WO2021014685A1 - Procédé de production de plaque de polarisation circulaire mince - Google Patents

Procédé de production de plaque de polarisation circulaire mince Download PDF

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Publication number
WO2021014685A1
WO2021014685A1 PCT/JP2020/012191 JP2020012191W WO2021014685A1 WO 2021014685 A1 WO2021014685 A1 WO 2021014685A1 JP 2020012191 W JP2020012191 W JP 2020012191W WO 2021014685 A1 WO2021014685 A1 WO 2021014685A1
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WO
WIPO (PCT)
Prior art keywords
liquid crystal
polarizing plate
layer
crystal oriented
solidified layer
Prior art date
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PCT/JP2020/012191
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English (en)
Japanese (ja)
Inventor
理 小島
圭太 小川
Original Assignee
日東電工株式会社
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Application filed by 日東電工株式会社 filed Critical 日東電工株式会社
Priority to CN202080052466.XA priority Critical patent/CN114144707A/zh
Priority to KR1020227001628A priority patent/KR20220035386A/ko
Publication of WO2021014685A1 publication Critical patent/WO2021014685A1/fr

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3083—Birefringent or phase retarding elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
    • B32B37/14—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/02—Physical, chemical or physicochemical properties
    • B32B7/023—Optical properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/04—Interconnection of layers
    • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
    • 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

Definitions

  • the present invention relates to a method for manufacturing a thin circular polarizing plate.
  • circular polarizing plates are used for the purpose of improving display characteristics and preventing reflection.
  • a polarizer and a retardation film typically form an angle of 45 ° between the absorption axis of the polarizer and the slow axis of the retardation film. It is laminated in this way. Further, due to the demand for thinning of the organic EL panel, thinning of the circular polarizing plate is required.
  • the present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to have excellent runnability during roll transport, suppression of winding tightening during stagnation during roll transport, and appearance of a film.
  • An object of the present invention is to provide a method for manufacturing a thin circular polarizing plate in which defects are suppressed.
  • the method for producing a circular polarizing plate of the present invention includes a step of forming a liquid crystal oriented solidified layer on the surface of a substrate, a step of adhering the liquid crystal oriented solidified layer on the surface of the polarizing plate, and a step of bonding the liquid crystal oriented solidified layer of the polarizing plate.
  • the thickness of the circularly polarizing plate is 45 ⁇ m or less, including a step of temporarily attaching a separator to the side of the pressure-sensitive adhesive layer opposite to the liquid crystal oriented solidified layer so that the separator can be peeled off.
  • the surface protective film comprises a polyethylene resin or a polyethylene terephthalate resin. In one embodiment, the thickness of the surface protective film is 25 ⁇ m or more.
  • the polarizing plate and the liquid crystal oriented solidifying layer are bonded together via a photocurable adhesive.
  • the liquid crystal oriented solidified layer functions as a ⁇ / 4 plate.
  • another liquid crystal oriented solidified layer is further attached to the opposite side of the liquid crystal oriented solidified layer from the polarizing plate.
  • one of the liquid crystal oriented solidified layer and the other liquid crystal oriented solidified layer functions as a ⁇ / 2 plate, and the other functions as a ⁇ / 4 plate.
  • a liquid crystal oriented solidified layer formed on a base material is attached to the polarizing plate, and a surface protective film is temporarily attached before the base material is peeled off.
  • the following excellent effects can be obtained. That is, in the manufacturing process of the thin circular polarizing plate, the running performance during roll transport is excellent (for example, breakage is suppressed), and poor adhesive deformation, adhesive dents, etc. due to winding tightening during stagnation during roll transport are suppressed. At the same time, poor appearance of the obtained circularly polarizing plate (for example, stains on the visual side) is suppressed.
  • FIGS. 1 to (g) are schematic cross-sectional views for explaining the method for manufacturing a circularly polarizing plate according to the embodiment of the present invention in order of steps. It is the schematic sectional drawing of the circular polarizing plate obtained by the manufacturing method of one Embodiment of this invention.
  • FIGS. 1 (a) to 1 (g) are schematic cross-sectional views for explaining a method for manufacturing a circularly polarizing plate according to an embodiment of the present invention in order of steps.
  • each step of the method for manufacturing a circularly polarizing plate will be described in detail with reference to FIGS. 1 (a) to 1 (g).
  • the polarizing plate 10 is prepared.
  • the polarizing plate 10 typically includes a polarizing element and a protective layer arranged on at least one side of the polarizing element.
  • Protective layers may be placed on either side of the polarizer.
  • the protective layer 11 is arranged on one side of the polarizer 12.
  • the resin film forming the polarizer may be a single-layer resin film or a laminated body having two or more layers.
  • the polarizer composed of a single-layer resin film include a hydrophilic polymer film such as a polyvinyl alcohol (PVA) -based film, a partially formalized PVA-based film, and an ethylene / vinyl acetate copolymer system partially saponified film.
  • a hydrophilic polymer film such as a polyvinyl alcohol (PVA) -based film, a partially formalized PVA-based film, and an ethylene / vinyl acetate copolymer system partially saponified film.
  • PVA polyvinyl alcohol
  • a partially formalized PVA-based film ethylene / vinyl acetate copolymer system partially saponified film
  • examples thereof include those which have been dyed and stretched with a bicolor substance such as iodine or a bicolor dye, and polyene-based oriented films such as a dehydrated product of PVA and a dehydrogenated product of polyvinyl chloride.
  • the dyeing with iodine is performed, for example, by immersing a PVA-based film in an aqueous iodine solution.
  • the draw ratio of the uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment or while dyeing. Moreover, you may dye after stretching.
  • the PVA-based film is subjected to a swelling treatment, a cross-linking treatment, a washing treatment, a drying treatment and the like. For example, by immersing the PVA-based film in water and washing it with water before dyeing, it is possible not only to clean the dirt on the surface of the PVA-based film and the blocking inhibitor, but also to swell the PVA-based film to prevent uneven dyeing. Can be prevented.
  • the polarizer obtained by using the laminate include a laminate of a resin base material and a PVA-based resin layer (PVA-based resin film) laminated on the resin base material, or a resin base material and the resin.
  • Examples thereof include a polarizer obtained by using a laminate with a PVA-based resin layer coated and formed on a base material.
  • the polarizer obtained by using the laminate of the resin base material and the PVA-based resin layer coated and formed on the resin base material is, for example, a resin base material obtained by applying a PVA-based resin solution to the resin base material and drying it.
  • stretching typically includes immersing the laminate in an aqueous boric acid solution for stretching. Further, stretching may further include, if necessary, stretching the laminate in the air at a high temperature (eg, 95 ° C. or higher) prior to stretching in boric acid aqueous solution.
  • a high temperature eg, 95 ° C. or higher
  • the obtained resin base material / polarizer laminate may be used as it is (that is, the resin base material may be used as a protective layer for the polarizer), and the resin base material is peeled off from the resin base material / polarizer laminate. Then, an arbitrary appropriate protective layer according to the purpose may be laminated on the peeled surface. Details of the method for producing such a polarizer 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.
  • the thickness of the polarizer is preferably 15 ⁇ m or less when the polarizer is obtained by using a laminate of a resin base material and a PVA-based resin layer (PVA-based resin film) laminated on the resin base material. It is more preferably 1 ⁇ m to 12 ⁇ m, further preferably 3 ⁇ m to 12 ⁇ m, and particularly preferably 3 ⁇ m to 8 ⁇ m.
  • the thickness of the polarizer is preferably more than 15 ⁇ m and 40 ⁇ m or less. is there.
  • the protective layer is formed of any suitable film that can be used as a protective layer for the polarizer.
  • the resin film forming material include (meth) acrylic resin, cellulose resin such as diacetyl cellulose and triacetyl cellulose, cycloolefin resin such as norbornene resin, olefin resin such as polypropylene, and polyethylene terephthalate resin. Examples thereof include ester-based resins such as, polyamide-based resins, polycarbonate-based resins, and copolymer resins thereof.
  • a (meth) acrylic resin is preferable.
  • the "(meth) acrylic resin” refers to an acrylic resin and / or a methacrylic resin.
  • the (meth) acrylic resin having a glutarimide structure is used as the (meth) acrylic resin.
  • Examples of the (meth) acrylic resin having a glutarimide structure include JP-A-2006-309033, JP-A-2006-317560, JP-A-2006-328329, and JP-A. 2006-328334, 2006-337491, 2006-337492, 2006-337493, 2006-337569, 2007-009182, 2009- It is described in JP-A-161744 and JP-A-2010-284840. These statements are incorporated herein by reference.
  • the thickness of the protective layer is preferably 5 mm or less, more preferably 1 mm or less, further preferably 1 ⁇ m to 500 ⁇ m, and most preferably 5 ⁇ m to 150 ⁇ m.
  • the thickness of the protective layer is the thickness including the thickness of the surface treatment layer.
  • the protective layer is attached to the polarizer via an arbitrary appropriate adhesive layer (adhesive layer, adhesive layer).
  • the liquid crystal oriented solidified layer 21 is bonded to the surface of the polarizing plate 10 (polarizer 12 in the illustrated example). Specifically, the liquid crystal oriented solidified layer 21 is formed on an arbitrary suitable base material 30, and the laminate of the base material 30 and the liquid crystal oriented solidified layer 21 is bonded to the polarizing plate 10.
  • the liquid crystal oriented solidified layer and the polarizing plate are typically bonded to each other via a photocurable adhesive. Examples of the photocurable adhesive include an ultraviolet curable adhesive.
  • the liquid crystal oriented solidified layer is an oriented solidified layer of a liquid crystal compound.
  • the liquid crystal alignment solidified layer 21 is subjected to an orientation treatment on the surface of the base material 30, and a coating liquid containing a 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. Preferably, a triacetyl cellulose (TAC) film is used.
  • the difference between nx and ny of the obtained liquid crystal alignment solidification layer can be remarkably increased as compared with the non-liquid crystal material, so that a desired in-plane phase difference can be obtained.
  • the thickness of the liquid crystal oriented solidified layer can be remarkably reduced. As a result, it is possible to reduce the thickness and weight of the circular polarizing plate.
  • the term "oriented solidified layer” refers to a layer in which a liquid crystal compound is oriented in a predetermined direction within 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 liquid crystal oriented solidified 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 liquid crystal oriented solidified 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 liquid crystal oriented solidified layer is not affected by temperature changes and is extremely stable.
  • 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 EP0261712, DE19504224, DE4408171, and GB2280445
  • 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-Sillicon-CC3767.
  • the liquid crystal monomer for example, a nematic liquid crystal monomer is preferable.
  • 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 may 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 substrate surface.
  • 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 liquid crystal 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 oriented solidification 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 °.
  • Discotic liquid crystal compounds generally have cyclic mother nuclei such as benzene, 1,3,5-triazine, and calix arene in the center of the molecule, and linear alkyl groups, alkoxy groups, and substituted benzoyls.
  • 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., described in Vol. 71, p. 111 (1981).
  • the thickness thereof is preferably 0.5 ⁇ m to 7 ⁇ m, and more preferably 1 ⁇ m to 5 ⁇ m.
  • the liquid crystal oriented solidified layer is typically provided to impart antireflection properties to the polarizing plate, and can function as a ⁇ / 4 plate when the liquid crystal oriented solidified layer is a single layer.
  • the in-plane retardation Re (550) of the liquid crystal oriented solidified layer is preferably 100 nm to 190 nm, more preferably 110 nm to 170 nm, and further preferably 130 nm to 160 nm.
  • the Nz coefficient of the liquid crystal oriented solidified 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 circular polarizing plate is used in an image display device.
  • the liquid crystal oriented solidified layer may exhibit a reverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light, and exhibits a positive wavelength dispersion characteristic in which the retardation value decreases according to the wavelength of the measurement light. Alternatively, it may exhibit a flat wavelength dispersion characteristic in which the phase difference value hardly changes depending on the wavelength of the measurement light.
  • the liquid crystal oriented solidified layer exhibits reverse dispersion wavelength characteristics.
  • the Re (450) / Re (550) of the liquid crystal oriented solidified 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 liquid crystal oriented solidified layer and the absorption axis of the polarizer is preferably 40 ° to 50 °, more preferably 42 ° to 48 °, and even more preferably about 45 °. ..
  • the angle ⁇ is in such a range, by using the liquid crystal oriented solidified layer as the ⁇ / 4 plate as described above, it has very excellent circular polarization characteristics (as a result, very excellent antireflection characteristics).
  • a circular polarizing plate can be obtained.
  • the slow axis direction of the liquid crystal oriented solidified layer can correspond to the above-mentioned orientation processing direction.
  • the production method of the present invention further comprises laminating another liquid crystal oriented solidified layer 22 on the opposite side of the liquid crystal oriented solidified layer 21 to the polarizing plate 10 as shown in FIG. 1 (c). .. Specifically, it is as follows. First, another liquid crystal oriented solidifying layer 22 is formed on the base material 30 in the same manner as described above. Next, the liquid crystal oriented solidifying layer 21 is formed on another base material (not shown) in the same manner as described above. At this time, each orientation treatment direction corresponds to the slow axis direction of each orientation solidification layer described later.
  • the liquid crystal oriented solidified layer 21 is bonded to another liquid crystal oriented solidified layer 22, and a laminated body having the liquid crystal oriented solidified layer 21, another liquid crystal oriented solidified layer 22, and the base material 30 in this order is produced.
  • the liquid crystal oriented solidified layer 21 and another liquid crystal oriented solidified layer 22 are bonded to each other via any suitable adhesive.
  • the obtained laminate is bonded to the polarizing plate in the same manner as described above. In this way, a laminated body as shown in FIG. 1C is obtained.
  • one of the liquid crystal oriented solidified layer and the other liquid crystal oriented solidified layer is ⁇ . It functions as a / 2 plate and the other as a ⁇ / 4 plate. Therefore, the thickness of the liquid crystal oriented solidified layer and another liquid crystal oriented solidified layer can be adjusted so as to obtain a desired in-plane phase difference of the ⁇ / 4 plate or the ⁇ / 2 plate.
  • the thickness of the liquid crystal oriented solidified layer is, for example, 2.0 ⁇ m to 3.0 ⁇ m.
  • the thickness of the liquid crystal oriented solidified layer is, for example, 1.0 ⁇ m to 2.0 ⁇ m.
  • the in-plane retardation Re (550) of the liquid crystal 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 another liquid crystal oriented solidified layer is as described above with respect to the single oriented solidified layer.
  • the angle formed by the slow axis of the liquid crystal oriented solidified layer and the absorption axis of the polarizer is preferably 10 ° to 20 °, more preferably 12 ° to 18 °, and even more preferably about 15 °.
  • the angle formed by the slow axis of another liquid crystal oriented solidifying layer and the absorption axis of the polarizer is preferably 70 ° to 80 °, more preferably 72 ° to 78 °, and even more preferably about 75 °. is there.
  • liquid crystal compounds constituting the liquid crystal oriented solidified layer and another liquid crystal oriented solidified layer, the method for forming the liquid crystal oriented solidified layer and the liquid crystal oriented solidified layer, the optical properties, and the like are as described above for the single layer oriented solidified layer. ..
  • the surface protective film 40 is temporarily attached to the side of the polarizing plate 10 opposite to the liquid crystal oriented solidifying layer 21 so as to be peelable. More specifically, the surface protective film 40 includes a base film and an adhesive layer, and the surface protective film 40 and the polarizing plate 10 are bonded to each other via the adhesive layer. In the subsequent steps, the case where the liquid crystal oriented solidifying layer 21 and another liquid crystal oriented solidifying layer 22 are bonded to each other will be described, but it is the same even if the liquid crystal oriented solidifying layer is a single layer. It is self-evident.
  • the base film of the surface protective film 40 may be composed of any suitable resin film.
  • the resin film forming material include olefin resins such as polyethylene resins, ester resins such as polyethylene terephthalate resins, cycloolefin resins such as norbornene resins, polyamide resins, polycarbonate resins, and copolymers thereof. Examples include resin. A polyethylene-based resin or a polyethylene terephthalate-based resin is preferable. With such a material, in the manufacturing process of the circular polarizing plate, the runnability during roll transport is excellent, the adhesive deformation defect due to the stagnation during roll transport can be suppressed, and the appearance defect of the film can be suppressed. ..
  • the thickness of the base film is preferably 10 ⁇ m to 100 ⁇ m, more preferably 20 ⁇ m to 50 ⁇ m. With such a thickness, there is an advantage that deformation is unlikely to occur even if tension is applied during transportation and / or bonding.
  • the tensile elastic modulus of the base film is preferably 1.0 ⁇ 10 8 Pa to 5.0 ⁇ 10 9 Pa, and more preferably 2.0 ⁇ 10 8 Pa to 3.0 ⁇ 10 9 Pa.
  • the tensile elastic modulus of the base film is within such a range, in the manufacturing process of the circularly polarizing plate, the running performance during roll transport is excellent, and the adhesive deformation defect due to the winding tightening during stagnation during roll transport is suppressed. Poor appearance of the film can be suppressed.
  • any suitable pressure-sensitive adhesive can be adopted.
  • the base resin of the pressure-sensitive adhesive include acrylic resin, styrene resin, and silicone resin. Acrylic resins are preferable from the viewpoints of chemical resistance, adhesion for preventing the infiltration of the treatment liquid during immersion, degree of freedom to the adherend, and the like.
  • the cross-linking agent that can be contained in the pressure-sensitive adhesive include isocyanate compounds, epoxy compounds, and aziridine compounds.
  • the pressure-sensitive adhesive may contain, for example, a silane coupling agent. The formulation of the pressure-sensitive adhesive can be appropriately set according to the purpose.
  • the thickness of the pressure-sensitive adhesive layer is preferably 3 ⁇ m or less, more preferably 1 ⁇ m or less.
  • the lower limit of the thickness is, for example, 0.1 ⁇ m.
  • the thickness of the surface protective film is preferably 25 ⁇ m or more, more preferably 30 ⁇ m or more, and more preferably 35 ⁇ m or more.
  • the upper limit of the thickness of the surface protective film can be, for example, 100 ⁇ m.
  • the thickness of the surface protective film means the total thickness of the base film and the pressure-sensitive adhesive layer.
  • the base material 30 is peeled off from another liquid crystal oriented solidifying layer 22 with the surface protective film 40 temporarily attached.
  • the running performance during roll transfer is excellent (for example, breakage is suppressed) in the manufacturing process of the thin circular polarizing plate, and the roll transfer is performed.
  • Poor deformation of the adhesive due to tightening during stagnation, dents in the adhesive, and the like are suppressed, and poor appearance of the obtained circularly polarizing plate (for example, stains on the visual side) is suppressed.
  • the thickness of the surface protective film is within the range described in A-3, such an effect becomes remarkable.
  • the pressure-sensitive adhesive layer may be typically composed of an acrylic pressure-sensitive adhesive.
  • the thickness of the pressure-sensitive adhesive layer is preferably 50 ⁇ m or less, more preferably 30 ⁇ m or less, and further preferably 20 ⁇ m or less.
  • the lower limit of the thickness of the pressure-sensitive adhesive layer can be, for example, 1 ⁇ m.
  • the separator protects the adhesive layer until actual use and enables the formation of rolls of a circular polarizing plate.
  • the surface protective film 40 and the separator 60 can be peeled off from the optical laminate shown in FIG. 1 (g) obtained by the above manufacturing method. In this way, the circular polarizing plate 100 as shown in FIG. 2 is obtained.
  • the thickness of the circular polarizing plate is 45 ⁇ m or less, preferably 40 ⁇ m or less.
  • the lower limit of the thickness of the circularly polarizing plate can be, for example, 10 ⁇ m.
  • the thickness of the circularly polarizing plate means the total thickness from the polarizing plate to another liquid crystal oriented solidified layer (that is, the thickness of the circularly polarizing plate does not include the thickness of the surface protective film, the pressure-sensitive adhesive layer, and the separator. ).
  • a circular polarizing plate was collected and pasted on a smooth blackboard (CLAREX manufactured by Nitto Jushi Kogyo Co., Ltd.), and the adhesive unevenness was visually recognized in the entire width.
  • the case was evaluated as x, the case where the adhesive unevenness was visually recognized with a width of half or less was evaluated as ⁇ , and the case where the adhesive unevenness was not visually recognized was evaluated as ⁇ .
  • Example 1 Preparation of Polarizer
  • a thermoplastic resin base material an amorphous isophthal copolymer polyethylene terephthalate film (thickness: 100 ⁇ m) having a long shape, a water absorption of 0.75%, and a Tg of about 75 ° C. was used. ..
  • One side of the resin base material was corona-treated. 100 weight of PVA-based resin in which polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosefimer Z410”) are mixed at a ratio of 9: 1.
  • a PVA aqueous solution (coating solution) was prepared by dissolving 13 parts by weight of potassium iodide in water.
  • 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.
  • Polarizing Plate Acrylic film (surface refractive index 1.50, 20 ⁇ m) is applied as a protective layer on the surface of the polarizer obtained above (the surface opposite to the resin substrate), and an ultraviolet curable adhesive is applied. It was pasted together. Specifically, the curable adhesive was coated so as to have a total thickness of 1.0 ⁇ m, and bonded using a roll machine. Then, UV light was irradiated from the protective layer side to cure the adhesive. Next, after slitting both ends, the resin base material was peeled off to obtain a long polarizing plate (width: 1300 mm) having a protective layer / polarizer configuration.
  • 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 1 mJ / cm 2 using a metal halide lamp, and the liquid crystal layer was cured to form a liquid crystal oriented solidified layer on the TAC film.
  • Another TAC film in the same manner as above, except that the coating thickness was changed and the orientation processing direction was set to be 75 ° when viewed from the visual side with respect to the direction of the absorber's absorption axis.
  • Another liquid crystal oriented solidified layer was formed on the film.
  • the liquid crystal oriented solidified layer was attached to another liquid crystal oriented solidified layer, and the TAC film was peeled off to prepare a laminate having the liquid crystal oriented solidified layer, another liquid crystal oriented solidified layer, and another TAC film in this order. ..
  • the liquid crystal oriented solidified layer and another liquid crystal oriented solidified layer are bonded to each other in the above 2. It was carried out through the ultraviolet curable adhesive (thickness 1.0 ⁇ m) used in.
  • the obtained laminate is subjected to the above 2. It was attached to the above polarizing plate via the ultraviolet curable adhesive (thickness 1.0 ⁇ m) used in. In this way, a laminate having a structure of a polarizing plate / a liquid crystal oriented solidified layer / another liquid crystal oriented solidified layer / a base material (another TAC film) was obtained.
  • a surface protective film (E-MASK RP109F, manufactured by Nitto Denko KK) was temporarily attached to the side opposite to the liquid crystal oriented solidified layer of the polarizing plate so as to be peelable. Then, another TAC film as a base material was peeled off from another liquid crystal oriented solidifying layer. A pressure-sensitive adhesive layer (acrylic pressure-sensitive adhesive, thickness: 50 ⁇ m) was formed on the peeled surface of the other liquid crystal oriented solidified layer. In the step of forming the pressure-sensitive adhesive layer, the evaluation of (1) above was performed.
  • E-MASK RP109F manufactured by Nitto Denko KK
  • a separator was temporarily attached to the side of the pressure-sensitive adhesive layer opposite to the liquid crystal oriented solidified layer so that it could be peeled off.
  • an optical laminate having a structure of a surface protective film / polarizing plate / liquid crystal oriented solidified layer / another liquid crystal oriented solidified layer / adhesive layer / separator was obtained.
  • the thickness of the base film of the surface protective film was 38 ⁇ m, and the thickness of the surface protective film was 48 ⁇ m.
  • the tensile modulus of the surface protective film was 2.0 ⁇ 10 9 Pa.
  • the obtained optical laminate was subjected to the evaluations (2) to (3) above. The results are shown in Table 1.
  • the thickness of the circularly polarizing plate (excluding the adhesive) obtained by peeling the surface protective film and the separator from the optical laminate was 31 ⁇ m.
  • Example 2 An optical laminate was obtained in the same manner as in Example 1 except that E-MASK RP149C (manufactured by Nitto Denko KK) was used as the surface protective film.
  • the thickness of the base film of the surface protective film was 50 ⁇ m, and the thickness of the surface protective film was 60 ⁇ m.
  • the tensile modulus of the surface protective film was 2.0 ⁇ 10 9 Pa.
  • the obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 3 An optical laminate was obtained in the same manner as in Example 1 except that Tretec 7832E (manufactured by Toray Industries, Inc.) was used as the surface protective film.
  • the thickness of the base film of the surface protective film and the thickness of the surface protective film were 25 ⁇ m.
  • the tensile modulus of the surface protective film was 3.0 ⁇ 10 8 Pa.
  • the obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 4 An optical laminate was obtained in the same manner as in Example 1 except that Tretec 7832C (manufactured by Toray Industries, Inc.) was used as the surface protective film.
  • the thickness of the base film of the surface protective film and the thickness of the surface protective film were 30 ⁇ m.
  • the tensile modulus of the surface protective film was 3.0 ⁇ 10 8 Pa.
  • the obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 5 A long length as in Example 1 except that a cycloolefin-based unstretched film with a hard coat layer (manufactured by Nippon Zeon Co., Ltd., thickness: 27 ⁇ m) was used as the protective layer of the polarizing plate instead of the acrylic stretched film.
  • An optical laminate having a shape-like retardation layer and a polarizing plate with a hard coat layer was obtained.
  • the obtained optical laminate was subjected to the same evaluation as in Example 1.
  • the thickness of the circular polarizing plate excluding the pressure-sensitive adhesive obtained by peeling the surface protective film and the separator from the optical laminate was 38 ⁇ m.
  • Example 1 An optical laminate was obtained in the same manner as in Example 1 except that the surface protective film was not used. The obtained optical laminate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • the optical laminate obtained according to the examples of the present invention has excellent runnability during roll transport, suppresses poor adhesive deformation due to stagnation during roll transport, and suppresses poor adhesive deformation of the film. It can be seen that the poor appearance is suppressed. Further, it can be seen that by using a thick surface protective film, poor adhesive deformation due to winding during stagnation is further suppressed (comparison between Examples 1 and 2 and Examples 3 and 4).
  • the circular polarizing plate obtained by the manufacturing method of the present invention is suitably used for an image display device such as a liquid crystal display device (LCD) and an organic electroluminescence display device (OLED).
  • LCD liquid crystal display device
  • OLED organic electroluminescence display device
  • Polarizing plate 11
  • Protective layer 12 Polarizer 21
  • Liquid crystal oriented solidifying layer 22 Another liquid crystal oriented solidifying layer 30
  • Base material 40
  • Surface protective film 50 Adhesive layer 60
  • Separator 100 Circular polarizing plate

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  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Polarising Elements (AREA)
  • Liquid Crystal (AREA)
  • Laminated Bodies (AREA)

Abstract

La présente invention concerne un procédé de production d'une plaque de polarisation circulaire mince, ledit procédé présentant une excellente aptitude au déplacement pendant le transport de rouleau, tout en étant supprimé dans des défauts de déformation d'adhésif dus à un enroulement étanche pendant la stagnation du moyen de transport de rouleau, ce qui permet de supprimer les défauts d'aspect d'un film. Un procédé de production d'une plaque de polarisation circulaire selon la présente invention comprend : une étape consistant à former une couche de fixation d'alignement de cristaux liquides sur la surface d'un matériau de base ; une étape consistant à lier la couche de fixation d'alignement de cristaux liquides à la surface d'une plaque de polarisation ; une étape de liaison provisoire d'un film de protection de surface à une surface de la plaque de polarisation de manière amovible, ladite surface étant sur le côté inverse de la couche de fixation d'alignement de cristaux liquides ; une étape consistant à retirer le matériau de base de la couche de fixation d'alignement de cristaux liquides ; une étape consistant à former une couche adhésive sur la surface d'élimination de la couche de fixation d'alignement de cristaux liquides ; et une étape de liaison provisoire d'un séparateur à une surface de la couche adhésive de manière amovible, ladite surface étant sur le côté opposé à la couche de fixation d'alignement de cristaux liquides.
PCT/JP2020/012191 2019-07-22 2020-03-19 Procédé de production de plaque de polarisation circulaire mince WO2021014685A1 (fr)

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JP2007304317A (ja) * 2006-05-11 2007-11-22 Nitto Denko Corp 偏光板用表面保護フィルム、該表面保護フィルムで保護された偏光板および画像表示装置
JP2019101269A (ja) * 2017-12-04 2019-06-24 住友化学株式会社 光学積層体及びその製造方法

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CA2316828C (fr) 1998-10-30 2010-02-23 Teijin Limited Retardateur de film et dispositif optique l'utilisant
JP4553258B2 (ja) * 2005-02-25 2010-09-29 日東電工株式会社 楕円偏光板の製造方法および楕円偏光板を用いた画像表示装置
JP2008009403A (ja) * 2006-05-30 2008-01-17 Nippon Oil Corp 楕円偏光板、楕円偏光板の製造方法および液晶表示装置
WO2013114583A1 (fr) * 2012-02-01 2013-08-08 住友化学株式会社 Procédé de fabrication pour une pellicule stratifiée polarisante et procédé de fabrication pour une plaque polarisante
JP6172980B2 (ja) * 2012-03-14 2017-08-02 日東電工株式会社 液晶表示パネルの製造方法
CN105229504A (zh) * 2013-05-21 2016-01-06 富士胶片株式会社 偏振片及其制造方法以及转印材料
WO2015152157A1 (fr) * 2014-03-31 2015-10-08 富士フイルム株式会社 Plaque de polarisation, dispositif d'affichage d'image et dispositif d'affichage à cristaux liquides
JP6925808B2 (ja) * 2017-01-26 2021-08-25 日東電工株式会社 光学積層体の製造方法および画像表示装置の製造方法

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JP2007304317A (ja) * 2006-05-11 2007-11-22 Nitto Denko Corp 偏光板用表面保護フィルム、該表面保護フィルムで保護された偏光板および画像表示装置
JP2019101269A (ja) * 2017-12-04 2019-06-24 住友化学株式会社 光学積層体及びその製造方法

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TW202106518A (zh) 2021-02-16
TWI820331B (zh) 2023-11-01

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