WO2021220740A1 - 偏光板および光学機能層付偏光板 - Google Patents

偏光板および光学機能層付偏光板 Download PDF

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Publication number
WO2021220740A1
WO2021220740A1 PCT/JP2021/014706 JP2021014706W WO2021220740A1 WO 2021220740 A1 WO2021220740 A1 WO 2021220740A1 JP 2021014706 W JP2021014706 W JP 2021014706W WO 2021220740 A1 WO2021220740 A1 WO 2021220740A1
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Prior art keywords
layer
polarizing plate
protective layer
epoxy resin
polarizer
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PCT/JP2021/014706
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English (en)
French (fr)
Japanese (ja)
Inventor
和哉 三輪
卓史 上条
大介 濱本
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日東電工株式会社
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Priority claimed from JP2020110539A external-priority patent/JP2021177229A/ja
Application filed by 日東電工株式会社 filed Critical 日東電工株式会社
Priority to KR1020227037387A priority Critical patent/KR20230002504A/ko
Priority to CN202180031624.8A priority patent/CN115485593A/zh
Publication of WO2021220740A1 publication Critical patent/WO2021220740A1/ja

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
    • 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
    • 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
    • G02F1/13363—Birefringent elements, e.g. for optical compensation
    • 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
    • G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/02—Details

Definitions

  • the present invention relates to a polarizing plate and a polarizing plate with an optical functional layer.
  • a polarizing plate is often arranged on at least one side of a display cell due to the image forming method.
  • image display devices have become thinner and more flexible, and along with this, there is a strong demand for thinner polarizing plates.
  • the thinner the polarizing plate the more remarkable the problem of durability that the optical characteristics in a heating and humidifying environment deteriorate.
  • the present invention has been made to solve the above-mentioned conventional problems, and its main purpose is a polarizing plate and an optical functional layer that achieve both excellent durability and excellent flexibility despite being extremely thin.
  • the purpose is to provide a polarizing plate.
  • the polarizing plate of the present invention includes a polarizing element and a protective layer arranged on one side of the polarizing element.
  • This protective layer is composed of a photocationic cured product of an epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton, or a solidified product of a coating film of an organic solvent solution of an epoxy resin. Has been done.
  • the total thickness of this polarizing plate is 20 ⁇ m or less.
  • the protective layer is a photocationic cured product of an epoxy resin having at least one selected from the group consisting of the aromatic skeleton and the hydrogenated aromatic skeleton, further comprising an oxetane resin. ..
  • the softening temperature of the protective layer is 100 ° C. or higher.
  • the protective layer has a thickness of 10 ⁇ m or less.
  • the thickness of the polarizer is 10 ⁇ m or less.
  • the epoxy resin having at least one selected from the group consisting of the aromatic skeleton and the hydrogenated aromatic skeleton is an epoxy resin having a biphenyl skeleton.
  • a polarizing plate with an optical functional layer is provided.
  • the polarizing plate with an optical functional layer includes the polarizing plate and an optical functional layer arranged on the opposite side of the protective layer of the polarizer. The total thickness of this polarizing plate with an optical functional layer is 25 ⁇ m or less.
  • the optical functional layer functions as a protective layer separate from the protective layer.
  • the optical functional layer is a retardation layer having a circularly polarized light function or an elliptically polarized light function.
  • the protective layer is coated with a photocationic cured product of an epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton or an organic solvent solution of the epoxy resin. It is composed of a solidified film. Therefore, it is possible to provide a polarizing plate having both excellent durability and excellent flexibility and a polarizing plate with an optical functional layer.
  • Refractive index (nx, ny, nz) “Nx” is the refractive index in the direction in which the in-plane refractive index is maximized (that is, the slow-phase axis direction), and “ny” is the in-plane direction orthogonal to the slow-phase axis (that is, the phase-advance axis direction). Is the refractive index of, and "nz” is the refractive index in the thickness direction.
  • In-plane phase difference (Re) “Re ( ⁇ )” is an in-plane phase difference measured with light having a wavelength of ⁇ nm at 23 ° C.
  • Re (550) is an in-plane phase difference measured with light having a wavelength of 550 nm at 23 ° C.
  • Phase difference in the thickness direction (Rth) is a phase difference in the thickness direction measured with light having a wavelength of ⁇ nm at 23 ° C.
  • Rth (550) is a phase difference in the thickness direction measured with light having a wavelength of 550 nm at 23 ° C.
  • FIG. 1 is a schematic cross-sectional view of a polarizing plate according to one embodiment of the present invention.
  • the polarizing plate 100 of the illustrated example has a polarizing element 10 and a protective layer 20 arranged on one side of the polarizing element 10.
  • the total thickness of the polarizing plate 100 is 20 ⁇ m or less.
  • the protective layer 20 is a solidified product of a photocationic cured product of an epoxy resin or a coating film of an organic solvent solution of an epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton. ..
  • the protective layer is a layer formed by curing an epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton by photocationic polymerization, or an organic solvent of the epoxy resin. It is a solidified coating film of the solution.
  • the thickness of the polarizer 10 is preferably 10 ⁇ m or less.
  • the thickness of the protective layer 20 is preferably 10 ⁇ m or less.
  • the softening temperature of the protective layer is preferably 100 ° C. or higher. The softening temperature of the protective layer can be determined by the epoxy resin used.
  • the total thickness of the polarizing plate 100 is 20 ⁇ m or less, preferably 15 ⁇ m or less, and more preferably 10 ⁇ m or less. According to the present invention, it is possible to provide a polarizing plate having both excellent durability and excellent flexibility even when the total thickness of the polarizing plate is within the above range.
  • the total thickness of the polarizing plate is, for example, 5 ⁇ m or more.
  • Each layer or optical film constituting the polarizing plate is typically bonded via an adhesive layer.
  • the adhesive layer include an adhesive layer and an adhesive layer.
  • the adhesive layer can be preferably adopted. With such a configuration, the polarizing plate can be further thinned.
  • Typical examples of the adhesive constituting the adhesive layer include an active energy ray-curable adhesive (for example, an ultraviolet curable adhesive).
  • the thickness of the polarizing plate can be extremely thin. Therefore, it can be suitably applied to a flexible image display device. More preferably, the image display device has a curved shape (substantially a curved display screen) and / or is bendable or bendable. Specific examples of the image display device include a liquid crystal display device and an electroluminescence (EL) display device (for example, an organic EL display device and an inorganic EL display device). Needless to say, the above description does not prevent the polarizing plate of the present invention from being applied to a normal image display device.
  • EL electroluminescence
  • FIG. 2 is a schematic cross-sectional view of a polarizing plate with an optical functional layer according to one embodiment of the present invention.
  • the polarizing plate 110 with an optical functional layer of the illustrated example includes a polarizing element 10, a protective layer 20 arranged on one side of the polarizer, and an optical functional layer 30 arranged on the other side of the polarizer. ..
  • the total thickness of the polarizing plate with an optical functional layer is 25 ⁇ m or less.
  • the polarizing plate 10 and the polarizing plate 100 are used as the protective layer 20.
  • the total thickness of the polarizing plate 110 with an optical functional layer is 25 ⁇ m or less, preferably 20 ⁇ m or less, and more preferably 15 ⁇ m or less. According to the present invention, it is possible to provide a polarizing plate having both excellent durability and excellent flexibility even when the total thickness of the polarizing plate is within the above range.
  • the total thickness of the polarizing plate with an optical functional layer is, for example, 10 ⁇ m or more.
  • the optical functional layer functions as a protective layer separate from the protective layer 20.
  • a protective layer can also function as a retardation layer having predetermined retardation and optical characteristics.
  • the optical functional layer is a retardation layer having a circularly polarized light function or an elliptically polarized light function.
  • Such a retardation layer can also function as a protective layer for the polarizer.
  • the retardation layer is an orientation-solidified layer of a liquid crystal compound.
  • the retardation layer may be a single layer of the orientation solidification layer, or may have a laminated structure of the first orientation solidification layer and the second orientation solidification layer.
  • a polarizing plate in which the optical functional layer is a retardation layer may be referred to as a polarizing plate with a retardation layer.
  • Each layer or optical film constituting the polarizing plate with an optical functional layer is typically bonded via an adhesive layer.
  • the adhesive layer include an adhesive layer and an adhesive layer.
  • the adhesive layer can be preferably adopted. With such a configuration, the polarizing plate with an optical functional layer can be further thinned.
  • Typical examples of the adhesive constituting the adhesive layer include an active energy ray-curable adhesive (for example, an ultraviolet curable adhesive).
  • a polarizing plate provided with an optical functional layer that functions as a retardation layer may be further provided with another retardation layer.
  • Another retardation layer is typically provided on the outside (opposite side of the polarizer 10) of the optical functional layer (phase difference layer) 30.
  • Such another retardation layer is preferably provided when the retardation layer is a single layer of an oriented solidification layer.
  • the optical functional layer (phase difference layer) 30 may be referred to as a first retardation layer, and another retardation layer may be referred to as a second retardation layer.
  • the polarizing plate with an optical functional layer may further include other retardation layers.
  • the optical characteristics for example, refractive index characteristics, in-plane retardation, Nz coefficient, photoelastic coefficient
  • thickness, arrangement position, and the like of the other retardation layers can be appropriately set according to the purpose.
  • the polarizing plate with an optical functional layer may be provided with a conductive layer or an isotropic base material with a conductive layer.
  • the conductive layer or the isotropic base material with the conductive layer is typically provided on the outside of the optical functional layer 30 (opposite to the polarizer 10).
  • the polarizing plate is a polarizing plate with a retardation layer having a retardation layer and another retardation layer, the other retardation layer and the conductive layer or the isotropic base material with the conductive layer are typically positioned. It is provided in this order from the phase difference layer (optical functional layer) 30 side.
  • the polarizing plate or the polarizing plate with a retardation layer has a so-called touch sensor incorporated between an image display cell (for example, an organic EL cell) and the polarizing plate. It can be applied to an inner touch panel type input display device.
  • an image display cell for example, an organic EL cell
  • the protective layer is a solidification of a photocationically cured product of an epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton, or a coating film of an organic solvent solution of an epoxy resin.
  • the simple substance transmittance Ts can be measured using, for example, an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, product name "V7100").
  • the degree of polarization P is calculated by the following equation from the single transmittance (Ts), the parallel transmittance (Tp) and the orthogonal transmittance (Tc) measured using an ultraviolet-visible spectrophotometer.
  • Polarization degree (P) (%) ⁇ (Tp-Tc) / (Tp + Tc) ⁇ 1/2 ⁇ 100
  • the Ts, Tp, and Tc are Y values measured by the JIS Z 8701 2 degree field of view (C light source) and corrected for luminosity factor.
  • Ts and P are substantially properties of the polarizer.
  • ⁇ Ts and ⁇ P are calculated by the following formulas, respectively.
  • Ts 0 is the single transmittance before leaving (initial)
  • Ts 48 is the single transmittance after leaving
  • P 0 is the degree of polarization before leaving (initial)
  • P 48 is after leaving.
  • ⁇ Ts is preferably 3.0% or less, more preferably 2.7% or less, still more preferably 2.4% or less.
  • ⁇ P is preferably ⁇ 1.0% to 0%, more preferably ⁇ 0.5% to 0%, and even more preferably ⁇ 0.3% to 0%.
  • an adhesive layer (not shown) is provided on the opposite side of the optical functional layer from the polarizer, and the polarizing plate can be attached to the image display cell. Further, it is preferable that a release film is temporarily attached to the surface of the pressure-sensitive adhesive layer until the polarizing plate is used. By temporarily attaching the release film, the pressure-sensitive adhesive layer can be protected and rolls can be formed.
  • the polarizing plate and the polarizing plate with an optical functional layer of the present invention may be single-wafered or elongated.
  • the term "long” means an elongated shape having a length sufficiently long with respect to the width, and for example, an elongated shape having a length of 10 times or more, preferably 20 times or more with respect to the width. include.
  • the elongated polarizing plate can be wound in a roll shape.
  • Polarizer As the polarizer, any suitable polarizer can be adopted.
  • the polarizer can typically be made using a laminate of two or more layers. The method for manufacturing the polarizer will be described later in Section F as a method for manufacturing the polarizing plate.
  • the thickness of the polarizer is preferably 10 ⁇ m or less, more preferably 1 ⁇ m to 8 ⁇ m, further preferably 1 ⁇ m to 7 ⁇ m, and particularly preferably 2 ⁇ m to 5 ⁇ m.
  • the boric acid content of the polarizer is preferably 10% by weight or more, more preferably 13% by weight to 25% by weight.
  • the boric acid content can be calculated as, for example, the amount of boric acid contained in the polarizer per unit weight by using the following formula from the neutralization method.
  • the iodine content of the polarizer is preferably 2% by weight or more, more preferably 2% by weight to 10% by weight.
  • the iodine content of the polarizer is in such a range, the ease of curl adjustment at the time of bonding is well maintained due to the synergistic effect with the above boric acid content, and the curl at the time of heating is maintained. It is possible to improve the appearance durability at the time of heating while satisfactorily suppressing the above.
  • the term "iodine content” means the amount of all iodine contained in the polarizer (PVA-based resin film).
  • Iodine content means the amount of iodine that includes all of these forms.
  • the iodine content can be calculated, for example, by the calibration curve method of fluorescent X-ray analysis.
  • the polyiodine ion exists in a state in which a PVA-iodine complex is formed in the polarizer. By forming such a complex, absorption dichroism can be exhibited in the wavelength range of visible light.
  • a complex of PVA and tri-iodide ion (PVA ⁇ I 3 -) has a light absorption peak around 470 nm
  • a complex of PVA and five iodide ion (PVA ⁇ I 5 -) is 600nm near Has an absorptive peak.
  • polyiodine ions can absorb light over a wide range of visible light, depending on their morphology.
  • iodine ion (I ⁇ ) has an absorption peak near 230 nm and is not substantially involved in the absorption of visible light. Therefore, polyiodine ions present in the form of a complex with PVA may be mainly involved in the absorption performance of the polarizer.
  • the polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm.
  • the simple substance transmittance Ts of the polarizer is preferably 40% to 48%, more preferably 41% to 46%.
  • the degree of polarization P of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and further preferably 99.9% or more.
  • the protective layer is a photocationically cured epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton. It is composed of things. By using such a protective layer, it is possible to provide a polarizing plate having both excellent durability and excellent flexibility, and a polarizing plate with an optical functional layer. As described above, since the protective layer is a photocationic cured product, the composition for forming the protective layer contains a photocationic polymerization initiator.
  • the photocationic polymerization initiator is a photosensitizer having a function of a photoacid generator, and a typical example thereof is an ionic onium salt composed of a cationic portion and an anionic portion.
  • the cation part absorbs light and the anion part becomes a source of acid.
  • Ring-opening polymerization of the epoxy group proceeds by the acid generated from this photocationic polymerization initiator.
  • the protective layer which is the obtained photocationic cured product, has a high softening temperature, and the amount of iodine adsorbed can be reduced. Therefore, it is possible to provide a polarizing plate capable of achieving both excellent durability and excellent flexibility.
  • Epoxy Resin As the epoxy resin, any suitable epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton can be used. Examples of the aromatic skeleton include a benzene ring, a naphthalene ring, a fluorene ring and the like. Only one type of epoxy resin may be used, or two or more types may be used in combination. An epoxy resin having a biphenyl skeleton is preferably used as the aromatic skeleton. By using an epoxy resin having a biphenyl skeleton, a polarizing plate having both better durability and better flexibility can be provided. Hereinafter, as a representative example, an epoxy resin having a biphenyl skeleton will be described in detail.
  • the epoxy resin having a biphenyl skeleton is an epoxy resin containing the following structure. Only one type of epoxy resin having a biphenyl skeleton may be used, or two or more types may be used in combination.
  • R 1 to R 8 independently represent a hydrogen atom, a linear or branched substituted or unsubstituted hydrocarbon group having 1 to 12 carbon atoms, or a halogen element).
  • R 1 to R 8 independently represent a hydrogen atom, a linear or branched hydrocarbon group having 1 to 12 carbon atoms, or a halogen element.
  • Examples of the linear or branched substituted or unsubstituted hydrocarbon group having 1 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group and a sec-butyl group.
  • n-pentyl group isopentyl group, neopentyl group, tert-pentyl group, cyclopentyl group, n-hexyl group, isohexyl group, cyclohexyl group, n-heptyl group, cycloheptyl group, methylcyclohexyl group, n- Octyl group, cyclooctyl group, n-nonyl group, 3,3,5-trimethylcyclohexyl group, n-decyl group, cyclodecyl group, n-undecyl group, n-dodecyl group, cyclododecyl group, phenyl group, benzyl group, Examples thereof include a methylbenzyl group, a dimethylbenzyl group, a trimethylbenzyl group, a naphthylmethyl group, a pheneth
  • the linear or branched substituted or unsubstituted hydrocarbon group having 1 to 12 carbon atoms preferably has 1 to 1 to 12 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group and an n-butyl group.
  • An alkyl group of 4 can be mentioned.
  • Preferred examples of the halogen element include fluorine and bromine.
  • the epoxy resin having a biphenyl skeleton is an epoxy resin represented by the following formula. (In the formula, R 1 to R 8 are as described above, and n represents an integer of 0 to 6).
  • the epoxy resin having a biphenyl skeleton is an epoxy resin having only a biphenyl skeleton.
  • the epoxy resin having a biphenyl skeleton may contain a chemical structure other than the biphenyl skeleton.
  • the chemical structure other than the biphenyl skeleton include a bisphenol skeleton, an alicyclic structure, an aromatic ring structure and the like.
  • the proportion (molar ratio) of the chemical structure other than the biphenyl skeleton is preferably smaller than that of the biphenyl skeleton.
  • a commercially available product may be used as the epoxy resin having a biphenyl skeleton.
  • Examples of commercially available products include, for example, Mitsubishi Chemical Corporation, trade names: jER YX4000, jER YX4000H, jER YL6121, jER YL664, jER YL6677, jER YL6810, jER YL7399 and the like.
  • the epoxy resin having a biphenyl skeleton preferably has a glass transition temperature (Tg) of 100 ° C. or higher.
  • Tg glass transition temperature
  • the softening temperature of the protective layer is also approximately 100 ° C. or higher.
  • the obtained polarizing plate containing the protective layer tends to have excellent durability.
  • the Tg of the epoxy resin having a biphenyl skeleton is preferably 110 ° C. or higher, more preferably 120 ° C. or higher, still more preferably 125 ° C. or higher.
  • the Tg of the epoxy resin having a biphenyl skeleton is preferably 300 ° C.
  • Tg of the epoxy resin having a biphenyl skeleton is in such a range, moldability and processability can be excellent.
  • the epoxy equivalent of the epoxy resin having a biphenyl skeleton is preferably 100 g / equivalent or more, more preferably 150 g / equivalent or more, and further preferably 200 g / equivalent or more.
  • the epoxy equivalent of the epoxy resin having a biphenyl skeleton is preferably 3000 g / equivalent or less, more preferably 2500 g / equivalent or less, and further preferably 2000 g / equivalent or less.
  • an epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton may be used in combination with another resin. That is, a blend of an epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton and another resin may be used for forming the protective layer.
  • Other resins include, for example, thermoplastic resins such as styrene resins, polyethylenes, polypropylenes, polyamides, polyphenylene sulfides, polyether ether ketones, polyesters, polysulfones, polyphenylene oxides, polyacetals, polyimides, polyetherimides, and acrylic resins.
  • curable resins such as oxetane resins.
  • an acrylic resin and an oxetane resin are used.
  • the type and blending amount of the resin to be used in combination can be appropriately set according to the purpose and the desired properties of the obtained film.
  • a styrene resin can be used in combination as a retardation control agent.
  • any suitable acrylic resin can be used.
  • the (meth) acrylic compound for example, a (meth) acrylic compound having one (meth) acryloyl group in the molecule (hereinafter, also referred to as “monofunctional (meth) acrylic compound”), in the molecule.
  • examples thereof include (meth) acrylic compounds having two or more (meth) acryloyl groups (hereinafter, also referred to as “polyfunctional (meth) acrylic compounds”).
  • These (meth) acrylic compounds may be used alone or in combination of two or more.
  • These acrylic resins are described in, for example, Japanese Patent Application Laid-Open No. 2019-168500. The entire description of the publication is incorporated herein by reference.
  • any suitable compound having one or more oxetanyl groups in the molecule is used.
  • Oxetane compound having one oxetane group in the molecule such as oxetane, 3-ethyl-3- (oxylanylmethoxy) oxetane, (meth) acrylic acid (3-ethyloxetane-3-yl) methyl; 3-ethyl- 3 ⁇ [(3-ethyloxetane-3-yl) methoxy] methyl ⁇ oxetane, 1,4-bis [(3-ethyl-3-oxetanyl) methoxymethyl] benzene, 4,4'-bis [(3-ethyl) -3-oxetanyl) methoxymethyl]
  • An oxetane compound having two or more oxetane groups in the molecule such as biphenyl; and the like. Only one kind of these oxetane resins may be used, or two or more kinds may be combined.
  • 3-ethyl-3-hydroxymethyloxetane 1,4-bis [(3-ethyl-3-oxetanyl) methoxymethyl] benzene, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, 3-ethyl -3- (Oxylanylmethoxy) oxetane, (meth) acrylate (3-ethyloxetane-3-yl) methyl, 3-ethyl-3 ⁇ [(3-ethyloxetane-3-yl) methoxy] methyl ⁇ oxetane Etc. are used.
  • These oxetane resins are easily available and can be excellent in dilutability (low viscosity) and compatibility.
  • an oxetane resin having a molecular weight of 500 or less and liquid at room temperature (25 ° C.) is preferably used from the viewpoint of compatibility and adhesiveness. In one embodiment, it preferably contains an oxetane compound containing two or more oxetanel groups in the molecule, one oxetaneyl group and one (meth) acryloyl group or one epoxy group in the molecule.
  • Oxetane compounds are used, more preferably 3-ethyl-3 ⁇ [(3-ethyloxetane-3-yl) methoxy] methyl ⁇ oxetane, 3-ethyl-3- (oxylanylmethoxy) oxetane, (meth) acrylic. Acid (3-ethyloxetane-3-yl) methyl is used.
  • oxetane resin a commercially available product may be used. Specifically, Aron Oxetane OXT-101, Aron Oxetane OXT-121, Aron Oxetane OXT-212, and Aron Oxetane OXT-221 (all manufactured by Toagosei Co., Ltd.) can be used. Preferably, Aron Oxetane OXT-101 and Aron Oxetane OXT-221 can be used.
  • an epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton is used in combination with another resin
  • the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton is used.
  • the content of the epoxy resin having at least one selected from the group consisting of the aromatic skeleton and the hydrogenated aromatic skeleton in the blend of the epoxy resin having at least one selected and the other resin is preferable. It is 50% by weight to 100% by weight, more preferably 60% by weight to 100% by weight, still more preferably 70% by weight to 100% by weight, and particularly preferably 80% by weight to 100% by weight. If the content is less than 50% by weight, the heat resistance of the protective layer and sufficient adhesion to the polarizer may not be obtained.
  • the content of the oxetane resin is preferably 1 part by weight to 50 parts by weight with respect to 100 parts by weight of the total amount of the epoxy resin having a biphenyl skeleton and the oxetane resin. , More preferably 5 parts by weight to 45 parts by weight, still more preferably 10 parts by weight to 40 parts by weight. Within the above range, the curability can be improved, and the adhesion between the protective layer and the polarizer can also be improved.
  • the photocationic polymerization initiator is a photosensitizer having a function of a photoacid generator, and a typical example thereof is an ionic onium salt composed of a cationic portion and an anionic portion. In this onium salt, the cation part absorbs light and the anion part becomes a source of acid. Ring-opening polymerization of the epoxy group proceeds by the acid generated from this photocationic polymerization initiator.
  • any suitable compound capable of curing an epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton by irradiation with light such as ultraviolet rays. Can be used. Only one type of photocationic polymerization initiator may be used, or two or more types may be used in combination.
  • photocationic polymerization initiator examples include triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, p- (phenylthio) phenyldiphenylsulfonium hexafluoroantimonate, p- (phenylthio) phenyldiphenylsulfonium hexafluorophosphate, and the like.
  • a triphenylsulfonium salt-based hexafluoroantimonate type photocationic polymerization initiator and a diphenyliodonium salt-based hexafluoroantimonate type photocationic polymerization initiator are used.
  • a commercially available product may be used as the photocationic polymerization initiator.
  • Commercially available products include triphenylsulfonium salt-based hexafluoroantimonate type SP-170 (manufactured by ADEKA), CPI-101A (manufactured by San-Apro), WPAG-1056 (manufactured by Wako Pure Chemical Industries, Ltd.), and diphenyliodonium salt-based.
  • Hexafluoroantimonate type WPI-116 manufactured by Wako Pure Chemical Industries, Ltd.
  • WPI-116 manufactured by Wako Pure Chemical Industries, Ltd.
  • the content of the photocationic polymerization initiator is preferably from 0.1 part by weight with respect to 100 parts by weight of the epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton. It is 3 parts by weight, more preferably 0.25 parts by weight to 2 parts by weight. If the content of the photocationic polymerization initiator is less than 0.1 parts by weight, it may not be sufficiently cured even when irradiated with light (ultraviolet rays).
  • the protective layer is composed of a solidification of the coating film of an organic solvent solution of epoxy resin.
  • Epoxy resin The epoxy resin preferably has a glass transition temperature (Tg) of 100 ° C. or higher. As a result, the softening temperature of the protective layer is also approximately 100 ° C. or higher. When the Tg of the epoxy resin is 100 ° C. or higher, the polarizing plate containing the protective layer obtained from such a resin tends to have excellent durability.
  • the Tg of the epoxy resin is preferably 110 ° C. or higher, more preferably 120 ° C. or higher, still more preferably 125 ° C. or higher.
  • the Tg of the epoxy resin is preferably 300 ° C. or lower, more preferably 250 ° C. or lower, still more preferably 200 ° C. or lower, and particularly preferably 160 ° C. or lower. When the Tg of the epoxy resin is in such a range, moldability and processability can be excellent.
  • the epoxy resin any suitable epoxy resin can be adopted as long as it has Tg as described above.
  • the epoxy resin typically refers to a resin having an epoxy group in its molecular structure.
  • an epoxy resin having an aromatic ring in the molecular structure is preferably used.
  • an epoxy resin having a higher Tg can be obtained.
  • the aromatic ring in the epoxy resin having an aromatic ring in the molecular structure include a benzene ring, a naphthalene ring, a fluorene ring and the like. Only one type of epoxy resin may be used, or two or more types may be used in combination. When two or more kinds of epoxy resins are used, an epoxy resin containing an aromatic ring and an epoxy resin not containing an aromatic ring may be used in combination.
  • epoxy resin having an aromatic ring in its molecular structure examples include bisphenol A diglycidyl ether type epoxy resin, bisphenol F diglycidyl ether type epoxy resin, bisphenol S diglycidyl ether type epoxy resin, and resorcin diglycidyl ether.
  • Type epoxy resin hydroquinone diglycidyl ether type epoxy resin, terephthalic acid diglycidyl ester type epoxy resin, bisphenoxyethanol full orange glycidyl ether type epoxy resin, bisphenol full orange glycidyl ether type epoxy resin, biscresol full orange glycidyl ether type epoxy resin, etc.
  • Epoxy resin having two epoxy groups Novorak type epoxy resin, N, N, O-triglycidyl-P- or -m-aminophenol type epoxy resin, N, N, O-triglycidyl-4-amino-m -Or-5-Amino-o-cresol type epoxy resin, 1,1,1- (triglycidyloxyphenyl) methane type epoxy resin, etc.
  • Epoxy resin having three epoxy groups glycidylamine type epoxy resin (for example, diamino) Examples thereof include epoxy resins having four epoxy groups such as diphenylmethane type, diaminodiphenylsulfone type, and metaxylene diamine type).
  • a glycidyl ester type epoxy resin such as hexahydrophthalic anhydride type epoxy resin, tetrahydrophthalic anhydride type epoxy resin, dimer acid type epoxy resin, and p-oxybenzoic acid type may be used.
  • the weight average molecular weight of the epoxy resin is preferably 1,000,000 to 2000000, more preferably 5000 to 1,000,000, further preferably 10000 to 500000, particularly preferably 50,000 to 500000, and most preferably 60000 to 150,000.
  • the weight average molecular weight can be determined by polystyrene conversion using, for example, a gel permeation chromatograph (GPC system, manufactured by Tosoh). Tetrahydrofuran can be used as the solvent.
  • the epoxy equivalent of the epoxy resin is preferably 1000 g / equivalent or more, more preferably 3000 g / equivalent or more, and further preferably 5000 g / equivalent or more.
  • the epoxy equivalent of the epoxy resin is preferably 30,000 g / equivalent or less, more preferably 25,000 equivalent or less, still more preferably 20,000 g / equivalent or less.
  • the epoxy equivalent is in the above range, a more stable protective layer can be obtained.
  • the "epoxy equivalent” means "the mass of an epoxy resin containing 1 equivalent of an epoxy group” and can be measured according to JIS K7236.
  • the epoxy resin and another resin may be used in combination. That is, a blend of the epoxy resin and another resin may be used for molding the protective layer.
  • other resins include thermoplastic resins such as styrene resin, polyethylene, polypropylene, polyamide, polyphenylene sulfide, polyether ether ketone, polyester, polysulfone, polyphenylene oxide, polyacetal, polyimide, and polyetherimide.
  • the type and blending amount of the resin to be used in combination can be appropriately set according to the purpose and the desired properties of the obtained film.
  • a styrene resin can be used in combination as a retardation control agent.
  • the content of the epoxy resin in the blend of the epoxy resin and the other resin is preferably 50% by weight to 100% by weight, more preferably 60% by weight to 100% by weight. It is more preferably 70% by weight to 100% by weight, and particularly preferably 80% by weight to 100% by weight. If the content is less than 50% by weight, the heat resistance of the protective layer and sufficient adhesion to the polarizer may not be obtained.
  • the protective layer is a photocationically cured product of an epoxy resin or an organic solvent of an epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton. It is composed of a solidified coating film of the solution.
  • the thickness of the protective layer is preferably 10 ⁇ m or less, more preferably 7 ⁇ m or less, still more preferably 5 ⁇ m or less, and particularly preferably 3 ⁇ m or less.
  • the thickness of the protective layer can be, for example, 1 ⁇ m or more.
  • a photocationically cured product of an epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton, or a solidified product of a coating film of an organic solvent solution of an epoxy resin is an aqueous solution or an aqueous dispersion.
  • the solidified water-based coating film it has the advantage of being excellent in humidification durability because it has low moisture absorption and moisture permeability. As a result, it is possible to realize a polarizing plate having excellent durability that can maintain the optical characteristics even in a heating and humidifying environment.
  • the softening temperature of the protective layer is preferably 100 ° C. or higher. When the softening temperature of the protective layer is 100 ° C. or higher, the obtained polarizing plate containing the protective layer tends to have excellent durability.
  • the softening temperature of the protective layer is preferably 110 ° C. or higher, more preferably 120 ° C. or higher, and even more preferably 125 ° C. or higher.
  • the softening temperature of the protective layer is preferably 300 ° C. or lower, more preferably 250 ° C. or lower, still more preferably 200 ° C. or lower, and particularly preferably 160 ° C. or lower. When the softening point of the protective layer is within such a range, moldability and workability can be excellent.
  • the iodine adsorption amount of the protective layer is preferably 25% by weight or less, more preferably 10% by weight or less, further preferably 6.0% by weight or less, and particularly preferably 3.0% by weight or less. ..
  • the amount of iodine adsorbed can be measured by the following method.
  • the composition for forming a protective layer is applied to a base material (PET film) with an applicator to form a protective layer (thickness of about 3 ⁇ m).
  • the obtained PET film with a protective layer is cut into 1 cm ⁇ 1 cm (1 cm 2 ) to be used as a sample, and collected and weighed in a headspace vial (20 mL capacity).
  • a screw tube bottle (1.5 mL capacity) containing 1 mL of an iodine solution (iodine concentration 1% by weight, potassium iodide concentration 7% by weight) is also placed in this headspace vial and sealed.
  • the headspace vial is placed in a dryer at 65 ° C. and heated for 6 hours. As a result, I 2 in the gas state is adsorbed on the sample.
  • the sample is collected in a ceramic boat and burned using an automatic sample combustion device, and the generated gas is collected in 10 mL of the absorbing liquid.
  • this absorbing solution is prepared in 15 mL with pure water, and IC quantitative analysis is performed on the undiluted solution or the appropriately diluted solution.
  • the amount of iodine adsorbed is almost 0 when the same measurement is performed only with the PET film.
  • the amount of iodine adsorbed is almost 0 when the same measurement is performed only with the PET film.
  • the amount of iodine adsorbed % by weight from the following formula. Is calculated.
  • Iodine adsorption amount Iodine weight obtained by IC quantitative analysis / Weight of protective layer alone x 100
  • the following measuring device can be used.
  • Automatic sample combustion device "AQF-2100H” manufactured by Mitsubishi Chemical Analytech Co., Ltd.
  • the protective layer is preferably substantially optically isotropic.
  • substantially optically isotropic means that the phase difference at a wavelength of 550 nm is ⁇ 50 nm to +50 nm.
  • the in-plane retardation Re (550) is more preferably ⁇ 30 nm to +30 nm, further preferably ⁇ 10 nm to +10 nm, and particularly preferably 0 nm to 2 nm.
  • the phase difference Rth (550) in the thickness direction is more preferably ⁇ 5 nm to + 5 nm, further preferably -3 nm to + 3 nm, and particularly preferably -2 nm to + 2 nm.
  • Re (550) is an in-plane phase difference of the film measured with light having a wavelength of 550 nm at 23 ° C.
  • Rth (550) is a phase difference in the thickness direction of the film measured with light having a wavelength of 550 nm at 23 ° C.
  • nx is the refractive index in the direction in which the in-plane refractive index is maximized (that is, the slow-phase axis direction), and ny is the in-plane direction orthogonal to the slow-phase axis (that is, the phase-advancing axis direction). It is the refractive index, nz is the refractive index in the thickness direction, and d is the thickness (nm) of the film.
  • the light transmittance is preferably 85% or more, more preferably 88% or more, still more preferably 90% or more. When the light transmittance is in such a range, the desired transparency can be ensured.
  • the light transmittance can be measured, for example, by a method according to ASTM-D-1003.
  • the haze of the protective layer is preferably 5% or less, more preferably 3% or less, still more preferably 1.5% or less, and particularly preferably 1% or less.
  • the haze is 5% or less, a good clear feeling can be given to the film. Further, even when the polarizing plate on the visual side of the image display device is used, the displayed contents can be visually recognized satisfactorily.
  • the YI at a thickness of 3 ⁇ m of the protective layer is preferably 1.27 or less, more preferably 1.25 or less, still more preferably 1.23 or less, and particularly preferably 1.20 or less. If the YI exceeds 1.3, the optical transparency may be insufficient.
  • the b value (a measure of hue according to the hunter's color system) at a thickness of 3 ⁇ m of the protective layer is preferably less than 1.5, more preferably 1.0 or less. When the b value is 1.5 or more, an undesired color may appear.
  • a sample of the film constituting the protective layer is cut into 3 cm squares, and a high-speed integrating sphere type spectral transmittance measuring machine (trade name: DOT-3C: manufactured by Murakami Color Technology Laboratory) is used to determine the hue. Can be obtained by measuring and evaluating the hue according to the color system of the hunter.
  • the protective layer (for example, a photocationic cured product of an epoxy resin having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton and a solidified product of an epoxy resin coating film) is depending on the purpose. It may contain any suitable additive.
  • additives include ultraviolet absorbers; leveling agents; antioxidants such as hindered phenol-based, phosphorus-based, and sulfur-based; stabilizers such as light-resistant stabilizers, weather-resistant stabilizers, and heat-stabilizing agents; glass fibers, Reinforcing materials such as carbon fibers; Near infrared absorbers; Flame retardants such as tris (dibromopropyl) phosphate, triallyl phosphate, antimony oxide; Antistatic agents such as anionic, cationic and nonionic surfactants; Inorganic pigments , Organic pigments, colorants such as dyes; organic fillers or inorganic fillers; resin modifiers; organic fillers and inorganic fillers; plasticizers; lubricants; antistatic agents; flame retardants; and the like. Additives are usually added to the solution during film formation. The type, number, combination, amount of additive, etc. of the additive can be appropriately set according to the purpose.
  • An easy-adhesion layer may be formed on the polarizer side of the protective layer.
  • the easy-adhesion layer contains, for example, an aqueous polyurethane and an oxazoline-based cross-linking agent. By forming such an easy-adhesion layer, the adhesion between the protective layer and the polarizer can be improved.
  • a hard coat layer may be formed on the protective layer. The hard coat layer can be formed when the protective layer is used as the visible protective layer of the visible polarizing plate. When both the easy-adhesion layer and the hard coat layer are formed, typically they can be formed on different sides of the protective layer, respectively.
  • Optical functional layer D-1 Optical functional layer which is a protective layer
  • the protective layer is preferably a thin protective layer having a thickness of 20 ⁇ m or less.
  • the thickness of the protective layer is more preferably 18 ⁇ m or less, further preferably 15 ⁇ m or less, and particularly preferably 10 ⁇ m or less.
  • the thickness of the protective layer can be, for example, 1 ⁇ m or more.
  • the protective layer may be made of a resin film or a solidified coating film.
  • the resin constituting the resin film include cycloolefin-based resin and acrylic-based resin.
  • the solidified coating film may be, for example, a solidified coating film of a predetermined acrylic resin in an organic solvent solution, or a solidified coating film of the above-mentioned epoxy resin in an organic solvent solution.
  • the protective layer is composed of a solidified coating film, the thickness can be significantly reduced as compared with the resin film.
  • the protective layer (optical functional layer) may be a photocationically cured product of an epoxy resin having the above aromatic skeleton and hydrogenated aromatic skeleton.
  • the protective layer (optical functional layer) is typically arranged on the image display cell side when the polarizing plate is applied to the image display device.
  • the protective layer is preferably optically isotropic.
  • optically isotropic means that the in-plane retardation Re (550) is 0 nm to 10 nm and the thickness direction retardation Rth (550) is -10 nm to +10 nm. say.
  • the protective layer may be a retardation layer having any suitable retardation value.
  • the in-plane retardation Re (550) of the protective layer (phase difference layer) is, for example, 110 nm to 150 nm.
  • the retardation layer is a stretched film of a resin film. It may be an oriented solidified layer of a liquid crystal compound. It is preferably an oriented solidified layer of the liquid crystal compound.
  • the oriented solidified layer of the liquid crystal compound will be described in detail.
  • the retardation layer made of a stretched film of a resin film is described in, for example, JP-A-2017-54093 and JP-A-2018-60014. The description of these publications is incorporated herein by reference.
  • the "aligned solidified layer” means a layer in which the liquid crystal compound is oriented in a predetermined direction in the layer and the oriented state is fixed.
  • the “oriented solidified layer” is a concept including an oriented cured layer obtained by curing a liquid crystal monomer as described later.
  • the rod-shaped liquid crystal compounds are typically oriented in a state of being aligned in the slow-phase axial direction of the first retardation layer (homogeneous orientation).
  • the liquid crystal compound examples include a liquid crystal compound (nematic liquid crystal) in which the liquid crystal phase is a nematic phase.
  • a liquid crystal compound for example, a liquid crystal polymer or a liquid crystal monomer can be used.
  • the liquid crystal expression mechanism of the liquid crystal compound may be either lyotropic or thermotropic.
  • the liquid crystal polymer and the liquid crystal monomer may be used alone or in combination.
  • the liquid crystal monomer is preferably a polymerizable monomer and a crosslinkable monomer. This is because the orientation state of the liquid crystal monomer can be fixed by polymerizing or cross-linking (that is, curing) the liquid crystal monomer. After the liquid crystal monomers are oriented, for example, if the liquid crystal monomers are polymerized or crosslinked with each other, the oriented state can be fixed.
  • the polymer is formed by polymerization, and the three-dimensional network structure is formed by cross-linking, but these are non-liquid crystal.
  • the formed first retardation layer does not undergo a transition to a liquid crystal phase, a glass phase, or a crystal phase due to a temperature change peculiar to a liquid crystal compound, for example.
  • the first retardation layer becomes an extremely stable retardation layer that is not affected by temperature changes.
  • the temperature range in which the liquid crystal monomer exhibits liquid crystallinity differs depending on the type. Specifically, the temperature range is preferably 40 ° C. to 120 ° C., more preferably 50 ° C. to 100 ° C., and most preferably 60 ° C. to 90 ° C.
  • any suitable liquid crystal monomer can be adopted as the liquid crystal monomer.
  • the polymerizable mesogen compounds described in Special Tables 2002-533742 WO00 / 37585
  • EP358208 US5211877
  • EP66137 US4388453
  • WO93 / 22397 EP02671712, DE19504224, DE4408171, GB2280445 and the like
  • Specific examples of such a polymerizable mesogen compound include, for example, BASF's trade name LC242, Merck's trade name E7, and Wacker-Chem's trade name LC-Silicon-CC3767.
  • the liquid crystal monomer for example, a nematic liquid crystal monomer is preferable.
  • the solidified layer is subjected to an orientation treatment on the surface of a predetermined base material, and a coating liquid containing the liquid crystal compound is applied to the surface to orient the liquid crystal compound in a direction corresponding to the orientation treatment. It can be formed by fixing the orientation state.
  • the substrate is any suitable resin film and the oriented solidified layer formed on the substrate can be transferred to the surface of the polarizer 10.
  • any appropriate orientation treatment can be adopted.
  • Specific examples thereof include mechanical orientation treatment, physical orientation treatment, and chemical orientation treatment.
  • Specific examples of the mechanical orientation treatment include a rubbing treatment and a stretching treatment.
  • Specific examples of the physical orientation treatment include magnetic field orientation treatment and electric field orientation treatment.
  • Specific examples of the chemical alignment treatment include an orthorhombic deposition method and a photoalignment treatment.
  • As the treatment conditions for various orientation treatments any appropriate conditions can be adopted depending on the purpose.
  • the orientation of the liquid crystal compound is performed by treating at a temperature indicating the liquid crystal phase according to the type of the liquid crystal compound. By performing such temperature treatment, the liquid crystal compound takes a liquid crystal state, and the liquid crystal compound is oriented according to the orientation treatment direction of the surface of the base material.
  • the orientation state is fixed by cooling the liquid crystal compound oriented as described above.
  • the orientation state is fixed by subjecting the liquid crystal compound oriented as described above to a polymerization treatment or a crosslinking treatment.
  • liquid crystal compound and details of the method for forming the oriented solidified layer are described in JP-A-2006-163343. The description of this publication is incorporated herein by reference.
  • the oriented solidified layer is a form in which the discotic liquid crystal compound is oriented in any of vertical orientation, hybrid orientation, and inclined orientation.
  • the disk surface of the discotic liquid crystal compound is oriented substantially perpendicular to the film surface of the first retardation layer.
  • the average value of the angles formed by the film surface and the disk surface of the discotic liquid crystal compound is preferably 70 ° to 90 °, more preferably 80 ° to 90 °. , More preferably, it means that it is 85 ° to 90 °.
  • a discotic liquid crystal compound generally has a cyclic mother nuclei such as benzene, 1,3,5-triazine, and calix arene in the center of the molecule, and has a linear alkyl group, an alkoxy group, and a substituted benzoyl.
  • Typical examples of discotic liquid crystals include C.I. Research report by Destrade et al., Mol. Cryst. Liq. Cryst. Benzene derivatives, triphenylene derivatives, tolucene derivatives, phthalocyanine derivatives, and B.I.
  • the retardation layer (optical functional layer) 30 is a single layer of the orientation-solidified layer of the liquid crystal compound.
  • the retardation layer hereinafter, may be referred to as the first retardation layer as described above
  • the thickness thereof is preferably 0.5 ⁇ m to 7 ⁇ m. , More preferably 1 ⁇ m to 5 ⁇ m.
  • the first retardation layer is typically provided to impart antireflection characteristics to the polarizing plate, and functions as a ⁇ / 4 plate when the first retardation layer is a single layer of an orientation solidification layer. Can be done.
  • the in-plane retardation Re (550) of the first retardation layer is preferably 100 nm to 190 nm, more preferably 110 nm to 170 nm, and even more preferably 130 nm to 160 nm.
  • the Nz coefficient of the first retardation layer is preferably 0.9 to 1.5, and more preferably 0.9 to 1.3. By satisfying such a relationship, a very excellent reflected hue can be achieved when the obtained polarizing plate with a retardation layer is used in an image display device.
  • the first retardation layer may exhibit a reverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light, and a positive wavelength dispersion characteristic in which the retardation value decreases according to the wavelength of the measurement light. It may be shown, or may show a flat wavelength dispersion characteristic in which the phase difference value hardly changes with the wavelength of the measurement light.
  • the first retardation layer exhibits inverse dispersion wavelength characteristics.
  • the Re (450) / Re (550) of the retardation layer is preferably 0.8 or more and less than 1, and more preferably 0.8 or more and 0.95 or less. With such a configuration, very excellent antireflection characteristics can be realized.
  • the angle ⁇ formed by the slow axis of the first retardation layer and the absorption axis of the polarizer 10 is preferably 40 ° to 50 °, more preferably 42 ° to 48 °, and even more preferably about 45 °. °. If the angle ⁇ is in such a range, by using the ⁇ / 4 plate as the first retardation layer as described above, very excellent circularly polarized light characteristics (as a result, very excellent antireflection characteristics). A polarizing plate with a retardation layer having the above can be obtained.
  • the first retardation layer may have a laminated structure of a first oriented solidified layer and a second oriented solidified layer.
  • either one of the first oriented solidified layer and the second oriented solidified layer may function as a ⁇ / 4 plate, and the other may function as a ⁇ / 2 plate. Therefore, the thicknesses of the first oriented solidified layer and the second oriented solidified layer can be adjusted so as to obtain a desired in-plane phase difference between the ⁇ / 4 plate or the ⁇ / 2 plate.
  • the thickness of the first oriented solidified layer is, for example, 2.0 ⁇ m to 3.0 ⁇ m.
  • the thickness of the second oriented solidified layer is, for example, 1.0 ⁇ m to 2.0 ⁇ m.
  • the in-plane retardation Re (550) of the first oriented solidified layer is preferably 200 nm to 300 nm, more preferably 230 nm to 290 nm, and further preferably 250 nm to 280 nm.
  • the in-plane retardation Re (550) of the second oriented solidified layer is as described above with respect to the single oriented solidified layer.
  • the angle formed by the slow axis of the first oriented solidification layer and the absorption axis of the polarizer is preferably 10 ° to 20 °, more preferably 12 ° to 18 °, and even more preferably about 15 °. be.
  • the angle formed by the slow axis of the second oriented solidification layer and the absorption axis of the polarizer is preferably 70 ° to 80 °, more preferably 72 ° to 78 °, and even more preferably about 75 °. be.
  • liquid crystal compounds constituting the first oriented solidified layer and the second oriented solidified layer are described above with respect to the single oriented solidified layer. As explained in.
  • the second retardation layer is preferably provided when the first retardation layer is a single layer of the orientation solidification layer.
  • the retardation Rth (550) in the thickness direction of the second retardation layer is preferably ⁇ 50 nm to ⁇ 300 nm, more preferably ⁇ 70 nm to ⁇ 250 nm, still more preferably ⁇ 90 nm to ⁇ 200 nm, and particularly preferably ⁇ 100 nm to. -180 nm.
  • the second retardation layer preferably consists of a film containing a liquid crystal material fixed in a homeotropic orientation.
  • the liquid crystal material (liquid crystal compound) that can be homeotropically oriented may be a liquid crystal monomer or a liquid crystal polymer.
  • Specific examples of the liquid crystal compound and the method for forming the retardation layer include the liquid crystal compounds described in [0020] to [0028] of JP-A-2002-333642 and the method for forming the retardation layer.
  • the thickness of the second retardation layer is preferably 0.5 ⁇ m to 10 ⁇ m, more preferably 0.5 ⁇ m to 8 ⁇ m, and even more preferably 0.5 ⁇ m to 5 ⁇ m.
  • the conductive layer is made of any suitable base material by any suitable film forming method (for example, vacuum deposition method, sputtering method, CVD method, ion plating method, spray method, etc.). It can be formed by forming a metal oxide film on top of it.
  • suitable film forming method for example, vacuum deposition method, sputtering method, CVD method, ion plating method, spray method, etc.
  • the metal oxide include indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimon composite oxide, zinc-aluminum composite oxide, and indium-zinc composite oxide. Of these, indium-tin composite oxide (ITO) is preferable.
  • the thickness of the conductive layer is preferably 50 nm or less, more preferably 35 nm or less.
  • the thickness of the conductive layer is preferably 10 nm or more.
  • the conductive layer may be transferred from the base material to an optical functional layer (or a second retardation layer if present), and the conductive layer alone may be used as a constituent layer of a polarizing plate with a retardation layer. It may be laminated on the optical functional layer (or the second retardation layer if present) as a laminate with the material (base material with a conductive layer).
  • the substrate is optically isotropic, and therefore the conductive layer can be used in the polarizing plate as an isotropic substrate with a conductive layer.
  • any suitable isotropic base material can be adopted as the optically isotropic base material (isotropic base material).
  • the material constituting the isotropic base material include a material having a resin having no conjugate system such as a norbornene resin and an olefin resin as a main skeleton, and an acrylic resin having a cyclic structure such as a lactone ring and a glutarimide ring. Examples include the material contained in the main chain. When such a material is used, when an isotropic base material is formed, the occurrence of the phase difference due to the orientation of the molecular chains can be suppressed to be small.
  • the thickness of the isotropic base material is preferably 50 ⁇ m or less, more preferably 35 ⁇ m or less.
  • the thickness of the isotropic base material is, for example, 20 ⁇ m or more.
  • the conductive layer and / or the conductive layer of the isotropic base material with the conductive layer can be patterned as needed. By patterning, a conductive portion and an insulating portion can be formed. As a result, electrodes can be formed.
  • the electrode can function as a touch sensor electrode that senses contact with the touch panel.
  • any suitable method can be adopted. Specific examples of the patterning method include a wet etching method and a screen printing method.
  • Method for manufacturing polarizing plate F-1 Method for producing a polarizer
  • the method for producing a polarizer according to the above item B is a polyvinyl alcohol-based resin containing a halide and a polyvinyl alcohol-based resin (PVA-based resin) on one side of a long thermoplastic resin base material.
  • a layer (PVA-based resin layer) is formed to form a laminated body, and the laminated body is heated in the width direction while being conveyed in the longitudinal direction by aerial auxiliary stretching treatment, dyeing treatment, and underwater stretching treatment.
  • a drying shrinkage treatment for shrinking by 2% or more, and a drying shrinkage treatment, which are performed in this order, are included.
  • the content of the halide in the PVA-based resin layer is preferably 5 parts by weight to 20 parts by weight with respect to 100 parts by weight of the PVA-based resin.
  • the drying shrinkage treatment is preferably carried out using a heating roll, and the temperature of the heating roll is preferably 60 ° C. to 120 ° C. According to such a manufacturing method, the above-mentioned polarizer can be obtained.
  • a laminate containing a PVA-based resin layer containing a halide stretching the laminate to multi-step stretching including aerial auxiliary stretching and underwater stretching, and heating the stretched laminate with a heating roll.
  • a polarizer having excellent optical characteristics typically, single transmittance and degree of polarization
  • the laminated body can be uniformly shrunk over the entire laminated body while being conveyed.
  • a heating roll in the drying shrinkage treatment step the laminated body can be uniformly shrunk over the entire laminated body while being conveyed.
  • a polarizer having excellent optical characteristics can be stably produced, and the variation in the optical characteristics of the polarizer (particularly, the single transmittance) can be suppressed. can do.
  • the halide and the drying shrinkage treatment will be described. Details of manufacturing methods other than these are described in, for example, Japanese Patent Application Laid-Open No. 2012-73580 and Japanese Patent No. 6470455. The entire description of the publication is incorporated herein by reference.
  • a PVA-based resin layer containing a halide and a PVA-based resin can be formed by applying a coating liquid containing a halide and a PVA-based resin onto a thermoplastic resin base material and drying the coating film.
  • the coating liquid is typically a solution in which the above-mentioned halide and the above-mentioned PVA-based resin are dissolved in a solvent.
  • the solvent include water, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, various glycols, polyhydric alcohols such as trimethylpropane, and amines such as ethylenediamine and diethylenetriamine. These may be used alone or in combination of two or more.
  • the PVA-based resin concentration of the solution is preferably 3 parts by weight to 20 parts by weight with respect to 100 parts by weight of the solvent. With such a resin concentration, a uniform coating film can be formed in close contact with the thermoplastic resin base material.
  • any suitable halide can be adopted.
  • iodide and sodium chloride can be mentioned.
  • Iodides include, for example, potassium iodide, sodium iodide, and lithium iodide. Of these, potassium iodide is preferred.
  • the amount of the halide in the coating liquid is preferably 5 parts by weight to 20 parts by weight, and more preferably 10 parts by weight to 15 parts by weight with respect to 100 parts by weight of the PVA-based resin. If the amount of the halide is too large, the halide may bleed out and the finally obtained polarizer may become cloudy.
  • the stretching of the PVA-based resin layer increases the orientation of the polyvinyl alcohol molecules in the PVA-based resin.
  • the stretched PVA-based resin layer is immersed in a liquid containing water, the polyvinyl alcohol molecules become more oriented. The orientation may be disturbed and the orientation may decrease.
  • the laminate of the thermoplastic resin base material and the PVA-based resin layer is stretched in boric acid water, the laminate is stretched in boric acid water at a relatively high temperature in order to stabilize the stretching of the thermoplastic resin base material.
  • the tendency of the degree of orientation to decrease is remarkable.
  • stretching a PVA film alone in boric acid water is generally performed at 60 ° C.
  • stretching of a laminate of A-PET (thermoplastic resin base material) and a PVA-based resin layer is performed. It is carried out at a high temperature of about 70 ° C., and in this case, the orientation of PVA at the initial stage of stretching may decrease before it is increased by stretching in water.
  • a laminate of a PVA-based resin layer containing a halide and a thermoplastic resin base material is prepared, and the laminate is stretched at a high temperature (auxiliary stretching) in the air before being stretched in boric acid water.
  • Crystallization of the PVA-based resin in the PVA-based resin layer of the laminated body after the auxiliary stretching can be promoted.
  • the disorder of the orientation of the polyvinyl alcohol molecules and the decrease in the orientation can be suppressed as compared with the case where the PVA-based resin layer does not contain a halide.
  • the optical characteristics of the polarizer obtained through a treatment step of immersing the laminate in a liquid such as a dyeing treatment and a stretching treatment in water, can be improved.
  • the dry shrinkage treatment may be carried out by heating the entire zone by zone heating, or by heating the transport roll (using a so-called heating roll) (heating roll drying method). Preferably, both are used.
  • heating roll heating roll drying method
  • the crystallization of the thermoplastic resin base material can be efficiently promoted and the crystallinity can be increased, which is relatively low. Even at the drying temperature, the crystallinity of the thermoplastic resin base material can be satisfactorily increased.
  • the rigidity of the thermoplastic resin base material is increased, and the thermoplastic resin base material is in a state of being able to withstand the shrinkage of the PVA-based resin layer due to drying, and curling is suppressed.
  • the laminated body can be dried while being maintained in a flat state, so that not only curling but also wrinkles can be suppressed.
  • the laminated body can be improved in optical characteristics by shrinking in the width direction by a drying shrinkage treatment. This is because the orientation of PVA and the PVA / iodine complex can be effectively enhanced.
  • the shrinkage ratio in the width direction of the laminate by the drying shrinkage treatment is preferably 2% to 10%, more preferably 2% to 8%, and particularly preferably 4% to 6%.
  • FIG. 3 is a schematic view showing an example of the drying shrinkage treatment.
  • the laminate 200 is dried while being transported by the transport rolls R1 to R6 heated to a predetermined temperature and the guide rolls G1 to G4.
  • the transport rolls R1 to R6 are arranged so as to alternately and continuously heat the surface of the PVA resin layer and the surface of the thermoplastic resin base material.
  • one surface of the laminate 200 (for example, thermoplastic) is arranged.
  • the transport rolls R1 to R6 may be arranged so as to continuously heat only the resin base material surface).
  • Drying conditions can be controlled by adjusting the heating temperature of the transport roll (temperature of the heating roll), the number of heating rolls, the contact time with the heating roll, and the like.
  • the temperature of the heating roll is preferably 60 ° C. to 120 ° C., more preferably 65 ° C. to 100 ° C., and particularly preferably 70 ° C. to 80 ° C.
  • the crystallinity of the thermoplastic resin can be satisfactorily increased, curling can be satisfactorily suppressed, and an optical laminate having extremely excellent durability can be produced.
  • the temperature of the heating roll can be measured with a contact thermometer. In the illustrated example, six transport rolls are provided, but there is no particular limitation as long as there are a plurality of transport rolls.
  • the number of transport rolls is usually 2 to 40, preferably 4 to 30.
  • the contact time (total contact time) between the laminate and the heating roll is preferably 1 second to 300 seconds, more preferably 1 to 20 seconds, and further preferably 1 to 10 seconds.
  • the heating roll may be provided in a heating furnace (for example, an oven) or in a normal production line (in a room temperature environment). Preferably, it is provided in a heating furnace provided with a blowing means.
  • a heating furnace provided with a blowing means.
  • the temperature of hot air drying is preferably 30 ° C to 100 ° C.
  • the hot air drying time is preferably 1 second to 300 seconds.
  • the wind speed of hot air is preferably about 10 m / s to 30 m / s. The wind speed is the wind speed in the heating furnace and can be measured by a mini-vane type digital anemometer.
  • a washing treatment is performed after the underwater stretching treatment and before the drying shrinkage treatment.
  • the cleaning treatment is typically performed by immersing a PVA-based resin layer in an aqueous potassium iodide solution.
  • thermoplastic resin base material / polarizer a laminate of a thermoplastic resin base material / polarizer.
  • the protective layer can be formed by any suitable method.
  • an epoxy resin and light having at least one selected from the group consisting of an aromatic skeleton and a hydrogenated aromatic skeleton on the surface of the laminate obtained in the above F-1 term for example, the surface of a polarizer.
  • a protective layer can be formed by applying a composition containing a cationic polymerization initiator to form a coating film and irradiating the coating film with light (for example, ultraviolet rays).
  • an epoxy resin typically, an epoxy resin having a biphenyl skeleton
  • any suitable solvent capable of dissolving or uniformly dispersing the curing agent can be used.
  • the solvent include ethyl acetate, toluene, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclopentanone, and cyclohexanone.
  • the epoxy resin concentration of the solution is preferably 10 parts by weight to 30 parts by weight with respect to 100 parts by weight of the solvent. With such a resin concentration, a uniform coating film in close contact with the polarizer can be formed.
  • the content of the curing agent is as described in Item C above.
  • the solution may be applied to any suitable substrate or to a polarizer.
  • the cured product of the coating film formed on the substrate is transferred to the polarizer.
  • a protective layer is directly formed on the polarizer by curing the coating film by, for example, light irradiation.
  • the solution is applied to the polarizer and a protective layer is formed directly on the polarizer.
  • the adhesive layer or the pressure-sensitive adhesive layer required for transfer can be omitted, so that the polarizing plate can be further thinned.
  • Any suitable method can be adopted as the method for applying the solution. Specific examples include a roll coating method, a spin coating method, a wire bar coating method, a dip coating method, a die coating method, a curtain coating method, a spray coating method, and a knife coating method (comma coating method, etc.).
  • the coating film When the coating film is cured by light irradiation, the coating film can be irradiated with light (typically ultraviolet rays) so as to have an arbitrary appropriate irradiation amount using an arbitrary appropriate light source.
  • a light source of ultraviolet rays for example, a low pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, an electrodeless lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a chemical lamp, a black light, an LED lamp and the like can be used.
  • the dose of ultraviolet rays for example, 2mJ / cm 2 ⁇ 3000mJ / cm 2, preferably 10mJ / cm 2 ⁇ 2000mJ / cm 2.
  • the irradiation dose when using a high pressure mercury lamp as a light source, is usually 5mJ / cm 2 ⁇ 3000mJ / cm 2, preferably at the conditions of 50mJ / cm 2 ⁇ 2000mJ / cm 2.
  • the irradiation amount is usually 2 mJ / cm 2 to 2000 mJ / cm 2, preferably 10 mJ / cm 2 to 1000 mJ / cm 2 .
  • the irradiation time can be set to an arbitrary appropriate value according to the type of light source, the distance between the light source and the coating surface, the coating thickness, and other conditions.
  • the irradiation time is usually several seconds to several tens of seconds, and may be a fraction of a second. Irradiation of light can be performed from any suitable direction. From the viewpoint of preventing non-uniform curing, it is preferable to irradiate from the coated surface side of the protective layer forming composition.
  • the heat treatment can be carried out at any suitable temperature and time.
  • the heating temperature is, for example, 80 ° C. to 250 ° C., preferably 100 ° C. to 150 ° C.
  • the heating time is, for example, 10 seconds to 2 hours, preferably 5 minutes to 1 hour.
  • a composition containing an epoxy resin is applied to the surface of the laminate obtained in item F-1 (for example, the surface of a polarizer) to form a coating film, and the coating film is solidified.
  • a protective layer can be formed.
  • the epoxy resin concentration of the solution is preferably 3 to 20 parts by weight with respect to 100 parts by weight of the solvent. With such a resin concentration, a uniform coating film in close contact with the polarizer can be formed.
  • the solution may be applied to any suitable substrate or to a polarizer.
  • the solidified material of the coating film formed on the substrate is transferred to the polarizer.
  • the protective layer is directly formed on the polarizer by drying (solidifying) the coating film.
  • the solution is applied to the polarizer and a protective layer is formed directly on the polarizer.
  • Any suitable method can be adopted as the method for applying the solution. Specific examples include a roll coating method, a spin coating method, a wire bar coating method, a dip coating method, a die coating method, a curtain coating method, a spray coating method, and a knife coating method (comma coating method, etc.).
  • a protective layer that is a solidified product of the coating film can be formed.
  • the drying temperature is preferably 100 ° C. or lower, more preferably 50 ° C. to 70 ° C. When the drying temperature is in such a range, it is possible to prevent an adverse effect on the polarizer.
  • the drying time can vary depending on the drying temperature. The drying time can be, for example, 1 minute to 10 minutes.
  • the protective layer is formed, and as a result, a laminate of the thermoplastic resin base material / polarizer / protective layer can be obtained.
  • a polarizing plate having a polarizing element 10 and a protective layer 20 as shown in FIG. 1 can be obtained.
  • a resin film constituting another protective layer is attached to the polarizer surface of the laminate of the thermoplastic resin base material / polarizer, and then the thermoplastic resin base material is peeled off to form a protective layer on the peeled surface. You may. In this case, a polarizing plate having another protective layer can be obtained.
  • a polarizing plate with an optical functional layer can be manufactured by any suitable method. For example, it can be produced by producing a polarizing plate by the method described in the above item F, and laminating or transferring an arbitrary appropriate optical functional layer on the polarizer side of the polarizing plate.
  • the optical functional layer may be laminated on the polarizer via any suitable adhesive layer, or may be formed directly on the polarizer.
  • a protective layer (thickness: about 3 ⁇ m) was formed on one side of the PET film in the same manner as in the formation of the protective layer in each Example and Comparative Example.
  • the obtained PET film with a protective layer was cut into 1 cm ⁇ 1 cm (1 cm 2 ) to be used as a sample, and collected and weighed in a headspace vial (20 mL capacity).
  • a screw tube bottle (1.5 mL capacity) containing 1 mL of an iodine solution (iodine concentration 1% by weight, potassium iodide concentration 7% by weight) was also placed in this headspace vial and sealed. Then, the headspace vial was placed in a dryer at 65 ° C.
  • Iodine adsorption amount Iodine weight obtained by IC quantitative analysis / Weight of protective layer alone x 100
  • the measuring device and measuring conditions are as follows. [measuring device] Automatic sample combustion device: "AQF-2100H” manufactured by Mitsubishi Chemical Analytech Co., Ltd. IC (anion): "ICS-3000" manufactured by Thermo Fisher Scientific.
  • the single transmittance (Ts), the parallel transmittance (Tp) and the orthogonal transmittance (Tc) were measured, and the degree of polarization (P) was calculated by the following equation.
  • the measurement light was incident from the protective layer side.
  • Polarization degree (P) (%) ⁇ (Tp-Tc) / (Tp + Tc) ⁇ 1/2 ⁇ 100
  • the Ts, Tp, and Tc are Y values measured by the JIS Z 8701 2 degree field of view (C light source) and corrected for luminosity factor.
  • Ts and P are substantially properties of the polarizer.
  • the polarizing plate with an optical functional layer was left in an oven at 85 ° C.
  • ⁇ P (%) P 48 ⁇ P 0
  • a test piece 50 mm ⁇ having two sides facing each other in the direction orthogonal to the absorption axis direction of the polarizer and the absorption axis direction. 50 mm was cut out, and the test piece was attached to a non-alkali glass plate with an adhesive so that the protective layer was on the outside to prepare a test sample. From the obtained results of ⁇ Ts and ⁇ P, evaluation was made according to the following criteria.
  • ⁇ Ts is less than 2.0%, ⁇ P is -1.0% to 0% Possible: ⁇ Ts is 2.0% or more and less than 5.0%, ⁇ P is -3.0% or more and less than -1.0% Defective :: ⁇ Ts is 5.0% or more and ⁇ P is less than -3.0%, or , Color loss occurs
  • the bending was performed so that the optical functional layer or the retardation layer of the measurement sample was on the inside by sliding the gripping portion while gripping the longitudinal end portion of the measurement sample. It was evaluated according to the following criteria. Good: No cracks occurred after 50,000 bends Defective: Cracks and / or creases occurred on any of the components after less than 50,000 bends. If the measurement sample cracks, the cracks are absorbed shafts. It was along the direction orthogonal to (the width direction of the measurement sample).
  • Example 1 1. Fabrication of Laminate of Polarizer / Resin Base Material Amorphous isophthal copolymer polyethylene terephthalate film (thickness: 100 ⁇ m) as a resin base material, which is long, has a water absorption rate of 0.75%, and has a Tg of about 75 ° C. Was used. One side of the resin substrate was corona-treated. Polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Mitsubishi Chemical Co., Ltd., trade name "Gosefimer Z410”) are mixed in a ratio of 9: 1 to 100 parts by weight of PVA-based resin.
  • a PVA aqueous solution (coating liquid).
  • the PVA aqueous solution was applied to the corona-treated surface of the resin base material and dried at 60 ° C. to form a PVA-based resin layer having a thickness of 13 ⁇ m to prepare a laminate.
  • the obtained laminate was uniaxially stretched at the free end 2.4 times in the longitudinal direction (longitudinal direction) between rolls having different peripheral speeds in an oven at 130 ° C. (aerial auxiliary stretching treatment). Next, the laminate was immersed in an insolubilizing bath at a liquid temperature of 40 ° C.
  • the surface of a polyethylene terephthalate (PET) film was rubbed with a rubbing cloth and subjected to an orientation treatment.
  • the direction of the orientation treatment was set to be 15 ° when viewed from the visual side with respect to the direction of the absorption axis of the polarizer when the polarizing plate was attached.
  • the liquid crystal coating liquid was applied to the alignment-treated surface with a bar coater, and the liquid crystal compound was oriented by heating and drying at 90 ° C. for 2 minutes.
  • the liquid crystal layer thus formed was irradiated with light of 100 mJ / cm 2 using a metal halide lamp, and the liquid crystal layer was cured to form a liquid crystal oriented solidified layer A on the PET film.
  • a base material with an adhesive was attached to the surface of the oriented solidification layer B for reinforcement.
  • the resin base material is peeled off, and a retardation layer having a structure of a polarizer / an adhesive layer / a retardation layer (first orientation solidification layer / adhesion layer / second orientation solidification layer) / a base material with an adhesive is used.
  • a polarizing plate with a polarizing plate was obtained.
  • the obtained protective layer forming composition was applied to the surface of the polarizer of the polarizing plate with a retardation layer obtained above using a wire bar, and the coating film was dried at 60 ° C. for 3 minutes.
  • a protective layer was formed by irradiating ultraviolet rays with a high-pressure mercury lamp so that the integrated light intensity was 600 mJ / cm 2.
  • the thickness of the protective layer was 3 ⁇ m.
  • the base material with the pressure-sensitive adhesive layer was peeled off to obtain a polarizing plate (protective layer (photocationic curing layer of epoxy resin) / polarizer / retardation layer) provided with an optical functional layer.
  • the total thickness of the polarizing plate was 14 ⁇ m.
  • the obtained polarizing plate was subjected to the above evaluation. The results are shown in Table 1.
  • Example 2 A polarizing plate (protective layer (hardened epoxy resin)) was used in the same manner as in Example 1 except that a cycloolefin resin (COP) film (thickness 13 ⁇ m) was used as another protective layer instead of the retardation layer as the optical functional layer. Layer) / Polarizer / Protective layer (COP film)) was prepared. The total thickness of the polarizing plate was 22 ⁇ m. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • COP cycloolefin resin
  • Example 3 Polarizing plate (protective layer (hardened layer of epoxy resin) / Polarizer) was prepared. The total thickness of the polarizing plate was 8 ⁇ m. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 4 15 parts of epoxy resin with biphenyl skeleton (manufactured by Mitsubishi Chemical Co., Ltd., trade name: jER (registered trademark) YX4000) and 10 parts by weight of oxetane resin (manufactured by Toagosei Co., Ltd., trade name: Aron Oxetane (registered trademark) OXT-221) , was dissolved in 73 parts of methyl ethyl ketone to obtain an epoxy resin solution.
  • jER registered trademark
  • oxetane resin manufactured by Toagosei Co., Ltd., trade name: Aron Oxetane (registered trademark) OXT-221
  • Example 5 An optical functional layer was provided in the same manner as in Example 1 except that a bisphenol type epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name: jER® 828) was used instead of the epoxy resin having a biphenyl skeleton. A polarizing plate (protective layer (hardened layer of epoxy resin) / polarizer / retardation layer) was obtained. The total thickness of the polarizing plate was 14 ⁇ m. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 6 Polarized light having an optical functional layer in the same manner as in Example 4 except that a bisphenol type epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name: jER (registered trademark) 828) was used instead of the epoxy resin having a biphenyl skeleton. A plate (protective layer (photocationic curing layer of epoxy resin) / polarizer / retardation layer) was obtained. The total thickness of the polarizing plate was 14 ⁇ m. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 7 The optical functional layer was formed in the same manner as in Example 1 except that a hydrogenated bisphenol type epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., trade name: jER (registered trademark) YX8000) was used instead of the epoxy resin having a biphenyl skeleton. A provided polarizing plate (protective layer (hardened layer of epoxy resin) / polarizer / retardation layer) was obtained. The total thickness of the polarizing plate was 14 ⁇ m. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 8 The optical functional layer was formed in the same manner as in Example 4 except that a hydrogenated bisphenol type epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., trade name: jER (registered trademark) YX8000) was used instead of the epoxy resin having a biphenyl skeleton. A provided polarizing plate (protective layer (hardened layer of epoxy resin) / polarizer / retardation layer) was obtained. The total thickness of the polarizing plate was 14 ⁇ m. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 9 A polarizing plate having an optical functional layer was prepared in the same manner as in Example 1 except that the protective layer was prepared as follows.
  • Epoxy resin 1 manufactured by Mitsubishi Chemical Corporation, trade name: jER (registered trademark) 1256B40, weight average molecular weight: 40,000, epoxy equivalent: 7350
  • jER registered trademark
  • This epoxy resin solution is applied to the surface of the polarizing plate of the polarizing plate with a retardation layer (polarizer / adhesive layer / retardation layer / substrate with adhesive for reinforcement) used in Example 1 using a wire bar.
  • the coating film was dried at 60 ° C.
  • Example 10 Same as in Example 9 except that epoxy resin 2 (manufactured by Mitsubishi Chemical Corporation, trade name: jER (registered trademark) YX6954BH30, weight average molecular weight: 36000, epoxy equivalent: 13000) was used instead of epoxy resin 1. Formed a protective layer. The thickness of the protective layer was 3 ⁇ m. A polarizing plate (protective layer (solidified layer of epoxy resin coating film) / polarizer / retardation layer) having an optical functional layer was obtained in the same manner as in Example 9 except that this protective layer was used. The total thickness of the polarizing plate was 14 ⁇ m. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • a polyurethane-based water-dispersed resin manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Superflex SF210
  • a polyurethane-based water-dispersed resin has a thickness of 0.1 ⁇ m on the polarizer. To form an easy-adhesion layer.
  • an acrylic resin which is a copolymer of methyl methacrylate / ethyl acrylate (molar ratio 55/45) (manufactured by Kusumoto Kasei Co., Ltd., product name "B-" 722 ") 20 parts were dissolved in 80 parts of methyl ethyl ketone to obtain an acrylic resin solution (20%).
  • this acrylic resin solution is applied onto the easy-adhesion layer on the polarizing element surface of the polarizing plate obtained in 1 above using a wire bar, and the coating film is dried at 60 ° C. for 5 minutes to form the coating film.
  • a polarizing plate having an optical functional layer (protective layer (solidified layer of acrylic resin) / polarizing element / retardation layer) is provided in the same manner as in Example 1 except that a protective layer formed as a solidified substance is formed. Obtained. The thickness of the polarizing plate was 14 ⁇ m. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1. Since color loss occurred in the polarizing plate after the humidification test, ⁇ Ts and ⁇ P could not be measured.
  • Example 3 A protective layer (solidified coating film) was formed in the same manner as in Example 1 except that an aqueous polyester resin (manufactured by Mitsubishi Chemical Corporation, trade name: Nichigo Polyester WR905) was used. A polarizing plate with a retardation layer was produced in the same manner as in Example 1 except that this protective layer was used. The thickness of the polarizing plate was 14 ⁇ m. Since color loss occurred in the polarizing plate after the humidification test, ⁇ Ts and ⁇ P could not be measured. The results are shown in Table 1.
  • Example 4 A protective layer (solidified coating film) was formed in the same manner as in Example 1 except that an aqueous polyurethane resin (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., product name "Superflex SF210") was used. A polarizing plate with a retardation layer was produced in the same manner as in Example 1 except that this protective layer was used. Since color loss occurred in the polarizing plate after the humidification test, ⁇ Ts and ⁇ P could not be measured. The results are shown in Table 1.
  • the polarizing plate of the present invention is suitably used for an image display device.
  • image display devices include portable devices such as mobile information terminals (PDAs), smartphones, mobile phones, clocks, digital cameras, and portable game machines; OA devices such as personal computer monitors, laptop computers, and copiers; video cameras and televisions. , Home appliances such as microwave ovens; Back monitors, car navigation system monitors, car audio and other in-vehicle devices; Digital signage, commercial store information monitors and other exhibition devices; Surveillance monitors and other security devices; Nursing care Nursing care / medical equipment such as monitors for medical use and monitors for medical use;
  • Polarizer 10 Polarizer 20 Protective layer 30 Optical functional layer 100 Polarizing plate 110 Polarizing plate with optical functional layer
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JP2020046622A (ja) * 2018-09-21 2020-03-26 住友化学株式会社 偏光フィルム並びにそれを含む偏光板および表示装置
WO2020066830A1 (ja) * 2018-09-28 2020-04-02 住友化学株式会社 光学積層体、偏光板複合体、及び画像表示装置
JP2020095264A (ja) * 2018-11-29 2020-06-18 日東電工株式会社 粘着剤層付き偏光フィルム及び画像表示装置
JP2020095262A (ja) * 2018-11-29 2020-06-18 日東電工株式会社 タッチセンシング機能付液晶パネル、液晶表示装置および粘着剤層付き偏光フィルム

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