TWI343870B - High brightness light diffusion sheet for backlight unit of liquid crystal display and method for manufacturing the same - Google Patents

Description

1343870 IX. Description of the Invention: [Technical Field] The present invention relates to a high-intensity light diffusing plate applied to a backlight module of a liquid crystal display and a manufacturing method thereof, and more particularly, to a backlight module of a liquid crystal display The high-intensity light diffusing plate can prevent birefringence, clogging, and scratches occurring thereon, and a method of manufacturing the high-intensity light diffusing plate. [Prior Art] ® Recently, liquid crystal displays (LCDs) have been increasingly used as monitors for notebook computers, large-size monitors for desktop computers, and monitors for televisions. Therefore, the demand for large-size and high-brightness backlight modules of these liquid crystal displays has also increased. The first figure shows an embodiment of a backlight module that has been primarily employed. As shown in the first figure, the backlight module includes a cathode fluorescent lamp (especially a cold cathode fluorescent lamp (CCFL)) as a light source plate φ (LGP) 120. The backlight module also includes a light diffusing plate 130, prism plates 140 and 150, and a protective plate 160. The components are stacked on the light emitting surface of one of the light guide plates 120 in this order. A reflective plate is stacked on the other surface of the light guide plate 120. The surface is opposite to the light emitting surface. The light diffusing plate 130 of the backlight module diffuses light to the entire surface of a battalion and converts light refracting into uniform light and strikes a front surface of the backlight module. The light is located at the light diffusing plate. The light source 100 is emitted from one side or back of the 13 inch. The light diffusing plate 130 comprises a light diffusing layer, a bottom plate and a back surface 1343870 coating layer. The composition for forming the light diffusion layer comprises a bonding resin, a hardener, an antistatic agent, light diffusing particles, and a solvent. The light diffusing particles are blended with the bonding resin to increase the transmittance and diffusivity of the light. For the light-diffusing particles, various organic and inorganic particles can be used. In the case where organic particles are used as the calendering diffusion particles, an organic solvent such as ethanol, acetone, methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), ethyl acetate or hydrazine is used. . The organic solvent has a large specific gravity different from that of general light-diffusing particles. For this reason, the dispersibility of the light-diffusing particles in an organic solvent is lowered. Further, the light diffusing particles will precipitate during the waiting time of the manufacturing process. Therefore, the granules are unevenly dispersed in the light diffusion layer. Further, the above solvent has an I. point. Therefore, it is difficult to obtain the leveling property 〇eveiingp which causes the shell to be flattened during the drying process after coating. The back coating layer of the light diffusing plate U0 is mounted at a position directly connected to the tube. The coating must have heat resistance against the heat generated by the light source. The middle two adjacent to the position of the back coating layer performs a process of modulating the light guide plate core 17: generating vibrations, and the vibration causes friction between the back coating layer and the light guiding surface, thereby scratching The back coating layer, according to which the back coating layer must have a very high surface hardness. SUMMARY OF THE INVENTION The description/presentation of the present invention occurs in the above-mentioned problem, and the purpose of the present invention is to provide a high-intensity light diffusing plate for the backlight module of the a0' (four) backlight module. Reducing the luminance, reducing the scratches occurring on the back surface of the light diffusing plate 1343870 and eliminating the defects and the plug β. Another object of the present invention is to provide a manufacturing method for manufacturing a liquid crystal model The high-intensity light diffusing plate of the group can increase the brightness, reduce the scratches occurring on the back side of the light diffusing plate and eliminate the blockage. According to one aspect of the present invention, a high-intensity light diffusing plate applied to a backlight module of a liquid crystal display can be used to achieve the above and other objects. The s-Huangguang light diffusing plate comprises: a bottom plate; a light diffusion The layer is formed on one surface of the bottom plate, wherein the light diffusion layer comprises light diffusion particles (the specific gravity of which is 1 2 g/cm 3 'the coefficient of variation of the particle size does not exceed 15%, and the coefficient of variation is the following list Calculated by the formula) to adjust the rate of precipitation of the light-diffusing particles (the specific gravity 〇.82 to L0 g/cm3 'boiling point 130 to 140. (3), and the difference between the refractive indices of the light-diffusing particles The value is not greater than one of the first joining resins of 〇〇 1. [Formula] Coefficient of variation == (standard deviation + average) χΙΟΟ; and a back coating layer is formed on the other surface of the bottom plate. The top coating layer comprises a bead having a coefficient of friction of not more than 0.36 (MIU) and a second bonding resin having a tensile modulus of not more than 300 MPa. The solid content of the component may be 38 to 42%. It is a mixture containing butyl acetate and one of diphenylbenzene. Based on 100 parts by weight of butyl acetate, the mixed solution may contain 2 to 150 parts by weight of xylene in 1343870. _ Based on 100 parts by weight of the first bonding resin, the composition may have 3 Up to 140 parts by weight of the light-diffusing particles. The light-diffusing particles may contain two particles having different average particle diameters. The specific gravity of the solvent may be 0.86 to 1.0 g/cm3. The beads may be nylon substrates. Or the compound of the base material. Further, the first joint resin may be an ultraviolet curable amine-based acrylic resin, and the ultraviolet curable urethane-acrylic resin may be a ternary copolymer, which is composed of tris(2-propenyloxyethyl)isocyanate, acetonitrile, (!-methyleneethyl)bis(4)·^phenyloxy-2 , - - Ethylene dimethylene oxide _2 Shan Yi Xuan two subunits) and the purpose of the gas - oxygen - _ hexyl phenyl ketone. According to another aspect of the present invention, a manufacturing method is provided for manufacturing a high-intensity light diffusing plate applied to a backlight module of a liquid crystal display, and the manufacturing method comprises preparing a light diffusing layer solution, which comprises The light-diffusing particle particle, the variation of the ** is more than 15%, and the coefficient of variation is calculated by the above formula), the solvent (specific gravity: 0.82 to gW:) & - the bonding resin 1 is applied to the light-diffusing layer solution For the stupid================================================================================================= "Resin. 'The beads and - the second is connected to the preparation of the component, the light-diffusing particles can be average particle size particles. 3 ##种不同1343870 [Embodiment] Hyun reference accompanying drawings in detail DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) The present invention has been described with respect to the preferred embodiments of the present invention. Should be regarded as a limited invention The scope and spirit of the present invention will be more clearly illustrated in the drawings, and thus in the drawings, the dimensions or thicknesses of various thin: or domains are exaggerated. The second drawing shows the application according to the present invention. A light-diffusing plate of the present invention has a bottom plate 210, and a light-diffusing layer 200 formed on the upper surface of the bottom plate 21 and laminated on the bottom plate 21〇. One of the lower surfaces is coated with a layer 220. The light diffusing layer 200 scatters or refracts light emitted by the LCD backlight module, thereby uniformly diffusing the light onto the entire surface of a screen. The composition of the light diffusion layer 2 includes a first resin, a hardener, a light diffusing particle, an antistatic agent, a dispersing agent, and a solvent. The solvent is the first bonding resin, the hardening. a material, the light-diffusing particle, the antistatic agent, and a material in which the dispersing agent is dissolved, so that the energy is particularly good. The t ^ mixture should have high dispersibility for the first bonding resin and the first diffusion particles.兮 scattered in the In a joining resin, in the manufacturing process of the board according to the present invention, the solvent should also prevent the light-expanding: particles; in the first joining resin of the 1J4387〇shai, that is, preventing the light-diffusing particles from being unhooked The ground material is dispersed in the first bonding resin. Therefore, the specific gravity of the solvent may be 〇82 to hOg/cm3. Preferably, the specific gravity of the solvent is 0.86 to i.〇g/cm3, and the point of the Buddha is 130 to 140 ° C.

When the specific gravity of the solvent is lower than 〇, 82 g/cm3, the dispersibility of the optically-dispersible particles is lowered, and during the manufacturing process, the light-diffusing particles are soaked; Therefore, the solution must be agitated again. In other words, when the specific gravity of the solvent is higher than 1.0 g/cm3, the solvent will become heavier than the first bonding resin, and thus may be aggregated under the first bonding resin, and then dried after the light is diffused. A stain appears on the layer 200. A mixed solution containing butyl ethoxide and _ T can be used as a reading agent for cnr. However, the solvent is not limited to the mixture', but various materials having a specific gravity of 〇 & to 1. 〇g/cm3 may be used as the solvent. Preferably, η, 疋 is calculated on the basis of 1 part by weight of acetic acid, and it is between 20 and 150 parts by weight.

mixing. When the content of xylene is more than 20 parts by weight, the surface tension of the liquid is small, and liquid droplets remain after application. On the other hand, when the content of xylene is less than 150 parts by weight, because the dimethyl stupidity

Oh, so the drying process cannot be performed smoothly. The residue ', 'H, skin Λ, 甲, can also be condensed & 成 斑 ° ° 再 再 再 再 再 再 再 再 再 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂 溶剂The layer 200 has a flattening property after drying and drying. If the boiling point of the solvent is lower than 13 (TC, the solvent may evaporate before the coating of the coating layer 200 to obtain a desired leveling property. Another aspect - if the boiling point of the solvent is higher than M (rc, the substrate 210 It will curl, so a load is applied during the drying process to cause a process loss. 10 1343870 According to the present invention, the light-diffusing particles have a specific gravity of 1.0 to 1.2 g/cm 3 and a coefficient of variation of particle size of not more than 15%. The iso-light-diffusing particles may comprise particles of an acrylic substrate consisting of methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, n-butyl methacrylate, n-butyl methyl methacrylate. Made of acrylic acid, methacrylic acid, a copolymer thereof or a ternary copolymer thereof, olefin substrate particles made of polyethylene, polystyrene or polypropylene, or as multi-layer and multi-component particles An organic particle obtained by forming a copolymer or a homopolymer particle of a conjugated olefinic substrate and coated with a monomer different from the copolymer or the homopolymer layer. , the light diffusing particles Methyl acrylate (PMMA). Further, for the optically diffusing particles, particles having a refractive index slightly different or equivalent to the first bonding resin may be used. The coefficient of variation is defined as a table. Formula: "coefficient of variation = (standard deviation + average) xlOO". Usually, the coefficient of variation is often used to indicate the out-of-potential. φ In the present invention, the coefficient of variation is used to replace the standard deviation which varies with the mean value. The coefficient of variation can be used to manage the distribution of the light diffusing particles and apply the managed distribution to a desired process regardless of the average value. As defined by the coefficient of variation described above, the coefficient of variation is closer to zero, the particle In the present invention, light-diffusing particles having a particle size variation coefficient of not more than 15% are used in order to maximize the light diffusion effect, that is, when the coefficient of variation of the light-diffusing particles exceeds 15%. During the initial coating process of the light diffusion layer 200, even though the coating thickness of the light diffusion layer 200 is equal to the average particle diameter of the light diffusion particles, the particles of the light diffusion 1343*870 are dispersed. The size distribution is wide, and the light-diffusing particles are stacked in a multi-layered form rather than a single layer. Therefore, the light diffusion effect is reduced. The light-diffusing particles may be particles having two different average particle diameters. The particles having a larger average particle diameter are coated on one surface of the bottom plate 210, and the particles having a smaller average particle diameter are filled in the gap defined by the larger particles coated. The structure can improve the diffusivity of light incident on the back surface of the bottom plate 210. For example, considering that the light-diffusing particles contain two particles having different average particle diameters of ® 20//m and 10//m, when the two kinds of particles are varied When the coefficients are not more than 15%, the grain size distribution is reduced. Therefore, in this case, when the light entering the back surface of the substrate 210 is diffused, uniform light can be obtained. As a result, it causes the linearity of the light, which proceeds forward. This is because the particles having an average particle diameter of 20/zm are stacked in a single layer by the narrow average particle size distribution of the light-diffusing particles, and the average particle diameter is l〇. The /zm particles are squeezed into the large size particles of the layer φ stack. Thereby, the diffusibility of the light incident on the back surface of the bottom plate 210 is improved. As described above, in order to uniformly disperse small particles in the spaces between the large particles, in addition to adjusting the grain size distribution of the particles, it is necessary to increase the solid content of the mixed solution. Preferably, the mixed solution has a solid content of from 38 to 42%. When the solid content of the mixed solution is less than 38%, the viscosity of the mixed solution is greatly reduced. Therefore, it is difficult for the coated light-diffusing layer 200 to obtain a desired thickness uniformity, and it is difficult to obtain a desired luminance uniformity. When the solids content of the component is higher than 42%, the viscosity of the component will increase significantly. As a result of 12 1343870, droplets may remain after the coating process is completed, and stains may be generated. Here, the solid content means the percentage of the other components of the component excluding the solvent. Further, preferably, the light-diffusing particles have a specific gravity of 1.0 to 1.2 g/cm 3 . This limitation is determined by considering the relationship with the specific gravity of the solvent used. When the specific gravity of the light-diffusing particles is less than 1.0 g/cm 3 , it may be lower than the specific gravity of the solvent used, so that the dispersibility of the specific light-diffusing particles in the solvent may be lowered. At this time, it is also difficult to control the thickness distribution of the coated light diffusion layer 200. • On the other hand, when the specific gravity of the light-diffusing particles is higher than 1.2 g/cm3, the precipitation speed of the light-diffusing particles in the solvent is unexpectedly increased. As a result, the solvent must be re-mixed frequently during the coating process, resulting in a process loss. In order to increase the linearity of the light radiated to the front surface of the light diffusing plate, and therefore, in order to increase the luminance of the light diffusing plate, it is preferred to adjust the refractive index of the light diffusing particles to be similar to the first joining resin. More preferably, the refractive index difference between the light diffusing particles and the first bonding resin is less than 〇.〇1. When the difference in refractive index between the light-diffusing particles and the first bonding resin is not more than 0.01, the luminance of the light emitted from the front surface of the light-diffusing sheet can be increased. The first bonding resin has a dry thickness corresponding to 5G to 75% of the average particle diameter of the optically dispersed particles. When the dry thickness of the first bonding resin is lower than the average particle diameter 料 of the light-diffusing particles, it is difficult to fixedly support the light diffusion particle layer by the first bonding resin. On the other hand, when the dry thickness of the first-joining resin is higher than the average particle of the light-diffusing particles: 75%, the light-diffusing effect is reduced. c S ) 13 1343870 The light transmission and diffusion of the light-reinforcing expander (4) is related to the content of the light-diffusing particles contained in the first-bonding resin. In order to achieve high light transmittance and diffusivity, the content of the light-diffusing particles contained in the first bonding resin is preferably from 4 to 4 parts by weight based on 1 part by weight of the first bonding resin. . When the content of the light-diffusing particles is less than the weight of the cents, the light diffusing effect by light scattering is lowered. On the other hand, when the content of the light-diffusing particles is more than 14 parts by weight, the transmittance of light is lowered. • When the component contains the first bonding resin, it is advantageous for the light diffusion layer 2GG to be highly attached to the substrate 21G. Further, the first bonding resin should have characteristics compatible with the light-diffusing particles. 'Acrylic resin was used as the first bonding resin. Preferably, the acryl resin has a refractive index (iv) of L49 such that the refractive index difference between the first bonding resin and the light diffusing particles is not more than 〇.〇1. For example, considering light diffusing particles made of PMMA, which has the same refractive index as the acrylic resin, that is, M9, is emitted by the LCD backlight module, and the light entering the light diffusing plate is linearly advanced to the LCD. The entire screen surface is used to improve the brightness. In order to increase the properties of the first bonding resin, such as heat resistance, abrasion resistance and adhesion, a curing agent may be added to the component of the light diffusion layer 2, and the dispersing agent in the composition of the light diffusion layer 200 may be used as a dispersing agent. The composition is maintained in a uniform state before the composition is applied to the bottom plate 210. The type of dispersant is not limited. 14 1343870

The bottom plate 210 of the present invention is a transparent support. The bottom plate / is selected from the group consisting of polyether oxime (PES), polyacrylic acid (pAR), polyether sulfimine (p system, polyethylene terephthalate (PEN), polyethylene terephthalate (pH ding) Manufactured from at least one of polysulfonate (PPS), polydecyl propyl, polyethylenimine, polycarbonate (TAC), and cellulose acetate propionate (CAP) The bottom plate 210 is preferably made of PET. The bottom plate 210 must have excellent properties for the first bonding resin, and the transmittance is not less than 9〇% of the light incident on the back surface of the bottom plate 210, and is evenly spaced. The surface smoothness does not cause variations in luminance. Preferably, the readout is wide and the thickness of 21 〇 has a thickness of 5 〇 to 25 〇 / / m. When the thickness of the bottom plate 210 is 杈 50 / zm, the bottom plate 210 is difficult to Processing in the manufacturing process. When the thickness of the bottom plate 210 is greater than 250/zm, the structure of the bottom plate 21〇* does not conform to the trend of the recent appearance of the LCD module. The back coating layer 220 is placed on the bottom plate 210. The lower surface, the a-side coating layer 220 includes a bead having a coefficient of friction of not more than 0 36 (MIU) = a back and a force modulus of not more than 30 MPa. The second joining resin. Here, the MIU refers to an average value of the coefficient of friction (no unit) measured using KES, and has no unit because the back coating layer 220 is one element on the back surface of the light diffusing plate ( For example, a light guide plate is in contact with each other, so in the process of assembling the light guide plate, friction will inevitably occur at the interface between the back coating layer 220 and the light guide plate. Such friction will be generated on the light guide plate. Typically, the light guide plate is made of acrylic resin and has a coefficient of friction between 〇.37 and Q 38 (L) (3). Accordingly, the frictional residual of the beads is not greater than Q 36 ( MIU), to avoid scratching on the light guide plate 15 I34J870. The material with the coefficient of friction coefficient * is larger than G.36 (MIU), such as methyl oxysulfide powder or resistance theory The powder (for example, ply-I2) is 'but not limited to the above materials. The methyl oxalate powder or the anti-rotation powder is inherently elastic, thereby preventing the beads from being used with the light guide plate. Inevitably occurring between the back coating layer 220 and the light guide plate Therefore, the tensile modulus of the second bonding resin is not more than 300 MPa, which is less than the tensile elastic modulus of the acrylic resin laminated on a typical light guiding plate, which is _ 爿譲 tender and preventable. Scratching the back coating layer is fine. That is, according to the present invention, the back coating layer 220 and the light guiding plate can be simultaneously prevented from being damaged. The first bonding resin can be any tension modulus of not more than 300. For example, the second bonding resin may be made of an ultraviolet curable urethane-acrylic resin, preferably, tris(2-propyloxyethyl) isocyanate vinegar _ 2 acrylic acid, (1 methylene ethyl) bis (仏 • t styloxy oxygen: 2,1-ethane dimethylene oxide 2,1_ethylidene dimethylene) ester and 1-hydrogen oxygen-ring The hexyl-phenyl hydrazine is made of the ternary copolymer formed. The ternary copolymer can be a bulk copolymer or a random copolymer. The ternary copolymer has a glass transition temperature (Tg) of about 52 tons and an amount of about 4,500 - the average molecular weight. "The lunar coating layer 220 provides an anti-blocking property to the light diffusing plate to increase the usability when assembling or reassembling the backlight module. Further, the back coating layer 220 To prevent scratching caused by friction with a light diffusing plate containing light diffusing particles, the light guiding plate uses 1343870 for a large-size screen LCD. Here, the anti-blocking property refers to the property of preventing blocking, and the blocking refers to integration. The light diffusing plate is disposed adjacent to the structure of the light diffusing plate, such as the light guiding plate. In order to provide anti-blocking properties, the beads must be partially protruded from the back coating layer 22G and the beads are reduced. Preferably, the particles are coated from the f-face by a protrusion of 3 to 5 〃m. The beads reduce the contact area between the domain plate and the light guide plate, thereby reducing the contact area. Contact between the light board and the light board.

The non-waxing in the coating solution can be mixed by adjusting one of the bonding agent and the particles

The hair components are caused to protrude from the surface of the back coating layer 22 . That is, the number of a bar coater is determined by the solid content. Thereby, since the thickness of the back coating layer 220 is uniform before drying, the thickness of the second layer is reduced and the grain size of the particles is not changed after drying, so the beads can The protrusion from the back coating layer 22 is about 3 #m. When the beads are raised from the surface of the back coating layer 220, the thickness of the protrusion is lower than 3 / / J. At m 4 'the back coating layer 220 and the light guide plate can be blocked. "4: 0 When the thickness of the surface of the back coating layer 220 is higher than the thickness of the surface of the back coating layer 220, the scratch on the light guiding plate may be dust = @面 coating layer 220 may be In the process of manufacturing the backlight module, it is contaminated by dirt or impurities. In order to avoid the above-mentioned static reading back coating layer 220 of the back coating layer 220, an antistatic agent may be contained. The production of this resistance is not limited to a specific material, but any of the commonly used products in this art can be used. 17 1343870 Fig. 6 is an exploded perspective view showing a backlight module of a liquid crystal display, which is a light diffusing plate according to another embodiment of the present invention. Referring to the sixth drawing, a multi-layer light diffusing plate 630 having three layers is stacked on a light-emitting surface of a light guiding plate 620 using a cold cathode fluorescent lamp as the light source 600. A reflecting plate 610 is provided on the other surface of the light emitting surface relative to the light guiding plate 620. Although the multilayer light diffusion plate 630 is represented by three layers in accordance with the present embodiment, the multilayer light diffusion plate 630 may also be two or four layers. A conventional seesaw increases the linearity of the light, which in turn increases the brightness of the place, which is expensive and therefore increases manufacturing costs. However, the multilayer light diffusing plate of the present invention in which the light diffusing particle layers overlap each other increases the linearity of the light and thereby increases the luminance at the same time and reduces the manufacturing cost. 0 Hereinafter, a backlight module applied to the liquid crystal display will be described. A method of manufacturing a high-intensity light diffusing plate according to a preferred embodiment of the present invention. The method comprises: (S1) preparing a light diffusion layer solution comprising a coefficient of variation of a particle size as a list of light diffusing particles of no more than 15%, a first-tree stalk and a specific gravity of 0.82 to 1. 〇g/ One of the solvents of cm3. Number two (standard deviation: average) xl 〇 0; ester (PET) light green layer solution on the surface of one of the phthalic acid silicate plates, and drying the applied solution; 18 1343870 (S3) formation contains A back coating layer having a coefficient of friction of not more than 0.36 (MIU) and a second bonding resin formed on the other surface of the PET substrate. In the step S1, the light-diffusing particles may contain two particles of different average particle diameters. In the step S1, when the specific gravity of the solvent is less than 0.82 g/cm3, the dispersibility of the light-diffusing particles in the solvent will be lowered, and the light-diffusing particles will precipitate in the solvent during the manufacturing process. in. Accordingly, the solution must be disturbed again. On the other hand, when the specific gravity of the solvent is higher than 1.0 g/cm3 ® , the solvent will become heavier than the first bonding resin, and thus may be aggregated under the first bonding resin after coating. As a result, stains may appear after drying. A mixed solution containing one of butyl acetate and xylene can be used as the solvent. However, the solvent is not limited to the mixture, but various materials having a specific gravity of 0.82 to 1.0 g/cm3 may be used as the solvent. When the specific gravity of the solvent is close to the specific gravity of the light-diffusing particles, the light-diffusing particles can be uniformly dispersed in the solvent during the period from the dissolution process to the coating process. In this case φ, according to this, the light-diffusing particles do not precipitate as time increases. When the light-diffusing particles are precipitated as the coating time elapses, a smaller amount of the light-diffusing particles are distributed in a pile which is subsequently produced. As a result, although the astigmatism value is reduced, the light diffusion efficiency is reduced between the stacks. On the other hand, a relatively large amount of the light-diffusing particles are distributed in a stack which is generated earlier, and it is difficult to arrange the light-diffusing particles in a single layer in each stack. Further, a severe astigmatism deviation will occur locally between the stacks. Thereafter, the light-diffusing particles are dropped into the solvent. Here, the size of the light-diffusing particles is adjusted so that the coefficient of variation of the particle size of 19 1343870 does not exceed 15%. The size of the light-diffusing particles can be adjusted by various filters which can be made of cotton, embossed, porous metal, metal fiber or the like. In order to increase the filtration efficiency, a method can be used to generate a pressure difference across the filter, or to use a centrifugal separation principle. Further, ultrafiltration can be carried out using a sponge film or a cellophane film. Other light-diffusing particles having a different average value from the dropped light-diffusing particles may be additionally dropped into the solvent. Other features of the light-diffusing particles are substantially the same or similar to those of the above-described light diffusing plate, and thus detailed description thereof will be omitted herein. The first bonding resin is dissolved in the light diffusion layer solution. The first bonding resin must have a high adhesion to the substrate 210 and compatibility with the light-diffusing particles. Further, the content of the light-diffusing particles is 40 to 140 parts by weight based on 100 parts by weight of the first bonding resin. The material of the first bonding resin is not particularly limited. Preferably, a acryl resin is used as the first bonding resin, which has a refractive index which is almost similar to ΡΜΜΑ. In order to increase the properties of the first bonding resin, such as heat resistance, abrasion resistance and adhesion, a hardener may be added to the composition of the light diffusion layer 200. Thereafter, in order to prepare a light diffusion layer solution in which the light diffusion particles are uniformly dispersed, a conventional mixer can be used. Here, the mixing or dispersion process is performed for 1 hour at 100 to 300 rpm to disperse 20 1343870 of the light-diffusing particles in a solution, and then the solution is defoamed by about 3 Torr at 50 to loo rpm. minute. In the above mixing conditions, the mixing speed is applied to uniformly disperse the light-diffusing particles in the solution, and the solution is effectively defoamed. When the mixing speed is too high, the solution will generate a large amount of bubbles. On the other hand, when the mixing speed is too low, the time required for the manufacturing process is prolonged, thereby reducing the yield of the light diffusion. Thereafter, in step S2, a light diffusion layer solution is applied to the surface of one of the base plates made of polyethylene terephthalate (PET), and dried. Here, the bottom plate is made of PET, which has high heat resistance and workability. Furthermore, the bottom plate may be selected from the group consisting of polyether oxime (PES), polyacrylic acid (PAR), polyether phthalimide (PEI), polyethylene dicarboxylate (pen), and polyethylene terephthalate. PET), polyphenylene sulfide (ppS), polyallyl, polyimine, polycarbonate (PC), cellulose triacetate (TAC) and cellulose acetate propionate (CAp) It is produced as long as the above materials have high heat resistance and workability. The PET substrate has a thickness of 50 to 250 / / m. Other features of the bottom plate are as described above, and thus detailed descriptions thereof will be omitted herein. Thereafter, the light diffusion layer solution was applied to the PET substrate. Here, various coating methods such as a spin coating method, a screen coating method, and a bar coating method are employed. It is preferred to use a bar coating method because it is suitable for mass production and continuous production. Using the bar coating method, the light diffusion layer solution can be applied to a thickness of about 20/m on the PET substrate. Thereafter, the ρΕτ substrate and the light diffusion layer solution coated thereon are dried. Here, various drying methods such as hot air drying, infrared 21 1343870 drying, and ultraviolet drying may be employed by separate or combined means. After the above drying process, the coated light-diffusing layer solution towel is dissolved in four (4) portions to form a light-diffusing layer. Finally, in step S3, a bead H coating layer having a coefficient of friction of not more than 〇36 (圃) is included, and the second bonding resin is formed on the other surface of the PET substrate. By having a coefficient of friction of not more than 〇.36 (MIU), the beads can have _ anti-blocking properties and can avoid friction between the light guide plate and a member (eg, a light guide plate) located on the back side of the light diffusing plate. A scratch is generated on the light guide plate. Other features of the beads are as described above, and thus detailed descriptions thereof will be omitted herein. The lower the coefficient of friction of the beads, the more beneficial the beads are. Preferably, the beads have a coefficient of friction no greater than 〇 36 (_). For example, it is made of a material having a coefficient of friction of not more than 〇.36 (just), such as = oxygen-fired powder or resistant powder (for example, resistance to _12), but is not limited to the above. :(:V:e plate and ===; tree; - dissolves the beads, but can be used in this field is not limited to a specific material to the second joint tree "it such as thiol ethyl fluorene toluene The scratch resistance and the tensile elastic modulus may be any material having - anti-blocking property, the bonding resin may be - violet, and not more than 3_a. The second grease, and the ultraviolet curable; the cured amino group Dilute acid tree-based copolymer, the ternary total = formic acid, acrylic resin can be one or three, ♦ 5 systems from bis(2-propoxyethyl) isocyanide 22 1343870 Quinic acid, (1-methyleneethyl) bis(4,1-phenylene oxide-2,1-ethane-sinter-monooxy-2,1-ethenediethylene) In the solvent, the antistatic agent may be added to the solvent. The antistatic agent is not limited to a specific material, but a product commonly used in the field may be used. Forming the back coating layer, the solvent containing the beads and the second bonding resin should be added to a mixing process. The mixing process can be carried out by using the mixed light diffusion layer solution used in step S1. The same mixing method is carried out. Thereafter, the solvent is uniformly mixed and the solvent of the second bonding resin is applied to the other surface of the PET substrate to be dried in step S2, and dried in the same manner as in step S1. The solvent is dried in the same manner as the diffusion layer solution. In the following, the invention will be described in more detail with reference to the following examples. However, the description of the examples should not be construed as limiting the invention. The diffusion layer solution is obtained by using an acrylic resin having a refractive index of 1.49, a polyisocyanate 5 g as a hardener, and a particle of 75 g made of polydecyl decyl acrylate (PMMA by Japan Institute of Chemistry) Manufactured by JI Engineering Co., Ltd. as a light-diffusing particle with a refractive index of 1.49, a specific gravity of 1.19 g/cm3, a size of 20//m, a particle size coefficient of variation of 7%), mixed with 112 g of butyl acetate and In a solvent of 48 g of diphenylbenzene (the specific gravity of the solvent is 0.878 g/cm3 and the boiling point is 133.29 ° C), 23 ^ 343870 = preparing a mixed solution, using a homomixer to apply the mixed solution, jOOOO rpm and calendar After 1 hour of dispersion, the mixed solution was defoamed for 2 hours. The light diffusion layer solution was applied to a surface having a thickness of 125/zm PET substrate by using a bar coater, followed by drying. / Thereby, a pET plate having a thickness of 20am of the light diffusion layer is obtained. 1 After the 'preparation-back coating layer solution, by UV-curable soil, the scorpion S-acrylic resin l〇 〇g (Nat〇k〇 Coatings Co., Ltd., SB_243), its glass transition temperature is about 52. (: and a force bomb is 25 MPa), non-ionic interface activity as an antistatic agent And <, and a bead made of methyl decane having a coefficient of friction of 〇'32 (MIU), 2 g, dissolved in a mixed solution containing 50 g of anthraquinone and 5 〇g of mercaptoethyl ketone. This back coating layer solution was applied onto the other surface of the PET sheet provided with the light diffusion layer using a bar coater, followed by drying at a temperature of 1 °c. in an air oven for 30 seconds. Next, the coating on the PET plate was hardened by ultraviolet rays having a radiation intensity of 6 〇〇 mJ/cm 2 . Thereby, a light diffusing plate having the back coating layer having a thickness of 4 • protruding beads was produced. Implementing You | 2 Preparing a light diffusion layer solution by using 100 g of unsaturated polyester resin having a refractive index of 149, 5 g of polyisocyanate as a hardener, and 75 g of PM made of polymethyl methacrylate (PMMA) It is manufactured by Japan Institute of Chemical Engineering and Engineering Co., Ltd. as a light diffusing particle with a refractive index of 1.49' specific gravity S 1.19gW' size of 1Q//m, particle size coefficient of variation of 7%), mixed with butyl acetate. 65g of ester 65g and 16g of xylene, a solvent (the specific gravity of the solvent is 879.879g/cm3 and a boiling point of 131.86 ° C) to prepare a mixed solution, and a homomixer is used to apply a 1000 rpm to the mixed solution for a period of time. The mixed solution was defoamed for about 2 hours in a 1 hour dispersion process. The light diffusion layer solution was applied to a surface of a substrate having a thickness of 125 m/m by using a bar coater, followed by drying. Thereby, a PET plate having a thickness of 20 / / m of the light diffusion layer was obtained. Thereafter, a back coating layer solution was prepared by using UV curable urethane acrylic resin 1 (10) g (manufactured by Natoko Paint Co., Ltd., ''SB-243') and a force elastic modulus of 25 〇Mpa), 5g of nonionic surfactant as antistatic agent and 2g of beads with a coefficient of friction of 0.34 (MIU) made from 耐__12, dissolved in a toluene 5 methyl ethyl ketone 5 A mixed solution was applied to the other surface of the m-plate provided with the light-diffusing layer using a bar coater, followed by drying in a temperature HKTC hot air oven for 3 () seconds.紫外线 UV-curing with a light-intensity intensity of 60 GmI/c^ is applied to the ρΕτ plate: This is used to manufacture a light-diffusing sheet having the back-coated layer with a thickness-containing bead. Example 3 Adoption and Example 1 The same method was used to fabricate a light diffusing plate, except that a solvent containing butyl acetate and dimethyl benzene was used (the solvent specific gravity was 0.876 g/cm3 and the point of the buddha was 134,7. 1343870 f Example 4 Preparation of a light diffusion layer solution by refractive index 149 acryl resin l〇〇g, polyisocyanate 5g as hardener, 126g made of polymethyl methacrylate (PMMA is manufactured by Japan Institute of Chemical Engineering and Engineering Co., Ltd.) , 49, specific gravity is i, 19g/cm3,

The particle size is 20//m, the particle size variation coefficient is 7%) and the particle 14g made of polymethyl ketone ethyl phthalate is manufactured by Japan Institute of Chemical Engineering Co., Ltd., and its refractive index is U9. , the specific gravity is ία g / cm3, the size is 10 / zm, the particle size coefficient of variation is 9 5%), mixed in a solvent containing butyl acetate] 6 2 g and dimethyl stupid 6 9 g (the specific gravity of the solvent is 0.878 g/cm3 and a boiling point of 133.29t) to prepare a mixed solution, using a homomixer to apply a dispersion process of 1 rpm and 1 hour to the mixed solution, and then defoaming the mixed solution by about 2 hour. The light diffusion layer solution was applied to a surface having a thickness of 125 #mPET by using a bar coater, followed by drying. Thereby, one of the light diffusion layers having a thickness of 20/z m is obtained. Thereafter, a back coating layer solution was prepared by using a UV-based amine-based methyl propylene resin 100 g (manufactured by Natoko Paint Co., Ltd., "sb_243", and the temperature was about hunger - Tensile elastic modulus is hired pa), with friction system (four) 0.32 (MIU ^= made of cut-to-oxygen sinusoidal deduction... Dan... g, dissolved in - containing 曱 brand read doxy ketone, which - mixed night Applying a bar coater to the other hot air box with the material layer to dry for 3 seconds. Next, 26 1343870 hardens the PET by ultraviolet light having a radiation intensity of 600 mJ/cm 2 . Coating on the board. By this, a light diffusing plate having a back coating layer having a thickness of 4/zm protruding beads was fabricated.

A light diffusion layer solution is prepared by using a UV-curable amino phthalate-acrylic resin l〇〇g having a refractive index of 1.47 and a particle of 75 g made of polymethyl methacrylate (PMMA system) Manufactured by Japan Sekisui Plastics Co., Ltd. as a light-diffusing particle with a refractive index of 149, a size of 20/zrn and a particle size coefficient of variation of 35%), mixed with a solvent of methyl ethyl ketone (MEK) 128g. (the solvent has a specific gravity of 〇8〇2g/cm3 and a boiling point of 79.6C) to prepare a mixed solution, and a homogenizer is used to apply a dispersion process of the mixture to a rpm and a lapse of several hours. The mixed solution was defoamed for about 2 hours. The light diffusion layer solution was applied to a surface having a thickness of 125 / / m PET substrate by using a bar coater, followed by drying. Thereby, a PET plate having the thickness of the light diffusion layer was obtained. Thereafter, the 'preparation-back coating layer solution is a non-ionic surfactant which is an antistatic agent by using a thermosetting acrylic bonding resin, (manufactured by Han _ aekyung CHEMICAL, whose glass transition temperature is about (10) art). 3g and beads made of PMMA with a molar ratio of 0.38 (MIU) 2g 'dissolved in a stupid heart. Applying the back coating layer solution to the other surface of the PET sheet having the light diffusion layer using a bar coater, followed by "temperature" in the hot air material, thereby producing a bead having a thickness-containing thickness The light diffusing plate of the back coating layer 27 1343870 was tested. Test Example 1 The light diffusing plates of the above Examples 1 to 4 and Comparative Example 1 were evaluated by the following methods: (1) Scratch resistance The scratch on the light diffusing plate was observed by a friction test with a light guide plate. Here, a surface property testing machine "HEIDON-14DR" manufactured by Nippon Shinto Scientific Co., Ltd. was used. The speed was set to 4500 _/min, the reciprocating distance was set to 15 mm, the number of repetitions was set to 2000, and a weight of 50 g was applied. The inspection by the naked eye was used as the result of the evaluation. The third a diagram shows a comparison example 1 A photograph of the surface state of the produced light diffusing plate after the friction test, and the φ3b diagram shows a photograph of the surface state of the light diffusing plate produced in accordance with Example 4 of the present invention after the friction test. Third a and third b, when the light diffusing plate is in contact with the light guiding plate, since the friction coefficient of the beads is small, it can be seen that a small number of scratches are formed on the light diffusing plate of the present invention. The elasticity of the second bonding resin ensures a distance that allows the beads to move, thereby reducing the damage of the scratch. ^ (2) Evaluation of wear resistance using a whole machine (taber abraser, using a wear 28 13343870 The wheel CS-17 and a load Ikg) were used to measure the abrasion resistance of the back coating layer of each of the light diffusing plates produced in Example 4 and Comparative Example 1. 'Each light diffusing plate was prepared into a dish shape A test piece is mounted on the test piece and rotated, thereby abrading the test piece. Next, the weight of the abrasion test piece is measured. The fifth figure shows the test result of the light diffusion plate. The fifth figure shows a graph of the wear resistance test results of the light diffusing plate, which are made according to the embodiment 4 of the present invention and the comparative example 1. Referring to the fifth figure, according to the comparative example The amount of reduction of the test piece of the prepared light diffusing plate, It is proportional to the increase in revolutions per minute (rpm) of the wear wheel. On the other hand, the test piece of the light diffusing plate made in Example 4 of the present invention has a reduction amount close to zero until the minute of the wear wheel The number reached approximately 300 rpm, and since then the number of revolutions per minute of the wear wheel reached 1000 rpm. The reduction was still maintained at a low value. Further, according to the inspection of the naked eye, it was made according to Comparative Example 1. The second bonding resin of the light-diffusing sheet is peeled off. On the other hand, any portion of the second bonding resin of the test piece of the light-diffusing sheet prepared in Example 4 is not peeled off. Therefore, the light-diffusing sheet of the present invention can be observed. It has excellent wear resistance. (3) The luminance evaluation was performed using a device called BM7 (manufactured by Topcon Corporation), and the measurement angle was 1 degree. Measure a total of 29 1343870 sections of a light diffuser. The nine measurement areas are numbered. Fig. 4 is a view showing a luminance measuring area of a light diffusing plate according to another embodiment of the present invention. Table 1 shows the luminance measured in nine regions of each light diffusing plate using the above apparatus. These light diffusing plates were produced in accordance with Examples 1 to 4 and Comparative Example 1. Table 1 1 2 3 4 5 6 7 8 9 Average stimulating rate (%) Example 1 3737 3246 3293 3258 3521 3425 3178 3206 3078 3327 1.2 Example 2 3713 3218 3265 3238 3509 3389 3154 3178 3086 3306 0.5 Example 3 3792 3281 3325 3313 3569 3433 3214 3262 3142 3370 2.5 Example 4 3836 3309 3345 3317 3593 3485 3269 3305 3178 3404 3.5 Comparative Example 1 3689 3198 3242 3214 3493 3401 3126 3166 3066 3288 0.0 As shown in Table 1, the measurement is compared Example 1 The luminance of the region 1 30 1343870 to 9 of the light diffusing plate was prepared, and the average luminance was calculated. Next, the average luminance of each of the light diffusing plates was calculated in accordance with Examples 1 to 4, and compared with the average luminance of the light diffusing plate produced in Comparative Example 1. Thereby, the increase rate of the average luminance of each of the light diffusing plates produced in accordance with Examples 1 to 4 was calculated. Namely, the average luminance of the light diffusing plate prepared in Comparative Example 1 was taken as a reference luminance. Referring to Table 1, it is understood that the average luminance increase rates of the light diffusing sheets produced in Examples 1 to 4 were 1.2%, 0.5%, 2.5%, and 3.5%, respectively.

From the above results, compared with the conventional light diffusing plate which causes the birefringence caused by the multi-layer configuration of the beads to cause low luminance, it can be proved that the first diffusion plate of the present invention is configured by a single layer of beads, eliminating clogging and reducing the cause and effect. ~a A scratch caused by friction of a light guide plate adjacent to the back surface of the light diffusing plate to achieve an improvement in luminance. It is apparent from the above that the present invention provides a high-intensity light diffusing plate applied to a backlight module of a liquid crystal display, which increases brightness, reduces scratches occurring on the back surface of the light diffusing plate, and eliminates clogging and provides a manufacturing process. Method of light diffusing plate. While the invention has been described with respect to the preferred embodiments of the present invention, it will be understood that various modifications, additions and substitutions may be made without departing from the scope and spirit of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and other advantages of the present invention will become more apparent from the <RTIgt; The first figure shows a schematic exploded view of a conventional liquid crystal display backlight module 31 1343870; the second figure shows a cross-sectional view of a light diffusing plate according to an embodiment of the present invention; A photograph showing a state of the surface of the light diffusing plate after the friction test, the light diffusing plate being made according to Comparative Example 1; and the third b drawing showing a photo of the surface state of the light diffusing plate after the friction test, the light diffusing plate The fourth embodiment is based on the fourth embodiment of the present invention; the fourth figure is a schematic view of the light diffusion plate according to another embodiment of the present invention; the fifth figure shows the wear resistance test result of the light diffusion plate. One of the charts, 'the light diffusing plate is made according to the fourth embodiment of the present invention and the comparative example 1; and the sixth drawing is an exploded perspective view of the liquid crystal display backlight module, which is based on the present invention. A light diffusing plate of one embodiment. Φ [Description of main component symbols] 100 light source 110 reflector 120 light guide plate 130 light diffusion plate 140 稜鏡 plate 150 prism plate 160 protection plate 200 light diffusion layer 32

Claims (1)

1343870 Announcement 10, the scope of application for patents: 1 'Repaired [color version revision date: 2010/08/06 正衣 A high-intensity light diffusing plate applied to a liquid crystal display-backlight module, including: Bayi bottom plate; - light The diffusion layer is formed on the surface of the bottom plate, wherein the damage layer of the light diffusion layer comprises light diffusing particles (specific gravity) 〇 to 1.2 g/cm 3 , and the particle coefficient of variation is not more than 15%, and the coefficient of variation is the following formula Calculated to obtain a solvent for adjusting the precipitation rate of the light-diffusing particles. (Specific gravity 〇.82 to 1'0 g/cm3, Foshan 130 to 14 (TC) and a first bonding resin, the refraction thereof The difference between the refractive index and the refractive index of the light diffusing particles is not more than 0.01, [Formula] coefficient of variation = (standard deviation + average) xl 〇〇; and a back coating layer is formed on the other surface of the bottom plate, wherein The back coating layer comprises a bead having a coefficient of friction of not more than 0 36 (MIU), and a second bonding resin having a tensile modulus of not more than 3 GG MPa; wherein: the solvent of 5 kel is containing butyl acetate and two p One of benzene mixed solutions, and Calculated based on 100 parts by weight of butyl acetate, the mixed solution contains 20 to 150 parts by weight of xylene; and the composition contains 40 to 140 parts by weight of the light based on 100 parts by weight of the first bonding resin Diffusion particles; the beads are made of a nylon substrate or a ruthenium substrate; and the second bonding resin is a UV-curable urethane- Ζ 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 0/08/06 · Acrylic resin 2. As in the high-intensity light diffusing plate of claim 1, the solid content of the component is 38 to 42%. 3. If the patent application is the first item The high-intensity light-diffusing sheet, wherein the light-diffusing particles may contain two particles having different average particle diameters. 4. The high-intensity light-diffusing sheet of claim 1, wherein the specific gravity of the solvent may be 0.86 to 1.0 g/cm3. 5. The high-intensity light diffusing plate according to claim 1, wherein the violet-external cured urethane-acrylic resin may be a ternary copolymer, the ternary copolymerization Tris(2-propoxyethyl) isocyanate Tris(2-acryloxyethyl)isocyanurate-2-propenoic acid, (1-indolylethyl) bis(4,1-phenylene oxide-2,1-ethane II) (1,1-phenyleneoxy-2,l-ethanediyloxy-2,1-ethanediylester) and 1-hydrogen-cyclohexyl -Phenyl ketone (1-hydroxy-cyclohexyl-phenyl ketone) is composed of jin. 1 35 1343870 200 210 220 Two a diagram 1343870 Revised revision date: 2010/08/06 Third b diagram 2 3 4 5 1 6 7 8 9 Fourth diagram 1343870 Revision revision period: 20丨0/08/06 &gt; 2 ο Fifth picture Figure VI