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WO2020196507A1 - Dispositif d'affichage à cristaux liquides de type à réflexion - Google Patents

Dispositif d'affichage à cristaux liquides de type à réflexion Download PDF

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Publication number
WO2020196507A1
WO2020196507A1 PCT/JP2020/012986 JP2020012986W WO2020196507A1 WO 2020196507 A1 WO2020196507 A1 WO 2020196507A1 JP 2020012986 W JP2020012986 W JP 2020012986W WO 2020196507 A1 WO2020196507 A1 WO 2020196507A1
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Prior art keywords
liquid crystal
crystal layer
cholesteric liquid
group
layer
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Ceased
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PCT/JP2020/012986
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English (en)
Japanese (ja)
Inventor
雄二郎 矢内
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Fujifilm Corp
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Fujifilm Corp
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Priority to JP2021509445A priority Critical patent/JP7192096B2/ja
Publication of WO2020196507A1 publication Critical patent/WO2020196507A1/fr
Anticipated expiration legal-status Critical
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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/22—Absorbing filters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors

Definitions

  • the present invention relates to a reflective liquid crystal display device.
  • the cholesteric liquid crystal layer is known as a layer having a property of selectively reflecting either right-handed circularly polarized light or left-handed circularly polarized light in a specific wavelength range. Therefore, it has been developed for various purposes, and is used as a reflective member of an image display device such as a liquid crystal display device, for example.
  • Patent Document 1 states, "In an anisotropic optical element having an anisotropic optical property with respect to the normal direction of the element plane, a molecularly oriented cholesteric liquid crystal composed of a polymerizable liquid crystal exhibiting cholesteric regularity.
  • the layer has a cholesteric liquid crystal layer formed so as to have a flat layer plane, and the spiral axis main direction defined as the average of the spiral axis directions of the liquid crystal domains in the cholesteric liquid crystal layer is the layer plane.
  • An anisotropic optical element characterized in that it is tilted by a predetermined angle with respect to the normal direction.
  • Patent Document 2 states that "a first color filter and a predetermined rotation are provided on a surface facing the upper substrate of the lower substrate of the liquid crystal cell in which the liquid crystal is sandwiched between the upper substrate and the lower substrate facing each other.
  • a cholesteric liquid crystal layer that reflects a part of the circular polarization having a direction and transmits a part thereof and a second color filter are provided on the lower substrate in this order, and the outer surface side of the upper substrate and the lower substrate
  • a liquid crystal display device characterized in that a first polarizing plate and a second polarizing plate are provided on the outer surface side, respectively.
  • Patent Document 2 In the reflection mode of the liquid crystal display device of Patent Document 2, the light incident from the upper substrate side passes through the liquid crystal cell and is reflected by the cholesteric liquid crystal layer, and the reflected light passes through the liquid crystal cell and is emitted to the visual recognition side. Display the image by. That is, Patent Document 2 describes that a cholesteric liquid crystal layer is used as a reflective member in a reflective liquid crystal display device.
  • the reflective liquid crystal display device due to the structure of the reflective liquid crystal display device, light is reflected even on the surface.
  • the reflection of light on the surface is specular.
  • the conventional cholesteric liquid crystal layer is specularly reflected. Therefore, the angle of the reflected light reflected on the surface becomes equal to the angle of the reflected light reflected by the reflecting member (cholesteric liquid crystal layer), and the two reflected lights overlap when viewed from the observer side on the display screen.
  • the two reflected lights overlap when viewed from the observer side on the display screen.
  • it is conceivable to install a film that suppresses reflection on the surface but when an anti-glare film is installed on the surface, the contrast is lowered and the image resolution is lowered.
  • the low-reflection film is installed on the surface, there is a problem that the display screen becomes difficult to see due to the reflected light on the surface in the case of a light source having a large amount of light such as sunlight.
  • An object of the present invention is to solve such a problem, and to provide a highly visible reflective liquid crystal display device.
  • the present invention solves the problem by the following configuration.
  • a linear polarizer, a liquid crystal cell, a ⁇ / 4 plate, and a cholesteric liquid crystal layer formed by using a liquid crystal compound are provided in this order.
  • the direction of the molecular axis of the liquid crystal compound is changed while continuously rotating along at least one direction in the plane.
  • Reflective type in which the arrangement direction of bright and dark parts derived from the cholesteric liquid crystal phase observed by a scanning electron microscope in a cross section perpendicular to the main surface of the cholesteric liquid crystal layer is inclined with respect to the main surface of the cholesteric liquid crystal layer. Liquid crystal display device.
  • the cholesteric liquid crystal layer has two or more regions in which the bright and dark portions have different inclination directions.
  • the reflective liquid crystal display device according to any one of [1] to [4], which has two or more cholesteric liquid crystal layers having different pitches of bright and dark areas.
  • the reflective liquid crystal display device according to any one of [1] to [5], which has a light absorbing layer on the side of the cholesteric liquid crystal layer opposite to the liquid crystal cell.
  • the reflective liquid crystal display device according to any one of [1] to [6], which does not have a backlight.
  • FIG. 1 It is a figure which conceptually shows an example of the structure of the reflective liquid crystal display device of this invention. It is a figure for demonstrating the operation of the reflective liquid crystal display device shown in FIG. It is a figure for demonstrating the operation of the reflective liquid crystal display device shown in FIG. It is a figure for demonstrating the operation of the conventional reflective liquid crystal display device. It is a figure for demonstrating the operation of the reflective liquid crystal display device shown in FIG. It is a schematic diagram of the XY plane of the cholesteric liquid crystal layer 10. It is a schematic diagram of the XZ plane of the cholesteric liquid crystal layer 10.
  • FIG. 5 is a schematic cross-sectional view for explaining an example of an embodiment of a composition layer satisfying condition 1 in step 2-1. It is sectional drawing of the laminated body 50.
  • a graph plotting the relationship between the spiral inducing force (HTP: Helical Twisting Power) ( ⁇ m -1 ) ⁇ concentration (mass%) and the light irradiation dose (mJ / cm 2 ) for each of the chiral agent A and the chiral agent B. It is a schematic diagram.
  • HTP Helical Twisting Power
  • the numerical range represented by using “-” in the present specification means a range including the numerical values before and after “-” as the lower limit value and the upper limit value.
  • “(meth) acrylate” is a notation representing both acrylate and methacrylate
  • “(meth) acryloyl group” is a notation representing both an acryloyl group and a methacryloyl group.
  • “(Meta) acrylic” is a notation that represents both acrylic and methacrylic.
  • “identical” shall include an error range generally tolerated in the art.
  • “identical” with respect to an angle means that the difference from an exact angle is within a range of less than 5 degrees unless otherwise specified. The difference from the exact angle is preferably less than 4 degrees, more preferably less than 3 degrees.
  • the reflective liquid crystal display device of the present invention It has a linear polarizer, a liquid crystal cell, a ⁇ / 4 plate, and a cholesteric liquid crystal layer formed by using a liquid crystal compound in this order. On at least one of the pair of main surfaces of the cholesteric liquid crystal layer, the direction of the molecular axis of the liquid crystal compound is changed while continuously rotating along at least one direction in the plane.
  • Reflective type in which the arrangement direction of bright and dark parts derived from the cholesteric liquid crystal phase observed by a scanning electron microscope in a cross section perpendicular to the main surface of the cholesteric liquid crystal layer is inclined with respect to the main surface of the cholesteric liquid crystal layer. It is a liquid crystal display device.
  • embodiments of the reflective liquid crystal display device of the present invention will be described with reference to the drawings.
  • FIG. 1 shows a diagram conceptually showing an example of the configuration of the reflective liquid crystal display device of the present invention.
  • the reflective liquid crystal display device 80 shown in FIG. 1 has a linear polarizing element 84, a liquid crystal cell 82, a ⁇ / 4 plate 86, a cholesteric liquid crystal layer 10, and a light absorbing layer 88 in this order.
  • the reflective liquid crystal display device 80 does not have a backlight, and reflects external light incident on the device from the linear polarizer 84 side by the cholesteric liquid crystal layer 10 and transmits the external light through the liquid crystal cell 82 to perform display. It is a type liquid crystal display device.
  • the reflective liquid crystal display device of the present invention is not limited to a configuration without a backlight.
  • the reflective liquid crystal display device of the present invention has a back light and has a transmission mode in which the light of the backlight is transmitted for display and a reflection mode in which external light is reflected by the cholesteric liquid crystal layer for display.
  • the configuration may be switchable.
  • the linear polarized light 84 has a polarization axis in one direction and has a function of transmitting specific linearly polarized light.
  • a general linear polarizing plate such as an absorption type polarizing plate containing an iodine compound and a reflection type polarizing plate such as a wire grid can be used.
  • the polarization axis is synonymous with the transmission axis.
  • an iodine-based polarizing plate for example, an iodine-based polarizing plate, a dye-based polarizing plate using a bicolor dye, and a polyene-based polarizing plate can be used.
  • Iodine-based polarizing plates and dye-based polarizing plates are generally produced by adsorbing iodine or a dichroic dye on polyvinyl alcohol and stretching the polarizing plate.
  • the linear polarizer 84 converts external light into linearly polarized light and causes it to enter the liquid crystal cell.
  • Examples of the liquid crystal cell 82 include known liquid crystal image display elements.
  • the drive mode of the liquid crystal cell is not particularly limited, and specific examples include various modes such as IPS (In Plane Switching) mode, FFS (Fringe Field Switching) mode, VA (Vertical Alignment) mode, and TN (Twisted Nematic) mode. Modes can be mentioned.
  • the liquid crystal cell 82 selects whether to transmit the linearly polarized light transmitted through the linearly polarizing element 84 while maintaining the polarization direction or to transmit the polarization direction by rotating the polarization direction by 90 °, depending on whether the voltage is turned on or off.
  • the ⁇ / 4 plate may be composed of only an optically anisotropic layer having a ⁇ / 4 function, or may have a structure in which an optically anisotropic layer having a ⁇ / 4 function is formed on a support. It is good, but when the ⁇ / 4 plate has a support, it is intended that the combination of the support and the optically anisotropic layer is the ⁇ / 4 plate.
  • a known ⁇ / 4 plate can be used as the ⁇ / 4 plate 86.
  • the ⁇ / 4 plate 86 is made of a material having a reverse dispersion of the double refractive index. As a result, the ⁇ / 4 plate 86 can handle light having a wide band wavelength.
  • the ⁇ / 4 plate 86 converts the linearly polarized light transmitted through the liquid crystal cell 82 into circularly polarized light. In addition, the circularly polarized light reflected by the cholesteric liquid crystal layer is converted into linearly polarized light.
  • the cholesteric liquid crystal layer 10 is a layer formed by cholesteric orientation of a liquid crystal compound.
  • the cholesteric liquid crystal layer 10 has wavelength selective reflectivity and circular polarization selective reflectivity. That is, the cholesteric liquid crystal layer 10 reflects right-circular polarization or left-circular polarization of the selective reflection wavelength, and transmits light in another wavelength region and light in another turning direction.
  • the cholesteric liquid crystal layer 10 reflects this circularly polarized light if the turning direction of the circularly polarized light transmitted through the ⁇ / 4 plate 86 is the same as the turning direction of the circularly polarized light reflected by the cholesteric liquid crystal layer 10. Further, the cholesteric liquid crystal layer 10 transmits the circularly polarized light if the turning direction of the circularly polarized light transmitted through the ⁇ / 4 plate 86 is opposite to the turning direction of the circularly polarized light reflected by the cholesteric liquid crystal layer 10.
  • the cholesteric liquid crystal layer 10 will be described in detail later.
  • the light absorption layer 88 is preferably a layer that the reflective liquid crystal display device of the present invention has.
  • the light absorption layer 88 absorbs at least a part of the light having a wavelength transmitted through the cholesteric liquid crystal layer 10. By having the light absorption layer 88, the visibility of the reflected light reflected by the cholesteric liquid crystal layer 10 can be improved.
  • the resin may contain a light absorbing material.
  • a light absorbing material For example, when the light to be absorbed is visible light, a colored (particularly black) resin material, paper, an inorganic material, or the like can be used as the absorption layer.
  • the light absorbing material is not limited, and a known light absorbing material can be used depending on the wavelength range to be absorbed.
  • an inorganic pigment such as carbon black or iron black, an organic pigment such as an insoluble azo pigment, or a known light absorber such as a dye such as azo or anthraquinone. it can.
  • each layer is shown in a separated state for explanation.
  • FIG. 2 the polarization state of the transmitted light after passing through each layer is shown on the left side of each layer.
  • the linear polarizer 84 has an absorption axis substantially in the vertical direction in the drawing as shown by the broken line arrow. Therefore, the light transmitted through the linear polarizing element 84 is linearly polarized in the left-right direction in FIG. 2 in the vibration direction.
  • the linearly polarized light transmitted through the linearly polarized light 84 is incident on the liquid crystal cell 82.
  • the liquid crystal cell 82 is in a state of transmitting the linearly polarized light transmitted through the linearly polarized light 84 while maintaining the polarization direction by turning the voltage on or off. Therefore, the liquid crystal cell 82 transmits light while maintaining the polarized state of the incident linearly polarized light. That is, in the example shown in FIG. 2, the light after passing through the liquid crystal cell 82 is linearly polarized in the left-right direction in FIG.
  • the linearly polarized light transmitted through the liquid crystal cell 82 is incident on the ⁇ / 4 plate 86.
  • the ⁇ / 4 plate 86 converts the incident linearly polarized light into circularly polarized light.
  • the ⁇ / 4 plate 86 converts linearly polarized light in the left-right direction in FIG. 2 into left circularly polarized light. Therefore, the light after passing through the ⁇ / 4 plate 86 is left circularly polarized.
  • the left circularly polarized light transmitted through the ⁇ / 4 plate 86 is incident on the cholesteric liquid crystal layer 10.
  • the cholesteric liquid crystal layer 10 is a cholesteric liquid crystal layer that reflects right circularly polarized light and transmits left circularly polarized light. Therefore, in the example shown in FIG. 2, the cholesteric liquid crystal layer 10 transmits the left circularly polarized light incident from the ⁇ / 4 plate 86 side.
  • the left circularly polarized light transmitted through the cholesteric liquid crystal layer 10 is incident on the light absorption layer 88.
  • the light absorption layer 88 absorbs the incident left circular polarization.
  • the external light incident from the linear polarizing plate 84 side is not reflected in the reflective liquid crystal display device 80, so that the reflective liquid crystal display device 80 is on the linear polarizing plate 84 side (display surface). Does not emit light to the side). As a result, the reflective liquid crystal display device 80 displays black.
  • the polarization state of the transmitted light after passing through each layer is shown on the left side of each layer, and the polarization state of the reflected light after passing through each layer is shown on the right side of each layer.
  • the linear polarizer 84 When external light is incident from the linear polarizer 84 side, the light transmitted through the linear polarizer 84 becomes linearly polarized light.
  • the linear polarizer 84 has an absorption axis substantially in the vertical direction in the drawing as shown by the broken line arrow. Therefore, the light transmitted through the linear polarizing element 84 is linearly polarized in the left-right direction in FIG.
  • the linearly polarized light transmitted through the linearly polarized light 84 is incident on the liquid crystal cell 82.
  • the liquid crystal cell 82 is in a state of transmitting the linearly polarized light transmitted through the linearly polarized light 84 by rotating the polarization direction by 90 ° depending on whether the voltage is turned on or off. Therefore, the liquid crystal cell 82 transmits the incident linearly polarized light by rotating the polarization direction by 90 °. That is, in the example shown in FIG. 3, the light after passing through the liquid crystal cell 82 is linearly polarized in the vertical direction in FIG.
  • the linearly polarized light transmitted through the liquid crystal cell 82 is incident on the ⁇ / 4 plate 86. Since the ⁇ / 4 plate 86 converts the linearly polarized light in the left-right direction in FIG. 3 into the left circular polarization, the linearly polarized light in the vertical direction in FIG. 3 is converted into the right circular polarization. Therefore, in the example shown in FIG. 3, the light after passing through the ⁇ / 4 plate 86 is right-handed circularly polarized light.
  • the right circularly polarized light transmitted through the ⁇ / 4 plate 86 is incident on the cholesteric liquid crystal layer 10.
  • the cholesteric liquid crystal layer 10 is a cholesteric liquid crystal layer that reflects right circularly polarized light and transmits left circularly polarized light. Therefore, in the example shown in FIG. 3, the cholesteric liquid crystal layer 10 reflects the right circularly polarized light incident from the ⁇ / 4 plate 86 side.
  • the right circularly polarized light reflected by the cholesteric liquid crystal layer 10 is incident on the ⁇ / 4 plate 86. Since the ⁇ / 4 plate 86 converts the linearly polarized light in the vertical direction in FIG. 3 into right circular polarization, the incident right circularly polarized light is converted into linearly polarized light in the vertical direction in FIG.
  • the linearly polarized light transmitted through the ⁇ / 4 plate 86 is incident on the liquid crystal cell 82.
  • the liquid crystal cell 82 is in a state of transmitting the linearly polarized light transmitted through the linear polarizing element 84 by rotating the polarization direction by 90 ° by turning the voltage on or off. Therefore, the liquid crystal cell 82 transmits the incident linearly polarized light by rotating the polarization direction by 90 °. That is, in the example shown in FIG. 3, the light after passing through the liquid crystal cell 82 is linearly polarized in the left-right direction in FIG.
  • the linearly polarized light transmitted through the liquid crystal cell 82 is incident on the linearly polarized light element 84.
  • the linear polarizer 84 has an absorption axis substantially in the vertical direction in the drawing. Therefore, the linearly polarized light in the left-right direction passes through the linearly polarized light 84.
  • the external light incident from the linear polarizing plate 84 side is reflected by the cholesteric liquid crystal layer 10 in the reflective liquid crystal display 80, and the linear polarizing plate 84 of the reflective liquid crystal display 80. Light is emitted to the side (display surface side). As a result, the reflective liquid crystal display device 80 displays white.
  • the reflective liquid crystal display device 80 displays an image by performing the above-mentioned black display or white display for each pixel.
  • black display or white display was described in FIGS. 2 and 3, when displaying the halftone between white and black, the twisted state of the light when passing through the liquid crystal cell 82 is changed. Therefore, the amount of light emitted from the linear polarizing plate 84 side (display surface side) of the reflective liquid crystal display device 80 can be adjusted.
  • the reflective liquid crystal display device 80 may have a color filter, and color display is performed by performing the above-mentioned white display and black display in the wavelength range corresponding to each color of the color filter for each pixel. Can be done. Further, from the viewpoint of performing color display, the reflective liquid crystal display device 80 has a cholesteric liquid crystal layer having a selective reflection wavelength corresponding to each color, that is, two or more cholesteric liquid crystal layers having different pitches of bright and dark areas. Is preferable.
  • a cholesteric liquid crystal layer having a selective reflection wavelength corresponding to a red region having a cholesteric liquid crystal layer having a selective reflection wavelength corresponding to a green region, and a cholesteric liquid crystal layer having a selective reflection wavelength corresponding to a blue region.
  • a cholesteric liquid crystal layer having a selective reflection wavelength corresponding to a red region having a cholesteric liquid crystal layer having a selective reflection wavelength corresponding to a green region
  • a cholesteric liquid crystal layer having a selective reflection wavelength corresponding to a blue region is preferable.
  • the reflective liquid crystal display device in the reflective liquid crystal display device, light is reflected even on the surface due to its structure. That is, as shown in FIG. 4, a part of the external light I 1 incident on the reflective liquid crystal display device passes through the liquid crystal cell or the like and is reflected by the cholesteric liquid crystal layer 200 (reflected light I 1r ). Part of the external light I 2 is reflected on the surface of the reflective liquid crystal display device (reflected light I 2r ).
  • the conventional cholesteric liquid crystal layer 200 mirror-reflects light with respect to the surface of the cholesteric liquid crystal layer 200. Therefore, as shown in FIG.
  • the traveling direction of the reflected light I 2r reflected on the surface of the reflective liquid crystal display device and the traveling direction of the reflected light I 1r reflected by the cholesteric liquid crystal layer 200 are substantially the same. Therefore, there is a problem that the two reflected lights overlap and the display screen becomes difficult to see when viewed from the observer U side.
  • the liquid crystal cell 82 and the cholesteric liquid crystal layer are not shown.
  • the direction of the molecular axis of the liquid crystal compound changes while continuously rotating along at least one direction in the plane on at least one of the pair of main planes.
  • the arrangement direction of the bright and dark parts derived from the cholesteric liquid crystal phase observed by a scanning electron microscope (SEM) in a cross section perpendicular to the main surface of the cholesteric liquid crystal layer has a liquid crystal orientation pattern. It has a structure that is inclined with respect to the main surface of the.
  • the cholesteric liquid crystal layer reflects light with a surface parallel to the bright and dark areas (hereinafter, also referred to as light and dark lines) observed in the SEM cross section as a reflecting surface. Further, the reflection on this reflecting surface is specular reflection. Therefore, the cholesteric liquid crystal layer 10 having a light and dark line inclined with respect to the main surface reflects the incident light at an angle different from the incident angle with respect to the main surface.
  • the fact that the cholesteric liquid crystal layer 10 has a property of reflecting incident light at an angle different from the incident angle with respect to the main surface is also referred to as having reflection anisotropy.
  • the traveling direction of the reflected light I 1r reflected by the cholesteric liquid crystal layer 10 is different from the traveling direction of the reflected light I 2r reflected on the surface of the reflective liquid crystal display device. ..
  • the influence of the reflected light I 2r reflected on the surface of the reflective liquid crystal display device can be reduced and the visibility can be improved.
  • cholesteric liquid crystal layer used in the reflective liquid crystal display device of the present invention will be described in detail below. In the present invention, it is sufficient for the cholesteric liquid crystal layer to retain the optical properties of the cholesteric liquid crystal phase in the layer, and the liquid crystal compound in the layer does not have to exhibit liquid crystal properties.
  • FIG. 6 and 7 show a schematic diagram conceptually showing the orientation state of the liquid crystal compound in the cholesteric liquid crystal layer.
  • FIG. 6 is a schematic view showing the orientation state of the liquid crystal compound in the planes of the main surface 11 and the main surface 12 of the cholesteric liquid crystal layer 10 having a pair of main surfaces 13 composed of the main surface 11 and the main surface 12.
  • FIG. 7 is a schematic cross-sectional view showing the state of the cholesteric liquid crystal phase in the cross section perpendicular to the main surface 11 and the main surface 12.
  • FIG. 6 corresponds to a schematic view of the XY plane of the cholesteric liquid crystal layer 10
  • FIG. 7 corresponds to a schematic view of the XY plane of the cholesteric liquid crystal layer 10.
  • the mode of the rod-shaped liquid crystal compound as the liquid crystal compound will be described as an example.
  • the liquid crystal compounds 14 are arranged along a plurality of array axes D 1 parallel to each other in the XY plane, and the respective array axes are arranged.
  • the orientation of the molecular axis L 1 of the liquid crystal compound 14 has a liquid crystal orientation pattern that changes while continuously rotating in one direction in the plane along the arrangement axis D 1 .
  • the array axis D 1 is oriented in the X direction.
  • the liquid crystal compounds 14 having the same molecular axis L 1 are oriented at equal intervals.
  • the "direction of the molecular axis L 1 of the liquid crystal compound 14 is changed while continuously rotating in one direction in the plane along the array axis D 1" is the molecular axis L 1 of the liquid crystal compound 14 angle between the array axis D 1 is, are different depending on the position of the alignment axis D 1 direction, theta 1 + 180 ° from the angle is theta 1 along the array axis D 1 to the molecular axis L 1 and the array axis D 1 or it means that gradually changes to ⁇ 1 -180 °. That is, a plurality of liquid crystal compounds 14 arranged along the array axis D 1, as shown in FIG.
  • molecular axis L 1 is changed while rotating by a predetermined angle along the array axis D 1.
  • the molecular axis L 1 of the liquid crystal compound 14 is intended to be the molecular major axis of the rod-shaped liquid crystal compound.
  • the molecular axis L 1 of the liquid crystal compound 14 is intended to be an axis parallel to the normal direction of the disk-shaped liquid crystal compound with respect to the disk surface.
  • FIG. 7 shows a schematic view of the XX plane of the cholesteric liquid crystal layer 10.
  • the molecular axis L 1 of the liquid crystal compound 14 is inclined with respect to the main surface 11 and the main surface 12 (XY plane). ..
  • the average angle (average tilt angle) ⁇ 3 formed by the molecular axis L 1 of the liquid crystal compound 14 and the main surface 11 and the main surface 12 (XY plane) is preferably 5 to 45 °, more preferably 12 to 22 °. ..
  • the angle ⁇ 3 can be measured by observing the XX plane of the cholesteric liquid crystal layer 10 with a polarizing microscope.
  • the molecular axis L 1 of the liquid crystal compound 14 is inclined or oriented in the same direction with respect to the main surface 11 and the main surface 12 (XY plane). Is preferable.
  • the average angle is determined by measuring the angle formed by the molecular axis L 1 of the liquid crystal compound 14 and the main surface 11 and the main surface 12 at any five or more points in the polarization microscope observation of the cross section of the cholesteric liquid crystal layer. Is the arithmetic mean value.
  • the spiral axis C 1 derived from the cholesteric liquid crystal phase has a main surface 11 and a main surface 12 (XY planes). It is tilted at a predetermined angle with respect to. That is, the reflection surface (plane in which the liquid crystal compounds orthogonal to the spiral axis C 1 and having the same azimuth angle exist) T 1 of the cholesteric liquid crystal layer 10 is substantially relative to the main surface 11 and the main surface 12 (XY planes). It is tilted in a certain direction.
  • the "liquid crystal molecules having the same azimuth angle” refer to liquid crystal molecules having the same orientation direction of the molecular axes when projected onto the main surface 11 and the main surface 12 (XY planes).
  • the arrangement direction P 1 in which the bright portions 15 and the dark portions 16 are alternately arranged as shown in FIG. 8 is the main surface 11 and the main surface 11.
  • a striped pattern is observed that is inclined at a predetermined angle ⁇ 2 with respect to the surface 12 (XY surface).
  • two bright parts 15 and two dark parts 16 in FIG. 8 correspond to one pitch of the spiral (one winding number of the spiral).
  • the molecular axis L 1 of the liquid crystal compound 14 is substantially orthogonal to the arrangement direction P 1 in which the bright portions 15 and the dark portions 16 are alternately arranged.
  • the angle formed by the molecular axis L 1 and the arrangement direction P 1 is preferably 80 to 90 °, more preferably 85 to 90 °.
  • FIG. 9 shows a schematic cross-sectional view of the conventional cholesteric liquid crystal layer. Specifically, FIG. 9 shows a state of the cholesteric liquid crystal layer in a cross section perpendicular to the main surface 23 of the cholesteric liquid crystal layer 20 having a pair of main surfaces 23 including the main surface 21 and the main surface 22.
  • the main surface 21 and the main surface 22 of the cholesteric liquid crystal layer 20 will be referred to as XY planes
  • the cross section perpendicular to the XY planes will be described as XY planes. That is, FIG.
  • the spiral axis C 2 derived from the cholesteric liquid crystal phase is perpendicular to the main surface 21 and the main surface 22 (XY planes), and the reflective surface T 2 is the main surface 21. And a plane parallel to the main plane 22 (XY plane).
  • the molecular axis L 2 of the liquid crystal compound 24 is not inclined with respect to the main surface 21 and the main surface 22 (XY planes). In other words, the molecular axis L 2 is parallel to the main surface 21 and the main surface 22 (XY planes). Therefore, as shown in FIG.
  • the arrangement direction P 2 in which the bright portions 25 and the dark portions 26 are alternately arranged is the main surface 21 and the main surface 22. It is perpendicular to (XY plane). Since the cholesteric liquid crystal phase is specularly reflective, for example, when light is incident on the cholesteric liquid crystal layer 20 from an oblique direction, the light is reflected obliquely at a reflection angle of the same angle as the incident angle (in FIG. 9). See arrow). Therefore, as described with reference to FIG.
  • the traveling direction of the reflected light I 2r reflected on the surface of the reflective liquid crystal display device and the traveling direction of the reflected light I 1r reflected by the cholesteric liquid crystal layer 200 are approximately one.
  • the display screen becomes difficult to see because the two reflected lights overlap.
  • the cholesteric liquid crystal layer 10 shown in FIGS. 6 and 7 is reflected because its reflecting surface T 1 is inclined in a predetermined direction with respect to the main surface 11 and the main surface 12 (XY surfaces).
  • the traveling direction of the reflected light I 1r reflected by the cholesteric liquid crystal layer 10 is different from the traveling direction of the reflected light I 2r reflected by the surface of the reflective liquid crystal display device.
  • the directions are different, and the influence of the reflected light I 2r reflected on the surface of the reflective liquid crystal display device can be reduced to improve the visibility.
  • the cholesteric liquid crystal phase is known to exhibit selective reflectivity at specific wavelengths.
  • the cholesteric liquid crystal phase exhibits selective reflectivity to either left or right circularly polarized light at a specific wavelength. Whether the reflected light is right-handed or left-handed depends on the twisting direction (sense) of the spiral of the cholesteric liquid crystal phase.
  • the selective reflection of circular polarization by the cholesteric liquid crystal phase reflects the right circular polarization when the spiral twisting direction of the cholesteric liquid crystal phase is right, and the left circular polarization when the spiral twisting direction is left.
  • the direction of rotation of the cholesteric liquid crystal phase can be adjusted by the type of the liquid crystal compound forming the optically anisotropic layer and / or the type of the chiral agent added.
  • ⁇ n can be adjusted by the type of the liquid crystal compound forming the cholesteric liquid crystal layer, the mixing ratio thereof, and the temperature at the time of fixing the orientation.
  • the full width at half maximum of the reflection wavelength region is adjusted according to the use of the cholesteric liquid crystal layer, and may be, for example, 10 to 500 nm, preferably 20 to 300 nm, and more preferably 30 to 100 nm.
  • the bright portion 15 and the dark portion 16 of the cholesteric liquid crystal layer 10 are configured to be linear, but the present invention is not limited to this, as in the cholesteric liquid crystal layer 30 shown in FIG. ,
  • the shape of the light-dark line composed of the bright part 35 and the dark part 36 derived from the cholesteric liquid crystal phase observed by SEM on the XZ plane may be wavy (wavy structure).
  • the surfaces parallel to the bright and dark areas are the reflective surfaces. Therefore, by making the shape of the bright part and the dark part derived from the cholesteric liquid crystal phase of the cholesteric liquid crystal layer wavy, the reflective surface becomes wavy. Therefore, the reflection angle of the reflected light on the cholesteric liquid crystal layer 30 differs depending on the position, and light diffusivity can be obtained.
  • the shape of the light-dark line consisting of the bright part 35 and the dark part 36 derived from the cholesteric liquid crystal phase of the cholesteric liquid crystal layer 30 is wavy (wavy structure), that the angle formed by the spiral axis and the surface of the cholesteric liquid crystal layer is periodic. It is a layer having a structure that changes to.
  • the cholesteric liquid crystal layer 30 is a layer in which the normal of the line formed by the dark portion and the angle formed by the surface of the cholesteric liquid crystal layer in the cross-sectional view observed by SEM change periodically.
  • the wavy structure has the following configuration.
  • the point where one end of the dark part intersects the main surface or side surface of the cholesteric liquid crystal layer is a1
  • the point where the other end of the dark part intersects the main surface or side surface of the cholesteric liquid crystal layer is a2.
  • the line segment consisting of the point a2 and the point a2 is used as the reference line. Assuming that the angle formed by the tangent line at a certain point in the dark part and the reference line is the inclination angle of the dark part, the wavy structure has a fluctuation amount of the inclination angle in the linear shape formed by the dark part of 5 ° or more.
  • the arrangement of the molecular axis L 3 of the liquid crystal compound 34 on one main surface 31 is shown in the plane as shown in FIG. It is easy to form by orienting so as to face a certain direction.
  • the arrangement of the molecular axis L 3 of the liquid crystal compound 34 on the other main surface 32 has the same orientation as the XY plane of the cholesteric liquid crystal layer 10 shown in FIG. Further, the XX plane of the cholesteric liquid crystal layer 30 has the same orientation as the XX plane of the cholesteric liquid crystal layer 10.
  • the cholesteric liquid crystal layer 30, the liquid crystal compound 34 is the molecular axis L 3 tilting aligned in a predetermined direction to the principal surface 31 and major surface 32 (X-Y plane), and the helical axis from the cholesteric liquid crystal phase It is inclined at a predetermined angle with respect to the main surface 31 and the main surface 32 (XY surfaces).
  • the cholesteric liquid crystal layer 30 in which the bright portion 35 and the dark portion 36 are wavy varies along the arrangement axis by one cycle ⁇ of the length in which the direction of the molecular axis of the liquid crystal compound is rotated by 180 ° in the liquid crystal orientation pattern described later. It can also be formed by making it. Alternatively, as another method, there is also a method of adding a surfactant to the liquid crystal composition for forming the cholesteric liquid crystal layer.
  • the liquid crystal compound 14 is obliquely oriented with respect to the main surface 11 and the main surface 12 (XY plane) on the XX plane, and the molecular axis L 1 thereof is inclined.
  • the orientation of the molecular axis L 1 of the liquid crystal compound 14 changes while continuously rotating in one direction in the plane along the arrangement axis D 1 . ..
  • the cholesteric liquid crystal layer 10 exhibits high linearity in the bright and dark lines composed of the bright and dark parts derived from the cholesteric liquid crystal phase observed by SEM on the XX plane. As a result, it has low haze and high transparency.
  • FIG. 13 and 14 show schematic views of another example of the cholesteric liquid crystal layer used in the present invention.
  • FIG. 13 conceptually shows the orientation state of the liquid crystal compound on the main surface 41 and the main surface 42 of the cholesteric liquid crystal layer 40 having a pair of main surfaces 43 composed of the main surface 41 and the main surface 42. It is a schematic diagram. Further, FIG.
  • FIG. 14 shows the state of the cholesteric liquid crystal layer in a cross section perpendicular to the main surface 43 of the cholesteric liquid crystal layer 40.
  • the main surface 41 and the main surface 42 of the cholesteric liquid crystal layer 40 will be referred to as XY planes, and the cross section perpendicular to the XY planes will be described as XY planes. That is, FIG. 14 is a schematic view of the cholesteric liquid crystal layer 40 on the XY plane, and FIG. 14 is a schematic view of the cholesteric liquid crystal layer 40 on the XY plane. As shown in FIG.
  • the liquid crystal compounds 44 are arranged along a plurality of array axes D 2 parallel to each other in the XY plane, and the respective array axes are arranged.
  • the orientation of the molecular axis L 4 of the liquid crystal compound 44 changes while continuously rotating in one direction in the plane along the array axis D 2 . That is, the orientation state of the liquid crystal compound 44 on the XY plane of the cholesteric liquid crystal layer 40 is the same as the orientation state of the liquid crystal compound 14 on the XY plane of the cholesteric liquid crystal layer 10 shown in FIG.
  • the molecular axis L 4 of the liquid crystal compound 44 is not inclined with respect to the main plane 41 and the main plane 42 (XY plane). In other words, the molecular axis L 4 is parallel to the main surface 41 and the main surface 42 (XY planes). Since the cholesteric liquid crystal layer 40 has the XY plane shown in FIG. 13 and the XY plane shown in FIG. 14, the spiral shaft C 3 derived from the cholesteric liquid crystal phase has a main surface 41 and a main surface 42 (X).
  • the molecular axis L 1 is arranged in the arrangement direction P 1 in which the bright portions 15 and the dark portions 16 observed by SEM observation on the XZ plane are alternately arranged.
  • the direction of the spiral axis C 1 is substantially parallel to the arrangement direction P 1 in which the bright portion 15 and the dark portion 16 are arranged alternately.
  • the spiral axis C 3 is perpendicular to the main surface 41 and the main surface 42 (XY surfaces), it spirals with the incident direction of light incident from an oblique direction.
  • the angle formed by the direction of the axis C 3 is larger. That is, the incident direction of the light incident from the oblique direction and the direction of the spiral axis C 3 become more non-parallel. Therefore, the cholesteric liquid crystal layer 10 has a higher degree of circular polarization in the reflected light on the reflecting surface than the cholesteric liquid crystal layer 40.
  • the orientation of the molecular axis L 1 of the liquid crystal compound 14 is in the plane along the arrangement axis D 1 on both the main surfaces 11 and the main surfaces 12.
  • the direction of the molecular axis of the liquid crystal compound continuously rotates in one direction in the plane along the arrangement axis on only one main surface.
  • it may be in a changing form.
  • the arrangement axis existing on one main surface and the arrangement axis existing on the other main surface are parallel.
  • the cholesteric liquid crystal layer may have a form in which a plurality of regions having different intervals between the lines (bright lines) formed by the bright parts derived from the cholesteric liquid crystal phase observed by SEM on the XX plane may exist.
  • two bright areas and two dark areas correspond to one spiral pitch. That is, in each region where the distance between the bright lines derived from the cholesteric liquid crystal phase is different from each other, the spiral pitch is different for each region, so that the center wavelength ⁇ of selective reflection is also different.
  • the cholesteric liquid crystal layer, region A G, and the blue light wavelength range with a center wavelength of the selective reflection region A R having a center wavelength of the selective reflection to red light wavelength region, green wavelength region A form having a region A B having a central wavelength of selective reflection can be mentioned.
  • Regions A R , A G , and A B are carried out by irradiating the main surface with light from an oblique direction (preferably, irradiating light from a direction substantially parallel to the arrangement direction). It can be formed by mask exposure (patterned exposure).
  • the cholesteric liquid crystal layer preferably has a region in which the spiral pitch continuously changes in an arbitrary direction in the main surface.
  • the regions A R , the regions A G , and the regions A B are continuously arranged in an arbitrary direction in the plane of the main surface.
  • the cholesteric liquid crystal layer has a region in which the distance between the lines formed by the bright portions derived from the cholesteric liquid crystal phase observed by SEM on the XX plane is continuously changed.
  • the cholesteric liquid crystal layer 10 has a region A R , a region A G , and a region A B , but the present invention is not limited thereto.
  • the cholesteric liquid crystal layer may have two or more regions having different selective reflection wavelengths. Further, the center wavelength of selective reflection may be infrared or ultraviolet.
  • the above one cycle ⁇ corresponds to the interval between light and dark lines in the reflection polarization microscope observation. Therefore, the coefficient of variation (standard deviation / mean value) of one cycle ⁇ may be calculated by measuring the distance between the light and dark lines in the reflection polarizing microscope observation at 10 points on both main surfaces of the cholesteric liquid crystal layer.
  • the cholesteric liquid crystal layer of the present invention has two or more regions on at least one main surface of the cholesteric liquid crystal layer in which the direction of the molecular axis of the liquid crystal compound changes while continuously rotating in the plane.
  • it may be configured to reflect light in different directions in two or more regions. That is, it may be configured to have two or more regions having different orientations of the arrangement axes.
  • the cholesteric liquid crystal layer may have two or more regions in which the inclination directions of the bright portion and the dark portion are different, and may reflect light in different directions in the two or more regions.
  • FIG. 15 shows an example of a configuration having two or more regions having different orientations of the arrangement axes.
  • FIG. 15 is a schematic view showing the XY planes of the cholesteric liquid crystal layer.
  • the cholesteric liquid crystal layer 60 shown in FIG. 15 has a configuration in which four types of regions A 1 to A 4 having different arrangement axis orientations are arranged in the X direction and the Y direction.
  • each of the areas A 1 to A 4 has a substantially square shape, and the area A 2 is arranged on the right side of the area A 1 in the X direction and below the Y direction of the area A 2.
  • the area A 3 is arranged, and the area A 4 is arranged on the left side of the area A 3 in the X direction as one set, and this set is arranged in the X direction and the Y direction.
  • FIG. 15 Although only 4 ⁇ 4 regions are shown in FIG. 15, a large number of regions A 1 to A 4 are arranged in the plane of the cholesteric liquid crystal layer 60.
  • the arrangement directions of the liquid crystal compounds in each region are different.
  • the direction of the arrow is the direction in which the inclination of the light / dark line rises when viewed in the XZ cross section, and in the following description, the direction in which the inclination of the light / dark line rises is also arranged in this direction.
  • the liquid crystal compound is not shown in FIG. 15, it is the same as the liquid crystal compound 14 shown in FIG. 6 except that the orientation of the arrangement axis is different.
  • one arrangement axis (arrow) is shown, but the liquid crystal compounds are arranged along a plurality of arrangement axes parallel to each other in the XY planes of each region.
  • the liquid crystal compounds are arranged to the left in the X direction. That is, in the region A 1 , the direction of the molecular axis of the liquid crystal compound changes while continuously rotating in one direction in the plane along the arrangement axis in the X direction. Further, when the region A 1 is viewed in the XX cross section, the inclination of the light and dark lines rises to the left in FIG.
  • the liquid crystal compounds are arranged downward in the Y direction. That is, in region A 2 , the direction of the molecular axis of the liquid crystal compound changes while continuously rotating in one direction in the plane along the arrangement axis in the Y direction. Further, when the region A 2 is viewed in the YY cross section, the inclination of the light and dark lines rises in the downward direction in FIG.
  • the liquid crystal compounds are arranged to the right in the X direction. That is, in the area A 3, the orientation of the molecular axis of the liquid crystal compound is changed while continuously rotating in one direction in the plane along the array axis in the X direction. Further, when viewed area A 3 by the X-Z cross section, which rises inclined light and dark lines in the right direction in FIG. 15.
  • the liquid crystal compounds are arranged upward in the Y direction. That is, in the region A 4 , the direction of the molecular axis of the liquid crystal compound changes while continuously rotating in one direction in the plane along the arrangement axis in the Y direction. Further, when the region A 4 is viewed in the YY cross section, the inclination of the light and dark lines rises in the upward direction in FIG.
  • the area A 1 when light from the front direction of the cholesteric liquid crystal layer 60 (the direction perpendicular to the plane of FIG. 15) is incident, the area A 1, the light is reflected in a direction inclined to the X-direction rightward. Further, in the region A 2 , the light is reflected in the direction inclined upward in the Y direction. Further, in the region A 3, the light is reflected in a direction inclined to the X-direction left. Further, in the region A 4 , the light is reflected in the direction inclined downward in the Y direction.
  • the cholesteric liquid crystal layer having regions having different directions of the array axes scatter the light incident from one direction in a plurality of directions, so that the viewing angle can be widened. Further, since the cholesteric liquid crystal layer has anisotropy in the reflection direction, both transparency and brightness can be achieved. Further, the viewing angle can be widened in a specific direction by adjusting the arrangement direction (direction of the arrangement axis) of the liquid crystal compound in each region and the inclination angle of the bright part and the dark part.
  • the cholesteric liquid crystal layer 60 has a configuration having four types of regions having different arrangement axis directions, but is not limited to this, and two or three types having different arrangement axis directions, Alternatively, the configuration may have five or more types of regions. Further, the cholesteric liquid crystal layer 60 has a configuration in which four types of regions having different arrangement axis directions are arranged in a predetermined pattern, but the present invention is not limited to this, and the arrangement pattern of each region is various arrangement patterns. be able to. Further, the cholesteric liquid crystal layer 60 has a square shape in each region, but the shape is not limited to this, and each region can have various shapes.
  • each region of the cholesteric liquid crystal layer 60 has a configuration in which the directions of the array axes are different, but the configuration is not limited to this, the directions of the array axes are the same, and the inclination angles of the bright and dark areas are different. It may have different regions.
  • the array axes may be gently connected to each other in the vicinity of the boundary between regions having different directions of the array axes.
  • the configuration has a plurality of regions in which the orientation of the arrangement axis is constant, but the present invention is not limited to this, and the orientation of the arrangement axis may be gradually changed in the plane.
  • a manufacturing method for manufacturing a cholesteric liquid crystal layer used in the reflective liquid crystal display device of the present invention a predetermined liquid crystal layer is used as an alignment substrate for the cholesteric liquid crystal layer, and the spiral inducing force (HTP) is changed by light irradiation.
  • the spiral inducing force examples thereof include a method using a liquid crystal composition containing a chiral agent X or a chiral agent Y whose spiral inducing force changes with a temperature change. The method for producing the cholesteric liquid crystal layer will be described in detail below.
  • Step 1 Using a composition containing a disk-shaped liquid crystal compound, a step 1 of forming a liquid crystal layer in which the molecular axis of the disk-shaped liquid crystal compound is inclined with respect to the surface on at least one surface.
  • Step 2 It has a step 2 of forming a cholesteric liquid crystal layer on the liquid crystal layer by using a composition containing a liquid crystal compound.
  • steps 1 and 2 will be described in detail by taking the above-mentioned cholesteric liquid crystal layer 10 as an example.
  • Step 1 is a step of forming a liquid crystal layer using a composition containing a disk-shaped liquid crystal compound.
  • the molecular axis of the disk-shaped liquid crystal compound is inclined with respect to the surface.
  • the disk-shaped liquid crystal compound is oriented so that its molecular axis is inclined with respect to the surface.
  • a cholesteric liquid crystal layer is formed on the inclined oriented surface of the liquid crystal layer having a surface (hereinafter, also referred to as “inclined oriented surface”) in which the disk-shaped liquid crystal compound is inclined oriented.
  • step 1 is not particularly limited, and it is preferable to include the following steps 1-1 and the following steps 1-2.
  • a method for tilting or aligning the disk-shaped liquid crystal compound a method (step 1-1) of forming a composition layer using a substrate on which a rubbing alignment film having a pretilt angle is arranged on the surface is shown.
  • the method for inclining orienting the disk-shaped liquid crystal compound is not limited to this, and may be, for example, a method of adding a surfactant to the composition for forming a liquid crystal layer (for example, step 1-1'below). In this case, in step 1, the following step 1-1'may be performed instead of step 1-1.
  • Step 1-1' A step of forming a composition layer on a substrate (a rubbing alignment film may not be arranged on the surface) using a composition containing a disk-shaped liquid crystal compound and a surfactant.
  • the composition layer is cured in step 1 as described later.
  • Step 1-1 A step of forming a composition layer on a substrate on which a rubbing alignment film having a pretilt angle is arranged on the surface using a composition containing a disk-shaped liquid crystal compound (composition for forming a liquid crystal layer). 2: Step of orienting the disk-shaped compound in the composition layer Step 1 will be described below.
  • the substrate is a plate that supports the composition layer described later. Of these, a transparent substrate is preferable.
  • the transparent substrate is intended to be a substrate having a visible light transmittance of 60% or more, and the transmittance is preferably 80% or more, more preferably 90% or more.
  • the material constituting the substrate is not particularly limited, and for example, cellulose-based polymer, polycarbonate-based polymer, polyester-based polymer, (meth) acrylic-based polymer, styrene-based polymer, polyolefin-based polymer, vinyl chloride-based polymer, amide-based polymer, imide.
  • the substrate may contain various additives such as UV (ultraviolet) absorber, matting fine particles, plasticizer, deterioration inhibitor, and release agent.
  • the substrate preferably has low birefringence in the visible light region.
  • the phase difference of the substrate at a wavelength of 550 nm is preferably 50 nm or less, more preferably 20 nm or less.
  • the thickness of the substrate is not particularly limited, but is preferably 10 to 200 ⁇ m, more preferably 20 to 100 ⁇ m from the viewpoint of thinning and handleability.
  • the above thickness is intended as an average thickness, and the thickness of any five points on the substrate is measured and calculated and averaged.
  • the thickness of the liquid crystal layer and the thickness of the cholesteric liquid crystal layer which will be described later, are also the same.
  • the type of rubbing alignment film having a pretilt angle is not particularly limited, but for example, a polyvinyl alcohol alignment film, a polyimide alignment film, or the like can be used.
  • the composition for forming a liquid crystal layer contains a disk-shaped liquid crystal compound.
  • the disk-shaped liquid crystal compound is not particularly limited, and known compounds can be used, but among them, those having a triphenylene skeleton are preferable.
  • the disk-shaped liquid crystal compound may have a polymerizable group.
  • the type of the polymerizable group is not particularly limited, and a functional group capable of an addition polymerization reaction is preferable, and a polymerizable ethylenically unsaturated group or a ring-polymerizable group is more preferable.
  • a (meth) acryloyl group a vinyl group, a styryl group, an allyl group, an epoxy group, or an oxetane group is preferable, and a (meth) acryloyl group is more preferable.
  • the composition for forming a liquid crystal layer may contain a polymerization initiator.
  • the composition for forming a liquid crystal layer preferably contains a polymerization initiator.
  • the polymerization initiator is preferably a photopolymerization initiator capable of initiating a polymerization reaction by irradiation with ultraviolet rays. Examples of the photopolymerization initiator include ⁇ -carbonyl compounds (described in US Pat. Nos. 2,376,661 and 236,670), acidoin ethers (described in US Pat. No. 2,448,828), and ⁇ -hydrogen-substituted aromatic acidoines.
  • the content of the polymerization initiator in the liquid crystal layer forming composition (the total amount when a plurality of types of polymerization initiators are contained) is not particularly limited, but is 0.1 with respect to the total mass of the disk-shaped liquid crystal compound. It is preferably from 20% by mass, more preferably 1.0 to 8.0% by mass.
  • the composition for forming a liquid crystal layer may contain a surfactant that may be unevenly distributed on the surface of the composition layer on the substrate side and / or the surface on the side opposite to the substrate.
  • a surfactant When the liquid crystal layer forming composition contains a surfactant, the disk-shaped compound is likely to be oriented at a desired inclination angle.
  • the surfactant include onium salt compounds (described in JP2012-208397), boronic acid compounds (described in JP2013-542201), and perfluoroalkyl compounds (described in Patent No. 4592225, Neos). (Surfactant, etc.), and polymers containing these functional groups.
  • the surfactant may be used alone or in combination of two or more.
  • the content of the surfactant in the liquid crystal layer forming composition (the total amount when a plurality of types of surfactants are contained) is not particularly limited, but is 0.01 to 0.01 to the total mass of the disk-shaped compound. 10% by mass is preferable, 0.01 to 5.0% by mass is more preferable, and 0.01 to 2.0% by mass is further preferable.
  • the composition for forming a liquid crystal layer may contain a solvent.
  • the solvent include water and organic solvents.
  • the organic solvent include amides such as N, N-dimethylformamide; sulfoxides such as dimethyl sulfoxide; heterocyclic compounds such as pyridine; hydrocarbons such as benzene and hexane; alkyl halides such as chloroform and dichloromethane.
  • Esters such as methyl acetate, butyl acetate, and propylene glycol monoethyl ether acetate; ketones such as acetone, methyl ethyl ketone, cyclohexanone, and cyclopentanone; ethers such as tetrahydrofuran and 1,2-dimethoxyethane; 1, 4-Butandiol diacetate; and the like. These may be used alone or in combination of two or more.
  • the composition for forming a liquid crystal layer includes one or more kinds of antioxidants, ultraviolet absorbers, sensitizers, stabilizers, plasticizers, chain transfer agents, polymerization inhibitors, defoamers, leveling agents, etc. It may contain thickeners, flame retardants, surfactants, dispersants, and other additives such as colorants such as dyes and pigments.
  • the step of forming the composition layer on the substrate is preferably the step of forming the coating film of the above-mentioned liquid crystal layer forming composition on the substrate.
  • the coating method is not particularly limited, and examples thereof include a wire bar coating method, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, and a die coating method. If necessary, after applying the liquid crystal layer forming composition, a treatment of drying the coating film applied on the substrate may be performed. The solvent can be removed from the coating film by carrying out the drying treatment.
  • the film thickness of the coating film is not particularly limited, but is preferably 0.1 to 20 ⁇ m, more preferably 0.2 to 15 ⁇ m, and even more preferably 0.5 to 10 ⁇ m.
  • Step 1-2 is preferably a step of orienting the disk-shaped compound in the composition layer by heating the coating film.
  • a heating condition it is preferable to heat the composition layer at 40 to 150 ° C. (preferably 60 to 100 ° C.) for 0.5 to 5 minutes (preferably 0.5 to 2 minutes).
  • the disk-shaped liquid crystal compound has a polymerizable group
  • the method of curing treatment is not particularly limited, and examples thereof include photo-curing treatment and thermosetting treatment. Of these, light irradiation treatment is preferable, and ultraviolet irradiation treatment is more preferable.
  • the curing treatment is preferably a polymerization reaction by light irradiation (particularly ultraviolet irradiation), and more preferably a radical polymerization reaction by light irradiation (particularly ultraviolet irradiation).
  • a light source such as an ultraviolet lamp is used for ultraviolet irradiation.
  • the amount of ultraviolet irradiation energy is not particularly limited, but is generally preferably about 100 to 800 mJ / cm 2 .
  • the time for irradiating with ultraviolet rays is not particularly limited, but may be appropriately determined from the viewpoints of both sufficient strength and productivity of the obtained layer.
  • the average inclination angle (average tilt angle) of the disk-shaped liquid crystal compound with respect to the surface of the liquid crystal layer is preferably, for example, 20 to 90 °, and is preferably 20 to 80 °. Is more preferable, 30 to 80 ° is further preferable, and 30 to 65 ° is further preferable.
  • the average inclination angle was obtained by measuring the angle formed by the molecular axis of the disk-shaped liquid crystal compound and the surface of the liquid crystal layer at any five or more points in the observation of the cross section of the liquid crystal layer with a polarizing microscope, and arithmetically averaging them.
  • the average inclination angle of the disk-shaped liquid crystal compound with respect to the surface of the liquid crystal layer on the inclined alignment plane of the liquid crystal layer can be measured by observing the cross section of the liquid crystal layer with a polarizing microscope.
  • the inclined alignment surface of the liquid crystal layer has an azimuth angle regulating force of, for example, 0.00030 J / m 2 or less, preferably less than 0.00020 J / m 2 , preferably 0.00010 J / m 2 or less. Is more preferable, and 0.00005 J / m 2 or less is further preferable.
  • the lower limit is not particularly limited, but is, for example, 0.00000 J / m 2 or more.
  • the azimuth-regulating force of the liquid crystal layer on the inclined orientation plane can be measured by the method described in J. Appl. Phys. 1992, 33, L1242.
  • the direction of the molecular axis of the liquid crystal compound continuously rotates in one direction in the plane on the main surface of the cholesteric liquid crystal layer. It becomes easy to change. That is, taking the above-mentioned cholesteric liquid crystal layer 10 (see FIGS. 6 and 7) as an example, the liquid crystal compound 14 is formed on the XY planes by adjusting the azimuth angle restricting force on the inclined alignment plane of the liquid crystal layer.
  • Step 2 is a step of forming a cholesteric liquid crystal layer on the liquid crystal layer by using a composition containing a liquid crystal compound. The step 2 will be described below.
  • Step 2 preferably has the following step 2-1 and the following step 2-2.
  • Step 2-1 Step of forming a composition layer satisfying the following condition 1 or the following condition 2 on the liquid crystal layer formed in step 1.
  • Condition 1 At least a part of the liquid crystal compound in the composition layer is on the surface of the composition layer. On the other hand, the liquid crystal compound is inclined or oriented.
  • Condition 2 The liquid crystal compound is oriented so that the tilt angle of the liquid crystal compound in the composition layer continuously changes along the thickness direction.
  • Step 2-2 A step of forming a cholesteric liquid crystal layer by carrying out a treatment for cholesteric alignment of the liquid crystal compound in the composition layer. The steps 2-1 and 2-2 will be described below.
  • FIG. 16 shows a schematic cross-sectional view of a composition layer satisfying condition 1 obtained in step 2-1.
  • the liquid crystal compound 14 shown in FIG. 16 is a rod-shaped liquid crystal compound.
  • the composition layer 100 is formed on the liquid crystal layer 102 formed by using the disk-shaped liquid crystal compound.
  • the liquid crystal layer 102 has an inclined orientation surface 102a on the surface on the side in contact with the composition layer 100 in which the molecular axis of the disk-shaped liquid crystal compound is inclined with respect to the surface of the liquid crystal layer 102 (see FIG. 17).
  • the liquid crystal compound 14 is loosely oriented by the inclined alignment surface 102a, so that the liquid crystal compound 14 is loosely oriented with respect to the inclined alignment surface 102a. Orients to tilt.
  • the liquid crystal compound 14 is in a certain direction (uniaxial direction) so that the molecular axis L 1 of the liquid crystal compound 14 has a predetermined angle ⁇ 10 with respect to the surface of the composition layer 100. Oriented.
  • the liquid crystal compound 14 is oriented so that the molecular axis L 1 is at a predetermined angle ⁇ 10 with respect to the inclined alignment surface 102 a over the entire area of the composition layer 100 in the thickness direction R 1.
  • the composition layer satisfying the condition 1 obtained in step 2-1 it is sufficient that a part of the liquid crystal compound 14 is obliquely oriented, and the inclined alignment surface 102a side of the composition layer 100 is shown.
  • the liquid crystal compound 14 is composed of at least one of the surface (corresponding to the region A in FIG. 16) and the surface of the composition layer 100 opposite to the inclined orientation surface 102a side (corresponding to the region B in FIG. 16).
  • the molecular axis L 1 is oriented at a predetermined angle ⁇ 10 with respect to the surface of the material layer 100, and the liquid crystal compound 14 is placed on the surface of the composition layer 100 on the surface on the inclined orientation surface 102a side.
  • the molecular axis L 1 is obliquely oriented so as to have a predetermined angle ⁇ 10 .
  • the liquid crystal compound 14 is oriented so that the molecular axis L 1 has a predetermined angle ⁇ 10 with respect to the surface of the composition layer 100 in at least one of the region A and the region B, the following step 2
  • the cholesteric orientation of the liquid crystal compound 14 in the other region is caused by the orientation regulating force based on the oriented liquid crystal compound 14 in the region A and / or the region B. Can be induced.
  • the composition layer satisfying the above condition 2 corresponds to the composition layer 100 shown in FIG. 16 in which the liquid crystal compound 14 is hybrid-oriented with respect to the surface of the composition layer 100. .. That is, in the above description of FIG. 16, it corresponds to a mode in which the angle ⁇ 10 continuously changes in the thickness direction.
  • the liquid crystal compound 14 has a tilt angle ⁇ 20 (angle of the molecular axis L 1 with respect to the surface of the composition layer 100) that continuously changes along the thickness direction R 1 of the composition layer 100. Orientate.
  • the composition layer satisfying the condition 2 obtained in step 2-1 it is sufficient that a part of the liquid crystal compound 14 is hybrid-oriented, and the surface of the composition layer 100 on the inclined orientation surface 102a side (in FIG.
  • the liquid crystal compound 14 relates to the inclined alignment surface 102a on at least one of the surface (corresponding to the region A) and the surface of the composition layer 100 opposite to the inclined orientation surface 102a side (corresponding to the region B in FIG. 16).
  • the hybrid orientation is preferable, and the liquid crystal compound 14 is more preferably hybrid-oriented with respect to the surface of the composition layer 100 on the surface on the inclined alignment surface 102a side.
  • the angles ⁇ 10 and ⁇ 20 are not particularly limited unless they are 0 ° in the entire composition layer (when the angle ⁇ 10 is 0 ° in the entire composition layer, the molecular axis L 1 of the liquid crystal compound 14 is a liquid crystal. When the compound 14 is a rod-shaped liquid crystal compound, it is parallel to the inclined orientation plane 102a). In other words, it does not prevent the angles ⁇ 10 and ⁇ 20 from being 0 ° in some regions of the composition layer.
  • the angles ⁇ 10 and ⁇ 20 are, for example, 0 to 90 °. Among them, the angles ⁇ 10 and ⁇ 20 are preferably 0 to 50 °, more preferably 0 to 10 °.
  • the composition layer obtained in step 2-1 is preferably a composition layer satisfying condition 1 or 2, and more preferably a composition layer satisfying condition 2 in that the reflection anisotropy of the cholesteric liquid crystal layer is more excellent. preferable.
  • ⁇ Mechanism of action in step 2-2> After obtaining a composition layer satisfying Condition 1 or Condition 2 by the step 2-1 above, the liquid crystal compound in the composition layer is cholesterically oriented in the step 2-2 (in other words, the liquid crystal compound is cholesteric liquid crystal phase). As), forming a cholesteric liquid crystal layer. As a result, a cholesteric liquid crystal layer as shown in FIG. 17 (cholesteric liquid crystal layer 10 shown in FIGS. 6 and 7) is obtained.
  • the laminate 50 shown in FIG. 17 includes a liquid crystal layer 102 formed by using the disk-shaped liquid crystal compound 18, and a cholesteric liquid crystal layer 10 arranged so as to be in contact with the liquid crystal layer 102.
  • the molecular axis L 5 of the disk-shaped liquid crystal compound 18 is formed on the surface of the liquid crystal layer 102 (main surface 11 and main surface 12 (XY) of the cholesteric liquid crystal layer 10. It also has an inclined orientation surface 102a that is inclined with respect to the surface).
  • the disk-shaped liquid crystal compound 18 is oriented so that its molecular axis L 5 is inclined with respect to the surface of the liquid crystal layer 102.
  • the average inclination angle ⁇ 4 of the disk-shaped liquid crystal compound 18 with respect to the surface of the liquid crystal layer 102 (the angle ⁇ 5 formed by the surface of the liquid crystal layer 102 and the disk-shaped liquid crystal compound 18).
  • the average value of the angles) is, for example, preferably 20 to 90 °, more preferably 20 to 80 °, further preferably 30 to 80 °, and particularly preferably 30 to 65 °. preferable.
  • the average inclination angle ⁇ 5 of the disk-shaped liquid crystal compound 18 with respect to the surface of the liquid crystal layer 102 on the inclined alignment surface 102a of the liquid crystal layer 102 can be measured by observing the cross section of the liquid crystal layer with a polarizing microscope.
  • the average inclination angle is determined by measuring the angle formed by the molecular axis L 5 of the disk-shaped liquid crystal compound 18 and the surface of the liquid crystal layer 102 at any five or more points in the polarization microscope observation of the cross section of the liquid crystal layer. Is the arithmetic mean value.
  • the inclined alignment surface 102a of the liquid crystal layer 102 has an azimuth angle regulating force of, for example, 0.00030 J / m 2 or less, preferably less than 0.00020 J / m 2 , preferably 0.00010 J / m. 2 or less is more preferable, and 0.00005 J / m 2 or less is more preferable.
  • the lower limit is not particularly limited, but is, for example, 0.00000 J / m 2 or more.
  • the azimuth regulating force of the liquid crystal layer 102 on the inclined alignment surface 102a can be measured by the method described in J. Appl. Phys. 1992, 33, L1242. Although it is described in FIG.
  • the spiral axis of the cholesteric liquid crystal layer and the molecular axis of the disk-shaped liquid crystal compound are inclined in opposite directions, the inclined directions may be the same. Further, in the laminated body 50, it is sufficient that the orientation state of the disk-shaped liquid crystal compound 18 is maintained in the layer, and the composition in the layer does not need to exhibit liquid crystal property anymore.
  • the cholesteric liquid crystal layer 10 has already been described above.
  • the spiral inducing force (HTP) of the chiral agent is a factor indicating the spiral orientation ability represented by the following formula (1A).
  • Formula (1A) HTP 1 / (length of spiral pitch (unit: ⁇ m) ⁇ concentration of chiral agent in liquid crystal composition (mass%)) [ ⁇ m -1 ]
  • the HTP value is affected not only by the type of chiral auxiliary but also by the type of liquid crystal compound contained in the composition.
  • a composition containing a predetermined chiral agent X and a liquid crystal compound A and a composition containing a liquid crystal compound B different from the predetermined chiral agent X and the liquid crystal compound A are prepared, and both HTPs are prepared at the same temperature. When measured, the values may differ.
  • the spiral inducing force (HTP) of the chiral agent is also expressed by the following formula (1B).
  • HTP (average refractive index of liquid crystal compound) / ⁇ (concentration of chiral agent in liquid crystal composition (mass%)) ⁇ (center reflection wavelength (nm)) ⁇ [ ⁇ m -1 ]
  • the "chiral agent concentration in the liquid crystal composition" in the above formulas (1A) and (1B) corresponds to the total concentration of all chiral agents.
  • a cholesteric liquid crystal layer is formed using a liquid crystal composition containing a chiral agent X
  • the composition layer satisfying condition 1 or condition 2 is formed in step 2-1 and then the composition layer is formed in step 2-2.
  • a light irradiation treatment to cholesterically orient the liquid crystal compound in the composition layer. That is, in the above step 2-2, the liquid crystal compound in the composition layer is cholesterically oriented by changing the spiral inducing force of the chiral agent X in the composition layer by the light irradiation treatment.
  • the spiral inducing force for inducing the spiral of the liquid crystal compound is a weighted average of the chiral agent contained in the composition layer. It is considered that it generally corresponds to the spiral induced force.
  • the weighted average spiral inducing force referred to here is represented by the following formula (1C), for example, when two types of chiral agents (chiral agent A and chiral agent B) are used in combination.
  • the spiral-inducing force is a negative value. That is, for example, if helical twisting power of the chiral agent of 10 [mu] m -1, when the spiral direction of the spiral, which is induced by the chiral agent is the right represents the helical twisting power as 10 [mu] m -1. On the other hand, when the spiral direction of the spiral induced by the chiral agent is to the left, the spiral induced force is expressed as -10 ⁇ m -1 .
  • the weighted average spiral inducing force ( ⁇ m -1 ) obtained by the above formula (1C) can also be calculated from the above formula (1A) and the above formula (1B).
  • the weighted average spiral inducing force when the chiral agent A and the chiral agent B having the following characteristics are contained in the composition layer will be described.
  • the chiral agent A corresponds to the chiral agent X, has a left-handed ( ⁇ ) spiral-inducing force, and is a chiral agent that reduces the spiral-inducing force by light irradiation.
  • the chiral agent B is a chiral agent having a spiral-inducing force in the right direction (+), which is the opposite direction to the chiral agent A, and the spiral-inducing force does not change by light irradiation. ..
  • the spiral inducing force for inducing the spiral of the liquid crystal compound corresponds to the weighted average spiral inducing force of the chiral agent A and the chiral agent B.
  • the spiral inducing force for inducing the spiral of the liquid crystal compound increases as the irradiation light amount increases. It is considered that the spiral-inducing force increases in the direction (+) of the spiral induced by the chiral agent Y).
  • the absolute value of the weighted average spiral inducing force of the chiral agent in the composition layer formed in step 2-1 is not particularly limited, but the composition layer is easily formed. in point, for example, 0.0 preferably ⁇ 1.9 .mu.m -1, more preferably 0.0 ⁇ 1.5 ⁇ m -1, 0.0 ⁇ 0.5 ⁇ m -1 more preferably, zero is the most preferable (Fig. 18 reference).
  • the absolute value of the weighted average spiral inducing force of the chiral agent in the composition layer is not particularly limited as long as the liquid crystal compound can be cholesteric oriented.
  • step 2-1 the chiral agent X in the composition layer is inclined or hybridized by orienting the liquid crystal compound in the composition layer by canceling the spiral inducing force to substantially zero. It can be oriented.
  • step 2-2 the spiral-inducing force of the chiral agent X is changed to increase the weighted average spiral-inducing force of the chiral agent in the composition layer in the right direction (+) or the left direction (-). ), To obtain a cholesteric liquid crystal layer (for example, cholesteric liquid crystal layer 10).
  • the spiral inducing force for inducing the spiral of the liquid crystal compound is the weight of the chiral agent contained in the composition layer. It is considered to roughly correspond to the average spiral induced force.
  • the weighted average spiral inducing force referred to here is as described above.
  • the mechanism of action of the chiral agent Y will be described below by taking as an example an embodiment in which the liquid crystal compound in the composition layer is cholesterically oriented by performing a cooling treatment in step 2-2.
  • the chiral agent A corresponds to the chiral agent Y
  • the temperature T 12 in which the cooling process in step 2-2 is carried out (-) has a helical twisting power of the more and more is in a low temperature region left - chiral increase the helical twisting power of the () It is an agent.
  • the chiral agent B is a chiral agent having a spiral-inducing force in the right direction (+) opposite to that of the chiral agent A, and the spiral-inducing force does not change with a temperature change. ..
  • the time the temperature T 11 "helical twisting power of the chiral agent A ([mu] m -1) ⁇ concentration of the chiral agent A (wt%)" and "helical twisting power of the chiral agent B ([mu] m -1) ⁇ chiral agent B Concentration (% by mass) ”shall be equal.
  • the spiral inducing force for inducing the spiral of the liquid crystal compound corresponds to the weighted average spiral inducing force of the chiral agent A and the chiral agent B.
  • the spiral inducing force for inducing the spiral of the liquid crystal compound becomes the lower the temperature region, the more the chiral agent A It is considered that the spiral-inducing force increases in the direction (-) of the spiral induced by (corresponding to the chiral agent Y).
  • the absolute value of the weighted average spiral inducing force of the chiral agent in the composition layer is not particularly limited, but the composition layer satisfying condition 1 or condition 2 of step 2-1. (That is, in the case of the present embodiment, at the temperature T 11 where the orientation treatment of the liquid crystal compound for forming the composition layer satisfying the condition 1 or the condition 2 is carried out), the composition layer is formed.
  • the composition layer is formed.
  • 0.0 to 1.9 ⁇ m -1 is preferable
  • 0.0 to 1.5 ⁇ m -1 is more preferable
  • 0.0 to 0.5 ⁇ m -1 is further preferable
  • zero is most preferable.
  • the absolute value of the weighted average spiral inducing force of the chiral auxiliary in the composition layer is such that the liquid crystal compound can be cholesteric oriented.
  • 10.0 ⁇ m -1 or more is preferable, 10.0 to 200.0 ⁇ m -1 is more preferable, and 20.0 to 200.0 ⁇ m -1 is further preferable (see FIG. 21). That is, since the spiral-inducing force of the chiral agent Y cancels out to be substantially zero at the temperature T 11 , the liquid crystal compound can be tilted or hybrid-oriented.
  • the spiral inducing force of the chiral agent Y is increased by the cooling treatment or the heat treatment (temperature change to the temperature T 12 ) in step 2-2, and the weighted average spiral inducing force of the chiral agent in the composition layer is increased. Is increased in either the right direction (+) or the left direction ( ⁇ ) to obtain a cholesteric liquid crystal layer (for example, the cholesteric liquid crystal layer 10).
  • step 2 The procedure of step 2 will be described in detail below. In the following, a mode in which the liquid crystal composition containing the chiral agent X is used and a mode in which the liquid crystal composition containing the chiral agent Y is used will be described in detail.
  • Step 2X A step of forming a composition layer satisfying the following condition 1 or the following condition 2 on the liquid crystal layer using a liquid crystal composition containing a chiral agent X and a liquid crystal compound.
  • Step 2X-2 On the composition layer A step of forming a cholesteric liquid crystal layer by cholesterically aligning the liquid crystal compound in the composition layer by subjecting the composition layer to light irradiation Condition 1: At least a part of the liquid crystal compound in the composition layer is described above. Inclined orientation with respect to the surface of the composition layer Condition 2: The liquid crystal compound is oriented so that the tilt angle of the liquid crystal compound in the composition layer continuously changes along the thickness direction. When the liquid crystal compound has a polymerizable group, it is preferable that the composition layer is cured in step 2X as described later.
  • Step 2X-1 is a liquid crystal composition containing a chiral agent X and a liquid crystal compound (hereinafter, also referred to as “composition X”). Is a step of forming a composition layer satisfying the above-mentioned condition 1 or the above-mentioned condition 2 on the liquid crystal layer.
  • composition X will be described in detail, and then the procedure of the process will be described in detail.
  • composition X contains a liquid crystal compound and a chiral agent X whose spiral inducing force is changed by light irradiation.
  • the absolute value of the weighted average spiral inducing force of the chiral agent in the composition layer obtained in step 2X-1 is preferably 0.0 to 1.9 ⁇ m -1 in that the composition layer is easily formed. 0.0 more preferably ⁇ 1.5 [mu] m -1, more preferably 0.0 ⁇ 0.5 [mu] m -1, zero being the most preferred.
  • the composition X is a chiral agent that induces a spiral in the direction opposite to that of the chiral agent X (hereinafter, “chiral agent”).
  • chiral agent a chiral agent that induces a spiral in the direction opposite to that of the chiral agent X
  • XA chiral agent
  • the spiral inducing force of the chiral auxiliary X is offset to substantially zero during step 2X-1 (that is, the chiral agent in the composition layer obtained by step 2X-1). It is preferable to keep the weighted average spiral inducing force within the above predetermined range).
  • the chiral agent XA is more preferably a compound that does not change the spiral inducing force by the light irradiation treatment.
  • the weighted average spiral inducing force of the plurality of types of chiral agents X in the unlighted irradiation treatment is a spiral inducing force outside the above predetermined range.
  • "another chiral agent XA that induces a spiral in the direction opposite to that of the chiral agent X” is a chiral agent that induces a spiral in the opposite direction to the weighted average spiral-inducing force of the plurality of chiral agents X. Intended.
  • the chiral agent XA may not be used in combination.
  • liquid crystal compound is not particularly limited.
  • liquid crystal compounds can be classified into rod-shaped type (rod-shaped liquid crystal compound) and disk-shaped type (discotic liquid crystal compound, disk-shaped liquid crystal compound) according to their shape.
  • the rod-shaped type and the disk-shaped type include a low molecular weight type and a high molecular weight type, respectively.
  • a polymer generally refers to a polymer having a degree of polymerization of 100 or more (polymer physics / phase transition dynamics, by Masao Doi, p. 2, Iwanami Shoten, 1992).
  • any liquid crystal compound can be used.
  • two or more kinds of liquid crystal compounds may be used in combination.
  • the liquid crystal compound may have a polymerizable group.
  • the type of the polymerizable group is not particularly limited, and a functional group capable of an addition polymerization reaction is preferable, and a polymerizable ethylenically unsaturated group or a ring-polymerizable group is more preferable. More specifically, as the polymerizable group, a (meth) acryloyl group, a vinyl group, a styryl group, an allyl group, an epoxy group, or an oxetane group is preferable, and a (meth) acryloyl group is more preferable.
  • liquid crystal compound the liquid crystal compound represented by the following formula (I) is preferably used.
  • A represents a phenylene group which may have a substituent or a trans-1,4-cyclohexylene group which may have a substituent, and at least one of A has a substituent.
  • Q 1 and Q 2 each independently represent a hydrogen atom or a polymerizable group selected from the group consisting of the groups represented by the following formulas (Q-1) to (Q-5), however. Either Q 1 or Q 2 shows a polymerizable group;
  • A is a phenylene group which may have a substituent or a trans-1,4-cyclohexylene group which may have a substituent.
  • the phenylene group is preferably a 1,4-phenylene group.
  • At least one of A is a trans-1,4-cyclohexylene group which may have a substituent.
  • the m A's may be the same or different from each other.
  • M indicates an integer of 3 to 12, preferably an integer of 3 to 9, more preferably an integer of 3 to 7, and even more preferably an integer of 3 to 5.
  • the substituent which the phenylene group and the trans-1,4-cyclohexylene group in the formula (I) may have is not particularly limited, and for example, an alkyl group, a cycloalkyl group, an alkoxy group, or an alkyl ether.
  • Examples thereof include a substituent selected from the group consisting of a group, an amide group, an amino group, a halogen atom, and a group composed of a combination of two or more of the above substituents.
  • the phenylene group and the trans-1,4-cyclohexylene group may have 1 to 4 substituents. When having two or more substituents, the two or more substituents may be the same or different from each other.
  • the alkyl group may be either linear or branched.
  • the number of carbon atoms of the alkyl group is preferably 1 to 30, more preferably 1 to 10, and even more preferably 1 to 6.
  • Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group and neopentyl group.
  • Examples thereof include 1,1-dimethylpropyl group, n-hexyl group, isohexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group and the like.
  • the description of the alkyl group in the alkoxy group is the same as the description of the alkyl group.
  • specific examples of the alkylene group when referred to as an alkylene group include a divalent group obtained by removing one arbitrary hydrogen atom in each of the above-mentioned examples of an alkyl group.
  • Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
  • the carbon number of the cycloalkyl group is preferably 3 or more, more preferably 5 or more, preferably 20 or less, more preferably 10 or less, further preferably 8 or less, and particularly preferably 6 or less.
  • the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group and the like.
  • Substituents selected from are preferred.
  • X 3 represents a single bond, -O-, -S-, or -N (Sp 4- Q 4 )-, or a nitrogen atom forming a ring structure with Q 3 and Sp 3.
  • Sp 3 and Sp 4 are independently one or two in a single bond or a linear or branched alkylene group having 1 to 20 carbon atoms and a linear or branched alkylene group having 1 to 20 carbon atoms, respectively.
  • one or more -CH 2- in hydrogen atom, cycloalkyl group, and cycloalkyl group are -O-, -S-, -NH-, and -N (CH 3), respectively.
  • the m L's may be the same or different from each other.
  • Sp 1 and Sp 2 are independently one or two in a single bond or a linear or branched alkylene group having 1 to 20 carbon atoms and a linear or branched alkylene group having 1 to 20 carbon atoms, respectively.
  • Q 1 and Q 2 each independently represent a hydrogen atom or a polymerizable group selected from the group consisting of groups represented by the following formulas (Q-1) to (Q-5). However, either Q 1 or Q 2 shows a polymerizable group.
  • an acryloyl group (formula (Q-1)) or a methacryloyl group (formula (Q-2)) is preferable.
  • liquid crystal compound examples include a liquid crystal compound represented by the following formula (I-11), a liquid crystal compound represented by the formula (I-21), and a liquid crystal compound represented by the formula (I-31). Can be mentioned.
  • the compound represented by the formula (I) of JP2013-112631, the compound represented by the formula (I) of JP2010-70743, and the formula of JP2008-291218 A compound represented by (I), a compound represented by the formula (I) of Patent No. 4725516, a compound represented by the general formula (II) of JP2013-087109, and JP-A-2007-176927.
  • Liquid crystal compound represented by the formula (I-11) Liquid crystal compound represented by the formula (I-11)
  • R 11 represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or -Z 12- Sp 12- Q 12 .
  • R 2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
  • R 12 indicates a hydrogen atom or Sp 12- Q 12 , Sp 11 and Sp 12 are each independently a single bond, a linear or branched alkylene group having from carbon atoms 1 be replaced by Q 11 12, or carbon atoms which may be substituted by Q 11 1
  • a polymerizable group selected from Q 12 represents a polymerizable group selected from the group consisting of groups represented by hydrogen atom or formula (Q-1) ⁇ formula (Q-5), l 11 indicates an integer from 0 to 2 m 11 represents an integer of 1 or 2 and represents n 11 indicates an integer from 1 to 3 and represents A plurality of R 11, a plurality of L 11, a plurality of L 12, a plurality of l 11, a plurality of Z 11, a plurality of Sp 11, and a plurality of Q 11 may each be the same or different from each other.
  • the liquid crystal compound represented by the formula (I-11) is polymerizable as R 11 selected from the group consisting of groups in which Q 12 is represented by the formulas (Q-1) to (Q-5). It contains at least one of the groups -Z 12- Sp 12- Q 12 .
  • the 1,4-cyclohexylene groups contained in the liquid crystal compound represented by the formula (I-11) are all trans-1,4-cyclohexylene groups.
  • L 11 is a single bond
  • l 11 is 1 (dicyclohexyl group)
  • Q 11 is a formula (Q-1) to a formula (Q-5).
  • liquid crystal compound represented by formula (I-11) m 11 is 2, l 11 is 0, and also the two R 11 are both represent -Z 12 -Sp 12 -Q 12 , Q 12 and the like are compounds which are polymerizable groups selected from the group consisting of groups represented by the formula (Q-1) ⁇ formula (Q-5).
  • Liquid crystal compound represented by the formula (I-21) Liquid crystal compound represented by the formula (I-21)
  • Z 21 and Z 22 each independently represent a trans-1,4-cyclohexylene group which may have a substituent or a phenylene group which may have a substituent.
  • Each of the above substituents is 1 to 4 substituents independently selected from the group consisting of -CO-X 21- Sp 23- Q 23 , an alkyl group, and an alkoxy group.
  • m21 represents an integer of 1 or 2
  • n21 represents an integer of 0 or 1. When m21 indicates 2, n21 indicates 0, When m21 indicates 2, the two Z 21s may be the same or different.
  • At least one of Z 21 and Z 22 is a phenylene group which may have a substituent and is a phenylene group.
  • X 21 indicates -O-, -S-, or -N (Sp 25- Q 25 )-or indicates a nitrogen atom that forms a ring structure with Q 23 and Sp 23 .
  • r 21 represents an integer from 1 to 4 Sp 21 , Sp 22 , Sp 23 , and Sp 25 are independently single-bonded or linear or branched alkylene groups with 1 to 20 carbon atoms and linear or branched alkylene groups with 1 to 20 carbon atoms, respectively.
  • Each Q 21 and Q 22 independently represents either a polymerizable group selected from the group consisting of groups represented by the formula (Q-1) ⁇ formula (Q-5),
  • Q 25 is not a hydrogen atom when it represents any polymerizable group selected from the group and Sp 25 is a single bond.
  • the liquid crystal compound represented by the formula (I-21) preferably has a structure in which 1,4-phenylene groups and trans-1,4-cyclohexylene groups are alternately present, for example, m21 is 2.
  • n21 is 0, and, if Z 21 are each optionally substituted trans-1,4-cyclohexylene group, an arylene group optionally having a substituent from Q 21 side, Alternatively, the structure is such that m21 is 1, n21 is 1, Z 21 is an arylene group which may have a substituent, and Z 22 is an arylene group which may have a substituent. Is preferable.
  • Liquid crystal compound represented by formula (I-31) Liquid crystal compound represented by formula (I-31);
  • n31 and n32 independently represent integers from 0 to 4, respectively.
  • X 31 indicates a single bond, -O-, -S-, or -N (Sp 34- Q 34 )-or indicates a nitrogen atom forming a ring structure with Q 33 and Sp 33 .
  • Z 31 represents a phenylene group which may have a substituent and Z 32 represents a trans-1,4-cyclohexylene group which may have a substituent or a phenylene group which may have a substituent.
  • m31 indicates an integer of 1 or 2
  • m32 indicates an integer of 0 to 2
  • Q 31 and Q 32 each independently represent any polymerizable group selected from the group consisting of the groups represented by the formulas (Q-1) to (Q-5).
  • Q 33 and Q 34 one or more of -CH 2- is -O-, -S-, -NH-, and -N (CH 3) independently of hydrogen atom, cycloalkyl group, and cycloalkyl group.
  • liquid crystal compound represented by the formula (I-31) particularly preferable compounds include a compound in which Z 32 is a phenylene group and a compound in which m 32 is 0.
  • the compound represented by the formula (I) also preferably has a partial structure represented by the following formula (II).
  • formula (II) black circles indicate the bonding position with other parts of formula (I).
  • the substructure represented by the formula (II) may be included as a part of the substructure represented by the following formula (III) in the formula (I).
  • X 3 represents a single bond, -O-, -S-, or -N (Sp 4- Q 4 )-, or a nitrogen atom forming a ring structure with Q 3 and Sp 3.
  • X 3 is preferably single bond or O-.
  • the bonding position of R 1 and R 2 to each phenylene group is not particularly limited.
  • Sp 3 and Sp 4 are independently one or two in a single bond or a linear or branched alkylene group having 1 to 20 carbon atoms and a linear or branched alkylene group having 1 to 20 carbon atoms, respectively.
  • a linear or branched alkylene group having 1 to 10 carbon atoms is preferable, a straight chain alkylene group having 1 to 5 carbon atoms is more preferable, and a direct chain having 1 to 3 carbon atoms is preferable.
  • the alkylene group of the chain is more preferred.
  • one or more -CH 2- in hydrogen atom, cycloalkyl group, and cycloalkyl group are -O-, -S-, -NH-, and -N (CH 3), respectively.
  • the compound represented by the formula (I) has a structure represented by the following formula (II-2), for example.
  • Q 1 , Q 2 , Sp 1 , and Sp 2 are synonymous with the definitions of each group in the above formula (I).
  • X 3 , Sp 3 , Q 3 , R 1 , and R 2 are synonymous with the definitions of each group in the above formula (II).
  • the liquid crystal compound used in the present invention is a compound represented by the following formula (IV) described in JP-A-2014-198814, particularly one (meth) acrylate group represented by the formula (IV).
  • a polymerizable liquid crystal compound having the above is also preferably used.
  • a 1 represents an alkylene group having 2 to 18 carbon atoms, two or more CH 2 that is not one of the CH 2 or adjacent in the alkylene group is substituted by -O- May;
  • R 1 represents a hydrogen atom or a methyl group;
  • R 2 has a hydrogen atom, a halogen atom, a linear alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group, and a phenyl group, a vinyl group, a formyl group, a nitro group, and a cyano group which may have a substituent.
  • L 1 , L 2 , L 3 and L 4 independently have an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 5 carbon atoms, and 2 to 5 carbon atoms.
  • P represents an acrylic group, a methacryl group or a hydrogen atom
  • Z 5 is a single bond
  • NR 1- R 1 represents a hydrogen atom or a methyl group
  • T is 1 , 4-Phenylene
  • Sp represents a divalent aliphatic group having 1 to 12 carbon atoms which may have a substituent, and one CH 2 in the aliphatic group or two or more non-adjacent groups.
  • the compound represented by the above formula (IV) is preferably a compound represented by the following formula (V).
  • P represents an acrylic or methacrylic group
  • T represents 1,4-phenylene
  • n1 represents an integer of 3 to 6, and is preferably 3 or 4.
  • the above R 12 is represented by a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group, a phenyl group, an acryloylamino group, a methacryloylamino group, an allyloxy group, or the above formula (IV-3).
  • It may represent a methyl group, an ethyl group, a propyl group, a methoxy group, an ethoxy group, a phenyl group, an acryloylamino group, a methacryloylamino group, or a group represented by the above formula (IV-3). It is preferable to represent a methyl group, an ethyl group, a methoxy group, an ethoxy group, a phenyl group, an acryloylamino group, a methacryloylamino group, or a structure represented by the above formula (IV-3).
  • the liquid crystal compound used in the present invention is a compound represented by the following formula (VI) described in JP-A-2014-198814, particularly a (meth) acrylate group represented by the following formula (VI). Liquid crystal compounds that do not have the above are also preferably used.
  • P represents an acrylic group, a methacryl group or a hydrogen atom
  • R 1 represents a hydrogen atom or a methyl group
  • T represents 1,4-phenylene.
  • Sp represents a divalent aliphatic group having 1 to 12 carbon atoms which may have a substituent.
  • the compound represented by the above formula (VI) is preferably a compound represented by the following formula (VII). Equation (VII)
  • R 13 and R 14 are independently each of a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group, a phenyl group, an acryloylamino group, a methacryloylamino group, an allyloxy group, or the above formula ( Represents the structure represented by IV-3).
  • R 13 and R 14 are independently hydrogen atoms, linear alkyl groups having 1 to 4 carbon atoms, methoxy groups, ethoxy groups, phenyl groups, acryloylamino groups, methacryloylamino groups, allyloxy groups, or the above formulas.
  • liquid crystal compound used in the present invention examples include compounds represented by the following formula (VIII) described in JP-A-2014-198814, particularly two (meth) represented by the following formula (VIII).
  • Polymerizable liquid crystal compounds having an acrylate group are also preferably used.
  • a 2 and A 3 each independently represent an alkylene group having 2 to 18 carbon atoms, two or more CH 2 not one CH 2 or adjacent in the alkylene group, May be replaced with —O—;
  • R 5 and R 6 independently represent a hydrogen atom or a methyl group;
  • L 9 , L 10 , L 11 and L 12 independently have an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 5 carbon atoms, and 2 to 5 carbon atoms. It represents an acyl group of 4 or a halogen atom or a hydrogen atom, and at least one of L 9 , L 10 , L 11 and L 12 represents a group other than a hydrogen atom.
  • the compound represented by the above formula (VIII) is preferably a compound represented by the following formula (IX). Equation (IX)
  • n2 and n3 each independently represent an integer of 3-6; R 15 and R 16 each independently represent a hydrogen atom or a methyl group.
  • n2 and n3 independently represent integers of 3 to 6, and it is preferable that n2 and n3 are 4.
  • R 15 and R 16 each independently represent a hydrogen atom or a methyl group, and it is preferable that the above R 15 and R 16 represent a hydrogen atom.
  • Such a liquid crystal compound can be produced by a known method.
  • the chiral agent X is a compound that induces a spiral of a liquid crystal compound, and is not particularly limited as long as it is a chiral agent whose spiral-inducing force (HTP) changes by light irradiation. Further, the chiral agent X may be liquid crystal or non-liquid crystal.
  • the chiral agent X generally contains an asymmetric carbon atom. However, an axial asymmetric compound or a planar asymmetric compound that does not contain an asymmetric carbon atom can also be used as the chiral agent X.
  • the chiral agent X may have a polymerizable group.
  • Examples of the chiral agent X include so-called photoreactive chiral agents.
  • the photoreactive chiral agent is a compound having a chiral portion and a photoreactive portion whose structure is changed by light irradiation, and for example, the twisting force of the liquid crystal compound is significantly changed according to the amount of irradiation light.
  • Examples of photoreactive sites whose structure changes due to light irradiation include photochromic compounds (Kingo Uchida, Masahiro Irie, Chemical Industry, vol.64, 640p, 1999, Kingo Uchida, Masahiro Irie, Fine Chemicals, vol.28 (9), 15p. , 1999) and the like.
  • the structural change means decomposition, addition reaction, isomerization, dimerization reaction and the like caused by irradiation of the photoreactive site with light, and the structural change may be irreversible.
  • the chiral site include Hiroyuki Nohira, Review of Chemistry, No. 22 Liquid crystal chemistry, 73p: 1994, the asymmetric carbon and the like correspond.
  • Examples of the photoreactive chiral agent include the photoreactive chiral agent described in paragraphs 0044 to 0047 of JP-A-2001-159709, and the optically active compound described in paragraphs 0019 to 0043 of JP-A-2002-179669. , The optically active compounds described in paragraphs 0020 to 0044 of JP-A-2002-179633, the optically active compounds described in paragraphs 0016 to 0040 of JP-A-2002-179670, paragraphs 0017 to JP-A-2002-179668.
  • optically active compound described in 0050 examples include optically active compounds described in paragraphs 0020 to 0049 of Japanese Patent Application Laid-Open No. 179682.
  • the photoisomerization site includes a cinnamoyl site, a chalcone site, an azobenzene site, a stilbene site, or a stilbene site in that the absorption of visible light is small, photoisomerization is likely to occur, and the difference in spiral induced force before and after light irradiation is large.
  • the coumarin moiety is preferred, and the cinnamoyl moiety or chalcone moiety is more preferred.
  • the photoisomerization site corresponds to the photoreaction site whose structure is changed by the above-mentioned light irradiation.
  • the chiral agent X is preferably an isosorbide-based optically active compound, an isomannide-based optical compound, or a binaphthol-based optically active compound in that the difference in spiral-induced force before and after light irradiation is large. That is, the chiral agent X preferably has an isosorbide skeleton, an isomannide skeleton, or a binaphthol skeleton as the above-mentioned chiral moiety.
  • an isosorbide-based optically active compound or a binaphthol-based optically active compound is more preferable, and an isosorbide-based optically active compound is further preferable, in that the difference in spiral-induced force before and after light irradiation is large.
  • the chiral agent X may be used alone or in combination of two or more.
  • the total content of the chiral auxiliary in the composition X (the total content of all the chiral agents in the composition X) is preferably 2.0% by mass or more, preferably 3.0% by mass, based on the total mass of the liquid crystal compound. % Or more is more preferable.
  • the upper limit of the total content of the chiral auxiliary in the composition X is preferably 15.0% by mass or less, preferably 12.0% by mass, based on the total mass of the liquid crystal compound in terms of suppressing haze of the cholesteric liquid crystal layer. The following is more preferable.
  • composition X may contain components other than the liquid crystal compound and the chiral agent X.
  • the chiral agent XA is a compound that induces a spiral of a liquid crystal compound, and a chiral agent whose spiral-inducing force (HTP) does not change by light irradiation is preferable. Further, the chiral agent XA may be liquid crystal or non-liquid crystal.
  • the chiral agent XA generally contains an asymmetric carbon atom. However, an axial asymmetric compound or a planar asymmetric compound that does not contain an asymmetric carbon atom can also be used as the chiral agent XA.
  • the chiral agent XA may have a polymerizable group. As the chiral agent XA, a known chiral agent can be used.
  • the liquid crystal composition contains the chiral agent X alone and the chiral agent X has a spiral inducing force exceeding a predetermined range (for example, 0.0 to 1.9 ⁇ m -1 ) in the state of unlight irradiation treatment.
  • the chiral agent XA is preferably a chiral agent that induces a spiral in the direction opposite to that of the chiral agent X described above. That is, for example, when the spiral induced by the chiral agent X is in the right direction, the spiral induced by the chiral agent XA is in the left direction.
  • the chiral agent XA has the above-mentioned weighted average. It is preferably a chiral agent that induces a spiral in the opposite direction to the spiral-inducing force.
  • the composition X may contain a polymerization initiator.
  • the composition X contains a polymerization initiator.
  • the polymerization initiator include those similar to the polymerization initiator that can be contained in the liquid crystal layer.
  • the polymerization initiator that can be contained in the liquid crystal layer is as described above.
  • the content of the polymerization initiator in the composition X (the total amount when a plurality of types of polymerization initiators are contained) is not particularly limited, but is 0.1 to 20% by mass with respect to the total mass of the liquid crystal compound. It is preferably 1.0 to 8.0% by mass, more preferably 1.0 to 8.0% by mass.
  • the composition X may contain a surfactant that can be unevenly distributed on the surface of the composition layer on the side of the inclined alignment surface 102a and / or on the surface opposite to the inclined alignment surface 102a.
  • a surfactant that can be unevenly distributed on the surface of the composition layer on the side of the inclined alignment surface 102a and / or on the surface opposite to the inclined alignment surface 102a.
  • the orientation control agent contains a surfactant in the composition X, it becomes easy to obtain a composition layer satisfying the above condition 1 or the above condition 2, and a stable or rapid formation of a cholesteric liquid crystal phase becomes possible.
  • the surfactant include the same surfactants that can be contained in the liquid crystal layer.
  • the surfactant that can be contained in the liquid crystal layer is as described above.
  • Composition X is, inter alia, the composition layer to be formed in step 2X-1, the inclination angle with respect to tilt surface 102a faces the molecular axis L 1 of the liquid crystal compound 14 in a tilt surface 102a side surface (see FIG. 16) (For example, an onium salt compound (described in JP2012-208397)) and a surface of the liquid crystal compound 14 on the surface opposite to the inclined orientation surface 102a side of the molecular axis L 1 of the liquid crystal compound 14. It is preferable to contain a surfactant (for example, a polymer having a perfluoroalkyl group in the side chain) capable of controlling the inclination angle (see FIG. 16) with respect to the inclined orientation surface 102a. Further, when the composition X contains the above-mentioned surfactant, the obtained cholesteric liquid crystal layer has an advantage that the haze is small.
  • a surfactant for example, a polymer having a perfluoroalkyl group in the side
  • the surfactant may be used alone or in combination of two or more.
  • the content of the surfactant in the composition X is not particularly limited, but is 0.01 to 10% by mass with respect to the total mass of the liquid crystal compound. Preferably, 0.01 to 5.0% by mass is more preferable, and 0.01 to 2.0% by mass is further preferable.
  • the solvent composition X may contain a solvent.
  • the solvent include the same solvents that can be contained in the liquid crystal layer.
  • the solvent that can be contained in the liquid crystal layer is as described above.
  • Additives Composition X contains one or more antioxidants, UV absorbers, sensitizers, stabilizers, plasticizers, chain transfer agents, polymerization inhibitors, defoamers, levels. It may contain ringing agents, thickeners, flame retardants, surfactants, dispersants, and other additives such as coloring materials such as dyes and pigments.
  • one or more of the compounds constituting the composition X is a compound having a plurality of polymerizable groups (polyfunctional compound).
  • the total content of the compound having a plurality of polymerizable groups is preferably 80% by mass or more with respect to the total solid content in the composition X.
  • the solid content is a component that forms a cholesteric liquid crystal layer, and does not contain a solvent.
  • the compound having a plurality of polymerizable groups is a compound having two or more immobilizable groups in one molecule.
  • the polyfunctional compound contained in the composition X may have liquid crystallinity or may not have liquid crystallinity.
  • Step 2X-1 preferably includes the following step 2X-1-1 and the following step 2X-1-2.
  • Step 2X-1-1 A step of bringing the composition X into contact with the liquid crystal layer to form a coating film on the liquid crystal layer.
  • Step 2X-1-2 By heating the coating film, the above condition 1 Alternatively, a step of forming a composition layer satisfying the above condition 2.
  • Step 2X-1-1 Coating film forming step
  • the above-mentioned composition X is applied onto the liquid crystal layer.
  • the coating method is not particularly limited, and examples thereof include a wire bar coating method, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, and a die coating method.
  • the liquid crystal layer Prior to the application of the composition X, the liquid crystal layer may be subjected to a known rubbing treatment. If necessary, after the composition X is applied, a treatment of drying the coating film applied on the liquid crystal layer may be performed. The solvent can be removed from the coating film by carrying out the drying treatment.
  • the film thickness of the coating film is not particularly limited, but is preferably 0.1 to 20 ⁇ m, more preferably 0.2 to 15 ⁇ m, and 0.5 to 10 ⁇ m in that the cholesteric liquid crystal layer is more excellent in reflection anisotropy and haze. More preferred.
  • Step 2X-1-2 Composition layer forming step
  • the liquid crystal phase transition temperature of the composition X is preferably in the range of 10 to 250 ° C., more preferably in the range of 10 to 150 ° C. from the viewpoint of manufacturing suitability.
  • a composition layer satisfying the above condition 1 or the above condition 2 is obtained.
  • it is effective to give a pretilt angle to the interface and specific examples thereof include the following methods. (1) An orientation control agent that is unevenly distributed at the air interface and / or the liquid crystal layer interface and controls the orientation of the liquid crystal compound is added to the composition X. (2) A liquid crystal compound having a large pretilt at the interface is added to the composition X as a liquid crystal compound.
  • step 2X-2 the composition layer obtained in step 2X-1 is subjected to light irradiation treatment to change the spiral-inducing force of the chiral auxiliary X, and the liquid crystal compound in the composition layer is cholesterically oriented.
  • This is a process of forming a cholesteric liquid crystal layer.
  • the irradiation intensity of light irradiation in step 2X-2 is not particularly limited, and can be appropriately determined based on the spiral inducing force of the chiral agent X.
  • the irradiation intensity of light irradiation in step 2X-2 is generally preferably about 0.1 to 200 mW / cm 2 .
  • the time for irradiating light is not particularly limited, but may be appropriately determined from the viewpoints of both sufficient strength and productivity of the obtained layer.
  • the temperature of the composition layer at the time of light irradiation is, for example, 0 to 100 ° C., preferably 10 to 60 ° C.
  • the light used for light irradiation is not particularly limited as long as it is an active ray or radiation that changes the spiral inducing force of the chiral agent X.
  • the emission line spectrum of a mercury lamp far ultraviolet rays typified by an excima laser, and extreme ultraviolet rays ( EUV light: Extreme Ultraviolet), X-ray, ultraviolet rays, electron beam (EB: Electron Beam) and the like.
  • EUV light Extreme Ultraviolet
  • X-ray extreme ultraviolet rays
  • EB Electron Beam
  • ultraviolet rays are preferable.
  • the wind speed in the environment to which the composition layer is exposed is low in all the steps of step 2X.
  • the wind speed in the environment where the composition layer is exposed is preferably 1 m / s or less in all the steps of step 2X.
  • step 2X-2 a curing treatment for fixing the cholesteric orientation state is performed to form a cholesteric liquid crystal layer with the cholesteric orientation state fixed (that is, the curing treatment is performed at the same time as step 2X-2). To do) or (1) After the step 2X-2, there is further step 3X in which a curing treatment for fixing the cholesteric orientation state is performed to form a cholesteric liquid crystal layer in which the cholesteric orientation state is fixed.
  • the cholesteric liquid crystal layer obtained by performing the curing treatment corresponds to a layer in which the cholesteric liquid crystal phase is fixed.
  • the state in which the cholesteric liquid crystal phase is "immobilized” is the most typical and preferable mode in which the orientation of the liquid crystal compound which is the cholesteric liquid crystal phase is maintained. It is not limited to that, and specifically, in the temperature range of 0 to 50 ° C., and more severely, -30 to 70 ° C., the layer has no fluidity, and is oriented by an external field or an external force. It shall mean a state in which the fixed orientation form can be kept stable without causing a change.
  • the orientation state of the cholesteric liquid crystal phase by a curing reaction that proceeds by irradiation with ultraviolet rays.
  • the optical properties of the cholesteric liquid crystal phase are retained in the layer, and it is necessary that the composition in the layer finally exhibits liquid crystal properties. Absent.
  • the method of curing treatment is not particularly limited, and examples thereof include photo-curing treatment and thermosetting treatment. Of these, light irradiation treatment is preferable, and ultraviolet irradiation treatment is more preferable.
  • the liquid crystal compound is preferably a liquid crystal compound having a polymerizable group.
  • the curing treatment is preferably a polymerization reaction by light irradiation (particularly ultraviolet irradiation), and more preferably a radical polymerization reaction by light irradiation (particularly ultraviolet irradiation).
  • a light source such as an ultraviolet lamp is used for ultraviolet irradiation.
  • the amount of ultraviolet irradiation energy is not particularly limited, but is generally preferably about 100 to 800 mJ / cm 2 .
  • the time for irradiating with ultraviolet rays is not particularly limited, but may be appropriately determined from the viewpoints of both sufficient strength and productivity of the obtained layer.
  • step 2Y a method for producing a cholesteric liquid crystal layer using a liquid crystal composition containing a chiral agent Y
  • the manufacturing method 2Y has at least the following steps 2Y-1 and 2Y-2.
  • Step 2Y-1 Using a liquid crystal composition containing a chiral agent Y and a liquid crystal compound, a composition layer satisfying the following condition 1 or the following condition 2 is formed on the liquid crystal layer.
  • Step 2Y-2 The composition layer A step of forming a cholesteric liquid crystal layer by cholesterically aligning the liquid crystal compound in the composition layer by subjecting the liquid crystal compound to a cooling treatment or a heat treatment
  • Condition 1 At least a part of the liquid crystal compound in the composition layer
  • Condition 2 The liquid crystal compound is oriented with respect to the surface of the composition layer so that the tilt angle of the liquid crystal compound in the composition layer continuously changes along the thickness direction. Further, when the liquid crystal compound has a polymerizable group, it is preferable to carry out a curing treatment on the composition layer in step 2Y as described later.
  • Step 2Y-1 is a liquid crystal composition containing a chiral agent Y and a liquid crystal compound (hereinafter, also referred to as “composition Y”). Is a step of forming a composition layer satisfying the above-mentioned condition 1 or the above-mentioned condition 2 on the liquid crystal layer.
  • Step 2Y-1 is the same as Step 2X-1 described above except that the composition Y is used instead of the composition X, and the description thereof will be omitted.
  • composition Y contains a liquid crystal compound and a chiral agent Y whose spiral inducing force changes with a temperature change.
  • the absolute value of the weighted average spiral inducing force of the chiral agent in the composition layer is the orientation of the liquid crystal compound for forming the composition layer satisfying the above condition 1 or the above condition 2 in step 2Y-1. at a temperature T 11 which process is carried out, in that easy forming composition layer, for example, a 0.0 ⁇ 1.9 .mu.m -1, preferably 0.0 ⁇ 1.5 [mu] m -1, 0.0 ⁇ 0.5 ⁇ m -1 is more preferable, and zero is particularly preferable.
  • the composition Y when the chiral agent Y has a spiral-inducing force exceeding the predetermined range at the temperature T 11 , the composition Y induces a spiral in the direction opposite to that of the chiral agent Y at the temperature T 11 (hereinafter, (Also referred to as “chiral agent YA”) is included, and the spiral inducing force of the chiral agent Y is offset to substantially zero in step 2Y-1 (that is, the weighted average spiral inducing force of the chiral agent in the composition layer). Is set within the above-mentioned predetermined range). It is preferable that the chiral agent YA does not change the spiral inducing force due to a temperature change.
  • the liquid crystal composition contains a plurality of chiral agents Y as chiral agents
  • the weighted average spiral inducing force of the plurality of chiral agents Y at the temperature T 11 is a spiral inducing force outside the predetermined range.
  • "Another chiral agent YA that induces a spiral in the direction opposite to that of the chiral agent Y” is intended to be a chiral agent that induces a spiral in the opposite direction to the weighted average spiral-inducing force of the above-mentioned plurality of chiral agents Y.
  • the chiral agent Y alone does not have a spiral inducing force at the temperature T 11 and has a property of increasing the spiral inducing force by a temperature change, the chiral agent YA may not be used in combination.
  • composition Y various materials contained in the composition Y will be described. Of the materials contained in the composition Y, the components other than the chiral agent are the same as the materials contained in the composition X, and thus the description thereof will be omitted.
  • the chiral agent Y is a compound that induces a spiral of a liquid crystal compound, and is not particularly limited as long as it is a chiral agent whose spiral-inducing force is increased by cooling or heating.
  • the term "cooling or heating” as used herein means the cooling treatment or heat treatment performed in step 2Y-1.
  • the upper limit of the cooling or heating temperature is usually about ⁇ 150 ° C. (in other words, a chiral agent whose spiral inducing force is increased by cooling or heating within ⁇ 150 ° C. is preferable). Of these, a chiral agent whose spiral inducing force is increased by cooling is preferable.
  • the chiral agent Y may be liquid crystal or non-liquid crystal.
  • the chiral agents are various known chiral agents (for example, liquid crystal device handbook, Chapter 3, Section 4-3, TN (Twisted Nematic), STN (Super Twisted Nematic) chiral agents, page 199, Japan Society for the Promotion of Science 142. You can choose from (described in 1989, edited by the committee).
  • the chiral agent Y generally contains an asymmetric carbon atom. However, an axial asymmetric compound or a planar asymmetric compound that does not contain an asymmetric carbon atom can also be used as the chiral agent Y.
  • Examples of axially asymmetric or planar asymmetric compounds include binaphthyl, helicene, paracyclophane and derivatives thereof.
  • the chiral agent Y may have a polymerizable group.
  • the chiral agent Y is preferably an isosorbide-based optically active compound, an isomannide-based optically active compound, or a binaphthol-based optically active compound, and more preferably a binaphthol-based optically active compound, because the difference in spiral-induced force after a temperature change is large. ..
  • the total content of the chiral auxiliary in the composition Y (the total content of all the chiral agents in the composition Y) is preferably 2.0% by mass or more, preferably 3.0% by mass, based on the total mass of the liquid crystal compound. % Or more is more preferable.
  • the upper limit of the total content of the chiral auxiliary in the composition X is preferably 15.0% by mass or less, preferably 12.0% by mass, based on the total mass of the liquid crystal compound in terms of suppressing haze of the cholesteric liquid crystal layer. The following is more preferable. It should be noted that a smaller amount of the chiral agent Y is preferred because it tends not to affect the liquid crystallinity. Therefore, as the chiral agent Y, a compound having a strong twisting force is preferable so that a desired twisting orientation of a spiral pitch can be achieved even in a small amount.
  • the chiral agent YA is a compound that induces a spiral of a liquid crystal compound, and it is preferable that the spiral-inducing force (HTP) does not change due to a temperature change. Further, the chiral agent YA may be liquid crystal or non-liquid crystal.
  • the chiral agent XA generally contains an asymmetric carbon atom. However, an axial asymmetric compound or a planar asymmetric compound that does not contain an asymmetric carbon atom can also be used as the chiral agent YA.
  • the chiral agent YA may have a polymerizable group. As the chiral agent YA, a known chiral agent can be used.
  • the chiral agent YA is preferably a chiral agent that induces a spiral in the opposite direction to the above-mentioned chiral agent Y. That is, for example, when the spiral induced by the chiral agent Y is in the right direction, the spiral induced by the chiral agent YA is in the left direction.
  • the liquid crystal composition comprises plural kinds of chiral agent Y as a chiral agent, in such a temperature T 11 if the weighted average helical twisting power of a plurality of types of chiral agent Y exceeds the predetermined range, the chiral agent YA is ,
  • the chiral agent that induces a spiral in the opposite direction to the weighted average spiral inducing force is preferable.
  • step 2Y-2 the spiral inducing force of the chiral auxiliary Y is changed by subjecting the composition layer obtained in step 2Y-1 to a cooling treatment or a heat treatment, and the liquid crystal compound in the composition layer is cholesteric.
  • This is a step of orienting to form a cholesteric liquid crystal layer. In this step, it is particularly preferable to cool the composition layer.
  • the composition layer When cooling the composition layer, it is preferable to cool the composition layer so that the temperature of the composition layer is lowered by 30 ° C. or more because the reflection anisotropy of the cholesteric liquid crystal layer is more excellent. Among them, in that the above effect is more excellent, it is preferable to cool the composition layer so that the temperature is lowered by 40 ° C. or higher, and it is more preferable to cool the composition layer so that the temperature is lowered by 50 ° C. or higher.
  • the upper limit of the reduced temperature range of the cooling treatment is not particularly limited, but is usually about 150 ° C. In other words, the cooling treatment is performed so that the temperature of the composition layer satisfying the above condition 1 or the above condition 2 obtained in the step 1 before cooling is T-30 ° C or lower.
  • the cooling method is not particularly limited, and examples thereof include a method in which the liquid crystal layer on which the composition layer is arranged is allowed to stand in an atmosphere having a predetermined temperature.
  • the cooling rate in the cooling process is not limited, it is preferable to set the cooling rate to a certain level in that the reflection anisotropy of the cholesteric liquid crystal layer is more excellent.
  • the maximum value of the cooling rate in the cooling treatment is preferably 1 ° C. or higher per second, more preferably 2 ° C. or higher per second, and further preferably 3 ° C. or higher per second.
  • the upper limit of the cooling rate is not particularly limited, but is often 10 ° C. or less per second.
  • the wind speed in the environment to which the composition layer is exposed is low in all the steps of step 2Y.
  • the wind speed in the environment where the composition layer is exposed is preferably 1 m / s or less in all the steps of step 2Y.
  • the upper limit of the increased temperature range of the heat treatment is not particularly limited, but is usually about 150 ° C.
  • step 1 rubbing orientation is applied to a base material for forming the liquid crystal layer on the surface.
  • the alignment treatment step it is preferable to perform the orientation treatment so that the orientation direction is different for each predetermined region in the plane, including the alignment treatment step of performing at least one of the photo-orientation.
  • a masking member is used to form a photoalignment film having different orientation directions. It may be formed for each. Specifically, first, a photoalignment material is applied onto the substrate to form a coating layer. Next, a photo-alignment film having a different orientation direction is formed for each region by using the masking member MK in which a plurality of opening OPs are formed according to the arrangement pattern of one type of region as shown in FIG. In the masking member MK shown in FIG. 22, square opening OPs are arranged at predetermined intervals in the left-right direction and the up-down direction.
  • the distance between adjacent openings OP in the left-right direction or the up-down direction is equal to the length of one side of the opening OP.
  • the upward direction of the masking member MK in FIG. 22 will be described as the y 1 direction, and the right direction will be described as the x 1 direction.
  • such a masking member MK is placed on the photoalignment film 54, and the polarized ultraviolet light MU is irradiated from the laser light source LD via the linear polarizer LP. At that time, the polarized ultraviolet light MU irradiates the surface of the photoalignment film 54 from a predetermined direction at a predetermined polar angle from an oblique direction. In the example shown in FIG. 23, irradiation is performed from the X direction. Further, the masking member MK is installed so that the opening OP is arranged at a position that becomes the region A 1 when the cholesteric liquid crystal layer is formed on the photoalignment film 54.
  • this exposure determines the orientation direction of the photoalignment film at the position of region A 1 .
  • the masking member MK has the y 1 direction of the masking member MK coincided with the upward direction of the y direction in FIG. 23, and the x 1 direction of the masking member is the x direction of FIG. 23. It is arranged so that it matches the right direction.
  • the masking member MK is shifted to the right by the length of one side of the opening OP, and the masking member MK and the photoalignment film 54 are 90 ° clockwise with respect to the normal. Rotate. That is, the y 1 direction of the masking member MK coincides with the right direction in the x direction in FIG. 24, and the x 1 direction of the masking member coincides with the downward direction in the y direction in FIG. 24.
  • the polarized ultraviolet light MU is irradiated in the same manner as in the first exposure.
  • the opening OP is arranged at a position that becomes the region A 2 when the cholesteric liquid crystal layer is formed on the photoalignment film 54. Further, since the masking member MK and the photoalignment film 54 are rotated 90 ° clockwise, the irradiation direction of the polarized ultraviolet light MU is 90 ° different from the first irradiation direction. That is, this exposure determines the orientation direction of the photoalignment film at the position of region A 2 . Further, the orientation direction of the photoalignment film at the position of region A 2 is different from the orientation direction of region A 1 by 90 °.
  • the masking member MK is shifted downward by the length of one side of the opening OP, and the masking member MK and the photoalignment film 54 are 90 ° clockwise with respect to the normal. Rotate. That is, the y 1 direction of the masking member MK coincides with the downward direction in the y direction in FIG. 25, and the x 1 direction of the masking member coincides with the left direction in the x direction in FIG. 25.
  • the polarized ultraviolet light MU is irradiated in the same manner as in the first exposure.
  • the opening OP is arranged at a position that becomes the region A 3 when the cholesteric liquid crystal layer is formed on the photoalignment film 54. Further, since the masking member MK and the photoalignment film 54 are rotated 90 ° clockwise, the irradiation direction of the polarized ultraviolet light MU is 90 ° different from the second irradiation direction, that is, the first irradiation direction. Is 180 ° different. That is, by this exposure, the alignment direction of the photo-alignment film of the position at which the area A 3 is defined. Further, the orientation direction of the photoalignment film at the position of region A 3 is 180 ° different from the orientation direction of region A 1 .
  • the masking member MK is shifted to the left by the length of one side of the opening OP, and the masking member MK and the photoalignment film 54 are 90 ° clockwise with respect to the normal. Rotate. That is, the y 1 direction of the masking member MK coincides with the left direction in the x direction in FIG. 26, and the x 1 direction of the masking member coincides with the upward direction in the y direction in FIG. 26.
  • the polarized ultraviolet light MU is irradiated in the same manner as in the first exposure.
  • the opening OP is arranged at a position that becomes the region A 4 when the cholesteric liquid crystal layer is formed on the photoalignment film 54. Further, since the masking member MK and the photoalignment film 54 are rotated 90 ° clockwise, the irradiation direction of the polarized ultraviolet light MU is 90 ° different from the third irradiation direction, that is, the first irradiation direction. Are in different directions by 270 °. That is, by this exposure, the alignment direction of the photo-alignment film of the position at which the area A 4 is determined. Further, the orientation direction of the photoalignment film at the position of region A 4 is 270 ° different from the orientation direction of region A 1 .
  • the disc-shaped liquid crystal compound is used on the alignment film by performing the alignment treatment so that the orientation direction is different for each region in the plane of the alignment film for forming the liquid crystal layer on the surface.
  • the disk-shaped liquid crystal compounds are arranged in each region along the orientation direction. Therefore, by forming the cholesteric liquid crystal layer on the liquid crystal layer in which the disk-shaped liquid crystal compounds are arranged in different directions for each region by the method described above, the liquid crystal compound is formed along the arrangement direction of the disk-shaped liquid crystal compounds for each region. Axis of arrangement is formed. As a result, it is possible to form a cholesteric liquid crystal layer having two or more regions having different orientations of the arrangement axes as shown in FIG.
  • the liquid crystal compound in the cholesteric liquid crystal layer is used as the base layer when forming the cholesteric liquid crystal layer as described above.
  • An example is a method using an alignment film in which a pattern is formed so as to be arranged in.
  • a cholesteric liquid crystal layer having a predetermined liquid crystal alignment pattern immobilized on the cured layer of the liquid crystal composition can be obtained. Can be done.
  • a transparent support is preferable, and a transparent substrate similar to the substrate described above can be used.
  • a so-called photo-alignment film which is obtained by irradiating a photo-alignable material with polarized light or non-polarized light to form an alignment film, can also be used. That is, a light distribution material may be applied onto the support to prepare a photoalignment film. Polarized light irradiation can be performed from a direction perpendicular to or diagonally to the photoalignment film, and non-polarized light irradiation can be performed from an oblique direction to the photoalignment film. In particular, in the case of irradiation from an oblique direction, a pretilt angle can be imparted to the liquid crystal.
  • Examples of the photoalignment material used for the photoalignment film that can be used in the present invention include JP-A-2006-285197, JP-A-2007-76839, JP-A-2007-138138, and JP-A-2007-94071.
  • Preferable examples include photodimerizable compounds described in Japanese Patent Publication No., particularly synnamate compounds, chalcone compounds, and coumarin compounds. Particularly preferred are azo compounds, photocrosslinkable polyimides, polyamides, esters, synnamate compounds, and chalcone compounds.
  • FIG. 27 shows a schematic view of the exposure apparatus for the alignment film.
  • the exposure apparatus 61 includes a light source 64 including a laser 62 and a ⁇ / 2 plate 65, a polarization beam splitter 68 that separates the laser beam M from the laser 62 (light source 64) into two, and two separated light rays MA. , MB mirrors 70A, 70B and ⁇ / 4 plates 72A, 72B, respectively, arranged on the optical path of the MB.
  • lambda / 4 plate 72A and 72B is provided with an optical axes perpendicular to one another, lambda / 4 plate 72A is linearly polarized light P 0 on the right circularly polarized light P R, lambda / 4 plate 72B is left circularly linearly polarized light P 0 converting the polarization P L.
  • the light source 64 has a ⁇ / 2 plate 65, and emits linearly polarized light P 0 by changing the polarization direction of the laser beam M emitted by the laser 62.
  • lambda / 4 plate 72A is linearly polarized light P 0 (the ray MA) to the right circularly polarized light P R
  • lambda / 4 plate 72B is linearly polarized light P 0 (the rays MB) to the left circularly polarized light P L, converts respectively.
  • a support 52 having an alignment film 54 before the alignment pattern is formed is arranged in the exposed portion, and two light rays MA and MB are crossed and interfered with each other on the alignment film 54, and the interference light is transmitted to the alignment film 54. Irradiate and expose. Due to the interference at this time, the polarization state of the light applied to the alignment film 54 periodically changes in the form of interference fringes.
  • an alignment film hereinafter, also referred to as a pattern alignment film
  • the pitch of the orientation pattern can be changed by changing the intersection angle ⁇ of the two optical MAs and MBs.
  • a cholesteric liquid crystal layer having a liquid crystal alignment pattern corresponding to this period can be formed. .. Further, by rotating the optical axes of the ⁇ / 4 plates 72A and 72B by 90 °, respectively, the rotation direction of the optical axis of the liquid crystal compound in the liquid crystal alignment pattern can be reversed.
  • the direction of the optical axis of the liquid crystal compound in the cholesteric liquid crystal layer formed on the pattern alignment film changes while continuously rotating along at least one direction in the plane. It has an orientation pattern that orients the liquid crystal compound so that it becomes a liquid crystal orientation pattern.
  • the axis of the pattern alignment film is the axis along the direction in which the liquid crystal compound is oriented
  • the direction of the alignment axis of the pattern alignment film changes while continuously rotating along at least one direction in the plane. It can be said that it has an orientation pattern.
  • the orientation axis of the pattern alignment film can be detected by measuring the absorption anisotropy. For example, when the pattern alignment film is irradiated with rotating linearly polarized light and the amount of light transmitted through the pattern alignment film is measured, the direction in which the amount of light is maximum or minimum gradually changes along one direction in the plane. It changes and is observed.
  • the cholesteric liquid crystal layer can be formed by applying a multilayer of the liquid crystal composition on the pattern alignment film.
  • a liquid crystal composition is applied on an alignment film, heated, cooled, and then cured by ultraviolet rays to prepare a first liquid crystal immobilization layer, and then the second and subsequent layers are fixed to the liquid crystal. It means that the chemical layer is overcoated, applied, heated in the same manner, cooled, and then cured with ultraviolet rays.
  • the orientation direction of the alignment film can be reflected from the lower surface to the upper surface of the cholesteric liquid crystal layer even when the total thickness of the cholesteric liquid crystal layer is increased.
  • the above-mentioned rod-shaped liquid crystal compound and disk-shaped liquid crystal compound can be used.
  • the chiral agent contained in the liquid crystal composition in the present production method is not particularly limited, and known compounds (for example, Liquid Crystal Device Handbook, Chapter 3, Section 4-3, TN (twisted nematic), STN (for example) A chiral agent for Super Twisted Nematic), p. 199, edited by the 142nd Committee of the Japan Society for the Promotion of Science, described in 1989), isosorbide, isomannide derivatives and the like can be used.
  • the liquid crystal composition may contain a polymerization initiator, a cross-linking agent, an orientation control agent and the like, and further, if necessary, a polymerization inhibitor, an antioxidant, an ultraviolet absorber, light and the like.
  • Stabilizers, coloring materials, metal oxide fine particles and the like can be added within a range that does not deteriorate the optical performance and the like.
  • the reflective liquid crystal display device of the present invention may have another layer.
  • the optical compensation layer 90 may be provided between the liquid crystal cell 82 and the ⁇ / 4 plate 86.
  • the optical compensation layer 90 for example, a film having a phase difference such that the retardation Rth in the total thickness direction of the liquid crystal cell 82, the ⁇ / 4 plate 86, and the optical compensation layer 90 is 0 nm can be used. ..
  • the reflective liquid crystal display device has two or more cholesteric liquid crystal layers, even if any one of the two or more cholesteric liquid crystal layers has another layer between the cholesteric liquid crystal layers.
  • a liquid crystal layer, a rubbing alignment layer, or a light alignment layer may be included between the cholesteric liquid crystal layers.
  • the following coating liquid for forming an undercoat layer was continuously applied on the support 01 subjected to the alkali saponification treatment with a wire bar of # 8.
  • the support 01 on which the coating film was formed was dried with warm air at 60 ° C. for 60 seconds and further dried with warm air at 100 ° C. for 120 seconds to form an undercoat layer.
  • the above coating solution prepared with the compounds 3-1 to 3-5 is applied to the surface on the undercoat layer side of the support 01 on which the undercoat layer prepared above is formed, using the wire bar of # 4.4, and dried. did.
  • the disc-shaped liquid crystal compound was oriented by heating at 70 ° C. for 90 seconds. Immediately after that, the disk-shaped liquid crystal compound was polymerized by irradiating with ultraviolet rays of 290 mJ / cm 2 under a temperature condition of 70 ° C. to fix the orientation state. This is referred to as an optical compensation layer 01.
  • An air-cooled metal halide lamp (manufactured by Eye Graphics) is used as a UV (ultraviolet) lamp under air, and is directly above the alignment film P-1 formed above via an exposure mask and a wire grid polarizer.
  • an alignment pattern was imparted to the alignment film P-1 to form a pattern alignment film Q-1.
  • the illuminance of ultraviolet rays was 100 mW / cm 2 in the UV-A region (integration of wavelengths of 380 nm to 320 nm), and the irradiation amount was 50 mJ / cm 2 in the UV-A region.
  • the coating film coated with the following composition A-1 on the alignment film Q-1 was heated to 110 ° C. on a hot plate. Then, after cooling to 60 ° C., the coating film was irradiated with ultraviolet rays having a wavelength of 365 nm using a high-pressure mercury lamp in a nitrogen atmosphere at an irradiation amount of 100 mJ / cm 2 . As a result, the orientation of the liquid crystal compound was fixed.
  • the film thickness of the immobilized liquid crystal compound was 2.0 ⁇ m. This is referred to as an optical compensation layer 02.
  • Example 1 [Formation of inclined liquid crystal layer 1]
  • the alignment film P-1 was formed on the support 01 on which the undercoat layer was formed in the same manner as the optical compensation layer 02 described above.
  • the pattern alignment film Q-2 was formed by irradiating polarized ultraviolet rays from a direction inclined by 20 degrees from the normal of the surface of the alignment film P-1.
  • the following composition for inclined liquid crystal was continuously applied on the pattern alignment film Q-2 with a wire bar of # 2, and aged at 120 ° C. for 1 minute.
  • the applied composition for inclined liquid crystal was cured by irradiating with ultraviolet rays at an irradiation amount of 500 mJ / cm 2 at 30 ° C. in a nitrogen atmosphere to obtain an inclined liquid crystal layer 1. It was confirmed that the orientation of the liquid crystal of the inclined liquid crystal layer 1 was inclined by an average of 16 ° with respect to the transmission axis direction of the polarized ultraviolet rays.
  • S-1-Surfactant S-1- Surfactant S-1 is a compound described in Japanese Patent No. 5774518 and has the following structure.
  • cholesteric liquid crystal layer G1 Preparation of cholesteric liquid crystal layer G1
  • the composition of the following cholesteric liquid crystal layer G1 was continuously applied onto the formed inclined liquid crystal layer 1 with a wire bar of # 8, and then aged at 90 ° C. for 1 minute.
  • the aged composition layer is irradiated with light having a wavelength of 365 nm at 30 ° C. using a light source (UVP, 2UV, transilluminator) at an irradiation intensity of 2 mW / cm 2 for 60 seconds. did.
  • UVP UVP, 2UV, transilluminator
  • the polymerization reaction of the liquid crystal compound was carried out by irradiating ultraviolet rays at an irradiation amount of 500 mJ / cm 2 at 30 ° C. in a nitrogen atmosphere to obtain a cholesteric liquid crystal layer G1 in which the cholesteric orientation state was fixed.
  • the inclination angle of the bright part and the dark part (bright and dark line) derived from the cholesteric liquid crystal phase was 15 degrees, and the pitch was 370 nm.
  • the reflected circularly polarized light was left-handed circularly polarized light.
  • composition of Cholesteric Liquid Crystal Layer G1 A sample solution having the following composition was prepared.
  • the chiral agent compound CD-1 was synthesized by a general method according to the following synthesis procedure.
  • the chiral agent compound CD-1 is a chiral agent whose spiral direction is to the left and whose spiral-inducing force does not change due to temperature change or light irradiation.
  • chiral auxiliary compound CD-2 The following chiral auxiliary compound CD-2 was synthesized and used according to JP-A-2002-338575.
  • the chiral auxiliary compound CD-2 is a chiral agent whose spiral direction is to the right and whose spiral-inducing force changes by light irradiation (corresponding to chiral agent X).
  • an optical laminate 01 having a support 01, a pattern alignment film Q-2, an inclined liquid crystal layer 1, and a cholesteric liquid crystal layer G1 arranged on the inclined liquid crystal layer 1 was produced.
  • Example 2 In the same manner as in Example 1 except that the addition amounts of the chiral agent compound CD-1 and the chiral agent compound CD-2 were adjusted, the optical laminate 02 having the cholesteric liquid crystal layer B1 on the inclined liquid crystal layer 1 and the optical laminate 02 An optical laminate 03 having a cholesteric liquid crystal layer R1 on the inclined liquid crystal layer 1 was produced.
  • the inclination angle of the cholesteric liquid crystal layer B1 was 15 degrees, and the pitch was 300 nm.
  • the tilt angle of the cholesteric liquid crystal layer R1 was 15 degrees, and the pitch was 420 nm.
  • a reflective film 01 was prepared by laminating the optical laminates 02, 01, and 03 in the order of lamination via an adhesive (SK adhesive, manufactured by Soken Kagaku).
  • GW2280 (manufactured by BenQ) was disassembled, and the polarizing plates arranged on both sides of the liquid crystal cell were peeled off on both sides.
  • the polarizing plate 01 was attached to the surface of the liquid crystal cell on the visual side via an adhesive (SK Dyne, manufactured by Soken Kagaku).
  • the optical compensation layer 01, the optical compensation layer 02, the reflective film 01, and the black PET were bonded in this order on the liquid crystal cell using an adhesive (SK Dyne, manufactured by Soken Kagaku).
  • the optical compensation layer 02 and the optical laminate 02 of the reflective film 01 are arranged so as to be in contact with each other.
  • the optical compensation layer 02 is a ⁇ / 4 plate, and the orientation of the slow axis is arranged so as to be right circularly polarized light after passing through linearly polarized light.
  • the light source was arranged in the direction of inclination of the light and dark lines in the cholesteric liquid crystal layer of the reflective film 01.
  • An artificial solar illuminator XC-100 manufactured by Celic Co., Ltd. was used as a light source.
  • the light source was arranged so as to be incident from an angle of 50 degrees with respect to the normal of the panel, and the image was visually recognized from the front of the panel. As a result, it was confirmed that the image visibility was very high.
  • Example 2 [Formation of pattern alignment film]
  • the alignment film P-1 produced in Example 1 was irradiated with ultraviolet rays four times as shown below via an exposure mask to form a pattern alignment film Q-3.
  • the first exposure is a method of the surface of the alignment film P-1 via an air-cooled metal halide lamp (manufactured by Eye Graphics), a UV (ultraviolet) lamp, a wire grid polarizer and an exposure mask under air. Polarized ultraviolet rays were irradiated from a direction inclined by 20 degrees from the line.
  • a square opening (transmission portion) having a side of 100 ⁇ m was used, which was 10 cm square and was arranged vertically and horizontally at equal intervals of 100 ⁇ m.
  • the exposure mask In the second exposure, the exposure mask is shifted to the right by 100 ⁇ m from the time of the first exposure, and then the support 01 on which the alignment film P-1 is laminated and the exposure mask are 90 ° clockwise with respect to the normal. After the rotation, it was irradiated with polarized ultraviolet light as in the first exposure.
  • the exposure mask In the third exposure, the exposure mask is shifted downward by 100 ⁇ m from the time of the second exposure, and then the support 01 on which the alignment film P-1 is laminated and the exposure mask are 90 ° clockwise with respect to the normal. After the rotation, it was irradiated with polarized ultraviolet light as in the first exposure.
  • the exposure mask is shifted 100 ⁇ m to the left from the time of the third exposure, and then the support 01 on which the alignment film P-1 is laminated and the exposure mask are 90 ° clockwise with respect to the normal. After the rotation, it was irradiated with polarized ultraviolet light as in the first exposure.
  • the illuminance of ultraviolet rays was 100 mW / cm 2 in the UV-A region (integration of wavelengths of 380 nm to 320 nm) at any exposure, and the irradiation amount was 50 mJ / cm 2 in the UV-A region.
  • an optical laminate 04 having the support 01, the pattern alignment film Q-3, the inclined liquid crystal layer 2, and the cholesteric liquid crystal layer G2 arranged on the inclined liquid crystal layer 2 was produced.
  • the inclined liquid crystal composition was applied onto the alignment film Q-3 to form the inclined liquid crystal layer 2.
  • the composition of the cholesteric liquid crystal layer B1 was applied and cured on the inclined liquid crystal layer 2 in the same manner as in Example 1 to prepare the cholesteric liquid crystal layer B2.
  • the inclined liquid crystal composition was applied onto the alignment film Q-3 to form the inclined liquid crystal layer 2.
  • the composition of the cholesteric liquid crystal layer R1 was applied and cured on the inclined liquid crystal layer 2 in the same manner as in Example 1 to prepare the cholesteric liquid crystal layer R2.
  • An optical laminate 06 having 01, a pattern alignment film Q-3, an inclined liquid crystal layer 2, and a cholesteric liquid crystal layer R2 arranged on the inclined liquid crystal layer 2 was produced.
  • a reflective film 02 was prepared by laminating the optical laminates 05, 04, and 06 in the order of lamination via an adhesive (SK adhesive, manufactured by Soken Kagaku).
  • the reflective film 02 was incorporated into the GW2280 in the same manner as in the first embodiment except that the reflective film 01 was changed to the reflective film 02. At this time, the optical compensation layer 02 and the optical laminate 04 of the reflective film 02 are arranged so as to be in contact with each other.
  • the light source was arranged so that it was incident from an angle of 50 degrees with respect to the normal in any of the four sides, and the image from the front of the panel was visually recognized. It was confirmed that the image visibility from the front of the panel was very high regardless of which side of the four sides the light source was arranged.
  • the solution of the cholesteric liquid crystal composition 1 shown below was continuously applied with the wire bar of # 8. Then, the coating film of cholesteric liquid crystal composition 1 was aged at 90 ° C. for 1 minute. Subsequently, the coating film of the cholesteric liquid crystal composition 1 was irradiated with ultraviolet rays at an irradiation amount of 500 mJ / cm 2 at 30 ° C. in a nitrogen atmosphere to carry out a polymerization reaction of the liquid crystal compound, thereby fixing the cholesteric orientation state. The cholesteric liquid crystal layer G3 was obtained. As a result of analyzing the cross-sectional SEM image, the inclination angle was 0 degree and the pitch was 355 nm. The reflected circularly polarized light was right-handed circularly polarized light.
  • a solution of the cholesteric liquid crystal composition was applied onto the support 01 on which the rubbing-treated undercoat layer was formed in the same manner as described above except that the amount of the chiral agent A added was adjusted, and the cholesteric orientation state was changed.
  • An immobilized cholesteric liquid crystal layer B3 and a cholesteric liquid crystal layer R3 were obtained.
  • the tilt angle of the cholesteric liquid crystal layer B3 was 0 degrees and the pitch was 290.
  • the cholesteric liquid crystal layer R3 had an inclination angle of 0 degrees and a pitch of 405 nm.
  • the reflected circularly polarized light was right-handed circularly polarized light.
  • the optical laminate 07 and the support 01 having the support 01 and the cholesteric liquid crystal layer G3 arranged on the support 01, and the cholesteric liquid crystal layer B3 arranged on the support 01 are provided.
  • An optical laminate 09 having an optical laminate 08, a support 01, and a cholesteric liquid crystal layer R3 arranged on the support 01 was produced.
  • the optical laminates 08, 07, and 09 were laminated with an adhesive in the order of lamination to prepare a reflective film 03.
  • the reflective film 03 was incorporated into the GW2280 as in the first embodiment except that the reflective film 01 was changed to the reflective film 03. At this time, the optical compensation layer 02 and the cholesteric liquid crystal layer B3 of the reflective film 03 are arranged so as to be in contact with each other.
  • the light source was arranged so that it was incident from an angle of 50 degrees with respect to the normal in any of the four sides, and the image from the front of the panel was visually recognized. It was confirmed that the image visibility from the front of the panel was very poor regardless of which side of the four sides the light source was arranged.

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

Abstract

L'invention concerne un dispositif d'affichage à cristaux liquides de type à réflexion ayant une grande visibilité. La présente invention comprend un polariseur linéaire, une cellule à cristaux liquides, une plaque λ/4 et une couche de cristaux liquides cholestériques formée à l'aide d'un composé à cristaux liquides dans cet ordre. La couche de cristaux liquides cholestériques a un motif d'alignement de cristaux liquides dans lequel l'orientation de l'axe moléculaire du composé de cristaux liquides varie le long d'au moins une direction dans le plan, tout en tournant en continu dans au moins une surface principale parmi la paire de surfaces principales de la couche de cristaux liquides cholestériques, et la direction d'agencement de parties brillantes et de parties sombres dérivées de la phase de cristaux liquides cholestériques observées par microscope électronique à balayage dans une section transversale perpendiculaire aux surfaces principales de la couche de cristaux liquides cholestériques est inclinée par rapport aux surfaces principales de la couche de cristaux liquides cholestériques.
PCT/JP2020/012986 2019-03-28 2020-03-24 Dispositif d'affichage à cristaux liquides de type à réflexion Ceased WO2020196507A1 (fr)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023032644A1 (fr) * 2021-08-30 2023-03-09 富士フイルム株式会社 Film décoratif, corps moulé et article

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JPH10115828A (ja) * 1996-08-23 1998-05-06 Seiko Epson Corp 表示素子及びそれを用いた電子機器
JPH11231304A (ja) * 1998-02-10 1999-08-27 Citizen Watch Co Ltd 液晶表示装置
WO2017030176A1 (fr) * 2015-08-20 2017-02-23 富士フイルム株式会社 Système de projection et procédé de fabrication d'écran d'image intermédiaire de système de projection
WO2017169696A1 (fr) * 2016-03-28 2017-10-05 富士フイルム株式会社 Processus de production de couche réfléchissante, et couche réfléchissante

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JP2006293393A (ja) * 2006-07-05 2006-10-26 Seiko Epson Corp 反射板、反射板の製造方法、液晶装置、電子機器
JP6149006B2 (ja) * 2014-06-18 2017-06-14 富士フイルム株式会社 反射フィルムおよび反射フィルムを有するディスプレイ

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Publication number Priority date Publication date Assignee Title
JPH10115828A (ja) * 1996-08-23 1998-05-06 Seiko Epson Corp 表示素子及びそれを用いた電子機器
JPH11231304A (ja) * 1998-02-10 1999-08-27 Citizen Watch Co Ltd 液晶表示装置
WO2017030176A1 (fr) * 2015-08-20 2017-02-23 富士フイルム株式会社 Système de projection et procédé de fabrication d'écran d'image intermédiaire de système de projection
WO2017169696A1 (fr) * 2016-03-28 2017-10-05 富士フイルム株式会社 Processus de production de couche réfléchissante, et couche réfléchissante

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023032644A1 (fr) * 2021-08-30 2023-03-09 富士フイルム株式会社 Film décoratif, corps moulé et article

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