TW201020592A - Optical sheet and surface light source for liquid crystal display device - Google Patents

Abstract

The present invention provides an optical sheet containing a three-layer laminate resin sheet which is formed of a core layer and an outer layer laminated on the two surfaces of the said core layer without interposing an adhesion layer. The resin forming the said core layer is amorphism resin, a plural of convex-shaped strips formed on at least one side of the surface of the said outer layer. The glass transition temperature of resin forming each said outer layer is 80 DEG C and up. The main component of the resin forming the said each outer layer is the same resin. The glass transition temperature of resin forming the core layer is less than 10 DEG C.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical sheet such as a cymbal sheet and a backlight panel module using the same. [Prior Art] The liquid crystal display device is used for various purposes such as a notebook computer or a mobile phone device, and a television, a monitor, a car navigator, and the like. The liquid crystal display device has a structure that can be displayed by incorporating a backlight module as a light source and controlling light from the backlight module through a liquid crystal cell. The required characteristics of the backlight module are not only a light source for emitting light but also a bright and uniform illumination of the entire screen. The composition of the backlight panel module can be roughly divided into two types. There is a method called a direct type backlight and a method called a sidelight type backlight. The sidelight type backlight panel mainly uses a mobile phone or a notebook computer that is required to be thinner and smaller. It has the feature of using a light guide plate as a basic structure. In addition to the light guide plate, it is also used as a reflective film that functions to reflect light leaking from the back surface of the light guide plate and reuse it, and to diffuse the light emitted from the front surface of the light guide plate to enhance the front brightness. Many types of optical films, such as a concentrating sheet represented by a cymbal sheet and a brightness enhancing sheet which enhances brightness on a liquid crystal panel. The ruthenium sheet which is usually used is a one obtained by applying a photo-curable resin to a transparent substrate to form a ruthenium pattern (Patent Document 1); by heat-pressing a mold on a sheet made of a thermoplastic resin. A person who has formed a ruthenium pattern (Patent Document 2); or a ruthenium-based resin which is used for a base material in order to improve heat resistance. 201020592 (Patent Document 3). CITATION LIST Patent Literature Patent Literature 1: Japanese Patent Application Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. Problem ■ However, the ruthenium sheet produced by using the photocurable resin of Patent Document 1 is subjected to a durability test under heating or humidification conditions, and curls due to shrinkage of the photocurable resin forming the enamel layer. Therefore, when the backlight module is incorporated, color display quality problems occur. In the case of a liquid crystal display device, it is assumed that a mobile phone or the like tends to be small, and it is necessary to reduce the thickness of various optical sheets, such as a cymbal. When the ruthenium sheet produced by the photocurable resin is used, the film thickness of the support is reduced as the target is made thinner, and the curl is more likely to occur during the durability test, and the patent document is used. The tantalum sheet produced by the thermoplastic resin of 2 can suppress curling in the durability test compared to the photocurable resin, but bends in the range of the front surface of the sheet, that is, the flatness can be observed to be deteriorated. In particular, in the test under humidification conditions, there is a disadvantage that the planarity is remarkably deteriorated and the shape imparted on the surface is also deformed. In addition, although the optical sheet manufactured by the norbornene-based resin of the patent document 3 can improve the curling or planarity at the time of the durability test, since the 201020592 'Tg is too high, the uneven-shaped lens is pointed at the top. The shape is difficult. Further, since the uneven shape is formed and the mold is pressed against the resin, the mold has poor productivity. In view of the above, the present invention provides a molding method which does not take the following measures in the durability test without reducing the curl of the sheet and having good flatness. That is, the present invention and the two layers of the core layer are not permeable to the three-layered laminated body, wherein the surface of the outer layer constituting the outer side of the core is formed by the outer layer of the resin, and the resin of the main component is the glass transition temperature of the resin. When the glass transition temperature of the resin is low, the glass transition temperature of the resin is set to be the glass transition temperature of the resin (hereinafter, the molding accuracy cannot be improved, and if I is formed, the mold is raised to a high temperature when the shape of the mold is trapped. In view of the problem of the prior art, in order to solve the problem, the present invention is to solve the problem in view of the problem of the problem of the prior art, because the back surface of the prior art and the productivity are excellent, and even the thin surface is deformed by the uneven shape. The optical member of the present invention contains a resin-based amorphous resin having a layer composed of an outer layer formed by laminating a core layer, and is formed into a plurality of convex shapes and constituting the resin of the composition. ❿ 80 ° C or more, and more than 10 ° C or more of the core. Further, the backlight module of the present invention. According to the present invention, it is possible to provide It is excellent in moldability and productivity, and even if it is thin, it does not cause deformation of the uneven shape on the surface during the durability test, and the sheet is less curled and has excellent planarity. Moreover, 201020592 can be used to improve the optical sheet. [Embodiment] The optical sheet of the present invention is characterized in that it comprises a three-layer laminated body composed of a core layer and an outer layer which is formed by laminating both layers of the core layer. The resin-based amorphous resin of the core layer has a plurality of convex shapes on the surface of at least one outer layer, and a resin having the same composition as a main component of the resin constituting each outer layer, and a glass transition of the resin constituting the outer layers. The temperature (hereinafter, Tg) is 80 ° C or more, and is 10 ° C or more lower than the glass transition temperature of the resin constituting the core layer ( FIG. 1 ). The "outer layer / core layer / outer layer" 3 In addition to the laminated body, a layer for releasing the surface or a layer for adjusting the optical properties may be laminated. In this case, the thickness of each layer is preferably 1/5 or less of the thickness of the outer layer. total The three layers including the three-layer laminated body are 3 to 10 layers, and at least three layers are provided with one outer layer for forming a plurality of convex shapes on one side of the core layer imparting mechanical and thermal strength, and in another The side surface is provided with a resin having the same composition as the main component of the resin constituting the outer layer as a main component layer for suppressing curling. Thus, the main components of the resin constituting the outer layer of the double layer are the same composition, and the outer layers are the same. The heat shrinkage rate is substantially the same, and it is possible to suppress curling of the optical sheet due to heating or humidification. Here, the "main component" of the resin constituting the outer layer means a composition of 50% by weight or more of the resin constituting the outer layer. The resin is preferably 70% by weight or more, more preferably 95% by weight or more. In the outer layer of the present invention, the Tg of the resin constituting the outer layer is 80 ° C or higher. The Tg of the present invention is in accordance with JIS K 7121-1987. By measuring the differential scanning calorimeter (hereinafter, DSC) and determining the intermediate point 201020592 glass transition temperature in accordance with the following procedure. In other words, the ROBOTDSC "RDSC220" manufactured by SEIKO Electronics Co., Ltd. was used as the DSC, and the DISC STATION "SSC/5 20 0" manufactured by the company was used as the data analysis device, and the sample of 5 mg was filled in the aluminum dish, and The sample was heated to 300 ° C at a temperature increase rate of 20 ° C / min from a normal temperature to be melted for 5 minutes, and then rapidly cooled with liquid nitrogen. The Tg obtained by the measurement in this process was taken. When an optical sheet is used for a liquid crystal display device, a test which is only heated and subjected to heating and humidification is usually carried out as a durability test. The temperature system is mostly 60~80 °C, and the humidity system is mostly in the range of 80~95%. In particular, an optical film having a thickness of less than 60 μm, the curl became remarkable when tested under the conditions. When a ruthenium formed of ruthenium made of an acrylic UV-curable resin is formed on a conventional polyester resin, the curl is particularly increased. Therefore, it is necessary that the outer layer is not surface-formed and does not undergo deformation in the temperature and humidity range of the durability test described above. In other words, it is necessary that the Tg of the resin constituting the outer layer is higher than the above test temperature, i.e., 80 °C or higher. When the Tg is less than 8 (TC), the shape formed on the surface of the W sheet during the durability test is deformed or/the planarity of the sheet itself is deteriorated. When the optical sheet having a flatness is easily deteriorated is incorporated into the backlight module As the planarity deteriorates, uneven optical characteristics can be observed. The Tg of the resin constituting the outer layer is preferably 80 to 120 ° C. The Tg is greater than 120 ° C, because the Tg is too high, and the surface is accurately formed. It is difficult to increase the degree. For example, when the enamel sheet is given a pointed shape at the top, there is a case where it is impossible to form a shape such as a mold, and it is a case of a low-precision molded article in which the top is rounded. Also, since the surface is shaped, the mold is formed. The time to rise to a high temperature, the time required for the mold to be pressed against the resin, and the mold to be cooled for 201020592 is extremely long, resulting in deterioration of productivity. The resin constituting the outer layer of the present invention is not particularly limited as long as it satisfies the above Tg conditions. For example, polyethylene terephthalate, polyethylene 2,6-naphthalenedicarboxylate, propylene terephthalate, polybutylene terephthalate, cyclohexanedimethanol copolymerized polyester resin Isodecanoic acid copolymerized polyester resin A polyester resin such as a glycerol-copolymerized polyester resin or an olefin copolymerized polyester resin, or a polyolefin-based resin such as polyethylene, polypropylene, polymethylpentene or a cyclic polyolefin copolymer resin, or a polymethyl group. Acrylic acid resin such as methyl acrylate, polycarbonate, polystyrene, polyamine, polyether, polyester decylamine, polyether ester, polyvinyl chloride, and copolymers thereof, or A thermoplastic resin such as a mixture of such resins, etc. Among these, in terms of mechanical strength, heat resistance, dimensional stability, and surface formability, it is more preferable to use a cyclic polyolefin or a polyester resin, and The transparency, the yellowing property, the moisture permeability, and the dimensional change are very small, and the cyclic polyolefin is particularly preferable. Here, the cyclic polyolefin resin means a polymerizable ring having an ethylenic double bond in the ring. The cyclic olefin is exemplified by a decylene-based monomer (monocyclic or polycyclic). The cyclic polyolefin-based resin is preferably used in the present invention. Metapolymer, more than two a copolymer of a cyclic olefin, a copolymer of a cyclic olefin and a chain olefin, etc. As the cyclic polyolefin-based resin, for example, the composition represented by the following formula (1) (1) '201020592, wide·

—A —- B In the above formula (1), A represents a cyclic olefin monomer, and B represents a chain copolymerizable monomer. m in the formula represents a positive integer, and η represents 0 or a positive integer. As the cyclic olefin monomer represented by the above formula (1), a constituent unit represented by the following formula (2) or (3) can be used.

201020592 (3)

In the above formula (2), a and b-based surface temperatures R! to R4 represent a hydrogen atom, a hydrocarbon group, or a halogen atom - (CH2) x COOR9 (x represents a fluorene or a positive integer hydrocarbon group, a halogen atom, or a halogen-substituted hydrocarbon group) . Further, in the above formulas (3), c and d, R5 to Rs represent a hydrogen atom, a hydrocarbon group, or a halogenogen--(CH2)xco〇R1G (x represents a 0 or a positive whole, a hydrocarbon group, a halogen atom, Halogen-substituted hydrocarbon group) The cyclic olefin monomer type represented by the above A can be used as a ring or a positive integer of two or more types. Further, F, a halogen-substituted hydrocarbon group, is used. R9 represents a hydrogen atom, 0 or a positive integer. Further, f, a halogen-substituted hydrocarbon group, and a number. In the case of Rio, it is possible to use, for example, ethylene, in the case of a chain-like copolymerizable monomer represented by B of the above formula (1). An α-olefin such as propylene, butylene or pentene, (meth)acrylic acid, (meth)acrylate, acrylonitrile or maleic anhydride. Among these, it is preferred to use CX-olefins. The cyclic polyolefin resin of the present invention may be composed of one type of cyclic polyolefin resin, or may be used by blending two or more kinds of cyclic polyolefin resins. In order to control the mechanical properties such as thermal properties and strong elongation such as the glass transition temperature of the optical sheet, a method of blending two or more types of the resin is preferable. In the present invention, an amorphous resin is used as the resin constituting the core layer. As the resin for an optical sheet used in a liquid crystal display or the like, an amorphous resin excellent in transparency is usually used. In addition, when the amorphous resin is formed by melt extrusion, since it is not required to cool the crystallinity such as a crystalline resin, it can be slowly cooled, and a film having excellent thickness accuracy can be obtained. . The main component of the resin constituting the core layer is preferably a cyclic polyolefin resin, a polycarbonate resin, a polystyrene resin, an acrylic resin, or an amorphous W-based polyester resin. In particular, the cyclic polyolefin resin is excellent in transparency, yellowing property, moisture permeability, and very small in dimensional stability, and is suitable as a material for an optical sheet which achieves the effects of the present invention. Here, the "main component" of the resin constituting the core layer means a resin which is composed of 50% by weight or more of the resin constituting the core layer. Further, when a sheet made of an amorphous resin is processed to impart a surface shape, when the temperature is raised to a temperature equal to or higher than Tg, the shape can be observed to be deformed. Further, in order to impart planarity, the core layer Tg is preferably higher than the outer layer. Ring -11- 201020592 The polyolefin is suitable for the Tg. In this regard, it is also suitable as a main component of the resin constituting the core layer. In the present invention, the Tg of the resin constituting the outer layer is 10 ° C or more lower than the Tg of the resin constituting the core layer. When the difference in Tg is smaller than the lot, when the outer layer is formed into a convex shape by the flat plate pressing method, the core layer is also heated, and the entire optical sheet is deformed following the mold when the mold is peeled off, resulting in deterioration of planarity. Further, the Tg of the resin constituting the outer layer is preferably 10 to 100 ° C lower than the Tg of the resin constituting the core layer. When the difference in Tg is more than 100 °c, when the sheet e is formed by the co-extrusion method, the resin having a lower Tg is carbonized, resulting in deterioration of the quality of the sheet. The method for producing the three-layer laminate of the optical sheet of the present invention includes a method of producing a laminate by the following non-adhesive adhesive. (i) In two extruders, each of the resin constituting the support layer and the resin constituting the outer layer are melted and co-extruded from the nozzle onto the cooled casting drum to be processed into a sheet form (total Extrusion method). (ii) A method in which a resin constituting the outer layer is placed in an extruder to be melt-extruded and laminated from a nozzle to a sheet of a support layer made of a single film (melt lamination method). (iii) A method of separately performing heat-pressure bonding of a sheet of a support layer made of a single film, an outer sheet ', and a heated roll group or the like (thermal lamination method). (iv) In addition, there is a method of dissolving the outer layer sheet in a solvent and applying the solution on the sheet of the support layer and drying it (coating method). When the adhesive is passed through, 'because the working steps are increased and the cost is also increased' Not good. Among these, it is preferable to use a co-extrusion method in which co-extrusion is processed into a sheet-like co-extrusion method in a step by one step, which can be accurately produced -12-201020592. An example of a method of forming a plurality of convex shapes on the outer layer of the optical sheet of the present invention will be described using Fig. 2 . Both the optical sheet of the present invention having a convex shape before the outer layer and the mold having the shape in which the pattern to be transferred are reversed are heated to a glass transition temperature Tg of the resin constituting the outer layer, and butyl 8 + Within the temperature range of 601 or less (Fig. 2 (&)). Subsequently, the outer layer of the optical sheet is brought close to the uneven surface of the mold (Fig. 2(b)), and is directly pressurized at a predetermined pressure β for a predetermined period of time (Fig. 2(c)). Subsequently, the temperature is lowered while maintaining the pressurization state, and finally, the pressurizing pressure is released and the optical sheet is released from the mold (Fig. 2(d)). Further, as a method of forming the outer layer pattern, in addition to the method of pressing the flat plate as shown in Fig. 2 (plate press method), a roll-shaped mold having a pattern formed on the surface may be used to form a roll-like sheet. To obtain a roll-to-roll continuous forming of a roll-shaped molded article. In the case of forming a finer pattern having a fine aspect ratio, the flat pressurization method is excellent. In terms of productivity, the continuous molding of the package is superior to the flat press method. Further, in the case where the package is continuously formed into and out, since the optical sheet of the present invention has a core layer, compared to the single film composed of the resin constituting the outer layer, since the sheet itself has strong toughness and is excellent in forming, it is good. Fig. 3 is a view showing a preferred pattern of the convex shape of the outer layer of the optical sheet of the present invention. Fig. 3 (a) to (e) are perspective views showing a convex shape in a schematic manner. As a configuration of the arrangement of the convex shape in the surface of the outer layer formed on the surface of the outer layer - 13 to 201020592, a preferred example is a stripe pattern as shown in Figs. 3(a) to (c) (complex convex type) a shape in which each of the shapes has a convex shape extending in a direction, and the longitudinal directions of the plurality of convex shapes are substantially parallel to each other (the difference in the longitudinal direction is 5° or less, preferably 1° or less); And a pattern in which a shape such as a dome shape or a pyramid shape is formed as shown in Figs. 3(d) and (e). The stripe pattern illustrated in (a) to (c) of Fig. 3 will be described. Fig. 4 shows the cross-sectional shape in the vertical direction with respect to the longitudinal direction of the convex shape. • Preferred examples of the convex cross-sectional shape of each of the stripes include an isosceles triangle, an equilateral triangle, an isosceles right triangle, or a triangular shape (Fig. 4(a)), a semicircle, a semi-ellipse or a circular arc shape (Fig. 4(b), a regular sinusoidal curve, a random curve, etc. (Fig. 4(d)), etc. As shown in (a) and (b), the respective cross-sectional shapes may be repeating patterns of the same shape, as shown in FIG. 4(d), the regular-sized or randomly-arranged patterns of different sizes, or 4 (e) shown in the 'different shape gauges' or randomly arranged patterns, etc. are also preferred. Such 'different size or different shape rules or random arrangement, and as shown in Figure 4 (c) The shape of the gauge curve or the like is also preferable because it suppresses the possibility of causing light interference fringes or glare due to the shape formed on the surface of the sheet, and is also preferably used as shown in Fig. 4(f). In the cross section of each stripe, a flat portion is formed between the adjacent patterns. Since the light incident on the flat portion is highly likely to pass through the untransformed angle, as exemplified in FIGS. 4(a) to (e), the shape in which the flat portion is not formed between adjacent patterns is -14 - 201020592 Further, when the cross-sectional shape of each stripe is observed, the stripe length direction may be continuous and uniform stripe of the same shape and size, and may be stripe of the same shape but different in size (that is, highly oscillating), or may be a shape change. In addition, when the stripe is observed from the normal direction of the sheet, the stripe may be completely linear, and it may be suitable to use a stripe such as a wave. Therefore, the stripe is suitable. The distance (pitch) between them is also regular or random. Any one of them is suitable for use. Then, as shown in Fig. 3 (d) and (e), the shape is covered with a dome or a pyramid. The preferred pattern can be roughly divided into a hemispherical shape such as a dome shape or a polygonal pyramid shape such as a pyramid shape. In the hemispherical shape, a hemisphere and a shape in which the hemisphere is expanded and contracted in the height direction are exemplified ( When the shape of the sheet is different in the direction of the sheet surface, the shape may have an opposite direction. When the direction of the major axis of the respective shapes is aligned, the optical anisotropy can be induced. It is suitable for use in the arrangement of the stomach slices, the rule arrangement (the most dense charge, etc.), and the random arrangement. Further, in the case of the polygonal pyramid shape, for example, a triangular pyramid, a quadrangular pyramid, a hexagonal cone, and an octagonal cone are mentioned. Etc. At this time, the arrangement in the sheet surface is also suitable for use in any of the regular arrangement (most dense filling, etc.) and random arrangement. The shapes may be repeated in a single shape of the sheet. The pattern may be a composite shape in which a plurality of shape types are arranged. For example, as shown in Fig. 3 (a) to (c), a stripe pattern -15 - 201020592 is formed on the surface, particularly regarding the curl of the sheet. Since the directionality is also generated in accordance with the direction of the stripe, the effect of the optical sheet of the present invention is large. In other words, the present invention is effective as an optical sheet for a liquid crystal display device when the ruthenium sheet used for the brightness enhancement effect is produced. The embossed convex shape (cross-sectional shape) is formed by forming a triangular triangular prism in a substantially parallel manner. When the optical sheet of the present invention is a sheet, the apex angle of the triangle of the cross section is preferably 70 to 110°, preferably 80 to 100°, more preferably 90°. When the apex angle is less than 70° and greater than #110°, when the backlight module is incorporated, there is a case where the front brightness enhancement effect is insufficient. Further, in accordance with the configuration of the backlight panel, it is preferable to use the triangular shape of the cross section as the isosceles triangle, and it is preferable that the front side brightness enhancement effect is excellent in any of the configurations. The ruthenium sheet suitable for use as the optical sheet of the present invention is suitable for use in any of the cross-sections of the cross-section of the same shape and the arrangement of the different shapes. Further, the height in the film thickness direction of the crucible formed on the sheet surface can be viewed from the longitudinal direction of the triangular prism of the crucible. Further, in the sheet surface, the line at the top of the crucible may be linear or wavy. The laminate ratio of the outer layer of the optical sheet of the present invention to the core layer is not particularly limited, and is preferably the thickness (one surface) of the outer layer: the thickness of the core layer = 1: 〇 5 1 1 : 20, more preferably the thickness of the outer layer ( The thickness of one side···core layer=1: 1~1: 10. By setting the laminate ratio of the outer layer to the core layer to such a range, even if the film has a surface layer having a sufficient thickness, it is preferable to maintain the mechanical strength while reducing the curl of the entire optical sheet. Further, regarding the thickness between the outer layers of the two layers -16 - 201020592 provided on the core layer, in order to reduce the curl of the entire optical sheet, it is preferably 1:1 to 1:2. In the optical sheet of the present invention, in order to perform high-quality and high-yield pattern formation, from the lowest bottom of the convex shape of the convex shape to the bottom of the convex shape of the core layer (minimum crucible) and the interface between the outer layer and the core layer The distance, that is, the minimum outer layer thickness h, and the relationship between the apex of the convex shape and the bottom, that is, the convex height d, is preferably in the range of d/10ShS10d. The enthalpy of h is less than d/10, and when the mold is pressed against the surface layer, there is a case where it is difficult to fill the details of the mold. Further, when it is larger than l〇d, the characteristics of the pattern formed on the surface cannot be sufficiently exhibited, and the brightness may be lowered. In order to obtain such a shape, the thickness of the outer layer before forming the convex shape is preferably a thickness equal to or greater than the convex height d of the cross section of the formed convex shape. Further, the maximum convex height dmax of the cross section of the convex shape provided on the outer layer can be appropriately determined in accordance with the required optical characteristics, preferably 1 to 1 μm, more preferably 5 to 10 μm. By this range, the curl of the entire optical sheet can be reduced while maintaining the mechanical strength. The number of convex shapes with respect to the width of the optical sheet can be appropriately determined according to the required optical characteristics, preferably 5 or more with respect to 1 mm width, preferably 10 or more, and 20 or less. The above is better. When the density of the convex shape is 5 or more with respect to the width of 1 mm, the optical function becomes good. The total thickness of the optical sheet of the present invention is preferably 60 μm or less, more preferably 10 to 50 μm, and more preferably 30 to 50 μm. When the optical sheet is thin, the backlight module itself can be made thinner, and as a result, the design of the liquid crystal display device -17-201020592 is improved, which is preferable. However, when the thickness of the optical sheet is less than 10 μm, handling may become difficult when incorporated into the backlight module. Here, the "total thickness" optical sheet is a three-layer laminated body composed of an outer layer/core layer/outer layer, and when other layers (for example, a release layer to be described later) are further laminated, the other three are included. The thickness of all layers of the layered body. Further, when a convex shape is formed on the surface of the optical sheet, the thickness is measured from the vertex of the convex shape. In the optical sheet of the present invention, when the outer layer is formed into a convex shape, it is preferable to provide a release layer in advance on the surface of the outer layer which is in contact with the mold. As shown in Fig. 5(a), a release layer may be provided on the outer surface of either one of them, or a release layer may be provided on both outer surface surfaces as shown in Fig. 5(b). An optical sheet can be obtained by forming a pattern on the sheets of Figs. 5(a) and (b). By providing the release layer on the outer layer, the durability (repeated use) of the release coating formed on the surface of the mold can be improved, and even if a mold having a partial release effect disappears, the mold can be uniformly removed without problems. mold. Further, even if the mold is not subjected to the mold release treatment at all, the mold release layer can be released in advance on the sheet side, and the mold release treatment cost can be reduced, which is preferable. Moreover, since it is possible to prevent the formation pattern from collapsing due to resin adhesion when the optical sheet is released from the mold, or to be able to release the mold at a higher temperature, the cycle time can be shortened, and the molding accuracy and productivity are also good. Further, it is preferable that the slipperiness of the surface of the optical sheet is improved by the improvement in the scratch resistance, and the disadvantages caused by the process and the like can be reduced. The resin constituting the release layer is not particularly limited. It is preferably formed by using a polyfluorene-based resin, a fluorine-based resin, a fatty acid-based resin, a polyester-based resin, a dilute-based resin, and a melamine-based resin as a main component. Among these, a polyoxymethylene resin, a fluorine resin, or a fatty acid resin is more preferable. Further, the release layer may be formulated with, for example, an acrylic resin, a urethane resin, an epoxy resin, a urea resin, or a phenol resin in addition to the above-mentioned resin, and various additives such as an antistatic agent and a surfactant may be formulated. , antioxidants, heat stabilizers, weather stabilizers, UV absorbers, pigments, dyes, organic or inorganic microparticles, dips, nucleating agents, crosslinkers, etc. Further, the thickness of the release layer is not particularly limited, and is preferably 0.01 to 3 μm. When the thickness of the release layer is less than 〇.〇1 μm, the above-mentioned release improving effect may be lowered. The method for forming the release layer is not particularly limited, and various coating methods such as an in-line coating method, a reverse roll coating method, a gravure coating method, a rod coating method, a rod coating method, and the like can be used. Die coating or spray coating. In particular, since it can be applied simultaneously with the film formation of the substrate, a tandem coating method can be suitably used from the viewpoint of productivity and uniformity of coating. The basic structure of the direct type backlight module is explained. Inside the screen, a plurality of linear fluorescent tubes are arranged in parallel, and a light reflecting film is disposed on a lower side of the light source (in a direction opposite to the screen), and a diffusion plate and a diffusion sheet are provided on one side (screen side) of the light source. An optical member such as a cymbal or a brightening sheet. As the arrangement of the optical member on the upper side of the light source, it is preferable to use a diffusion plate directly above the light source and a brightness enhancement plate at the uppermost portion, and to use a diffusion sheet and/or between the two members for an arbitrary configuration. Or a cymbal is preferred. Further, the basic configuration of the edge type backlight module will be described. In the backlight panel type 19-201020592, a light guide plate for transmitting light and extending in a planar manner is used, and a linear shape (for example, a fluorescent tube) or a dot (for example, LED) is provided on the side of the light guide plate. The light source of the light source is provided with a light reflecting film on the lower side of the light guide plate (opposite to the screen), and an optical member such as a diffusion sheet, a cymbal sheet, or a brightness enhancement sheet is provided on the upper side (the screen side) of the light guide plate. . As the arrangement of the optical members on the upper side of the light source of the edge-light type backlight module, it is preferable to use the brightness-increasing sheet at the uppermost portion, and to use the diffusion sheet and/or between the light-guiding plate and the brightness-increasing sheet in an arbitrary configuration. The bracts are good. The optical sheet of the present invention can exert the effects of light diffusing property and condensing property of the diffusion sheet or the cymbal sheet by imparting the shape exemplified above. Therefore, the direct type backlight module can be disposed at the same position as the diffusion sheet or the dummy sheet. (Measurement and Evaluation Method) The following measurement was carried out under the conditions of a room temperature of 23 ° C and a humidity of 65%, unless otherwise specified. ® A. Tg measurement According to JIS K 7 1 2 1 - 1 987, using ROBOT DSC "RDSC220" manufactured by SEIKO Electronics Co., Ltd. as a differential scanning calorimeter (DSC), using the same company DISC STATION "SSC/5200" As a data analysis device, a sample of 5 mg was filled in an aluminum dish, and the sample was heated from a normal temperature to a temperature increase rate of 20 ° C /min to 300 ° C to be melted for 5 minutes. Subsequently, the liquid nitrogen was rapidly cooled, and the glass transition temperature (intermediate point glass transition temperature) was measured in the process. -20- 201020592 B · Cross-section observation The optical sheet is cut through the top of the convex shape and perpendicular to the plane on which the outer layer of the convex shape is formed, and cut at the cross section of the plurality of convex shapes to cut the optical sheet. Profile, and vapor-deposited lead-palladium in the cross section. This section was photographed and observed using a scanning electron microscope S-2100A manufactured by Hitachi, Ltd., and the size of the cross section of the sheet and the size of the convex shape given on the surface were measured. The method is to prevent the collapse of the shape by first immersing the optical sheet in liquid nitrogen, freezing it, and then cutting it, or by using another resin to bury it and then cutting it. C. Sheet thickness In the cross-sectional observation, the magnification was adjusted to 200 times as the entire sheet was viewed in the field of view, and the photograph was taken, and the length of the photograph was measured and the size between the two surfaces of the sheet was measured. At this time, when a convex shape is formed on the surface, the distance between the two surfaces is measured to be the largest. The 10 points arbitrarily selected from the sheet were measured, and the average enthalpy was determined as the sheet thickness. D. Outer layer thickness Η ^ In the section observation, the magnification is adjusted to 200 times in such a manner that the entire outer layer is included in the field of view, and the photograph is taken, and the length of the photograph is measured and the size between the two surfaces of the sheet is measured. At this time, when a convex shape is formed on the surface, the distance between the two surfaces is measured to be the largest. The 10 points arbitrarily selected from the sheet were measured, and the average enthalpy was determined as the outer layer thickness. In addition, when the interface between the outer layer and the core layer is unclear, it can be observed by a laser microscope in accordance with the material properties, by optical microscopy, or by transmission electron microscopy. - 201020592 Observed thin film sections for scanning electron microscopy. Further, when a release layer or a slippery layer or the like is formed on the surface of the outer layer along the convex shape, it is also measured as a part of the outer layer. E. The convex height d of the cross-section of the convex shape is taken in a cross-sectional view, and the magnification is adjusted to 200 times by the top (maximum 値) of the convex shape of 1 or more and 20 or less in the visual field. And determining the difference between the lowest height and the highest height of the cross section of the convex shape of the convex shape of any one of consecutively selected one point. The 値 which is measured and averaged at 10 or more points which are arbitrarily extracted in the sheet 値 is the convex height d which is the distance between the top and the bottom of the convex shape. That is, when the shape of the cross section is a repeating pattern of a single convex shape as shown in Fig. 4 (a), (b), and (f), the difference between the highest height and the lowest height of the convex shape is measured. Further, when the shape of the cross section is a pattern in which the different shapes are combined as shown in Figs. 4(d) and 4(e), the difference between the highest height and the lowest height among the repeating units is measured. Further, when the shape of the cross section is changed as shown in Fig. 4(c), the convex shape and the size of the convex shape are selected in the cross section, and the maximum height and the minimum height are measured. The difference. Further, in the pattern in which the shape of the dome or the pyramid shown in Figs. 3(d) and (e) is filled, the convex height d can be determined by applying the above-described criterion in accordance with the cross-sectional shape. F. The minimum outer layer thickness h is observed in the cross section, and the magnification is adjusted to 200 by including the bottom of the convex -22-.201020592 shape (minimum 値) and the interface between the outer layer and the core layer in the field of view. The photograph was taken in multiple times, and the minimum distance from the bottom of the convex shape of any of the consecutive 10 consecutive points was determined. The enthalpy measured and averaged at 1 point or more which was arbitrarily extracted in the sheet was taken as the minimum outer layer thickness h. G. Measurement of curling amount A sample of a size of 100 mm x 100 mm was placed in a constant temperature and humidity tester (manufactured by TABAI ESPEC, PR-3SPW), and placed under an 85 ° C, 85% RH condition for 240 hours. Immediately after taking it out from the constant temperature and humidity tester, the sample was placed on the table as a surface having a convex shape. The amount of curl of the four corners of the sample (the height from the film setting surface) was measured, and the average enthalpy was used as the amount of curl.平面. Planar evaluation A 100 mm XI 00 mm sample was placed in a constant temperature and humidity tester (TABAI ESPEC, PR-3SPW) and placed under an 85 ° C, 85% RH condition for 240 hours. After taking it out from the constant temperature and humidity tester, place the shaping surface W down on the table and observe the non-shaped surface. The evaluation method turns on two linear fluorescent lamps, and observes the fluorescent light image reflected on the non-shaped surface, and judges whether the image of the linear fluorescent lamp is deformed. The evaluation system was carried out by three individuals, and two individuals were judged to be C when they were judged to be deformed, B was judged when one person was deformed, and A was judged when all the persons were not deformed. I. Brightness evaluation

The 3.5-inch side-lit backlight (case, reflective film, and light guide) was turned on. After 10 minutes, a diffusion sheet (TORAY -23-.201020592, manufactured by SAEHAN, TDF18 7) was set on the light guide plate. For the sample, a two-dimensional luminance meter (manufactured by KONICA MINOLTA SENSING, CA-2 0 0 0) was used to measure the brightness in the front direction. The brightness was evaluated by the average 値 of a range of a square of 50 mm with one side of the center of the backlight as a center. In addition, the brightness evaluation was performed before and after the test (before and after the damp heat test) for 240 hours under the conditions of 85 ° C and 8 5% RH described in G and Η, and the brightness before the test was defined as "initial brightness" and the test was performed. The latter brightness is defined as "post-test brightness". ® EXAMPLES The measurement methods and evaluation methods of the respective examples and comparative examples will be described below. (Example 1) A cyclic polyolefin resin 1 ('TOPAS' 6013, Tg 130 ° C, manufactured by POLYPLASTICS Co., Ltd.) was prepared as a resin constituting the core layer, and cyclic polyolefin resins 1 and 2 (ring The olefin resin TOPAS '8007, Tg of 78 ° C, manufactured by POLYPLASTICS Co., Ltd.) was blended at a mass ratio of 60:40 (the Tg after blending was 110 ° C) as a resin constituting the outer layer. After drying at 100 °c m W for 6 hours, they were each melted at a temperature of 240 ° C in different extruders. Subsequently, the laminated resin extruded from the molten 3-layer co-extrusion nozzle was extruded in a sheet shape to a metal drum held at 100 °C. The laminated sheet 1 was obtained by winding up the speed of the metal drum to 25 m/min. Each of the laminate sheets 1 has a thickness of 7.5 μm, and the core layer has a thickness of 23 μm and an overall thickness of 38 μm. Subsequently, the following mold 1 and the above laminated sheet 1 were set at 135. (: heating for 1 minute, and maintaining the mold at a pressure of 2 MPa while maintaining the pressure of 2 MPa! and laminating sheets 1 -24 - 201020592 for 30 seconds. Then, after cooling to 70 ° C, the mold is released by demolding. The optical sheet 1 having a pattern in which the shape of the following mold 1 is reversed is provided on the surface of the laminated sheet 1. The total thickness of the optical sheet 1 (from the top to the back of the shaping surface) is 40 μm. (Mold 1) In-plane Pattern: Stripe (Fig. 1(a)) Individual shape: Isosceles right triangle (height d: 10 μm) Spacing between adjacent patterns (p): 20 μm® Size: 100 mm X 100 mm (pattern area) The curling amount, the flatness, and the brightness characteristics of the optical sheet 1 are as shown in Table 2. As a result of the evaluation of the brightness characteristics, it was confirmed that the optical sheet 1 can maintain the brightness of the backlight after the moisture heat resistance test, and the heat resistance is known. (Example 2) An optical sheet® 2 was obtained in the same manner as in Example 1 except that a mold having a pitch P between adjacent patterns of 15 μm and a height d of 7.5 μm was used. The curl of the optical sheet 2 was obtained. The quantity, planarity, and brightness characteristics are as shown in Table 2. As a result of the evaluation of the characteristics, it was confirmed that the optical sheet 2 was able to maintain the brightness of the backlight after the damp heat resistance test, and it was found that the heat resistance was excellent. (Example 3) In Example 1, the extrusion of the respective extruders was adjusted. The thickness of the outer layer and the thickness of the core layer were changed by the same amount as in the first embodiment except that the thickness of each of the outer layers was 9 μm, the thickness of the core layer was 30 μm, and the laminated sheet 2 having a total thickness of 48 μm was used. The optical sheet 3 was obtained in the same manner. The curl amount, planarity, and brightness characteristics of the optical sheet 3 were as shown in Table 2. As a result of evaluation of the luminance characteristics, it was confirmed that the optical sheet 3 was subjected to the moist heat test. It is also possible to maintain the brightness of the backlight panel and to obtain excellent heat and humidity resistance. (Example 4) The same procedure as in Example 3 was carried out except that a mold having a pitch p of 15 μm and a height d of 7 to 5 μm between adjacent patterns was used. The optical sheet 4. The curling amount, planarity, and brightness characteristics of the optical sheet 4 are as shown in Table 2. As a result of evaluation of the luminance characteristics, it was confirmed that the optical sheet 4 can also keep the backlight bright after the moisture resistance test. It is known that the heat and humidity resistance is excellent. (Example 5) In Example 1, the extrusion amount of each extruder was adjusted to change the thickness of the outer layer and the thickness of the core layer, except that the thickness of each outer layer was used. The optical sheet 5 was obtained in the same manner as in Example 1 except that the thickness of the core layer was 40 μm and the laminated sheet 3 having a thickness of 58 μm as a whole was obtained. The curl amount, planarity, and brightness characteristics of the optical sheet 5 were as follows. As a result of the evaluation of the luminance characteristics, it was confirmed that the optical sheet 5 was able to maintain the brightness of the backlight after the wet heat resistance test, and it was found that the heat resistance was excellent. (Example 6) In addition to the use of the spacing between adjacent patterns The optical sheet 6 was obtained in the same manner as in Example 5 except that the crucible was 15 μm and the height d was 7.5 μm. The curl amount, planarity, and brightness characteristics of the optical sheet 6 are shown in Table 2. As a result of the evaluation of the luminance characteristics, it was confirmed that the optical sheet 6 can maintain the brightness of the backlight after the heat and humidity resistance test, and it is found that the heat and humidity resistance is excellent. (Example 7) -26-.201020592 (Manufacture of polyethylene naphthalate particles (PEN)) 0.018 by weight of 100 parts by weight of dimethyl 2,6-naphthalenedicarboxylate and 60 parts by weight of ethylene glycol The parts by weight of magnesium acetate tetrahydrate and 0.003 parts by weight of acetic acid monohydrate are used as a vinegar parent exchange medium, and after transesterification at 170~240 ° C and 0.5 kg/cm 2 , 0. 004 parts by weight of trimethyl phosphate is added. To complete the transesterification reaction. Further, 0.23 parts by weight of antimony trioxide was added as a polymerization catalyst', and a polycondensation reaction was carried out under high temperature and high vacuum to obtain polyethylene naphthalate (PEN) particles having an intrinsic viscosity of 0.60 dl/g. The laminated sheet 4 was obtained in the same manner as in Example 1 except that the cyclic polyolefin resin 1 was used for the core layer 1 and PEN l (Tg: 116 ° C) was used for the outer layer. The thickness of each of the outer layers of the laminate 4 is 9 microns, the thickness of the core layer is 20 microns, and the overall thickness is 38 microns. Subsequently, the same procedure as in Example 1 was carried out except that the laminated sheet 4 was used, and the optical sheet 7» was obtained. The curling amount, planarity, and brightness characteristics of the optical sheet 7 are shown in Table 2. As a result of the evaluation of the luminance characteristics, it was confirmed that the brightness of the backlight sheet of the optical sheet 7 was lower than that of the flaw before the heat resistance test after the heat resistance test. (Example 8) A polystyrene resin 1 (SX100, Tg of 100 ° C, PS Japan) was used as the resin constituting the core layer, except that the polycarbonate UTARFLON, Tg was 145 ° C, and manufactured by Idemitsu Kogyo Co., Ltd. The laminated sheet 5 was obtained in the same manner as in Example 1 except that the resin constituting the outer layer was used. The thickness of each of the outer layers of the laminated sheets 5 is 9 μm, the thickness of the core layer is 20 μm, and the overall thickness is 38 μm. Subsequently, the optical sheet 8 was obtained in the same manner as in Example 1 of -27-201020592 except that the laminated sheet 5 was used. The curl amount, planarity, and brightness characteristics of the optical sheet 8 are shown in Table 2. As a result of the evaluation of the luminance characteristics, it was confirmed that the brightness of the backlight sheet of the optical sheet 8 after the heat resistance test was somewhat lower than that before the heat resistance test. (Example 9) The pressure-stacked sheet 1 was held between a roll-shaped mold 1 set at 180 ° C and a nip roll by a device as shown in Fig. 6, and the sheet was peeled off using a peeling roll to be taken up. An optical sheet 9 is obtained. Also, the line speed is 10 meters per minute. (Roller mold 1) In-plane pattern: stripe shape (Fig. 1 (a), parallel to the direction of rotation) Shape: Isosceles right triangle (height d: 10 μm) Spacing between adjacent patterns (P) : 20 Micron size: 100 mm 寛, Φ 3 Å The curling amount, planarity, and brightness characteristics of the optical sheet 9 are shown in Table 2. As a result of the evaluation of the luminance characteristics, it was confirmed that the optical sheet 9 can maintain the brightness of the backlight after the wet heat resistance test, and it is found that the heat and humidity resistance is excellent. (Example 10) A resin which constitutes a core layer is used as a resin constituting a core layer, and a polystyrene-based resin 1 is used as a resin constituting the outer layer, except that the cyclic polyolefin-based resins 1 and 2 are blended at a mass ratio of 60:40. The laminated sheet 6 was obtained in the same manner as in Example 1. The thickness of each of the outer layers of the laminated sheets 6 is 9 microns, the thickness of the core layer is 20 microns, and the overall thickness is 38 microns. Subsequently, an optical sheet -28 - 201020592 10 ° was obtained in the same manner as in Example 1 except that the laminated sheet 6 was used. The curling amount, planarity, and brightness characteristics of the optical sheet 10 were as shown in Table 2]. As a result of the evaluation of the luminance characteristics, it was confirmed that the brightness of the backlight sheet of the optical sheet 10 was slightly lower than that before the heat resistance test after the moisture resistance test. (Comparative Example 1) The cyclic olefin-based resin 2 was dried at 60 ° C for 6 hours, put into an extruder, heated and melted at 230 ° C, and extruded from a T-shaped die to a temperature maintained at 50 ° C. Metal drum. The single layer sheet 1 having a thickness of 38 μm was obtained by winding the speed of the metal drum to 25 m/min. Subsequently, the above-mentioned mold 1 and the above-mentioned single-layer sheet 1 were heated at ll 〇 ° C for 1 minute, and while maintaining the temperature at 110 ° C, the mold 1 and the single-layer sheet 1 were pressure-bonded for 30 seconds at a pressure of 2 MP a. Subsequently, after cooling to 50 °C, the optical sheet 11 having a pattern in which the shape of the following mold 1 is reversed on the surface of the single-layer sheet 1 is obtained by demolding the mold. The total thickness of the optical sheet 11 (from the top to the back of the shaping surface) was 40 μm, and the planarity was deteriorated during molding. The curl amount, planarity, and brightness characteristics of the optical sheet 11 are shown in Table 2. As a result of evaluation of the luminance characteristics, it was found that the brightness of the backlight panel was lowered after the optical sheet 11 was subjected to the moist heat resistance test. (Comparative Example 2) A single-layer sheet 2 was obtained in the same manner as in Comparative Example 1, except that the cyclic polyolefin-based resins 1 and 2 were blended at a mass ratio of 60:40. Subsequently, the above-mentioned mold 1 and the above-mentioned single-layer sheet 2 were heated at 135 ° C for 1 -29 to 201020592 minutes, and the mold 1 and the single-layer sheet 2 were pressure-bonded for 30 seconds at a pressure of 2 MPa while maintaining 135 °C. Subsequently, after cooling to 70 ° C, the optical sheet 12 having a pattern in which the shape of the following mold 1 is reversed on the surface of the single-layer sheet 2 is obtained by demolding the mold. The total thickness of the optical sheet 12 (from the top to the back of the shaping surface) was 40 μm, and the planarity was deteriorated during molding. The curl amount, planarity, and brightness characteristics of the optical sheet 12 are shown in Table 2. As a result of evaluation of the luminance characteristics, it was found that the optical sheet 12 was not observed to have a decrease in luminance of the backlight after the moisture heat resistance test. (Comparative Example 3) The same procedure as in Example 1 was carried out except that the thickness of the outer layer was 7.5 μm, the thickness of the outer layer was 30.5 μm, and the laminated sheet 7 having a total thickness of 38 μm was obtained by melting the two-layer co-extrusion nozzle. An optical sheet 13 was obtained. However, when the sheet was produced, curl of 10 mm or more was produced and it was not changed after the durability test. (Comparative Example 4) The following coating agent 1 was placed on the uneven surface of the mold 1, and a 30 μm transparent polyethylene terephthalate (PET film) was placed thereon and used from the PET film side. The ultrahigh pressure mercury lamp was irradiated with 1 J/m 2 to harden the coating agent, and the optical sheet 14 was obtained by demolding the mold. Further, the total thickness of the optical sheet 14 (from the top to the back of the forming surface) was 40 μm. (Applicator 1) KAYARAD R-55 1 (manufactured by Nippon Kayaku Co., Ltd.) 60 parts by mass of KAYARAD R-128H (manufactured by Nippon Kayaku Co., Ltd.) 40 parts by mass of DAROCUR1 1 73 (manufactured by CIBA Japan Co., Ltd.) 4 Parts by mass -30 - 201020592 The amount of curling, planarity, and brightness of the optical sheet 14 are shown in Table 2. After the temperature of 85 ° C and the humidity of 85% for 240 hours, the optical sheet 13 was remarkably curled (curved on the shaping surface side) after the temperature of 85 ° C and the humidity of 85% for 240 hours (after the damp heat resistance test). In addition, the optical sheet 14 was incorporated into the backlight for evaluation before and after the heat and humidity resistance test, and the brightness was evaluated. However, since the curl occurred after the moisture heat resistance test, the end portion was floated and could not be evaluated. (Comparative Example 5) ® The cyclic polyolefin resin 1 was prepared as a resin constituting the core layer, and the cyclic polyolefin resin 2 (cyclic olefin resin TOPAS '8007, Tg was 78 ° C, manufactured by POLYPLASTICS Co., Ltd.) was used as the resin. The resin that constitutes the outer layer. These were dried at 60 ° C for 6 hours and then each melted at a temperature of 2 70 ° C in different extruders. Subsequently, the laminated resin extruded from the molten 3-layer co-extrusion nozzle was sheet-likely extruded to a metal drum maintained at 1 °C. The laminated sheet 8 was obtained by winding up the speed of the metal drum to 25 m/min. Subsequently, the mold 1 and the laminated sheet 8 were heated at 110 ° C for 1 minute, and the mold 1 and the laminated sheet 8 were pressure-bonded at a pressure of 2 MPa for 30 seconds while maintaining the temperature at 110 °C. Subsequently, after cooling to 50 °C, the optical sheet 15 having a pattern in which the shape of the following mold 1 is reversed on the surface of the laminated sheet 8 is obtained by demolding the mold. The total thickness of the optical sheet 15 was 40 μm. The curl amount, planarity, and brightness characteristics of the optical sheet 15 are shown in Table 2. After 240 hours at a temperature of 85 ° C and a humidity of 85%, the planarity deteriorated. Further, as a result of the evaluation of the luminance characteristics, the brightness of the backlight sheet of the optical sheet 15 after the moisture-resistant heat test was also largely lowered. -31- .201020592 (Comparative Example 6) (Production of polyethylene terephthalate (PET)) Using citric acid as an acid component and ethylene glycol as a diol component, and with respect to the obtained polyester particles, Antimony trioxide (polymerization catalyst) was added in a manner of converting 锑 atoms to 3 OO ppm, and a polycondensation reaction was carried out to obtain a polyethylene terephthalate having an intrinsic viscosity of 0.63 (11/8 and a carboxyl terminal group of 40 equivalents/ton). Ester (PET). The cyclic polyolefin resin 1 is prepared as a resin constituting the core layer, ❹ PET1 (Tg: 67. 〇 as the outer layer of the resin, and PEN1 as the other side of the outer layer of the resin. 1 and PEN1 are dried at 100 ° C for 1 hour at 100 ° C and then at a temperature of 240 ° C in different extruders. Subsequently, the nozzles will be squeezed from the molten 3 layers. The laminated resin was extruded in the form of a sheet into a metal drum held at 100° C. The laminated sheet 9 was obtained by winding the speed of the metal drum at 25 m/min. The laminated sheets 9 were each The thickness of the skin layer is either 7.5 microns, the thickness of the core layer is 23 microns, and the overall thickness is 38 microns. The mold 1 and the laminated sheet 9 described below were heated at 110 ° C for 1 minute, and the PET 1 side of the mold 1 and the laminated sheet 9 were pressure-bonded at a pressure of 2 MPa for 30 seconds while maintaining the temperature at 2 ° C. Then, it was cooled to 50. After ° C, the optical sheet 16 was obtained by demolding the mold. The total thickness of the optical sheet 16 (from the top to the back of the shaping surface) was 40 μm. However, a curl of 5 mm was produced when the sheet was produced, and durability was obtained. After the test, the film was curled at a thickness of 10 mm or more and the brightness could not be measured. (Comparative Example 7) 32-201020592 The optical sheet 17 was obtained in the same manner as in Example 9 except that the above-mentioned single layer sheet 2 was used. The total thickness of the optical sheet 17 ( 40 μm from the top to the back of the shaping surface, but the planarity deteriorates when peeling off from the peeling roll. The curling amount, planarity, and brightness characteristics of the optical sheet 17 are as shown in Table 2. As a result of the evaluation, the brightness of the backlight sheet was not observed after the damp heat resistance test of the optical sheet 17, but it was found that the brightness before the test was lower than that of Example 1. (Comparative Example 8) Polyolefin resin 1 and 2 in a mass ratio of 50: 50 The laminated sheet 10 was obtained in the same manner as in Example 1 except that the polystyrene resin 1 was used as the resin constituting the outer layer as the resin constituting the core layer. The thickness of each of the outer layers of the sheet 10 was 9 μm, the thickness of the core layer was 20 μm, and the whole was 38 μm. Then, the optical sheet 18 was obtained in the same manner as in Example 1 except that the laminated sheet was used. The total thickness of the optical sheet 18 (from the top to the back of the shaping surface) was 40 μm, but the planarity was deteriorated during molding. The curl amount, planarity, and brightness characteristics of the optical sheet 18 are shown in Table 2. Evaluation results of the brightness characteristics The optical sheet 18 was slightly reduced in brightness after the heat and humidity resistance test as compared with the enthalpy before the heat resistance test. The following items can be clearly seen from Table 1. In the present invention, it is understood that in the present invention, "the cyclic polyolefin resin is used in the core layer and the surface layer, and the decrease in luminance can be suppressed under the durability test". Further, from Example 1 and Comparative Example 1, 2, it was found that the planarity can be improved by providing the core layer energy -33-.201020592, and it is known from the comparative examples 3 and 4 that the curl can be suppressed by having a three-layer symmetrical structure. Moreover, from Example 1 and Comparative Example 5, it was found that the layer was laminated on the outer layer.

A resin having a Tg of 80 ° C or higher can suppress the decrease in brightness before and after the durability test. From Example 1 and Comparative Example 6, it was found that curling can be suppressed by the same composition of the outer layer. Further, from Example 9 and Comparative Example 7, it was found that a roll-to-roll manufacturing apparatus as shown in Fig. 6 can also produce a sheet having excellent flatness. Further, from Example 10 and Comparative Example 8, it was found that a sheet having excellent planarity can be produced by setting the difference in Tg between the core layer and the outer layer to 10 °C or higher. -34- 201020592 [I嗽] The size of the prism (micron) m 岖〇vj 〇wj Ο wj 〇τ-Η 〇〇Ο o ο o Ο 〇〇〇〇v〇ϊ—Η 1 < s rH Total thickness of different flakes (micron) 〇〇ss 〇〇〇ο o ο o Ο T TgfC of the resin constituting each layer) _1 Difference inch ο I t 闵1 CN ι〇$ ^ 1 〇 〇〇〇 〇〇〇 I -Η 〇1 < ο f—Η ο tH 1 4 8 I1· 1 〇1-^ 8 1 1 o »' 1 i I 〇〇^ sf 8 1—^ 1 core layer Η»—Η rH 沄rH 沄g 沄ϊ—Η 沄1—Η 1—Η 沄1-Η oo oo ο 沄Ψ · ^ 8 r· < r— »'' \ 〇Η 主 The main component of the resin constituting each layer 1 » Polyester Resin polyolefin resin fiber polyurea resin! Cyclic polyolefin resin polyolefin resin cyclic polyolefin resin polyethylene terephthalate cyclostyrene resin 靼 country equipment i ring styrene resin • 1 fiber poly Olefin resin Acrylic resin, polycondensation, hydrocarbon resin, Π m m Zhao η 1 Cyclostyrene resin core layer: Cyclic polyether hydrocarbon resin Hydrocarbon resin" Polycarbonate resin! ΰπι im η mi Polyolefin resin cyclic polyolefin resin m 蘧 Hub K i Polycarbonate resin Μ m η κ Pen 酹 sg mmi Cyclic polyolefin resin m M mmm Helmet m Young polyolefin resin polyethylene terephthalate colloidal resin, polyether hydrocarbon resin, polyether resin, polycondensation, hydrocarbon resin, m Μ mmm, Zhao m layer, cn cn, cn, CO CO, CO CO m, CO CO, Η CN CO cn ^ < Example 1 1 Example 2 I Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparison Example 6 Comparative Example 7 Comparative Example 8 ^丨201020592 Table 2] Curl amount (3⁄4 m) Planar initial luminance (cd/m2) Bright after test (cd/m2) Example 1 0 A 1350 1350 Example 2 0 A 1330 1330 Example 3 0 A 1350 1350 Example 4 0 A 1330 1330 Example 5 0 A 1350 1350 Example 6 0 A 1330 1330 Example 7 0 A 1380 1330 Example 8 0 A 1380 1330 Example 9 0 A 1350 1350 " Example 10 0 A 1360 1330 Comparative Example 1 0 C 1350 1000 Comparative Example 2 0 B 1350 1350 Comparative Example 3 10 or more C - • Comparative Example 4 10 or more c 1350 - Comparative Example 5 2 c 1380 900 Comparative Example 6 10 or more c Comparative Example 7 2 c 1300 1300 Comparative Example 8 0 c 1360 1330 Industrial use possibility The optical sheet of the invention can be applied to various fields such as members for a liquid crystal display device. [Schematic description of the drawings] Fig. 1 is a view schematically showing the configuration of an optical sheet of the present invention. Fig. 2 (a) to (d) are diagrams showing the steps of forming a convex shape on the outer layer of the optical sheet of the present invention. Fig. 3 (a) to (e) are diagrams showing the convex (four)-shaped squint of the optical sheet of the present invention (a) to (c) stripe shape, (d) The dome shape and (e) are pyramidal shapes. • 36- 201020592 Fig. 4 (a) to (f) are each a cross-sectional view of a convex shape of an outer layer of the optical sheet of the present invention. Fig. 5 (a) and (b) schematically illustrate the constitution of the optical sheet of the present invention in which the release layer is formed, and (c) and (d) schematically illustrate the formation of the convex shape in the outer layer. The composition of the film. Fig. 6 is a schematic view showing the manufacturing apparatus of the optical sheets of Example 9 and Comparative Example 7. [Simple description of component symbols]

d Convex height of the profile of the convex shape h From the convex bottom of the profile of the convex shape to the thickness of the core layer 厚度 The thickness of the outer layer of the optical sheet Ρ The convex spacing of the profile of the convex shape

-37-

Claims (1)

201020592 VII. Patent application scope · 1. An optical sheet which is formed by adhering a layer of a layer of a layer forming the core layer to form a resin having a fat glass transition temperature, and is reduced by 10 ° c or more φ 2. As in the patent application range, the main component of the fat is ring 3. As the main component of the resin of the first layer of the patent application, the top surface of the convex shape is vertical and horizontal. The convex height of the cross section of the cut surface is 60 μm or less < 5 . As in the patent application range, the plural convex shape is in the length of the number convex shape 6. The liquid crystal display device is in any of items 1 to 5 - contains A three-layer laminated resin sheet composed of a core layer and a non-transmissive outer layer on both sides of the core layer, wherein the lipid-based amorphous resin has at least one of the outer plurality of convex shapes and constitutes a tree of the outer layers When the temperature is 80 ° C or higher, the main component is an optical sheet having the same glass transition temperature as the resin constituting the core layer, and the optical sheet of the polyolefin resin constituting the core layer 1 or 2 Which constitutes the same composition of each foreign system Cyclic polyolefin. The optical sheet of any one of the items 1 to 3, wherein the convex portion is formed by cutting the plurality of convex shapes formed by the outer layer of the convex shape, and the convex shape is 1 to 10 μm, and the optical sheet The total thickness of the optical sheet of any one of items 1 to 4, wherein the one direction extends into a convex shape, and the complex directions are parallel to each other, and the surface light source is mounted as claimed in the patent application. Made of optical sheets. -38-