TW201015119A - Optical plate and backlight unit using the same - Google Patents

Abstract

The present invention aims to provide an optical plate and a backlight unit using the same, the optical plate can easily and reliably control optical functions of each region on the optical plate surface to improve brightness uniformity of the backlight unit as well as promote thinness. The optical plate of this invention has a transparent substrate layer and an optical layer laminated on the substrate layer surface, characterized in that the optical layer has plural light diffusion parts laminated in scattering manner on the substrate layer surface; the light diffusion parts contain light diffusion agent and its binder, wherein the light diffusion parts preferably are formed to be convex-lens like, and the light diffusion agent preferably has a mass ratio above 0.1 or below 2 with respect to the binder, and the average diameter D of the light diffusion parts preferably is set to be 10μ.

Description

[Technical Field] The present invention relates to an optical sheet and a backlight unit, and more particularly to an optical sheet suitable for use in a liquid crystal display device and a backlight unit using the same . [Prior Art] The Φ liquid crystal display device is widely used as a backlight in which a liquid crystal layer is irradiated from the back surface to emit light, and is provided with an edge light type or a straight line on the lower surface side of the liquid crystal layer (b0tt0m light) Type of backlight unit. As shown in FIG. 4, the sidelight type backlight unit 7020 basically includes a linear light source 21 as a light source, a square plate-shaped light guide plate 22 disposed at an end portion along the light source 21, and A variety of optical sheets 23 laminated on the surface side of the light guide plate 22. The optical sheet 23 has a specific optical function such as refraction and diffusion, and specifically corresponds to the light guide plate 22, the light diffusing sheet 24 having a light diffusing function disposed on the surface side of the light guide plate 22, and the light diffusing sheet 24 The surface side of the diffusion sheet 24 has a ruthenium sheet 25 or the like which has a function of refracting toward the normal side. The function of the backlight unit 2 is described below. First, the light incident from the light source 21 to the light guide plate 22 is reflected by a reflection point or a reflection sheet (not shown) on the inner surface of the light guide plate 22, and the surface of the light guide plate 22 is irradiated. Exit. The light emitted from the light guide plate 22 is incident on the light diffusion sheet 24, diffused by the light diffusion sheet 24, and then emitted from the surface of the light diffusion sheet 24. Thereafter, the light emitted from the surface of the light-diffusing sheet 24 is incident on the cymbal sheet 25, and the surface of the lens 25 is made of (4) h prism. P 25a is emitted as a light ray 3 201015119 showing a distribution of peaks in a substantially normal direction. As described above, the light emitted from the light source 21 is diffused by the light diffusion sheet 24, and is refracted by the prism sheet 25 so as to show a peak in a substantially normal direction, thereby illuminating the liquid crystal layer on the surface side (not shown). ) The whole face. In addition, although not shown in the figure, it is based on the relaxation of the condensing characteristics of the cymbal sheet 25 or the protection of the crotch portion 25a or the adhesion between the liquid crystal panel such as a polarizing plate and the cymbal sheet. As the light-diffusing sheet 24 provided in the backlight unit 20, the surface of the transparent base material layer made of a synthetic resin is coated with a bead of a bead coating type (bead). The light-diffusing sheet is exemplified by the above-mentioned Japanese Patent Publication No. Hei 7-5305, JP-A-200-89/7, and the like. The light-diffusing sheet can function as a light diffusion by the fine uneven shape of the surface. In the above conventional light-diffusing sheet, the bead layer is laminated on the entire surface of the substrate layer by coating, and the light diffusion sheet exhibits a substantially uniform light diffusion function. The case of the cymbal is also the same as above. On the other hand, the backlight unit tends to increase the brightness in the vicinity of the light source 21 in the structure. Therefore, it is possible to ensure the average brightness of the entire surface of the liquid crystal panel by processing the surface of the light guide plate 22 or the like. However, most of the processing of the surface of the light guide panel 22 is injection molding, and it takes time to form a metal mold for injection molding, so that the lead time required for correction of the surface pattern or the like is long, and there is also a need to manufacture a plurality of products. The problem of time. [Patent Document 1] Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. An object of the present invention is to provide an optical sheet and a backlight unit using the same, which can easily and surely control optical functions of respective regions of the optical sheet surface, improve uniformity of the backlight unit, and promote thinning. Means for Solving the Problems The present invention for solving the above problems is an optical sheet comprising a transparent substrate layer and an optical layer laminated on the surface of the substrate layer, characterized in that the optical layer has scatter a plurality of light diffusing portions which are laminated on the surface of the substrate layer; the light diffusing portion contains a light diffusing agent and a binder. Since the optical sheet has a plurality of light diffusing portions which are layered on the surface of the base material layer, the optical sheet has a portion where the light is diffused and a portion where the light is not diffused, and the light diffusibility varies depending on the area on the sheet. different. In short, the β ° ray optical sheet can be used to adjust the position of the laminated portion of the optical layer to diffuse the desired intensity of the desired position on the optical sheet, and to finely adjust the vertical light diffusibility of each sheet surface. Further, the optical sheet can be diffused and deposited on the base material layer by printing, so that the arrangement of the laminated portion can be easily adjusted. The light diffusing portion is preferably formed in a convex lens shape. By forming the light-diffusing portion into a convex lens shape, the light diffusibility can be improved, and the light diffusibility can be easily controlled. The mass ratio of the light diffusing agent to the binder is preferably 〇1 or more. By setting the mass ratio of the light diffusing agent to the above range, it is possible to effectively exhibit the light diffusibility of 201015119.

The average value of the light diffusing portion M () is preferably 1 以上 or more and 300 / zm or less. By forming the optical layer from m M . s by a convex lenticular light diffusing agent having the above diameter, the optical function of the optical sheet can be controlled simply and surely. The average height (Ηι) of the light diffusing portion with respect to the average straightness ratio (H丨/D)' is preferably 〇.5 or less than 0.5. By setting the height ratio (Hl/D) of the light-diffusing portion to the above range, optical functions such as diffusion and a variable angle toward the normal direction side can be improved. The absolute value (d...) of the difference between the refractive index (ηι) of the light diffusing agent and the refractive index (10) of the binder in the light diffusing portion is preferably 〇5 or more. By having the above-mentioned refractive index difference between the light diffusing agent and the binder, effective condensing, refracting toward the normal direction side, diffusion, and the like can be performed. The particle diameter of the light diffusing agent in the light diffusing portion is preferably 〇""claw or more 20" or less. If the particle diameter of the light diffusing agent is less than the above range, the light diffusing effect may be insufficient 'relatively'. When the particle diameter of the light diffusing agent exceeds the above range, it is difficult to arrange the binder forming the light diffusing portion. The layering ratio of the light diffusing portion in the optical layer is preferably 10% or more and 90% or less. When the layering ratio is in the above range, the optical function such as diffusion can be easily controlled. The arrangement pattern of the surface of the base layer of the light diffusion portion is preferably a regular two-corner lattice pattern. The regular triangular lattice pattern can diffuse the lenticular light. Therefore, the regular triangular lattice pattern can easily increase the filling rate of the convex lenticular light diffusing portion, and greatly enhance the optical functions such as refraction and diffusion toward the normal direction 201015119 side. The pattern of the surface of the substrate layer may also be a random pattern. The above random pattern can reduce the pattern generated when the lenticular sheet is overlapped with other optical parts. Preferably, the back surface of the base material layer has a corrugated crucible shape, and the height ratio (h2/p) of the average height (H2) of the crucible to the crucible spacing (p) is 〇_〇5 or more. When the back surface of the base material layer has the above-described height m ratio of the prism shape, the optical function such as refraction and diffusion toward the normal direction side can be greatly enhanced. Therefore, the light emitted from the light source is dispersed. The light is guided to a backlight unit for a liquid crystal display device on the surface side thereof, and the brightness can be adjusted in each region. If the optical sheet has an optical function such as high diffusion or variable angle, the optical sheet can be used for brightness adjustment. And the quality is improved by the uniformity of the brightness. The convex lenticular shape here means that the cross-sectional shape has a convex shape, and the meandering planar shape is not limited to a circular shape. The "average height (Ηι)" means the average vertical distance from the base surface to the topmost portion of the convex lens-shaped light diffusion portion. The monthly average direct service (D) means the average diameter of the base of the lenticular light-diffusing portion. The "layering ratio" means the ratio of the light diffusing portion per unit area in the surface projection shape of the optical sheet. The "normal triangle lattice pattern" means an equilateral triangle whose surface is divided into the same shape, and the apexes of the triangular shape are provided with a pattern of light diffusion portions. The "average height (Η."" means the average vertical distance from the base surface to the apex of the prism. In addition, the "稜鏡 spacing (P)" means the distance between the average vertices in the cross-sectional shape of the 7 7 201015119 Advantageous Effects of Invention According to the above description, the optical sheet of the present invention and the backlight unit using the same can easily and reliably control the optical function of each region of the optical sheet surface to improve the brightness uniformity of the backlight unit and promote the reduction in thickness. EMBODIMENT OF THE INVENTION The embodiments of the present invention will be described in detail below with reference to the drawings. Fig. 1 (4) and (8) are schematic partial plan views and schematic partial cross-sectional views of an optical sheet according to a specific embodiment of the present invention; 2 is a schematic partial cross-sectional view showing an optical sheet of a different form from the optical sheet of FIG. 1, and FIG. 3 is a view showing the optical layer of the surface of the schematic section 2 of the backlight unit having the optical sheet of FIG. 2: 2 Because it needs to penetrate light, it is especially colorless and transparent.

(4) The synthetic resin used in the P m layer, and I is particularly limited to 'for example, polyethylene terephthalate ethylene acetonate, acrylic resin, polycarbonate cellulose urate, weather resistant gas, polyolefin, E-ring curing resin. It is preferable that the wire-curable resin and the electronic phthalic acid phthalate are excellent in polyethylene terephthalate which is excellent in transparency and high in strength. The thickness of the base film 2 (flatness) of the polyethylene terephthalate having improved flexural properties is not particularly limited, and the example 201015119 may be 50 " m or more, 800 " m or less, preferably ΐ 〇〇μ m or more and 600 or less m. When the thickness of the base film 2 is less than the above range, when the backlight unit or the like is exposed to a hot environment, curling and difficulty in use may occur. On the other hand, if the thickness of the base film 2 exceeds the above range, the brightness of the liquid crystal display device may be lowered, and the thickness of the backlight unit is increased, so that the thickness of the liquid crystal display device is required to be thinner. The optical layer 3 is composed of a plurality of lenticular light-diffusing portions 4, and 0 includes a light diffusing agent 5 and an adhesive 6. This light diffusing agent 5 is covered with the adhesive 6. The light diffusing agent 5 included in the light diffusing portion 4 can uniformly diffuse the light transmitted through the light diffusing portion 4 as described above. Further, the fine convex portion is formed on the surface of the light diffusing portion 4 in a substantially uniform and substantially tight manner by the light diffusing agent 5. The light can be further diffused by the refraction of the fine meniscus lens formed on the surface of the optical sheet. The light diffusing portion 4 has a convex lens shape. According to this means, by having the shape of the convex lens, the angle of refraction of the light of the surface of the light diffusing portion 4 can be adjusted, and the light can be further diffused and angled toward the normal side. The light diffusing portion 4 is disposed on the surface of the substrate layer 2 in a relatively tight and geometric manner. The light diffusion layer 4 is disposed on the surface of the substrate layer 2 in an equilateral triangle lattice pattern. Therefore, the arrangement intervals of the light diffusing portions 4 are all fixed. This arrangement pattern allows the light diffusing portion 4 to be disposed in the most dense manner, thereby enhancing the optical functions such as the diffusion function and the variable angle function of the optical sheet 1. The lower limit of the layering ratio of the light diffusing portion 4 is 1% by weight, particularly preferably 15%, and most preferably 20%. By setting the layering ratio of the light-diffusing portion 4 to the lower limit or higher, the area occupied by the light-diffusing sheet 4 in the surface of the optical sheet can be increased, and the optical function of the optical sheet 1 can be further enhanced. The upper limit of the layering ratio of the light diffusing portion 4 is 90%, particularly preferably 75%, preferably 6% by weight. By setting the layering ratio of the light diffusing portion 4 to the upper limit or lower, the arrangement of the light diffusing sheet 4 in the surface of the optical + u-chip can be freely moved, and

Simple control of optical functions. The average diameter (9) of the T-light diffusing portion 4 is 1 〇/_ or more, preferably 4 〇" or less. By setting the diameter of the light diffusing portion 4 to the above range, the unwinding can be easily and surely controlled. Optical functions such as dispersing and variable angle. In addition, the diameter of the light-diffusing portion 4 can be + same. The same can be changed with the position of the sheet. For example, by the light of the portion to be brightened The diameter of the diffuser is increased by the amount of 'there is a slight adjustment of the binarity in the optical sheet. In addition, the ten-sided shape of the light diffusion is not limited to a circular shape', and an elliptical 'quadric shape may be appropriately used. Polygons such as hexagons. The average height (Ηι) of the first diffusing portion 4 is preferably equal to or less than (9) (9), and is preferably -·〇' straight "D). By setting the twist ratio of the light diffusing portion 4 to the above range, it is possible to diffuse the light having the convex lens shape on the right side J to the surface of the light diffusing portion 4, and to function as a convex lens. The diffusion of light, the angle of change toward the normal direction, and so on. The light diffusing agent 5 has a filler and an organic filler which diffuse light. For example, ruthenium dioxide, ruthenium alumina, alumina, oxidized, bismuth oxysulfide, magnesium ruthenate, or a mixture thereof may be used. As an organic filler..^ It can be used as a material. For example, it can be used: Acrylic tree, acrylonitrile resin, polyamine-based work, 9-polyethylene, polystyrene, I-acrylonitrile, polyfluorene Amines, etc. Among them, A is preferably an acrylic 201015119 resin having high transparency, and more preferably polymethyl methacrylate (PMMA). In other respects, it may contain fluorescent materials. The shape of the light diffusing agent 5 is not particularly limited, and examples thereof include a spherical shape, a spindle shape, a needle shape, a rod shape, a cubic shape, a plate shape, a scaly shape, and a fiber shape. Among them, it is preferably excellent in light diffusibility. Spherical beads. The lower limit of the average particle diameter of the light diffusing agent 5 is preferably 2 or more preferably 5 μm. The other side, the average particle size of the light diffusing agent 5

The upper limit is preferably 5 〇/^m, more preferably 2 (^m, most preferably l5/zm. The reason is that 'if the average particle diameter of the light diffusion 5 does not reach the above range, the light diffusing agent 5 The unevenness of the surface of the formed optical layer 3 may change, and the light diffusibility necessary for the light diffusion sheet may not be satisfied. Conversely, if the average particle diameter of the light diffusing agent 5 exceeds the above range, the optical sheet 丨The thickness of the light diffusing agent 5 is increased, and it is difficult to uniformly diffuse. The average particle diameter of the light diffusing agent 5 is obtained by randomly amplifying the light diffusing agent 5 by a microscope to obtain the diameter of the particles and averaging them. Further, when the light diffusing agent 5 is non-spherical, the length of the light diffusing agent 5 in any direction and the length of the light diffusing agent 5 perpendicular to the above direction are averaged. The light diffusing agent 5 is opposed to the bonding agent 6 The mass ratio is 〇>1 or more and 2 or less, and particularly preferably 0.3 or more 〇·5 or less. The reason is that if the mass ratio of the light diffusing agent 5 is less than the above range, the light diffusibility may be insufficient. The mass ratio of the light diffusing agent 5 exceeds the above range, and the J fixed light The effect of the diffusing agent 5 is lowered. The absolute value (| ηι-η2 | ) of the difference between the refractive index (ηι) of the light diffusing agent 5 and the refractive index (η2) of the binder 6 is preferably 〇〇5 or more. The light diffusing agent 5 11 201015119 and the binder 6 have the above refractive index difference, because the interface between the light diffusing agent 5 and the bonding agent 6 can be effectively used not only at the interface between the substrate layer 2 and the optical layer 3 but also at the surface of the optical layer 3. Since the refraction is generated, it is possible to efficiently condense, refract or diffuse toward the normal side, diffuse, etc. The binder 6 is formed by crosslinking and curing a polymer composition containing a base polymer. 6 The light diffusing agent 5 can be disposed and fixed on the surface of the base material layer 2. Further, the polymer composition for forming the adhesive 6 can be appropriately blended with, for example, a micro inorganic filler or a hardener in addition to the base polymer. , dispersants, various leveling agents, UV absorbers, antioxidants, viscous modifiers, slip agents, light stabilizers, fluorescent materials, etc.

The base polymer is not limited to, and examples thereof include acrylic acid: a resin, an aminocarboxylic acid I-based resin, a polyester resin, a gas-based resin, a H-amine imide, and an epoxy resin. The ultraviolet curable resin or the like may be used in combination with the above polymers or the like. Which of the above bases? The polythene is highly processable and can be coated

The polyol is preferred. Further, for adhesion: hand =:, from the viewpoint of improving light transmittance, it is preferable that the object itself is "colorless and transparent". For example, the monomer component of the monomer is polymerized to obtain a polyester polyol obtained under the conditions of (4) unsaturated; or two or more kinds of hydroxy groups are used in combination. 4 These may be used singly or as: hydroxyethyl ester containing a trans-unsaturated monomer, 2-hydroxypropenyl acrylate, (a) § 曰, methacrylic acid such as 2-2-hydroxyethyl acrylate, 12 201015119 Hydroxy-containing unsaturated monomer such as 2-propyl propyl acrylate, propylene alcohol, propylene glycol crotonol crotyl alcohol; (b) for example, ethylene glycol, ethylene ethoxide, propanol, epoxy Propylene, butanediol, butyl epoxide, hydrazine, 4 pairs (by fluorenyl) cyclohexane, phenyl glycidyl ether, glycidyl decanoate, placce 丨 FMd (manufactured by Daicel Chemical Industries, Inc.) a dihydric alcohol or an epoxy compound, which is reacted with an unsaturated carboxylic acid such as acrylic acid, methyl acetoacetate, cis-butane diacid, fumaric acid, crotonic acid or itaconic acid to obtain a hydroxyl group-containing unsaturated monomer or the like. The above polyol can be produced by polymerizing one or more selected from the group consisting of the radical-containing unsaturated monomers. Further, the above polyterpene alcohol may be selected from the group consisting of ethyl acrylate, acrylic acid, isopropyl acrylate, n-butyl acrylate, tert-butyl acrylate, ethyl hexyl acrylate, ethyl methacrylate. , n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, ethylhexyl methacrylate, glycidyl methacrylate, fluorenyl hydrazide Cyclohexyl acrylate, styrene, vinyl methyl, 1-mercaptostyrene, acrylic acid, methacrylic acid, acrylonitrile, vinyl acetate, vinyl propionate, vinyl stearate, propylene acetate, hexane Diallyl acrylate, diallyl itaconate, diethyl maleate, ethylene ethylene, ethylene oxide, acrylamide, N-hydroxydecyl acrylamide, N-butoxymethyl a hydrazine amide, a diacetone acrylamide, an ethylene, propylene, an isobutylene or the like, or two or more ethylenically unsaturated monomers, and a hydroxyl group-containing unsaturated monomer selected from the above (a) and (b) It is produced by polymerization. The number average molecular weight of the polyol obtained by polymerizing the monomer component containing a hydroxyl group-containing unsaturated monomer to obtain 13 201015119 is 丨〇〇〇 or more, and (9) (10) or less is preferably 5,000 or more and 1 Torr or less. Further, the value of the warp value is not less than 10,000, more preferably 1 〇 or more, and 2 〇〇 or less, and more preferably 2 〇 or more '15 〇 or less. As the polyester polyol obtained under the condition of excess hydroxyl group, (), for example, ethyl alcohol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 15_Pentanediol, neopentyl glycol, hexanediol ' ι ❹ hexaol 2,2,4-didecyl 丨, 3 · pentanediol, trimethylolpropane, hexane triol, C Triol, pentaerythritol, cyclohexanediol, hydrogenated bisphenol A, bis(hydroxyindenyl)cyclohexene, p-benzoic acid double (minus 6 secret), isocyanuric acid tris(ylethyl) vinegar, o-benzene Di-methanol and other _, Xiao (4) such as cis-butyl succinic acid, anti-butyl succinate + butyric acid, sebacic acid, sebacic acid, trimellitic acid, p-formic acid, phthalic acid A polybasic acid such as isophthalic acid is produced by reacting a propylene glycol, a hexanediol, or a m' tri-methyl propylene polyol in a number of groups having a carboxyl group number greater than that of the polybasic acid. The amount of the polyglycol polyol obtained under the conditions of excess radicals is 500 or more and 300 or less, preferably 2 Å or more and 1 Å or less. Further, it is preferably 1 Å or more, 200 or less, more preferably 20 or more and 15 Å or less. The polyol used as the base polymer of the polymer composition is preferably obtained by polymerizing a single: component containing the above-mentioned polyester polyol and the above-mentioned ethylenically unsaturated monomer. A non-sterol of a thin base unit or the like. The polystyrene polyol or acrylic polyol is used as a substrate. The adhesive 6 of the material has high transparency and weather resistance, and can suppress yellowing of the anti-adhesive layer 3 14 201015119, particularly by using an acrylic polyol as a base polymer and a diffusing agent made of an acrylic resin. 5, to reduce the refraction, reflection, etc. required for the interface of the diffuser port 5, and to enhance the optical function such as the directional light diffusion function and the light transmittance of the optical #丨. Further, either of the polynonanol and the acrylic polyol may be used, or both may be used. Further, regarding the number of hydroxyl groups in the above polyester polyol and acrylic polyol, as long as it satisfies every! Two or more molecules may be contained, and two are particularly limited. However, if the helmet value is less than or equal to the solid content, the number of crosslinking points is reduced, and solvent resistance, water resistance, and heat resistance of the film are lowered. tendency. The heat resistance of the polymer composition in which the binder 6 is formed, such as the degree of slippage 3 and the prior art sheet, is improved. The inorganic substance to be added to the filler is not particularly limited, and is preferably an inorganic metal oxide compound having a network structure. The metal element constituting the constituent material is, for example, preferably an element selected from the group consisting of the fluorocarbon to form an inorganic milk group, and more preferably selected from the group consisting of elemental period 3, 2 to 6 and most preferably selected from the group consisting of ^b... The family of the family. In terms of fruit and uniform dispersibility, it is a heat-reducing effect. It is best for 锨 μ Λ μ μ μ μ μ 70 70 70 70 70 70 70 70 70 70 70 70 70 70 胶 胶 胶 胶 胶 胶 胶 胶 胶 胶 胶 胶 胶 胶 胶^ The shape may be spherical, needle-like, plate-like, or scaly micro: the particle shape of the inorganic filler is not particularly limited. The lower limit of the average particle diameter of any of the minute inorganic fillers such as a shape or a crushed shape is preferably 5 nm, more preferably 15 201015119 is 10 nm. On the other hand, the average of the fine inorganic fillers is preferably one for two, and the reason that the two particles are less than the above range, the surface energy of the fine inorganic filler is such that the agglomeration is liable to occur, and vice versa. When the average particle diameter exceeds the above range, white turbidity occurs due to the influence of short wavelength, and the transparency of the optical sheet is maintained all the way. In addition, the lower limit of the mass ratio of the inorganic filler (the mass ratio of the inorganic component to the polymerization amount of the binder 1) is preferably 5 parts, more preferably 5 parts by weight. The upper limit of the mass ratio of the other & micro inorganic filler is preferably 5 parts, more preferably 2 parts by weight. The reason for this is that if the mass ratio of the fine inorganic filler is not within the range: the heat resistance of the optical sheet may not be sufficiently exhibited, and if the mass ratio exceeds the above range, it is difficult to blend the human polymer composition. Thereby, it is possible to lower the light transmittance of the optical layer 3. ❹: The micro inorganic filler ' can be used to have an organic poly I immobilized on its surface. By using a micro inorganic filler to which the above organic polymer is fixed, it is possible to improve the dispersibility of the inorganic filler in the binder 6 or the affinity of the inorganic filler to the binder. The organic polymer, regarding its molecular weight, The shape, composition, presence or absence of a functional group, and the like are not particularly limited, and any organic polymer can be used. Further, the shape of the organic polymer can be any shape such as a linear chain, a branched form, or a crosslinked structure. Specific examples of the polymer include, for example, (fluorenyl) acrylic resin, euthanasia, urethane, polyvinyl acetate, polyethylene or polyacrylonitrile, polystyrene, partial A polyester such as ethylene disulfide or polyethylene terephthalate 16 201015119 ester or the like; or a resin obtained by partially modifying a functional group such as an amine group, an epoxy group, a hydroxyl group or a carboxyl group. Among them, an organic polymer containing a (meth)acrylic acid unit such as a (meth)propionic acid resin, a (meth)acrylic acid-styrene resin, or a (meth)acrylic acid/polyacetic resin is used. It is preferred that the essential component has a film forming function. On the other hand, a resin which is compatible with the base polymer of the above polymer composition is preferred. Therefore, it is preferably contained in the polymer composition. Substrate polymer

Have the same composition. Further, the fine particles of the fine inorganic filler may also contain an organic polymer. Thereby, the softness and toughness of the inorganic substance of the core which is a minute inorganic filler can be imparted. The organic polymer may be used as long as it contains an alkyloxy group, and the content thereof is preferably __ or more and 5 G _ or less of the fine inorganic filler having an organic polymer. The dispersibility in the affinity between the matrix resins constituting the binder 6 is exemplified by the alkoxy group. j The second alkoxy group means a bond with a metal element forming a fine particle skeleton. The R is a wire that can also be replaced, and the r in the microparticles

Can be the same or different. Specific examples of R and T W as R include a mercapto group, an ethyl propyl group, an isopropyl group, and an n-butyl group. Preferably, the alkoxy group of the same metal as the inorganic filler is used, so that when the filler is colloidal and hardened, it is preferred to use a base. / The organic polycondensation of the alkoxy group of the von metal is not particularly limited as to the content of the compound of the inorganic filler to which the organic polymer is immobilized. The amount of the compound is not limited, but is preferably 0.5 mass based on the micro inorganic filler. % or more and 5% by mass or less. The above-mentioned organic polymer fixed to the fine inorganic filler is a compound containing a hydroxyl group, and the polymer composition constituting the binder 6 may contain a polyfunctional isocyanate compound selected from two or more functional groups reactive with a hydroxyl group. At least one of a melamine compound and an amine resin. Thereby, the micro inorganic filler and the matrix resin of the binder 6 are bonded by a crosslinked structure, thereby improving storage stability, stain resistance, flexibility, weather resistance, storage stability, and the like, and further obtaining the obtained film. Has a luster. The substrate polymer of the above binder 6 is preferably a polyol having a cycloalkyl group. As described above, by introducing a cycloalkyl group into the poly 7L alcohol as the base polymer constituting the binder 6, the hydrophobicity of the water repellency and the like of the binder 6 can be increased, and under high temperature and high humidity conditions, The bending resistance, dimensional stability, and the like of the optical sheet i are improved. Further, the basic properties of the coating film such as weather resistance, hardness, thickness feeling, and solvent resistance of the optical layer 3 are improved. Further, the affinity between the binder 6 and the fine inorganic filler having the organic polymer fixed on the surface and the uniform dispersibility of the fine inorganic filler are further improved. The ring base group is not particularly limited, and examples thereof include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecylcyclodecylcyclodecene group, a cyclododecan group, and Ring tridecyl, cyclotetradecyl, cyclopentadecyl, cyclohexadecyl, cyclohexadecyl, cyclooctadecyl and the like. The polyol having the above cycloalkyl group is obtained by copolymerizing a polymerizable unsaturated monomer having a cycloalkyl group. The polymerizable unsaturated monomer having a cycloalkyl group means a poly 18 201015119-unsaturated monomer having at least one cycloalkyl group in the molecule. The polymerizable unsaturated monomer is not particularly limited, and examples thereof include cyclohexyl (meth)acrylate, nonylcyclohexyl (meth)acrylate, and t-butylcyclohexyl (meth)acrylate. Cyclododecyl (meth)acrylate or the like. Further, the polymer composition may contain an isocyanate as a hardener. By containing an isocyanate hardener in the polymer composition, it is possible to form a more advanced and firm parent structure, and the film properties of the optical layer 3 are further increased to be improved. As the isocyanate, the same ones as the above polyfunctional isocyanate compound can be used. Among them, an aliphatic isocyanate which is preferably used to prevent yellowing of the film is particularly useful when a polyol is used as the substrate polymer, and hexamethylene diiso-gas vinegar may be used as a curing agent for the polymer composition. Two or more kinds of isophora diisocyanate vinegar and xylene diisocyanate vinegar may be used in combination. When these hardeners are used, the rate of hardening of the polymer composition becomes large. Therefore, even if a cationic substance which imparts a dispersion of an ampoule S to the micro inorganic filler is used as an antistatic agent, it is possible to sufficiently remedy the cause. The reduction in the rate of hardening reaction caused by the cationic antistatic agent. Further, an increase in the curing reaction rate of the polymer composition imparts uniformity of the fine inorganic filler in the binder. As a result, the optical sheet Η significantly suppresses deflection and yellowing caused by heat, ultraviolet rays, and the like. Further, the above polymer composition may also contain an antistatic agent. By forming the binder 6 with the polymer composition in which the antistatic agent is mixed, the optical sheet 1 can exhibit an antistatic effect, thereby preventing adsorption of dust or being difficult to overlap with the ruthenium or the like due to static electricity. The problem. In addition, if the anti-19 201015119 electrostatic agent is applied to the surface, the surface will be viscous and the antistatic agent will be kneaded in the polymer composition/subtraction: the salt pair::: the electrostatic agent is not particularly limited, for example, Anion-based antistatic agent such as -I acid salt or phosyl phosphate, cationic antimony agent such as quaternary ammonium salt, imixin ==, etc. 1 ethane (4), polyoxyethylene shanxuan monostearate, ethanol Non-ionic antistatic agents such as amines, and southern molecular antistatic agents such as enoic acid. Among them, an antistatic effect is preferred: a large cationic antistatic agent exhibits an antistatic effect by adding a small amount of the cationic antistatic agent. Further, the above polymer composition may also contain an ultraviolet absorber. By forming the binder 6 with the polymer composition containing the ultraviolet ray (four), the optical sheet can be imparted with an ultraviolet ray function, and the ultraviolet ray emitted from the light source of the backlight unit can be isolated to prevent the ultraviolet ray from being caused by the ultraviolet ray layer. damage. The ultraviolet absorber is not particularly limited as long as it is a compound which can absorb ultraviolet rays and efficiently convert it into heat energy and is stable to light. The towel preferably has a high ultraviolet absorbing function, is compatible with the above-mentioned base polymer, and can be stably present in the base polymer, and is a sulphuric acid-based ultraviolet absorbing agent or a benzophenone-based ultraviolet absorbing agent. As the agent, the stupid triazole-based ultraviolet absorber, and the cyanoacrylate-based ultraviolet absorber, those selected from the group or two or more may be used. Further, as the ultraviolet absorber, a polymer having an ultraviolet absorbing group in a molecular chain (for example, "Yudaburu UV" series manufactured by Nippon Shokubai Co., Ltd., etc.) can be preferably used. By using the polymer 'having an ultraviolet absorbing layer of the ultraviolet absorbing layer of the polymer of the polymer of the polymer of the polymer of the absorbing agent of the ultraviolet ray of the absorbing agent, the ultraviolet absorbing function can be prevented from deteriorating due to the bleed out of the ultraviolet absorbing agent. Further, a polymer having an ultraviolet absorbing group in a molecular chain may be used as a base polymer of the binder 5. Further, the polymer having the external absorption group bonded thereto may be used as the substrate polymer of the binder 5, and the base polymer may further contain an ultraviolet absorber, thereby further improving the ultraviolet absorption function. The lower limit of the content of the above ultraviolet absorber relative to the base polymer of the binder 较佳 is preferably 0.1% by mass, more preferably 丨% by mass, most preferably 3% by mass; and the upper limit of the above content of the ultraviolet absorbing agent' It is preferably 10% by mass 'more preferably 8% by mass' and most preferably 5% by mass. When the mass ratio of the ultraviolet absorber to the base polymer is less than the lower limit, the substrate sheet for an optical sheet cannot effectively exhibit the ultraviolet absorbing function, and if the mass ratio of the ultraviolet absorber exceeds the upper limit, The substrate polymer is adversely affected, and the strength, longevity, and the like of the binder 6 are lowered. « Φ can use a UV stabilizer (including a base polymer with a UV-stabilizing group bonded to a molecular bond) instead of the above UV absorber, or use a UV stabilizer 舆 UV absorber at the same time. By the ultraviolet stabilizer, radicals generated by ultraviolet rays, active oxygen, and the like can be deactivated, and ultraviolet stability, weather resistance, and the like can be improved from t. As the ultraviolet stabilizer, a hindered amine-based ultraviolet scenting agent having high stability to ultraviolet rays can be suitably used. Furthermore, by using an ultraviolet absorber and a UV stabilizer, the deterioration of ultraviolet rays and weather resistance can be remarkably improved. Next, the manufacturing method of the optical sheet 1 is carried out. (IV) 1 Optical 21 201015119 The manufacturing method of the sheet 1 has the following steps: a step of producing a polymer composition for an optical layer, which is a mixture of light diffusion in a polymer composition constituting the binder 6. And a step of forming the optical layer 3, the surface layer of the base material layer 2 is a polymer composition for the optical layer, and is hardened. As a method of forming a polymer composition for an optical layer on the surface layer of the base material layer 2, there is a method of laminating a polymer composition for light diffusion by printing. The printing method is not particularly limited, and gravure printing, screen printing, ink jet printing, laser printing, or the like can be used. The optical sheet 11 of Fig. 2 includes a base material layer 12 and an optical layer 3 provided on the surface side of the base material layer 12. A corrugated crotch portion 13 is provided on the back side of the base material layer 12. Since the optical layer 3 is the same as the above-described optical sheet, the same reference numerals are used and the description thereof is omitted. The crotch portion 13 is provided on the entire back surface of the optical sheet 11, and has a corrugated rib shape in cross section. The height ratio (H2) of the average height (H2) of the crucible to the crucible spacing (P) is preferably 〇.05 or more and 〇5 or less, and particularly preferably 0·1 or more and 0.2 or less. . In the optical sheet, the light is reflected, diffused, refracted, and the like in the dam portion J3, so that the optical function such as refraction and diffusion toward the normal direction side of the entire optical sheet u can be improved. The crotch portion 13 may be formed integrally with the base material layer 12 or may be formed separately from the base material layer. Since the prism portion 13 needs to pass light, it is formed of a transparent, particularly colorless, transparent synthetic resin. Specifically, the same synthetic resin as the substrate layer 12 can be used. The side light type backlight unit shown in FIG. 3 includes a light guide plate 7, and a pair of linear light sources 8 disposed on both sides of the light guide plate 7 and an optical sheet disposed on the surface side of the light guide plate 22 201015119 7 . The light emitted from the light source 8 and emitted from the surface of the light guide plate 7 has a strong peak which is inclined at a predetermined angle by the #4·, + /a ί normal direction, but the backlight unit is borrowed, The light-diffusing function on the front side and the variable-angle function on the normal-direction side side of the optical sheet 11 have a relatively high optical function, and the front side is brightened and the brightness is uniformized. In addition, the neon-type backlight unit has four or six light sources 8 for the fashion meter. Further, the optical sheet of the present invention is not limited to the above-described embodiment. For example, the arrangement of the dots f' is not limited to the above-described regular triangular lattice pattern which can be densely filled, and may be a square lattice pattern or a random pattern. The random pattern can reduce the fold generated when the optical sheet is overlapped with other optical parts. In addition, the diameter of the point can be set to be smaller near the light source, and along with the far

The light source is set to be large, and the density of the dots is set to be lower as the distance from the light source is applied, and an uneven light diffusion portion is laminated on the sheet. The brightness of the diffused light on the sheet can be adjusted by the change of the light diffusing portion. Further, the optical sheet can also be used as a light guide plate. By using the light guide plate, it is possible to shorten the lead time required for the reduction of the thickness and shape correction of the backlight unit. EXAMPLES Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited to the description of the examples. [Comparative Example 1] A substrate made of transparent polyethylene terephthalate having a thickness of 300 μm was used as the substrate layer. As the polymer composition for a light-diffusing layer, a polymer composition composed of beads made of an acrylic resin, an acrylic polyol (adhesive), and a solvent is used. The mass ratio of the acrylic resin beads to the acrylic polyol was 23 201015119 0.2. The above bead system uses only small-diameter monodisperse beads having an average particle diameter of 1 〇/zm and a coefficient of variation 〇 1 . The polymer composition for a light-diffusion layer was deposited on the surface of the base material layer by a gravure coating method of 6 g/m2 (converted solid content) to obtain an optical sheet of Comparative Example 1. [Comparative Example 2] An optical sheet of Comparative Example 2 was produced by printing a polymer composition for a light-diffusing layer and an acrylic polyol by a screen printing, and laminating the surface of the substrate layer in a convex lens shape or a scatter pattern. The light diffusion portion of the optical sheet of Comparative Example 2 had an average diameter of 60 m and a laminate ratio of 5 %, and the arrangement pattern was a regular triangular lattice pattern. Other than the above, it was the same as Comparative Example 1 described above. [Examples 1 to 8] The mass ratio of the acrylic resin beads as the polymer composition for a light diffusion layer to the acrylic polyol (adhesive) was set to 〇", 〇·3, 〇.4, respectively. 〇5, i, 15, and 2 were laminated on the surface of the substrate layer in a convex lens shape or a scatter pattern by screen printing, and the optical sheets of Examples 1 to 8 were obtained. Other than the above, it was the same as Comparative Example 2 described above. [Examples 9 to 19] The back surface of the base material layer was processed to have a 稜鏡 height ratio (H2/p) of 〇·〇5, 0.1, 〇.2, 〇3, 〇4, 〇5, 〇6, respectively. , 〇7, 〇8, 〇9, i wavy shape of the 稜鏡. The mass ratio of the acrylic resin beads as the polymer composition for the light diffusion layer to the acrylic polyol (adhesive) was set to 0.2 Å by land printing and laminated in a convex lens shape or a scatter pattern. The optical sheets of Examples 9 to 19 were produced on the surface of each base material layer. The light diffusion portions of the optical sheets of Examples 9 to 19 had an average diameter of 60/zm, a laminate ratio of 50%, and 24 201015119. The pattern was a regular triangular lattice pattern. In addition, the above-mentioned comparative example [characteristic evaluation] The optical sheets of the above-described examples 1 to 8 and the optical sheets of the comparative example 2 were incorporated in an edge-light type backlight unit as an actual light-diffusing sheet, and the front surface thereof was measured. Brightness uniformity and average frontal brightness. The surface-to-speech system was used to measure the front luminance in the plane of the optical sheet, and the ratio of the minimum value of the luminance to the maximum luminance was obtained. The results are shown in the following table. ^义表1 Surface uniformity front luminance (cd/m2) Comparative Example 1 (light diffusing agent mass ratio: 02) 0.962 4570 Comparative Example 2 (light diffusing agent mass ratio: 〇, 0.852 5035 Example 1 (light diffusing agent mass) Ratio: 0. Π 0.935 5015 Example 2 (light diffusing agent mass ratio: 〇 2 >) 0.957 4995 Example 3 (light diffusing agent mass ratio: ο』) 0.965 4980 Example 4 (light diffusing agent mass ratio: 0.4) 0.970 4975 Example 5 (Light diffusing agent mass ratio: ο.) H 0.970 4965 Example 6 (light diffusing agent mass ratio: L0) 0.968 4950 Example 7 (light diffusing agent mass ratio: 15) 0.969 4920 Example 8 ( Light diffusing agent mass ratio: 2.0) 0.965 4880 As shown in Table 1 above, the optical sheets of Examples 1 to 8 have an optical sheet of Comparative Example 1 having a light-diffusing layer as compared with the entire surface layer of the substrate layer. The surface uniformity' has a high frontal brightness. Further, the optical sheets of Examples 1 to 8 have higher surface uniformity than the optical sheets of Comparative Example 2 containing no light diffusion layer and are not inferior to the comparative examples. The front brightness of 2. In addition, the optical sheets of 25 201015119 ~ 8 are compared and displayed. When the mass ratio of the light diffusing agent to the adhesive or the ''' agent is 〇·i or more, the surface uniformity is improved, and when the mass ratio is 〇3 or more, the surface uniformity is particularly improved. Next, using Examples 9 to 9 The optical sheet was incorporated into a direct type backlight unit as an actual light diffusion sheet, and the light diffusibility was evaluated. The evaluation of the light diffusibility was visually confirmed by visually observing the disappearance of the light image from the surface when the backlight was irradiated. And the evaluation is based on the following criteria: (a) The lamp image is hardly visible ◎ (b) The lamp image is not easily visible 〇 (c) The lamp image is slightly visible △

(d) The lamp image X is clearly visible. The results are shown in Table 2 below. Table 2 ~---_ First Broadcasting Example 9 (稜鏡 height ratio: 0.05) —- ^ ΊΉ IJL· ___〇 Example 10 (prism height ratio: 0.1) ©) Example 11 (稜鏡 Height Ratio: 0.2) --- ◎ Example 12 (稜鏡 height ratio: 〇. 3) ______ 〇 Example 13 (稜鏡 height ratio: 〇·4) ~ Example 14 (prism height ratio: 0.5) Example 15 (稜鏡 height ratio··0.6) __Λ Example 16 (稜鏡 height ratio: 0.7), _ 实施 Example 17 (prism height ratio: 0.8) ~~----^ 实施 Example 18 (prism height ratio: 0.9) ^--------- -_Δ -__Δ Example 19 (稜鏡 height ratio: 1.0) 26 201015119 As shown in Table 2 above, the optical sheets of Examples 9 to 19 were compared and displayed: When the exit height ratio is 0.05 or more and 〇5 or less, the light diffusibility is improved, and when the isotropic ratio is 0.1 or more and 0.2 or less, the light diffusibility is particularly improved. Industrial availability. As described above, the optical sheet of the present invention can be used for the constituent elements of the backlight unit of the liquid crystal display device, and is particularly suitable for a transmissive liquid crystal display device. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic plan view (a) and a schematic partial cross-sectional view (b) showing an optical sheet according to a specific embodiment of the present invention. Fig. 2 is a schematic partial cross-sectional view showing an optical sheet of a different form from the optical sheet of Fig. 1. Fig. 3 is a schematic plan view showing a backlight unit including the optical sheet of Fig. 2. Fig. 4 is a schematic view showing a schematic portion of a conventional sidelight type backlight unit. [Main component symbol description] 1 Optical sheet 2 Substrate layer 3 Optical layer 4 Light diffusing portion 5 Light diffusing agent 6 Adhesive agent 27 201015119 7 8 11 12 13 20 21 22 23 24 25 25a Light guide plate source optical sheet substrate layer背光 背光 backlight unit light source light guide © Optical sheet light diffuser prism sheet prism section 〇 28

Claims (1)

201015119 VII. Patent Application Range: 1. An optical sheet is provided with a transparent substrate layer and an optical layer laminated on the surface of the substrate layer, characterized in that: S/Light layer has a scatter layer laminated on the substrate layer a plurality of light diffusing portions on the surface; the light diffusing portion contains a light diffusing agent and a binder. 2. The optical sheet of claim 1, wherein the light diffusing portion 0 is in the form of a convex lens. 3. The optical sheet of claim 1, wherein the mass ratio of the light diffusing agent to the binder is 0.1 or more and 2 or less. 4. The optical sheet of claim 1, wherein the light diffusing portion has an average diameter (D) of i 〇 / z m or more and 3 〇〇 y or less. 5. The optical sheet of claim 1, wherein the average degree of the light diffusing portion (the height of the HJ relative to the average diameter is 〇〇5 or more and 0.5 or less than the old 丨/(7). Ο 6. If applying for a patent The optical sheet of the first aspect, wherein the absolute value (I ηι-η2 | ) of the difference between the refractive index (ηι) of the light diffusing agent and the refractive index (Π2) of the binder in the light diffusing portion is 0.05 or more. The optical sheet of claim 1, wherein the average particle diameter of the light diffusing agent in the light diffusing portion is 〇.丨"m or more 2〇# claws. 8· Optical sheet of claim 1 The optical layer of the light-diffusing portion of the optical layer is in the range of 1% by mass to 9% by weight. The optical sheet of the substrate of the light-diffusing portion is provided with a pattern of the surface of the substrate layer of the light-diffusing portion. An optical sheet of the invention of claim i, wherein the pattern of the surface of the substrate layer of the light diffusing portion is a random pattern. 11. The optical of the item i of claim a sheet, wherein the back side of the substrate layer has a corrugated 稜鏡 shape, rib The height ratio (H2) of the mirror to the prism pitch (P) is 0 05 or more and 5 or less. 12. Liquid crystal display | The f light unit is used to light the light source. Dispersing, and directing the light to the surface side thereof, and characterized in that: and the optical sheet of any one of the claims 1 to " is applied. ' VIII. Schema: (such as the next page ) 30