TW200804872A - Light diffusion sheet for a display device - Google Patents

Abstract

A light diffusion sheet for a display device includes a base layer having a base resin mixture of a methacrylate-styrene copolymer and a methylmethacrylate-styrene copolymer and about 0.2 to 20 ppwb of a first light diffuser, and at least one coating layer on the base layer, the coating layer including a methylmethacrylate-styrene copolymer base coating resin, about 0.1 to 30 ppwb of a second light diffuser, about 0.01 to 2 ppwb of an UV absorber, and about 0.001 to 10 ppwb of an antistatic agent.

Description

200804872, IX. Description of the Invention: [Technical Field of the Invention] The present invention relates to a light diffusing sheet for a display device and, in particular, to a light diffusing sheet of a liquid crystal display. It can improve light resistance, luminous efficiency, and light diffusivity. [Prior Art] In general, a liquid crystal display (LCD) is a type of flat panel display. It utilizes an applied electric field to the liquid crystals in the two substrates and controls the intensity of the electric field to control the amount of light transmitted by the external light source through the substrate to display the image. The external light source is a backlight unit (BLU). Thus, a conventional liquid crystal display has a backlight unit disposed on a rear surface thereof. Now, the conventional backlight unit is not an edge-lit backlight unit, and is a backlight unit that is directly down. Among them, the edge-lit backlight unit is a light-screen 70 used for a thin screen, such as a screen of a notebook or a desktop computer. The direct-back type 10-light unit is used for large-sized devices, such as LCD TVs, τν). A conventional direct type backlight unit includes a light source for emitting vertical light to a panel of a liquid crystal display, and penetrating at least one of the reflection sheets and a dummy light diffusion sheet. The light diffusing sheet is used to scatter the light emitted from the light source so that the light can be uniformly dispersed and spread over the panel of the liquid crystal display. A conventional light diffusing sheet includes a light diffuser and a transparent thermoplastic film base layer' and a light diffusing agent is positioned on the film base layer, wherein the film base layer is, for example, methacrylic, styrene, or ring. a resin such as olefin 200804872, a cycloolefin or a polycarbonate. However, for a backlight unit, for example, when used in a large-sized liquid crystal television, it is possible to provide sufficient brightness by increasing the light emitted from the light source. However, the increase in the amount of light causes the heat source generated by the backlight unit to be greatly increased, resulting in distortion of the light diffusing sheet. In particular, a transparent film base layer of a conventional light diffusing sheet formed of a conventional base resin, for example, a transparent film base layer formed of methacrylic acid and styrene resin, which is deformed by an excessive heat source generated by a light source of the backlight unit . Therefore, in the industry, it is indeed necessary to have a light diffusing film that can resist the south heat source, and the light diffusing film must also have sufficient optical properties and formability. SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a light diffusing sheet to substantially overcome the aforementioned technical disadvantages. According to a feature of the embodiment of the present invention, a light diffusing sheet for a display device is proposed and the light diffusing sheet has strong light resistance. In order to enable the foregoing or other features and advantages of the present invention to be readily understood in accordance with one aspect of the present invention, a light diffusing sheet for a display device is proposed. The light diffusing sheet comprises a base layer and at least one coating layer. The base layer comprises a base resin and a first light diffusing agent, and the base resin is a mixture of a mercapto acrylate-styrene copolymer and a monomethyl methacrylate styrene copolymer. The content is 0.2ppwb-20ppwb °, the coating layer is located above the substrate layer, and the coating layer comprises a coated substrate tree 200804872

χ ιχν. χ vyju/^F fat, a second light diffusing agent, an ultraviolet light absorber and an antistatic agent, coated base resin-based methacrylate-styrene copolymer, second light diffusing agent The content is 0.1ppwb-30ppwb, the content of the ultraviolet light absorber is 0.01ppwb-2ppwb, and the content of the antistatic agent is 〇.〇〇lppwb-10ppwb ° The thickness of the base layer is 100//ml〇〇〇〇//m The thickness of the coating layer is 10 β m-1000βτα 〇

The methacrylic acid-based styrene-ethyl ester-containing copolymer of the basal layer comprises: 2% to 20% by weight of methyl propyl succinic acid g monomer and one part by weight of 80% to 98% styrene single body. The methacrylate methacrylate-styrene copolymer of the base layer comprises from 6% to 94% by weight of methyl methacrylate monomer and from 6% to 94% by weight of styrene, monomer. The first light diffusing agent of the base layer comprises a siloxane composition having a content of 0.1 ppwb-lOppwb and an acrylic composition having a content of 0.1 ppwb-lOppwb, wherein the average diameter of the siloxane composition For l/zm-20#m, the average light balance of the acrylate composition is 1 // m-20" m 〇1 β m~50. The second light diffusing agent of the decane coating layer comprises an average diameter of / / acrylate composition, an average diameter of 1 / zm ~ 2 〇 / zm composition or a combination of acrylate composition and 矽 垸 composition. The composition of the oxacillin, including a polydimethylsiloxane, _ take a 7 ^ water, a street, Xi Xi oxygen shirt

A combination of one or more of (polydiethylsiloxane) and a silicone resin having a three-dimensional network structure. E 200804872 Acrylate composition, methyl methacrylate, ethyl methacrylate, butyl methacrylate, monomethyl methacrylate Cyclomethyl methacrylate, phenyl methacrylate, benzyl methacrylate, methyl acrylate, acetyl acrylate One of ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, and benzyl aery late or A combination of multiples. The coating layer of the ultraviolet light absorbing agent is used to absorb ultraviolet light having a wavelength of from 250 nm to 280 nm. The ultraviolet light absorber is one of benzophenone, benzotriazole, cyanoacrylate, and a nickel complex salt. Or a combination of more than one. The antistatic agent of the coating layer is a polyether imide amide, a polyether ester, a polyether ester amide, a polyalkylene glycol. (polyalkylene glycol), <11^11 metal dodecylbenzene sulfonate), a tertiary amine compound (tertiary - . - ·/..: ; - amine), a quaternary ammonium compound ), a combination of one or more of sodium chloride, and an alkyl amine. The coating layer further includes blowing agents, plasticizers 200804872 (plasticizers), antioxidants, thermal stabilizers, lubricants, K_- (flameretardants), fillers ( Fillers), release agents, dyes, pigments, anti-dropping agents, nucleating agents, light stabilizers, or combinations of the foregoing . The coating layer includes an embossed pattern which is an amorphous embossed pattern, and the surface roughness of the embossed pattern is 〇 10 /zm - 20 / zm. The coating layer further includes a light stabilizer. The light diffusing sheet further includes two coating layers, and the base layer is lost between the two coating layers. In accordance with another aspect of the present invention, a backlight unit is also proposed in order to facilitate the understanding of the foregoing or other features and advantages of the present invention. The backlight unit includes a light source, at least one reflective sheet, and a light diffusing sheet. The light diffusion sheet comprises a base layer comprising a base resin and a first light diffusing agent, and the base resin is a methacrylic acid ester-polystyrene copolymer and a methyl methacrylate - the mixture of the stupid ethylene copolymer and the content of the light-emitting material is O. The coating layer is located above the substrate layer, and the coating layer comprises a coating base resin, a second light diffusing agent, an ultraviolet light absorber, and An antistatic agent, coated with a base resin (UPpWb-30PPwb, the content of the ultraviolet light absorber is 0.01 ppWb-2PpWb, and the content of the antistatic agent is 〇〇〇ippwb_i〇卯~7. According to another aspect of the present invention In addition, the foregoing or other features and advantages of the present invention are more readily understood, and a display device is proposed herein. This display is 200804872.

The 3F display device includes a display panel and a backlight unit. The backlight unit comprises a light source and a light diffusion sheet, the light diffusion sheet comprises a base layer and at least one coating layer, the base layer comprises a base resin and a first light diffusing agent 'base resin type thiol acrylate-styrene a mixture of a copolymer and a monomethyl methacrylate-styrene copolymer having a first light diffusing agent content of 0.2 ppwb to 20 ppwb, a coating layer on the base layer, the coating layer comprising a coated base resin, a first a two-light diffusing agent, an ultraviolet light absorbing agent and an antistatic agent, and the coating base resin is a methacrylate methacrylate phenethyl hydrazine Φ mer. The content of the second light diffusing agent is 0.1 ppwb-30 ppwb, ultraviolet The content of the light absorbing agent is 〇.〇lppwb-2ppwb, and the content of the antistatic agent is OJOlppwb~lOppwb. Wherein, the display device is a liquid crystal display. In order to make the above-mentioned contents of the present invention more comprehensible, the following detailed description, preferred embodiments, and the accompanying drawings are described in detail as follows: [Embodiment] Submitted on July 7, 2006 and 2006, respectively. December 5th _ Korean Patent Application Nos. 10-2006-0064065 and 10_2006-0122521 'The patent name is "Light Diffusion Sheet for LCD Back Light Unit" The entire contents are incorporated herein by reference. The invention will be described in detail hereinafter with reference to the accompanying drawings, which are exemplified by a preferred embodiment of the invention. However, the present invention may be embodied in many different forms and the invention is not limited by the embodiments. On the contrary, the present invention is fully and exhaustively disclosed in the preferred embodiment. 11 200804872r = 2' is to convey the hair (4) ^ clearly, and the size of the light domain is expanded in Guanzhong. And in the text 'When the laminate or element is mentioned at t % d, the laminate or component is directly above the other layer or the other - directly above the soil," or there are other intermediate layers. The board or component is on the other substrate, below

The plate or component is directly on the other plate or another substrate, directly below, =: in one or more intermediate layers. In the case of "middle", it means that the layer two =: two = or there are - one or more intermediate layers = and, in the text, the same component: use the same reference. Referring to Figures 1 and h, there is shown a light diffusing sheet according to a preferred embodiment of the present invention, wherein the light diffusing sheet is applied to a display device, and the display device is, for example, a liquid crystal I player. The i-th and second figures will be described in more detail below. The light diffusing sheet 20 as shown in Fig. 1 comprises a base layer 200 and at least one coating layer 210, and the coating layer 210 is located above the base layer 200. When the light diffusing sheet 20 is applied to a display device (not shown), the base layer 200 of the light diffusing sheet 20 serves as a supporting substrate of the light diffusing sheet 20. The thickness of the base layer 200 can be about 100 to 1 〇〇〇〇 #111, that is, the distance along the 7-axis. The base layer 200 comprises a base resin of about 100 parts by weight and a light diffusing agent of about 0.2 to 20 parts by weight, and the light diffusing agent has an average diameter of about 1/zm to 20/zm. In this regard, it should be noted that the weight component 12

2008048723F is based on the weight of the base resin of the base layer 200 or based on the weight of the coated base resin of the coating layer 210. That is, the weight component in the base resin of the 1Q0 weight component, or "parts by weight per 100 parts by weight of the base resin", is calculated by weight. More specifically, for the weight component of the base layer 200, "ppwb" is based on the base resin of the base layer 200. For the weight component of the coating layer 210, ppwb is based on the coating base of the coating layer 21〇. This will be explained in more detail below. • Further, the base layer 200 includes a base resin, a base resin, a methacrylate styrene (MS) copolymer, and a methyl methacrylate. A mixture of styrene, MMS) copolymers. MS and MMS are mixed by suitable techniques such as emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, and others. technology. • The MS copolymer comprises from 1% to 20% by weight of methacrylic acid ester monomer and from 80% to 98% by weight of styrene monomer. Preferably, the MS copolymer comprises from 5% to 1% by weight of methacrylate monomer and from 90% to 95% by weight of styrene monomer. It is based on polystyrene, and the average molecular weight of the ruthenium-ST copolymer is about 200,000 to 35 Å. The MMS copolymer comprises from 6% to 94% by weight of the methacrylate monomer and from 6% to 94% by weight of the styrene monomer. 13

2008048723F And preferably, the MMS copolymer comprises from 20% to 80% by weight of methacrylate monomer and from 20% to 80% by weight of styrene monomer. It is based on polystyrene, and the average molecular weight of the MMs copolymer is about 70, 〇〇〇~3〇〇, 〇〇〇. The light diffusing agent of the base layer 200 includes a plurality of organic particles or a plurality of inorganic particles. The organic particles are, for example, anthracycline, a fluorinated polymer (such as Teflon), acrylate and/or styrene. The inorganic particles are, for example, carbonic acid, barium sulfate, titanium dioxide, cesium hydroxide, cerium oxide, glass, shale, mica, white carbon 〇n, magnesium oxide and/or zinc oxide. The organic particles or inorganic particles are dispersed in a mixture of the base resins, and the refractive index of the mixture with the base resin differs by about 〇 〇 2 〇 13 . In the present embodiment t, the light diffusing agent comprises an oxime composition having an O.lppwb-lOppwb content and an acrylate composition having a content of 0.1 ppwb-lOppwv. The average composition of the decane is l/m-20/zm, and the average diameter of the acrylate composition is ^^20 // m. For example, the composition of the Xixi oxygen burning can be a cross-linked oxirane resin having a spherical cross-linked particle, and the cross-linked decane resin is included in the dish to be solid and evil. Oxygen resin (sili (3) ne resin), polydialkyl siloxane resin, a three-dimensional network of oxygen resin, and other materials. The stone oxide resin which is solid at room temperature is, for example, a silica gel with a low degree of crosslinking and a high fluidity, and a silicone resin having a high degree of crosslinking and high hardness. The polydialkylsiloxane resin is, for example, p-polymethoxysil xane and polydiethylsiloxane. Has a three-dimensional network junction 14

200804872! The hydroxy resin of F is, for example, an epoxy-containing oxo-containing siloxane. In the scope of the theory, such as the use of cross-linked decane resin, the light diffusing agent can be given excellent wettability, so that the light diffusing agent can significantly reduce the yellowing caused by the illumination of the light source (yellowing) ).

The oxidizing composition has a lower refractive index than the other organic crosslinking compounds. More specifically, the composition of the decane has a fold ratio of about 1.40-L43. Therefore, the light diffusing rate and the light transmittance of the light-diffusing sheet 20 can be imparted to the light-diffusing sheet 20 in comparison with other organic cross-linking resins, even if only a small amount of decane is used in comparison with other organic cross-linking resins. By exemplifying the acrylate composition, the acrylate composition in the light diffusing agent of the base layer 2 includes an acrylic monofunctional monomer (such as propylene brewing vinegar), - (tetra) acid methyl ketone, and the like. A combination of a monomer and each of the foregoing acrylate compositions. The alkyl acrylate is, for example, ethyl acrylate, methyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, phenyl decyl acrylate. The alkyl methacrylate is, for example, ethyl methacrylate, mercapto methacrylate, butyl methacrylate, cyclopropyl methacrylate, phenyl methacrylate or benzyl methacrylate. Further, the acrylate composition may be a spherical crosslinked particle, and the acrylate composition has a refractive index of about 1.46-1.56. In this regard, the refractive index of the acrylate composition varies depending on the content of the methyl acetonate and the MS copolymer. That is, increasing the content of the group or the halogen group increases the refractive index of the acrylate composition. The base layer 2GG of the light diffusion sheet 2G further includes an impact resistance modifier. The impact agent is used to reinforce the base layer 2 2008 15 200804872; f, for example, the base layer 200 can be provided with high impact resistance and high flexibility. The impactor comprises an elastomer such as acrylate rubber, mercapto acrylate rubber, polybutyl acrylate rubber, and others. As shown in Fig. 1, at least one coating layer 210 of the light diffusing sheet 20 is formed over the base layer 200 and has a thickness of about 10 // m to 1,000 # m. The coating layer 210 of the light diffusion sheet 20 comprises a coated base resin of about 100 parts by weight, a light diffusing agent having a content of about 0.1 ppwb to 30 ppwb,

An ultraviolet light absorber (UV) having a content of about 0.01 ppwb 2 ppwb

Absorber), an antistatic agent having a content of about 〇〇.〇〇ippwb-10ppwb. Wherein the average diameter of the light diffusing agent is about . The coated base resin of the coating layer 210 is different from the base resin of the base layer 2〇〇. In detail, the coated base resin of the coating layer 21 includes an MMS copolymer. The MMS co-hydrate of the coating layer of the coating layer 21 is substantially similar to the base resin of the base layer 2, such as the MMS copolymer, including one weight percent.甲基 甲基 甲基 甲基 及 及 及 及 及 及 6% 6% 6% 6% _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ combination. In the present embodiment, the combination of the acrylate composition and/or the decane composition of the t-light diffusing agent is substantially the same and/or the composition of the yttrium oxide, and the acrylic layer of the base layer 200 The ester New Zealand 210 will no longer elaborate on its detailed ingredients. However, the average diameter of the coating is different from that of the base layer. In the theoretical scope, the light diffusing agent of the coating layer 210 can control the brightness and gloss of the surface of the coating layer 210. For example, in the case of an irregularly shaped surface of the coating layer 21, the appearance of the irregularly shaped surface can be enhanced, the light transmittance and the light diffusivity can be reduced, or the light transmittance and the light diffusivity can be prevented from being lowered. .

The ultraviolet light absorber of the coating layer 210 shields the ultraviolet light emitted from the light source to protect the light diffusion sheet 20. The ultraviolet light absorber may be any material capable of absorbing light having a wavelength of from 250 nm to 280 nm. By ultraviolet light absorber, for example, the ultraviolet light absorber may be benzophenone, benzotriazole, cyanoacrylate, saliCyiate. And a combination of one or more of a nickel complex salt. The ultraviolet light absorber may be added with a light stabilizer to reduce its free radical, thereby improving the durability of the entire coated base resin. The light stabilizer is any material capable of reducing any composition drop of the light diffusion sheet 20, for example, a hindered amine. The antistatic agent of the coating layer 210 can reduce the charge outside the coating layer 21. In particular, the MMS copolymer has a relatively high and significant resistance, which means that static electricity is easily generated on the surface of the MMS copolymer, and electric dust is accumulated and adsorbed on the surface of the MMS copolymer. However, the dust combines the surface properties of the low-light diffusion sheet 20, causing the light-emitting effect of the light-diffusing sheet 20 to fall, and causing a light stain (lamp (^Ό〇1〇Γ^1〇η)). The antistatic agent of layer 210 is used to reduce the static electricity on the surface thereof, thereby extinguishing a large amount of dust on the surface of the coating. The antistatic agent includes a polysulfonium sulfite.

200804872,P

---------——3F, a polyether ester, a polyether ester amino compound, a polyalkylene glycol, an alkali metal dodecylbenzenesulfonate, a tertiary amine compound, a season A combination of one or more of an ammonium compound, a sodium monohydrate, and a monoalkylamine compound. The light diffusing sheet 20 further includes one or more additives. The additives include a blowing agent, a plasticizer, an antioxidant, a heat stabilizer, a lubricant, a flame retardant, a filler, a pinning agent, a colorant, a dye, an anti-separating agent, a nucleating agent, or a combination of the foregoing various additives. For example, the use of a foaming agent in the light diffusing sheet 2 () can reduce the yellowing phenomenon of the light diffusing sheet 2 due to resin cracking. The coating layer 210 has at least one irregularly shaped surface. For example, the β-coating layer has an amorphous embossing pattern 211 on its surface such that light from the light source to the [CD panel can be scattered, diffused or concentrated via the light diffusing sheet 20 . In particular, when light penetrates from the pores of the amorphous embossed pattern 211 of the coating layer 210, the transmitted light diffuses, for example, in several directions, thereby enhancing the light transmittance and light of the light diffusing sheet 2 Diffusion rate, and can improve the overall luminosity of the LCD. The surface roughness of the amorphous embossed pattern 211 of the coating layer 210 is 〇.1μπι-2〇 //m, which is the average vertical height difference of a plurality of irregularities of the surface of the coating layer 210. The formation of the irregularly shaped surface of the coating layer 210 is, for example, by press processing, UV resin coating and processing, and directing process via a Polish roll) and other methods. For example, the polishing roll forms a plurality of irregularities on the surface of the coating layer 210.

The 200804872!F area, so that the evenly scattered light emitted by the light source to the LCD (such as bright-line uniform scattered light) becomes dim. The shape of the irregular shaped surface is, for example, dependent on the distance between the light sources, the distance between the light diffusing sheet and the light source, the brightness of the light source, and other conditions. Since the coating layer 210 is applied to the base layer 200, the amorphous embossed pattern 211 of the coating layer 210 is disposed on a surface different from the base layer 200. The base layer 200 and the coating layer 210 are bonded to each other by an appropriate method, such as injection molding, extrusion φ molding, vacuum molding, thermal-press molding, Coextrusion molding, film deposition, solvent adhesion, surface coating, lamination and others, the composition of the light diffusing sheet 20 is by thermoplastic Forming techniques are used for mixing, such as injection molding, extrusion molding, vacuum forming, hot press forming, co-cast forming, and the like. For example, multilayej>extrusion molding is to separately mix the base layer 2 and the coating layer 21〇_, and put the respective mixture into a feed block (feed block). Die) or a multi-tube mold (muiti-maiiif〇ld die). Further, a multi-layered board is formed by polishing rolling, which is a structure in which a plurality of layers are stacked along the y-axis, and for example, a light-diffusing sheet 2 having a double-layered plate structure can be formed. According to another embodiment of the present invention, a light diffusing sheet 21 has a plurality of coating layers 21A. The light-diffusing sheet 21 is the same as the light-diffusing sheet 2 except that it has a plurality of coating layers 21 。. For example, as shown in Fig. 2, the coating layer 210 is adhered to the base layer 2〇〇 in a laminated manner.

2008048723F Surface. In other words, the substrate layer 200 is located in at least two of the coating layers 2 . Further, other forms of the base layer 200 and the coating layer 21 are also within the scope of the present invention. According to an embodiment of the present invention, in the base layer paste, the base resin mixture of MS and S can improve the thermal resistance, light resistance and optical properties of the base layer 2, and the spherical radiance The composition and/or the acrylic acid composition can impart a 2GG superior (4) domain diffusivity and light transmittance to the basal layer. - In addition, the uniformity of light dispersion can be increased if the organic light diffusing agent is used instead of the conventional inorganic light diffusing agent. Moreover, the use of an organic light diffusing agent can also reduce the loss of production equipment and the reduction of adsorbed particles. Similarly, the composition of the coating layer 21 according to the embodiment of the present invention can greatly reduce the general phenomenon caused by light and/or heat long-term irradiation, and greatly reduce dust adsorbed by static electricity. The addition of the antistatic agent and the light stabilizer to the coating layer 210 can reduce the production cost. Therefore, when the light diffusing sheet of the embodiment of the present invention is used in a display device (e.g., a liquid crystal display), the display characteristics can be improved, and at the same time, the production cost can be reduced. The following will be combined with some κ examples to make the invention easier to understand. However, these examples are not intended to limit the scope of the invention. EXAMPLES Example 1: Fabrication of a base layer: A base layer of a ruthenium weight component was prepared by mixing a methacrylate-stupid ethylene (MS) copolymer and a methyl methacrylate-styrene (MMS) copolymer. The addition content is set to 2 ppwb; the g oxy-resin particles and the content are 2 卯 _ 20

The acrylic vinegar of 2008048723F cross-links the particles to the base resin to form a component of the base layer. Wherein the average diameter of the epoxy resin particles was 2 #m (purchased from GE T〇shiba Silicone Co., Ltd.). The average diameter of the acrylate crosslinked particles was 8 # πι (purchased from Sekisui Chemical c., Ltd.). Production of coating layer: A coating base resin having a weight of 1 Å was formed from a mercapto acrylate-styrene (MS) copolymer. An acrylic acid cross-linking particle having an iQppWb content, an antistatic agent containing i as Ippwb, and a light stabilizing agent having a content of 1 to 0% are applied to the base resin to form a coating layer. The average diameter of the acrylate parent % particles is 20 # m (purchased from sekisui Chemical Co" Ltd.) 制作 multilayer light diffusing sheet is produced: respectively, and the composition of the base layer and the composition of the coating layer are respectively injected into the die casting machine In the "extruder", after melting and grinding, the composition of the base layer and the composition of the coating layer are placed in a feeding mold to form a multilayer light diffusing sheet by rolling. The multilayer light diffusing sheet is a base layer. After sandwiching the three laminated layers of the two coating layers, the thickness of each coating layer was measured to be 100 #m, and the thickness of the substrate layer was measured to be 1,800/zm. Example Control Group 1: According to Example 1 The procedure was to produce a multilayer light-diffusing sheet, except that polystyrene (PS) resin was used as the coating base resin, and the rest was the same as the procedure of Example 1. The polystyrene resin was purchased from, PS Japan Corp.". Example control group 2 : 21 200804872

* --.w * »* ^ v # 3F A multilayer light-diffusing sheet was prepared according to the procedure of Example 1, except that polymethylmethacrylate (PMMA) resin was used as the base resin. The procedure for group 1 is the same. Among them, polymethacrylic acid vinegar resin was purchased from "Mitsubishi Rayon Corp/,. Example Control Group 3: A multilayer light-diffusing sheet was produced according to the procedure of Example 1, except that polystyrene (PS) resin was used as the base resin. The rest is the same as the example control group 1. The polystyrene resin is purchased from "PS Japan".

Corp." Example 1 and Example Control Group 1-3 The composition of each base layer and the composition of each coating layer are summarized as shown in Table 1 below. Table 1 Sample Composition Example 1 Example Control Group 1 Example Control Group 2 Example Control Group 3 Base Layer base resin MS/MMS MS/MMS PMMA PS Silicone resin light diffusing agent (ppwb) 2 2 2 2 Acrylate composition (ppwb) 2 2 2 2 Coating layer coating base resin MS PS PS PS Acrylate composition (ppwb 10 10 10 10 Antistatic agent (ppyb) 1.1.11 Light stabilizer (ppwb) 1 1 1 1 The sag of each multilayer light diffusing sheet formed in Example 1 and the example control group 1_3 will be evaluated. And optical properties. In each test, each of the multilayer light-diffusing sheets was prepared into test pieces having a size of 5 Omm X 3 Omm X 2 mm, and one side of each test piece was fixed. 22 200804872, as shown in Table 2' As shown, the resin of Example 1 (i.e., the base resin including the MS and MMS mixture) exhibited the best sag result, i.e., the sag value was 1 mm. In other words, the variation of the test piece of Example 1 for the application of the heat source. The smallest, so it has the best thermal resistance. Table 3 optical test results Example 1 Example control group 1 Example control group 2 Example control group 3 Light resistance (ΔΥΙ) 8 11 5 15 Light transmittance (%) 5U 52.0 62.3 53, 2 Light scattering property (%) 93.1 93.0 92.9 93.1 Luminous efficiency ( Cd/m2) 11,120 11,110 11,141 11,124 As shown in Table 3, the resin C of Example 1 is a base resin comprising a mixture of MS and 1^]8), compared with the example control group 1-3, Example 1 shows The most excellent ultraviolet light resistance, and its light transmittance, light diffusivity and luminous efficiency are still substantially the same as in the example control group 1-3. As shown in Figures 4A and 4B, an embodiment in accordance with the present invention The light diffusing film is applied to a display device. More specifically, as shown in FIGS. 3A and 3B, the backlight units 40 and 41 of the liquid crystal display (not shown) respectively include at least one light source 100 and one. The reflection sheet 110 and the light diffusion sheets 20 and 21. Here, in FIGS. 4A and 4B, the backlight units 40 and 41 are respectively applied to the liquid crystal displays 400 and 410. Light diffusion using the embodiment of the present invention The backlight unit of the film can be formed by an amorphous embossed pattern on the light diffusion sheet. Improved penetration of the light and a light diffusion rate, and thereby enhance brightness. In addition, embodiments of the present invention 24

2008048723F The backlight unit of the light diffusing film of % can be made of ms/mms resin, and has excellent light reduction and wettability. The backlight unit of the light diffusing sheet of the embodiment of the present invention has a relatively low wear and damage of the production equipment as compared with the conventional moonlight single 70. In view of the above, the present invention has been disclosed in a preferred embodiment, and is not intended to limit the present invention. Those skilled in the art to which the invention pertains can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

25 200804872, BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing a light diffusing sheet according to a preferred embodiment of the present invention. Fig. 2 is a schematic view showing a light diffusing sheet according to another preferred embodiment of the present invention. Fig. 3A is a cross-sectional view showing a backlight unit according to the light diffusion sheet of Fig. 1 of the present invention. Fig. 3B is a cross-sectional view showing the back light unit according to the light diffusing sheet of Fig. 2 of the present invention. Fig. 4A is an exploded view showing a display device according to the light diffusing sheet of Fig. 1 of the present invention. Fig. 4B is an exploded view showing the display device in accordance with the light diffusing sheet of Fig. 2 of the present invention. [Description of main component symbols] 20, 21: Light diffusing film • 40, 41: Backlight unit 100: Light source 110: Reflecting sheet 200: Base layer 210: Coating layer 211: Embossed pattern 400, 410: Liquid crystal display device 26

Claims (1)

200804872; f X. Patent application scope: 1. A light diffusion sheet for a display device, the light diffusion sheet comprising: a base layer comprising: a base resin, the base resin is a a mixture of a methacrylate styrene (ΜΑ-ST) copolymer and a methylmethacrylate styrene (MMA-ST) copolymer; and a first light diffusing agent (light diffuser), the content of the first light diffusing agent is s0.2ppwb-20ppwb by weight of 100 parts by weight of the base resin (ppwb); and at least one coating The layer is located above the base layer, the coating layer comprises: a coated base resin, the coated base resin is a methyl methacrylate-styrene copolymer; a second light diffusing agent, the second light diffusing agent The content by weight per 100 parts by weight of the base coating resin (ppwb) is 0.1 ppwb-30ppwb; a UV absorber, the content of the ultraviolet light absorber is O.Olppwb-2ppwb based on the weight of the coated base resin; and an antistatic agent, the antistatic agent is used in the amount of The weight percentage of the coating base resin is 27 200804872 jl ixv* jl ry -fu / *; F O.OOlppwb-lOppwb ° 2 The light diffusion sheet of claim i, wherein the base layer The mercapto acrylate-stupyl ethylene sulphide comprises from 1% to 20% by weight of a methacrylic acid vinegar single vessel and one liter by weight of 80% to 98% styrene monomer. 3. If you apply for a patent scope! The light diffusion sheet of the present invention, wherein the methacrylic acid bismuth benzoate copolymer of the base layer comprises a 6% to 94% by weight of a methyl methacrylate monomer and a weight percentage of Spring 6%-94% styrene monomer. 4. The light diffusing sheet of claim 1, wherein the first light diffusing agent comprises a siloxane composition having a content of 〇lppwb-10ppwb and a content of 〇lppwb-i〇ppwb An acrylic composition wherein the siloxane composition has an average diameter of 1/Zm, 2 Å/m, and the acrylate composition has an average diameter of m. 5. The light diffusing sheet of claim 1, wherein the second light diffusing agent of the coating layer comprises an acrylate having an average diameter of 10 and an average diameter of 1 #m~20 /zm. An oxy-oxygen composition or a combination of the acrylate composition and the oxalate. 6. The light-diffusing sheet of claim 5, wherein the second light diffusing agent of the coating layer comprises the sulfoxane composition, comprising polydimethylsiloxane a combination of one or more of polydiethylsiloxane and a silicone resin having a three-dimensional structure. 7. The light diffusing sheet of claim 5, wherein the second light diffusing agent of the coating layer of the 28 2008048723F ___________3F comprises the acrylate composition, which is a fluorenyl methacrylate (methyl) Methacrylate), ethyl methacrylate, butyl methacrylate, CyCl〇hexyl methacrylate, phenyl methacrylate , benzyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl φ A combination of one or more of acrylate), phenyl acrylate, and benzyl acrylate. 8. The light diffusing sheet of claim 1, wherein the ultraviolet light absorber is for absorbing ultraviolet light having a wavelength of from 250 nm to 280 nm. 9. The light diffusing sheet of claim 1, wherein the ultraviolet light absorber is benzophenone, benzotriazole, cyanoacrylate. And a combination of one or more of a nickel 10-based complex complex salt. The light diffusion sheet of claim 1, wherein the antistatic agent is a polyether imide amide, a polyether ester, a polyether vinegar. Polyether ester amide, polyalkylene glycol, twelfth benzene sulphate alkali metal (&11^1111^1&1 dodecylbenzene sulfonate), a tertiary amine compound (tertiary A combination of one or more of amine), quaternary ammonium, sodium monochloride (sodiiim 29 200804872, chloride), and an alkyl amine. The light diffusing sheet of the invention of claim 1, wherein the base layer has a thickness of 100A-10000/zm. The light-diffusing sheet of claim 1, wherein the coating layer has a thickness of from 10 Å/m to 1000 Å. 13. The light diffusing sheet of claim 1, wherein the coating layer comprises an embossed pattern. The light diffusing sheet of claim 13, wherein the embossed pattern is amorphous, and the surface roughness of the embossed pattern is 0.1//111.20//m. The light diffusing sheet of claim 1, wherein the coating layer further comprises a light stabilizer. The light diffusing sheet of claim 1, wherein the light diffusing sheet comprises two coating layers. 17. The light diffusing sheet of claim 16, wherein the base layer is sandwiched between the two coating layers. 1δ· A backlight unit comprising: a light source; at least a reflective sheet; and a light diffusing sheet comprising a base layer and at least one coating layer, the base layer comprising a base resin and a first light diffusion The base resin is a mixture of a monomethacrylate-styrene copolymer and a mono-Sq-styrene copolymer, and the content of the first light diffusing agent is 30 200804872f 0.2ppwb-20ppwb, the coating The layer is located above the substrate layer, the coating layer comprises a coating base resin, a second light diffusing agent, an ultraviolet light absorber and an antistatic agent, and the coating base resin is a bismuth based acrylic vinegar _ a stupid ethylene copolymer, the content of the second light diffusing agent is O.lppwbJOppwb, the content of the ultraviolet light absorber is 〇.〇lppwb-2ppwb, and the content of the antistatic agent is O.OOlppwb-lOppwb 〇19· The device comprises: a display panel; and a backlight unit comprising a light source and a light diffusing sheet, the light diffusing sheet comprising a base layer and at least one coating layer, the base layer comprising a base resin and a first light diffusing agent, the base resin is a mixture of a monomethacrylate-stupid ethylene copolymer and a methyl methacrylate-styrene copolymer, and the content of the first light diffusing agent is 〇2ppwb - 2 〇 ppwb, the coating layer is on the base layer 'The coating layer comprises a coating base resin, a second light diffusing agent, an ultraviolet light absorbing agent and an antistatic agent, and the coating base resin system a mercaptomethyl acrylate-styrene copolymer, the content of the second light diffusing agent is 〇.lppwb-30PPwb, the content of the ultraviolet light absorbing agent is 0.01 ppwb-2 ppwb, and the content of the antistatic agent is (XOOlppwb~lOppwb., 20) The display device according to claim 19, wherein the display device is a liquid crystal display.