WO2015041316A1 - Liquid crystal display device and light conversion member - Google Patents

Liquid crystal display device and light conversion member Download PDF

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Publication number
WO2015041316A1
WO2015041316A1 PCT/JP2014/074827 JP2014074827W WO2015041316A1 WO 2015041316 A1 WO2015041316 A1 WO 2015041316A1 JP 2014074827 W JP2014074827 W JP 2014074827W WO 2015041316 A1 WO2015041316 A1 WO 2015041316A1
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Prior art keywords
light
liquid crystal
quantum dots
wavelength
crystal display
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PCT/JP2014/074827
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French (fr)
Japanese (ja)
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隆 米本
齊藤　之人
直良 山田
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富士フイルム株式会社
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Publication of WO2015041316A1 publication Critical patent/WO2015041316A1/en

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    • 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
    • G02F1/1336—Illuminating devices
    • G02F1/133617—Illumination with ultraviolet light; Luminescent elements or materials associated to the cell
    • 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
    • G02F2202/00—Materials and properties
    • G02F2202/36—Micro- or nanomaterials

Definitions

  • the present invention relates to a liquid crystal display device and a light conversion member. More specifically, the present invention relates to a liquid crystal display device having a large aperture ratio of a color filter and a good white balance, and a light conversion member used in the liquid crystal display device.
  • the liquid crystal display device is composed of at least a backlight and a liquid crystal cell, and usually further includes members such as a backlight side polarizing plate and a viewing side polarizing plate.
  • Patent Document 1 discloses a color filter having a light conversion layer and having a black matrix and four or more colored regions including red, green, and blue. Are listed.
  • quantum dots also referred to as Quantum Dot, QD, and quantum dots
  • QD quantum dots
  • quantum dots have attracted attention as light emitting materials (see Patent Document 2).
  • excitation light enters a light conversion member including quantum dots from a backlight
  • the quantum dots are excited and emit fluorescence.
  • white light can be realized by emitting bright line light of red light, green light, and blue light (RGB).
  • Patent 4720802 US2012 / 0113672A1
  • the display of the CF4 primary color configuration having an LED light source has a performance problem that the aperture ratio of the CF is reduced and the display is likely to burn-in due to the complicated pixel structure.
  • the CF4 primary color configuration having an LED light source has material-related restrictions on the emission spectrum of the LED light source and the transmittance of the CF. Therefore, the light quantity of each color emitted from the color filter is balanced and incorporated in the liquid crystal display device.
  • the problem to be solved by the present invention is to provide a liquid crystal display device in which the color filter has a high aperture ratio and a good white balance.
  • a quantum dot emits fluorescence having a wavelength corresponding to the particle size, and therefore, a quantum dot light source is a mixture of quantum dots having different particle sizes. It has been found that the emission color and emission intensity ratio can be easily controlled by arbitrarily adjusting the ratio. Accordingly, as a result of further intensive studies, the present inventors have combined the quantum dot light source and the four primary colors CF, thereby requiring the size of the pixel (colored region) that is necessary when combining the LED light source and the four primary colors CF. I came to find that it was not necessary to change each color.
  • the present invention which is a specific means for solving the above problems, is as follows.
  • a liquid crystal display device having at least a backlight and a color filter in which a colored region that selectively transmits light in a partial wavelength band of light emitted from the backlight is formed in a pattern;
  • a backlight having a light source and a light conversion member having a light conversion layer including at least two types of quantum dots excited by light incident from the light source and emitting fluorescence;
  • the color filter includes four or more colored regions, and Including at least a blue colored region having a transmittance peak wavelength of 400 to 480 nm, a green colored region having a transmittance peak wavelength of 500 to 560 nm, and a red colored region having a transmittance peak wavelength of 600 nm or more,
  • the ratio of the area of the colored region of each color to the average value Aave of the area of the colored region of each color included in the color filter is 0.8 to 1.2 in the colored regions of all colors.
  • the color filter includes a yellow colored region having a transmittance peak wavelength of 560 to 600 nm.
  • the color filter preferably includes a cyan colored region having a transmittance peak wavelength of 480 to 500 nm.
  • the backlight has an emission center wavelength of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm, The emission intensity ratio at each emission center wavelength is preferably 1: 0.17 to 0.45: 0.13 to 0.4.
  • the backlight has an emission center wavelength of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm, The emission intensity ratio at each emission center wavelength is preferably 1: 0.26 to 0.63: 0.39 to 1.15.
  • the color filter further includes a cyan colored region having a transmittance peak wavelength of 480 to 500 nm, and The backlight has an emission center wavelength of at least 400 to 480 nm, 500 to 600 nm and 600 to 680 nm; The emission intensity ratio at each emission center wavelength is preferably 1: 0.19 to 0.45: 0.19 to 0.6.
  • the light conversion layer includes a quantum dot (A) having an emission center wavelength in a wavelength range of 600 nm to 680 nm, Containing one or more quantum dots (Z) having an emission center wavelength in a shorter wavelength band than the dots (A), In the light conversion layer, the quantum dots (A) are preferably unevenly distributed on the excitation light incident side with respect to the quantum dots (Z).
  • the liquid crystal display device according to any one of [1] to [7] has a liquid crystal cell including a color filter, The liquid crystal cell is preferably in the VA mode.
  • FIG. 1A and 1B are schematic views showing an example of a backlight unit including a light conversion member used in one embodiment of the liquid crystal display device of the present invention.
  • FIG. 2A is a schematic diagram showing an example of the shape of the colored region of each color of the color filter used in one embodiment of the liquid crystal display device of the present invention.
  • FIG. 2B is a schematic view showing an example of the shape of the colored region of each color of the color filter used in the liquid crystal display device outside the scope of the present invention.
  • FIG. 3 is a schematic view showing another example of the shape of the colored region of each color of the color filter used in one embodiment of the liquid crystal display device of the present invention.
  • FIG. 4 is a schematic view showing an example of a light conversion member used in one embodiment of the liquid crystal display device of the present invention.
  • FIG. 5 is a schematic view showing another example of the light conversion member used in one embodiment of the liquid crystal display device of the present invention.
  • a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
  • the peak wavelength of transmittance refers to a wavelength at which the transmittance reaches a maximum value.
  • the emission center wavelength means a wavelength at which the emission intensity becomes a maximum value.
  • the “half-value width” of a peak refers to the width of the peak at a peak height of 1 ⁇ 2.
  • light having the emission center wavelength in the wavelength band of 430 to 480 nm is called blue light
  • light having the emission center wavelength in the wavelength band of 500 to 600 nm is called green light
  • the emission center wavelength is in the wavelength band of 600 to 680 nm.
  • the light having a color is called red light.
  • a liquid crystal display device includes at least a backlight and a color filter in which colored regions that selectively transmit light in a partial wavelength band of light emitted from the backlight are formed in a pattern.
  • the color filter includes four or more colored regions, and Including at least a blue colored region having a transmittance peak wavelength of 400 to 480 nm, a green colored region having a transmittance peak wavelength of 500 to 560 nm, and a red colored region having a transmittance peak wavelength of 600 nm or more,
  • the ratio of the area of the colored region of each color to the average value Aave of the area of the colored region of each color included in the color filter is 0.8 to 1.2 in the colored regions of all colors.
  • ⁇ Configuration of liquid crystal display device> At least a backlight and a color filter in which a colored region that selectively transmits light in a part of the wavelength band of light emitted from the backlight is formed in a pattern.
  • the liquid crystal display device preferably has a backlight-side polarizing plate on the backlight-side surface of the liquid crystal cell.
  • the backlight side polarizing plate may or may not include a polarizing plate protective film on the surface of the backlight side polarizer on the backlight side, but it is preferably included.
  • the backlight side polarizing plate preferably has a configuration in which a polarizer is sandwiched between two polarizing plate protective films.
  • the polarizing plate protective film on the side closer to the liquid crystal cell with respect to the polarizer is referred to as the inner side polarizing plate protective film
  • the polarizing plate protective film on the side farther from the liquid crystal cell with respect to the polarizer is referred to as the outer side polarizing plate. It is called a protective film.
  • the backlight side polarizing plate may have a retardation film as an inner side polarizing plate protective film on the liquid crystal cell side.
  • a retardation film a known cellulose acylate film or the like can be used.
  • the liquid crystal display device preferably has a display-side polarizing plate on the surface opposite to the backlight side surface of the liquid crystal cell.
  • the display-side polarizing plate preferably has a configuration in which a polarizer is sandwiched between two polarizing plate protective films.
  • a polarizing plate protective film is an inner side polarizing plate protective film, and a polarizing plate protective film is an outer side polarizing plate protective film.
  • the driving mode of the liquid crystal cell is not particularly limited, and is twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), and optically compensated bend cell (OCB).
  • TN twisted nematic
  • STN super twisted nematic
  • VA vertical alignment
  • IPS in-plane switching
  • OCB optically compensated bend cell
  • the liquid crystal cell is preferably VA mode, OCB mode, IPS mode, or TN mode, more preferably VA mode, but is not limited thereto.
  • the configuration shown in FIG. 2 of Japanese Patent Application Laid-Open No. 2008-262161 is given as an example.
  • the specific configuration of the liquid crystal display device is not particularly limited, and a known configuration can be adopted.
  • a liquid crystal cell having a liquid crystal layer sandwiched between substrates provided with electrodes on at least one of the opposite sides is provided, and the liquid crystal cell is arranged between two polarizing plates.
  • the liquid crystal display device includes a liquid crystal cell in which liquid crystal is sealed between upper and lower substrates, and displays an image by changing the alignment state of the liquid crystal by applying a voltage. Furthermore, it has an accompanying functional layer such as a polarizing plate protective film, an optical compensation member that performs optical compensation, and an adhesive layer as necessary.
  • the liquid crystal display device includes a color filter.
  • the surface layer may be disposed.
  • liquid crystal cell the polarizing plate, the polarizing plate protective film, and the like constituting the liquid crystal display device according to one embodiment of the present invention
  • those prepared by known methods and commercially available products can be used without any limitation.
  • it can.
  • each member which comprises the liquid crystal display device of this invention is demonstrated.
  • the liquid crystal display device of the present invention has a color filter in which colored regions that selectively transmit light in a part of the wavelength band of light emitted from the backlight are formed in a pattern for each color, A blue colored region containing four or more colored regions and having a transmittance peak wavelength of 400 to 480 nm, a green colored region having a transmittance peak wavelength of 500 to 560 nm, and a transmittance peak wavelength of 600 nm
  • the ratio of the area of the colored region of each color to the average value Aave of the colored regions of the respective colors included in the color filter is 0.8 to 1 in all the colored regions. .2.
  • the colored region of the color filter is sometimes called a pixel.
  • the color filter includes a colored region having four or more colors, a blue colored region having a transmittance peak wavelength of 400 to 480 nm, and a green colored region having a transmittance peak wavelength of 500 to 560 nm. And at least a red colored region having a transmittance peak wavelength of 600 nm or more.
  • the peak wavelength of the transmittance of the blue colored region is preferably in the wavelength band of 430 to 480 nm, and more preferably in the wavelength band of 450 to 475 nm.
  • the peak wavelength of the transmittance of the green colored region is preferably in the wavelength band of 510 to 560 nm, and more preferably in the wavelength band of 520 to 550 nm.
  • Colored regions other than the blue colored region, the green colored region, and the red colored region include a yellow colored region having a transmittance peak wavelength of 560 to 600 nm, and cyan having a transmittance peak wavelength of 480 to 500 nm. Can be mentioned.
  • the number of colors in the colored region of the color filter is 4 or more, preferably 4 to 8, more preferably 4 to 6, and particularly preferably 4 or 5.
  • the colored region of the color filter is 5 or more, it is preferable to have both a yellow colored region having a transmittance peak wavelength of 560 to 600 nm and a cyan colored region having a transmittance peak wavelength of 480 to 500 nm. .
  • the peak wavelength of the transmittance of the yellow colored region is preferably in the wavelength band of 560 to 585 nm, and more preferably in the wavelength band of 565 to 580 nm.
  • the peak wavelength of the transmittance of the cyan colored region is preferably in the wavelength band of 485 to 500 nm, and more preferably in the wavelength band of 490 to 500 nm.
  • a liquid crystal display an intended color is displayed by adjusting a voltage applied to a liquid crystal layer and controlling light transmittance of each color.
  • the transmittance changes mainly due to the angle dependency of the retardation of the liquid crystal layer, so that a color different from the front is displayed.
  • the color filter multi-primary color brings about an effect of increasing the choice of transmittance of each color when displaying the front color.
  • the option for displaying yellow is not only the display by mixing the red colored area and the green colored area.
  • the option for displaying yellow is not only the display by mixing the red colored area and the green colored area.
  • this improvement in oblique coloring is effective in liquid crystal display devices of all modes such as TN, VA, and IPS, but the effect is remarkable in the VA mode in which oblique overexposure is observed. It can be seen.
  • An example of the VA mode is a PVA mode.
  • FIG. 2A, FIG. 2B, and FIG. 3 show an example of one unit constituting the pattern of the colored region of the color filter.
  • 2A, 2B, and 3 illustrate the case where the color region of the color filter 30 has four colors, the present invention is not limited to such an embodiment.
  • FIG. 2A illustrates a color filter 30 having a shape in which a blue colored region 21, a red colored region 22, a green colored region 23, and a yellow colored region 24 are approximated to a rectangle and have substantially the same area. It is a pattern.
  • the aperture ratio can be increased by using colored regions of each color having such a shape. Moreover, the burn-in described below can be suppressed.
  • the areas of the colored regions of the colors of the color filter are different as shown in FIG. 2B, nonuniformity occurs in the capacitance between the liquid crystal layer and the liquid crystal layer and the signal line. For this reason, an offset is generated in the AC voltage applied to the liquid crystal layer, and the liquid crystal display device is likely to be burned.
  • the burn-in of the liquid crystal display device is often visually recognized as being particularly colored. From the viewpoint of preventing burn-in, the ratio of the area of the colored region of each color to the average value Aave of the colored region of each color is preferably 0.8 to 1.2, preferably 0.9 to 1.1. Is more preferably 0.98 to 1.02.
  • the aperture ratio of the color filter can be further increased as compared with the colored area pattern of FIG. This is preferable.
  • the colored regions of each color that is, the blue colored region 21, the red colored region 22, the green colored region 23, and the yellow colored region 24 have a shape approximate to a square and the same area. It is.
  • Various known methods can be used as a method for forming the colored region. For example, when forming colored regions of each color such as R, G, and B, a desired black matrix and a colored region pattern of each color such as R, G, and B are formed on a glass substrate using a photomask and a photoresist.
  • a color filter it is also preferable to produce a color filter by the materials, curable compositions, and production methods described in JP 2011-221515 A and JP 2007-299014 A, and the contents of these publications are incorporated in the present invention.
  • Preferred characteristics of the color filter are described in Japanese Patent Application Laid-Open No. 2011-221515, Japanese Patent Application Laid-Open No. 2008-083611, and the like, and the contents of these publications are incorporated in the present invention.
  • it is preferable that one wavelength is 590 nm to 610 nm and the other wavelength is 470 nm to 500 nm in the colored region showing green.
  • region which shows green is 590 nm or more and 600 nm or less. Furthermore, it is preferable that the maximum transmittance in the colored region showing green is 80% or more. It is preferable that the wavelength having the maximum transmittance in the colored region showing green is 530 nm or more and 560 nm or less. In the colored region showing green, the transmittance at the wavelength of the emission peak is preferably 10% or less of the maximum transmittance.
  • the transmittance at 580 nm to 590 nm is preferably 10% or less of the maximum transmittance.
  • color filter pigment known pigments can be used without any limitation. Currently, a pigment is generally used, but a color filter having a colored region with a dye may be used as long as it is a pigment that can control spectroscopy and ensure process stability and reliability.
  • a black matrix is preferably disposed between the colored regions.
  • the material for forming the black stripe include a material using a sputtered film of a metal such as chromium, and a light-shielding photosensitive composition in which a photosensitive resin and a black colorant are combined.
  • the black colorant include carbon black, titanium carbon, iron oxide, titanium oxide, graphite, and the like. Among these, carbon black is preferable.
  • the liquid crystal display device can further include a TFT substrate having a thin layer transistor (hereinafter also referred to as TFT).
  • TFT thin layer transistor
  • the thin film transistor preferably includes an oxide semiconductor layer having a carrier concentration of less than 1 ⁇ 10 14 / cm 3 .
  • a preferred embodiment of the thin layer transistor is described in Japanese Patent Application Laid-Open No. 2011-141522, and the content of this publication is incorporated in the present invention.
  • the liquid crystal display device of the present invention has at least a backlight.
  • the backlight preferably includes a light source and a light conversion member having a light conversion layer including at least two types of quantum dots that are excited by light incident from the light source and emit fluorescence.
  • the backlight unit preferably has an emission center wavelength of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm.
  • the backlight when the color filter includes a yellow colored region having a transmittance peak wavelength of 560 to 600 nm, the backlight has emission center wavelengths of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm
  • the emission intensity ratio at the emission center wavelength is preferably 1: 0.17 to 0.45: 0.13 to 0.4, and is preferably 1: 0.2 to 0.4: 0.15 to 0.35. It is more preferable that the ratio is 1: 0.2 to 0.3: 0.2 to 0.3.
  • the backlight when the color filter includes a cyan colored region having a transmittance peak wavelength of 480 to 500 nm, the backlight has emission center wavelengths of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm,
  • the emission intensity ratio at the emission center wavelength is preferably 1: 0.26 to 0.63: 0.39 to 1.15, and preferably 1: 0.26 to 0.55: 0.50 to 1.10. It is more preferable that the ratio is 1: 0.26 to 0.50: 0.50 to 1.05.
  • the backlight when the color filter includes a yellow colored region having a transmittance peak wavelength of 560 to 600 nm and a cyan colored region having a transmittance peak wavelength of 480 to 500 nm, the backlight has at least 400 to
  • the emission center wavelengths are preferably 480 nm, 500 to 600 nm, and 600 to 680 nm, and the emission intensity ratio at each emission center wavelength is preferably 1: 0.19 to 0.45: 0.19 to 0.6. : 0.25 to 0.45: 0.19 to 0.55 is more preferable, and 1: 0.3 to 0.45: 0.19 to 0.5 is particularly preferable.
  • the backlight unit has a light emission intensity peak with a light emission center wavelength in a wavelength band of 430 to 480 nm and a half-value width of 100 nm or less so as to realize high luminance and high color reproducibility by a three-wavelength light source.
  • the wavelength band of blue light emitted from the backlight unit is preferably 450 to 480 nm, and more preferably 460 to 470 nm.
  • the wavelength band of the green light emitted from the backlight unit is preferably 520 to 550 nm, and more preferably 530 to 540 nm.
  • the wavelength band of red light emitted from the backlight unit is preferably 610 to 650 nm, and more preferably 620 to 640 nm.
  • the half-value widths of the emission intensity of blue light, green light, and red light emitted from the backlight unit are all preferably 80 nm or less, more preferably 50 nm or less, and 45 nm or less. It is more preferable that it is 40 nm or less. Among these, it is particularly preferable that the half-value width of each emission intensity of blue light is 30 nm or less.
  • the backlight unit includes a light source together with at least the light conversion member.
  • a light source that emits blue light having an emission center wavelength in the wavelength band of 430 nm to 480 nm, for example, a blue light emitting diode that emits blue light can be used.
  • the light conversion layer may include at least quantum dots (A) that are excited by excitation light and emit red light, and quantum dots (B) that emit green light. preferable.
  • white light can be embodied by blue light emitted from the light source and transmitted through the light conversion member, and red light and green light emitted from the light conversion member.
  • a light source that emits ultraviolet light having an emission center wavelength in the wavelength band of 300 nm to 430 nm, for example, an ultraviolet light emitting diode can be used.
  • the light conversion layer includes quantum dots (C) that are excited by excitation light and emit blue light together with the quantum dots (A) and (B).
  • white light can be embodied by red light, green light, and blue light emitted from the light conversion member.
  • the configuration of the backlight unit may be an edge light system using a light guide plate, a reflection plate, or the like as a constituent member.
  • FIG. 1 shows an example of an edge light type backlight unit
  • the backlight unit according to one embodiment of the present invention may be a direct type. Any known light guide plate can be used without any limitation.
  • the backlight unit can include a reflecting member at the rear of the light source.
  • a reflecting member at the rear of the light source.
  • a well-known thing can be used, and it is described in patent 3416302, patent 3363565, patent 4091978, patent 3448626, etc., The content of these gazettes is this Incorporated into the invention.
  • the backlight unit has a blue wavelength selection filter that selectively transmits light having a wavelength shorter than 500 nm of blue light. It is also preferable that the backlight unit has a red wavelength selection filter that selectively transmits light having a wavelength longer than 500 nm of red light.
  • a blue wavelength selection filter or a red wavelength selection filter A well-known thing can be used. Such a filter is described in Japanese Patent Application Laid-Open No. 2008-52067, and the content of this publication is incorporated in the present invention.
  • the backlight unit preferably further includes a known diffusion plate, diffusion sheet, prism sheet (for example, BEF series manufactured by Sumitomo 3M Limited), and a light guide.
  • a known diffusion plate for example, BEF series manufactured by Sumitomo 3M Limited
  • prism sheet for example, BEF series manufactured by Sumitomo 3M Limited
  • a light guide for example, BEF series manufactured by Sumitomo 3M Limited
  • Other members are also described in Japanese Patent No. 3416302, Japanese Patent No. 3363565, Japanese Patent No. 4091978, Japanese Patent No. 3448626, and the contents of these publications are incorporated in the present invention.
  • the light conversion member is a light conversion member having a light conversion layer including quantum dots that are excited by incident excitation light and emit fluorescence.
  • the light conversion layer includes a quantum dot (A) having an emission center wavelength in a wavelength range of 600 nm to 680 nm and one or more quantum dots (Z) having an emission center wavelength in a shorter wavelength band than the quantum dot (A). And).
  • the quantum dots (A) are preferably unevenly distributed on the excitation light incident side with respect to the quantum dots (Z).
  • the quantum dots (A) are relatively unevenly distributed on the excitation light incident side with respect to the quantum dots (Z) means that the light conversion layer is on an arbitrary surface perpendicular to the incident light, When divided into two areas of the incident side area and the emission side area, the abundance ratio of the quantum dots (A) existing in the incident side area is the quantum dot (Z) (there may be only one kind, two or more kinds It is more than the abundance ratio existing in the incident side region.
  • the light conversion layer The abundance ratio [A1 / (A1 + A2)] of the quantum dots (A) in the incident side region with respect to all the quantum dots (A) (A1 + A2) included in the incident side region with respect to all the quantum dots (Z1 + Z2) included in the light conversion layer That is larger than the abundance ratio [Z1 / (Z1 + Z2)] of the quantum dots (Z), that is, satisfying the following formula (1).
  • the uneven distribution of quantum dots in the light conversion layer is measured by cutting the light conversion layer at an arbitrary location, observing the cross section with an electron microscope, measuring the number of quantum dots, and calculating with the following formula: it can.
  • the direction perpendicular to the excitation light incident side surface and the emission side surface of the light conversion layer is taken as the x-axis.
  • the normalized number density distribution of the quantum dots (A) is ⁇ A (x), and the normalized number density distribution of the quantum dots (Z) is ⁇ Z (x). That means Is established.
  • ⁇ represented by the following formula is defined as an index representing the uneven distribution of quantum dots (A) and (Z).
  • ⁇ 0, the quantum dots (A) This means that it is unevenly distributed to the emission side without having a region mixed with the dot (Z).
  • ⁇ 0.5.
  • ⁇ is preferably greater than 0.5
  • ⁇ is more preferably greater than 0.7
  • ⁇ is more preferably greater than 0.8
  • ⁇ is greater than 0.95. Larger is even more preferable.
  • the quantum dot (A) which is a quantum dot that emits red light
  • the quantum dot (A) is distributed in the quantum dot (A) relative to the excitation light incident side relative to the quantum dot (Z). It is possible to prevent the dots (Z) from being excited and absorbing the emitted fluorescence. Thereby, the light emission efficiency of the light conversion member containing a quantum dot can be improved.
  • the light conversion member is preferably included as a constituent member of the backlight unit of the liquid crystal display device.
  • FIG. 1 is a schematic view showing an example of a backlight unit including a light conversion member used in one embodiment of the liquid crystal display device of the present invention.
  • the backlight unit 31 includes a light source 31A and a light guide plate 31B for use as a surface light source.
  • the light conversion member is disposed on the path of light emitted from the light guide plate.
  • the light conversion member is disposed between the light guide plate and the light source.
  • light emitted from the light guide plate 31B enters the light conversion member 31C.
  • FIG. 1 shows that light emitted from the light guide plate 31B enters the light conversion member 31C.
  • the light emitted from the light source 31A arranged at the edge portion of the light guide plate 31B is blue light 32, and the liquid crystal is displayed from the surface of the light guide plate 31B on the liquid crystal cell (not shown) side. It is emitted toward the cell.
  • the light conversion member 31C disposed on the path of the light (blue light 32) emitted from the light guide plate 31B has the quantum dots (A) that are excited by the blue light 32 and emit the red light 34, and the blue light 32. It includes at least quantum dots (B) that are excited to emit green light 33. In this way, the backlight unit 31 emits the excited green light 33 and red light 34 and the blue light 32 transmitted through the light conversion member 31C.
  • FIG. 1B is the same as the embodiment shown in FIG. 1A except that the arrangement of the light conversion member and the light guide plate is different.
  • the excited green light 33 and red light 34, and the blue light 32 transmitted through the light conversion member 31C are emitted from the light conversion member 31C and incident on the light guide plate. Realized.
  • the light conversion member has at least a light conversion layer including quantum dots that are excited by incident excitation light and emit fluorescence.
  • the light conversion layer includes a quantum dot (A) having an emission center wavelength in a wavelength range of 600 nm to 680 nm and one or more types of quantum dots (Z) having an emission center wavelength in a shorter wavelength band than the quantum dot (A). It is preferable to contain.
  • the quantum dots (A) can emit red light upon receiving excitation light.
  • the quantum dot (Z) preferably includes a quantum dot (B) having an emission center wavelength in a wavelength range of 500 nm to 600 nm. This quantum dot (B) can emit green light upon receiving excitation light.
  • blue light is incident on a light conversion member having a light conversion layer including quantum dots emitting red light and quantum dots emitting green light. A possible light conversion member can be obtained.
  • the quantum dot light source can easily adjust the emission color and emission intensity ratio by arbitrarily adjusting the mixing ratio of quantum dots with different particle sizes. Can be controlled.
  • the light emission intensity ratio of each color of the backlight and the mixing ratio of quantum dots having different particle diameters can be arbitrarily adjusted. For example, the following embodiments are preferable.
  • the backlight when the color filter includes a yellow colored region having a transmittance peak wavelength of 560 to 600 nm, the backlight has emission center wavelengths of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm, It is preferable that the emission intensity ratio at the emission center wavelength is 1: 0.17 to 0.45: 0.13 to 0.4. At this time, the quantum dot having the emission center wavelength in the wavelength band of 600 nm to 680 nm.
  • the mixing ratio in the light conversion layer of (A) and the quantum dot (B) having the emission center wavelength in the wavelength range of 500 nm to 600 nm is preferably 1: 3 to 4: 1, and 1: 2 to The ratio is more preferably 3: 1, and particularly preferably 2: 3 to 3: 2.
  • the color filter includes a cyan colored region having a transmittance peak wavelength of 480 to 500 nm
  • the backlight has emission center wavelengths of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm
  • the light emission intensity ratio at the emission center wavelength is preferably 1: 0.26 to 0.63: 0.39 to 1.15.
  • the quantum dot having the emission center wavelength in the wavelength band of 600 nm to 680 nm is preferably 1: 5 to 2: 1, and 1: 5 to 5: 4 is more preferable, and 1: 4 to 1: 1 is particularly preferable.
  • the backlight when the color filter includes a yellow colored region having a transmittance peak wavelength of 560 to 600 nm and a cyan colored region having a transmittance peak wavelength of 480 to 500 nm, the backlight has at least 400 to Preferably, the emission center wavelengths are 480 nm, 500 to 600 nm, and 600 to 680 nm, and the emission intensity ratio at each emission center wavelength is 1: 0.19 to 0.45: 0.19 to 0.6.
  • the mixing ratio in the light conversion layer of the quantum dot (A) having the emission center wavelength in the wavelength band of 600 nm to 680 nm and the quantum dot (B) having the emission center wavelength in the wavelength band of 500 nm to 600 nm is 1: 3 to 3: 1 is preferable, 2: 5 to 5: 2 is more preferable, and 3: 5 to 5: 2 is preferable. It is particularly preferred.
  • the quantum dots (A) absorb the light emitted by the quantum dots (Z), it is difficult to achieve high light emission efficiency. It is.
  • the quantum dots (A) are more unevenly distributed on the excitation light incident side with respect to the quantum dots (Z). preferable.
  • the incident light is preferentially absorbed by the quantum dots (Z), The quantum dots (Z) emit fluorescence.
  • the fluorescence emitted from the quantum dot (Z) is absorbed by the quantum dot (A).
  • the light incident on the light conversion layer is preferentially absorbed by the quantum dots (A), so that the quantum dots (A) first emit light. ,preferable.
  • the red light emitted by the quantum dot (A) is not absorbed by the quantum dot (B) having the emission center wavelength in a shorter wavelength band than the quantum dot (Z) or the amount of absorption thereof is small.
  • the light emitted by A) can be used with high efficiency.
  • the quantum dot (Z) may be only one kind of quantum dot or two or more kinds of quantum dots.
  • the quantum dot (Z) includes a quantum dot having an emission center wavelength in a shorter wavelength band than the quantum dot (B), preferably a quantum dot (C) having an emission center wavelength in a wavelength band of 400 nm to 500 nm. You can also.
  • Quantum dots (C) are quantum dots that are excited to emit blue light.
  • the quantum dot (A) emits light by including the quantum dot (C) together with the quantum dot (A) and (B) in the light conversion layer.
  • White light can be realized by emitting RGB bright line light using red light, green light emitted from the quantum dots (B), and blue light emitted from the quantum dots (C).
  • the quantum dots (B) are preferably unevenly distributed on the excitation light incident side with respect to the quantum dots (C).
  • the light conversion member of the present invention which is the above-described novel light conversion member has a light conversion layer including at least four types of quantum dots which are excited by incident excitation light and emit fluorescence.
  • the light conversion layer including at least four types of quantum dots that are excited by incident excitation light and emit fluorescence emits a wavelength band of 480 to 500 nm.
  • quantum dots emitting cyan fluorescent light having an emission center wavelength, and quantum dots emitting yellow fluorescent light having an emission center wavelength in a wavelength band of 560 to 600 nm can be included.
  • the quantum dots (A) and the quantum dots (B) may be uniformly dispersed in the layer.
  • the green light emitted from the quantum dots (B) is absorbed by the quantum dots (A).
  • FIG. 5 is an explanatory diagram of a light conversion member according to one embodiment of the present invention.
  • the quantum dot (A) (symbol 3 in the figure) is excited with respect to the quantum dot (B) (symbol 2 in the figure) having an emission center wavelength in a shorter wavelength band than the quantum dot (A). It is relatively unevenly distributed on the light incident side.
  • the first quantum dot layer 102A including only the quantum dots (A) as the quantum dots and the second quantum including only the quantum dots (B) as the quantum dots.
  • the dot layer 102B is laminated directly adjacent.
  • Such a quantum dot layer can be produced by dispersing quantum dots in a resin material.
  • the shape of the quantum dot layer is not particularly limited, and may be any shape such as a sheet shape or a bar shape.
  • the quantum dots for example, paragraphs 0060 to 0066 of JP2012-169271A can be referred to, but the quantum dots are not limited thereto.
  • the quantum dots commercially available products can be used without any limitation.
  • the emission wavelength of the quantum dots can usually be adjusted by the composition and size of the particles.
  • the light conversion layer has a shorter wavelength band than the quantum dots (B) and has a light emission center wavelength in the wavelength band of 400 nm to 500 nm.
  • a third quantum dot including the dot (C) as a quantum dot may be included.
  • Such a light conversion member uses, for example, a light source (UV light source) having a light emission center wavelength in a wavelength band of 300 nm to 430 nm as a light source, thereby emitting white light by emitting red light, green light, and blue light. It can be embodied.
  • the light conversion layer may include a quantum dot (D) having an emission center wavelength in a wavelength band of 560 nm to 600 nm, or a quantum dot (E) having an emission center wavelength in a wavelength band of 480 nm to 500 nm.
  • D quantum dot
  • E quantum dot
  • a liquid crystal display device including such a light conversion member has a large amount of light at the time of yellow and cyan color development and can display an image with excellent gradation.
  • the sheet-like quantum dot layer is preferably produced by a coating method.
  • a sheet-like quantum dot layer can be obtained by applying a polymerizable composition (a curable composition) containing quantum dots on a substrate and then performing a curing treatment by light irradiation or the like. it can.
  • two or more quantum dot layers can be laminated by sequentially applying and curing polymerizable compositions having different compositions, quantum dot concentrations, or composition and quantum dot concentrations.
  • the concentration of the quantum dots can be continuously or gradually increased by applying from the highest concentration to the lowest concentration or vice versa. It is also possible to produce a quantum dot layer that changes with time.
  • the coating may be performed by simultaneous multilayer coating (the upper layer is coated while the lower layer is undried) or sequentially by multilayer coating (after the lower layer is dried, preferably after curing, the upper layer is coated). According to the sequential multilayer coating, inter-layer mixing is unlikely to occur. Therefore, in order to obtain a quantum dot layer including only one kind of quantum dots, it is preferable to perform sequential multilayer coating.
  • the polymerizable compound used for preparing the polymerizable composition is not particularly limited. From the viewpoint of transparency and adhesion of the cured film after curing, (meth) acrylate compounds such as monofunctional or polyfunctional (meth) acrylate monomers, polymers thereof, prepolymers, and the like are preferable.
  • (meth) acrylate compounds such as monofunctional or polyfunctional (meth) acrylate monomers, polymers thereof, prepolymers, and the like are preferable.
  • description with "(meth) acrylate” shall be used by the meaning of at least any one of an acrylate and a methacrylate. The same applies to “(meth) acryloyl” and the like.
  • Monofunctional (meth) acrylate monomers include acrylic acid and methacrylic acid, derivatives thereof, and more specifically, monomers having one polymerizable unsaturated bond ((meth) acryloyl group) of (meth) acrylic acid in the molecule Can be mentioned. Reference can be made to WO2012 / 0777807A1 paragraph 0022 for specific examples thereof.
  • the details can be referred to WO2012 / 0777807A1 paragraph 0024.
  • the polyfunctional (meth) acrylate compound those described in paragraphs 0023 to 0036 of JP2013-043382A can also be used.
  • the amount of the polyfunctional (meth) acrylate monomer used is preferably 5 parts by mass or more from the viewpoint of coating strength with respect to 100 parts by mass of the total amount of polymerizable compounds contained in the polymerizable composition. From the viewpoint of suppressing the gelation of the product, it is preferably 95 parts by mass or less.
  • the polymerizable composition can contain a known radical initiator as a polymerization initiator.
  • a radical initiator as a polymerization initiator.
  • the polymerization initiator is preferably 0.1 mol% or more, more preferably 0.5 to 2 mol% of the total amount of the polymerizable compound contained in the polymerizable composition.
  • Quantum dots may be added to the polymerizable composition in the form of particles, or may be added in the form of a dispersion dispersed in a solvent.
  • the addition in the state of a dispersion is preferable from the viewpoint of suppressing the aggregation of the quantum dot particles.
  • the solvent used here is not particularly limited.
  • the quantum dots can be added in an amount of, for example, about 0.1 to 10 parts by mass with respect to 100 parts by mass of the total composition.
  • the polymerizable composition containing the quantum dots described above can be applied to a suitable support and dried to remove the solvent, and then polymerized and cured by light irradiation or the like to obtain a quantum dot layer.
  • Application methods include curtain coating, dip coating, spin coating, print coating, spray coating, slot coating, roll coating, slide coating, blade coating, gravure coating, wire bar method, etc. A well-known coating method is mentioned.
  • the curing conditions can be appropriately set according to the type of polymerizable compound used and the composition of the polymerizable composition.
  • the total thickness of the light conversion layer is preferably 500 ⁇ m or less from the viewpoint of obtaining sufficient excitation light transmittance, and is preferably 1 ⁇ m or more from the viewpoint of obtaining sufficient fluorescence.
  • the thickness of one layer is preferably in the range of 1 to 300 ⁇ m, more preferably in the range of 10 to 250 ⁇ m.
  • the light conversion member may have a light scattering structure on the surface of the light conversion layer (quantum dot layer).
  • the light emitted from the light conversion layer undergoes total reflection depending on the angle of incidence on the adjacent layer interface having a different refractive index, and is guided inside the display device, resulting in a decrease in light extraction efficiency. Therefore, providing the light scattering structure on the emission side to improve the light extraction efficiency is effective for further improving the light emission efficiency of the light conversion member.
  • Examples of such a light scattering structure include a surface uneven structure. As the surface concavo-convex structure, it is preferable to provide a large number of fine concavo-convex portions on the entire surface on the emission side of the light conversion member.
  • the surface concavo-convex structure can be formed by a known method such as embossing or an etching resist described in JP2013-039802. Moreover, a surface uneven
  • corrugated structure can also be provided by bonding together a commercially available prism sheet.
  • the light conversion member may have a light scattering layer (light extraction layer) as a layer adjacent to the quantum dot layer.
  • a light scattering layer light extraction layer
  • the light extraction efficiency can be increased as in the case of providing the light scattering structure.
  • the light scattering layer is preferably a resin layer in which scattering particles are dispersed in a matrix material containing at least a binder resin.
  • a scattering particle there is no restriction
  • the difference in refractive index from the matrix material constituting the entire light scattering layer is preferably 0.02 or more.
  • the scattering particles only one type of particle may be used, or a plurality of types of particles may be used in combination.
  • the scattering particles may be inorganic particles or organic particles. Details thereof can be referred to paragraph 0022 of JP 2010-198735 A.
  • the film thickness of the light scattering layer is not particularly limited and is a dry film thickness, for example, about 0.5 ⁇ m to 50 ⁇ m, but can be appropriately selected according to the purpose. From the viewpoint of oxygen barrier properties and light transmittance, the range is preferably 1 ⁇ m to 20 ⁇ m, more preferably 2 ⁇ m to 10 ⁇ m, and still more preferably 3 ⁇ m to 7 ⁇ m.
  • the example which provides the light-scattering layer containing scattering particles was shown as a structure for improving light extraction efficiency, light extraction efficiency can also be improved by making scattering particles exist in a light conversion layer.
  • the details of the scattering particles are the same as described above.
  • To obtain a quantum dot layer containing scattering particles together with quantum dots by adding scattering particles to the polymerizable composition for preparing the quantum dot layer in the form of particles or as a dispersion dispersed in an appropriate solvent. Can do.
  • the weight density of the amount of scattering particles in the quantum dot layer is preferably 2% or more from the viewpoint of improving light extraction efficiency.
  • the amount of scattering particles increases, the amount of quantum dots in the layer relatively decreases. From the viewpoint of improving the quantum dot filling rate, the weight density of scattering particles in the quantum dot layer should be less than 30%. Is preferred.
  • Barrier films may be provided on both surfaces of the light conversion layer.
  • the light conversion member may be provided with a light scattering layer as a layer directly adjacent to the emission-side barrier film.
  • the light scattering layer is not only provided as a layer directly adjacent to the barrier film located on the exit side, but may be in a form adjacent to the exit side of the light conversion layer, or a form adjacent to the incident side of the light conversion layer. .
  • the scattering particles may be present in the light conversion layer.
  • the barrier film is preferably a film having an oxygen barrier property, and can play a role in preventing quantum dots from being deteriorated by oxygen over time and quantum efficiency (luminous efficiency) being lowered. More specifically, the photooxidation reaction of the quantum dots by the excitation light can be suppressed.
  • a film having an oxygen permeability of less than 1.00 cm 3 / (m 2 ⁇ day ⁇ atm) is preferable to use as the barrier film.
  • a barrier film can be an organic layer, an inorganic layer, or a laminated film of two or more layers of an organic layer and an inorganic layer. Details thereof will be described later.
  • the barrier film may be disposed only on the incident side or may be disposed only on the emission side. From the viewpoint of maintaining the quantum efficiency better for a longer period, it is preferable to arrange barrier films on both the incident side and the emission side of the light conversion layer. By combining the light scattering layer and the barrier film in this way, it is possible to maintain higher luminous efficiency for a long period of time.
  • a light scattering layer may be provided as a layer directly adjacent to the emission side barrier film, and a light reflection layer may be provided as a layer directly adjacent to the incident side barrier film. Providing the light reflection layer on the excitation light incident side of the light conversion layer is effective in improving the light utilization efficiency.
  • the light reflecting layer is preferably a cholesteric layer, and details will be described later.
  • the oxygen permeability of the barrier film is preferably 1.00 cm 3 / (m 2 ⁇ day ⁇ atm) or less, more preferably 0.50 cm 3 / (m 2 ⁇ day ⁇ atm) or less, and still more preferably. 0.10cm 3 / (m 2 ⁇ day ⁇ atm) or less, more preferably 0.01cm 3 / (m 2 ⁇ day ⁇ atm) or less.
  • the water vapor permeability of the barrier film 0.5g / (m 2 ⁇ day ) or less, preferably 0.1g / (m 2 ⁇ day) or less, particularly 0.05g / (m 2 ⁇ day) or less Is preferred.
  • the oxygen permeability is a value measured using an oxygen gas permeability measuring device (manufactured by MOCON, OX-TRAN 2/20: trade name) under the conditions of a measurement temperature of 23 ° C. and a relative humidity of 90%.
  • the water vapor transmission rate was measured using a water vapor transmission rate measuring device (manufactured by MOCON, PERMATRAN-W 3/31: trade name) under the conditions of a measurement temperature of 37.8 ° C. and a relative humidity of 100%. Value.
  • the barrier film may be an organic or inorganic single layer, or may be a laminated structure of two or more layers.
  • a barrier film can be obtained by forming two or more organic or inorganic layers on a substrate.
  • a layer structure of the barrier film for example, a structure in which the base material / inorganic layer / organic layer is laminated in this order from the light conversion layer side to the outside, and the base material / inorganic layer / organic layer / inorganic layer in this order.
  • stacking order is not specifically limited.
  • the substrate is preferably a transparent substrate that is transparent to visible light.
  • transparent to visible light means that the linear transmittance in the visible light region is 80% or more, preferably 85% or more.
  • the light transmittance used as a measure of transparency is measured by measuring the total light transmittance and the amount of scattered light using the method described in JIS-K7105, that is, using an integrating sphere light transmittance measuring device. It can be calculated by subtracting the rate.
  • paragraphs 0046 to 0052 of JP-A-2007-290369 and paragraphs 0040 to 0055 of JP-A-2005-096108 can be referred to.
  • the thickness of the substrate is preferably in the range of 10 ⁇ m to 500 ⁇ m, more preferably in the range of 10 to 200 ⁇ m, particularly in the range of 20 to 100 ⁇ m from the viewpoint of impact resistance, handling in the production of the barrier film, and the like.
  • the thickness of the inorganic layer is preferably 10 nm to 500 nm, more preferably 10 nm to 300 nm, and particularly preferably 10 nm to 150 nm.
  • the film thickness of the inorganic layer is within the above-described range, it is possible to suppress reflection on the barrier film while achieving good gas barrier properties, and to suppress a decrease in total light transmittance. Because.
  • the inorganic layer is preferably a silicon oxide film, a silicon nitride film, or a silicon oxynitride film. This is because these films have good adhesion to the organic film, so that even better gas barrier properties can be realized.
  • the organic layer preferably contains a cardo polymer.
  • the thickness of the organic layer is preferably in the range of 0.05 ⁇ m to 10 ⁇ m, and more preferably in the range of 0.5 to 10 ⁇ m.
  • the thickness of the organic layer is preferably in the range of 0.5 to 10 ⁇ m, and more preferably in the range of 1 to 5 ⁇ m. Further, when formed by a dry coating method, it is preferably in the range of 0.05 ⁇ m to 5 ⁇ m, and more preferably in the range of 0.05 ⁇ m to 1 ⁇ m. This is because when the film thickness of the organic layer formed by the wet coating method or the dry coating method is within the above-described range, the adhesion with the inorganic layer can be further improved.
  • a single layer (consisting of one layer) optical thin film can be laminated on the air interface on the barrier film.
  • a low refractive index layer having a refractive index n (535) of the optical thin film at a wavelength of 535 nm is lower than a refractive index nu (535) of a layer directly adjacent to the optical thin film in the barrier film.
  • the refractive index n (535) of the optical thin film at a wavelength of 535 nm is preferably 1.20 to 1.51, more preferably 1.30 to 1.46, and further preferably 1.40 to 1.46. preferable.
  • the optical thin film preferably has an optical thickness obtained by multiplying the refractive index and the film thickness satisfying any one of the following formulas (2-1), (2-2), and (2-3).
  • Formula (2-1) 1.15 ⁇ m ⁇ n (535) ⁇ d ⁇ 1.25 ⁇ m
  • Formula (2-2) 1.42 ⁇ m ⁇ n (535) ⁇ d ⁇ 1.52 ⁇ m
  • Formula (2-3) 1.69 ⁇ m ⁇ n (535) ⁇ d ⁇ 1.79 ⁇ m
  • n (535) represents the refractive index of the optical thin film at a wavelength of 535 nm
  • d represents the thickness (unit: ⁇ m) of the optical thin film.
  • the optical thin film satisfies any one of the following formulas (2-1A), (2-2A), and (2-3A), and in particular, satisfies the following formula (2-2A): preferable.
  • Formula (2-1A) 1.16 ⁇ m ⁇ n (535) ⁇ d ⁇ 1.24 ⁇ m
  • Formula (2-2A) 1.46 ⁇ m ⁇ n (535) ⁇ d ⁇ 1.51 ⁇ m
  • Formula (2-3A) 1.70 ⁇ m ⁇ n (535) ⁇ d ⁇ 1.78 ⁇ m
  • n (535) represents the refractive index of the optical thin film at a wavelength of 535 nm
  • d represents the thickness of the optical thin film (unit: ⁇ m).
  • the thickness d of the optical thin film is preferably 0.5 to 2 ⁇ m, and more preferably 0.7 to 1.5 ⁇ m.
  • the constituent components of the optical thin film known components can be used.
  • a material suitable for the organic layer of the barrier film can be used.
  • the barrier film on which the optical thin film is laminated may be laminated with the light conversion layer so that the optical thin film surface is on the air interface side, or vice versa.
  • the light reflecting layer is preferably a cholesteric layer.
  • a manufacturing method of the light reflection layer formed by fixing the cholesteric liquid crystal phase used for the aspect of a light reflection layer can be used, and the contents of these publications are incorporated in the present invention.
  • cholesteric liquid crystal an appropriate one may be used and there is no particular limitation.
  • the use of a liquid crystal polymer is advantageous from the standpoints of the superimposition efficiency of the liquid crystal layer and the thinning.
  • a cholesteric liquid crystal molecule having a large birefringence is preferable because the wavelength range of selective reflection is widened.
  • liquid crystal polymer examples include main chain type liquid crystal polymers such as polyester, side chain type liquid crystal polymers composed of acrylic main chain, methacryl main chain, siloxane main chain, and the like, nematic liquid crystal polymers containing a low molecular chiral agent, and introduction of chiral components. Any suitable liquid crystal polymer, nematic and cholesteric mixed liquid crystal polymer can be used. A glass transition temperature of 30 to 150 ° C. is preferable from the viewpoint of handleability.
  • the cholesteric liquid crystal layer can be formed by applying it directly to the polarization separator through an appropriate alignment film such as polyimide, polyvinyl alcohol, or obliquely deposited layer of SiO, or the alignment temperature of the liquid crystal polymer comprising a transparent film. It can be carried out by an appropriate method such as a method of applying to an unaltered support through an alignment film, if necessary. As the support, one having a phase difference as small as possible can be preferably used from the viewpoint of preventing the change of the polarization state. Further, a superposition method of a cholesteric liquid crystal layer through an alignment film can also be adopted.
  • an appropriate alignment film such as polyimide, polyvinyl alcohol, or obliquely deposited layer of SiO, or the alignment temperature of the liquid crystal polymer comprising a transparent film. It can be carried out by an appropriate method such as a method of applying to an unaltered support through an alignment film, if necessary. As the support, one having a phase difference as small as possible can
  • the liquid crystal polymer can be applied by a method in which a liquid material such as a solvent solution or a molten liquid is heated by an appropriate method such as a roll coating method, a gravure printing method, or a spin coating method. .
  • the thickness of the cholesteric liquid crystal layer to be formed is preferably 0.5 to 100 ⁇ m from the viewpoints of selective reflectivity, orientation disorder and prevention of transmittance decrease.
  • a dielectric multilayer film can be used for the light reflecting layer.
  • the method for producing a dielectric multilayer film using a film is not particularly limited. The contents of these publications are incorporated in the present invention.
  • the dielectric multilayer film may be referred to as a dielectric multilayer reflective polarizing plate or a birefringence interference polarizer having an alternating multilayer film.
  • These dielectric multilayer films can selectively reflect the wavelength by adjusting the film thickness and refractive index, and can be preferably used in this embodiment.
  • these films often reflect polarized light only in a specific direction due to refractive index anisotropy, in this case, if two of these films are used orthogonally, all polarized light can be reflected. preferable.
  • the dielectric multilayer film is preferably thin, preferably in the range of 5 to 100 ⁇ m, more preferably in the range of 10 to 50 ⁇ m, and in the range of 5 to 20 ⁇ m. Further preferred.
  • Preparation Example 1 ⁇ Preparation of red pigment (Rp) curable composition> The formulations shown in Table 1 below were mixed to prepare a red pigment (Rp) curable composition.
  • Preparation Example 2 ⁇ Preparation of blue pigment (Bp) curable composition> A blue pigment (Bp) curable composition was prepared by mixing the formulations shown in Table 2 below.
  • a TFT element was produced on a glass substrate according to Example 20 described in JP-A-2009-141341, and a protective film was further formed on the TFT element. Subsequently, after forming a contact hole in the protective film, an ITO transparent electrode electrically connected to the TFT element was formed on the protective film to produce an array substrate. An ITO transparent electrode is formed on the produced color filter substrate by sputtering. Then, according to Example 1 of Japanese Patent Application Laid-Open No. 2006-64921, a portion corresponding to the upper part of the partition wall (black matrix) on the ITO film is formed. A spacer was formed.
  • the transparent electrodes of the produced array substrate and color filter substrate were each patterned for PVA (Patterned Vertical Alignment) mode, and an alignment film made of vertical polyimide was further provided thereon. Thereafter, a UV curable resin sealant is applied by a dispenser method to a position corresponding to the outer periphery of the black matrix provided around the colored region group of each color of the color filter, and a PVA mode liquid crystal is dropped.
  • the substrate was bonded to the substrate, and the bonded substrate was irradiated with UV, followed by heat treatment to cure the sealant.
  • the liquid crystal cell used for each comparative example and an Example was produced.
  • Quantum Dot-Containing Polymerizable Composition A was obtained by mixing 0.54 ml of trimethylolpropane acrylate, 2.4 ml of lauryl methacrylate and Irgacure 819 manufactured by BASF as a photopolymerization initiator. With respect to 100 mg of the resulting polymerizable composition A, a toluene dispersion of quantum dots was prepared with a quantum dot (A) having an emission peak in the wavelength band of 600 to 680 nm and a shorter wavelength range than the quantum dot (A).
  • Quantum dots (B) having an emission center wavelength and having an emission peak in the wavelength band of 500 to 600 nm are added so as to have the content (concentration) described in Table 6 or 7 below, followed by drying under reduced pressure. It went for 30 minutes. Stirring was performed until the quantum dots were dispersed to obtain a dispersion M (quantum dot-containing polymerizable composition).
  • Example 1 (Assembly of backlight)
  • a light source that is a blue LED (Nichia B-LED: Royal Blue, main wavelength 445 nm, half-value width 20 nm)
  • a quantum dot light source A was prepared by combining one diffusion sheet and two prism sheets taken from a commercially available liquid crystal display device on the rear side on the viewing side of the reflecting member and the wavelength conversion member.
  • the quantum dot (A) having an emission peak in the wavelength band of 600 to 680 nm, the emission center wavelength in a shorter wavelength region than the quantum dot (A), and the emission peak of 500 Luminescence intensity of blue light (B), green light (G) and red light (R) emitted from the backlight by changing the content ratio of the quantum dots (B) in the wavelength band of ⁇ 600 nm in the light conversion layer
  • a light conversion layer was prepared so that the ratio was adjusted as shown in Table 6 or 7 below.
  • the light emission intensity of red light (R) can be increased by increasing the content ratio of the quantum dots (A) in the light conversion layer, and the green light can be increased by increasing the content ratio of the quantum dots (B) in the light conversion layer.
  • the emission intensity of (G) can be increased.
  • quantum dot light sources A2 to A15 were produced in the same manner as in Example 1 except that the light conversion members thus obtained were used.
  • the composition of the quantum dots in the light conversion member used in each example and comparative example is shown in Table 6 or 7 below.
  • Comparative Example 1 A liquid crystal display device of Comparative Example 1 was produced in the same manner as in Comparative Example 3 except that the white LED (not including quantum dots) attached to a commercially available liquid crystal display device as a backlight unit was used as it was.
  • Comparative Example 2 A liquid crystal display device of Comparative Example 2 was produced in the same manner as in Example 1 except that a white LED (not including quantum dots) attached to a commercially available liquid crystal display device as a backlight unit was used as it was.
  • Example 16 A liquid crystal display device of Example 16 was produced in the same manner as in Example 1 except that the backlight unit was changed to the quantum dot light source D in which the light conversion member was changed as follows. The outline is shown below.
  • Quantum Dot-Containing Polymerizable Composition A was obtained by mixing 0.54 ml of trimethylolpropane acrylate, 2.4 ml of lauryl methacrylate and Irgacure 819 manufactured by BASF as a photopolymerization initiator. With respect to 100 mg of the resulting polymerizable composition A, a toluene dispersion of quantum dots was prepared with a quantum dot (A) having an emission peak in the wavelength band of 600 to 680 nm and a shorter wavelength range than the quantum dot (A).
  • the quantum dots (C) in the wavelength band of 400 to 500 nm were added so as to have the content (concentration) described in Table 6 or 7 below, followed by drying under reduced pressure for 30 minutes. Stirring was performed until the quantum dots were dispersed to obtain a dispersion M2 (quantum dot-containing polymerizable composition).
  • the UV narrow-band backlight unit used in Example 16 includes a UV light-emitting diode (Nichia UV-LED: NC4U133A, main wavelength 365 nm, half-value width 9 nm) as a light source. Moreover, a reflective member is provided in the rear part of the light source.
  • a UV light-emitting diode Nia UV-LED: NC4U133A, main wavelength 365 nm, half-value width 9 nm
  • a reflective member is provided in the rear part of the light source.
  • Example 16 (Assembly of backlight)
  • a light source that is a UV light emitting diode (Nichia UV-LED: NC4U133A, main wavelength 365 nm, half-value width 9 nm)
  • a reflection member light at the rear of the light source
  • a quantum dot light source D was prepared by combining one diffusion sheet and two prism sheets taken from a commercially available liquid crystal display device on the viewing side of the conversion member.
  • the aperture ratio of the liquid crystal cell was measured using the stereomicroscope (the Leica Microsystems make, MZ16A), and the following ratings were given.
  • the liquid crystal display device of the present invention had a large aperture ratio of the color filter and a good white balance.
  • Comparative Example 1 when using a conventional white LED backlight that does not include quantum dots, and using four-color CFs that have non-uniform color areas and are outside the scope of the invention, the aperture ratio of the color filter is small I understood it.
  • Comparative Example 2 when the area of the colored region of each color is made uniform with the configuration using the conventional white LED backlight not including the quantum dots of Comparative Example 1, the chromaticity point is shifted and the white balance is poor. It turns out that it is not suitable as a display.
  • Example 21 In the first embodiment, instead of forming rectangular colored areas in a pattern in a row as shown in FIG. 2A, square colored areas are formed in a square shape as shown in FIG. A color filter having a pattern arrangement was manufactured. Otherwise, the liquid crystal display device of Example 21 was manufactured in the same manner as Example 1. When Example 21 was evaluated, the color filter in which the colored regions of each color of the square were arranged in a square shape as in Example 21 had a pattern in which the colored regions of each color of the rectangle of Example 1 were arranged in a line. It was found that the aperture ratio was superior to that of the color filter formed in (1). In addition, as for the liquid crystal display device of Example 21, when judged by visual recognition, it was found that the problem of image sticking did not occur.
  • Example 22 ⁇ Production of backlight> (Production of light conversion member (quantum dot film)) 1.
  • Preparation of Barrier Film 10 A barrier laminate was formed on one side of a polyethylene terephthalate film (PET film, manufactured by Toyobo Co., Ltd., trade name: Cosmo Shine A4300, thickness 50 ⁇ m) by the following procedure.
  • PET film manufactured by Toyobo Co., Ltd., trade name: Cosmo Shine A4300, thickness 50 ⁇ m
  • TMPTA manufactured by Daicel Cytec Co., Ltd.
  • a photopolymerization initiator manufactured by Lamberti Co., Ltd., ESACURE KTO46
  • This coating solution was applied onto the PET film with a roll toe roll using a die coater, and passed through a drying zone at 50 ° C. for 3 minutes. Thereafter, ultraviolet rays were irradiated in a nitrogen atmosphere (accumulated dose: about 600 mJ / cm 2 ), cured by UV curing, and wound up.
  • the thickness of the first organic layer formed on the support was 1 ⁇ m.
  • an inorganic layer (silicon nitride layer) was formed on the surface of the organic layer using a roll-to-roll CVD apparatus.
  • Silane gas (flow rate 160 sccm), ammonia gas (flow rate 370 sccm), hydrogen gas (flow rate 590 sccm), and nitrogen gas (flow rate 240 sccm) were used as source gases.
  • a high frequency power supply having a frequency of 13.56 MHz was used as the power supply.
  • the film forming pressure was 40 Pa, and the reached film thickness was 50 nm.
  • the oxygen permeability of the barrier film 10 was 0.01 cm 3 / (m 2 ⁇ day ⁇ atm) or less.
  • Quantum Dot-Containing Polymerizable Composition The following quantum dot dispersion 1 was prepared and filtered through a polypropylene filter having a pore size of 0.2 ⁇ m, and then dried under reduced pressure for 30 minutes and used as a coating solution.
  • Quantum dot-containing polymerizable composition 1 composition for organic layer 1 containing quantum dots
  • Toluene dispersion of quantum dots 1 (light emission maximum: 520 nm) 10 parts by weight
  • Toluene dispersion of quantum dots 2 (light emission maximum: 630 nm) 1 part by weight lauryl methacrylate 80.8 parts by weight trimethylolpropane triacrylate 18.2 parts by weight light 1 part by mass of polymerization initiator (Irgacure 819 (manufactured by BASF))
  • the quantum dot concentration of the toluene dispersion of quantum dots 1 and 2 is 1% by mass
  • First barrier film 10 is prepared, and the quantum dot-containing polymerizable composition 1 is applied on the surface of the inorganic layer with a die coater while continuously transporting at a tension of 1 m / min and 60 N / m. A coating film having a thickness of 50 ⁇ m was formed.
  • the first barrier film 10 on which the coating film is formed is wound around a backup roller, and the second barrier film 10 is laminated on the coating film so that the inorganic layer surface is in contact with the coating film. And it wound around a backup roller in the state which pinched
  • the diameter of the backup roller was 300 mm, and the temperature of the backup roller was 50 ° C.
  • the irradiation amount of ultraviolet rays was 2000 mJ.
  • L1 was 50 mm, L2 was 1 mm, and L3 was 50 mm.
  • the coated film was cured by irradiation with ultraviolet rays to form a cured layer (light conversion layer), and a laminated film (light conversion member a) was produced.
  • the thickness of the cured layer of the laminated film was 50 ⁇ 2 ⁇ m.
  • the thickness accuracy of the hardened layer was as good as ⁇ 4%.
  • production of wrinkles was not seen by the laminated
  • the quantum dot light source G described in Example 22 was produced by incorporating the light conversion member a thus obtained in the same manner as in Example 1.
  • Example 23 In the same manner as in the quantum dot light source G, except that a toluene dispersion of quantum dots 3 (luminescence maximum: 580 nm, described as Y in the table below) was newly added to the quantum dot-containing polymerizable composition 1.
  • the quantum dot light source H described in 1 was produced.
  • Example 24 In the same manner as in the quantum dot light source G, except that a toluene dispersion of the quantum dots 4 (luminescence maximum: 490 nm, described as C in the table below) was newly added to the quantum dot-containing polymerizable composition 1.
  • the quantum dot light source I described in 1 was produced.
  • Quantum dot-containing polymerizable composition 1 is newly added with a toluene dispersion of quantum dots 3 (luminescence maximum: 580 nm, described as Y in the table below) and a toluene dispersion of quantum dots 5 (luminescence maximum: 450 nm, in the tables below).
  • a light conversion member was prepared in the same manner as the light conversion member a except that (described as B) was added. The obtained light conversion member was incorporated into a backlight unit combined with a UV light emitting diode in the same manner as the quantum dot light source D, thereby producing a quantum dot light source J described in Example 25.
  • the quantum dot-containing polymerizable composition 1 is newly added to a toluene dispersion of quantum dots 4 (luminescence maximum: 490 nm, described as C in the following table) and a toluene dispersion of quantum dots 5 (luminescence maximum: 450 nm, in the following table).
  • a light conversion member was prepared in the same manner as the light conversion member a except that (described as B) was added.
  • the obtained light conversion member was incorporated into a backlight unit combined with a UV light emitting diode in the same manner as the quantum dot light source D, thereby producing a quantum dot light source K described in Example 26.
  • Example 1 ⁇ Manufacture of liquid crystal display devices>
  • the liquid crystal of Examples 22 to 26 was used in the same manner as in Example 1 except that instead of the quantum dot light source A as the backlight unit, quantum dot light sources G, H, I, J, or K were used.
  • a display device was manufactured.
  • the present invention is useful in the field of manufacturing liquid crystal display devices.
  • 102, 104 Light conversion layer 2: Quantum dot (B) 3: Quantum dot (A) 102A: Quantum dot layer including only quantum dots (A) as quantum dots 102B: Quantum dot layer including only quantum dots (B) as quantum dots 21: Blue colored regions 22: Red colored regions 23: Green colored regions 24: Yellow colored region 30: Color filter 31: Backlight unit 31A: Light source 31B: Light guide plate 31C: Light conversion member 32: Blue light 33: Green light 34: Red light

Abstract

A liquid crystal display device that has a backlight, and a color filter on which are formed, as patterns, colored regions that selectively transmit light in wavelength bands that are part of the light radiated from the backlight. The backlight has a light source, and a light conversion member that has a light conversion layer including two or more types of quantum dots that are excited by the light entering from the light source and emit fluorescence. The color filter includes four or more colored regions, including a blue colored region that has a peak transmittance wavelength of 400-480 nm, a green colored region that has a peak transmittance wavelength of 500-560 nm, and a red colored region that has a peak transmittance wavelength of 600 nm or more. The ratio of the area of the colored region for each color to the average value (Aave) of the areas of the colored regions included in the color filter is 0.8-1.2 for the colored region of every color. The color filter has a large aperture ratio and a favorable white balance.

Description

液晶表示装置および光変換部材Liquid crystal display device and light conversion member
　本発明は、液晶表示装置および光変換部材に関するものである。より詳しくは、カラーフィルタの開口率が大きく、良好なホワイトバランスを有する液晶表示装置およびこの液晶表示装置に用いられる光変換部材に関する。 The present invention relates to a liquid crystal display device and a light conversion member. More specifically, the present invention relates to a liquid crystal display device having a large aperture ratio of a color filter and a good white balance, and a light conversion member used in the liquid crystal display device.
　液晶表示装置（以下、ＬＣＤとも言う）などのフラットパネルディスプレイは、消費電力が小さく、省スペースの画像表示装置として年々その用途が広がっている。液晶表示装置は、少なくともバックライトと液晶セルとから構成され、通常、更に、バックライト側偏光板、視認側偏光板などの部材が含まれる。 Flat panel displays such as liquid crystal display devices (hereinafter also referred to as LCDs) consume less power and are increasingly used as space-saving image display devices year by year. The liquid crystal display device is composed of at least a backlight and a liquid crystal cell, and usually further includes members such as a backlight side polarizing plate and a viewing side polarizing plate.
　近年のフラットパネルディスプレイ市場において、ＬＣＤ性能改善として色再現性向上が進行している。色再現性向上技術の１つとして、ＬＥＤ光源を有するディスプレイに新たに黄色のカラーフィルター（以下、ＣＦとも言う）を追加したＣＦ４原色構成が知られており、市販されている（例えばＬＣ－４６ＸＦ３、ＳＨＡＲＰ製、ＬＥＤ、２０１０）。また、例えば特許文献１には、光変換層付きであり、ブラックマトリックスと、レッド、グリーン、ブルーを含む４色以上の着色領域を有するカラーフィルタが開示されており、シアンやイエローの着色領域が挙げられている。 In the recent flat panel display market, color reproducibility is improving as LCD performance improvement. As one of the techniques for improving color reproducibility, a CF4 primary color configuration in which a yellow color filter (hereinafter also referred to as CF) is newly added to a display having an LED light source is known and commercially available (for example, LC-46XF3 , SHARP, LED, 2010). Further, for example, Patent Document 1 discloses a color filter having a light conversion layer and having a black matrix and four or more colored regions including red, green, and blue. Are listed.
　一方、フラットパネルディスプレイ市場では、近年、発光材料として、量子ドット（Ｑｕａｎｔｕｍ　Ｄｏｔ、ＱＤ、量子点とも呼ばれる。）が注目を集めている（特許文献２参照）。例えば、バックライトから量子ドットを含む光変換部材に励起光が入射すると、量子ドットが励起され蛍光を発光する。ここで異なる発光特性を有する量子ドットを用いることで、赤色光、緑色光、青色光（ＲＧＢ）の輝線光を発光させて白色光を具現化することができる。 On the other hand, in the flat panel display market, in recent years, quantum dots (also referred to as Quantum Dot, QD, and quantum dots) have attracted attention as light emitting materials (see Patent Document 2). For example, when excitation light enters a light conversion member including quantum dots from a backlight, the quantum dots are excited and emit fluorescence. Here, by using quantum dots having different emission characteristics, white light can be realized by emitting bright line light of red light, green light, and blue light (RGB).
特許４７２０８０２号Patent 4720802 ＵＳ２０１２／０１１３６７２Ａ１号公報US2012 / 0113672A1
　ＬＥＤ光源を有するＣＦ４原色構成のディスプレイは、画素構造が複雑となることで、ＣＦの開口率が低下し、またディスプレイの焼きつきが生じやすいという性能上の課題があった。同時に、ＬＥＤ光源を有するＣＦ４原色構成は、ＬＥＤ光源の発光スペクトルおよびＣＦの透過率に材料起因の制約があるため、カラーフィルタから出射される各色の光量のバランスを取り、液晶表示装置に組み込んだときに良好なホワイトバランスを実現するためには、カラーフィルタの画素（着色領域）の大きさを色毎に変える必要があった（図２（Ｂ）参照）。 The display of the CF4 primary color configuration having an LED light source has a performance problem that the aperture ratio of the CF is reduced and the display is likely to burn-in due to the complicated pixel structure. At the same time, the CF4 primary color configuration having an LED light source has material-related restrictions on the emission spectrum of the LED light source and the transmittance of the CF. Therefore, the light quantity of each color emitted from the color filter is balanced and incorporated in the liquid crystal display device. Sometimes, in order to realize a good white balance, it is necessary to change the size of the color filter pixel (colored region) for each color (see FIG. 2B).
　本発明が解決しようとする課題は、カラーフィルタの開口率が高く、良好なホワイトバランスを有する液晶表示装置を提供することである。 The problem to be solved by the present invention is to provide a liquid crystal display device in which the color filter has a high aperture ratio and a good white balance.
　本発明者らは、上記課題を解決するために鋭意検討を重ねた結果、量子ドットは粒径に応じた波長の蛍光を発する特徴を有するため、量子ドット光源は、異なる粒径の量子ドット混合比率を任意に調整することで、発光色および発光強度比を容易に制御することができることを見出すに至った。
　そこで、本発明者らはさらに鋭意検討を重ねた結果、量子ドット光源と４原色ＣＦとを組み合わせることで、ＬＥＤ光源と４原色ＣＦを組み合わせるときに必要であった、画素（着色領域）のサイズの色毎の変更が不要となることを見出すに至った。その結果、着色領域のサイズを特定の範囲を満たす程度に色ごとに均一化することでＣＦの開口率が高く、良好なホワイトバランスを有するＣＦ４原色ディスプレイを実現できることを見出し、本発明を完成させた。
　上記課題を解決するための具体的な手段である本発明は以下のとおりである。 As a result of intensive studies to solve the above problems, the present inventors have a feature that a quantum dot emits fluorescence having a wavelength corresponding to the particle size, and therefore, a quantum dot light source is a mixture of quantum dots having different particle sizes. It has been found that the emission color and emission intensity ratio can be easily controlled by arbitrarily adjusting the ratio.
Accordingly, as a result of further intensive studies, the present inventors have combined the quantum dot light source and the four primary colors CF, thereby requiring the size of the pixel (colored region) that is necessary when combining the LED light source and the four primary colors CF. I came to find that it was not necessary to change each color. As a result, it has been found that a CF4 primary color display having a high CF aperture ratio and a good white balance can be realized by making the size of the colored region uniform for each color so as to satisfy a specific range, and the present invention has been completed. It was.
The present invention, which is a specific means for solving the above problems, is as follows.
［１］　少なくともバックライトと、バックライトから出射された光の一部の波長帯域の光を選択的に透過させる着色領域がパターン状に形成されたカラーフィルタとを有する液晶表示装置であり；
　バックライトが、光源と、光源から入射する光により励起され蛍光を発光する量子ドットを少なくとも２種類以上含む光変換層を有する光変換部材とを有し；
　カラーフィルタが、４色以上の着色領域を含み、かつ、
　透過率のピーク波長が４００～４８０ｎｍである青色の着色領域、透過率のピーク波長が５００～５６０ｎｍである緑色の着色領域および透過率のピーク波長が６００ｎｍ以上である赤色の着色領域を少なくとも含み、
　カラーフィルタに含まれる各色の着色領域の面積の平均値Ａａｖｅに対する、各色の着色領域の面積の比が、すべての色の着色領域において０．８～１．２である、
液晶表示装置。
［２］　［１］に記載の液晶表示装置は、カラーフィルタが、透過率のピーク波長が５６０～６００ｎｍである黄色の着色領域を含むことが好ましい。
［３］　［１］または［２］に記載の液晶表示装置は、カラーフィルタが、透過率のピーク波長が４８０～５００ｎｍであるシアンの着色領域を含むことが好ましい。
［４］　［２］に記載の液晶表示装置は、バックライトが、少なくとも４００～４８０ｎｍ、５００～６００ｎｍおよび６００～６８０ｎｍに発光中心波長を有し、
　各発光中心波長における発光強度比が１：０．１７～０．４５：０．１３～０．４であることが好ましい。
［５］　［３］に記載の液晶表示装置は、バックライトが、少なくとも４００～４８０ｎｍ、５００～６００ｎｍおよび６００～６８０ｎｍに発光中心波長を有し、
　各発光中心波長における発光強度比が１：０．２６～０．６３：０．３９～１．１５であることが好ましい。
［６］　［２］に記載の液晶表示装置は、カラーフィルタが、さらに透過率のピーク波長が４８０～５００ｎｍであるシアンの着色領域を含み、かつ、
　バックライトが、少なくとも４００～４８０ｎｍ、５００～６００ｎｍおよび６００～６８０ｎｍに発光中心波長を有し、
　各発光中心波長における発光強度比が１：０．１９～０．４５：０．１９～０．６であることが好ましい。
［７］　［１］～［６］のいずれか一つに記載の液晶表示装置は、光変換層は、６００ｎｍ～６８０ｎｍの範囲の波長帯域に発光中心波長を有する量子ドット（Ａ）と、量子ドット（Ａ）よりも短波長帯域に発光中心波長を有する一種以上の量子ドット（Ｚ）と、を含有し、
　光変換層において、量子ドット（Ａ）が、量子ドット（Ｚ）に対して励起光入射側に相対的に偏在していることが好ましい。
［８］　［１］～［７］のいずれか一つに記載の液晶表示装置は、カラーフィルタを含む液晶セルを有し、
　液晶セルがＶＡモードであることが好ましい。
［９］　入射する励起光により励起され蛍光を発光する量子ドットを少なくとも４種類以上含む光変換層を有する、光変換部材。 [1] A liquid crystal display device having at least a backlight and a color filter in which a colored region that selectively transmits light in a partial wavelength band of light emitted from the backlight is formed in a pattern;
A backlight having a light source and a light conversion member having a light conversion layer including at least two types of quantum dots excited by light incident from the light source and emitting fluorescence;
The color filter includes four or more colored regions, and
Including at least a blue colored region having a transmittance peak wavelength of 400 to 480 nm, a green colored region having a transmittance peak wavelength of 500 to 560 nm, and a red colored region having a transmittance peak wavelength of 600 nm or more,
The ratio of the area of the colored region of each color to the average value Aave of the area of the colored region of each color included in the color filter is 0.8 to 1.2 in the colored regions of all colors.
Liquid crystal display device.
[2] In the liquid crystal display device according to [1], it is preferable that the color filter includes a yellow colored region having a transmittance peak wavelength of 560 to 600 nm.
[3] In the liquid crystal display device according to [1] or [2], the color filter preferably includes a cyan colored region having a transmittance peak wavelength of 480 to 500 nm.
[4] In the liquid crystal display device according to [2], the backlight has an emission center wavelength of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm,
The emission intensity ratio at each emission center wavelength is preferably 1: 0.17 to 0.45: 0.13 to 0.4.
[5] In the liquid crystal display device according to [3], the backlight has an emission center wavelength of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm,
The emission intensity ratio at each emission center wavelength is preferably 1: 0.26 to 0.63: 0.39 to 1.15.
[6] In the liquid crystal display device according to [2], the color filter further includes a cyan colored region having a transmittance peak wavelength of 480 to 500 nm, and
The backlight has an emission center wavelength of at least 400 to 480 nm, 500 to 600 nm and 600 to 680 nm;
The emission intensity ratio at each emission center wavelength is preferably 1: 0.19 to 0.45: 0.19 to 0.6.
[7] In the liquid crystal display device according to any one of [1] to [6], the light conversion layer includes a quantum dot (A) having an emission center wavelength in a wavelength range of 600 nm to 680 nm, Containing one or more quantum dots (Z) having an emission center wavelength in a shorter wavelength band than the dots (A),
In the light conversion layer, the quantum dots (A) are preferably unevenly distributed on the excitation light incident side with respect to the quantum dots (Z).
[8] The liquid crystal display device according to any one of [1] to [7] has a liquid crystal cell including a color filter,
The liquid crystal cell is preferably in the VA mode.
[9] A light conversion member having a light conversion layer including at least four types of quantum dots that are excited by incident excitation light and emit fluorescence.
　本発明によれば、カラーフィルタの開口率が大きく、良好なホワイトバランスを有する液晶表示装置を提供することができる。 According to the present invention, it is possible to provide a liquid crystal display device having a large aperture ratio of the color filter and a good white balance.
図１（ａ）、（ｂ）は、本発明の液晶表示装置の一態様に用いられる光変換部材を含むバックライトユニットの一例を示した概略図である。1A and 1B are schematic views showing an example of a backlight unit including a light conversion member used in one embodiment of the liquid crystal display device of the present invention. 図２（Ａ）は、本発明の液晶表示装置の一態様に用いられるカラーフィルタの各色の着色領域の形状の一例を示した概略図である。図２（Ｂ）は、本発明の範囲外である液晶表示装置に用いられるカラーフィルタの各色の着色領域の形状の一例を示した概略図である。FIG. 2A is a schematic diagram showing an example of the shape of the colored region of each color of the color filter used in one embodiment of the liquid crystal display device of the present invention. FIG. 2B is a schematic view showing an example of the shape of the colored region of each color of the color filter used in the liquid crystal display device outside the scope of the present invention. 図３は、本発明の液晶表示装置の一態様に用いられるカラーフィルタの各色の着色領域の形状の他の一例を示した概略図である。FIG. 3 is a schematic view showing another example of the shape of the colored region of each color of the color filter used in one embodiment of the liquid crystal display device of the present invention. 図４は、本発明の液晶表示装置の一態様に用いられる光変換部材の一例を示した概略図である。FIG. 4 is a schematic view showing an example of a light conversion member used in one embodiment of the liquid crystal display device of the present invention. 図５は、本発明の液晶表示装置の一態様に用いられる光変換部材の他の一例を示した概略図である。FIG. 5 is a schematic view showing another example of the light conversion member used in one embodiment of the liquid crystal display device of the present invention.
　以下に記載する構成要件の説明は、本発明の代表的な実施態様に基づいてなされることがあるが、本発明はそのような実施態様に限定されるものではない。なお、本明細書において「～」を用いて表される数値範囲は、「～」の前後に記載される数値を下限値および上限値として含む範囲を意味する。
　本明細書中、透過率のピーク波長とは、透過率が最大値となるときの波長のことをいう。
　本明細書中、発光中心波長とは、発光強度が最大値となるときの波長のことをいう。
　また、本発明および本明細書中、ピークの「半値幅」とは、ピーク高さ１／２でのピークの幅のことを言う。また、４３０～４８０ｎｍの波長帯域に発光中心波長を有する光を青色光と呼び、５００～６００ｎｍの波長帯域に発光中心波長を有する光を緑色光と呼び、６００～６８０ｎｍの波長帯域に発光中心波長を有する光を赤色光と呼ぶ。 The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
In the present specification, the peak wavelength of transmittance refers to a wavelength at which the transmittance reaches a maximum value.
In the present specification, the emission center wavelength means a wavelength at which the emission intensity becomes a maximum value.
Further, in the present invention and the present specification, the “half-value width” of a peak refers to the width of the peak at a peak height of ½. Also, light having the emission center wavelength in the wavelength band of 430 to 480 nm is called blue light, light having the emission center wavelength in the wavelength band of 500 to 600 nm is called green light, and the emission center wavelength is in the wavelength band of 600 to 680 nm. The light having a color is called red light.
［液晶表示装置］
　本発明の液晶表示装置は、少なくともバックライトと、バックライトから出射された光の一部の波長帯域の光を選択的に透過させる着色領域がパターン状に形成されたカラーフィルタとを有する液晶表示装置であり；
　バックライトが、光源と、この光源から入射する光により励起され蛍光を発光する量子ドットを少なくとも２種類以上含む光変換層を有する光変換部材とを有し；
　カラーフィルタが、４色以上の着色領域を含み、かつ、
　透過率のピーク波長が４００～４８０ｎｍである青色の着色領域、透過率のピーク波長が５００～５６０ｎｍである緑色の着色領域および透過率のピーク波長が６００ｎｍ以上である赤色の着色領域を少なくとも含み、
　カラーフィルタに含まれる各色の着色領域の面積の平均値Ａａｖｅに対する、各色の着色領域の面積の比が、すべての色の着色領域において０．８～１．２である。
　このような構成により、本発明の液晶表示装置は、カラーフィルタの開口率が大きく、良好なホワイトバランスを有する。 [Liquid Crystal Display]
A liquid crystal display device according to the present invention includes at least a backlight and a color filter in which colored regions that selectively transmit light in a partial wavelength band of light emitted from the backlight are formed in a pattern. A device;
A backlight having a light source and a light conversion member having a light conversion layer including at least two kinds of quantum dots excited by light incident from the light source and emitting fluorescence;
The color filter includes four or more colored regions, and
Including at least a blue colored region having a transmittance peak wavelength of 400 to 480 nm, a green colored region having a transmittance peak wavelength of 500 to 560 nm, and a red colored region having a transmittance peak wavelength of 600 nm or more,
The ratio of the area of the colored region of each color to the average value Aave of the area of the colored region of each color included in the color filter is 0.8 to 1.2 in the colored regions of all colors.
With such a configuration, the liquid crystal display device of the present invention has a large aperture ratio of the color filter and a good white balance.
＜液晶表示装置の構成＞
　少なくともバックライトと、バックライトから出射された光の一部の波長帯域の光を選択的に透過させる着色領域がパターン状に形成されたカラーフィルタとを有する。 <Configuration of liquid crystal display device>
At least a backlight and a color filter in which a colored region that selectively transmits light in a part of the wavelength band of light emitted from the backlight is formed in a pattern.
　液晶表示装置は、液晶セルのバックライト側の面にバックライト側偏光板を有することが好ましい。バックライト側偏光板は、バックライト側偏光子のバックライト側の表面に、偏光板保護フィルムを含んでいても、含んでいなくてもよいが、含んでいることが好ましい。
　バックライト側偏光板は、偏光子が、２枚の偏光板保護フィルムで挟まれた構成であることが好ましい。
　本明細書中、偏光子に対して液晶セルに近い側の偏光板保護フィルムをインナー側偏光板保護フィルムと言い、偏光子に対して液晶セルから遠い側の偏光板保護フィルムをアウター側偏光板保護フィルムと言う。 The liquid crystal display device preferably has a backlight-side polarizing plate on the backlight-side surface of the liquid crystal cell. The backlight side polarizing plate may or may not include a polarizing plate protective film on the surface of the backlight side polarizer on the backlight side, but it is preferably included.
The backlight side polarizing plate preferably has a configuration in which a polarizer is sandwiched between two polarizing plate protective films.
In this specification, the polarizing plate protective film on the side closer to the liquid crystal cell with respect to the polarizer is referred to as the inner side polarizing plate protective film, and the polarizing plate protective film on the side farther from the liquid crystal cell with respect to the polarizer is referred to as the outer side polarizing plate. It is called a protective film.
　バックライト側偏光板は、液晶セル側のインナー側偏光板保護フィルムとして、位相差フィルムを有していてもよい。このような位相差フィルムとしては、公知のセルロースアシレートフィルム等を用いることができる。 The backlight side polarizing plate may have a retardation film as an inner side polarizing plate protective film on the liquid crystal cell side. As such a retardation film, a known cellulose acylate film or the like can be used.
　液晶表示装置は、液晶セルのバックライト側の面とは反対側の面に、表示側偏光板を有することが好ましい。表示側偏光板は、偏光子が、２枚の偏光板保護フィルムで挟まれた構成であることが好ましい。偏光板保護フィルムがインナー側偏光板保護フィルムであり、偏光板保護フィルムがアウター側偏光板保護フィルムである。 The liquid crystal display device preferably has a display-side polarizing plate on the surface opposite to the backlight side surface of the liquid crystal cell. The display-side polarizing plate preferably has a configuration in which a polarizer is sandwiched between two polarizing plate protective films. A polarizing plate protective film is an inner side polarizing plate protective film, and a polarizing plate protective film is an outer side polarizing plate protective film.
＜液晶表示装置の液晶セルの構成＞
　液晶セルの駆動モードについては特に制限はなく、ツイステットネマチック（ＴＮ）、スーパーツイステットネマチック（ＳＴＮ）、バーティカルアライメント（ＶＡ）、インプレインスイッチング（ＩＰＳ）、オプティカリーコンペンセイテットベンドセル（ＯＣＢ）等の種々のモードを利用することができる。液晶セルは、ＶＡモード、ＯＣＢモード、ＩＰＳモード、またはＴＮモードであることが好ましく、ＶＡモードであることがより好ましいが、これらに限定されるものではない。ＶＡモードの液晶表示装置の構成としては、特開２００８－２６２１６１号公報の図２に示す構成が一例として挙げられる。ただし、液晶表示装置の具体的構成には特に制限はなく、公知の構成を採用することができる。 <Configuration of liquid crystal cell of liquid crystal display device>
The driving mode of the liquid crystal cell is not particularly limited, and is twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), and optically compensated bend cell (OCB). Various modes such as can be used. The liquid crystal cell is preferably VA mode, OCB mode, IPS mode, or TN mode, more preferably VA mode, but is not limited thereto. As an example of the configuration of the VA mode liquid crystal display device, the configuration shown in FIG. 2 of Japanese Patent Application Laid-Open No. 2008-262161 is given as an example. However, the specific configuration of the liquid crystal display device is not particularly limited, and a known configuration can be adopted.
　液晶表示装置の一実施形態では、対向する少なくとも一方に電極を設けた基板間に液晶層を挟持した液晶セルを有し、この液晶セルは２枚の偏光板の間に配置して構成される。液晶表示装置は、上下基板間に液晶が封入された液晶セルを備え、電圧印加により液晶の配向状態を変化させて画像の表示を行う。さらに必要に応じて偏光板保護フィルムや光学補償を行う光学補償部材、接着層などの付随する機能層を有する。また、液晶表示装置は、カラーフィルタを有する。さらに、薄層トランジスタ基板、レンズフィルム、拡散シート、ハードコート層、反射防止層、低反射層、アンチグレア層等とともに（又はそれに替えて）、前方散乱層、プライマー層、帯電防止層、下塗り層等の表面層が配置されていてもよい。 In one embodiment of the liquid crystal display device, a liquid crystal cell having a liquid crystal layer sandwiched between substrates provided with electrodes on at least one of the opposite sides is provided, and the liquid crystal cell is arranged between two polarizing plates. The liquid crystal display device includes a liquid crystal cell in which liquid crystal is sealed between upper and lower substrates, and displays an image by changing the alignment state of the liquid crystal by applying a voltage. Furthermore, it has an accompanying functional layer such as a polarizing plate protective film, an optical compensation member that performs optical compensation, and an adhesive layer as necessary. The liquid crystal display device includes a color filter. Furthermore, along with (or instead of) thin-layer transistor substrates, lens films, diffusion sheets, hard coat layers, antireflection layers, low reflection layers, antiglare layers, etc., forward scattering layers, primer layers, antistatic layers, undercoat layers, etc. The surface layer may be disposed.
　本発明の一態様にかかる液晶表示装置を構成する液晶セル、偏光板、偏光板保護フィルム等については特に限定はなく、公知の方法で作製されるものや市販品を、何ら制限なく用いることができる。また、各層の間に、接着層等の公知の中間層を設けることも、もちろん可能である。
　以下、本発明の液晶表示装置を構成する各部材の説明をする。 There is no particular limitation on the liquid crystal cell, the polarizing plate, the polarizing plate protective film, and the like constituting the liquid crystal display device according to one embodiment of the present invention, and those prepared by known methods and commercially available products can be used without any limitation. it can. It is of course possible to provide a known intermediate layer such as an adhesive layer between the layers.
Hereafter, each member which comprises the liquid crystal display device of this invention is demonstrated.
（カラーフィルタ）
　本発明の液晶表示装置は、バックライトから出射された光の一部の波長帯域の光を選択的に透過させる着色領域が各色にパターン状に形成されたカラーフィルタを有し、カラーフィルタが、４色以上の着色領域を含み、かつ、透過率のピーク波長が４００～４８０ｎｍである青色の着色領域、透過率のピーク波長が５００～５６０ｎｍである緑色の着色領域および透過率のピーク波長が６００ｎｍ以上である赤色の着色領域を少なくとも含み、カラーフィルタに含まれる各色の着色領域の面積の平均値Ａａｖｅに対する、各色の着色領域の面積の比が、すべての色の着色領域において０．８～１．２である。
　なお、カラーフィルタの着色領域は、画素と呼ばれることがある。 (Color filter)
The liquid crystal display device of the present invention has a color filter in which colored regions that selectively transmit light in a part of the wavelength band of light emitted from the backlight are formed in a pattern for each color, A blue colored region containing four or more colored regions and having a transmittance peak wavelength of 400 to 480 nm, a green colored region having a transmittance peak wavelength of 500 to 560 nm, and a transmittance peak wavelength of 600 nm The ratio of the area of the colored region of each color to the average value Aave of the colored regions of the respective colors included in the color filter is 0.8 to 1 in all the colored regions. .2.
The colored region of the color filter is sometimes called a pixel.
　本発明では、カラーフィルタが、４色以上の着色領域を含み、かつ、透過率のピーク波長が４００～４８０ｎｍである青色の着色領域、透過率のピーク波長が５００～５６０ｎｍである緑色の着色領域および透過率のピーク波長が６００ｎｍ以上である赤色の着色領域を少なくとも含む。
　青色の着色領域の透過率のピーク波長は４３０～４８０ｎｍの波長帯域に存在することが好ましく、４５０～４７５ｎｍの波長帯域に存在することがより好ましい。
　緑色の着色領域の透過率のピーク波長は５１０～５６０ｎｍの波長帯域に存在することが好ましく、５２０～５５０ｎｍの波長帯域に存在することがより好ましい。
　青色の着色領域、緑色の着色領域および赤色の着色領域以外の着色領域としては、透過率のピーク波長が５６０～６００ｎｍである黄色の着色領域や、透過率のピーク波長が４８０～５００ｎｍであるシアンの着色領域を挙げることができる。
　カラーフィルタの着色領域の色数は、４以上であり、４～８であることが好ましく、４～６であることがより好ましく、４または５であることが特に好ましい。
　カラーフィルタの着色領域が５以上である場合、透過率のピーク波長が５６０～６００ｎｍである黄色の着色領域と、透過率のピーク波長が４８０～５００ｎｍであるシアンの着色領域をともに有することが好ましい。
　黄色の着色領域の透過率のピーク波長は５６０～５８５ｎｍの波長帯域に存在することが好ましく、５６５～５８０ｎｍの波長帯域に存在することがより好ましい。
　シアンの着色領域の透過率のピーク波長は４８５～５００ｎｍの波長帯域に存在することが好ましく、４９０～５００ｎｍの波長帯域に存在することがより好ましい。 In the present invention, the color filter includes a colored region having four or more colors, a blue colored region having a transmittance peak wavelength of 400 to 480 nm, and a green colored region having a transmittance peak wavelength of 500 to 560 nm. And at least a red colored region having a transmittance peak wavelength of 600 nm or more.
The peak wavelength of the transmittance of the blue colored region is preferably in the wavelength band of 430 to 480 nm, and more preferably in the wavelength band of 450 to 475 nm.
The peak wavelength of the transmittance of the green colored region is preferably in the wavelength band of 510 to 560 nm, and more preferably in the wavelength band of 520 to 550 nm.
Colored regions other than the blue colored region, the green colored region, and the red colored region include a yellow colored region having a transmittance peak wavelength of 560 to 600 nm, and cyan having a transmittance peak wavelength of 480 to 500 nm. Can be mentioned.
The number of colors in the colored region of the color filter is 4 or more, preferably 4 to 8, more preferably 4 to 6, and particularly preferably 4 or 5.
When the colored region of the color filter is 5 or more, it is preferable to have both a yellow colored region having a transmittance peak wavelength of 560 to 600 nm and a cyan colored region having a transmittance peak wavelength of 480 to 500 nm. .
The peak wavelength of the transmittance of the yellow colored region is preferably in the wavelength band of 560 to 585 nm, and more preferably in the wavelength band of 565 to 580 nm.
The peak wavelength of the transmittance of the cyan colored region is preferably in the wavelength band of 485 to 500 nm, and more preferably in the wavelength band of 490 to 500 nm.
－カラーフィルタ多原色化による斜め色味付きの改善－
　カラーフィルタ多原色化の利点の一つとして、斜め色味付きの改善が挙げられる。
　液晶ディスプレイでは、液晶層に印加する電圧を調整し、各色の光の透過率を制御することで、意図した色を表示する。正面で意図した色を表示した場合、その画素を斜めから視認すると、主に液晶層のリタデーションの角度依存性によって透過率が変化するため、正面と異なる色が表示されてしまう。
　カラーフィルタ多原色化は、正面である色を表示する場合の、各色の透過率の選択肢を増やす効果をもたらす。例えば、赤・緑・青の着色領域を持つ液晶表示装置に、新たに黄色着色領域を追加した場合、黄色を表示する際の選択肢が、赤着色領域と緑着色領域の混合による表示だけでなく、黄色着色領域のみでの表示が可能となる。
　このように正面の色表示の選択肢が増えると、斜め色味付きを勘案して、正面の色表示方法を選択することが可能となり、斜め色味付きの少ない液晶表示装置の提供が可能となる。
　この斜め色味付きの改善は、原理上、ＴＮ、ＶＡ、ＩＰＳなどあらゆるモードの液晶表示装置にて効果が見られるが、斜めでの白とびが見られるＶＡモードにて、その効果が顕著に見られる。なお、ＶＡモードの例としては、ＰＶＡモードを挙げることができる。 -Improvement in diagonal colors by using multiple primary color filters-
One of the advantages of using color filters with multiple primary colors is an improvement in oblique coloring.
In a liquid crystal display, an intended color is displayed by adjusting a voltage applied to a liquid crystal layer and controlling light transmittance of each color. When the intended color is displayed on the front, when the pixel is viewed obliquely, the transmittance changes mainly due to the angle dependency of the retardation of the liquid crystal layer, so that a color different from the front is displayed.
The color filter multi-primary color brings about an effect of increasing the choice of transmittance of each color when displaying the front color. For example, if a new yellow colored area is added to a liquid crystal display device with red, green, and blue colored areas, the option for displaying yellow is not only the display by mixing the red colored area and the green colored area. Thus, it is possible to display only in the yellow colored area.
As the number of options for front color display increases in this way, it becomes possible to select a front color display method in consideration of diagonal coloring, and it is possible to provide a liquid crystal display device with little diagonal coloring. .
In principle, this improvement in oblique coloring is effective in liquid crystal display devices of all modes such as TN, VA, and IPS, but the effect is remarkable in the VA mode in which oblique overexposure is observed. It can be seen. An example of the VA mode is a PVA mode.
－焼きつき－
　カラーフィルタの着色領域はパターン状に形成される。具体的には、カラーフィルタに含まれる各色の着色領域が色ごとに同じ形状に形成され、各色の着色領域が周期的に繰り返されて形成される。
　図２（Ａ）、図２（Ｂ）および図３にカラーフィルタの着色領域のパターンを構成する１単位の例を示す。図２（Ａ）、図２（Ｂ）および図３はカラーフィルタ３０の着色領域が４色である場合について説明するが、本発明はこのような態様に限定されるものではない。
　図２（Ａ）は、青色の着色領域２１、赤色の着色領域２２、緑色の着色領域２３、黄色の着色領域２４が長方形に近似される形状であって、ほぼ同じ面積であるカラーフィルタ３０のパターンである。このような形状の各色の着色領域とすることで、開口率を大きくすることができる。また、以下に説明する焼きつきを抑制することができる。
　図２（Ｂ）のようにカラーフィルタ各色の着色領域の面積が異なると、液晶層および液晶層と信号線間の静電容量に不均一性が生じる。そのため液晶層に印加される交流電圧にオフセットが生じて、液晶表示装置の焼きつきが発生しやすくなる。
　この液晶表示装置の焼きつきは、特に色付きとして視認されることが多い。
　焼きつき防止の観点では、各色の着色領域の面積の平均値Ａａｖｅ対する各色の着色領域の面積の比が０．８～１．２であることが好ましく、０．９～１．１であることがさらに好ましく、０．９８～１．０２であることが特にさらに好ましい。 -Burn-
The colored region of the color filter is formed in a pattern. Specifically, the colored regions of each color included in the color filter are formed in the same shape for each color, and the colored regions of each color are formed periodically and repeatedly.
FIG. 2A, FIG. 2B, and FIG. 3 show an example of one unit constituting the pattern of the colored region of the color filter. 2A, 2B, and 3 illustrate the case where the color region of the color filter 30 has four colors, the present invention is not limited to such an embodiment.
FIG. 2A illustrates a color filter 30 having a shape in which a blue colored region 21, a red colored region 22, a green colored region 23, and a yellow colored region 24 are approximated to a rectangle and have substantially the same area. It is a pattern. The aperture ratio can be increased by using colored regions of each color having such a shape. Moreover, the burn-in described below can be suppressed.
When the areas of the colored regions of the colors of the color filter are different as shown in FIG. 2B, nonuniformity occurs in the capacitance between the liquid crystal layer and the liquid crystal layer and the signal line. For this reason, an offset is generated in the AC voltage applied to the liquid crystal layer, and the liquid crystal display device is likely to be burned.
The burn-in of the liquid crystal display device is often visually recognized as being particularly colored.
From the viewpoint of preventing burn-in, the ratio of the area of the colored region of each color to the average value Aave of the colored region of each color is preferably 0.8 to 1.2, preferably 0.9 to 1.1. Is more preferably 0.98 to 1.02.
　一方、図３のように同じ面積の各色の着色領域を田の字型に配置したパターンとすると、図２（Ａ）の形状の着色領域のパターンとするよりも、さらにカラーフィルタの開口率を高めることができ、好ましい。図３に示すカラーフィルタ３０では、各色の着色領域、すなわち青色の着色領域２１、赤色の着色領域２２、緑色の着色領域２３、黄色の着色領域２４は正方形に近似される形状であって同じ面積である。 On the other hand, when the colored areas of the same area having the same area as shown in FIG. 3 are arranged in a square shape, the aperture ratio of the color filter can be further increased as compared with the colored area pattern of FIG. This is preferable. In the color filter 30 shown in FIG. 3, the colored regions of each color, that is, the blue colored region 21, the red colored region 22, the green colored region 23, and the yellow colored region 24 have a shape approximate to a square and the same area. It is.
　着色領域の形成方法としては、公知の種々の方法を使用することができる。例えばＲ、Ｇ、Ｂなど各色の着色領域を形成する場合、ガラス基板上にフォトマスク、およびフォトレジストを用いて所望のブラックマトリックス、およびＲ、Ｇ、Ｂなど各色の着色領域パターンを形成することもできるし、また、Ｒ、Ｇ、Ｂなど各色の着色領域用着色インクを用いて、所定の幅のブラックマトリクス、およびｎ個置きにブラックマトリクスの幅よりも広いブラックマトリックスで区分された領域内（凸部で囲まれた凹部）に、インクジェット方式の印刷装置を用いて所望の濃度になるまでインク組成物の吐出を行い、Ｒ、Ｇ、Ｂなどの各色の着色領域のパターンからなるカラーフィルタを作製することもできる。画像着色後は、ベーク等することで各着色領域及びブラックマトリックスを完全に硬化させてもよい。また、特開２０１１－２２１５１５号公報や特開２００７－２９９０１４号公報に記載の材料や硬化性組成物、製造方法によってカラーフィルタを作製することも好ましく、これらの公報の内容は本発明に組み込まれる。
　カラーフィルタの好ましい特性は特開２０１１－２２１５１５号公報や特開２００８－０８３６１１号公報などに記載されており、これらの公報の内容は本発明に組み込まれる。
　例えば、緑色を示す着色領域における最大透過率の半分の透過率となる波長は、一方が５９０ｎｍ以上６１０ｎｍ以下であり、他方が４７０ｎｍ以上５００ｎｍ以下であることが好ましい。また、緑色を示す着色領域において最大透過率の半分の透過率となる波長は、一方が５９０ｎｍ以上６００ｎｍ以下であることが好ましい。さらに緑色を示す着色領域における最大透過率は８０％以上であることが好ましい。緑色を示す着色領域において最大透過率となる波長は５３０ｎｍ以上５６０ｎｍ以下であることが好ましい。
　緑色を示す着色領域において、発光ピークの波長における透過率は、最大透過率の１０％以下であることが好ましい。 Various known methods can be used as a method for forming the colored region. For example, when forming colored regions of each color such as R, G, and B, a desired black matrix and a colored region pattern of each color such as R, G, and B are formed on a glass substrate using a photomask and a photoresist. In addition, using colored inks for colored areas of each color such as R, G, B, etc., in an area divided by a black matrix of a predetermined width and a black matrix wider than the width of the black matrix every nth A color filter composed of a colored region pattern of R, G, B, etc., by discharging an ink composition to a (concave portion surrounded by convex portions) using an ink jet printing apparatus until a desired concentration is obtained. Can also be produced. After coloring the image, each colored region and the black matrix may be completely cured by baking or the like. It is also preferable to produce a color filter by the materials, curable compositions, and production methods described in JP 2011-221515 A and JP 2007-299014 A, and the contents of these publications are incorporated in the present invention. .
Preferred characteristics of the color filter are described in Japanese Patent Application Laid-Open No. 2011-221515, Japanese Patent Application Laid-Open No. 2008-083611, and the like, and the contents of these publications are incorporated in the present invention.
For example, it is preferable that one wavelength is 590 nm to 610 nm and the other wavelength is 470 nm to 500 nm in the colored region showing green. Moreover, it is preferable that the wavelength which becomes the transmittance | permeability of half the maximum transmittance in the colored area | region which shows green is 590 nm or more and 600 nm or less. Furthermore, it is preferable that the maximum transmittance in the colored region showing green is 80% or more. It is preferable that the wavelength having the maximum transmittance in the colored region showing green is 530 nm or more and 560 nm or less.
In the colored region showing green, the transmittance at the wavelength of the emission peak is preferably 10% or less of the maximum transmittance.
　赤色を示す着色領域は、５８０ｎｍ以上５９０ｎｍ以下における透過率が最大透過率の１０％以下であることが好ましい。 In the colored region showing red, the transmittance at 580 nm to 590 nm is preferably 10% or less of the maximum transmittance.
　カラーフィルタ用顔料としては、公知のものを何ら制限なく用いることができる。なお、現在は、一般的に顔料を用いているが、分光を制御でき、プロセス安定性、信頼性が確保できる色素であれば、染料による着色領域を有するカラーフィルタであってもよい。 As the color filter pigment, known pigments can be used without any limitation. Currently, a pigment is generally used, but a color filter having a colored region with a dye may be used as long as it is a pigment that can control spectroscopy and ensure process stability and reliability.
（ブラックマトリックス）
　液晶表示装置には、各着色領域の間にブラックマトリックスが配置されていることが好ましい。ブラックストライプを形成する材料としては、クロム等の金属のスパッタ膜を用いたもの、感光性樹脂と黒色着色剤等を組み合わせた遮光性感光性組成物などが挙げられる。黒色着色剤の具体例としては、カーボンブラック、チタンカーボン、酸化鉄、酸化チタン、黒鉛などが挙げられ、中でも、カーボンブラックが好ましい。 (Black matrix)
In the liquid crystal display device, a black matrix is preferably disposed between the colored regions. Examples of the material for forming the black stripe include a material using a sputtered film of a metal such as chromium, and a light-shielding photosensitive composition in which a photosensitive resin and a black colorant are combined. Specific examples of the black colorant include carbon black, titanium carbon, iron oxide, titanium oxide, graphite, and the like. Among these, carbon black is preferable.
（薄層トランジスタ）
　液晶表示装置は、さらに薄層トランジスタ（以下、ＴＦＴとも言う）を有するＴＦＴ基板を有することもできる。薄層トランジスタは、キャリア濃度が１×１０１４／ｃｍ３未満である酸化物半導体層を有することが好ましい。薄層トランジスタの好ましい態様については特開２０１１－１４１５２２号公報に記載されており、この公報の内容は本発明に組み込まれる。 (Thin layer transistor)
The liquid crystal display device can further include a TFT substrate having a thin layer transistor (hereinafter also referred to as TFT). The thin film transistor preferably includes an oxide semiconductor layer having a carrier concentration of less than 1 × 10 14 / cm 3 . A preferred embodiment of the thin layer transistor is described in Japanese Patent Application Laid-Open No. 2011-141522, and the content of this publication is incorporated in the present invention.
＜バックライトユニット＞
　本発明の液晶表示装置は、少なくともバックライトを有する。バックライトが、光源と、光源から入射する光により励起され蛍光を発光する量子ドットを少なくとも２種類以上含む光変換層を有する光変換部材とを有することが好ましい。 <Backlight unit>
The liquid crystal display device of the present invention has at least a backlight. The backlight preferably includes a light source and a light conversion member having a light conversion layer including at least two types of quantum dots that are excited by light incident from the light source and emit fluorescence.
（バックライトユニットの発光波長）
　バックライトユニットは、少なくとも４００～４８０ｎｍ、５００～６００ｎｍおよび６００～６８０ｎｍに発光中心波長を有することが好ましい。
　本発明ではカラーフィルタが透過率のピーク波長が５６０～６００ｎｍである黄色の着色領域を含む場合、バックライトが、少なくとも４００～４８０ｎｍ、５００～６００ｎｍおよび６００～６８０ｎｍに発光中心波長を有し、各発光中心波長における発光強度比が１：０．１７～０．４５：０．１３～０．４であることが好ましく、１：０．２～０．４：０．１５～０．３５であることがより好ましく、１：０．２～０．３：０．２～０．３であることが特に好ましい。
　本発明ではカラーフィルタが透過率のピーク波長が４８０～５００ｎｍであるシアンの着色領域を含む場合、バックライトが、少なくとも４００～４８０ｎｍ、５００～６００ｎｍおよび６００～６８０ｎｍに発光中心波長を有し、各発光中心波長における発光強度比が１：０．２６～０．６３：０．３９～１．１５であることが好ましく、１：０．２６～０．５５：０．５０～１．１０であることがより好ましく、１：０．２６～０．５０：０．５０～１．０５であることが特に好ましい。
　本発明ではカラーフィルタが透過率のピーク波長が５６０～６００ｎｍである黄色の着色領域と、さらに透過率のピーク波長が４８０～５００ｎｍであるシアンの着色領域を含む場合、バックライトが、少なくとも４００～４８０ｎｍ、５００～６００ｎｍおよび６００～６８０ｎｍに発光中心波長を有し、各発光中心波長における発光強度比が１：０．１９～０．４５：０．１９～０．６であることが好ましく、１：０．２５～０．４５：０．１９～０．５５であることがより好ましく、１：０．３～０．４５：０．１９～０．５であることが特に好ましい。 (Emission wavelength of backlight unit)
The backlight unit preferably has an emission center wavelength of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm.
In the present invention, when the color filter includes a yellow colored region having a transmittance peak wavelength of 560 to 600 nm, the backlight has emission center wavelengths of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm, The emission intensity ratio at the emission center wavelength is preferably 1: 0.17 to 0.45: 0.13 to 0.4, and is preferably 1: 0.2 to 0.4: 0.15 to 0.35. It is more preferable that the ratio is 1: 0.2 to 0.3: 0.2 to 0.3.
In the present invention, when the color filter includes a cyan colored region having a transmittance peak wavelength of 480 to 500 nm, the backlight has emission center wavelengths of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm, The emission intensity ratio at the emission center wavelength is preferably 1: 0.26 to 0.63: 0.39 to 1.15, and preferably 1: 0.26 to 0.55: 0.50 to 1.10. It is more preferable that the ratio is 1: 0.26 to 0.50: 0.50 to 1.05.
In the present invention, when the color filter includes a yellow colored region having a transmittance peak wavelength of 560 to 600 nm and a cyan colored region having a transmittance peak wavelength of 480 to 500 nm, the backlight has at least 400 to The emission center wavelengths are preferably 480 nm, 500 to 600 nm, and 600 to 680 nm, and the emission intensity ratio at each emission center wavelength is preferably 1: 0.19 to 0.45: 0.19 to 0.6. : 0.25 to 0.45: 0.19 to 0.55 is more preferable, and 1: 0.3 to 0.45: 0.19 to 0.5 is particularly preferable.
　また、バックライトユニットは、３波長光源により高輝度かつ高い色再現性を実現すべく、４３０～４８０ｎｍの波長帯域に発光中心波長を有し、半値幅が１００ｎｍ以下である発光強度のピークを有する青色光と、５００～６００ｎｍの波長帯域に発光中心波長を有し、半値幅が１００ｎｍ以下である発光強度のピークを有する緑色光と、６００～６８０ｎｍの波長帯域に発光中心波長を有し、半値幅が１００ｎｍ以下である発光強度のピークを有する赤色光と、を発光することがより好ましい。
　より一層の輝度および色再現性の向上の観点から、バックライトユニットが発光する青色光の波長帯域は、４５０～４８０ｎｍであることが好ましく、４６０～４７０ｎｍであることがより好ましい。
　同様の観点から、バックライトユニットが発光する緑色光の波長帯域は、５２０～５５０ｎｍであることが好ましく、５３０～５４０ｎｍであることがより好ましい。
　また、同様の観点から、バックライトユニットが発光する赤色光の波長帯域は、６１０～６５０ｎｍであることが好ましく、６２０～６４０ｎｍであることがより好ましい。 In addition, the backlight unit has a light emission intensity peak with a light emission center wavelength in a wavelength band of 430 to 480 nm and a half-value width of 100 nm or less so as to realize high luminance and high color reproducibility by a three-wavelength light source. Blue light, green light having an emission center wavelength in a wavelength band of 500 to 600 nm and a peak of emission intensity having a half width of 100 nm or less, an emission center wavelength in a wavelength band of 600 to 680 nm, It is more preferable to emit red light having a peak of emission intensity having a value width of 100 nm or less.
From the viewpoint of further improving luminance and color reproducibility, the wavelength band of blue light emitted from the backlight unit is preferably 450 to 480 nm, and more preferably 460 to 470 nm.
From the same viewpoint, the wavelength band of the green light emitted from the backlight unit is preferably 520 to 550 nm, and more preferably 530 to 540 nm.
From the same viewpoint, the wavelength band of red light emitted from the backlight unit is preferably 610 to 650 nm, and more preferably 620 to 640 nm.
　また同様の観点から、バックライトユニットが発光する青色光、緑色光および赤色光の各発光強度の半値幅は、いずれも８０ｎｍ以下であることが好ましく、５０ｎｍ以下であることがより好ましく、４５ｎｍ以下であることがさらに好ましく、４０ｎｍ以下であることが一層好ましい。これらの中でも、青色光の各発光強度の半値幅が３０ｎｍ以下であることが、特に好ましい。 From the same viewpoint, the half-value widths of the emission intensity of blue light, green light, and red light emitted from the backlight unit are all preferably 80 nm or less, more preferably 50 nm or less, and 45 nm or less. It is more preferable that it is 40 nm or less. Among these, it is particularly preferable that the half-value width of each emission intensity of blue light is 30 nm or less.
　バックライトユニットは、少なくとも、上記光変換部材とともに、光源を含む。一態様では、光源として、４３０ｎｍ～４８０ｎｍの波長帯域に発光中心波長を有する青色光を発光するもの、例えば、青色光を発光する青色発光ダイオードを用いることができる。青色光を発光する光源を用いる場合、光変換層には、少なくとも、励起光により励起され赤色光を発光する量子ドット（Ａ）と、緑色光を発光する量子ドット（Ｂ）が含まれることが好ましい。これにより、光源から発光され光変換部材を透過した青色光と、光変換部材から発光される赤色光および緑色光により、白色光を具現化することができる。
　または他の態様では、光源として、３００ｎｍ～４３０ｎｍの波長帯域に発光中心波長を有する紫外光を発光するもの、例えば、紫外光発光ダイオードを用いることができる。この場合、光変換層には、量子ドット（Ａ）、（Ｂ）とともに、励起光により励起され青色光を発光する量子ドット（Ｃ）が含まれることが好ましい。これにより、光変換部材から発光される赤色光、緑色光および青色光により、白色光を具現化することができる。 The backlight unit includes a light source together with at least the light conversion member. In one embodiment, a light source that emits blue light having an emission center wavelength in the wavelength band of 430 nm to 480 nm, for example, a blue light emitting diode that emits blue light can be used. When using a light source that emits blue light, the light conversion layer may include at least quantum dots (A) that are excited by excitation light and emit red light, and quantum dots (B) that emit green light. preferable. Thereby, white light can be embodied by blue light emitted from the light source and transmitted through the light conversion member, and red light and green light emitted from the light conversion member.
Alternatively, in another aspect, a light source that emits ultraviolet light having an emission center wavelength in the wavelength band of 300 nm to 430 nm, for example, an ultraviolet light emitting diode can be used. In this case, it is preferable that the light conversion layer includes quantum dots (C) that are excited by excitation light and emit blue light together with the quantum dots (A) and (B). Thereby, white light can be embodied by red light, green light, and blue light emitted from the light conversion member.
（バックライトユニットの構成）
　バックライトユニットの構成としては、導光板や反射板などを構成部材とするエッジライト方式であることができる。図１には、エッジライト方式のバックライトユニットの例を示したが、本発明の一態様にかかるバックライトユニットは、直下型方式であっても構わない。導光板としては、公知のものを何ら制限なく使用することができる。 (Configuration of backlight unit)
The configuration of the backlight unit may be an edge light system using a light guide plate, a reflection plate, or the like as a constituent member. Although FIG. 1 shows an example of an edge light type backlight unit, the backlight unit according to one embodiment of the present invention may be a direct type. Any known light guide plate can be used without any limitation.
　また、バックライトユニットは、光源の後部に、反射部材を備えることもできる。このような反射部材としては特に制限は無く、公知のものを用いることができ、特許３４１６３０２号、特許３３６３５６５号、特許４０９１９７８号、特許３４４８６２６号などに記載されており、これらの公報の内容は本発明に組み込まれる。 Also, the backlight unit can include a reflecting member at the rear of the light source. There is no restriction | limiting in particular as such a reflecting member, A well-known thing can be used, and it is described in patent 3416302, patent 3363565, patent 4091978, patent 3448626, etc., The content of these gazettes is this Incorporated into the invention.
　バックライトユニットが、青色光のうち５００ｎｍよりも短波長の光を選択的に透過する青色用波長選択フィルタを有することも、好ましい。
　また、バックライトユニットが、赤色光のうち５００ｎｍよりも長波長の光を選択的に透過する赤色用波長選択フィルタを有することも、好ましい。
このような青色用波長選択フィルタや赤色用波長選択フィルタとしては特に制限は無く、公知のものを用いることができる。そのようなフィルタは、特開２００８－５２０６７号公報などに記載されており、この公報の内容は本発明に組み込まれる。 It is also preferable that the backlight unit has a blue wavelength selection filter that selectively transmits light having a wavelength shorter than 500 nm of blue light.
It is also preferable that the backlight unit has a red wavelength selection filter that selectively transmits light having a wavelength longer than 500 nm of red light.
There is no restriction | limiting in particular as such a blue wavelength selection filter or a red wavelength selection filter, A well-known thing can be used. Such a filter is described in Japanese Patent Application Laid-Open No. 2008-52067, and the content of this publication is incorporated in the present invention.
　バックライトユニットは、その他、公知の拡散板や拡散シート、プリズムシート（例えば、住友スリーエム社製ＢＥＦシリーズなど）、導光器を備えていることも好ましい。その他の部材についても、特許３４１６３０２号、特許３３６３５６５号、特許４０９１９７８号、特許３４４８６２６号などに記載されており、これらの公報の内容は本発明に組み込まれる。 The backlight unit preferably further includes a known diffusion plate, diffusion sheet, prism sheet (for example, BEF series manufactured by Sumitomo 3M Limited), and a light guide. Other members are also described in Japanese Patent No. 3416302, Japanese Patent No. 3363565, Japanese Patent No. 4091978, Japanese Patent No. 3448626, and the contents of these publications are incorporated in the present invention.
（光変換部材）
　本発明の一態様にかかる光変換部材は、入射する励起光により励起され蛍光を発光する量子ドットを含む光変換層を有する光変換部材である。
　上記光変換層は、６００ｎｍ～６８０ｎｍの範囲の波長帯域に発光中心波長を有する量子ドット（Ａ）と、量子ドット（Ａ）よりも短波長帯域に発光中心波長を有する一種以上の量子ドット（Ｚ）と、を含有することが好ましい。
　そして上記光変換層において、量子ドット（Ａ）は、量子ドット（Ｚ）に対して励起光入射側に相対的に偏在していることが好ましい。ここで、量子ドット（Ａ）が、量子ドット（Ｚ）に対して励起光入射側に相対的に偏在しているとは、光変換層を入射光に対して垂直な任意の面にて、入射側領域と出射側領域の２領域に分割した際に、入射側領域内に存在する量子ドット（Ａ）の存在比率が、量子ドット（Ｚ）（一種のみであることもあり、二種以上であることもある。）の入射側領域内に存在する存在比率よりも多いことをいう。より詳しくは、量子ドット（Ａ）が入射側領域にＡ１個、出射側領域にＡ２個、量子ドット（Ｚ）が入射側領域にＺ１個、出射側領域にＺ２個存在した場合、光変換層に含まれる全量子ドット（Ａ）（Ａ１＋Ａ２）に対する入射側領域の量子ドット（Ａ）の存在比率［Ａ１／（Ａ１＋Ａ２）］が、光変換層に含まれる全量子ドット（Ｚ１＋Ｚ２）に対する入射側領域の量子ドット（Ｚ）の存在比率［Ｚ１／（Ｚ１＋Ｚ２）］より大きいこと、つまり、以下の式（１）を満たすことを指す。
　Ａ１／（Ａ１＋Ａ２）＞Ｚ１／（Ｚ１＋Ｚ２）　　・・・（１） (Light conversion member)
The light conversion member according to one embodiment of the present invention is a light conversion member having a light conversion layer including quantum dots that are excited by incident excitation light and emit fluorescence.
The light conversion layer includes a quantum dot (A) having an emission center wavelength in a wavelength range of 600 nm to 680 nm and one or more quantum dots (Z) having an emission center wavelength in a shorter wavelength band than the quantum dot (A). And).
In the light conversion layer, the quantum dots (A) are preferably unevenly distributed on the excitation light incident side with respect to the quantum dots (Z). Here, that the quantum dots (A) are relatively unevenly distributed on the excitation light incident side with respect to the quantum dots (Z) means that the light conversion layer is on an arbitrary surface perpendicular to the incident light, When divided into two areas of the incident side area and the emission side area, the abundance ratio of the quantum dots (A) existing in the incident side area is the quantum dot (Z) (there may be only one kind, two or more kinds It is more than the abundance ratio existing in the incident side region. More specifically, when there are A1 quantum dots (A) in the incident side region, A2 pieces in the output side region, Z1 pieces in the incident side region, and Z2 pieces in the output side region, the light conversion layer The abundance ratio [A1 / (A1 + A2)] of the quantum dots (A) in the incident side region with respect to all the quantum dots (A) (A1 + A2) included in the incident side region with respect to all the quantum dots (Z1 + Z2) included in the light conversion layer That is larger than the abundance ratio [Z1 / (Z1 + Z2)] of the quantum dots (Z), that is, satisfying the following formula (1).
A1 / (A1 + A2)> Z1 / (Z1 + Z2) (1)
　光変換層における量子ドットの偏在については、光変換層を任意の箇所で切断し、その断面を、電子顕微鏡を用いて観察し量子ドットの個数を計測し、以下の式で算出することで測定できる。
　光変換層の励起光入射側表面および出射側表面に垂直な方向をｘ軸とする。ｘ軸に沿った光変換層の厚みをＬとし、ｘ＝０が励起光入射側表面、ｘ＝Ｌが出射側と定義する。量子ドット（Ａ）の規格化数密度分布をφＡ（ｘ）、量子ドット（Ｚ）の規格化数密度分布をφＺ（ｘ）とする。
つまり、
Figure JPOXMLDOC01-appb-M000001
 が成立する。
量子ドット（Ａ）、（Ｚ）の偏在性を表す指標として、下式で表されるΦを定義する。
Figure JPOXMLDOC01-appb-M000002
 　Φ＝１の場合、量子ドット（Ａ）は、量子ドット（Ｚ）と混ざりあう領域を持つことなく入射側へ偏在しており、一方、Φ＝０の場合、量子ドット（Ａ）は、量子ドット（Ｚ）と混ざりあう領域を持つことなく出射側へ偏在していることを表す。
　また、量子ドット（Ａ）および量子ドット（Ｚ）が、混合され均一に分散している場合、Φ＝０．５となる。
　量子ドットの発光効率の観点から、Φが０．５より大きいことが好ましく、Φが０．７より大きいことがより好ましく、Φが０．８より大きいことがさらに好ましく、Φが０．９５より大きいことがより一層好ましい。 The uneven distribution of quantum dots in the light conversion layer is measured by cutting the light conversion layer at an arbitrary location, observing the cross section with an electron microscope, measuring the number of quantum dots, and calculating with the following formula: it can.
The direction perpendicular to the excitation light incident side surface and the emission side surface of the light conversion layer is taken as the x-axis. The thickness of the light conversion layer along the x axis is defined as L, where x = 0 is defined as the excitation light incident side surface and x = L is defined as the emission side. The normalized number density distribution of the quantum dots (A) is φA (x), and the normalized number density distribution of the quantum dots (Z) is φZ (x).
That means
Figure JPOXMLDOC01-appb-M000001
 Is established.
Φ represented by the following formula is defined as an index representing the uneven distribution of quantum dots (A) and (Z).
Figure JPOXMLDOC01-appb-M000002
 When Φ = 1, the quantum dots (A) are unevenly distributed to the incident side without having a region mixed with the quantum dots (Z). On the other hand, when Φ = 0, the quantum dots (A) This means that it is unevenly distributed to the emission side without having a region mixed with the dot (Z).
When the quantum dots (A) and the quantum dots (Z) are mixed and uniformly dispersed, Φ = 0.5.
From the viewpoint of the luminous efficiency of the quantum dots, Φ is preferably greater than 0.5, Φ is more preferably greater than 0.7, Φ is more preferably greater than 0.8, and Φ is greater than 0.95. Larger is even more preferable.
　上記のように、量子ドット（Ａ）を、量子ドット（Ｚ）に対して励起光入射側に相対的に偏在させることにより、赤色光を発光する量子ドットである量子ドット（Ａ）が、量子ドット（Ｚ）が励起し発光した蛍光を吸収することを防ぐことができる。これにより、量子ドットを含む光変換部材の発光効率を高めることができる。 As described above, the quantum dot (A), which is a quantum dot that emits red light, is distributed in the quantum dot (A) relative to the excitation light incident side relative to the quantum dot (Z). It is possible to prevent the dots (Z) from being excited and absorbing the emitted fluorescence. Thereby, the light emission efficiency of the light conversion member containing a quantum dot can be improved.
　光変換部材は、好ましくは、液晶表示装置のバックライトユニットの構成部材として含まれる。 The light conversion member is preferably included as a constituent member of the backlight unit of the liquid crystal display device.
　図１は、本発明の液晶表示装置の一態様に用いられる光変換部材を含むバックライトユニットの一例を示した概略図である。図１中、バックライトユニット３１は、光源３１Ａと、面光源とするための導光板３１Ｂを備える。図１（ａ）に示す例では、光変換部材は、導光板から出射される光の経路上に配置されている。一方、図１（ｂ）に示す例では、光変換部材は、導光板と光源との間に配置されている。
　そして図１（ａ）に示す例では、導光板３１Ｂから出射される光が、光変換部材３１Ｃに入射する。図１（ａ）に示す例では、導光板３１Ｂのエッジ部に配置された光源３１Ａから出射される光は青色光３２であり、導光板３１Ｂの液晶セル（図示せず）側の面から液晶セルに向けて出射される。導光板３１Ｂから出射された光（青色光３２）の経路上に配置された光変換部材３１Ｃには、青色光３２により励起され赤色光３４を発光する量子ドット（Ａ）と、青色光３２により励起され緑色光３３を発光する量子ドット（Ｂ）を、少なくとも含む。このようにしてバックライトユニット３１からは、励起された緑色光３３および赤色光３４、ならびに光変換部材３１Ｃを透過した青色光３２が出射される。こうしてＲＧＢの輝線光を発光させることで、白色光を具現化することができる。
　図１（ｂ）に示す例は、光変換部材と導光板の配置が異なる点以外は、図１（ａ）に示す態様と同様である。図１（ｂ）に示す例では、光変換部材３１Ｃから、励起された緑色光３３および赤色光３４、ならびに光変換部材３１Ｃを透過した青色光３２が出射され導光板に入射し、面光源が実現される。 FIG. 1 is a schematic view showing an example of a backlight unit including a light conversion member used in one embodiment of the liquid crystal display device of the present invention. In FIG. 1, the backlight unit 31 includes a light source 31A and a light guide plate 31B for use as a surface light source. In the example shown in FIG. 1A, the light conversion member is disposed on the path of light emitted from the light guide plate. On the other hand, in the example shown in FIG. 1B, the light conversion member is disposed between the light guide plate and the light source.
In the example shown in FIG. 1A, light emitted from the light guide plate 31B enters the light conversion member 31C. In the example shown in FIG. 1A, the light emitted from the light source 31A arranged at the edge portion of the light guide plate 31B is blue light 32, and the liquid crystal is displayed from the surface of the light guide plate 31B on the liquid crystal cell (not shown) side. It is emitted toward the cell. The light conversion member 31C disposed on the path of the light (blue light 32) emitted from the light guide plate 31B has the quantum dots (A) that are excited by the blue light 32 and emit the red light 34, and the blue light 32. It includes at least quantum dots (B) that are excited to emit green light 33. In this way, the backlight unit 31 emits the excited green light 33 and red light 34 and the blue light 32 transmitted through the light conversion member 31C. By emitting RGB bright line light in this way, white light can be realized.
The example shown in FIG. 1B is the same as the embodiment shown in FIG. 1A except that the arrangement of the light conversion member and the light guide plate is different. In the example shown in FIG. 1B, the excited green light 33 and red light 34, and the blue light 32 transmitted through the light conversion member 31C are emitted from the light conversion member 31C and incident on the light guide plate. Realized.
－光変換層－
　光変換部材は、少なくとも、入射する励起光により励起され蛍光を発光する量子ドットを含む光変換層を有する。 -Light conversion layer-
The light conversion member has at least a light conversion layer including quantum dots that are excited by incident excitation light and emit fluorescence.
　光変換層は、６００ｎｍ～６８０ｎｍの範囲の波長帯域に発光中心波長を有する量子ドット（Ａ）と、量子ドット（Ａ）よりも短波長帯域に発光中心波長を有する一種以上の量子ドット（Ｚ）と、を含有することが好ましい。量子ドット（Ａ）は、励起光を受けて赤色光を発光することができる。一方、量子ドット（Ｚ）は、好ましくは、５００ｎｍ～６００ｎｍの範囲の波長帯域に発光中心波長を有する量子ドット（Ｂ）を含む。この量子ドット（Ｂ）は、励起光を受けて緑色光を発光することができる。このように、赤色光を発光する量子ドットと緑色光を発光する量子ドットを含む光変換層を有する光変換部材に、例えば青色光を入射させることで、上述の通り、ＲＧＢの輝線光を発光可能な光変換部材を得ることができる。 The light conversion layer includes a quantum dot (A) having an emission center wavelength in a wavelength range of 600 nm to 680 nm and one or more types of quantum dots (Z) having an emission center wavelength in a shorter wavelength band than the quantum dot (A). It is preferable to contain. The quantum dots (A) can emit red light upon receiving excitation light. On the other hand, the quantum dot (Z) preferably includes a quantum dot (B) having an emission center wavelength in a wavelength range of 500 nm to 600 nm. This quantum dot (B) can emit green light upon receiving excitation light. Thus, as described above, for example, blue light is incident on a light conversion member having a light conversion layer including quantum dots emitting red light and quantum dots emitting green light. A possible light conversion member can be obtained.
　ここで、量子ドットは粒径に応じた波長の蛍光を発する特徴を有するため、量子ドット光源は、異なる粒径の量子ドット混合比率を任意に調整することで、発光色および発光強度比を容易に制御することができる。バックライトの各色の光の発光強度比と、異なる粒径の量子ドットの混合比率は、任意に調整することができる。例えば、以下の態様が好ましい。
　本発明ではカラーフィルタが透過率のピーク波長が５６０～６００ｎｍである黄色の着色領域を含む場合、バックライトが、少なくとも４００～４８０ｎｍ、５００～６００ｎｍおよび６００～６８０ｎｍに発光中心波長を有し、各発光中心波長における発光強度比が１：０．１７～０．４５：０．１３～０．４であることが好ましいが、このとき６００ｎｍ～６８０ｎｍの範囲の波長帯域に発光中心波長を有する量子ドット（Ａ）と５００ｎｍ～６００ｎｍの範囲の波長帯域に発光中心波長を有する量子ドット（Ｂ）の光変換層中における混合比率は、１：３～４：１であることが好ましく、１：２～３：１であることがより好ましく、２：３～３：２であることが特に好ましい。
　本発明ではカラーフィルタが透過率のピーク波長が４８０～５００ｎｍであるシアンの着色領域を含む場合、バックライトが、少なくとも４００～４８０ｎｍ、５００～６００ｎｍおよび６００～６８０ｎｍに発光中心波長を有し、各発光中心波長における発光強度比が１：０．２６～０．６３：０．３９～１．１５であることが好ましいが、このとき６００ｎｍ～６８０ｎｍの範囲の波長帯域に発光中心波長を有する量子ドット（Ａ）と５００ｎｍ～６００ｎｍの範囲の波長帯域に発光中心波長を有する量子ドット（Ｂ）の光変換層中における混合比率は、１：５～２：１であることが好ましく、１：５～５：４であることがより好ましく、１：４～１：１であることが特に好ましい。
　本発明ではカラーフィルタが透過率のピーク波長が５６０～６００ｎｍである黄色の着色領域と、さらに透過率のピーク波長が４８０～５００ｎｍであるシアンの着色領域を含む場合、バックライトが、少なくとも４００～４８０ｎｍ、５００～６００ｎｍおよび６００～６８０ｎｍに発光中心波長を有し、各発光中心波長における発光強度比が１：０．１９～０．４５：０．１９～０．６であることが好ましいが、このとき６００ｎｍ～６８０ｎｍの範囲の波長帯域に発光中心波長を有する量子ドット（Ａ）と５００ｎｍ～６００ｎｍの範囲の波長帯域に発光中心波長を有する量子ドット（Ｂ）の光変換層中における混合比率は、１：３～３：１であることが好ましく、２：５～５：２であることがより好ましく、３：５～５：２であることが特に好ましい。 Here, since the quantum dot has the feature of emitting fluorescence with a wavelength according to the particle size, the quantum dot light source can easily adjust the emission color and emission intensity ratio by arbitrarily adjusting the mixing ratio of quantum dots with different particle sizes. Can be controlled. The light emission intensity ratio of each color of the backlight and the mixing ratio of quantum dots having different particle diameters can be arbitrarily adjusted. For example, the following embodiments are preferable.
In the present invention, when the color filter includes a yellow colored region having a transmittance peak wavelength of 560 to 600 nm, the backlight has emission center wavelengths of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm, It is preferable that the emission intensity ratio at the emission center wavelength is 1: 0.17 to 0.45: 0.13 to 0.4. At this time, the quantum dot having the emission center wavelength in the wavelength band of 600 nm to 680 nm. The mixing ratio in the light conversion layer of (A) and the quantum dot (B) having the emission center wavelength in the wavelength range of 500 nm to 600 nm is preferably 1: 3 to 4: 1, and 1: 2 to The ratio is more preferably 3: 1, and particularly preferably 2: 3 to 3: 2.
In the present invention, when the color filter includes a cyan colored region having a transmittance peak wavelength of 480 to 500 nm, the backlight has emission center wavelengths of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm, The light emission intensity ratio at the emission center wavelength is preferably 1: 0.26 to 0.63: 0.39 to 1.15. At this time, the quantum dot having the emission center wavelength in the wavelength band of 600 nm to 680 nm. The mixing ratio of (A) and quantum dots (B) having an emission center wavelength in the wavelength band of 500 nm to 600 nm in the light conversion layer is preferably 1: 5 to 2: 1, and 1: 5 to 5: 4 is more preferable, and 1: 4 to 1: 1 is particularly preferable.
In the present invention, when the color filter includes a yellow colored region having a transmittance peak wavelength of 560 to 600 nm and a cyan colored region having a transmittance peak wavelength of 480 to 500 nm, the backlight has at least 400 to Preferably, the emission center wavelengths are 480 nm, 500 to 600 nm, and 600 to 680 nm, and the emission intensity ratio at each emission center wavelength is 1: 0.19 to 0.45: 0.19 to 0.6. At this time, the mixing ratio in the light conversion layer of the quantum dot (A) having the emission center wavelength in the wavelength band of 600 nm to 680 nm and the quantum dot (B) having the emission center wavelength in the wavelength band of 500 nm to 600 nm is 1: 3 to 3: 1 is preferable, 2: 5 to 5: 2 is more preferable, and 3: 5 to 5: 2 is preferable. It is particularly preferred.
　一方、先に記載したように、このような光変換部材において、量子ドット（Ａ）が、量子ドット（Ｚ）が発光した光を吸収してしまっては、高い発光効率を実現することは困難である。これに対し本発明の一態様にかかる光変換部材では、光変換層において、量子ドット（Ａ）が、量子ドット（Ｚ）に対して励起光入射側に相対的に偏在していることがより好ましい。この逆に、量子ドット（Ｚ）が量子ドット（Ａ）よりも励起光入射側に相対的に偏在している光変換層では、入射した光は量子ドット（Ｚ）に優先的に吸収され、量子ドット（Ｚ）が蛍光を発光する。赤色光を発光する量子ドット（Ａ）の吸光スペクトルは赤色光よりも短波長側に広がっているため、量子ドット（Ｚ）が発光した蛍光は、量子ドット（Ａ）により吸収されてしまう。これに対し上述の本発明の一態様にかかる光変換部材では、光変換層に入射した光は、量子ドット（Ａ）に優先的に吸光されるため、まず量子ドット（Ａ）が発光するため、好ましい。量子ドット（Ａ）により発光された赤色光は、量子ドット（Ｚ）よりも短波長帯域に発光中心波長を有する量子ドット（Ｂ）に吸収されないか、またはその吸収量は少ないため、量子ドット（Ａ）により発光された光を高効率で利用することができる。 On the other hand, as described above, in such a light conversion member, if the quantum dots (A) absorb the light emitted by the quantum dots (Z), it is difficult to achieve high light emission efficiency. It is. In contrast, in the light conversion member according to one embodiment of the present invention, in the light conversion layer, the quantum dots (A) are more unevenly distributed on the excitation light incident side with respect to the quantum dots (Z). preferable. On the contrary, in the light conversion layer in which the quantum dots (Z) are relatively unevenly distributed on the excitation light incident side with respect to the quantum dots (A), the incident light is preferentially absorbed by the quantum dots (Z), The quantum dots (Z) emit fluorescence. Since the absorption spectrum of the quantum dot (A) that emits red light spreads to the shorter wavelength side than the red light, the fluorescence emitted from the quantum dot (Z) is absorbed by the quantum dot (A). On the other hand, in the light conversion member according to one embodiment of the present invention described above, the light incident on the light conversion layer is preferentially absorbed by the quantum dots (A), so that the quantum dots (A) first emit light. ,preferable. The red light emitted by the quantum dot (A) is not absorbed by the quantum dot (B) having the emission center wavelength in a shorter wavelength band than the quantum dot (Z) or the amount of absorption thereof is small. The light emitted by A) can be used with high efficiency.
　なお量子ドット（Ｚ）は、一種の量子ドットのみであってもよく、二種以上の量子ドットであってもよい。例えば量子ドット（Ｚ）として、量子ドット（Ｂ）よりも短波長帯域に発光中心波長を有する量子ドット、好ましくは、４００ｎｍ～５００ｎｍの波長帯域に発光中心波長を有する量子ドット（Ｃ）を含むこともできる。 Note that the quantum dot (Z) may be only one kind of quantum dot or two or more kinds of quantum dots. For example, the quantum dot (Z) includes a quantum dot having an emission center wavelength in a shorter wavelength band than the quantum dot (B), preferably a quantum dot (C) having an emission center wavelength in a wavelength band of 400 nm to 500 nm. You can also.
　量子ドット（Ｃ）は、励起して青色光を発光する量子ドットである。例えば光源として、３００～４３０ｎｍの紫外光を発光する光源を用いる場合、光変換層に量子ドット（Ａ）、（Ｂ）とともに量子ドット（Ｃ）を含むことにより、量子ドット（Ａ）が発光する赤色光、量子ドット（Ｂ）が発光する緑色光、および量子ドット（Ｃ）が発光する青色光により、ＲＧＢの輝線光を発光させることで、白色光を具現化することができる。この場合には、前述の理由から、量子ドット（Ｂ）は、量子ドット（Ｃ）に対して励起光入射側に相対的に偏在させることが好ましい。 Quantum dots (C) are quantum dots that are excited to emit blue light. For example, when a light source that emits ultraviolet light of 300 to 430 nm is used as the light source, the quantum dot (A) emits light by including the quantum dot (C) together with the quantum dot (A) and (B) in the light conversion layer. White light can be realized by emitting RGB bright line light using red light, green light emitted from the quantum dots (B), and blue light emitted from the quantum dots (C). In this case, for the reasons described above, the quantum dots (B) are preferably unevenly distributed on the excitation light incident side with respect to the quantum dots (C).
　光変換部材の中でも、以下に説明する新規な光変換部材を本発明の液晶表示装置に用いることができる。上述の新規な光変換部材である本発明の光変換部材は、入射する励起光により励起され蛍光を発光する量子ドットを少なくとも４種類以上含む光変換層を有する。入射する励起光により励起され蛍光を発光する量子ドットを少なくとも４種類以上含む光変換層には、上述の量子ドット（Ａ）、（Ｂ）および（Ｃ）に加えて、４８０～５００ｎｍの波長帯域に発光中心波長を有するシアンの蛍光発光をする量子ドットや、５６０～６００ｎｍの波長帯域に発光中心波長を有する黄色の蛍光発光をする量子ドットなどを含めることができる。 Among the light conversion members, a novel light conversion member described below can be used in the liquid crystal display device of the present invention. The light conversion member of the present invention which is the above-described novel light conversion member has a light conversion layer including at least four types of quantum dots which are excited by incident excitation light and emit fluorescence. In addition to the quantum dots (A), (B), and (C) described above, the light conversion layer including at least four types of quantum dots that are excited by incident excitation light and emit fluorescence emits a wavelength band of 480 to 500 nm. In addition, quantum dots emitting cyan fluorescent light having an emission center wavelength, and quantum dots emitting yellow fluorescent light having an emission center wavelength in a wavelength band of 560 to 600 nm can be included.
　以下に、光変換層における量子ドット（Ａ）の偏在の具体的態様について説明する。以下に説明する図面において、図中の下方が入射側、上方が出射側である。 Hereinafter, specific modes of uneven distribution of quantum dots (A) in the light conversion layer will be described. In the drawings described below, the lower side in the figure is the incident side, and the upper side is the outgoing side.
　光変換層では、量子ドット（Ａ）および量子ドット（Ｂ）が、層内で均一に分散していてもよい。このような光変換層へ励起光が入射すると、先に説明したように、量子ドット（Ｂ）が発光した緑色光が、量子ドット（Ａ）に吸収される。 In the light conversion layer, the quantum dots (A) and the quantum dots (B) may be uniformly dispersed in the layer. When excitation light enters such a light conversion layer, as described above, the green light emitted from the quantum dots (B) is absorbed by the quantum dots (A).
　一方、図５は、本発明の一態様にかかる光変換部材の説明図である。図５では、量子ドット（Ａ）（図中、符号３）が、量子ドット（Ａ）よりも短波長帯域に発光中心波長を有する量子ドット（Ｂ）（図中、符号２）に対して励起光入射側に相対的に偏在している。 On the other hand, FIG. 5 is an explanatory diagram of a light conversion member according to one embodiment of the present invention. In FIG. 5, the quantum dot (A) (symbol 3 in the figure) is excited with respect to the quantum dot (B) (symbol 2 in the figure) having an emission center wavelength in a shorter wavelength band than the quantum dot (A). It is relatively unevenly distributed on the light incident side.
　図５に示す光変換部材では、光変換層１０２において、量子ドットとして量子ドット（Ａ）のみを含む第一の量子ドット層１０２Ａと、量子ドットとして量子ドット（Ｂ）のみを含む第二の量子ドット層１０２Ｂが、直接隣接して積層されている。このような量子ドット層は、量子ドットを、樹脂材料中に分散させることにより作製することができる。量子ドット層の形状は特に限定されるものではなく、シート状、バー状等の任意の形状であることができる。量子ドットについては、例えば特開２０１２－１６９２７１号公報の段落００６０～００６６を参照することができるが、ここに記載のものに限定されるものではない。量子ドットとしては、市販品を何ら制限なく用いることができる。量子ドットの発光波長は、通常、粒子の組成、サイズにより調整することができる。 In the light conversion member shown in FIG. 5, in the light conversion layer 102, the first quantum dot layer 102A including only the quantum dots (A) as the quantum dots and the second quantum including only the quantum dots (B) as the quantum dots. The dot layer 102B is laminated directly adjacent. Such a quantum dot layer can be produced by dispersing quantum dots in a resin material. The shape of the quantum dot layer is not particularly limited, and may be any shape such as a sheet shape or a bar shape. As for the quantum dots, for example, paragraphs 0060 to 0066 of JP2012-169271A can be referred to, but the quantum dots are not limited thereto. As the quantum dots, commercially available products can be used without any limitation. The emission wavelength of the quantum dots can usually be adjusted by the composition and size of the particles.
　光変換層は、量子ドットとして量子ドット（Ａ）および量子ドット（Ｂ）に加えて、量子ドット（Ｂ）よりも短波長帯域であって、４００ｎｍ～５００ｎｍの波長帯域に発光中心波長を有する量子ドット（Ｃ）を量子ドットとして含む第三の量子ドットが含まれていてもよい。このような光変換部材は、例えば光源として３００ｎｍ～４３０ｎｍの波長帯域に発光中心波長を有する光源（ＵＶ光源）を用いることにより、赤色光、緑色光、青色光が発光することで、白色光を具現化することができるものである。 In addition to the quantum dots (A) and quantum dots (B) as the quantum dots, the light conversion layer has a shorter wavelength band than the quantum dots (B) and has a light emission center wavelength in the wavelength band of 400 nm to 500 nm. A third quantum dot including the dot (C) as a quantum dot may be included. Such a light conversion member uses, for example, a light source (UV light source) having a light emission center wavelength in a wavelength band of 300 nm to 430 nm as a light source, thereby emitting white light by emitting red light, green light, and blue light. It can be embodied.
　光変換層は、５６０ｎｍ～６００ｎｍの波長帯域に発光中心波長を有する量子ドット（Ｄ）、もしくは、４８０ｎｍ～５００ｎｍの波長帯域に発光中心波長を有する量子ドット（Ｅ）、が含まれていてもよい。このような光変換部材を含む液晶表示装置は、黄色およびシアン発色時の光量が多く、階調性に優れた画像の表示が可能となる。 The light conversion layer may include a quantum dot (D) having an emission center wavelength in a wavelength band of 560 nm to 600 nm, or a quantum dot (E) having an emission center wavelength in a wavelength band of 480 nm to 500 nm. . A liquid crystal display device including such a light conversion member has a large amount of light at the time of yellow and cyan color development and can display an image with excellent gradation.
－光変換層の他の成分、光変換層の形成方法－
　シート状の量子ドット層は、好ましくは塗布法により作製される。具体的には、量子ドットを含む重合性組成物（硬化性組成物）を基材上等に塗布し、次いで光照射等により硬化処理を施すことにより、シート状の量子ドット層を得ることができる。また、組成、量子ドット濃度、または組成および量子ドット濃度の異なる重合性組成物を順次塗布、硬化することにより、二層以上の量子ドット層を積層することができる。または、同種の量子ドットを異なる濃度で含む二種以上の重合性組成物を、高濃度のものから低濃度の順に、またはその逆の順に塗布することにより、量子ドットの濃度が連続的ないし段階的に変化する量子ドット層を作製することもできる。塗布は、同時重層塗布（下層が未乾燥のうちに上層を塗布）により行ってもよく、逐次重層塗布（下層の乾燥後、好ましくは硬化後に、上層を塗布）により行ってもよい。逐次重層塗布によれば、層間の混ざり合いが生じにくいため、一種の量子ドットのみを含む量子ドット層を得るためには、逐次重層塗布を行うことが好ましい。一方、同種の量子ドットを含み濃度の異なる二種以上の重合性組成物を積層することで量子ドットの濃度が連続的に変化する量子ドット層を得る際には、同時重層塗布、逐次重層塗布とも好ましい。 -Other components of the light conversion layer and method for forming the light conversion layer-
The sheet-like quantum dot layer is preferably produced by a coating method. Specifically, a sheet-like quantum dot layer can be obtained by applying a polymerizable composition (a curable composition) containing quantum dots on a substrate and then performing a curing treatment by light irradiation or the like. it can. Also, two or more quantum dot layers can be laminated by sequentially applying and curing polymerizable compositions having different compositions, quantum dot concentrations, or composition and quantum dot concentrations. Alternatively, by applying two or more polymerizable compositions containing the same kind of quantum dots at different concentrations, the concentration of the quantum dots can be continuously or gradually increased by applying from the highest concentration to the lowest concentration or vice versa. It is also possible to produce a quantum dot layer that changes with time. The coating may be performed by simultaneous multilayer coating (the upper layer is coated while the lower layer is undried) or sequentially by multilayer coating (after the lower layer is dried, preferably after curing, the upper layer is coated). According to the sequential multilayer coating, inter-layer mixing is unlikely to occur. Therefore, in order to obtain a quantum dot layer including only one kind of quantum dots, it is preferable to perform sequential multilayer coating. On the other hand, when obtaining a quantum dot layer in which the concentration of quantum dots changes continuously by laminating two or more kinds of polymerizable compositions containing the same type of quantum dots and different concentrations, simultaneous multilayer coating and sequential multilayer coating Both are preferable.
　重合性組成物の作製に用いる重合性化合物は特に限定されるものではない。硬化後の硬化被膜の透明性、密着性等の観点からは、単官能または多官能（メタ）アクリレートモノマー等の（メタ）アクリレート化合物や、そのポリマー、プレポリマー等が好ましい。なお本発明および本明細書において、「（メタ）アクリレート」との記載は、アクリレートとメタクリレートとの少なくともいずれかの意味で用いるものとする。「（メタ）アクリロイル」等も同様である。 The polymerizable compound used for preparing the polymerizable composition is not particularly limited. From the viewpoint of transparency and adhesion of the cured film after curing, (meth) acrylate compounds such as monofunctional or polyfunctional (meth) acrylate monomers, polymers thereof, prepolymers, and the like are preferable. In addition, in this invention and this specification, description with "(meth) acrylate" shall be used by the meaning of at least any one of an acrylate and a methacrylate. The same applies to “(meth) acryloyl” and the like.
　単官能（メタ）アクリレートモノマーとしては、アクリル酸およびメタクリル酸、それらの誘導体、より詳しくは、（メタ）アクリル酸の重合性不飽和結合（（メタ）アクリロイル基）を分子内に１個有するモノマーを挙げることができる。それらの具体例については、ＷＯ２０１２／０７７８０７Ａ１段落００２２を参照できる。 Monofunctional (meth) acrylate monomers include acrylic acid and methacrylic acid, derivatives thereof, and more specifically, monomers having one polymerizable unsaturated bond ((meth) acryloyl group) of (meth) acrylic acid in the molecule Can be mentioned. Reference can be made to WO2012 / 0777807A1 paragraph 0022 for specific examples thereof.
　上記（メタ）アクリル酸の重合性不飽和結合（（メタ）アクリロイル基）を１分子内に１個有するモノマーと共に、（メタ）アクリロイル基を分子内に２個以上有する多官能（メタ）アクリレートモノマーを併用することもできる。その詳細については、ＷＯ２０１２／０７７８０７Ａ１段落００２４を参照できる。また、多官能（メタ）アクリレート化合物として、特開２０１３－０４３３８２号公報段落００２３～００３６に記載のものを用いることもできる。更に、特許第５１２９４５８号明細書段落００１４～００１７に記載の一般式（４）～（６）で表されるアルキル鎖含有（メタ）アクリレートモノマーを使用することも可能である。 Polyfunctional (meth) acrylate monomer having two or more (meth) acryloyl groups in the molecule together with a monomer having one polymerizable unsaturated bond ((meth) acryloyl group) in one molecule. Can also be used together. The details can be referred to WO2012 / 0777807A1 paragraph 0024. As the polyfunctional (meth) acrylate compound, those described in paragraphs 0023 to 0036 of JP2013-043382A can also be used. Furthermore, it is also possible to use alkyl chain-containing (meth) acrylate monomers represented by the general formulas (4) to (6) described in paragraphs [0014] to [0017] of Japanese Patent No. 5129458.
　多官能（メタ）アクリレートモノマーの使用量は、重合性組成物に含まれる重合性化合物の全量１００質量部に対して、塗膜強度の観点からは、５質量部以上とすることが好ましく、組成物のゲル化抑制の観点からは、９５質量部以下とすることが好ましい。 The amount of the polyfunctional (meth) acrylate monomer used is preferably 5 parts by mass or more from the viewpoint of coating strength with respect to 100 parts by mass of the total amount of polymerizable compounds contained in the polymerizable composition. From the viewpoint of suppressing the gelation of the product, it is preferably 95 parts by mass or less.
　上記重合性組成物は、重合開始剤としては、公知のラジカル開始剤を含むことができる。重合開始剤については、例えば、特開２０１３－０４３３８２号公報段落００３７を参照できる。重合開始剤は、重合性組成物に含まれる重合性化合物の全量の０．１モル％以上であることが好ましく、０．５～２モル％であることがより好ましい。 The polymerizable composition can contain a known radical initiator as a polymerization initiator. As for the polymerization initiator, reference can be made, for example, to paragraph 0037 of JP2013-043382A. The polymerization initiator is preferably 0.1 mol% or more, more preferably 0.5 to 2 mol% of the total amount of the polymerizable compound contained in the polymerizable composition.
　量子ドットは、上記重合性組成物に粒子の状態で添加してもよく、溶媒に分散した分散液の状態で添加してもよい。分散液の状態で添加することが、量子ドットの粒子の凝集を抑制する観点から、好ましい。ここで使用される溶媒は、特に限定されるものではない。量子ドットは、組成物の全量１００質量部に対して、例えば０．１～１０質量部程度添加することができる。 Quantum dots may be added to the polymerizable composition in the form of particles, or may be added in the form of a dispersion dispersed in a solvent. The addition in the state of a dispersion is preferable from the viewpoint of suppressing the aggregation of the quantum dot particles. The solvent used here is not particularly limited. The quantum dots can be added in an amount of, for example, about 0.1 to 10 parts by mass with respect to 100 parts by mass of the total composition.
　以上説明した量子ドットを含む重合性組成物を、適当な支持体上に塗布、乾燥して溶媒を除去するとともに、その後、光照射等により重合硬化させて、量子ドット層を得ることができる。塗布方法としてはカーテンコーティング法、ディップコーティング法、スピンコーティング法、印刷コーティング法、スプレーコーティング法、スロットコーティング法、ロールコーティング法、スライドコーテティング法、ブレードコーティング法、グラビアコーティング法、ワイヤーバー法等の公知の塗布方法が挙げられる。また、硬化条件は、使用する重合性化合物の種類や重合性組成物の組成に応じて、適宜設定することができる。
　光変換層の総厚は、十分な励起光透過率を得る観点からは５００μｍ以下であることが好ましく、十分な蛍光を得る観点からは１μｍ以上であることが好ましい。より好ましくは１００～４００μｍの範囲である。また、光変換層が複数の量子ドット層または量子ドット混合層を含む場合、一層の膜厚は、好ましくは１～３００μｍの範囲であり、より好ましくは１０～２５０μｍの範囲である。 The polymerizable composition containing the quantum dots described above can be applied to a suitable support and dried to remove the solvent, and then polymerized and cured by light irradiation or the like to obtain a quantum dot layer. Application methods include curtain coating, dip coating, spin coating, print coating, spray coating, slot coating, roll coating, slide coating, blade coating, gravure coating, wire bar method, etc. A well-known coating method is mentioned. The curing conditions can be appropriately set according to the type of polymerizable compound used and the composition of the polymerizable composition.
The total thickness of the light conversion layer is preferably 500 μm or less from the viewpoint of obtaining sufficient excitation light transmittance, and is preferably 1 μm or more from the viewpoint of obtaining sufficient fluorescence. More preferably, it is in the range of 100 to 400 μm. When the light conversion layer includes a plurality of quantum dot layers or quantum dot mixed layers, the thickness of one layer is preferably in the range of 1 to 300 μm, more preferably in the range of 10 to 250 μm.
－光変換層以外の層－
　光変換部材は、光変換層（量子ドット層）の表面に、光散乱構造を有していてもよい。光変換層において発光された光は、屈折率の異なる隣接層界面に入射する角度によっては全反射を起こし、表示装置内部を導波してしまい、光取り出し効率が低下してしまう。そこで、光散乱構造を出射側に設け、光取り出し効率を向上させることは、光変換部材の発光効率の更なる向上に有効である。そのような光散乱構造としては、表面凹凸構造を挙げることができる。表面凹凸構造としては、光変換部材の出射側表面全面に微細な凹凸を多数設けることが好ましい。表面凹凸構造は、特開２０１３－０３９８０２号公報に記載の型押しや、エッチングレジスト等の公知の方法により形成することができる。また、市販のプリズムシートを貼り合わせることにより、表面凹凸構造を設けることもできる。 -Layers other than the light conversion layer-
The light conversion member may have a light scattering structure on the surface of the light conversion layer (quantum dot layer). The light emitted from the light conversion layer undergoes total reflection depending on the angle of incidence on the adjacent layer interface having a different refractive index, and is guided inside the display device, resulting in a decrease in light extraction efficiency. Therefore, providing the light scattering structure on the emission side to improve the light extraction efficiency is effective for further improving the light emission efficiency of the light conversion member. Examples of such a light scattering structure include a surface uneven structure. As the surface concavo-convex structure, it is preferable to provide a large number of fine concavo-convex portions on the entire surface on the emission side of the light conversion member. The surface concavo-convex structure can be formed by a known method such as embossing or an etching resist described in JP2013-039802. Moreover, a surface uneven | corrugated structure can also be provided by bonding together a commercially available prism sheet.
　光変換部材は、量子ドット層に隣接する層として、光散乱層（光取り出し層）を有していてもよい。光変換部材の出射側に光散乱層を設けることにより、上記の光散乱構造を設ける場合と同様、光取り出し効率を高めることができる。 The light conversion member may have a light scattering layer (light extraction layer) as a layer adjacent to the quantum dot layer. By providing the light scattering layer on the emission side of the light conversion member, the light extraction efficiency can be increased as in the case of providing the light scattering structure.
　上記光散乱層は、好ましくは、散乱粒子が少なくともとバインダー樹脂を含むマトリックス材中に分散した樹脂層である。散乱粒子としては、特に制限はなく、目的に応じて適宜選択することができる。散乱粒子は、取り出し効率の更なる向上の観点からは、光散乱層全体を構成するマトリックス材との屈折率の差が０．０２以上であることが好ましい。散乱粒子は、１種類の粒子のみを用いてもよく、また、複数の種類の粒子を組み合わせて用いてもよい。散乱粒子は、無機粒子であってもよく、有機粒子であってもよい。その詳細については、特開２０１０－１９８７３５号公報段落００２２を参照できる。また、光散乱層を構成するバインダー樹脂等の各種成分および光散乱層の作製方法については、同公報段落００２３～００２８、段落００３３～００３５を参照できる。光散乱層の膜厚は特に制限はなく、乾燥膜厚で、例えば０．５μｍ～５０μｍ程度であるが、目的に応じて適宜選択することができる。酸素バリア性と光透過性の観点からは、１μｍ～２０μｍの範囲であることが好ましく、２μｍ～１０μｍの範囲であることがより好ましく、３μｍ～７μｍの範囲であることが更に好ましい。 The light scattering layer is preferably a resin layer in which scattering particles are dispersed in a matrix material containing at least a binder resin. There is no restriction | limiting in particular as a scattering particle, According to the objective, it can select suitably. From the viewpoint of further improving the extraction efficiency of the scattering particles, the difference in refractive index from the matrix material constituting the entire light scattering layer is preferably 0.02 or more. As the scattering particles, only one type of particle may be used, or a plurality of types of particles may be used in combination. The scattering particles may be inorganic particles or organic particles. Details thereof can be referred to paragraph 0022 of JP 2010-198735 A. For various components such as a binder resin constituting the light scattering layer and a method for producing the light scattering layer, paragraphs 0023 to 0028 and 0033 to 0035 can be referred to. The film thickness of the light scattering layer is not particularly limited and is a dry film thickness, for example, about 0.5 μm to 50 μm, but can be appropriately selected according to the purpose. From the viewpoint of oxygen barrier properties and light transmittance, the range is preferably 1 μm to 20 μm, more preferably 2 μm to 10 μm, and still more preferably 3 μm to 7 μm.
　なお、光取り出し効率向上のための構成として、散乱粒子を含む光散乱層を設ける例を示したが、散乱粒子を光変換層に存在させることにより、光取り出し効率を向上させることもできる。散乱粒子の詳細は、上記と同様である。量子ドット層作製のための重合性組成物に、粒子の状態で、または適当な溶媒に分散した分散液として、散乱粒子を添加することにより、量子ドットとともに散乱粒子を含む量子ドット層を得ることができる。
　量子ドット層における散乱粒子量の重量密度は、２％以上とすることが、光取り出し効率向上の観点から好ましい。一方、散乱粒子量が増えるほど相対的に層内の量子ドット量は減ることになるため、量子ドット充填率向上の観点からは、量子ドット層における散乱粒子の重量密度は３０％未満とすることが好ましい。 In addition, although the example which provides the light-scattering layer containing scattering particles was shown as a structure for improving light extraction efficiency, light extraction efficiency can also be improved by making scattering particles exist in a light conversion layer. The details of the scattering particles are the same as described above. To obtain a quantum dot layer containing scattering particles together with quantum dots by adding scattering particles to the polymerizable composition for preparing the quantum dot layer in the form of particles or as a dispersion dispersed in an appropriate solvent. Can do.
The weight density of the amount of scattering particles in the quantum dot layer is preferably 2% or more from the viewpoint of improving light extraction efficiency. On the other hand, as the amount of scattering particles increases, the amount of quantum dots in the layer relatively decreases. From the viewpoint of improving the quantum dot filling rate, the weight density of scattering particles in the quantum dot layer should be less than 30%. Is preferred.
　光変換層の両面に、バリアフィルムが設けられていてもよい。
　更に、光変換部材は、出射側バリアフィルムに直接隣接する層として、光散乱層が設けられていてもよい。光散乱層は、出射側に位置するバリアフィルムに直接隣接する層として設けるだけでなく、光変換層の出射側に隣接する形態、または光変換層の入射側に隣接する形態であってもよい。また、散乱粒子を光変換層に存在させる形態であってもよい。
　バリアフィルムは、好ましくは、酸素バリア性を有するフィルムであって、酸素により量子ドットが経時的に劣化し量子効率（発光効率）が低下することを防ぐ役割を果たすことができる。より詳しくは、励起光による量子ドットの光酸化反応を抑制することができる。長期にわたり高い量子効率を得る観点から、バリアフィルムとしては、酸素透過度が１．００ｃｍ３／（ｍ２・ｄａｙ・ａｔｍ）未満のフィルムを用いることが好ましい。このようなバリアフィルムは、有機層、無機層、または有機層と無機層の二層以上の積層フィルムであることができる。その詳細は、後述する。なお、バリアフィルムは入射側のみに配置してもよく、出射側のみに配置してもよい。量子効率を、より長期間良好に維持する観点からは、光変換層の入射側および出射側の両方に、バリアフィルムを配置することが好ましい。
　このように光散乱層とバリアフィルムを組み合わせることにより、より一層高い発光効率を、長期間維持することが可能となる。 Barrier films may be provided on both surfaces of the light conversion layer.
Further, the light conversion member may be provided with a light scattering layer as a layer directly adjacent to the emission-side barrier film. The light scattering layer is not only provided as a layer directly adjacent to the barrier film located on the exit side, but may be in a form adjacent to the exit side of the light conversion layer, or a form adjacent to the incident side of the light conversion layer. . Further, the scattering particles may be present in the light conversion layer.
The barrier film is preferably a film having an oxygen barrier property, and can play a role in preventing quantum dots from being deteriorated by oxygen over time and quantum efficiency (luminous efficiency) being lowered. More specifically, the photooxidation reaction of the quantum dots by the excitation light can be suppressed. From the viewpoint of obtaining high quantum efficiency over a long period of time, it is preferable to use a film having an oxygen permeability of less than 1.00 cm 3 / (m 2 · day · atm) as the barrier film. Such a barrier film can be an organic layer, an inorganic layer, or a laminated film of two or more layers of an organic layer and an inorganic layer. Details thereof will be described later. The barrier film may be disposed only on the incident side or may be disposed only on the emission side. From the viewpoint of maintaining the quantum efficiency better for a longer period, it is preferable to arrange barrier films on both the incident side and the emission side of the light conversion layer.
By combining the light scattering layer and the barrier film in this way, it is possible to maintain higher luminous efficiency for a long period of time.
　出射側のバリアフィルムと直接隣接する層として光散乱層が、入射側のバリアフィルムと直接隣接する層として光反射層が、それぞれ設けられていてもよい。光変換層の励起光入射側に光反射層を設けることは、光利用効率を高めるうえで有効である。光反射層は、好ましくはコレステリック層であり、詳細は後述する。 A light scattering layer may be provided as a layer directly adjacent to the emission side barrier film, and a light reflection layer may be provided as a layer directly adjacent to the incident side barrier film. Providing the light reflection layer on the excitation light incident side of the light conversion layer is effective in improving the light utilization efficiency. The light reflecting layer is preferably a cholesteric layer, and details will be described later.
　以上、図面に基づき本発明の一態様にかかる光変換部材の具体的態様について説明したが、本発明は、これら具体的態様に限定されるものではなく、各種の変形も本発明に包含されることはいうまでもない。また、上記において直接隣接する層として説明した層間に、接着層等の任意の層を配置することも、もちろん可能である。 As mentioned above, although the specific aspect of the light conversion member concerning one aspect | mode of this invention was demonstrated based on drawing, this invention is not limited to these specific aspects, Various deformation | transformation is also included by this invention. Needless to say. It is of course possible to arrange an arbitrary layer such as an adhesive layer between the layers described above as the layers directly adjacent to each other.
－－バリアフィルム－－
　次に、上述のバリアフィルムについて説明する。 --- Barrier film--
Next, the above barrier film will be described.
　バリアフィルムの酸素透過度は、好ましくは前述の通り、１．００ｃｍ３／（ｍ２・ｄａｙ・ａｔｍ）以下、より好ましくは０．５０ｃｍ３／（ｍ２・ｄａｙ・ａｔｍ）以下、更に好ましくは０．１０ｃｍ３／（ｍ２・ｄａｙ・ａｔｍ）以下、一層好ましくは０．０１ｃｍ３／（ｍ２・ｄａｙ・ａｔｍ）以下である。
　一方、バリアフィルムの水蒸気透過率は、０．５ｇ／（ｍ２・ｄａｙ）以下、中でも０．１ｇ／（ｍ２・ｄａｙ）以下、特に０．０５ｇ／（ｍ２・ｄａｙ）以下であることが好ましい。水蒸気透過率が低いバリアフィルムによれば、水蒸気等の水分による量子ドットの劣化を防ぐことができる。
　ここで、上記酸素透過度は、測定温度２３℃、相対湿度９０％の条件下で、酸素ガス透過率測定装置（ＭＯＣＯＮ社製、ＯＸ－ＴＲＡＮ　２／２０：商品名）を用いて測定した値であり、上記水蒸気透過率は、測定温度３７．８℃、相対湿度１００％の条件下で、水蒸気透過率測定装置（ＭＯＣＯＮ社製、ＰＥＲＭＡＴＲＡＮ－Ｗ　３／３１：商品名）を用いて測定した値である。 As described above, the oxygen permeability of the barrier film is preferably 1.00 cm 3 / (m 2 · day · atm) or less, more preferably 0.50 cm 3 / (m 2 · day · atm) or less, and still more preferably. 0.10cm 3 / (m 2 · day · atm) or less, more preferably 0.01cm 3 / (m 2 · day · atm) or less.
On the other hand it, the water vapor permeability of the barrier film, 0.5g / (m 2 · day ) or less, preferably 0.1g / (m 2 · day) or less, particularly 0.05g / (m 2 · day) or less Is preferred. According to the barrier film having a low water vapor transmission rate, it is possible to prevent the quantum dots from being deteriorated by water such as water vapor.
Here, the oxygen permeability is a value measured using an oxygen gas permeability measuring device (manufactured by MOCON, OX-TRAN 2/20: trade name) under the conditions of a measurement temperature of 23 ° C. and a relative humidity of 90%. The water vapor transmission rate was measured using a water vapor transmission rate measuring device (manufactured by MOCON, PERMATRAN-W 3/31: trade name) under the conditions of a measurement temperature of 37.8 ° C. and a relative humidity of 100%. Value.
　バリアフィルムは、有機または無機の単層であってもよく、二層以上の積層構造であってもよい。例えば、基材上に二層以上の有機ないし無機層を形成することにより、バリアフィルムを得ることができる。バリアフィルムの層構成としては、例えば、光変換層側から外側に向かい、基材／無機層／有機層がこの順に積層されている構成、基材／無機層／有機層／無機層がこの順に積層されている構成等を挙げることができるが、積層順序は特に限定されるものではない。 The barrier film may be an organic or inorganic single layer, or may be a laminated structure of two or more layers. For example, a barrier film can be obtained by forming two or more organic or inorganic layers on a substrate. As a layer structure of the barrier film, for example, a structure in which the base material / inorganic layer / organic layer is laminated in this order from the light conversion layer side to the outside, and the base material / inorganic layer / organic layer / inorganic layer in this order. Although the structure etc. which are laminated | stacked can be mentioned, the lamination | stacking order is not specifically limited.
　基材としては、可視光に対して透明である透明基材であることが好ましい。ここで可視光に対して透明とは、可視光領域における線透過率が、８０％以上、好ましくは８５％以上であることをいう。透明の尺度として用いられる光線透過率は、ＪＩＳ－Ｋ７１０５に記載された方法、すなわち積分球式光線透過率測定装置を用いて全光線透過率および散乱光量を測定し、全光線透過率から拡散透過率を引いて算出することができる。基材については、特開２００７－２９０３６９号公報段落００４６～００５２、特開２００５－０９６１０８号公報段落００４０～００５５を参照できる。基材の厚さは、耐衝撃性、バリアフィルムの製造におけるハンドリング等の観点から、１０μｍ～５００μｍの範囲内、中でも１０～２００μｍの範囲内、特に２０～１００μｍの範囲内であることが好ましい。 The substrate is preferably a transparent substrate that is transparent to visible light. Here, “transparent to visible light” means that the linear transmittance in the visible light region is 80% or more, preferably 85% or more. The light transmittance used as a measure of transparency is measured by measuring the total light transmittance and the amount of scattered light using the method described in JIS-K7105, that is, using an integrating sphere light transmittance measuring device. It can be calculated by subtracting the rate. Regarding the base material, paragraphs 0046 to 0052 of JP-A-2007-290369 and paragraphs 0040 to 0055 of JP-A-2005-096108 can be referred to. The thickness of the substrate is preferably in the range of 10 μm to 500 μm, more preferably in the range of 10 to 200 μm, particularly in the range of 20 to 100 μm from the viewpoint of impact resistance, handling in the production of the barrier film, and the like.
　無機層については、特開２００７－２９０３６９号公報段落００４３～００４５、特開２００５－０９６１０８号公報段落００６４～００６８を参照できる。無機層の膜厚は、１０ｎｍ～５００ｎｍ、中でも１０ｎｍ～３００ｎｍ、特に１０ｎｍ～１５０ｎｍの範囲内であることが好ましい。無機層の膜厚が、上述した範囲内であることにより、良好なガスバリア性を実現しつつ、バリアフィルムにおける反射を抑制することができ、全光線透過率が低下することを抑制することができるからである。中でも、無機層は、酸化ケイ素膜、窒化ケイ素膜、または酸化窒化珪素膜であることが好ましい。これらの膜は、有機膜との密着性が良好であることから、より一層良好なガスバリア性を実現することができるからである。 Regarding the inorganic layer, reference can be made to paragraphs 0043 to 0045 of JP-A-2007-290369 and paragraphs 0064 to 0068 of JP-A-2005-096108. The thickness of the inorganic layer is preferably 10 nm to 500 nm, more preferably 10 nm to 300 nm, and particularly preferably 10 nm to 150 nm. When the film thickness of the inorganic layer is within the above-described range, it is possible to suppress reflection on the barrier film while achieving good gas barrier properties, and to suppress a decrease in total light transmittance. Because. Among these, the inorganic layer is preferably a silicon oxide film, a silicon nitride film, or a silicon oxynitride film. This is because these films have good adhesion to the organic film, so that even better gas barrier properties can be realized.
　有機層については、特開２００７－２９０３６９号公報段落００２０～００４２、特開２００５－０９６１０８号公報段落００７４～０１０５を参照できる。なお有機層は、カルドポリマーを含むことが好ましい。これにより、有機層と隣接する層または基材との密着性、特に、無機層とも密着性が良好になり、より一層優れたガスバリア性を実現することができるからである。カルドポリマーの詳細については、上述の特開２００５－０９６１０８号公報段落００８５～００９５を参照できる。有機層の膜厚は、０．０５μｍ～１０μｍの範囲内であることが好ましく、中でも０．５～１０μｍの範囲内であることが好ましい。有機層がウェットコーティング法により形成される場合には、有機層の膜厚は、０．５～１０μｍの範囲内、中でも１μｍ～５μｍの範囲内であることが好ましい。また、ドライコーティング法により形成される場合には、０．０５μｍ～５μｍの範囲内、中でも０．０５μｍ～１μｍの範囲内であることが好ましい。ウェットコーティング法またはドライコーティング法により形成される有機層の膜厚が上述した範囲内であることにより、無機層との密着性をより良好なものとすることができるからである。 Regarding the organic layer, reference can be made to paragraphs 0020 to 0042 of JP-A-2007-290369 and paragraphs 0074 to 0105 of JP-A-2005-096108. The organic layer preferably contains a cardo polymer. Thereby, the adhesion between the organic layer and the adjacent layer or substrate, in particular, the adhesion with the inorganic layer is improved, and a further excellent gas barrier property can be realized. For details of the cardo polymer, reference can be made to paragraphs 0085 to 0095 of JP-A-2005-096108 described above. The thickness of the organic layer is preferably in the range of 0.05 μm to 10 μm, and more preferably in the range of 0.5 to 10 μm. When the organic layer is formed by a wet coating method, the thickness of the organic layer is preferably in the range of 0.5 to 10 μm, and more preferably in the range of 1 to 5 μm. Further, when formed by a dry coating method, it is preferably in the range of 0.05 μm to 5 μm, and more preferably in the range of 0.05 μm to 1 μm. This is because when the film thickness of the organic layer formed by the wet coating method or the dry coating method is within the above-described range, the adhesion with the inorganic layer can be further improved.
　バリアフィルムのその他詳細については、上述の特開２００７－２９０３６９号公報、特開２００５－０９６１０８号公報、更にＵＳ２０１２／０１１３６７２Ａ１の記載を参照できる。 For other details of the barrier film, reference can be made to the descriptions in JP-A-2007-290369, JP-A-2005-096108 and US2012 / 0113672A1.
－－光学薄膜－－
　一態様では、バリアフィルム上に、空気界面に単層（１層からなる）の光学薄膜を積層することもできる。このような光学薄膜としては、波長５３５ｎｍにおける光学薄膜の屈折率ｎ（５３５）が、バリアフィルムにおいて光学薄膜と直接隣接する層の屈折率ｎｕ（５３５）よりも屈折率の低い低屈折率層が好ましい。このような光学薄膜をバリアフィルムに隣接配置することにより、より一層の輝度向上および色再現性の向上を達成することができる。波長５３５ｎｍにおける光学薄膜の屈折率ｎ（５３５）は、１．２０～１．５１であることが好ましく、１．３０～１．４６であることがより好ましく、１．４０～１．４６が更に好ましい。 --- Optical thin film--
In one embodiment, a single layer (consisting of one layer) optical thin film can be laminated on the air interface on the barrier film. As such an optical thin film, a low refractive index layer having a refractive index n (535) of the optical thin film at a wavelength of 535 nm is lower than a refractive index nu (535) of a layer directly adjacent to the optical thin film in the barrier film. preferable. By arranging such an optical thin film adjacent to the barrier film, it is possible to achieve further improvement in luminance and color reproducibility. The refractive index n (535) of the optical thin film at a wavelength of 535 nm is preferably 1.20 to 1.51, more preferably 1.30 to 1.46, and further preferably 1.40 to 1.46. preferable.
　また、上記光学薄膜は、屈折率と膜厚を掛け合わせた光学厚みが、下記式（２－１）、（２－２）および（２－３）のいずれか１つを満たすことが好ましい。
式（２－１）　１．１５μｍ≦ｎ（５３５）×ｄ≦１．２５μｍ
式（２－２）　１．４２μｍ≦ｎ（５３５）×ｄ≦１．５２μｍ
式（２－３）　１．６９μｍ≦ｎ（５３５）×ｄ≦１．７９μｍ
（式（２－１）、（２－２）および（２－３）中、ｎ（５３５）は波長５３５ｎｍにおける光学薄膜の屈折率を表し、ｄは光学薄膜の厚さ（単位：μｍ）を表す。）
　好ましい一態様では、上記光学薄膜が、下記式（２－１Ａ）、（２－２Ａ）および（２－３Ａ）のいずれか１つを満たし、中でも、下記式（２－２Ａ）を満たすことが好ましい。
式（２－１Ａ）　１．１６μｍ≦ｎ（５３５）×ｄ≦１．２４μｍ
式（２－２Ａ）　１．４６μｍ≦ｎ（５３５）×ｄ≦１．５１μｍ
式（２－３Ａ）　１．７０μｍ≦ｎ（５３５）×ｄ≦１．７８μｍ
（式（２－１Ａ）、（２－２Ａ）および（２－３Ａ）中、ｎ（５３５）は波長５３５ｎｍにおける光学薄膜の屈折率を表し、ｄは光学薄膜の厚さ（単位：μｍ）を表す。）
　なお、光学薄膜の厚さｄは、０．５～２μｍであることが好ましく、０．７～１．５μｍであることがより好ましい。光学薄膜の構成成分としては、公知のものを用いることができる。例えば、バリアフィルムの有機層を構成可能な材料として好適なもの等を用いることができる。 The optical thin film preferably has an optical thickness obtained by multiplying the refractive index and the film thickness satisfying any one of the following formulas (2-1), (2-2), and (2-3).
Formula (2-1) 1.15 μm ≦ n (535) × d ≦ 1.25 μm
Formula (2-2) 1.42 μm ≦ n (535) × d ≦ 1.52 μm
Formula (2-3) 1.69 μm ≦ n (535) × d ≦ 1.79 μm
(In the formulas (2-1), (2-2) and (2-3), n (535) represents the refractive index of the optical thin film at a wavelength of 535 nm, and d represents the thickness (unit: μm) of the optical thin film. To express.)
In a preferred embodiment, the optical thin film satisfies any one of the following formulas (2-1A), (2-2A), and (2-3A), and in particular, satisfies the following formula (2-2A): preferable.
Formula (2-1A) 1.16 μm ≦ n (535) × d ≦ 1.24 μm
Formula (2-2A) 1.46 μm ≦ n (535) × d ≦ 1.51 μm
Formula (2-3A) 1.70 μm ≦ n (535) × d ≦ 1.78 μm
(In the formulas (2-1A), (2-2A) and (2-3A), n (535) represents the refractive index of the optical thin film at a wavelength of 535 nm, and d represents the thickness of the optical thin film (unit: μm). To express.)
Note that the thickness d of the optical thin film is preferably 0.5 to 2 μm, and more preferably 0.7 to 1.5 μm. As the constituent components of the optical thin film, known components can be used. For example, a material suitable for the organic layer of the barrier film can be used.
　上記光学薄膜が積層されたバリアフィルムは、光学薄膜面が空気界面側に来るように光変換層と積層してもよく、その逆の構成としてもよい。 The barrier film on which the optical thin film is laminated may be laminated with the light conversion layer so that the optical thin film surface is on the air interface side, or vice versa.
－－光反射層－－
　光反射層は、好ましくはコレステリック層である。光反射層の態様に用いられるコレステリック液晶相を固定してなる光反射層の製造方法としては特に制限はない。例えば、特開平１－１３３００３号公報、特許３４１６３０２号、特許３３６３５６５号、特開平８－２７１７３１号公報に記載の方法を用いることができ、これらの公報の内容は本発明に組み込まれる。 -Light reflection layer-
The light reflecting layer is preferably a cholesteric layer. There is no restriction | limiting in particular as a manufacturing method of the light reflection layer formed by fixing the cholesteric liquid crystal phase used for the aspect of a light reflection layer. For example, methods described in JP-A-1-133003, JP-A-3416302, JP-A-3363565, and JP-A-8-271731 can be used, and the contents of these publications are incorporated in the present invention.
　上記のコレステリック液晶層の重畳に際しては、右まわりの円偏光と左回りの円偏光反射する組合せで用いることが望ましい。具体的には右捩れのコレステリック液晶と左捩れのコレステリック液晶を積層して得られる。これにより全ての偏光を反射することができ、反射の効率を高めることができる。 When superimposing the cholesteric liquid crystal layers, it is desirable to use a combination of right-handed circularly polarized light and left-handed circularly polarized light. Specifically, it is obtained by stacking right-twisted cholesteric liquid crystal and left-twisted cholesteric liquid crystal. Thereby, all polarized light can be reflected and the efficiency of reflection can be improved.
　コレステリック液晶としては、適宜なものを用いてよく、特に限定はない。液晶層の重畳効率や薄膜化などの点より液晶ポリマーの使用が有利である。また複屈折の大きいコレステリック液晶分子ほど選択反射の波長域が広くなって好ましい。 As the cholesteric liquid crystal, an appropriate one may be used and there is no particular limitation. The use of a liquid crystal polymer is advantageous from the standpoints of the superimposition efficiency of the liquid crystal layer and the thinning. A cholesteric liquid crystal molecule having a large birefringence is preferable because the wavelength range of selective reflection is widened.
　上記の液晶ポリマーとしては、例えばポリエステル等の主鎖型液晶ポリマー、アクリル主鎖やメタクリル主鎖、シロキサン主鎖等からなる側鎖型液晶ポリマー、低分子カイラル剤含有のネマチック液晶ポリマー、キラル成分導入の液晶ポリマー、ネマチック系とコレステリック系の混合液晶ポリマーなどの適宜なものを用いることができる。取扱性等の点よりは、ガラス転移温度が３０～１５０℃のものが好ましい。 Examples of the liquid crystal polymer include main chain type liquid crystal polymers such as polyester, side chain type liquid crystal polymers composed of acrylic main chain, methacryl main chain, siloxane main chain, and the like, nematic liquid crystal polymers containing a low molecular chiral agent, and introduction of chiral components. Any suitable liquid crystal polymer, nematic and cholesteric mixed liquid crystal polymer can be used. A glass transition temperature of 30 to 150 ° C. is preferable from the viewpoint of handleability.
　コレステリック液晶層の形成は、偏光分離板に必要に応じポリイミドやポリビニルアルコール、ＳｉＯの斜方蒸着層等の適宜な配向膜を介して直接塗布する方式、透明フィルムなどからなる液晶ポリマーの配向温度で変質しない支持体に必要に応じ配向膜を介して塗布する方式などの適宜な方式で行うことができる。支持体としては、偏光の状態変化を防止する点などより位相差が可及的に小さいものが好ましく用いうる。また配向膜を介したコレステリック液晶層の重畳方式なども採ることができる。 The cholesteric liquid crystal layer can be formed by applying it directly to the polarization separator through an appropriate alignment film such as polyimide, polyvinyl alcohol, or obliquely deposited layer of SiO, or the alignment temperature of the liquid crystal polymer comprising a transparent film. It can be carried out by an appropriate method such as a method of applying to an unaltered support through an alignment film, if necessary. As the support, one having a phase difference as small as possible can be preferably used from the viewpoint of preventing the change of the polarization state. Further, a superposition method of a cholesteric liquid crystal layer through an alignment film can also be adopted.
　なお液晶ポリマーの塗布は、溶剤による溶液や加熱による溶融液等の液状物としたものを、ロールコーティング方式やグラビア印刷方式、スピンコート方式などの適宜な方式で展開する方法などにより行うことができる。形成するコレステリック液晶層の厚さは、選択反射性、配向乱れや透過率低下の防止等の点より、０．５～１００μｍが好ましい。 The liquid crystal polymer can be applied by a method in which a liquid material such as a solvent solution or a molten liquid is heated by an appropriate method such as a roll coating method, a gravure printing method, or a spin coating method. . The thickness of the cholesteric liquid crystal layer to be formed is preferably 0.5 to 100 μm from the viewpoints of selective reflectivity, orientation disorder and prevention of transmittance decrease.
　また、光反射層には誘電体多層膜を用いることもできる。フィルムを用いた誘電体多層膜の製造方法としては特に制限はなく、例えば、特許３１８７８２１号、特許３７０４３６４号、特許４０３７８３５号、特許４０９１９７８号、特許３７０９４０２号、特許４８６０７２９号、特許３４４８６２６号などに記載の方法を参考に製造することができ、これらの公報の内容は本発明に組み込まれる。なお、誘電体多層膜は、誘電体多層反射偏光板や、交互多層膜の複屈折干渉偏光子と言われることもある。これらの誘電体多層膜は膜厚および屈折率を調整することにより選択的に波長を反射することをでき、本態様に好ましく用いることが出来る。また、これらのフィルムは屈折率異方性のため特定方向のみ偏光を反射することが多いため、その場合にはこれらのフィルムを直交して２枚用いると全ての偏光を反射することが出来るため好ましい。これ以外にも屈折率の異なる無機膜を積層蒸着させる構造で等方体材料を用いて誘電体多層膜にすることもでき、これについてはＹｅｈ著　“Ｏｐｔｉｃａｌ　Ｗａｖｅｓ　ｉｎ　Ｌａｙｅｒｅｄ　Ｍｅｄｉａ”（ＷＩＬＬＥＹ　Ｉｎｔｅｒｓｃｉｅｎｃｅ社）に記載がある。 Also, a dielectric multilayer film can be used for the light reflecting layer. The method for producing a dielectric multilayer film using a film is not particularly limited. The contents of these publications are incorporated in the present invention. The dielectric multilayer film may be referred to as a dielectric multilayer reflective polarizing plate or a birefringence interference polarizer having an alternating multilayer film. These dielectric multilayer films can selectively reflect the wavelength by adjusting the film thickness and refractive index, and can be preferably used in this embodiment. In addition, since these films often reflect polarized light only in a specific direction due to refractive index anisotropy, in this case, if two of these films are used orthogonally, all polarized light can be reflected. preferable. In addition to this, it is also possible to form a dielectric multilayer film using an isotropic material in a structure in which inorganic films having different refractive indexes are laminated and deposited, and this is described by Yeh, “Optical Waves in Layered Media” (WILLEY Interscience). There is a description.
　上記誘電体多層膜は、膜厚が薄い方が好ましく、膜厚が５～１００μｍの範囲であることが好ましく、１０～５０μｍの範囲であることがより好ましく、５～２０μｍの範囲であることがさらに好ましい。 The dielectric multilayer film is preferably thin, preferably in the range of 5 to 100 μm, more preferably in the range of 10 to 50 μm, and in the range of 5 to 20 μm. Further preferred.
　以下に実施例に基づき本発明をさらに具体的に説明する。以下の実施例に示す材料、使用量、割合、処理内容、処理手順等は、本発明の趣旨を逸脱しない限り適宜変更することができる。したがって、本発明の範囲は以下に示す具体例により限定的に解釈されるべきものではない。 Hereinafter, the present invention will be described more specifically based on examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.
［調製例１］
＜赤色顔料（Ｒｐ）硬化性組成物の調製＞
　下記表１の処方を混合して、赤色顔料（Ｒｐ）硬化性組成物を調製した。
Figure JPOXMLDOC01-appb-T000003
 ［調製例２］
＜青色顔料（Ｂｐ）硬化性組成物の調製＞
　下記表２の処方を混合して、青色顔料（Ｂｐ）硬化性組成物を調製した。
Figure JPOXMLDOC01-appb-T000004
 [Preparation Example 1]
<Preparation of red pigment (Rp) curable composition>
The formulations shown in Table 1 below were mixed to prepare a red pigment (Rp) curable composition.
Figure JPOXMLDOC01-appb-T000003
 [Preparation Example 2]
<Preparation of blue pigment (Bp) curable composition>
A blue pigment (Bp) curable composition was prepared by mixing the formulations shown in Table 2 below.
Figure JPOXMLDOC01-appb-T000004
［調製例３］
＜緑色顔料（Ｇｐ）硬化性組成物の調製＞
　下記表３の処方を混合して、緑色顔料（Ｇｐ）硬化性組成物を調製した。
Figure JPOXMLDOC01-appb-T000005
 [Preparation Example 3]
<Preparation of green pigment (Gp) curable composition>
The formulation shown in Table 3 below was mixed to prepare a green pigment (Gp) curable composition.
Figure JPOXMLDOC01-appb-T000005
［調製例４］
＜黄色（Ｙ）硬化性組成物の調製＞
　下記表４の処方を混合して、黄色硬化性組成物を調製した。
Figure JPOXMLDOC01-appb-T000006
 [Preparation Example 4]
<Preparation of yellow (Y) curable composition>
The yellow curable composition was prepared by mixing the formulations shown in Table 4 below.
Figure JPOXMLDOC01-appb-T000006
［調製例５］
＜シアン顔料硬化性組成物の調製＞
　下記の処方を混合して、シアン顔料硬化性組成物を調製した。
Figure JPOXMLDOC01-appb-T000007
 [Preparation Example 5]
<Preparation of Cyan Pigment Curable Composition>
The following formulation was mixed to prepare a cyan pigment curable composition.
Figure JPOXMLDOC01-appb-T000007
［比較例３～５、実施例１～１５］
＜カラーフィルタの作製＞
　下記表６または７に示す組み合わせで、各色の着色領域（各画素に対応）の面積比を調整して、図２（Ａ）に形状を示した面積比が均一なパターン状の各色の着色領域、または図２に形状の一例を示した面積比が不均一な（Ｂ）パターン状の各色の着色領域を有する各比較例及び実施例に用いるカラーフィルタを作製した。
　具体的には、各調製例で調製した各色の硬化性組成物を、５５０ｍｍ×６５０ｍｍのガラス基板（１７３７、コーニング社製）上に、スリットコーターで塗布し、９０℃のオーブンで６０秒間乾燥させた（プリベーク）。その後、塗膜の全面に２００ｍＪ／ｃｍ２にて（照度２０ｍＷ／ｃｍ２）露光し、露光後の塗布膜をアルカリ現像液（ＣＤＫ－１、富士フイルムエレクトロニクスマテリアルズ株式会社製）の１質量％水溶液にて覆い、６０秒間静止した。静止後、純水をシャワー状に散布して現像液を洗い流した。そして、上記のように露光及び現像処理が施された塗布膜を２２０℃のオーブンで１時間加熱処理し（ポストベーク）、ガラス基板上にカラーフィルタ構成用の着色樹脂被膜を形成し、カラーフィルタがガラス基板上に形成されたカラーフィルタ基板を作製した。ただし、各色の着色領域の面積の調整は、露光の際に、各色の着色領域の開口部の面積を表６または７に示す面積比となるように調整したフォトマスクを用いることで実現した。 [Comparative Examples 3-5, Examples 1-15]
<Production of color filter>
By adjusting the area ratio of the colored regions (corresponding to the respective pixels) of the respective colors in the combinations shown in Table 6 or 7 below, the colored regions of the respective colors having a uniform area ratio shown in FIG. Alternatively, a color filter used in each comparative example and example having a colored region of each color in a pattern shape (B) with a non-uniform area ratio shown in FIG. 2 as an example of the shape was prepared.
Specifically, the curable composition of each color prepared in each preparation example was applied on a 550 mm × 650 mm glass substrate (1737, manufactured by Corning) with a slit coater and dried in an oven at 90 ° C. for 60 seconds. (Pre-baked). Thereafter, the entire surface of the coating film was exposed at 200 mJ / cm 2 (illuminance 20 mW / cm 2 ), and the coated film after the exposure was 1% by mass of an alkali developer (CDK-1, manufactured by Fuji Film Electronics Materials Co., Ltd.). Covered with aqueous solution and allowed to stand for 60 seconds. After standing still, pure water was sprayed in a shower to wash away the developer. The coating film that has been exposed and developed as described above is heated in an oven at 220 ° C. for 1 hour (post-baking) to form a colored resin film for constituting a color filter on the glass substrate, and the color filter Produced a color filter substrate formed on a glass substrate. However, the adjustment of the area of the colored region of each color was realized by using a photomask in which the area of the opening of the colored region of each color was adjusted to the area ratio shown in Table 6 or 7 at the time of exposure.
＜ＶＡ液晶セルの作製＞
　ガラス基板上に、特開２００９－１４１３４１号公報中に記載の実施例２０に従い、ＴＦＴ素子を作製し、さらにＴＦＴ素子上に保護膜を形成した。続いて、保護膜にコンタクトホールを形成した後、上記保護膜上に、ＴＦＴ素子と電気的に接続したＩＴＯの透明電極を形成し、アレイ基板を作製した。
　上記作製したカラーフィルタ基板上に、ＩＴＯの透明電極をスパッタリングにより形成し、次いで、特開２００６－６４９２１号公報の実施例１に従い、このＩＴＯ膜上の隔壁（ブラックマトリックス）上部に相当する部分にスペーサを形成した。
　作製したアレイ基板及びカラーフィルタ基板の透明電極にそれぞれＰＶＡ（Ｐａｔｔｅｒｎｅｄ　Ｖｅｒｔｉｃａｌ　Ａｌｉｇｎｍｅｎｔ）モード用にパターニングを施し、その上に更に垂直ポリイミドよりなる配向膜を設けた。
　その後、カラーフィルタの各色の着色領域群を取り囲むように周囲に設けられたブラックマトリクス外枠に相当する位置に紫外線硬化樹脂のシール剤をディスペンサ方式により塗布し、ＰＶＡモード用液晶を滴下し、アレイ基板と貼り合わせ、貼り合わされた基板をＵＶ照射した後、熱処理してシール剤を硬化させた。このようにして各比較例及び実施例に用いる液晶セルを作製した。 <Production of VA liquid crystal cell>
A TFT element was produced on a glass substrate according to Example 20 described in JP-A-2009-141341, and a protective film was further formed on the TFT element. Subsequently, after forming a contact hole in the protective film, an ITO transparent electrode electrically connected to the TFT element was formed on the protective film to produce an array substrate.
An ITO transparent electrode is formed on the produced color filter substrate by sputtering. Then, according to Example 1 of Japanese Patent Application Laid-Open No. 2006-64921, a portion corresponding to the upper part of the partition wall (black matrix) on the ITO film is formed. A spacer was formed.
The transparent electrodes of the produced array substrate and color filter substrate were each patterned for PVA (Patterned Vertical Alignment) mode, and an alignment film made of vertical polyimide was further provided thereon.
Thereafter, a UV curable resin sealant is applied by a dispenser method to a position corresponding to the outer periphery of the black matrix provided around the colored region group of each color of the color filter, and a PVA mode liquid crystal is dropped. The substrate was bonded to the substrate, and the bonded substrate was irradiated with UV, followed by heat treatment to cure the sealant. Thus, the liquid crystal cell used for each comparative example and an Example was produced.
＜バックライトの作製＞
（光変換部材（量子ドットフィルム）の作製）
１．量子ドット含有重合性組成物の調製
　トリメチロールプロパンアクリレート０．５４ｍｌとラウリルメタクリレート２．４ｍｌと光重合開始剤としてＢＡＳＦ社製Ｉｒｇａｃｕｒｅ　８１９を混合して重合性組成物Ａを得た。得られた重合性組成物Ａ１００ｍｇに対して、量子ドットのトルエン分散液を、発光のピークが６００～６８０ｎｍの波長帯域にある量子ドット（Ａ）と、量子ドット（Ａ）よりも短波長域に発光中心波長を有し、かつ発光のピークが５００～６００ｎｍの波長帯域にある量子ドット（Ｂ）とが下記表６または７に記載の含有量（濃度）になるように添加し、減圧乾燥を３０分行った。量子ドットが分散されるまで、撹拌を行い、分散液Ｍ（量子ドット含有重合性組成物）を得た。 <Production of backlight>
(Production of light conversion member (quantum dot film))
1. Preparation of Quantum Dot-Containing Polymerizable Composition A polymerizable composition A was obtained by mixing 0.54 ml of trimethylolpropane acrylate, 2.4 ml of lauryl methacrylate and Irgacure 819 manufactured by BASF as a photopolymerization initiator. With respect to 100 mg of the resulting polymerizable composition A, a toluene dispersion of quantum dots was prepared with a quantum dot (A) having an emission peak in the wavelength band of 600 to 680 nm and a shorter wavelength range than the quantum dot (A). Quantum dots (B) having an emission center wavelength and having an emission peak in the wavelength band of 500 to 600 nm are added so as to have the content (concentration) described in Table 6 or 7 below, followed by drying under reduced pressure. It went for 30 minutes. Stirring was performed until the quantum dots were dispersed to obtain a dispersion M (quantum dot-containing polymerizable composition).
２．量子ドット材料（Ｇ，Ｒ）を有する光変換層１０４の作製（図４に示す光変換部材の作製）
　ガラス板状に、分散液Ｍを２８０μｍの膜厚になるように塗布し、ガラス板状に感光層を形成した。感光層に対し、空気面側から、ＵＶ露光機（ＨＯＹＡ　ＣＡＮＤＥＯ　ＯＰＴＲＯＮＩＣＳ社製ＥＸＥＣＵＲＥ　３０００Ｗ）を用いて、窒素雰囲気下で、５Ｊ／ｃｍ２で露光して、上記感光層を硬化させ、露光膜（硬化膜）を得た。露光した後、硬化膜をガラス板から剥離し、量子ドット材料（Ｇ，Ｒ）を有する光変換部材（光変換層１０４を含む）を得た。 2. Production of light conversion layer 104 having quantum dot material (G, R) (production of light conversion member shown in FIG. 4)
The dispersion M was applied to a glass plate so as to have a film thickness of 280 μm, and a photosensitive layer was formed on the glass plate. From the air surface side, the photosensitive layer is exposed at 5 J / cm 2 in a nitrogen atmosphere using a UV exposure machine (EXECURE 3000W manufactured by HOYA CANDEO OPTRONICS) to cure the photosensitive layer, thereby exposing the photosensitive layer ( A cured film) was obtained. After the exposure, the cured film was peeled from the glass plate to obtain a light conversion member (including the light conversion layer 104) having the quantum dot material (G, R).
　上記光変換層１０４について、前述の電子顕微鏡による観察によりΦを求めたところ、Φ＝０．５であり、図４に示すように、二種の量子ドットが混合され均一に分散していることが確認された。 Regarding the light conversion layer 104, when Φ was obtained by observation with the above-mentioned electron microscope, Φ = 0.5, and two kinds of quantum dots were mixed and uniformly dispersed as shown in FIG. Was confirmed.
（バックライトの組み立て）
　実施例１および比較例３～５では、このようにして得られた光変換部材と、青色ＬＥＤ（日亜Ｂ－ＬＥＤ：Ｒｏｙａｌ　Ｂｌｕｅ、主波長４４５ｎｍ、半値幅２０ｎｍ）である光源と、光源の後部に反射部材と波長変換部材の視認側に市販の液晶表示装置から取り出した１枚の拡散シートと２枚のプリズムシートを組み合わせて、量子ドット光源Ａを作製した。
　実施例２～１５では、発光のピークが６００～６８０ｎｍの波長帯域にある量子ドット（Ａ）と、量子ドット（Ａ）よりも短波長域に発光中心波長を有し、かつ発光のピークが５００～６００ｎｍの波長帯域にある量子ドット（Ｂ）の光変換層中における含有比率を変更して、バックライトの発光する青色光（Ｂ）、緑色光（Ｇ）および赤色光（Ｒ）の発光強度比が下記表６または７に記載のとおりとなるように調整した、光変換層を調製した。量子ドット（Ａ）の光変換層中における含有比率を高めることで赤色光（Ｒ）の発光強度を高めることができ、量子ドット（Ｂ）の光変換層中における含有比率を高めることで緑色光（Ｇ）の発光強度を高めることができる。実施例２～１５では、このようにして得られた各光変換部材を用いた以外は実施例１と同様にして、量子ドット光源Ａ２～Ａ１５を作製した。
　各実施例および比較例で用いる光変換部材中の量子ドットの組成を下記表６または７に示した。 (Assembly of backlight)
In Example 1 and Comparative Examples 3 to 5, the light conversion member thus obtained, a light source that is a blue LED (Nichia B-LED: Royal Blue, main wavelength 445 nm, half-value width 20 nm), A quantum dot light source A was prepared by combining one diffusion sheet and two prism sheets taken from a commercially available liquid crystal display device on the rear side on the viewing side of the reflecting member and the wavelength conversion member.
In Examples 2 to 15, the quantum dot (A) having an emission peak in the wavelength band of 600 to 680 nm, the emission center wavelength in a shorter wavelength region than the quantum dot (A), and the emission peak of 500 Luminescence intensity of blue light (B), green light (G) and red light (R) emitted from the backlight by changing the content ratio of the quantum dots (B) in the wavelength band of ˜600 nm in the light conversion layer A light conversion layer was prepared so that the ratio was adjusted as shown in Table 6 or 7 below. The light emission intensity of red light (R) can be increased by increasing the content ratio of the quantum dots (A) in the light conversion layer, and the green light can be increased by increasing the content ratio of the quantum dots (B) in the light conversion layer. The emission intensity of (G) can be increased. In Examples 2 to 15, quantum dot light sources A2 to A15 were produced in the same manner as in Example 1 except that the light conversion members thus obtained were used.
The composition of the quantum dots in the light conversion member used in each example and comparative example is shown in Table 6 or 7 below.
＜液晶表示装置の製造＞
　市販の液晶表示装置（ＳＨＡＲＰ社製、商品名ＬＣ－４６ＸＦ３）を分解し、バックライトユニットを上記にて製造した量子ドット光源Ａ１～Ａ１５に変更し、液晶セルを上記にて製造したカラーフィルタを含む液晶セルに変更し、実施例１～１５および比較例３～５の液晶表示装置を製造した。 <Manufacture of liquid crystal display devices>
A commercially available liquid crystal display device (manufactured by SHARP, trade name LC-46XF3) was disassembled, the backlight unit was changed to the quantum dot light sources A1 to A15 manufactured above, and the color filter manufactured above was replaced with the color filter manufactured above. The liquid crystal display device of Examples 1 to 15 and Comparative Examples 3 to 5 was manufactured by changing to the liquid crystal cell.
［比較例１］
　バックライトユニットとして市販の液晶表示装置に付属の白色ＬＥＤ（量子ドットを含まない）をそのまま用いた以外は比較例３と同様にして、比較例１の液晶表示装置を作製した。 [Comparative Example 1]
A liquid crystal display device of Comparative Example 1 was produced in the same manner as in Comparative Example 3 except that the white LED (not including quantum dots) attached to a commercially available liquid crystal display device as a backlight unit was used as it was.
［比較例２］
　バックライトユニットとして市販の液晶表示装置に付属の白色ＬＥＤ（量子ドットを含まない）をそのまま用いた以外は実施例１と同様にして、比較例２の液晶表示装置を作製した。 [Comparative Example 2]
A liquid crystal display device of Comparative Example 2 was produced in the same manner as in Example 1 except that a white LED (not including quantum dots) attached to a commercially available liquid crystal display device as a backlight unit was used as it was.
［実施例１６］
　バックライトユニットを、光変換部材が以下のように変更された量子ドット光源Ｄに変更した以外は実施例１と同様にして、実施例１６の液晶表示装置を作製した。
　概要を以下に示す。 [Example 16]
A liquid crystal display device of Example 16 was produced in the same manner as in Example 1 except that the backlight unit was changed to the quantum dot light source D in which the light conversion member was changed as follows.
The outline is shown below.
＜量子ドット材料（Ｂ，Ｇ，Ｒ）の作製＞
１．量子ドット含有重合性組成物の調製
　トリメチロールプロパンアクリレート０．５４ｍｌとラウリルメタクリレート２．４ｍｌと光重合開始剤としてＢＡＳＦ社製Ｉｒｇａｃｕｒｅ　８１９を混合して重合性組成物Ａを得た。得られた重合性組成物Ａ１００ｍｇに対して、量子ドットのトルエン分散液を、発光のピークが６００～６８０ｎｍの波長帯域にある量子ドット（Ａ）と、量子ドット（Ａ）よりも短波長域に発光中心波長を有し、かつ発光のピークが５００～６００ｎｍの波長帯域にある量子ドット（Ｂ）と、量子ドット（Ｂ）よりも短波長域に発光中心波長を有し、かつ発光のピークが４００～５００ｎｍの波長帯域にある量子ドット（Ｃ）とが下記表６または７に記載の含有量（濃度）になるように添加し、減圧乾燥を３０分行った。量子ドットが分散されるまで、撹拌を行い、分散液Ｍ２（量子ドット含有重合性組成物）を得た。 <Production of quantum dot materials (B, G, R)>
1. Preparation of Quantum Dot-Containing Polymerizable Composition A polymerizable composition A was obtained by mixing 0.54 ml of trimethylolpropane acrylate, 2.4 ml of lauryl methacrylate and Irgacure 819 manufactured by BASF as a photopolymerization initiator. With respect to 100 mg of the resulting polymerizable composition A, a toluene dispersion of quantum dots was prepared with a quantum dot (A) having an emission peak in the wavelength band of 600 to 680 nm and a shorter wavelength range than the quantum dot (A). A quantum dot (B) having an emission center wavelength and an emission peak in the wavelength band of 500 to 600 nm, an emission center wavelength in a shorter wavelength range than the quantum dot (B), and an emission peak The quantum dots (C) in the wavelength band of 400 to 500 nm were added so as to have the content (concentration) described in Table 6 or 7 below, followed by drying under reduced pressure for 30 minutes. Stirring was performed until the quantum dots were dispersed to obtain a dispersion M2 (quantum dot-containing polymerizable composition).
２．量子ドット材料（Ｇ、Ｂ、Ｒ）を有する光変換層１０４の作製（図４に示す光変換部材の作製）
　ガラス板状に、分散液Ｍ２を２８０μｍの膜厚になるように塗布し、ガラス板状に感光層を形成した。感光層に対し、空気面側から、ＵＶ露光機（ＨＯＹＡ　ＣＡＮＤＥＯ　ＯＰＴＲＯＮＩＣＳ社製ＥＸＥＣＵＲＥ　３０００Ｗ）を用いて、窒素雰囲気下で、５Ｊ／ｃｍ２で露光して、上記感光層を硬化させ、露光膜（硬化膜）を得た。露光した後、硬化膜をガラス板から剥離し、量子ドット材料（Ｇ、Ｂ、Ｒ）を有する光変換部材（光変換層１０４を含む）を得た。 2. Production of light conversion layer 104 having quantum dot material (G, B, R) (production of light conversion member shown in FIG. 4)
Dispersion M2 was applied to a glass plate so as to have a film thickness of 280 μm, and a photosensitive layer was formed on the glass plate. From the air surface side, the photosensitive layer is exposed at 5 J / cm 2 in a nitrogen atmosphere using a UV exposure machine (EXECURE 3000W manufactured by HOYA CANDEO OPTRONICS) to cure the photosensitive layer, thereby exposing the photosensitive layer ( A cured film) was obtained. After the exposure, the cured film was peeled from the glass plate to obtain a light conversion member (including the light conversion layer 104) having a quantum dot material (G, B, R).
　実施例１６で用いたＵＶ狭帯域バックライトユニットは、光源としてＵＶ発光ダイオード（日亜ＵＶ－ＬＥＤ：ＮＣ４Ｕ１３３Ａ、主波長３６５ｎｍ、半値幅９ｎｍ）を備える。また、光源の後部に反射部材を備える。 The UV narrow-band backlight unit used in Example 16 includes a UV light-emitting diode (Nichia UV-LED: NC4U133A, main wavelength 365 nm, half-value width 9 nm) as a light source. Moreover, a reflective member is provided in the rear part of the light source.
（バックライトの組み立て）
　実施例１６では、このようにして得られた光変換部材と、ＵＶ発光ダイオード（日亜ＵＶ－ＬＥＤ：ＮＣ４Ｕ１３３Ａ、主波長３６５ｎｍ、半値幅９ｎｍ）である光源と、光源の後部に反射部材、光変換部材の視認側に市販の液晶表示装置から取り出した１枚の拡散シートと２枚のプリズムシートと組み合わせて、量子ドット光源Ｄを作製した。 (Assembly of backlight)
In Example 16, the light conversion member thus obtained, a light source that is a UV light emitting diode (Nichia UV-LED: NC4U133A, main wavelength 365 nm, half-value width 9 nm), a reflection member, light at the rear of the light source A quantum dot light source D was prepared by combining one diffusion sheet and two prism sheets taken from a commercially available liquid crystal display device on the viewing side of the conversion member.
［評価方法］
　次に、作製した各実施例および比較例の液晶表示装置に関して以下のように評価を行った。使用したバックライトとカラーフィルタの組み合わせ、および評価結果を下記表６および７に示す。 [Evaluation methods]
Next, the liquid crystal display devices of the produced examples and comparative examples were evaluated as follows. The combinations of backlight and color filter used and the evaluation results are shown in Tables 6 and 7 below.
＜開口率の測定＞
　各実施例および比較例の液晶表示装置について、液晶セルの開口率を、実体顕微鏡（ライカマイクロシステムズ製、ＭＺ１６Ａ）を用いて測定し、以下の評点をつけた。
Ａ：比較例１に対して、５％以上の開口率向上が見られる。
Ｂ：比較例１に対して、１％以上５％未満の開口率向上が見られる。
Ｃ：比較例１に対して、１％以上の開口率向上が見られなかった。 <Measurement of aperture ratio>
About the liquid crystal display device of each Example and a comparative example, the aperture ratio of the liquid crystal cell was measured using the stereomicroscope (the Leica Microsystems make, MZ16A), and the following ratings were given.
A: An opening ratio improvement of 5% or more is observed with respect to Comparative Example 1.
B: An improvement in aperture ratio of 1% or more and less than 5% is observed with respect to Comparative Example 1.
C: No improvement in aperture ratio of 1% or more was observed with respect to Comparative Example 1.
＜色度点の評価＞
　各実施例および比較例の液晶表示装置について、カラーフィルタの各着色領域（画素）の色度を、顕微分光光度計（オリンパス光学工業株式会社製、ＯＳＰ１００）を用いて測定した。また、ホワイトバランス（白色の色度）は、得られた各着色領域のＸＹＺ表色値に、着色領域の面積を乗じて加算し、白色のＸＹＺ表色値を得ることにより、求めた。
　なお、ｘｙ色度図上にて白色の色度と、等色温度・等偏差線との対応を取ることで、相関色温度を求め、以下の評点をつけた。
Ａ：白色の色温度が７０００℃以上５００００℃未満かつ黒体軌跡からの偏差Δｕｖが－０．０２以上０．０２以下。
Ｂ：Ａの範囲外。 <Evaluation of chromaticity point>
About the liquid crystal display device of each Example and the comparative example, the chromaticity of each coloring area | region (pixel) of a color filter was measured using the microspectrophotometer (The Olympus Optical Co., Ltd. make, OSP100). Further, the white balance (white chromaticity) was obtained by multiplying the obtained XYZ color value of each colored region by the area of the colored region to obtain a white XYZ color value.
In addition, the correlation color temperature was calculated | required by taking correspondence with white chromaticity and an equal color temperature and an equal deviation line on an xy chromaticity diagram, and the following ratings were given.
A: The white color temperature is 7000 ° C. or higher and lower than 50000 ° C., and the deviation Δuv from the black body locus is −0.02 or more and 0.02 or less.
B: Outside the range of A.
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000009
Figure JPOXMLDOC01-appb-T000009
　上記表６および７より、本発明の液晶表示装置は、カラーフィルタの開口率が大きく、良好なホワイトバランスを有することがわかった。
　比較例１より、量子ドットを含まない従来の白色ＬＥＤバックライトを用い、各色の着色領域の面積が不均一であり発明の範囲外である４色ＣＦを用いる場合、カラーフィルタの開口率が小さいことがわかった。
　比較例２より、比較例１の従来の量子ドットを含まない白色ＬＥＤバックライトを用いた構成のままで各色の着色領域の面積を均一とする場合、色度点がずれてしまいホワイトバランスが悪くディスプレイとして適さないことがわかった。
　比較例３より、比較例１の量子ドットを含まない白色ＬＥＤバックライトを、量子ドットを含むバックライト化しても、カラーフィルタの各色の着色領域の面積比が本発明の範囲外である場合、開口率は改善されないことがわかった。
　比較例４、５より、各色の着色領域の面積のうち、３色は等しいが、１色のみ異なるために発明の範囲外である場合、カラーフィルタの開口率は、比較例１に対して改善はするが、十分ではないことがわかった。
　なお、各実施例の液晶表示装置は、視認で判断したところ、焼きつきの問題も生じていないことがわかった。 From Tables 6 and 7 above, it was found that the liquid crystal display device of the present invention had a large aperture ratio of the color filter and a good white balance.
From Comparative Example 1, when using a conventional white LED backlight that does not include quantum dots, and using four-color CFs that have non-uniform color areas and are outside the scope of the invention, the aperture ratio of the color filter is small I understood it.
Compared with Comparative Example 2, when the area of the colored region of each color is made uniform with the configuration using the conventional white LED backlight not including the quantum dots of Comparative Example 1, the chromaticity point is shifted and the white balance is poor. It turns out that it is not suitable as a display.
From Comparative Example 3, even if the white LED backlight that does not include the quantum dots of Comparative Example 1 is converted to a backlight that includes quantum dots, the area ratio of the colored regions of each color of the color filter is outside the scope of the present invention. It was found that the aperture ratio was not improved.
From the comparative examples 4 and 5, when the three colors are the same among the areas of the colored regions of the respective colors, but only one color is different and is out of the scope of the invention, the aperture ratio of the color filter is improved with respect to the comparative example 1. I found out that it was not enough.
The liquid crystal display device of each example was judged by visual observation, and it was found that there was no problem of image sticking.
［実施例２１］
　実施例１において、図２（Ａ）に示すような配置に長方形の各色の着色領域を一列にパターン状に形成する代わりに、図３に示すように正方形の各色の着色領域を田の字型にパターン配置したカラーフィルタを製造した。
　その他は実施例１と同様にして、実施例２１の液晶表示装置を製造した。
　実施例２１を評価したところ、実施例２１のように正方形の各色の着色領域を田の字型にパターン配置したカラーフィルタの方が、実施例１の長方形の各色の着色領域を一列にパターン状に形成したカラーフィルタよりも、開口率に優れていたことがわかった。
　なお、実施例２１の液晶表示装置は、視認で判断したところ、焼きつきの問題も生じていないことがわかった。 [Example 21]
In the first embodiment, instead of forming rectangular colored areas in a pattern in a row as shown in FIG. 2A, square colored areas are formed in a square shape as shown in FIG. A color filter having a pattern arrangement was manufactured.
Otherwise, the liquid crystal display device of Example 21 was manufactured in the same manner as Example 1.
When Example 21 was evaluated, the color filter in which the colored regions of each color of the square were arranged in a square shape as in Example 21 had a pattern in which the colored regions of each color of the rectangle of Example 1 were arranged in a line. It was found that the aperture ratio was superior to that of the color filter formed in (1).
In addition, as for the liquid crystal display device of Example 21, when judged by visual recognition, it was found that the problem of image sticking did not occur.
［実施例２２］
＜バックライトの作製＞
（光変換部材（量子ドットフィルム）の作製）
１．バリアフィルム１０の作製
　ポリエチレンテレフタレートフィルム（ＰＥＴフィルム、東洋紡社製、商品名：コスモシャインＡ４３００、厚さ５０μｍ）の片面側に以下の手順でバリア性積層体を形成した。
　ＴＭＰＴＡ（ダイセルサイテック社製）および光重合開始剤（ランベルティ社製、ＥＳＡＣＵＲＥ　ＫＴＯ４６）を用意し、質量比率として９５：５となるように秤量し、これらをメチルエチルケトンに溶解させ、固形分濃度１５％の塗布液とした。この塗布液を、ダイコーターを用いてロールトウロールにて上記ＰＥＴフィルム上に塗布し、５０℃の乾燥ゾーンを３分間通過させた。その後、窒素雰囲気下で紫外線を照射（積算照射量約６００ｍＪ／ｃｍ２）し、ＵＶ硬化にて硬化させ、巻き取った。支持体（上記ＰＥＴフィルム）上に形成された第一有機層の厚さは、１μｍであった。 [Example 22]
<Production of backlight>
(Production of light conversion member (quantum dot film))
1. Preparation of Barrier Film 10 A barrier laminate was formed on one side of a polyethylene terephthalate film (PET film, manufactured by Toyobo Co., Ltd., trade name: Cosmo Shine A4300, thickness 50 μm) by the following procedure.
TMPTA (manufactured by Daicel Cytec Co., Ltd.) and a photopolymerization initiator (manufactured by Lamberti Co., Ltd., ESACURE KTO46) are prepared, weighed so that the mass ratio is 95: 5, dissolved in methyl ethyl ketone, and a solid content concentration of 15% It was set as the coating liquid. This coating solution was applied onto the PET film with a roll toe roll using a die coater, and passed through a drying zone at 50 ° C. for 3 minutes. Thereafter, ultraviolet rays were irradiated in a nitrogen atmosphere (accumulated dose: about 600 mJ / cm 2 ), cured by UV curing, and wound up. The thickness of the first organic layer formed on the support (the PET film) was 1 μm.
　次に、ロールトウロールのＣＶＤ装置を用いて、上記有機層の表面に無機層（窒化ケイ素層）を形成した。原料ガスとして、シランガス（流量１６０ｓｃｃｍ）、アンモニアガス（流量３７０ｓｃｃｍ）、水素ガス（流量５９０ｓｃｃｍ）、および窒素ガス（流量２４０ｓｃｃｍ）を用いた。電源として、周波数１３．５６ＭＨｚの高周波電源を用いた。製膜圧力は４０Ｐａ、到達膜厚は５０ｎｍであった。このようにして支持体の上に有機層および無機層がこの順に積層されたバリアフィルム１０を作製した。
　バリアフィルム１０の酸素透過度は０．０１ｃｍ３／（ｍ２・ｄａｙ・ａｔｍ）以下であった。 Next, an inorganic layer (silicon nitride layer) was formed on the surface of the organic layer using a roll-to-roll CVD apparatus. Silane gas (flow rate 160 sccm), ammonia gas (flow rate 370 sccm), hydrogen gas (flow rate 590 sccm), and nitrogen gas (flow rate 240 sccm) were used as source gases. A high frequency power supply having a frequency of 13.56 MHz was used as the power supply. The film forming pressure was 40 Pa, and the reached film thickness was 50 nm. Thus, the barrier film 10 in which the organic layer and the inorganic layer were laminated in this order on the support was produced.
The oxygen permeability of the barrier film 10 was 0.01 cm 3 / (m 2 · day · atm) or less.
２．量子ドット含有重合性組成物の調製
　下記の量子ドット分散液１を調製し、孔径０．２μｍのポリプロピレン製フィルタでろ過した後、３０分間減圧乾燥して塗布液として用いた。 2. Preparation of Quantum Dot-Containing Polymerizable Composition The following quantum dot dispersion 1 was prepared and filtered through a polypropylene filter having a pore size of 0.2 μm, and then dried under reduced pressure for 30 minutes and used as a coating solution.
──────────────────────────────────
量子ドット含有重合性組成物１（量子ドットを含有する有機層１用組成）
──────────────────────────────────
量子ドット１のトルエン分散液（発光極大：５２０ｎｍ）　　　１０質量部
量子ドット２のトルエン分散液（発光極大：６３０ｎｍ）　　　　１質量部
ラウリルメタクリレート　　　　　　　　　　　　　　　　８０．８質量部
トリメチロールプロパントリアクリレート　　　　　　　　１８．２質量部
光重合開始剤　　　　　　　　　　　　　　　　　　　　　　　　１質量部
（イルガキュア８１９（ＢＡＳＦ社製）
──────────────────────────────────
（上記において、量子ドット１、２のトルエン分散液の量子ドット濃度は１質量％である） ──────────────────────────────────
Quantum dot-containing polymerizable composition 1 (composition for organic layer 1 containing quantum dots)
──────────────────────────────────
Toluene dispersion of quantum dots 1 (light emission maximum: 520 nm) 10 parts by weight Toluene dispersion of quantum dots 2 (light emission maximum: 630 nm) 1 part by weight lauryl methacrylate 80.8 parts by weight trimethylolpropane triacrylate 18.2 parts by weight light 1 part by mass of polymerization initiator (Irgacure 819 (manufactured by BASF))
──────────────────────────────────
(In the above, the quantum dot concentration of the toluene dispersion of quantum dots 1 and 2 is 1% by mass)
３．波長変換層の作製
　第１のバリアフィルム１０を用意し、１ｍ／分、６０Ｎ／ｍの張力で連続搬送しながら、無機層面上に量子ドット含有重合性組成物１をダイコーターにて塗布し、５０μｍの厚さの塗膜を形成した。次いで、塗膜の形成された第１のバリアフィルム１０をバックアップローラに巻きかけ、塗膜の上に第２のバリアフィルム１０を無機層面が塗膜に接する向きでラミネートし、その後、第１、および第２のバリアフィルム１０で塗膜を挟持した状態でバックアップローラに巻きかけ、連続搬送しながら紫外線を照射した。 3. Preparation of wavelength conversion layer First barrier film 10 is prepared, and the quantum dot-containing polymerizable composition 1 is applied on the surface of the inorganic layer with a die coater while continuously transporting at a tension of 1 m / min and 60 N / m. A coating film having a thickness of 50 μm was formed. Next, the first barrier film 10 on which the coating film is formed is wound around a backup roller, and the second barrier film 10 is laminated on the coating film so that the inorganic layer surface is in contact with the coating film. And it wound around a backup roller in the state which pinched | interposed the coating film with the 2nd barrier film 10, and irradiated the ultraviolet-ray, conveying continuously.
　バックアップローラの直径はφ３００ｍｍであり、バックアップローラの温度は５０℃であった。紫外線の照射量は２０００ｍＪであった。また、Ｌ１は５０ｍｍ、Ｌ２は１ｍｍ、Ｌ３は５０ｍｍであった。 The diameter of the backup roller was 300 mm, and the temperature of the backup roller was 50 ° C. The irradiation amount of ultraviolet rays was 2000 mJ. L1 was 50 mm, L2 was 1 mm, and L3 was 50 mm.
　紫外線の照射により塗膜を硬化させて硬化層（光変換層）を形成し、積層フィルム（光変換部材ａ）を製造した。積層フィルムの硬化層の厚みは５０±２μｍであった。硬化層の厚み精度は±４％と良好であった。また、積層フィルムにはシワの発生が見られなかった。 The coated film was cured by irradiation with ultraviolet rays to form a cured layer (light conversion layer), and a laminated film (light conversion member a) was produced. The thickness of the cured layer of the laminated film was 50 ± 2 μm. The thickness accuracy of the hardened layer was as good as ± 4%. Moreover, generation | occurrence | production of wrinkles was not seen by the laminated | multilayer film.
（バックライトの組み立て）
　このようにして得られた光変換部材ａを実施例１と同様に組み込むことで、実施例２２に記載の量子ドット光源Ｇを作製した。 (Assembly of backlight)
The quantum dot light source G described in Example 22 was produced by incorporating the light conversion member a thus obtained in the same manner as in Example 1.
　量子ドット含有重合性組成物１に新たに量子ドット３のトルエン分散液（発光極大：５８０ｎｍ、下記表にはＹと記載）を加えた以外は、量子ドット光源Ｇと同様にして、実施例２３に記載の量子ドット光源Ｈを作製した。 Example 23 In the same manner as in the quantum dot light source G, except that a toluene dispersion of quantum dots 3 (luminescence maximum: 580 nm, described as Y in the table below) was newly added to the quantum dot-containing polymerizable composition 1. The quantum dot light source H described in 1 was produced.
　量子ドット含有重合性組成物１に新たに量子ドット４のトルエン分散液（発光極大：４９０ｎｍ、下記表にはＣと記載）を加えた以外は、量子ドット光源Ｇと同様にして、実施例２４に記載の量子ドット光源Ｉを作製した。 Example 24 In the same manner as in the quantum dot light source G, except that a toluene dispersion of the quantum dots 4 (luminescence maximum: 490 nm, described as C in the table below) was newly added to the quantum dot-containing polymerizable composition 1. The quantum dot light source I described in 1 was produced.
　量子ドット含有重合性組成物１に新たに量子ドット３のトルエン分散液（発光極大：５８０ｎｍ、下記表にはＹと記載）と量子ドット５のトルエン分散液(発光極大：４５０ｎｍ、下記表にはＢと記載)を加えた以外は、光変換部材ａと同様にして光変換部材を作製した。得られた光変換部材を量子ドット光源Ｄと同様にＵＶ発光ダイオードと組み合わせたバックライトユニットに組み込むことで、実施例２５に記載の量子ドット光源Ｊを作製した。 Quantum dot-containing polymerizable composition 1 is newly added with a toluene dispersion of quantum dots 3 (luminescence maximum: 580 nm, described as Y in the table below) and a toluene dispersion of quantum dots 5 (luminescence maximum: 450 nm, in the tables below). A light conversion member was prepared in the same manner as the light conversion member a except that (described as B) was added. The obtained light conversion member was incorporated into a backlight unit combined with a UV light emitting diode in the same manner as the quantum dot light source D, thereby producing a quantum dot light source J described in Example 25.
　量子ドット含有重合性組成物１に新たに量子ドット４のトルエン分散液（発光極大：４９０ｎｍ、下記表にはＣと記載）と量子ドット５のトルエン分散液(発光極大：４５０ｎｍ、下記表にはＢと記載)を加えた以外は、光変換部材ａと同様にして光変換部材を作製した。得られた光変換部材を量子ドット光源Ｄと同様にＵＶ発光ダイオードと組み合わせたバックライトユニットに組み込むことで、実施例２６に記載の量子ドット光源Ｋを作製した。 The quantum dot-containing polymerizable composition 1 is newly added to a toluene dispersion of quantum dots 4 (luminescence maximum: 490 nm, described as C in the following table) and a toluene dispersion of quantum dots 5 (luminescence maximum: 450 nm, in the following table). A light conversion member was prepared in the same manner as the light conversion member a except that (described as B) was added. The obtained light conversion member was incorporated into a backlight unit combined with a UV light emitting diode in the same manner as the quantum dot light source D, thereby producing a quantum dot light source K described in Example 26.
＜液晶表示装置の製造＞
　実施例１において、バックライトユニットとして量子ドット光源Ａの代わりに、量子ドット光源Ｇ、Ｈ、Ｉ、ＪまたはＫをそれぞれ用いた以外は実施例１と同様にして、実施例２２～２６の液晶表示装置を製造した。 <Manufacture of liquid crystal display devices>
In Example 1, the liquid crystal of Examples 22 to 26 was used in the same manner as in Example 1 except that instead of the quantum dot light source A as the backlight unit, quantum dot light sources G, H, I, J, or K were used. A display device was manufactured.
［評価方法］
　次に、作製した実施例２２～２６の液晶表示装置に関して、開口率および色度点を実施例１と同様の方法で評価を行った。比較例１、２、実施例１および２２～２６について、使用したバックライトとカラーフィルタの組み合わせ、および評価結果を下記表８に示す。
　下記表８に示したとおり、本発明の液晶表示装置はバリアフィルムを有する光変換層を備えた場合も、カラーフィルタの開口率が大きく、良好なホワイトバランスを有することがわかった。
　また、実施例２５および２６より、本発明の液晶表示装置は、光変換部材が量子ドットを４種類以上含む場合でも、カラーフィルタの開口率が大きく、良好なホワイトバランスを有することがわかった。 [Evaluation methods]
Next, with respect to the manufactured liquid crystal display devices of Examples 22 to 26, the aperture ratio and chromaticity point were evaluated in the same manner as in Example 1. For Comparative Examples 1 and 2, Examples 1 and 22 to 26, the combinations of backlights and color filters used and the evaluation results are shown in Table 8 below.
As shown in Table 8 below, it was found that the liquid crystal display device of the present invention also had a good white balance with a large aperture ratio of the color filter even when the light conversion layer having the barrier film was provided.
Further, from Examples 25 and 26, it was found that the liquid crystal display device of the present invention had a large white area ratio and a good white balance even when the light conversion member contained four or more types of quantum dots.
Figure JPOXMLDOC01-appb-T000010
Figure JPOXMLDOC01-appb-T000010
　本発明は、液晶表示装置の製造分野において有用である。 The present invention is useful in the field of manufacturing liquid crystal display devices.
１０２、１０４：光変換層
２：量子ドット（Ｂ）
３：量子ドット（Ａ）
１０２Ａ：量子ドットとして量子ドット（Ａ）のみを含む量子ドット層
１０２Ｂ：量子ドットとして量子ドット（Ｂ）のみを含む量子ドット層
２１：青色の着色領域
２２：赤色の着色領域
２３：緑色の着色領域
２４：黄色の着色領域
３０：カラーフィルタ
３１：バックライトユニット
３１Ａ：光源
３１Ｂ：導光板
３１Ｃ：光変換部材
３２：青色光
３３：緑色光
３４：赤色光 102, 104: Light conversion layer 2: Quantum dot (B)
3: Quantum dot (A)
102A: Quantum dot layer including only quantum dots (A) as quantum dots 102B: Quantum dot layer including only quantum dots (B) as quantum dots 21: Blue colored regions 22: Red colored regions 23: Green colored regions 24: Yellow colored region 30: Color filter 31: Backlight unit 31A: Light source 31B: Light guide plate 31C: Light conversion member 32: Blue light 33: Green light 34: Red light

Claims (9)

  1. 　少なくともバックライトと、前記バックライトから出射された光の一部の波長帯域の光を選択的に透過させる着色領域がパターン状に形成されたカラーフィルタとを有する液晶表示装置であり；
    　前記バックライトが、光源と、前記光源から入射する光により励起され蛍光を発光する量子ドットを少なくとも２種類以上含む光変換層を有する光変換部材とを有し；
    　前記カラーフィルタが、４色以上の着色領域を含み、かつ、
    　透過率のピーク波長が４００～４８０ｎｍである青色の着色領域、透過率のピーク波長が５００～５６０ｎｍである緑色の着色領域および透過率のピーク波長が６００ｎｍ以上である赤色の着色領域を少なくとも含み、
    　前記カラーフィルタに含まれる各色の着色領域の面積の平均値Ａａｖｅに対する、各色の着色領域の面積の比が、すべての色の着色領域において０．８～１．２である、
    液晶表示装置。     A liquid crystal display device having at least a backlight and a color filter in which a colored region that selectively transmits light in a partial wavelength band of light emitted from the backlight is formed in a pattern;
    The backlight includes a light source and a light conversion member having a light conversion layer including at least two types of quantum dots excited by light incident from the light source to emit fluorescence;
    The color filter includes four or more colored regions, and
    Including at least a blue colored region having a transmittance peak wavelength of 400 to 480 nm, a green colored region having a transmittance peak wavelength of 500 to 560 nm, and a red colored region having a transmittance peak wavelength of 600 nm or more,
    The ratio of the area of the colored region of each color to the average value Aave of the area of the colored region of each color included in the color filter is 0.8 to 1.2 in the colored regions of all colors.
    Liquid crystal display device.
  2. 　前記カラーフィルタが、透過率のピーク波長が５６０～６００ｎｍである黄色の着色領域を含む、請求項１に記載の液晶表示装置。 The liquid crystal display device according to claim 1, wherein the color filter includes a yellow colored region having a transmittance peak wavelength of 560 to 600 nm.
  3. 　前記カラーフィルタが、透過率のピーク波長が４８０～５００ｎｍであるシアンの着色領域を含む、請求項１または２に記載の液晶表示装置。 3. The liquid crystal display device according to claim 1, wherein the color filter includes a cyan colored region having a transmittance peak wavelength of 480 to 500 nm.
  4. 　前記バックライトが、少なくとも４００～４８０ｎｍ、５００～６００ｎｍおよび６００～６８０ｎｍに発光中心波長を有し、
    　各発光中心波長における発光強度比が１：０．１７～０．４５：０．１３～０．４である、請求項２に記載の液晶表示装置。     The backlight has an emission center wavelength of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm;
    The liquid crystal display device according to claim 2, wherein the emission intensity ratio at each emission center wavelength is 1: 0.17 to 0.45: 0.13 to 0.4.
  5. 　前記バックライトが、少なくとも４００～４８０ｎｍ、５００～６００ｎｍおよび６００～６８０ｎｍに発光中心波長を有し、
    　各発光中心波長における発光強度比が１：０．２６～０．６３：０．３９～１．１５である、請求項３に記載の液晶表示装置。     The backlight has an emission center wavelength of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm;
    The liquid crystal display device according to claim 3, wherein the emission intensity ratio at each emission center wavelength is 1: 0.26 to 0.63: 0.39 to 1.15.
  6. 　前記カラーフィルタが、さらに透過率のピーク波長が４８０～５００ｎｍであるシアンの着色領域を含み、かつ、
    　前記バックライトが、少なくとも４００～４８０ｎｍ、５００～６００ｎｍおよび６００～６８０ｎｍに発光中心波長を有し、
    　各発光中心波長における発光強度比が１：０．１９～０．４５：０．１９～０．６である、請求項２に記載の液晶表示装置。     The color filter further includes a cyan colored region having a transmittance peak wavelength of 480 to 500 nm, and
    The backlight has an emission center wavelength of at least 400 to 480 nm, 500 to 600 nm, and 600 to 680 nm;
    3. The liquid crystal display device according to claim 2, wherein the emission intensity ratio at each emission center wavelength is 1: 0.19 to 0.45: 0.19 to 0.6.
  7. 　前記光変換層は、６００ｎｍ～６８０ｎｍの範囲の波長帯域に発光中心波長を有する量子ドットＡと、量子ドットＡよりも短波長帯域に発光中心波長を有する一種以上の量子ドットＺと、を含有し、
    　前記光変換層において、量子ドットＡが、量子ドットＺに対して励起光入射側に相対的に偏在している、請求項１～６のいずれか一項に記載の液晶表示装置。     The light conversion layer contains quantum dots A having an emission center wavelength in a wavelength range of 600 nm to 680 nm, and one or more quantum dots Z having an emission center wavelength in a shorter wavelength band than the quantum dots A. ,
    7. The liquid crystal display device according to claim 1, wherein in the light conversion layer, the quantum dots A are unevenly distributed on the excitation light incident side with respect to the quantum dots Z.
  8. 　前記カラーフィルタを含む液晶セルを有し、
    　前記液晶セルがＶＡモードである、請求項１～７のいずれか一項に記載の液晶表示装置。     A liquid crystal cell including the color filter;
    The liquid crystal display device according to any one of claims 1 to 7, wherein the liquid crystal cell is in a VA mode.
  9. 　入射する励起光により励起され蛍光を発光する量子ドットを少なくとも４種類以上含む光変換層を有する、光変換部材。 A light conversion member having a light conversion layer including at least four types of quantum dots that are excited by incident excitation light and emit fluorescence.
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