WO2023189811A1 - Polarizing film, layered polarizing film, image display panel, and image display device - Google Patents

Polarizing film, layered polarizing film, image display panel, and image display device Download PDF

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Publication number
WO2023189811A1
WO2023189811A1 PCT/JP2023/010848 JP2023010848W WO2023189811A1 WO 2023189811 A1 WO2023189811 A1 WO 2023189811A1 JP 2023010848 W JP2023010848 W JP 2023010848W WO 2023189811 A1 WO2023189811 A1 WO 2023189811A1
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Prior art keywords
polarizing film
film
transparent protective
protective film
image display
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PCT/JP2023/010848
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French (fr)
Japanese (ja)
Inventor
慎太朗 三木
勝則 高田
亮 菅野
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日東電工株式会社
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Publication of WO2023189811A1 publication Critical patent/WO2023189811A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/80—Constructional details
    • H10K50/86—Arrangements for improving contrast, e.g. preventing reflection of ambient light
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays

Definitions

  • the present invention relates to a polarizing film, a laminated polarizing film, an image display panel, and an image display device.
  • polarizing films used in various image display devices such as liquid crystal display devices and organic EL display devices have been dyed (using iodine, dichroic dyes, etc.) because they have both high transmittance and high degree of polarization.
  • a polyvinyl alcohol film (containing a dichroic substance) is used.
  • the polarizing film is manufactured by subjecting a polyvinyl alcohol film to various treatments such as swelling, dyeing, crosslinking, and stretching in a bath, followed by washing and drying.
  • the polarizing film is usually used as a polarizing film (polarizing plate) in which a transparent protective film such as triacetyl cellulose is bonded to one or both sides of the polarizing film using an adhesive.
  • the polarizing film is used as a laminated polarizing film (optical laminate) by laminating other optical layers as necessary, and the polarizing film or the laminated polarizing film (optical laminate) is used as a liquid crystal cell or an organic laminate. It is used as an image display panel bonded to an image display cell such as an EL element, and further, the image display panel is attached to a front transparent plate (window layer), a touch panel, etc. on the viewing side via an adhesive layer or an adhesive layer. It is bonded to the front transparent member of and used as the various image display devices mentioned above (Patent Document 1).
  • an object of the present invention is to provide a polarizing film that can suppress curling.
  • Another object of the present invention is to provide a laminated polarizing film, an image display panel, and an image display device using the above polarizing film.
  • the present invention provides a polarizing film constituting an image display panel, wherein the polarizing film includes, in order, a first transparent protective film, a polarizing film, and a second transparent protective film, and At least one of the first transparent protective film and the second transparent protective film is directly bonded to the polarizing film without an adhesive layer or an adhesive layer, and the first transparent protective film
  • the film is a transparent protective film on the viewing side, and relates to a polarizing film whose thickness is thinner than the thickness of the second transparent protective film.
  • the present invention also relates to a laminated polarizing film in which the polarizing film is bonded to an optical layer.
  • the present invention also relates to an image display panel in which the side of the polarizing film opposite to the viewing side of the polarizing film, or the side opposite to the viewing side of the polarizing film of the laminated polarizing film is bonded to an image display cell.
  • the present invention also relates to an image display device including a front transparent member on the polarizing film or laminated polarizing film side of the image display panel.
  • the polarizing film of the present invention is a polarizing film constituting an image display panel, and the polarizing film is provided with a first transparent protective film, a polarizing film, and a second transparent protective film in this order, At least one of the first transparent protective film and the second transparent protective film is directly bonded to the polarizing film without using an adhesive layer or an adhesive layer, and
  • the protective film is a transparent protective film on the viewing side, and is thinner than the second transparent protective film, so the presence of adhesive will reduce the effects of distortion due to shrinkage, especially if the protective film on the viewing side is thin. However, by not using an adhesive, it is possible to reduce the shrinkage force and prevent curling.
  • FIG. 1 is a schematic cross-sectional view showing one form of a polarizing film. 1 is a schematic cross-sectional view showing one form of an image display panel and an image display device.
  • FIG. 1 is a schematic cross-sectional view showing one form of the polarizing film of the present invention.
  • a polarizing film in which a first transparent protective film 12, a polarizing film 11, and a second transparent protective film 13 on the viewing side are directly joined in this order without using an adhesive layer or a pressure-sensitive adhesive layer. 10 is shown.
  • FIG. 2 is a schematic cross-sectional view showing one form of the image display panel and image display device of the present invention.
  • FIG. 2 shows an embodiment of an image display panel 100 in which the opposite side of the polarizing film 10 to the viewing side of the polarizing film is bonded to the image display cell 90 via an adhesive layer or an adhesive layer 30.
  • FIG. 2 shows one embodiment of an image display device 200 that includes a front transparent member 80 on the polarizing film side of the image display panel 100 via an adhesive layer or an adhesive layer 20.
  • the polarizing film of the present invention is a polarizing film constituting an image display panel, and the polarizing film is provided with a first transparent protective film, a polarizing film, and a second transparent protective film in this order, At least one of the first transparent protective film and the second transparent protective film is directly bonded to the polarizing film without using an adhesive layer or an adhesive layer, and
  • the protective film is a transparent protective film on the viewing side, and has a thickness thinner than the thickness of the second transparent protective film. Note that the viewing side (viewing surface) means the viewing side of the image display panel.
  • the polarizing film is formed by adsorbing and aligning a dichroic substance such as iodine or a dichroic dye onto a polyvinyl alcohol film.
  • the polarizing film is preferably an iodine-based polarizing film containing iodine as the dichroic substance from the viewpoint of initial polarization performance of the polarizing film.
  • the polyvinyl alcohol (PVA)-based film can be used without any particular restriction, as long as it has transparency in the visible light region and disperses and adsorbs dichroic substances such as iodine and dichroic dyes.
  • the material for the polyvinyl alcohol film include polyvinyl alcohol or derivatives thereof.
  • the polyvinyl alcohol derivatives include polyvinyl formal, polyvinyl acetal; olefins such as ethylene and propylene; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and those modified with their alkyl esters, acrylamide, etc. can be mentioned.
  • the average degree of polymerization of the polyvinyl alcohol is preferably about 100 to 10,000, more preferably about 1,000 to 10,000, and even more preferably about 1,500 to 4,500.
  • the saponification degree of the polyvinyl alcohol is preferably about 80 to 100 mol%, more preferably about 95 mol% to 99.95 mol%.
  • the said average polymerization degree and the said saponification degree can be calculated
  • the polarizing film is obtained by a conventional polarizing film manufacturing method, for example, by subjecting the polyvinyl alcohol film to an optional swelling process and washing process, and at least a dyeing process, a crosslinking process, and a stretching process. .
  • the thickness of the polarizing film is preferably 1 ⁇ m or more, more preferably 2 ⁇ m or more, from the viewpoint of improving the initial polarization degree of the polarizing film, and 15 ⁇ m or less from the viewpoint of preventing panel warpage.
  • the thickness is preferably 10 ⁇ m or less, more preferably 8 ⁇ m or less.
  • the following thin film is used, in which a laminate including a polyvinyl alcohol resin layer formed on a thermoplastic resin base material is used as the polyvinyl alcohol film. A method for manufacturing a polarizing film can be applied.
  • the polarizing film is obtained by a conventional polarizing film manufacturing method.
  • the first transparent protective film is a transparent protective film on the viewing side, and is thinner than the second transparent protective film. Note that, hereinafter, either the first transparent protective film or the second transparent protective film will also be simply referred to as a transparent protective film.
  • the thickness of the first transparent protective film can be determined as appropriate, but from the viewpoint of mechanical strength of the polarizing film, it is preferably 1 ⁇ m or more, more preferably 3 ⁇ m or more, and 5 ⁇ m or more. Further, from the viewpoint of making the polarizing film thinner, it is preferably 50 ⁇ m or less, more preferably 30 ⁇ m or less, and even more preferably 20 ⁇ m or less. Further, the thickness of the second transparent protective film can be determined as appropriate, but from the viewpoint of mechanical strength of the polarizing film, it is preferably 10 ⁇ m or more, more preferably 20 ⁇ m or more, and From the viewpoint of making the polarizing film thinner, the thickness is preferably 100 ⁇ m or less, more preferably 40 ⁇ m or less.
  • the ratio of the thickness of the second transparent protective film to the thickness of the first transparent protective film is 1. It is preferably 2 or more, more preferably 1.5 or more, and from the viewpoint of thinning, it is preferably 10.0 or less, and more preferably 5.0 or less.
  • the first and second transparent protective films are not particularly limited, and various transparent protective films used for polarizing films can be used.
  • a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc. is used.
  • the thermoplastic resin include cellulose ester resins such as triacetylcellulose, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyether sulfone resins, polysulfone resins, polycarbonate resins, nylon, and aromatic resins.
  • Polyamide resins such as group polyamides, polyimide resins, polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers, (meth)acrylic resins, cyclic polyolefin resins having a cyclo or norbornene structure (norbornene resins) ), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof.
  • the transparent protective film may include a cured layer formed from a thermosetting resin or an ultraviolet curable resin such as (meth)acrylic, urethane, acrylic urethane, epoxy, silicone, or the like.
  • cellulose ester resins, polycarbonate resins, (meth)acrylic resins, cyclic polyolefin resins, and polyester resins are preferred.
  • a retardation plate having a front retardation of 40 nm or more and/or a thickness direction retardation of 80 nm or more can be used.
  • the frontal retardation is usually controlled in the range of 40 to 200 nm
  • the thickness direction retardation is usually controlled in the range of 80 to 300 nm.
  • the retardation plate also functions as a transparent protective film, so that it is possible to reduce the thickness.
  • the retardation plate examples include a birefringent film formed by uniaxially or biaxially stretching a polymer material, an oriented film of a liquid crystal polymer, and an oriented layer of a liquid crystal polymer supported by a film.
  • the thickness of the retardation plate is not particularly limited, but is generally about 1 to 150 ⁇ m.
  • the phase plate may be used by bonding it to a transparent protective film that does not have a phase difference.
  • the transparent protective film may contain any suitable additives such as ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, color inhibitors, flame retardants, antistatic agents, pigments, colorants, etc. You can stay there. In particular, when the transparent protective film contains an ultraviolet absorber, the light resistance of the polarizing film can be improved.
  • a hard coat layer such as a hard coat layer, an anti-reflection layer, an anti-sticking layer, a diffusion layer or an anti-glare layer can be provided on the surfaces of the first and second transparent protective films on which the polarizing film is not attached.
  • a hard coat layer such as a hard coat layer, an anti-reflection layer, an anti-sticking layer, a diffusion layer or an anti-glare layer
  • other layers such as the hard coat layer, anti-reflection layer, anti-sticking layer, diffusion layer, and anti-glare layer can be provided on the protective film itself, or may be provided separately from the protective film. You can also do it.
  • At least one of the first transparent protective film and the second transparent protective film is directly bonded to the polarizing film without using an adhesive layer or an adhesive layer.
  • the methods of directly bonding at least one of the first transparent protective film and the second transparent protective film to the polarizing film without using an adhesive layer or an adhesive layer include a pressure bonding method, an ultraviolet ray , a method of bonding by irradiating energy rays such as electron beams, etc.
  • the bonding surface of either or both of the transparent protective film and the polarizing film may be A preferred method is to perform surface treatment by irradiating ultraviolet light, then bonding through a volatile medium, and then drying the volatile medium.
  • the presence of the volatile medium allows for close adhesion to the bonding surfaces without air bubbles, etc., and furthermore, drying the volatile medium significantly increases the adhesive strength of the bonding surfaces (interfaces).
  • the ultraviolet light preferably has a wavelength of 250 to 100 nm, more preferably 200 to 100 nm, and particularly preferably 172 nm using a xenon excimer lamp from the viewpoint of mass productivity.
  • the illumination intensity of the ultraviolet light is preferably 1 mW/cm 2 or more, more preferably 50 mW/cm 2 or more from the viewpoint of processing capacity.
  • the cumulative light amount is preferably 1 mJ/cm 2 or more from the viewpoint of adhesiveness, more preferably 50 mJ/cm 2 or more, and 5000 mJ/cm 2 or less from the viewpoint of damage to the film. It is preferable that it is, and it is more preferable that it is 2000 mJ/cm 2 or less.
  • the temperature at the time of ultraviolet light irradiation is not particularly limited, and from the viewpoint of stabilizing surface modification, it is preferably about 0 to 50 °C, more preferably about 10 to 40 °C, and the polarizing film For production purposes, it is convenient to use room temperature. Further, the atmosphere during ultraviolet light irradiation only needs to have an oxygen concentration of 21% or less, and from the viewpoint of processing efficiency, the oxygen concentration is preferably 7.0% or less.
  • the volatile medium is not particularly limited, and from the viewpoint of drying efficiency, solvents such as water, ethanol, toluene, cyclohexane, acetone, etc. are preferred, and from the viewpoint of the environment, water is more preferred.
  • the heating temperature may be sufficient as long as it can appropriately dry the volatile medium; for example, when the volatile medium is water, it is preferably about 40 to 80°C, more preferably about 50 to 70°C. .
  • the drying time cannot be absolutely determined because it is affected by the temperature of the polarizing film, it is preferably about 1 minute to 60 minutes, more preferably about 3 minutes to 15 minutes.
  • the drying step may be performed only once, or may be performed multiple times as necessary.
  • the above lamination can be performed using a roll laminator or the like.
  • the bonding interface between the polarizing film and the transparent protective film may include a modified layer or a high elastic layer resulting from the treatment during bonding.
  • the adhesive force (peel strength) at the bonding surface between the transparent protective film and the polarizing film is 0.5 N/min when peel strength is measured at a peel angle of 90° and a peel speed of 1000 mm/min. It is preferably 15 mm or more, more preferably 1.0 N/15 mm or more, even more preferably 1.2 N/15 mm or more, even more preferably 2.0 N/15 mm or more.
  • the other surface of the polarizing film that is not the bonded surface may be directly bonded to the transparent protective film as described above without using an adhesive layer or an adhesive layer.
  • the above-mentioned transparent protective film may be bonded via a pressure-sensitive adhesive layer or an adhesive layer.
  • various adhesives used in polarizing films can be used, such as rubber adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, vinyl adhesives, etc.
  • Examples include alkyl ether adhesives, polyvinyl alcohol adhesives, polyvinylporolidone adhesives, polyacrylamide adhesives, cellulose adhesives, and the like.
  • acrylic adhesives are preferred.
  • various adhesives used for polarizing films can be used, such as isocyanate adhesive, polyvinyl alcohol adhesive, gelatin adhesive, vinyl latex, etc. and water-based polyester. These adhesives are usually used as adhesives made of an aqueous solution (aqueous adhesives), and contain a solid content of 0.5 to 60% by weight.
  • aqueous adhesives aqueous adhesives
  • examples of the adhesive include active energy ray curable adhesives such as ultraviolet ray curable adhesives and electron beam curable adhesives.
  • active energy ray-curable adhesive include (meth)acrylate adhesives.
  • Examples of the curable component in the (meth)acrylate adhesive include a compound having a (meth)acryloyl group and a compound having a vinyl group.
  • Examples of compounds having a (meth)acryloyl group include alkyl (meth)acrylates having 1 to 20 carbon atoms, alicyclic alkyl (meth)acrylates, and polycyclic alkyl (meth)acrylates. ) acrylate; hydroxyl group-containing (meth)acrylate; epoxy group-containing (meth)acrylate such as glycidyl (meth)acrylate; and the like.
  • (Meth)acrylate adhesives include hydroxyethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, (meth)acrylamide, and (meth)acrylate. It may also contain nitrogen-containing monomers such as acryloylmorpholine.
  • the (meth)acrylate adhesive contains tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, cyclic trimethylolpropane formal acrylate, dioxane glycol diacrylate, EO as a crosslinking component.
  • a compound having an epoxy group or an oxetanyl group can also be used as a cationic polymerization-curable adhesive.
  • the compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various commonly known curable epoxy compounds can be used.
  • a compound having an epoxy group or an oxetanyl group can also be used as a cationic polymerization-curable adhesive.
  • active energy ray-curable adhesives such as (meth)acrylate adhesives are preferred.
  • the adhesive may be applied to either the transparent protective film side or the polarizing film side, or both.
  • a drying step is performed as necessary to form an adhesive layer consisting of a coated and dried layer. After the drying step, ultraviolet rays or electron beams can be irradiated if necessary.
  • the thickness of the adhesive layer is not particularly limited, and when a water-based adhesive or the like is used, it is preferably about 30 to 5000 nm, more preferably about 100 to 1000 nm. When using an electron beam curing adhesive or the like, the thickness is preferably about 0.1 to 100 ⁇ m, more preferably about 0.5 to 10 ⁇ m.
  • the laminated polarizing film (optical laminate) of the present invention has the polarizing film bonded to an optical layer.
  • the optical layer is not particularly limited, but for example, it can be used to form a liquid crystal display device such as a reflective plate, a semi-transmissive plate, a retardation plate (including a 1/2 or 1/4 wavelength plate), a viewing angle compensation film, etc.
  • One or more optical layers that are sometimes used can be used.
  • the laminated polarizing film is particularly a reflective polarizing film or a semi-transmissive polarizing film in which the polarizing film is further laminated with a reflective plate or a transflective plate, and a retardation plate is further laminated in the polarizing film.
  • Examples include an elliptical polarizing film or a circularly polarizing film, a wide viewing angle polarizing film in which a viewing angle compensation film is further laminated on the polarizing film, or a polarizing film in which a brightness enhancement film is further laminated on the polarizing film.
  • an image display cell such as a liquid crystal cell or an organic EL element, and other front transparent members such as a front transparent plate or a touch panel on the viewing side are provided.
  • An adhesive layer for bonding the members together may be provided.
  • a pressure-sensitive adhesive layer is suitable as the adhesive layer.
  • the adhesive forming the adhesive layer is not particularly limited, but examples include those having a base polymer such as an acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine-based polymer, or a rubber-based polymer. It can be selected and used as appropriate.
  • pressure-sensitive adhesives containing acrylic polymers that have excellent optical transparency, exhibit appropriate wettability, cohesiveness, and adhesive properties, and are excellent in weather resistance, heat resistance, etc. are preferably used.
  • the adhesive layer can be attached to one or both sides of the polarizing film or the laminated polarizing film using an appropriate method.
  • an appropriate method for attaching the adhesive layer, for example, a method of preparing an adhesive solution and applying it directly onto the polarizing film or the laminated polarizing film using an appropriate developing method such as a casting method or a coating method, or a method of applying the adhesive solution directly onto the polarizing film or the laminated polarizing film, or using a separator.
  • Examples include a method of forming an adhesive layer thereon and transferring it onto the polarizing film or the laminated polarizing film.
  • the thickness of the adhesive layer can be determined as appropriate depending on the purpose of use, adhesive strength, etc., and is generally 1 to 500 ⁇ m, preferably 5 to 200 ⁇ m, and more preferably 10 to 100 ⁇ m.
  • the polarizing film or the laminated polarizing film in which an adhesive layer is provided on at least one surface is referred to as a polarizing film with an adhesive layer or a laminated polarizing film with an adhesive layer.
  • the opposite side of the polarizing film to the viewing side of the polarizing film, or the side opposite to the viewing side of the polarizing film of the laminated polarizing film is bonded to the image display cell.
  • the image display device of the present invention includes a front transparent member on the polarizing film or laminated polarizing film side (viewing side) of the image display panel.
  • Examples of the image display cell include a liquid crystal cell and an organic EL cell.
  • Examples of the liquid crystal cell include a reflective liquid crystal cell that uses external light, a transmissive liquid crystal cell that uses light from a light source such as a backlight, and a transflective liquid crystal cell that uses both external light and light from a light source. Any semi-reflective liquid crystal cell may be used.
  • the image display device includes a polarizing film on the side opposite to the viewing side of the image display cell (liquid crystal cell), and further includes a light source. Placed. It is preferable that the polarizing film on the light source side and the liquid crystal cell are bonded together via a suitable adhesive layer.
  • any type of driving method can be used, such as VA mode, IPS mode, TN mode, STN mode, or bend alignment ( ⁇ type).
  • organic EL cell for example, a cell in which a transparent electrode, an organic light-emitting layer, and a metal electrode are sequentially laminated on a transparent substrate to form a light-emitting body (organic electroluminescence light-emitting body) is preferably used.
  • the organic light emitting layer is a laminate of various organic thin films, such as a laminate of a hole injection layer made of a triphenylamine derivative or the like and a light emitting layer made of a fluorescent organic solid such as anthracene;
  • Various layer configurations can be adopted, such as a laminate of a light emitting layer and an electron injection layer made of a perylene derivative, or a laminate of a hole injection layer, a light emitting layer, and an electron injection layer.
  • Examples of the front transparent member disposed on the viewing side of the image display cell include a front transparent plate (window layer), a touch panel, and the like.
  • a transparent plate having appropriate mechanical strength and thickness is used.
  • a transparent plate for example, a transparent resin plate such as acrylic resin or polycarbonate resin, or a glass plate is used.
  • the touch panel for example, various touch panels such as a resistive film type, a capacitance type, an optical type, an ultrasonic type, etc., a glass plate, a transparent resin plate, etc. having a touch sensor function are used.
  • a capacitive touch panel is used as the front transparent member, it is preferable that a front transparent plate made of glass or a transparent resin plate is provided further on the viewing side than the touch panel.
  • Example 1> ⁇ Preparation of polarizing film> A laminate in which a 9 ⁇ m thick PVA layer was formed on an amorphous PET base material was subjected to auxiliary stretching in the air at a stretching temperature of 130°C to produce a stretched laminate, and then the stretched laminate was dyed to produce a colored laminate. Then, the colored laminate was stretched in boric acid water at a stretching temperature of 65 degrees to obtain an optical film containing a 5 ⁇ m thick polarizing film, which was stretched together with the amorphous PET base material so that the total stretching ratio was 5.94 times. A laminate was produced.
  • the PVA molecules of the PVA layer formed on the amorphous PET base material are highly oriented, and the iodine adsorbed by dyeing is oriented in one direction as a polyiodine ion complex.
  • An optical film laminate containing a polarizing film with a thickness of 5 ⁇ m was obtained.
  • COP cycloolefin polymer
  • ZF14 cycloolefin polymer
  • those with a curl of less than 2 mm are indicated by ⁇
  • those with a curl of 2 mm or more but less than 3 mm are indicated by ⁇
  • those with a curl of 3 mm or more and less than 5 mm are indicated by ⁇
  • those with a curl of 5 mm or more are indicated by ⁇ .
  • a double-sided tape (No. 500, manufactured by Nitto Denko Corporation) was attached to the first transparent protective film side of the polarizing film in which the above polarizing film, the first transparent protective film, and the second transparent protective film were directly bonded. Furthermore, the polarizing film was cut out to a size of 200 mm in parallel to the stretching direction and 15 mm in the perpendicular direction, and a cut was made with a cutter knife between the polarizing film and the first transparent protective film, and then the release film of the double-sided tape was cut out. It was peeled off and the adhesive side was attached to a glass plate.
  • the polarizing film and the first transparent protective film were peeled in a 90-degree direction at a peeling speed of 1000 mm/min using a flexible angle adhesive/film peeling analyzer (VPA-2, manufactured by Kyowa Interface Science Co., Ltd.), and the peel strength ( N/15mm) was measured.
  • VPN-2 flexible angle adhesive/film peeling analyzer
  • the polarizing film and the second transparent protective film were peeled in a 90-degree direction at a peeling speed of 1000 mm/min using a flexible angle adhesive/film peeling analyzer (VPA-2, manufactured by Kyowa Interface Science Co., Ltd.), and the peel strength ( N/15mm) was measured.
  • VPN-2 flexible angle adhesive/film peeling analyzer
  • Example 2 A 23 ⁇ m thick cycloolefin resin film (Nippon Zeon Co., Ltd., ZF12) was used as the second transparent protective film, and a 13 ⁇ m thick cycloolefin resin film (Nippon Zeon Co., Ltd.) was used as the first transparent protective film. , ZF14) was used, a polarizing film in which transparent protective films were directly bonded to both sides of the polarizing film was obtained in the same manner as in Example 1.
  • a 5 ⁇ m thick cycloolefin resin film (cycloolefin polymer (COP) film (trade name "Zeonor Film ZF14”) was added to 84 g of a 2:3 mixed solvent of 2,4-trichlorobenzene and toluene. '') to prepare a COP solution, apply the prepared COP solution on the PET film (release liner) using bar coater #13, and then dry it in an oven at 60 ° C for 3 minutes.
  • COP cycloolefin polymer
  • Transparent protection was applied to both sides of the polarizing film in the same manner as in Example 1, except that a cycloolefin resin film with a release liner was used, in which a 5 ⁇ m thick COP film was laminated on the release liner. A polarizing film in which the films were directly bonded was obtained.
  • ⁇ Comparative example 1> As a second transparent protective film, the following active energy ray-curable adhesive was applied to a 13 ⁇ m thick cycloolefin resin film (Nippon Zeon Co., Ltd., ZF14) using a bar coater, and a laminator was used to apply Example 1. It was bonded to the polarizing film surface of the optical film laminate containing the polarizing film with a thickness of 5 ⁇ m obtained in . In this state, active energy rays were irradiated from the transparent protective film side to cure the adhesive.
  • cycloolefin resin film Nippon Zeon Co., Ltd., ZF14
  • the PET base material on the opposite side of the second transparent protective film was peeled off, and the 3 ⁇ m thick cycloolefin resin film described in Example 1 was applied as the first transparent protective film using the same procedure as above.
  • a polarizing film was obtained in which a transparent protective film was in contact with both sides of the polarizing film via an active energy ray adhesive.
  • [Active energy ray curable adhesive] 16.5 parts by weight of 2-hydroxyethyl acrylamide (manufactured by KJ Chemicals, trade name: HEAA), 1 part by weight of 4-vinylphenylboronic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 2-hydroxy-3-phenoxypropyl acrylate (manufactured by Toa) 30.5 parts by weight of 1,9-nonanediol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Aronix M-5700), 25 parts by weight of 1,9-nonanediol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Light Acrylate 1,9ND-A), hydroxypivalic acid 13 parts by weight of diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Light Acrylate HPP-A), 15 parts by weight of oligomer formed by poly
  • ⁇ Comparative example 2> A 23 ⁇ m thick cycloolefin resin film (Nippon Zeon Co., Ltd., ZF12) was used as the second transparent protective film, and a 13 ⁇ m thick cycloolefin resin film (Nippon Zeon Co., Ltd.) was used as the first transparent protective film. , ZF14) was used, the same operation as in Comparative Example 1 was performed to obtain a polarizing film in which transparent protective films were in contact with both surfaces of the polarizing film via a UV adhesive.
  • Example 1 The same evaluation as in Example 1 was performed using the polarizing films obtained in each of the above Examples and Comparative Examples. The results are shown in Table 1.
  • Polarizing film 11 Polarizing film 12: First transparent protective film 13: Second transparent protective film 20 and 30: Adhesive layer or adhesive layer 80: Front transparent member 90: Image display cell 100: Image display Panel 200: Image display device

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Abstract

This polarizing film which constitutes an image display panel comprises: a first transparent protection film; a polarizing film; and a second transparent protection film in the stated order. At least one of the first and second transparent protection films is directly joined to the polarizing film without a tackifying layer or an adhesive layer therebetween. The first transparent protection film is a transparent protection film on a viewing side and has a thickness thinner than the second transparent protection film. The polarizing film can suppress curling.

Description

偏光フィルム、積層偏光フィルム、画像表示パネル、及び画像表示装置Polarizing film, laminated polarizing film, image display panel, and image display device
　本発明は、偏光フィルム、積層偏光フィルム、画像表示パネル、及び画像表示装置に関する。 The present invention relates to a polarizing film, a laminated polarizing film, an image display panel, and an image display device.
　従来、液晶表示装置や有機ＥＬ表示装置等の各種画像表示装置に用いる偏光膜としては、高透過率と高偏光度を兼ね備えていることから、染色処理された（ヨウ素や二色性染料等の二色性物質を含有する）ポリビニルアルコール系フィルムが用いられている。当該偏光膜は、ポリビニルアルコール系フィルムに、浴中にて、例えば、膨潤、染色、架橋、延伸等の各処理を施した後に、洗浄処理を施してから、乾燥することにより製造される。また前記偏光膜は、通常、その片面又は両面にトリアセチルセルロース等の透明保護フィルムが接着剤を用いて貼合された偏光フィルム（偏光板）として用いられている。 Conventionally, polarizing films used in various image display devices such as liquid crystal display devices and organic EL display devices have been dyed (using iodine, dichroic dyes, etc.) because they have both high transmittance and high degree of polarization. A polyvinyl alcohol film (containing a dichroic substance) is used. The polarizing film is manufactured by subjecting a polyvinyl alcohol film to various treatments such as swelling, dyeing, crosslinking, and stretching in a bath, followed by washing and drying. Further, the polarizing film is usually used as a polarizing film (polarizing plate) in which a transparent protective film such as triacetyl cellulose is bonded to one or both sides of the polarizing film using an adhesive.
　前記偏光フィルムは、必要に応じ、他の光学層を積層して積層偏光フィルム（光学積層体）として用いられ、また、前記偏光フィルムあるいは前記積層偏光フィルム（光学積層体）は、液晶セルや有機ＥＬ素子等の画像表示セルに貼り合わされた画像表示パネルとして用いられ、さらに、前記画像表示パネルは、粘着剤層や接着剤層を介して、視認側における前面透明板（ウインドウ層）やタッチパネル等の前面透明部材に貼合されて、上記の各種画像表示装置として用いられる（特許文献１）。 The polarizing film is used as a laminated polarizing film (optical laminate) by laminating other optical layers as necessary, and the polarizing film or the laminated polarizing film (optical laminate) is used as a liquid crystal cell or an organic laminate. It is used as an image display panel bonded to an image display cell such as an EL element, and further, the image display panel is attached to a front transparent plate (window layer), a touch panel, etc. on the viewing side via an adhesive layer or an adhesive layer. It is bonded to the front transparent member of and used as the various image display devices mentioned above (Patent Document 1).
　また、上記の偏光フィルム（偏光板）としては、偏光膜と透明保護フィルムが、接着剤層又は粘着剤層を介さずに、直接、貼合されている偏光フィルムも知られている（特許文献２－５）。 Furthermore, as the above-mentioned polarizing film (polarizing plate), there is also known a polarizing film in which a polarizing film and a transparent protective film are directly laminated without using an adhesive layer or a pressure-sensitive adhesive layer (Patent Document 2-5).
特開２０１４－１０２３５３号公報Japanese Patent Application Publication No. 2014-102353 国際公開第２００５／０８５９１８号International Publication No. 2005/085918 特開２００２－３０３７２５号公報Japanese Patent Application Publication No. 2002-303725 特開２００２－３０３７２６号公報Japanese Patent Application Publication No. 2002-303726 特開２００２－３０３７２７号公報Japanese Patent Application Publication No. 2002-303727
　偏光膜や偏光フィルムは、薄膜化の要望が強いが、上記のように、偏光膜と透明保護フィルムが接着剤層を介して貼り合わされている場合、接着剤層は接着剤の硬化時に応力が蓄積されやすく、偏光フィルムのカールの原因となる問題があった。特に、上記の画像表示装置において、視認側の透明保護フィルムがセル側の透明保護フィルムよりも薄い場合、視認側とセル側で応力のかかり方に差が発生し、薄い方の透明保護フィルムにカールが偏る課題があった。 There is a strong demand for thinner polarizing films and polarizing films, but as mentioned above, when a polarizing film and a transparent protective film are bonded together via an adhesive layer, the adhesive layer is exposed to stress when the adhesive hardens. There was a problem that it easily accumulated and caused curling of the polarizing film. In particular, in the above-mentioned image display device, if the transparent protective film on the viewing side is thinner than the transparent protective film on the cell side, there will be a difference in the way stress is applied between the viewing side and the cell side, and the thinner transparent protective film will There was an issue where the curls were uneven.
　以上のような事情に鑑み、本発明は、カールを抑制できる偏光フィルムを提供することを目的とする。 In view of the above circumstances, an object of the present invention is to provide a polarizing film that can suppress curling.
　また、本発明は、上記の偏光フィルムを用いた積層偏光フィルム、画像表示パネル、及び画像表示装置を提供することを目的とする。 Another object of the present invention is to provide a laminated polarizing film, an image display panel, and an image display device using the above polarizing film.
　すなわち、本発明は、画像表示パネルを構成する偏光フィルムであって、前記偏光フィルムは、第１の透明保護フィルム、偏光膜、及び第２の透明保護フィルムが、順に、備えられており、前記第１の透明保護フィルム、及び前記第２の透明保護フィルムの少なくとも一方は、前記偏光膜と、粘着剤層又は接着剤層を介さずに、直接、接合されており、前記第１の透明保護フィルムは、視認側の透明保護フィルムであり、かつ、厚みが前記第２の透明保護フィルムの厚みよりも薄い偏光フィルムに関する。 That is, the present invention provides a polarizing film constituting an image display panel, wherein the polarizing film includes, in order, a first transparent protective film, a polarizing film, and a second transparent protective film, and At least one of the first transparent protective film and the second transparent protective film is directly bonded to the polarizing film without an adhesive layer or an adhesive layer, and the first transparent protective film The film is a transparent protective film on the viewing side, and relates to a polarizing film whose thickness is thinner than the thickness of the second transparent protective film.
　また、本発明は、前記偏光フィルムが光学層に貼り合わされている積層偏光フィルムに関する。 The present invention also relates to a laminated polarizing film in which the polarizing film is bonded to an optical layer.
　また、本発明は、画像表示セルに、前記偏光フィルムの偏光膜の視認側の反対側、又は前記積層偏光フィルムの偏光膜の視認側の反対側が貼り合わされている画像表示パネルに関する。 The present invention also relates to an image display panel in which the side of the polarizing film opposite to the viewing side of the polarizing film, or the side opposite to the viewing side of the polarizing film of the laminated polarizing film is bonded to an image display cell.
　また、本発明は、前記画像表示パネルの偏光フィルム又は積層偏光フィルム側に、前面透明部材を備える画像表示装置に関する。 The present invention also relates to an image display device including a front transparent member on the polarizing film or laminated polarizing film side of the image display panel.
　本発明の偏光フィルムにおける効果の作用メカニズムの詳細は、以下のように推定される。ただし、本発明は、この作用メカニズムに限定して解釈されない。 The details of the working mechanism of the effect in the polarizing film of the present invention are estimated as follows. However, the present invention is not construed as being limited to this mechanism of action.
　本発明の偏光フィルムは、画像表示パネルを構成する偏光フィルムであって、前記偏光フィルムは、第１の透明保護フィルム、偏光膜、及び第２の透明保護フィルムが、順に、備えられており、前記第１の透明保護フィルム、及び前記第２の透明保護フィルムの少なくとも一方は、前記偏光膜と、粘着剤層又は接着剤層を介さずに、直接、接合されており、前記第１の透明保護フィルムは、視認側の透明保護フィルムであり、かつ、厚みが前記第２の透明保護フィルムの厚みよりも薄いため、接着剤が存在すると収縮によるひずみの影響を特に視認側の保護フィルムが薄いときに受けてしまうが、接着剤を使用しないことで収縮力を低減することが可能となり、カールを抑制できる。 The polarizing film of the present invention is a polarizing film constituting an image display panel, and the polarizing film is provided with a first transparent protective film, a polarizing film, and a second transparent protective film in this order, At least one of the first transparent protective film and the second transparent protective film is directly bonded to the polarizing film without using an adhesive layer or an adhesive layer, and The protective film is a transparent protective film on the viewing side, and is thinner than the second transparent protective film, so the presence of adhesive will reduce the effects of distortion due to shrinkage, especially if the protective film on the viewing side is thin. However, by not using an adhesive, it is possible to reduce the shrinkage force and prevent curling.
偏光フィルムの一形態を示す模式的断面図である。FIG. 1 is a schematic cross-sectional view showing one form of a polarizing film. 画像表示パネル及び画像表示装置の一形態を示す模式的断面図である。1 is a schematic cross-sectional view showing one form of an image display panel and an image display device.
　図１は、本発明の偏光フィルムの一形態を示す模式的断面図である。図１では、視認側の第１の透明保護フィルム１２、偏光膜１１、第２の透明保護フィルム１３が、順に、接着剤層又は粘着剤層を介さずに、直接、接合されている偏光フィルム１０の一態様を示す。 FIG. 1 is a schematic cross-sectional view showing one form of the polarizing film of the present invention. In FIG. 1, a polarizing film in which a first transparent protective film 12, a polarizing film 11, and a second transparent protective film 13 on the viewing side are directly joined in this order without using an adhesive layer or a pressure-sensitive adhesive layer. 10 is shown.
　図２は、本発明の画像表示パネル及び画像表示装置の一形態を示す模式的断面図である。図２では、画像表示セル９０に、偏光フィルム１０の偏光膜の視認側の反対側が粘着剤層又は接着剤層３０を介して貼り合わされている画像表示パネル１００の一態様を示す。また、図２では、画像表示パネル１００の偏光フィルム側に、粘着剤層又は接着剤層２０を介して前面透明部材８０を備える画像表示装置２００の一態様を示す。 FIG. 2 is a schematic cross-sectional view showing one form of the image display panel and image display device of the present invention. FIG. 2 shows an embodiment of an image display panel 100 in which the opposite side of the polarizing film 10 to the viewing side of the polarizing film is bonded to the image display cell 90 via an adhesive layer or an adhesive layer 30. Further, FIG. 2 shows one embodiment of an image display device 200 that includes a front transparent member 80 on the polarizing film side of the image display panel 100 via an adhesive layer or an adhesive layer 20.
＜偏光フィルム＞
　本発明の偏光フィルムは、画像表示パネルを構成する偏光フィルムであって、前記偏光フィルムは、第１の透明保護フィルム、偏光膜、及び第２の透明保護フィルムが、順に、備えられており、前記第１の透明保護フィルム、及び前記第２の透明保護フィルムの少なくとも一方は、前記偏光膜と、粘着剤層又は接着剤層を介さずに、直接、接合されており、前記第１の透明保護フィルムは、視認側の透明保護フィルムであり、かつ、厚みが前記第２の透明保護フィルムの厚みよりも薄い。なお、視認側（視認面）とは、前記画像表示パネルの視認側を意味する。 <Polarizing film>
The polarizing film of the present invention is a polarizing film constituting an image display panel, and the polarizing film is provided with a first transparent protective film, a polarizing film, and a second transparent protective film in this order, At least one of the first transparent protective film and the second transparent protective film is directly bonded to the polarizing film without using an adhesive layer or an adhesive layer, and The protective film is a transparent protective film on the viewing side, and has a thickness thinner than the thickness of the second transparent protective film. Note that the viewing side (viewing surface) means the viewing side of the image display panel.
＜偏光膜＞
　前記偏光膜は、ポリビニルアルコール系フィルムにヨウ素や二色性染料等の二色性物質が吸着配向して形成される。前記偏光膜は、偏光膜の初期の偏光性能の観点から、前記二色性物質としてヨウ素を含む、ヨウ素系偏光膜が好ましい。 <Polarizing film>
The polarizing film is formed by adsorbing and aligning a dichroic substance such as iodine or a dichroic dye onto a polyvinyl alcohol film. The polarizing film is preferably an iodine-based polarizing film containing iodine as the dichroic substance from the viewpoint of initial polarization performance of the polarizing film.
　前記ポリビニルアルコール（ＰＶＡ）系フィルムは、可視光領域において透光性を有し、ヨウ素や二色性染料等の二色性物質を分散吸着するものを特に制限なく使用できる。前記ポリビニルアルコール系フィルムの材料としては、ポリビニルアルコール又はその誘導体が挙げられる。前記ポリビニルアルコールの誘導体としては、例えば、ポリビニルホルマール、ポリビニルアセタール；エチレン、プロピレン等のオレフィン；アクリル酸、メタクリル酸、クロトン酸等の不飽和カルボン酸、及びそのアルキルエステル、アクリルアミド等で変性したもの等が挙げられる。前記ポリビニルアルコールは、平均重合度が１００～１０，０００程度であることが好ましく、１，０００～１０，０００程度であることがより好ましく、１，５００～４，５００程度であることがさらに好ましい。また、前記ポリビニルアルコールは、ケン化度が８０～１００モル％程度であることが好ましく、９５モル％～９９．９５モル程度であることがより好ましい。なお、前記平均重合度及び前記ケン化度は、ＪＩＳ　Ｋ　６７２６に準じて求めることができる。 The polyvinyl alcohol (PVA)-based film can be used without any particular restriction, as long as it has transparency in the visible light region and disperses and adsorbs dichroic substances such as iodine and dichroic dyes. Examples of the material for the polyvinyl alcohol film include polyvinyl alcohol or derivatives thereof. Examples of the polyvinyl alcohol derivatives include polyvinyl formal, polyvinyl acetal; olefins such as ethylene and propylene; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and those modified with their alkyl esters, acrylamide, etc. can be mentioned. The average degree of polymerization of the polyvinyl alcohol is preferably about 100 to 10,000, more preferably about 1,000 to 10,000, and even more preferably about 1,500 to 4,500. . Further, the saponification degree of the polyvinyl alcohol is preferably about 80 to 100 mol%, more preferably about 95 mol% to 99.95 mol%. In addition, the said average polymerization degree and the said saponification degree can be calculated|required according to JISK6726.
　前記偏光膜は、従前の偏光膜の製造方法により得られ、例えば、前記ポリビニルアルコール系フィルムに、任意の膨潤工程及び洗浄工程と、少なくとも、染色工程、架橋工程、及び延伸工程を施して得られる。 The polarizing film is obtained by a conventional polarizing film manufacturing method, for example, by subjecting the polyvinyl alcohol film to an optional swelling process and washing process, and at least a dyeing process, a crosslinking process, and a stretching process. .
　前記偏光膜は、偏光膜の初期の偏光度を向上させる観点から、厚みが１μｍ以上であることが好ましく、２μｍ以上であることがより好ましく、そして、パネルの反りを防止する観点から、１５μｍ以下であることが好ましく、１０μｍ以下であることがより好ましく、８μｍ以下であることがさらに好ましい。とくに、厚みが８μｍ程度以下の偏光膜を得るためには、前記ポリビニルアルコール系フィルムとして、熱可塑性樹脂基材上に製膜されたポリビニルアルコール系樹脂層を含む積層体を用いる、以下の薄型の偏光膜の製造方法が適用できる。 The thickness of the polarizing film is preferably 1 μm or more, more preferably 2 μm or more, from the viewpoint of improving the initial polarization degree of the polarizing film, and 15 μm or less from the viewpoint of preventing panel warpage. The thickness is preferably 10 μm or less, more preferably 8 μm or less. In particular, in order to obtain a polarizing film with a thickness of about 8 μm or less, the following thin film is used, in which a laminate including a polyvinyl alcohol resin layer formed on a thermoplastic resin base material is used as the polyvinyl alcohol film. A method for manufacturing a polarizing film can be applied.
　偏光膜（薄型の偏光膜）は、従前の偏光膜の製造方法により得られ、例えば、長尺状の熱可塑性樹脂基材の片側に、ポリビニルアルコール系樹脂（ＰＶＡ系樹脂）を含むポリビニルアルコール系樹脂層（ＰＶＡ系樹脂層）を形成して積層体を準備する工程と、得られた積層体を長手方向に搬送しながら、前記積層体に、任意の不溶化処理工程、架橋処理工程、及び洗浄処理工程と、少なくとも、空中補助延伸処理工程、染色処理工程、及び水中延伸処理工程を施して得られる。 The polarizing film (thin polarizing film) is obtained by a conventional polarizing film manufacturing method. A step of forming a resin layer (PVA resin layer) to prepare a laminate, and while conveying the obtained laminate in the longitudinal direction, the laminate is subjected to an optional insolubilization treatment step, a crosslinking treatment step, and washing. It is obtained by performing a treatment step, and at least an in-air auxiliary stretching treatment step, a dyeing treatment step, and an underwater stretching treatment step.
＜第１及び第２の透明保護フィルム＞
　前記第１の透明保護フィルムは、視認側の透明保護フィルムであり、厚みが前記第２の透明保護フィルムの厚みよりも薄い。なお、以下、第１の透明保護フィルム、及び第２の透明保護フィルムのいずれかを、単に、透明保護フィルムともいう。 <First and second transparent protective films>
The first transparent protective film is a transparent protective film on the viewing side, and is thinner than the second transparent protective film. Note that, hereinafter, either the first transparent protective film or the second transparent protective film will also be simply referred to as a transparent protective film.
　前記第１の透明保護フィルムの厚さは、適宜に決定しうるが、偏光フィルムの機械的強度の観点から、１μｍ以上であることが好ましく、３μｍ以上であることがより好ましく、５μｍ以上であることがさらに好ましく、そして、偏光フィルムの薄膜化の観点から、５０μｍ以下であることが好ましく、３０μｍ以下であることがより好ましく、２０μｍ以下であることがさらに好ましい。また、前記第２の透明保護フィルムの厚さは、適宜に決定しうるが、偏光フィルムの機械的強度の観点から、１０μｍ以上であることが好ましく、２０μｍ以上であることがより好ましく、そして、偏光フィルムの薄膜化の観点から、１００μｍ以下であることが好ましく、４０μｍ以下であることがより好ましい。 The thickness of the first transparent protective film can be determined as appropriate, but from the viewpoint of mechanical strength of the polarizing film, it is preferably 1 μm or more, more preferably 3 μm or more, and 5 μm or more. Further, from the viewpoint of making the polarizing film thinner, it is preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. Further, the thickness of the second transparent protective film can be determined as appropriate, but from the viewpoint of mechanical strength of the polarizing film, it is preferably 10 μm or more, more preferably 20 μm or more, and From the viewpoint of making the polarizing film thinner, the thickness is preferably 100 μm or less, more preferably 40 μm or less.
　前記第２の透明保護フィルムの厚みと前記第１の透明保護フィルムの厚みの比（第２の透明保護フィルムの厚み／第１の透明保護フィルムの厚み）は、カール抑制の観点から、１．２以上であることが好ましく、１．５以上であることがより好ましく、そして、薄肉化の観点から、１０．０以下であることが好ましく、５．０以下であることがより好ましい。 The ratio of the thickness of the second transparent protective film to the thickness of the first transparent protective film (thickness of the second transparent protective film/thickness of the first transparent protective film) is 1. It is preferably 2 or more, more preferably 1.5 or more, and from the viewpoint of thinning, it is preferably 10.0 or less, and more preferably 5.0 or less.
　前記第１及び第２の透明保護フィルムは、特に制限されず、偏光フィルムに用いられている各種の透明保護フィルムを用いることができる。前記透明保護フィルムを構成する材料としては、例えば、透明性、機械的強度、熱安定性、水分遮断性、等方性等に優れる熱可塑性樹脂が用いられる。前記熱可塑性樹脂としては、例えば、トリアセチルセルロール等のセルロールエステル系樹脂、ポリエチレンテレフタレートやポリエチレンナフタレート等のポリエステル系樹脂、ポリエーテルスルホン系樹脂、ポリスルホン系樹脂、ポリカーボネート系樹脂、ナイロンや芳香族ポリアミド等のポリアミド系樹脂、ポリイミド系樹脂、ポリエチレン、ポリプロピレン、エチレン・プロピレン共重合体の如きポリオレフィン系樹脂、（メタ）アクリル系樹脂、シクロ系ないしはノルボルネン構造を有する環状ポリオレフィン系樹脂（ノルボルネン系樹脂）、ポリアリレート系樹脂、ポリスチレン系樹脂、ポリビニルアルコール系樹脂、及びこれらの混合物があげられる。また、前記透明保護フィルムは、（メタ）アクリル系、ウレタン系、アクリルウレタン系、エポキシ系、シリコーン系等の熱硬化性樹脂又は紫外線硬化型樹脂から形成される硬化層を用いることができる。これらの中でも、セルロールエステル系樹脂、ポリカーボネート系樹脂、（メタ）アクリル系樹脂、環状ポリオレフィン系樹脂、ポリエステル系樹脂が好適である。 The first and second transparent protective films are not particularly limited, and various transparent protective films used for polarizing films can be used. As the material constituting the transparent protective film, for example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc. is used. Examples of the thermoplastic resin include cellulose ester resins such as triacetylcellulose, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyether sulfone resins, polysulfone resins, polycarbonate resins, nylon, and aromatic resins. Polyamide resins such as group polyamides, polyimide resins, polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers, (meth)acrylic resins, cyclic polyolefin resins having a cyclo or norbornene structure (norbornene resins) ), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. Further, the transparent protective film may include a cured layer formed from a thermosetting resin or an ultraviolet curable resin such as (meth)acrylic, urethane, acrylic urethane, epoxy, silicone, or the like. Among these, cellulose ester resins, polycarbonate resins, (meth)acrylic resins, cyclic polyolefin resins, and polyester resins are preferred.
　前記透明保護フィルムは、正面位相差が４０ｎｍ以上及び／又は、厚み方向位相差が８０ｎｍ以上の位相差を有する位相差板を用いることができる。正面位相差は、通常、４０～２００ｎｍの範囲に、厚み方向位相差は、通常、８０～３００ｎｍの範囲に制御される。前記透明保護フィルムとして位相差板を用いる場合には、当該位相差板が透明保護フィルムとしても機能するため、薄型化を図ることができる。 As the transparent protective film, a retardation plate having a front retardation of 40 nm or more and/or a thickness direction retardation of 80 nm or more can be used. The frontal retardation is usually controlled in the range of 40 to 200 nm, and the thickness direction retardation is usually controlled in the range of 80 to 300 nm. When a retardation plate is used as the transparent protective film, the retardation plate also functions as a transparent protective film, so that it is possible to reduce the thickness.
　前記位相差板としては、例えば、高分子素材を一軸又は二軸延伸処理してなる複屈折性フィルム、液晶ポリマーの配向フィルム、液晶ポリマーの配向層をフィルムにて支持したもの等が挙げられる。位相差板の厚さは特に制限されないが、１～１５０μｍ程度が一般的である。なお、位相差を有しない透明保護フィルムに前記位相板を貼り合わせて使用してもよい。 Examples of the retardation plate include a birefringent film formed by uniaxially or biaxially stretching a polymer material, an oriented film of a liquid crystal polymer, and an oriented layer of a liquid crystal polymer supported by a film. The thickness of the retardation plate is not particularly limited, but is generally about 1 to 150 μm. Note that the phase plate may be used by bonding it to a transparent protective film that does not have a phase difference.
　前記透明保護フィルムには、紫外線吸収剤、酸化防止剤、滑剤、可塑剤、離型剤、着色防止剤、難燃剤、帯電防止剤、顔料、着色剤等の任意の適切な添加剤を含んでいてもよい。とくに、前記透明保護フィルムに紫外線吸収剤を含む場合、偏光フィルムの耐光性を向上できる。 The transparent protective film may contain any suitable additives such as ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, color inhibitors, flame retardants, antistatic agents, pigments, colorants, etc. You can stay there. In particular, when the transparent protective film contains an ultraviolet absorber, the light resistance of the polarizing film can be improved.
　前記第１及び第２の透明保護フィルムの偏光膜を貼り合わせない面には、ハードコート層、反射防止層、スティッキング防止層、拡散層ないしアンチグレア層等の他の層を設けることができる。なお、上記ハードコート層、反射防止層、スティッキング防止層、拡散層やアンチグレア層等の他の層は、保護フィルムそのものに設けることができるほか、別途、保護フィルムとは別体のものとして設けることもできる。 Other layers such as a hard coat layer, an anti-reflection layer, an anti-sticking layer, a diffusion layer or an anti-glare layer can be provided on the surfaces of the first and second transparent protective films on which the polarizing film is not attached. Note that other layers such as the hard coat layer, anti-reflection layer, anti-sticking layer, diffusion layer, and anti-glare layer can be provided on the protective film itself, or may be provided separately from the protective film. You can also do it.
　前記第１の透明保護フィルム、及び前記第２の透明保護フィルムの少なくとも一方は、前記偏光膜と、粘着剤層又は接着剤層を介さずに、直接、接合されている。 At least one of the first transparent protective film and the second transparent protective film is directly bonded to the polarizing film without using an adhesive layer or an adhesive layer.
　前記第１の透明保護フィルム、及び前記第２の透明保護フィルムの少なくとも一方を、前記偏光膜と、粘着剤層又は接着剤層を介さずに、直接、接合する方法は、圧着する方法、紫外線、電子線等のエネルギー線を照射して貼合する方法等が挙げられ、とくに、接着性を高める観点から、上記の透明保護フィルムと前記偏光膜のいずれか一方、又は両方の貼合面に紫外光を照射して表面処理をした後、揮発性媒体を介して貼合し、当該揮発性媒体を乾燥する方法が好ましい。前記揮発性媒体が存在することにより、貼合面に気泡等が入らずに密着でき、さらに、揮発性媒体を乾燥することにより、著しく接合面（界面）の接着力が高まる。紫外光としては、例えば、波長が２５０－１００ｎｍであることが好ましく、２００－１００ｎｍであることがより好ましく、なかでもキセノンエキシマランプを使用した１７２ｎｍの波長が、量産性の観点から特に好ましい。 The methods of directly bonding at least one of the first transparent protective film and the second transparent protective film to the polarizing film without using an adhesive layer or an adhesive layer include a pressure bonding method, an ultraviolet ray , a method of bonding by irradiating energy rays such as electron beams, etc. In particular, from the viewpoint of improving adhesiveness, the bonding surface of either or both of the transparent protective film and the polarizing film may be A preferred method is to perform surface treatment by irradiating ultraviolet light, then bonding through a volatile medium, and then drying the volatile medium. The presence of the volatile medium allows for close adhesion to the bonding surfaces without air bubbles, etc., and furthermore, drying the volatile medium significantly increases the adhesive strength of the bonding surfaces (interfaces). The ultraviolet light preferably has a wavelength of 250 to 100 nm, more preferably 200 to 100 nm, and particularly preferably 172 nm using a xenon excimer lamp from the viewpoint of mass productivity.
　また、上記の紫外光は、照度が、処理能力の観点から、１ｍＷ／ｃｍ２以上であることが好ましく、５０ｍＷ／ｃｍ２以上であることがより好ましい。また、積算光量が、接着性の観点から、１ｍＪ／ｃｍ２以上であることが好ましく、５０ｍＪ／ｃｍ２以上であることがより好ましく、そして、フィルムへのダメージの観点から、５０００ｍＪ／ｃｍ２以下であることが好ましく、２０００ｍＪ／ｃｍ２以下であることがより好ましい。また、紫外光照射時における温度は、特に限定されず、表面改質の安定化の観点から、０～５０℃程度であることが好ましく、１０～４０℃程度であることがより好ましく、偏光フィルムの生産上、室温であることが簡便である。また、紫外光照射時における雰囲気は、酸素濃度が２１％以下であればよく、処理効率の観点から、酸素濃度は７．０％以下が好ましい。 Further, the illumination intensity of the ultraviolet light is preferably 1 mW/cm 2 or more, more preferably 50 mW/cm 2 or more from the viewpoint of processing capacity. Further, the cumulative light amount is preferably 1 mJ/cm 2 or more from the viewpoint of adhesiveness, more preferably 50 mJ/cm 2 or more, and 5000 mJ/cm 2 or less from the viewpoint of damage to the film. It is preferable that it is, and it is more preferable that it is 2000 mJ/cm 2 or less. Further, the temperature at the time of ultraviolet light irradiation is not particularly limited, and from the viewpoint of stabilizing surface modification, it is preferably about 0 to 50 °C, more preferably about 10 to 40 °C, and the polarizing film For production purposes, it is convenient to use room temperature. Further, the atmosphere during ultraviolet light irradiation only needs to have an oxygen concentration of 21% or less, and from the viewpoint of processing efficiency, the oxygen concentration is preferably 7.0% or less.
　前記揮発性媒体は、特に限定されず、乾燥効率の観点から、水、エタノール、トルエン、シクロヘキサン、アセトンなどの溶剤が好ましく、環境の観点から、水がより好ましい。 The volatile medium is not particularly limited, and from the viewpoint of drying efficiency, solvents such as water, ethanol, toluene, cyclohexane, acetone, etc. are preferred, and from the viewpoint of the environment, water is more preferred.
　前記加熱の温度は、前記揮発性媒体を適切に乾燥できればよく、例えば、前記揮発性媒体が水の場合、４０～８０℃程度であることが好ましく、５０～７０℃程度であることがより好ましい。また、前記乾燥の時間は、偏光膜の温度の影響を受けるため一概に決定できないが、１分～６０分間程度であることが好ましく、３～１５分間程度であることがより好ましい。前記乾燥工程は１回だけ実施されてもよく、必要に応じて複数回実施されてもよい。 The heating temperature may be sufficient as long as it can appropriately dry the volatile medium; for example, when the volatile medium is water, it is preferably about 40 to 80°C, more preferably about 50 to 70°C. . Although the drying time cannot be absolutely determined because it is affected by the temperature of the polarizing film, it is preferably about 1 minute to 60 minutes, more preferably about 3 minutes to 15 minutes. The drying step may be performed only once, or may be performed multiple times as necessary.
　上記の貼合は、ロールラミネーターなどにより行うことができる。 The above lamination can be performed using a roll laminator or the like.
　前記偏光膜と前記透明保護フィルムの接合界面は、貼合時の処理に由来する改質層や高弾性層があってもよい。 The bonding interface between the polarizing film and the transparent protective film may include a modified layer or a high elastic layer resulting from the treatment during bonding.
　前記偏光フィルムにおいて、上記の透明保護フィルムと前記偏光膜との接合面における接着力（剥離強度）は、剥離角度９０°、剥離速度１０００ｍｍ／分の条件下の剥離強度測定で、０．５Ｎ／１５ｍｍ以上であることが好ましく、１．０Ｎ／１５ｍｍ以上であることがより好ましく、１．２Ｎ／１５ｍｍ以上であることがさらに好ましく、２．０Ｎ／１５ｍｍ以上であることがよりさらに好ましい。 In the polarizing film, the adhesive force (peel strength) at the bonding surface between the transparent protective film and the polarizing film is 0.5 N/min when peel strength is measured at a peel angle of 90° and a peel speed of 1000 mm/min. It is preferably 15 mm or more, more preferably 1.0 N/15 mm or more, even more preferably 1.2 N/15 mm or more, even more preferably 2.0 N/15 mm or more.
　前記偏光フィルムにおいて、上記の接合面ではない偏光膜の他面は、上記の透明保護フィルムが、粘着剤層又は接着剤層を介さずに、上述のように、直接、接合されていてもよく、また、上記の透明保護フィルムが、粘着剤層又は接着剤層を介して、貼合されていてもよい。 In the polarizing film, the other surface of the polarizing film that is not the bonded surface may be directly bonded to the transparent protective film as described above without using an adhesive layer or an adhesive layer. Moreover, the above-mentioned transparent protective film may be bonded via a pressure-sensitive adhesive layer or an adhesive layer.
　前記粘着剤層を形成する粘着剤としては、偏光フィルムに用いられている各種の粘着剤を適用でき、例えば、ゴム系粘着剤、アクリル系粘着剤、シリコーン系粘着剤、ウレタン系粘着剤、ビニルアルキルエーテル系粘着剤、ポリビニルアルコール系粘着剤、ポリビニルポロリドン系粘着剤、ポリアクリルアミド系粘着剤、セルロース系粘着剤等が挙げられる。これらの中でも、アクリル系粘着剤が好適である。 As the adhesive forming the adhesive layer, various adhesives used in polarizing films can be used, such as rubber adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, vinyl adhesives, etc. Examples include alkyl ether adhesives, polyvinyl alcohol adhesives, polyvinylporolidone adhesives, polyacrylamide adhesives, cellulose adhesives, and the like. Among these, acrylic adhesives are preferred.
　また、前記接着剤層を形成する接着剤としては、偏光フィルムに用いられている各種の接着剤を適用でき、例えば、イソシアネート系接着剤、ポリビニルアルコール系接着剤、ゼラチン系接着剤、ビニル系ラテックス系、水系ポリエステル等が挙げられる。これら接着剤は、通常、水溶液からなる接着剤（水系接着剤）として用いられ、０．５～６０重量％の固形分を含有してなる。前記接着剤としては、上記の他、紫外線硬化型接着剤、電子線硬化型接着剤等の活性エネルギー線硬化型接着剤が挙げられる。前記活性エネルギー線硬化型接着剤としては、例えば、（メタ）アクリレート系接着剤が挙げられる。前記（メタ）アクリレート系接着剤における硬化性成分としては、例えば、（メタ）アクリロイル基を有する化合物、ビニル基を有する化合物が挙げられる。（メタ）アクリロイル基を有する化合物としては、例えば、炭素数が１～２０の鎖状アルキル（メタ）アクリレート、脂環式アルキル（メタ）アクリレート、多環式アルキル（メタ）アクリレート等のアルキル（メタ）アクリレート；ヒドロキシル基含有（メタ）アクリレート；グリシジル（メタ）アクリレート等のエポキシ基含有（メタ）アクリレート等が挙げられる。（メタ）アクリレート系接着剤は、ヒドロキシエチル（メタ）アクリルアミド、Ｎ‐メチロール（メタ）アクリルアミド、Ｎ‐メトキシメチル（メタ）アクリルアミド、Ｎ‐エトキシメチル（メタ）アクリルアミド、（メタ）アクリルアミド、（メタ）アクリロイルモルホリン等の窒素含有モノマーを含んでいてもよい。（メタ）アクリレート系接着剤は、架橋成分として、トリプロピレングリコールジアクリレート、１，９－ノナンジオールジアクリレート、トリシクロデカンジメタノールジアクリレート、環状トリメチロールプロパンフォルマルアクリレート、ジオキサングリコールジアクリレート、ＥＯ変性ジグリセリンテトラアクリレート等の多官能モノマーを含んでいてもよい。また、カチオン重合硬化型接着剤としてエポキシ基やオキセタニル基を有する化合物も使用することができる。エポキシ基を有する化合物は、分子内に少なくとも２個のエポキシ基を有するものであれば特に限定されず、一般に知られている各種の硬化性エポキシ化合物を用いることができる。また、カチオン重合硬化型接着剤としてエポキシ基やオキセタニル基を有する化合物も使用することができる。これらの中でも、硬化性・生産性の観点から、（メタ）アクリレート系接着剤の活性エネルギー線硬化型接着剤が好ましい。 Further, as the adhesive forming the adhesive layer, various adhesives used for polarizing films can be used, such as isocyanate adhesive, polyvinyl alcohol adhesive, gelatin adhesive, vinyl latex, etc. and water-based polyester. These adhesives are usually used as adhesives made of an aqueous solution (aqueous adhesives), and contain a solid content of 0.5 to 60% by weight. In addition to the above adhesives, examples of the adhesive include active energy ray curable adhesives such as ultraviolet ray curable adhesives and electron beam curable adhesives. Examples of the active energy ray-curable adhesive include (meth)acrylate adhesives. Examples of the curable component in the (meth)acrylate adhesive include a compound having a (meth)acryloyl group and a compound having a vinyl group. Examples of compounds having a (meth)acryloyl group include alkyl (meth)acrylates having 1 to 20 carbon atoms, alicyclic alkyl (meth)acrylates, and polycyclic alkyl (meth)acrylates. ) acrylate; hydroxyl group-containing (meth)acrylate; epoxy group-containing (meth)acrylate such as glycidyl (meth)acrylate; and the like. (Meth)acrylate adhesives include hydroxyethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, (meth)acrylamide, and (meth)acrylate. It may also contain nitrogen-containing monomers such as acryloylmorpholine. The (meth)acrylate adhesive contains tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, cyclic trimethylolpropane formal acrylate, dioxane glycol diacrylate, EO as a crosslinking component. It may also contain a polyfunctional monomer such as modified diglycerol tetraacrylate. Moreover, a compound having an epoxy group or an oxetanyl group can also be used as a cationic polymerization-curable adhesive. The compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various commonly known curable epoxy compounds can be used. Moreover, a compound having an epoxy group or an oxetanyl group can also be used as a cationic polymerization-curable adhesive. Among these, from the viewpoint of curability and productivity, active energy ray-curable adhesives such as (meth)acrylate adhesives are preferred.
　前記接着剤の塗布は、透明保護フィルム側、前記偏光膜側のいずれに行ってもよく、両者に行ってもよい。貼り合わせ後には、必要に応じ乾燥工程を施し、塗布乾燥層からなる接着剤層を形成する。前記乾燥工程の後には、必要に応じ、紫外線や電子線を照射することができる。前記接着剤層の厚さは、特に制限されず、水系接着剤等を用いる場合には、３０～５０００ｎｍ程度であることが好ましく、１００～１０００ｎｍ程度であることがより好ましく、紫外線硬化型接着剤、電子線硬化型接着剤等を用いる場合には、０．１～１００μｍ程度であることが好ましく、０．５～１０μｍ程度であることがより好ましい。 The adhesive may be applied to either the transparent protective film side or the polarizing film side, or both. After bonding, a drying step is performed as necessary to form an adhesive layer consisting of a coated and dried layer. After the drying step, ultraviolet rays or electron beams can be irradiated if necessary. The thickness of the adhesive layer is not particularly limited, and when a water-based adhesive or the like is used, it is preferably about 30 to 5000 nm, more preferably about 100 to 1000 nm. When using an electron beam curing adhesive or the like, the thickness is preferably about 0.1 to 100 μm, more preferably about 0.5 to 10 μm.
＜積層偏光フィルム＞
　本発明の積層偏光フィルム（光学積層体）は、前記偏光フィルムが光学層に貼り合わされているものである。前記光学層は特に限定はないが、例えば、反射板や半透過板、位相差板（１／２や１／４等の波長板を含む）、視野角補償フィルム等の液晶表示装置等の形成に用いられることのある光学層を１層又は２層以上用いることができる。前記積層偏光フィルムとしては、特に、前記偏光フィルムに更に反射板又は半透過反射板が積層されてなる反射型偏光フィルム又は半透過型偏光フィルム、前記偏光フィルムに更に位相差板が積層されてなる楕円偏光フィルム又は円偏光フィルム、前記偏光フィルムに更に視角補償フィルムが積層されてなる広視野角偏光フィルム、あるいは前記偏光フィルムに更に輝度向上フィルムが積層されてなる偏光フィルムが挙げられる。 <Laminated polarizing film>
The laminated polarizing film (optical laminate) of the present invention has the polarizing film bonded to an optical layer. The optical layer is not particularly limited, but for example, it can be used to form a liquid crystal display device such as a reflective plate, a semi-transmissive plate, a retardation plate (including a 1/2 or 1/4 wavelength plate), a viewing angle compensation film, etc. One or more optical layers that are sometimes used can be used. The laminated polarizing film is particularly a reflective polarizing film or a semi-transmissive polarizing film in which the polarizing film is further laminated with a reflective plate or a transflective plate, and a retardation plate is further laminated in the polarizing film. Examples include an elliptical polarizing film or a circularly polarizing film, a wide viewing angle polarizing film in which a viewing angle compensation film is further laminated on the polarizing film, or a polarizing film in which a brightness enhancement film is further laminated on the polarizing film.
　前記偏光フィルム、あるいは前記積層偏光フィルムの一方の面あるいは両方の面には、液晶セルや有機ＥＬ素子等の画像表示セルと、視認側における前面透明板やタッチパネル等の前面透明部材等の他の部材を貼り合わせるための接着剤層が付設されてもよい。当該接着剤層としては、粘着剤層が好適である。前記粘着剤層を形成する粘着剤は特に制限されないが、例えば、アクリル系重合体、シリコーン系ポリマー、ポリエステル、ポリウレタン、ポリアミド、ポリエーテル、フッ素系やゴム系等のポリマーをベースポリマーとするものを適宜に選択して用いることができる。特に、アクリル系重合体を含む粘着剤のように、光学的透明性に優れ、適度な濡れ性と凝集性と接着性を示し、耐候性や耐熱性等に優れるものが好ましく用いられる。 On one or both sides of the polarizing film or the laminated polarizing film, an image display cell such as a liquid crystal cell or an organic EL element, and other front transparent members such as a front transparent plate or a touch panel on the viewing side are provided. An adhesive layer for bonding the members together may be provided. A pressure-sensitive adhesive layer is suitable as the adhesive layer. The adhesive forming the adhesive layer is not particularly limited, but examples include those having a base polymer such as an acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine-based polymer, or a rubber-based polymer. It can be selected and used as appropriate. In particular, pressure-sensitive adhesives containing acrylic polymers that have excellent optical transparency, exhibit appropriate wettability, cohesiveness, and adhesive properties, and are excellent in weather resistance, heat resistance, etc. are preferably used.
　前記偏光フィルムや前記積層偏光フィルムの片面又は両面への粘着剤層の付設は、適宜な方式で行いうる。粘着剤層の付設としては、例えば、粘着剤溶液を調製し、それを流延方式や塗布方式等の適宜な展開方式で前記偏光フィルムや前記積層偏光フィルム上に直接付設する方式、あるいは、セパレータ上に粘着剤層を形成して、それを前記偏光フィルムや前記積層偏光フィルム上に移着する方式等が挙げられる。前記粘着剤層の厚さは、使用目的や接着力等に応じて適宜に決定でき、一般には１～５００μｍであり、５～２００μｍであることが好ましく、１０～１００μｍであることがより好ましい。このように、前記偏光フィルムや前記積層偏光フィルムの少なくとも一方の面に粘着剤層が設けられたものを、粘着剤層付き偏光フィルム、又は粘着剤層付き積層偏光フィルムという。 The adhesive layer can be attached to one or both sides of the polarizing film or the laminated polarizing film using an appropriate method. For attaching the adhesive layer, for example, a method of preparing an adhesive solution and applying it directly onto the polarizing film or the laminated polarizing film using an appropriate developing method such as a casting method or a coating method, or a method of applying the adhesive solution directly onto the polarizing film or the laminated polarizing film, or using a separator. Examples include a method of forming an adhesive layer thereon and transferring it onto the polarizing film or the laminated polarizing film. The thickness of the adhesive layer can be determined as appropriate depending on the purpose of use, adhesive strength, etc., and is generally 1 to 500 μm, preferably 5 to 200 μm, and more preferably 10 to 100 μm. In this way, the polarizing film or the laminated polarizing film in which an adhesive layer is provided on at least one surface is referred to as a polarizing film with an adhesive layer or a laminated polarizing film with an adhesive layer.
＜画像表示パネル及び画像表示装置＞
　本発明の画像表示パネルは、画像表示セルに、前記偏光フィルムの偏光膜の視認側の反対側、又は前記積層偏光フィルムの偏光膜の視認側の反対側が貼り合わされているものである。また、本発明の画像表示装置は、前記画像表示パネルの偏光フィルム又は積層偏光フィルム側（視認側）に、前面透明部材を備えるものである。 <Image display panel and image display device>
In the image display panel of the present invention, the opposite side of the polarizing film to the viewing side of the polarizing film, or the side opposite to the viewing side of the polarizing film of the laminated polarizing film is bonded to the image display cell. Further, the image display device of the present invention includes a front transparent member on the polarizing film or laminated polarizing film side (viewing side) of the image display panel.
　前記画像表示セルとしては、例えば、液晶セルや有機ＥＬセル等が挙げられる。前記液晶セルとしては、例えば、外光を利用する反射型液晶セル、バックライト等の光源からの光を利用する透過型液晶セル、外部からの光と光源からの光の両者を利用する半透過半反射型液晶セルのいずれを用いてもよい。前記液晶セルが光源からの光を利用するものである場合、画像表示装置（液晶表示装置）は、画像表示セル（液晶セル）の視認側と反対側にも偏光フィルムが配置され、さらに光源が配置される。当該光源側の偏光フィルムと液晶セルとは、適宜の接着剤層を介して貼り合せられていることが好ましい。前記液晶セルの駆動方式としては、例えば、ＶＡモード、ＩＰＳモード、ＴＮモード、ＳＴＮモードやベンド配向（π型）等の任意なタイプのものを用いうる。 Examples of the image display cell include a liquid crystal cell and an organic EL cell. Examples of the liquid crystal cell include a reflective liquid crystal cell that uses external light, a transmissive liquid crystal cell that uses light from a light source such as a backlight, and a transflective liquid crystal cell that uses both external light and light from a light source. Any semi-reflective liquid crystal cell may be used. When the liquid crystal cell uses light from a light source, the image display device (liquid crystal display device) includes a polarizing film on the side opposite to the viewing side of the image display cell (liquid crystal cell), and further includes a light source. Placed. It is preferable that the polarizing film on the light source side and the liquid crystal cell are bonded together via a suitable adhesive layer. As a driving method for the liquid crystal cell, any type of driving method can be used, such as VA mode, IPS mode, TN mode, STN mode, or bend alignment (π type).
　前記有機ＥＬセルとしては、例えば、透明基板上に透明電極と有機発光層と金属電極とを順に積層して発光体（有機エレクトロルミネセンス発光体）を形成したもの等が好適に用いられる。前記有機発光層は、種々の有機薄膜の積層体であり、例えば、トリフェニルアミン誘導体等からなる正孔注入層と、アントラセン等の蛍光性の有機固体からなる発光層との積層体や、これらの発光層とペリレン誘導体等からなる電子注入層の積層体、あるいは正孔注入層、発光層、及び電子注入層の積層体等、種々層構成が採用され得る。 As the organic EL cell, for example, a cell in which a transparent electrode, an organic light-emitting layer, and a metal electrode are sequentially laminated on a transparent substrate to form a light-emitting body (organic electroluminescence light-emitting body) is preferably used. The organic light emitting layer is a laminate of various organic thin films, such as a laminate of a hole injection layer made of a triphenylamine derivative or the like and a light emitting layer made of a fluorescent organic solid such as anthracene; Various layer configurations can be adopted, such as a laminate of a light emitting layer and an electron injection layer made of a perylene derivative, or a laminate of a hole injection layer, a light emitting layer, and an electron injection layer.
　前記画像表示セルの視認側に配置される前面透明部材としては、例えば、前面透明板（ウインドウ層）やタッチパネル等が挙げられる。前記前面透明板としては、適宜の機械強度及び厚みを有する透明板が用いられる。このような透明板としては、例えば、アクリル系樹脂やポリカーボネート系樹脂のような透明樹脂板、あるいはガラス板等が用いられる。前記タッチパネルとしては、例えば、抵抗膜方式、静電容量方式、光学方式、超音波方式等の各種タッチパネルや、タッチセンサー機能を備えるガラス板や透明樹脂板等が用いられる。前記前面透明部材として静電容量方式のタッチパネルが用いられる場合、タッチパネルよりもさらに視認側に、ガラスや透明樹脂板からなる前面透明板が設けられることが好ましい。 Examples of the front transparent member disposed on the viewing side of the image display cell include a front transparent plate (window layer), a touch panel, and the like. As the front transparent plate, a transparent plate having appropriate mechanical strength and thickness is used. As such a transparent plate, for example, a transparent resin plate such as acrylic resin or polycarbonate resin, or a glass plate is used. As the touch panel, for example, various touch panels such as a resistive film type, a capacitance type, an optical type, an ultrasonic type, etc., a glass plate, a transparent resin plate, etc. having a touch sensor function are used. When a capacitive touch panel is used as the front transparent member, it is preferable that a front transparent plate made of glass or a transparent resin plate is provided further on the viewing side than the touch panel.
　以下に実施例を挙げて本発明をさらに詳細に説明するが、本発明はこれらの実施例のみに限定されるものではない。 The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples.
＜実施例１＞
＜偏光膜の作製＞
　非晶性ＰＥＴ基材に９μｍ厚のＰＶＡ層が製膜された積層体を延伸温度１３０℃の空中補助延伸によって延伸積層体を生成し、次に、延伸積層体を染色によって着色積層体を生成し、さらに着色積層体を延伸温度６５度のホウ酸水中延伸によって総延伸倍率が５．９４倍になるように非晶性ＰＥＴ基材と一体に延伸された５μｍ厚の偏光膜を含む光学フィルム積層体を生成した。このような２段延伸によって非晶性ＰＥＴ基材に製膜されたＰＶＡ層のＰＶＡ分子が高次に配向され、染色によって吸着されたヨウ素がポリヨウ素イオン錯体として一方向に高次に配向された厚さ５μｍの偏光膜を含む光学フィルム積層体を得た。 <Example 1>
<Preparation of polarizing film>
A laminate in which a 9 μm thick PVA layer was formed on an amorphous PET base material was subjected to auxiliary stretching in the air at a stretching temperature of 130°C to produce a stretched laminate, and then the stretched laminate was dyed to produce a colored laminate. Then, the colored laminate was stretched in boric acid water at a stretching temperature of 65 degrees to obtain an optical film containing a 5 μm thick polarizing film, which was stretched together with the amorphous PET base material so that the total stretching ratio was 5.94 times. A laminate was produced. Through such two-step stretching, the PVA molecules of the PVA layer formed on the amorphous PET base material are highly oriented, and the iodine adsorbed by dyeing is oriented in one direction as a polyiodine ion complex. An optical film laminate containing a polarizing film with a thickness of 5 μm was obtained.
＜偏光フィルムの作製＞
　酸素濃度約２．５％の窒素置換雰囲気下において、上記で得られた偏光膜を含む光学フィルム積層体の偏光膜面、及び、第２の透明保護フィルムとして、厚み１３μｍのシクロオレフィン系樹脂フィルム（日本ゼオン社製、ＺＦ１４）に、エキシマＵＶ処理装置（ウシオ電機株式会社製、ＳＶＣ３４２Ｓ－１Ｎ２－ＭＮ３－ＫＷＯ１、キセノンエキシマランプ）を用い、エキシマＵＶ光（波長１７２ｎｍ、ピーク照度７５ｍＷ／ｃｍ２、積算光量４５０ｍＪ／ｃｍ２）を照射し、表面改質を施した。続いて、各フィルムの表面改質面に水を塗布し、水が乾燥する前に、ラミネーターを用いて偏光膜と透明保護フィルムを貼り合わせた後、６０℃のオーブンで５分３０秒間乾燥させ、偏光膜と第２の透明保護フィルムが直接接合した偏光フィルムを得た。また、当該偏光フィルムのＰＥＴ基材を剥離し、上記と同様の手順で、第１の透明保護フィルムとして、厚み３μｍのシクロオレフィン系樹脂フィルム（２，４－トリクロロベンゼンとトルエンとの２：３混合溶剤９０ｇに、シクロオレフィン系ポリマー（ＣＯＰ）フィルム（商品名「ゼオノアフィルムＺＦ１４」）１０ｇを添加し、ＣＯＰ溶液を調製した後、バーコーター＃１３を用いて、ＰＥＴフィルム（剥離ライナー）上に調製したＣＯＰ溶液を塗工し、その後６０℃のオーブンで３分間乾燥させることにより、剥離ライナー上に厚み３μｍのＣＯＰ膜が積層された、剥離ライナー付きシクロオレフィン系樹脂フィルム。）を貼り合わせ、偏光膜の両面に透明保護フィルムが直接接合している偏光フィルムを得た。 <Preparation of polarizing film>
In a nitrogen-substituted atmosphere with an oxygen concentration of about 2.5%, the polarizing film surface of the optical film laminate containing the polarizing film obtained above and a cycloolefin resin film with a thickness of 13 μm as a second transparent protective film were removed. Excimer UV light (wavelength 172 nm, peak illuminance 75 mW/cm 2 , Surface modification was performed by irradiating with an integrated light amount of 450 mJ/cm 2 ). Next, water was applied to the surface-modified surface of each film, and before the water dried, the polarizing film and transparent protective film were pasted together using a laminator, and then dried in an oven at 60°C for 5 minutes and 30 seconds. A polarizing film in which the polarizing film and the second transparent protective film were directly bonded was obtained. Further, the PET base material of the polarizing film was peeled off, and a 3 μm thick cycloolefin resin film (2:4-trichlorobenzene and toluene) was prepared as a first transparent protective film using the same procedure as above. 10 g of cycloolefin polymer (COP) film (trade name "Zeonor Film ZF14") was added to 90 g of mixed solvent to prepare a COP solution, and then coated on PET film (release liner) using bar coater #13. By applying the prepared COP solution and then drying it in an oven at 60°C for 3 minutes, a cycloolefin resin film with a release liner, in which a 3 μm thick COP film is laminated on the release liner, is bonded. A polarizing film was obtained in which transparent protective films were directly bonded to both sides of the polarizing film.
＜カールの評価＞
　上記の偏光膜と透明保護フィルムが直接接合した偏光フィルムのＰＥＴ基材を剥離した後、２３℃相対湿度５５％環境で７２時間調湿し、１００ｍｍ×１００ｍｍで切り出し、樹脂フィルムの面を上にしてフィルムの４隅それぞれの水平面からの高さを測定し、４点の平均値を、フィルムのカールとした。表では、カールが２ｍｍ未満のものを◎、２ｍｍ以上３ｍｍ未満のものを〇、３ｍｍ以上５ｍｍ未満のものを△、５ｍｍ以上のものを×で示している。 <Evaluation of curl>
After peeling off the PET base material of the polarizing film to which the above polarizing film and transparent protective film were directly bonded, the humidity was controlled at 23°C and 55% relative humidity for 72 hours, and cut into 100 mm x 100 mm, with the resin film side facing up. The height from the horizontal plane of each of the four corners of the film was measured, and the average value of the four points was taken as the curl of the film. In the table, those with a curl of less than 2 mm are indicated by ◎, those with a curl of 2 mm or more but less than 3 mm are indicated by ○, those with a curl of 3 mm or more and less than 5 mm are indicated by △, and those with a curl of 5 mm or more are indicated by ×.
＜第１の透明保護フィルムの接着力（剥離強度）の評価＞
　上記の偏光膜と第１の透明保護フィルムならびに第２の透明保護フィルムが直接接合した偏光フィルムの第１の透明保護フィルム側に両面テープ（Ｎｏ．５００、日東電工社製）を貼り合わせた。さらに、偏光膜の延伸方向と平行に２００ｍｍ、直行方向に１５ｍｍの大きさに切り出し、偏光膜と第１の透明保護フィルムとの間にカッターナイフで切り込みを入れた後、両面テープの剥離フィルムを剥がし、粘着剤面をガラス板に貼り合わせた。角度自在タイプ粘着・皮膜剥離解析装置（ＶＰＡ－２、協和界面化学社製）により、９０度方向に偏光膜と第１の透明保護フィルムとを剥離速度１０００ｍｍ／ｍｉｎで剥離し、その剥離強度（Ｎ／１５ｍｍ）を測定した。 <Evaluation of adhesive strength (peel strength) of first transparent protective film>
A double-sided tape (No. 500, manufactured by Nitto Denko Corporation) was attached to the first transparent protective film side of the polarizing film in which the above polarizing film, the first transparent protective film, and the second transparent protective film were directly bonded. Furthermore, the polarizing film was cut out to a size of 200 mm in parallel to the stretching direction and 15 mm in the perpendicular direction, and a cut was made with a cutter knife between the polarizing film and the first transparent protective film, and then the release film of the double-sided tape was cut out. It was peeled off and the adhesive side was attached to a glass plate. The polarizing film and the first transparent protective film were peeled in a 90-degree direction at a peeling speed of 1000 mm/min using a flexible angle adhesive/film peeling analyzer (VPA-2, manufactured by Kyowa Interface Science Co., Ltd.), and the peel strength ( N/15mm) was measured.
＜第２の透明保護フィルムの接着力（剥離強度）の評価＞
　上記の偏光膜と第１の透明保護フィルムならびに第２の透明保護フィルムが直接接合した偏光フィルムの第２の透明保護フィルム側ＰＥＴ基材を剥離し、剥離面に両面テープ（Ｎｏ．５００、日東電工社製）を貼り合わせた。さらに、偏光膜の延伸方向と平行に２００ｍｍ、直行方向に１５ｍｍの大きさに切り出し、偏光膜と第２の透明保護フィルムとの間にカッターナイフで切り込みを入れた後、両面テープの剥離フィルムを剥がし、粘着剤面をガラス板に貼り合わせた。角度自在タイプ粘着・皮膜剥離解析装置（ＶＰＡ－２、協和界面化学社製）により、９０度方向に偏光膜と第２の透明保護フィルムとを剥離速度１０００ｍｍ／ｍｉｎで剥離し、その剥離強度（Ｎ／１５ｍｍ）を測定した。 <Evaluation of the adhesive strength (peel strength) of the second transparent protective film>
Peel off the PET base material on the second transparent protective film side of the polarizing film to which the above polarizing film, first transparent protective film, and second transparent protective film are directly bonded, and apply double-sided tape (No. 500, Nitto) to the peeled surface. (manufactured by Denkosha) was pasted together. Furthermore, the polarizing film was cut out to a size of 200 mm in parallel to the stretching direction and 15 mm in the perpendicular direction, and a cut was made with a cutter knife between the polarizing film and the second transparent protective film, and then the release film of the double-sided tape was cut out. It was peeled off and the adhesive side was attached to a glass plate. The polarizing film and the second transparent protective film were peeled in a 90-degree direction at a peeling speed of 1000 mm/min using a flexible angle adhesive/film peeling analyzer (VPA-2, manufactured by Kyowa Interface Science Co., Ltd.), and the peel strength ( N/15mm) was measured.
＜実施例２＞
　第２の透明保護フィルムとして、厚み２３μｍのシクロオレフィン系樹脂フィルム（日本ゼオン社製、ＺＦ１２）を用いたこと、第１の透明保護フィルムとして、厚み１３μｍのシクロオレフィン系樹脂フィルム（日本ゼオン社製、ＺＦ１４）を用いたこと以外は、実施例１と同様の操作にて、偏光膜の両面に透明保護フィルムが直接接合している偏光フィルムを得た。 <Example 2>
A 23 μm thick cycloolefin resin film (Nippon Zeon Co., Ltd., ZF12) was used as the second transparent protective film, and a 13 μm thick cycloolefin resin film (Nippon Zeon Co., Ltd.) was used as the first transparent protective film. , ZF14) was used, a polarizing film in which transparent protective films were directly bonded to both sides of the polarizing film was obtained in the same manner as in Example 1.
＜実施例３＞
　第１の透明保護フィルムとして、厚み５μｍのシクロオレフィン系樹脂フィルム（２，４－トリクロロベンゼンとトルエンとの２：３混合溶剤８４ｇに、シクロオレフィン系ポリマー（ＣＯＰ）フィルム（商品名「ゼオノアフィルムＺＦ１４」）１６ｇを添加し、ＣＯＰ溶液を調製した後、バーコーター＃１３を用いて、ＰＥＴフィルム（剥離ライナー）上に調製したＣＯＰ溶液を塗工し、その後６０℃のオーブンで３分間乾燥させることにより、剥離ライナー上に厚み５μｍのＣＯＰ膜が積層された、剥離ライナー付きシクロオレフィン系樹脂フィルム。）を用いたこと以外は、実施例１と同様の操作にて、偏光膜の両面に透明保護フィルムが直接接合している偏光フィルムを得た。 <Example 3>
As the first transparent protective film, a 5 μm thick cycloolefin resin film (cycloolefin polymer (COP) film (trade name "Zeonor Film ZF14") was added to 84 g of a 2:3 mixed solvent of 2,4-trichlorobenzene and toluene. '') to prepare a COP solution, apply the prepared COP solution on the PET film (release liner) using bar coater #13, and then dry it in an oven at 60 ° C for 3 minutes. Transparent protection was applied to both sides of the polarizing film in the same manner as in Example 1, except that a cycloolefin resin film with a release liner was used, in which a 5 μm thick COP film was laminated on the release liner. A polarizing film in which the films were directly bonded was obtained.
＜実施例４＞
＜偏光膜の作製＞
　平均重合度２４００、ケン化度９９．９モル％の厚み４５μｍのポリビニルアルコールフィルムを、３０℃の温水中に６０秒間浸漬し膨潤させた。次いで、ヨウ素／ヨウ化カリウム（重量比＝１／７）の濃度０．３％の水溶液に浸漬し、２．６倍まで延伸させながらフィルムを染色した。その後、６５℃の４重量％ホウ酸水溶液中で、トータルの延伸倍率が６倍となるように延伸を行った。延伸後に、５５℃のオーブンにて１分間乾燥を行い、ＰＶＡ系偏光膜を得た。この偏光膜の厚さは１８μｍ、水分率は１５重量％であった。 <Example 4>
<Preparation of polarizing film>
A polyvinyl alcohol film having a thickness of 45 μm and having an average degree of polymerization of 2400 and a degree of saponification of 99.9 mol % was immersed in warm water at 30° C. for 60 seconds to swell. Next, the film was immersed in an aqueous solution of iodine/potassium iodide (weight ratio = 1/7) with a concentration of 0.3% and dyed while being stretched to 2.6 times. Thereafter, stretching was performed in a 4% by weight aqueous boric acid solution at 65° C. so that the total stretching ratio was 6 times. After stretching, it was dried in an oven at 55° C. for 1 minute to obtain a PVA-based polarizing film. The thickness of this polarizing film was 18 μm, and the moisture content was 15% by weight.
＜偏光フィルムの作製＞
　上記で得られた偏光膜を用い、実施例２と同様の操作にて、偏光膜の両面に透明保護フィルムが直接接合している偏光フィルムを得た。 <Preparation of polarizing film>
Using the polarizing film obtained above, a polarizing film in which transparent protective films were directly bonded to both sides of the polarizing film was obtained in the same manner as in Example 2.
＜比較例１＞
　第２の透明保護フィルムとして、厚み１３μｍのシクロオレフィン系樹脂フィルム（日本ゼオン社製、ＺＦ１４）に、下記の活性エネルギー線硬化型接着剤をバーコーターで塗布し、ラミネーターを用いて、実施例１で得られた厚さ５μｍの偏光膜を含む光学フィルム積層体の偏光膜面と貼り合わせた。その状態で透明保護フィルム側から、活性エネルギー線照射を行い、接着剤を硬化させた。また、第２の透明保護フィルムの反対面にあるＰＥＴ基材を剥離し、上記と同様の手順で、第１の透明保護フィルムとして、実施例１に記載の厚み３μｍのシクロオレフィン系樹脂フィルムを貼り合わせ、偏光膜の両面に透明保護フィルムが活性エネルギー線接着剤を介して接している偏光フィルムを得た。
［活性エネルギー線硬化型接着剤］
　２－ヒドロキシエチルアクリルアミド（ＫＪケミカルズ社製、商品名：ＨＥＡＡ）１６．５重量部、４－ビニルフェニルボロン酸（東京化成工業社製）１重量部、２－ヒドロキシ－３－フェノキシプロピルアクリレート（東亞合成社製、商品名：アロニックスＭ－５７００）３０．５重量部、１，９－ノナンジオールジアクリレート（共栄社化学社製、商品名：ライトアクリレート１，９ＮＤ－Ａ）２５重量部、ヒドロキシピバリン酸ジアクリレート（共栄社化学社製、商品名：ライトアクリレートＨＰＰ－Ａ）１３重量部、（メタ）アクリレートを重合してなるオリゴマー（東亞合成社製、商品名：ＡＲＦＯＮ　ＵＰ－１１９０）１５重量部、２－メチル－１－［４－（メチルチオ）フェニル］－２－モルフォニルプロパン－１－オン（ＩＧＭ　ｒｅｓｉｎｓ社製、商品名：Ｏｍｎｉｒａｄ　９０７）３重量部、２，４－ジエチルチオキサントン（日本化薬社製、商品名：ＫＡＹＡＣＵＲＥ－ＤＥＴＸ－Ｓ）３重量部
［活性エネルギー線］
　活性エネルギー線として、可視光線（ガリウム封入メタルハライドランプ）　照射装置：Ｈｅｒａｅｕｓ社製Ｌｉｇｈｔ　ＨＡＭＭＥＲ１０　バルブ：Ｖバルブ　ピーク照度：８００ｍＷ／ｃｍ２、積算照射量８００／ｍＪ／ｃｍ２（波長３８０～４４０ｎｍ）を使用した。なお、可視光線の照度は、Ｓｏｌａｔｅｌｌ社製Ｓｏｌａ－Ｃｈｅｃｋシステムを使用して測定した。 <Comparative example 1>
As a second transparent protective film, the following active energy ray-curable adhesive was applied to a 13 μm thick cycloolefin resin film (Nippon Zeon Co., Ltd., ZF14) using a bar coater, and a laminator was used to apply Example 1. It was bonded to the polarizing film surface of the optical film laminate containing the polarizing film with a thickness of 5 μm obtained in . In this state, active energy rays were irradiated from the transparent protective film side to cure the adhesive. Further, the PET base material on the opposite side of the second transparent protective film was peeled off, and the 3 μm thick cycloolefin resin film described in Example 1 was applied as the first transparent protective film using the same procedure as above. By pasting together, a polarizing film was obtained in which a transparent protective film was in contact with both sides of the polarizing film via an active energy ray adhesive.
[Active energy ray curable adhesive]
16.5 parts by weight of 2-hydroxyethyl acrylamide (manufactured by KJ Chemicals, trade name: HEAA), 1 part by weight of 4-vinylphenylboronic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 2-hydroxy-3-phenoxypropyl acrylate (manufactured by Toa) 30.5 parts by weight of 1,9-nonanediol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Aronix M-5700), 25 parts by weight of 1,9-nonanediol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Light Acrylate 1,9ND-A), hydroxypivalic acid 13 parts by weight of diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Light Acrylate HPP-A), 15 parts by weight of oligomer formed by polymerizing (meth)acrylate (manufactured by Toagosei Co., Ltd., trade name: ARFON UP-1190), 2 -Methyl-1-[4-(methylthio)phenyl]-2-morphonylpropan-1-one (IGM resins, trade name: Omnirad 907) 3 parts by weight, 2,4-diethylthioxanthone (Nippon Kayaku Co., Ltd.) manufactured by KAYACURE-DETX-S) 3 parts by weight [Active energy ray]
Visible light (gallium-filled metal halide lamp) Irradiation device: Light HAMMER10 manufactured by Heraeus Bulb: V bulb Peak illuminance: 800 mW/cm 2 , cumulative irradiation amount 800/mJ/cm 2 (wavelength 380 to 440 nm) was used as the active energy ray. did. Note that the illuminance of visible light was measured using a Sola-Check system manufactured by Solatell.
＜比較例２＞
　第２の透明保護フィルムとして、厚み２３μｍのシクロオレフィン系樹脂フィルム（日本ゼオン社製、ＺＦ１２）を用いたこと、第１の透明保護フィルムとして、厚み１３μｍのシクロオレフィン系樹脂フィルム（日本ゼオン社製、ＺＦ１４）を用いたこと以外は、比較例１と同様の操作にて、偏光膜の両面に透明保護フィルムがＵＶ接着剤を介して接している偏光フィルムを得た。 <Comparative example 2>
A 23 μm thick cycloolefin resin film (Nippon Zeon Co., Ltd., ZF12) was used as the second transparent protective film, and a 13 μm thick cycloolefin resin film (Nippon Zeon Co., Ltd.) was used as the first transparent protective film. , ZF14) was used, the same operation as in Comparative Example 1 was performed to obtain a polarizing film in which transparent protective films were in contact with both surfaces of the polarizing film via a UV adhesive.
　上記の各実施例及び比較例で得た偏光フィルムを用い、実施例１と同様の評価を行った。結果を表１に示す。 The same evaluation as in Example 1 was performed using the polarizing films obtained in each of the above Examples and Comparative Examples. The results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　１０：偏光フィルム
　１１：偏光膜
　１２：第１の透明保護フィルム
　１３：第２の透明保護フィルム
　２０、及び３０：粘着剤層又は接着剤層
　８０：前面透明部材
　９０：画像表示セル
　１００：画像表示パネル
　２００：画像表示装置 10: Polarizing film 11: Polarizing film 12: First transparent protective film 13: Second transparent protective film 20 and 30: Adhesive layer or adhesive layer 80: Front transparent member 90: Image display cell 100: Image display Panel 200: Image display device

Claims (8)

  1. 　画像表示パネルを構成する偏光フィルムであって、
    　前記偏光フィルムは、第１の透明保護フィルム、偏光膜、及び第２の透明保護フィルムが、順に、備えられており、
    　前記第１の透明保護フィルム、及び前記第２の透明保護フィルムの少なくとも一方は、前記偏光膜と、粘着剤層又は接着剤層を介さずに、直接、接合されており、
    　前記第１の透明保護フィルムは、視認側の透明保護フィルムであり、かつ、厚みが前記第２の透明保護フィルムの厚みよりも薄いことを特徴とする偏光フィルム。     A polarizing film constituting an image display panel,
    The polarizing film includes a first transparent protective film, a polarizing film, and a second transparent protective film in this order,
    At least one of the first transparent protective film and the second transparent protective film is directly bonded to the polarizing film without an adhesive layer or an adhesive layer,
    The polarizing film is characterized in that the first transparent protective film is a transparent protective film on the viewing side and has a thickness thinner than that of the second transparent protective film.
  2. 　前記第２の透明保護フィルムの厚みが１０μｍ以上であることを特徴とする請求項１に記載の偏光フィルム。 The polarizing film according to claim 1, wherein the second transparent protective film has a thickness of 10 μm or more.
  3. 　前記偏光膜の厚みが２０μｍ以下であることが特徴とする請求項１又は２に記載の偏光フィルム。 The polarizing film according to claim 1 or 2, wherein the polarizing film has a thickness of 20 μm or less.
  4. 　前記第２の透明保護フィルムの厚みと前記第１の透明保護フィルムの厚みの比（第２の透明保護フィルムの厚み／第１の透明保護フィルムの厚み）が１．２以上であることを特徴とする請求項１～３のいずれかに記載の偏光フィルム。 The ratio of the thickness of the second transparent protective film to the thickness of the first transparent protective film (thickness of the second transparent protective film/thickness of the first transparent protective film) is 1.2 or more. The polarizing film according to any one of claims 1 to 3.
  5. 　前記第１の透明保護フィルム、及び前記第２の透明保護フィルムが、前記偏光膜と、粘着剤層又は接着剤層を介さずに、直接、接合されていることを特徴とする請求項１～４のいずれかに記載の偏光フィルム。 Claims 1 to 3, wherein the first transparent protective film and the second transparent protective film are directly bonded to the polarizing film without using an adhesive layer or an adhesive layer. 4. The polarizing film according to any one of 4.
  6. 　請求項１～５のいずかれに記載の偏光フィルムが光学層に貼り合わされていることを特徴とする積層偏光フィルム。 A laminated polarizing film, characterized in that the polarizing film according to any one of claims 1 to 5 is laminated to an optical layer.
  7. 　画像表示セルに、請求項１～５のいずかれに記載の偏光フィルムの偏光膜の視認側の反対側、又は請求項６に記載の積層偏光フィルムの偏光膜の視認側の反対側が貼り合わされていることを特徴とする画像表示パネル。 The side opposite to the viewing side of the polarizing film of the polarizing film according to any one of claims 1 to 5, or the side opposite to the viewing side of the polarizing film of the laminated polarizing film according to claim 6 is bonded to the image display cell. An image display panel characterized by:
  8. 　請求項７に記載の画像表示パネルの偏光フィルム又は積層偏光フィルム側に、前面透明部材を備えることを特徴とする画像表示装置。 An image display device comprising a front transparent member on the polarizing film or laminated polarizing film side of the image display panel according to claim 7.
PCT/JP2023/010848 2022-03-30 2023-03-20 Polarizing film, layered polarizing film, image display panel, and image display device WO2023189811A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008122502A (en) * 2006-11-09 2008-05-29 Sumitomo Chemical Co Ltd Method of manufacturing polarizing plate
JP2016224307A (en) * 2015-06-01 2016-12-28 日東電工株式会社 Polarization film with adhesive layers on both sides, and image display unit
JP2017196823A (en) * 2016-04-28 2017-11-02 ウシオ電機株式会社 Method and device for producing joined structure
KR20220112592A (en) * 2021-02-04 2022-08-11 동우 화인켐 주식회사 Polarizer plate comprising protection film and the method for peeling the protection film

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008122502A (en) * 2006-11-09 2008-05-29 Sumitomo Chemical Co Ltd Method of manufacturing polarizing plate
JP2016224307A (en) * 2015-06-01 2016-12-28 日東電工株式会社 Polarization film with adhesive layers on both sides, and image display unit
JP2017196823A (en) * 2016-04-28 2017-11-02 ウシオ電機株式会社 Method and device for producing joined structure
KR20220112592A (en) * 2021-02-04 2022-08-11 동우 화인켐 주식회사 Polarizer plate comprising protection film and the method for peeling the protection film

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