JP2007078885A - Display optical sheet and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical sheet and a display optical sheet which are suitably manufactured with a simple process and in high quality without degrading adhesion strength when optical sheets are to each other, and also to provide a manufacturing method of the display optical sheet. <P>SOLUTION: An aqueous solution containing an aqueous antistatic agent and a fluorine type surface active agent is applied onto optical sheets 12, 14, 16, 18 of which the flat plane size is a product size or more so that the thickness after drying falls into the range of 0.03 to 0.2 g/m<SP>2</SP>to form a coated film. The optical sheets are stacked and, thereafter, are bonded to each other on at least one joint part 10A, and the peripheries of a stacked body of the optical sheets after adhesion are cut into a product size. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical sheet for display and a manufacturing method thereof, for example, an optical sheet for display in which a prism sheet and a light diffusion sheet are integrally formed, and a manufacturing method thereof.

  In recent years, a film that diffuses light from a light source such as a light guide plate, a lens film that condenses light in the front direction, and the like are used for electronic displays such as liquid crystal display elements and organic EL.

  In this case, there are many examples in which various optical films (sheets) are laminated. For example, in Patent Document 1, a reflective polarizing film, a retardation film, and a semi-transmissive semi-reflective layer are laminated in an arbitrary order, and further, an absorptive polarizing film is laminated outside these three layers. A semi-reflective polarizing film is provided. And as many as five layers of films are interposed between the light source device and the liquid crystal cell. With this configuration, it is said that screen luminance is increased or power consumption is suppressed.

Patent Documents 2 to 4 disclose a film in which the functions of one light diffusion film and a lens film are integrated.
JP 2004-184575 A Japanese Patent Laid-Open No. 7-230001 Japanese Patent No. 3123006 JP-A-5-341132

  However, in the above-described conventional configuration, it is required to go through a number of processes in order to laminate a number of layers of film, which complicates the process and inevitably increases the cost.

  Further, since the surface of a flat lens such as a lenticular lens or a prism sheet is easily damaged or dirty, it is generally delivered in a state where a protective sheet is stuck on the surface.

  However, such a protective sheet is only discarded after being peeled from the flat lens, and is not preferable because it is not only a waste of resources but also increases costs. Moreover, the operation | work which peels a protective sheet from a flat lens is required, and will also reduce productivity by that much. Further, when the protective sheet is peeled off from the flat lens, contamination such as dust is easily attached to the flat lens by peeling charging, and there are many problems in terms of quality.

  Also, when laminating multiple layers of films (sheets), the film tends to be damaged due to rubbing during lamination, rubbing due to thermal expansion / shrinkage, rubbing due to handling, and the like.

  In the process of assembling the backlight unit for the liquid crystal display panel and the process of punching or cutting the optical sheet used for it into a predetermined shape, it is necessary to remove static electricity by an ionizer or the like in order to prevent dust from adhering to the sheet surface. , Spraying an aqueous solution of an antistatic agent, or providing an antistatic agent film with a spray or the like.

  However, since the method using static elimination air is to prevent temporary charging in the assembly line and processing process, there is no antistatic effect when used after long periods of time (such as after assembly) after transportation to an assembly manufacturer, An optical sheet for a display provided with an antistatic agent film lacks uniformity in optical performance, and in the secondary processing in which a diffusion sheet and a prism sheet are bonded together to form a composite, the antistatic agent adhered to the surface There was a problem that the adhesive strength was lowered.

  The present invention has been made in view of such circumstances, and a laminate of sheet-like materials used for display applications such as liquid crystal display elements can be easily obtained without lowering the adhesive strength between the sheet-like materials. It is an object of the present invention to provide a display optical sheet suitable for manufacturing in a high quality process and a manufacturing method thereof.

The present invention according to claim 1 is an optical sheet for display in which two or more optical sheets are laminated, and the optical sheets are bonded to each other at least at one or more locations. A coating film containing a water-soluble antistatic agent and a fluorosurfactant is provided on at least one of the mating surfaces so as to have a thickness in the range of 0.03 to 0.2 g / m ^2. An optical sheet for display is provided.

  Here, the optical sheet is a general term for various sheets having optical functions, and is a diffusion sheet, a polarizing plate (diffusion sheet film), various lens sheets (lenticular lens, fly-eye lens (amber eye lens), prism). Sheet) and the like, but also includes a protective sheet (protective film) that hardly performs an optical function.

According to the present invention, at least one of the mating surfaces of the optical sheet has a coating film containing a water-soluble antistatic agent and a fluorosurfactant in the range of 0.03 to 0.2 g / m ² . In the secondary processing in which the antistatic effect is imparted to the optical sheet by being provided so as to have a thickness, and the two or more optical sheets are bonded together to form a composite, the adhesive surface However, it will not peel off under normal handling. That is, the present inventor not only imparts an antistatic effect by a coating film containing not only a water-soluble antistatic agent but also a fluorosurfactant, and also suppresses a decrease in adhesive strength due to the antistatic agent. And found that the adhesion is improved. That is, it is possible to improve the decrease in adhesion between films due to the antistatic agent without impairing the antistatic effect by providing wettability with the fluorosurfactant. Here, the thickness of the coating film is in a range of 0.03~0.2g / m ^2, the thin and wettability not only antistatic effect can not be obtained than 0.03 g / m ² was obtained This is because if it is thicker than 0.2 g / m ² , the optical characteristics and appearance are affected by visible light.

  Therefore, the optical sheet for display according to the present invention is excellent in antistatic property over a long period of time, and also excellent in adhesiveness between the optical sheets, and the film thickness is less than the visible light wavelength. The transparency of the material is not impaired, the surface appearance is exactly the same as that of the untreated product, the antifogging property is good, and the fogging inside the backlight unit due to temperature change is remarkably improved, and the There is an effect of improving scratch resistance. Thereby, not only in the processing step, but also in the backlight assembly step, dust adhesion during handling of the optical sheet is reduced, and the quality is improved.

According to the second aspect of the present invention, a light diffusion sheet is laminated on at least one front surface and / or back surface of a lens sheet in which convex lenses formed in one axial direction are adjacently arranged on substantially the entire surface. An optical sheet for display in which the lens sheet and the light diffusing sheet are bonded at least at one or more locations, and at least one of the respective mating surfaces of the lens sheet and the light diffusing sheet Has a coating film containing a water-soluble antistatic agent and a fluorosurfactant so as to have a thickness in the range of 0.03 to 0.2 g / m ² . An optical sheet is provided.

Furthermore, in the present invention according to claim 3, two lens sheets each having a convex lens formed in one axial direction adjacent to each other and arranged on substantially the entire surface are laminated, and the light diffusion sheet is formed of the lens sheet. It is an optical sheet for a display which is laminated on the front surface and / or the back surface of a laminate, and the lens sheets and the lens sheet and the diffusion sheet are bonded to each other at least at one or more locations. And at least one of the mating surfaces of the lens sheet and the diffusion sheet has a coating film containing a water-soluble antistatic agent and a fluorosurfactant in the range of 0.03 to 0.2 g / m ² . The display optical sheet is provided so as to have a thickness of 5 mm.

  These inventions describe the optical sheet in the invention of the optical sheet for display according to claim 1, with respect to the light diffusion sheet and the lens sheet.

  The “lens sheet” is typically a lenticular lens or a prism sheet, and includes a diffraction grating.

  A fourth aspect of the present invention is characterized in that, in the inventions of the first to third aspects, the water-soluble antistatic agent is a cationic antistatic agent.

  In the antistatic of the optical sheet, since the water-soluble antistatic agent is a cationic antistatic agent, a sufficient antistatic effect can be obtained even with a thin film thickness.

The present invention according to claim 5 is an aqueous solution containing a water-soluble antistatic agent and a fluorosurfactant on at least one of the mating surfaces of each of two or more optical sheets whose planar size is equal to or greater than the product size. A coating film forming step for forming a coating film so that the thickness after drying is in the range of 0.03 to 0.2 g / m ² , and the two or more optical sheets in which the planar size of the sheet is not less than the product size A laminating step of laminating the two or more optical sheets, a bonding step of bonding the two or more optical sheets to each other at at least one location, and a cutting step of cutting the laminate of the two or more optical sheets into a product size. A method for producing an optical sheet for display is provided.

  According to the present invention, two or more optical sheets having a planar size equal to or larger than the product size are laminated, the laminated body is cut into a product size, and the optical sheets are joined at at least one or more locations.

  Therefore, it is possible to omit the step of cutting a number of films (sheets) into product sizes, and it is possible to omit the step of laminating layers of films (sheets) while positioning them. Further, the above-described problem due to the protective sheet does not occur, and it is advantageous in terms of cost and quality.

Furthermore, in the coating step, the aqueous solution containing the water-soluble antistatic agent and the fluorosurfactant is applied so that the thickness after drying is in the range of 0.03 to 0.2 g / m ² . Adhesion is improved.

  As described above, according to the present invention, it is possible to provide a method for manufacturing an optical sheet for a display that is suitable for manufacturing with a simple process and high quality without reducing the adhesive strength between sheet-like materials. it can.

  Here, since “the planar size of the sheet is equal to or larger than the product size”, not only the planar size of the lens sheet or the diffusion sheet is larger than the product size, but also the planar size of the lens sheet or the diffusion sheet is the product size. The same case is also included. In such a case, one or more sides of the lens sheet or the diffusion sheet may not be cut in the cutting step.

According to a sixth aspect of the present invention, there is provided a lens sheet in which convex lenses formed in the axial direction are adjacently arranged on substantially the entire surface and the planar size of the sheet is equal to or larger than the product size. The thickness after drying an aqueous solution containing a water-soluble antistatic agent and a fluorosurfactant on at least one of the respective mating surfaces of the light diffusing sheet is 0.03 to 0.2 g / m ² . A coating film forming process for forming a coating film, a laminating process for laminating a light diffusion sheet on the front surface and / or the back surface of the lens sheet, and the lens sheet for at least one of the lens sheets; A bonding step of bonding the light diffusion sheet and the light diffusion sheet at at least one place, and a cutting step of cutting the laminate of the light diffusion sheet and the lens sheet into a product size. It provides a method for producing an optical sheet for a display according to claim.

Furthermore, the present invention according to claim 7 is a lens sheet in which convex lenses formed in the axial direction are adjacently arranged on substantially the entire surface and the planar size of the sheet is equal to or larger than the product size. The thickness after drying an aqueous solution containing a water-soluble antistatic agent and a fluorosurfactant on at least one of the respective mating surfaces of the light diffusing sheet is 0.03 to 0.2 g / m ² . A coating film forming step to form a coating film, and a lamination step of laminating two of the lens sheets, and laminating a light diffusion sheet on the front surface and / or back surface of the lens sheet laminate, The bonding step of bonding the lens sheets to each other and the lens sheet and the light diffusion sheet at at least one place, and the peripheral edge of the laminate of the light diffusion sheet and the lens sheet as a product size Providing a cutting process of the cross-sectional, a method for producing an optical sheet for a display, characterized in that it comprises a.

  These inventions describe the optical sheet for the light diffusion sheet and the lens sheet in the invention of the method for producing an optical sheet for display according to claim 5.

  An eighth aspect of the invention is characterized in that, in the inventions of the fifth to seventh aspects, the coating step is performed by an aerosol spraying method.

  In this aerosol spray method, excellent wettability is obtained on the surface of optical sheets such as light diffusion sheets and prism sheets, and the particles spread in a uniform thin film without agglomeration. Even if it is a sheet | seat, it becomes possible to form the uniform coating film of an ultra-thin film easily on this sheet | seat only by exposing to aerosol spray.

  As described above, according to the present invention, there is no reduction in the adhesive strength when the optical sheets are bonded to each other. A manufacturing method thereof can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. First, the configuration of examples (first to sixth embodiments) of display optical sheets manufactured by the method for manufacturing display optical sheets according to the present invention will be described, and then the method for manufacturing these display optical sheets will be described. To do.

  FIG. 1 is a cross-sectional view showing a configuration of an example (first embodiment) of a display optical sheet manufactured by the method for manufacturing a display optical sheet according to the present invention.

  The optical sheet for display 10 is an optical sheet module in which a first diffusion sheet 12, a first prism sheet 14, a second prism sheet 16, and a second diffusion sheet 18 are laminated in order from the bottom. is there.

  The first diffusion sheet 12 and the second diffusion sheet 18 are sheets in which beads are fixed to the surface (one side) of a transparent film (support) with a binder, and have predetermined light diffusion performance. The first diffusion sheet 12 and the second diffusion sheet 18 have different bead diameters (average particle diameter), and light diffusion performances are also different.

  A resin film can be used for the transparent film (support) used for the first diffusion sheet 12 and the second diffusion sheet 18. As the material of the resin fill, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyester, polyolefin, acrylic, polystyrene, polycarbonate, polyamide, PET (polyethylene terephthalate), biaxially stretched polyethylene terephthalate, Known materials such as polyethylene naphthalate, polyamideimide, polyimide, aromatic polyamide, cellulose acylate, cellulose triacetate, cellulose acetate propionate, and cellulose diacetate can be used. Of these, polyester, cellulose acylate, acrylic, polycarbonate, and polyolefin can be preferably used.

  The bead diameters of the first diffusion sheet 12 and the second diffusion sheet 18 need to be 100 μm or less, and preferably 25 μm or less. For example, the average particle size can be 17 μm within a predetermined distribution range of 7 to 38 μm.

  The first prism sheet 14 and the second prism sheet 16 are lens sheets in which convex lenses formed in one axial direction are adjacently arranged on substantially the entire surface. For example, the pitch is 50 μm and the height of the unevenness. 25 μm, and the apex angle of the convex portion can be 90 degrees (right angle).

  The first prism sheet 14 and the second prism sheet 16 are arranged so that the axes of the convex lenses (prisms) are substantially orthogonal to each other. That is, in FIG. 1, the axis of the convex lens of the first prism sheet 14 is arranged in a direction perpendicular to the paper surface, and the axis of the convex lens of the second prism sheet 16 is arranged in a direction parallel to the paper surface. Yes. In FIG. 1, the second prism sheet 16 is shown in a direction different from the actual direction so that it can be understood that the cross section of the second prism sheet 16 is a convex lens.

  The material and manufacturing method of the first prism sheet 14 and the second prism sheet 16 can take various known modes. For example, a sheet-shaped resin material extruded from a die is placed opposite to the transfer roller that rotates at approximately the same speed as the resin material extrusion speed (a prism sheet reverse type is formed on the surface). A method for producing a resin sheet can be employed in which the pressure is sandwiched between nip roller plates rotating at the same speed and the uneven shape on the surface of the transfer roller is transferred to the resin material.

  In addition, a method of manufacturing a resin sheet in which a transfer mold plate (stamper) on which a reversal type of a prism sheet is formed and a resin plate are laminated by hot pressing and press molding by thermal transfer can be employed.

  As a resin material used in such a manufacturing method, a thermoplastic resin can be used, for example, polymethyl methacrylate resin (PMMA), polycarbonate resin, polystyrene resin, MS resin, AS resin, polypropylene resin, polyethylene resin. , Polyethylene terephthalate resin, polyvinyl chloride resin (PVC), thermoplastic elastomer, or a copolymer thereof, cycloolefin polymer, and the like.

  Further, as another manufacturing method, on the surface of the same transparent film (polyester, cellulose acylate, acrylic, polycarbonate, polyolefin, etc.) used for the first diffusion sheet 12 and the second diffusion sheet 18, A method of manufacturing a resin sheet that transfers and forms unevenness on the surface of the uneven roller (the reverse type of the prism sheet is formed on the surface) can be employed.

  More specifically, a transparent film in which an adhesive layer and a resin layer (for example, UV curable resin) are formed in two or more layers is continuously run by sequentially applying an adhesive and a resin to the surface. The transparent film is wound around a rotating concavo-convex roller, the concavo-convex surface of the concavo-convex roller is transferred to the resin layer, and the resin layer is cured in a state where the transparent film is wound around the concavo-convex roller (for example, UV irradiation). The manufacturing method of a concavo-convex sheet can be adopted. Note that no adhesive is required.

  In addition, the manufacturing method of the 1st prism sheet 14 and the 2nd prism sheet 16 is not necessarily limited to said example, If a desired uneven | corrugated shape can be formed on the surface, another manufacturing method can also be employ | adopted. .

  As shown in FIG. 1, the left and right end portions of the display optical sheet 10 are integrated with each other by a joint portion 10 </ b> A. For example, the bonding portion 10A is bonded by applying an adhesive on the upper surface of each sheet (the first diffusion sheet 12, the first prism sheet 14, and the second prism sheet 16).

  The display optical sheet 10 described above is disposed, for example, between a light source device and a liquid crystal cell, and is used so as to form a liquid crystal display element as a whole. In this case, in addition to the various merits already described (the optical sheet for display can be manufactured at a low cost and high quality with a simpler process than before), the assemble work of the liquid crystal display element is also very easy. can get.

  Next, another example (second embodiment) of the optical sheet for display manufactured by the method for manufacturing an optical sheet for display according to the present invention will be described. FIG. 2 is a cross-sectional view showing the configuration of the display optical sheet 20. In addition, the same code | symbol is attached | subjected about the same and similar member as FIG. 1 (1st Embodiment), and the detailed description is abbreviate | omitted.

  The display optical sheet 20 is an optical sheet in which a diffusion sheet 12, a first prism sheet 14, and a second prism sheet 16 are laminated in order from the bottom. The second diffusion sheet 18 is omitted when a wide diffusion performance is not required as in the display optical sheet 10 described above.

  As shown in FIG. 2, the left and right end portions of the display optical sheet 20 are integrated with each other by a joint portion 20 </ b> A. This joining method is substantially the same as in the first embodiment.

  The display optical sheet 20 described above is disposed, for example, between the light source device and the liquid crystal cell, and is used so as to form a liquid crystal display element as a whole, as in the first embodiment.

  Next, still another example (third embodiment) of the optical sheet for display manufactured by the method for manufacturing an optical sheet for display according to the present invention will be described. FIG. 3 is a cross-sectional view showing a configuration of the display optical sheet 30. In addition, the same code | symbol is attached | subjected about the same and similar member as FIG. 1 (1st Embodiment) and FIG. 2 (1st Embodiment), and the detailed description is abbreviate | omitted.

  The optical sheet for display 30 is an optical sheet in which the first diffusion sheet 12, the prism sheet 14, and the second diffusion sheet 18 are laminated in order from the bottom.

  In the display optical sheet 30, the second prism sheet 16 is omitted when the diffusion performance in the direction perpendicular to the paper surface as in the display optical sheet 10 described above is not required.

  As shown in FIG. 3, the left and right ends of the display optical sheet 30 are integrated with each other through a joint 30 </ b> A. This joining method is substantially the same as in the first embodiment.

  The display optical sheet 30 described above is disposed, for example, between the light source device and the liquid crystal cell, and used to form a liquid crystal display element as a whole, as in the first embodiment.

  Next, still another example (fourth embodiment) of the display optical sheet manufactured by the method for manufacturing a display optical sheet according to the present invention will be described. FIG. 4 is a cross-sectional view showing a configuration of the display optical sheet 40. In addition, the same code | symbol is attached | subjected about the member similar to FIG. 1 (1st Embodiment), FIG. 2 (2nd Embodiment), etc., and the detailed description is abbreviate | omitted.

  The display optical sheet 40 is an optical sheet in which the diffusion sheet 12 and the prism sheet 14 are laminated in order from the bottom. The second diffusion sheet 18 is omitted when a wide diffusion performance is not required as in the display optical sheet 10 described above, and a diffusion performance in a direction perpendicular to the paper surface as in the display optical sheet 10 described above is required. If not, the second prism sheet 16 is omitted.

  As shown in FIG. 4, the left and right ends of the display optical sheet 40 are integrated with each other by a joint 40 </ b> A. This joining method is substantially the same as in the first embodiment.

  The display optical sheet 40 described above is arranged, for example, between the light source device and the liquid crystal cell and used to form a liquid crystal display element as a whole, as in the first embodiment.

  Next, another example (fifth embodiment) of a display optical sheet manufactured by the method for manufacturing a display optical sheet according to the present invention will be described. FIG. 5 is a cross-sectional view showing the configuration of the display optical sheet 50. In addition, the same code | symbol is attached | subjected about the member similar to FIG. 1 (1st Embodiment), FIG. 2 (2nd Embodiment), etc., and the detailed description is abbreviate | omitted.

  The optical sheet for display 50 is an optical sheet in which the first prism sheet 14, the second prism sheet 16, and the diffusion sheet 18 are laminated in order from the bottom. The first diffusion sheet 12 is omitted when a wide diffusion performance is not required as in the optical sheet for display 10 described above.

  As shown in FIG. 5, the left and right ends of the display optical sheet 50 are integrated with each other through a joint 50 </ b> A. This joining method is substantially the same as in the first embodiment.

  The display optical sheet 50 described above is disposed between the light source device and the liquid crystal cell, for example, as in the first embodiment, and used to form a liquid crystal display element as a whole.

  Next, another example (sixth embodiment) of the optical sheet for display manufactured by the method for manufacturing an optical sheet for display according to the present invention will be described. FIG. 6 is a cross-sectional view showing the configuration of the display optical sheet 50. In addition, the same code | symbol is attached | subjected about the member similar to FIG. 1 (1st Embodiment), FIG. 2 (2nd Embodiment), etc., and the detailed description is abbreviate | omitted.

  The display optical sheet 60 is an optical sheet in which the first prism sheet 14 and the diffusion sheet 18 are laminated in order from the bottom. The first diffusion sheet 12 is omitted when a wide diffusion performance like the above-described optical sheet for display 10 is not required, and a diffusion performance in a direction perpendicular to the paper surface like the optical sheet for display 10 described above is required. If not, the second prism sheet 16 is omitted.

  As shown in FIG. 6, the left and right ends of the display optical sheet 60 are integrated with each other by a joint 60 </ b> A. This joining method is substantially the same as in the first embodiment.

  The display optical sheet 60 described above is disposed, for example, between the light source device and the liquid crystal cell, and used to form a liquid crystal display element as a whole, as in the first embodiment.

  Next, the manufacturing method (1st-6th manufacturing method) of the optical sheet for displays is demonstrated. This manufacturing method can be commonly applied to the above-described display optical sheets 10 to 60. However, for the convenience of description, the case where the manufacturing method is applied to a four-layer display optical sheet (first embodiment) will be described. To do.

  FIG. 7 is a configuration diagram of a display optical sheet manufacturing line 11 applied to the first manufacturing method. The rolls 12B, 14B, 16B, and 18B provided at the left end of the figure are respectively the first diffusion sheet 12, the first prism sheet 14, and the second prism sheet 16 shown in FIG. And a roll around which the second diffusion sheet 18 is wound.

  The rolls 12B, 14B, 16B, and 18B are respectively supported by the rotation shafts of unillustrated feeding means, and the first diffusion sheet 12 and the first prism sheet 14 are provided by the rolls 12B, 14B, 16B, and 18B. The second prism sheet 16 and the second diffusion sheet 18 can be fed out at substantially the same speed.

  The first diffusion sheet 12, the first prism sheet 14, the second prism sheet 16, and the second diffusion sheet 18 that have been fed out are water-soluble antistatic agents by coating film forming means P, P. And a coating film made of a fluorosurfactant is formed (coating film forming process), and finally supported on the guide rollers G, G... (Lamination process).

  In the coating means P, a water-soluble antistatic agent and a fluorosurfactant are provided on at least the surfaces of the first diffusion sheet 12, the first prism sheet 14, the second prism sheet 16, and the second diffusion sheet 18, respectively. Is formed so as to have a thickness in the range of 0.03 to 0.2 g / m <2>.

  Further, the method for forming a coating film on the light diffusing sheets 12 and 18 and the prism sheets 14 and 16 with an aqueous solution of a water-soluble antistatic agent and a fluorosurfactant is not particularly limited. Various methods such as a spray method and an aerosol spray method are possible, but the aerosol spray method, particularly the aerosol spray method using a mist generation method using an ultrasonic oscillator, is most preferable in terms of maintaining optical performance and appearance. In this aerosol spraying method, excellent wettability characteristics are obtained on the surfaces of the light diffusion sheets 12 and 18 and the prism sheets 14 and 16, and the particles spread in a uniform thin film without agglomeration. Even in the case of the light diffusion sheets 12 and 18 and the prism sheets 14 and 16, it is possible to easily form a uniform coating film of ultrathin film simultaneously on both the front and back surfaces of the sheet only by being exposed to aerosol spray. A conventionally known method is applied to the aerosol spraying method itself.

  The water-soluble antistatic agent used is a water-soluble antistatic agent usually used for antistatic of synthetic resins, such as lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, lauryldiethanolamine, stearylamine hydrochloride Cationic antistatic agents such as salts, anionic antistatic agents such as alkylamine phosphate ethanol, potassium alkylphosphate, alkylbenzenesulfonates, polyethylene glycol monooleate, polyoxyethylene sorbitan monooleate, etc. Nonionic antistatic agents can be mentioned, among which cationic antistatic agents are particularly preferably used. In the antistatic of optical sheets such as a light diffusion sheet and a prism sheet, the water-soluble antistatic agent is a cationic antistatic agent, so that a sufficient antistatic effect can be obtained even with a thin film thickness.

  Examples of the fluorosurfactant include fluoroalkylcarboxylate (alkali metal salt, alkaline earth metal obtained, amine salt), perfluoroalkylcarboxylate, fluoroalkyl phosphate ester salt, perfluoroalkyl phosphate. Ester salt, polyoxyethylene perfluoroalkyl phosphate ester salt, perfluoroalkyl sulfate ester salt, polyoxyethylene perfluoroalkyl sulfate ester salt, perfluoroalkylsulfonamide derivative, perfluoroalkylamine salt, Perfluoroalkyl quaternary ammonium salts, perfluoroalkyl imidazolidine derivatives, perfluoroalkyl betaines, polyoxyethyl perfluoroalkyl phenols, polyoxyethyl perfluoroalkylamines, perfluoroalkyl carboxylic acids Sorbitan esters, etc. It is.

  Specific examples of such surfactants include sodium 16-fluorohexadecylcarboxylate, perfluorooctylcarboxylic acid N, N-diethanolamine, sodium perfluorodecylphosphate, sodium perfluorooctylphosphate, Polyoxyethylene perfluorooctyl phosphate sodium, N-polyoxyethylene-N-ethyl perfluorooctylsulfonamide, N, N-di (polyoxyethylene) perfluorooctylsulfonamide, N-polyoxyethylene-N -Butyl perfluorodecylsulfonamide, N-polyoxyethylene-N-ethyl perfluorooctadecyl sulfonamide, perfluorooctadecyl-N-ethyldimethylammonium salt, perfluorododecyltrimethylammonium salt, parf Looctadecyl betaine, polyoxyethylene perfluorooctyl ether, polyoxyethylene perfluorooctadecenyl ether, polyoxyethylene perfluorohexylamine and perfluorododecylcarboxylic acid sorbitan ester, etc. Are used alone or in combination of two or more.

The film thickness of the coating film containing the water-soluble antistatic agent and the fluorosurfactant is appropriately adjusted according to the application conditions such as the concentration of the water-soluble antistatic agent and the fluorosurfactant in the aqueous solution or the treatment time. However, by making the thickness in the range of 0.03 to 0.2 g / m ² after drying, an antistatic effect can be imparted to an optical sheet such as a diffusion sheet or a prism sheet, In the secondary processing in which optical sheets, which will be described later, are bonded together to form a composite, the bonded surface will not be peeled off during normal handling. That is, not only the antistatic effect is imparted by the coating film containing not only the water-soluble antistatic agent but also the fluorosurfactant, and the adhesive strength is suppressed from being lowered by the antistatic agent, thereby improving the adhesiveness. To do. That is, it is possible to improve the decrease in adhesion between films due to the antistatic agent without impairing the antistatic effect by providing wettability with the fluorosurfactant. Here, the thickness of the coating film is in a range of 0.03~0.2g / m ^2, the thin and wettability not only antistatic effect can not be obtained than 0.03 g / m ² was obtained This is because if it is thicker than 0.2 g / m ² , the optical characteristics and appearance are affected by visible light.

  In addition, after forming the coating film of the aqueous solution containing the water-soluble antistatic agent and the fluorosurfactant by the coating film forming means P, P ..., the coating film is formed by drying this, The drying method itself may be performed by a generally known method such as air drying at room temperature, leaving under a predetermined temperature condition, or blowing warm air.

  As a laser beam irradiation apparatus including the laser head 24, a YAG laser irradiation apparatus having a wavelength of 355 to 1064 nm, a semiconductor laser irradiation apparatus, a carbon dioxide laser irradiation apparatus having a wavelength of 9 to 11 μm, and the like can be employed. The oscillation method may be continuous oscillation or pulse oscillation. However, in order to perform welding at approximately the same time as cutting, doting by pulse oscillation is preferable because the appearance is good.

  The output and frequency required for welding (joining process) almost simultaneously with the cutting (cutting process) vary depending on the material feed speed, laser beam scanning speed, material thickness, etc. Good welding results can be obtained under the conditions of 50 W and a frequency of 100 kHz or less.

  The laser head 24 is attached to an X drive robot axis or an XY drive robot axis that can move in the X direction (sheet width direction) or the XY direction, and can perform positioning to an arbitrary position and arbitrary trajectory movement. The entire laser head 24 may be moved according to the irradiation pattern of the laser beam, but the laser head 24 is separately placed (fixed), and only the laser beam is guided by the optical fiber to simplify the moving mechanism in the XY directions. You can also

  It is also possible to provide a known mechanism (suction device or the like) that sucks smoke generated during cutting by the laser head 24 and during welding.

Laser light is irradiated from the laser head 24 to the cut / joined portion on the periphery of the laminate, and the irradiation head is irradiated.
While moving the pot at a constant speed, the periphery of the laminate is cut into a product size and melted and joined.

  On the other hand, the sheet laminate 34 from which the display optical sheet 10 is punched out by the laser head 24 is wound around a winding roll 36 of a winding device (not shown in detail).

  According to the first manufacturing method of the optical sheet for display described above, the following effects can be obtained.

1) Scratch failure reduction effect If the upper and lower surfaces of the lens sheets (the first prism sheet 14 and the second prism sheet 16) are damaged, the scratches are conspicuous due to the lens effect. On the other hand, when the bottom surface of the diffusion sheet (the first diffusion sheet 12 or the second diffusion sheet 18) is scratched, the scratches are not noticeable because the light is diffused. For this reason, preventing damage to the lens sheet leads to reduction of scratches. Although scratches are often attached during handling after sheet processing, since the diffusion sheet serves as a protective sheet by combining the lens sheet with the diffusion sheet, failure due to scratches can be reduced. In particular, the effect is great in the first example display optical sheet 10 (see FIG. 1) and the second example display optical sheet 30 (see FIG. 3) in which the lens sheet does not appear on the surface.

  Furthermore, by applying an aqueous solution containing a water-soluble antistatic agent and a fluorosurfactant, the coating film protects the sheet surface, and the scratch resistance is improved as compared with those not provided with a coating film. Therefore, the failure due to scratches can be further reduced.

2) Effect of reducing assembly man-hour For example, when the optical sheet for display 10 of the first example (see FIG. 1) is used in the assembly of the liquid crystal display element, the assembly man-hour is only one process for incorporating the optical sheet for display 10. On the other hand, when the conventional product is used, the first diffusion sheet is incorporated ⇒ The first lens sheet is peeled off from the back surface protective sheet ⇒ The first lens sheet is peeled off from the surface protective sheet ⇒ The first lens sheet is incorporated ⇒ Eight steps are required: peeling off the back surface protection sheet of the second lens sheet → peeling the surface protection sheet of the second lens sheet → incorporation of the second lens sheet → incorporation of the second diffusion sheet. Thus, according to the first manufacturing method, a significant reduction in assembly man-hours can be achieved, and the product cost can be reduced.

3) Reduction effect of protective sheet In many cases, a protective sheet is attached to the front and back of a lens sheet to prevent scratches. This protective sheet is discarded after the lens sheet is assembled, and is very wasteful. According to this embodiment, this protective sheet can be saved by using the diffusion sheet as a protective sheet.

  Specifically, one protective sheet can be reduced in the display optical sheet 40 (see FIG. 4) of the fourth example and the display optical sheet 60 (see FIG. 6) of the sixth example, and the third example In the display optical sheet 30 (see FIG. 3), two protective sheets can be reduced, the display optical sheet 20 in the second example (see FIG. 2), and the display optical sheet 50 in the fifth example (see FIG. 5). 3), three protective sheets can be reduced, and four protective sheets can be reduced in the display optical sheet 10 of the first example (see FIG. 1).

4) Dust adhesion preventing effect Optical films such as lens sheets and diffusion sheets are likely to be charged with dust because the film surface is easily charged in the processing step. Since such adhesion of dust can be prevented, a high-quality optical sheet for display that does not contain dust can be provided.

5) Effect of improving adhesiveness In the secondary processing to make a composite by bonding optical sheets such as lens sheets and diffusion sheets, the adhesive surface is peeled off in normal handling by the coating layer containing the fluorosurfactant. Disappears. Therefore, it will lead to reduction of the time cost which requires a response | compatibility by peeling at the time of the handling after the processing of the optical sheet for a display.

  Next, the 2nd manufacturing method of the optical sheet for displays is demonstrated. FIG. 8 is a configuration diagram of a display optical sheet production line 21 applied to the second production method. In addition, the same code | symbol is attached | subjected about the same and similar member as the optical sheet production line 11 for display which concerns on a 1st manufacturing method (refer FIG. 7), and the detailed description is abbreviate | omitted.

  In the display optical sheet production line 21, dispensers 42, 44, 46 and a punching press device 48 are employed instead of the laser head 24 of the display optical sheet production line 11.

  The dispensers 42, 44, and 46 are supply devices that discharge the adhesive from the tip. The dispenser 42 supplies adhesive to the first diffusion sheet 12 in order to bond the first diffusion sheet 12 and the first prism sheet 14, and the dispenser 44 is used for the first prism sheet 14. In order to bond the first prism sheet 16 and the second prism sheet 16, an adhesive is supplied to the first prism sheet 14, and the dispenser 46 bonds the second prism sheet 16 and the second diffusion sheet 18. Therefore, an adhesive is supplied to the second prism sheet 16.

  The adhesive supplied from the dispensers 42, 44 and 46 is preferably an adhesive that is bonded with the aid of heat or a catalyst. Specifically, general adhesives such as silicon adhesives, polyurethane adhesives, polyester adhesives, epoxy adhesives, cyanoacrylate adhesives, and acrylic adhesives can be used.

  Since the display optical sheets 10 to 60 may be used at high temperatures, an adhesive that is stable even at room temperature to 120 ° C. is preferable. Among these, epoxy adhesives are excellent in strength and heat resistance, and can be suitably used. Since the cyanoacrylate adhesive is excellent in immediate effect and strength, it can be used for the production of an efficient optical sheet for display. Polyester adhesives are particularly suitable because they are excellent in strength and processability.

  These adhesives are roughly classified into a thermosetting type, a hot melt type, and a two-component mixed type depending on the bonding method, and a thermosetting type or a hot melt type capable of continuous production is preferably used. Whatever adhesive is used, the coating thickness is preferably 0.5 μm to 50 μm.

  Moreover, it is preferable to provide a drying means for drying the adhesive between the downstream press roller (guide roller G). The drying means is not particularly limited, and examples include known drying methods such as drying with warm air or hot air, drying with dehumidified air, and the like.

  The dispensers 42, 44, and 46 are attached to an X drive robot shaft or an XY drive robot shaft that can move in the X direction (sheet width direction) or XY direction, and can perform positioning to an arbitrary position and arbitrary trajectory movement. It has become.

  An adhesive is supplied from these dispensers 42, 44, and 46 to the joining portion at the periphery of the laminate, and the periphery of the laminate is joined by a downstream press roller (guide roller G) while the laminate is conveyed.

  A punching press device 48 downstream of the dispensers 42, 44, and 46 is a device that cuts the periphery of the laminate into a product size. In this punching press device 48, the blade is inserted into the central portion of the bonded portion, so that the entire punched sheet (display optical sheet 10 to 60) or only the end portion of any piece is bonded. The obtained composite sheet can be obtained.

  Next, the 3rd manufacturing method of the optical sheet for displays is demonstrated. FIG. 9 is a configuration diagram of a display optical sheet manufacturing line 31 applied to the third manufacturing method. The same or similar members are used in the display optical sheet manufacturing line 11 according to the first manufacturing method and the display optical sheet manufacturing line 21 (see FIGS. 7 and 8) according to the second manufacturing method. Reference numerals are assigned and detailed description thereof is omitted.

  In this display optical sheet production line 31, tape feeders 52, 54 and 56 are employed in place of the dispensers 42, 44 and 46 of the display optical sheet production line 21. Each of the tape supply devices 52, 54 and 56 is a supply device for supplying a double-sided tape from the tip.

  The tape supply device 52 supplies double-sided tape to the surface of the first diffusion sheet 12 in order to bond the first diffusion sheet 12 and the first prism sheet 14, and the tape supply device 54 In order to bond the first prism sheet 14 and the second prism sheet 16, a double-sided tape is supplied to the surface of the first prism sheet 14, and the tape supply device 56 includes the second prism sheet 16. A double-sided tape is supplied to the second prism sheet 16 in order to bond the first diffusion sheet 18 and the second diffusion sheet 18.

  The double-sided tape supplied from the tape supply devices 52, 54 and 56 is one in which an adhesive is applied to both sides. As the adhesive for this double-sided tape, a highly adhesive acrylic copolymer resin can be used, but other adhesives such as silicone, natural rubber and synthetic rubber can be used. It is preferable to use an acrylic pressure-sensitive adhesive in consideration of physical strength such as property, price and the like.

  The tape supply devices 52, 54 and 56 for supplying the double-sided tape can be used by using a commercially available general-purpose tape dispenser. The tape supply devices 52, 54, and 56 are attached to a single-axis moving mechanism that can move to an arbitrary position in the X direction (sheet width direction), and the position of applying the double-sided tape can be changed according to the punching pattern. it can.

  Further, the fixed portion of the tape supply devices 52, 54 and 56 has a pivot mechanism, and the tape supply pattern in an oblique direction is obtained by changing the position of the tape supply devices 52, 54 and 56 in synchronization with the sheet feeding speed. It is a mechanism that can cope with.

  Next, the 4th manufacturing method of the optical sheet for displays is demonstrated. FIG. 10 is a configuration diagram of a display optical sheet production line 41 applied to the fourth production method. In addition, the same code | symbol is attached | subjected about the member similar to the optical sheet manufacturing line for display which concerns on a 1st manufacturing method-the 3rd manufacturing method (refer FIGS. 7-9), and the detailed description is given. Omitted.

  In this display optical sheet production line 41, ultrasonic horns 62, 64, 66 are employed instead of the dispensers 42, 44, 46 of the display optical sheet production line 21. The ultrasonic horns 62, 64 and 66 are respectively arranged on the downstream side of the press roller (guide roller G).

  The ultrasonic horns 62, 64 and 66 are devices for fusing two or more laminated sheets. That is, the ultrasonic horn 62 is for fusing the first diffusion sheet 12 and the first prism sheet 14, and the ultrasonic horn 64 is for the first prism sheet 14, the second prism sheet 16, and the like. The ultrasonic horn 66 is for fusing the joint portion 19 of the second prism sheet 16 and the second diffusion sheet 18 together.

  Ultrasonic horns 62, 64, and 66 (ultrasonic welding devices) are conventionally known, and a type that raises and lowers the horn with an air cylinder and a type that raises and lowers the horn with a servo motor are known. However, any type of ultrasonic welding apparatus can be applied as long as the sheets can be welded together by applying ultrasonic vibration while applying a load to the sheets.

  The position control of the ultrasonic horns 62, 64 and 66 is only required to switch the position in the width direction of the sheet when the punching pattern is horizontal with respect to the sheet feeding direction. In such a case, a swing mechanism that can change the traveling direction of the ultrasonic horns 62, 64, and 66 to an arbitrary direction is provided, and it can be handled by moving in the width direction in synchronization with the movement amount of the seat. .

  The setting conditions of the ultrasonic horns 62, 64 and 66 may be determined within a range in which the fused portion is not melted by heat. If necessary, the bonded portion is bonded by an air cooling mechanism such as air blowing after bonding (fusion). It may be cooled.

  Next, the 5th manufacturing method of the optical sheet for displays is demonstrated. FIG. 11 is a configuration diagram of a display optical sheet manufacturing line 51 applied to the fifth manufacturing method. Members that are the same as or similar to the optical sheet manufacturing line for displays of the first manufacturing method to the fourth manufacturing method are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the display optical sheet production line 51, laser heads 72, 74, and 76 are employed instead of the ultrasonic horns 62, 64, and 66 of the display optical sheet production line 41. The laser heads 72, 74, and 76 are disposed on the downstream side of the press roller (guide roller G), similarly to the ultrasonic horns 62, 64, and 66.

  The laser heads 72, 74, and 76 are devices for fusing two or more stacked sheets, similarly to the ultrasonic horns 62, 64, and 66. In other words, the laser head 72 fuses the first diffusion sheet 12 and the first prism sheet 14, and the laser head 74 fuses the first prism sheet 14 and the second prism sheet 16. The laser head 76 is for fusing the second prism sheet 16 and the second diffusion sheet 18 together.

  The laser heads 72, 74, and 76 are used only for the joining process, unlike the laser head 24 in the optical sheet manufacturing line 11 for display shown in FIG. 7 (first manufacturing method), and the cutting process is performed by a punching press device 48. Done. However, the basic specifications and peripheral configuration of the laser heads 72, 74, and 76 are substantially the same as those in the first manufacturing method.

  The setting conditions of the laser heads 72, 74, and 76 may be determined within a range in which the fused portion is not melted by heat. If necessary, the bonded portion is cooled by an air cooling mechanism such as air blowing after bonding (fusion). May be.

  Next, the 6th manufacturing method of the optical sheet for displays is demonstrated. FIG. 12 is a configuration diagram of a display optical sheet manufacturing line 61 applied to the sixth manufacturing method. In addition, the same code | symbol is attached | subjected about the member similar to the optical sheet manufacturing line for display which concerns on the 1st manufacturing method-the 5th manufacturing method (refer FIGS. 7-11), and the detailed description is given. Omitted.

  In this display optical sheet production line 61, one laser head 78 is employed in place of the three laser heads 72, 74 and 76 of the display optical sheet production line 51. The laser head 78 is disposed on the downstream side of the press roller (guide roller G).

  The laser head 78 is a device that fuses two or more stacked sheets. That is, the laser head 78 fuses the laminated body of the first diffusion sheet 12, the first prism sheet 14, the second prism sheet 16, and the second diffusion sheet 18.

  Unlike the laser head 24 in the optical sheet production line 11 for display shown in FIG. 7 (first production method), the laser head 78 is used only for the joining process, and the cutting process is performed by the punching press device 48. However, the basic specifications and peripheral configuration of the laser head 78 are substantially the same as those in the first manufacturing method.

  The setting condition of the laser head 78 may be determined within a range in which the fused portion is not melted by heat. If necessary, the bonded portion may be cooled by an air cooling mechanism such as air blowing after bonding (fusion). .

  FIG. 13 is a diagram for explaining a planar arrangement of sheets (optical sheets for display 10 to 60) punched from the laminate in the first manufacturing method, and FIG. 14 is used in the second to sixth manufacturing methods. It is a figure explaining planar arrangement | positioning of the sheet | seat (optical sheet for displays 10-60) punched from a laminated body.

  13A shows a state in which fusion (joining process) and punching (cutting process) parallel to the transport direction of the laminate are performed, and FIG. 13B shows the state in which the laminate is transported. A state in which fusion (joining process) and punching (cutting process) are performed in an oblique direction is shown. In the figure, the point on the peripheral edge of the sheet punched out from the laminate indicates the fused part.

  14A shows a state in which fusion or adhesion (bonding process) is performed in a direction parallel to and orthogonal to the transport direction of the laminate, and FIG. 14B shows a state in which the laminate is transported. A state where fusion or adhesion (joining process) is performed in an oblique direction is shown. In the figure, the point on the peripheral edge of the sheet punched out from the laminate indicates a fusion point or an adhesion point.

  As described above, according to the present invention, when manufacturing an optical sheet for a display, the adhesive strength when the optical sheets are bonded to each other does not decrease, and the quality is improved by a simple process. Can be manufactured.

    Moreover, according to this invention, the following effects are also acquired.

1) Improvement of Product Value by Cost Reduction and Thinning Optical sheets used for large liquid crystal televisions need rigidity, and therefore, the thickness of the support is about twice that of the conventional one. However, since the optical sheet according to the present invention is a composite of the sheets, it can have sufficient rigidity without increasing the thickness of each sheet, and the thickness of each layer can be reduced.

2) Improved performance by preventing reduction of light collection effect Some products have a matte backside to prevent scratches on the lens sheet (to make the scratches less noticeable). The optical sheet according to the present invention is not necessary, and not only the production cost can be reduced, but also the light collection effect can be prevented from being reduced by the mat treatment, and the performance is improved.

3) Improvement of antifogging property Provided so that a coating film containing a water-soluble antistatic agent and a fluorosurfactant on at least the surface of the optical sheet has a thickness in the range of 0.03 to 0.2 g / m ^2. As a result, fogging due to temperature change or the like when the optical sheet for display according to the present invention is used inside the backlight unit of the liquid crystal display device is remarkably improved.

  As mentioned above, although each example of embodiment of the manufacturing method of the optical sheet for a display which concerns on this invention was demonstrated, this invention is not limited to the example of the said embodiment, Various aspects can be taken.

  For example, in the example of this embodiment, the prisms of the first prism sheet 14 and the second prism sheet 16 are facing upward in any case, but the prisms can be stacked with the prisms facing downward.

  Moreover, the layer structure of the optical sheet for display is not limited to the example of embodiment, For example, a protective sheet can also be laminated | stacked on an up-and-down surface.

  Furthermore, in the example of the present embodiment, an aqueous solution containing a water-soluble antistatic agent and a fluorosurfactant is applied by the application means P, P... Forms applied in the manufacture of the sheet are also possible.

  Even if it is the above structures, it acts similarly to this embodiment and the same effect is acquired.

[Create prism sheet]
Prism sheets used for the first prism sheet 14 and the second prism sheet 16 were prepared. This prism sheet is used in common for the first prism sheet 14 and the second prism sheet 16.

-Preparation of resin solution The compounds shown in the table of Fig. 15 were mixed at the stated weight ratio, heated to 50 ° C and dissolved by stirring to obtain a resin solution. In addition, the name and content of each compound are as follows.

EB3700: Everkrill 3700, manufactured by Daicel UC Corporation,
Bisphenol A type epoxy acrylate,
(Viscosity: 2200 mPa · s / 65 ° C)
BPE200: NK ester BPE-200, manufactured by Shin-Nakamura Chemical Co., Ltd.
Ethylene oxide-added bisphenol A methacrylate,
(Viscosity: 590 mPa · s / 25 ° C)
BR-31: New Frontier BR-31, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
Tribromophenoxyethyl acrylate,
(Solid at normal temperature, melting point 50 ° C or higher)
LR8883X: Lucirin LR8883X, a north radical generator manufactured by BASF Corporation,
Ethyl-2,4,6-trimethylbenzoylethoxyphenyl osphine oxide MEK: methyl ethyl ketone The prism sheet was manufactured using the prism sheet manufacturing apparatus having the configuration shown in FIG.

  As the sheet W, a transparent PET (polyethylene terephthalate) film having a width of 500 mm and a thickness of 100 μm was used.

  As the embossing roller 83, a roller made of S45C having a length (width direction of the sheet W) of 700 mm and a diameter of 300 mm and having a surface material of nickel was used. Grooves with a pitch of 50 μm in the roller axial direction were formed on the entire circumference of the surface of the roller by cutting using a diamond tool (single point). The cross-sectional shape of the groove is a triangular shape with an apex angle of 90 degrees, and the bottom of the groove is a triangular shape with a 90 degree without a flat portion. That is, the groove width is 50 μm and the groove depth is about 25 μm. Since this groove is endless with no seam in the circumferential direction of the roller, the embossing roller 83 can form a lenticular lens (prism sheet) having a triangular cross section on the sheet W. The surface of the roller was plated with nickel after the grooves were processed.

  As the coating means 82, a die coater using an extrusion type coating head 82C was used.

  As the coating solution F (resin solution), a solution having the composition described in the table of FIG. 15 was used. The supply amount of each coating liquid F to the coating head 82C was controlled by the supply device 82B so that the wet thickness of the coating liquid F (resin) was 20 μm after drying the organic solvent.

As the drying means 89, a hot air circulation type drying apparatus was used. The temperature of the hot air was 100 ° C.
As the nip roller 84, a roller having a diameter of 200 mm and a silicon rubber layer having a rubber hardness of 90 formed on the surface thereof was used. The nip pressure (effective nip pressure) for pressing the sheet W by the emboss roller 83 and the nip roller 84 was 0.5 Pa.
A metal halide lamp was used as the resin curing means 85, and irradiation was performed with an energy of 1000 mJ / cm ² .

  As described above, a prism sheet having a concavo-convex pattern was obtained.

[Creation of the first diffusion sheet 12]
A first diffusion sheet 12 (under diffusion sheet) was produced by forming each layer in the order of the undercoat layer, the backcoat layer, and the light diffusion layer by the following method.
-Undercoat layer On one side of a polyethylene terephthalate film (support) with a thickness of 100 μm, the following composition
Liquid A as a coating liquid for the undercoat layer was applied with a wire bar (wire size: # 10) and dried at 120 ° C. for 2 minutes to obtain an undercoat layer having a thickness of 1.5 μm.

(Coating solution for undercoat layer)
Methanol 4165g
Julimer SP-50T (Nippon Pure Chemicals) 1495g
339 g of cyclohexanone
Julimer MB-1X (Nippon Pure Chemicals Co., Ltd.) 1.85g
(Organic particles: polymethylmethacrylate cross-linked type, spherical ultrafine particles with a weight average particle size of 6.2 μm)
-Back coat layer On the opposite side of the support on which the undercoat layer was applied, the B liquid as the back coat layer coating liquid having the following composition was applied with a wire bar (wire size: # 10), and 120 ° The film was dried at C for 2 minutes to obtain a backcoat layer having a thickness of 2.0 μm.

(Coating solution for back coat layer)
4171g of methanol
Julimer SP-65T (Nippon Pure Chemicals) 1487g
340 g of cyclohexanone
Julimer MB-1X (Nippon Pure Chemicals Co., Ltd.) 2.68g
(Organic particles: polymethylmethacrylate cross-linked type, spherical ultrafine particles with a weight average particle size of 6.2 μm)
-Light diffusing layer C liquid as a light diffusing layer coating solution having the following composition is applied to the undercoat layer side of the support prepared as described above with a light bar (wire size: # 22) and dried at 120 ° C for 2 minutes. To obtain a light diffusion layer. In addition, although mentioned later, this light-diffusion layer obtained what apply | coated immediately after preparing C liquid, and what apply | coated after adjusting C liquid and leaving still for 2 hours, respectively.

(Coating liquid for light diffusion layer)
Cyclohexanone 20.84g
Disparon PFA-230 Solid content 20% by mass 0.74g
(Particle sedimentation inhibitor: fatty acid amide, manufactured by Enomoto Kasei Co., Ltd.)
Acrylic resin (Dianar BR-117, manufactured by Mitsubishi Rayon Co., Ltd.) 20% by mass methyl ethyl ketone solution 17.85 g
Julimer MB-20X (Nippon Pure Chemicals) 11.29g
(Organic particles: polymethylmethacrylate cross-linked type, spherical ultrafine particles with a weight average particle diameter of 18 μm)
F780F (Dainippon Ink Co., Ltd.) 0.03g
(Methyl ethyl ketone 30% by mass solution)
[Creation of Second Diffusion Sheet 18]
The same conditions and the same as those of the first diffusion sheet 12 except that the addition amount of the Jurimer MB-20X in the light diffusion layer of the first diffusion sheet 12 is changed from 11.29 g to 1.13 g. A second diffusion sheet 18 (upper diffusion sheet) was produced by flow.

[Preparation of Optical Sheet 10 for Display: Example]
Using a commercially available ultrasonic oscillation type aerosol spraying device, each sheet (the first 1st) was placed under a fine mist of an aqueous solution containing 2% by weight of stearyltrimethylammonium chloride and 0.2% by weight of a fluorine-based nonionic surfactant. The diffusion sheet 12, the first prism sheet 14, the second prism sheet 16, and the second diffusion sheet 18) are exposed for 5 seconds, and then naturally dried to form a coating film having a thickness of 0.04 g / m ^2. The sheet | seat which has is obtained. The surface specific resistance value of these samples was measured, and the light diffusion sheet and the prism sheet were overlapped, and the four sides were bonded by a commercially available ultrasonic welding seal device to prepare a composite sheet.

[Creation of optical sheet for display: comparative example]
Each sheet (the first diffusion sheet 12, the first prism sheet 14, the second prism sheet 16, and the second diffusion sheet 18) is overlapped, and the four sides are bonded by a commercially available ultrasonic welding sealing device. A composite sheet was produced.

[Evaluation of optical sheet for display]
The optical sheet for display of the example has a surface specific resistance value of 2.5 × 10 ¹⁰ Ω, which is a sufficiently small resistance value to prevent adhesion of dust, and the adhesive strength is sufficient without being peeled off by normal handling. There was no problem with optical performance and appearance.

  As a comparison of the adhesive strength, 100 sets of each of the examples and comparative examples were subjected to normal handling, and those in which peeling was recognized were determined as NG. In the example, NG was only one set out of 100 sets. On the other hand, among the 100 sets of the comparative example, NG was 24 sets. From the above comparison results, according to the examples of the present invention, there was an antistatic effect and the adhesion between sheets was improved.

The figure which shows the cross-sectional structure of the optical sheet for a display which concerns on a 1st example. The figure which shows the cross-sectional structure of the optical sheet for a display which concerns on a 2nd example. The figure which shows the cross-sectional structure of the optical sheet for a display which concerns on a 3rd example. The figure which shows the cross-sectional structure of the optical sheet for a display which concerns on a 4th example. The figure which shows the cross-sectional structure of the optical sheet for a display which concerns on a 5th example. The figure which shows the cross-sectional structure of the optical sheet for a display which concerns on a 6th example. Configuration diagram of optical sheet manufacturing line for display applied to first manufacturing method Configuration diagram of optical sheet production line for display applied to second production method Configuration diagram of optical sheet manufacturing line for display applied to third manufacturing method Configuration diagram of optical sheet manufacturing line for display applied to fourth manufacturing method Configuration diagram of optical sheet manufacturing line for display applied to fifth manufacturing method Configuration diagram of optical sheet manufacturing line for display applied to sixth manufacturing method The figure explaining the plane arrangement | positioning of the sheet | seat punched out from a laminated body in a 1st manufacturing method. The figure explaining the planar arrangement | positioning of the sheet | seat punched from a laminated body in the 2nd-6th manufacturing method. Table showing the composition of the resin liquid used to create the prism sheet Configuration diagram of prism sheet manufacturing equipment

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Optical sheet for display, 11 ... Optical sheet manufacturing line for display, 12 ... 1st diffusion sheet, 12B ... Roll, 14 ... 1st prism sheet, 16 ... 2nd prism sheet, 18 ... 2nd diffusion Sheet, 20 ... Optical sheet for display, 20 ... Solid concentration, 21 ... Optical sheet production line for display, 24 ... Laser head, 26 ... Conveyor, 28 ... Adsorption lateral transfer device, 30 ... Optical sheet for display, 31 ... Optical sheet production line for display, 32 ... stacking device, 34 ... laminate, 36 ... roll, 40 ... optical sheet for display, 41 ... optical sheet production line for display, 42 ... dispenser, 44 ... dispenser, 46 ... dispenser, 48 ... Pressing device, 50 ... Melting point, 51 ... Optical sheet production line for display 52 ... Tape supply device, 54 ... Tape supply device, 56 ... Tape supply device, 60 ... Optical sheet for display, 61 ... Optical sheet production line for display, 62 ... Ultrasonic horn, 64 ... Ultrasonic horn, 66 ... Ultrasonic Horn, 72 ... Laser head, 74 ... Laser head, 76 ... Laser head, 78 ... Laser head, 82 ... Coating means, 82B ... Supply device, 82C ... Coating head, 83 ... Emboss roller, 84 ... Nip roller, 85 ... Resin curing Means G: guide roller P: coating film forming means (aerosol spraying device)

Claims (8)

Two or more optical sheets are laminated, and the optical sheets for display are bonded to each other at least at one or more locations,
In at least one of the mating surfaces of the two or more optical sheets,
An optical sheet for display, wherein a coating film containing a water-soluble antistatic agent and a fluorosurfactant is provided so as to have a thickness in the range of 0.03 to 0.2 g / m ² . A light diffusion sheet is laminated on at least one front surface and / or back surface of a lens sheet in which convex lenses formed in one axial direction are adjacently arranged on substantially the entire surface, and the lens sheet and the light diffusion sheet Is an optical sheet for display that is bonded at least at one or more locations,
On at least one of the mating surfaces of the lens sheet and the light diffusion sheet,
An optical sheet for display, wherein a coating film containing a water-soluble antistatic agent and a fluorosurfactant is provided so as to have a thickness in the range of 0.03 to 0.2 g / m ² . Two lens sheets each having a convex lens formed in one axial direction adjacent to each other and arranged on substantially the entire surface are laminated, and a light diffusion sheet is laminated on the front surface and / or the back surface of the lens sheet laminate. An optical sheet for a display in which the lens sheets and the lens sheet and the diffusion sheet are bonded at least at one or more locations,
At least one of the lens sheets and the mating surfaces of the lens sheet and the diffusion sheet,
An optical sheet for display, wherein a coating film containing a water-soluble antistatic agent and a fluorosurfactant is provided so as to have a thickness in the range of 0.03 to 0.2 g / m ² .   The optical sheet for display according to claim 1, wherein the water-soluble antistatic agent is a cationic antistatic agent. The thickness after drying an aqueous solution containing a water-soluble antistatic agent and a fluorosurfactant on at least one of the mating surfaces of two or more optical sheets whose planar size is not less than the product size is 0.03. A coating film forming step of forming a coating film to be in a range of ~ 0.2 g / m ² ;
A laminating step of laminating the two or more optical sheets, wherein the planar size of the sheet is not less than the product size;
A bonding step of bonding the two or more optical sheets to each other at at least one location;
A cutting step of cutting the laminate of the two or more optical sheets into a product size;
A method for producing an optical sheet for display. Convex surfaces of a lens sheet in which convex lenses formed in the axial direction are adjacent and arranged on substantially the entire surface have a planar size of the sheet that is equal to or larger than the product size and a light diffusion sheet in which the planar size of the sheet is equal to or larger than the product size A coating film is formed so that the thickness after drying an aqueous solution containing a water-soluble antistatic agent and a fluorosurfactant is at least 0.03 to 0.2 g / m ² in at least one of Process,
A laminating step in which a light diffusing sheet is disposed on the front surface and / or back surface of the lens sheet and laminated on at least one of the lens sheets;
A bonding step of bonding the lens sheet and the light diffusion sheet in at least one place;
A cutting step of cutting the laminate of the light diffusion sheet and the lens sheet into a product size;
A method for producing an optical sheet for display. Convex surfaces of a lens sheet in which convex lenses formed in the axial direction are adjacent and arranged on substantially the entire surface have a planar size of the sheet that is equal to or larger than the product size and a light diffusion sheet in which the planar size of the sheet is equal to or larger than the product size A coating film is formed so that the thickness after drying an aqueous solution containing a water-soluble antistatic agent and a fluorosurfactant is at least 0.03 to 0.2 g / m ² in at least one of Process,
A lamination step of laminating two of the lens sheets, and laminating a light diffusion sheet on the front surface and / or back surface of the laminated body of the lens sheets;
A bonding step of bonding the lens sheets to each other and the lens sheet and the light diffusion sheet at at least one location;
A cutting step of cutting the periphery of the laminate of the light diffusion sheet and the lens sheet into a product size;
A method for producing an optical sheet for display. The method for producing an optical sheet for display according to any one of claims 5 to 7, wherein the coating film forming step for forming the coating film is performed by an aerosol spraying method.

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