WO2017221638A1 - Polarizing plate set - Google Patents

Polarizing plate set Download PDF

Info

Publication number
WO2017221638A1
WO2017221638A1 PCT/JP2017/019837 JP2017019837W WO2017221638A1 WO 2017221638 A1 WO2017221638 A1 WO 2017221638A1 JP 2017019837 W JP2017019837 W JP 2017019837W WO 2017221638 A1 WO2017221638 A1 WO 2017221638A1
Authority
WO
WIPO (PCT)
Prior art keywords
polarizing plate
polarizer
adhesive layer
sensitive adhesive
pressure
Prior art date
Application number
PCT/JP2017/019837
Other languages
French (fr)
Japanese (ja)
Inventor
白石　貴志
Original Assignee
住友化学株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 住友化学株式会社 filed Critical 住友化学株式会社
Priority to KR1020197000590A priority Critical patent/KR102412245B1/en
Priority to CN201780038092.4A priority patent/CN109313306B/en
Publication of WO2017221638A1 publication Critical patent/WO2017221638A1/en

Links

Images

Classifications

    • 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

Definitions

  • the present invention relates to a polarizing plate set that can be used for various optical applications.
  • Patent Document 1 discloses a liquid crystal panel in which polarizers are arranged on the front side and the back side of a liquid crystal cell.
  • Patent Document 2 discloses an optical laminate that is disposed on the front side and the back side of a liquid crystal cell. According to the liquid crystal panel disclosed in Patent Document 1 and the optical laminate disclosed in Patent Document 2, the relationship between the thickness of the polarizing film disposed on the front side and the thickness of the polarizing film disposed on the back side is specified. Therefore, attempts have been made to reduce the warpage of the liquid crystal panel.
  • the liquid crystal panel may be peeled off from the touch panel or the backlight unit may be dropped due to warpage of the liquid crystal panel in a humid heat environment.
  • problems such as.
  • an object of the present invention is to provide a polarizing plate set capable of suppressing the warpage of the liquid crystal panel in a humid heat environment as well as the warpage of the liquid crystal panel in a high temperature environment.
  • a polarizing plate set including a back side polarizing plate disposed on one surface side of the liquid crystal cell and a front side polarizing plate disposed on the other surface side,
  • the back side polarizing plate has a reflective polarizing plate, a first pressure-sensitive adhesive layer, a first polarizer, a first protective film, and a second pressure-sensitive adhesive layer.
  • the front side polarizing plate has a third pressure-sensitive adhesive layer, a second polarizer, and a second protective film
  • a difference dF ⁇ dR obtained by subtracting the thickness dR ( ⁇ m) of the first polarizer in the back-side polarizing plate from the thickness dF ( ⁇ m) of the second polarizer in the front-side polarizing plate is defined as ⁇ d ( ⁇ m).
  • 0 ⁇ m ⁇ d ⁇ 5 ⁇ m The angle formed by the absorption axis of the second polarizer in the front-side polarizing plate and the absorption axis of the first polarizer in the rear-side polarizing plate is 90 ° ⁇ 1 °.
  • Polarizing plate set is 90 ° ⁇ 1 °.
  • the pair of polarizing plates is the polarizing plate set according to any one of [1] to [3],
  • the second protective film, the second polarizer, the third pressure-sensitive adhesive layer, the liquid crystal cell, the second pressure-sensitive adhesive layer, the first protective film, the first polarizer, the first pressure-sensitive adhesive layer, and the reflection A liquid crystal panel in which type polarizing plates are laminated in this order.
  • a polarizing plate set comprising a back side polarizing plate disposed on one surface side of the liquid crystal cell and a front side polarizing plate disposed on the other surface side,
  • the back side polarizing plate has a reflective polarizing plate, a first pressure-sensitive adhesive layer, a first polarizer, a first protective film, and a second pressure-sensitive adhesive layer.
  • the front side polarizing plate has a third pressure-sensitive adhesive layer, a second polarizer, and a second protective film
  • a difference dF ⁇ dR obtained by subtracting the thickness dR ( ⁇ m) of the first polarizer in the back-side polarizing plate from the thickness dF ( ⁇ m) of the second polarizer in the front-side polarizing plate is defined as ⁇ d ( ⁇ m).
  • 0 ⁇ m ⁇ d ⁇ 5 ⁇ m The angle formed by the absorption axis of the second polarizer in the front-side polarizing plate and the absorption axis of the first polarizer in the rear-side polarizing plate is 90 ° ⁇ 1 °. It is a polarizing plate set.
  • the liquid crystal panel provided with the set of polarizing plates of the present invention it is possible to prevent the liquid crystal panel from peeling off the touch panel or the backlight unit from falling off, and to obtain a display device with small display unevenness. it can.
  • the polarizing plate set of the present invention includes a back side polarizing plate 10 disposed on one surface side of the liquid crystal cell 30 and a front side polarizing plate 20 disposed on the other surface side.
  • the back side polarizing plate 10 includes a reflective polarizing plate 11, a first pressure-sensitive adhesive layer 12, a first polarizer 13, a first protective film 14, and a second pressure-sensitive adhesive layer 15.
  • the back side polarizing plate 10 can have an additional layer if desired.
  • the back side polarizing plate 10 includes a reflective polarizing plate 11, a first pressure-sensitive adhesive layer 12, a first polarizer 13, a first protective film 14, and a second pressure-sensitive adhesive layer 15. It is the polarizing plate laminated
  • the front side polarizing plate 20 includes a third pressure-sensitive adhesive layer 21, a second polarizer 22, and a second protective film 23.
  • the front side polarizing plate 20 may have further layers as desired.
  • the front-side polarizing plate 20 is a polarizing plate in which a third pressure-sensitive adhesive layer 21, a second polarizer 22, and a second protective film 23 are laminated in this order.
  • the front side polarizing plate 20 may further have a protective film between the third pressure-sensitive adhesive layer 21 and the second polarizer 22 (not shown). That is, the front side polarizing plate 20 may have protective films on both surfaces of the second polarizer 22.
  • the back surface side polarizing plate in this invention is bonded by the surface on the opposite side to the surface at the side of visual recognition of a liquid crystal cell, for example.
  • the back-side polarizing plate may be bonded to the liquid crystal cell so as to be adjacent to a light source provided in the liquid crystal panel, such as a backlight.
  • a narrow double-sided tape may be attached to the edge of the back polarizing plate, and the backlight unit may be attached.
  • the front side polarizing plate in this invention is bonded by the surface at the side of visual recognition of a liquid crystal cell, for example.
  • the polarizing plate set shown in FIG. 1, that is, the back side polarizing plate 10 and the front side polarizing plate 20 may be provided with a layer other than the above-described layers.
  • the polarizers 13 and 22 and the protective films 14 and 23 are usually bonded together via an adhesive layer.
  • the thickness of the second polarizer in the front side polarizing plate 20 is dF
  • the thickness of the first polarizer in the back side polarizing plate 10 is dR
  • the difference dF ⁇ dR obtained by subtracting the thickness dR ( ⁇ m) of the first polarizer in the rear polarizing plate 10 from the thickness dF ( ⁇ m) of the second polarizer in the side polarizing plate 20 is ⁇ d ( ⁇ m)
  • It has a relationship of 0 ⁇ m ⁇ d ⁇ 5 ⁇ m, more preferably a relationship of 1 ⁇ m ⁇ d ⁇ 5 ⁇ m.
  • ⁇ d ( ⁇ m) which is the difference obtained by subtracting the thickness dR from the thickness dF, is within such a range
  • the laminate (liquid crystal panel) of the front side polarizing plate, glass (liquid crystal cell), and back side polarizing plate can be obtained. Even when exposed to high temperature (for example, 85 ° C., humidity 5%) for a long time, the amount of warpage of the laminate is small. Furthermore, even if the laminated body of the front-side polarizing plate, the glass, and the rear-side polarizing plate is placed in a wet heat environment (for example, 60 ° C., humidity 90%), the warpage of the laminated body is suppressed.
  • a wet heat environment for example, 60 ° C., humidity 90%
  • the laminate including the polarizing plate set of the present invention has a small amount of warping when placed in a wet heat environment and a high temperature environment, and thus has a wet heat resistance and a heat resistance, and from a touch panel in a high temperature environment and a wet heat environment. It is thought that there will be no peeling off of the backlight unit or falling off of the backlight unit. In addition, display unevenness caused by warping after the high temperature environment and wet heat environment test is reduced. Further, since ⁇ d ( ⁇ m) has such a relationship, the polarizing plate set of the present invention can be applied to liquid crystal panels having various sizes and thicknesses. In the present specification, the high temperature environment is described as an example of a temperature of 85 ° C.
  • the high temperature environment may mean an environment where the polarizing plate or the like is exposed to, for example, a temperature of 70 ° C. to 95 ° C. and a humidity of 0% to 20% for at least 30 to 60 minutes.
  • the wet heat environment is described under the conditions of a temperature of 60 ° C. and a humidity of 90%.
  • the moist heat environment may mean an environment where the polarizing plate or the like is exposed to a temperature of 50 ° C. to 80 ° C. and a humidity of 60% to 95% for at least 30 minutes to 60 minutes.
  • the thickness dR of the first polarizer of the back side polarizing plate is 15 ⁇ m or less, and more preferably 0.1 ⁇ m or more and 13 ⁇ m or less. Since the back-side polarizing plate has a reflective polarizing plate, the back-side polarizing plate can be made thinner as the first polarizer is thinner.
  • Measurement of each thickness of the polarizing plate set in the present invention can be performed using a measurement method known in the technical field.
  • the angle formed by the absorption axis of the second polarizer in the front-side polarizing plate and the absorption axis of the first polarizer in the rear-side polarizing plate is 90 ° ⁇ 1 °, more preferably 90 ° ⁇ 0. .5 ° range.
  • FIG. 2 is a diagram illustrating the relationship between the absorption axes of the polarizers according to one embodiment of the present invention.
  • the absorption axis of the first polarizer in the back side polarizing plate 10 is represented by 10a
  • the transmission axis of the first polarizer is represented by 10b
  • the long side of the back side polarizing plate is indicated by 10c.
  • the absorption axis of the second polarizer of the front side polarizing plate 20 is represented by 20a
  • the transmission axis of the second polarizer is represented by 20b.
  • the angle formed between the absorption axis 10a of the first polarizer and the absorption axis 20a of the second polarizer is 90 ° ⁇ 1 ° as described above.
  • This angle can be represented, for example, as an angle ⁇ in FIG.
  • the angle formed by the absorption axis of the first polarizer in the back side polarizing plate and the long side of the back side polarizing plate (first polarizer) is 0 ° ⁇ 1 °.
  • the angle formed above is 0 ° ⁇ 0.5 °.
  • the absorption axis of the second polarizer in the front side polarizing plate may be described as the absorption axis of the front side polarizing plate, and the absorption axis of the first polarizer in the back side polarizing plate may be It may be the absorption axis of the back side polarizing plate.
  • a difference dF ⁇ dR obtained by subtracting the thickness dR ( ⁇ m) of the first polarizer in the back side polarizing plate from the thickness dF ( ⁇ m) of the second polarizer in the front side polarizing plate is obtained. If ⁇ d ( ⁇ m), By satisfying 0 ⁇ m ⁇ d ⁇ 5 ⁇ m, for example, even if a liquid crystal panel having a front side polarizing plate, a glass plate, and a back side polarizing plate is exposed to a humid heat environment under high temperature conditions, these warpages can be suppressed.
  • a polarizing plate for example, a reflective polarizing plate, a 1st adhesive layer, a 1st polarizer, a 1st protective film, and 2nd
  • the pressure-sensitive adhesive layer can warp together.
  • the third pressure-sensitive adhesive layer, the second polarizer and the second protective film can warp together. Therefore, the back side polarizing plate and the front side polarizing plate in the present invention usually cannot cause delamination between at least one of these layers.
  • warp may occur in either one of the back side polarizing plate and the front side polarizing plate, and both the back side polarizing plate and the front side polarizing plate may warp.
  • Such warpage can be evaluated by measuring the amount of warpage in the present invention.
  • the warpage amount may be evaluated by measuring the warpage amount under wet heat conditions, or may be evaluated by measuring the warpage amount under high temperature conditions.
  • the third pressure-sensitive adhesive on the front side polarizing plate and the second pressure-sensitive adhesive layer on the back side polarizing plate are bonded to the front and back of the glass panel, and the environment is 60 ° C. and humidity is 90%. After standing for 250 hours, the glass panel was placed with the back side polarizing plate facing down, and the relative height of lifting from the horizontal surface of the measurement table was measured.
  • the third pressure-sensitive adhesive on the front-side polarizing plate and the second pressure-sensitive adhesive layer on the rear-side polarizing plate are bonded to the front and back of the glass panel, and the environment is 85 ° C. and humidity is 5%.
  • a glass panel was installed so that the back side polarizing plate would be down, and the relative height of lifting from the horizontal surface of the measuring table was measured.
  • the reflective polarizing plate is also called a brightness enhancement film, and a polarization conversion element having a function of separating light emitted from a light source (backlight) into transmitted polarized light and reflected polarized light or scattered polarized light is used.
  • a polarization conversion element having a function of separating light emitted from a light source (backlight) into transmitted polarized light and reflected polarized light or scattered polarized light is used.
  • the reflective polarizing plate and the polarizer is laminated in contact with the first pressure-sensitive adhesive layer.
  • the reflective polarizing plate can be, for example, an anisotropic reflective polarizer.
  • An example of the anisotropic reflective polarizer is an anisotropic multiple thin film that transmits linearly polarized light in one vibration direction and reflects linearly polarized light in the other vibration direction, and a specific example thereof is DBEF manufactured by 3M. (Japanese Patent Laid-Open No. 4-268505).
  • Such a reflective polarizing plate is a reflective polarizing plate formed by stretching a multilayer laminate composed of at least two thin films having different refractive index anisotropies. Therefore, such a reflective polarizing plate has at least two thin films, and the stretched at least two thin films have different refractive index anisotropy.
  • anisotropic reflective polarizer is a composite of a cholesteric liquid crystal layer and a ⁇ / 4 plate, and a specific example thereof is a PCF manufactured by Nitto Denko Corporation (JP-A-11-231130, etc.).
  • an anisotropic reflective polarizer is a reflective grid polarizer, a specific example of which is a metal grid reflective polarizer (US) that emits reflected polarized light even in the visible light region by finely processing the metal.
  • US metal grid reflective polarizer
  • Patent No. 6288840 and the like discloses a film obtained by adding metal fine particles into a polymer matrix and stretching.
  • An optical layer such as a hard coat layer, an antiglare layer, a light diffusion layer, or a retardation layer having a retardation value of 1 ⁇ 4 wavelength is provided on the surface of the reflective polarizing plate opposite to the first pressure-sensitive adhesive layer. May be.
  • the thickness of the reflective polarizing plate can be about 5 to 100 ⁇ m, but is preferably 10 to 40 ⁇ m, more preferably 10 to 30 ⁇ m from the viewpoint of reducing warpage as a liquid crystal panel.
  • the surface of the reflective polarizing plate on the first pressure-sensitive adhesive layer side can be subjected to a surface activation treatment.
  • This surface activation treatment is performed prior to bonding of the reflective polarizing plate and the first pressure-sensitive adhesive layer.
  • the surface activation treatment can be a surface hydrophilization treatment, and may be a dry treatment or a wet treatment.
  • the dry treatment include discharge treatment such as corona treatment, plasma treatment and glow discharge treatment; flame treatment; ozone treatment; UV ozone treatment; ionizing active ray treatment such as ultraviolet treatment and electron beam treatment.
  • the wet treatment include ultrasonic treatment using a solvent such as water or acetone, alkali treatment, anchor coat treatment, and the like. These processes may be performed alone or in combination of two or more.
  • the surface activation treatment is preferably a corona treatment and / or a plasma treatment from the viewpoint of the effect of suppressing peeling of the reflective polarizing plate in a humid heat environment and the productivity of the polarizing plate.
  • a corona treatment and / or a plasma treatment from the viewpoint of the effect of suppressing peeling of the reflective polarizing plate in a humid heat environment and the productivity of the polarizing plate.
  • a surface activation treatment may also be performed on the surface of the first pressure-sensitive adhesive layer on the luminance reflective polarizing plate side.
  • the first pressure-sensitive adhesive layer is a layer interposed between the first polarizer and the reflective polarizing plate.
  • the first pressure-sensitive adhesive layer is typically directly laminated on the polarizer so that the first polarizer and the first pressure-sensitive adhesive layer are in contact with each other.
  • the first pressure-sensitive adhesive layer can be composed of a pressure-sensitive adhesive composition whose main component is a resin such as acrylic, rubber-based, urethane-based, ester-based, silicone-based, or polyvinyl ether-based.
  • a pressure-sensitive adhesive composition having an acrylic resin excellent in transparency, weather resistance, heat resistance and the like as a base polymer is preferable.
  • the pressure-sensitive adhesive composition may be an active energy ray curable type or a thermosetting type.
  • acrylic base polymer examples include (meth) acrylic acid ester bases such as butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Polymers and copolymer base polymers using two or more of these (meth) acrylic acid esters are preferably used.
  • the base polymer is preferably copolymerized with a polar monomer.
  • polar monomers examples include (meth) acrylic acid, 2-hydroxypropyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, glycidyl ( Mention may be made of monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group and the like, such as (meth) acrylate.
  • the pressure-sensitive adhesive composition usually further contains a crosslinking agent.
  • a crosslinking agent a metal ion having a valence of 2 or more, which forms a carboxylic acid metal salt with a carboxyl group; a polyamine compound, which forms an amide bond with a carboxyl group; Examples thereof include epoxy compounds and polyols that form ester bonds with carboxyl groups; polyisocyanate compounds that form amide bonds with carboxyl groups. Of these, polyisocyanate compounds are preferred.
  • the active energy ray-curable pressure-sensitive adhesive composition has a property of being cured by irradiation with active energy rays such as ultraviolet rays and electron beams, and has an adhesive property even before irradiation with active energy rays. It is a pressure-sensitive adhesive composition having such a property that it can be adhered to an adherend such as the like and can be cured by irradiation with active energy rays to adjust the adhesion.
  • the active energy ray-curable pressure-sensitive adhesive composition is preferably ultraviolet curable.
  • the active energy ray-curable pressure-sensitive adhesive composition further contains an active energy ray-polymerizable compound in addition to the base polymer and the crosslinking agent. Further, if necessary, a photopolymerization initiator, a photosensitizer and the like may be contained.
  • the pressure-sensitive adhesive composition contains fine particles for imparting light scattering properties; beads; resins other than the base polymer; tackifiers; fillers; antioxidants; ultraviolet absorbers; pigments; be able to.
  • the first pressure-sensitive adhesive layer can be formed by applying an organic solvent diluted solution of the above pressure-sensitive adhesive composition on a substrate and drying it.
  • the substrate can be a polarizer, a reflective polarizing plate, a separator or the like.
  • a desired cured product can be obtained by irradiating the formed pressure-sensitive adhesive layer with active energy rays.
  • the first pressure-sensitive adhesive layer preferably exhibits a storage elastic modulus of 0.15 to 1.2 MPa in a temperature range of 23 to 80 ° C.
  • a storage elastic modulus 0.15 to 1.2 MPa in a temperature range of 23 to 80 ° C.
  • “Shows a storage elastic modulus of 0.15 to 1.2 MPa in a temperature range of 23 to 80 ° C.” means that the storage elastic modulus is a value within the above range at any temperature within this range. . Since the storage elastic modulus usually decreases gradually as the temperature rises, if both the storage elastic modulus at 23 ° C. and 80 ° C. are within the above range, the storage elastic modulus within the above range is exhibited at the temperature in this range. Can be seen.
  • the storage elastic modulus of the first pressure-sensitive adhesive layer can be measured using a commercially available viscoelasticity measuring device, for example, a viscoelasticity measuring device “DYNAMIC ANALYZER RDA II” manufactured by REOMETRI as shown in the examples below. it can.
  • an active energy ray-curable type is further prepared by further adding an oligomer, specifically, a urethane acrylate-based oligomer, to a pressure-sensitive adhesive composition containing a base polymer and a crosslinking agent.
  • the pressure-sensitive adhesive composition preferably an ultraviolet curable pressure-sensitive adhesive composition
  • the adhesive layer is appropriately cured by irradiating active energy rays.
  • the thickness of the first pressure-sensitive adhesive layer can be 30 ⁇ m or less.
  • the thickness is preferably 25 ⁇ m or less, particularly preferably 20 ⁇ m or less, and particularly preferably 15 ⁇ m or less.
  • the thickness of the 1st adhesive layer exists in such a range, the dimensional change of a polarizing plate can be suppressed, maintaining favorable workability.
  • the thickness of the first pressure-sensitive adhesive layer can be adjusted as appropriate so that the interlayer thickness falls within a predetermined range.
  • a polarizer is an absorptive polarizer that has the property of absorbing linearly polarized light having a vibration plane parallel to the absorption axis and transmitting linearly polarized light having a vibration plane perpendicular to the absorption axis (parallel to the transmission axis). is there.
  • the first polarizer and the second polarizer used in the polarizing plate set of the present invention may be the same polarizer or different polarizers as long as the thicknesses have a predetermined relationship.
  • a polarizing film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol resin film can be suitably used.
  • the polarizer is, for example, a step of uniaxially stretching a polyvinyl alcohol resin film; a step of adsorbing a dichroic dye by dyeing the polyvinyl alcohol resin film with a dichroic dye; a polyvinyl on which the dichroic dye is adsorbed It can be produced by a method comprising a step of treating an alcohol-based resin film with a boric acid aqueous solution; and a step of washing with water after the treatment with the boric acid aqueous solution.
  • polyvinyl alcohol resin a saponified polyvinyl acetate resin
  • examples of the polyvinyl acetate resin include, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, copolymers with other monomers copolymerizable with vinyl acetate.
  • examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, acrylamides having ammonium groups, and the like.
  • the degree of saponification of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more.
  • the polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used.
  • the average degree of polymerization of the polyvinyl alcohol resin is usually about 1000 to 10,000, and preferably about 1500 to 5,000.
  • the average degree of polymerization of the polyvinyl alcohol resin can be determined according to JIS K 6726.
  • a film obtained by forming such a polyvinyl alcohol resin is used as an original film of a polarizer (polarizing film).
  • the method for forming the polyvinyl alcohol-based resin into a film is not particularly limited, and a known method is employed.
  • the thickness of the polyvinyl alcohol-based raw film is not particularly limited, but in order to make the thickness of the polarizer 15 ⁇ m or less, for example, it is preferable to use an original film having a thickness of about 5 to 35 ⁇ m.
  • the uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after the dyeing of the dichroic dye.
  • this uniaxial stretching may be performed before boric acid treatment or during boric acid treatment. Moreover, you may uniaxially stretch in these several steps.
  • rolls having different peripheral speeds may be uniaxially stretched or may be stretched uniaxially using a hot roll.
  • the uniaxial stretching may be dry stretching in which stretching is performed in the air, or may be wet stretching in which stretching is performed in a state where a polyvinyl alcohol-based resin film is swollen using a solvent.
  • the draw ratio is usually about 3 to 8 times.
  • a method for dyeing a polyvinyl alcohol resin film with a dichroic dye for example, a method of immersing the film in an aqueous solution containing the dichroic dye is employed.
  • the dichroic dye iodine or a dichroic organic dye is used.
  • the polyvinyl alcohol-type resin film performs the immersion process to water before a dyeing process.
  • a method of immersing a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide is usually employed.
  • the iodine content in this aqueous solution can be about 0.01 to 1 part by weight per 100 parts by weight of water.
  • the content of potassium iodide can be about 0.5 to 20 parts by weight per 100 parts by weight of water.
  • the temperature of the aqueous solution can be about 20 to 40 ° C.
  • a method of immersing a polyvinyl alcohol-based resin film in an aqueous solution containing a dichroic organic dye is usually employed.
  • the aqueous solution containing the dichroic organic dye may contain an inorganic salt such as sodium sulfate as a dyeing assistant.
  • the content of the dichroic organic dye in this aqueous solution can be about 1 ⁇ 10 ⁇ 4 to 10 parts by weight per 100 parts by weight of water.
  • the temperature of the aqueous solution can be about 20 to 80 ° C.
  • boric acid treatment after dyeing with a dichroic dye a method of immersing a dyed polyvinyl alcohol-based resin film in a boric acid-containing aqueous solution is usually employed.
  • the boric acid-containing aqueous solution preferably contains potassium iodide.
  • the amount of boric acid in the boric acid-containing aqueous solution can be about 2 to 15 parts by weight per 100 parts by weight of water.
  • the amount of potassium iodide in this aqueous solution can be about 0.1 to 15 parts by weight per 100 parts by weight of water.
  • the temperature of the aqueous solution can be 50 ° C. or higher, for example, 50 to 85 ° C.
  • the polyvinyl alcohol resin film after the boric acid treatment is usually washed with water.
  • the water washing treatment can be performed, for example, by immersing a boric acid-treated polyvinyl alcohol resin film in water.
  • the water washing treatment may be performed with water containing potassium iodide.
  • the water temperature in the water washing treatment is usually about 5 to 40 ° C.
  • a polarizer is obtained by performing a drying process after washing with water.
  • the drying process can be performed using a hot air dryer or a far infrared heater.
  • the thickness of the polarizer is preferably 15 ⁇ m or less, and more preferably 13 ⁇ m or less.
  • the thickness of the polarizer is usually 4 ⁇ m or more.
  • the thickness dR of the first polarizer in the back side polarizing plate is 15 ⁇ m or less.
  • the thickness dF of the second polarizer in the front side polarizing plate is 15 ⁇ m or less, and more preferably 0.1 ⁇ m or more and 13 ⁇ m or less.
  • the thickness of the polarizer can be adjusted as appropriate so that the thickness does not deviate from the scope of the present invention.
  • a 1st protective film is a film laminated
  • a 2nd protective film is a film laminated
  • the first protective film and the second protective film may be the same film or different films.
  • the protective film is a light-transmitting (preferably optically transparent) thermoplastic resin, for example, a polyolefin such as a chain polyolefin resin (polypropylene resin, etc.) or a cyclic polyolefin resin (norbornene resin, etc.).
  • Cellulose resins such as triacetyl cellulose and diacetyl cellulose; Polyester resins such as polyethylene terephthalate and polybutylene terephthalate; Polycarbonate resins; Acrylic resins such as (meth) acrylic resins; Polystyrene resins; Polyvinyl chloride resin; Acrylonitrile butadiene styrene resin; Acrylonitrile styrene resin; Polyvinyl acetate resin; Polyvinylidene chloride resin; Polyamide resin; Polyacetal resin; Modified polyphenylene ether It may be a film made of polyimide resin or the like; system resin; polysulfone resins; poly (ether sulfone) resins; polyarylate resin; polyamide-imide resin. Among them, it is preferable to use a polyolefin resin or an acrylic resin, and it is particularly preferable to use a cyclic polyolefin resin.
  • chain polyolefin resin examples include a homopolymer of a chain olefin such as a polyethylene resin and a polypropylene resin, and a copolymer composed of two or more chain olefins.
  • Cyclic polyolefin-based resin is a general term for resins that are polymerized using cyclic olefins as polymerization units.
  • Specific examples of cyclic polyolefin resins include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers of cyclic olefins and chain olefins such as ethylene and propylene (typically Are random copolymers), graft polymers obtained by modifying them with unsaturated carboxylic acids or derivatives thereof, and hydrides thereof.
  • the protective film according to the present invention contains a cyclic polyolefin resin.
  • Cellulosic resins are those in which some or all of the hydrogen atoms in the hydroxyl groups of cellulose obtained from raw material cellulose such as cotton linter and wood pulp (hardwood pulp, conifer pulp) are substituted with acetyl groups, propionyl groups and / or butyryl groups. Further, it refers to a cellulose organic acid ester or a cellulose mixed organic acid ester. Examples include cellulose acetates, propionic acid esters, butyric acid esters, and mixed esters thereof.
  • the acrylic resin film include a film containing a methyl methacrylate resin.
  • the methyl methacrylate resin is a polymer containing 50% by weight or more of methyl methacrylate units.
  • the content of methyl methacrylate units is preferably 70% by weight or more, and may be 100% by weight.
  • the polymer having a methyl methacrylate unit of 100% by weight is a methyl methacrylate homopolymer obtained by polymerizing methyl methacrylate alone.
  • This methyl methacrylate-based resin is usually a monofunctional monomer mainly composed of methyl methacrylate and a polyfunctional monomer used as necessary, as a radical polymerization initiator and as required. It can be obtained by polymerization in the presence of a chain transfer agent.
  • Monofunctional monomers that can be copolymerized with methyl methacrylate include, for example, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, and 2-hydroxy methacrylate.
  • Acrylic acid esters such as: 2- (hydroxymethyl) methyl acrylate, 3- (hydroxyethyl) methyl acrylate, 2- (hydroxymethyl) ethyl acrylate, and 2- (hydroxymethyl) Hydroxyacrylic esters such as butyl acrylate; Unsaturated acids such as methacrylic acid and acrylic acid; Halogenated styrenes such as chlorostyrene and bromostyrene; Substituted styrenes such as vinyltoluene and ⁇ -methylstyrene; Acrylonitrile and methacrylate Examples thereof include unsaturated nitriles such
  • Examples of the polyfunctional monomer that can be copolymerized with methyl methacrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and tetraethylene glycol di (meth) acrylate.
  • Nonaethylene glycol di (meth) acrylate, and ethylene glycol such as tetradecaethylene glycol (meth) acrylate or the oligomers of both end hydroxyl groups esterified with acrylic acid or methacrylic acid; both ends of propylene glycol or its oligomer Hydroxyl ester of hydroxyl group with acrylic acid or methacrylic acid; neopentyl glycol di (meth) acrylate, hexanediol di (meth) acrylate, and butanediol A hydroxyl group of a dihydric alcohol such as (meth) acrylate esterified with acrylic acid or methacrylic acid; bisphenol A, an alkylene oxide adduct of bisphenol A, or both hydroxyl groups of these halogen-substituted products are acrylic acid or methacrylic acid Esterified with polyhydric alcohols such as trimethylolpropane and pentaerythritol with acrylic acid or methacryl
  • ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate and neopentyl glycol dimethacrylate are preferably used.
  • the methyl methacrylate resin may be a modified methyl methacrylate resin modified by performing a reaction between functional groups of the resin.
  • the reaction include, for example, depolymerization condensation in a polymer chain between a methyl ester group of methyl acrylate and a hydroxyl group of methyl 2- (hydroxymethyl) acrylate, and a carboxyl group of acrylic acid and 2- (hydroxymethyl).
  • Intrapolymer dehydration condensation reaction with hydroxyl group of methyl acrylate is a modified methyl methacrylate resin modified by performing a reaction between functional groups of the resin. Examples of the reaction include, for example, depolymerization condensation in a polymer chain between a methyl ester group of methyl acrylate and a hydroxyl group of methyl 2- (hydroxymethyl) acrylate, and a carboxyl group of acrylic acid and 2- (hydroxymethyl).
  • a retardation value of substantially zero means that the in-plane retardation value at a wavelength of 590 nm is 10 nm or less, the absolute value of the thickness direction retardation value at a wavelength of 590 nm is 10 nm or less, and the thickness direction position at a wavelength of 480 to 750 nm.
  • the absolute value of the phase difference value is 15 nm or less.
  • the protective film may be stretched and / or shrunk to give a suitable retardation value.
  • the thickness of the protective film can be about 1 to 30 ⁇ m, but it is preferably 5 to 25 ⁇ m, more preferably 5 to 20 ⁇ m from the viewpoints of strength and handleability. When the thickness is within this range, the polarizer is mechanically protected, and the polarizer does not shrink even when exposed to a humid heat environment, and stable optical characteristics can be maintained. In addition, the thickness of a protective film can be adjusted suitably so that the said interlayer thickness may become a predetermined range.
  • the protective film can be bonded to the polarizer through an adhesive layer.
  • an adhesive layer As the adhesive forming the adhesive layer, a water-based adhesive or an active energy ray-curable adhesive can be used.
  • the water-based adhesive examples include an adhesive made of a polyvinyl alcohol-based resin aqueous solution and an aqueous two-component urethane emulsion adhesive.
  • a water-based adhesive composed of a polyvinyl alcohol-based resin aqueous solution is preferably used.
  • Polyvinyl alcohol resins include vinyl alcohol homopolymers obtained by saponifying polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith.
  • a polyvinyl alcohol copolymer obtained by saponifying a polymer, a modified polyvinyl alcohol polymer obtained by partially modifying the hydroxyl group thereof, or the like can be used.
  • the water-based adhesive can contain a crosslinking agent such as an aldehyde compound, an epoxy compound, a melamine compound, a methylol compound, an isocyanate compound, an amine compound, or a polyvalent
  • a drying step in order to remove water contained in the water-based adhesive after bonding the polarizer and the protective film.
  • a curing step for curing at a temperature of about 20 to 45 ° C. may be provided.
  • the active energy ray-curable adhesive refers to an adhesive that cures when irradiated with active energy rays such as ultraviolet rays, for example, an adhesive containing a polymerizable compound and a photopolymerization initiator, an adhesive containing a photoreactive resin, Examples thereof include a binder resin and a photoreactive crosslinking agent.
  • the polymerizable compound include photopolymerizable monomers such as a photocurable epoxy monomer, a photocurable acrylic monomer, and a photocurable urethane monomer, and oligomers derived from the photopolymerizable monomer.
  • the photopolymerization initiator examples include those containing substances that generate active species such as neutral radicals, anion radicals, and cation radicals upon irradiation with active energy rays such as ultraviolet rays.
  • active energy ray-curable adhesive containing a polymerizable compound and a photopolymerization initiator an adhesive containing a photocurable epoxy monomer and a cationic photopolymerization initiator can be preferably used.
  • an active energy ray-curable adhesive When using an active energy ray-curable adhesive, after bonding a polarizer and a protective film, a drying step is performed as necessary, and then the active energy ray-curable adhesive is irradiated by irradiating active energy rays. A curing step for curing is performed.
  • the light source of the active energy ray is not particularly limited, but ultraviolet light having a light emission distribution at a wavelength of 400 nm or less is preferable.
  • a wave excitation mercury lamp, a metal halide lamp, etc. can be used.
  • saponification treatment, corona treatment, plasma treatment, or the like can be performed on at least one of the pasting surfaces.
  • the pressure-sensitive adhesive forming the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer conventionally known ones may be appropriately selected, and a high temperature environment, a humid heat environment or an environment where high and low temperatures are repeated are exposed to the polarizing plate. It is sufficient that the adhesive layer has a degree of adhesion that does not cause peeling. Specific examples include acrylic pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, and acrylic pressure-sensitive adhesives are particularly preferable in terms of transparency, weather resistance, heat resistance, and processability.
  • the first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer, and / or the third pressure-sensitive adhesive layer may use the same type of pressure-sensitive adhesive, or may use different types of pressure-sensitive adhesives.
  • the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer are formed from an acrylic pressure-sensitive adhesive.
  • a tackifier for the adhesive, if necessary, a tackifier, plasticizer, glass fiber, glass beads, metal powder, other inorganic powders, fillers, pigments, colorants, fillers, antioxidants, UV absorbers Various additives such as an antistatic agent and a silane coupling agent may be appropriately blended.
  • the pressure-sensitive adhesive layer is usually formed by applying a pressure-sensitive adhesive solution onto a release sheet and drying.
  • a pressure-sensitive adhesive solution onto a release sheet and drying.
  • roll coating methods such as reverse coating and gravure coating, spin coating methods, screen coating methods, fountain coating methods, dipping methods, spraying methods and the like can be employed.
  • the release sheet provided with the pressure-sensitive adhesive layer is used by a method of transferring the release sheet.
  • the thickness of the pressure-sensitive adhesive layer is usually about 3 to 30 ⁇ m, preferably 10 to 30 ⁇ m, and more preferably 10 to 25 ⁇ m.
  • the polarizing plate when the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer have such thicknesses, the polarizing plate can be prevented from being broken, and when incorporated in a liquid crystal display device, The occurrence of light leakage can be suppressed.
  • the thickness of a 2nd adhesive layer and a 3rd adhesive layer can be suitably adjusted so that the said interlayer thickness may become a predetermined range.
  • the storage elastic modulus at 80 ° C. of the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer is preferably 0.025 MPa or more, more preferably 0.07 MPa or more. If the storage elastic modulus of the pressure-sensitive adhesive layer is less than 0.025 MPa, the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer may cause cohesive failure, and if the cohesive failure is significant, only the appearance of the polarizing plate is adversely affected. In addition, when incorporated in a liquid crystal display device, light leakage occurs at the end of the liquid crystal panel, which adversely affects the display. Preferably, the storage elastic modulus at 80 ° C.
  • the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer is 1.1 MPa or less, preferably 0.9 MPa or less. If the storage elastic modulus of the pressure-sensitive adhesive layer at 80 ° C. exceeds 1.1 MPa, the heat-resistant durability deteriorates against the second pressure-sensitive adhesive layer, the third pressure-sensitive adhesive layer and the glass or panel, and bubbles are generated between the layers. It becomes easy.
  • a separator may be provided to protect the surface of the second adhesive layer and the third adhesive layer until they are bonded to another member.
  • the back-side polarizing plate of the present invention includes, for example, a step of subjecting the surface on the first pressure-sensitive adhesive layer side of the reflective polarizing plate to a surface activation treatment, and the first surface on the surface subjected to the surface activation treatment. It is produced through a process of laminating an adhesive layer.
  • the back side polarizing plate of this invention is a surface on the opposite side to the 1st polarizer in bonding a 1st protective film through the adhesive bond layer on the single side
  • laminating the second pressure-sensitive adhesive layer, bonding the first pressure-sensitive adhesive layer to the surface of the first polarizer opposite to the first protective film, and the first polarizer in the first pressure-sensitive adhesive layer Includes laminating a reflective polarizing plate on the opposite surface.
  • a separator may be temporarily attached to the outer surface of the second pressure-sensitive adhesive layer, and a surface activation treatment may be performed on the bonding surface of the first pressure-sensitive adhesive layer with the reflective polarizing plate.
  • the method of laminating the reflective polarizing plate to the first pressure-sensitive adhesive layer may be a single wafer laminating method or a sheet / roll composite laminating method as described in JP-A-2004-262071. Also good. In addition, when it can be produced in a long length and the required quantity is large, a roll-to-roll bonding method is also useful.
  • the method for producing the back side polarizing plate of the present invention can be produced by a method known in the technical field.
  • the manufacturing method of the back side polarizing plate of this invention can be produced by a well-known method in the said technical field.
  • the front-side polarizing plate can be obtained through the same steps as the manufacturing method of the back-side polarizing plate described above.
  • the polarizing plate set according to the present invention can be preferably applied to a liquid crystal panel.
  • the liquid crystal panel includes a liquid crystal cell and a polarizing plate according to the present invention bonded to the surface thereof. Bonding of the back-side polarizing plate to the liquid crystal cell can be performed via the second pressure-sensitive adhesive layer.
  • the back side polarizing plate according to the present invention is usually used as a polarizing plate disposed on the backlight side of the liquid crystal cell.
  • the front side polarizing plate can be bonded to the liquid crystal cell via the third pressure-sensitive adhesive layer.
  • the front side polarizing plate according to the present invention is usually used as a polarizing plate disposed on the viewing side of the liquid crystal cell.
  • the pair of polarizing plates is the polarizing plate set,
  • the second protective film, the second polarizer, the third pressure-sensitive adhesive layer, the liquid crystal cell, the second pressure-sensitive adhesive layer, the first protective film, the first polarizer, the first pressure-sensitive adhesive layer, and the reflection A liquid crystal panel in which mold-type polarizing plates are laminated in this order is provided.
  • the driving method of the liquid crystal cell may be any conventionally known method, but is preferably the IPS mode.
  • the liquid crystal panel using the polarizing plate according to the present invention is excellent in wet heat durability.
  • an organic electroluminescence display device can be obtained by bonding each polarizing plate to an organic electroluminescence display via the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer.
  • the film thickness was measured according to the following.
  • this polarizer may be referred to as a polarizer (23 ⁇ m).
  • this polarizer may be referred to as a polarizer (12 ⁇ m).
  • this polarizer was washed with pure water at 26 ° C. for 20 seconds and then dried at 65 ° C. to obtain a polarizer having a thickness of 7 ⁇ m in which iodine was adsorbed and oriented on the polyvinyl alcohol film.
  • this polarizer may be referred to as a polarizer (7 ⁇ m).
  • a commercially available pressure-sensitive adhesive sheet in which an acrylic pressure-sensitive adhesive layer having a thickness of 20 ⁇ m is provided on a release-treated surface of a polyethylene terephthalate film (release film) having a thickness of 38 ⁇ m that has been subjected to a release treatment. No urethane acrylate oligomer is blended.
  • Reflective polarizing plate-1 As the reflective polarizing plate-1, “Advanced Polarizer Film, Version 3” (thickness: 26 ⁇ m) manufactured by 3M was used.
  • HC-TAC a triacetyl cellulose film having a thickness of 32 ⁇ m and a hard coat surface (manufactured by Toppan TOMOEGAWA Optical Film, 25KCHC-TC), TAC: 25 ⁇ m thick triacetylcellulose film (TAC) [trade name “KC2UA” manufactured by Konica Minolta, Inc.]
  • COP-1 An unstretched 23 ⁇ m-thick norbornene resin film (trade name “ZEONOR” manufactured by Nippon Zeon Co., Ltd.)
  • COP-2 An unstretched 13 ⁇ m-thick norbornene resin film (trade name “ZEONOR” manufactured by Nippon Zeon Co., Ltd.)
  • Preparation of water-based adhesive 3 parts by weight of a carboxyl group-modified polyvinyl alcohol [“KL-318” manufactured by Kuraray Co., Ltd.] was dissolved in 100 parts by weight of water to prepare an aqueous polyvinyl alcohol solution.
  • aqueous polyvinyl alcohol solution 3 parts by weight of a carboxyl group-modified polyvinyl alcohol [“KL-318” manufactured by Kuraray Co., Ltd.] was dissolved in 100 parts by weight of water to prepare an aqueous polyvinyl alcohol solution.
  • water-soluble polyamide epoxy resin (“Smile Resin 650 (30) manufactured by Taoka Chemical Industry Co., Ltd., solid concentration: 30% by weight)” was added to 100 parts by weight of water. Mixing at a ratio, an aqueous adhesive was obtained.
  • FIG. 1 Preparation example of front side polarizing plate A
  • a water-based adhesive is applied to one side of a polarizer (12 ⁇ m), HC-TAC is bonded as a second protective film, and COP-1 is laminated on the opposite side using the above-mentioned adhesive, and 80 ° C.
  • the protective film and the polarizer were bonded together by drying for 5 minutes. After pasting, it was cured at 40 ° C. for 168 hours. Further, a third pressure-sensitive adhesive layer was bonded to the surface of COP-1 opposite to the polarizer.
  • This laminate was designated as a front side polarizing plate A.
  • the laminate has a rectangular shape with a long side length of 155.25 mm and a short side length of 95.90 mm.
  • a front side polarizing plate A was prepared in the same manner as the front side polarizing plate A, except that the polarizer of the front side polarizing plate A was changed to a polarizer (11 ⁇ m). This laminate was designated as a front side polarizing plate B.
  • a front side polarizing plate A was prepared in the same manner as the front side polarizing plate A except that the polarizer of the front side polarizing plate A was changed to a polarizer (23 ⁇ m). This laminate was designated as a front side polarizing plate C.
  • Example of production of back side polarizing plate (Example of production of back side polarizing plate A)
  • a water-based adhesive is applied to one side of a polarizer (11 ⁇ m), TAC is bonded as a protective film, and the other side is used to laminate COP-2 as a first protective film using the adhesive described above.
  • the protective film and the polarizer were bonded by drying at 5 ° C. for 5 minutes. After pasting, it was cured at 40 ° C. for 168 hours. Further, the second pressure-sensitive adhesive layer was bonded to the surface of COP-2 opposite to the polarizer. Furthermore, a reflective polarizing plate was bonded to the surface of the TAC opposite to the polarizer through a first adhesive.
  • This laminate was designated as a back side polarizing plate A.
  • the laminate has a rectangular shape with a long side length of 155.25 mm and a short side length of 95.90 mm.
  • the back side polarizing plate B was prepared in the same manner as the back side polarizing plate B except that the polarizer of the back side polarizing plate B was changed to a polarizer (7 ⁇ m). This laminate was designated as a front side polarizing plate C.
  • the back side polarizing plate A was prepared in the same manner as the back side polarizing plate A, except that the polarizer of the back side polarizing plate A was changed to a polarizer (12 ⁇ m). This laminate was designated as a front side polarizing plate D.
  • Table 1 shows the structures of the polarizing plates in Examples and Comparative Examples obtained as described above. Moreover, the physical property evaluation of each obtained polarizing plate was performed according to the following description. The results are shown in Table 1.
  • the curvature amount was measured with the following method. First, in the produced back side polarizing plate, the surface opposite to the first protective film in the second pressure-sensitive adhesive layer is pasted on glass having a thickness of 0.4 mm (manufactured by Corning, product number: EAGLE XG (registered trademark) ). Combined. Next, the surface opposite to the second polarizer in the third pressure-sensitive adhesive layer of the front side polarizing plate was bonded to the surface opposite to the second pressure-sensitive adhesive layer side in the glass.
  • the first polarizer in the back side polarizing plate is bonded so that the angle between the absorption axis of the second polarizer in the front side polarizing plate and the absorption axis of the first polarizer in the back side polarizing plate is 90 °.
  • a laminate was prepared so that the angle formed by the absorption axis of the polarizer and the long side of the back-side polarizing plate was 0 °.
  • the laminate having the configuration of the rear side polarizing plate / glass / front side polarizing plate was allowed to stand for 250 hours in an environment of 60 ° C. and humidity of 90%.
  • the laminate was taken out from the test tank and placed on a measuring table of a two-dimensional measuring device (manufactured by Nikon Corporation, NEXIV (registered trademark) MR-12072) so that the front polarizing plate was on the upper side.
  • the surface of the measuring table was focused, and the height from the reference focal point was measured by focusing on each of the 25 points on the glass sample surface.
  • the difference between the maximum value and the minimum value at the 25 measurement points was defined as the amount of warpage. Specifically, the point 40 shown in FIG.
  • the 25 points shown in FIG. 3 are points in a region 7 mm inside from the end of the polarizing plate, and the short side direction is provided at intervals of about 20 mm, and the long side direction is provided at intervals of about 35 mm.
  • symbol 50 shows a polarizing plate and 60 shows a glass plate.
  • Table 1 The results are shown in Table 1. In the examples, in all samples, the entire laminate was not lifted or peeled off, and no floating or peeling between layers was observed. ⁇ Judgment> The case where the amount of warpage of the glass sample that was allowed to stand in a humid heat environment was less than 0.6 mm was designated as “ ⁇ ”. The case where the amount of warpage of the glass sample placed in a humid heat environment was 0.6 mm or more was defined as “x”.
  • the polarizing plate set of this invention is a case where a polarizing plate is exposed to a moist heat environment on high temperature conditions, the curvature of a liquid crystal panel is suppressed. Furthermore, cohesive failure of the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer can be suppressed. Moreover, even when the polarizing plate of the present invention is exposed to a wet heat environment under high temperature conditions, the visibility of the polarizing plate is very good, and light leakage of the polarizing plate does not occur.
  • the polarizing plate set of the present invention has a small amount of warping when placed in a humid heat environment and a high temperature environment, peeling from the touch panel and falling off of the backlight unit can be reduced or avoided. In addition, display unevenness caused by warpage that may be caused by exposure to a high temperature environment and a moist heat environment is reduced.
  • a polarizing plate set in which, for example, warpage due to shrinkage of a polarizer and a reflective polarizing plate is suppressed. Furthermore, according to this invention, the polarizing plate set by which the cohesive failure of the adhesive layer bonded by the glass substrate of the liquid crystal cell was also suppressed is provided.

Landscapes

  • 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)

Abstract

[Problem] To provide a polarizing plate set capable of minimizing warpage and reducing display unevenness caused by potential warpage when placed in a moisture-resistant and heat-resistant environment. [Solution] Provided is a polarizing plate set comprising a rear polarizing plate disposed on one surface of a liquid crystal cell and a front polarizing plate disposed on the other surface. The rear polarizing plate includes a reflective polarizing plate, a first adhesive layer, a first polarizer, a first protective film, and a second adhesive layer. The front polarizing plate includes a third adhesive layer, a second polarizer, and a second protective film. The formula 0 µm < Δd < 5 µm is satisfied if dF − dR is equal to Δd (µm), where dF (µm) represents the thickness of the second polarizer in the front polarizing plate and dR represents the thickness of the first polarizer in the rear polarizing plate. The angle between the absorption axis of the second polarizer in the front polarizing plate and the absorption axis of the first polarizer in the rear polarizing plate is 90°±1°.

Description

偏光板セットPolarizing plate set
　本発明は、様々な光学用途に使用できる偏光板セットに関する。 The present invention relates to a polarizing plate set that can be used for various optical applications.
　液晶表示装置の画像形成方式に起因して、液晶セルの両側に偏光子が配置されている。
　例えば、特許文献１には、液晶セルの前面側と背面側に偏光子が配置された液晶パネルが開示されている。また、特許文献２には、液晶セルの前面側と背面側に配置する光学積層体が開示されている。
　上記特許文献１に開示された液晶パネルおよび特許文献２に開示された光学積層体によると、前面側に配置された偏光膜と背面側に配置された偏光膜の厚さの関係を規定することにより、液晶パネルの反りを低減することが試みられている。 Due to the image forming method of the liquid crystal display device, polarizers are arranged on both sides of the liquid crystal cell.
For example, Patent Document 1 discloses a liquid crystal panel in which polarizers are arranged on the front side and the back side of a liquid crystal cell. Patent Document 2 discloses an optical laminate that is disposed on the front side and the back side of a liquid crystal cell.
According to the liquid crystal panel disclosed in Patent Document 1 and the optical laminate disclosed in Patent Document 2, the relationship between the thickness of the polarizing film disposed on the front side and the thickness of the polarizing film disposed on the back side is specified. Therefore, attempts have been made to reduce the warpage of the liquid crystal panel.
特開２０１２－５８４２９号公報JP 2012-58429 A 特開２０１３－３７１１５号公報JP 2013-37115 A
　従来は、高温環境下の反りにのみ着目し、これを制御しさえすれば液晶パネルの反りが問題となることはなかったが、液晶セルの厚みが薄くなるにつれ（例えば液晶セルを構成するガラス基板の厚みが０．５ｍｍ以下）、湿熱環境（例えば、６０℃、湿度９０％）下で生じる僅かな寸法変化量により生じる偏光板の応力により、液晶セルの反りが顕著に確認されることが判明した。
　特許文献１および２に開示されている発明は、用いる保護フィルム、偏光板の構造等の条件によっては、湿熱環境下における液晶パネルの反りにより、液晶パネルがタッチパネルから剥がれたり、バックライトユニットが脱落したりするなどの問題が存在している。 Conventionally, attention has been paid only to warping in a high-temperature environment, and if this is controlled, warping of the liquid crystal panel has not been a problem. However, as the thickness of the liquid crystal cell becomes thinner (for example, the glass constituting the liquid crystal cell). It is confirmed that the warpage of the liquid crystal cell is remarkably confirmed by the stress of the polarizing plate caused by a slight amount of dimensional change that occurs in a humid heat environment (for example, 60 ° C., humidity 90%). found.
In the inventions disclosed in Patent Documents 1 and 2, depending on conditions such as the protective film used and the structure of the polarizing plate, the liquid crystal panel may be peeled off from the touch panel or the backlight unit may be dropped due to warpage of the liquid crystal panel in a humid heat environment. There are problems such as.
　そこで、本発明は、高温環境下における液晶パネルの反りはもとより、湿熱環境下における液晶パネルの反りを抑制できる偏光板セットを提供することを目的とする。 Accordingly, an object of the present invention is to provide a polarizing plate set capable of suppressing the warpage of the liquid crystal panel in a humid heat environment as well as the warpage of the liquid crystal panel in a high temperature environment.
　本発明は、以下を含む。
［１］液晶セルの一方の面側に配置される背面側偏光板と、他方の面側に配置される前面側偏光板とを含む、偏光板セットであって、
　前記背面側偏光板は、反射型偏光板と、第１粘着剤層と、第１偏光子と、第１保護フィルムと、第２粘着剤層とを有し、
　前記前面側偏光板は、第３粘着剤層と、第２偏光子と、第２保護フィルムとを有し、
　前記前面側偏光板における第２偏光子の厚さｄＦ（μｍ）から、前記背面側偏光板における第１偏光子の厚さｄＲ（μｍ）を差し引いた差ｄＦ－ｄＲをΔｄ（μｍ）とした場合、０μｍ＜Δｄ＜５μｍであり、
前記前面側偏光板における第２偏光子の吸収軸と、前記背面側偏光板における第１偏光子の吸収軸とのなす角度が９０°±１°である、
偏光板セット。
［２］前記背面側偏光板における第１偏光子の吸収軸と前記背面側偏光板の長辺とのなす角度が０°±０．５°である、［１］に記載の偏光板セット。
［３］前記反射型偏光板は、少なくとも２層の薄膜を有し、前記少なくとも２層の薄膜は、屈折率異方性が異なる、［１］または［２］に記載の偏光板セット。
［４］液晶セルと、その両面に配置された一対の偏光板を有し、
　前記一対の偏光板は、［１］から［３］のいずれか１に記載の偏光板セットであり、
　第２保護フィルムと、第２偏光子と、第３粘着剤層と、液晶セルと、第２粘着剤層と、第１保護フィルムと、第１偏光子と、第１粘着剤層と、反射型偏光板がこの順で積層されている、液晶パネル。 The present invention includes the following.
[1] A polarizing plate set including a back side polarizing plate disposed on one surface side of the liquid crystal cell and a front side polarizing plate disposed on the other surface side,
The back side polarizing plate has a reflective polarizing plate, a first pressure-sensitive adhesive layer, a first polarizer, a first protective film, and a second pressure-sensitive adhesive layer.
The front side polarizing plate has a third pressure-sensitive adhesive layer, a second polarizer, and a second protective film,
A difference dF−dR obtained by subtracting the thickness dR (μm) of the first polarizer in the back-side polarizing plate from the thickness dF (μm) of the second polarizer in the front-side polarizing plate is defined as Δd (μm). And 0 μm <Δd <5 μm,
The angle formed by the absorption axis of the second polarizer in the front-side polarizing plate and the absorption axis of the first polarizer in the rear-side polarizing plate is 90 ° ± 1 °.
Polarizing plate set.
[2] The polarizing plate set according to [1], wherein an angle formed between the absorption axis of the first polarizer and the long side of the rear polarizing plate in the rear polarizing plate is 0 ° ± 0.5 °.
[3] The polarizing plate set according to [1] or [2], wherein the reflective polarizing plate has at least two thin films, and the at least two thin films have different refractive index anisotropy.
[4] A liquid crystal cell and a pair of polarizing plates arranged on both sides thereof,
The pair of polarizing plates is the polarizing plate set according to any one of [1] to [3],
The second protective film, the second polarizer, the third pressure-sensitive adhesive layer, the liquid crystal cell, the second pressure-sensitive adhesive layer, the first protective film, the first polarizer, the first pressure-sensitive adhesive layer, and the reflection A liquid crystal panel in which type polarizing plates are laminated in this order.
　本発明によれば、湿熱環境及び高温環境にさらした際に、液晶パネルの反りを小さくすることができる偏光板のセットを得ることができる。 According to the present invention, it is possible to obtain a set of polarizing plates capable of reducing the warpage of the liquid crystal panel when exposed to a humid heat environment and a high temperature environment.
本発明の偏光板セットにおける一態様を説明する概略断面図である。It is a schematic sectional drawing explaining the one aspect | mode in the polarizing plate set of this invention. 前面側偏光板の吸収軸と背面側偏光板の吸収軸とのなす角度を説明する概略図である。It is the schematic explaining the angle which the absorption axis of a front side polarizing plate and the absorption axis of a back side polarizing plate make. 反り量の測定を説明する図である。It is a figure explaining measurement of the amount of curvature.
　以下、本発明に係る偏光板セットについて適宜図を用いて説明するが、本発明はこれらの態様に限定されるものではない。 Hereinafter, the polarizing plate set according to the present invention will be described with reference to the drawings as appropriate, but the present invention is not limited to these embodiments.
　液晶セルの一方の面側に配置される背面側偏光板と、他方の面側に配置される前面側偏光板とを含む、偏光板セットであって、
　前記背面側偏光板は、反射型偏光板と、第１粘着剤層と、第１偏光子と、第１保護フィルムと、第２粘着剤層とを有し、
　前記前面側偏光板は、第３粘着剤層と、第２偏光子と、第２保護フィルムとを有し、
　前記前面側偏光板における第２偏光子の厚さｄＦ（μｍ）から、前記背面側偏光板における第１偏光子の厚さｄＲ（μｍ）を差し引いた差ｄＦ－ｄＲをΔｄ（μｍ）とした場合、０μｍ＜Δｄ＜５μｍであり、
前記前面側偏光板における第２偏光子の吸収軸と、前記背面側偏光板における第１偏光子の吸収軸とのなす角度が９０°±１°である、
偏光板セットである。
　例えば、本発明の偏光板のセットを備えた液晶パネルによれば、液晶パネルがタッチパネルから剥がれたり、バックライトユニットが脱落したりすることを抑制でき、また表示ムラの小さな表示装置を得ることができる。 A polarizing plate set comprising a back side polarizing plate disposed on one surface side of the liquid crystal cell and a front side polarizing plate disposed on the other surface side,
The back side polarizing plate has a reflective polarizing plate, a first pressure-sensitive adhesive layer, a first polarizer, a first protective film, and a second pressure-sensitive adhesive layer.
The front side polarizing plate has a third pressure-sensitive adhesive layer, a second polarizer, and a second protective film,
A difference dF−dR obtained by subtracting the thickness dR (μm) of the first polarizer in the back-side polarizing plate from the thickness dF (μm) of the second polarizer in the front-side polarizing plate is defined as Δd (μm). And 0 μm <Δd <5 μm,
The angle formed by the absorption axis of the second polarizer in the front-side polarizing plate and the absorption axis of the first polarizer in the rear-side polarizing plate is 90 ° ± 1 °.
It is a polarizing plate set.
For example, according to the liquid crystal panel provided with the set of polarizing plates of the present invention, it is possible to prevent the liquid crystal panel from peeling off the touch panel or the backlight unit from falling off, and to obtain a display device with small display unevenness. it can.
　本発明の偏光板セットは、図１に示すように、液晶セル３０の一方の面側に配置される背面側偏光板１０と、他方の面側に配置される前面側偏光板２０とを含む。背面側偏光板１０は、反射型偏光板１１と、第１粘着剤層１２と、第１偏光子１３と、第１保護フィルム１４と、第２粘着剤層１５とを有する。一態様において、背面側偏光板１０は、所望により、更なる層を有し得る。 As shown in FIG. 1, the polarizing plate set of the present invention includes a back side polarizing plate 10 disposed on one surface side of the liquid crystal cell 30 and a front side polarizing plate 20 disposed on the other surface side. . The back side polarizing plate 10 includes a reflective polarizing plate 11, a first pressure-sensitive adhesive layer 12, a first polarizer 13, a first protective film 14, and a second pressure-sensitive adhesive layer 15. In one aspect, the back side polarizing plate 10 can have an additional layer if desired.
　別の態様においては、背面側偏光板１０は、反射型偏光板１１と、第１粘着剤層１２と、第１偏光子１３と、第１保護フィルム１４と、第２粘着剤層１５とがこの順で積層された偏光板である。また、背面側偏光板１０は第１粘着剤層１２と第１偏光子１３との間に保護フィルムをさらに有していてもよい（図示せず）。すなわち、背面側偏光板１０は第１偏光子１３の両面に保護フィルムを有していてもよい。 In another aspect, the back side polarizing plate 10 includes a reflective polarizing plate 11, a first pressure-sensitive adhesive layer 12, a first polarizer 13, a first protective film 14, and a second pressure-sensitive adhesive layer 15. It is the polarizing plate laminated | stacked in this order. Moreover, the back side polarizing plate 10 may further have a protective film between the 1st adhesive layer 12 and the 1st polarizer 13 (not shown). That is, the back side polarizing plate 10 may have protective films on both surfaces of the first polarizer 13.
　前面側偏光板２０は、第３粘着剤層２１と、第２偏光子２２と、第２保護フィルム２３とを有する。前面側偏光板２０は、所望により、更なる層を有し得る。
　別の態様において、前面側偏光板２０は、第３粘着剤層２１と、第２偏光子２２と、第２保護フィルム２３とがこの順で積層された偏光板である。また、前面側偏光板２０は第３粘着剤層２１と第２偏光子２２との間に保護フィルムをさらに有していてもよい（図示せず）。すなわち前面側偏光板２０は第２偏光子２２の両面に保護フィルムを有していてもよい。 The front side polarizing plate 20 includes a third pressure-sensitive adhesive layer 21, a second polarizer 22, and a second protective film 23. The front side polarizing plate 20 may have further layers as desired.
In another aspect, the front-side polarizing plate 20 is a polarizing plate in which a third pressure-sensitive adhesive layer 21, a second polarizer 22, and a second protective film 23 are laminated in this order. Moreover, the front side polarizing plate 20 may further have a protective film between the third pressure-sensitive adhesive layer 21 and the second polarizer 22 (not shown). That is, the front side polarizing plate 20 may have protective films on both surfaces of the second polarizer 22.
　本発明における背面側偏光板は、例えば、液晶セルの視認側の面とは反対側の面に貼合される。一態様において、背面側偏光板は、液晶パネルに設けられた光源、例えばバックライトなどと隣接するよう、液晶セルに貼合されてもよい。さらに、背面偏光板の縁に幅の狭い両面テープを貼り付けて、バックライトユニットを貼り付けてもよい。
　一方、本発明における前面側偏光板は、例えば、液晶セルの視認側の面に貼合される。 The back surface side polarizing plate in this invention is bonded by the surface on the opposite side to the surface at the side of visual recognition of a liquid crystal cell, for example. In one embodiment, the back-side polarizing plate may be bonded to the liquid crystal cell so as to be adjacent to a light source provided in the liquid crystal panel, such as a backlight. Furthermore, a narrow double-sided tape may be attached to the edge of the back polarizing plate, and the backlight unit may be attached.
On the other hand, the front side polarizing plate in this invention is bonded by the surface at the side of visual recognition of a liquid crystal cell, for example.
　図１には示されていないが、例えば、図１に示される偏光板セット、すなわち、背面側偏光板１０および前面側偏光板２０には、上述した層以外の層を設けてもよい。また、偏光子１３、２２と保護フィルム１４、２３は、通常、接着剤層を介して、貼り合わされている。 Although not shown in FIG. 1, for example, the polarizing plate set shown in FIG. 1, that is, the back side polarizing plate 10 and the front side polarizing plate 20 may be provided with a layer other than the above-described layers. Moreover, the polarizers 13 and 22 and the protective films 14 and 23 are usually bonded together via an adhesive layer.
　本発明の偏光板セットは、図１に示すように、前面側偏光板２０における第２偏光子の厚さをｄＦとし、背面側偏光板１０における第１偏光子の厚さをｄＲとし、前面側偏光板２０における第２偏光子の厚さｄＦ（μｍ）から、背面側偏光板１０における第１偏光子の厚さｄＲ（μｍ）を差し引いた差ｄＦ－ｄＲをΔｄ（μｍ）とした場合、
０μｍ＜Δｄ＜５μｍの関係を有し、より好ましくは、１μｍ＜Δｄ＜５μｍの関係を有する。 In the polarizing plate set of the present invention, as shown in FIG. 1, the thickness of the second polarizer in the front side polarizing plate 20 is dF, the thickness of the first polarizer in the back side polarizing plate 10 is dR, When the difference dF−dR obtained by subtracting the thickness dR (μm) of the first polarizer in the rear polarizing plate 10 from the thickness dF (μm) of the second polarizer in the side polarizing plate 20 is Δd (μm) ,
It has a relationship of 0 μm <Δd <5 μm, more preferably a relationship of 1 μm <Δd <5 μm.
　厚さｄＦから厚さｄＲを差し引いた差であるΔｄ（μｍ）がこのような範囲であることにより、前面側偏光板とガラス（液晶セル）と背面側偏光板の積層体（液晶パネル）が高温（例えば、８５℃、湿度５％）に長時間曝された場合においても、積層体の反り量が小さい。さらに、前面側偏光板とガラスと背面側偏光板の積層体が、湿熱環境（例えば、６０℃、湿度９０％）の条件下に置かれたとしても、積層体の反りは抑制される。
　このように、本発明の偏光板セットを備える積層体は、湿熱環境および高温環境に配置した際に反り量が小さいため、耐湿熱性および耐熱性を備え、高温環境および湿熱環境下でのタッチパネルからの剥がれやバックライトユニットの脱落がなくなると考えられる。
また、高温環境および湿熱環境試験後の反りに起因して発生する表示ムラの低減につながる。
　また、Δｄ（μｍ）がこのような関係を有することにより、様々な大きさ、厚さを有する液晶パネルに、本発明の偏光板セットを適用できる。
　なお、本明細書において、高温環境は、一例として、８５℃の温度について説明される。本発明において、高温環境は、例えば、７０℃～９５℃の温度、０％～２０％の湿度に、少なくとも３０～６０分間、偏光板等が曝される環境を意味し得る。
　また、湿熱環境は、一例として、６０℃の温度、湿度９０％の条件について説明される。本発明において、湿熱環境は、例えば、５０℃～８０℃の温度、６０％～９５％の湿度に、少なくとも３０分間～６０分間、偏光板等が曝される環境を意味し得る。 Since Δd (μm), which is the difference obtained by subtracting the thickness dR from the thickness dF, is within such a range, the laminate (liquid crystal panel) of the front side polarizing plate, glass (liquid crystal cell), and back side polarizing plate can be obtained. Even when exposed to high temperature (for example, 85 ° C., humidity 5%) for a long time, the amount of warpage of the laminate is small. Furthermore, even if the laminated body of the front-side polarizing plate, the glass, and the rear-side polarizing plate is placed in a wet heat environment (for example, 60 ° C., humidity 90%), the warpage of the laminated body is suppressed.
As described above, the laminate including the polarizing plate set of the present invention has a small amount of warping when placed in a wet heat environment and a high temperature environment, and thus has a wet heat resistance and a heat resistance, and from a touch panel in a high temperature environment and a wet heat environment. It is thought that there will be no peeling off of the backlight unit or falling off of the backlight unit.
In addition, display unevenness caused by warping after the high temperature environment and wet heat environment test is reduced.
Further, since Δd (μm) has such a relationship, the polarizing plate set of the present invention can be applied to liquid crystal panels having various sizes and thicknesses.
In the present specification, the high temperature environment is described as an example of a temperature of 85 ° C. In the present invention, the high temperature environment may mean an environment where the polarizing plate or the like is exposed to, for example, a temperature of 70 ° C. to 95 ° C. and a humidity of 0% to 20% for at least 30 to 60 minutes.
In addition, as an example, the wet heat environment is described under the conditions of a temperature of 60 ° C. and a humidity of 90%. In the present invention, the moist heat environment may mean an environment where the polarizing plate or the like is exposed to a temperature of 50 ° C. to 80 ° C. and a humidity of 60% to 95% for at least 30 minutes to 60 minutes.
　一態様において、背面側偏光板の第１偏光子の厚さｄＲは、１５μｍ以下であり、より好ましくは、０．１μｍ以上１３μｍ以下である。
　背面側偏光板は、反射型偏光板を有するため、第１偏光子の厚みは薄いほど背面側偏光板の薄型化を達成できる。 In one embodiment, the thickness dR of the first polarizer of the back side polarizing plate is 15 μm or less, and more preferably 0.1 μm or more and 13 μm or less.
Since the back-side polarizing plate has a reflective polarizing plate, the back-side polarizing plate can be made thinner as the first polarizer is thinner.
　本発明における偏光板セットの各厚さの測定は、当該技術分野において公知の測定方法を用いて行える。 Measurement of each thickness of the polarizing plate set in the present invention can be performed using a measurement method known in the technical field.
　本発明において、前面側偏光板における第２偏光子の吸収軸と、背面側偏光板における第１偏光子の吸収軸とのなす角度は９０°±１°であり、より好ましくは９０°±０．５°の範囲である。 In the present invention, the angle formed by the absorption axis of the second polarizer in the front-side polarizing plate and the absorption axis of the first polarizer in the rear-side polarizing plate is 90 ° ± 1 °, more preferably 90 ° ± 0. .5 ° range.
　例えば、図２は、本発明の一態様における、偏光子の吸収軸の関係を例示する図である。図２において、背面側偏光板１０における第１偏光子の吸収軸は１０ａで表され、第１偏光子の透過軸は１０ｂで表される。また、背面側偏光板の長辺は、１０ｃで示される。
一方、図２において、前面側偏光板２０の第２偏光子の吸収軸は２０ａで表され、第２偏光子の透過軸は２０ｂで表される。
　本発明においては、第１偏光子の吸収軸１０ａと、第２偏光子の吸収軸２０ａとのなす角度は、上述のように、９０°±１°である。この角度は、例えば、図２における角度αとして表すことができる。 For example, FIG. 2 is a diagram illustrating the relationship between the absorption axes of the polarizers according to one embodiment of the present invention. In FIG. 2, the absorption axis of the first polarizer in the back side polarizing plate 10 is represented by 10a, and the transmission axis of the first polarizer is represented by 10b. The long side of the back side polarizing plate is indicated by 10c.
On the other hand, in FIG. 2, the absorption axis of the second polarizer of the front side polarizing plate 20 is represented by 20a, and the transmission axis of the second polarizer is represented by 20b.
In the present invention, the angle formed between the absorption axis 10a of the first polarizer and the absorption axis 20a of the second polarizer is 90 ° ± 1 ° as described above. This angle can be represented, for example, as an angle α in FIG.
　一態様においては、背面側偏光板における第１偏光子の吸収軸と、前記背面側偏光板（第１偏光子）の長辺とのなす角度は０°±１°であり、別の態様では、上記なす角度は０°±０．５°である。 In one aspect, the angle formed by the absorption axis of the first polarizer in the back side polarizing plate and the long side of the back side polarizing plate (first polarizer) is 0 ° ± 1 °. The angle formed above is 0 ° ± 0.5 °.
　なお、本発明において、前面側偏光板における第２偏光子の吸収軸を、前面側偏光板の吸収軸と記載することがあり、また、背面側偏光板における第１偏光子の吸収軸を、背面側偏光板の吸収軸とすることがある。 In the present invention, the absorption axis of the second polarizer in the front side polarizing plate may be described as the absorption axis of the front side polarizing plate, and the absorption axis of the first polarizer in the back side polarizing plate may be It may be the absorption axis of the back side polarizing plate.
　本発明の偏光板セットにおいて、前面側偏光板における第２偏光子の厚さｄＦ（μｍ）から、背面側偏光板における第１偏光子の厚さｄＲ（μｍ）を差し引いた差ｄＦ－ｄＲをΔｄ（μｍ）とした場合、
０μｍ＜Δｄ＜５μｍであることにより、例えば、前面側偏光板とガラス板と背面側偏光板を有する液晶パネルを、高温条件下、湿熱環境下に曝したとしても、これらの反りを抑制できる。 In the polarizing plate set of the present invention, a difference dF−dR obtained by subtracting the thickness dR (μm) of the first polarizer in the back side polarizing plate from the thickness dF (μm) of the second polarizer in the front side polarizing plate is obtained. If Δd (μm),
By satisfying 0 μm <Δd <5 μm, for example, even if a liquid crystal panel having a front side polarizing plate, a glass plate, and a back side polarizing plate is exposed to a humid heat environment under high temperature conditions, these warpages can be suppressed.
　なお、本発明における偏光板を高温条件下に曝し、偏光板に僅かな反りが生じ得る場合、例えば、反射型偏光板、第１粘着剤層、第１偏光子、第１保護フィルムおよび第２粘着剤層は一体となって反り得る。同様に、第３粘着剤層、第２偏光子および第２保護フィルムは一体となって反り得る。
　したがって、本発明における背面側偏光板と、前面側偏光板は、通常、これらの層間の少なくとも１つの層間において層間剥離は生じ得ない。
　なお、背面側偏光板または前面側偏光板のいずれか一方に反りが生じ得る場合があり、背面側偏光板または前面側偏光板が共に反り得る場合がある。 In addition, when the polarizing plate in this invention is exposed to high temperature conditions and a slight curvature may arise in a polarizing plate, for example, a reflective polarizing plate, a 1st adhesive layer, a 1st polarizer, a 1st protective film, and 2nd The pressure-sensitive adhesive layer can warp together. Similarly, the third pressure-sensitive adhesive layer, the second polarizer and the second protective film can warp together.
Therefore, the back side polarizing plate and the front side polarizing plate in the present invention usually cannot cause delamination between at least one of these layers.
In addition, warp may occur in either one of the back side polarizing plate and the front side polarizing plate, and both the back side polarizing plate and the front side polarizing plate may warp.
　このような反りについて、本発明においては、反り量等を測定することにより評価できる。例えば、この反り量は、湿熱条件における反り量を測定することにより評価してもよく、高温条件における反り量を測定することにより評価してもよい。
　例えば、湿熱条件における反り量を測定する場合、前面側偏光板の第３粘着剤と背面側偏光板の第２粘着層をガラスパネルの表裏に貼合せ、６０℃、湿度９０％の環境下に２５０時間静置した後、ガラスパネルを背面側偏光板が下になるように設置し、測定台の水平面からの浮き上がりの相対高さを測定したものである。 Such warpage can be evaluated by measuring the amount of warpage in the present invention. For example, the warpage amount may be evaluated by measuring the warpage amount under wet heat conditions, or may be evaluated by measuring the warpage amount under high temperature conditions.
For example, when measuring the amount of warpage under wet heat conditions, the third pressure-sensitive adhesive on the front side polarizing plate and the second pressure-sensitive adhesive layer on the back side polarizing plate are bonded to the front and back of the glass panel, and the environment is 60 ° C. and humidity is 90%. After standing for 250 hours, the glass panel was placed with the back side polarizing plate facing down, and the relative height of lifting from the horizontal surface of the measurement table was measured.
　例えば、高温状態における反り量を測定する場合、前面側偏光板の第３粘着剤と背面側偏光板の第２粘着層をガラスパネルの表裏に貼合せ、８５℃、湿度５％の環境下に２５０時間静置した後、背面側偏光板が下になるようにガラスパネルを設置し、測定台の水平面からの浮き上がりの相対高さを測定したものである。 For example, when measuring the amount of warpage in a high temperature state, the third pressure-sensitive adhesive on the front-side polarizing plate and the second pressure-sensitive adhesive layer on the rear-side polarizing plate are bonded to the front and back of the glass panel, and the environment is 85 ° C. and humidity is 5%. After leaving still for 250 hours, a glass panel was installed so that the back side polarizing plate would be down, and the relative height of lifting from the horizontal surface of the measuring table was measured.
［反射型偏光板］
　反射型偏光板は、輝度向上フィルムとも称され、光源（バックライト）からの出射光を透過偏光と反射偏光または散乱偏光に分離するような機能を有する偏光変換素子が用いられる。上述のように、反射型偏光板と偏光子を所定の関係で配置することにより、反射偏光または散乱偏光である再帰光を利用して、偏光子から出射される直線偏光の出射効率を向上させることができる。例えば反射型偏光板は、第１粘着剤層に接して積層される。 [Reflective polarizing plate]
The reflective polarizing plate is also called a brightness enhancement film, and a polarization conversion element having a function of separating light emitted from a light source (backlight) into transmitted polarized light and reflected polarized light or scattered polarized light is used. As described above, by arranging the reflective polarizing plate and the polarizer in a predetermined relationship, the return efficiency of the linearly polarized light emitted from the polarizer is improved by using the recursive light that is reflected polarized light or scattered polarized light. be able to. For example, the reflective polarizing plate is laminated in contact with the first pressure-sensitive adhesive layer.
　反射型偏光板は、例えば、異方性反射偏光子であることができる。異方性反射偏光子の一例は、一方の振動方向の直線偏光を透過し、他方の振動方向の直線偏光を反射する異方性多重薄膜であり、その具体例は３Ｍ社製のＤＢＥＦである（特開平４－２６８５０５号公報等）。このような反射型偏光板は、屈折率異方性が異なる少なくとも２層の薄膜で構成された多層積層体を延伸してなる反射型偏光板である。よって、このような反射型偏光板は、少なくとも２層の薄膜を有し、延伸された少なくとも２層の薄膜は、屈折率異方性が異なるものである。 The reflective polarizing plate can be, for example, an anisotropic reflective polarizer. An example of the anisotropic reflective polarizer is an anisotropic multiple thin film that transmits linearly polarized light in one vibration direction and reflects linearly polarized light in the other vibration direction, and a specific example thereof is DBEF manufactured by 3M. (Japanese Patent Laid-Open No. 4-268505). Such a reflective polarizing plate is a reflective polarizing plate formed by stretching a multilayer laminate composed of at least two thin films having different refractive index anisotropies. Therefore, such a reflective polarizing plate has at least two thin films, and the stretched at least two thin films have different refractive index anisotropy.
　異方性反射偏光子の他の一例は、コレステリック液晶層とλ／４板との複合体であり、その具体例は日東電工株式会社製のＰＣＦである（特開平１１－２３１１３０号公報等）。異方性反射偏光子のさらに他の一例は、反射グリッド偏光子であり、その具体例は、金属に微細加工を施して可視光領域でも反射偏光を出射するような金属格子反射偏光子（米国特許第６２８８８４０号明細書等）、金属微粒子を高分子マトリックス中に添加して延伸したフィルム（特開平８－１８４７０１号公報）である。 Another example of the anisotropic reflective polarizer is a composite of a cholesteric liquid crystal layer and a λ / 4 plate, and a specific example thereof is a PCF manufactured by Nitto Denko Corporation (JP-A-11-231130, etc.). . Yet another example of an anisotropic reflective polarizer is a reflective grid polarizer, a specific example of which is a metal grid reflective polarizer (US) that emits reflected polarized light even in the visible light region by finely processing the metal. Patent No. 6288840 and the like), and a film (JP-A-8-184701) obtained by adding metal fine particles into a polymer matrix and stretching.
　反射型偏光板における第１粘着剤層とは反対側の面に、ハードコート層、防眩層、光拡散層、１／４波長の位相差値を持つ位相差層のような光学層を設けてもよい。光学層の形成により、バックライトテープとの密着性や表示画像の均一性を向上させ得る。反射型偏光板の厚みは、５～１００μｍ程度であることができるが、液晶パネルとしての反りを低減する観点から、好ましくは１０～４０μｍ、より好ましくは１０～３０μｍである。 An optical layer such as a hard coat layer, an antiglare layer, a light diffusion layer, or a retardation layer having a retardation value of ¼ wavelength is provided on the surface of the reflective polarizing plate opposite to the first pressure-sensitive adhesive layer. May be. By forming the optical layer, the adhesion to the backlight tape and the uniformity of the display image can be improved. The thickness of the reflective polarizing plate can be about 5 to 100 μm, but is preferably 10 to 40 μm, more preferably 10 to 30 μm from the viewpoint of reducing warpage as a liquid crystal panel.
　本発明の偏光板セットにおいて、反射型偏光板における第１粘着剤層側の表面には表面活性化処理が施され得る。この表面活性化処理は、反射型偏光板と第１粘着剤層との貼合に先立って行われる。これにより、湿熱環境下において第１粘着剤層と反射型偏光板との間での剥がれが生じにくい、湿熱耐久性に優れた偏光板が得られる。 In the polarizing plate set of the present invention, the surface of the reflective polarizing plate on the first pressure-sensitive adhesive layer side can be subjected to a surface activation treatment. This surface activation treatment is performed prior to bonding of the reflective polarizing plate and the first pressure-sensitive adhesive layer. Thereby, the polarizing plate excellent in wet heat durability in which peeling between a 1st adhesive layer and a reflective polarizing plate does not arise easily in a wet heat environment is obtained.
　表面活性化処理は、表面の親水化処理であることができ、乾式処理でもよいし湿式処理でもよい。乾式処理としては、例えば、コロナ処理、プラズマ処理、グロー放電処理のような放電処理；火炎処理；オゾン処理；ＵＶオゾン処理；紫外線処理、電子線処理のような電離活性線処理等が挙げられる。湿式処理としては、例えば、水やアセトンのような溶媒を用いた超音波処理、アルカリ処理、アンカーコート処理等を例示できる。これらの処理は、単独で行ってもよいし、２つ以上を組み合わせて行ってもよい。 The surface activation treatment can be a surface hydrophilization treatment, and may be a dry treatment or a wet treatment. Examples of the dry treatment include discharge treatment such as corona treatment, plasma treatment and glow discharge treatment; flame treatment; ozone treatment; UV ozone treatment; ionizing active ray treatment such as ultraviolet treatment and electron beam treatment. Examples of the wet treatment include ultrasonic treatment using a solvent such as water or acetone, alkali treatment, anchor coat treatment, and the like. These processes may be performed alone or in combination of two or more.
　中でも、湿熱環境下における反射型偏光板の剥がれ抑制効果および偏光板の生産性の観点から、表面活性化処理は、コロナ処理および／またはプラズマ処理であることが好ましい。これらの表面活性化処理によれば、反射型偏光板の厚みが薄く、例えば３０μｍ以下の場合であっても、湿熱環境下における第１粘着剤層と反射型偏光板との間での剥がれを効果的に抑制することができる。なお、第１粘着剤層における輝度反射型偏光板側の表面にも表面活性化処理を併せて施してもよい。 In particular, the surface activation treatment is preferably a corona treatment and / or a plasma treatment from the viewpoint of the effect of suppressing peeling of the reflective polarizing plate in a humid heat environment and the productivity of the polarizing plate. According to these surface activation treatments, even when the thickness of the reflective polarizing plate is thin, for example, 30 μm or less, peeling between the first pressure-sensitive adhesive layer and the reflective polarizing plate in a humid heat environment is prevented. It can be effectively suppressed. A surface activation treatment may also be performed on the surface of the first pressure-sensitive adhesive layer on the luminance reflective polarizing plate side.
［第１粘着剤層］
　第１粘着剤層は、第１偏光子と反射型偏光板との間に介在する層である。第１粘着剤層は、典型的には、第１偏光子と第１粘着剤層とが接するように偏光子に直接積層される。
第１粘着剤層は、アクリル系、ゴム系、ウレタン系、エステル系、シリコーン系、ポリビニルエーテル系のような樹脂を主成分とする粘着剤組成物で構成することができる。中でも、透明性、耐候性、耐熱性等に優れるアクリル系樹脂をベースポリマーとする粘着剤組成物が好適である。粘着剤組成物は、活性エネルギー線硬化型、熱硬化型であってもよい。 [First adhesive layer]
The first pressure-sensitive adhesive layer is a layer interposed between the first polarizer and the reflective polarizing plate. The first pressure-sensitive adhesive layer is typically directly laminated on the polarizer so that the first polarizer and the first pressure-sensitive adhesive layer are in contact with each other.
The first pressure-sensitive adhesive layer can be composed of a pressure-sensitive adhesive composition whose main component is a resin such as acrylic, rubber-based, urethane-based, ester-based, silicone-based, or polyvinyl ether-based. Among these, a pressure-sensitive adhesive composition having an acrylic resin excellent in transparency, weather resistance, heat resistance and the like as a base polymer is preferable. The pressure-sensitive adhesive composition may be an active energy ray curable type or a thermosetting type.
　上記アクリル系ベースポリマーとしては、例えば、（メタ）アクリル酸ブチル、（メタ）アクリル酸エチル、（メタ）アクリル酸イソオクチル、（メタ）アクリル酸２－エチルヘキシルのような（メタ）アクリル酸エステル系ベースポリマーや、これらの（メタ）アクリル酸エステルを２種類以上用いた共重合系ベースポリマーが好適に用いられる。ベースポリマーには、極性モノマーを共重合させることが好ましい。極性モノマーとしては、例えば、（メタ）アクリル酸、（メタ）アクリル酸２－ヒドロキシプロピル、（メタ）アクリル酸ヒドロキシエチル、（メタ）アクリルアミド、Ｎ，Ｎ－ジメチルアミノエチル（メタ）アクリレート、グリシジル（メタ）アクリレートのような、カルボキシル基、水酸基、アミド基、アミノ基、エポキシ基等を有するモノマーを挙げることができる。 Examples of the acrylic base polymer include (meth) acrylic acid ester bases such as butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Polymers and copolymer base polymers using two or more of these (meth) acrylic acid esters are preferably used. The base polymer is preferably copolymerized with a polar monomer. Examples of polar monomers include (meth) acrylic acid, 2-hydroxypropyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, glycidyl ( Mention may be made of monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group and the like, such as (meth) acrylate.
　粘着剤組成物は通常、架橋剤をさらに含有する。架橋剤としては、２価以上の金属イオンであって、カルボキシル基との間でカルボン酸金属塩を形成するもの；ポリアミン化合物であって、カルボキシル基との間でアミド結合を形成するもの；ポリエポキシ化合物やポリオールであって、カルボキシル基との間でエステル結合を形成するもの；ポリイソシアネート化合物であって、カルボキシル基との間でアミド結合を形成するものが例示される。中でも、ポリイソシアネート化合物が好ましい。 The pressure-sensitive adhesive composition usually further contains a crosslinking agent. As a crosslinking agent, a metal ion having a valence of 2 or more, which forms a carboxylic acid metal salt with a carboxyl group; a polyamine compound, which forms an amide bond with a carboxyl group; Examples thereof include epoxy compounds and polyols that form ester bonds with carboxyl groups; polyisocyanate compounds that form amide bonds with carboxyl groups. Of these, polyisocyanate compounds are preferred.
　活性エネルギー線硬化型粘着剤組成物とは、紫外線や電子線のような活性エネルギー線の照射を受けて硬化する性質を有しており、活性エネルギー線照射前においても粘着性を有してフィルム等の被着体に密着させることができ、活性エネルギー線の照射によって硬化して密着力の調整ができる性質を有する粘着剤組成物である。活性エネルギー線硬化型粘着剤組成物は、紫外線硬化型であることが好ましい。活性エネルギー線硬化型粘着剤組成物は、ベースポリマー、架橋剤に加えて、活性エネルギー線重合性化合物をさらに含有する。さらに必要に応じて、光重合開始剤や光増感剤等を含有させることもある。 The active energy ray-curable pressure-sensitive adhesive composition has a property of being cured by irradiation with active energy rays such as ultraviolet rays and electron beams, and has an adhesive property even before irradiation with active energy rays. It is a pressure-sensitive adhesive composition having such a property that it can be adhered to an adherend such as the like and can be cured by irradiation with active energy rays to adjust the adhesion. The active energy ray-curable pressure-sensitive adhesive composition is preferably ultraviolet curable. The active energy ray-curable pressure-sensitive adhesive composition further contains an active energy ray-polymerizable compound in addition to the base polymer and the crosslinking agent. Further, if necessary, a photopolymerization initiator, a photosensitizer and the like may be contained.
　粘着剤組成物は、光散乱性を付与するための微粒子；ビーズ；ベースポリマー以外の樹脂；粘着性付与剤；充填剤；酸化防止剤；紫外線吸収剤；顔料；着色剤等の添加剤を含むことができる。 The pressure-sensitive adhesive composition contains fine particles for imparting light scattering properties; beads; resins other than the base polymer; tackifiers; fillers; antioxidants; ultraviolet absorbers; pigments; be able to.
　第１粘着剤層は、上記粘着剤組成物の有機溶剤希釈液を基材上に塗布し、乾燥させることにより形成することができる。基材は、偏光子、反射型偏光板、セパレータ等であることができる。活性エネルギー線硬化型粘着剤組成物を用いた場合は、形成された粘着剤層に、活性エネルギー線を照射することにより所望の硬化物とすることができる。 The first pressure-sensitive adhesive layer can be formed by applying an organic solvent diluted solution of the above pressure-sensitive adhesive composition on a substrate and drying it. The substrate can be a polarizer, a reflective polarizing plate, a separator or the like. When the active energy ray-curable pressure-sensitive adhesive composition is used, a desired cured product can be obtained by irradiating the formed pressure-sensitive adhesive layer with active energy rays.
　第１粘着剤層は、２３～８０℃の温度範囲において０．１５～１．２ＭＰａの貯蔵弾性率を示すものであることが好ましい。これにより、高温および湿熱環境下において偏光子の収縮に伴って発生しやすい寸法変化を抑制して、偏光板の耐久性を高めることができる。また、偏光板を搭載した液晶パネル（例えば中小型モバイル端末用の液晶パネル）が高温および湿熱環境下に置かれた場合にも、偏光板の動きが抑制されるので、液晶パネルの信頼性を高めることができる。 The first pressure-sensitive adhesive layer preferably exhibits a storage elastic modulus of 0.15 to 1.2 MPa in a temperature range of 23 to 80 ° C. Thereby, the dimensional change which is easy to generate | occur | produce with shrinkage | contraction of a polarizer in high temperature and wet heat environment can be suppressed, and durability of a polarizing plate can be improved. In addition, when a liquid crystal panel with a polarizing plate (for example, a liquid crystal panel for a small-to-medium-sized mobile terminal) is placed in a high-temperature and humid environment, the movement of the polarizing plate is suppressed, so the reliability of the liquid crystal panel is improved. Can be increased.
　「２３～８０℃の温度範囲において０．１５～１．２ＭＰａの貯蔵弾性率を示す」とは、この範囲のいずれの温度においても、貯蔵弾性率が上記範囲内の値であることを意味する。貯蔵弾性率は通常、温度上昇に伴って漸減するので、２３℃および８０℃における貯蔵弾性率がいずれも上記範囲に入っていれば、この範囲の温度において、上記範囲内の貯蔵弾性率を示すとみることができる。第１粘着剤層の貯蔵弾性率は、市販の粘弾性測定装置、例えば、後掲の実施例に示すようなＲＥＯＭＥＴＲＩＣ社製の粘弾性測定装置「ＤＹＮＡＭＩＣ　ＡＮＡＬＹＺＥＲ　ＲＤＡ　ＩＩ」を用いて測定することができる。 “Shows a storage elastic modulus of 0.15 to 1.2 MPa in a temperature range of 23 to 80 ° C.” means that the storage elastic modulus is a value within the above range at any temperature within this range. . Since the storage elastic modulus usually decreases gradually as the temperature rises, if both the storage elastic modulus at 23 ° C. and 80 ° C. are within the above range, the storage elastic modulus within the above range is exhibited at the temperature in this range. Can be seen. The storage elastic modulus of the first pressure-sensitive adhesive layer can be measured using a commercially available viscoelasticity measuring device, for example, a viscoelasticity measuring device “DYNAMIC ANALYZER RDA II” manufactured by REOMETRI as shown in the examples below. it can.
　貯蔵弾性率を上記範囲に調整するための方法としては、ベースポリマーおよび架橋剤を含む粘着剤組成物に、オリゴマー、具体的には、ウレタンアクリレート系のオリゴマーをさらに添加して活性エネルギー線硬化型粘着剤組成物（好ましくは紫外線硬化型粘着剤組成物）とすることが挙げられる。より好ましくは、活性エネルギー線を照射して粘着剤層を適度に硬化させる。 As a method for adjusting the storage elastic modulus to the above range, an active energy ray-curable type is further prepared by further adding an oligomer, specifically, a urethane acrylate-based oligomer, to a pressure-sensitive adhesive composition containing a base polymer and a crosslinking agent. The pressure-sensitive adhesive composition (preferably an ultraviolet curable pressure-sensitive adhesive composition) is mentioned. More preferably, the adhesive layer is appropriately cured by irradiating active energy rays.
　第１粘着剤層の厚みは、３０μｍ以下であり得る。好ましくは２５μｍ以下、特に好ましくは２０μｍ以下、とりわけ好ましくは１５μｍ以下である。第１粘着剤層の厚みがこのような範囲にあることにより、良好な加工性を保ちつつ、偏光板の寸法変化を抑制できる。なお、第１粘着剤層の厚さは、上記層間厚みが所定の範囲となるように、適宜調整できる。 The thickness of the first pressure-sensitive adhesive layer can be 30 μm or less. The thickness is preferably 25 μm or less, particularly preferably 20 μm or less, and particularly preferably 15 μm or less. When the thickness of the 1st adhesive layer exists in such a range, the dimensional change of a polarizing plate can be suppressed, maintaining favorable workability. In addition, the thickness of the first pressure-sensitive adhesive layer can be adjusted as appropriate so that the interlayer thickness falls within a predetermined range.
［偏光子］
　偏光子は、その吸収軸に平行な振動面をもつ直線偏光を吸収し、吸収軸に直交する（透過軸と平行な）振動面をもつ直線偏光を透過する性質を有する吸収型の偏光子である。本発明の偏光板セットに用いられる第１偏光子および第２偏光子は、その厚さが所定の関係を有する限り、同一の偏光子であってもよく、それぞれ異なる偏光子であってもよい。例えば、ポリビニルアルコール系樹脂フィルムに二色性色素を吸着配向させた偏光フィルムを好適に用いることができる。偏光子は、例えば、ポリビニルアルコール系樹脂フィルムを一軸延伸する工程；ポリビニルアルコール系樹脂フィルムを二色性色素で染色することにより二色性色素を吸着させる工程；二色性色素が吸着されたポリビニルアルコール系樹脂フィルムをホウ酸水溶液で処理する工程；および、ホウ酸水溶液による処理後に水洗する工程を含む方法によって製造できる。 [Polarizer]
A polarizer is an absorptive polarizer that has the property of absorbing linearly polarized light having a vibration plane parallel to the absorption axis and transmitting linearly polarized light having a vibration plane perpendicular to the absorption axis (parallel to the transmission axis). is there. The first polarizer and the second polarizer used in the polarizing plate set of the present invention may be the same polarizer or different polarizers as long as the thicknesses have a predetermined relationship. . For example, a polarizing film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol resin film can be suitably used. The polarizer is, for example, a step of uniaxially stretching a polyvinyl alcohol resin film; a step of adsorbing a dichroic dye by dyeing the polyvinyl alcohol resin film with a dichroic dye; a polyvinyl on which the dichroic dye is adsorbed It can be produced by a method comprising a step of treating an alcohol-based resin film with a boric acid aqueous solution; and a step of washing with water after the treatment with the boric acid aqueous solution.
　ポリビニルアルコール系樹脂としては、ポリ酢酸ビニル系樹脂をケン化したものを用いることができる。ポリ酢酸ビニル系樹脂としては、酢酸ビニルの単独重合体であるポリ酢酸ビニルの他、酢酸ビニルと共重合可能な他の単量体との共重合体等が挙げられる。酢酸ビニルに共重合可能な他の単量体の例は、不飽和カルボン酸類、オレフィン類、ビニルエーテル類、不飽和スルホン酸類およびアンモニウム基を有するアクリルアミド類等を含む。 As the polyvinyl alcohol resin, a saponified polyvinyl acetate resin can be used. Examples of the polyvinyl acetate resin include, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, copolymers with other monomers copolymerizable with vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, acrylamides having ammonium groups, and the like.
　ポリビニルアルコール系樹脂のケン化度は通常、８５～１００ｍｏｌ％程度であり、９８ｍｏｌ％以上が好ましい。ポリビニルアルコール系樹脂は変性されていてもよく、例えば、アルデヒド類で変性されたポリビニルホルマールまたはポリビニルアセタール等を用いることもできる。ポリビニルアルコール系樹脂の平均重合度は通常、１０００～１００００程度であり、１５００～５０００程度が好ましい。ポリビニルアルコール系樹脂の平均重合度は、ＪＩＳ　Ｋ　６７２６に準拠して求めることができる。 The degree of saponification of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The average degree of polymerization of the polyvinyl alcohol resin is usually about 1000 to 10,000, and preferably about 1500 to 5,000. The average degree of polymerization of the polyvinyl alcohol resin can be determined according to JIS K 6726.
　このようなポリビニルアルコール系樹脂を製膜したものが、偏光子（偏光フィルム）の原反フィルムとして用いられる。ポリビニルアルコール系樹脂を製膜する方法は、特に限定されるものではなく、公知の方法が採用される。ポリビニルアルコール系原反フィルムの厚みは特に制限されないが、偏光子の厚みを、例えば１５μｍ以下とするためには、５～３５μｍ程度の原反フィルムを用いることが好ましい。 A film obtained by forming such a polyvinyl alcohol resin is used as an original film of a polarizer (polarizing film). The method for forming the polyvinyl alcohol-based resin into a film is not particularly limited, and a known method is employed. The thickness of the polyvinyl alcohol-based raw film is not particularly limited, but in order to make the thickness of the polarizer 15 μm or less, for example, it is preferable to use an original film having a thickness of about 5 to 35 μm.
　ポリビニルアルコール系樹脂フィルムの一軸延伸は、二色性色素の染色前、染色と同時、または染色の後に行うことができる。一軸延伸を染色の後で行う場合、この一軸延伸は、ホウ酸処理の前またはホウ酸処理中に行ってもよい。また、これらの複数の段階で一軸延伸を行ってもよい。 The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after the dyeing of the dichroic dye. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before boric acid treatment or during boric acid treatment. Moreover, you may uniaxially stretch in these several steps.
　一軸延伸にあたっては、周速の異なるロール間で一軸に延伸してもよいし、熱ロールを用いて一軸に延伸してもよい。また一軸延伸は、大気中で延伸を行う乾式延伸であってもよいし、溶剤を用いてポリビニルアルコール系樹脂フィルムを膨潤させた状態で延伸を行う湿式延伸であってもよい。延伸倍率は通常、３～８倍程度である。 In the uniaxial stretching, rolls having different peripheral speeds may be uniaxially stretched or may be stretched uniaxially using a hot roll. The uniaxial stretching may be dry stretching in which stretching is performed in the air, or may be wet stretching in which stretching is performed in a state where a polyvinyl alcohol-based resin film is swollen using a solvent. The draw ratio is usually about 3 to 8 times.
　ポリビニルアルコール系樹脂フィルムを二色性色素で染色する方法としては、例えば、該フィルムを二色性色素が含有された水溶液に浸漬する方法が採用される。二色性色素として、ヨウ素や二色性有機染料が用いられる。なお、ポリビニルアルコール系樹脂フィルムは、染色処理の前に水への浸漬処理を施しておくことが好ましい。 As a method for dyeing a polyvinyl alcohol resin film with a dichroic dye, for example, a method of immersing the film in an aqueous solution containing the dichroic dye is employed. As the dichroic dye, iodine or a dichroic organic dye is used. In addition, it is preferable that the polyvinyl alcohol-type resin film performs the immersion process to water before a dyeing process.
　ヨウ素による染色処理としては通常、ヨウ素およびヨウ化カリウムを含有する水溶液に、ポリビニルアルコール系樹脂フィルムを浸漬する方法が採用される。この水溶液におけるヨウ素の含有量は、水１００重量部あたり０．０１～１重量部程度であることができる。ヨウ化カリウムの含有量は、水１００重量部あたり０．５～２０重量部程度であることができる。また、この水溶液の温度は、２０～４０℃程度であることができる。一方、二色性有機染料による染色処理としては通常、二色性有機染料を含有する水溶液に、ポリビニルアルコール系樹脂フィルムを浸漬する方法が採用される。二色性有機染料を含有する水溶液は、硫酸ナトリウム等の無機塩を染色助剤として含有していてもよい。この水溶液における二色性有機染料の含有量は、水１００重量部あたり１×１０-4～１０重量部程度であることができる。この水溶液の温度は、２０～８０℃程度であることができる。 As a dyeing treatment with iodine, a method of immersing a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide is usually employed. The iodine content in this aqueous solution can be about 0.01 to 1 part by weight per 100 parts by weight of water. The content of potassium iodide can be about 0.5 to 20 parts by weight per 100 parts by weight of water. The temperature of the aqueous solution can be about 20 to 40 ° C. On the other hand, as a dyeing treatment with a dichroic organic dye, a method of immersing a polyvinyl alcohol-based resin film in an aqueous solution containing a dichroic organic dye is usually employed. The aqueous solution containing the dichroic organic dye may contain an inorganic salt such as sodium sulfate as a dyeing assistant. The content of the dichroic organic dye in this aqueous solution can be about 1 × 10 −4 to 10 parts by weight per 100 parts by weight of water. The temperature of the aqueous solution can be about 20 to 80 ° C.
　二色性色素による染色後のホウ酸処理としては通常、染色されたポリビニルアルコール系樹脂フィルムをホウ酸含有水溶液に浸漬する方法が採用される。二色性色素としてヨウ素を用いる場合、このホウ酸含有水溶液は、ヨウ化カリウムを含有することが好ましい。
ホウ酸含有水溶液におけるホウ酸の量は、水１００重量部あたり２～１５重量部程度であることができる。この水溶液におけるヨウ化カリウムの量は、水１００重量部あたり０．１～１５重量部程度であることができる。この水溶液の温度は、５０℃以上であることができ、例えば５０～８５℃である。 As boric acid treatment after dyeing with a dichroic dye, a method of immersing a dyed polyvinyl alcohol-based resin film in a boric acid-containing aqueous solution is usually employed. When iodine is used as the dichroic dye, the boric acid-containing aqueous solution preferably contains potassium iodide.
The amount of boric acid in the boric acid-containing aqueous solution can be about 2 to 15 parts by weight per 100 parts by weight of water. The amount of potassium iodide in this aqueous solution can be about 0.1 to 15 parts by weight per 100 parts by weight of water. The temperature of the aqueous solution can be 50 ° C. or higher, for example, 50 to 85 ° C.
　ホウ酸処理後のポリビニルアルコール系樹脂フィルムは通常、水洗処理される。水洗処理は、例えば、ホウ酸処理されたポリビニルアルコール系樹脂フィルムを水に浸漬することにより行うことができる。水洗処理は、ヨウ化カリウムを含有する水により行ってもよい水洗処理における水の温度は通常、５～４０℃程度である。 The polyvinyl alcohol resin film after the boric acid treatment is usually washed with water. The water washing treatment can be performed, for example, by immersing a boric acid-treated polyvinyl alcohol resin film in water. The water washing treatment may be performed with water containing potassium iodide. The water temperature in the water washing treatment is usually about 5 to 40 ° C.
　水洗後に乾燥処理を施して、偏光子が得られる。乾燥処理は、熱風乾燥機や遠赤外線ヒーターを用いて行うことができる。偏光子の厚みは１５μｍ以下であることが好ましく、１３μｍ以下であることがより好ましい。偏光子の厚みは通常、４μｍ以上である。一態様においては、背面側偏光板における第１偏光子の厚さｄＲは、１５μｍ以下である。一態様においては、前面側偏光板における第２偏光子の厚さｄＦは、１５μｍ以下であり、より好ましくは、０．１μｍ以上１３μｍ以下である。
　なお、偏光子の厚さは、本発明の範囲を逸脱しない範囲となるように、適宜調整できる。 A polarizer is obtained by performing a drying process after washing with water. The drying process can be performed using a hot air dryer or a far infrared heater. The thickness of the polarizer is preferably 15 μm or less, and more preferably 13 μm or less. The thickness of the polarizer is usually 4 μm or more. In one embodiment, the thickness dR of the first polarizer in the back side polarizing plate is 15 μm or less. In one embodiment, the thickness dF of the second polarizer in the front side polarizing plate is 15 μm or less, and more preferably 0.1 μm or more and 13 μm or less.
In addition, the thickness of the polarizer can be adjusted as appropriate so that the thickness does not deviate from the scope of the present invention.
［保護フィルム］
　第１保護フィルムは、第１偏光子における第１粘着剤層とは反対側の面に積層されるフィルムである。第２保護フィルムは、第２偏光子における第３粘着剤層とは反対側の面に積層されるフィルムである。第１保護フィルムおよび第２保護フィルムは同一のフィルムであってもよく、異なるフィルムであってもよい。
　保護フィルムは、透光性を有する（好ましくは光学的に透明な）熱可塑性樹脂、例えば、鎖状ポリオレフィン系樹脂（ポリプロピレン系樹脂等）、環状ポリオレフィン系樹脂（ノルボルネン系樹脂等）のようなポリオレフィン系樹脂；トリアセチルセルロース、ジアセチルセルロースのようなセルロース系樹脂；ポリエチレンテレフタレート、ポリブチレンテレフタレートのようなポリエステル系樹脂；ポリカーボネート系樹脂；（メタ）アクリル系樹脂のようなアクリル系樹脂；ポリスチレン系樹脂；ポリ塩化ビニル系樹脂；アクリロニトリル・ブタジエン・スチレン系樹脂；アクリロニトリル・スチレン系樹脂；ポリ酢酸ビニル系樹脂；ポリ塩化ビニリデン系樹脂；ポリアミド系樹脂；ポリアセタール系樹脂；変性ポリフェニレンエーテル系樹脂；ポリスルホン系樹脂；ポリエーテルスルホン系樹脂；ポリアリレート系樹脂；ポリアミドイミド系樹脂；ポリイミド系樹脂等からなるフィルムであることができる。中でも、ポリオレフィン系樹脂またはアクリル系樹脂を用いることが好ましく、特に好ましくは環状ポリオレフィン系樹脂を用いることが好ましい。 [Protective film]
A 1st protective film is a film laminated | stacked on the surface on the opposite side to the 1st adhesive layer in a 1st polarizer. A 2nd protective film is a film laminated | stacked on the surface on the opposite side to the 3rd adhesive layer in a 2nd polarizer. The first protective film and the second protective film may be the same film or different films.
The protective film is a light-transmitting (preferably optically transparent) thermoplastic resin, for example, a polyolefin such as a chain polyolefin resin (polypropylene resin, etc.) or a cyclic polyolefin resin (norbornene resin, etc.). Cellulose resins such as triacetyl cellulose and diacetyl cellulose; Polyester resins such as polyethylene terephthalate and polybutylene terephthalate; Polycarbonate resins; Acrylic resins such as (meth) acrylic resins; Polystyrene resins; Polyvinyl chloride resin; Acrylonitrile butadiene styrene resin; Acrylonitrile styrene resin; Polyvinyl acetate resin; Polyvinylidene chloride resin; Polyamide resin; Polyacetal resin; Modified polyphenylene ether It may be a film made of polyimide resin or the like; system resin; polysulfone resins; poly (ether sulfone) resins; polyarylate resin; polyamide-imide resin. Among them, it is preferable to use a polyolefin resin or an acrylic resin, and it is particularly preferable to use a cyclic polyolefin resin.
　鎖状ポリオレフィン系樹脂としては、ポリエチレン樹脂、ポリプロピレン樹脂のような鎖状オレフィンの単独重合体のほか、２種以上の鎖状オレフィンからなる共重合体を挙げることができる。 Examples of the chain polyolefin resin include a homopolymer of a chain olefin such as a polyethylene resin and a polypropylene resin, and a copolymer composed of two or more chain olefins.
　環状ポリオレフィン系樹脂は、環状オレフィンを重合単位として重合される樹脂の総称である。環状ポリオレフィン系樹脂の具体例を挙げれば、環状オレフィンの開環（共）重合体、環状オレフィンの付加重合体、環状オレフィンとエチレン、プロピレンのような鎖状オレフィンとの共重合体（代表的にはランダム共重合体）、およびこれらを不飽和カルボン酸やその誘導体で変性したグラフト重合体、並びにそれらの水素化物等である。中でも、環状オレフィンとしてノルボルネンや多環ノルボルネン系モノマー等のノルボルネン系モノマーを用いたノルボルネン系樹脂が好ましく用いられる。好ましい態様において、本発明に係る保護フィルムは、環状ポリオレフィン系樹脂を含む。 Cyclic polyolefin-based resin is a general term for resins that are polymerized using cyclic olefins as polymerization units. Specific examples of cyclic polyolefin resins include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers of cyclic olefins and chain olefins such as ethylene and propylene (typically Are random copolymers), graft polymers obtained by modifying them with unsaturated carboxylic acids or derivatives thereof, and hydrides thereof. Among these, norbornene resins using norbornene monomers such as norbornene and polycyclic norbornene monomers as cyclic olefins are preferably used. In a preferred embodiment, the protective film according to the present invention contains a cyclic polyolefin resin.
　セルロース系樹脂とは、綿花リンタや木材パルプ（広葉樹パルプ、針葉樹パルプ）等の原料セルロースから得られるセルロースの水酸基における水素原子の一部または全部がアセチル基、プロピオニル基および／またはブチリル基で置換された、セルロース有機酸エステルまたはセルロース混合有機酸エステルをいう。例えば、セルロースの酢酸エステル、プロピオン酸エステル、酪酸エステル、およびそれらの混合エステル等からなるものが挙げられる。 Cellulosic resins are those in which some or all of the hydrogen atoms in the hydroxyl groups of cellulose obtained from raw material cellulose such as cotton linter and wood pulp (hardwood pulp, conifer pulp) are substituted with acetyl groups, propionyl groups and / or butyryl groups. Further, it refers to a cellulose organic acid ester or a cellulose mixed organic acid ester. Examples include cellulose acetates, propionic acid esters, butyric acid esters, and mixed esters thereof.
　アクリル系樹脂フィルムの好ましい具体例としては、メタクリル酸メチル系樹脂を含むフィルムを挙げることができる。メタクリル酸メチル系樹脂とは、メタクリル酸メチル単位を５０重量％以上含む重合体である。メタクリル酸メチル単位の含有量は、好ましくは７０重量％以上であり、１００重量％であってもよい。メタクリル酸メチル単位が１００重量％の重合体は、メタクリル酸メチルを単独で重合させて得られるメタクリル酸メチル単独重合体である。 Preferable specific examples of the acrylic resin film include a film containing a methyl methacrylate resin. The methyl methacrylate resin is a polymer containing 50% by weight or more of methyl methacrylate units. The content of methyl methacrylate units is preferably 70% by weight or more, and may be 100% by weight. The polymer having a methyl methacrylate unit of 100% by weight is a methyl methacrylate homopolymer obtained by polymerizing methyl methacrylate alone.
　このメタクリル酸メチル系樹脂は、通常、メタクリル酸メチルを主成分とする単官能単量体および必要に応じて使用される多官能単量体を、ラジカル重合開始剤および必要に応じて使用される連鎖移動剤の共存下に重合することにより得ることができる。 This methyl methacrylate-based resin is usually a monofunctional monomer mainly composed of methyl methacrylate and a polyfunctional monomer used as necessary, as a radical polymerization initiator and as required. It can be obtained by polymerization in the presence of a chain transfer agent.
　メタクリル酸メチルと共重合し得る単官能単量体としては、たとえば、メタクリル酸エチル、メタクリル酸ブチル、メタクリル酸シクロヘキシル、メタクリル酸フェニル、メタクリル酸ベンジル、メタクリル酸２－エチルヘキシル、およびメタクリル酸２－ヒドロキシエチル等のメタクリル酸メチル以外のメタクリル酸エステル類；アクリル酸メチル、アクリル酸エチル、アクリル酸ブチル、アクリル酸シクロヘキシル、アクリル酸フェニル、アクリル酸ベンジル、アクリル酸２－エチルヘキシル、およびアクリル酸２－ヒドロキシエチル等のアクリル酸エステル類；２－（ヒドロキシメチル）アクリル酸メチル、３－（ヒドロキシエチル）アクリル酸メチル、２－（ヒドロキシメチル）アクリル酸エチル、および２－（ヒドロキシメチル）アクリル酸ブチル等のヒドロキシアクリル酸エステル類；メタクリル酸およびアクリル酸等の不飽和酸類；クロロスチレンおよびブロモスチレン等のハロゲン化スチレン類；ビニルトルエンおよびα－メチルスチレン等の置換スチレン類；アクリロニトリルおよびメタクリロニトリル等の不飽和ニトリル類；無水マレイン酸および無水シトラコン酸等の不飽和酸無水物類；ならびにフェニルマレイミドおよびシクロヘキシルマレイミド等の不飽和イミド類等を挙げることができる。このような単量体は、それぞれ単独で用いられてもよいし、２種以上を組み合わせて用いられてもよい。 Monofunctional monomers that can be copolymerized with methyl methacrylate include, for example, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, and 2-hydroxy methacrylate. Methacrylic acid esters other than methyl methacrylate such as ethyl; methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, and 2-hydroxyethyl acrylate Acrylic acid esters such as: 2- (hydroxymethyl) methyl acrylate, 3- (hydroxyethyl) methyl acrylate, 2- (hydroxymethyl) ethyl acrylate, and 2- (hydroxymethyl) Hydroxyacrylic esters such as butyl acrylate; Unsaturated acids such as methacrylic acid and acrylic acid; Halogenated styrenes such as chlorostyrene and bromostyrene; Substituted styrenes such as vinyltoluene and α-methylstyrene; Acrylonitrile and methacrylate Examples thereof include unsaturated nitriles such as nitrile; unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride; and unsaturated imides such as phenylmaleimide and cyclohexylmaleimide. Such monomers may be used alone or in combination of two or more.
　メタクリル酸メチルと共重合し得る多官能単量体としては、たとえば、エチレングリコールジ（メタ）アクリレート、ジエチレングリコールジ（メタ）アクリレート、トリエチレングリコールジ（メタ）アクリレート、テトラエチレングリコールジ（メタ）アクリレート、ノナエチレングリコールジ（メタ）アクリレート、およびテトラデカエチレングリコール（メタ）アクリレート等のエチレングリコールまたはそのオリゴマーの両末端水酸基をアクリル酸またはメタクリル酸でエステル化したもの；プロピレングリコールまたはそのオリゴマーの両末端水酸基をアクリル酸またはメタクリル酸でエステル化したもの；ネオペンチルグリコールジ（メタ）アクリレート、ヘキサンジオールジ（メタ）アクリレート、およびブタンジオールジ（メタ）アクリレート等の２価アルコールの水酸基をアクリル酸またはメタクリル酸でエステル化したもの；ビスフェノールＡ、ビスフェノールＡのアルキレンオキシド付加物、またはこれらのハロゲン置換体の両末端水酸基をアクリル酸またはメタクリル酸でエステル化したもの；トリメチロールプロパンおよびペンタエリスリトール等の多価アルコールをアクリル酸またはメタクリル酸でエステル化したもの、ならびにこれら末端水酸基にグリシジルアクリレートまたはグリシジルメタクリレートのエポキシ基を開環付加させたもの；コハク酸、アジピン酸、テレフタル酸、フタル酸、これらのハロゲン置換体等の二塩基酸、およびこれらのアルキレンオキシド付加物等にグリシジルアクリレートまたはグリシジルメタクリレートのエポキシ基を開環付加させたもの；アリール（メタ）アクリレート；およびジビニルベンゼン等のジアリール化合物等が挙げられる。中でも、エチレングリコールジメタクリレート、テトラエチレングリコールジメタクリレートおよびネオペンチルグリコールジメタクリレートが好ましく用いられる。 Examples of the polyfunctional monomer that can be copolymerized with methyl methacrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and tetraethylene glycol di (meth) acrylate. , Nonaethylene glycol di (meth) acrylate, and ethylene glycol such as tetradecaethylene glycol (meth) acrylate or the oligomers of both end hydroxyl groups esterified with acrylic acid or methacrylic acid; both ends of propylene glycol or its oligomer Hydroxyl ester of hydroxyl group with acrylic acid or methacrylic acid; neopentyl glycol di (meth) acrylate, hexanediol di (meth) acrylate, and butanediol A hydroxyl group of a dihydric alcohol such as (meth) acrylate esterified with acrylic acid or methacrylic acid; bisphenol A, an alkylene oxide adduct of bisphenol A, or both hydroxyl groups of these halogen-substituted products are acrylic acid or methacrylic acid Esterified with polyhydric alcohols such as trimethylolpropane and pentaerythritol with acrylic acid or methacrylic acid, and those obtained by ring-opening addition of an epoxy group of glycidyl acrylate or glycidyl methacrylate to the terminal hydroxyl groups; Ethyl succinic acid, adipic acid, terephthalic acid, phthalic acid, dibasic acids such as these halogen-substituted products, and alkylene oxide adducts thereof can be added to glycidyl acrylate or glycidyl methacrylate. Those were the carboxy groups by ring-opening addition; aryl (meth) acrylate; and diaryl compounds of divinylbenzene, and the like. Among these, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate and neopentyl glycol dimethacrylate are preferably used.
　メタクリル酸メチル系樹脂は、該樹脂が有する官能基間の反応を行なうことによって変性された変性メタクリル酸メチル系樹脂であってもよい。その反応としては、たとえば、アクリル酸メチルのメチルエステル基と２－（ヒドロキシメチル）アクリル酸メチルの水酸基との高分子鎖内脱メタノール縮合反応、および、アクリル酸のカルボキシル基と２－（ヒドロキシメチル）アクリル酸メチルの水酸基との高分子鎖内脱水縮合反応等が挙げられる。 The methyl methacrylate resin may be a modified methyl methacrylate resin modified by performing a reaction between functional groups of the resin. Examples of the reaction include, for example, depolymerization condensation in a polymer chain between a methyl ester group of methyl acrylate and a hydroxyl group of methyl 2- (hydroxymethyl) acrylate, and a carboxyl group of acrylic acid and 2- (hydroxymethyl). ) Intrapolymer dehydration condensation reaction with hydroxyl group of methyl acrylate.
　保護フィルムの位相差値を、液晶パネルに好適な値に制御することも有用である。例えば、インプレーンスイッチング（ＩＰＳ）モードの液晶パネルには、実質的に位相差値がゼロのフィルムを用いることが好ましい。実質的に位相差値がゼロとは、波長５９０ｎｍにおける面内位相差値が１０ｎｍ以下であり、波長５９０ｎｍにおける厚み方向位相差値の絶対値が１０ｎｍ以下であり、波長４８０～７５０ｎｍにおける厚み方向位相差値の絶対値が１５ｎｍ以下であることをいう。 It is also useful to control the retardation value of the protective film to a value suitable for a liquid crystal panel. For example, it is preferable to use a film having a substantially zero retardation value for an in-plane switching (IPS) mode liquid crystal panel. A retardation value of substantially zero means that the in-plane retardation value at a wavelength of 590 nm is 10 nm or less, the absolute value of the thickness direction retardation value at a wavelength of 590 nm is 10 nm or less, and the thickness direction position at a wavelength of 480 to 750 nm. The absolute value of the phase difference value is 15 nm or less.
　液晶パネルのモードによっては、保護フィルムに延伸および／または収縮加工を行い、好適な位相差値を付与してもよい。 Depending on the mode of the liquid crystal panel, the protective film may be stretched and / or shrunk to give a suitable retardation value.
　保護フィルムの厚みは１～３０μｍ程度であることができるが、強度や取扱性等の観点から５～２５μｍが好ましく、５～２０μｍがより好ましい。この範囲内の厚みであれば、偏光子を機械的に保護し、湿熱環境下に曝されても偏光子が収縮せず、安定した光学特性を保つことができる。なお、保護フィルムの厚さは、上記層間厚みが所定の範囲となるように、適宜調整できる。 The thickness of the protective film can be about 1 to 30 μm, but it is preferably 5 to 25 μm, more preferably 5 to 20 μm from the viewpoints of strength and handleability. When the thickness is within this range, the polarizer is mechanically protected, and the polarizer does not shrink even when exposed to a humid heat environment, and stable optical characteristics can be maintained. In addition, the thickness of a protective film can be adjusted suitably so that the said interlayer thickness may become a predetermined range.
　保護フィルムは、接着剤層を介して偏光子に貼合することができる。接着剤層を形成する接着剤としては、水系接着剤または活性エネルギー線硬化性接着剤を用いることができる。 The protective film can be bonded to the polarizer through an adhesive layer. As the adhesive forming the adhesive layer, a water-based adhesive or an active energy ray-curable adhesive can be used.
　水系接着剤としては、ポリビニルアルコール系樹脂水溶液からなる接着剤、水系二液型ウレタン系エマルジョン接着剤等が挙げられる。中でもポリビニルアルコール系樹脂水溶液からなる水系接着剤が好適に用いられる。ポリビニルアルコール系樹脂としては、酢酸ビニルの単独重合体であるポリ酢酸ビニルをケン化処理して得られるビニルアルコールホモポリマーのほか、酢酸ビニルとこれに共重合可能な他の単量体との共重合体をケン化処理して得られるポリビニルアルコール系共重合体、またはそれらの水酸基を部分的に変性した変性ポリビニルアルコール系重合体等を用いることができる。水系接着剤は、アルデヒド化合物、エポキシ化合物、メラミン系化合物、メチロール化合物、イソシアネート化合物、アミン化合物、多価金属塩等の架橋剤を含むことができる。 Examples of the water-based adhesive include an adhesive made of a polyvinyl alcohol-based resin aqueous solution and an aqueous two-component urethane emulsion adhesive. Among these, a water-based adhesive composed of a polyvinyl alcohol-based resin aqueous solution is preferably used. Polyvinyl alcohol resins include vinyl alcohol homopolymers obtained by saponifying polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. A polyvinyl alcohol copolymer obtained by saponifying a polymer, a modified polyvinyl alcohol polymer obtained by partially modifying the hydroxyl group thereof, or the like can be used. The water-based adhesive can contain a crosslinking agent such as an aldehyde compound, an epoxy compound, a melamine compound, a methylol compound, an isocyanate compound, an amine compound, or a polyvalent metal salt.
　水系接着剤を使用する場合は、偏光子と保護フィルムとを貼合した後、水系接着剤中に含まれる水を除去するために乾燥させる工程を実施することが好ましい。乾燥工程後、例えば２０～４５℃程度の温度で養生する養生工程を設けてもよい。 When using a water-based adhesive, it is preferable to carry out a drying step in order to remove water contained in the water-based adhesive after bonding the polarizer and the protective film. After the drying step, for example, a curing step for curing at a temperature of about 20 to 45 ° C. may be provided.
　上記活性エネルギー線硬化性接着剤は、紫外線などの活性エネルギー線を照射することで硬化する接着剤をいい、例えば、重合性化合物および光重合開始剤を含むもの、光反応性樹脂を含むもの、バインダー樹脂および光反応性架橋剤を含むもの等を挙げることができる。重合性化合物としては、光硬化性エポキシ系モノマー、光硬化性アクリル系モノマー、光硬化性ウレタン系モノマーのような光重合性モノマーや、光重合性モノマーに由来するオリゴマーを挙げることができる。光重合開始剤としては、紫外線のような活性エネルギー線の照射により中性ラジカル、アニオンラジカル、カチオンラジカルのような活性種を発生する物質を含むものを挙げることができる。重合性化合物および光重合開始剤を含む活性エネルギー線硬化性接着剤として、光硬化性エポキシ系モノマーおよび光カチオン重合開始剤を含むものを好ましく用いることができる。 The active energy ray-curable adhesive refers to an adhesive that cures when irradiated with active energy rays such as ultraviolet rays, for example, an adhesive containing a polymerizable compound and a photopolymerization initiator, an adhesive containing a photoreactive resin, Examples thereof include a binder resin and a photoreactive crosslinking agent. Examples of the polymerizable compound include photopolymerizable monomers such as a photocurable epoxy monomer, a photocurable acrylic monomer, and a photocurable urethane monomer, and oligomers derived from the photopolymerizable monomer. Examples of the photopolymerization initiator include those containing substances that generate active species such as neutral radicals, anion radicals, and cation radicals upon irradiation with active energy rays such as ultraviolet rays. As the active energy ray-curable adhesive containing a polymerizable compound and a photopolymerization initiator, an adhesive containing a photocurable epoxy monomer and a cationic photopolymerization initiator can be preferably used.
　活性エネルギー線硬化性接着剤を用いる場合は、偏光子と保護フィルムとを貼合した後、必要に応じて乾燥工程を行い、次いで活性エネルギー線を照射することによって活性エネルギー線硬化性接着剤を硬化させる硬化工程を行う。活性エネルギー線の光源は特に限定されないが、波長４００ｎｍ以下に発光分布を有する紫外線が好ましく、具体的には、低圧水銀灯、中圧水銀灯、高圧水銀灯、超高圧水銀灯、ケミカルランプ、ブラックライトランプ、マイクロウェーブ励起水銀灯、メタルハライドランプ等を用いることができる。 When using an active energy ray-curable adhesive, after bonding a polarizer and a protective film, a drying step is performed as necessary, and then the active energy ray-curable adhesive is irradiated by irradiating active energy rays. A curing step for curing is performed. The light source of the active energy ray is not particularly limited, but ultraviolet light having a light emission distribution at a wavelength of 400 nm or less is preferable. A wave excitation mercury lamp, a metal halide lamp, etc. can be used.
　偏光子と保護フィルムとを貼合するにあたっては、これらの少なくともいずれか一方の貼合面にケン化処理、コロナ処理、プラズマ処理等を施すことができる。 In pasting the polarizer and the protective film, saponification treatment, corona treatment, plasma treatment, or the like can be performed on at least one of the pasting surfaces.
［第２および第３粘着剤層］
　第２粘着剤層および第３粘着剤層を形成する粘着剤としては、従来公知のものを適宜選択すればよく、偏光板がさらされる高温環境、湿熱環境または高温と低温が繰り返されるような環境下において、剥れなどが生じない程度の接着性を有するものであればよい。具体的には、アクリル系粘着剤、シリコーン系粘着剤、ゴム系粘着剤などを挙げることができ、透明性、耐候性、耐熱性、加工性の点で、アクリル系粘着剤が特に好ましい。
　また、第１粘着剤層および第２粘着剤層および／または第３粘着剤層は同種の粘着剤を用いてもよく、異なる種類の粘着剤を用いてもよい。
　好ましい態様において、第２粘着剤層および第３粘着剤層はアクリル系粘着剤から形成される。 [Second and third pressure-sensitive adhesive layers]
As the pressure-sensitive adhesive forming the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer, conventionally known ones may be appropriately selected, and a high temperature environment, a humid heat environment or an environment where high and low temperatures are repeated are exposed to the polarizing plate. It is sufficient that the adhesive layer has a degree of adhesion that does not cause peeling. Specific examples include acrylic pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, and acrylic pressure-sensitive adhesives are particularly preferable in terms of transparency, weather resistance, heat resistance, and processability.
The first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer, and / or the third pressure-sensitive adhesive layer may use the same type of pressure-sensitive adhesive, or may use different types of pressure-sensitive adhesives.
In a preferred embodiment, the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer are formed from an acrylic pressure-sensitive adhesive.
　粘着剤には、必要に応じ、粘着付与剤、可塑剤、ガラス繊維、ガラスビーズ、金属粉、その他の無機粉末等からなる充填剤、顔料、着色剤、充填剤、酸化防止剤、紫外線吸収剤、帯電防止剤、シランカップリング剤など、各種の添加剤を適宜に配合してもよい。 For the adhesive, if necessary, a tackifier, plasticizer, glass fiber, glass beads, metal powder, other inorganic powders, fillers, pigments, colorants, fillers, antioxidants, UV absorbers Various additives such as an antistatic agent and a silane coupling agent may be appropriately blended.
　粘着剤層は、通常、粘着剤の溶液を離型シート上に粘着剤を塗布し、乾燥することにより形成される。離型シート上への塗布は、例えば、リバースコーティング、グラビアコーティング等のロールコーティング法、スピンコーティング法、スクリーンコーティング法、ファウンテンコーティング法、ディッピング法、スプレー法などを採用できる。粘着剤層を設けた離型シートは、これを転写する方法等により利用される。粘着剤層の厚さは、通常３～３０μｍ程度であり、好ましくは１０～３０μｍであり、より好ましくは、１０～２５μｍである。好ましい態様において、第２粘着剤層、第３粘着剤層がこのような厚みを有することにより、偏光板が破壊することを抑制でき、液晶表示装置に組み込んだときに、液晶パネルの端部に光漏れが生じることを抑制できる。なお、第２粘着剤層、第３粘着剤層の厚さを、上記層間厚みが所定の範囲となるように、適宜調整できる。 The pressure-sensitive adhesive layer is usually formed by applying a pressure-sensitive adhesive solution onto a release sheet and drying. For application onto the release sheet, for example, roll coating methods such as reverse coating and gravure coating, spin coating methods, screen coating methods, fountain coating methods, dipping methods, spraying methods and the like can be employed. The release sheet provided with the pressure-sensitive adhesive layer is used by a method of transferring the release sheet. The thickness of the pressure-sensitive adhesive layer is usually about 3 to 30 μm, preferably 10 to 30 μm, and more preferably 10 to 25 μm. In a preferred embodiment, when the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer have such thicknesses, the polarizing plate can be prevented from being broken, and when incorporated in a liquid crystal display device, The occurrence of light leakage can be suppressed. In addition, the thickness of a 2nd adhesive layer and a 3rd adhesive layer can be suitably adjusted so that the said interlayer thickness may become a predetermined range.
　第２粘着剤層、第３粘着剤層の８０℃における貯蔵弾性率は、好ましくは０．０２５ＭＰａ以上であり、より好ましくは０．０７ＭＰａ以上である。粘着剤層の貯蔵弾性率が０．０２５ＭＰａ未満であると、第２粘着剤層、第３粘着剤層の凝集破壊が生じ得、凝集破壊が著しいと、偏光板の外観に悪影響が及ぼされるだけでなく、液晶表示装置に組み込んだときに、液晶パネルの端部に光漏れが生じ、表示に悪影響がある。好ましくは、第２粘着剤層、第３粘着剤層の８０℃における貯蔵弾性率は、１．１ＭＰａ以下であり、好ましくは０．９ＭＰａ以下である。８０℃における粘着剤層の貯蔵弾性率が１．１ＭＰａを超えると、第２粘着剤層、第３粘着剤層とガラス或いはパネルとに対して耐熱耐久性が悪くなり、層間に気泡が発生し易くなる。 The storage elastic modulus at 80 ° C. of the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer is preferably 0.025 MPa or more, more preferably 0.07 MPa or more. If the storage elastic modulus of the pressure-sensitive adhesive layer is less than 0.025 MPa, the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer may cause cohesive failure, and if the cohesive failure is significant, only the appearance of the polarizing plate is adversely affected. In addition, when incorporated in a liquid crystal display device, light leakage occurs at the end of the liquid crystal panel, which adversely affects the display. Preferably, the storage elastic modulus at 80 ° C. of the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer is 1.1 MPa or less, preferably 0.9 MPa or less. If the storage elastic modulus of the pressure-sensitive adhesive layer at 80 ° C. exceeds 1.1 MPa, the heat-resistant durability deteriorates against the second pressure-sensitive adhesive layer, the third pressure-sensitive adhesive layer and the glass or panel, and bubbles are generated between the layers. It becomes easy.
　第２粘着剤層、第３粘着剤層を他の部材に貼合するまで、その表面を保護するためにセパレータを設けてもよい。例えば、ポリエチレンテレフタレートのような透明樹脂からなるフィルムに、シリコーン系等の離型剤による処理を施したものが用いられる。 A separator may be provided to protect the surface of the second adhesive layer and the third adhesive layer until they are bonded to another member. For example, a film made of a transparent resin such as polyethylene terephthalate, which has been treated with a release agent such as silicone, is used.
　［背面側偏光板の製造方法］
　本発明の背面側偏光板は、例えば、反射型偏光板における第１粘着剤層側の表面に、表面活性化処理を施す工程、および、表面活性化処理を施した上記表面上に、第１粘着剤層を積層する工程を経て作製される。 [Production method of back side polarizing plate]
The back-side polarizing plate of the present invention includes, for example, a step of subjecting the surface on the first pressure-sensitive adhesive layer side of the reflective polarizing plate to a surface activation treatment, and the first surface on the surface subjected to the surface activation treatment. It is produced through a process of laminating an adhesive layer.
　また、本発明の背面側偏光板は、例えば、偏光子の片面に第１保護フィルムを、接着剤層を介して貼合すること、第１保護フィルムにおける第１偏光子とは反対側の面に、第２粘着剤層を積層すること、第１偏光子における第１保護フィルムとは反対側の面に第１粘着剤層を貼合すること、第１粘着剤層における第１偏光子とは反対側の面に反射型偏光板を積層することを含む。これらの工程を経ることにより、本発明の背面側偏光板が得られる。なお、第２粘着剤層の外面にはセパレータを仮着してもよく、第１粘着剤層における反射型偏光板との貼合面に、表面活性化処理を施してもよい。 Moreover, the back side polarizing plate of this invention is a surface on the opposite side to the 1st polarizer in bonding a 1st protective film through the adhesive bond layer on the single side | surface of a polarizer, for example. And laminating the second pressure-sensitive adhesive layer, bonding the first pressure-sensitive adhesive layer to the surface of the first polarizer opposite to the first protective film, and the first polarizer in the first pressure-sensitive adhesive layer Includes laminating a reflective polarizing plate on the opposite surface. By passing through these steps, the back side polarizing plate of the present invention is obtained. In addition, a separator may be temporarily attached to the outer surface of the second pressure-sensitive adhesive layer, and a surface activation treatment may be performed on the bonding surface of the first pressure-sensitive adhesive layer with the reflective polarizing plate.
　第１粘着剤層への反射型偏光板の貼合方法は、枚葉貼合法であってもよいし、特開２００４－２６２０７１号公報に記載されるようなシート・ロール複合貼合法であってもよい。また、長尺で生産でき、かつ必要数量が大きい場合には、ロール・ツー・ロールによる貼合手法も有用である。 The method of laminating the reflective polarizing plate to the first pressure-sensitive adhesive layer may be a single wafer laminating method or a sheet / roll composite laminating method as described in JP-A-2004-262071. Also good. In addition, when it can be produced in a long length and the required quantity is large, a roll-to-roll bonding method is also useful.
　このように、本発明の背面側偏光板の製造方法は、当該技術分野において公知の方法により作製できる。 Thus, the method for producing the back side polarizing plate of the present invention can be produced by a method known in the technical field.
　［前面側偏光板の製造方法］
　本発明の背面側偏光板の製造方法は、当該技術分野において公知の方法により作製できる。例えば、上述した背面側偏光板の製造方法と同様の工程を経て、前面側偏光板を得ることができる。 [Production method of front-side polarizing plate]
The manufacturing method of the back side polarizing plate of this invention can be produced by a well-known method in the said technical field. For example, the front-side polarizing plate can be obtained through the same steps as the manufacturing method of the back-side polarizing plate described above.
　［液晶パネル］
　本発明に係る偏光板セットは、液晶パネルに好ましく適用できる。液晶パネルは、液晶セルと、その表面に貼合される本発明に係る偏光板とを含む。液晶セルへの背面側偏光板の貼合は、第２粘着剤層を介して行い得る。本発明に係る背面側偏光板は通常、液晶セルのバックライト側に配置される偏光板として用いられる。
　一方、前面側偏光板は、第３粘着剤層を介して液晶セルへ貼合され得る。本発明に係る前面側偏光板は通常、液晶セルの視認側に配置される偏光板として用いられる。 [LCD panel]
The polarizing plate set according to the present invention can be preferably applied to a liquid crystal panel. The liquid crystal panel includes a liquid crystal cell and a polarizing plate according to the present invention bonded to the surface thereof. Bonding of the back-side polarizing plate to the liquid crystal cell can be performed via the second pressure-sensitive adhesive layer. The back side polarizing plate according to the present invention is usually used as a polarizing plate disposed on the backlight side of the liquid crystal cell.
On the other hand, the front side polarizing plate can be bonded to the liquid crystal cell via the third pressure-sensitive adhesive layer. The front side polarizing plate according to the present invention is usually used as a polarizing plate disposed on the viewing side of the liquid crystal cell.
　一態様においては、液晶セルと、その両面に配置された一対の偏光板を有し、
　前記一対の偏光板は、上記偏光板セットであり、
　第２保護フィルムと、第２偏光子と、第３粘着剤層と、液晶セルと、第２粘着剤層と、第１保護フィルムと、第１偏光子と、第１粘着剤層と、反射型偏光板がこの順で積層されている液晶パネルが提供される。 In one aspect, the liquid crystal cell and a pair of polarizing plates disposed on both sides thereof,
The pair of polarizing plates is the polarizing plate set,
The second protective film, the second polarizer, the third pressure-sensitive adhesive layer, the liquid crystal cell, the second pressure-sensitive adhesive layer, the first protective film, the first polarizer, the first pressure-sensitive adhesive layer, and the reflection A liquid crystal panel in which mold-type polarizing plates are laminated in this order is provided.
　液晶セルの駆動方式は、従来公知のいかなる方式であってもよいが、好ましくはＩＰＳモードである。本発明に係る偏光板を用いた液晶パネルは、湿熱耐久性に優れている。 The driving method of the liquid crystal cell may be any conventionally known method, but is preferably the IPS mode. The liquid crystal panel using the polarizing plate according to the present invention is excellent in wet heat durability.
　本発明は、第２粘着剤層、第３粘着剤層を介して各偏光板を有機エレクトロルミネッセンスディスプレイに貼合することにより、有機エレクトロルミネッセンス表示装置を得ることができる。 In the present invention, an organic electroluminescence display device can be obtained by bonding each polarizing plate to an organic electroluminescence display via the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer.
　以下、実施例を示して本発明をさらに具体的に説明するが、本発明はこれらの例によって限定されるものではない。例中、含有量または使用量を表す％および部は、特記ない限り重量基準である。 Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the examples, “%” and “part” representing the content or the amount used are based on weight unless otherwise specified.
　なお、フィルムの厚さは下記に従って測定した。 The film thickness was measured according to the following.
　（１）フィルム厚さの測定
　株式会社ニコン製のデジタルマイクロメーター「ＭＨ－１５Ｍ」を用いて測定した。 (1) Measurement of film thickness The film thickness was measured using a digital micrometer “MH-15M” manufactured by Nikon Corporation.
　［偏光子の作製］
　（製造例Ｐ１）
　厚さ６０μｍのポリビニルアルコールフィルム（平均重合度約２４００、ケン化度９９．９モル％以上）を乾式延伸により約５倍に縦一軸延伸し、さらに緊張状態を保ったまま、６０℃の純水に１分間浸漬した後、ヨウ素／ヨウ化カリウム／水の重量比が０．０５／５／１００である２８℃の水溶液に６０秒間浸漬した。その後、ヨウ化カリウム／ホウ酸／水の重量比が８．５／８．５／１００である７２℃の水溶液に３００秒間浸漬した。引き続き２６℃の純水で２０秒間洗浄した後、６５℃で乾燥処理を行って、ポリビニルアルコールフィルムにヨウ素が吸着配向している、厚さ２３μｍの偏光子を得た。以下において、この偏光子を偏光子（２３μｍ）と記載する場合がある。 [Production of polarizer]
(Production Example P1)
A 60 μm-thick polyvinyl alcohol film (average polymerization degree of about 2400, saponification degree of 99.9 mol% or more) is about 5 times longitudinally uniaxially stretched by dry stretching, and further maintained at 60 ° C. with pure water at 60 ° C. And then immersed in a 28 ° C. aqueous solution having a weight ratio of iodine / potassium iodide / water of 0.05 / 5/100 for 60 seconds. Then, it was immersed for 300 seconds in 72 degreeC aqueous solution whose weight ratio of potassium iodide / boric acid / water is 8.5 / 8.5 / 100. Subsequently, after washing with pure water at 26 ° C. for 20 seconds, drying treatment was performed at 65 ° C. to obtain a polarizer having a thickness of 23 μm in which iodine was adsorbed and oriented on the polyvinyl alcohol film. Hereinafter, this polarizer may be referred to as a polarizer (23 μm).
　（製造例Ｐ２）
　厚さ３０μｍのポリビニルアルコールフィルム（平均重合度約２４００、ケン化度９９．９モル％以上）を乾式延伸により約５倍に縦一軸延伸し、さらに緊張状態を保ったまま、６０℃の純水に１分間浸漬した後、ヨウ素／ヨウ化カリウム／水の重量比が０．０５／５／１００である２８℃の水溶液に６０秒間浸漬した。その後、ヨウ化カリウム／ホウ酸／水の重量比が８．５／８．５／１００である７２℃の水溶液に３００秒間浸漬した。引き続き２６℃の純水で２０秒間洗浄した後、６５℃で乾燥処理を行って、ポリビニルアルコールフィルムにヨウ素が吸着配向している、厚さ１２μｍの偏光子を得た。以下において、この偏光子を偏光子（１２μｍ）と記載する場合がある。 (Production Example P2)
A 30 μm-thick polyvinyl alcohol film (average polymerization degree of about 2400, saponification degree of 99.9 mol% or more) is about 5 times longitudinally uniaxially stretched by dry stretching, and further maintained at 60 ° C. with pure water at 60 ° C. And then immersed in a 28 ° C. aqueous solution having a weight ratio of iodine / potassium iodide / water of 0.05 / 5/100 for 60 seconds. Then, it was immersed for 300 seconds in 72 degreeC aqueous solution whose weight ratio of potassium iodide / boric acid / water is 8.5 / 8.5 / 100. Subsequently, after washing with pure water at 26 ° C. for 20 seconds, drying treatment was performed at 65 ° C. to obtain a polarizer having a thickness of 12 μm in which iodine was adsorbed and oriented on the polyvinyl alcohol film. Hereinafter, this polarizer may be referred to as a polarizer (12 μm).
　（製造例Ｐ３）
　製造例Ｐ２の延伸倍率を調整した以外は、同様の方法で作製し、ポリビニルアルコールフィルムにヨウ素が吸着配向している厚さ１１μｍの偏光子を得た。以下において、この偏光子を偏光子（１１μｍ）と記載する場合がある。 (Production Example P3)
A polarizer having a thickness of 11 μm was produced by the same method except that the stretching ratio of Production Example P2 was adjusted, and iodine was adsorbed and oriented on the polyvinyl alcohol film. Hereinafter, this polarizer may be referred to as a polarizer (11 μm).
　（製造例Ｐ４）
　厚さ２０μｍのポリビニルアルコールフィルム（平均重合度約２,４００、ケン化度９９.９モル％以上）を、乾式延伸により約５倍に一軸延伸し、さらに緊張状態を保ったまま、６０℃の純水に１分間浸漬した後、ヨウ素／ヨウ化カリウム／水の重量比が０.０５／５／１００の水溶液に２８℃で６０秒間浸漬した。その後、ヨウ化カリウム／ホウ酸／水の重量比が８.５／８.５／１００の水溶液に７２℃で３００秒間浸漬した。引き続き２６℃の純水で２０秒間洗浄した後、６５℃で乾燥し、ポリビニルアルコールフィルムにヨウ素が吸着配向している、厚さ７μｍの偏光子を得た。以下において、この偏光子を偏光子（７μｍ）と記載する場合がある。 (Production Example P4)
A 20 μm-thick polyvinyl alcohol film (average polymerization degree of about 2,400, saponification degree of 99.9 mol% or more) was uniaxially stretched about 5 times by dry stretching, and further kept at 60 ° C. while maintaining the tension state. After being immersed in pure water for 1 minute, it was immersed in an aqueous solution having a weight ratio of iodine / potassium iodide / water of 0.05 / 5/100 at 28 ° C. for 60 seconds. Then, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water of 8.5 / 8.5 / 100 at 72 ° C. for 300 seconds. Subsequently, the film was washed with pure water at 26 ° C. for 20 seconds and then dried at 65 ° C. to obtain a polarizer having a thickness of 7 μm in which iodine was adsorbed and oriented on the polyvinyl alcohol film. Hereinafter, this polarizer may be referred to as a polarizer (7 μm).
　（製造例Ｐ５）
　製造例Ｐ４の延伸倍率を調整した以外は、同様の方法で作製し、ポリビニルアルコールフィルムにヨウ素が吸着配向している厚さ８μｍの偏光子を得た。以下において、この偏光子を偏光子（８μｍ）と記載する場合がある。 (Production Example P5)
Except for adjusting the draw ratio of Production Example P4, a polarizer was produced in the same manner to obtain a polarizer having a thickness of 8 μm in which iodine was adsorbed and oriented on the polyvinyl alcohol film. Hereinafter, this polarizer may be referred to as a polarizer (8 μm).
　［第１粘着剤層の調製例］
　アクリル酸ブチルとアクリル酸との共重合体にウレタンアクリレートオリゴマー及びイソシアネート系架橋剤を添加した有機溶剤溶液を、離型処理が施された厚さ３８μｍのポリエチレンテレフタレートフィルム（剥離フィルム）の離型処理面に、ダイコーターにより乾燥後の厚みが５μｍとなるように塗工し、乾燥させて得た粘着剤シートを得た。 [Example of preparation of first pressure-sensitive adhesive layer]
Release treatment of a 38 μm-thick polyethylene terephthalate film (release film) obtained by releasing an organic solvent solution obtained by adding a urethane acrylate oligomer and an isocyanate-based crosslinking agent to a copolymer of butyl acrylate and acrylic acid The pressure-sensitive adhesive sheet was obtained by coating the surface with a die coater so that the thickness after drying was 5 μm and drying.
　［第２粘着剤層および第３粘着剤層の調製例］
　離型処理が施された厚みが３８μｍのポリエチレンテレフタレートフィルム（剥離フィルム）の離型処理面に厚さ２０μｍのアクリル系粘着剤層が設けられている市販の粘着剤シート。ウレタンアクリレートオリゴマーは配合されていない。 [Example of Preparation of Second Adhesive Layer and Third Adhesive Layer]
A commercially available pressure-sensitive adhesive sheet in which an acrylic pressure-sensitive adhesive layer having a thickness of 20 μm is provided on a release-treated surface of a polyethylene terephthalate film (release film) having a thickness of 38 μm that has been subjected to a release treatment. No urethane acrylate oligomer is blended.
　［反射型偏光板］
　反射型偏光板－１として、３Ｍ社製の「Ａｄｖａｎｃｅｄ　Ｐｏｌａｒｉｚｅｒ　Ｆｉｌｍ，Ｖｅｒｓｉｏｎ　３」（厚さ２６μｍ）を使用した。 [Reflective polarizing plate]
As the reflective polarizing plate-1, “Advanced Polarizer Film, Version 3” (thickness: 26 μm) manufactured by 3M was used.
　［保護フィルム］
　以下の保護フィルムを使用した。
ＨＣ－ＴＡＣ：厚さ３２μｍであり、表面がハードコート処理されたトリアセチルセルロースフィルム（株式会社トッパンＴＯＭＯＥＧＡＷＡオプティカルフィルム製、２５ＫＣＨＣ－ＴＣ）、

ＴＡＣ：厚さ２５μｍのトリアセチルセルロースフィルム（ＴＡＣ）〔コニカミノルタ株式会社製の商品名「ＫＣ２ＵＡ」〕　

ＣＯＰ－１：延伸されていない厚さ２３μｍのノルボルネン系樹脂フィルム〔日本ゼオン株式会社製の商品名「ＺＥＯＮＯＲ」〕

ＣＯＰ－２：延伸されていない厚さ１３μｍのノルボルネン系樹脂フィルム〔日本ゼオン株式会社製の商品名「ＺＥＯＮＯＲ」〕 [Protective film]
The following protective films were used.
HC-TAC: a triacetyl cellulose film having a thickness of 32 μm and a hard coat surface (manufactured by Toppan TOMOEGAWA Optical Film, 25KCHC-TC),

TAC: 25 μm thick triacetylcellulose film (TAC) [trade name “KC2UA” manufactured by Konica Minolta, Inc.]

COP-1: An unstretched 23 μm-thick norbornene resin film (trade name “ZEONOR” manufactured by Nippon Zeon Co., Ltd.)

COP-2: An unstretched 13 μm-thick norbornene resin film (trade name “ZEONOR” manufactured by Nippon Zeon Co., Ltd.)
　「水系接着剤の調製」
　水１００重量部に対し、カルボキシル基変性ポリビニルアルコール〔株式会社クラレ製の「ＫＬ－３１８」〕を３重量部溶解して、ポリビニルアルコール水溶液を調製した。得られた水溶液に水溶性ポリアミドエポキシ樹脂〔田岡化学工業株式会社製の「スミレーズレジン６５０（３０）」、固形分濃度３０重量％〕を、水１００重量部に対し、１．５重量部の割合で混合して、水系接着剤を得た。 "Preparation of water-based adhesive"
3 parts by weight of a carboxyl group-modified polyvinyl alcohol [“KL-318” manufactured by Kuraray Co., Ltd.] was dissolved in 100 parts by weight of water to prepare an aqueous polyvinyl alcohol solution. To the obtained aqueous solution, 1.5 parts by weight of water-soluble polyamide epoxy resin (“Smile Resin 650 (30) manufactured by Taoka Chemical Industry Co., Ltd., solid concentration: 30% by weight)” was added to 100 parts by weight of water. Mixing at a ratio, an aqueous adhesive was obtained.
　［前面側偏光板の作製例］
　（前面側偏光板Ａの作製例）
偏光子（１２μｍ）の片側に、水系接着剤を塗布し、第２保護フィルムとしてＨＣ－ＴＡＣを貼り合せ、その反対側には前記の接着剤を用いて、ＣＯＰ－１を積層させ、８０℃で５分間乾燥することにより、保護フィルムと偏光子とを貼合した。貼合後、４０℃で１６８時間養生した。さらに、ＣＯＰ－１における偏光子とは反対側の表面に、第３粘着剤層を貼合した。この積層体を前面側偏光板Ａとした。なお、積層体は長辺の長さが１５５．２５ｍｍ、短辺の長さが９５．９０ｍｍの矩形形状である。 [Preparation example of front side polarizing plate]
(Preparation example of front side polarizing plate A)
A water-based adhesive is applied to one side of a polarizer (12 μm), HC-TAC is bonded as a second protective film, and COP-1 is laminated on the opposite side using the above-mentioned adhesive, and 80 ° C. The protective film and the polarizer were bonded together by drying for 5 minutes. After pasting, it was cured at 40 ° C. for 168 hours. Further, a third pressure-sensitive adhesive layer was bonded to the surface of COP-1 opposite to the polarizer. This laminate was designated as a front side polarizing plate A. The laminate has a rectangular shape with a long side length of 155.25 mm and a short side length of 95.90 mm.
　（前面側偏光板Ｂの作製例）
前面側偏光板Ａの偏光子を偏光子(１１μｍ)に変更した以外は、前面側偏光板Ａと同様に作製した。この積層体を前面側偏光板Ｂとした。 (Preparation example of front side polarizing plate B)
A front side polarizing plate A was prepared in the same manner as the front side polarizing plate A, except that the polarizer of the front side polarizing plate A was changed to a polarizer (11 μm). This laminate was designated as a front side polarizing plate B.
　（前面側偏光板Ｃの作製例）
前面側偏光板Ａの偏光子を偏光子(２３μｍ)に変更した以外は、前面側偏光板Ａと同様に作製した。この積層体を前面側偏光板Ｃとした。 (Preparation example of front side polarizing plate C)
A front side polarizing plate A was prepared in the same manner as the front side polarizing plate A except that the polarizer of the front side polarizing plate A was changed to a polarizer (23 μm). This laminate was designated as a front side polarizing plate C.
　［背面側偏光板の作製例］
　（背面側偏光板Ａの作製例）
偏光子（１１μｍ）の片側に、水系接着剤を塗布し、保護フィルムとしてＴＡＣを貼り合せ、その反対側には前記の接着剤を用いて、第１保護フィルムとしてＣＯＰ－２を積層させ、８０℃で５分間乾燥することにより、保護フィルムと偏光子とを貼合した。貼合後、４０℃で１６８時間養生した。さらに、ＣＯＰ－２における偏光子とは反対側の表面に、第２粘着剤層を貼合した。さらに、ＴＡＣにおける偏光子とは反対側の表面に第１粘着剤を介して、反射型偏光板を貼り合せた。この積層体を背面側偏光板Ａとした。なお、積層体は長辺の長さが１５５．２５ｍｍ、短辺の長さが９５．９０ｍｍの矩形形状である。 [Example of production of back side polarizing plate]
(Example of production of back side polarizing plate A)
A water-based adhesive is applied to one side of a polarizer (11 μm), TAC is bonded as a protective film, and the other side is used to laminate COP-2 as a first protective film using the adhesive described above. The protective film and the polarizer were bonded by drying at 5 ° C. for 5 minutes. After pasting, it was cured at 40 ° C. for 168 hours. Further, the second pressure-sensitive adhesive layer was bonded to the surface of COP-2 opposite to the polarizer. Furthermore, a reflective polarizing plate was bonded to the surface of the TAC opposite to the polarizer through a first adhesive. This laminate was designated as a back side polarizing plate A. The laminate has a rectangular shape with a long side length of 155.25 mm and a short side length of 95.90 mm.
（背面側偏光板Ｂの作製例）
偏光子（８μｍ）の片側に、水系接着剤を塗布し、第１保護フィルムとしてＣＯＰ－２を積層させ、８０℃で５分間乾燥することにより、保護フィルムと偏光子とを貼合した。さらに、ＣＯＰ－２における偏光子とは反対側の表面に、第２粘着剤層を貼合した。さらに、偏光子における第１保護フィルムとは反対側の表面に第１粘着剤を介して、反射型偏光板を貼り合せた。この積層体を背面側偏光板Ｂとした。なお、積層体は長辺の長さが１５５．２５ｍｍ、短辺の長さが９５．９０ｍｍの矩形形状である。 (Preparation example of back side polarizing plate B)
A water-based adhesive was applied to one side of the polarizer (8 μm), COP-2 was laminated as a first protective film, and dried at 80 ° C. for 5 minutes to bond the protective film and the polarizer. Further, the second pressure-sensitive adhesive layer was bonded to the surface of COP-2 opposite to the polarizer. Furthermore, the reflective polarizing plate was bonded together through the 1st adhesive on the surface on the opposite side to the 1st protective film in a polarizer. This laminate was designated as a back side polarizing plate B. The laminate has a rectangular shape with a long side length of 155.25 mm and a short side length of 95.90 mm.
　（背面側偏光板Ｃの作製例）
背面側偏光板Ｂの偏光子を偏光子(７μｍ)に変更した以外は、背面側偏光板Ｂと同様に作製した。この積層体を前面側偏光板Ｃとした。 (Example of production of back side polarizing plate C)
The back side polarizing plate B was prepared in the same manner as the back side polarizing plate B except that the polarizer of the back side polarizing plate B was changed to a polarizer (7 μm). This laminate was designated as a front side polarizing plate C.
（背面側偏光板Ｄの作製例）
背面側偏光板Ａの偏光子を偏光子(１２μｍ)に変更した以外は、背面側偏光板Ａと同様に作製した。この積層体を前面側偏光板Ｄとした。 (Preparation example of the back side polarizing plate D)
The back side polarizing plate A was prepared in the same manner as the back side polarizing plate A, except that the polarizer of the back side polarizing plate A was changed to a polarizer (12 μm). This laminate was designated as a front side polarizing plate D.
　このようにして得られた、実施例および比較例における偏光板の構成を表１に示す。また、得られた各偏光板の物性評価を、以下の記載に従い行った。結果を表１に示す。 Table 1 shows the structures of the polarizing plates in Examples and Comparative Examples obtained as described above. Moreover, the physical property evaluation of each obtained polarizing plate was performed according to the following description. The results are shown in Table 1.
　［反り量の測定］
　（積層体の作製）
　上記で作製した偏光板について、反り量を次の方法で測定した。まず、作製した背面側偏光板において、第２粘着剤層における第１保護フィルムとは反対側の面を、厚み０．４ｍｍのガラス（コーニング社製、品番：ＥＡＧＬＥ　ＸＧ(登録商標)）に貼合せた。
　次いで、前面側偏光板の第３粘着剤層における第２偏光子とは反対側の面を、上記ガラスにおける第２粘着剤層側とは反対側の面に貼合せた。
　前面側偏光板における第２偏光子の吸収軸と、前記背面側偏光板における第１偏光子の吸収軸とのなす角度が９０°となるように貼合せ、かつ、背面側偏光板における第１偏光子の吸収軸と背面側偏光板の長辺とのなす角度が０°となるように、積層体を作製した。 [Measurement of warpage]
(Production of laminate)
About the polarizing plate produced above, the curvature amount was measured with the following method. First, in the produced back side polarizing plate, the surface opposite to the first protective film in the second pressure-sensitive adhesive layer is pasted on glass having a thickness of 0.4 mm (manufactured by Corning, product number: EAGLE XG (registered trademark) ). Combined.
Next, the surface opposite to the second polarizer in the third pressure-sensitive adhesive layer of the front side polarizing plate was bonded to the surface opposite to the second pressure-sensitive adhesive layer side in the glass.
The first polarizer in the back side polarizing plate is bonded so that the angle between the absorption axis of the second polarizer in the front side polarizing plate and the absorption axis of the first polarizer in the back side polarizing plate is 90 °. A laminate was prepared so that the angle formed by the absorption axis of the polarizer and the long side of the back-side polarizing plate was 0 °.
　（湿熱環境での反り）
　背面側偏光板／ガラス／前面側偏光板の構成を有する積層体を、６０℃、湿度９０％の環境下に、２５０時間静置した。試験槽から積層体を取り出し、前面側偏光板が上側となるよう、二次元測定器（株式会社ニコン製、ＮＥＸＩＶ（登録商標）　ＭＲ－１２０７２）の測定台上に置いた。
　次いで、測定台の表面に焦点を合わせ、そこを基準とし、ガラスサンプル面上の２５点にそれぞれ焦点を合わせ、基準とした焦点からの高さを測定した。２５点の測定点における高さの最大値と最小値との差を反り量とした。具体的には、図３に示す点４０を測定点とした。図３で示される２５個の点は、偏光板の端部から７ｍｍ内側の領域における点であり、短辺方向は約２０ｍｍ間隔で、長辺方向は約３５ｍｍ間隔で設けられた。また、図３において、符号５０は偏光板を示し、６０はガラス板を示す。
　判定は以下のようにした。結果を表１に示す。
　なお、実施例においては、いずれのサンプルにおいても積層体全体の浮き、剥がれ、各層間の浮き、剥がれは認められなかった。
＜判定＞
湿熱環境下に静置したガラスサンプルの反り量が０．６ｍｍ未満の場合を「○」とした。
湿熱環境下に静置したガラスサンプルの反り量が０．６ｍｍ以上の場合を「×」とした。 (Warpage in wet heat environment)
The laminate having the configuration of the rear side polarizing plate / glass / front side polarizing plate was allowed to stand for 250 hours in an environment of 60 ° C. and humidity of 90%. The laminate was taken out from the test tank and placed on a measuring table of a two-dimensional measuring device (manufactured by Nikon Corporation, NEXIV (registered trademark) MR-12072) so that the front polarizing plate was on the upper side.
Next, the surface of the measuring table was focused, and the height from the reference focal point was measured by focusing on each of the 25 points on the glass sample surface. The difference between the maximum value and the minimum value at the 25 measurement points was defined as the amount of warpage. Specifically, the point 40 shown in FIG. The 25 points shown in FIG. 3 are points in a region 7 mm inside from the end of the polarizing plate, and the short side direction is provided at intervals of about 20 mm, and the long side direction is provided at intervals of about 35 mm. Moreover, in FIG. 3, the code | symbol 50 shows a polarizing plate and 60 shows a glass plate.
The judgment was as follows. The results are shown in Table 1.
In the examples, in all samples, the entire laminate was not lifted or peeled off, and no floating or peeling between layers was observed.
<Judgment>
The case where the amount of warpage of the glass sample that was allowed to stand in a humid heat environment was less than 0.6 mm was designated as “◯”.
The case where the amount of warpage of the glass sample placed in a humid heat environment was 0.6 mm or more was defined as “x”.
　（高温環境での反り）
　背面側偏光板／ガラス／前面側偏光板の構成を有する積層体において、前面側偏光板が上側となるよう、上記積層体を、８５℃、湿度５％の環境下に、２５０時間静置した。試験槽から積層体を取り出し、前面側偏光板が上側となるよう、反りが生じた積層体を、二次元測定器（株式会社ニコン製、ＮＥＸＩＶ（登録商標）　ＭＲ－１２０７２）の測定台上に置いた。上述した方法と同様にして、反り量を測定した。
＜判定＞
高温環境下に静置したガラスサンプルの反り量が０.６ｍｍ以下の場合を「○」とした。
高温環境下に静置したガラスサンプルの反り量が０.６ｍｍ超の場合を「×」とした。 (Warp in high temperature environment)
In the laminate having the configuration of the rear-side polarizing plate / glass / front-side polarizing plate, the laminate was allowed to stand for 250 hours in an environment of 85 ° C. and 5% humidity so that the front-side polarizing plate was on the upper side. . Remove the laminate from the test tank and place the warped laminate on the measurement table of a two-dimensional measuring instrument (Nikon Corporation, NEXIV (registered trademark) MR-12072) so that the front polarizing plate is on the upper side. placed. The amount of warpage was measured in the same manner as described above.
<Judgment>
The case where the amount of warpage of the glass sample placed in a high temperature environment was 0.6 mm or less was defined as “◯”.
The case where the amount of warpage of the glass sample placed in a high-temperature environment was more than 0.6 mm was designated as “x”.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　このような結果より、本発明の偏光板セットは、偏光板が高温条件下、湿熱環境下に曝された場合であっても、液晶パネルの反りが抑制される。さらに、第２粘着剤層および第３粘着剤層の凝集破壊を抑制できる。また、本発明の偏光板は、高温条件下、湿熱環境下に曝された場合であっても、偏光板の視認性は極めて良好であり、偏光板の光抜けも生じない。
　このように、本発明の偏光板セットは、湿熱環境および高温環境に配置した際に反り量が小さいため、タッチパネルからの剥がれやバックライトユニットの脱落を低減または回避できる。また、高温環境および湿熱環境に曝されることで生じ得る反りに起因して発生する表示ムラの低減につながる。 From such a result, even if the polarizing plate set of this invention is a case where a polarizing plate is exposed to a moist heat environment on high temperature conditions, the curvature of a liquid crystal panel is suppressed. Furthermore, cohesive failure of the second pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer can be suppressed. Moreover, even when the polarizing plate of the present invention is exposed to a wet heat environment under high temperature conditions, the visibility of the polarizing plate is very good, and light leakage of the polarizing plate does not occur.
As described above, since the polarizing plate set of the present invention has a small amount of warping when placed in a humid heat environment and a high temperature environment, peeling from the touch panel and falling off of the backlight unit can be reduced or avoided. In addition, display unevenness caused by warpage that may be caused by exposure to a high temperature environment and a moist heat environment is reduced.
　本発明によれば、例えば偏光子および反射型偏光板の収縮に起因する反りが抑制された偏光板セットが提供される。さらに、本発明によれば、液晶セルのガラス基板に貼合された粘着剤層の凝集破壊も抑制された偏光板セットが提供される。 According to the present invention, there is provided a polarizing plate set in which, for example, warpage due to shrinkage of a polarizer and a reflective polarizing plate is suppressed. Furthermore, according to this invention, the polarizing plate set by which the cohesive failure of the adhesive layer bonded by the glass substrate of the liquid crystal cell was also suppressed is provided.
　　１０　背面側偏光板
　　１１　反射型偏光板
　　１２　第１粘着剤層
　　１３　第１偏光子
　　１４　第１保護フィルム
　　１５　第２粘着剤層
　　２０　前面側偏光板
　　２１　第３粘着剤層
　　２２　第２偏光子
　　２３　第２保護フィルム
　　３０　液晶セル
　　４０　測定点
　　５０　偏光板
　　６０　ガラス板 DESCRIPTION OF SYMBOLS 10 Back side polarizing plate 11 Reflective type polarizing plate 12 1st adhesive layer 13 1st polarizer 14 1st protective film 15 2nd adhesive layer 20 Front side polarizing plate 21 3rd adhesive layer 22 2nd polarizer 23 1st 2 protective film 30 liquid crystal cell 40 measuring point 50 polarizing plate 60 glass plate

Claims (4)

  1. 　液晶セルの一方の面側に配置される背面側偏光板と、他方の面側に配置される前面側偏光板とを含む、偏光板セットであって、
    　前記背面側偏光板は、反射型偏光板と、第１粘着剤層と、第１偏光子と、第１保護フィルムと、第２粘着剤層とを有し、
    　前記前面側偏光板は、第３粘着剤層と、第２偏光子と、第２保護フィルムとを有し、
    　前記前面側偏光板における第２偏光子の厚さｄＦ（μｍ）から、前記背面側偏光板における第１偏光子の厚さｄＲ（μｍ）を差し引いた差ｄＦ－ｄＲをΔｄ（μｍ）とした場合、０μｍ＜Δｄ＜５μｍであり、
    前記前面側偏光板における第２偏光子の吸収軸と、前記背面側偏光板における第１偏光子の吸収軸とのなす角度が９０°±１°である、
    偏光板セット。     A polarizing plate set comprising a back side polarizing plate disposed on one surface side of the liquid crystal cell and a front side polarizing plate disposed on the other surface side,
    The back side polarizing plate has a reflective polarizing plate, a first pressure-sensitive adhesive layer, a first polarizer, a first protective film, and a second pressure-sensitive adhesive layer.
    The front side polarizing plate has a third pressure-sensitive adhesive layer, a second polarizer, and a second protective film,
    A difference dF−dR obtained by subtracting the thickness dR (μm) of the first polarizer in the back-side polarizing plate from the thickness dF (μm) of the second polarizer in the front-side polarizing plate is defined as Δd (μm). And 0 μm <Δd <5 μm,
    The angle formed by the absorption axis of the second polarizer in the front-side polarizing plate and the absorption axis of the first polarizer in the rear-side polarizing plate is 90 ° ± 1 °.
    Polarizing plate set.
  2. 　前記背面側偏光板における第１偏光子の吸収軸と前記背面側偏光板の長辺とのなす角度が０°±０．５°である、請求項１に記載の偏光板セット。 The polarizing plate set according to claim 1, wherein an angle formed between an absorption axis of the first polarizer and a long side of the back side polarizing plate in the back side polarizing plate is 0 ° ± 0.5 °.
  3. 　前記反射型偏光板は、少なくとも２層の薄膜を有し、前記少なくとも２層の薄膜は、屈折率異方性が異なる、請求項１または２に記載の偏光板セット。 The polarizing plate set according to claim 1 or 2, wherein the reflective polarizing plate has at least two thin films, and the at least two thin films have different refractive index anisotropy.
  4. 　液晶セルと、その両面に配置された一対の偏光板を有し、
    　前記一対の偏光板は、請求項１から３のいずれか１項に記載の偏光板セットであり、
    　前記第２保護フィルムと、第２偏光子と、第３粘着剤層と、液晶セルと、第２粘着剤層と、第１保護フィルムと、第１偏光子と、第１粘着剤層と、反射型偏光板がこの順で積層されている、液晶パネル。     A liquid crystal cell and a pair of polarizing plates disposed on both sides thereof,
    The pair of polarizing plates is the polarizing plate set according to any one of claims 1 to 3,
    The second protective film, the second polarizer, the third pressure-sensitive adhesive layer, the liquid crystal cell, the second pressure-sensitive adhesive layer, the first protective film, the first polarizer, and the first pressure-sensitive adhesive layer; A liquid crystal panel in which reflective polarizing plates are laminated in this order.
PCT/JP2017/019837 2016-06-21 2017-05-29 Polarizing plate set WO2017221638A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
KR1020197000590A KR102412245B1 (en) 2016-06-21 2017-05-29 Polarizer set
CN201780038092.4A CN109313306B (en) 2016-06-21 2017-05-29 Polarizing plate assembly

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2016-122961 2016-06-21
JP2016122961A JP6887222B2 (en) 2016-06-21 2016-06-21 Polarizing plate set

Publications (1)

Publication Number Publication Date
WO2017221638A1 true WO2017221638A1 (en) 2017-12-28

Family

ID=60783972

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2017/019837 WO2017221638A1 (en) 2016-06-21 2017-05-29 Polarizing plate set

Country Status (5)

Country Link
JP (1) JP6887222B2 (en)
KR (1) KR102412245B1 (en)
CN (1) CN109313306B (en)
TW (1) TWI726116B (en)
WO (1) WO2017221638A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2021085995A (en) * 2019-11-27 2021-06-03 日本カーバイド工業株式会社 Adhesive composition for polarizing plate, polarizing plate with adhesive layer, optical member, and display device
JP2021174002A (en) 2020-04-20 2021-11-01 日東電工株式会社 Polarizing film, laminated polarizing film, image display panel, and image display device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007058183A (en) * 2005-07-27 2007-03-08 Fujifilm Corp Polarizing plate and image display device using the same
WO2013187134A1 (en) * 2012-06-11 2013-12-19 富士フイルム株式会社 Liquid crystal display device
WO2015156250A1 (en) * 2014-04-07 2015-10-15 富士フイルム株式会社 Liquid crystal display device
WO2016006626A1 (en) * 2014-07-08 2016-01-14 富士フイルム株式会社 Liquid crystal panel, liquid crystal display device, and reflective polarizing plate and method for manufacturing same
JP2016071378A (en) * 2014-09-30 2016-05-09 住友化学株式会社 Manufacturing method of polarizing plate, set of polarizing plate, liquid crystal panel, and liquid crystal display device

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002207211A (en) * 2001-01-11 2002-07-26 Nitto Denko Corp Liquid crystal panel and liquid crystal display device
WO2006040954A1 (en) * 2004-10-08 2006-04-20 Daicel Chemical Industries, Ltd. Protective film for polarizing film and polarizing multilayer body
US20070081115A1 (en) * 2005-07-27 2007-04-12 Fujifilm Corporation Polarizing plate and image display device using the same
JP2009163216A (en) * 2007-12-11 2009-07-23 Sumitomo Chemical Co Ltd Set of polarizing plate, and liquid crystal panel and liquid crystal display using the same
JP5066554B2 (en) * 2009-07-17 2012-11-07 株式会社ジャパンディスプレイイースト Liquid crystal display
JP2011170234A (en) * 2010-02-22 2011-09-01 Sumitomo Chemical Co Ltd Liquid crystal display device
JP2011248178A (en) * 2010-05-28 2011-12-08 Sumitomo Chemical Co Ltd Liquid crystal display device
JP5473840B2 (en) * 2010-09-08 2014-04-16 日東電工株式会社 Liquid crystal panel and liquid crystal display device
JP6083924B2 (en) 2011-08-05 2017-02-22 日東電工株式会社 Optical laminate, optical laminate set and liquid crystal panel using them
JP6403936B2 (en) * 2012-08-08 2018-10-10 住友化学株式会社 Polarizing plate and liquid crystal display panel using the same
JP6310645B2 (en) * 2013-05-20 2018-04-11 日東電工株式会社 Optical member, polarizing plate set and liquid crystal display device
JP6294043B2 (en) * 2013-10-10 2018-03-14 住友化学株式会社 Set of polarizing plates
JP2016066047A (en) * 2014-03-25 2016-04-28 住友化学株式会社 Polarizing plate and liquid crystal panel

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007058183A (en) * 2005-07-27 2007-03-08 Fujifilm Corp Polarizing plate and image display device using the same
WO2013187134A1 (en) * 2012-06-11 2013-12-19 富士フイルム株式会社 Liquid crystal display device
WO2015156250A1 (en) * 2014-04-07 2015-10-15 富士フイルム株式会社 Liquid crystal display device
WO2016006626A1 (en) * 2014-07-08 2016-01-14 富士フイルム株式会社 Liquid crystal panel, liquid crystal display device, and reflective polarizing plate and method for manufacturing same
JP2016071378A (en) * 2014-09-30 2016-05-09 住友化学株式会社 Manufacturing method of polarizing plate, set of polarizing plate, liquid crystal panel, and liquid crystal display device

Also Published As

Publication number Publication date
KR102412245B1 (en) 2022-06-23
CN109313306B (en) 2021-08-31
KR20190020732A (en) 2019-03-04
TW201804182A (en) 2018-02-01
CN109313306A (en) 2019-02-05
JP6887222B2 (en) 2021-06-16
JP2017227731A (en) 2017-12-28
TWI726116B (en) 2021-05-01

Similar Documents

Publication Publication Date Title
JP6258911B2 (en) Polarizing plate with protective film and laminate including the same
JP2017161915A (en) Polarizing plate with protective film and laminate including the same
JP6324366B2 (en) Polarizer
WO2017212960A1 (en) Polarizing plate set
KR20160076435A (en) Polarizing plate and fabrication method for the same, and polarizing plate set, liquid crystal panel, liquid crystal display device
JP2020101815A (en) Polarizing plate set
JP2016071378A (en) Manufacturing method of polarizing plate, set of polarizing plate, liquid crystal panel, and liquid crystal display device
KR102571905B1 (en) Set of polarizing plates and liquid crystal panel
WO2017221638A1 (en) Polarizing plate set
JP6775551B2 (en) Polarizing plate set and liquid crystal panel
JP7226473B2 (en) A set of polarizers and a liquid crystal panel
KR102605997B1 (en) Polarizing plate set and liquid crystal panel
JP6455545B2 (en) Set of polarizing plates
WO2018034081A1 (en) Polarizing plate set

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17815107

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 20197000590

Country of ref document: KR

Kind code of ref document: A

122 Ep: pct application non-entry in european phase

Ref document number: 17815107

Country of ref document: EP

Kind code of ref document: A1