Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
• • G—PHYSICS
  • G02—OPTICS
  • 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
  • G02F1/13363—Birefringent elements, e.g. for optical compensation
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
  • G02F1/13363—Birefringent elements, e.g. for optical compensation
  • G02F1/133633—Birefringent elements, e.g. for optical compensation using mesogenic materials
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
  • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
  • H10K59/10—OLED displays
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
  • H10K59/50—OLEDs integrated with light modulating elements, e.g. with electrochromic elements, photochromic elements or liquid crystal elements

Definitions

• the present invention relates to an optical laminate and an image display device.
• Image display devices such as liquid crystal display devices and organic EL display devices are widely used as displays for smartphones, notebook computers, and the like. In recent years, these devices have become thinner and lighter, making them easier to carry, and so they are increasingly being used on public transport such as trains and airplanes, as well as in public places such as libraries and restaurants. Therefore, due to the need to protect personal and confidential information, there is a demand for technology that prevents others from peeking at the contents displayed on image display devices.
• Patent Document 1 describes an optical laminate having, in this order, at least a first light-absorption anisotropic layer, a refractive index anisotropic layer containing a liquid crystal compound having one or more twisted structures, and a second light-absorption anisotropic layer, in which the refractive index anisotropic layer is a liquid crystal cell (e.g., a TN liquid crystal cell capable of electrically switching birefringence) ([Claim 1], [Claim 4], [Claim 5]).
• a liquid crystal cell e.g., a TN liquid crystal cell capable of electrically switching birefringence
• Patent Document 1 The inventors applied the optical laminate described in Patent Document 1 to an image display device and evaluated its characteristics. They found that when the viewing angle was switched using a liquid crystal cell as the refractive index anisotropic layer, there was room for improvement in the color tint of the display screen compared to an image display device that did not have a viewing angle switching function.
• the present invention aims to provide an optical laminate and an image display device that can suppress color tinting on the display screen when used in an image display device with a viewing angle switching function.
• the present inventors conducted extensive research to achieve the above object and discovered that by using an optical laminate having a specific optically absorptive anisotropic layer satisfying prescribed requirements in at least one of a first optically absorptive anisotropic layer and a second optically absorptive anisotropic layer together with a liquid crystal cell, color tinting on the display screen can be suppressed when the laminate is applied to an image display device having a viewing angle switching function, and thus completed the present invention. That is, the present inventors have found that the above problems can be solved by the following configuration.
• a liquid crystal display device comprising a first optically absorptive anisotropic layer, a liquid crystal cell, and a second optically absorptive anisotropic layer in this order;
• An optical laminate wherein at least one of a first optically absorptive anisotropic layer and a second optically absorptive anisotropic layer is a specific optically absorptive anisotropic layer that satisfies all of the following requirements 1 to 3:
• Requirement 1 A dichroic substance is contained.
• Requirement 2 The angle between the central axis of transmittance of the optically absorptive anisotropic layer and the normal direction to the surface of the optically absorptive anisotropic layer is from 0° to 40°.
• Requirement 3 The difference in the degree of orientation of the optically absorptive anisotropic layer at wavelengths of 450 nm, 550 nm and 650 nm is 0.025 or less.
• the present invention provides an optical laminate and an image display device that can suppress color tinting on the display screen when used in an image display device with a viewing angle switching function.
• FIG. 1 is a conceptual diagram showing an example of an embodiment of an inorganic EL light-emitting element (a so-called micro LED (light-emitting diode)).
• a so-called micro LED light-emitting diode
• parallel and orthogonal do not mean parallel and orthogonal in the strict sense, but rather mean a range of parallel ⁇ 5° and orthogonal ⁇ 5°, respectively.
• each component may be a single substance corresponding to the component, or two or more substances may be used in combination.
• the content of that component refers to the total content of the substances used in combination, unless otherwise specified.
• (meth)acrylate is a notation that represents “acrylate” or “methacrylate”
• (meth)acrylic is a notation that represents “acrylic” or “methacrylic”
• (meth)acryloyl is a notation that represents "acryloyl” or “methacryloyl”.
• Re( ⁇ ) and Rth( ⁇ ) respectively represent the in-plane retardation and the retardation in the thickness direction at a wavelength ⁇ .
• the wavelength ⁇ is 550 nm.
• Re( ⁇ ) and Rth( ⁇ ) are values measured at a wavelength ⁇ using an AxoScan (manufactured by Axometrics).
• AxoScan manufactured by Axometrics.
• Re( ⁇ ) R0( ⁇ )
• NAR-4T Abbe refractometer
• the measurement can be performed using a multi-wavelength Abbe refractometer DR-M2 (manufactured by Atago Co., Ltd.) in combination with an interference filter.
• values in the Polymer Handbook JOHN WILEY & SONS, INC.
• catalogs of various optical films can be used.
• Examples of average refractive index values of major optical films are as follows: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).
• the optical laminate of the present invention is an optical laminate having a first optically absorptive anisotropic layer, a liquid crystal cell, and a second optically absorptive anisotropic layer in this order.
• at least one of the first optically absorptive anisotropic layer and the second optically absorptive anisotropic layer is a specific optically absorptive anisotropic layer which satisfies all of the following requirements 1 to 3.
• Requirement 1 A dichroic substance is contained.
• Requirement 2 The angle between the central axis of transmittance of the optically absorptive anisotropic layer and the normal direction to the surface of the optically absorptive anisotropic layer is from 0° to 40°.
• Requirement 3 The difference in the degree of orientation of the optically absorptive anisotropic layer at wavelengths of 450 nm, 550 nm and 650 nm is 0.025 or less.
• the central axis of transmittance of the optically absorptive anisotropic layer means the direction showing the highest transmittance when the transmittance is measured by changing the inclination angle (polar angle) and inclination direction (azimuth angle) relative to the normal direction of the optically absorptive anisotropic layer surface.
• the Mueller matrix at a wavelength of 550 nm is measured using AxoScan (manufactured by Axometrics).
• the azimuth angle at which the transmittance central axis is tilted is first found, and then, in a plane including the normal direction of the optically absorptive anisotropic layer along that azimuth angle (a plane including the transmittance central axis and perpendicular to the layer surface), the polar angle, which is the angle with respect to the normal direction of the optically absorptive anisotropic layer surface, is changed from -70 to 70° in 1° increments, and the Mueller matrix at a wavelength of 550 nm is measured, and the transmittance of the optically absorptive anisotropic layer is derived.
• the central axis of transmittance means the direction of the absorption axis (the direction of the long axis of the molecule) of the dichroic material contained in each light absorption anisotropic layer.
• the degrees of orientation of the optically absorptive anisotropic layer at wavelengths of 450 nm, 550 nm and 650 nm are calculated by the following method. Specifically, using an AxoScan (manufactured by Axometrics), the Mueller matrix is measured at 5° intervals in the polar angle range of ⁇ 70° to 70° in the in-plane slow axis direction, and kx( ⁇ ), ky( ⁇ ), and kz( ⁇ ) are determined by fitting. Next, the absorption anisotropies Ao( ⁇ ) and Ae( ⁇ ) are determined according to the following formulas (A) to (D), and the degree of orientation S is calculated according to the following formula (E).
• the difference in the degree of orientation specified in the above-mentioned requirement 3 refers to the maximum difference among the difference in the degree of orientation at wavelengths of 450 nm and 550 nm, the difference in the degree of orientation at wavelengths of 450 nm and 650 nm, and the difference in the degree of orientation at wavelengths of 550 nm and 650 nm.
• the specific optically absorptive anisotropic layer satisfies the above-mentioned requirements 1 to 3 (particularly requirement 3), the influence of the retardation state in the liquid crystal cell (for example, a state in which the in-plane retardation is ⁇ /2), i.e., the variation in the absorption amounts of blue light, green light, and red light in the optically absorptive anisotropic layer, is reduced, and it is considered that this makes it possible to suppress coloring of the display screen.
• the retardation state in the liquid crystal cell for example, a state in which the in-plane retardation is ⁇ /2
• the variation in the absorption amounts of blue light, green light, and red light in the optically absorptive anisotropic layer is reduced, and it is considered that this makes it possible to suppress coloring of the display screen.
• the first optically absorptive anisotropic layer and the second optically absorptive anisotropic layer in the optical laminate of the present invention are not particularly limited as long as at least one of them is a specific optically absorptive anisotropic layer, and may be any of the following: an embodiment in which both the first optically absorptive anisotropic layer and the second optically absorptive anisotropic layer are specific optically absorptive anisotropic layers; an embodiment in which the first optically absorptive anisotropic layer is a specific optically absorptive anisotropic layer and the second optically absorptive anisotropic layer is an optically absorptive anisotropic layer not corresponding to a specific optically absorptive anisotropic layer (hereinafter also abbreviated as "another optically absorptive ani
• the specific optically absorptive anisotropic layer is an optically absorptive anisotropic layer containing a dichroic substance (see requirement 1), and is preferably an optically absorptive anisotropic layer containing a liquid crystal compound together with the dichroic substance, and more preferably a layer in which the orientation states of the liquid crystal compound and the dichroic substance are fixed. Furthermore, the angle between the central axis of transmittance of the specific optically absorptive anisotropic layer and the normal direction to the surface of the specific optically absorptive anisotropic layer is, as described above, from 0° to 40° (see requirement 2).
• the angle is preferably from 0° to 35°, more preferably from 0° to 20°, and even more preferably from 0° to less than 15°.
• the difference ( ⁇ S) in the degree of orientation of the specific optical absorption anisotropic layer at wavelengths of 450 nm, 550 nm, and 650 nm is, as described above, 0.025 or less (see requirement 3), but is preferably 0.020 or less, and more preferably 0.010 to 0.000, in order to further suppress coloring of the display screen.
• the haze value of the specific light absorption anisotropic layer is preferably 0.3% or less for the reason that the image becomes easily distinguishable.
• the haze value herein refers to the haze measured in accordance with JIS K7136:2000 "Determination of haze for plastic transparent materials", and refers to the value measured using a haze meter (e.g., NDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.)) in an environment of 25°C and relative humidity of 55%.
• the other optically absorptive anisotropic layer is an optically absorptive anisotropic layer not corresponding to the specific optically absorptive anisotropic layer, and for example, a conventionally known absorptive polarizer and reflective polarizer can be used.
• the absorption-type polarizer include iodine-based polarizers, dye-based polarizers using a dichroic dye, polyene-based polarizers, etc.
• Iodine-based polarizers and dye-based polarizers include coating-type polarizers and stretching-type polarizers, and either can be used, but a polarizer produced by adsorbing iodine or a dichroic dye to polyvinyl alcohol and stretching it is preferable.
• a polarizer produced by adsorbing iodine or a dichroic dye to polyvinyl alcohol and stretching it is preferable.
• the reflective polarizer a polarizer in which thin films with different birefringence are laminated, a wire grid type polarizer, a polarizer in which a cholesteric liquid crystal having a selective reflection region is combined with a quarter-wave plate, or the like is used.
• the other optically absorptive anisotropic layer is preferably an optically absorptive anisotropic layer containing a dichroic substance, like the specific optically absorptive anisotropic layer, more preferably an optically absorptive anisotropic layer containing a liquid crystal compound together with the dichroic substance, and even more preferably a layer in which the orientation state of the liquid crystal compound and the dichroic substance is fixed.
• the central axis of transmittance of the other optically absorptive anisotropic layer may be in the in-plane direction of the other optically absorptive anisotropic layer.
• the difference in the degree of orientation of the other optically absorptive anisotropic layers at wavelengths of 450 nm, 550 nm and 650 nm is preferably 0.025 or less, more preferably 0.020 or less, and even more preferably 0.010 to 0.000.
• the dichroic substance contained in the specific light absorption anisotropic layer and the dichroic substance that may be contained in the other light absorption anisotropic layers refer to substances whose absorbance varies depending on the direction.
• the dichroic substance may or may not exhibit liquid crystallinity.
• the dichroic substance is not particularly limited, and examples thereof include visible light absorbing substances (dichroic dyes), luminescent substances (fluorescent substances, phosphorescent substances), ultraviolet absorbing substances, infrared absorbing substances, nonlinear optical substances, carbon nanotubes, and inorganic substances (e.g., quantum rods), and any conventionally known dichroic substance (dichroic dye) can be used.
• a dichroic azo dye compound As the dichroic substance, a dichroic azo dye compound is preferable.
• the dichroic azo dye compound means an azo dye compound whose absorbance varies depending on the direction.
• the dichroic azo dye compound may or may not exhibit liquid crystallinity. When the dichroic azo dye compound exhibits liquid crystallinity, it may exhibit either nematic or smectic properties.
• the temperature range in which the liquid crystal phase is exhibited is preferably room temperature (about 20 to 28°C) to 300°C, and more preferably 50 to 200°C from the viewpoints of handling and manufacturing suitability.
• three or more dichroic azo dye compounds may be used in combination.
• a first dichroic azo dye compound a second dichroic azo dye compound, and at least one dye compound (a third dichroic azo dye compound) having a maximum absorption wavelength in the wavelength range of 380 nm or more and less than 455 nm in combination.
• the dichroic azo dye compound preferably has a crosslinkable group.
• the crosslinkable group include a (meth)acryloyl group, an epoxy group, an oxetanyl group, and a styryl group, and among these, a (meth)acryloyl group is preferable.
• the content of the dichroic substance is not particularly limited, but because the degree of orientation of the light-absorptive anisotropic layer to be formed is high, the content is preferably 3% by mass or more, more preferably 8% by mass or more, even more preferably 10% by mass or more, and particularly preferably 10 to 30% by mass, based on the total mass of the light-absorptive anisotropic layer.
• the total amount of the multiple dichroic substances is preferably in the above-mentioned range.
• the content of the first dichroic azo dye compound is preferably 9 to 12 mass % relative to the total mass of the optically absorptive anisotropic layer
• the content of the second dichroic azo dye compound is preferably 1 to 2 mass % relative to the total mass of the optically absorptive anisotropic layer
• the content of the third dichroic azo dye compound is preferably 4 to 7 mass % relative to the total mass of the optically absorptive anisotropic layer.
• the light absorption anisotropic layer preferably contains a liquid crystal compound, which can align the dichroic material with a higher degree of orientation while preventing the dichroic material from precipitating.
• a liquid crystal compound either a polymer liquid crystal compound or a low molecular weight liquid crystal compound can be used.
• a polymer liquid crystal compound it is preferable to use a polymer liquid crystal compound because it can increase the degree of orientation.
• a high molecular weight liquid crystal compound and a low molecular weight liquid crystal compound may be used in combination.
• the term "polymeric liquid crystal compound” refers to a liquid crystal compound having a repeating unit in the chemical structure.
• the term "low molecular weight liquid crystal compound” refers to a liquid crystal compound that does not have a repeating unit in its chemical structure.
• the polymer liquid crystal compound include the thermotropic liquid crystal polymer described in JP-A-2011-237513 and the polymer liquid crystal compound described in paragraphs [0012] to [0042] of WO 2018/199096.
• the low molecular weight liquid crystal compound include the liquid crystal compounds described in paragraphs [0072] to [0088] of JP-A-2013-228706, and among them, liquid crystal compounds exhibiting smectic properties are preferable.
• the smectic phase examples include a smectic A phase and a smectic C phase, but may also be a higher order smectic phase (e.g., a smectic B phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, a smectic L phase, etc.).
• a nematic phase may also be exhibited.
• the liquid crystal compound is a liquid crystal compound that exhibits any one of the liquid crystal states of smectic B phase, E phase, F phase, G phase, H phase, I phase, J phase, K phase, and L phase, because this results in a higher contrast.
• a compound represented by the following formula (A-1) is preferable.
• Formula (A-1) Q1-V1-SP1-X1-(Ma-La)na-X2-SP2-V2-Q2
• Q1 and Q2 each independently represent a polymerizable group.
• V1, V2, X1 and X2 each independently represent a single bond or a divalent linking group.
• SP1 and SP2 each independently represent a divalent spacer group.
• Ma represents an aromatic ring, an aliphatic ring or a heterocycle, each of which may have a substituent, provided that multiple Ma's may be the same or different.
• La represents a single bond or a divalent linking group, provided that multiple La may be the same or different.
• na represents an integer of 2 to 10.
• the polymerizable group represented by Q1 and Q2 is preferably a radically polymerizable group (radical polymerizable group) or a cationic polymerizable group (cationically polymerizable group).
• a known radical polymerizable group can be used, and an acryloyloxy group or a methacryloyloxy group is preferred. It is known that the polymerization rate of an acryloyloxy group tends to be high, and an acryloyloxy group is preferred from the viewpoint of improving productivity, but a methacryloyloxy group can also be used as a polymerizable group.
• a known cationic polymerizable group can be used, for example, an alicyclic ether group, a cyclic acetal group, a cyclic lactone group, a cyclic thioether group, a spiro orthoester group, and a vinyloxy group.
• an alicyclic ether group or a vinyloxy group is preferable, and an epoxy group, an oxetanyl group, or a vinyloxy group is more preferable.
• Preferred examples of polymerizable groups include those represented by the following formulas (P-1) to (P-30).
• R P represents a hydrogen atom, a halogen atom, a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, an aryl group having 1 to 20 carbon atoms, a heterocyclic group (also referred to as a heterocyclic group), a cyano group, a hydroxy group, a nitro group, a carboxy group, an aryloxy group, a silyloxy group, a heterocyclic oxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group (including an anilino group), an ammonio
• R Ps may be the same or different.
• the radical polymerizable group is preferably a vinyl group represented by the above formula (P-1), a butadiene group represented by the above formula (P-2), a (meth)acrylic group represented by the above formula (P-4), a (meth)acrylamide group represented by the above formula (P-5), a vinyl acetate group represented by the above formula (P-6), a fumaric acid ester group represented by the above formula (P-7), a styryl group represented by the above formula (P-8), a vinylpyrrolidone group represented by the above formula (P-9), a maleic anhydride represented by the above formula (P-11), or a maleimide group represented by the above formula (P-12).
• the cationic polymerizable group is preferably a vinyl ether group represented by the above formula (P-18), an epoxy group represented by the above formula (P-19), or an oxetanyl group represented by the above formula (P-20).
• examples of the divalent spacer group represented by SP1 and SP2 include linear, branched or cyclic alkylene groups having 1 to 50 carbon atoms, and heterocyclic groups having 1 to 20 carbon atoms.
• the carbon atoms of the alkylene group and the heterocyclic group are -O-, -Si(CH 3 ) 2 -, -(Si(CH 3 ) 2 O) g -, -(OSi(CH 3 ) 2 ) g - (g represents an integer of 1 to 10), -N(Z)-, -C(Z) ⁇ C(Z')-, -C(Z) ⁇ N-, -N ⁇ C(Z)-, -C(Z) 2 -C(Z') 2 -, -C(O)-, -OC(O)-, -C(O)O-, -O-C(O)O-, -N(Z)C(O)-, -C(O)N(
• the hydrogen atoms of the alkylene groups and heterocyclic groups may be substituted with a halogen atom, a cyano group, -ZH , -OH, -OZH , -COOH, -C(O) ZH , -C(O ) OZH , -OC(O) ZH , -OC ( O) OZH , -NZHZH ' , -NZHC ( O ) ZH ' , -NZHC ( O) OZH ' , -C(O)NZHZH ' , -OC(O)NZHZH ' , -NZHC (O)NZH'OZH ' ', -SH , -SZH , -C(S)ZH, -C ( O) SZH , or -SC(O ) ZH .
• Each of ' and Z" independently represents an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or -L-Q (L represents a single bond or a divalent linking group.
• L represents a single bond or a divalent linking group.
• Specific examples of the divalent linking group are the same as those of V1 described above.
• Q represents a crosslinkable group, and examples thereof include the polymerizable groups represented by Q1 or Q2 described above. Among these, the polymerizable groups represented by formulas (P-1) to (P-30) described above are preferred.).
• MA represents an aromatic ring, an aliphatic ring, or a heterocycle which may have a substituent, and is preferably a 4- to 15-membered ring.
• MA may be a monocycle or a condensed ring, and multiple MAs may be the same or different.
• the aromatic ring represented by MA include a phenylene group, a naphthylene group, a fluorene-diyl group, an anthracene-diyl group, and a tetracene-diyl group. From the viewpoints of the diversity of mesogen skeleton designs and the availability of raw materials, the phenylene group and the naphthylene group are preferred.
• Examples of the aliphatic ring represented by MA include a cyclopentylene group and a cyclohexylene group, and the carbon atom may be substituted with -O-, -Si(CH 3 ) 2 -, -N(Z)-, -C(O)-, (Z independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group, an aryl group, a cyano group, or a halogen atom), -S-, -C(S)-, -S(O)-, -SO 2 -, or a group consisting of a combination of two or more of these groups.
• Examples of atoms other than carbon constituting the heterocycle represented by MA include nitrogen atoms, sulfur atoms, and oxygen atoms. When the heterocycle has a plurality of atoms constituting the ring other than carbon, these may be the same or different.
• Specific examples of the heterocycle include, for example, a pyridylene group (pyridine-diyl group), a pyridazine-diyl group, an imidazole-diyl group, a thienylene group (thiophene-diyl group), a quinolylene group (quinoline-diyl group), an isoquinolylene group (isoquinoline-diyl group), an oxazole-diyl group, a thiazole-diyl group, an oxadiazole-diyl group, a benzothiazole-diyl group, a benzothiadiazole-diyl group, a phthalimid
• D 1 represents —S—, —O—, or NR 11 —
• R 11 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms
• Y1 represents an aromatic hydrocarbon group having 6 to 12 carbon atoms or an aromatic heterocyclic group having 3 to 12 carbon atoms.
• Z 1 , Z 2 , and Z 3 each independently represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a halogen atom, a cyano group, a nitro group, -NR 12 R 13 , or SR 12.
• Z 1 and Z 2 may bond to each other to form an aromatic ring or an aromatic heterocycle
• R 12 and R 13 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
• a 1 and A 2 each independently represent a group selected from the group consisting of -O-, -NR 21 - (R 21 represents a hydrogen atom or a substituent), -S- and -CO-.
• E represents a hydrogen atom or a nonmetallic atom of Groups 14 to 16 which may have a substituent bonded thereto.
• Ax represents an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of aromatic hydrocarbon rings and aromatic heterocycles
• Ay represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, or an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of aromatic hydrocarbon rings and aromatic heterocycles, the aromatic rings possessed by Ax and Ay may have a substituent, and Ax and Ay may be bonded to form a ring.
• D2 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent.
• Y 1 when Y 1 is an aromatic hydrocarbon group having 6 to 12 carbon atoms, it may be a monocyclic or polycyclic ring. When Y 1 is an aromatic heterocyclic group having 3 to 12 carbon atoms, it may be a monocyclic or polycyclic ring.
• a 1 and A 2 when A 1 and A 2 represent —NR 21 —, the substituent of R 21 can be found, for example, in paragraphs 0035 to 0045 of JP-A No. 2008-107767, the contents of which are incorporated herein by reference.
• R' represents a substituent, and examples of the substituent include those described in paragraphs [0035] to [0045] of JP2008-107767A, and a nitrogen atom is preferred.
• examples of the substituent that the aromatic ring, aliphatic ring or heterocycle may have include, for example, a halogen atom, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, an aryl group having 1 to 20 carbon atoms, a heterocyclic group (also referred to as a heterocyclic group), a cyano group, a hydroxy group, a nitro group, a carboxy group, an aryloxy group, a silyloxy group, a heterocyclic oxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxy
• substituents examples include an nio group, an acylamino group, an aminocarbonylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfamoylamino group, an alkyl or arylsulfonylamino group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, a sulfamoyl group, a sulfo group, an alkyl or arylsulfinyl group, an alkyl or arylsulfonyl group, an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, an aryl or heterocyclic azo group, an imido group, a phosphino group, a phosphinyl group, a phosphinyloxy group,
• na represents an integer from 2 to 10, and preferably an integer from 2 to 8.
• Smectic liquid crystal compounds include, for example, the compounds described in paragraphs [0033] to [0039] of JP2008-19240A, paragraphs [0037] to [0041] of JP2008-214269A, and paragraphs [0033] to [0040] of JP2006-215437A, as well as the structures shown below, but are not limited to these.
• the content of the smectic liquid crystal compound is preferably 50 to 99% by mass, and more preferably 60 to 95% by mass, based on the total solid mass of the liquid crystal composition.
• the amount of the liquid crystal compound is not particularly limited, but is preferably 50 to 99% by mass, and more preferably 75 to 90% by mass, based on the total mass of the light absorbing anisotropic layer.
• the optically absorptive anisotropic layer (particularly the specific optically absorptive anisotropic layer) preferably contains a fluorine-based vertical alignment agent having a boronic acid group, since this can suppress deterioration of the surface state due to alignment disorder.
• a fluorine-based vertical alignment agent having a boronic acid group is a copolymer having a repeating unit A represented by the following formula (A-1) and a repeating unit B represented by the following formula (B-1).
• R1 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.
• LF1 represents a single bond or a divalent linking group.
• RF1 represents a group containing a fluorine atom.
• R2 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.
• L2 represents a single bond or a divalent linking group selected from the group consisting of -O-, -S-, -COO-, -OCO-, -CONR L1 -, -NR L1 COO-, -CR L1 N-, a substituted or unsubstituted divalent aliphatic group, a substituted or unsubstituted divalent aromatic group, and combinations thereof, and R L1 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.
• R3 and R4 each independently represent a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, and R3 and R4 may be linked to each other via an alkylene linking group, an arylene linking group, or a linking group consisting of a combination thereof.
• R 1 represents, as described above, a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Among them, a hydrogen atom or an alkyl group having 1 to 10 carbon atoms is preferable, a hydrogen atom or an alkyl group having 1 to 4 carbon atoms is more preferable, and a hydrogen atom or a methyl group is even more preferable.
• LF 1 represents a single bond or a divalent linking group as described above, and among them, a divalent linking group selected from the group consisting of -O-, -COO-, -OCO-, a divalent aliphatic group, and a combination thereof is preferable.
• examples of the divalent aliphatic group include divalent aliphatic chain groups and aliphatic cyclic groups.
• divalent aliphatic chain group an alkylene group having 1 to 20 carbon atoms is preferable, and an alkylene group having 1 to 10 carbon atoms is more preferable.
• divalent aliphatic cyclic group a cycloalkylene group having 3 to 20 carbon atoms is preferable, and a cycloalkylene group having 3 to 15 carbon atoms is more preferable.
• LF1 is preferably --COO-- or --OCO--, and more preferably --COO--.
• RF 1 represents a group containing a fluorine atom, as described above.
• an alkyl group having 1 to 20 carbon atoms in which at least one hydrogen atom has been substituted with a fluorine atom (hereinafter, also referred to as a "fluoroalkyl group”) is preferable, a fluoroalkyl group having 1 to 18 carbon atoms is more preferable, and a fluoroalkyl group having 2 to 15 carbon atoms is even more preferable.
• the fluoroalkyl group contains at least one -CF3 group.
• the number of fluorine atoms is preferably 1-25, more preferably 3-21, and most preferably 5-21.
• the repeating unit represented by the above formula (A-1) is preferably a repeating unit represented by the following formula (A-1-1).
• R 1 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, similar to R 1 in the above formula (A-1), and the preferred embodiments are also the same.
• ma and na each independently represent an integer of 0 to 19.
• ma is preferably an integer of 1 to 8, and more preferably an integer of 1 to 5.
• na is preferably an integer of 1 to 15, more preferably an integer of 1 to 12, even more preferably an integer of 2 to 10, and most preferably an integer of 5 to 7.
• ma and na together represent an integer of 0 to 19.
• monomers forming the repeating units represented by the above formula (A-1) or (A-1-1) include 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3,3-pentafluoropropyl (meth)acrylate, 2-(perfluorobutyl)ethyl (meth)acrylate, 2-(perfluorohexyl)ethyl (meth)acrylate, 2-(perfluorooctyl)ethyl (meth)acrylate, 2-(perfluorodecyl)ethyl (meth)acrylate, 2-(perfluoro-3-methylbutyl)ethyl (meth)acrylate, 2-(perfluoro-5-methylhexyl)ethyl (meth)acrylate, and the like.
• acrylates examples include 2-(perfluoro-7-methyloctyl)ethyl (meth)acrylate, 3-perfluorobutyl-2-hydroxypropyl (meth)acrylate, 3-perfluorohexyl-2-hydroxypropyl (meth)acrylate, 3-perfluorooctyl-2-hydroxypropyl (meth)acrylate, 3-(perfluoro-3-methylbutyl)-2-hydroxypropyl (meth)acrylate, 3-(perfluoro-5-methylhexyl)-2-hydroxypropyl (meth)acrylate, and 3-(perfluoro-7-methyloctyl)-2-hydroxypropyl (meth)acrylate.
• R 2 each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Among them, a hydrogen atom or an alkyl group having 1 to 10 carbon atoms is preferable, a hydrogen atom or an alkyl group having 1 to 4 carbon atoms is more preferable, and a hydrogen atom or a methyl group is even more preferable.
• L 2 represents a single bond or a divalent linking group selected from the group consisting of -O-, -S-, -COO-, -OCO-, -CONR L1 -, -NR L1 COO-, -CR L1 N-, a substituted or unsubstituted divalent aliphatic group, a substituted or unsubstituted divalent aromatic group, and combinations thereof, and R L1 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.
• examples of the substituted or unsubstituted divalent aliphatic group represented by one embodiment of L2 include an alkylene group having 1 to 20 carbon atoms which may have a substituent, or a cycloalkylene group having 3 to 20 carbon atoms which may have a substituent (e.g., a cyclohexylene group).
• an alkylene group having 1 to 15 carbon atoms is preferable, an alkylene group having 1 to 8 carbon atoms is more preferable, and a methylene group, an ethylene group, a propylene group, or a butylene group is even more preferable.
• the substituted or unsubstituted divalent aromatic group represented by one embodiment of L2 includes a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent.
• the divalent aromatic hydrocarbon group includes, for example, a group obtained by removing one hydrogen atom each from two carbon atoms constituting the ring structure of an aromatic hydrocarbon ring such as a benzene ring, a naphthalene ring, an anthracene ring, a triphenylene ring, or a fluorene ring, and among them, a phenylene group or a naphthylene group obtained by removing one hydrogen atom each from two carbon atoms constituting the ring structure of a benzene ring or a naphthalene ring is preferred.
• the divalent aromatic heterocyclic group includes a group obtained by removing one hydrogen atom each from two carbon atoms constituting the ring structure of an aromatic hydrocarbon
• Examples of the substituent that the divalent aliphatic group or the divalent aromatic group may have include an alkyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, an alkylamino group, a dialkylamino group, an alkylamide group, an alkenyl group, an alkynyl group, a halogen atom, a cyano group, a nitro group, an alkylthiol group, and an N-alkylcarbamate group.
• the alkyl group having 1 to 20 carbon atoms represented by one embodiment of R L1 described above is preferably an alkyl group having 1 to 6 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group.
• R 3 and R 4 each independently represent a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, and R 3 and R 4 may be linked to each other via an alkylene linking group, an arylene linking group, or a linking group consisting of a combination thereof.
• the substituted or unsubstituted aliphatic hydrocarbon group represented by one embodiment of R3 and R4 includes an alkyl group, an alkenyl group, or an alkynyl group, each of which may have a substituent.
• the alkyl group include straight-chain, branched, and cyclic alkyl groups such as a methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, hexadecyl group, octadecyl group, eicosyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexy
• alkenyl group examples include straight-chain, branched and cyclic alkenyl groups such as vinyl, 1-propenyl, 1-butenyl, 1-methyl-1-propenyl, 1-cyclopentenyl and 1-cyclohexenyl groups.
• alkynyl group examples include an ethynyl group, a 1-propynyl group, a 1-butynyl group, and a 1-octynyl group.
• Examples of the substituted or unsubstituted aryl group represented by one embodiment of R3 and R4 include a condensed ring formed by one to four benzene rings and a condensed ring formed by a benzene ring and an unsaturated five-membered ring. Specific examples include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenabutenyl group, a fluorenyl group, and a pyrenyl group.
• Examples of the substituted or unsubstituted heteroaryl group represented by one embodiment of R3 and R4 include heteroaryl groups obtained by removing one hydrogen atom from a heteroaromatic ring containing one or more heteroatoms selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom.
• heteroaromatic ring containing one or more heteroatoms selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom include pyrrole, furan, thiophene, pyrazole, imidazole, triazole, oxazole, isoxazole, oxadiazole, thiazole, thiadiazole, indole, carbazole, benzofuran, dibenzofuran, thianaphthene, dibenzothiophene, indazole benzimidazole, anthranil, benzisoxazole, benzoxazole, benzothiazole, purine, pyridine, pyridazine, pyrimidine, pyrazine, triazine, quinoline, acridine, isoquinoline, phthalazine, quinazoline, quinoxaline, naphthyridine, phenanthroline, and pteridine.
• R3 and R4 may have include an alkyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, an alkylamino group, a dialkylamino group, an alkylamide group, an alkenyl group, an alkynyl group, a halogen atom, a cyano group, a nitro group, an alkylthiol group, and an N-alkylcarbamate group.
• monomer that forms the repeating unit represented by formula (B-1) include the monomers represented by formulas II-1 to II-12 below.
• the content of the vertical alignment agent is preferably from 0.1 to 400% by mass, and more preferably from 0.5 to 350% by mass, based on the total mass of the liquid crystal compound.
• the vertical alignment agent may be used alone or in combination of two or more. When two or more vertical alignment agents are used, the total amount thereof is preferably within the above range.
• the optically absorptive anisotropic layer is preferably formed using a composition for forming an optically absorptive anisotropic layer, which contains a dichroic material and a liquid crystal compound.
• the composition for forming the light absorptive anisotropic layer preferably contains a solvent, which will be described later, in addition to the dichroic substance and the liquid crystal compound, and may further contain the other components described above.
• the dichroic substance contained in the composition for forming an optically absorptive anisotropic layer includes dichroic substances that can be contained in an optically absorptive anisotropic layer.
• the content of the dichroic material relative to the total solid mass of the composition for forming the optically absorptive anisotropic layer is preferably the same as the content of the dichroic material relative to the total mass of the optically absorptive anisotropic layer.
• total solid content in the composition for forming an optically absorptive anisotropic layer refers to components excluding the solvent, and specific examples of the solid content include the dichroic material, the liquid crystal compound, and the other components described above.
• the liquid crystal compound and other components that can be contained in the composition for forming the optically absorptive anisotropic layer are the same as the liquid crystal compound and other components that can be contained in the optically absorptive anisotropic layer, respectively.
• the content of the liquid crystal compound and other components relative to the total solid mass of the composition for forming the optically absorptive anisotropic layer is preferably the same as the content of the liquid crystal compound and other components relative to the total mass of the optically absorptive anisotropic layer.
• the composition for forming the optically absorptive anisotropic layer preferably contains a solvent from the viewpoint of workability.
• the solvent include organic solvents such as ketones, ethers, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, halogenated carbons, esters, alcohols, cellosolves, cellosolve acetates, sulfoxides, amides, and heterocyclic compounds, as well as water. These solvents may be used alone or in combination of two or more. Of these solvents, organic solvents are preferred, with halocarbons or ketones being more preferred.
• the content of the solvent is preferably 80 to 99 mass %, more preferably 83 to 97 mass %, and even more preferably 85 to 95 mass %, based on the total mass of the composition for forming the optically absorptive anisotropic layer.
• the composition for forming the optically absorptive anisotropic layer may contain a polymerization initiator.
• the polymerization initiator is not particularly limited, but is preferably a compound having photosensitivity, that is, a photopolymerization initiator.
• a photopolymerization initiator commercially available products can be used, such as Irgacure 184, Irgacure 907, Irgacure 369, Irgacure 651, Irgacure 819, Irgacure OXE-01, and Irgacure OXE-02, all of which are manufactured by BASF.
• the polymerization initiator may be used alone or in combination of two or more kinds.
• the content of the polymerization initiator is preferably from 0.01 to 30% by mass, more preferably from 0.1 to 15% by mass, based on the total solid content of the composition for forming the optically absorptive anisotropic layer.
• the method for producing the optically absorptive anisotropic layer is not particularly limited, but from the viewpoint of achieving a higher degree of orientation of the dichroic substance, a method comprising, in this order, a step of forming a coating film by applying a composition for forming an optically absorptive anisotropic layer, which contains a dichroic substance and a liquid crystal compound, onto an alignment film (hereinafter also referred to as a "coating film forming step”), and a step of orienting the liquid crystal component contained in the coating film (hereinafter also referred to as an "orientation step") is preferred.
• the liquid crystal component includes not only the above-mentioned liquid crystal compounds but also dichroic substances having liquid crystal properties. Each step will be described below.
• the coating film forming step is a step of forming a coating film by applying the above-mentioned composition for forming an optically absorptive anisotropic layer onto an alignment film.
• Examples of methods for applying the composition for forming the optically absorptive anisotropic layer include known methods such as roll coating, gravure printing, spin coating, wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spraying, and inkjet printing.
• the alignment film may be any film that can align the liquid crystal component that can be contained in the composition for forming an optically absorptive anisotropic layer.
• the alignment layer can be provided by a method such as rubbing an organic compound (preferably a polymer) on the film surface, oblique deposition of an inorganic compound, formation of a layer having microgrooves, or accumulation of an organic compound (e.g., ⁇ -tricosanoic acid, dioctadecylmethylammonium chloride, methyl stearate) by the Langmuir-Blodgett method (LB film).
• LB film Langmuir-Blodgett method
• an alignment film formed by a rubbing treatment is preferred from the viewpoint of ease of control of the pretilt angle of the alignment film, and a photo-alignment film formed by light irradiation is also preferred from the viewpoint of uniformity of alignment.
• a photo-alignment film containing an azobenzene dye or polyvinyl cinnamate or the like is used as the photo-alignment film.
• anisotropy with a slope to the normal direction of the photo-alignment layer is generated, and an optically absorbing anisotropic layer is then aligned on top of this, thereby orienting the dichroic material in the optically absorbing anisotropic layer.
• a liquid crystal layer in which liquid crystal compounds are hybrid-aligned can also be used as the alignment film.
• the alignment step is a step of aligning the liquid crystal components (especially the dichroic material) contained in the coating film.
• the dichroic material is aligned along the liquid crystal compound aligned by the alignment film.
• the orientation step may include a drying treatment. By the drying treatment, components such as a solvent can be removed from the coating film.
• the drying treatment may be performed by leaving the coating film at room temperature for a predetermined time (for example, natural drying), or may be performed by heating and/or blowing air.
• the alignment step preferably includes a heat treatment, which allows the dichroic material contained in the coating film to be more oriented and increases the degree of orientation of the dichroic material.
• the heat treatment is preferably performed at 10 to 250° C., more preferably at 25 to 190° C.
• the heating time is preferably 1 to 300 seconds, more preferably 1 to 60 seconds.
• the heat treatment is preferably carried out multiple times (particularly twice) because this makes it easier to make the difference in the degree of orientation at wavelengths of 450 nm, 550 nm and 650 nm in the optically absorptive anisotropic layer to be manufactured 0.025 or less.
• the orientation step may include a cooling treatment carried out after the heating treatment.
• the cooling treatment is a treatment for cooling the coated film after heating to about 20 to 45°C. This further fixes the orientation of the dichroic material contained in the coated film, and the degree of orientation of the dichroic material is increased.
• the cooling means is not particularly limited and can be carried out by a known method. Regarding the cooling treatment carried out between the two heating treatments, it is preferable to cool the coating film after the first heating treatment to about 30 to 45°C, because this makes it easier to make the difference in the degree of orientation of the optically absorptive anisotropic layer to 0.025 or less at wavelengths of 450 nm, 550 nm, and 650 nm.
• the present production method may include a step of curing the light absorptive anisotropic layer (hereinafter also referred to as a "curing step") after the above-mentioned alignment step.
• the curing step is carried out, for example, by heating and/or light irradiation (exposure), and among these, the curing step is preferably carried out by light irradiation.
• the light source used for curing may be various light sources such as infrared light, visible light, or ultraviolet light, but ultraviolet light is preferred.
• ultraviolet light may be irradiated while heating during curing, or ultraviolet light may be irradiated through a filter that transmits only specific wavelengths.
• the exposure may be carried out in a nitrogen atmosphere.
• the curing of the light absorption anisotropic layer proceeds by radical polymerization, it is preferable to carry out the exposure in a nitrogen atmosphere, since inhibition of polymerization by oxygen is reduced.
• the thickness of the light absorption anisotropic layer is not particularly limited, but in terms of the superior effect of the present invention, a thickness of 0.5 to 7 ⁇ m is preferred, and 1.0 to 3 ⁇ m is even more preferred.
• the liquid crystal cell in the optical laminate of the present invention is not particularly limited as long as it is a liquid crystal cell that constitutes a liquid crystal panel capable of electrically switching birefringence.
• a liquid crystal cell is preferably in a VA (Vertical Alignment) mode, an OCB (Opticaly Compensated Bend) mode, an IPS (In-Plane-Switching) mode, or a TN (Twisted Nematic) mode, but is not limited to these.
• the liquid crystal cell is a VA mode cell in which the in-plane retardation at a wavelength of 550 nm can be switched between 0 nm and 120 to 160 nm, or between 0 nm and 250 to 300 nm.
• the light-absorption anisotropic layer that is arranged on the viewing side when used in an image display device is a specific light-absorption anisotropic layer, and the other is another light-absorption anisotropic layer (particularly, a light-absorption anisotropic layer having a transmittance central axis in the plane).
• the liquid crystal cell (VA mode) it is preferable to set the liquid crystal cell (VA mode) so that the angle between the in-plane slow axis of the liquid crystal layer generated when a voltage is applied to the liquid crystal cell (VA mode) and the transmission axis of the other light absorptive anisotropic layer is 45°.
• the liquid crystal cell is of an IPS mode and has an in-plane retardation of 120 to 160 nm or 250 to 300 nm at a wavelength of 550 nm.
• the light-absorption anisotropic layer that is arranged on the viewing side when used in an image display device is a specific light-absorption anisotropic layer, and the other is another light-absorption anisotropic layer (particularly, a light-absorption anisotropic layer having a transmittance central axis in the plane).
• the liquid crystal layer of the liquid crystal cell IPS mode
• the angle between the in-plane slow axis of the liquid crystal layer and the transmission axis of the other optically absorptive anisotropic layer when the voltage is ON is 0°
• the angle between the in-plane slow axis of the liquid crystal layer and the transmission axis of the other optically absorptive anisotropic layer when the voltage is OFF is 45°.
• the liquid crystal cell is in TN mode and is a cell in which the twist angle of the orientation can be switched between 0° and 90° or between 0° and 270°.
• both the first optically absorptive anisotropic layer and the second optically absorptive anisotropic layer are specific optically absorptive anisotropic layers; and of the first optically absorptive anisotropic layer and the second optically absorptive anisotropic layer, the one arranged on the viewing side when used in an image display device is the specific optically absorptive anisotropic layer, and the other is another optically absorptive anisotropic layer (an optically absorptive anisotropic layer having a transmittance central axis in-plane).
• the viewing angle can be switched between omnidirectional transmission and omnidirectional light blocking by switching the twist angle between 0° and 90°
• the viewing angle can be switched between top and bottom light blocking (left and right transmission) and left and right light blocking (top and bottom transmission) by switching the twist angle between 0° and 90°.
• the optical layered body of the present invention may include a support.
• the type of the support is not particularly limited, and a known support can be used.
• a transparent support is preferable.
• the transparent support means a support having a visible light transmittance of 60% or more, preferably 80% or more, and more preferably 90% or more.
• Examples of the support include a glass substrate and a polymer film.
• Examples of materials for the polymer film include cellulose-based polymers; acrylic-based polymers having acrylic ester polymers such as polymethyl methacrylate and lactone ring-containing polymers; thermoplastic norbornene-based polymers; polycarbonate-based polymers; polyester-based polymers such as polyethylene terephthalate and polyethylene naphthalate; styrene-based polymers such as polystyrene and acrylonitrile styrene copolymers; polyolefin-based polymers such as polyethylene, polypropylene and ethylene-propylene copolymers; vinyl chloride-based polymers; amide-based polymers such as nylon and aromatic polyamides; imide-based polymers; sulfone-based polymers; polyethersulfone-based polymers; polyetheretherketone-based polymers; polyphenylene sulfide-based polymers; vinylidene chloride-based poly
• the optical layered body of the present invention is a layer formed using a composition containing a liquid crystal compound
• the optical layered body of the present invention has an alignment film as an adjacent layer.
• the alignment film include layers of polyvinyl alcohol and polyimide, which may or may not have been subjected to rubbing treatment; photoalignment films of polyvinyl cinnamate and azo dyes, which may or may not have been subjected to polarized light exposure treatment; and the like.
• the thickness of the alignment film is preferably from 0.01 to 10 ⁇ m, and more preferably from 0.01 to 1 ⁇ m.
• the optical layered body of the present invention may have a pressure-sensitive adhesive layer.
• the adhesive layer is preferably a transparent, optically isotropic adhesive similar to those used in ordinary image display devices, and a pressure-sensitive adhesive is usually used.
• the adhesive layer may contain appropriate additives such as crosslinkers (e.g., isocyanate-based crosslinkers, epoxy-based crosslinkers, etc.), tackifiers (e.g., rosin derivative resins, polyterpene resins, petroleum resins, oil-soluble phenolic resins, etc.), plasticizers, fillers, antioxidants, surfactants, UV absorbers, light stabilizers, and antioxidants.
• crosslinkers e.g., isocyanate-based crosslinkers, epoxy-based crosslinkers, etc.
• tackifiers e.g., rosin derivative resins, polyterpene resins, petroleum resins, oil-soluble phenolic resins, etc.
• plasticizers e.g., rosin derivative resins, polyterpene resins, petroleum resins, oil-soluble phenolic resins, etc.
• fillers e.g., antioxidants, surfactants, UV absorbers, light stabilizers, and antioxidants.
• the optical layered body of the present invention may have an adhesive layer.
• the adhesive layer exhibits adhesiveness by drying or reaction after lamination.
• Polyvinyl alcohol adhesives (PVA adhesives) develop adhesive properties when dried, making it possible to bond materials together.
• PVA adhesives Polyvinyl alcohol adhesives
• Specific examples of curable adhesives that develop adhesiveness through a reaction include active energy ray curable adhesives such as (meth)acrylate adhesives and cationic polymerization curable adhesives.
• (meth)acrylate means acrylate and/or methacrylate.
• the curable components in (meth)acrylate adhesives include compounds having a (meth)acryloyl group and compounds having a vinyl group.
• compounds having an epoxy group or an oxetanyl group can also be used as cationic polymerization curable adhesives.
• the compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various commonly known curable epoxy compounds can be used.
• preferred epoxy compounds include compounds having at least two epoxy groups and at least one aromatic ring in the molecule (aromatic epoxy compounds), and compounds having at least two epoxy groups in the molecule, at least one of which is formed between two adjacent carbon atoms constituting an alicyclic ring (alicyclic epoxy compounds).
• an ultraviolet-curing adhesive that is cured by irradiation with ultraviolet light is preferably used.
• the optical layered body of the present invention may have a B plate.
• the B plate includes a positive B plate and a negative B plate.
• the refractive index in the slow axis direction in the film plane (the direction in which the refractive index in the plane is maximum) is nx
• the refractive index in the direction perpendicular to the slow axis in the plane is ny
• the refractive index in the thickness direction is nz
• the positive B plate satisfies the relationship of formula (B1)
• the negative B plate satisfies the relationship of formula (B2).
• Formula (B2) nx>ny>nz
• the positive B plate has a negative retardation in the thickness direction
• the negative B plate has a positive retardation in the thickness direction.
• the in-plane retardation of the B plate at a wavelength of 550 nm is not particularly limited, but is preferably from 100 to 200 nm, more preferably from 150 to 200 nm, in terms of better effects of the present invention.
• the absolute value of the retardation in the thickness direction of the B plate at a wavelength of 550 nm is not particularly limited, but is preferably 100 to 500 nm, more preferably 120 to 400 nm, in terms of superior effects of the present invention.
• the material that makes up the B plate may be a layer formed using a liquid crystal compound or a resin film.
• the image display device of the present invention is an image display device having a viewing angle switching function and having the optical laminate of the present invention described above, and it is preferable that the image display device is arranged so that the specific light absorption anisotropic layer in the optical laminate of the present invention described above is on the viewing side.
• the image display device of the present invention may be configured so that the viewing angles of a plurality of regions within the display screen can be switched independently.
• the display element used in the image display device of the present invention is not particularly limited, and examples thereof include a liquid crystal cell, an organic electroluminescence (hereinafter abbreviated as "EL") display panel, a plasma display panel, and a micro LED.
• a liquid crystal cell, an organic EL display panel, or a micro LED is preferable.
• the display device of the present invention is preferably a liquid crystal display device using a liquid crystal cell as a display element, an organic EL display device using an organic EL display panel as a display element, or a micro LED display device using an inorganic EL light emitting element as a display element.
• Some image display devices are thin and can be molded into a curved surface.
• the optically anisotropic absorbing film used in the present invention is thin and easy to bend, so that it can be suitably applied to image display devices having a curved display surface. Some image display devices have a pixel density of more than 250 ppi, making it possible to display images with high resolution.
• the optically anisotropic absorbing film used in the present invention can be suitably applied to such high resolution image display devices without causing moire.
• the micro LED may be an EL substrate having a two-dimensional arrangement of a light-emitting section 24 having minute inorganic EL light-emitting elements, that is, an R light-emitting element 12R, a G light-emitting element 12G, and a B light-emitting element 12B, as conceptually shown in FIG. 1 .
• the following composition for forming an optically absorptive anisotropic layer 1 was continuously applied with a wire bar, heated at 120° C. for 60 seconds, and then cooled to 35° C. Next, it was heated at 80° C. for 60 seconds, and cooled again to room temperature. Thereafter, ultraviolet light was irradiated for 2 seconds using an LED lamp (center wavelength 365 nm) under irradiation conditions of an illuminance of 200 mW/ cm2 , thereby forming an optically absorptive anisotropic layer A1 on the alignment film 1.
• the optically absorptive anisotropic layer A1 had a thickness of 3.5 ⁇ m.
• the prepared optically absorbing anisotropic layer A1 was measured for the angle between the transmittance central axis of the optically absorbing anisotropic layer and the normal direction to the surface of the optically absorbing anisotropic layer (hereinafter abbreviated as "transmittance central axis angle ⁇ "), the degree of orientation at wavelengths of 450, 550, and 650 nm and the difference therebetween ( ⁇ S), and the haze value using the methods described above.
• the results are shown in Table 1 below.
• a coating solution having the following composition was continuously applied onto the formed optically absorptive anisotropic layer A1 using a wire bar, and then dried for 2 minutes with hot air at 100° C. to form a polyvinyl alcohol (PVA) orientation layer (oxygen barrier layer B1) having a thickness of 0.5 ⁇ m on the optically absorptive anisotropic layer A.
• PVA polyvinyl alcohol
• an optical film 1 was obtained that had a cellulose acylate film, an alignment film 1, a light absorption anisotropic layer A1, and an oxygen barrier layer B1 adjacent to each other in this order.
• TN Liquid Crystal Cell for Viewing Angle Switching
• a horizontal alignment type polyimide alignment film was applied to two glass substrates with ITO electrodes, and after high temperature drying to form the alignment film, a rubbing treatment was performed so that a TN cell could be formed. Specifically, the alignment treatment was performed so that the top and bottom were twisted by 90 degrees. Next, a thermosetting sealant was spread on one side of the two substrates and bead spacers (diameter 5 ⁇ m) were spread on the other side. The two substrates were then bonded together, vacuum-packed, and heat-treated to form an empty liquid crystal cell.
• the liquid crystal layer is twisted at a twist angle of 90° between the upper and lower substrates when no voltage is applied, and a TN liquid crystal cell is completed in which the liquid crystal is oriented vertically when voltage is applied.
• a liquid crystal cell with a twist structure of any ⁇ nd can be formed.
• optical laminate (viewing angle switching cell)
• the oxygen barrier layer B1 side of the optical film 1 prepared above was attached to both sides of the TN liquid crystal cell prepared above using a commercially available adhesive SK2057 (manufactured by Soken Chemical Engineering Co., Ltd.) so that the oxygen barrier layer B1 side of the optical film 1 prepared above faced the TN liquid crystal cell side, thereby preparing an optical laminate A1.
• Example 2 [Fabrication of Image Display Device A2 Having Viewing Angle Switching Function]
• An image display device A2 having a viewing angle switching function was produced in the same manner as in Example 1, except that the optically absorptive anisotropic layer forming composition 1 was changed to the optically absorptive anisotropic layer forming composition 2 described below.
• the transmittance central axis angle ⁇ , the orientation degrees and their differences ( ⁇ S) at wavelengths of 450, 550, and 650 nm, and the haze value of the optically absorptive anisotropic layer formed from the optically absorptive anisotropic layer-forming composition 2 were measured by the methods described above. The results are shown in Table 1 below. It was also found that the twist angle of the fabricated image display device A2 could be switched between 0° and 90° by turning the voltage of the TN liquid crystal cell on and off, and the viewing angle could be switched between omnidirectional transmission and omnidirectional light blocking accordingly.
• Example 3 [Preparation of Image Display Device A3 Having Viewing Angle Switching Function]
• An image display device A3 having a viewing angle switching function was produced in the same manner as in Example 1, except that in the formation of the optically absorptive anisotropic layer A1, the heating temperature after cooling at 35° C. was changed from 80° C. to 75° C.
• the light absorption anisotropic layers formed at different heating temperatures were measured for transmittance central axis angle ⁇ , orientation degrees and their differences ( ⁇ S) at wavelengths of 450, 550, and 650 nm, and haze value by the above-mentioned methods.
• Table 1 It was found that the twist angle of the produced image display device A3 could be switched between 0° and 90° by turning the voltage of the TN liquid crystal cell on and off, and accordingly the viewing angle could be switched between omnidirectional transmission and omnidirectional light blocking.
• Example 4 [Preparation of Polarizing Plate] A polarizing plate having a polarizer thickness of 8 ⁇ m and one side of the polarizer (other optically absorptive anisotropic layer) exposed was prepared in the same manner as in the one-side protective film-attached polarizing plate 02 described in WO 2015/166991.
• optical laminate (viewing angle switching cell)
• the polarizing plate prepared above was attached to one side of the TN liquid crystal cell prepared in Example 1 using a commercially available adhesive SK2057 (manufactured by Soken Chemical Industries, Ltd.) so that the polarizer surface faced the TN liquid crystal side.
• the oxygen-blocking layer B1 side of the optical film 1 produced in Example 1 was attached to the surface of the TN liquid crystal cell opposite to the surface to which the polarizing plate was attached, using a commercially available adhesive SK2057 (manufactured by Soken Chemical Engineering Co., Ltd.), so that the layer B1 side was facing the TN liquid crystal cell, thereby producing an optical laminate A4.
• Example 5 [Preparation of VA Liquid Crystal Cell 1 for Viewing Angle Switching]
• a liquid crystal material having negative dielectric anisotropy (MLC6608, manufactured by Merck) was dropped between the glass substrates to form a liquid crystal layer between the glass substrates, thereby producing a VA liquid crystal cell 1.
• the thickness of the liquid crystal layer was adjusted so that the in-plane retardation of the liquid crystal layer (i.e., the product ⁇ n ⁇ d of the thickness d ( ⁇ m) of the liquid crystal layer and the refractive index anisotropy ⁇ n) was 140 nm ( ⁇ /4).
• the liquid crystal material was aligned vertically, and when a voltage was applied, the liquid crystal was aligned horizontally, completing a VN liquid crystal cell 1 in which in-plane retardation was expressed.
• Example 4 [Preparation of Optical Laminate (Viewing Angle Switching Cell)]
• the polarizing plate prepared in Example 4 was attached to one surface of the VN liquid crystal cell 1 prepared above using a commercially available adhesive SK2057 (manufactured by Soken Chemical Industries, Ltd.) so that the polarizing surface faced the VN liquid crystal cell side.
• the oxygen barrier layer B1 side of the optical film 1 produced in Example 1 was attached to the surface of the VN liquid crystal cell 1 opposite to the surface to which the polarizing plate was attached, using a commercially available adhesive SK2057 (manufactured by Soken Chemical & Engineering Co., Ltd.), so as to face the VN liquid crystal cell side, to produce an optical laminate A5.
• the VA liquid crystal cell 1 was placed so that the in-plane slow axis of the liquid crystal layer (horizontal alignment) generated when a voltage was applied to the VA liquid crystal cell 1 formed an angle of 45° with the transmission axis of the polarizer (another light absorptive anisotropic layer).
• An image display device A5 having a viewing angle switching function was produced in the same manner as in Example 4, except that the optical laminate A4 was changed to the optical laminate A5. It was found that for the produced image display device A5, the in-plane retardation of the liquid crystal layer was switched between 0 and ⁇ /4 by turning the voltage of the VA liquid crystal cell OFF and ON, and accordingly the viewing angle could be switched between up and down light blocking (left and right transmission) and omnidirectional transmission.
• Example 6 In the preparation of the VA liquid crystal cell 1 for viewing angle switching in Example 5, except that the thickness of the liquid crystal layer was changed so that the retardation of the liquid crystal layer was changed from 140 nm to 275 nm ( ⁇ /2), VA liquid crystal cell 2 was prepared in the same manner as in the preparation of the VA liquid crystal cell 1. An image display device A6 having a viewing angle switching function was produced in the same manner as in Example 5, except that the VA liquid crystal cell 1 was changed to the VA liquid crystal cell 2.
• the in-plane retardation of the liquid crystal layer was switched between 0 and ⁇ /2 by turning the voltage of the VA liquid crystal cell OFF and ON, and accordingly the viewing angle could be switched between top and bottom light blocking (left and right transmission) and left and right light blocking (top and bottom transmission).
• Example 7 [Fabrication of IPS Liquid Crystal Cell for Viewing Angle Switching] An IPS liquid crystal cell having a liquid crystal layer between two glass substrates was prepared. When forming the liquid crystal cell, a photo-alignment treatment was performed on the glass substrate with reference to Example 11 of JP-A-2005-351924 to form an alignment layer, and the liquid crystal compound in the liquid crystal cell was aligned. The tilt angle of the liquid crystal compound with respect to the substrate surface was 0.1°. The ⁇ n of the liquid crystal compound in the liquid crystal layer was 0.08625 at a wavelength of 550 nm, and the ⁇ nd was adjusted by adjusting the distance (gap; d) between the substrates. The in-plane retardation of the liquid crystal layer was 275 nm ( ⁇ /2).
• Example 4 Preparation of optical laminate (viewing angle switching cell)
• the polarizing plate prepared in Example 4 was attached to one surface of the IPS liquid crystal cell prepared above using a commercially available adhesive SK2057 (manufactured by Soken Chemical Industries, Ltd.) so that the polarizing plate surface faced the IPS liquid crystal cell.
• the oxygen barrier layer B1 side of the optical film 1 produced in Example 1 was attached to the surface of the IPS liquid crystal cell opposite to the surface to which the polarizing plate was attached, using a commercially available adhesive SK2057 (manufactured by Soken Chemical & Engineering Co., Ltd.), so as to face the IPS liquid crystal cell, to produce an optical laminate A7.
• the liquid crystal layer in the IPS liquid crystal cell was set so that the angle between the in-plane slow axis of the liquid crystal layer and the transmission axis of the polarizer (another light absorptive anisotropic layer) when the voltage was ON was 0°, and the angle between the in-plane slow axis of the liquid crystal layer and the transmission axis of the polarizer (another light absorptive anisotropic layer) when the voltage was OFF was 45°.
• An image display device A7 having a viewing angle switching function was produced in the same manner as in Example 4, except that the optical laminate A4 was changed to the optical laminate A7. It was found that for the produced image display device A7, the angle between the in-plane slow axis of the liquid crystal layer in the IPS liquid crystal cell and the transmission axis of the polarizer (another light-absorption anisotropic layer) can be switched between 0° and 45° by turning the voltage of the IPS liquid crystal cell ON and OFF, and accordingly, the viewing angle can be switched between top and bottom light blocking (left and right transmission) and left and right light blocking (top and bottom transmission).
• Example 8 ⁇ Formation of Alignment Film 2> A TAC film with an alignment layer was prepared in the same manner as in Example 1, and the following composition liquid E1 for forming a photo-alignment layer was further applied onto the alignment layer, followed by drying for 2 minutes at 60° C. Thereafter, the resulting coating film was irradiated with ultraviolet light (irradiation dose 2000 mJ/cm 2 ) from an oblique direction using an ultraviolet exposure device, to prepare an alignment layer 2 (photo-alignment film) having a thickness of 0.03 ⁇ m.
• ultraviolet light irradiation dose 2000 mJ/cm 2
• composition liquid E1 for forming a photo-alignment layer was prepared according to the following composition, dissolved for 1 hour with stirring, and filtered through a filter having a pore size of 0.45 ⁇ m.
• An optically absorptive anisotropic layer A8 was prepared in the same manner as in Example 1, except that the alignment film 1 was changed to the alignment film 2.
• the transmittance central axis angle ⁇ , the orientation degrees and their differences ( ⁇ S) at wavelengths of 450, 550, and 650 nm, and the haze value of the produced optically absorptive anisotropic layer A8 were measured by the methods described above. The results are shown in Table 2 below.
• An image display device A8 having a viewing angle switching function was produced in the same manner as in Example 1, except that the optically absorptive anisotropic layer A1 was changed to the optically absorptive anisotropic layer A8. It was found that the twist angle of the produced image display device A8 could be switched between 0° and 90° by turning the voltage of the TN liquid crystal cell on and off, and accordingly the viewing angle could be switched between omnidirectional transmission and omnidirectional light blocking.
• Example 9 [Preparation of Image Display Device A9 Having Viewing Angle Switching Function] An image display device A9 having a viewing angle switching function was produced in the same manner as in Example 1, except that the optically absorptive anisotropic layer forming composition 1 was changed to the optically absorptive anisotropic layer forming composition 3 described below.
• the transmittance central axis angle ⁇ , the orientation degrees and their differences ( ⁇ S) at wavelengths of 450, 550, and 650 nm, and the haze value of the optically absorptive anisotropic layer formed from the optically absorptive anisotropic layer-forming composition 3 were measured by the methods described above. The results are shown in Table 2 below. It was also found that the twist angle of the fabricated image display device A9 could be switched between 0° and 90° by turning the voltage of the TN liquid crystal cell on and off, and accordingly the viewing angle could be switched between omnidirectional transmission and omnidirectional light blocking.
• Low molecular weight liquid crystal compound M-2 [a mixture of the following liquid crystal compounds (RA), (RB), and (RC) in a mass ratio of 84:14:2]
• Example 10 [Fabrication of Image Display Device A10 Having Viewing Angle Switching Function] An image display device A10 having a viewing angle switching function was produced in the same manner as in Example 1, except that the optically absorptive anisotropic layer forming composition 1 was changed to the optically absorptive anisotropic layer forming composition 4 described below.
• the transmittance central axis angle ⁇ , the orientation degrees and their differences ( ⁇ S) at wavelengths of 450, 550, and 650 nm, and the haze value of the optically absorptive anisotropic layer formed from the optically absorptive anisotropic layer-forming composition 4 were measured by the methods described above. The results are shown in Table 2 below. It was also found that the twist angle of the fabricated image display device A10 could be switched between 0° and 90° by turning the voltage of the TN liquid crystal cell on and off, and the viewing angle could be switched between omnidirectional transmission and omnidirectional light blocking accordingly.
• Example 11 [Preparation of Image Display Device A11 Having Viewing Angle Switching Function] An image display device A11 having a viewing angle switching function was produced in the same manner as in Example 1, except that the optically absorptive anisotropic layer forming composition 1 was changed to the optically absorptive anisotropic layer forming composition 5 described below.
• the transmittance central axis angle ⁇ , the orientation degrees and their differences ( ⁇ S) at wavelengths of 450, 550, and 650 nm, and the haze value of the optically absorptive anisotropic layer formed from the optically absorptive anisotropic layer-forming composition 5 were measured by the methods described above. The results are shown in Table 2 below. It was also found that the twist angle of the fabricated image display device A11 could be switched between 0° and 90° by turning the voltage of the TN liquid crystal cell on and off, and the viewing angle could be switched between omnidirectional transmission and omnidirectional light blocking accordingly.
• composition of optically absorptive anisotropic layer forming composition 5 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ - 0.78 parts by mass of the dichroic material D-1 - 0.21 parts by mass of the dichroic material D-4 - 1.39 parts by mass of the dichroic material D-5 - 7.39 parts by mass of the low molecular weight liquid crystal compound M-3 - 2.46 parts by mass of the low molecular weight liquid crystal compound M-4 - 0.71 parts by mass of IRGACURE 369 (manufactured by BASF) - 0.036 parts by mass of BYK-361N (manufactured by BYK-Chemie) - 87
• the stretched film was heat-treated under the following conditions to perform heat setting while holding both ends of the stretched film by gripping the ends with tenter clips so that the width was constant (within a range of expansion or contraction of 3%).
• Heat fixing temperature 165°C
• heat fixing time 30 seconds
• both ends were trimmed and the film was wound up at a tension of 25 kg/m to obtain a film roll with a width of 1340 mm and a roll length of 2000 m.
• the in-plane retardation of the obtained stretched film at a wavelength of 550 nm was 160 nm
• the retardation in the thickness direction at a wavelength of 550 nm was 390 nm
• the film thickness was 80 ⁇ m. This was used as the B plate.
• the polarizing plate prepared in Example 4 was attached to one side of the IPS liquid crystal cell prepared in Example 7 using a commercially available adhesive SK2057 (manufactured by Soken Chemical Engineering Co., Ltd.) so that the polarizer surface faced the IPS liquid crystal cell side.
• the B plate prepared above was attached to the surface of the IPS liquid crystal cell opposite to the surface to which the polarizing plate was attached, using a commercially available adhesive SK2057 (manufactured by Soken Chemical Industries, Ltd.).
• the oxygen barrier layer B1 side of the optical film 1 produced in Example 1 was bonded to the B plate side using a commercially available adhesive SK2057 (manufactured by Soken Chemical & Engineering Co., Ltd.) to produce an optical laminate A12.
• the liquid crystal layer in the IPS liquid crystal cell was set so that the angle between the in-plane slow axis of the liquid crystal layer and the transmission axis of the polarizer (other light absorptive anisotropic layer) when the voltage was ON was 0°, and the angle between the in-plane slow axis of the liquid crystal layer and the transmission axis of the polarizer (other light absorptive anisotropic layer) when the voltage was OFF was 45°.
• An image display device A12 having a viewing angle switching function was produced in the same manner as in Example 4, except that the optical laminate A4 was changed to the optical laminate A12. It was found that for the produced image display device A12, the angle between the in-plane slow axis of the liquid crystal layer in the IPS liquid crystal cell and the transmission axis of the polarizer (another light-absorption anisotropic layer) can be switched between 0° and 45° by turning the voltage of the IPS liquid crystal cell ON and OFF, and accordingly, the viewing angle can be switched between top and bottom light blocking (left and right transmission) and left and right light blocking (top and bottom transmission).
• Example 13 [Fabrication of an image display device having a viewing angle switching function]
• Cosmoshine Super Birefringent Type (SRF, manufactured by Toyobo Co., Ltd.) (depolarizing film) was attached to the display screen of a Galaxy S7+ (manufactured by Samsung), a tablet equipped with an organic EL display device, using a commercially available adhesive SK2057 (manufactured by Soken Chemical Industries, Ltd.).
• the optical laminate A7 produced in Example 7 was placed on the depolarizing film to produce an image display device A13 having a viewing angle switching function.
• the angle between the in-plane slow axis of the liquid crystal layer in the IPS liquid crystal cell and the transmission axis of the polarizer can be switched between 0° and 45° by turning the voltage of the IPS liquid crystal cell ON and OFF, and accordingly, the viewing angle can be switched between top and bottom light blocking (left and right transmission) and left and right light blocking (top and bottom transmission).
• Example 14 [Fabrication of an image display device having a viewing angle switching function] Three-color LEDs (PICOLED, model number SMLP34RGB, manufactured by ROHM Co., Ltd.) were arranged in a two-dimensional lattice on a printed circuit board so that the area ratio of the LEDs (light-emitting elements) was 30%. In the areas where no LEDs were arranged, a black layer made of a black matrix material for liquid crystal display devices was formed by photolithography. In this way, an EL substrate was produced (see Figure 1). Next, the optical laminate A1 produced in Example 1 was placed on the EL substrate 1 to produce an image display device A14 having a viewing angle switching function. It was also found that the twist angle of the fabricated image display device A14 could be switched between 0° and 90° by turning the voltage of the TN liquid crystal cell on and off, and accordingly the viewing angle could be switched between omnidirectional transmission and omnidirectional light blocking.
• PICOLED model number SMLP34RGB, manufactured by ROHM Co.,
• Example 1 [Fabrication of Image Display Device B1 Having Viewing Angle Switching Function] An image display device B1 having a viewing angle switching function was produced in the same manner as in Example 1, except that in Example 1, composition 1 for forming an optically absorptive anisotropic layer was changed to composition 6 for forming an optically absorptive anisotropic layer described below, and the cooling temperature after heating at 120°C was changed from 35°C to 23°C.
• the transmittance central axis angle ⁇ , the orientation degrees and their differences ( ⁇ S) at wavelengths of 450, 550, and 650 nm, and the haze value of the optically absorptive anisotropic layer formed from the optically absorptive anisotropic layer-forming composition 6 were measured by the methods described above. The results are shown in Table 2 below. It was also found that the twist angle of the fabricated image display device B1 could be switched between 0° and 90° by turning the voltage of the TN liquid crystal cell on and off, and the viewing angle could be switched between omnidirectional transmission and omnidirectional light blocking accordingly.
• composition of composition 6 for forming optically absorptive anisotropic layer ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ - 0.87 parts by mass of dichroic substance D-7 shown below - 1.06 parts by mass of dichroic substance D-8 shown below - 4.41 parts by mass of polymer liquid crystal compound P-3 shown below - 0.005 parts by mass of IRGACUREOXE-02 (manufactured by BASF) - 0.08 parts by mass of compound E-1 shown above - 0.08 parts by mass of compound E-2 shown above - 0.10 parts by mass of surfactant F-2 shown below - 79.39 parts by mass of cyclopentanone - 14.01
• the angle between the in-plane slow axis of the liquid crystal layer in the IPS liquid crystal cell and the transmission axis of the polarizer can be switched between 0° and 45° by turning the voltage of the IPS liquid crystal cell ON and OFF, and accordingly, the viewing angle can be switched between top and bottom light blocking (left and right transmission) and left and right light blocking (top and bottom transmission).
• B Compared to the display screen of the Galaxy S7+ to which a depolarizing film is attached, the color tone of the display screen of the image display device having a viewing angle switching function is a little noticeable.
• C Compared to the display screen of the Galaxy S7+ to which a depolarizing film is attached, the color tone of the display screen of the image display device having a viewing angle switching function is bothersome.
• B Compared to the display screen of the micro LED display device without the viewing angle switching function, the color of the display screen of the image display device with the viewing angle switching function is a little worrisome.
• C Compared to the display screen of a micro LED display device without a viewing angle switching function, the color of the display screen of an image display device with a viewing angle switching function is noticeable.
• Example 1 a comparison between Example 1 and Example 2 revealed that when the difference ( ⁇ S) in the degree of orientation of the specific optically absorptive anisotropic layer at wavelengths of 450 nm, 550 nm and 650 nm was 0.020 or less, coloring of the display screen could be further suppressed. Moreover, from a comparison between Example 1 and Example 8, it was found that when the transmittance central axis angle ⁇ was equal to or greater than 0° and less than 15°, coloring on the display screen could be further suppressed.

Landscapes

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

Priority Applications (4)

Applications Claiming Priority (4)

Related Child Applications (1)

Publications (1)

Family

ID=91485634

Family Applications (1)

Country Status (5)

Citations (48)

• 2023
  • 2023-11-17 JP JP2024564232A patent/JPWO2024127911A1/ja active Pending
  • 2023-11-17 EP EP23903209.7A patent/EP4636445A4/en active Pending
  • 2023-11-17 CN CN202380079010.6A patent/CN120225928A/zh active Pending
  • 2023-11-17 WO PCT/JP2023/041506 patent/WO2024127911A1/ja not_active Ceased
• 2025
  • 2025-04-30 US US19/195,178 patent/US20250258403A1/en active Pending

Patent Citations (48)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events