backlight unit of the liquid crystal display device, characterized in that 10 ~ 1000㎛. The method of claim 1, The thickness of the coating layer is a light diffusion plate for a backlight unit of the liquid crystal display device, characterized in that 5 ~ 100㎛. The method of claim 1, The substrate layer and the coating layer are each manufactured by a molding method selected from injection molding, extrusion molding, vacuum molding, hot press molding, and coextrusion molding, and are adhered or adhered to each other. Light diffuser plate for the unit. A backlight unit of a liquid crystal display device comprising the light diffusion plate of claim 1. A liquid crystal display device comprising the backlight unit of claim 18.

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