WO2022019469A1 - Polarizing plate and optical display device comprising same - Google Patents

Polarizing plate and optical display device comprising same Download PDF

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Publication number
WO2022019469A1
WO2022019469A1 PCT/KR2021/006861 KR2021006861W WO2022019469A1 WO 2022019469 A1 WO2022019469 A1 WO 2022019469A1 KR 2021006861 W KR2021006861 W KR 2021006861W WO 2022019469 A1 WO2022019469 A1 WO 2022019469A1
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Prior art keywords
retardation plate
retardation
plate
equation
wavelength
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PCT/KR2021/006861
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French (fr)
Korean (ko)
Inventor
김봉춘
구준모
신광호
유정훈
이상흠
조은솔
황선오
Original Assignee
삼성에스디아이 주식회사
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Publication of WO2022019469A1 publication Critical patent/WO2022019469A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3083—Birefringent or phase retarding elements
    • 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
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3016—Polarising elements involving passive liquid crystal 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
    • G02F1/13363—Birefringent elements, e.g. for optical compensation
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/50—OLEDs integrated with light modulating elements, e.g. with electrochromic elements, photochromic elements or liquid crystal elements
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/80—Constructional details
    • H10K59/8791—Arrangements for improving contrast, e.g. preventing reflection of ambient light

Definitions

  • the present invention relates to a polarizing plate and an optical display device including the same. More particularly, the present invention relates to a polarizing plate having a remarkably low reflectance at an incident angle of 60° and achieving a thinning effect, and an optical display device including the same.
  • the organic light emitting diode display device may have poor visibility and contrast due to reflection of external light.
  • a polarizing plate is provided with a one-sheet retardation film or a two-sheet retardation film.
  • the two-sheet retarder has a better antireflection function, and the two-sheet retarder is usually included in the polarizing plate.
  • the retardation plate may be prepared by stretching a polymer film in an unstretched state, or may be formed by coating and drying or curing a liquid crystal composition.
  • the retardation plate formed of the liquid crystal composition is thinner than the retardation plate made of a polymer film, so the thickness of the polarizing plate can be reduced and it is relatively economical.
  • a retardation plate formed of a liquid crystal composition particularly a polarizing plate having a retardation plate having a degree of biaxiality of about 1 at a wavelength of 550 nm, has a limit in lowering the antireflection function.
  • An object of the present invention is to provide a polarizing plate having a remarkably low reflectance at an incident angle of 60°.
  • Another object of the present invention is to provide a polarizing plate having a significantly lower manufacturing cost compared to a polymer-type retardation film, which is excellent in economical efficiency, and has a thickness reduction effect.
  • One aspect of the present invention is a polarizing plate.
  • the polarizing plate includes a polarizer and a first retardation plate and a second retardation plate sequentially stacked on a lower surface of the polarizer, wherein the first retardation plate has an in-plane retardation (Re) of about 180 nm to about 240 nm at a wavelength of 550 nm, and the The second retardation plate has an in-plane retardation of about 90 nm to about 130 nm at a wavelength of 550 nm, the first retardation plate and the second retardation plate have a degree of biaxiality (NZ) of about 0.95 to about 1.05 at a wavelength of 550 nm, respectively, and the first The first retarder plate and the second retarder plate satisfy Equation 1, Equation 2, Equation 3 and Equation 4:
  • Re (second retardation plate) about ([0.4 x Re (first retardation plate)] + ⁇ )
  • Re (first retardation plate) is the in-plane retardation of the first retardation plate at a wavelength of 550 nm (unit: nm)
  • Re (second retardation plate) is the in-plane retardation of the second retardation plate at a wavelength of 550 nm (unit: nm)
  • Rth is the thickness direction retardation of the first retarder at a wavelength of 550 nm (unit: nm),
  • Rth (second retardation plate) is the thickness direction retardation of the second retardation plate at a wavelength of 550 nm (unit: nm),
  • ⁇ (first retardation plate) is the angle formed by the slow axis of the first retardation plate with respect to the transmission axis of the polarizer (unit: °)),
  • ⁇ (second retardation plate) about ([2 x ⁇ (first retardation plate)] + 45° + ⁇ )
  • ⁇ (first retardation plate) is the angle (unit: °) formed by the slow axis of the first retardation plate with respect to the transmission axis of the polarizer;
  • ⁇ (second retardation plate) is the angle (unit: °) formed by the slow axis of the second retardation plate with respect to the transmission axis of the polarizer;
  • the first retardation plate and the second retardation plate may each include a liquid crystal layer.
  • the liquid crystal layer may include a nematic liquid crystal.
  • the first retardation plate and the second retardation plate may each have a degree of biaxiality (NZ) of about 0.96 to about 1.04 at a wavelength of 550 nm.
  • Rth (first retardation plate) in Equation 2 may be about 50 nm to about 150 nm.
  • Rth (second retardation plate) in Equation 2 may be about 30 nm to about 80 nm.
  • ⁇ (the second retardation plate) in Equation 4 may be about 10° to about 40°.
  • the first retardation plate and the second retardation plate may each have a constant wavelength dispersion property.
  • the in-plane retardation of the laminate of the first retardation plate and the second retardation plate may be about 140 nm to about 190 nm at a wavelength of 550 nm.
  • the polarizing plate may further include a third retardation plate including a positive C layer.
  • the third retardation plate may have a thickness direction retardation of about -300 nm to about 0 nm at a wavelength of 550 nm.
  • the third retardation plate may be included in a lower surface of the second retardation plate.
  • a protective layer may be further formed on the upper surface of the polarizer.
  • One aspect of the present invention is an optical display device.
  • the optical display device includes the polarizing plate of the present invention.
  • the present invention provides a polarizing plate having a remarkably low reflectance at an incident angle of 60°.
  • the present invention provides a polarizing plate having excellent economic feasibility and thinning effect due to a significantly lower manufacturing cost compared to a polymer-type retardation film.
  • FIG. 1 is a cross-sectional view of a polarizing plate according to an embodiment of the present invention.
  • in-plane retardation (Re) is represented by the following formula A
  • the “thickness direction retardation (Rth)” is represented by the following formula B
  • the "biaxiality (NZ)” can be represented by the following formula C have:
  • NZ (nx - nz)/(nx - ny)
  • nx, ny, and nz are refractive indices in the slow axis direction, fast axis direction, and thickness direction of the optical element, respectively, at the measurement wavelength, and d is the thickness of the optical element. (unit: nm)).
  • the measurement wavelength may be 450 nm, 550 nm, or 650 nm.
  • short wavelength dispersion is Re(450)/Re(550)
  • long wavelength dispersion is Re(650)/Re(550)
  • Re (450), Re (550), and Re (650) mean in-plane retardation (Re) at wavelengths of 450 nm, 550 nm, and 650 nm of an optical element alone or an optical element stack, respectively.
  • X to Y when referring to a numerical range means X or more and Y or less (X ⁇ and ⁇ Y).
  • the polarizing plate of the present invention has a retardation plate formed of a liquid crystal composition, the manufacturing cost is significantly lower than that of the polymer-type retardation film, so it is excellent in economic feasibility and has a remarkable thickness reduction effect, and the reflectance is remarkably low at an incident angle of 60°, so that the screen quality is remarkable was excellent. Accordingly, the polarizing plate of the present invention may be used as an anti-reflection polarizing plate in a light emitting device display including an organic light emitting diode (OLED) display device.
  • OLED organic light emitting diode
  • the polarizing plate may have a specular component excluded (SCE) reflectance of about 6.0% or less at an incident angle of 60° when applied to an optical display device, for example, about 0% or more and about 6.0% or less.
  • SCE specular component excluded
  • the screen quality can be improved. for example about 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 or 6%.
  • FIG. 1 a polarizing plate according to an embodiment of the present invention will be described with reference to FIG. 1 .
  • the polarizing plate is a polarizer 110 , a protective film 140 stacked on the upper surface of the polarizer 110 , and a first retardation plate sequentially stacked from the polarizer 110 on the lower surface of the polarizer 110 . 120 and the second phase difference plate 130 .
  • the protective film 140 corresponds to a specific example of a protective layer including a protective coating layer and the like.
  • the first retardation plate 120 and the second retardation plate 130 may each include a liquid crystal layer.
  • the liquid crystal layer has a relatively small thickness compared to the polymer type retardation film, so that the thickness reduction effect of the polarizing plate can be increased.
  • the liquid crystal layer is manufactured by coating and/or drying compared to a polymer-type retardation film that involves a stretching process for realizing the retardation, it is manufactured by a simple manufacturing process and thus has excellent manufacturing processability.
  • the thickness of each of the first retardation plate 120 and the second retardation plate 130 may be the same or different.
  • the thickness of each of the first retardation plate 120 and the second retardation plate 130 may be about 10 ⁇ m or less, for example, about 0 ⁇ m to about 10 ⁇ m, and about 1 ⁇ m to about 5 ⁇ m. In the above range, it is easy to implement the retardation described in detail below and may help to reduce the thickness of the polarizing plate.
  • the liquid crystal layer will be described in more detail below.
  • each of the first retardation plate 120 and the second retardation plate 130 is about 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4 , 5, 6, 7, 8, 9 or 10 ⁇ m.
  • the first retardation plate 120 and the second retardation plate 130 each have a degree of biaxiality (NZ) of about 0.95 to about 1.05 at a wavelength of 550 nm.
  • NZ degree of biaxiality
  • a liquid crystal layer is used as a retardation plate among polarizing plates, but a retardation plate having the above-described degree of biaxiality, that is, a rod-shaped nematic liquid crystal layer is used. Because the rod-shaped nematic liquid crystal has a high order parameter and is well arranged even at low anchoring energy, there is no deviation in optical properties, and it is cheaper than other liquid crystals and can be obtained in large quantities, so it can be easily mass-produced.
  • the degree of biaxiality at a wavelength of 550 nm of the first retardation plate 120 and the second retardation plate 130 may be the same or different, preferably about 0.96 to about 1.04, more preferably about 0.97 to about 1.03, most preferably It can be about 1. In one embodiment, the degree of biaxiality at a wavelength of 550 nm of the first retardation plate 120 and the second retardation plate 130 may be substantially the same. “Substantially the same" means that the difference in the degree of biaxiality is from about 0 to about 0.05.
  • first retardation plate 120 and the second retardation plate 130 each have a degree of biaxiality (NZ) of about 0.95, 0.96, 0.97, 0.98, 0.99, 1, 1.01, 1.02, 1.03, 1.04 at a wavelength of 550 nm. or 1.05.
  • NZ degree of biaxiality
  • the first retardation plate 120 has an in-plane retardation of about 180 nm to about 240 nm at a wavelength of 550 nm
  • the second retardation plate 130 has an in-plane retardation of about 90 nm to about 130 nm at a wavelength of 550 nm.
  • the first retardation plate and the second retardation plate act on the light incident from the polarizer to help lower the reflectance.
  • the in-plane retardation at a wavelength of 550 nm may be about 190 nm to about 240 nm for the first retardation plate, about 95 nm to about 130 nm for the second retardation plate, and about 115 nm to about 130 nm.
  • the first retardation plate 120 has an in-plane retardation Re of about 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194 at a wavelength of 550 nm.
  • the second retardation plate 130 has an in-plane retardation Re of about 90, 91, 92, 93, 94, 95, 97, 97, 98, 99, 100, 101, 102, 103, 104 at a wavelength of 550 nm. , 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129 or 130 nm.
  • a first retardation plate and a second retardation plate each having the above-described degree of biaxiality and in-plane retardation are provided, and the following Equations 1, 2, 3 and 4 are simultaneously satisfied.
  • the reflectance can be significantly lowered at an incident angle of 60°, thereby significantly improving the screen quality:
  • Re (second retardation plate) about ([0.4 x Re (first retardation plate)] + ⁇ )
  • Re (first retardation plate) is the in-plane retardation of the first retardation plate at a wavelength of 550 nm (unit: nm)
  • Re (second retardation plate) is the in-plane retardation of the second retardation plate at a wavelength of 550 nm (unit: nm)
  • Rth is the thickness direction retardation of the first retarder at a wavelength of 550 nm (unit: nm),
  • Rth (second retardation plate) is the thickness direction retardation of the second retardation plate at a wavelength of 550 nm (unit: nm),
  • ⁇ (the first retardation plate) is the angle (unit: °) formed by the slow axis of the first retardation plate with respect to the transmission axis of the polarizer;
  • ⁇ (second retardation plate) about ([2 x ⁇ (first retardation plate)] + 45° + ⁇ )
  • ⁇ (first retardation plate) is the angle (unit: °) formed by the slow axis of the first retardation plate with respect to the transmission axis of the polarizer;
  • ⁇ (second retardation plate) is the angle (unit: °) formed by the slow axis of the second retardation plate with respect to the transmission axis of the polarizer;
  • a polarizing plate that does not satisfy any one of Equation 1, Equation 2, Equation 3, and Equation 4 cannot implement the effect of the present invention, and thus cannot obtain a significant reflectance reduction effect at an incident angle of 60°.
  • Equation 1 is a relational expression between Re of the first retarder and Re of the second retarder. Even if the first retardation plate and the second retardation plate each have the above-described Re values, if Equation 1 is not satisfied, it means that the effects of the present invention cannot be properly obtained.
  • ⁇ is about 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43 or 44 nm.
  • Equation 2 is a relational expression between the retardation in the thickness direction Rth of the first retarder and the retardation in the thickness direction Rth of the second retarder.
  • first retardation plate and the second retardation plate satisfy Equation 2 above, the effect of the present invention can be obtained.
  • may be about 145 nm to about 170 nm, more preferably about 150 nm to about 160 nm.
  • is about 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179 or 180 nm.
  • Rth (first retardation plate) in Equation 2 is a positive value, and may be from about 50 nm to about 150 nm, specifically from about 80 nm to about 120 nm. In the above range, Equation 2 may be easily reached, and it may be easy to implement the effect of the present invention.
  • Rth (first retardation plate) is about 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 97, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137,
  • Rth (second retardation plate) in Equation 2 is a positive value, and may be about 30 nm to about 80 nm, specifically about 50 nm to about 60 nm. In the above range, Equation 2 may be easily reached, and it may be easy to implement the effect of the present invention.
  • Rth (second retardation plate) is about 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 or 80 nm.
  • Equation 3 is an angle formed by the slow axis of the first retardation plate 120 with respect to the transmission axis of the polarizer 110 .
  • the transmission axis of the polarizer may be a TD (transverse direction) of the polarizer.
  • ⁇ the first retardation plate
  • ⁇ the first retardation plate
  • Equation 4 is the angle between the slow axis of the first retardation plate 120 with respect to the transmission axis of the polarizer 110 and the angle between the slow axis of the second retardation plate 130 with respect to the transmission axis of the polarizer 110 is a relational expression.
  • the first retardation plate and the second retardation plate are arranged to satisfy Equation 4 above, it may be easy to achieve the effect of the present invention.
  • ⁇ may be about 2, 3, 4, 5, 6 or 7°.
  • ⁇ (the second retardation plate) may be about 10° to about 40°, more preferably about 15° to about 35°. In the above range, it is possible to lower the reflectance by the polarizing plate.
  • ⁇ (the second phase difference plate) is about 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 , 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40°.
  • Each of the first retardation plate 120 and the second retardation plate 130 may have forward wavelength dispersion, but the entirety may have reverse wavelength dispersion. Through this, the polarizing plate may lower the reflectance at the side.
  • the "forward wavelength dispersion” and “reverse wavelength dispersion” may be determined by short wavelength dispersion and long wavelength dispersion, as known to those skilled in the art.
  • the first retardation plate 120 and the second retardation plate 130 may each include a liquid crystal layer.
  • the liquid crystal layer has the above-described degree of biaxiality, in-plane retardation, and thickness direction retardation, there is no particular limitation on the material constituting the liquid crystal layer.
  • the liquid crystal layer may be formed of a composition including at least one of a liquid crystal polymer and a polymerizable liquid crystal compound.
  • the liquid crystal layer may be of a nematic type, a discotic type, or the like, and preferably a nematic type.
  • the first retardation plate may include a nematic liquid crystal layer
  • the second retardation plate may include a nematic liquid crystal layer.
  • the in-plane retardation at a wavelength of 550 nm may be about 140 nm to about 190 nm, preferably about 150 nm to about 170 nm. In the above range, it is possible to lower the reflectance.
  • the in-plane retardation at a wavelength of 550 nm is about 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150 , 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175 , 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189 or 190 nm.
  • the first retardation plate 120 may be directly formed on the second retardation plate 130 .
  • the "directly formed” means that any adhesive layer or adhesive layer is not included between the first retardation plate 120 and the second retardation plate 130 .
  • first retardation plate 120 may be laminated on the second retardation plate 130 by an adhesive (eg, pressure-sensitive adhesive (PSA)).
  • adhesive eg, pressure-sensitive adhesive (PSA)
  • the first retardation plate 120 may be adhered to the polarizer 110 by a first adhesive layer.
  • the first adhesive layer may be formed of, for example, at least one of a water-based adhesive and a photocurable adhesive.
  • adhesion between the protective film and the polarizer and adhesion between the polarizer and the first retardation plate can be achieved by one light irradiation, so that the manufacturing processability of the polarizing plate can be improved.
  • the first adhesive layer may have a thickness of about 0.1 ⁇ m to about 10 ⁇ m, specifically, about 0.5 ⁇ m to about 5 ⁇ m.
  • the first adhesive layer may have a thickness of about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 ⁇ m.
  • an adhesive layer or an adhesive layer is formed on the lower surface of the second retardation plate 130 , and the polarizing plate is applied to the light emitting display device through an adhesive layer (eg, a pressure sensitive adhesive) or an adhesive layer. It can be laminated on the panel for use.
  • an adhesive layer eg, a pressure sensitive adhesive
  • the polarizer 110 converts incident natural light or polarized light into linearly polarized light in a specific direction, and may be manufactured from a polymer film containing polyvinyl alcohol-based resin as a main component.
  • the polarizer 110 may be manufactured by dyeing the polymer film with iodine or a dichroic dye and stretching it in the machine direction (MD). Specifically, it may be prepared through a swelling process, a dyeing step, an stretching step, and a crosslinking step.
  • the polarizer 110 may have a total light transmittance of about 40% or more, for example, about 40% to about 47%, and a polarization degree of about 99% or more, for example, about 99% to about 100%. Within the above range, anti-reflection performance may be improved when combined with the first retardation plate and the second retardation plate.
  • the polarizer 110 has a total light transmittance of about 40, 41, 42, 43, 44, 45, 46, or 47%, and a polarization degree of about 99, 99.1, 99.2, 99.3, 99.4, 99.5, 99.6, 99.7, 99.8 , 99.9 or 100%.
  • the polarizer 110 may have a thickness of about 2 ⁇ m to about 30 ⁇ m, specifically, about 4 ⁇ m to about 25 ⁇ m, and may be used in a polarizing plate within the above range.
  • the polarizer 110 has a thickness of about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29 or 30 ⁇ m.
  • the protective film 140 may be formed on the upper surface of the polarizer 110 , thereby protecting the polarizer from the external environment and increasing the mechanical strength of the polarizer.
  • the protective film 140 protects the polarizer 110 from the external environment.
  • an optically transparent film for example, cellulose-based, polyethylene terephthalate, polybutylene terephthalate, polyethylene or Polyester type, cyclic polyolefin type, polycarbonate type, polyethersulfone type, polysulfone type, polyamide type, polyimide type, polyolefin type, polyarylate type, including phthalate (PET) and polybutylene naphthalate type
  • PET phthalate
  • the film may be made of one or more of polyvinyl alcohol-based, polyvinyl chloride-based, and polyvinylidene chloride-based resins. Specifically, TAC or PET film may be used.
  • the protective film 140 may have a thickness of about 5 ⁇ m to about 70 ⁇ m, specifically, about 15 ⁇ m to about 45 ⁇ m, and may be used for a polarizing plate within the above range.
  • the protective film 140 has a thickness of about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69 or 70 nm.
  • a functional coating layer is formed on the upper surface of the protective film 140 to provide an additional function to the polarizing plate. and the like, and these may be formed alone or by stacking two or more types.
  • the protective film 140 may be adhered to the polarizer 110 through a second adhesive layer.
  • the second adhesive layer may be formed of at least one of a water-based adhesive and a photocurable adhesive.
  • the second adhesive layer is formed of a photocurable adhesive, so that the adhesion between the protective film and the polarizer and the adhesion between the polarizer and the first retardation layer plate can be achieved by one light irradiation, so that the manufacturing processability of the polarizing plate can be improved. have.
  • the photocurable adhesive may be formed of the adhesive composition for forming the above-described first adhesive layer.
  • the photoinitiator may include a photoinitiator that has an absorption action for light having a wavelength of about 300 nm to about 400 nm and initiates a reaction therethrough.
  • the photoinitiator may include at least one of a photoradical initiator and a photocationic initiator.
  • the second adhesive layer may have a thickness of about 0.1 ⁇ m to about 10 ⁇ m, specifically, about 0.5 ⁇ m to about 5 ⁇ m. Within the above range, it can be used for a polarizing plate.
  • the second adhesive layer has a thickness of about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 ⁇ m. can be
  • the polarizing plate of this embodiment may further include a third retardation plate.
  • the third retardation plate includes a positive C layer in which nz>nx ⁇ ny (nx, ny, and nz are the refractive indices in the slow axis direction, fast axis direction, and thickness direction of the third retardation plate at a wavelength of 550 nm, respectively).
  • the third retardation plate may be included in the polarizing plate to significantly lower the reflectance.
  • the polarizing plate may have a reflectance of about 3.5% or less at an incident angle of 60°, for example, about 0% to about 3.5%. Within the above range, the screen quality can be improved.
  • a polarizing plate has a reflectance of about 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4 or 3.5%.
  • the third retardation plate may have a thickness direction retardation of about -300 nm to about 0 nm, for example, about -100 nm to about 0 nm, and about -90 nm to about -20 nm at a wavelength of 550 nm. In the above range, the above-described reflectance effect can be obtained.
  • the third retardation plate has about -300, -290, -280, -270, -260, -250, -240, -230, -220, -210, -200, - 190, -180, -170, -160, -150, -140, -130, -120, -110, -100, -95, -90, -85, -80, -75, -70, -65, -60, -55, -50, -45, -40, -35, -30, -25, -20, -15, -10, -5 or 0 nm.
  • the third retardation plate may have an in-plane retardation of about 0 nm to about 10 nm at a wavelength of 550 nm, for example, about 0 nm to about 5 nm.
  • the thickness direction retardation described above can be easily reached.
  • the third retardation plate has about 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, It can be 8, 9 or 10 nm.
  • the third retardation plate may have a thickness of 10 ⁇ m or less, for example, more than 0 ⁇ m and 10 ⁇ m or less. Within the above range, it is possible to implement a thickness direction retardation.
  • the third retardation plate has a thickness of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 ⁇ m. can be
  • the third retardation plate may be formed of a liquid crystal layer.
  • the liquid crystal layer may be formed of a conventional material known to implement the above-described retardation in the thickness direction.
  • the third retardation plate may be formed of a composition including a cellulose ester-based or aromatic-based polymer.
  • the polarizing plate includes a polarizer, a protective film laminated on the upper surface of the polarizer, and a first retardation plate, a second retardation plate, and a third retardation plate sequentially stacked from the polarizer on the lower surface of the polarizer.
  • the lower surface of the second retardation plate for example, is substantially the same as the polarizing plate according to an embodiment of the present invention, except that a third retardation plate is additionally included between the second retardation plate and the adhesive layer (or adhesive layer) .
  • the optical display device of the present invention includes the polarizing plate of the embodiment of the present invention.
  • the optical display device may include an organic light emitting diode (OLED) display device and a liquid crystal display device.
  • OLED organic light emitting diode
  • the organic light emitting diode display device may include an organic light emitting diode panel including a flexible substrate, and the polarizing plate of the present invention laminated on the organic light emitting diode panel.
  • the organic light emitting diode display device may include an organic light emitting diode panel including a non-flexible substrate, and the polarizing plate of the present invention laminated on the organic light emitting diode panel.
  • a polarizer having a light transmittance of 45% was prepared by stretching a polyvinyl alcohol-based film (PS#60, Kuraray, Japan, thickness before stretching: 60 ⁇ m) 6 times in an aqueous solution of iodine at 55°C.
  • HC-TAC film (Toppan, 25FJCHCN-TC, thickness: 32 ⁇ m) was laminated on the upper surface of the prepared polarizer as a protective film.
  • a first retardation plate liquid crystal layer, nematic liquid crystal, constant wavelength dispersibility, DNP company, thickness: 2 ⁇ m
  • a second retardation plate liquid crystal layer having the specifications of Table 1 below , nematic liquid crystal, positive wavelength dispersion, DNP Corporation, thickness: 1 ⁇ m
  • a polarizing plate was manufactured in the same manner as in Example 1, except that the configuration of the first retardation plate and the second retardation plate in Example 1 was changed as shown in Table 1 below.
  • Example 1 the configuration of the first retardation plate and the second retardation plate was changed as shown in Table 2 below, and a third retardation plate (positive C plate, made of a cellulose ester-based composition) was formed on the lower surface of the second retardation plate.
  • a polarizing plate was manufactured in the same manner as in Example 1, except that a protective film, a polarizer, a first retardation plate, a second retardation plate, and a third retardation plate were laminated in the order of additional lamination.
  • Example 1 a polarizing plate was manufactured in the same manner as in Example 1, except that the configuration of the first retardation plate and the second retardation plate was changed as shown in Table 1 below.
  • Re, Rth, and NZ of each of the first retardation plate, the second retardation plate, and the third retardation plate were measured at a wavelength of 550 nm using Axoscan (Axometry).
  • Reflectance (unit: %): The reflectance was calculated using the Extended Jones Matrix calculation method (a calculation method that can know the values from the front and side) assuming complete reflection by parameterizing each layer of the polarizing plate. However, the outermost primary reflection was excluded from the calculation.
  • ⁇ (first retardation plate) the angle formed by the slow axis of the first retardation plate with respect to the transmission axis of the polarizer (unit: °)
  • ⁇ (second retardation plate) the angle formed by the slow axis of the second retardation plate with respect to the transmission axis of the polarizer (unit: °)
  • the polarizing plate of the present invention significantly lowered the reflectance at an incident angle of 60° from the side.
  • the polarizing plate of the comparative example which does not satisfy any one of Equation 1, Equation 2, Equation 3, and Equation 4, had significantly higher reflectance at an incident angle of 60° from the side compared to the Example.

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Abstract

Provided are a polarizing plate and an optical display device comprising same, the polarizing plate comprising: a polarizer; and a first phase retarder and a second phase retarder successively laminated on the bottom surface of the polarizer, wherein the first phase retarder has an in-plane phase retardation (Re) of about 180nm to about 240nm at a wavelength of 550nm, the second phase retarder has an in-plane phase retardation (Re) of about 90nm to about 130nm at a wavelength of 550nm, the first phase retarder and the second phase retarder each have a degree of biaxiality (NZ) of about 0.95 to about 1.05 at a wavelength of 550nm, and the first phase retarder and the second phase retarder satisfy equation 1, equation 2, equation 3, and equation 4.

Description

편광판 및 이를 포함하는 광학표시장치Polarizing plate and optical display including same
본 발명은 편광판 및 이를 포함하는 광학표시장치에 관한 것이다. 보다 상세하게는, 본 발명은 입사각 60°에서 반사율이 현저하게 낮고 박형화 효과를 얻을 수 있는 편광판 및 이를 포함하는 광학표시장치에 관한 것이다.The present invention relates to a polarizing plate and an optical display device including the same. More particularly, the present invention relates to a polarizing plate having a remarkably low reflectance at an incident angle of 60° and achieving a thinning effect, and an optical display device including the same.
유기발광소자 표시장치는 외부광의 반사로 인하여 시인성과 콘트라스트가 떨어질 수 있고, 이를 해소하기 위해 편광자와 위상차 필름을 포함하는 편광판을 사용함으로써 반사된 외부광이 외부로 새어나오지 않게 하게 반사 방지 기능을 구현할 수 있다.The organic light emitting diode display device may have poor visibility and contrast due to reflection of external light. can
일반적으로 편광판은 1매형의 위상차 필름 또는 2매형의 위상차 필름을 구비한다. 1매형의 위상차판 대비 2매형의 위상차판은 반사 방지 기능이 더 우수하여, 2매형의 위상차판이 편광판에 통상 포함된다. 위상차판은 미연신 상태의 고분자 필름을 연신시켜 제조될 수도 있고 또는 액정형 조성물을 코팅 및 건조 또는 경화하여 형성될 수도 있다. 액정형 조성물로 형성된 위상차판은 고분자 필름으로 제조된 위상차판 대비 두께가 얇아 편광판의 두께를 박형화시킬 수 있고 상대적으로 경제적이라는 장점이 있다. 그러나, 액정형 조성물로 형성된 위상차판 특히 파장 550nm에서 이축성 정도가 약 1인 위상차판을 구비하는 편광판은 반사 방지 기능을 낮추는데 한계가 있어 왔다.In general, a polarizing plate is provided with a one-sheet retardation film or a two-sheet retardation film. Compared to the single-sheet retarder, the two-sheet retarder has a better antireflection function, and the two-sheet retarder is usually included in the polarizing plate. The retardation plate may be prepared by stretching a polymer film in an unstretched state, or may be formed by coating and drying or curing a liquid crystal composition. The retardation plate formed of the liquid crystal composition is thinner than the retardation plate made of a polymer film, so the thickness of the polarizing plate can be reduced and it is relatively economical. However, a retardation plate formed of a liquid crystal composition, particularly a polarizing plate having a retardation plate having a degree of biaxiality of about 1 at a wavelength of 550 nm, has a limit in lowering the antireflection function.
본 발명의 배경기술은 한국공개특허 10-2013-0103595호 등에 개시되어 있다.Background art of the present invention is disclosed in Korean Patent Publication No. 10-2013-0103595 and the like.
본 발명의 목적은 입사각 60°에서 반사율이 현저하게 낮은 편광판을 제공하는 것이다.An object of the present invention is to provide a polarizing plate having a remarkably low reflectance at an incident angle of 60°.
본 발명의 다른 목적은 고분자형 위상차 필름 대비 제조 비용이 현저하게 낮아 경제성이 우수하고 두께 박형화 효과가 있는 편광판을 제공하는 것이다.Another object of the present invention is to provide a polarizing plate having a significantly lower manufacturing cost compared to a polymer-type retardation film, which is excellent in economical efficiency, and has a thickness reduction effect.
본 발명의 일 관점은 편광판이다.One aspect of the present invention is a polarizing plate.
편광판은 편광자 및 상기 편광자의 하부면에 순차적으로 적층된 제1위상차판, 제2위상차판을 포함하고, 상기 제1위상차판은 파장 550nm에서 면내 위상차 (Re)가 약 180nm 내지 약 240nm이고, 상기 제2위상차판은 파장 550nm에서 면내 위상차가 약 90nm 내지 약 130nm이고, 상기 제1위상차판, 상기 제2위상차판은 각각 파장 550nm에서 이축성 정도(NZ)가 약 0.95 내지 약 1.05이고, 상기 제1위상차판, 상기 제2위상차판은 식 1, 식 2, 식 3 그리고 식 4를 만족한다:The polarizing plate includes a polarizer and a first retardation plate and a second retardation plate sequentially stacked on a lower surface of the polarizer, wherein the first retardation plate has an in-plane retardation (Re) of about 180 nm to about 240 nm at a wavelength of 550 nm, and the The second retardation plate has an in-plane retardation of about 90 nm to about 130 nm at a wavelength of 550 nm, the first retardation plate and the second retardation plate have a degree of biaxiality (NZ) of about 0.95 to about 1.05 at a wavelength of 550 nm, respectively, and the first The first retarder plate and the second retarder plate satisfy Equation 1, Equation 2, Equation 3 and Equation 4:
[식 1][Equation 1]
Re(제2위상차판) = 약([0.4 x Re(제1위상차판)] + α)Re (second retardation plate) = about ([0.4 x Re (first retardation plate)] + α)
(상기 식 1에서,(In Equation 1 above,
Re(제1위상차판)은 파장 550nm에서 제1위상차판의 면내 위상차(단위:nm)Re (first retardation plate) is the in-plane retardation of the first retardation plate at a wavelength of 550 nm (unit: nm)
Re(제2위상차판)은 파장 550nm에서 제2위상차판의 면내 위상차(단위:nm)Re (second retardation plate) is the in-plane retardation of the second retardation plate at a wavelength of 550 nm (unit: nm)
약 23nm ≤ α ≤ 약 44nm)about 23 nm ≤ α ≤ about 44 nm)
[식 2][Equation 2]
약 140nm ≤ ｜Rth(제1위상차판)｜ + ｜Rth(제2위상차판)｜ ≤ 약 180nmAbout 140 nm ≤ ｜Rth (first retardation plate)｜ + ｜Rth (second retardation plate)｜ ≤ about 180 nm
(상기 식 2에서,(In Equation 2 above,
Rth(제1위상차판)은 파장 550nm에서 제1위상차판의 두께 방향 위상차(단위:nm),Rth (first retarder) is the thickness direction retardation of the first retarder at a wavelength of 550 nm (unit: nm),
Rth(제2위상차판)은 파장 550nm에서 제2위상차판의 두께 방향 위상차(단위:nm)),Rth (second retardation plate) is the thickness direction retardation of the second retardation plate at a wavelength of 550 nm (unit: nm),
[식 3][Equation 3]
약 72° ≤ θ(제1위상차판) ≤ 약 82°About 72° ≤ θ (first phase difference plate) ≤ about 82°
(상기 식 3에서,(In Equation 3 above,
θ(제1위상차판)은 편광자의 투과축에 대한 제1위상차판의 지상축이 이루는 각도(단위: °)),θ (first retardation plate) is the angle formed by the slow axis of the first retardation plate with respect to the transmission axis of the polarizer (unit: °)),
[식 4][Equation 4]
θ(제2위상차판) = 약([2 x θ(제1위상차판)] + 45° + β)θ (second retardation plate) = about ([2 x θ (first retardation plate)] + 45° + β)
(상기 식 4에서,(in Equation 4 above,
θ(제1위상차판)은 편광자의 투과축에 대한 제1위상차판의 지상축(slow axis)이 이루는 각도(단위: °),θ (first retardation plate) is the angle (unit: °) formed by the slow axis of the first retardation plate with respect to the transmission axis of the polarizer;
θ(제2위상차판)은 편광자의 투과축에 대한 제2위상차판의 지상축이 이루는 각도(단위: °),θ (second retardation plate) is the angle (unit: °) formed by the slow axis of the second retardation plate with respect to the transmission axis of the polarizer;
약 2° ≤ β ≤ 약 7°).about 2° ≤ β ≤ about 7°).
2.1에서, 상기 제1위상차판, 상기 제2위상차판은 각각 액정층을 포함할 수 있다.In 2.1, the first retardation plate and the second retardation plate may each include a liquid crystal layer.
3.2에서, 상기 액정층은 네마틱 액정을 포함할 수 있다.In 3.2, the liquid crystal layer may include a nematic liquid crystal.
4.1-3에서, 상기 제1위상차판, 상기 제2위상차판은 각각 파장 550nm에서 이축성 정도(NZ)가 약 0.96 내지 약 1.04일 수 있다.In 4.1-3, the first retardation plate and the second retardation plate may each have a degree of biaxiality (NZ) of about 0.96 to about 1.04 at a wavelength of 550 nm.
5.1-4에서, 상기 식 2에서 Rth(제1위상차판)은 약 50nm 내지 약 150nm일 수 있다.In 5.1-4, Rth (first retardation plate) in Equation 2 may be about 50 nm to about 150 nm.
6.1-5에서, 상기 식 2에서 Rth(제2위상차판)은 약 30nm 내지 약 80nm일 수 있다.In 6.1-5, Rth (second retardation plate) in Equation 2 may be about 30 nm to about 80 nm.
7.1-6에서, 상기 식 4에서 θ(제2위상차판)은 약 10° 내지 약 40°일 수 있다.In 7.1-6, θ (the second retardation plate) in Equation 4 may be about 10° to about 40°.
8.1-7에서, 상기 제1위상차판, 상기 제2위상차판은 각각 정파장 분산성일 수 있다.In 8.1-7, the first retardation plate and the second retardation plate may each have a constant wavelength dispersion property.
9.1-8에서, 상기 제1위상차판과 상기 제2위상차판의 적층체는 파장 550nm에서 면내 위상차가 약 140nm 내지 약 190nm일 수 있다.In 9.1-8, the in-plane retardation of the laminate of the first retardation plate and the second retardation plate may be about 140 nm to about 190 nm at a wavelength of 550 nm.
10.1-9에서, 상기 편광판은 포지티브 C 층을 포함하는 제3위상차판을 추가로 포함할 수 있다.In 10.1-9, the polarizing plate may further include a third retardation plate including a positive C layer.
11.10에서, 상기 제3위상차판은 파장 550nm에서 두께 방향 위상차가 약 -300nm 내지 약 0nm일 수 있다.In 11.10, the third retardation plate may have a thickness direction retardation of about -300 nm to about 0 nm at a wavelength of 550 nm.
12.10에서, 상기 제3위상차판은 상기 제2위상차판의 하부면에 포함될 수 있다.In 12.10, the third retardation plate may be included in a lower surface of the second retardation plate.
13.1-12에서, 상기 편광자의 상부면에 보호층이 더 형성될 수 있다.In 13.1-12, a protective layer may be further formed on the upper surface of the polarizer.
본 발명의 일 관점은 광학표시장치이다.One aspect of the present invention is an optical display device.
광학표시장치는 본 발명의 편광판을 포함한다.The optical display device includes the polarizing plate of the present invention.
본 발명은 입사각 60°에서 반사율이 현저하게 낮은 편광판을 제공하였다.The present invention provides a polarizing plate having a remarkably low reflectance at an incident angle of 60°.
본 발명은 고분자형 위상차 필름 대비 제조 비용이 현저하게 낮아 경제성이 우수하고 두께 박형화 효과가 있는 편광판을 제공하였다.The present invention provides a polarizing plate having excellent economic feasibility and thinning effect due to a significantly lower manufacturing cost compared to a polymer-type retardation film.
도 1은 본 발명 일 실시예의 편광판의 단면도이다.1 is a cross-sectional view of a polarizing plate according to an embodiment of the present invention.
첨부한 도면을 참고하여 본 발명을 실시예에 의해 본 발명이 속하는 기술 분야에서 통상의 지식을 가진 자가 용이하게 실시할 수 있도록 상세히 설명한다. 본 발명은 여러 가지 상이한 형태로 구현될 수 있으며 여기에서 설명하는 실시예에 한정되지 않는다. 도면에서 본 발명을 명확하게 설명하기 위해서 설명과 관계없는 부분은 생략하였으며, 명세서 전체를 통하여 동일 또는 유사한 구성 요소에 대해서는 동일한 명칭을 사용하였다. 도면에서 각 구성 요소의 길이, 크기는 본 발명을 설명하기 위한 것으로 본 발명이 도면에 기재된 각 구성 요소의 길이, 크기에 제한되는 것은 아니다.With reference to the accompanying drawings, the present invention will be described in detail so as to be easily practiced by those of ordinary skill in the art to which the present invention pertains by way of example. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the same names are used for the same or similar components throughout the specification. The length and size of each component in the drawings are for explaining the present invention, and the present invention is not limited to the length and size of each component described in the drawings.
본 명세서에서 "상부"와 "하부"는 도면을 기준으로 정의한 것이고, 보는 시각에 따라 "상부"가 "하부"로 "하부"가 "상부"로 변경될 수 있다.In this specification, "upper" and "lower" are defined based on the drawings, and "upper" may be changed to "lower" and "lower" to "upper" depending on the viewing angle.
본 명세서에서 "면내 위상차(Re)"는 하기 식 A로 표시되고, "두께 방향 위상차(Rth)"는 하기 식 B로 표시되고, "이축성 정도(NZ)"는 하기 식 C로 표시될 수 있다:In the present specification, the "in-plane retardation (Re)" is represented by the following formula A, the "thickness direction retardation (Rth)" is represented by the following formula B, and the "biaxiality (NZ)" can be represented by the following formula C have:
[식 A][Formula A]
Re = (nx - ny) x dRe = (nx - ny) x d
[식 B][Formula B]
Rth = ((nx + ny)/2 - nz) x dRth = ((nx + ny)/2 - nz) x d
[식 C][Formula C]
NZ = (nx - nz)/(nx - ny)NZ = (nx - nz)/(nx - ny)
(상기 식 A 내지 식 C에서, nx, ny, nz는 측정 파장에서 각각 광학 소자의 지상축(slow axis) 방향, 진상축(fast axis) 방향, 두께 방향의 굴절률이고, d는 광학 소자의 두께(단위:nm)이다). 상기 식 A 내지 식 C에서 측정 파장은 450nm, 550nm 또는 650nm가 될 수 있다.(In Equations A to C, nx, ny, and nz are refractive indices in the slow axis direction, fast axis direction, and thickness direction of the optical element, respectively, at the measurement wavelength, and d is the thickness of the optical element. (unit: nm)). In Formulas A to C, the measurement wavelength may be 450 nm, 550 nm, or 650 nm.
본 명세서에서 "단파장 분산성"은 Re(450)/Re(550)이고, "장파장 분산성"은 Re(650)/Re(550)이다. Re(450), Re(550), Re(650)은 각각 광학소자 단독 또는 광학소자 적층체의 파장 450nm, 550nm 및 650nm에서의 면내 위상차(Re)를 의미한다.In the present specification, "short wavelength dispersion" is Re(450)/Re(550), and "long wavelength dispersion" is Re(650)/Re(550). Re (450), Re (550), and Re (650) mean in-plane retardation (Re) at wavelengths of 450 nm, 550 nm, and 650 nm of an optical element alone or an optical element stack, respectively.
본 명세서에서 수치 범위를 나타낼 때 "X 내지 Y"는 X 이상 Y 이하(X ≤ 그리고 ≤ Y)를 의미한다.In the present specification, "X to Y" when referring to a numerical range means X or more and Y or less (X ≤ and ≤ Y).
본 발명의 편광판은 액정형 조성물로 형성된 위상차판을 구비함으로써 고분자형 위상차 필름 대비 제조 비용이 현저하게 낮아 경제성이 우수하고 두께 박형화 효과가 현저하며, 입사각 60°에서 반사율이 현저하게 낮아서 화면 품질이 현저하게 우수하였다. 이에, 본 발명의 편광판은 유기발광소자(OLED) 표시장치 등을 포함하는 발광소자 표시장치에 있어서 반사 방지용 편광판으로 사용될 수 있다.Since the polarizing plate of the present invention has a retardation plate formed of a liquid crystal composition, the manufacturing cost is significantly lower than that of the polymer-type retardation film, so it is excellent in economic feasibility and has a remarkable thickness reduction effect, and the reflectance is remarkably low at an incident angle of 60°, so that the screen quality is remarkable was excellent. Accordingly, the polarizing plate of the present invention may be used as an anti-reflection polarizing plate in a light emitting device display including an organic light emitting diode (OLED) display device.
일 구체예에서, 편광판은 광학표시장치에 적용시 입사각 60°에서 SCE(Specular Component Excluded) 반사율이 약 6.0% 이하, 예를 들면 약 0% 이상 약 6.0% 이하가 될 수 있다. 상기 범위에서, 화면 품질을 개선할 수 있다. 예를 들면 약 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 또는 6%일 수 있다.In one embodiment, the polarizing plate may have a specular component excluded (SCE) reflectance of about 6.0% or less at an incident angle of 60° when applied to an optical display device, for example, about 0% or more and about 6.0% or less. Within the above range, the screen quality can be improved. for example about 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 or 6%.
이하, 본 발명 일 실시예의 편광판을 도 1을 참고하여 설명한다.Hereinafter, a polarizing plate according to an embodiment of the present invention will be described with reference to FIG. 1 .
도 1을 참고하면, 편광판은 편광자(110), 편광자(110)의 상부면에 적층된 보호 필름(140) 및 편광자(110)의 하부면에 편광자(110)로부터 순차적으로 적층된 제1위상차판(120)과 제2위상차판(130)을 포함한다. 보호 필름(140)은 보호 코팅층 등을 포함하는 보호층의 일 구체예에 해당된다.Referring to FIG. 1 , the polarizing plate is a polarizer 110 , a protective film 140 stacked on the upper surface of the polarizer 110 , and a first retardation plate sequentially stacked from the polarizer 110 on the lower surface of the polarizer 110 . 120 and the second phase difference plate 130 . The protective film 140 corresponds to a specific example of a protective layer including a protective coating layer and the like.
제1위상차판과 제2위상차판1st phase difference plate and 2nd phase difference plate
제1위상차판(120), 제2위상차판(130)은 각각 액정층을 포함할 수 있다.The first retardation plate 120 and the second retardation plate 130 may each include a liquid crystal layer.
액정층은 고분자형 위상차 필름 대비 두께가 상대적으로 작아 편광판의 두께 박형화 효과를 높일 수 있다. 또한, 액정층은 위상차 구현을 위해 연신 과정을 수반하는 고분자형 위상차 필름 대비 코팅 및/또는 건조에 의해 제조되므로 간단한 제조 공정으로 제조되어 제조 공정성이 우수하다.The liquid crystal layer has a relatively small thickness compared to the polymer type retardation film, so that the thickness reduction effect of the polarizing plate can be increased. In addition, since the liquid crystal layer is manufactured by coating and/or drying compared to a polymer-type retardation film that involves a stretching process for realizing the retardation, it is manufactured by a simple manufacturing process and thus has excellent manufacturing processability.
일 구체예에서, 제1위상차판(120), 제2위상차판(130) 각각의 두께는 동일하거나 다를 수 있다. 예를 들면 제1위상차판(120), 제2위상차판(130) 각각의 두께는 약 10㎛ 이하, 예를 들면 약 0㎛ 내지 약 10㎛, 약 1㎛ 내지 약 5㎛가 될 수 있다. 상기 범위에서, 하기 상술되는 위상차 구현에 용이하고 편광판의 두께를 박형화하는데 도움이 될 수 있다. 액정층에 대해서는 하기에서 보다 상술된다. 예를 들면 제1위상차판(120), 제2위상차판(130) 각각의 두께는 약 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 또는 10㎛ 일 수 있다.In one embodiment, the thickness of each of the first retardation plate 120 and the second retardation plate 130 may be the same or different. For example, the thickness of each of the first retardation plate 120 and the second retardation plate 130 may be about 10 μm or less, for example, about 0 μm to about 10 μm, and about 1 μm to about 5 μm. In the above range, it is easy to implement the retardation described in detail below and may help to reduce the thickness of the polarizing plate. The liquid crystal layer will be described in more detail below. For example, the thickness of each of the first retardation plate 120 and the second retardation plate 130 is about 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4 , 5, 6, 7, 8, 9 or 10 μm.
제1위상차판(120), 제2위상차판(130)은 각각 파장 550nm에서 이축성 정도(NZ)가 약 0.95 내지 약 1.05이다. 본 발명에서는 편광판 중 위상차판으로서 액정층을 사용하되 상술 이축성 정도를 갖는 위상차판, 즉 봉상형 네마틱 액정층을 사용한다. 봉상형 네마틱 액정은 Order Parameter가 높아 낮은 Anchoring 에너지에서도 배열이 잘되기 때문에 광학 특성의 편차가 없고 다른 액정에 비해 가격이 저렴하고 대량으로 확보할 수 있기 때문에 대량 생산에 용이할 수 있다.The first retardation plate 120 and the second retardation plate 130 each have a degree of biaxiality (NZ) of about 0.95 to about 1.05 at a wavelength of 550 nm. In the present invention, a liquid crystal layer is used as a retardation plate among polarizing plates, but a retardation plate having the above-described degree of biaxiality, that is, a rod-shaped nematic liquid crystal layer is used. Because the rod-shaped nematic liquid crystal has a high order parameter and is well arranged even at low anchoring energy, there is no deviation in optical properties, and it is cheaper than other liquid crystals and can be obtained in large quantities, so it can be easily mass-produced.
제1위상차판(120), 제2위상차판(130)의 파장 550nm에서 이축성 정도는 동일하거나 다를 수 있으며, 바람직하게는 약 0.96 내지 약 1.04, 더 바람직하게는 약 0.97 내지 약 1.03, 가장 바람직하게는 약 1이 될 수 있다. 일 구체예에서, 제1위상차판(120), 제2위상차판(130)의 파장 550nm에서 이축성 정도는 실질적으로 동일할 수 있다. 상기 "실질적으로 동일"은 이축성 정도의 차이가 약 0 내지 약 0.05인 것을 의미한다. 예를 들면 제1위상차판(120), 제2위상차판(130)은 각각 파장 550nm에서 이축성 정도(NZ)가 약 0.95, 0.96, 0.97, 0.98, 0.99, 1, 1.01, 1.02, 1.03, 1.04 또는 1.05 일 수 있다.The degree of biaxiality at a wavelength of 550 nm of the first retardation plate 120 and the second retardation plate 130 may be the same or different, preferably about 0.96 to about 1.04, more preferably about 0.97 to about 1.03, most preferably It can be about 1. In one embodiment, the degree of biaxiality at a wavelength of 550 nm of the first retardation plate 120 and the second retardation plate 130 may be substantially the same. "Substantially the same" means that the difference in the degree of biaxiality is from about 0 to about 0.05. For example, the first retardation plate 120 and the second retardation plate 130 each have a degree of biaxiality (NZ) of about 0.95, 0.96, 0.97, 0.98, 0.99, 1, 1.01, 1.02, 1.03, 1.04 at a wavelength of 550 nm. or 1.05.
제1위상차판(120)은 파장 550nm에서 면내 위상차(Re)가 약 180nm 내지 약 240nm이고, 제2위상차판(130)은 파장 550nm에서 면내 위상차가 약 90nm 내지 약 130nm이다. 상기 범위에서, 제1위상차판과 제2위상차판이 편광자로부터 입사되는 광에 작용하여 반사율을 낮추는데 도움을 수 있다. 예를 들면, 파장 550nm에서 면내 위상차가 제1위상차판은 약 190nm 내지 약 240nm, 제2위상차판은 약 95nm 내지 약 130nm, 약 115nm 내지 약 130nm가 될 수 있다.The first retardation plate 120 has an in-plane retardation of about 180 nm to about 240 nm at a wavelength of 550 nm, and the second retardation plate 130 has an in-plane retardation of about 90 nm to about 130 nm at a wavelength of 550 nm. In the above range, the first retardation plate and the second retardation plate act on the light incident from the polarizer to help lower the reflectance. For example, the in-plane retardation at a wavelength of 550 nm may be about 190 nm to about 240 nm for the first retardation plate, about 95 nm to about 130 nm for the second retardation plate, and about 115 nm to about 130 nm.
예를 들면 제1위상차판(120)은 파장 550nm에서 면내 위상차(Re)가 약 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239 또는 240nm일 수 있다.For example, the first retardation plate 120 has an in-plane retardation Re of about 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194 at a wavelength of 550 nm. , 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219 , 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239 or 240 nm.
예를 들면 제2위상차판(130)은 파장 550nm에서 면내 위상차(Re)가 약 90, 91, 92, 93, 94, 95, 97, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129 또는 130nm일 수 있다.For example, the second retardation plate 130 has an in-plane retardation Re of about 90, 91, 92, 93, 94, 95, 97, 97, 98, 99, 100, 101, 102, 103, 104 at a wavelength of 550 nm. , 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129 or 130 nm.
본 발명에서는 상술 이축성 정도 및 면내 위상차를 각각 갖는 제1위상차판과 제2위상차판을 구비하되, 하기 식 1, 식 2, 식 3 그리고 식 4를 동시에 만족시킨다. 그 결과, 편광판 사용시 입사각 60°에서 반사율을 현저하게 낮추어 화면 품질을 현저하게 높일 수 있다:In the present invention, a first retardation plate and a second retardation plate each having the above-described degree of biaxiality and in-plane retardation are provided, and the following Equations 1, 2, 3 and 4 are simultaneously satisfied. As a result, when a polarizing plate is used, the reflectance can be significantly lowered at an incident angle of 60°, thereby significantly improving the screen quality:
[식 1][Equation 1]
Re(제2위상차판) = 약([0.4 x Re(제1위상차판)] + α)Re (second retardation plate) = about ([0.4 x Re (first retardation plate)] + α)
(상기 식 1에서, (In Equation 1 above,
Re(제1위상차판)은 파장 550nm에서 제1위상차판의 면내 위상차(단위:nm)Re (first retardation plate) is the in-plane retardation of the first retardation plate at a wavelength of 550 nm (unit: nm)
Re(제2위상차판)은 파장 550nm에서 제2위상차판의 면내 위상차(단위:nm)Re (second retardation plate) is the in-plane retardation of the second retardation plate at a wavelength of 550 nm (unit: nm)
약 23nm ≤ α ≤ 약 44nm)about 23 nm ≤ α ≤ about 44 nm)
[식 2][Equation 2]
약 140nm ≤ ｜Rth(제1위상차판)｜ + ｜Rth(제2위상차판)｜ ≤ 약 180nmAbout 140 nm ≤ ｜Rth (first retardation plate)｜ + ｜Rth (second retardation plate)｜ ≤ about 180 nm
(상기 식 2에서,(In Equation 2 above,
Rth(제1위상차판)은 파장 550nm에서 제1위상차판의 두께 방향 위상차(단위:nm),Rth (first retarder) is the thickness direction retardation of the first retarder at a wavelength of 550 nm (unit: nm),
Rth(제2위상차판)은 파장 550nm에서 제2위상차판의 두께 방향 위상차(단위:nm)),Rth (second retardation plate) is the thickness direction retardation of the second retardation plate at a wavelength of 550 nm (unit: nm),
[식 3][Equation 3]
약 72° ≤ θ(제1위상차판) ≤ 약 82°About 72° ≤ θ (first phase difference plate) ≤ about 82°
(상기 식 3에서,(In Equation 3 above,
θ(제1위상차판)은 편광자의 투과축에 대한 제1위상차판의 지상축(slow axis)이 이루는 각도(단위: °)),θ (the first retardation plate) is the angle (unit: °) formed by the slow axis of the first retardation plate with respect to the transmission axis of the polarizer;
[식 4][Equation 4]
θ(제2위상차판) = 약([2 x θ(제1위상차판)] + 45° + β)θ (second retardation plate) = about ([2 x θ (first retardation plate)] + 45° + β)
(상기 식 4에서,(in Equation 4 above,
θ(제1위상차판)은 편광자의 투과축에 대한 제1위상차판의 지상축이 이루는 각도(단위: °),θ (first retardation plate) is the angle (unit: °) formed by the slow axis of the first retardation plate with respect to the transmission axis of the polarizer;
θ(제2위상차판)은 편광자의 투과축에 대한 제2위상차판의 지상축이 이루는 각도(단위: °),θ (second retardation plate) is the angle (unit: °) formed by the slow axis of the second retardation plate with respect to the transmission axis of the polarizer;
약 2° ≤ β ≤ 약 7°).about 2° ≤ β ≤ about 7°).
상기 식 1, 식 2, 식 3, 식 4 중 어느 하나라도 만족하지 않는 편광판은 본 발명의 효과를 구현할 수 없어, 입사각 60°에서 현저한 반사율 저감 효과를 얻을 수 없다.A polarizing plate that does not satisfy any one of Equation 1, Equation 2, Equation 3, and Equation 4 cannot implement the effect of the present invention, and thus cannot obtain a significant reflectance reduction effect at an incident angle of 60°.
상기 식 1은 제1위상차판의 Re와 제2위상차판의 Re 간의 관계식이다. 제1위상차판, 제2위상차판이 각각 상술한 Re 값을 갖더라도 상기 식 1을 만족하지 못한다면 본 발명의 효과를 제대로 얻을 수 없음을 의미한다. 바람직하게는, 상기 식 1에서 약 23nm ≤ α ≤ 약 35nm일 수 있다. 예를 들면 상기 식 1에서 상기 α는, 약 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43 또는 44nm일 수 있다.Equation 1 is a relational expression between Re of the first retarder and Re of the second retarder. Even if the first retardation plate and the second retardation plate each have the above-described Re values, if Equation 1 is not satisfied, it means that the effects of the present invention cannot be properly obtained. Preferably, in Equation 1, about 23 nm ≤ α ≤ about 35 nm. For example, in Formula 1, α is about 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43 or 44 nm.
상기 식 2는 제1위상차판의 두께 방향 위상차 Rth와 제2위상차판의 두께 방향 위상차 Rth 간의 관계식이다. 제1위상차판과 제2위상차판이 상기 식 2를 만족할 때 본 발명의 효과를 얻을 수 있다. 바람직하게는, 상기 식 2에서 ｜Rth(제1위상차판)｜ + ｜Rth(제2위상차판)｜은 약 145nm 내지 약 170nm, 더 바람직하게는 약 150nm 내지 약 160nm가 될 수 있다.Equation 2 is a relational expression between the retardation in the thickness direction Rth of the first retarder and the retardation in the thickness direction Rth of the second retarder. When the first retardation plate and the second retardation plate satisfy Equation 2 above, the effect of the present invention can be obtained. Preferably, in Equation 2, |Rth (first retardation plate)| + |Rth (second retardation plate)| may be about 145 nm to about 170 nm, more preferably about 150 nm to about 160 nm.
예를 들면 상기 식 2에서 ｜Rth(제1위상차판)｜ + ｜Rth(제2위상차판)｜은 약 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179 또는 180nm일 수 있다.For example, in Equation 2, |Rth (first phase difference plate) | + |Rth (second phase difference plate) | is about 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179 or 180 nm.
일 구체예에서, 상기 식 2에서 Rth(제1위상차판)는 양(+)의 값이며, 약 50nm 내지 약 150nm, 구체적으로 약 80nm 내지 약 120nm가 될 수 있다. 상기 범위에서, 상기 식 2에 용이하게 도달될 수 있고, 본 발명의 효과 구현에 용이할 수 있다. 예를 들면 상기 식 2에서 Rth(제1위상차판)는 약 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 97, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149 또는 150nm 일 수 있다.In one embodiment, Rth (first retardation plate) in Equation 2 is a positive value, and may be from about 50 nm to about 150 nm, specifically from about 80 nm to about 120 nm. In the above range, Equation 2 may be easily reached, and it may be easy to implement the effect of the present invention. For example, in Equation 2, Rth (first retardation plate) is about 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 97, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149 or 150 nm.
일 구체예에서, 상기 식 2에서 Rth(제2위상차판)는 양(+)의 값이며, 약 30nm 내지 약 80nm, 구체적으로 약 50nm 내지 약 60nm가 될 수 있다. 상기 범위에서, 상기 식 2에 용이하게 도달될 수 있고, 본 발명의 효과 구현에 용이할 수 있다. 예를 들면 상기 식 2에서 Rth(제2위상차판)는 약 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 또는 80nm 일 수 있다.In one embodiment, Rth (second retardation plate) in Equation 2 is a positive value, and may be about 30 nm to about 80 nm, specifically about 50 nm to about 60 nm. In the above range, Equation 2 may be easily reached, and it may be easy to implement the effect of the present invention. For example, in Equation 2, Rth (second retardation plate) is about 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 or 80 nm.
상기 식 3은 편광자(110)의 투과축에 대한 제1위상차판(120)의 지상축이 이루는 각도이다. 식 3을 만족함으로써 본 발명의 효과에 도달하는데 용이할 수 있다. 일반적으로, 편광자의 투과축은 편광자의 TD(transverse direction)가 될 수 있다. 예를 들면 상기 식 3에서 상기 θ(제1위상차판)는, 약 72, 73, 74, 75, 76, 77, 78, 79, 80, 81 또는 82°일 수 있다.Equation 3 is an angle formed by the slow axis of the first retardation plate 120 with respect to the transmission axis of the polarizer 110 . By satisfying Equation 3, it may be easy to reach the effect of the present invention. In general, the transmission axis of the polarizer may be a TD (transverse direction) of the polarizer. For example, in Equation 3, θ (the first retardation plate) may be about 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, or 82°.
상기 식 4는 편광자(110)의 투과축에 대한 제1위상차판(120)의 지상축 간의 각도와, 편광자(110)의 투과축에 대한 제2위상차판(130)의 지상축 간의 각도 사이의 관계식이다. 제1위상차판과 제2위상차판이 상기 식 4를 만족하도록 배치될 때, 본 발명의 효과에 도달하는데 용이할 수 있다.Equation 4 is the angle between the slow axis of the first retardation plate 120 with respect to the transmission axis of the polarizer 110 and the angle between the slow axis of the second retardation plate 130 with respect to the transmission axis of the polarizer 110 is a relational expression. When the first retardation plate and the second retardation plate are arranged to satisfy Equation 4 above, it may be easy to achieve the effect of the present invention.
상기 식 4에서 θ(제2위상차판) 각도 계산시 계산값이 180° 이상이면 계산값에서 180°를 차감하여 계산된다. 예를 들어, θ(제1위상차판)이 82°일 때 β가 7°이면 계산값은 216°가 되며, 180°를 차감하여 θ(제2위상차판)은 36°로 계산된다. 즉, θ(제2위상차판) = 약([2 x θ(제1위상차판)] + 45° + β - 180°)로 계산될 수 있다.In Equation 4, if the calculated value is 180° or more when calculating the θ (second phase difference plate) angle, it is calculated by subtracting 180° from the calculated value. For example, when θ (first retardation plate) is 82° and β is 7°, the calculated value becomes 216°, and θ (second retardation plate) is calculated as 36° by subtracting 180°. That is, it can be calculated as θ (second retardation plate) = about ([2 x θ (first retardation plate)] + 45° + β - 180°).
예를 들면 상기 β 는 약 2, 3, 4, 5, 6 또는 7°일 수 있다.For example, β may be about 2, 3, 4, 5, 6 or 7°.
바람직하게는, 상기 식 4에서 θ(제2위상차판)은 약 10° 내지 약 40°, 더 바람직하게는 약 15° 내지 약 35°가 될 수 있다. 상기 범위에서, 편광판에 의한 반사율을 낮출 수 있다. 예를 들면 식 4에서 θ(제2위상차판)은 약 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 또는 40°가 될 수 있다.Preferably, in Equation 4, θ (the second retardation plate) may be about 10° to about 40°, more preferably about 15° to about 35°. In the above range, it is possible to lower the reflectance by the polarizing plate. For example, in Equation 4, θ (the second phase difference plate) is about 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 , 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40°.
제1위상차판(120)과 제2위상차판(130) 각각은 정파장 분산성이지만 전체는 역파장 분산성이 될 수 있다. 이를 통해, 편광판은 측면에서의 반사율을 낮출 수 있다. 상기 "정파장 분산성", "역파장 분산성"은 당업자에게 알려진 바와 같이 단파장 분산성, 장파장 분산성에 의해 결정될 수 있다.Each of the first retardation plate 120 and the second retardation plate 130 may have forward wavelength dispersion, but the entirety may have reverse wavelength dispersion. Through this, the polarizing plate may lower the reflectance at the side. The "forward wavelength dispersion" and "reverse wavelength dispersion" may be determined by short wavelength dispersion and long wavelength dispersion, as known to those skilled in the art.
제1위상차판(120), 제2위상차판(130)은 각각 액정층을 포함할 수 있다. 액정층은 상술한 이축성 정도, 면내 위상차 및 두께 방향 위상차를 갖도록 한다면 액정층을 구성하는 물질에 특별한 제한을 두지 않는다. 액정층은 액정 폴리머, 중합성 액정 화합물 중 1종 이상을 포함하는 조성물로 형성될 수 있다.The first retardation plate 120 and the second retardation plate 130 may each include a liquid crystal layer. As long as the liquid crystal layer has the above-described degree of biaxiality, in-plane retardation, and thickness direction retardation, there is no particular limitation on the material constituting the liquid crystal layer. The liquid crystal layer may be formed of a composition including at least one of a liquid crystal polymer and a polymerizable liquid crystal compound.
액정층은 네마틱형, 디스코틱형 등이 될 수 있고, 바람직하게는 네마틱형이 될 수 있다. 일 구체예에서, 제1위상차판은 네마틱형 액정층을 포함하고, 제2위상차판은 네마틱형 액정층을 포함할 수 있다.The liquid crystal layer may be of a nematic type, a discotic type, or the like, and preferably a nematic type. In one embodiment, the first retardation plate may include a nematic liquid crystal layer, and the second retardation plate may include a nematic liquid crystal layer.
제1위상차판(120)과 제2위상차판(130)의 적층체는 파장 550nm에서 면내 위상차가 약 140nm 내지 약 190nm, 바람직하게는 약 150nm 내지 약 170nm가 될수 있다. 상기 범위에서, 반사율을 낮출 수 있다. 예를 들면 제1위상차판(120)과 제2위상차판(130)의 적층체는 파장 550nm에서 면내 위상차가 약140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189 또는 190nm 일 수 있다.In the laminate of the first retardation plate 120 and the second retardation plate 130 , the in-plane retardation at a wavelength of 550 nm may be about 140 nm to about 190 nm, preferably about 150 nm to about 170 nm. In the above range, it is possible to lower the reflectance. For example, in the laminate of the first retardation plate 120 and the second retardation plate 130, the in-plane retardation at a wavelength of 550 nm is about 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150 , 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175 , 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189 or 190 nm.
일 구체예에서, 제1위상차판(120)은 제2위상차판(130)에 직접적으로 형성될 수 있다. 상기 "직접적으로 형성"은 제1위상차판(120)과 제2위상차판(130) 사이에 임의의 점착층, 접착층이 포함되지 않음을 의미한다.In one embodiment, the first retardation plate 120 may be directly formed on the second retardation plate 130 . The "directly formed" means that any adhesive layer or adhesive layer is not included between the first retardation plate 120 and the second retardation plate 130 .
다른 구체예에서, 제1위상차판(120)은 점착제(예: 감압 점착제(PSA))에 의해 제2위상차판(130)에 적층될 수도 있다.In another embodiment, the first retardation plate 120 may be laminated on the second retardation plate 130 by an adhesive (eg, pressure-sensitive adhesive (PSA)).
도 1에서 도시되지 않았지만, 제1위상차판(120)은 제1접착층에 의해 편광자(110)에 접착될 수 있다. 제1접착층은 예를 들면 수계 접착제, 광경화형 접착제 중 1종 이상으로 형성될 수 있다. 바람직하게는, 제1접착층은 광경화형 접착제로 형성됨으로써, 보호 필름과 편광자 간의 접착, 편광자와 제1위상차판 간의 접착을 1회의 광 조사에 의해 달성할 수 있어, 편광판의 제조 공정성을 개선할 수 있다. 제1접착층은 두께가 약 0.1㎛ 내지 약 10㎛, 구체적으로 약 0.5㎛ 내지 약 5㎛가 될 수 있다. 상기 범위에서, 편광판에 사용될 수 있다. 예를 들면 제1접착층은 두께가 약 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 또는 10㎛가 될 수 있다.Although not shown in FIG. 1 , the first retardation plate 120 may be adhered to the polarizer 110 by a first adhesive layer. The first adhesive layer may be formed of, for example, at least one of a water-based adhesive and a photocurable adhesive. Preferably, since the first adhesive layer is formed of a photocurable adhesive, adhesion between the protective film and the polarizer and adhesion between the polarizer and the first retardation plate can be achieved by one light irradiation, so that the manufacturing processability of the polarizing plate can be improved. have. The first adhesive layer may have a thickness of about 0.1 μm to about 10 μm, specifically, about 0.5 μm to about 5 μm. Within the above range, it can be used for a polarizing plate. For example, the first adhesive layer may have a thickness of about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 μm. can
도 1에서 도시되지 않았지만, 제2위상차판(130)의 하부면에는 점착층 또는 접착층이 형성되어, 편광판을 점착층(예: 감압 점착층(Pressure sensitive adhesive)) 또는 접착층을 매개로 발광표시장치용 패널 상에 적층시킬 수 있다.Although not shown in FIG. 1 , an adhesive layer or an adhesive layer is formed on the lower surface of the second retardation plate 130 , and the polarizing plate is applied to the light emitting display device through an adhesive layer (eg, a pressure sensitive adhesive) or an adhesive layer. It can be laminated on the panel for use.
편광자polarizer
편광자(110)는 입사된 자연광 또는 편광을 중 특정 방향의 직선 편광으로 변환시키는 것으로, 폴리비닐알코올계 수지를 주성분으로 하는 고분자 필름으로부터 제조될 수 있다. 구체적으로, 편광자(110)는 상기 고분자 필름을 요오드나 이색성 염료를 염색시키고, 이를 MD(machine direction)로 연신시켜 제조될 수 있다. 구체적으로, 팽윤 과정, 염색 단계, 연신 단계, 가교 단계를 거쳐 제조될 수 있다.The polarizer 110 converts incident natural light or polarized light into linearly polarized light in a specific direction, and may be manufactured from a polymer film containing polyvinyl alcohol-based resin as a main component. Specifically, the polarizer 110 may be manufactured by dyeing the polymer film with iodine or a dichroic dye and stretching it in the machine direction (MD). Specifically, it may be prepared through a swelling process, a dyeing step, an stretching step, and a crosslinking step.
편광자(110)는 전광선 투과율이 약 40% 이상, 예를 들면 약 40% 내지 약 47%, 편광도가 약 99% 이상, 예를 들면 약 99% 내지 약 100%가 될 수 있다. 상기 범위에서, 제1위상차판, 제2위상차판과 조합시 반사 방지 성능을 높일 수 있다. 예를 들면 편광자(110)는 전광선 투과율이 약 40, 41, 42, 43, 44, 45, 46 또는 47% 이며, 편광도가 약 99, 99.1, 99.2, 99.3, 99.4, 99.5, 99.6, 99.7, 99.8, 99.9 또는 100%가 될 수 있다.The polarizer 110 may have a total light transmittance of about 40% or more, for example, about 40% to about 47%, and a polarization degree of about 99% or more, for example, about 99% to about 100%. Within the above range, anti-reflection performance may be improved when combined with the first retardation plate and the second retardation plate. For example, the polarizer 110 has a total light transmittance of about 40, 41, 42, 43, 44, 45, 46, or 47%, and a polarization degree of about 99, 99.1, 99.2, 99.3, 99.4, 99.5, 99.6, 99.7, 99.8 , 99.9 or 100%.
편광자(110)는 두께가 약 2㎛ 내지 약 30㎛, 구체적으로 약 4㎛ 내지 약 25㎛가 될 수 있고, 상기 범위에서 편광판에 사용될 수 있다. 예를 들면 편광자(110)는 두께가 약 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 또는 30㎛가 될 수 있다.The polarizer 110 may have a thickness of about 2 μm to about 30 μm, specifically, about 4 μm to about 25 μm, and may be used in a polarizing plate within the above range. For example, the polarizer 110 has a thickness of about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29 or 30 μm.
보호 필름protective film
보호 필름(140)은 편광자(110)의 상부면에 형성됨으로써, 편광자를 외부 환경으로부터 보호하고, 편광판의 기계적 강도를 높이는 효과가 더 있을 수 있다. The protective film 140 may be formed on the upper surface of the polarizer 110 , thereby protecting the polarizer from the external environment and increasing the mechanical strength of the polarizer.
보호 필름(140)은 편광자(110)를 외부 환경으로부터 보호하는데, 광학적 투명 필름으로서, 예를 들면 트리아세틸셀룰로스(TAC) 등을 포함하는 셀룰로오스계, 폴리에틸렌테레프탈레이트, 폴리부틸렌테레프탈레이트, 폴리에틸렌나프탈레이트(PET), 폴리부틸렌나프탈레이트 등을 포함하는 폴리에스테르계, 고리형 폴리올레핀계, 폴리카보네이트계, 폴리에테르술폰계, 폴리술폰계, 폴리아미드계, 폴리이미드계, 폴리올레핀계, 폴리아릴레이트계, 폴리비닐알코올계, 폴리염화비닐계, 폴리염화비닐리덴계 중 하나 이상의 수지로 된 필름이 될 수 있다. 구체적으로, TAC, PET 필름을 사용할 수 있다.The protective film 140 protects the polarizer 110 from the external environment. As an optically transparent film, for example, cellulose-based, polyethylene terephthalate, polybutylene terephthalate, polyethylene or Polyester type, cyclic polyolefin type, polycarbonate type, polyethersulfone type, polysulfone type, polyamide type, polyimide type, polyolefin type, polyarylate type, including phthalate (PET) and polybutylene naphthalate type, The film may be made of one or more of polyvinyl alcohol-based, polyvinyl chloride-based, and polyvinylidene chloride-based resins. Specifically, TAC or PET film may be used.
보호 필름(140)은 두께가 약 5㎛ 내지 약 70㎛, 구체적으로 약 15㎛ 내지 약 45㎛가 될 수 있고, 상기 범위에서 편광판에 사용할 수 있다. 예를 들면 보호필름(140)은 두께가 약 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69 또는 70nm일 수 있다.The protective film 140 may have a thickness of about 5 μm to about 70 μm, specifically, about 15 μm to about 45 μm, and may be used for a polarizing plate within the above range. For example, the protective film 140 has a thickness of about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69 or 70 nm.
도 1에서 도시되지 않았지만, 보호 필름(140)의 상부면에는 기능성 코팅층이 형성되어 편광판에 추가 기능을 제공할 수 있는데, 예를 들면 기능성 코팅층은 하드코팅층, 내지문성층, 반사방지층, 안티글레어층 등이 될 수 있고, 이들은 단독 또는 2종 이상으로 적층되어 형성될 수 있다.Although not shown in FIG. 1 , a functional coating layer is formed on the upper surface of the protective film 140 to provide an additional function to the polarizing plate. and the like, and these may be formed alone or by stacking two or more types.
도 1에서 도시되지 않았지만, 보호 필름(140)은 편광자(110)에 제2접착층을 통해 접착될 수 있다. 제2접착층은 수계 접착제, 광경화형 접착제 중 1종 이상으로 형성될 수 있다. 바람직하게는, 제2접착층은 광경화형 접착제로 형성됨으로써, 보호필름과 편광자 간의 접착, 편광자와 제1위상차층판 간의 접착을 1회의 광 조사에 의해 달성할 수 있어, 편광판의 제조 공정성을 개선할 수 있다.Although not shown in FIG. 1 , the protective film 140 may be adhered to the polarizer 110 through a second adhesive layer. The second adhesive layer may be formed of at least one of a water-based adhesive and a photocurable adhesive. Preferably, the second adhesive layer is formed of a photocurable adhesive, so that the adhesion between the protective film and the polarizer and the adhesion between the polarizer and the first retardation layer plate can be achieved by one light irradiation, so that the manufacturing processability of the polarizing plate can be improved. have.
일 구체예에서, 광경화형 접착제는 상술한 제1접착층을 형성하는 접착제 조성물로 형성될 수 있다. 일 구체예에서, 광개시제는 파장 약 300nm 내지 약 400nm의 광에 대해 흡수 작용을 가지며 이를 통해 반응을 개시하는 광개시제를 포함할 수 있다. 광개시제는 광 라디칼 개시제, 광 양이온 개시제 중 1종 이상을 포함할 수 있다. 제2접착층은 두께가 약 0.1㎛ 내지 약 10㎛, 구체적으로 약 0.5㎛ 내지 약 5㎛가 될 수 있다. 상기 범위에서, 편광판에 사용될 수 있다. 예를 들면 상기 제2접착층은 두께가 약 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 또는 10㎛가 될 수 있다.In one embodiment, the photocurable adhesive may be formed of the adhesive composition for forming the above-described first adhesive layer. In one embodiment, the photoinitiator may include a photoinitiator that has an absorption action for light having a wavelength of about 300 nm to about 400 nm and initiates a reaction therethrough. The photoinitiator may include at least one of a photoradical initiator and a photocationic initiator. The second adhesive layer may have a thickness of about 0.1 μm to about 10 μm, specifically, about 0.5 μm to about 5 μm. Within the above range, it can be used for a polarizing plate. For example, the second adhesive layer has a thickness of about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 μm. can be
이하, 본 발명 다른 실시예의 편광판을 설명한다.Hereinafter, a polarizing plate of another embodiment of the present invention will be described.
본 실시예의 편광판은 제3위상차판을 추가로 포함할 수 있다.The polarizing plate of this embodiment may further include a third retardation plate.
제3위상차판은 nz>nx≒ny(nx, ny, nz는 각각 파장 550nm에서 제3위상차판의 지상축 방향, 진상축 방향, 두께 방향의 굴절률이다)인 포지티브 C 층을 포함한다. 제3위상차판은 편광판에 포함되어 반사율을 현저하게 낮출 수 있다. 일 구체예에서, 편광판은 입사각 60°에서 반사율이 약 3.5% 이하, 예를 들면 약 0% 내지 약 3.5%가 될 수 있다. 상기 범위에서, 화면 품질을 개선할 수 있다. 예를 들면 편광판은 입사각 60°에서 반사율이 약 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4 또는 3.5% 일 수 있다.The third retardation plate includes a positive C layer in which nz>nx≒ny (nx, ny, and nz are the refractive indices in the slow axis direction, fast axis direction, and thickness direction of the third retardation plate at a wavelength of 550 nm, respectively). The third retardation plate may be included in the polarizing plate to significantly lower the reflectance. In one embodiment, the polarizing plate may have a reflectance of about 3.5% or less at an incident angle of 60°, for example, about 0% to about 3.5%. Within the above range, the screen quality can be improved. For example, a polarizing plate has a reflectance of about 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4 or 3.5%.
제3위상차판은 파장 550nm에서 두께 방향 위상차가 약 -300nm 내지 약 0nm, 예를 들면, 약 -100nm 내지 약 0nm, 약 -90nm 내지 약 -20nm가 될 수 있다. 상기 범위에서, 상술한 반사율 효과를 얻을 수 있다. 예를 들면 제3위상차판은 파장 550nm에서 두께 방향 위상차가 약 -300, -290, -280, -270, -260, -250, -240, -230, -220, -210, -200, -190, -180, -170, -160, -150, -140, -130, -120, -110, -100, -95, -90, -85, -80, -75, -70, -65, -60, -55, -50, -45, -40, -35, -30, -25, -20, -15, -10, -5 또는 0nm 일 수 있다.The third retardation plate may have a thickness direction retardation of about -300 nm to about 0 nm, for example, about -100 nm to about 0 nm, and about -90 nm to about -20 nm at a wavelength of 550 nm. In the above range, the above-described reflectance effect can be obtained. For example, the third retardation plate has about -300, -290, -280, -270, -260, -250, -240, -230, -220, -210, -200, - 190, -180, -170, -160, -150, -140, -130, -120, -110, -100, -95, -90, -85, -80, -75, -70, -65, -60, -55, -50, -45, -40, -35, -30, -25, -20, -15, -10, -5 or 0 nm.
제3위상차판은 파장 550nm에서 면내 위상차가 약 0nm 내지 약 10nm, 예를 들면 약 0nm 내지 약 5nm가 될 수 있다. 상기 범위에서, 상술한 두께 방향 위상차에 용이하게 도달될 수 있다. 예를 들면 상기 제3위상차판은 파장 550nm에서 면내 위상차가 약 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 또는 10nm 일 수 있다.The third retardation plate may have an in-plane retardation of about 0 nm to about 10 nm at a wavelength of 550 nm, for example, about 0 nm to about 5 nm. In the above range, the thickness direction retardation described above can be easily reached. For example, the third retardation plate has about 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, It can be 8, 9 or 10 nm.
제3위상차판은 두께가 10㎛ 이하, 예를 들면 0㎛ 초과 10㎛ 이하가 될 수 있다. 상기 범위에서, 두께 방향 위상차를 구현할 수 있다. 예를 들면 상기 제3위상차판은 두께가 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 또는 10㎛가 될 수 있다.The third retardation plate may have a thickness of 10 μm or less, for example, more than 0 μm and 10 μm or less. Within the above range, it is possible to implement a thickness direction retardation. For example, the third retardation plate has a thickness of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 μm. can be
일 구체예에서, 제3위상차판은 액정층으로 형성될 수 있다. 액정층은 상술한 두께 방향 위상차를 구현하도록 알려진 통상의 물질로 형성될 수 있다.In one embodiment, the third retardation plate may be formed of a liquid crystal layer. The liquid crystal layer may be formed of a conventional material known to implement the above-described retardation in the thickness direction.
다른 구체예에서, 제3위상차판은 셀룰로스 에스테르계 또는 방향족계 고분자를 포함하는 조성물로 형성될 수도 있다. In another embodiment, the third retardation plate may be formed of a composition including a cellulose ester-based or aromatic-based polymer.
일 구체예에서, 편광판은 편광자, 편광자의 상부면에 적층된 보호 필름 및 편광자의 하부면에 편광자로부터 순차적으로 적층된 제1위상차판, 제2위상차판, 제3위상차판을 포함한다. 제2위상차판의 하부면 예를 들면 제2위상차판과 점착층(또는 접착층) 사이에 제3위상차판이 추가로 포함된 점을 제외하고는 본 발명의 일 실시예에 따른 편광판과 실질적으로 동일하다.In one embodiment, the polarizing plate includes a polarizer, a protective film laminated on the upper surface of the polarizer, and a first retardation plate, a second retardation plate, and a third retardation plate sequentially stacked from the polarizer on the lower surface of the polarizer. The lower surface of the second retardation plate, for example, is substantially the same as the polarizing plate according to an embodiment of the present invention, except that a third retardation plate is additionally included between the second retardation plate and the adhesive layer (or adhesive layer) .
본 발명의 광학표시장치는 본 발명 실시예의 편광판을 포함한다. 광학표시장치는 유기발광소자(OLED) 표시장치, 액정표시장치를 포함할 수 있다.The optical display device of the present invention includes the polarizing plate of the embodiment of the present invention. The optical display device may include an organic light emitting diode (OLED) display device and a liquid crystal display device.
일 구체예에서, 유기발광소자 표시장치는 플렉서블형 기판을 포함하는 유기발광소자 패널, 상기 유기발광소자 패널 상에 적층된 본 발명의 편광판을 포함할 수 있다.In one embodiment, the organic light emitting diode display device may include an organic light emitting diode panel including a flexible substrate, and the polarizing plate of the present invention laminated on the organic light emitting diode panel.
다른 구체예에서, 유기발광소자 표시장치는 비-플렉서블형 기판을 포함하는 유기발광소자 패널, 상기 유기발광소자 패널 상에 적층된 본 발명의 편광판을 포함할 수 있다.In another embodiment, the organic light emitting diode display device may include an organic light emitting diode panel including a non-flexible substrate, and the polarizing plate of the present invention laminated on the organic light emitting diode panel.
이하, 본 발명의 바람직한 실시예를 통해 본 발명의 구성 및 작용을 더욱 상세히 설명하기로 한다. 다만, 이는 본 발명의 바람직한 예시로 제시된 것이며 어떠한 의미로도 이에 의해 본 발명이 제한되는 것으로 해석될 수는 없다.Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention and cannot be construed as limiting the present invention in any sense.
실시예 1Example 1
폴리비닐알코올계 필름(PS#60, 일본 Kuraray社, 연신 전 두께: 60㎛)을 55℃요오드 수용액에서 6배로 연신하여 광 투과율 45%의 편광자를 제조하였다.A polarizer having a light transmittance of 45% was prepared by stretching a polyvinyl alcohol-based film (PS#60, Kuraray, Japan, thickness before stretching: 60 μm) 6 times in an aqueous solution of iodine at 55°C.
상기 제조한 편광자의 상부면에 보호 필름으로 HC-TAC 필름(Toppan, 25FJCHCN-TC, 두께: 32㎛)을 합지하였다. 편광자의 하부면에 편광자의 하부면으로부터 하기 표 1의 사양을 갖는 제1위상차판(액정층, 네마틱 액정, 정파장 분산성, DNP社, 두께: 2㎛), 제2위상차판(액정층, 네마틱 액정, 정파장 분산성, DNP社, 두께: 1㎛)을 순서대로 합지시켜 편광판을 제조하였다.An HC-TAC film (Toppan, 25FJCHCN-TC, thickness: 32 μm) was laminated on the upper surface of the prepared polarizer as a protective film. On the lower surface of the polarizer, from the lower surface of the polarizer, a first retardation plate (liquid crystal layer, nematic liquid crystal, constant wavelength dispersibility, DNP company, thickness: 2 μm), a second retardation plate (liquid crystal layer) having the specifications of Table 1 below , nematic liquid crystal, positive wavelength dispersion, DNP Corporation, thickness: 1 μm) were laminated in this order to prepare a polarizing plate.
실시예 2 내지 실시예 4Examples 2 to 4
실시예 1에서 제1위상차판, 제2위상차판의 구성을 하기 표 1과 같이 변경한 것을 제외하고는 실시예 1과 동일한 방법으로 편광판을 제조하였다.A polarizing plate was manufactured in the same manner as in Example 1, except that the configuration of the first retardation plate and the second retardation plate in Example 1 was changed as shown in Table 1 below.
실시예 5 내지 실시예 8Examples 5 to 8
실시예 1에서, 제1위상차판, 제2위상차판의 구성을 하기 표 2와 같이 변경하고, 제2위상차판의 하부면에 제3 위상차판(포지티브 C 플레이트, 셀룰로스 에스테르계 조성물로 제조)을 추가로 적층시켜, 보호 필름, 편광자, 제1위상차판, 제2위상차판, 제3위상차판의 순서로 적층시킨 것을 제외하고는 실시예 1과 동일한 방법으로 편광판을 제조하였다.In Example 1, the configuration of the first retardation plate and the second retardation plate was changed as shown in Table 2 below, and a third retardation plate (positive C plate, made of a cellulose ester-based composition) was formed on the lower surface of the second retardation plate. A polarizing plate was manufactured in the same manner as in Example 1, except that a protective film, a polarizer, a first retardation plate, a second retardation plate, and a third retardation plate were laminated in the order of additional lamination.
비교예 1 내지 비교예 8Comparative Examples 1 to 8
실시예 1에서, 제1위상차판, 제2위상차판의 구성을 하기 표 1과 같이 변경한 것을 제외하고는 실시예 1과 동일한 방법을 실시하여 편광판을 제조하였다.In Example 1, a polarizing plate was manufactured in the same manner as in Example 1, except that the configuration of the first retardation plate and the second retardation plate was changed as shown in Table 1 below.
제1위상차판, 제2위상차판, 제3위상차판 각각의 Re, Rth, NZ는 Axoscan (Axometry社)를 사용하여 파장 550nm에서 측정하였다.Re, Rth, and NZ of each of the first retardation plate, the second retardation plate, and the third retardation plate were measured at a wavelength of 550 nm using Axoscan (Axometry).
실시예와 비교예의 편광판을 가지고 반사율을 아래의 방법으로 평가하고 하기 표 1, 표 2에 나타내었다.Using the polarizing plates of Examples and Comparative Examples, the reflectance was evaluated by the following method, and is shown in Tables 1 and 2 below.
반사율(단위:%): 반사율은 상기 편광판의 각각의 층을 파라메터화하여 완전 반사를 가정하여 Extended Jones Matrix 계산 방식(정면과 측면에서의 값을 알 수 있는 계산 방식)을 이용하여 계산하였다. 단, 최외곽 1차 반사는 계산에서 제외했다.Reflectance (unit: %): The reflectance was calculated using the Extended Jones Matrix calculation method (a calculation method that can know the values from the front and side) assuming complete reflection by parameterizing each layer of the polarizing plate. However, the outermost primary reflection was excluded from the calculation.
[표 1][Table 1]
Figure PCTKR2021006861-appb-I000001
Figure PCTKR2021006861-appb-I000001
[표 2][Table 2]
Figure PCTKR2021006861-appb-I000002
Figure PCTKR2021006861-appb-I000002
θ(제1위상차판): 편광자의 투과축에 대해 제1위상차판의 지상축이 이루는 각도(단위:°)θ (first retardation plate): the angle formed by the slow axis of the first retardation plate with respect to the transmission axis of the polarizer (unit: °)
θ(제2위상차판): 편광자의 투과축에 대해 제2위상차판의 지상축이 이루는 각도(단위:°)θ (second retardation plate): the angle formed by the slow axis of the second retardation plate with respect to the transmission axis of the polarizer (unit: °)
상기 표 1, 표 2에서와 같이, 본 발명의 편광판은 측면 60° 입사각에서의 반사율을 현저하게 낮추었다. 반면에, 상기 표 1에서와 같이, 식 1, 식 2, 식 3, 식 4 중 어느 하나라도 만족하지 않는 비교예의 편광판은 실시예 대비 측면 60° 입사각에서의 반사율이 현저하게 높았다.As shown in Tables 1 and 2, the polarizing plate of the present invention significantly lowered the reflectance at an incident angle of 60° from the side. On the other hand, as shown in Table 1, the polarizing plate of the comparative example, which does not satisfy any one of Equation 1, Equation 2, Equation 3, and Equation 4, had significantly higher reflectance at an incident angle of 60° from the side compared to the Example.
본 발명의 단순한 변형 내지 변경은 이 분야의 통상의 지식을 가진 자에 의하여 용이하게 실시될 수 있으며, 이러한 변형이나 변경은 모두 본 발명의 영역에 포함되는 것으로 볼 수 있다.Simple modifications or changes of the present invention can be easily carried out by those of ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (14)

  1. 편광자 및 상기 편광자의 하부면에 순차적으로 적층된 제1위상차판, 제2위상차판을 포함하는 편광판으로서,A polarizing plate comprising a polarizer and a first retardation plate and a second retardation plate sequentially stacked on a lower surface of the polarizer,
    상기 제1위상차판은 파장 550nm에서 면내 위상차 (Re)가 약 180nm 내지 약 240nm이고, 상기 제2위상차판은 파장 550nm에서 면내 위상차가 약 90nm 내지 약 130nm이고, 상기 제1위상차판, 상기 제2위상차판은 각각 파장 550nm에서 이축성 정도(NZ)가 약 0.95 내지 약 1.05이고,The first retardation plate has an in-plane retardation (Re) of about 180 nm to about 240 nm at a wavelength of 550 nm, the second retardation plate has an in-plane retardation of about 90 nm to about 130 nm at a wavelength of 550 nm, the first retardation plate, the second The retardation plate has a degree of biaxiality (NZ) of about 0.95 to about 1.05 at a wavelength of 550 nm, respectively,
    상기 제1위상차판, 상기 제2위상차판은 식 1, 식 2, 식 3 그리고 식 4를 만족하는 것인, 편광판:The first retardation plate and the second retardation plate satisfy Equation 1, Equation 2, Equation 3 and Equation 4, a polarizing plate:
    [식 1][Equation 1]
    Re(제2위상차판) = 약 ([0.4 x Re(제1위상차판)] + α)Re (second retardation plate) = about ([0.4 x Re (first retardation plate)] + α)
    (상기 식 1에서,(In Equation 1 above,
    Re(제1위상차판)은 파장 550nm에서 제1위상차판의 면내 위상차(단위:nm)Re (first retardation plate) is the in-plane retardation of the first retardation plate at a wavelength of 550 nm (unit: nm)
    Re(제2위상차판)은 파장 550nm에서 제2위상차판의 면내 위상차(단위:nm)Re (second retardation plate) is the in-plane retardation of the second retardation plate at a wavelength of 550 nm (unit: nm)
    약 23nm ≤ α ≤ 약 44nm)about 23 nm ≤ α ≤ about 44 nm)
    [식 2][Equation 2]
    약 140nm ≤ ｜Rth(제1위상차판)｜ + ｜Rth(제2위상차판)｜ ≤ 약 180nmAbout 140 nm ≤ ｜Rth (first retardation plate)｜ + ｜Rth (second retardation plate)｜ ≤ about 180 nm
    (상기 식 2에서,(In Equation 2 above,
    Rth(제1위상차판)은 파장 550nm에서 제1위상차판의 두께 방향 위상차(단위:nm),Rth (first retarder) is the thickness direction retardation of the first retarder at a wavelength of 550 nm (unit: nm),
    Rth(제2위상차판)은 파장 550nm에서 제2위상차판의 두께 방향 위상차(단위:nm)),Rth (second retardation plate) is the thickness direction retardation of the second retardation plate at a wavelength of 550 nm (unit: nm),
    [식 3][Equation 3]
    약 72°≤ θ(제1위상차판) ≤ 약 82°About 72°≤ θ (first phase difference plate) ≤ about 82°
    (상기 식 3에서,(In Equation 3 above,
    θ(제1위상차판)은 편광자의 투과축에 대한 제1위상차판의 지상축이 이루는 각도(단위: °)),θ (first retardation plate) is the angle formed by the slow axis of the first retardation plate with respect to the transmission axis of the polarizer (unit: °)),
    [식 4][Equation 4]
    θ(제2위상차판) = 약 ([2 x θ(제1위상차판)] + 45° + β)θ (second phase difference plate) = about ([2 x θ (first phase difference plate)] + 45° + β)
    (상기 식 4에서,(in Equation 4 above,
    θ(제1위상차판)은 편광자의 투과축에 대한 제1위상차판의 지상축(slow axis)이 이루는 각도(단위: °),θ (first retardation plate) is the angle (unit: °) formed by the slow axis of the first retardation plate with respect to the transmission axis of the polarizer;
    θ(제2위상차판)은 편광자의 투과축에 대한 제2위상차판의 지상축이 이루는 각도(단위: °),θ (second retardation plate) is the angle (unit: °) formed by the slow axis of the second retardation plate with respect to the transmission axis of the polarizer;
    약 2° ≤ β ≤ 약 7°).about 2° ≤ β ≤ about 7°).
  2. 제1항에 있어서, 상기 제1위상차판, 상기 제2위상차판은 각각 액정층을 포함하는 것인, 편광판.The polarizing plate of claim 1 , wherein the first retardation plate and the second retardation plate each include a liquid crystal layer.
  3. 제2항에 있어서, 상기 액정층은 네마틱 액정을 포함하는 것인, 편광판.The polarizing plate according to claim 2, wherein the liquid crystal layer includes a nematic liquid crystal.
  4. 제1항에 있어서, 상기 제1위상차판, 상기 제2위상차판은 각각 파장 550nm에서 이축성 정도(NZ)가 약 0.96 내지 약 1.04인 것인, 편광판.The polarizing plate according to claim 1, wherein the first retardation plate and the second retardation plate each have a degree of biaxiality (NZ) of about 0.96 to about 1.04 at a wavelength of 550 nm.
  5. 제1항에 있어서, 상기 식 2에서 Rth(제1위상차판)은 약 50nm 내지 약 150nm인 것인, 편광판.The polarizing plate according to claim 1, wherein Rth (first retardation plate) in Equation 2 is about 50 nm to about 150 nm.
  6. 제1항에 있어서, 상기 식 2에서 Rth(제2위상차판)은 약 30nm 내지 약 80nm인 것인, 편광판.The polarizing plate according to claim 1, wherein Rth (second retardation plate) in Equation 2 is about 30 nm to about 80 nm.
  7. 제1항에 있어서, 상기 식 4에서 θ(제2위상차판)은 약 10° 내지 약 40°인 것인, 편광판.The polarizing plate according to claim 1, wherein θ (second retardation plate) in Equation 4 is about 10° to about 40°.
  8. 제1항에 있어서, 상기 제1위상차판, 상기 제2위상차판은 각각 정파장 분산성인 것인, 편광판.The polarizing plate according to claim 1, wherein the first retardation plate and the second retardation plate each have a constant wavelength dispersion property.
  9. 제1항에 있어서, 상기 제1위상차판과 상기 제2위상차판의 적층체는 파장 550nm에서 면내 위상차가 약 140nm 내지 약 190nm인 것인, 편광판.The polarizing plate according to claim 1, wherein the laminate of the first retardation plate and the second retardation plate has an in-plane retardation of about 140 nm to about 190 nm at a wavelength of 550 nm.
  10. 제1항에 있어서, 상기 편광판은 포지티브 C 층을 포함하는 제3위상차판을 추가로 포함하는 것인, 편광판.The polarizing plate of claim 1 , wherein the polarizing plate further comprises a third retardation plate including a positive C layer.
  11. 제10항에 있어서, 상기 제3위상차판은 상기 제2위상차판의 하부면에 포함되는 것인, 편광판.The polarizing plate of claim 10 , wherein the third retardation plate is included on a lower surface of the second retardation plate.
  12. 제10항에 있어서, 상기 제3위상차판은 파장 550nm에서 두께 방향 위상차가 약 -300nm 내지 약 0nm인 것인, 편광판.The polarizing plate according to claim 10, wherein the third retardation plate has a thickness direction retardation of about -300 nm to about 0 nm at a wavelength of 550 nm.
  13. 제1항에 있어서, 상기 편광자의 상부면에 보호층이 더 형성된 것인, 편광판.The polarizing plate of claim 1, wherein a protective layer is further formed on an upper surface of the polarizer.
  14. 제1항 내지 제13항 중 어느 한 항의 편광판을 포함하는 광학표시장치.An optical display device comprising the polarizing plate of any one of claims 1 to 13.
PCT/KR2021/006861 2020-07-21 2021-06-02 Polarizing plate and optical display device comprising same WO2022019469A1 (en)

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