Optical film and optical display panel

Abstract

To provide a sheet-shaped optical film capable of manufacturing an optical display panel while suppressing deterioration of handling ability in a sheet-to-panel method.SOLUTION: Disclosed is an optical film having a constitution in which a release film, an adhesive layer, a polarizing film, and a surface protective layer are laminated in this order. The thickness of the polarizing film is 60 μm or less. The thickness of the surface protective film is equal to or less than 0.8≤(the thickness of the surface protective film) / (the thickness of the polarizing film).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an optical film and an optical display panel. [Background technology]

[0002] A method in which a sheet of polarizing film is attached to an optical cell (hereinafter referred to as "sheet-to-plate") (For example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-039238 A [Patent Document 2] JP 2009-062108 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, as optical display panels have become thinner, they are becoming thinner than ever before (for example, 60 μm thick). Polarizing films with a thickness of less than 1 μm are currently being developed. However, the elastic modulus is weak, and twisting and curling are likely to occur. Therefore, the polarizing film is thin. In the case of seat-to-panel systems, although technology has improved over the years, The process involves transporting the polarizing film, peeling off the release film, and attaching the polarizing film piece to the liquid crystal cell. There is concern that handling, such as bonding, will be difficult and yields will decrease.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and is a method for manufacturing a seat-to-panel seat using the seat-to-panel method. In addition, the present invention can be used to suitably manufacture an optical display panel using a thin polarizing film. The purpose of this website is to provide educational films. [Means for solving the problem]

[0006] The present invention comprises a release film, a pressure-sensitive adhesive layer, a polarizing film, and a surface protective film in this order. An optical film having a configuration in which The polarizing film has a thickness of 60 μm or less, The surface protection film has a thickness of 0.8≦(thickness of surface protection film) / (polarizing film The relation between the thickness of the film and the thickness of the cylinder is satisfied.

[0007] According to this configuration, the polarizing film is thin, but the surface protection film is thick (specifically, In this case, the thickness of the surface protection film is set to 0.8 or less (thickness of the surface protection film) / (thickness of the polarizing film). The elastic modulus of the polarizing film has been increased, and the polarizing film in the sheet-to-panel system Therefore, the sheet-to-panel method is used to make thin Thus, an optical display panel having a thin polarizing film laminated thereon can be suitably produced.

[0008] In one embodiment of the above invention, the surface protection film has a thickness of The surface protection film satisfies the following assembly requirements: In the printing process, the surface protection film needs to be peeled off from the optical display panel. The thicker the film, the more the surface protection film will adhere to the optical display panel when peeling it off. The action of grabbing the edge of the film and starting to peel it off becomes difficult. When peeling the surface protection film from the optical display panel, delamination of the optical film (e.g., Peeling between polarizer and polarizer protective film, Peeling between adhesive layer and polarizing film, Adhesion The risk of peeling between the adhesive layer and the optical cell increases. The thickness of the surface protection film is adjusted so that the following relationship is satisfied: (thickness of the polarizing film) / (thickness of the polarizing film)≦3.0. By controlling the surface protective film, the peelability can be improved and the interlayer of the optical film can be improved. Peeling can be suppressed.

[0009] In one embodiment of the present invention, the surface protection film is provided with a polarizing film via a second adhesive layer. In another embodiment, the protective film is a self-adhesive film. It is a film.

[0010] In one embodiment of the present invention, the polarizing film includes a polarizer having a thickness of 10 μm or less. Such polarizing films containing polarizers with a thickness of 10 μm or less have a high elastic modulus. As a result, there is no twisting, curling, etc. in the sheet-to-panel method. Therefore, the present invention is particularly suitable for such a polarizing film.

[0011] In one embodiment of the present invention, the release film is peeled off and adhered to one surface of the optical cell. An optical display panel having a structure in which an adhesive layer, a polarizing film, and a surface protection film are laminated in this order. It is used to manufacture fabrics.

[0012] Another invention relates to a method for manufacturing an optical cell, comprising: forming a pressure sensitive adhesive layer, a polarizing film, and a surface protective film on one side of the optical cell; An optical display panel having a configuration in which the following elements are stacked in this order: The polarizing film has a thickness of 60 μm or less, The surface protection film has a thickness of 0.8≦(thickness of surface protection film) / (polarizing film It is an optical display panel that satisfies the above requirements for the thickness of the display.

[0013] In one embodiment of the above invention, the surface protection film has a thickness of The thickness / (polarizing film thickness)≦3.0 is satisfied.

[0014] In one embodiment of the invention, the optical cell is a liquid crystal cell or an organic EL cell. [Brief description of the drawings]

[0015] [Figure 1] Schematic cross-sectional view of optical film in sheet form [Diagram 2] FIG. 4 is a cross-sectional schematic diagram of an optical film in a sheet state according to another embodiment. [Diagram 3] A schematic perspective view of a sheet of optical film attached to an optical cell DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The optical film 10 of the present invention will be described below with reference to FIGS. 1 is a schematic cross-sectional view of a film 10. The optical film 10 includes a release film 15, a first adhesive The layer 11, the polarizing film 12, the second adhesive layer 13 and the surface protection film 14 are laminated in this order. It has a layered structure.

[0017] In another embodiment shown in FIG. 2, the surface protection film 14 is made of a self-adhesive film. The polarizing film 12 is laminated thereon without an adhesive layer.

[0018] <Polarizing film> In the present invention, a polarizing film having a thickness of 60 μm or less is used. From the viewpoint of thinning, the thickness is preferably 55 μm or less, and more preferably 50 μm or less. The polarizing film is preferably, for example, (1) a polarizer having protective films on both sides thereof in this order. (2) A protective film is placed on only one side of the polarizer. Examples of such a structure include a laminated structure (one-sided protective polarizing film).

[0019] (Polarizer) The polarizer used is made of a polyvinyl alcohol resin. For example, polyvinyl alcohol films, partially formalized polyvinyl alcohol films, etc. Hydrophilic polymer films such as partially saponified ethylene-vinyl acetate copolymer films The film is uniaxially stretched after absorbing iodine or a dichroic dye. Examples include dehydrated polyester films, dehydrochlorinated polyvinyl chloride films, and other polyene-based oriented films. Among these, polyvinyl alcohol films and dichroic substances such as iodine are used. A polarizer having the above structure is preferable.

[0020] A polarizer obtained by dyeing a polyvinyl alcohol film with iodine and stretching it uniaxially is, for example, Polyvinyl alcohol is dyed by immersing it in an aqueous solution of iodine, and the film is stretched to 3 to 7 times its original length. It can be made by stretching. If necessary, it may contain boric acid, zinc sulfate, zinc chloride, etc. Alternatively, it may be immersed in an aqueous solution of potassium iodide or the like. If necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. By washing the polyvinyl alcohol film with water, dirt on the surface of the polyvinyl alcohol film can be removed. In addition to being able to clean the anti-blocking agent, polyvinyl alcohol-based film This also has the effect of preventing unevenness in the dyeing by swelling the dye. It may be performed after dyeing, or it may be performed while dyeing, or it may be performed after dyeing with iodine. It can be stretched in aqueous solutions of boric acid and potassium iodide, or in a water bath. .

[0021] The thickness of the polarizer is preferably 10 μm or less from the viewpoint of thinning, and more preferably 8 μm or less. The thickness of the polarizer is preferably 1 μm or less, more preferably 7 μm or less, and even more preferably 6 μm or less. The thickness is preferably 2 μm or more, and more preferably 3 μm or more. It has little thickness unevenness, excellent visibility, and little dimensional change, so it is durable against thermal shock. Excellent performance.

[0022] On the other hand, in polarizing films containing polarizers with a thickness of 10 μm or less, the film's elastic modulus becomes evident. This significantly reduces the temperature, which can cause twisting and curling in the sheet-to-panel system. Therefore, the present invention is particularly suitable for such a polarizing film.

[0023] Representative examples of thin polarizers include: Patent No. 4751486 specification, Patent No. 4751481 specification, Patent No. 4815544 specification, Patent No. 5048120 specification, International Publication No. 2014 / 077599, International Publication No. 2014 / 077636, or a thin polarizer obtained by the manufacturing method described therein. Some examples include:

[0024] The polarizer has optical properties represented by a single transmittance T and a polarization degree P that satisfy the following formula: P>-(10 0.929T-42.4 -1) × 100 (where T<42.3), or It is preferable that the condition P≧99.9 (where T≧42.3) is satisfied. The polarizer configured to satisfy the above conditions is primarily intended for use in a large display device. It has the performance required for LCD TV displays. Ratio of 1000:1 or more and maximum brightness of 500cd / m 2 That's it. Other uses include, for example For example, it is attached to the visible side of an organic EL cell.

[0025] The thin polarizer is produced by a process including a step of stretching a laminate and a step of dyeing the laminate. However, it can be stretched at a high magnification and has improved polarization performance, which is why it is popular with the public. 6, Patent No. 4751481, and Patent No. 4815544 The method of producing the cellulose acylate according to the present invention includes a step of stretching the cellulose acylate in an aqueous solution of boric acid. 4751481 and 4815544, It is preferable that the film is obtained by a process including a step of auxiliary in-air stretching before stretching. The thin polarizer is made of a polyvinyl alcohol resin (hereinafter referred to as PVA resin) layer and a stretching film. It can be obtained by a manufacturing method including a step of stretching a resin substrate in a laminate state and a step of dyeing the same. With this manufacturing method, even if the PVA resin layer is thin, it is supported by the stretchable resin substrate. This makes it possible to perform stretching without problems such as breakage due to stretching.

[0026] (Protective film) The materials that make up the protective film must have transparency, mechanical strength, thermal stability, moisture barrier properties, It is preferable to use a material that has excellent isotropy. For example, polyethylene terephthalate or polyethylene Polyester polymers such as naphthalene, diacetyl cellulose, triacetyl cellulose cellulose-based polymers such as cellulose; acrylic polymers such as polymethyl methacrylate; styrene such as polystyrene and acrylonitrile-styrene copolymer (AS resin) Polyethylene, polypropylene, polycarbonate, etc. Polyolefins having cyclo- or norbornene structures, ethylene / propylene Polyolefin polymers such as pyrene copolymers, vinyl chloride polymers, nylon and aromatic Amide polymers such as aromatic polyamides, imide polymers, sulfone polymers, poly Ethersulfone polymers, polyetheretherketone polymers, polyphenylene Sulfide-based polymers, vinyl alcohol-based polymers, vinylidene chloride-based polymers, vinyl Butyral polymers, arylate polymers, polyoxymethylene polymers, epoxy The polymer forming the protective film may be an oxy-based polymer or a blend of the above polymers. It is cited as an example of a rimmer.

[0027] The protective film may contain one or more suitable additives. Examples of the agents include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, and coloring inhibitors. Examples of the additives include flame retardants, nucleating agents, antistatic agents, pigments, and colorants. The content of the thermoplastic resin is preferably 50 to 100% by weight, more preferably 50 to 99% by weight. %, more preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. When the content of the above thermoplastic resin in the protective film is 50% by weight or less, the thermoplastic resin There is a risk that the inherent high transparency and other properties may not be fully exhibited.

[0028] The protective film may also be a retardation film, a brightness enhancing film, a diffusion film, or the like. There can be.

[0029] The thickness of the protective film is 5 to 50 μm, taking into consideration the strength, ease of handling, thinness, etc. The thickness is preferably equal to or less than this, and more preferably from 5 to 45 μm.

[0030] On the surface of the protective film to which the polarizer is not attached, a hard coat layer, an anti-reflection layer, a stain Functional layers such as an anti-sticking layer, a diffusion layer, or an anti-glare layer can be provided. The above-mentioned hard coat layer, anti-reflection layer, anti-sticking layer, diffusion layer and anti-glare layer The functional layer can be provided on the transparent protective film itself, or it can be provided on a separate transparent protective film. It may also be provided as a separate entity from the film.

[0031] (intervening layer) The protective film and the polarizer are provided with an adhesive layer, a pressure-sensitive adhesive layer, an undercoat layer (primer layer), etc. In this case, it is preferable to laminate the two materials without any air gaps by using an intervening layer. It is.

[0032] The adhesive layer is formed by an adhesive. The type of adhesive is not particularly limited, and various types may be used. The adhesive layer is not particularly limited as long as it is optically transparent. Various types of adhesives are used, including water-based, solvent-based, hot melt-based, and active energy ray-curable types. However, a water-based adhesive or an active energy ray-curable adhesive is preferred.

[0033] Water-based adhesives include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, and Examples of the adhesive include tin adhesives, vinyl latex adhesives, and water-based polyester adhesives. It is usually used as an adhesive consisting of an aqueous solution, and usually contains 0.5 to 60% by weight of solids. It has.

[0034] Active energy ray curing adhesives are made by electron beams, ultraviolet rays (radical curing type, cationic curing type ) are adhesives that cure when exposed to active energy rays, such as electron beam curing, ultraviolet The active energy ray curable adhesive can be, for example, a photocurable adhesive. A radical curing adhesive can be used. Photo-radical curing type active energy ray curing When the adhesive is used as an ultraviolet curing type, the adhesive contains a radical polymerizable compound. and a photopolymerization initiator.

[0035] In addition, when laminating the polarizer and the protective film, there is a transparent protective film and an adhesive layer between them. The adhesive layer may have a polyester backbone, a polyether backbone, or a tertiary ether backbone. Polycarbonate skeleton, Polyurethane skeleton, Silicone, Polyamide skeleton, Poly It can be formed from various resins having a polyimide skeleton, polyvinyl alcohol skeleton, etc. These polymer resins can be used alone or in combination of two or more. In addition, other additives may be added to form the easy-adhesion layer. Stabilizers such as additives, ultraviolet absorbers, antioxidants, and heat stabilizers may also be used.

[0036] The adhesive layer is formed from an adhesive. Various adhesives can be used as the adhesive. For example, rubber-based adhesives, acrylic-based adhesives, silicone-based adhesives, urethane-based adhesives, Vinyl alkyl ether adhesives, polyvinylpyrrolidone adhesives, polyacrylamide Adhesive bases include cellulose-based adhesives and the like. Among the above pressure-sensitive adhesives, a polymer having excellent optical transparency and suitable wettability is selected. Acrylic adhesives are popular because they have excellent adhesive and cohesive properties, and are excellent in weather resistance and heat resistance. An adhesive is preferably used.

[0037] The undercoat layer (primer layer) is formed to improve the adhesion between the polarizer and the protective film. The materials constituting the primer layer are a base film and polyvinyl alcohol. There are no particular limitations on the material as long as it exhibits a relatively strong adhesive force to both the resin layer and the base resin layer. For example, a thermoplastic resin having excellent transparency, thermal stability, stretchability, etc. is used. Examples of the resin include acrylic resin, polyolefin resin, polyester resin, Examples of the resin include polyvinyl alcohol-based resins and mixtures thereof.

[0038] <Surface protection film> The surface protection film is an optical film that is laminated on one side of the polarizing film (with a pressure-sensitive adhesive layer). The surface protection film is 0.8 mm thick and is attached to the polarizing film (the surface that is not covered by the polarizing film). ≦(thickness of surface protective film) / (thickness of polarizing film), and thus the sheet This improves the handling of optical films in panel-to-panel systems. Surface In order to strengthen the elasticity (modulus) of the entire optical film, the protective film is made of 1.0≦( It is preferable that the thickness of the polarizing film satisfies the following relationship: (thickness of surface protective film) / (thickness of polarizing film). On the other hand, the thicker the surface protection film, the more difficult it is to remove the surface protection film from the optical display panel. When peeling from the optical film, the initial peeling becomes difficult (peelability becomes poor), and the interlayer Since there is a risk of peeling, the surface protection film should be (protection film thickness / polarizing filter It is preferable that the ratio of the thickness of the protective film to the thickness of the polarizing film is ≦3.0. It is preferable that the thickness of the film) is ≦2.5.

[0039] The surface protection film is laminated to the polarizing film via an adhesive layer, or is self-adhesive. It is composed of a type of film and is laminated onto a polarizing film without an adhesive layer. From the viewpoint of protecting the polarizing film, it is laminated to the polarizing film via an adhesive layer ( As a surface protection film, isotropic is preferable from the viewpoint of inspection and management. A film material having a uniform thickness or close to isotropy is selected. For example, polyester resins such as polyethylene terephthalate film, cellulose resins, Acetate resin, polyethersulfone resin, polycarbonate resin, polyamide Transparent resins such as polyimide resins, polyolefin resins, and acrylic resins. Ma Among these, polyester resins are preferred. The surface protection film is It may also be used as a laminate of one or more film materials, and A stretched film can also be used. The thickness of the surface protection film is 0.8≦(surface protection There are no particular limitations as long as the ratio (thickness of protective film) / (thickness of polarizing film) is satisfied, but it is preferable that the thickness is 35 It is preferable that the thickness is from 38 μm to 100 μm or less, and more preferably from 38 μm to 100 μm or less. It is preferable that:

[0040] The adhesive used for laminating the surface protection film includes (meth)acrylic polymers, Silicone polymers, polyesters, polyurethanes, polyamides, polyethers, fluorines Appropriately select and use adhesives that have polymers such as silicones or rubbers as the base polymer. From the viewpoints of transparency, weather resistance, heat resistance, etc., acrylic polymers are used as the base polymer. The thickness of the adhesive layer (dry film thickness) is determined based on the required adhesiveness. The thickness is determined depending on the adhesion, and is usually about 1 to 100 μm, preferably 5 to 50 μm.

[0041] The surface protection film is provided with a silicone-treated, long-chain A release treatment layer can be provided using low-adhesion materials such as alkyl-treated or fluorine-treated. .

[0042] <Adhesive layer> To form the adhesive layer, any suitable adhesive can be used, and there is no particular limitation on the type of adhesive. Adhesives include rubber adhesives, acrylic adhesives, silicone adhesives, and urethane adhesives. vinyl alkyl ether adhesives, polyvinyl alcohol adhesives, polyvinyl Examples include diphenylpyrrolidone adhesives, polyacrylamide adhesives, and cellulose adhesives. can be done.

[0043] Among these adhesives, adhesives having excellent optical transparency, appropriate wettability, cohesiveness, and adhesiveness are preferred. Those that exhibit such characteristics and have excellent weather resistance and heat resistance are preferably used. As a material exhibiting this property, an acrylic adhesive is preferably used.

[0044] The method for forming the adhesive layer can be, for example, a method for forming the adhesive layer by using a release film ( The adhesive layer is formed by applying it to a separator, drying and removing the polymerization solvent, etc., and then the adhesive layer is formed as shown in Figure 2( In the embodiment of A), the film is transferred to a polarizer (or to a transparent protective film in the embodiment of FIG. 2(B)). 2(A) (or a transparent protective film in the embodiment of FIG. 2(B)). and then drying and removing the polymerization solvent, etc., to form an adhesive layer on the polarizer. In addition, when applying the adhesive, at least one solvent other than the polymerization solvent may be used. Fresh addition of the above solvent may be made.

[0045] As the release-treated release film, a silicone release liner is preferably used. In the process of forming a pressure-sensitive adhesive layer by applying the pressure-sensitive adhesive of the present invention onto such a liner and drying it, In this case, as a method for drying the adhesive, a suitable method can be adopted depending on the purpose. Preferably, the coating film is dried by heating. The temperature is preferably 40° C. to 200° C., more preferably 50° C. to 180° C., and particularly preferably By setting the heating temperature in the above range, excellent adhesive properties can be obtained. It is possible to obtain a pressure-sensitive adhesive having the above properties.

[0046] The drying time can be appropriately selected. The drying time is preferably 5 seconds to 2 seconds. The time is preferably 0 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

[0047] The pressure-sensitive adhesive layer can be formed by various methods. , kiss roll coat, gravure coat, reverse coat, roll brush, spray Coating, dip roll coating, bar coating, knife coating, air knife coating, Examples of methods include ten-coating, lip-coating, and extrusion coating using a die coater. can be done.

[0048] The thickness of the pressure-sensitive adhesive layer is not particularly limited, and is, for example, about 1 to 100 μm. The thickness is preferably 2 to 50 μm, more preferably 2 to 40 μm, and even more preferably 5 to 35 μm. be.

[0049] <Release film> The release film protects the adhesive layer until it is put to practical use. Examples of such materials include polyethylene, polypropylene, polyethylene terephthalate, and polyethylene. Plastic films such as sterilized film, paper, cloth, porous materials such as nonwoven fabric, nets Examples of suitable thin sheets include foam sheets, metal foils, and laminates thereof. However, a plastic film is preferably used because of its excellent surface smoothness.

[0050] The plastic film is particularly preferably a film capable of protecting the adhesive layer. Examples of the film include, but are not limited to, polyethylene film, polypropylene film, polybutene film, etc. Film, polybutadiene film, polymethylpentene film, polyvinyl chloride film , vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film Polyurethane film, ethylene-vinyl acetate copolymer film Some examples include:

[0051] The thickness of the release film is usually 5 to 200 μm, preferably 5 to 100 μm, and more preferably The thickness is preferably 5 to 50 μm. The separator may be made of a silicone-based material or a fluororesin-based material, if necessary. Fluorine-based, long-chain alkyl-based or fatty acid amide-based release agents, silica powder, etc. It is also possible to carry out antifouling treatment, and antistatic treatment such as coating, kneading, and deposition. The surface of the release film is treated with silicone, long-chain alkyl, fluorine, or the like. By appropriately performing a release treatment, the releasability from the pressure-sensitive adhesive layer can be further improved. .

[0052] The optical display panel of the present invention will be described below with reference to FIG. 3. FIG. 3 shows an optical cell C FIG. 1 is a schematic perspective view of an optical film 10 in a sheet state attached to one main body of an optical cell C. The optical film 10 is provided in a sheet state on the surface. The length of the first side of the main surface of the optical cell C is When x1 and y1 are the length of the second side perpendicular to the first side, the sheet-shaped optical film 10 When the length of the first side is x2 and the length of the second side perpendicular to the first side is y2, x1>x2, y1> y2. This relationship is the relationship of the optical film corresponding to the main surface size of the optical cell of the present invention. However, the present invention is not limited to this, and the relationship may be x1=x2, y1=y2. In this case, x1>y1, but this is not limited, and x1=y2 or x1 <y1であっ This is also fine.

[0053] Even if the polarizing film 12 is thin, the surface protection film 14 is thick, so that the polarizing film 12 is thin. In the panel-to-panel method, the single-sheet state of this embodiment can be achieved without impairing handling. The optical film 10 can be preferably attached to the optical cell C.

[0054] That is, the first adhesive layer 11, the polarizing film 12, the second adhesive layer 13, the third adhesive layer 14, the fourth adhesive layer 15, the fourth adhesive layer 16, the fifth adhesive layer 17, the fifth adhesive layer 18, the fifth adhesive layer 19, the sixth ... 2. An optical display panel having a pressure-sensitive adhesive layer 13 and a surface protection film 14 laminated in this order. In the manufacturing process, the optical film 10 of the present embodiment in a sheet state can be suitably used. The optical filter from which the release film 15 has been peeled off by a panel-to-panel type lamination device. The film 10 is bonded to the optical cell C.

[0055] <Optical cell> (Liquid crystal cells, liquid crystal display panels) The liquid crystal cell is formed by a pair of substrates (a first substrate (the viewing side) Pa and a second substrate (the back side)) that are arranged opposite to each other. The liquid crystal layer is sealed between the Pb) and the liquid crystal cell. However, to achieve high contrast, the vertical alignment (VA) mode and in-plane switching are required. It is preferable to use a liquid crystal cell in an in-plane switching (IPS) mode. A polarizing film is attached to one or both sides of the crystal cell, and it can be driven as needed. The circuit is installed.

[0056] (Organic EL cells, organic EL display panels) Organic EL cells, which are another type of optical cell, are configured with an electroluminescent layer sandwiched between a pair of electrodes. Organic EL cells are available in a variety of types, including top emission, bottom emission, and double emission. Any type of organic EL display panel, such as blue emission type, can be used. The panel is made of an organic EL cell with a polarizing film attached to one or both sides. A drive circuit is incorporated as required. EXAMPLES

[0057] The present invention will be described below with reference to examples, but the present invention is not limited to the examples shown below. In addition, all parts and percentages in each example are by weight. The room temperature storage conditions for all samples were 23°C and 65% RH.

[0058] <Polarizing film> (Preparation of polarizer A0) Amorphous isophthalic acid copolymerized polyethylene terephthalate with a water absorption rate of 0.75% and a Tg of 75°C. One side of the base material (IPA copolymerized PET) film (thickness: 100 μm) is corona-treated. Then, polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2) was applied to the corona-treated surface. mol%) and acetoacetyl-modified PVA (polymerization degree 1200, acetoacetyl-modification degree 4. 6%, saponification degree 99.0 mol% or more, product name "GOHSEFYMER" manufactured by Nippon Synthetic Chemical Industry Co., Ltd. A 9:1 ratio aqueous solution of 11μm-thick 100% ethylenediaminetetraacetate (Z200) was applied at 25°C and dried to form a 11μm-thick film. A PVA-based resin layer was formed to prepare a laminate. The obtained laminate was then rolled in the machine direction (longitudinal direction) between rolls with different peripheral speeds in an oven at 120°C. ) and then uniaxially stretched at the free end to 2.0 times the original size (air-assisted stretching treatment). Next, the laminate was placed in an insolubilizing bath (4 parts by weight of boric acid per 100 parts by weight of water) at a liquid temperature of 30°C. The mixture was immersed in an aqueous solution of boric acid obtained by mixing the above two parts for 30 seconds (insolubilization treatment). Next, the polarizing plate is immersed in a dye bath at a liquid temperature of 30°C, and the iodine concentration and immersion time are adjusted so that the polarizing plate has a predetermined transmittance. The immersion time was adjusted. In this example, iodine was added at 0. 2 parts by weight of potassium iodide and 1.0 part by weight of potassium iodide were added to the iodine aqueous solution obtained, and the mixture was left for 60 seconds. The fabric was then soaked for 10 minutes (dyeing treatment). Next, a crosslinking bath (containing 3 parts by weight of potassium iodide per 100 parts by weight of water) with a liquid temperature of 30°C was added. The mixture was mixed with 3 parts by weight of boric acid to obtain an aqueous solution of boric acid, and the mixture was immersed for 30 seconds (crosslinking treatment). reason). Thereafter, the laminate was immersed in a boric acid solution (4 parts by weight of boric acid per 100 parts by weight of water) at a liquid temperature of 70°C. parts by weight and 5 parts by weight of potassium iodide) The film is uniaxially stretched between rolls with different peripheral speeds so that the total stretch ratio is 5.5 times in the longitudinal direction. The film was stretched in water (stretching treatment in water). Thereafter, the laminate was placed in a cleaning bath (4 parts by weight of potassium iodide per 100 parts by weight of water) at a liquid temperature of 30°C. The mixture was immersed in an aqueous solution obtained by mixing 10 parts by weight of the mixture (cleaning treatment). In this manner, an optical film laminate including a polarizer having a thickness of 5 μm was obtained.

[0059] (Creating protective film) Protective film: A (meth)acrylic resin film having a lactone ring structure with a thickness of 40 μm. The adhesion-promoting surface of the film was subjected to corona treatment before use.

[0060] (Preparation of adhesive to be applied to protective film) N-Hydroxyethylacrylamide (HEAA) 40 parts by weight and acryloylmorpholin 60 parts by weight of ACMO and 3 parts by weight of photoinitiator "IRGACURE 819" (BASF) The weight parts were mixed to prepare an ultraviolet-curing adhesive.

[0061] (Preparation of Polarizing Film A) The above ultraviolet-curable adhesive is cured on one surface of the polarizer A0 of the above optical film laminate. The protective film is laminated while applying the adhesive so that the thickness of the adhesive layer is 0.5 μm. After that, ultraviolet rays were applied as active energy rays to harden the adhesive. , gallium-filled metal halide lamp, irradiation equipment: Fusion UV Systems ,Inc. Light HAMMER10, bulb: V bulb, peak illuminance: 160 0mW / cm2, cumulative irradiation amount 1000 / mJ / cm2 (wavelength 380~440nm) The UV light intensity was measured using the Sola-Check system manufactured by Solatell. Next, the amorphous PET substrate was peeled off to prepare polarizing film A using a thin polarizer. The optical properties of the obtained polarizing film A were a single transmittance of 42.8% and a polarization degree of 99.9%. The thickness of the polarizing film A was 45.5 μm.

[0062] (Preparation of Polarizing Film B) In the same manner as the polarizing film A, the polarizer A0 was The above transparent protective film was attached to both sides. Optical properties of the obtained polarizing film B with one side protected The transmittance was 42.8% and the polarization degree was 99.99%. The thickness of the polarizing film B was 86 μm. m.

[0063] <Formation of adhesive layer> Into a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer, and a stirrer, 100 g of butyl acrylate was added. 0 parts, acrylic acid 3 parts, 2-hydroxyethyl acrylate 0.1 parts and 2,2'-azo A solution was prepared by adding 0.3 parts of bisisobutyronitrile together with ethyl acetate. The solution was stirred while blowing in nitrogen gas and reacted at 55°C for 8 hours to obtain the weight average molecular weight A solution containing an acrylic polymer having a mass of 2.2 million was obtained. Acrylic polyamide resin containing ethyl acetate was added to the solution to adjust the solids concentration to 30%. A mer solution was obtained.

[0064] 0.5 parts of ethylenediaminetetraacetate (I) as a crosslinking agent for 100 parts of the solid content of the acrylic polymer solution A crosslinking agent whose main component is a compound having a socyanate group (manufactured by Nippon Polyurethane Co., Ltd., product (Product name: Coronate L) and 0.075 parts of γ-glycidyl ether as a silane coupling agent. Dipropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., product name "KMB-403") and The adhesive solution was mixed in this order to prepare an adhesive solution. Surface of release film (separator) made of polyethylene terephthalate film (thickness 38 μm) The adhesive layer (first adhesive layer) is then applied to the first adhesive layer so that the thickness after drying is 25 μm. (corresponding to

[0065] <Preparation of Adhesive Layer-Attached Polarizing Film A1> Next, the release-treated surface of the release film (separator) is attached to the polarizer side of the polarizing film A. The pressure-sensitive adhesive layer formed on the polarizing film was attached to the polarizing film to prepare a pressure-sensitive adhesive layer-attached polarizing film. The thickness of the optical film A1 is 45.5+25+38=108.5 μm.

[0066] <Lamination of surface protection film> The surface protection film is a polyester resin film manufactured by Nitto Denko Corporation, product name RP301. The thicknesses were 25 μm, 38 μm, 50 μm, 75 μm, 100 μm, and 150 μm. The thickness of the adhesive layer (corresponding to the second adhesive layer) was 21 μm. m.

[0067] Example 1 The optical film in the sheet state of Example 1 was attached to the pressure-sensitive adhesive layer-attached polarizing film A1 with a thickness of 38 mm. The structure is one in which a surface protection film of 300 μm is laminated. (Thickness of surface protection film) / (Thickness of polarizing film)=38 / 45.5=0.84( Round off to the nearest third place, and so on.) Trigger peel force = 0.3 [N / 15 mm] The initial peel strength is measured as follows. , 15mm x 100mm (absorption axis direction is 50mm) and 100mm x 15mm (absorption axis direction is 50mm) The cellophane was cut into pieces (100 mm thick) and each piece was attached to a 0.5 mm thick non-alkali glass sheet. The tape is attached to the short edge of the optical film laminated to the non-alkali glass, and then the tape is attached to the short edge of the optical film laminated to the non-alkali glass. The surface protection film was peeled off at 180° peel speed of 0.3 m / min using a ron. The peak value of the peeling force at that time was taken as the "initial peeling force." (absorption axis direction is 50mm) and 100mm x 15mm (absorption axis direction is 100mm) The initial peel strength was measured and the average value was used. The initial peel strength was measured at room temperature.

[0068] Example 2 The optical film in the sheet state of Example 2 was attached to the pressure-sensitive adhesive layer-attached polarizing film A1 with a thickness of 50 mm. The structure is one in which a surface protection film of 300 μm is laminated. (Thickness of surface protection film) / (Thickness of polarizing film)=50 / 45.5=1.10 Trigger peel force = 0.7 [N / 15mm]

[0069] Example 3 The optical film in the sheet state of Example 3 was attached to the pressure-sensitive adhesive layer-attached polarizing film A1 with a thickness of 75 mm. The structure is one in which a surface protection film of 300 μm is laminated. (Thickness of surface protection film) / (Thickness of polarizing film)=75 / 45.5=1.65 Trigger peel force = 1.5 [N / 15mm]

[0070] Example 4 The optical film in the sheet state of Example 4 was attached to the pressure-sensitive adhesive layer-attached polarizing film A1 with a thickness of 10 The structure is laminated with a surface protection film of 0 μm. (Thickness of surface protection film) / (Thickness of polarizing film)=100 / 45.5=2.20 Trigger peel force = 2.5 [N / 15mm]

[0071] Example 5 The optical film in the sheet state of Example 5 was attached to the pressure-sensitive adhesive layer-attached polarizing film A1 with a thickness of 15 mm. The structure is laminated with a surface protection film of 0 μm. (Thickness of surface protection film) / (Thickness of polarizing film)=150 / 45.5=3.30 Trigger peel force = 5.0 [N / 15mm]

[0072] Comparative Example 1 The optical film in the sheet state of Comparative Example 1 was attached to the pressure-sensitive adhesive layer-attached polarizing film A1 with a thickness of 25 mm. The structure is one in which a surface protection film of 300 μm is laminated. (Thickness of surface protection film) / (Thickness of polarizing film)=25 / 45.5=0.55 Trigger peel force = 0.2 [N / 15 mm]

[0073] <Preparation of pressure-sensitive adhesive layer-attached polarizing film B1> Next, the release-treated surface of the release film (separator) is attached to the polarizer side of the polarizing film B. The pressure-sensitive adhesive layer formed on the polarizing film was attached to the polarizing film to prepare a pressure-sensitive adhesive layer-attached polarizing film. The thickness of the optical film B1 is 86+25+38=149 μm.

[0074] (Reference example 1) The optical film in the sheet state of Reference Example 1 was attached to the pressure-sensitive adhesive layer-attached polarizing film B1 with a thickness of 38 mm. The structure is one in which a surface protection film of 300 μm is laminated. (Thickness of surface protection film) / (Thickness of polarizing film)=38 / 86=0.44 Trigger peel force = 0.3 [N / 15 mm]

[0075] (Reference example 2) The optical film in the sheet state of Reference Example 2 was attached to the pressure-sensitive adhesive layer-attached polarizing film B1 with a thickness of 20 The structure is laminated with a surface protection film of 0 μm. (Thickness of surface protection film) / (Thickness of polarizing film)=200 / 86=2.33 Trigger peel force = 5.0 [N / 15mm]

[0076] Using a sheet-to-panel type device, the above-mentioned Examples 1 to 5, Comparative Example 1, Reference Example 1, and After removing the release film, the optical film in the sheet state of 2 is placed on a glass plate (optical cell). As a result, the optical fibers in the sheet state of Examples 1 to 5 were bonded to each other (replacement products) (n=100 times). The film had no problems with handling and could be favorably attached to the optical cell. However, in Example 5, the surface protective film was peeled off from the optical film attached to the glass plate. When peeling the film, the peeling was heavy and the polarizing film delaminated between the layers. In Comparative Examples 1 and 2, the polarizing film was thick, so the overall size was thick. The optical film in the sheet state in 2 is difficult to handle, and it is difficult to bond it to the optical cell with precision. The results showed that 30% of the products were defective. [Explanation of symbols]

[0077] 10 Optical film sheets 11 First adhesive layer 12 Polarizing film 13 Second adhesive layer 14 Surface protection film 15 Release film C Optical Cell

Claims

1. A sheet-like optical film having a configuration in which a release film, a first pressure-sensitive adhesive layer, a polarizing film, and a surface protective film are laminated in this order, the surface protection film is laminated to the polarizing film via a second adhesive layer or a self-adhesive film, The polarizing film has a polarizer and protective films provided on both sides of the polarizer, and the polarizing film has a thickness of 90 μm or less, provided that a brightness enhancement film is excluded from the configuration of the polarizing film; the surface protection film has a thickness that satisfies the relational expression 0.4≦(thickness of surface protection film) / (thickness of polarizing film)≦2.4; The optical film in a sheet state is cut into 15 mm x 100 mm (absorption axis direction is 15 mm) and 100 mm x 15 mm (absorption axis direction is 100 mm), each of which is laminated to a 0.5 mm thick alkali-free glass, cellophane tape is attached to the short side edge of the optical film laminated to the alkali-free glass, and the surface protective film is peeled off using a Tensilon at a 180° peel speed of 0.3 m / min, resulting in a peak value of the peel force (initial peel force) of 0.3 to 5.0 [N / 15 mm].

2. The sheet-like optical film according to claim 1 , wherein the polarizing film comprises a polarizer having a thickness of 10 μm or less.

3. 3. The sheet-like optical film according to claim 1 or 2, which is used to manufacture an optical display panel in which the release film is peeled off and a sheet-like optical film having a structure in which an adhesive layer, a polarizing film, a surface protective film and a release treatment layer are laminated in this order on one side of an optical cell is provided.

4. An optical display panel in which a sheet-like optical film is provided on one surface of an optical cell, the sheet-like optical film having a configuration in which a first pressure-sensitive adhesive layer, a polarizing film, and a surface protective film are laminated in this order, the surface protection film is laminated to the polarizing film via a second adhesive layer or a self-adhesive film, The polarizing film has a polarizer and protective films provided on both sides of the polarizer, and the polarizing film has a thickness of 90 μm or less, provided that a brightness enhancement film is excluded from the configuration of the polarizing film; the surface protection film has a thickness that satisfies the relational expression 0.4≦(thickness of surface protection film) / (thickness of polarizing film)≦2.4; The optical film in a sheet state is cut into 15 mm x 100 mm (absorption axis direction is 15 mm) and 100 mm x 15 mm (absorption axis direction is 100 mm), each of which is laminated to a 0.5 mm thick non-alkali glass, cellophane tape is attached to the short side edge of the optical film laminated to the non-alkali glass, and the surface protective film is peeled off using a Tensilon at a 180° peel speed of 0.3 m / min, resulting in a peak peel force (initial peel force) of 0.3 to 5.0 [N / 15 mm].

5. 5. The optical display panel according to claim 4, wherein the optical cell is a liquid crystal cell or an organic EL cell.

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